Organización para Estudios Tropicales (OET)

Biblioteca – BINABITROP

Bibliografía actualizada al 30 de enero del 2008

Desde 1996, la Organización para Estudios Tropicales (OET) a través de su Biblioteca ha desarrollado y consolidado la “Bibliografía Nacional en Biología Tropical” (BINABITROP), proyecto único en el país cuyo objetivo principal es rescatar las publicaciones científicas que tratan sobre Costa Rica, generadas a lo largo de los años, tanto dentro como fuera del país, para reunirlas en una base de datos disponible al público gratuitamente en la Internet. De esta forma la OET colabora con conservar, aumentar y difundir conocimientos generados a partir de nuestra riqueza natural.

Objetivos de BINABITROP

1. Detectar las publicaciones nacionales y extranjeras sobre biología tropical costarricense y temas relacionados.

2. Difundir esta información mediante el sitio web de la OET.

3. Mantener comunicación con científicos generadores de la información, a fin de incrementar la bibliografía.

4. Facilitar las publicaciones a los interesados o remitirlos a las bibliotecas que las poseen.

Contenido de la Base de Datos

Destaca las referencias de publicaciones periódicas y tesis. Actualmente la Base de Datos cuenta con 32 800 registros de monografías, publicaciones periódicas, tesis, congresos, y otros. La Base de Datos puede ser accesada en la siguiente dirección: http://www.ots.ac.cr/binabitrop/

Agradecimiento a Joanne Fuentes Molina, por su desinteresada colaboración en el diseño de la portada.

Más información

M. Sc. Gilbert Fuentes González Master Ana Beatriz Azofeifa Mora Investigador Coordinadora Sistema de Bibliotecas OET gilbert@ots.ac.cr library@ots.ac.cr

¿Qué es el calentamiento global?

El calentamiento global se refiere al incremento observado en la temperatura promedio de la superficie terrestre acaecido en décadas recientes. Esta temperatura ha aumentado en promedio 0.74° C (1.3° F) en los últimos 100 años, tanto sobre la tierra como los océanos. ¿No son normales los cambios en la temperatura de la Tierra a lo largo de su historia? Sí, las temperaturas de la Tierra han cambiado dramáticamente durante millones de años en la historia de nuestro planeta. Estos cambios han generado variaciones igualmente dramáticas en los niveles de los océanos, en la cantidad de tierra cubierta por glaciares y por bosques tropicales. ¿Por qué la temperatura está cambiando tan rápidamente? Los científicos consideran que el calentamiento global es causado principalmente por un incremento en los “gases invernadero”, constituidos primordialmente por dióxido de carbono, pero también por metano, vapor de agua y dióxido de azufre- en la atmósfera. Este aumento es causado esencialmente por la combustión de combustiles fósiles y la deforestación. ¿Por qué representa este cambio un problema? Porque incluso un pequeño aumento en la temperatura puede causar el derretimiento de los glaciares. Además, las altas temperaturas en algunas partes del mundo están asociadas con reducciones extremas en la lluvia o en un incremento de la intensidad de las tormentas. ¿De qué forma interactúan las plantas y los bosques en este proceso? Las plantas toman dióxido de carbono de la atmósfera y lo utilizan en su proceso de fotosíntesis para crecer y producir alimento para el resto del planeta. La composición física (biomasa) de las plantas es aproximadamente 50% carbono. ¿Por qué importa que los trópicos estén un poco más calientes? De todas formas los trópicos son calientes y ahí no hay glaciares que puedan derretirse De antemano sabemos que los trópicos son una parte importante del ciclo del carbono global, porque mucha de la vegetación del mundo se localiza en los trópicos. Y los árboles del trópico son muy sensibles a la temperatura. ¿Por qué es importante la investigación en los trópicos? La mayoría de la investigación sobre cambio climático se realiza en latitudes templadas- Europa, América del Norte, la tundra Ártica. Pero gran parte de la vegetación mundial y la fotosíntesis mayor se encuentran en los trópicos. ¿Está el cambio climático global relacionado con otros temas ecológicos? Sí, con otros temas ecológicos sumamente importantes, tales como biodiversidad, fragmentación del hábitat y corredores biológicos. Si las poblaciones de animales y plantas están restringidas a pequeños fragmentos de hábitat no tendrían la posibilidad de sobrevivir si las condiciones de su hábitat cambian. ¿Por qué Costa Rica es tan importante en la investigación de los trópicos? Costa Rica ha sido durante muchos años líder en generar conciencia ambiental. Costa Rica posee muchas áreas protegidas públicas y privadas, un sistema que alienta a los propietarios de tierra a preservar sus bosques y un alto nivel de conciencia ambiental entre sus ciudadanos. ¿Por qué la gente habla sobre neutralidad de carbono? Ser “carbono neutral” significa tomar tanto carbono de la atmósfera como el que se está liberando en ella. Este concepto se puede aplicar tanto a individuos, como corporaciones, o a todo un país. Si usted maneja un automóvil que utiliza gasolina, usted está liberando carbono en la atmósfera. Y si usted está plantando árboles, usted está tomando carbono de la atmósfera.

¿Qué podemos hacer para ayudar al balance global de carbono? Hay muchas cosas que podemos hacer para ayudar al balance global de carbono:

• Usar menos gas, carbón y petróleo, para no depositar más dióxido de carbono en la atmósfera. • Proteger a los árboles grandes y a los bosques viejos porque ellos son nuestros almacenes de carbono. •

¿Qué está haciendo la Organización para Estudios Tropicales (OET) para proteger el ambiente y combatir el calentamiento global? La OET está trabajando en todas las formas posibles para mejorar el presupuesto global del carbono:

• La misión de la OET es promover la educación, la investigación científica y el uso responsable de los recursos naturales en los trópicos.

Le invitamos a unirse a nuestros esfuerzos para entender los cambios que están afectando nuestros ecosistemas y el mundo natural tal como lo conocemos. Su contribución realmente puede ayudar a mejorar el presupuesto global de carbono. Preguntas y respuestas elaboradas por la Dra. Deedra McClearn, Directora de la Estación Biológica La Selva Calentamiento Global (Según Wikipedia, la enciclopedia libre)

http://es.wikipedia.org/wiki/Calentamiento_global

Calentamiento global es un término utilizado habitualmente en dos sentidos:

1. Es el fenómeno observado en las medidas de la temperatura que muestra en promedio un aumento en la

temperatura de la atmósfera terrestre y de los océanos en las últimas décadas.

2. Es una teoría que predice, a partir de proyecciones basadas en simulaciones computacionales, un

crecimiento futuro de las temperaturas.

Algunas veces se utilizan las denominaciones cambio climático, que designa a cualquier cambio en el clima, o cambio climático antropogénico, donde se considera implícitamente la influencia de la actividad humana. Calentamiento global y efecto invernadero no son sinónimos. El efecto invernadero acrecentado por la contaminación puede ser, según algunas teorías, la causa del calentamiento global observado.

La temperatura del planeta ha venido elevándose desde mediados del siglo XIX, cuando se puso fin a la etapa conocida como la pequeña edad de hielo.

Predicciones basadas en diferentes modelos del incremento de la temperatura media global respecto de su valor en el año 2000.

Cualquier tipo de cambio climático además implica cambios en otras variables. La complejidad del problema y sus múltiples interacciones hacen que la única manera de evaluar estos cambios sea mediante el uso de modelos computacionales que intentan simular la física de la atmósfera y del océano y que tienen una precisión limitada debido al desconocimiento del funcionamiento de la atmósfera.

La teoría antropogénica predice que el calentamiento global continuará si lo hacen las emisiones de gases de efecto invernadero (GEI). El cuerpo de la ONU encargado del análisis de los datos científicos es el Panel Intergubernamental del Cambio Climático (IPCC, por sus siglas en inglés de Inter-Governmental Panel on Climate Change). El IPCC indica que "[...]La mayoría de los aumentos observados en las temperaturas medias del globo desde la mitad del siglo XX son muy probablemente debidos al aumento observado en las concentraciones de GEI antropogénicas."[1] . Sin embargo, existen algunas discrepancias al respecto de que el dióxido de carbono sea el gas de efecto invernadero que más influye en el Calentamiento Global de origen antropogénico.

El Protocolo de Kyoto, acuerdo promovido por el IPCC, promueve una reducción de emisiones contaminantes (principalmente CO2). El protocolo ha sido tachado en ciertas ocasiones de injusto, ya que el incremento de las emisiones tradicionalmente está asociado al desarrollo económico, con lo que las naciones a las que más afectaría el cumplimiento de este protocolo podrían ser aquellas zonas menos desarrolladas. Global Warming (From Wikipedia, the free encyclopedia) http://en.wikipedia.org/wiki/Global_warming Global warming is the increase in the average temperature of the Earth's near-surface air and oceans in recent decades and its projected continuation.

The global average air temperature near the Earth's surface rose 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the 100 year period ending in 2005, which is higher than the earlier estimate of 0.6 ± 0.2 °C for the period ending in 2000.[1] The Intergovernmental Panel on Climate Change (IPCC) concludes "most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations"[1] via the greenhouse effect. Natural phenomena such as solar variation combined with volcanoes probably had a small warming effect from pre-industrial times to 1950 and a small cooling effect from 1950 onward.[2][3] These basic conclusions have been endorsed by at least 30 scientific societies and academies of science,[4] including all of the national academies of science of the major industrialized countries.[5][6][7] While individual scientists have voiced disagreement with the conclusions of the IPCC[8], the overwhelming majority of scientists working on climate change are in agreement with the conclusions.[9][10]

Climate model projections summarized by the IPCC indicate that average global surface temperature will likely rise a further 1.1 to 6.4 °C (2.0 to 11.5 °F) during the 21st century.[1] The range of values results from the use of differing scenarios of future greenhouse gas emissions as well as models with differing climate sensitivity. Although most studies focus on the period up to 2100, warming and sea level rise are expected to continue for more than a millennium even if greenhouse gas levels are stabilized. The delay in reaching equilibrium is a result of the large heat capacity of the oceans.[1]

Increasing global temperature will cause sea level to rise, and is expected to increase the intensity of extreme weather events and to change the amount and pattern of precipitation. Other effects of global warming include changes in agricultural yields, trade routes, glacier retreat, species extinctions and increases in the ranges of disease vectors.

Remaining scientific uncertainties include the amount of warming expected in the future, and how warming and related changes will vary from region to region around the globe. There is ongoing political and public debate worldwide regarding what, if any, action should be taken to reduce or reverse future warming or to adapt to its expected consequences. Most national governments have signed and ratified the Kyoto Protocol, aimed at reducing greenhouse gas emissions.

Climate Change (From GLOBAL SPACE FLIGHT CENTER) http://gcmd.nasa.gov/Resources/pointers/glob_warm.html

Concept definition:

The long-term fluctuations in temperature, precipitation, wind, and all other aspects of the Earth's climate. External processes, such as solar-irradiance variations, variations of the Earth's orbital parameters (eccentricity, precession, and inclination), lithosphere motions, and volcanic activity, are factors in climatic variation. Internal variations of the climate system, e.g., changes in the abundance of greenhouse gases, also may produce fluctuations of sufficient magnitude and variability to explain observed climate change through the feedback processes interrelating the components of the climate system.

Cambio Climático (Según Wikipedia, la enciclopedia libre)

http://es.wikipedia.org/wiki/Cambio_climatico

Se llama cambio climático a la modificación del clima con respecto al historial climático a una escala global o regional. Tales cambios se producen a muy diversas escalas de tiempo y sobre todos los parámetros climáticos: temperatura, precipitaciones, nubosidad, etcétera. Son debidos a causas naturales y, en los últimos siglos, también a la acción de la humanidad.[sin referencias]

El término suele usarse, de forma poco apropiada, para hacer referencia tan solo a los cambios climáticos que suceden en el presente, utilizándolo como sinónimo de calentamiento global. La Convención Marco de las Naciones Unidas sobre el Cambio Climático usa el término cambio climático sólo para referirse al cambio por causas humanas:

Por 'cambio climático' se entiende un cambio de clima atribuido directa o indirectamente a la actividad humana que altera la composición de la atmósfera mundial y que se suma a la variabilidad natural del clima observada durante períodos de tiempo comparables.

Al producido constantemente por causas naturales lo denomina variabilidad natural del clima. En algunos casos, para referirse al cambio de origen humano se usa también la expresión cambio climático antropogénico.

Además del calentamiento global, el cambio climático implica cambios en otras variables como las lluvias globales y sus patrones, la cobertura de nubes y todos los demás elementos del sistema atmosférico. La complejidad del problema y sus múltiples interacciones hacen que la única manera de evaluar estos cambios sea mediante el uso de modelos computacionales que intentan simular la física de la atmósfera y de los océanos y que tienen una precisión muy limitada debido al desconocimiento actual del funcionamiento de la atmósfera.

Climate Change (From Wikipedia, the free encyclopedia)

Is the variation in the Earth's global climate or in regional climates over time. It involves changes in the variability or average state of the atmosphere over durations ranging from decades to millions of years. These changes can be caused by dynamic process on Earth, external forces including variations in sunlight intensity, and more recently by human activities.

In recent usage, especially in the context of environmental policy, the term "climate change" often refers to changes in modern climate (see global warming). For information on temperature measurements over various periods, and the data sources available, see temperature record. For attribution of climate change over the past century, see attribution of recent climate change

INDICE DE DESCRIPTORES

ABRUPT CLIMATE CHANGE 263 ABUNDANCE 211, 305 ACALYPHA 178 ACCUMULATION 182, 229 ACETYLENE 038, 042 ACETYLENE INHIBITION 311 ACID PRECIPITATION AND SOIL 159 ACID SOILS 167 ACTIVITIES IMPLEMENTED JOINTLY 093, 124, 128, 136, 219 ADAPTABILITY 307 ADAPTATION SCIENCE 140 ADULT MORTALITY 312 ADULTS 215, 261 AERIAL PARTS 010, 245 AEROSOLS 231 AEROSOLS AND PARTICLES 231 AEROSOLS FROM BIOMASS BURNING 231 AFRICA 072, 134, 276, 303 AFRICANIZED HONEYBEES 253 AGALYCHNIS 159

AGE CALIBRATION 243 AGE DATING 177 AGE TREES 018 AGRICULTURAL DEVELOPMENT 058 AGRICULTURAL EXPANSION 284 AGRICULTURAL LANDS 145, 160 AGRICULTURAL POLICIES 129 AGRICULTURAL PRACTICES 076 AGRICULTURAL SOILS 161 AGRICULTURE 077, 153, 193, 253, 265, 276 AGRICULTURE ACTIVITY 090 AGRICULTURE VULNERABILITY 155 AGROCHEMICALS 193 AGROFORESTRY 039, 062, 073, 101, 107, 168, 204, 241, 247, 285, 292, 311 AGROSILVOPASTORAL SYSTEMS 062, 073 AIR 042, 295 AIR POLLUTION 035, 046, 090, 095, 102, 110, 116, 122, 133, 176, 231 AIR TEMPERATURE 007, 013, 022, 101, 180, 205, 294 AIRCRAFT OBSERVATIONS 277

ALAS PROJECT 240 ALCHORNEA 033, 178 ALGAE 243 ALLEY CROPPING 204, 241, 285 ALLOMETRIC EQUATION 245 ALLOPHANIC SOILS 189 ALLVIUM 203 ALTITUDINAL DISTRIBUTION 172 AMAZONIA 183 AMERICA 071 AMERINDIAN 292 AMMONIA 035, 038, 048, 145, 160, 161 AMMONIA OXIDIZING BACTERIA 222, 235, 260 AMMONIUM 163, 165, 184, 235, 260 AMMONIUM CHLORIDE 035 AMPHIBIAN DECLINES 083, 092, 103, 106, 152, 159, 185, 216, 221, 244, 251, 259, 262, 274, 282, 308, 312 AMPHIBIANS 083, 092, 103, 106, 152, 159, 185, 215, 216, 221, 244, 251, 256, 259, 261, 262, 274, 282, 308, 312 ANALYSIS 045, 264

ANDIRA INERMIS 253 ANEMOMETERS 030 ANIMAL BEHAVIOUR 082 ANIMAL ECOLOGY 082 ANIMAL POPULATIONS 061 ANIMALS 037, 045, 060, 061, 082, 083, 092, 103, 106, 108, 152, 158, 159, 172, 177, 185, 211, 213, 215, 216, 221, 240, 244, 251, 253, 256, 259, 261, 262, 264, 266, 273, 274, 278, 282, 288, 298, 305, 308, 310, 312 ANIONS 038, 081 ANNONACEAE 018 ANNUAL RECRUITMENT 191, 198 ANNUAL STREAMFLOW 086 ANNUAL TREE GROWTH 021 ANTARCTIC OZONE HOLE 277 ANTHOPHORIDAE 253 ANTHOZOA 196, 288 ANTHROPOGENIC DISTURBANCES 125, 298 ANTIGUA 288 ANTS 240, 305 ANURANS 092, 103, 106, 152, 159, 185, 215, 216, 221, 244, 251, 256, 259, 261, 262, 274, 312 APHIDIDAE 082

APIDAE 253 APIS MELLIFERA 253 ARACEAE 160 ARCHAEOLOGY 178 AREA DE CONSERVACION ARENAL HUETAR NORTE 113, 115, 117, 156, 174, 175, 192, 195, 217, 228, 245, 257 AREA DE CONSERVACION ARENAL TILARAN 003, 004, 026, 044, 056, 092, 106, 111, 152, 156, 159, 174, 175, 178, 182, 185, 192, 195, 213, 217, 218, 223, 226, 228, 229, 230, 240, 244, 249, 251, 256, 259, 262, 267, 268, 274, 276, 279, 282, 287, 297, 299, 305, 312 AREA DE CONSERVACION CORDILLERA VOLCANICA CENTRAL 001, 002, 005, 006, 007, 008, 009, 010, 011, 012, 013, 014, 015, 016, 017, 018, 019, 020, 021, 022, 023, 024, 025, 027, 028, 029, 030, 031, 032, 035, 036, 038, 042, 043, 044, 046, 047, 048, 049, 051, 053, 054, 056, 062, 074, 076, 081, 086, 088, 091, 095, 096, 097, 098, 099, 100, 101, 103, 105, 120, 123, 127, 139, 142, 143, 144, 145, 146, 151, 154, 156, 160, 164, 171, 176, 180, 187, 188, 189, 192, 194, 195, 200, 201, 203, 204, 205, 211, 214, 217, 219, 222, 231, 235, 241, 245, 250, 255, 257, 260, 266, 270, 277, 278, 280, 283, 285, 293, 294, 300, 302, 306, 308, 311, 312 AREA DE CONSERVACION GUANACASTE 037, 044, 118, 125, 132, 158, 179, 191, 195, 196, 198, 253, 266, 286, 298 AREA DE CONSERVACION LA AMISTAD CARIBE 060, 086, 118, 177, 195, 218, 242, 248, 256, 289, 292 AREA DE CONSERVACION LA AMISTAD PACIFICO

044, 045, 056, 083, 118, 152, 159, 188, 195, 216, 218, 242, 243, 248, 252, 254, 256, 263, 264, 272, 282, 304 AREA DE CONSERVACION OSA 044, 086, 157, 195 AREA DE CONSERVACION PACIFICO CENTRAL 086, 195, 290 AREA DE CONSERVACION TEMPISQUE 033, 044, 052, 087, 118, 170, 188, 195, 253, 286, 310 AREA DE CONSERVACION TORTUGUERO 041, 044, 116, 126, 127, 129, 137, 156, 174, 175, 192, 195, 202, 215, 217, 228, 261, 306, 310 ARECACEAE 012 ARTHROPOD ASSEMBLAGES 240, 305 ARTHROPODS 060, 061, 082, 177, 240, 253, 266, 278, 305 ASCOMYCOTA 035 ASIA 071, 072, 119, 161, 197, 276, 289, 303 ASSESSMENT 118, 295 ASTREOPORA 288 ATELOPUS CHIRIQUIENSIS 083, 159, 216, 282 ATELOPUS COYNEI 282 ATELOPUS IGNESCENS 282 ATELOPUS LONGIROSTRIS 282 ATELOPUS MINDOENSIS 282 ATELOPUS MUCUBAJIENSIS 282 ATELOPUS PINANGOI

282 ATELOPUS PLANISPINA 282 ATELOPUS VARIUS 159, 262, 282 ATLANTIC LOWLANDS 042, 156, 174, 175, 192, 217, 223, 228, 249, 267, 279 ATLANTIC ZONE 089, 095, 096, 097, 098, 099, 100, 105, 107, 116 ATMOSPHERE 034, 043, 046, 051, 068, 076, 077, 080, 081, 088, 091, 102, 142, 171, 176, 193, 197, 200, 207 ATMOSPHERIC CARBON 020, 107, 114, 163, 165, 166, 167, 168, 184 ATMOSPHERIC CARBON SEQUESTRATION 169, 170, 186, 309 ATMOSPHERIC CHEMISTRY 003, 004, 026, 043, 046, 049, 053, 054, 068, 074, 080, 081, 090, 091, 102, 127, 142, 143, 144, 145, 146, 164, 171, 176, 202, 306 ATMOSPHERIC CIRCULATION 231 ATMOSPHERIC CO2 151, 187, 189 ATMOSPHERIC COMPOSITION AND STRUCTURE 023, 231 ATMOSPHERIC DISTRIBUTION 295 ATMOSPHERIC DISTURBANCES 086 ATMOSPHERIC METHANE 291 ATMOSPHERIC NITROUS OXIDE 144, 145 ATMOSPHERIC PARTICULATES 231 ATMOSPHERIC WATER-BALANCE 297

ATTITUDES 173, 212 AULACOSEIRA 243 AUSTRALASIA 082 AUSTRALIA 150, 276 BACILLARIOPHYCEAE 243 BACTERIA 222 BAGACES (CANTON) 253 BAHIA CULEBRA 125, 158, 196, 298 BAJO PACUARE 086 BALIZIA ELEGANS 018, 280 BANANA PLANTATIONS 080, 097 BANANA SOILS 080 BARRO COLORADO NATURE MONUMENT 002, 103, 266 BASELINE 247 BASELINES 195, 208, 270, 283 BAT HABITAT 211 BAT POPULATIONS AND DISTRIBUTION 213 BATRACHOCHYTRIUM DENDROBATIDIS 244, 262, 282, 312 BATS 211, 213 BEEF CATTLE 168 BEHAVIOUR 061

BELIZE 104, 197, 236, 237, 295, 307 BELOWGROUND 016, 201 BIO-DEGRADABLE WASTES 068 BIOCHEMICAL OXYGEN DEMAND 068 BIOCLIMATOLOGY 002 BIODEGRADABILITY 250 BIODEGRADATION 189 BIODIVERSITY 002, 006, 058, 073, 079, 082, 104, 112, 130, 131, 135, 150, 166, 177, 179, 181, 183, 186, 190, 193, 198, 210, 211, 222, 224, 225, 226, 235, 240, 251, 253, 256, 260, 287, 298, 299, 305 BIODIVERSITY CONSERVATION 104, 122, 139 BIODIVERSITY HOTSPOT 224 BIODIVERSITY LOSS 230 BIOGENIC EMISSIONS 075, 076 BIOGENIC VOLATILE ORGANIC COMPOUNDS 012 BIOGEOCHEMICAL CONTROLS 291 BIOGEOCHEMISTRY 024, 088, 189, 200, 302 BIOGEOGRAPHY 225, 228, 252 BIOGRAPHIES 015 BIOINDICATOR PLANTS 035 BIOLOGIC CHANGES 059 BIOLOGICAL ACTIVITY IN SOIL

038, 081 BIOLOGICAL ADAPTATION 140 BIOLOGICAL COMPETITION 061 BIOLOGICAL CONTROL 211 BIOLOGICAL EFFECTS 156, 217, 218, 223, 228, 249, 267, 279 BIOLOGICAL PARAMETERS 125, 196, 298 BIOLOGICAL PRODUCTION 189 BIOLOGICAL VARIABLES 230 BIOLOGY 082, 310 BIOMASS 003, 004, 009, 022, 026, 048, 067, 068, 107, 118, 138, 149, 182, 229, 231, 232, 260 BIOMASS BURNING 003, 004, 026, 076, 231 BIOMASS COMPOSITION 191, 198 BIOMASS OF EPIPHYTES 056 BIOMONITORING TESTER 035 BIOPROSPECTING 193, 226, 287 BIOSPHERE/ATMOSPHERE INTERACTIONS 023, 231 BIRDS 061, 092, 108, 172, 185, 259, 274 BOCAS DEL TORO 060 BOLITOGLOSSA MINUTULA 083, 159, 216 BOLITOGLOSSINI 083, 159, 216 BOLIVIA

072, 162, 197, 246, 282, 284, 303 BOMBACACEAE 142, 170 BOMBACOPSIS QUINATA 170 BOMBYCILLIDAE 172 BORAGINACEAE 107, 113, 115, 117 BOSQUE ETERNO DE LOS NIÑOS 276 BRIBRI DE TALAMANCA 292 BROMELIACEAE 215, 261 BROMINATED FLAME RETARDANTS 295 BRYOPHYTA 004, 026, 252 BUFO PERIGLENES 092, 106, 159, 185, 221, 251, 256, 259, 262, 274, 276 BUFONIDAE 092, 106, 152, 159, 185, 221, 251, 256, 259, 262, 274, 276, 282 BURNING 046, 048, 176 BURNING NITRIC OXIDE EMISSION 046, 176 BURSERACEAE 018 BUTTRESSES 009, 022 BYRSONIMA CRASSIFOLIA 253 C3 041 C4 041 CACAO PLANTATIONS 292, 312

CALCINATION 068 CALCIUM 024, 302 CALLOPHYLLUM BRASILIENSE 245, 280 CAMBIUM 119 CAÑAS (CANTON) 087 CANDELARIA DE PURISCAL 086 CANOPY 004, 005, 010, 012, 013, 026, 123, 182, 205, 229, 231, 240, 255, 294, 305 CANOPY FOGGING 240 CARBON 010, 013, 014, 025, 031, 041, 088, 118, 132, 179, 200, 205, 232, 236, 237, 238, 255, 258, 271, 281, 294, 296 CARBON ACCUMULATOR 027, 032, 303 CARBON AEROSOL OBSERVATION TECHNIQUES 231 CARBON BALANCE 027, 032, 303 CARBON BUDGET 032 CARBON CREDITS 209, 234, 257 CARBON CYCLE 007, 009, 011, 013, 014, 015, 016, 017, 022, 025, 027, 029, 030, 032, 041, 044, 048, 068, 118, 139, 180, 183, 194, 201, 205, 246, 251, 254, 255, 260, 294, 303 CARBON DIOXIDE 012, 017, 022, 028, 029, 030, 031, 032, 035, 041, 048, 068, 073, 082, 090, 116, 117, 120, 121, 123, 131, 134, 142, 144, 151, 153, 162, 163, 165, 167, 168, 169, 170, 171, 184, 187, 189, 190, 199, 203, 204, 209, 214, 232, 233, 234, 241, 247,

251, 257, 272, 278, 285, 293, 294, 300, 303, 309 CARBON DYNAMICS 007, 009, 011, 014, 015, 016, 022, 025, 029, 030, 201, 294 CARBON EXCHANGE 007, 009, 011, 013, 015, 016, 022, 029, 030, 180, 201, 205, 255, 294 CARBON FIXATION 063, 093, 112, 113, 115, 117, 124, 128, 131, 136, 139, 190, 194, 204, 219, 232, 241, 245, 280, 285, 291 CARBON FLUXES 007, 009, 011, 013, 014, 015, 016, 022, 025, 029, 030, 032, 041, 153, 180, 195, 201, 203, 205, 255, 269, 270, 283, 294, 303 CARBON INPUT 204, 241, 285 CARBON MARKET 209, 234, 257 CARBON MONOXIDE 035, 068, 090, 153, 220 CARBON NET LOSS 027, 032, 303 CARBON OFFSETS 136 CARBON PARTICLE DEPOSITION 231 CARBON POOLS 006, 208 CARBON SEQUESTRATION 044, 093, 107, 113, 114, 115, 117, 118, 123, 124, 128, 131, 136, 138, 139, 150, 153, 163, 165, 166, 167, 168, 179, 183, 184, 190, 194, 197, 204, 209, 219, 232, 233, 234, 241, 246, 254, 257, 271, 272, 281, 285, 291, 292, 296 CARBON SINK 009, 022, 093, 124, 128, 139, 153, 194, 219, 245, 254, 271, 280 CARBON STOCKS 006, 011, 014, 015, 025 CARBON STORAGE

063, 067, 068, 090, 093, 113, 115, 117, 124, 128, 138, 139, 149, 194, 219, 245, 254, 271, 272, 280, 291 CARBON STORAGE EQUATIONS 044 CARBON STORAGE FORECASTS 208, 269 CARBON-SINK SERVICES 190 CARBONATE FOSSIL 037 CARBONO PROJECT 005, 006, 007, 009, 010, 011, 013, 014, 015, 016, 018, 022, 025, 027, 201, 203, 205, 231, 250, 255, 278, 294 CARETTA CARETTA 310 CARIACO WATERSHED 057 CARIARI (DISTRITO) 137, 215, 261 CARIBBEAN SEA 231 CARICA PAPAYA 145, 160 CARICACEAE 145, 160 CASE STUDIES 071, 116, 131, 132, 179, 190, 194 CATABOLIC DIVERSITY 260 CATABOLIC POTENTIAL 260 CATIE 204, 241, 285 CATION EXCHANGE CAPACITY 041 CATTLE 109 CATTLE RANCHING 284 CAUDATA 083, 103, 159, 216, 221

CECROPIA 178 CECROPIACEAE 178 CEDRELA ODORATA 254, 272 CENTRAL AMERICAN DROUGHT CORRIDOR 286 CENTRAL AMERICAN MONSOON 263 CENTRIS 253 CENTRO CIENTIFICO TROPICAL 276 CENTROLENELLA PROSOBLEPON 092 CENTROLENIDAE 092, 103, 152, 159 CERRADO 162 CERRO BUENAVISTA 263 CERRO CHIRRIPO 045, 264 CERRO DE LA MUERTE 242, 248, 263 CERRO DE LAS VUELTAS 195 CERRO KAMUK 242, 248, 263 CERTIFICATION 118, 132, 179 CERTIFIED TRADABLE OFFSETS 122 CH4 OXIDATION 154 CHANGES IN SPECIES COMPOSITION 210 CHARCOAL 045, 178, 264 CHELONIA MYDAS 310

CHELONIA MYDAS AGASSIZI 310 CHELONIIDAE 310 CHEMICAL CONTAMINANTS 159 CHILE 071 CHINA 071, 072, 161, 289 CHIROPTERA 211, 213 CHLORANTHACEAE 178 CHLORIDE 035 CHLOROFLOUROCARBONS 068, 090 CHRONOLOGY 248 CHYTRIDIALES 244, 262, 282, 312 CHYTRIDIOMYCOSIS 092, 244, 262, 282, 312 CHYTRIDIOMYCOTINA 244, 262, 312 CITIZEN SCIENCE 230 CLADISTIC ANALYSIS 172 CLEAN DEVELOPMENT MECHANISM 093, 124, 128, 136, 219, 247, 272 CLIMATE 001, 008, 019, 045, 065, 085, 094, 119, 135, 156, 174, 175, 180, 192, 193, 197, 201, 206, 217, 223, 225, 228, 249, 264, 267, 268, 271, 279, 286, 301, 307 CLIMATE HISTORY 264 CLIMATE MODIFICATION 225 CLIMATE VARIABILITY 201, 307

CLIMATIC CHANGE 001, 002, 003, 004, 005, 006, 007, 008, 009, 010, 011, 012, 013, 014, 015, 016, 017, 018, 019, 020, 021, 022, 023, 024, 025, 026, 027, 028, 029, 030, 031, 032, 033, 034, 035, 036, 037, 038, 039, 040, 041, 042, 043, 044, 045, 046, 047, 048, 049, 050, 051, 052, 053, 054, 055, 056, 057, 058, 059, 060, 061, 062, 063, 064, 065, 066, 067, 068, 069, 070, 071, 072, 073, 074, 075, 076, 077, 078, 079, 080, 081, 082, 083, 084, 085, 086, 087, 088, 089, 090, 091, 092, 093, 094, 095, 096, 097, 098, 099, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329 CLIMATIC FACTORS 086, 129, 253 CLIMATIC IMPACT 267 CLIMATOLOGY

050, 053, 086, 198, 209, 215, 257, 261 CLOSING OF CENTRAL AMERICAN ISTHMUS EFFECT 060 CLOUD FORESTS 003, 004, 026, 106, 182, 185, 229, 240, 251, 259, 299, 305 CLOUD FORMATION 111, 218, 228 CLOUD WATER CHEMISTRY 003, 004, 026 CLOUDS 111, 156, 174, 175, 192, 217, 218, 223, 228, 230, 249, 267, 279 CLUE-CR 066 CLUSIACEAE 245, 280 CNIDARIA 037, 158, 288, 298 COAST IVORY 276 COASTAL RESOURCES 155 COASTAL-MARINE ENVIRONMENT 193 COCCOLITHOPHORIDS 273 COCHRANELLA 159 CODEFORSA 257 COFFEA ARABICA 039, 062, 073, 101, 163, 165, 184, 247, 254, 311 COFFEE 039, 062, 073, 163, 165, 184, 247, 254, 311 COLEOPTERA 082 COLOMBIA 246, 248, 265, 282, 284 COLOSTETHUS 159

COLPOPHYLLIA 288 COMBRETACEAE 245, 254, 272, 280 COMBUSTION PRODUCTS 231 COMMODITIES 179 COMMON BEAN 204, 241, 285 COMMON TINK FROG 312 COMMUNITIES 179, 181, 185, 186, 240, 259, 305 COMMUNITY COMPOSITION 222, 235, 260 COMMUNITY FORESTRY 132, 179 COMMUNITY INVOLVEMENT 132, 179 COMMUNITY POLICIES 230 COMMUNITY STRUCTURE 196, 222, 235, 260, 268 COMPACTION 041 COMPENSATION POINT 013 COMPUTER MODELS AND SIMULATIONS 052, 066, 094 CONSERVATION 061, 082, 188, 191, 198, 206, 209, 211, 224, 256, 257, 265, 308, 312 CONSERVATION ACTIVITIES 209, 234, 257 CONSERVATION AREAS 058, 112 CONSERVATION IMPLICATIONS 111 CONSERVATION MEASURES 310

CONSERVATION OF NATURAL RESOURCES 299 CONSTITUENT SOURCES AND SINKS 023 CONTROL 122, 179, 183 CONVENTION ON CLIMATE CHANGE 068 CONVERSION 041 COOPERATIVE BANKS 179 COOPEVEGA 257 CORAL BLEACHING 158 CORAL ECOLOGY 158 CORAL EXTINCTION 177 CORAL MORTALITY 037 CORAL REEF DEGRADATION 298 CORAL REEF ECOLOGY 157, 158, 298 CORAL REEFS 037, 125, 157, 158, 177, 193, 196, 288, 298 CORALS 177 CORDIA ALLIODORA 107, 113, 115, 117 CORDILLERA DE TALAMANCA 044, 045, 083, 159, 216, 242, 248, 252, 263, 264, 304 CORDILLERA DE TILARAN 178, 228, 276 CORDILLERA VOLCANICA CENTRAL 044 CORREDOR BIOLOGICO MESOAMERICANO 267

COST BENEFIT ANALYSIS 170, 293, 309 COSTA RICA 001, 002, 003, 004, 005, 006, 007, 008, 009, 010, 011, 012, 013, 014, 015, 016, 017, 018, 019, 020, 021, 022, 023, 024, 025, 026, 027, 028, 029, 030, 031, 032, 033, 034, 035, 036, 037, 038, 039, 040, 041, 042, 043, 044, 045, 046, 047, 048, 049, 050, 051, 052, 053, 054, 055, 056, 057, 058, 059, 060, 061, 062, 063, 064, 065, 066, 067, 068, 069, 070, 071, 072, 073, 074, 075, 076, 077, 078, 079, 080, 081, 082, 083, 084, 085, 086, 087, 088, 089, 090, 091, 092, 093, 094, 095, 096, 097, 098, 099, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329 COSTA RICA DOME 273 COSTS 123, 234

COVER MODEL 066 COYOLAR (DISTRITO) 086 CROP PRODUCTION 039, 062 CROPPING SYSTEMS 073, 204, 241, 285 CRUSTACEANS 060, 177 CUTANEOUS MYCOSIS 262, 312 CYCLONES 284, 290 CYPERALES 145, 160, 204, 207, 241, 285 CYPHASTREA 288 DATA ACCESS 028 DATABASES 047 DATASETS 015 DDD 295 DDE 295 DDT 295 DEBT FOR NATURE SWAPS 303 DECIDUOUS FORESTS 146 DECISION MAKING 058, 129 DECLINES 221, 282 DECOMPOSITION 041, 151, 187, 189, 260, 285 DEEP SEA DRILLING PROJECT 033, 060 DEEP SEA SEDIMENTS 258

DEFORESTATION 016, 041, 042, 043, 047, 048, 049, 054, 055, 063, 068, 074, 076, 079, 081, 085, 090, 110, 116, 118, 126, 127, 131, 133, 138, 147, 151, 156, 174, 175, 183, 186, 187, 188, 189, 190, 192, 195, 202, 210, 217, 223, 228, 232, 234, 244, 249, 251, 265, 267, 269, 270, 271, 276, 279, 281, 283, 284, 289, 291, 296, 305, 306 DEFORESTATION RATES 195, 269, 270, 283 DEFORMITIES 083, 103, 216 DEGRADATION 116 DEHYDRATION 277 DEL ORO CITRUS COMPANY 226, 287 DELTA 18O 242 DELTA-C-13 VALUES 151, 187, 189 DENDROBATES AURATUS 215, 261 DENDROBATIDAE 103, 215, 261 DENITRIFICATION 039, 042, 046, 054, 062, 088, 089, 095, 096, 097, 098, 099, 100, 102, 105, 137, 142, 143, 144, 145, 146, 160, 161, 164, 171, 176, 200, 311 DENMARK 276 DEPOSITION 003, 004, 026 DERMOCHELYIDAE 310 DERMOCHELYS CORIACEA 310 DESMODONTIDAE 211 DESMODUS ROTUNDUS 211

DEUTERIUM 301 DEVELOPMENT 215, 261, 281, 296 DEVELOPMENT AGENCIES 131, 190 DEVELOPMENT PROJECTS 132, 179 DIAMETER 001, 019 DIATOMS 243 DIELDRIN 295 DIET 172 DIPLORIA 288 DIPTERYX PANAMENSIS 018, 180, 245, 280 DIRECT ENERGY CONVERTERS 148 DIRECT IMPACTS 225 DISSOLVED INORGANIC NITROGEN 250 DISSOLVED ORGANIC CARBON 250 DISSOLVED ORGANIC NITROGEN 250 DISTRIBUTION 172, 181, 186, 188, 230, 251, 265, 298 DISTRIBUTION RANGES 252 DISTURBANCE 240, 305 DISTURBED HABITAT 240 DIVERSITY 252 DIVING 298

DRINKING WATER 064 DROUGHT 181, 193, 251, 286, 307 DROUGHT EFFECTS 286 DROUGHT INCREASED 021 DRY SEASON 003, 004, 026, 156, 174, 175, 192, 217, 267 DYNAMICS 041, 048, 138, 143, 144, 145, 147, 160 DYNAMICS FLUX 102, 142, 171 EARLY MIOCENE 288 EARLY PLEISTOCENE 288 EARTH SURFACE 152 EASTERN PACIFIC 033, 196, 273, 288 ECOLOGICAL BALANCE 073 ECOLOGICAL CONDITIONS INFLUENCE 208, 281, 296 ECOLOGICAL DISTRIBUTION 172 ECOLOGICAL FOOTPRINT 134 ECOLOGICAL IMPACT 251 ECOLOGICAL SERVICES 226, 287 ECOLOGY 008, 013, 014, 015, 019, 025, 027, 082, 092, 172, 180, 186, 191, 196, 198, 205, 225, 255, 262, 268, 274, 294, 303, 310 ECONOMIC ANALYSIS 123, 129 ECONOMIC DEVELOPMENT 058, 134

ECONOMIC EVALUATION 093, 124, 128, 168, 194, 219, 245 ECONOMIC GROWTH 284 ECONOMIC IMPACT 179 ECONOMIC INCENTIVES 122 ECONOMIC MODELS 138 ECONOMIC POLICIES 058 ECONOMIC SITUATION 112, 293 ECONOMIC VALUE 208, 269, 270, 281, 283, 296 ECONOMICS 073, 129, 209, 234, 257 ECOPHYSIOLOGY 028, 186 ECOSYSTEM DYNAMICS 024, 302 ECOSYSTEM FUNCTION 056, 222, 235, 260 ECOSYSTEMS 045, 051, 073, 146, 150, 161, 162, 181, 185, 193, 197, 206, 207, 208, 251, 256, 259, 264, 269, 270, 281, 283, 292, 296 ECOTOURISM 058, 179, 299 ECOTYPES 118 ECUADOR 157, 197, 244, 246, 265, 266, 276, 282, 284, 303 EDAPHIC EFFECTS 006 EDDY COVARIANCE 007, 013, 022, 205, 255, 294 EFFECTS 060, 135, 156, 174, 175, 180, 192, 217, 223, 228, 249, 251, 267, 268, 279 EFFICIENCY 058, 129, 148

EGG POACHING AND HARVESTING 310 EL NIÑO EFFECT 021, 125, 157, 158, 196, 298 EL NIÑO SOUTHERN OSCILLATION 013, 014, 015, 021, 024, 025, 064, 085, 086, 125, 157, 158, 181, 196, 205, 231, 251, 286, 294, 298, 302 ELECTROCHEMICAL CELLS 148 ELEUTHERODACTYLUS DIASTEMA 092, 312 ELEUTHERODACTYLUS PUNCTARIOLUS 083, 159, 216 ELEVATION 151, 187 EMBALSE ARENAL 178 EMERGENT TREES 018 ENCYONEMA LUNATUM 243 ENDANGERED SPECIES 159, 193, 256, 282, 308, 310, 312 ENDEMISM 274 ENDOSULFAN 295 ENERGY 104, 153 ENERGY BUDGET 156, 192, 217 ENERGY CONSERVATION 155 ENERGY CONSUMPTION 148 ENERGY EFFICIENCY 148 ENERGY INDUSTRY 090

ENERGY POLICY 058, 148 ENTERIC FERMENTATION 068, 090 ENVIRONMENT 030, 040, 104, 193, 236, 237, 295 ENVIRONMENT PROTECTION 173, 212 ENVIRONMENTAL CONSEQUENCES 220 ENVIRONMENTAL CONTROL 169 ENVIRONMENTAL EDUCATION 058, 193, 211, 292 ENVIRONMENTAL EDUCATION & POLICY 188 ENVIRONMENTAL FACTORS 185, 203, 259 ENVIRONMENTAL GOODS 112 ENVIRONMENTAL IMPACT ASSESSMENT 053, 070, 110, 133, 134, 162, 174, 175, 193, 196, 211 ENVIRONMENTAL INDICATORS 221 ENVIRONMENTAL LAW 122 ENVIRONMENTAL LEGISLATION 236, 237 ENVIRONMENTAL MIGRATION 286 ENVIRONMENTAL POLICIES 140, 148, 166, 179, 183, 193, 197, 226, 287 ENVIRONMENTAL PROTECTION 044, 058, 069, 114, 118, 132, 139, 169, 179, 226, 246, 247, 251, 287 ENVIRONMENTAL SERVICES 236, 237, 272 ENVIRONMENTAL SERVICES PAYMENT

093, 112, 122, 123, 124, 128, 131, 136, 139, 166, 168, 169, 170, 190, 193, 194, 219, 226, 245, 254, 257, 280, 287, 292, 299, 309 ENVIRONMENTAL TRANSPORT 046, 176 ENVIRONMETAL POLICY 188 ENZYME ACTIVITY 260 EPICHARIS 253 EPIDEMICS 159, 282 EPIPHYTES 056, 182, 186, 218, 229, 305 EPISODIC EMISSIONS 164 EQUILIBRIUM LINE ALTITUDE 248 EQUILIBRIUM THEORY 071 ERETMOCHELYS IMBRICATA 310 ERYTHRINA 073 ERYTHRINA FUSCA 062 ERYTHRINA POEPPIGIANA 039, 062, 101, 204, 241, 254, 272, 285 ESTACION EXPERIMENTAL LOS DIAMANTES 137 ESTIMATION 043, 068, 080, 081, 091, 102, 166 EUCALYPTUS DEGLUPTA 254, 272 EUNOTIA MINOR 243 EUPHORBIACEAE 178, 245, 280 EUROPE 082, 134, 135, 197, 209, 276

EUTRIC HAPLUDAND 041 EVALUATION 307 EVAPOTRANSPIRATION 111, 255 EVOLUTION 089, 095, 096, 097, 098, 099, 100, 105 EXPANSION OF AGRICULTURE 276 EXTINCT SPECIES 193 EXTINCTION 282 EXTREME WEATHER EVENTS 230 FABACEAE 101, 180, 211, 254 FABACEAE/MIM. 012, 018, 073, 254, 272, 280, 302 FABACEAE/PAP. 018, 073, 204, 241, 245, 253, 272, 280, 285 FAGACEAE 033, 252, 304 FARMING SYSTEMS 080, 091, 102, 129, 286 FARMLAND 042, 075 FARMS 168 FAVIA 288 FAVIIDAE 288 FAZENDA VITORIA 144, 146 FEED GRASSES 167 FEED LEGUMES 167 FEEDING HABITS 061 FERNS

045, 264 FERROMANGANESE CRUSTS 258 FERTILITY 285 FERTILIZATION 145, 154, 160, 164 FERTILIZERS 039, 062, 080, 091, 116, 154 FICUS 082 FIELD MEASUREMENTS 075, 076, 077, 091, 102 FIELD STATIONS 015, 027 FINANCIAL ANALYSIS 309 FINANCIAL RESOURCES 188 FIRE 045, 231, 264 FIRE EFFECTS 031 FIRE HISTORY 178, 264, 275 FIRST NATIONAL COMMUNICATION ON CLIMATE CHANGE 155 FISHERIES 110, 112, 133 FIXATION 073 FLACOURTIACEAE 302 FLOODING 193, 284, 289, 290 FLORENCIA DE TURRIALBA 029, 030, 031, 219 FLOWERING 230, 253 FLOWERING PHENOLOY 210 FLOWERING TIMING 052

FLUCTUATIONS 057, 248 FLUID-ROCK INTERACTIONS 258 FOG DRIP 297 FONAFIFO 122, 195, 226, 257, 270, 283, 287, 299, 309 FOOD AVAILABILITY 108 FOOD FOR MAN 310 FORAGING 061 FORAGING BEHAVIOUR 061 FORAMINIFERANS 037, 273 FORECAST METHODS 247 FORECASTING 094 FOREST BIOLOGY 186 FOREST CONSERVATION 150, 251 FOREST COVER 131, 190, 195, 269, 270, 283 FOREST DECLINE 284 FOREST DISTURBANCE 243 FOREST DYNAMICS 191, 198 FOREST ECOLOGY 017, 022, 028, 210, 211, 218, 225 FOREST ECONOMICS 093, 124, 128, 179, 183, 194, 219, 245 FOREST EVOLUTION 186 FOREST FELLING 032

FOREST FIRES 045, 193, 264 FOREST FRAGMENTATION 210 FOREST HABITAT 088, 200 FOREST INDUSTRY 193 FOREST INFLUENCES 038, 042, 081, 093, 123, 124, 128, 194, 219, 245, 280 FOREST LITTER 024, 031, 302 FOREST MANAGEMENT 048, 123, 132, 139, 179, 183, 191, 198, 232, 296 FOREST PLANTATIONS 093, 124, 128, 139, 170, 194, 219, 245, 247, 280, 309 FOREST PRODUCTS 281, 296 FOREST PROTECTION 048, 136 FOREST RESOURCES 104 FOREST RESTORATION 150 FOREST SOILS 017, 022, 024, 034, 036, 038, 041, 042, 043, 049, 053, 054, 068, 077, 081, 102, 127, 164, 202, 203, 247, 302, 306 FOREST VULNERABILITY 155 FORESTRY 001, 019, 041, 044, 048, 139, 191, 198, 246 FORESTRY INCENTIVES 117, 139 FORESTRY LAW 122 FORESTRY POLICIES 139, 179, 183 FORESTRY SECTOR 195, 270, 283 FORESTS

045, 049, 052, 074, 076, 136, 138, 166, 183, 186, 193, 197, 214, 236, 237, 264 FORESTS AND CLIMATE 156, 217, 223, 228, 249, 267, 279 FORMICIDAE 240, 305 FORTUNA DE PANAMA 083, 216 FOSSIL ASSEMBLAGES 060 FOSSIL CORALS 037 FOSSIL POLLEN 304 FOSSILS 059 FRACTIONATION 151, 187, 189 FRAGILITY 265 FRESHWATER 193, 299 FROGS 092, 106, 159, 185, 259, 262, 282 FRUGIVORY 061, 186 FRUIT TREES 073 FRUITING TIMES 230 FUNGI 035, 244, 262, 312 GAMBIA 072 GAP ANALYSIS 256 GARDINEROSERIS 288 GAS 051, 207 GAS DIFFUSION 278

GAS EMISSION BALANCE 199 GAS EMISSIONS 074, 090, 122, 127, 199, 202, 306 GAS EXCHANGE 049, 053, 054, 164 GAS FLUXES 088, 200 GASES 043, 053, 068, 072, 080, 081, 091, 102, 109, 161, 239 GATT 110 GENETIC DIVERSITY 135, 210 GENETIC DRIFT 210 GENETIC RESOURCES 193 GEOCHEMICAL CYCLES 023 GEOCHEMISTRY 258 GEOGRAPHICAL INFORMATION SYSTEMS 048, 088, 089, 095, 096, 097, 098, 099, 100, 105, 129, 137, 181, 200, 251 GEOLOGICAL AGES 060, 177, 242, 248, 263, 275, 288 GEOLOGICAL FACTORS 186 GEOLOGICAL HISTORY 172, 186 GEOLOGY 037, 060, 242, 263 GEOMORPHOLOGY 263 GEOPHYSICAL EVENTS 060 GEOPHYSICS 258 GEOSTATIONARY OPERATIONAL

ENVIRONMENTAL SATELLITE IMAGERY 156, 192, 217, 228 GIS 089, 095, 096, 097, 098, 099, 100, 105, 116, 137, 181, 251 GLACIAL DEPOSITS 045, 264 GLACIAL GEOLOGY 242, 263 GLACIAL-INTERGLACIAL CYCLES 177 GLIRICIDIA SEPIUM 204, 241, 285 GLOBAL ATMOSPHERIC CHANGES 056 GLOBAL CARBON BUDGET 009, 022 GLOBAL CARBON CYCLE 067, 149 GLOBAL CHANGE 028, 291 GLOBAL ENVIRONMENT FUND 303 GLOBAL ENVIRONMENTAL MARKET 233 GLOBAL FRACTIONATION 295 GLOBALIZATION 173, 212 GLOBIGERINA BULLOIDES 037 GLOSSOPHAGA COMMISSARISI 211 GLOSSOPHAGINAE 211 GLUCOSE 042 GLYCINE MAX 204, 241, 285 GMELINA ARBOREA 170, 233, 309 GOES SATELLITE IMAGERY

228 GOLDEN TOAD 092, 106, 185, 251, 259, 262, 274 GOLFO DE PAPAGAYO 037, 125, 158, 196, 298 GOMPHONEMA GRACILE 243 GOMPHONEMACEAE 243 GONIASTREA 288 GOVERNMENT BONDS 121 GOVERNMENT POLICY 140, 148 GRACILICUTES 222 GRASSES 077, 117 GRASSLAND BIOGEOCHEMISTRY 089, 095, 096, 097, 098, 099, 100, 105 GRASSLAND SOILS 034, 038, 041, 042, 049, 081, 091, 102, 127, 202, 306 GRASSLANDS 042, 054, 116, 142, 145, 160, 164, 167, 171 GREAT BARRIER REEF 157, 158 GREEN GROUPS' LEADERS 173, 212 GREEN MARKETS 209, 234, 257 GREENHOUSE EFFECT 002, 015, 022, 024, 027, 041, 043, 044, 048, 054, 055, 063, 064, 067, 068, 069, 072, 078, 080, 081, 087, 090, 091, 093, 094, 102, 112, 113, 115, 116, 117, 120, 122, 124, 128, 131, 134, 138, 139, 141, 143, 144, 145, 149, 153, 155, 162, 163, 164, 166, 183, 184, 185, 186, 188, 189, 190, 194, 199, 208, 213, 215, 219, 230, 233, 234, 239, 245, 246, 251, 256, 259, 261, 265, 269, 270, 272, 276,

277, 280, 281, 283, 284, 289, 292, 296, 299, 302 GREENHOUSE GAS MITIGATION 226, 287 GREENHOUSE GASES 048, 054, 067, 068, 070, 075, 088, 090, 110, 120, 122, 126, 129, 133, 149, 153, 155, 162, 163, 164, 165, 166, 183, 184, 197, 200, 202, 233, 254, 257, 272, 303 GROUNDWATER 297 GROUNDWATER POLLUTION 193 GROWTH 009, 014, 022, 025, 052, 123, 180 GROWTH PERIODICITY 052 GUACIMO (CANTON) 127, 129, 306 GUANACASTE (PROVINCIA) 085, 119, 129, 286, 306 GUAPILES (DISTRITO) 126 GUATEMALA 057, 104, 206, 236, 237, 246, 248, 256, 267, 284, 286, 307, 310 GUATTERIA AERUGIONOSA 018 GYMNOPHIONA 103 HABITAT ALTERATIONS 211 HABITAT DEGRADATION 210 HABITAT DESTRUCTION 253 HABITAT FRAGMENTATION 159 HABITAT LOSS 251 HABITAT MODIFICATION 159, 282 HABITAT USE

172 HABITATS 268, 305 HANDICRAFTS 112 HCB 295 HEAVY METALS 035 HEDYOSMUM 178 HEIGHT 005 HEMIEPIPHYTES 186 HEMIPTERA 082 HENAN 161 HEPATICAE 252 HEPTACHLORE 295 HERBICIDES 116 HERBIVORES 061, 186, 266 HIGH-ELEVATION SITES 106, 185, 259 HIGHLAND TROPICAL FORESTS 268 HIGHLY PRODUCTIVE COASTAL REGIONS 037 HISTORICAL DATA 208, 281, 296 HOJANCHA (CANTON) 170 HOLOCENE 045, 263, 264, 275 HOLOCENE CLIMATE SHIFTS 178 HOMO 045, 061, 264

HOMOPTERA 082 HONDURAS 104, 152, 197, 206, 236, 237, 246, 284, 286, 307 HONEYBEES 253 HORQUETAS DE SARAPIQUI 091, 154 HOUSE WREN 108 HUMAN ACTIVITY 152, 159, 178, 264 HUMAN DISTURBANCE 178, 265 HUMAN ECOLOGY 066 HUMAN IMPACT 243, 265 HUMAN LAND USE SYSTEM DYNAMICS 208, 281, 296 HUMAN POPULATION 251 HUMID TROPICS 137, 154 HUSBANDRY 168, 265 HYALINOBATRACHIUM 092, 159 HYALINOBATRACHIUM FLEISCHMANNI 092 HYDNOPHORA 288 HYDROCARBONS 220 HYDROGEN 291 HYDROGEN CHLORIDE 035 HYDROZOA 288 HYERONIMA ALCHORNEOIDES 001, 019, 245, 280

HYLA CALYPSA 083, 159, 216 HYLA PSEUDOPUMA 092 HYLA RIVULARIS 083, 159, 216 HYLIDAE 083, 092, 103, 152, 159, 216 HYMENOLOBIUM MESOAMERICANUM 001, 018, 019 HYMENOPTERA 082, 240, 253, 305 ICHNEUMONIDAE 082 IDEOLOGIES 173, 212 IICA 029, 030 IMPACT 050, 152, 159, 218, 264, 297 IMPACT IN TROPICAL FORESTS 056 IMPACT ON HATCHLING PRODUCTION 310 IMPLEMENTED JOINTLY PROJECT [RFCAIJP] 209 IMPORT OF USED CARS 220 IMPROVEMENT FELLINGS 123 INBIO 112, 135, 193, 226, 252, 263, 264, 265, 287 INBREEDING 210 INCENTIVE PROGRAMS 166 INCENTIVES 166 INCEPTISOLS 041, 042 INCREMENT 001, 019, 123

INDIA 289 INDICATORS FOR SUSTAINABLE DEVELOPMENT 134 INDICES OF VEGETATION PRODUCTIVITY 151, 187 INDIGENOUS COMMUNITIES 292 INDIGENOUS ORGANISMS 111, 225, 245, 280 INDIRECT IMPACTS 225 INDUSTRIA NACIONAL DE CEMENTO 233 INDUSTRIAL PROCESSES 153 INFLUENCE OF EPIPHYTES 056 INFRARED GAS ANALYZERS 017 INGA 073, 254, 272 INHIBITION 038, 081 INORGANIC NITROGEN 026 INPUTS 285 INSECTS 061, 082, 240, 253, 266, 278, 305 INSOLATION 022, 180, 230 INSTITUTIONAL FACTORS 140 INTEGRATED SYSTEMS 183 INTERACTIONS 186 INTERANNUAL VARIABILITY 181, 251, 263 INTERANNUAL VARIATION

014, 015, 025, 278 INTERFERENCE 061 INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE 140, 141 INTERNAL PRESSURES 188 INTERNATIONAL AGREEMENTS 155, 167 INTERNATIONAL COMPARISONS 134 INTERNATIONAL COOPERATION 179, 183, 197 INTERNATIONAL DEPOSITED FUELS 068 INTERNATIONAL TRADE 134, 138 INTERTROPICAL CONVERGENCE ZONE 227, 242, 263, 273, 301 INTRASPECIFIC VARIATION 253 INTRODUCED SPECIES 159 IPCC 140, 141 IRRIGATION 034 ISLA DE CAÑAS 310 ISLAS GALAPAGOS 157 ISOPODS 177 ISOPRENE 012 ISOPRENE EMISSION 012 ISOPTERA 082 ISOTOPE RATIOS 258

JANZEN-CONNELL MODEL 015 JOINT IMPLEMENTATION 048 JUNQUILLAL DE SANTA CRUZ 132, 179 KYOTO PROTOCOL 114, 136, 167, 236, 237, 247, 254, 271, 272 LA BOMBA 060 LA CASCADA 257 LA CHONTA DE EL GUARCO 057, 304 LA FORTUNA DE SAN CARLOS 113, 115, 117 LA NIÑA EVENT 286 LA PACIFICA ECOLOGICAL CENTRE 052 LA SELVA BIOLOGICAL STATION 001, 002, 005, 006, 007, 008, 009, 010, 011, 012, 013, 014, 015, 016, 017, 018, 019, 020, 021, 022, 023, 024, 025, 027, 028, 032, 036, 038, 042, 043, 046, 047, 049, 051, 053, 054, 074, 076, 081, 086, 088, 095, 096, 097, 098, 099, 100, 103, 105, 120, 127, 142, 143, 144, 145, 146, 151, 160, 164, 171, 176, 180, 187, 188, 189, 200, 201, 203, 205, 211, 214, 222, 231, 235, 245, 250, 255, 260, 266, 270, 278, 280, 283, 294, 300, 302, 306, 308, 312 LA SUERTE BIOLOGICAL STATION 215, 261 LA VIRGEN DE SARAPIQUI 123, 194, 257 LAETIA PROCERA 302 LAGO COTE 178 LAGO DE LAS MORRENAS 264

LAGO QUEXIL 057 LAGUNA LA YEGUADA 057 LAGUNA ZONCHO 243 LAKE 057 LAKE SEDIMENT 045, 178, 243, 264, 275 LAND CLEARING 102 LAND COVER 135, 147, 151, 187, 202, 214 LAND USE 016, 041, 043, 048, 055, 066, 068, 080, 081, 090, 095, 097, 098, 099, 100, 104, 105, 116, 118, 129, 134, 135, 138, 145, 147, 151, 156, 153, 160, 161, 174, 175, 183, 187, 189, 192, 195, 202, 214, 217, 222, 223, 228, 232, 235, 247, 249, 260, 267, 269, 270, 276, 279, 281, 283, 296, 297 LAND USE CHANGE 016, 066, 089, 090, 095, 096, 097, 098, 099, 100, 105, 138, 145, 151, 153, 160, 161, 187, 189, 202, 267, 276, 297 LAND USE CHOICE EFFECTS 208, 269 LANDSAT IMAGERY 156, 192, 217, 223, 228, 249, 279 LANDSCAPE ECOLOGY 006 LANDSCAPE SAMPLING 028 LANDSCAPE SCALE 088, 200 LANDSCAPING 166 LANDSLIDES 289 LARGE SCALE 208 LARVAE 215, 261, 266

LAS CRUCES BIOLOGICAL STATION 188, 243 LAS NUBES DE QUIZARRA 254 LAS PALMITAS 257 LAS VEGAS 054, 164 LASER ALTIMETER 010 LASER PROFILING SYSTEM 005 LASER RETURNS 005 LASER VEGETATION IMAGING SENSOR 005 LAST DEGLACIATION 263, 273 LAST GLACIAL MAXIMUM 248 LATE HOLOCENE 243 LATE NEOGENE 059, 060 LATE OLIGOCENE 288 LATE PLEISTOCENE 177, 248 LATE QUATERNARY 033 LEACHING 024, 039, 062, 116, 129, 302 LEAF LITTER 215, 261 LEAF PHENOLOGY 180 LECYTHIDACEAE 180 LECYTHIS AMPLA 001, 019, 180 LEG 170 258

LEG 205 258 LEGISLATION 155, 265, 310 LEPIDOCHELYS OLIVACEA 310 LEPIDOPTERA 061, 082, 266 LEPTODACTYLIDAE 092, 103, 152, 159, 312 LEPTOSERIS PAPYRACEA 158, 298 LIBERIA (CANTON) 253 LICHENES 035 LICHENIZED FUNGI 035 LIDAR REMOTE SENSING 010 LIFE HISTORY 215, 261 LIGHT 001, 019, 186 LIGHTNING 264 LILIOPSIDA 012, 033, 034, 045, 097, 107, 113, 115, 117, 145, 160, 178, 204, 207, 215, 241, 254, 261, 264, 272, 278, 285, 305 LIMNOLOGY 243 LINEAR MODELS 116 LIQUEFIED PETROLEUM GASES 068, 090 LISSAMPHIBIA 216, 221, 256, 262, 312 LITTER 024, 260, 302 LITTER LEACHATE 250 LIVESTOCK 109, 116, 168

LIZARDS 312 LLANURAS DE SAN CARLOS 156, 174, 175, 192, 217, 228 LLANURAS DE TORTUGUERO 044, 156, 174, 175, 192, 217, 228 LOCAL VEGETATION DEVELOPMENT 304 LOGGING 031, 123, 193, 284 LONG TIME PERIODS 208 LONG-RANGE TRANSPORT 295 LONG-TERM ECOLOGICAL RESEARCH 009, 015, 022, 027 LONG-TERM STUDIES 308, 312 LOS CUSINGOS NEOTROPICAL BIRD SANCTUARY 254, 272 LOSSES 039, 062 LOSSES FROM SOIL 039, 041, 062 LOWER STRATOSPHERE 277 LOWLAND DEFORESTATION 297 LOWLAND RAIN FORESTS 275 LOWLANDS 119 LUQUILLO EXPERIMENTAL FOREST 056, 146 LYMANTRIIDAE 082 MAGNESIUM 024, 302 MAGNOLIOPHYTA 001, 012, 018, 019, 033, 034, 039, 045, 056, 062, 073, 082, 094, 097, 101, 107, 113, 115,

117, 142, 145, 163, 165, 170, 178, 180, 184, 204, 207, 211, 215, 233, 241, 245, 253, 254, 261, 264, 272, 278, 280, 285, 292, 302, 304, 305, 309, 311 MAGNOLIOPSIDA 001, 012, 018, 019, 033, 039, 056, 062, 073, 082, 094, 101, 107, 113, 115, 117, 142, 145, 160, 163, 165, 170, 178, 180, 184, 204, 211, 233, 241, 245, 253, 254, 272, 278, 280, 285, 292, 302, 304, 305, 309, 311 MAIZE 034, 145, 160, 204, 207, 241, 285 MALACOSTRACA 177 MALPIGHIACEAE 253 MAMMALIAN EXTINCTIONS 224 MAMMALS 045, 061, 211, 213, 264 MANAGEMENT 142, 145, 160, 171, 196 MANAGEMENT CAPACITY 276 MANGROVES 112, 193 MAPS 214 MARINE RESOURCES 104 MARINE TURTLES 310 MARKET 148 MARKET CONSTRUCTION 209 MARKET FAILURES 284 MARKET INSTRUMENTS 130, 131, 150, 190 MARKETING 179, 281, 296 MARYLAND 266

MASS MORTALITY 152 MATHEMATICAL MODELS 088, 089, 096, 097, 098, 099, 100, 105, 116, 137, 161 MATURE FOREST 032 MAUI 053 MEASUREMENT 118 MEDICINAL PRODUCTS 112 MELANESIA 082 MELIACEAE 254, 272 MESOAMERICAN BIOLOGICAL CORRIDOR 267 MESOSCALE LANDSCAPES 006 MESOZOIC 060 METADATA STANDARDS 230 METEOROLOGY 030, 101 METHANE 049, 068, 081, 082, 090, 109, 126, 143, 145, 153, 160, 161, 163, 165, 168, 184, 199, 277 METHANE FLUX 088, 137, 154, 200 METHODOLOGY 047, 140 MICROBES 016, 222, 235, 260 MICROBIAL ACTIVITY 016 MICROBIAL COMMUNITY 260 MICROHABITAT 305 MICROHYLIDAE

103 MICROPARASITES 312 MICROSCOPIC CHARCOAL 275 MIGRATION 045, 211, 264, 286 MIGRATION EVENTS 230 MINERALIZATION 306 MINERALOGY 151, 187 MINING 284 MINQUARTIA GUIANENSIS 001, 018, 019 MISSING SPECIES 259 MISSOURI 266 MISTAKEN POLICY INTERVENTIONS 284 MITIGATION 048, 122, 130, 131, 150, 190, 208, 281, 292, 296 MODELING 111, 185, 306 MODELS 012, 040, 094, 095, 111, 129, 185, 247, 306 MOIN FORMATION 177 MOISTURE 160 MOLLUSCS 273 MONGOLIA 072 MONITORING 028, 118 MONITORING STUDY 035 MONOPOLIES

148 MONTANE RAIN FOREST 252 MONTANE REGIONS 244 MONTE CARLO MODELS 066 MONTE CARLO TECHNIQUES 137 MONTEVERDE CLOUD FOREST RESERVE 003, 004, 026, 044, 056, 092, 106, 111, 152, 156, 159, 174, 175, 182, 185, 192, 213, 217, 218, 223, 226, 229, 230, 240, 244, 249, 251, 256, 259, 262, 267, 268, 274, 276, 279, 282, 287, 297, 299, 305, 312 MONTEVERDE CONSERVATION LEAGUE 226, 287 MONTIPORA 288 MONTREAL PROTOCOL 303 MORACEAE 082 MORAVIA DE SAN CARLOS 257 MORPHOLOGICAL DIVERGENCE 172 MORTALITY 006, 083, 103, 157, 158, 198, 216 MORTALITY RATE 191, 198 MOSSES 252 MOTASTRAEA 288 MUCUNA URENS 211 MULTIPURPOSE TREES 204, 241, 285 MUSA 097, 254, 272 MUSACEAE

097, 254, 272 MYCORRHIZAE 031 MYOBATRACHIDAE 221 MYRICA 178 MYRICACEAE 178 MYRISTICACEAE 245, 280 MYRSINACEAE 178 MYRSINE 178 MYRTACEAE 254, 272 N2O 088, 142, 145, 160, 164, 171, 200, 311 N2O FLUXES 154 N2O PRODUCTION 137 NAFTA 110, 289 NAMIBIA 276 NATIONAL ACCOUNTING 112 NATIONAL PARKS 047, 058, 118, 195, 256, 270, 283 NATURAL ABUNDANCE 144 NATURAL DISASTERS 286, 289, 290 NATURAL ECOSYSTEMS 186 NATURAL ENEMIES 082 NATURAL FIRES 284 NATURAL FLUCTUATIONS 152

NATURAL REGENERATION 107, 113, 115, 117 NATURAL RESOURCE ECONOMICS 179 NATURAL RESOURCES 104, 110, 193, 236, 237 NATURAL RESOURCES EXPLOITATION 289 NATURAL SCENIC BEAUTY 226, 287 NATURE CONSERVATION 112, 122, 210, 296, 310 NEGUEV SETTLEMENT 129 NET CARBON UPTAKE 021 NET ECOSYSTEM EXCHANGE 013, 014, 025, 205, 255, 294 NET PRIMARY PRODUCTION 014, 025 NICARAGUA 104, 206, 236, 237, 246, 286, 307, 310 NICOYA (CANTON) 170 NITRATE NITROGEN 039, 042 NITRATES 038, 039, 062, 081, 163, 165, 184, 235, 260 NITRATES REACTIONS 046, 102, 176 NITRIC OXIDE 003, 004, 026, 038, 049, 074, 075, 076, 077, 080, 081, 088, 091, 102, 127, 137, 142, 143, 144, 146, 154, 164, 171, 200, 202, 306 NITRIC OXIDE EMISSION 046, 075, 091, 176 NITRIFICATION 036, 038, 046, 081, 102, 145, 146, 160, 176, 222, 235, 260, 311 NITRITES

038, 046, 081, 102, 176 NITROGEN 024, 031, 038, 039, 042, 062, 075, 081, 129, 258, 302, 306 NITROGEN AVAILABILITY 160 NITROGEN CYCLE 004, 026, 034, 039, 043, 053, 054, 062, 068, 080, 081, 091, 095, 096, 097, 102, 143, 144, 145, 160, 161, 164, 167, 171, 222, 235, 260 NITROGEN DIOXIDE 163, 184 NITROGEN DYNAMICS 285 NITROGEN FERTILIZERS 039, 062, 076, 077, 091, 163, 165, 184 NITROGEN FIXATION 004, 163, 170, 184 NITROGEN FLUXES 004, 026 NITROGEN MINERALIZATION 036 NITROGEN OXIDES 039, 062, 068, 074, 090, 116, 153, 161, 171, 220 NITROGEN RETENTION 003, 004, 026 NITROGEN STATUS 250 NITROGEN TRANSFORMATIONS 036 NITROSOMONAS 235, 260 NITROSOSPIRA 235, 260 NITROUS OXIDE 034, 036, 042, 043, 048, 049, 051, 053, 054, 068, 074, 075, 076, 077, 080, 088, 089, 090, 091, 095, 096, 097, 098, 099, 100, 102, 105, 116, 126, 127, 142, 143, 144, 145, 146, 153, 154, 160, 161, 163, 164, 165, 168, 171, 184, 199, 200, 207, 222, 235, 260, 306, 311 NITROUS OXIDE FLUX

043, 054, 068, 080, 081, 088, 127, 154, 200, 202, 207, 306 NON-MARKET BENEFITS 093, 124, 128, 194, 219 NON-METHANE VOLATILE COMPOUNDS 090 NONGOVERNMENTAL ORGANIZATIONS 162 NONWOOD FOREST PRODUCTS 232 NORTH/SOUTH DIVISION 173, 212 NORTHERN HEMISPHERE GLACIATION 060 NORWAY 209 NOX EMISSIONS 077, 102 NULL MODEL 092, 274 NUTRIENT AVAILABILITY 024, 302 NUTRIENT DYNAMICS 003, 004, 026 NUTRIENT INPUTS 056 NUTRIENTS 024, 051, 125, 186, 196, 298, 302 OAK FORESTS 304 OCEAN 157, 158 OCEAN CIRCULATION 057 OCEAN DRILLING PROJECT 258 OCEANIC CLIMATE AND HISTORY RECONSTRUCTION 037 OCEANIC CRUST 258 OCEANOGRAPHIC CHANGES

060 OCHROMA LAGOPUS 142 OIL BEES 253 OIL FLOWERS 253 OLACACEAE 018 OLD CANOPY 018 OLD GROWTH FOREST 009, 022, 024, 203, 302 ORGANIC CARBON 041, 214, 231 ORGANIC MATTER 138, 151, 187, 189, 258, 285 ORGANOCHLORINE PESTICIDES 295 ORGANOMINERAL COMPLEXES 041 ORNAMENTAL PLANTS 112 ORNAMENTAL REEF FISH EXTRACTION 298 ORYZA SATIVA 094 OSTRACODS 060, 273 OTS 001, 002, 007, 009, 010, 011, 012, 015, 016, 027, 029, 030, 039, 042, 043, 046, 047, 049, 051, 053, 054, 062, 074, 076, 081, 086, 151, 160, 164, 171, 176, 180, 187, 188, 189, 201, 203, 214, 231 OXYGEN 227, 242, 263 OXYGEN ISOTOPIC ANALYSIS 037 OXYGEN-18 301 OZONE 051, 126, 193, 277

OZONE DEPLETION 042, 152, 303 OZONE LAYER 078 OZONE PRECURSORS 075 OZONE PROTECTION 078 PACIFIC 086, 106, 185, 259 PACIFIC ISLANDS 082 PACIFIC MARGIN 258 PACIFIC SLOPE 087 PACUARE 086 PALEOBOTANY 033, 045, 178, 264 PALEOCEANOGRAPHY 059 PALEOCLIMATE 263, 304 PALEOECOLOGY 178, 304 PALEOENVIRONMENTS 057 PALEOGEOGRAPHY 304 PALEOBIOLOGY 177 PALEOCEANOGRAPHY 060, 273 PALEOCLIMATE CHANGE 177, 227, 242, 248, 263, 301 PALEOCLIMATE RECORDS 177, 227, 242, 248, 263, 301 PALEOECOLOGY 304 PALEOENVIRONMENT 177 PALEOLIMNOLOGY 243

PALEOVEGETATION 218 PALEOZOOLOGY 177 PALYNOLOGY 033, 178, 304 PANAMA 002, 057, 059, 060, 083, 103, 104, 152, 157, 172, 216, 227, 236, 237, 244, 246, 256, 265, 266, 273, 282, 286, 288, 301, 307, 310 PANAMA BASIN 273 PANDORA 086 PANICUM MAXIMUM 107, 113, 115, 117 PARAMO 045, 263, 264, 265 PARAMO ECOLOGY 045, 263, 264 PARAMO FIRES 045, 264 PARAMO VEGETATION 045, 264 PARASITISM RATES 266 PARASITOIDS 082, 266 PARMELIA 035 PARMELIACEAE 035 PARQUE INTERNACIONAL LA AMISTAD 118, 195, 256 PARQUE NACIONAL ARENAL 195 PARQUE NACIONAL BARBILLA 118, 195 PARQUE NACIONAL BARRA HONDA 118, 195 PARQUE NACIONAL BRAULIO CARRILLO

047, 151, 187, 189, 195, 214, 270 PARQUE NACIONAL CAHUITA 195 PARQUE NACIONAL CARARA 195 PARQUE NACIONAL CHIRRIPO 045, 056, 195, 242, 248, 263, 264 PARQUE NACIONAL CORCOVADO 044, 195 PARQUE NACIONAL GUANACASTE 044, 118, 195, 266 PARQUE NACIONAL JUAN CASTRO BLANCO 195 PARQUE NACIONAL MANUEL ANTONIO 195 PARQUE NACIONAL MARINO LAS BAULAS 310 PARQUE NACIONAL PALO VERDE 118, 188, 195 PARQUE NACIONAL PIEDRAS BLANCAS 118, 195 PARQUE NACIONAL RINCON DE LA VIEJA 044, 195 PARQUE NACIONAL SANTA ROSA 118, 191, 195, 198 PARQUE NACIONAL TAPANTI-MACIZO CERRO DE LA MUERTE 195 PARQUE NACIONAL TORTUGUERO 195, 310 PARQUE NACIONAL VOLCAN IRAZU 195 PARQUE NACIONAL VOLCAN POAS 056, 195

PARQUE NACIONAL VOLCAN TENORIO 195 PARQUE NACIONAL VOLCAN TURRIALBA 195 PARTICLE SIZE DISTRIBUTION 189 PASSIVE AIR SAMPLING 295 PASTURE HABITAT 088, 200 PASTURE LANDS 077, 091, 102 PASTURES 016, 034, 038, 042, 043, 049, 054, 068, 074, 076, 077, 081, 089, 091, 095, 096, 097, 098, 099, 100, 105, 116, 127, 137, 144, 154, 164, 202, 306 PATTERNS 006, 147 PAVONA 288 PAVONA CLAVUS 298 PCBS 295 PEASANT MIGRATION 286 PENINSULA DE NICOYA 033, 044 PENMAN-MONTEITH 255 PENTACLETHRA MACROLOBA 012, 018, 302 PERACARIDA 177 PERIODIC LEAF REPLACEMENT 052 PERIODICITY 119 PERMANENT FOREST STANDS 131, 190 PERMITS 197

PERSISTENT ORGANIC POLLUTANTS 295 PERU 072, 152, 246, 265, 282 PEST INSECTS 082, 211 PESTICIDES 110, 116, 129, 133, 295 PESTS 284 PETROLEUM 238 PHAINOPTILA MELANOXANTHA MELANOXANTHA 172 PHAINOPTILA MELANOXANTHA PARKERI 172 PHASEOLUS VULGARIS 204, 241, 285 PHENOLOGICAL DATA 230 PHENOLOGY 087, 119, 253 PHILIPPINES 072, 303 PHOSPHORUS 024, 031, 129, 302 PHOTOELECTRIC CELLS 148 PHOTOGRAMMETRY 047 PHOTOSYNTHESIS 012, 020, 073, 251 PHOTOSYNTHESIS EFFECT 021 PHOTOVOLTAIC CELLS 148 PHYLLOMEDUSA 159 PHYLLOSTOMIDAE 211 PHYSICAL PARAMETERS 125, 196, 298

PICEA SITCHENSIS 082 PINACEAE 082 PINNULARIA BRAUNII 243 PINOPHYTA 033, 082 PINUS 033 PIPER 033, 178 PIPERACEAE 033, 178 PITHECELLOBIUM ELEGANS 001, 019 PLANT BREEDING STRUCTURE 210 PLANT COMMUNITIES 167 PLANT DISPERSAL 251 PLANT GEOGRAPHY 225 PLANT GROWTH 120 PLANT PHENOLOGY 253 PLANT PHYSIOLOGY 180 PLANT SUCCESSION 049 PLANTATION CROP 160 PLANTATION FORESTRY 093, 124, 128, 219, 245, 280 PLANTS 001, 004, 012, 018, 019, 026, 033, 034, 039, 045, 052, 056, 062, 073, 082, 094, 097, 101, 107, 113, 115, 117, 142, 145, 160, 163, 165, 170, 178, 180, 184, 204, 207, 211, 215, 233, 241, 243, 245, 252, 253, 254, 261, 264, 272, 278, 280, 285, 292, 302, 304, 305, 309, 311 PLATYGYRA

288 PLAYA GRANDE 310 PLEISTOCENE 288 PLETHODONTIDAE 083, 159, 216 PLFA 260 PLIOCENE 060 POACEAE 034, 045, 094, 107, 113, 115, 117, 160, 178, 204, 207, 241, 264, 285 POCILLOPORA 158 POCILLOPORA DAMICORNIS 037 POCILLOPORA ELEGANS 298 POCILLOPORIDAE 037, 158, 298 POCOCI (CANTON) 041 PODOCARPACEAE 033 PODOCARPUS 033 POISON-DART FROGS 103, 215, 261 POLICIES 048, 122, 129, 208, 265 POLLEN 045, 057, 178, 264 POLLEN ANALYSIS 033, 045, 264 POLLEN DISPERSAL 211 POLLINATION 186, 210 POLLINATOR DECLINE 253 POLLINATORS 210, 253

POLLUTANTS 049, 053, 109, 166, 169, 209, 234, 257 POLLUTION 035, 049, 053, 071, 072, 083, 103, 109, 116, 135, 166, 169, 209, 216, 231, 234, 257, 295 POLLUTION CONTROL 118, 132, 138, 166, 179 POLLUTION CONTROL INDUSTRY 226, 287 POLLUTION DISPERSION 231 POLYBROMINATED DIPHENYL ETHERS 295 POLYCHLORINATED BIPHENYLS 295 POPULATION 251, 282, 308, 312 POPULATION DECLINE 092, 152, 159, 215, 216, 221, 261, 262, 274, 282 POPULATION DENSITY 284 POPULATION DYNAMICS 082, 092, 125, 172, 186, 196, 221, 262, 274, 298 POPULATION ECOLOGY 256 POPULATION GROWTH 251, 284 POPULATION SIZE 061 POPULATIONS 061, 108 POPULUS DELTOIDES X NIGRA 204, 241, 285 PORITES 288 PORITIDAE 288 POTASSIUM 024, 129, 302 POVERTY

281, 296 PRE-COLUMBIAN 243 PRECIPITATION 065, 086, 181, 227, 230, 242, 251, 263, 297, 301 PRECIPITATION TRENDS 040 PREDATORS 082 PREHISTORIC AGRICULTURE 178 PREHISTORIC HUMAN ACTIVITY 045, 178, 264 PRIESTLY-TAYLOR 255 PRIMARY FORESTS 004, 026, 232 PRIMARY PRODUCTION 251 PRIMATES 045, 061, 264 PRIVATE FORESTRY PROJECT 136 PROCESS MODELING 028, 137 PRODUCTIVITY 013, 014, 025, 110, 133, 205, 255, 280, 294 PROFITABILITY ANALYSIS 309 PROJECTS 118, 162, 197 PROKARYOTES 222 PRORIOS 226, 287 PROTECTED AREAS 112, 195, 224, 251, 256, 265, 270, 276, 283, 299 PROTIUM PITTIERI 018 PROTOZOANS 037 PSAMMOCORA SUPERFICIALIS

298 PTERIDOPHYTA 045, 264 PTILOGONATIDAE 172 PUERTO LIMON 060 PUERTO RICO 056, 143, 146, 152, 244, 288, 291 PUERTO VIEJO DE SARAPIQUI 048, 086, 257 PUPAE 266 PYRROPHYTA 037, 158, 298 QUANTIFICATION 129 QUANTITATIVE ANALYSIS 129 QUATERNARY 242, 263, 273 QUATERNARY GLACIATION 248 QUEBEC 173, 212 QUEENSLAND 221 QUEPOS (DISTRITO) 290 QUERCUS 033, 304 QUERCUS COPEYENSIS 252 QUERCUS FORESTS 252, 304 RABIES 211 RADIOCARBON DATING 018, 178 RAIN 021, 065, 086, 087, 119, 180 RAIN FORESTS 038, 042, 046, 081, 176

RAINFALL 301, 306 RAINFALL CHEMISTRY 003, 004, 026 RAINFALL DECREASE 191, 198 RAINFALL EVENTS 089, 095, 096, 097, 098, 099, 100, 105, 137 RANA VIBICARIA 083, 159, 216 RANIDAE 103, 152, 159 RATIOS 144 RECREATIONAL DIVING 196 RECRUITMENT 198 REDUCTION 291 REEF BUILDING CORAL 158 REFORESTATION 044, 136, 179, 193, 197, 209, 232, 233, 246, 257, 265, 309 REFORESTATION COSTS 232 REFUGIO NACIONAL DE VIDA SILVESTRE OSTIONAL 310 REGENERATION 158 REGIONAL MODELING 089, 095, 096, 097, 098, 099, 100, 105, 161 REGIONAL SCALE 214 RELATIVE HUMIDITY 111, 218 RELAXED EDDY ACCUMULATION 012 REMOTE SENSING 005, 047, 048, 152 RENEWABLE RESOURCES

155 REPRODUCTION 108, 157, 158, 172 REPRODUCTIVE BEHAVIOUR 172, 310 REPRODUCTIVE BIOLOGY 210 REPRODUCTIVE DEVELOPMENT 052 REPTILES 308, 310, 312 RESEARCH 015, 027, 188 RESEARCH METHODS 120 RESEARCH OPPORTUNITIES 015, 027 RESEARCH ORGANIZATIONS 188 RESERVA BIOLOGICA ALBERTO M. BRENES 195 RESERVA BIOLOGICA HITOY-CERERE 195 RESERVA BIOLOGICA ISLA DEL CAÑO 157 RESERVA BIOLOGICA LOMAS BARBUDAL 044, 118, 195 RESERVA DE LA BIOSFERA LA AMISTAD 218, 256 RESERVA NATURAL ABSOLUTA CABO BLANCO 195 RESERVE DESIGN 224, 256 RESOURCE CONSERVATION 058, 079, 139, 166, 310 RESOURCE MANAGEMENT 058, 193 RESOURCE UTILIZATION 058, 179 RESPIRATION

020, 031, 203 RESPIRATION EFFECT 021 RETRANSLOCATION 024, 302 RHEOBATRACHUS SILUS 221 RICE 094 RIO LAGARTO 282 RIO QUEPOS 290 RIO SIXAOLA 289 RIO TICO 257 ROADS 284 ROCKY MOUNTAINS 061 ROOST SITES 211 ROOT DISTURBANCE 143 ROOTS 017, 041, 107 RUBIACEAE 039, 062, 073, 101, 163, 165, 184, 247, 254, 311 RURAL COMMUNITIES 132, 179 RURAL DEVELOPMENT 058 RURAL POPULATION 281, 296 RUSSIA 197 SALAMANDERS 244 SALICACEAE 204, 241, 285 SALICALES 204, 241, 285

SALIENTIA 215, 261 SALINITY 125, 196, 298 SALT EFFECT 154 SAN CARLOS (CANTON) 245 SAN JOAQUIN 257 SAN JOSE (CIUDAD) 035, 277 SAN PEDRO DE BARVA 062, 311 SANTA BARBARA BASIN 037 SANTA ELENA CLOUD FOREST RESERVE 276 SANTO DOMINGO DE HEREDIA 062 SARAPIQUI (CANTON) 080, 086, 151, 187, 189, 245 SARCODINA 037 SATELLITE DATA 152 SATELLITE IMAGERY 048 SATURNIIDAE 082 SAURIA 312 SAVANNAS 167 SCENARIOS 116, 129 SCIENTISTS 015, 027 SCLERACTINIA 196, 288 SCLERACTINIAN CORALS 288 SEA 157, 158

SEA SURFACE TEMPERATURE 057 SEASONAL CHANGES 024, 273, 302 SEASONAL DROUGHT 052 SEASONAL DRY FORESTS 210 SEASONAL STREAMFLOW 086 SEASONAL VARIATION 231, 253 SEASONALITY 008, 024, 034, 087, 119, 203, 207, 302 SECONDARY FORESTS 004, 026, 102, 132, 179, 232, 245, 247, 280 SECONDARY SUCCESSION 186 SECONDARY TROPICAL RAIN FORESTS 046, 176 SEDIMENT 033, 037, 125, 178, 196, 243, 298 SEDIMENTARY DEPOSITS 037 SEED DISPERSAL 211 SEEDS 031 SELECTION 256 SENESCING LEAVES 024, 302 SEQUENCE 248 SEQUESTRATION 093, 124, 128, 194, 208, 219, 245, 269, 270, 283 SERPENTES 278 SEX RATIO 061

SHADE 039, 062, 101, 292 SHADE COFFEE PLANTATIONS 254, 272 SHADE PLANTS 039, 062, 073, 074, 254, 292 SHADING 254 SHORTGRASS STEPPE 088, 200 SIDERASTREA 288 SIDERASTREIDAE 288, 298 SILTATION 298 SILVICULTURE 123, 153, 251 SILVOPASTORAL SYSTEMS 107, 113, 115, 117, 163, 165, 168, 184 SIMAROUBA AMARA 018 SIMAROUBACEAE 018 SIMULATION MODELS 066, 089, 095, 096, 097, 098, 099, 100, 105, 110, 127, 133, 200, 202, 306 SINKS 234 SITE 565 033 SKELETAL EXTENSION RATES 288 SLOVAKIA 072 SMALL ENTERPRISES 307 SNOWLINE RECONSTRUCTIONS 248 SOCIAL GROUPS 286 SOCIAL IMPACT 179

SOCIAL MEANING 209 SOCIAL PARTICIPATION 209 SOCIAL STRUCTURE AND DEVELOPMENT 173, 212 SOCIOECONOMIC FACTORS 140 SOCIOECONOMICS 132, 179 SOCIOLOGY 173, 212 SOIL 006, 031, 032, 036, 038, 039, 041, 042, 043, 046, 049, 051, 054, 062, 068, 074, 080, 081, 088, 091, 107, 116, 117, 138, 165, 171, 176, 200, 207, 222, 235, 260, 263 SOIL AIR 038, 081 SOIL AMENDMENTS 042 SOIL ATMOSPHERE EXCHANGE 077 SOIL BIOLOGY 031 SOIL CALCIUM 024, 302 SOIL CARBON 017, 022, 151, 187, 189, 214 SOIL CARBON STABILIZATION 204, 241, 285 SOIL CARBON STORAGE 032 SOIL CHEMICAL PROPERTIES 189 SOIL CHEMISTRY 031, 041, 042, 054, 164 SOIL CLEARING 046, 176 SOIL CO2 CONCENTRATION 278 SOIL CO2 STORAGE 203

SOIL COMPACTION 049 SOIL DEGRADATION 193 SOIL DEPTH 041 SOIL DETERIORATION 048 SOIL DRIVEN 089, 095, 096, 097, 098, 099, 100, 105 SOIL EROSION 232 SOIL FAUNA 167 SOIL FERTILITY 024, 051, 126, 129, 163, 181, 184, 302 SOIL FLUXES 076, 077, 091, 102, 142, 171 SOIL FORMATION 250 SOIL GAS EMISSION 003, 004, 026, 053, 127, 202, 306 SOIL HYDRAULIC PROPERTIES 171 SOIL MAGNESIUM 024, 302 SOIL MINERALOGY 189 SOIL MOISTURE VARIATION 191, 198, 278 SOIL NITRIFIERS 222, 235, 260 SOIL NITROGEN 024, 036, 302 SOIL ORGANIC CARBON 016, 041, 285 SOIL ORGANIC MATTER 041, 203, 204, 241, 285 SOIL PARAMETERS 160 SOIL PH 041

SOIL PHOSPHORUS AVAILABILITY 024, 302 SOIL PLOWING 076 SOIL POTASSIUM 024, 302 SOIL PROFILES 203 SOIL RESPIRATION 278 SOIL SOLUTION 250 SOIL TEMPERATURE 203, 278 SOIL TEXTURE 151, 187, 189 SOIL TYPES 034, 036, 038, 041, 042, 081, 189, 203 SOIL WATER CONTENT 049, 201, 203 SOIL-ATMOSPHERE 300 SOLANACEAE 211 SOLANUM UMBELLATUM 211 SOLAR RADIATION 001, 007, 013, 019, 205, 255, 294 SOLID WASTES 068, 090, 153 SOLIDARITY 173, 212 SOLITARY BEES 253 SORPTION 250 SOURCE-SINK RELATIONS 013, 022, 205, 294 SOYBEANS 204, 241, 285 SPAIN 276

SPATIAL DISTRIBUTION 061, 295 SPATIAL SCALE 191, 198 SPATIAL VARIABILITY 088, 200, 203 SPECIES COMPOSITION 172 SPECIES DECLINE 092, 262, 274 SPECIES DISAPPEARANCE 083, 103, 159, 216, 221 SPECIES RICHNESS 253, 305 SPECTROMETER 277 SPELEOTHEMS 227, 242, 263, 301 SPHINGIDAE 082 SQUAMATA 312 STABILITY 041 STABILIZATION 189 STABLE CARBON ISOTOPES 151, 187 STABLE ISOTOPE VALUES 227, 242, 263, 301 STABLE ISOTOPIC COMPOSITION 297 STALAGMITES 227, 242, 263, 301 STAPHYLINIDAE 082 STAUROSIRA CONSTRUENS VAR. VENTER 243 STEM DENSITY 191, 198 STERCULIACEAE 292, 312 STORAGE

093, 118, 124, 128, 132, 139, 179, 189, 194, 219, 245 STORED CARBON 068, 090, 122 STRATEGIES 307 STRATIFICATION 305 STRATIGRAPHY 045, 059, 177, 242, 248, 263, 264 STRATOSPHERIC DESTRUCTION 053 STURNIRA LUDOVICI 211 SULFIDES 035 SULPHUR DIOXIDE 035, 153 SURFACE WATER POLLUTION 193 SURVEYS 072, 155 SUSTAINABILITY 058, 071, 112, 116, 123, 129, 132, 134, 168, 179, 183, 204, 209, 241, 257, 285 SUSTAINABLE DEVELOPMENT 104, 136, 188, 251 SUSTAINABLE FORESTRY 044, 139, 246 SUSTAINABLE TOURISM 193 SYNERGISMS 159 TADPOLES 215, 261 TALLGRASS PRAIRIE LANDSCAPE 088, 200 TARO 160 TAX DIFFERENTIATION 220 TAXES

071, 220 TEACHING FACILITIES 188 TECHNICAL COEFFICIENT 116 TECHNOLOGY 110, 133 TECHNOLOGY TRANSFER 155 TECTONA GRANDIS 170 TELEMETRY 186 TEMPERATE FOREST SOILS 137, 142 TEMPERATURE 014, 015, 020, 021, 025, 092, 106, 125, 157, 158, 185, 196, 201, 215, 230, 251, 259, 261, 262, 268, 277, 298 TEMPERATURE DECREASE 304 TEMPORAL SCALE 191, 198 TEMPORAL VARIATION 203 TENURE 276 TEPHROSTRATIGRAPHY 178 TERMINALIA AMAZONIA 245, 254, 272, 280 TERRABA 086 TERRESTRIAL BIOSPHERE MODEL 147 TERRESTRIAL ECOSYSTEMS 009, 022 TESTUDINATA 310 TEXAS 161 TEXTURE 160

THEOBROMA CACAO 292, 312 THERMAL STRATIFICATION 030 THERMOHALINE CIRCULATION 263 THREATS 265, 276 THROUGHFALL 250, 297 TIMBER 112 TIMING OF BREEDING 108 TIRIMBINA RAIN FOREST CENTRE 123, 194, 219, 293 TLC 289 TOADS 092, 106, 159, 185, 251, 256, 259, 274 TOPOGRAPHIC EFFECTS 006 TOPOGRAPHIC RELIEF 151, 187 TOPOGRAPHY 191, 198 TOURISM 226, 287 TOURISM DEVELOPMENT 058 TOURISM IMPACT 193 TOWER OBSERVATIONS 231 TRACE GAS EMISSIONS 075, 077 TRADE 159, 282 TRADE LIBERALIZATION 110, 133 TRADE POLICY 110 TRANSPIRATION

251 TREE CANOPY 182, 229 TREE COVER 272 TREE DEMOGRAPHY 015, 027 TREE GROWTH 008, 009, 015, 022, 027 TREE GROWTH PERIODICITY 008, 015, 027, 180 TREE RING ANALYSIS 018 TREE SPECIES COMPOSITION 191, 198 TREES PROJECT 001, 018 TRENDS 092, 106, 185, 187, 189, 251, 259, 262, 274 TROGLODYTES AEDON 108 TROGLODYTIDAE 108 TROPICAL AGRICULTURE 137 TROPICAL BIOTIC EVOLUTION 060 TROPICAL CLOUD FORESTS 092, 111, 156, 186, 213, 218, 223, 228, 249, 262, 267, 274, 276, 279, 297, 299, 305 TROPICAL DRY FORESTS 087, 119, 146, 181, 191, 198, 211, 251 TROPICAL ECOLOGY 188 TROPICAL FOREST PRESERVATION 131, 190 TROPICAL FORESTS 022, 034, 036, 042, 063, 067, 079, 093, 124, 126, 128, 149, 194, 208, 209, 219, 232, 234, 238, 257, 269, 270, 271, 281, 283, 291, 292, 296 TROPICAL GLACIERS

248 TROPICAL MONTANE CLOUD FORESTS 111 TROPICAL MONTANE FOREST 182, 229 TROPICAL MOUNTAIN 152 TROPICAL PACIFIC 157, 158 TROPICAL RAIN FORESTS 001, 005, 006, 007, 008, 009, 010, 011, 012, 013, 014, 015, 016, 018, 019, 020, 021, 022, 024, 025, 027, 028, 029, 030, 032, 036, 038, 042, 051, 054, 075, 077, 081, 087, 089, 091, 095, 096, 097, 098, 099, 100, 102, 105, 138, 142, 144, 145, 146, 151, 152, 154, 159, 160, 164, 171, 180, 181, 183, 186, 187, 189, 201, 203, 205, 214, 215, 222, 231, 235, 245, 250, 251, 255, 260, 261, 275, 278, 280, 293, 294, 300, 302, 312 TROPICAL SAVANNA 075, 076 TROPICAL SAVANNA SOILS 076 TROPICAL SCIENCE CENTER 272 TROPICAL SOILS 038, 041, 042, 081, 126, 164, 260 TROPICAL TREE PHENOLOGY 008, 015, 027, 180 TROPICAL WET FORESTS 146, 186 TROPICS 047, 049, 074, 167 TROPOPAUSE REGION 277 TROPOSPHERE 023, 051, 277 TUMOR GROWTH 125, 298 TUNISIA 276 TURBULENCE

030 TURNOVER 189 TURRIALBA (CANTON) 029, 030, 101, 204, 241, 285 TWENTY YEAR PERIOD CHANGE 198 ULTRAVIOLET RADIATION EXPOSURE 152 UNCERTAINTY 110, 133, 224 UNDISTURBED SITES 024, 201, 302 UNDISTURBED SOILS 201 UNITED KINGDOM 276 UNITED NATIONS FRAMEWORK CONVENTION ON CLIMATE CHANGE 155 UPWELLING SYSTEMS 037 URTICALES 033, 082 USA 037, 061, 075, 152, 161, 197, 207, 266, 276, 295, 312 USE IN DETECTION OF POLLUTION AND WEATHER CHANGE PATTERNS 221 UV RADIATION 152, 159 VALLE DE LA ESTRELLA 086 VALLE DE LAS MORRENAS 264 VALUATION 093, 124, 128, 134, 166, 183, 190, 194, 219, 245, 280 VALUATION OF CARBON-SINK SERVICES 093, 124, 128, 131, 194, 219 VAMPIRE BAT 211

VANISHING SPECIES 092, 159, 221, 256, 262, 274, 276, 282, 299, 308, 312 VAPOR PRESSURE DEFICIT 007, 013, 022, 205, 294 VAPOUR PRESSURE 013 VARIABILITY 001, 009, 015, 019, 022, 301 VEGETATION 001, 019, 038, 042, 045, 081, 147, 151, 164, 178, 187, 189, 264 VEGETATION DYNAMICS 066 VEGETATION HISTORY 275 VEGETATIONAL CHANGES 033 VEGETATIVE DEVELOPMENT 052 VEHICLE AGE 220 VELOCITY 101 VERBENACEAE 170, 233, 309 VERTICAL DISTRIBUTION 005 VIENNA CONVENTION 078 VIETNAM 071 VIRGIN FORESTS 123, 131, 190 VIRGINIA 266 VIROLA KOSCHNYI 245, 280 VOCHYSIA FERRUGINEA 245, 280, 302 VOCHYSIA GUATEMALENSIS 245, 280 VOCHYSIACEAE 245, 280, 302

VOLCAN ARENAL 178 VOLCAN BARVA 151, 187, 189 VOLCAN CHATO 178 VOLCAN CONGO 151, 187, 189 VOLCANISM 178 VULNERABILITY 224 VULNERABILITY OF PLANTS 225 WARMING EVENT 163, 165, 184 WASTE MANAGEMENT 090 WASTES 110, 133 WASTEWATER 153 WATER 038, 081, 112, 186, 206 WATER BALANCE 101 WATER CONSERVATION 166, 307 WATER CONSUMPTION 064 WATER FLOW 186 WATER MANAGEMENT

064 WATER POLLUTION 064 WATER QUALITY 064 WATER RESOURCES 064, 104, 155, 206 WATER STRESS 052 WATER TEMPERATURE 037 WATER VAPOR 092, 262, 277 WATER-FILLED PORE SPACE (WFPS) 306, 311 WATERSHED PROTECTION 150, 226, 287 WATERSHEDS 086, 150, 226, 287, 307 WEATHER 174, 175, 180, 185, 256, 259 WEATHER PATTERN 256 WET FORESTS 143, 144 WETLANDS 112, 193, 206 WILDLIFE PROTECTED AREAS 193 WILDLIFE PROTECTION 104, 298 WILDLIFE SPECIES EXTRACTION

193 WIND 007, 013, 022, 030, 101, 205, 255, 294 WOOD 183, 232, 300 WOOD INDUSTRY 174, 175 WOODLANDS 163, 165, 184 XANTHOSOMA SAGITTIFOLIUM 160 YOUNG REGROWTHS 032 YOUNGER DRYAS 057, 304 ZAMBIA 303 ZEA MAYS 034, 145, 160, 178, 204, 207, 241, 285 ZIMBABWE 072 ZINC 035 ZOANTHARIA 196 ZONA HUETAR NORTE 309 ZONA PROTECTORA LAS TABLAS 083, 152, 216, 282 ZYGIA LONGIFOLIA 012

INDICE DE AUTORES

Abarca-Monge, S 109, 163, 165, 168, 184, 199 Abler, D.G 110, 133 Achard, F 316 Aikin, K.C 277 Aldrich, M. (comp.) 299 Alfaro, M 237 Alfaro-Murillo, M 063 Allen, L.H., Jr 029, 030 Alpízar-Vaglio, E 206 Amador, M 329 Anchukaitis, K.J 322 Andelman, S.J 224, 256 Aniyar, S 150 Anonymous 121, 141, 323 Arford, M.R 178 Arrow, K 150 Asmerom, Y 177, 227, 301; 319 Atlas, E.L 319, 321 Aylward, B.A 226, 287 Baas, P 135 Babbar-Amighetti, L.I

039, 062 Bakarr, M.I 256 Baker, B 012 Ball, A 246 Barbosa, P 266 Barone, J.A 266 Barrantes-Montero, G 172 Barrantes-Moreno, G 112 Barrows, T 273 Bawa, K.S 210 Beardsley, T 120 Bebout, G.E 258 Becker, A 016 Beecher, N.A 315 Beghin, J 071 Belwared, G 316 Benegas-Negri, L.A 307 Bennet, J 069 Bentz, J.A 231 Berish, C.W 031 Berk, M.M. (ed.) 066

Bermúdez-Oconitrillo, R 169 Bermúdez-Ramírez, F 166 Berry, P 225 Blair, J.B 005, 010 Bohannan, B.J.M 222 Boitani, L 256 Bolaños-Vives, F 159, 282 Bolstad, P 017 Borchert, R 052, 087, 119 Borglin, S.E 291 Boscolo, M 270, 283 Bouma, J 129 Bouman, B.A.M 098, 105, 116, 129 Braatz, B.V. (ed.) 072 Bravo-Chacón, J 206 Brenes, T 203 Brenes-Vargas, A 065 Bright, A 321 Brooks, T.M 256 Brown, B.J 031 Brown, S 011, 067, 149, 246

Bryan, B 143 Bubb, P. (comp.) 299 Budd, A.F. 059, 060, 177 Bui, T.P 321 Burlingame, L.J 188 Burns, S.J 227, 301 Burrowes, P.A 244 Busch, C.B 195 Bustamante, M.R 262 Cajiao-Jiménez, M.V 310 Campbell, J 294 Campbell, J.H 106 Campos, M 085, 206 Candela, G 324 Carey, C 152, 276 Carlson, C.M 291 Carney, K.M 222, 235, 260 Carpio, C.E 219 Castro, F 282 Castro, J 329 Castro-Jiménez, E 112 Castro-Salazar, R 130, 131, 190, 238

Cavatassi, R 281, 296 Cedeño, J.R 159 Celarier, E.A 152 Chacón-Chaverri, D 310 Chaves-Cordero, G.A 159, 282 Chazdon, R.L 010 Chow, V.Y 321 Cervi-F., A.P 325 Clark, D.A 001, 006, 008, 009, 011, 012, 014, 016, 017, 018, 019, 020, 021, 022, 023, 024, 028, 327 Clark, D.B 001, 005, 006, 007, 008, 010, 011, 013, 014, 019, 327 Clark, K.L 003, 004, 026 Coates, A.G. (ed.) 059, 060 Coley, P.D 266 Coloma, L.A 159, 262 Connahs, H 266 Conrad, M.E 291 Consuegra, J.A 262 Córdoba-Muñoz, R 206 Cortés-Núñez, J 125, 157, 158 Cotton, M.A 059 Cowling, R.M

256 Craig, H 053 Crill, P.M 142, 145, 160, 164, 176 Cronin, T.M 060 Crump, M.L 103 Cubero-Moya, J.A 170 Curran, D.J 321 Curtis, P.S 017 Daily, G.C 061, 150 Dale, V.H 055 Dasgupta, P 150 Davidson, E.A 017, 075, 102, 144, 146 Davis, B 281, 296 de Camargo, P.B 144 Delgado-Rodríguez, M 289 Denslow, J.S 214 Dessus, S 071 Díaz-Hernández, A 169 Dieperink, C 209 Diniz, I.R 266 Dixon, R.K 197 Donnelly, M.A 103 Dore, M.H.I 183

Dore, M.H.I. ed.) 194 Dowsett, H.F 059, 060 Drake, J.B 010 Dubayah, R.O 005, 010 Dudley, N 276 Dun, S 114 Dunbar, R.B 037 Durand, C 212 Dyer, L.A 266 Echeverría-Bonilla, J 070, 220 Ehrlich, P.R 150 Ellsworth, D.S 017 Enquist, C.A.F 181, 191, 198 Erickson, H.E 074, 102, 146 Escribano-Montoya, J 169 Espinoza-Miranda, A 309 Ewel, J.J 031 Daube, B.C 321 Fahey, D.W 319 Fay, J 246 Federici, S.E 316 Fichtler, E 018

Figueres-Olsen, J.M 058, 148 Finegan, B 123, 219 Fisher, M.J 167 Fishpool, L.D.C 256 Fitzgerald, J.F 072 Fogden, M.P.L 092, 106, 262, 268 Fogden, M.P.L. (phot.) 259 Fogden, P. (phot.) 259 Foley, J.A 147 Folke, C 150 Fonseca, G.A.B 256 Foster, P.N 111, 218, 262 Fournier-Origgi, L.A 035, 073 Frankie, G.W 253 Fresco, L.O 066 Frolking, S.E 160 Gamboa, H, (il.) 310 Gámez-Hernández, L 130 Gao, R.S 319, 321 García, G 034, 207 García-Pérez, J.E 282 Garita-Cruz, D 166

Gaston, K.J 256 Geist, H 284 Gentry, G.L 266 George, R.K 086 Gering, J.C 240 Geron, C 012, 023 Gerow, K.G 088, 200, 202 Getty, S.R 177 Gholz, H.L 003, 004, 013, 026, 255 Ghosh, T.K 231 Glasbergen, P 209 Gómez-Flores, M 093, 123, 124, 128 Gordon, A.M 241, 285 Gorman, G.C 092 Gottlieb, E.W 321 Gradstein, S.R 252 Granich, F 050 Grassi, H.D 316 Grauel, B 145 Greenberg, J 012 Greeney, H.F 266 Griswold, T.L 253

Guariguata-Urbano, M.R. (ed.) 186 Guenther, A 012, 023 Guevara, R. (ed.) 194 Guswa, A.J 297 Guzmán, J 236 Guzmán, S.M 214 Guzmán-Espinal, H.M 157 Haber, W.A 230 Haberyan, K.A 243 Hallwachs, W 266 Hannah, L 251 Hanson, P.J 017 Harmand, J.M 311 Harriss, R.C 164 Hartshorn, G.S 002 Helmer, E.H 067, 149 Hendy, J 281, 296 Hengsdijk, H 129 Hergoualc'h, K 311 Herman, J.R 152 Herman, R.L 277 Herrick, J.D 023

Hidalgo, M 237 Hoffman, M 256 Hofstede, R.G.M 265 Hofton, M.A 010 Holland, E.A 046 Hollinger, D.Y 294 Holmes, B 185, 259 Holz, I 252 Hooghiemstra, H 304 Horn, S.P 033, 045, 243, 264, 275 Hostettler, S. (comp.) 299 Hovde, S.J 277 Hughes, R.F 138, 208 Hunter, M.D 082 Ibáñez, R.D 159, 282 Ibrahim, M.A 115, 117, 165 Imbach-Barton, P.A 325 Islebe, G.A 304 Jackson, B.C. (ed.) 059, 060 Jacobs, J.M 255 Jallow, B.P. (ed.) 072 Jansen, H.G.P 129

Jansson, A.M 150 Jansson, B.O 150 Janzen, D.H 266 Jiménez, R 321 Jiménez-Centeno, C.E 125, 158, 196, 298 Johnson, D 175 Johnson, K.G 288 Johnstone, N 220 Jordan, T.R 047 Kaiser, J 015 Kanninen, M 115, 117 Kappelle, M 135 Karl, T 023 Karlaganis, G 078 Karsenty, A 271 Kass, D.C.L 285 Kattan, G.H. (ed.) 186 Kautsky, N 150 Keeling, C.D 014 Keller, M 038, 042, 043, 046, 049, 074, 077, 080, 081, 088, 091, 096, 102, 126, 127, 142, 143, 144, 145, 146, 154, 160, 164, 176, 200, 202, 306 Kelly, K.K

277 Kelly, M 050 Kerr, S 138, 208, 269, 270, 281, 283, 296 Kim, K.R 053 Kingerlee, W 075 Klein, R.J.T 140 Kleinn, C 115, 117 Knox, R.G 010 Kok, M.T. (ed.) 066 Korbeck, R.G., Jr 215, 261 La Marca, E 159, 262, 282 Lachniet, M.S 227, 242, 248, 263, 301 Lambin, E 284 Lane, C.S 275 Laporte, S 086 LaVal, R.K 211, 213 Laurance, W.F 328 Law, B.E 017, 294 Lawrence, D.A 024 Lawton, R.O 156, 228, 249 League, B.L 264 Lei, Y.D 295

Leiva, M 237 Lemon, E 029, 030 León-Campos, A 158 León-Soler, A 125 Levin, S 150, 303 Leyden, B.W 057 Li, C.S 097, 161 Li, L 258 Lill, J.L 266 Lindegaard, K 179 Linder, E 142, 160 Lipper, L 296 Lipper. L 281 Lips, K.R 083, 159, 216, 244, 282 Liu, S 127, 138, 202, 306 Liu, S.P 208 Lizana, M 221 Locatelli, B 271 Loescher, H.W 007, 012, 013, 205, 231, 255, 294 Loewenstein, M 319 Long, J 256 Longino, J.T 240

Lopes, E.C 300 López-Musalem, A 107, 113, 115, 117 Lötters, S 282 Lovejoy, T.E. [ed.] 002, 251 Loyalka, S.K 231 Lubchenco, J 150 Lugo, A.E 056 Luo, Y 017 Luvall, J.C 047 Maass, J.M 034, 207 Maciver, D.C 140 Mackensen, J 203 Mahoney, M.J 319 Mahrt, L 294 Mäler, K.G 150 Manso, P 290 Manzanilla-Puppo, J 282 Marcy, T.P 319 Margolis, M 223 Marín, G. (il.) 310 Marquet, P.A 256 Márquez, R 221

Marquis, R.J 266 Martínez, I 273 Marty, C 282 Masters, K.L 262, 268 Matross, D.M 321 Matson, P.A 034, 036, 051, 207, 222, 260 Matteucci, H.J 316 McRobert, S.P 215, 261 Meir, E 224 Mejías-Esquivel, R 220 Mendelson, J.R., III 244 Méndez, A 237 Méndez, O.I 035 Merino-Viteri, A 262 Mery, G 197 Meyer, J.R 159 Middleton, E.M 152 Miranda-Quirós, M 209, 257, 326 Mitre, M.E 042 Mollicone, D 316 Molnar, S. (ed.) 072 Montagnini, F 280

Montenegro-Ballestero, J 109, 163, 165, 168, 184, 199 Morais, H.C 266 Moreira, A.G 162 Moreno-Díaz, M.L 257, 326 Morris, R.A 230 Muir, D.C.G 295 Müller, L.E 029, 030 Muñoz, A 159 Murdiyarso, D. (ed.) 072 Nadkarni, N.M 003, 004, 026, 182, 229, 240, 305 Nair, U.S 156, 192, 228 Neff, J.C 046, 176 Newell, S.E 297 Nieuwenhuyse, A 116, 129 Niles, J.O 246 Nobre, A.D 054, 164 Núñez, M 091 O'Brien, J.J 008, 180, 203 Oberbauer, S.F 007, 008, 011, 013, 231, 255, 327 Oelbermann, M 204, 241, 285 Olivas, P.C 327

Oliver, R 311 Olson, N 130 Ortiz, R 219 Orvis, K.H 275 Palo, M. (ed.) 197 Park, S 319, 321 Parra-Olea, G 244 Parsons, W.F.J 038, 042 Patterson, W.P 227, 301 Pedroni, L 122 Perdomo, M. (ed.) 072 Pérez, C.J 325 Pérez, M.E 288 Pérez, T 144 Perkins, S 025, 279 Perron, B 173, 212 Peters, R. [ed.] 002 Pfaff, A.S.P 138, 208, 269, 270, 281, 283, 296 Pfister, L 321 Pielke, R.A 156 Pilgrim, J.D 256 Piper, S.C 014

Piperno, D 227 Plant, R.A.J 089, 095, 096, 097, 098, 099, 100, 105, 116, 137 Polyak, V 301 Polzot, C 272 Polzot, C.L 254, 272 Popp, P.J 319 Porras, I.T 220, 257, 329 Possingham, H.P 224 Potosnak, M 023 Pounds, J.A 092, 106, 262, 268, 274, 282 Powers, J.S 151, 187, 189, 214 Pratt, L 232, 233, 234, 238 Pregitzer, K.S 017 Pressey, R.L 256 Pretty, J 246 Price, N 031 Prince, S.D 010 Puschendorf, R 262, 282 Quesada, F 292 Quesada-Mateo, C.A 048 Quinn, T.M 177 Radulovich, R

064 Raich, J.W 031, 032 Raes, A 316 Ramankutty, N 147 Ramírez, O.A 093, 123, 124, 128, 194, 219 Ramírez-Obando, P 084, 090 Randolph, J.C 017 Ray, D.K 267 Ray, E.A 277, 319 Read, J.M 214 Reaser, J.K 159 Redondo-Brenes, A 245, 280, 320 Reifsnyder, D.A 114 Reiners, W.A 042, 043, 049, 088, 127, 200, 202, 306 Repetto, R 303 Retana-Barrantes, J.A 094, 317, 318 Rhodes, A.L 297 Richard, E.C 277, 319 Ricklefs, R.E 266 Rincón, D 273 Rivera, M.M 143 Rizzardi, M 253

Rodrigues, A.S.L 256 Rodrígues-Rubí, J.A 101 Rodríguez, A.G 110, 133 Rodríguez, J 232, 236 Rodríguez-Chacón, J.E 166 Rodríguez-Chacón, J.E. (comp.) 104 Rodríguez-Rubí, L.E 293 Rodríguez-Sánchez, L 123 Rojas, A.V 236 Rojas, M 226, 287 Rojas-Araya, M 206 Rojas-Piedra, S.R 170 Roland-Hurst, D 071 Romo, D 159 Rompaey, R.A.V. (ed.) 066 Ron, S.R 159, 262 Ronchi, P 253 Rosenlof, K.H 277 Rosner, H 027 Rueda-Almonacid, J.V 282 Ruiz-Campos, E 125, 158 Rusin, R.J 152

Russo-Andrade, R.O 324 Ryan, M.G 327 Saborío-Trejos, V.F 065 Salas, A.W 159 Sánchez-Azofeifa, G.A 048, 138, 195, 262, 269, 270, 281, 283, 296 Sancho-Villalobos, F 234 Sanhueza, E 076 Sassa, K. (ed.) 093 Sathaye, J.A 195 Savage, J.M 092 Savage, K 017 Sayres, D.S 314 Scatena, F.N 056 Schaefer, D 003 Schimel, D.S 127, 138, 202, 306 Schipper, J 256 Schipper, R.A 129 Schlesinger, W.H 187, 189 Schlönvoigt, A.M 115, 117, 285 Schneider, S.H 111 Schonberg, L.A 240 Schulte, R

282 Schulze, G 316 Schwartzman, S 162 Schwendenmann, L.C 016, 201, 203, 250, 278 Sechrest, W 256 Segura-Bonilla, O 132, 179 Seltzer, G.O 227, 263 Seufert, F 316 Shen, L 295 Shortle, J.S 110, 133 Shulte-Bisping, H 016 Silver, W.L 143, 291 Simpson, D 150 Singer, M.S 266 Skiba, U 311 Smeets, E.M.W 134 Söderqvist, T 150 Solano, R 182, 229, 305 Solís, L 263 Somarriba-Chávez, E 292 Starrett, D 150 Stevenson, R.D 230 Stibig, G

316 Still, C.J 111, 262 Stireman, J.O 266 Stolton, S 276 Stork, N.E. (ed.) 082 Stuart, S.N 256 Subak, S 136 Swartz, W.H 319 Swisher, J.N 044 Tattenbach, F 122, 130 Teh, Y.A 291 Teixeira, C 295 Thevathasan, N.V 285 Thompson, T.L 277, 319 Tilman, D 150 Timmins, J 296 Tito, M.R 325 Tompson, R.V 231 Toral-C., E 282 Torres, A 174 Tosi-Olin, J.A., Jr 070, 138 Trines, E.P 118 Troy, R.F

277 Trujillo, W 167 Trumbore, S.E 144 Tuck, A.F 277 Twohy, C.H 321 Tyler, S.C 144 Umaña-Quesada, A 079 Underhill, L.G 256 Uusivuori, J. (ed.) 197 Vaillancourt, J.G 212 Valerín, N 310 Vallejo, A 325 van de Wiel, H. (comp.) 299 van der Mensbrugghe, D 071 van Vuuren, D.P 134 van Vuuren, M.M.I 135 Vázquez-Selem, L 248 Vega-Araya, E.E 233 Vega-García, H 286 Veldkamp, A 066 Veldkamp, E 011, 016, 041, 043, 046, 077, 080, 091, 097, 102, 145, 146, 154, 176, 203, 250, 278 Venegas-Gamboa, I

247 Verchot, L.V 146 Villalobos, M 292 Villalobos-Flores, R 094, 317, 318 Vinson, S.B 253 Vitousek, P.M 034, 036, 051, 207 Volkmann, C 034, 207 Voroney, R.P 241, 285 Wake, D.B 312 Walker, B 150 Walker, J 023 Waller, R.W 256 Wania, F 295 Watson-Céspedes, V 070, 138 Watt, A.D. (ed.) 082 Watts, M.E.J 256 Waylen, P.R 086 Weishampel, J.F 005, 010 Weitz, A.M 043, 046, 102, 142, 143, 145, 154, 160, 171, 176 Welch, R 047 Welch, R.M 156, 228 Wilkinson, J.W 152

Weinstock, E.M 319 Williams, N 308 Williamson, P 040 Wofsy, S.C 294, 319, 321 Wood, T.E 024, 302 Worbes, M 018 Wurster, C 227 Xiao, H 295 Xie, Y 256 Yanoviak, S.P 240, 305 Yokoyama, Y 273 Yoon, C.K 217 Young, B.E 108, 159, 262, 282 Young, C.E.F 197 Zak, D.R 017, 039 Zepp, R.G. (ed.) 126 Zwerver, S. (ed.) 066

PUBLICACIONES Publicación no.: 001 Climate-induced annual variation in canopy tree growth in a Costa Rican tropical rain forest [El clima induce la variación anual en el crecimiento del dosel en un bosque tropical lluvioso costarricense] / Clark, D.A.; Clark, D.B. (Organization for Tropical Studies. La Selva Biological Station, Apdo 676, San Pedro de Montes de Oca 2050, CR <E-mail: daclark@sloth.ots.ac.cr> <E-mail: dbclark@sloth.ots.ac.cr>). In: The Journal of Ecology (ISSN 0022-0477), v. 82, no. 4, p. 865-872. 1994. Data are presented and discussed on annual growth (diameter) over 8 yr (1984-92) for saplings and adults of nonpioneer tree species in a lowland neotropical rain forest at La Selva Biological Station, Costa Rica. The species included 5 emergents (Lecythis ampla, Hymenolobium mesoamericanum, Dipteryx panamensis, Pithecellobium elegans, Hyeronima alchorneoides) and one canopy species (Minquartia guianensis). Localización: Biblioteca OET: S2609. NBINA-2083. LS. Publicación no.: 002 Possible effects of global warming on the biological diversity in tropical forests [Posibles efectos del calentamiento global en la diversidad biológica en bosques tropicales] / Hartshorn, G.S.; Peters, R. [ed.]; Lovejoy, T.E. [ed.]. (Duke University, Box 90630, Durham, NC 27708-0630, US <E-mail: ghartsho@duke.edu> <E-mail: tlovejoy@worldbank.org>). In: Global warming and biological diversity. New Haven: Yale University Press, 1992. ISBN: 0-300-05930-2, p. 137-146. Introduction: Rampant deforestation, the inexorable advance of the agricultural frontier, species extinction, and the conservation of biological diversity are some of the principal problems facing those who would protect tropical forests. Global warming due to the greenhouse effect may also affect the composition and integrity of those few tropical forests that survive well into the next century. Tropical forests not only are the most species-rich ecosystems known on this planet but also are exceedingly complex ecologically. This chapter has three objectives: (1) to highlight briefly the ecological complexity and biological diversity of tropical forests; (2) to review documented effects of historically recent climatic fluctuations on tropical forest communities; and (3) to use these first two components for cautiously exploring possible effects of global warming on the biological diversity in tropical forests. My primary theater of experience is the humid forests of tropical America; hence, I will draw heavily on such well- known sites as the Smithsonian Tropical Research Institute's Barro Colorado Island (BCI) in Panama's Lake Gatún (Leigh et al. 1982, 1990) and the Organization for Tropical Studies' La Selva Biological Station in the Caribbean lowlands of Costa Rica (Clark 1990). I am focusing on mature or old-growth forests, with minimal or no direct human disturbance; thus young secondary forests, deforestation, restoration of degraded forest lands, soil fertility, nutrient cycling, and so on are beyond the purview of this chapter. Localización: Biblioteca OET: S1214. Publicación no.: 003 Cloud water and precipitation chemistry in a tropical montane forest, Monteverde, Costa Rica [Agua de las nubes y química de la lluvia en un bosque montano tropical, Monteverde, Costa Rica] / Clark, K.L.; Nadkarni, N.M.; Schaefer, D.; Gholz, H.L. (US Forest Service. Silas Little Experiment Forest, No Global Change Program, 501 4 Mile Rd, New Lisbon, NJ 08064, US <E-mail: kennethclark@fs.fed.us> <E-mail: nadkarnn@evergreen.edu> <E-mail: dshaete@upracd.upr.clu.edu>). In: Atmospheric Environment (ISSN 1352-2310), v. 32, no. 9, p. 1595-1603. 1998. Cloud water, mist and precipitation samples were collected at two sites in a tropical montane forest (TMF), Monteverde, Costa Rica. Cloud water, mist and wind-driven (u ‗ to 2 m s(-1)) precipitation samples were collected with passive cloud water-type collectors, and precipitation at low windspeeds (u 2 m²) was sampled with a bulk precipitation-type collector. Concentrations of H+, NO3-, and NH4+ in cloud water were 132 ± 150, 103 ± 82, and 149 ± 200 µmol l(-1) (mean ± 1 S.D), respectively. Concentrations of NO3-, NH4+, Ca-2(+) and K+ in cloud water samples collected at the middle and end of the dry season, which corresponded to biomass burning activities in the region, were significantly greater when compared to those collected early in the dry season. The mean concentration of H+ in cloud water at Monteverde was lower, but concentrations of NO3- and NH4+ were within the range of those collected at a number of montane sites in North America (62-195 µmol NO3- l(-1) and 74-184 mµ mol NH4+ l(-1)). Ion concentrations in mist were 2-24 times greater than those in both categories of precipitation. Ion concentrations in both categories of precipitation were generally within the range of those reported in bulk precipitation from other tropical premontane and TMF sites. Localización: Biblioteca OET: NBINA-6576. Publicación no.: 004 Deposition and net canopy retention of inorganic nitrogen and hydrogen ions in a neotropical montane cloud forest [Deposición y retención neta en el dosel del nitrógeno inorgánico y iones de hidrógeno en un bosque nuboso montano neotropical] / Clark, K.L.; Nadkarni, N.M.; Gholz, H.L. (US Forest Service. Silas Little Experiment Forest, No Global Change Program, 501 4 Mile Rd, New Lisbon, NJ 08064, US <E-mail: kennethclark@fs.fed.us> <E-mail: nadkarnn@evergreen.edu>). The Association for Tropical Biology & The Organization for Tropical Studies Annual Meeting. Abstracts, San Juan, PR, Jun 1-4, 1993. San Juan, PR: ATB/OTS, 1993. p. 56.

We monitored nitrate (NO3-), ammonium (NH4+), and hydrogen (H+) ions in cloud water (CW), bulk precipitation (BP), bulk cloud water and precipitation (BCWP), and throughfall (TF) for one year in a neotropical montane cloud forest, Monteverde, Costa Rica. Highest concentrations of NO3-, NH4+, and H+ in CW, BP, and BCWP coincided with the peak in agricultural and forest burning. NO3- + NH4+ totaled was 210 mol N ha(-1) yr(-1) in BP, and 420 mol N ha(-1) yr(-1) ub BCWP. Coupling a hydrologic model with the BP and BCWP data, we estimated total deposition to the canopy to be 700 mol N ha(-1) and 800 mol H+ ha(-1) yr(-1). NO3- + NH4+ in TF was 140±20 mol N ha(-1) yr(-1) and H+ was 50±12 mol H+ ha(-1) yr(-1). Eighty percent of NO3- + NH4+ and 90% of the H+ deposition was retained by the canopy. Net retention of N and H+ for adevective vs. convective events and for NO3- vs. NH4+ agreed closely with leaching experiments using epiphytic bryophytes and dead organic matter (DOM), suggesting that these components play a major role in N and H+ retention. Artificially acidified precipitation caused enhanced NH4+ loss from the bryophytes and DOM, indicating potential control over in-canopy N cycling processes by H+. Localización: Este es el resumen completo. Publicación no.: 005 Volumetric lidar return patterns from an old-growth tropical rainforest canopy / Weishampel, J.F.; Blair, J.B.; Dubayah, R.O.; Clark, D.B. (University of Central Florida. Department of Biology, Orlando, FL 32816-2368, US <E-mail: jweisham@mail.ucfedu> <E-mail: bryan@avalon.gsfc.nasa.gov> <E-mail: dbclark@sloth.ots.ac.cr>). In: International Journal of Remote Sensing (ISSN 0143-1161), v. 21, no. 2, p. 409-415. 2000. Rainforests represent the epitome of structural complexity in terrestrial ecosystems. However, measures of three-dimensional canopy structure are limited to a few areas typically 1 ha with construction crane or walkway/platform access. An innovative laser profiling system, the Laser Vegetation Imaging Sensor (LVIS), was used to map canopy structure (i.e. based on height and vertical distribution of laser returns) of a tropical rainforest in Costa Rica. Within a about 1 km area of mature rainforest, canopy top height ranged from 8.4 to 51.6 m based on the altimeter measures. The laser return density was most concentrated in the horizontal layer located 20-30 m above the ground. Spatial patterns of the return were found to be isotropic based on north-south versus east-west vertical return profiles and exhibited properties of self-similarity. Localización: Biblioteca OET: S5333. NBINA-3967. Publicación no.: 006 Landscape-scale variation in forest structure and biomass in a tropical rain forest / Clark, D.B.; Clark, D.A. (Organization for Tropical Studies. La Selva Biological Station, Apdo 676, San Pedro de Montes de Oca 2050, CR <E-mail: dbclark@sloth.ots.ac.cr> <E-mail: daclark@sloth.ots.ac.cr>). In: Forest Ecology and Management (ISSN 0378-1127), v. 137, no. 1/3, p. 185-198. 2000. A better understanding of the reasons for variation in tropical rain forest (TRF) structure is important for quantifying global above-ground biomass (AGBM). We used three data sets to estimate stem number, basal area, and AGBM over a 600-ha old-growth TRF landscape (La Selva Biological Station, N.E. Costa Rica). We analyzed the effects of soil type, slope angle, topographic position, and different sample designs and measurement techniques on these estimates. All three data sets were for woody stems greater than or equal to 10 cm in diameter. Estimated AGBM was determined from stand-level measurements using Brown's (Brown, 1997) allometric equation for Tropical Wet: Forest trees. One data set was from three subjectively-sited 4-ha plots (the 'OTS plots'), another was based on 1170 0.01 ha plots spaced on a regular grid (the 'Vegetation map plots'), and the third was from 18 0.5 ha plots (the 'Carbono plots') sited to provide unbiased samples of three edaphic conditions: hat inceptisol old alluvial terraces; Rat ultisol hill-tops; and steep ultisol slopes. Basal area, estimated AGBM and the contributions of major life forms were similar among studies, in spite of the differences in sampling design and measurement techniques. Although the Carbono plots on Rat inceptisols had significantly larger and fewer trees than those on ultisols, AGBM did not vary over the relatively small edaphic gradient in upland areas at La Selva. On residual soils, the largest trees were on the flattest topographic positions. Slope angle per se was not correlated with basal area or AGBM within the residual soils. Errors introduced by palm and liana lift: forms, as well as hollow trees, did not significantly affect AGBM estimates. In contrast, the methods used to measure buttressed trees had a large impact. Plot sizes of 0.35-0.5 ha were sufficient to achieve coefficients of variation of 12% for basal area with only six replicates in a given edaphic type. AGBM estimates ranged from 161 to 186 Mg/ha. These low values appear to be mainly due to the Tropical Wet Forest allometry equation used. This in turn may be indicative of a real and substantially lower ratio of biomass/basal area in Tropical Wet Forest than in Tropical Moist, as previously noted by Brown (1996). Our results indicate that for upland TRF landscapes with levels of environmental variation similar to La Selva, AGBM will be relatively insensitive to soil type and topography. However, because topography and soil type had much stronger effects on stem size, stand density, and spatial heterogeneity of sterns, stand dynamics may be more sensitive than AGBM to this range of conditions. We recommend that future studies of landscape-scale forest structure employ stratified sampling designs across major environmental gradients. Unbiased sampling with replication, combined with consistent and well-documented measurement techniques, will lead to a greatly improved understanding of the magnitude of and reasons for variation in forest structure and AGBM within TRF landscapes. Localización: Biblioteca OET: S6169. NBINA-2081.

Publicación no.: 007 Effects of climate factors on daytime carbon exchange from an old growth forest in Costa Rica [Efectos de los factores climáticos sobre el intercambio de carbono durante el día en un bosque de viejo crecimiento en Costa Rica] / Oberbauer, S.F.; Loescher, H.W.; Clark, D.B. (Florida International University. Department of Biological Sciences, Miami, FL 33199, US <E-mail: oberbaue@fiu.edu> <E-mail: hank.loescher@oregonstate.edu> <E-mail: dbclark@sloth.ots.ac.cr>). In: Selbyana (ISSN 0361-185X), v. 21, no. 1/2, p. 66-73. 2000. Eddy covariance measurements of CO2, H2O, and heat were conducted in tropical lowland wet forest at the La Selva Biological Station in Costa Rica. The system was based on a closed-path infrared gas analyzer with the sample inlets and sonic anemometer mounted on a 42-m tower. Prevailing winds were easterly from the Caribbean with little anthropogenic influence. The tower footprint was primary upland forest. Concurrent measurements included standard micrometeorological sensors for energy balance and six levels of continuous canopy profile sampling for CO2, H2O, and air temperatures. Canopy roughness at the site is very high and may contribute to mixing at low wind speeds. Data are presented for 39 days of daytime CO2 fluxes. Carbon dioxide fluxes at high irradiances ranged from -10 to -20 µmol m² S(-1). The response of CO2 fluxes to solar radiation was curvilinear and did not saturate under ambient irradiance regimes. No effects of vapor pressure deficit on ecosystem carbon exchange were detected during the study period. Temperature, however, appeared to affect daytime carbon exchange slightly. The results suggest that solar radiation input is the primary limiting climatic factor for carbon uptake. Localización: Biblioteca OET: S7047. Publicación no.: 008 Tropical rainforest tree growth periodicity [Periodicidad en el crecimiento de árboles del bosque lluvioso tropical] / O'Brien, J.J.; Oberbauer, S.F.; Clark, D.A.; Clark, D.B. (Florida International University. Department of Biological Sciences, Miami, FL 33199, US <E-mail: jjobrien@fs.fed.us> <E-mail: oberbaue@fiu.edu> <E-mail: daclark@sloth.ots.ac.cr> <E-mail: dbclark@sloth.ots.ac.cr>). Annual Meeting of The Ecological Society of America. 86th, abstracts, Monona Terrace Convention Center and University of Wisconsin, US. August 5-10, 2001. , v. 86, p. 168-169. Madison, WI: The Ecological Society of America, 2001. We report three years of growth periodicity among tree species within and between years as part of a larger study of climate effects on rainforest carbon dynamics. Monthly, we measured tree growth, leaf phenology, and reproductive phenology in 10 tree species at La Selva Biological Station, Costa Rica. To measure growth we installed band dendrometers on 10 individuals of each species. Trees chosen for measurement had well-illuminated crowns and stem diameters of 30-60 cm. Six species were evergreen, three were deciduous during the brief dry season, and one was leafless multiple times throughout the year. Two species flowered and fruited continuously, five reproduced yearly, and three reproduced supra-annually. The species grew an average of 6.2-23.3 mm in diameter over the three years. Analysis of variance revealed significant differences in growth among the species, and eight of the ten species showed some degree of growth periodicity. Five grew during the wet season, May to November, and three had frequent periods of dormancy throughout the year. Patterns of leaf exchange and reproductive phenology did not completely explain the observed variation in timing of growth. A model couples these data with concurrent climate measurements to predict how climate affects tree growth. Localización: Este es el resumen completo. Publicación no.: 009 Are tropical forests an important carbon sink? Reanalysis of the long-term plot data [¿Son los bosques tropicales importantes almacenadores del carbono? Reanálisis de los datos a largo plazo de parcelas] / Clark, D.A. (Organization for Tropical Studies. La Selva Biological Station, Apdo 676, San Pedro de Montes de Oca 2050, CR <E-mail: daclark@sloth.ots.ac.cr>). In: Ecological Applications (ISSN 1051-0761), v. 12, no. 1, p. 3-7. 2002. In a recent (1998) publication of Science, data from a large number of forest inventory plots were used to estimate biomass trends in old-growth tropical forests. Although no evidence was found of net biomass change in mature Paleotropical forests, old growth of the humid Neotropics was inferred to have been a substantial biomass carbon sink in recent decades. Methodological artifacts affected this analysis, however. Many humid Neotropical plots were measured strictly at breast height, where tropical trees frequently have buttresses and other protruberances. Because biomass allometric equations are based on above-buttress tree diameters, and because bole irregularities show disproportionately rapid radial increments, estimates of biomass and biomass increase must be based on above-buttress measurements. In addition, some plots were on recent floodplains, where forests undergo biomass accretion during primary succession. The data set includes 25 sites from the humid lowland Neotropics that were measured above buttresses with standard techniques and that were not on recent floodplains. Mean estimated biomass change for these sites was 0.3 Mg(.)ha(-1.)-yr(-1), with a 95% confidence interval including 0.0 (-0.3 to +0.9 Mg(.)ha(-1.)yr(-1)). While the Science study was a laudable attempt to address an important aspect of the global carbon budget, the underlying data do not indicate a significant biomass carbon sink in old-growth forests of the humid Neotropics. Localización: Biblioteca OET: S7732. NBINA-3833. Publicación no.: 010 Estimation of tropical forest structural characteristics using large-footprint lidar / Drake, J.B.; Dubayah, R.O.; Clark, D.B.; Knox, R.G.; Blair, J.B.; Hofton, M.A.; Chazdon, R.L.;

Weishampel, J.F.; Prince, S.D. (University of Georgia. Warnell School of Forest Resources, Athens, GA 30602-2152, US <E-mail: jdrake@smokey.forestry.uga.edu> <E-mail: dbclark@sloth.ots.ac.cr> <E-mail: bryan@avalon.gsfc.nasa.gov> <E-mail: mhofton@geog.umd.edu> <E-mail: chazdon@uconnvm.uconn.edu> <E-mail: jweisham@mail.ucfedu>). In: Remote Sensing of Environment (ISSN 0034-4257), v. 79, no. 2/3, p. 305-319. 2002. Quantification of forest structure is important for developing a better understanding of how forest ecosystems function. Additionally, estimation of forest structural attributes, such as aboveground biomass (AGBM), is an important step in identifying the amount of carbon in terrestrial vegetation pools and is central to global carbon cycle studies. Although current remote sensing techniques recover such tropical forest structure poorly, new large- footprint lidar instruments show great promise. As part of a prelaunch validation plan for the Vegetation Canopy Lidar (VCL) mission, the Laser Vegetation Imaging Sensor (LVIS), a large-footprint airborne scanning lidar, was flown over the La Selva Biological Station, a tropical wet forest site in Costa Rica. The primary objective of this study was to test the ability of large-footprint lidar instruments to recover forest structural characteristics across a spectrum of land cover types from pasture to secondary and primary tropical forests. LVIS metrics were able to predict field-derived quadratic mean stem diameter (QMSD), basal area, and AGBM with R² values of up to .93, .72, and .93, respectively. These relationships were significant and nonasymptotic through the entire range of conditions sampled at the La Selva. Our results confirm the ability of large-footprint lidar instruments to estimate important structural attributes, including biomass in dense tropical forests, and when taken along with similar results from studies in temperate forests,, strongly validate the VCL mission framework. Localización: Biblioteca OET: S7733. NBINA-4297. Publicación no.: 011 Stocks and flows of coarse woody debris across a tropical rain forest nutrient and topography gradient / Clark, D.B.; Clark, D.A.; Brown, S.; Oberbauer, S.F.; Veldkamp, E. (Organization for Tropical Studies. La Selva Biological Station, Apdo 676, San Pedro de Montes de Oca 2050, CR <E-mail: dbclark@sloth.ots.ac.cr> <E-mail: daclark@sloth.ots.ac.cr> <E-mail: oberbaue@fiu.edu> <E-mail: eveldka@gwdg.de>). In: Forest Ecology and Management (ISSN 0378-1127), v. 164, no. 1/3, p. 237-248. 2002. Large pieces of standing or fallen dead wood, known as coarse woody debris (CWD), play important roles intemperate forest carbon and nutrient cycles, and affect the abundance and distribution of many classes of organisms. CWD biomass and inputs are poorly documented in tropical rain forests (TRF), and the causes for their variation at landscape- scales in this biome have not been studied. We quantified standing and fallen CWD stocks and inputs in upland (non-swamp) old-growth TRF at the La Selva Biological Station, Costa Rica. We used a network of 18 0.5 ha plots sited in three edaphic conditions to analyze soil nutrient effects on CWD stocks and inputs controlling for topography, and to examine topographic effects controlling for soil nutrients. The edaphic conditions were flat inceptisols, flat ultisols, and steep ultisols. Chemical analyses confirmed the existence of an almost three-fold gradient in total P and K in the upper 1 m of soil. We also annually censused all live woody stems 10 cm diameter above buttresses in each plot in September/October from 1997 to 2000 to obtain data on stand structure and dynamics. Fallen CWD stocks averaged 46.3 Mg ha-1 (22.3 Mg C ha-1), while standing CWD averaged 6.5 Mg ha-1 (3.1 Mg C ha-1). There were no significant differences in volume or mass of standing or fallen CWD among edaphic conditions. Annual inputs of CWD averaged 4.9 Mg ha-1 (2.4 Mg C ha-1). Turnover time of fallen CWD was ca. 9 year. Neither stocks nor inputs were correlated with stand structure (number of trees per plot, plot basal area, or plot estimated above-ground biomass). Potential differences in CWD stocks and inputs among sites with different edaphic conditions may have been obscured by a 10-fold variation in tree mortality among plots and a two-fold variation in mean CWD input among years. Analysis of sample variance showed that stocks of CWD were adequately sampled with the 18 0.5 ha plot design, but that inputs were measured with low precision. At La Selva fallen and standing CWD stocks together equaled ca. 33% of estimated above-ground live woody biomass. Tropical rain forest CWD and its associated carbon are intermediate in pool size and turnover rate between fine litter and live trees. Our results show that scaling up TRF CWD estimates to larger spatial scales maybe more constrained by the quality of data obtained over single landscapes than by variation due to zonal soil nutrient and topographic conditions. Both the magnitude and vagility of TRF CWD pools are likely to change with global climate change, but the overall direction of change is uncertain. Localización: Biblioteca OET: NBINA-5999. Publicación no.: 012 Biogenic volatile organic compound emissions from a lowland tropical wet forest in Costa Rica [Emisiones de compuestos orgánicos volátiles biogénicos desde un bosque húmedo tropical de tierras bajas en Costa Rica] / Geron, C.; Guenther, A.; Greenberg, J.; Loescher, H.W.; Clark, D.A.; Baker, B. (US EPA. National Risk Management Research Laboratory, Research Triangle PK, NC 27711, US <E-mail: geron.chris@epa.gov> <E-mail: hank.loescher@oregonstate.edu> <E-mail: daclark@sloth.ots.ac.cr>). In: Atmospheric Environment (ISSN 1352-2310), v. 36, no. 23, p. 3793-3802. 2002. Twenty common plant species were screened for emissions of biogenic volatile organic compounds (BVOCs) at a lowland tropical wet forest site in Costa Rica. Ten of the species examined emitted substantial quantities of isoprene. These species accounted for 35-50% of the total basal area of old-growth forest on the major edaphic site types, indicating that a high proportion of the canopy leaf area is a source of isoprene. A limited

number of canopy-level BVOC flux measurements were also collected by relaxed eddy accumulation (REA). These measurements verify that the forest canopy in this region is indeed a significant source of isoprene. In addition, REA fluxes of methanol and especially acetone were also significant, exceeding model estimates and warranting future investigation at this site. Leaf monoterpene emissions were non-detectable or very low from the species surveyed, and ambient concentrations and REA fluxes likewise were very low. Although the isoprene emission rates reported here are largely consistent with phylogenetic relations found in other studies (at the family, genus, and species levels), two species in the family Mimosaceae, a group previously found to consist largely of non-isoprene emitters, emitted significant quantities of isoprene. One of these, Pentaclethra macroloba (Willd.) Kuntze, is by far the most abundant canopy tree species in the forests of this area, composing 30-40% of the total basal area. The other, Zygia longifolia (Humb. & Bonpl.) Britton & Rose is a common riparian species. Our results suggest that the source strength of BVOCs is important not only to tropical atmospheric chemistry, but also may be important in determining net ecosystem carbon exchange. Localización: Biblioteca OET: NBINA-686. Publicación no.: 013 Environmental controls on net ecosystem-level carbon exchange and productivity in a Central American tropical wet forest [Controles ambientales sobre el intercambio de carbono y productividad a nivel de ecosistema en un bosque húmedo tropical centroamericano] / Loescher, H.W.; Oberbauer, S.F.; Gholz, H.L.; Clark, D.B. (Oregon State University. Department of Forest Sciences, 321 Richardson Hall, Corvallis, OR 97331, US <E-mail: hank.loescher@oregonstate.edu> <E-mail: oberbaue@fiu.edu> <E-mail: dbclark@sloth.ots.ac.cr>). In: Global Change Biology (ISSN 1354-1013), v. 9, no. 3, p. 396-412. 2003. Difficulty in balancing the global carbon budget has lead to increased attention on tropical forests, which have been estimated to account for up to one third of global gross primary production. Whether tropical forests are sources, sinks, or neutral with respect to their carbon balance with the atmosphere remains unclear. To address this issue, estimates of net ecosystem exchange of carbon (NEE) were made for 3 years (1998-2000) using the eddy-covariance technique in a tropical wet forest in Costa Rica. Measurements were made from a 42m tower centred in an old-growth forest. Under unstable conditions, the measurement height was at least twice the estimated zeroplane height from the ground. The canopy at the site is extremely rough; under unstable conditions the median aerodynamic roughness length ranged from 2.4 to 3.6 m. No relationship between NEE and friction velocity was found using all of the 30-min averages. However, there was a linear relationship between the nighttime NEE and averaged u* (R2 = 0.98). The diurnal pattern rn of flux was similar to that found in other tropical forests, with mean daytime NEE ca. - 18 µmol CO2 m-2 s-1 and mean nighttime NEE 4.6 µmol CO2 m-2 s-1. However, because - 80% of the nighttime data in this forest were collected during laminar flow conditions ( 0.2 m-2 s-1), nighttime NEE was likely underestimated. Using an alternative analysis, mean nighttime NEE increased to 7.05 µmol CO2 m-2 s-1. There were interannual differences in NEE, but seasonal differences were not apparent. Irradiance accounted for - 51% of the variation in the daytime fluxes, with temperature and vapour pressure deficit together accounting for another - 20%. Light compensation points ranged from 100 to 207 µmol PPFD m-2 s-1. No was relationship was found between 30-min nighttime NEE and tower-top air temperature. A weak relationship was found between hourly nighttime NEE and canopy air temperature using data averaged hourly over the entire sampling period (Q10 Localización: Biblioteca OET: S8985. NBINA-4304. Publicación no.: 014 Tropical rain forest tree growth and atmospheric carbon dynamics linked to interannual temperature variation during 1984-2000 [Crecimiento del bosque lluvioso tropical y dinámica del carbono atmosférico ligados a la variación de la temperatura en diferentes años durante 1984-2000] / Clark, D.A.; Piper, S.C.; Keeling, C.D.; Clark, D.B. (Organization for Tropical Studies. La Selva Biological Station, Apdo 676, San Pedro de Montes de Oca 2050, CR <E-mail: daclark@sloth.ots.ac.cr> <E-mail: dbclark@sloth.ots.ac.cr>). In: Proceedings of the National Academy of Sciences of the United States of America (ISSN 5852-5857), v. 100, no. 10, p. 5852-5857. 2003. During 1984-2000, canopy tree growth in old-growth tropical rain forest at La Selva, Costa Rica, varied 2-fold among years. The trees' annual diameter increments in this 16-yr period were negatively correlated with annual means of daily minimum temperatures. The tree growth variations also negatively covaried with the net carbon exchange of the terrestrial tropics as a whole, as inferred from nearly pole-to-pole measurements of atmospheric carbon dioxide (CO2) interpreted by an inverse tracer-transport model. Strong reductions in tree growth and large inferred tropical releases of CO2 to the atmosphere occurred during the record-hot 1997-1998 El Nin~ o. These and other recent findings are consistent with decreased net primary production in tropical forests in the warmer years of the last two decades. As has been projected by recent process model studies, such a sensitivity of tropical forest productivity to on-going climate change would accelerate the rate of atmospheric CO2 accumulation. Localización: Biblioteca OET: S8984. NBINA-4303. Publicación no.: 015 An intimate knowledge of trees [Un conocimiento íntimo de los árboles] / Kaiser, J.

In: Science (ISSN 0036-8075), v. 300, p. 566-567. 2003. A husband-wife ecologist team whose 20-year study of tropical rainforests has yielded a wealth of insights now suggests that global warming could be worse than expected. Localización: Biblioteca OET: S8986. NBINA-4305. Publicación no.: 016 Substantial labile carbon stocks and microbial activity in deeply weathered soils below a tropical wet forest / Veldkamp, E.; Becker, A.; Schwendenmann, L.C.; Clark, D.A.; Shulte-Bisping, H. (Universität Göttingen. Institute of Soil Sciences & Forest Nutrition; Busgenweg 2, D-37077 Göttingen, DE <E-mail: eveldka@gwdg.de> <E-mail: lscwen@gwdg.de> <E-mail: daclark@sloth.ots.ac.cr>). In: Global Change Biology (ISSN 1354-1013), v. 9, p. 1171-1184. 2003. Contrary to large areas in Amazonia of tropical moist forests with a pronounced dry season, tropical wet forests in Costa Rica do not depend on deep roots to maintain an evergreen forest canopy through the year. At our Costa Rican tropical wet forestsites, we found a large carbon stock in the subsoil of deeply weathered Oxisols, even though only 0.04-0.2% of the measured root biomass ( 2 mm diameter) to 3 m depth was below 2 m. In addition, we demonstrate that 20% or more of this deep soil carbon (depending on soil type) can be mobilized after forest clearing for pasture establishment. Microbial activity between 0.3 and 3 m depth contributed about 50% to the microbial activity in these soils, confirming the importance of the subsoil in C cycling. Depending on soil type, forest clearing for pasture establishment led from no change to a slight addition of carbon in the topsoil (0-0.3 m depth). However, this effect was countered by a substantial loss of C stocks in the subsoil (1-3 m depth). Our results show that large stocks of relatively labile carbon are not limited to areas with a prolonged dry season, but can also be found in deeply weathered soils below tropical wet forests. Forest clearing in such areas may produce unexpectedly high C lossesfrom the subsoil. Localización: Biblioteca OET: NBINA-922. Publicación no.: 017 Belowground carbon allocation in forests estimated from litterfall and IRGA-based soil respiration measurements / Davidson, E.A.; Savage, K.; Bolstad, P.; Clark, D.A.; Curtis, P.S.; Ellsworth, D.S.; Hanson, P.J.; Law, B.E.; Luo, Y.; Pregitzer, K.S.; Randolph, J.C.; Zak, D.R. (The Woods Hole Research Center, POB 296, Woods Hole, MA 02543-0296, US <E-mail: edavidson@whrc.org> <E-mail: daclark@sloth.ots.ac.cr>). In: Agricultural and Forest Meteorology (ISSN 0168-1923), v. 113, p. 39-51. 2002. Allocation of C to belowground plant structures is one of the most important, yet least well quantified fluxes of C in terrestrial ecosystems. In a literature review of mature forests worldwide, Raich and Nadelhoffer (1989) suggested that total belowground carbon allocation (TBCA) could be estimated from the difference between annual rates of soil respiration and aboveground litterfall. Here we analyze new measurements of soil respiration and litterfall, including data from the Ameriflux network. Our results generally agree with Raich and Nadelhoffer's previous work. A regression analysis of data from mature forests produced the following relationship: annual soil respiration = 287 + 2.80 × annual litterfall. This regression slope indicates that, on average, soil respiration is roughly three times aboveground litterfall-C, which further implies that TBCA is roughly twice annual aboveground litterfall-C. These inferences are based on the uncertain assumption of soil C stocks being at steady state. Nevertheless, changes in soil C would have to be very large to modify the conclusion that TBCA is generally much larger than litterfall. Among only mature temperate hardwood forests, however, the correlation between litterfall and soil respiration was poor, and the correlation among years for a single site was also poor. Therefore, the regression cannot be relied upon to provide accurate estimates of soil respiration or TBCA for individual sites. Moreover, interannual variation in TBCA, short-term changes in C stocks, or different temporal scales controlling leaf litter production and soil respiration may cause important deviations from the global average. The regression slope for data from young forests is steeper, possibly indicating proportionally greater TBCA, but the steady-state assumption is more problematic for young forests. This method Allocation of C to belowground plant structures is one of the most important, yet least well quantified fluxes of C in terrestrial ecosystems. In a literaturereview of mature forests worldwide, Raich and Nadelhoffer (1989) suggested that total belowground carbon allocation (TBCA) could be estimated from the difference between annual rates of soil respiration and aboveground litterfall. Here we analyze new measurements of soil respiration and litterfall, including data from the Ameriflux network. Our results generally agree with Raich and Nadelhoffer's previous work. A regression analysis of data from mature forests produced the following relationship: annualsoil respiration = 287 + 2.80 × annual litterfall. This regression slope indicates that, on average, soil respiration is roughly three times aboveground litterfall-C, which further implies that TBCA is roughly twice annual aboveground litterfall-C. Theseinferences are based on the uncertain assumption of soil C stocks being at steady state. Nevertheless, changes in soil C would have to be very large to modify the conclusion that TBCA is generally much larger than litterfall. Among only mature temperate hardwood forests, however, the correlation between litterfall and soil respiration was poor, and the correlation among years for a single site was also poor. Therefore, the regression cannot be relied upon to provide accurate estimates of soil respiration or TBCA for individual sites. Moreover, interannual variation in TBCA, short-term changes in C stocks, or different temporal scales controlling leaf litter production and soil respiration may cause important deviations from the global average. The regression slope for data from young forests is steeper, possibly indicating proportionally greater TBCA, but the steady-state assumption is more problematic for young forests. This method for estimating TBCA

may be most appropriate where interannual variation is averaged over several years of observations and where a near-steady-state assumption of soil, litter, and root C stocks is least problematic. Localización: Biblioteca OET: NBINA-964. Publicación no.: 018 Age and long-term growth of trees in an old-growth tropical rain forest, based on analyses of tree rings and 14C [Edad y crecimiento y crecimiento a largo plazo de los árboles en un bosque lluvioso tropical de viejo crecimiento, con base al análisis de los anillos de crecimiento y radiocarbono (14C)] / Fichtler, E.; Clark, D.A.; Worbes, M. (Universtaet Goettingen. Institut für Forstbotank, Buesgenweg 2, Goettingen, DE <E-mail: daclark@sloth.ots.ac.cr>). In: Biotropica (ISSN 0006-3606), v. 35, no. 3, p. 306-317. 2003. In an old-growth tropical wet forest at La Selva, Costa Rica, we combined radiocarbon (14C) dating and tree-ring analysis to estimate the ages of large trees of canopy and emergent species spanning a broad range of wood densities and growth rates. Wecollected samples from the trunks of 29 fallen, dead individuals. We found that all eight sampled species formed visible growth rings, which varied considerably in distinctiveness. For five of the six species for which we combined wood anatomical studieswith 14C-dates (ring ages), the analyses demonstrated that growth rings were of annual formation. The oldest tree we found by direct ring counting was a Hymenolobium mesoamericanum Lima (Papilionaceae) specimen, with an age of ca. 530 years at the time of death. All other sampled individuals, including very large trees of slow-growing species, had died at ages between 200 and 300 years. These results show that, even in an everwet tropical rain forest, tree growth of many species can be rhythmic, with anannual periodicity. This study thus raises the possibility of extending tree-ring analyses throughout the tropical forest types lacking a strong dry season or annual flooding. Our findings and similar measurements from other tropical forests indicate that the maximum ages of tropical emergent trees are unlikely to be much greater than 600 years, and that these trees often die earlier from various natural causes. Localización: Biblioteca OET: B. NBINA-2073. Publicación no.: 019 Annual variation in tree growth in a tropical wet forest: impact of climate variability [Variación annual del crecimiento de árboles en un bosque húmedo tropical: impacto de la variabilidad climática] / Clark, D.A.; Clark, D.B. (Organization for Tropical Studies. La Selva Biological Station, Apdo 676, San Pedro de Montes de Oca 2050, CR <E-mail: daclark@sloth.ots.ac.cr> <E-mail: dbclark@sloth.ots.ac.cr>). Annual Meeting of the Association for Tropical Biology held at the AIBS (American Institute of Biological Sciences), San Antonio, TX, US, August 4-8, 1991. St. Louis, MO: Association for Tropical Biology, 1991. no pagination. (No abstract). Localización: Non available. Publicación no.: 020 Sources or sinks? The responses of tropical forests to current and future climate and atmospheric composition [¿Fuentes o sumideros? Las respuestas de los bosques tropicales al clima actual y futuro y a la composición atmosférica] / Clark, D.A. (Organization for Tropical Studies. La Selva Biological Station, Apdo 676, San Pedro de Montes de Oca 2050, CR <E-mail: daclark@sloth.ots.ac.cr>). In: Philosophical Transactions of the Royal Society of London. Series B. Biological Sciences (ISSN 0962-8436), v. 359, p. 477-491. 2004. How tropical rainforests are responding to the ongoing global changes in atmospheric composition and climate is little studied and poorly understood. Although rising atmospheric carbon dioxide (CO2) could enhance forest productivity, increased temperatures and drought are likely to diminish it. The limited field data have produced conflicting views of the net impacts of these changes so far. One set of studies has seemed to point to enhanced carbon uptake; however, questions have arisen about these findings, and recent experiments with tropical forest trees indicate carbon saturation of canopy leaves and no biomass increase under enhanced CO2. Other field observations indicate decreased forest productivity and increased tree mortality in recent years of peak temperatures and drought (strong El Niño episodes). To determine current climatic responses of forests around the world tropics will require careful annual monitoring of ecosystem performance in representative forests. To develop the necessaryprocess-level understanding of these responses will require intensified experimentation at the whole-tree and stand levels. Finally, a more complete understanding of tropical rainforest carbon cycling is needed for determining whether these ecosystems are carbon sinks or sources now, and how this status might change during the next century. Localización: Biblioteca OET: S9595. NBINA-1251. Publicación no.: 021 Responses of tropical forests to global warming and increased drought: the evidence to date and critical research needs [Respuestas de los bosques tropicales al calentamiento global e incremento de la sequía: la evidencia actual y necesidades críticas de investigación] / Clark, D.A. (Organization for Tropical Studies. La Selva Biological Station, Apdo 676, San Pedro de Montes de Oca 2050, CR <E-mail: daclark@sloth.ots.ac.cr>). Tropical Forests: Past, Present, Future. The Association for Tropical Biology Annual Meeting. Smithsonian Tropical Research Institute, Panama City, PA; July 29-Aug. 3, 2002. Panamá City: The Association for Tropical Biology, 2002. p. 20. (Abstract only). Recent process model studies indicate that increasing temperatures and associated decreases in rainfall in much of the tropics will decrease net carbon uptake of tropical forests through

impacts on both photosynthesis and respiration. A recent inversion model based on atmospheric data indicates that large carbon emissions from the terrestrial tropics have already occurred in years of peak temperatures and rainfall minima during 1978-1999. New evidence from ground-based studies supports these trends. In old-growth rain forest at La Selva, Costa Rica, annual tree growth was strongly negatively related to annual temperatures during 1984-2000, and forest-wide inventory plots showed a 39% reduction in biomass increment in the record-hot1997/98 El Niño. Long-term monitoring studies around the tropics indicated significantly increased tree mortality associated with that mega-Niño. Although the prevalence of still-air nights in tropical forests makes eddy covariance measurements problematic for estimating whole-forest carbon balance, lines of evidence from such studies in the Amazon and in Costa Rica suggest that carbon uptake by these forests is sensitive to even small temperature increases. Forest dry-down experiments in Amazonia show pervasive ecosystem impacts from increased drought. There is a pressing need to monitor annual forest performance in representative old-growth tropical forests worldwide, with standardized methods and publicly-accessible data and metadata. Until such data are available, the effects of climate change on tropical forests will remain poorly understood. Localización: Biblioteca OET: AD 519. Publicación no.: 022 Tropical forests and global warming: slowing it down or speeding it up? [Bosques tropicales y el calentamiento global: ¿reduciéndolo o aumentándolo?] / Clark, D.A. (Organization for Tropical Studies. La Selva Biological Station, Apdo 676, San Pedro de Montes de Oca 2050, CR <E-mail: daclark@sloth.ots.ac.cr>). In: Frontiers in Ecology and the Environment (ISSN 1540-9295), v. 2, no. 2, p. 73-80. 2004. The world's tropical forests take up and emit large amounts of carbon (C) through photosynthesis and respiration. Their response to global changes in the atmosphere and climate could therefore act as a feedback. Only recently has research been focused on the possibility that tropical forests may not be in C balance. There is currently a vigorous debate about whether these ecosystems might be accelerating or slowing down the rate of atmospheric CO2 accumulation, and thus global warming. The evidence is thin in either direction, and in some cases highly uncertain. Some findings raise the possibility that higher temperatures could make tropical forests increasing C sources to the atmosphere - a positive feedback effect. To project where our climate is headed, it is critical to resolve two questions: how tropical forests are reacting to changing climate, atmosphere and land use and how they will continue to respond over the coming decades. Localización: Biblioteca OET: NBINA-1776. Publicación no.: 023 Exchange processes of volatile organic compounds above a tropical rain forest: implications for modelling tropospheric chemistry above dense vegetation [Procesos de intercambio de compuestos orgánicos volátiles arriba de un bosque lluvioso tropical: implicaciones para el modelaje de la química troposférica por encima de una vegetación densa] / Karl, T.; Potosnak, M.; Guenther, A.; Clark, D.A.; Walker, J.; Herrick, J.D.; Geron, C. (National Center for Atmospheric Research. Atmospheric Chemistry Division, Boulder, CO, US <E-mail: daclark@sloth.ots.ac.cr>). In: Journal of Geophysical Research: Atmosphere (ISSN 0148-0227), v. 109, no. D18306, p. 1-19. 2004. [1] Disjunct eddy covariance in conjunction with continuous in-canopy, gradient measurements allowed for the first time to quantify the fine-scale source and sink distribution of some of the most abundant biogenic (isoprene, monoterpenes. methanol, acetaldehyde, and acetone) and photooxidized (MVK--MAC, acetone, acetaldehyde, acetic, and formic acid) VOCs in an old growth tropical rain forest. Our measurements revealed substantial isoprene emissions (up to 2.50 mg m h-1) and light-dependent monoterpene emissions (up to 0.33 mg m h-1) at the peak of the dry season (April and May 2003). Oxygenated species such as methanol, acetone, and acetaldehyde were typically emitted during daytime with net fluxes up to 0.50, 0.36, and 0.20 mg m-, h-1, respectively. When generalized for tropical rain forests, these fluxes would add up to a total emission of 36, 16, 19, 106, and 7.2 Tg/yr for methanol, acetaldehyde, acetone, isoprene, and monoterpenes, respectively. During nighttime we observed strong sinks for oxygenated and nitrogen-containing compounds such as methanol, acetone, acetaldehyde, MVK+MAC, and acetonitrile with deposition velocities close to the aerodynamic limit. This suggests that the canopy resistance (Re) is very small and not the rate-limiting step for the nighttime deposition of many VOCs. Our measured mean dry deposition velocities of methanol, acetone, acetaldehyde, MVK+MAC, and acetonitrile were a factor 10-20 higher than estimated from traditional deposition models. If our measurements are generalized, this could have important implications for the redistribution of VOCs in atmospheric chemistry models. Our observations indicate that the current understanding of reactive carbon exchange can only be seen as a first-order approximation. Localización: Biblioteca OET: S10174. Publicación no.: 024 Variation in leaf litter nutrients of a Costa Rican rain forest is related to precipitation [La variación en los nutrimentos de la hojarasca del suelo de un bosque lluvioso costarricense está relacionada con la precipitación] / Wood, T.E.; Lawrence, D.A.; Clark, D.A. (University of Virginia. Department of Environmental Sciences, P.O. Box 400123, Charlottesville, VA 22904, US <E-mail: tana@virginia.edu> <E-mail: daclark@sloth.ots.ac.cr>). In: Biogeochemistry (ISSN 0168-2563), v. 73, no. 2, p. 417-437. 2005.

By assessing current leaf litter nutrient dynamics, we may be able to predict responses of nutrient cycling in tropical ecosystems to future environmental change. The goal of this study was to assess whether nutrient cycling is related to seasonal variation in rainfall in a wet tropical forest. We examined leaf litter of an old-growth tropical rain forest in N.E. Costa Rica over a 4-year period to explore seasonal and inter-annual changes in leaf litter nutrient concentrations, and to evaluate potential short- and long-term drivers of variation in litter nutrient concentration, particularly that of phosphorus (P) and nitrogen (N). We also examined the temporal dynamics of calcium, potassium, and magnesium in the leaf litter. Leaf litter (P) and %N changed significantly with time, both seasonally and inter-annually. Seasonal changes in leaf litter (P) were strongly positively correlated with rainfall from the previous 2 weeks; cations, however, were inversely related to this measure of current rainfall, while %N was not related to rainfall. We propose that the positive relationship between current rainfall and leaf litter (P) is due to a response by the vegetation to an increase in nutrient availability and uptake. In contrast, given the negative relationship between current rainfall and cation concentrations, leaching from live leaf tissue is a more likely driver of short-term changes in cations. Should global climate change include altered rainfall patterns in this biome, one class of ecosystem-level responses could be significant changes in P and cation cycling. Localización: Biblioteca OET: NBINA-2698. Publicación no.: 025 Feel the heat: Rain forests may slow their growth in warmer world [Sienta el calor: Los bosques lluviosos pueden retardar su crecimiento en un mundo más caluroso] / Perkins, S. In: Science News (ISSN 0036-8423), v. 163, no. 17, p. 260. 2003. During a long-term research project in a Central American rain forest, mature trees grew more slowly in warm years than they did in cooler ones. This observation hints that tropical forests may become less efficient at removing planet-warming carbon dioxide from the atmosphere if global temperatures continue to rise. From 1984 to 2000, scientists studied the old-growth forest at La Selva, Costa Rica. Annually, the team measured the diameter of all mature trees within a 2 km² area. They found that diameter growth varied significantly from year to year and was related to average daily temperature. The annual tree growth from 1984 to 1986, the coolest interval during the period, averaged 81% greater than the growth tallied during the record hot spell related to the El Niño that began late in 1997. The average daily temperature difference between the two periods was about 1.4°C. Tree growth in the forest was also particularly slow during the El Niño year of 1987, says Deborah A. Clark, a biologist at University of Missouri, St. Louis. Clark and her colleagues report their results in an upcoming Proceedings of the National Academy of Sciences. Looking at global carbon dioxide measurements during the same period, the researchers noticed that quantitiesof the gas attributable to land plants in tropical regions increased during warm years. That phenomenon could stem from typical plant-growth characteristics, the researchers say. Plants use photosynthesis to convert sunlight, carbon dioxide, water, and nutrients into carbohydrates. When the plants tap into their stores of carbohydrates for chemical energy, however, they return carbon dioxide to the atmosphere, just as animals do, in the process called respiration. Although a plant's rate of photosynthesis begins to drop off above a temperature that's characteristic of its species, its rate of respiration continues to rise with increasing temperatures, says Clark. Most of the observed global spikes in carbon dioxide during warm years probably stemmed from the increased respiration of tropical land plants, but some may have been produced by other sources, such as forest fires or agricultural burning, says Stephen C. Piper, a biogeochemist at Scripps Institution of Oceanography in La Jolla, Calif., and acoauthor of the team's report. The growth rate of mature trees can be a useful indicator of the climate's effect on the rest of an ecosystem, says David S. Schimel of the National Center for Atmospheric Research in Boulder, Colo. The link that Clark's team discovered between slow growth rates in Costa Rican trees and increases in the atmospheric carbon dioxide traceable to tropical plants is "an innovative result that's hard to argue with," he says. Localización: Biblioteca OET: NBINA-3283. Publicación no.: 026 Retention of inorganic nitrogen by epiphytic bryophytes in a tropical montane forest [Retención de nitrógeno inorgánico por parte de Briofitas epífitas en una bosque tropical montano] / Clark, K.L.; Nadkarni, N.M.; Gholz, H.L. (US Forest Service. Silas Little Experiment Forest, No Global Change Program, 501 4 Mile Rd, New Lisbon, NJ 08064, US <E-mail: kennethclark@fs.fed.us> <E-mail: nadkarnn@evergreen.edu>). In: Biotropica (ISSN 0006-3606), v. 37, no. 3, p. 328-336. 2005. We developed and evaluated a model of the canopy of a tropical montane forest at Monteverde, Costa Rica, to estimate inorganic nitrogen (N) retention by epiphytes from atmospheric deposition. We first estimated net retention of inorganic N by samples of epiphytic bryophytes, epiphyte assemblages, vascular epiphyte foliage, and host tree foliage that we exposed to cloud water and precipitation solutions. Results were then scaled up to the ecosystem level using a multilayered model of the canopy derived from measurements of forest structure and epiphyte mass. The model was driven with hourly meteorological and event based atmospheric deposition data, and model predictions were evaluated against measurements of throughfall collected at the site. Model predictions were similar to field measurements for both event based and annual hydrologic and inorganic N fluxes in throughfall. Simulation of individual events indicated that epiphytic bryophytes and epiphyte assemblages retained 33-67 percent of the inorganic N deposited in cloud water and precipitation. On an annual basis, the model predicted that epiphytic components retained 3.4 kg N ha/yr, equivalent to 50 percent of the inorganic N in atmospheric deposition (6.8 kg N ha/yr). Our results

indicate that epiphytic bryophytes play a major role in N retention and cycling in this canopy by transforming highly mobile inorganic N (ca. 50% of atmospheric deposition is NO3 ) to less mobile (exchangeable NH4+) and recalcitrant forms in biomass and remaining litter and humus. Localización: Biblioteca OET: NBINA-4096. Publicación no.: 027 Rainforests: Carbon sink or carbon source? Could tropical forests soon contribute to global warming? [Bosques lluviosos: ¿almacenadores de carbono o fuente de carbono? ¿Podrían pronto contribuir los bosques tropicales al calentamiento global?] / Rosner, H. In: Seed [electronic magazine from seedmagazine.com], Apr./May, p. 59-67. 2006. Everything you thought you knew about the rainforest may soon prove completely wrong In a remote portion of Costa Rican jungle, a team of ecologists is measuring every known quantity about tropical forests-every piece of gunk that falls to the ground, every wisp of carbon that rises to the sky, how much air goes into the soil, what the bugs are eating. And they're finding that as the temperature rises from global warming, the rainforest-long thought to be a repository of greenhouse gas-grows more slowly. This discovery, and the data they've collected since making it, indicate that if the rainforest's temperature crosses a certain as-yet unknown threshold, there's a very good chance the trees will begin to decay, emitting carbon instead of storing it. And we all know what that means. Localización: Biblioteca OET: NBINA-4090. Publicación no.: 028 Detecting tropical forests' responses to global climatic and atmospheric change: current challenges and a way forward [Detectando respuestas de los bosques tropicales al cambio climático y atmosférico mundial: desafíos actuales y en camino] / Clark, D.A. (Organization for Tropical Studies. La Selva Biological Station, Apdo. 676, 2050 San Pedro de Montes de Oca, US <E-mail: daclark@sloth.ots.ac.cr>). In: Biotropica (ISSN 0006-3606), v. 39, no. 1, p. 4-19. 2007. Because of tropical forests disproportionate importance for world biodiversity and for the global carbon cycle, we urgently need to understand any effects on these ecosystems from the ongoing changes in climate and atmosphere. This review, intended to complement existing data reviews on this topic, focuses on three major classes of challenges that we currently face when trying to detect and interpret directional changes in tropical forests. One is the very limited existing information on the historical context of study sites. Lasting effects from past climate, natural disturbances, and/or human activities could be significantly affecting current-day processes in tropical forests and need to be investigated for all active field sites. Second, whileprogress has been made in recent years on standardizing and refining research approaches, a number of methods- and data-limitations continue to affect efforts both to detect within-forest changes and to relate them to ongoing environmental change. Important outstanding needs are improved sampling designs, longer time-series of observations, filling key data gaps, and data access. Finally, forest responses to ongoing environmental change are complex. The effects of many simultaneously changing environmental factors are integrated by the plants, and their responses can involve significant lags, carryovers, and non-linearities. Specifying effects of individual environmental changes, however, is required for accurate ecosystem-process models and thus for projecting future impacts on these forests. After discussing these several types of challenges and ways to address them, I conclude with a priority agenda for this critical area of research. Localización: Biblioteca OET: NBINA-5294. Publicación no.: 029 Carbon dioxide exchange of a tropical rain forest. Part II [Intercambio de dióxido de carbono de un bosque lluvioso tropical. Parte II] / Lemon, E.; Allen, L.H., Jr.; Müller, L.E. (Cornell University. Agronomy Department, Ithaca, N.Y. 14853, US). In: BioScience (ISSN 0006-3568), v. 20, no. 19, p. 1054-1059. 1970. (No abstract). Localización: Biblioteca OET: S492. Publicación no.: 030 Environment of a Costa Rican forest [Ambiente de un bosque costarricense] / Allen, L.H., Jr.; Lemon, E.; Müller, L.E. (USDA/ARS. Soil and Water Conservation Research Division, Beltsville, MD 20705, US). In: Ecology (ISSN 0012-9658), v. 53, no. 1, p. 102-111. 1972. Wind speed and turbulence were measured at five heights simultaneously in a Costa Rican forest with non-stalling, heated-thermocouple anemometers. A persistent daytime stable thermal stratification of the air beneath the top canopy decreased small-scale turbulence, which may increase boundary-layer resistance of leaf-to-air transport of water vapor and CO2. Three CO2 source layers (ground level, trunk space, and above the top canopy) and two CO2 sink layers (top canopy and bottom canopy) were found in this forest. Low nocturnal wind speed allowed CO2 from respiration to accumulate at night. Localización: Biblioteca OET: S1658. Publicación no.: 031 Slash and burn impacts on a Costa Rican wet forest site [Impactos de la corta y quema sobre un sitio de bosque húmedo costarricense] / Ewel, J.J.; Berish, C.W.; Brown, B.J.; Price, N.; Raich, J.W. (USDA Forest Service, Honolulu, HI 96813, US <E-mail: jackewel@gte.net> <E-mail: jraich@iastate.edu>). In: Ecology (ISSN 0012-9658), v. 62, no. 3, p. 816-829. 1981.

Three 33X33 m plots in 8- to 9-yr-old tropical evergreen forest at Turrialba, Costa Rica, interspersed with 70-yr-old patches were felled in Jan. 1979 and firewood removed from the site. Remaining vegetation was left through the dry season (mulching) then burned in March 1979. Nutrient budgets, rates of CO2 evolution from the soil, soil seed storage and plant growth were evaluated at each stage. Harvest of large trees removed more than 10% of all elements (C, S, P, K, Ca, Mg) except N. During the 11-wk mulching and drying period, 33% of K and 13% P disappeared, but losses of other elements were less than 6%. The burn volatilized 31% of the initial amount of C, 22% of N, and 49% of S. Post-burn wind and water erosion of ash and leaching removed 16% of N, 33% of K, 51% of P, 45% of Ca, 40% of Mg, and insignificant amounts of C and S. Soil CO2 evolution was greater from beneath 11-wk-old slash (3.6 g/m² daily of C) than from beneath the forest (2.5 g/m²), probably because slash conserved soil moisture better than actively transpiring forest. After burning, both field and forest soil evolved CO2 at about 4.5 g/m² daily of C. Soil seed storage fell from about 8000 seeds/m² (67 species) in the forest, to 6000 seeds/m² (51 species) after mulching and drying, to 3000 seeds/m² (37 species) after burning. Localización: Biblioteca OET: S2181. NBINA-5673. Publicación no.: 032 Carbon budget of a tropical soil under mature wet forest and young vegetation [Presupuesto de carbono de un suelo tropical bajo bosque húmedo maduro y vegetación joven] / Raich, J.W. (Iowa State University. Department of Ecology, Evolution and Organismal Biology, Ames, IA 50011, US <E-mail: jraich@iastate.edu>). Gainesville, FL: University of Florida, 1980. 107 p. Thesis, M.Sc, University of Florida, Department of Botany, Gainesville, FL (USA). The effects of tropical forest removal on the carbon budget of a soil were studied by measuring major storages (litter, roots, and organic matter) and flows (precipitation, litterfall, and CO2 evolution) of soil carbon in two types of vegetation: mature wet forest and one-year-old succession in La Selva Biological Station, a Costa Rican lowland. The mature-forest soil (litter plus roots and soil to a depth of 50 cm) contained2.5 kg/m² more carbon than did the soil beneath the young successional vegetation. The greatest reduction occurred in large dead wood; the forest contained1.8 kg/m² more carbon in.logs than did the regrowth. There was 6-7% less carbon in soil organic matter, and about 45% less non-woody litter and non-woody litterfall in the regrowth than in the forest. The greatest similarities between the two sites were in fine roots (about 114 g C/m² in both sites) and soil organic matter, which may indicate that the functioning of the soil community was not seriously impaired by forest removal. Litterfall, which averaged 2.8 g/m². day in the forest and 1.6 g/m². day in the regrowth, was the major source of soil carbon measured in this study, but carbon budgets indicate that root inputs to the soil were more than twice the carbon inputs in litterfall. The proportions of rainfall reaching the soil surface in throughfall and stem flow, respectively, were: 52% and 9% in the forest, and 68% and 4% in the regrowth. Average carbon concentrations in throughfall and stem flow were 12 and 13 mg/l, respectively, in the forest, and 14 and 10 mg/l in the regrowth. Rain water averaged 5 mg C/l. Precipitation inputs and leaching losses of soil carbon were 40 g/m².yr in both sites. The rate of soil CO2 evolution was higher in the young regrowth than in mature forest (7.1 and 5.3 g C/m².day). The regrowth was undergoing a net loss of stored soil carbon to the atmosphere. Localización: Biblioteca OET: Tesis 4. Publicación no.: 033 Preliminary pollen analysis of Quaternary sediments from Deep Sea Drilling Project Site 565, western Costa Rica [Análisis preliminar del polen de sedimentos del Cuaternario del Sitio 565 el Proyecto de Barrenamiento Profundo del Mar, Costa Rica occidental] / Horn, S.P. (The University of Tennessee. Department of Geography, 304 Burchfiel Geography Building, Knoxville, TN 37996-09251420, US <E-mail: shorn@utk.edu>). In: Initial Reports of the Sea Drilling Project, v. 84, p. 533-547. Washington, D.C.: U.S. Government Printing Office, 1985. Preliminary analyses of 32 samples from the upper 24 m of sediment recovered at Site 565 show changes in pollen frequencies that appear to reflect vegetational and climatic changes in southern Central America during the late Quaternary. Four pollen zones are recognized. In the lowest zone, Zone 4, the tropical pollen types Urticales, Piper, and Alchornea are common. Temperate forest taxa, particularly Pinus, Quercus, and Podocarpus, dominate Zones 3 and 2. Pollen spectra in Zone 1 are variable and show peaks in both temperate and tropical taxa. The record is estimated to cover most of the last glacial cycle. Localización: Biblioteca OET: S313. Publicación no.: 034 Nitrous oxide flux from dry tropical forests [Flujo de óxido nitroso de bosques secos tropicales] / Vitousek, P.M.; Matson, P.A.; Volkmann, C.; Maass, J.M.; García, G. (Stanford University. Department of Biological Sciences, Stanford, CA 94305, US). In: Global Biogeochemical Cycles (ISSN 0886-6236), v. 3, no. 4, p. 375-382. 1989. Fluxes of nitrous oxide were determined in several sites in drought-deciduous tropical forest, an extensive but little-studied biome. N2O-N fluxes from eight sites within intact Mexican forest averaged 0.91 ng cm-2 h-1 during the wet season; they were virtually absent in the dry season. Two subsistence maize fields yielded increased soil N2O-N fluxes, while five pastures were more variable. Watering during the dry season caused a substantial but short-lived pulse of N2O. Similar fluxes were observed in less-intensive sampling of dry-forest sites in Hawaii and Costa Rica. Overall, N2O fluxes from soils of dry tropical forests appear to be similar to those from moist tropical forests during the wet season and very low during the dry season.

Localización: Non available. Publicación no.: 035 Los líquenes como indicadores de la contaminación atmosférica en el área metropolitana de San José, Costa Rica [Lichens as atmospheric pollution indicators in the metropolitan area of San José, Costa Rica] / Méndez, O.I.; Fournier-Origgi, L.A. (Universidad de Costa Rica. Escuela de Biología, San José, CR). In: Revista de Biología Tropical (ISSN 0034-7744), v. 28, no. 1, p. 31-39. 1980. Lichens were used as a pollution indicators in the metropolitan area of San José, Costa Rica. Trasplants showed a positive correlation between the percentage of dead cells in the thallus and the ketone soluble substances deposited on it. Those parts of the city where pollution is greatest (industrial areas and heavy traffic) were also the ones where lichens suffered the most, and in some extreme cases the thallus died after 8 months of exposure. Besides this transplant experiment, the coverage of Parmelia lichens on the bark of several tree species was determined in some areas of the city. The results of these observations suggest that the city of San José has three different kinds of air environment in relation to lichen survival: normal, transitional and desertic, as reported for other cities of the world. The most frequent air pollutants in San José are: CO, CO2, C2H5OH, Cl2, HCl, H2S, H3PO4, H2CrO4, NO, NH3, NH4Cl, SO2 and Zn. Localización: Biblioteca OET: R. Publicación no.: 036 Cross-system comparisons of soil nitrogen transformations and nitrous oxide flux in tropical forest ecosystems [Comparaciones de sistemas cruzados de transformaciones del nitrógeno del suelo y flujo de óxido nitroso en ecosistemas de bosques tropicales] / Matson, P.A.; Vitousek, P.M. (NASA-Ames Research Center. Ecosystem Scientific and Technica , Moffett Field, CA 94035, US). In: Global Biogeochemical Cycles (ISSN 0886-6236), v. 1, no. 2, p. 163-170. 1987. Soil nitrogen transformations and nitrous oxide flux across the soil-air interface were measured in a range of tropical forest sites in Costa Rica, Brazil, and Hawaii. Nitrogen mineralization and nitrification potentials were high in the relatively fertile Costa Rica sites and the Amazonian oxisol/ultisols (1.5 ug-1 d-1 of N mineralized), intermediate in Amazonian white sand soils (0.5-0.8 ug-1 d-1) and low in the Hawaiian montane sites (0.5 ug g-1 d-1). Nitrous oxide fluxes ranged from 0 to 6.2 ng cm-2 h-1 of N; mean flux per site was highly correlated with mean nitrogen mineralization across 26 sites. These correlated patterns of nitrogen cycling and trace gas production could be useful in the development of regional- and global-scale estimates of nitrous oxide fluxes from tropical forests. Localización: Biblioteca OET: S2050. NBINA-7218. Publicación no.: 037 Sedimentation and the history of upwelling and climate in high fertility areas of the Northeastern Pacific Ocean [Sedimentación, la historia del afloramiento y el clima en áreas de mucha fertilidad del Océano Pacífico nororiental] / Dunbar, R.B. San Diego, CA: University of California, 1981. Dissertation, Ph.D., University of California, San Diego, CA (USA). In this thesis, I address two problems: (1) how sedimentation occurs in highly productive coastal regions, and (2) how sedimentary deposits and carbonate fossil remains accumulating in such areas can be used to reconstruct the history of oceanic climate and fertility. During the deployment of a suitcase-type sediment trap in the Santa Barbara Basin (California), fecal pellets comprised more than 60% of the total flux of 660 g m² yr(-1). During a second deployment in the Panama Basin, recognizable fecal pellets accounted for less than 2% of the total flux to the deep water column. A model is presented which relates pellet flux (and organic carbon flux) to the degree of pellet "robustness" produced by clay mineral incorporation. Detailed oxygen isotope profiles of branches of the rapidly-growing reef coral, Pocillopora damicornis, indicate that seasonal changes in temperature and seawater isotopic composition are precisely recorded. Oxygen isotopic analysis of fossil corals from the Gulf of Papagayo(Pacific coast of Costa Rica) indicate that widespread coral mortality in this area was related to exposure to cold water about 200 years ago. Water temperatures dropped due to an increase in trade-wind driven coastal upwelling during the height of the Little Ice Age. This is the first evidence for a low latitude expression of the Little Ice Age and the results imply that even minor climatic perturbations are accompanied by significant changes in oceanic and atmospheric circulation. ('18)O/('16)O ratiosin the planktonic foraminifera Globigerina bulloides in box cores from the varved sediments of the Santa Barbara Basin are positively correlated with the historical records of upwelling (sealevel, water temperature, and air temperature) from Port HuenemeLos Angeles, and San Diego. Isotope stratigraphies suggest that upwelling rates were greater during the Little Ice Age (about 50 to 400 years ago, with cold peaks at approximately 1900, 1870, 1810, and 1770) than today. An expanded record of the "11K" deglacial event is contained in the upper three meters of a radio-carbon dated piston core from San Clemente Basin (California). As recorded by ('18)O/('16)O and ('13)C/('12)C ratios in the planktonic and benthic foraminifera, the duration of the event is3000 years. The first event associated with deglaciation is a rapid increase in benthic (delta)('13)C (which may reflect the introduction of relatively "young" deep water) which preceeds by 500 to 1,000 years the planktonic (delta)('18)O change (recording rapid melting of the continental glaciers). Mixing of the isotopically depleted melt water into the deep ocean proceeds for the next 2000 to 2500 years. Localización: Non available.

Publicación no.: 038 Controls on nitric oxide emissions from tropical pasture and rain forest soils [Controles sobre las emisiones de óxido nítrico de potreros y suelos de bosques lluviosos tropicales] / Parsons, W.F.J.; Keller, M. (Rutgers University. Institute of Marine and Costal Sciences, Piscataway, NJ 08855, US <E-mail: michael.keller@unh.edu>). In: Biology and Fertility of Soils (ISSN 0178-2762), v. 20 no. 3, p. 151-156. 1995. In field studies, forest soils in the Atlantic Lowlands of Costa Rica emitted greater amounts of nitric oxide (NO) than soils from pastures that had been actively grazed for over 20 years following their conversion from forest. NO production from intact soil cores from these areas were measured. Laboratory tests using ammonium (NH4+), nitrate (NO3-), nitrite (NO2-), water, and acetylene (C2H2) additions demonstrated a response consistent with field studies. Forest soils cores produced more NO than pasture cores regardless of treatment. In forest soils the response to NH4+ solution was significantly greater than response to water or an ambient moisture control. Addition of 10 kPa C2H2 caused a marked decrease in NO production in forest soil cores. These responses suggest a nitrification-linked control over NO production. Large and rapid responses to NO2- additions suggest that chemical decomposition of this ion may contribute to NO production. Pasture soil cores did not show a significant response to any of the treatments including NO2-. Low porosity in the pasture soils may restrict emission of NO produced therein. Localización: Biblioteca OET: S5246. Publicación no.: 039 Nitrogen loss from coffee agroecosystems in Costa Rica: leaching and denitrification in the presence and absence of shade trees [Pérdida de nitrógeno de agroecosistemas de café en Costa Rica: percolación y desnitrificación en presencia y ausencia de árboles de sombra] / Babbar-Amighetti, L.I.; Zak, D.R. (Organix S.A., calle 3, ave. 3 y 5, Edificio Ferencz 5to piso, San José, CR <E-mail: liana@racsa.co.cr> <E-mail: drzak@umich.edu>). In: Journal of Environmental Quality (ISSN 0047-2425), v. 24, no. 2, p. 227-233. 1995. Nitrate leaching and the factors controlling denitrification in shaded and unshaded coffee (Coffea arabica) plantations were investigated in the Central Valley of Costa Rica; both plantation types were fertilized with 300 kg N/ha annually. Nitrate leaching was quantified using porous ceramic cup lysimeters placed 60 cm below the soil surface. Losses were estimated by multiplying the soil water NO3- concn by the monthly soil water excess, determined as the difference between precipitation and actual evapotranspiration. In addition, a laboratory experiment was conducted to investigate the influence of NO3-, C, and O2 availability on N2O production and total denitrification (N2O-N + N2-N). Annual leaching losses of NO3- were almost three times greater in unshaded plantations (24 kg NO3-/ha) than in shaded plantations (9 kg/ha). In contrast, mean total daily denitrification rates in control soil samples from shaded plantations were 60% higher (732 mug N2O-N/kg) than in unshaded plantations (455 mug N2O-N/kg). Carbon additions produced the largest increase in daily denitrification, generating a threefold increase (+C = 8396 mug N2O-N/kg; -C = 2985 mug N2O-N/kg) in both plantation types. Anaerobic conditions also significantly increased denitrification (+O2 = 4331 mug N2O-N/kg per day; -O2 = 6656 mug N2O-N/kg per day). In both plantation types, the potential for N loss via NO3- leaching was small compared with that for gaseous N loss. Localización: Biblioteca OET: S7255. Publicación no.: 040 Integrating earth systems science / Williamson, P. (University of East Anglia. School of Environmental Sciences, Norwich, GB). In: Ambio (ISSN 0044-7447), v. 23, no. 1, 103 pp. 1994. This special issue contains eighteen papers presented at the 3rd International Geosphere-Biosphere Programme (IGBP) Scientific Advisory Council meeting in Mexico in 1993. The papers address the following subjects: the carbon cycle; global change models; interactions and collaboration in global change across the social and natural sciences; science and policy making; palaeo-perspectives; the response of a coupled ocean-atmosphere model to increasing atmospheric carbon dioxide; global atmospheric-biospheric chemistry; biogeochemical interactions in the equatorial Pacific; landscape to regional-scale responses of terrestrial ecosystems to global change; the impact of rising carbon dioxide concentrations on the terrestrial biosphere; a vegetation classification logic based on remote sensing for use in global biogeochemical models; large-scale experimental and modelling studies of hydrological processes; changes in general circulation and its influence on precipitation trends in Central America (Costa Rica); global land-use/land cover change; perspectives on policy; development of the Inter-American Institute for Global Change Research; and the role of the European Union in global change research. Localización: Biblioteca OET: A. Publicación no.: 041 Organic carbon turnover in three tropical soils under pasture after deforestation [Funcionamiento del carbono orgánico en tres suelos tropicales bajo pastizales después de la deforestación] / Veldkamp, E. (Universität Göttingen. Institute of Soil Sciences & Forest Nutritrion; Busgenweg 2, D-37077 Göttingen, DE <E-mail: eveldka@gwdg.de>). In: Soil Science Society of America Journal (ISSN 0361-5995), v. 58, no. 1, p. 175-180. 1994. The changes in soil organic carbon (SOC) storage after deforestation in three soil types in the Atlantic Zone of Costa Rica were studied using the delta13C method. Changes in bulk density, which normally accompany land use changes, had a profound influence on the results of the calculations. Deforestation, followed by 25 yr of pasture, caused a net loss of 21.8 t/ha in SOC for an Eutric Hapludand and 1.5 t/ha for an Oxic

Humitropept. The SOC changes over time were studied on a deforestation sequence on an Andic Humitropept. In the first years after forest clearing, decomposition of tree roots caused an extra input of SOC, which influenced the delta13C signal. Decomposition of forest C and increase of pasture C were mathematically described for several depths. A marked influence of depth on decomposition rates was found. The strong stabilization of organic C by Al-organic matter complexes probably caused the relatively small net C loss from SOC since forest clearing. Localización: Biblioteca OET: Tesis 372. S7222. Publicación no.: 042 Nitrate limitation of N2O production and denitrification from tropical pasture and rain forest soils [Limitación de nitratos por la producción de óxido nitroso y desnitrificación de suelos de potreros tropicales y bosques lluviosos] / Parsons, W.F.J.; Mitre, M.E.; Keller, M.; Reiners, W.A. (University of Wyoming. Department of Botany, Laramie, WY 82071-3165, US <E-mail: michael.keller@unh.edu> <E-mail: reiners@uwyo.edu>). In: Biogeochemistry (ISSN 0168-2563), v. 22, no. 3, p. 179-193. 1993. Nitrous oxide production was measured in intact cores taken from active pasture and old-growth forest Inceptisols in the Atlantic Lowlands of Costa Rica. Aqueous KNO3 and/or glucose were added and the cores were incubated in the laboratory to determine if N2O production rates were either nitrogen or carbon limited. The differences in rates of denitrification among amended forest and pasture soils were determined by the addition of 10% C2H2. The forest soils were relatively insensitive to all amendment additions, including the acetylene block. Forest N2O production rates among the treatments did not differ from the controls and were lower than those of the pasture soils. With the addition of glucose plus nitrate to the forest soils, production of N2O was three times greater than the controls. This increase was not statistically significant. Pasture soils were nitrogen-limited as N2O production rates were increased by all nitrate-containing amendments. Denitrification was high in the pasture soils. The results are discussed with respect to the effects of agricultural land use practices and the impacts of disturbances on N2O release. Localización: Biblioteca OET: S2113. NBINA-7044. Publicación no.: 043 Effect of pasture age on soil trace-gas emissions from a deforested area of Costa Rica [Efecto de la edad del pasto sobre las emisiones de gases traza del suelo de áreas deforestadas de Costa Rica] / Keller, M.; Veldkamp, E.; Weitz, A.M.; Reiners, W.A. (U.S. Department of Forest Service. International Institute of Tropical Forestry, Río Piedras, PR 00928-5000, US <E-mail: michael.keller@unh.edu> <E-mail: eveldka@gwdg.de> <E-mail: aweitz@bgc-jena.mpg.de> <E-mail: reiners@uwyo.edu>). In: Nature (ISSN 0028-0836), v. 365, no. 6443, p. 244-246. 1993. Trace-gas fluxes were measured in pastures of varying ages since conversion from forest in Costa Rica. Nitrogen oxide fluxes peaked during the first 10 yr after conversion, but declined thereafter to values that were lower than the original forest fluxes. Previous estimates in the literature of increased nitrous oxide input to the atmosphere from conversion of forest to pasture had assumed that elevated fluxes were maintained. Localización: Biblioteca OET: S2024. LS. Publicación no.: 044 Cost and performance of CO2 storage in forestry projects [Costo y comportamiento del almacenamiento de CO2 en proyectos forestales] / Swisher, J.N. (Lund University. Environment and Energy Systems Studies, Gerdagatan 13, 22362 Lund, SE). In: Biomass and Bioenergy (ISSN 0961-9534), v. 1, no. 6, p. 317-328. 1992. In order to include forestry projects in a possible CO2 emission reduction regime, and to compare the costs of individual projects or national programmes, it is necessary to determine the rate of equivalency between carbon in fossil fuel emissions and carbon stored in different types of forestry projects. A comprehensive and consistent methodology is presented to account for costs and carbon flows of different categories of forestry projects. Application of the methodology to a set of projects in Central America is described. Several estimates have been made to date of the overall potential for carbon storage through global reforestation and the costs of such efforts, based on global macroeconomic estimates and extrapolations from current forest-sector experience. However, there has yet to be a consistent analysis of the magnitude and cost of carbon savings by a 'bottom-up' approach to sustainable forestry development. This methodology is applied to a set of projects proposed in Costa Rica and other Central American countries under the Tropical Forest Action Plan, to estimate a sample set of national CO2 reduction cost curves. Costs of carbon savings in forestry projects studied in Central America mostly fall between $5 and $13/ton C, depending on type of project, climate, and opportunity cost of land. These projects also promise socioeconomic benefits at the local level, provided they are adequately endowed with funding, training and institutional support. The total amount of CO2 storage potential is significant, about 100 million tons per country, but not enough to suggest that forestry can offset more than a few percent of global CO2 emissions from fossil fuel use. Localización: Biblioteca OET: S5392. Publicación no.: 045 Postglacial vegetation and fire history in the Chirripó paramo of Costa Rica [Vegetación postglacial e historia de incendios en el páramo del Chirripó de Costa Rica] / Horn, S.P. (The

University of Tennessee. Department of Geography, 304 Burchfiel Geography Building, Knoxville, TN 37996-09251420, US <E-mail: shorn@utk.edu>). In: Quaternary Research (ISSN 0033-5894), v. 40, no. 1, p. 107-116. 1993. Pollen and charcoal analysis of a 5.6-m sediment core from Lago de las Morrenas (9 degree 29'N, 83 degree 29'W; 3480 m) provides evidence of postglacial vegetation and fire history in the highlands of the Cordillera de Talamanca, Costa Rica. The site is presently surrounded by treeless paramo vegetation and apparently has been so since deglaciation about 10,000 yr B.P. Pollen spectra suggest no pronounced changes in vegetation since ice retreat. Fires set by people or lightning have burned the paramo repeatedly, with fire activity probably highest during the late Holocene, but these fires have not carved paramo from forest. Pollen percentages for Gramineae and other paramo taxa decline upward, whereas percentages for certain subalpine, lower montane, and lowland forest taxa increase slightly; these changes may reflect the impact of prehistoric human activity or slight upslope migrations of forest taxa owing to climatic warming. There is no clear evidence of higher timberlines during the mid-Holocene. Localización: Biblioteca OET: S4614. Publicación no.: 046 Fluxes of nitric oxide from soils following the clearing and burning of a secondary tropical rain forest [Flujos de óxico nítrico de suelos luego de la tala y quema de un bosque lluvioso tropical secundario] / Neff, J.C.; Keller, M.; Holland, E.A.; Weitz, A.M.; Veldkamp, E. (National Center for Atmospheric Research. Atmospheric Chemical Division, Boulder, CO, US <E-mail: michael.keller@unh.edu> <E-mail: aweitz@bgc-jena.mpg.de> <E-mail: eveldka@gwdg.de>). In: Journal of Geophysical Research: Atmosphere (ISSN 0148-0227), v.100(D12), no. 25, p. 913-25, 922. 1995. At sites in the Atlantic Lowlands of Costa Rica, clearing and burning of a secondary tropical rain forest caused a significant increase in soil nitric oxide emissions. Soil-atmospheric NO fluxes averaged 0.5 ng N/cm²-h prior to clearing and increased to 4.1 ng N/cm²-h following clearing and to greater than 12.0 ng N/cm²-h following burning. Soil NO emissions were elevated for a period of 3-4 mo following clearing, and fluxes peaked for 1-3 days following burning. We conducted a series of experiments with intact soil cores to determinate the probable mechanism responsible for elevated NO emissions from soils. In one set of experiments we added substrates for microbial nitrification (ammonium), denitrification (nitrate), and chemical denitrification (nitrite) to autoclaved (killed) and nonautoclaved (live) soil cores. Water-only additions were used as controls. Compared to water or nitrate additions, ammonium caused a significant increase in NO emissions from live cores. Water, ammonium, and nitrate additions had no effect on emissions from autoclaved cores. Nitrite soln. additions resulted in highly significant increases in NO emissions from both autoclaved and nonautoclaved soil cores. In a second set of experiments we treated intact soil cores with acetylene (1 kPa C2H2) to selectively inhibit nitrification and oxygen to inhibit denitrification. The oxygen treatment had no effect on NO production, while acetylene significantly reduced NO emissions. The results from major pathway for NO production in these soils. In contrast, microbial nitrification appears to be a critical process responsible for NO emissions throughout the clearing and burning period. Field experiments with acetylene as an inhibitor show that immediately following burning, chemical denitrification of nitrite deposited in ash supports a large peak in NO fluxes. Localización: Biblioteca OET: S2562. Publicación no.: 047 Geocoding and stereo display of tropical forest multisensor datasets / Welch, R.; Jordan, T.R.; Luvall, J.C. (The University of Georgia. Center for Remote Sensing and Mapping Science, Athens, GA 30602, US). In: Photogrammetric Engineering and Remote Sensing (ISSN 0099-1112), v. 56, no. 10, p. 1389-1392. 1990. Methodologies are described for the development of a multisensor geocoded dataset with stereo display to facilitate the building of databases that may be used to assess deforestation, thermal response, evapotranspiration and other parameters linked to climate change. Geocoding and registering are discussed for multisensor data (Thermal Infrared Multispectral Scanner (TIMS), Calibrated Airborne Multispectral Scanner (CAMS), SPOT High Resolution Visible (HRV) and Landsat Thematic Mapper (TM)) obtained for the Braulio Carrillo National Park, Costa Rica. Localización: Biblioteca OET: P. Publicación no.: 048 Deforestation, carbon dynamics, and sustainable mitigation measures in Costa Rica - The Puerto Viejo de Sarapiquí case study [Deforestación, dinámica del carbono y medidas sostenibles de mitigación en Costa Rica - Estudio de caso de Puerto Viejo de Sarapiquí] / Sánchez-Azofeifa, G.A.; Quesada-Mateo, C.A. (University of Alberta. Department of Earth and Atmospheric Sciences, Edmonton, Alberta T6G 2E3, CA <E-mail: arturo.sanchez@ualberta.ca> <E-mail: cquesada@cariari.ucr.ac.cr>). In: Interciencia (ISSN 0378-1844), v. 20, no. 6, p. 396-400. 1995. The definition of mitigation policies and implementation projects in developing countries must be based on solid scientific knowledge foundations. This knowledge basis must not only provide information on the response of physical systems, but must consider, besides, the social forces that induce the response of natural systems. In the present article, the role played by science and technology in the definition of

abatement policies is analyzed by means of a case-study in the Puerto Viejo de Sarapiquí area, in Costa Rica. Satellite information and geographical information systems are combined in order to understand the forces generating a change in the use of land in this area, as well in the building of a data-base which may permit the definition of long-term policies. It is concluded in this article that the success of any policy or program will only be achieved if these are included within a referential framework which is related to a strategy for a country's coherent and sustainable development. Localización: Biblioteca OET: I. Publicación no.: 049 Soil-atmosphere exchange of nitrous oxide, nitric oxide, and methane under secondary succession of pasture to forest in the Atlantic lowlands of Costa Rica [Intercambio del suelo a la atmósfera de óxido nitroso, óxido nítrico y metano bajo una sucesión secundaria de pastos a bosque en las tierras bajas del Atlántico de Costa Rica] / Keller, M.; Reiners, W.A. (U.S. Department of Forest Service. International Institute of Tropical Forestry, Río Piedras, PR 00928-5000, US <E-mail: michael.keller@unh.edu> <E-mail: reiners@uwyo.edu>). In: Global Biogeochemical Cycles (ISSN 0886-6236), v. 8, no. 4, p. 399-409. 1994. We investigated changes in soil-atmosphere flux of CH4, N2O, and NO resulting from the succession of pasture to forest in the Atlantic lowlands of Costa Rica. We studied a dozen sites intensively for over one year in order to measure rates and to understand controlling mechanisms for gas exchange. CH4 flux was controlled primarily by soil moisture content. Soil consumption of atmospheric CH4 was greatest when soil were relatively dry. Forest soils consumed CH4 while pasture soils which had poor drainage generally produced CH4. The seasonal pattern of N2O emissions correlated with soil exchangeable NO3-concentrations. Soil-atmosphere NO flux was greatest when soils were relatively dry. We found the largest NO emissions from abandoned pasture sites. Combining these data with those from another study in the Atlantic lowlands of Costa Rica that focused on deforestation, we present a 50-year chronosequence of trace gas emissions that extends from natural conditions, through disturbance and natural recovery. The soil-atmosphere fluxes of CH4 and N2O and of NO may be restored to predisturbance rates during secondary succession. The changes in trace gas emissions following deforestation, through pasture use and secondary succesion, may be explained conceptually through reference to two major controlling factors, nitrogen availability and soil-atmosphere diffusive exchange of gases as it is influenced by soil moisture content and soil compaction. Localización: Biblioteca OET: S2519. LS. NBINA-6918. Publicación no.: 050 A climate alliance for Central America [A debate with Max Campos Ortiz and Patricia Ramírez Obando of the National Meteorological Institute of Costa Rica] / Kelly, M.; Granich, F. In: Tiempo, v. 3, p. 1-3. 1991. (No abstract). Localización: Biblioteca OET: TIE. Publicación no.: 051 Tropical forests and trace gases: potential interactions between tropical biology and the atmospheric sciences [Bosques tropicales y gases traza: interacciones potenciales entre la biología tropical y las ciencias atmosféricas] / Vitousek, P.M.; Matson, P.A. (Stanford University. Department of Biological Sciences, Stanford, CA 94305, US). In: Biotropica (ISSN 0006-3606), v. 24, no. 2B, p. 233-239. 1992. Tropical forests are major contributors to the composition of the atmosphere, and anthropogenic changes to tropical ecosystems have driven changes in the atmosphere. Tropical biologists can make and have made significant contributions to understanding these effects, but we can also learn a great deal from the atmospheric sciences. In this paper, we show how knowledge about the functioning of tropical ecosystems can contribute to building a global source budget for a greenhouse gas (nitrous oxide), and how accumulating information from atmospheric measurements suggests that increased concentrations of a reactive gas (tropospheric ozone) represent a significant perturbation to tropical ecosystems-even in remote areas. Localización: Biblioteca OET: S1219. NBINA-3539. Publicación no.: 052 Computer simulation of tree growth periodicity and climatic hydroperiodicity in tropical forests [Simulación mediante computadora de la periodicidad del crecimiento del árbol y la hidroperiodicidad climática en bosques tropicales] / Borchert, R. (The University of Kansas. Division of Biological Sciences, 1200 Haworth Hall, Sunnyside Ave, Lawrence, KS 66045-7534, US <E-mail: borchert@ku.edu>). In: Biotropica (ISSN 0006-3606), v. 24, no. 3, p. 385-395. 1992. In most tropical trees, vegetative and reproductive development are distinctly periodic, but often poorly correlated with seasonal climatic change. Growth periodicity of individual trees is proposed here to reflect primarily an endogenous rhythm of vegetative growth resulting from periodic leaf replacement. This endogenous periodicity determines the species-specific timing of flowering and can be entrained secondarily to seasonal changes in water stress. These assumptions have been incorporated into a simple computer model which illustrates the effects of various degrees of seasonal drought on tree growth periodicity. A range of periodic growth patterns observed in individual trees and tree communities subject to increasing seasonal

drought can be simulated by the model suggesting that casual interactions similar to those operating in the model are sufficient to determine growth periodicity in tropical trees and forests. Localización: Biblioteca OET: B. Publicación no.: 053 Nitrogen-15 and Oxygen-18 characteristics of Nitrous Oxide: a global perspective [Nitrógeno-15 y Oxígeno-18 características del óxido nitroso: una visión mundial] / Kim, K.R.; Craig, H. (Seoul National University. Department of Oceanography, Seoul 151-742, KS). In: Science (ISSN 0036-8075), no. 262, p. 1855-1857. 1993. The global budget of N-2O shows a significant imbalance between the known rate of destruction in the stratosphere and the estimated rates of natural and anthropogenic production in soils and the ocean. Measurements of the 15N/14N and 18O/1-6O ratios in two major tropospheric sources of N-2O, tropical rain forest soils and fertilized soils, show that soil N-2O from a tropical rain forest in Costa Rica and from sugar-cane fields in Maui is strongly depleted in both 15N and 18O relative to mean tropospheric N-2O. A major source of heavy N-2O, enriched in both 15N and 18O, must therefore be present to balance the light N-2O from soils. One such source is the back-mixing flux of N-2O from the stratosphere, which is enriched in 15N and 18O by photolysis and chemistry. However these return fluxes of 15N and 18O are so great that a large oceanic flux of N-2O is required to balance the heavy isotope-enriched stratospheric flux. All these effects will be reflected in climatically related isotopic variations in trapped N-2O in polar ice cores. Localización: Biblioteca OET: S1601. LS. Publicación no.: 054 Nitrous oxide emissions from tropical soils [Emisiones de óxido nitroso de suelos tropicales] / Nobre, A.D. (Instituto Nacional de Pesquisas, Avenida Andre Araujo, 2936, BR-69083000 Manaus, Amazonas, BR <E-mail: anobre27@yahoo.com>). Durham, NH: University of New Hampshire, 1994. 141 p. Dissertation, Ph.D, University of New Hampshire, Durham, NH (USA). (No abstract). Localización: Biblioteca OET: Tesis 191. Publicación no.: 055 Emissions of greenhouse gases from tropical deforestion and subsequent uses of the land [Emisiones de gases de invernadero por la deforestación tropical y usos posteriores de la tierra] / Dale, V.H. In: Sustainable agriculture and the environment in the humid tropics Washington, D.C: National Academy Press, 1993. p. 215-260. (No abstract). Localización: Biblioteca OET: 333.76150913 N277s. Publicación no.: 056 Epiphytes and climate change research in the Caribbean: A proposal [Investigaciones sobre epífitas y cambio climático en el caribe: Una propuesta] / Lugo, A.E.; Scatena, F.N. (Institute of Tropical Forestry, USDA Forest Service, Southern Forest Experiment Station, Call Box 25000, Río Piedras 00928-2500, PR <E-mail: alugo@upr1.upr.clu.edu>). In: Selbyana (ISSN 0361-185X), v. 13, p. 123-130. 1992. The purpose of this paper is to call attention to the importance of epiphytes in understanding how global atmospheric changes impact tropical forests. The Luquillo Experimental Forest (LEF), like other peaks in the Caribbean, intercepts at least five major global weather systems: (1) trade winds originating in the Azores; (2) tropical depressions and hurricanes originating in western Africa; (3) northern cold fronts originating in the polar regions of North America; and systems originating (4) in the Pacific and (5) the Amazon basin. Each of these "global airsheds" has a particular return frequency, associated temperature and climatic conditions, and different chemical conditions in rain and cloud water. Epiphytes are the organisms with the closest interactions with these systems because they absorb water and nutrients directly from the atmosphere and their metabolism responds to prevailing conditions associated with each airshed. In order to detect effects of global change on epiphyte communities, ir will be necessary to build a long-term quantitative record of ecological information of these organisms. In this paper, we review the information available for the LEF and outline our proposed program to measure ecosystems effects of global change via elpiphytic communities. Our focus will be on biomass accumulation, nutrient uptake, and hydrological fluxes. Localización: Biblioteca OET: S3068. LC. Biblioteca Luis D. Tinoco: 581S. Publicación no.: 057 Evidence of the Younger Dryas in Central America / Leyden, B.W. (University of South Florida. Department of Geology, Tampa, FL 33620, US). In: Quaternary Science Reviews (ISSN 0277-3791), v. 14, no.9, p.833-839. 1995. Three sites provide records that address whether the Younger Dryas was manifest in Central America. Marine records from Barbados and the Cariaco Basin an discussed, as well as possible climatic forcing mechanisms. Sequences from montane La Chonta Bog, Costa Rica, and lowland Lake Quexil, Guatemala, record a temperature decline of 1.5-2.5 degrees C dated between 11,070-10,400 C-14 years BP and ca. 12,000-10,300 C-14 years BP, respectively. The record from Lake La Yeguada, Panama, does not include cooling, although significant reorganization of local a communities occurred during the Younger Dryas chronozone. Colder tropical SSTs throughout deglaciation contributed to sub- regional climatic variation, more intense monsoonal activity, and cooler air temperatures. However, the temperature reversals are not associated with the coldest tropical SSTs which occurred during meltwater pulses. The temperature reversals appear to be a response to extra-tropical conditions, presumably in the North Atlantic, which suggests that Younger Dryas

cooling extended as far south as Costa Rica. In Panama, monsoonal conditions may have blocked cooler temperatures. Precipitation continued to increase throughout deglaciation due to strong forcing by seasonal solar insolation in Central America while desiccation events occurred to the north and south. Localización: Biblioteca OET: S5746. NBINA-5191. Publicación no.: 058 Sustainable development: A new challenge for Costa Rica [Desarrollo sostenible: Un nuevo reto para Costa Rica] / Figueres-Olsen, J.M. (Fundación Costa Rica para el Desarrollo Sostenible (Entebbe), Apartado Postal 557-2250, Tres Ríos de La Unión, CR <http://www.entebbe.com>). In: SAIS Review (ISSN 0036-0775), v. 16, no. 1, p. 187-202. 1996. The sustainable development policy being pursued by Costa Rica is outlined. It is based on strategic social investment; macroeconomic balance; environmental protection and the participation of society in decision making. Examples are presented to illustrate steps taken to establish a positive relationship between the natural environment and growing economic needs. These include: the establishment and management of designated conservation areas; greenhouse gas emission control programmes; biodiversity conservation and utilization projects; the development of ecotourism in national parks; increasing environmental education; macroeconomic restructuring to create an open and more competitive economic environment; the use of renewable energy technologies; the adoption of more environmentally friendly farming practices; the encouragement of more efficient resource use by industry; and participation by more of society in decision making through discussion fora. Localización: Biblioteca OET: S7799. Publicación no.: 059 Graphic correlation of marine deposits from the Central American isthmus: implications for late neogene paleoceanography [Correlación gráfica de los depósitos marinos del istmo centroamericano: implicaciones para la paleoceoneografía del Neogeno tardío] / Dowsett, H.F.; Cotton, M.A.; Jackson, B.C, (ed.).; Budd, A.F, (ed.).; Coates, A.G, (ed.). (University of Iowa. Department of Geoscience, Iowa City, IA 52242, US <E-mail: ann-budd@uiowa.edu> <E-mail: coatesj@hardynet.com>). In: Evolution and environment in tropical America Chicago, IL: The University of Chicago Press, 1996. p. 57-75. ISBN: 0-22-638944-8. Introduction: The Late Neogene stratigraphy in Panama and Costa Rica preserves an extensive record of the marine biologic and climatic changes associated with the rise and closure of the Central American Isthmus. Creating a high-resolution temporal framework, within which stratigraphic sections found on the isthmus can be interpreted, is fundamental to our understanding of the history and importance of these events. Ironically, the planktonic zonations that have been the basis for refined temporal frameworks over the past few decades are now the primary stumbling block for future paleoceanographic work in ocean margin settings because of the implicit assumption of synchrony of fossil first and last occurrences. In this chapter we point out the problems associated with these conventional methods of biochronology and discuss the advantages associated with graphic correlation (GC). We first describe the graphic correlation technique and summarize a GC model for the Late Neogene, and then apply it to specific sequences from the Caribbean coast of Panama. Localización: Biblioteca OET: 560.45098 E93e. Publicación no.: 060 Biotic and oceanographic response to the Pliocene closing of the Central American isthmus [Respuesta biótica y oceanográfica para el cierre del istmo centroamericano en el Plioceno] / Cronin, T.M.; Dowsett, H.F.; Jackson, B.C, (ed.).; Budd, A.F, (ed.).; Coates, A.G, (ed.). (University of Iowa. Department of Geoscience, Iowa City, IA 52242, US <E-mail: ann-budd@uiowa.edu> <E-mail: coatesj@hardynet.com>). In: Evolution and environment in tropical America Chicago, IL: The University of Chicago Press, 1996. p. 76-104. ISBN: 0-22-638944-8. Introduction: The formation of the Central American Isthmus (CAI) during the Late Neogene closed an ocean gateway that had been open since the Mesozoic and simultaneously joined two long-isolated land masses. It was a key event for tropical biotic evolution, allowing the interchange of terrestrial species between North and South America (Marshall 1988) and isolating Pacific and Atlantic/Caribbean marine organisms (Jones and Hasson 1985; Stehli and Webb 1985). The oceanographic and climatic effects of the closure of the isthmus have also been debated, in part because this event coincides with the initiation of major Northern Hemisphere glaciation and the amplification of Milankovitch climatic cycles about 2.5 Ma (Shackleton et al. 1984; Raymo et al. 1989). Berggren (1972) and Berggren and Hollister (1974) postulated, on the basis of early Deep Sea Drilling Project (DSDP) results, that isthmus closure may have had a profound effect on North Atlantic paleoceanography, and possibly on global climate, by diverting warm, saline water to high latitudes, causing Late Pliocene Northern Hemisphere ice build-up. Keigwin (1978, 1982) also suggested that as Pacific and Caribbean waters ceased to mix, significant changes in North Atlantic Ocean structure occurred, such as increased surface salinities in the Caribbean and the intensification of the Gulf Stream. Rind and Chandler (1991) argued, on the basis of a general circulation model, that relatively small changes in ocean heat flux, due to ocean circulation changes caused by isthmus closure, can substantially alter global climate. In this chapter we examine the role of the CAI during the Pliocene in affecting tropical and extratropical oceanic and biotic events. We present evidence indicating there was near closure of the isthmus to surface water around 3.0-2.8 Ma, and perhaps again at about 2.0 Ma, which had major effects on marine

paleobiogeography and altered North Atlantic Ocean circulation to cause periods of Northern Hemispheric warmth. We will attempt to show, through the study of marine ostracodes and planktonic foraminifers from the North Atlantic/Caribbean, that the formation of the CAT directly or indirectly (1) increased North Atlantic oceanic heat flux from low to high latitudes at 3 Ma and possibly again at 2 Ma; (2) led to oceanic thermal gradients less steep than those today, thereby decreasing provinciality of marine organisms; (3) increased surface salinities but did not decrease sea surface temperatures in the Caribbean region. Localización: Biblioteca OET: 560.45098 E93e. Publicación no.: 061 Interactions between populations and resources [Interacciones entre poblaciones y recursos] / Daily, G.C. (Stanford University. Department of Biological Sciences, Center for Conservation Biology, Stanford CA 94305-5020, US <E-mail: gdaily@stanford.edu>). Stanford, CA: Stanford University, 1992. 203 p. Dissertation, Ph.D, Stanford University, Stanford, CA (USA). This dissertation consists several unrelated projects, each dealing with the interactions between animal populations and their resources in evolutionary and community level contexts. Three of the projects focus on the behavior of natural populations and communities of non-human species, while the other two explore several dimensions of humanity's present population and resource predicament. The first chapter investigates the factors that determine the spatial distribution of adults in an insect population and relates these to the evolution of insect mating systems. Field experiments showed that population size, sex ratio, and certain habitat features interact to produce predictable distributions of individuals in a Colorado butterfly population. The second chapter describes subtle, indirect interactions in a keystone species complex comprised of a woodpecker, certain willow species, aspen trees, and a heartwood fungus. In a subalpine, Rocky Mountain ecosystem, the persistance of two swallow species depends upon and the abundances of numerous other vertebrates and invertebrates is enhanced by the cooccurrence of each element of the complex. The third chapter examines the influence of social dominance status upon foraging behavior in large, heterospecific assemblages of birds at fruiting trees in Costa Rica. Individuals of subordinate species were interrupted more, tended to have shorter feeding bouts (especially during periods of high activity), and spent a smaller fraction of their foraging bouts actually feeding than did dominant species. Several possible ramifications of social dominance hierarchies at the population and community levels are discussed. Chapter four describes the results of a stochastic simulation model of the effects of rapid climatic change on agriculture and the global human population. The model suggests that even favorable climatic changes may not prevent a several-fold increase in deaths (over past levels) if population growth outpaces food production by about 0.8 percent per annum or more. Finally, the fifth chapter outlines the current human population-environment situation and developes a framework for analysing the carrying capacity of the planet for Homo sapiens. Biophysical and social dimensions of sustainability and carrying capacity are discussed. Localización: Non available. Publicación no.: 062 Nitrogen cycling in shaded and unshaded coffee plantations in the Central Valley of Costa Rica [Reciclaje de nitrógeno en cafetales sombreados y sin sombra en el Valle Central de Costa Rica] / Babbar-Amighetti, L.I. (Organix S.A., calle 3, ave. 3 y 5, Edificio Ferencz 5to piso, San José, CR <E-mail: liana@racsa.co.cr>). Ann Arbor, MI: The University of Michigan, 1993. 86 p. Dissertation, Ph.D, The University of Michigan, Ann Arbor, MI (USA). Coffee (Coffee arabica L.) management in Costa Rica is changing from plantations associated with shade trees to monocultures; both of which receive large additions of N through fertilization. Understanding patterns and processes of N cycling within coffee agro-ecosystems could lead to the development of management practices that maintain productivity while minimizing environmental damage. My study investigated the N dynamics in paired shaded and unshaded coffee plantations in the Central Valley, all fertilized with about 300 kg N ha(-1) y((-1). I quantified net N mineralization and nitrification, and microbial biomass N. Mean daily mineralization rates did not significantly differ between treatments (shaded = 38.9 mg N m² d(-1); unshaded = 29.4 mg N m² d(-1). However, net mineralization was significantly higher in shaded plantations (148 kg N ha(-1) y(-1) than in the unshaded (111 kg N ha(-1) y(-1). Small pools of microbial biomass N (shaded = 0.48 g m²; unshaded = 0.46 g m² suggested that N retention primarily occurs through plant uptake. I also investigated NO3- leaching and factors controlling denitrification, such as NO3-, C, and O2 availability. Annual NO3- leaching losses were 3 times greater in unshaded plantations (238 kg NO3-N ha(-1) y(-1) than those in the shaded (87 kg ha(-1) y(-1). In contrast, mean denitrification rates in shaded plantations were 60% higher (6774 µg N2O-N g(-1) d(-1) than those in unshaded plantations (4340 µg N2O-N g(-1) d(-1). Carbon additions (C6H12O6) elicited nearly a three-fold increase (-C = 2985 ug N2O-N g(-1) d(-1) to +C = 8396 µg N2O-N g(-1) d(-1) in both agroecosystems. Anaerobic conditions increased denitrification to a lesser extent (+O2 = 4331 µg N2O-N g(-1) d(-1); -O2 = 6656 µg N2O-N g(-1) d(-1). In both plantation types, potential N loss via denitrification was small compared to NO3- leaching. My results indicate that large N-fertilizer additions are unwarranted measures to sustain high coffee yields. In light of the large N loss through leaching, the presence of shade trees is an important factor reducing N loss. Localización: Non available.

Publicación no.: 063 Almacenamiento y fijación de carbono en ecosistemas forestales / Alfaro-Murillo, M. (Cámara Costarricense Forestal, Apdo. 1135-1002, San José, CR <E-mail: malfarom@racsa.co.cr>). In: Revista Forestal Centroamericana (ISSN 1021-0164), no. 19, p. 9-12. 1997. Hasta hace pocos años nadie se detenía a analizar el valor monetario de la provisión de agua, de la protección de la biodiversidad, la recreación o la fijación de carbono, pues se creía que el bosque de por sí tendría que brindar éstos y otros servicios. La alta deforestación de los bosques tropicales, ha puesto de manifiesto y enfrentado al ser humano a reconocer la gran cantidad de bienes y servicios que están desapareciendo, perjudicando no sólo a los pobladores que viven en los alrededores del bosque, sino a los habitantes de las ciudades. Una de las mayores consecuencias de la tala indiscriminada de los bosques es el efecto de invernadero, o sea, la concentración de gases en la atmósfera, que obstaculizan la salida de una parte de la radiación que entra a ésta. La autora de este artículo comparte sus ideas y algunos elementos que informan al lector sobre el efecto de invernadero y la opción que significa la fijación de carbono para países desarrollados, y en vías de desarrollo, pues los primeros pagarán por un servicio que prestan los bosques y los segundos recibirán incentivos económicos por protegerlos y conservarlos. Localización: Biblioteca OET: R. NBINA-7380. Publicación no.: 064 Sostenibilidad en el uso del agua en América Latina / Radulovich, R. (Universidad de Costa Rica. Escuela de Ingeniería Agrícola y AGROPLAN S.A., Apdo. 1567-1000, San José, CR <E-mail: rad@ns.fing.ucr.ac.cr>). In: Revista Forestal Centroamericana (ISSN 1021-0164), no. 18, p. 13-17. 1997. El agua, otrora un problema mayor sólo en zonas áridas, se ha convertido rápidamente en una limitante generalizada en sectores urbanos y rurales de las zonas húmedas de América Latina, por lo menos en lo que respecta a calidad. A pesar de que la región latinoamericana es la mejor provista del mundo en cantidad de agua per capita (Reiff 1990; FAO 1993), ésta se encuentra en peculiar distribución espacio-temporal y, debido a su voluminosidad, movilidad y requerimientos de calidad, es costoso manejarla. El crecimiento de la población, los fuertes incrementos en consumo per capita (riego, industria, estándares de vida), la contaminación de fuentes y la alteración de los ciclos hidrológicos locales, incluyendo deforestación, mal manejo de cuencas y disminución de los niveles freáticos, repercuten en que la disponibilidad de agua sea menor, en donde más se ocupa. Lo anterior no considera situaciones climáticas a mayor escala que se están dando de forma imprevisible, como por ejemplo: el efecto invernadero y el fenómeno del Niño. Este escenario se agrava debido a que históricamente se ha utilizado el agua de más fácil acceso y las nuevas fuentes u opciones generalmente traen consigo un costo mayor. Localización: Biblioteca OET: R. Publicación no.: 065 Changes in the general circulation and its influence on precipitation trends in Central America [Cambios en la circulación general y su influencia en las tendencias de la precipitación en Centroamérica] / Brenes-Vargas, A.; Saborío-Trejos, V.F. (Instituto Meteorológico Nacional. Departamento de Información, San José, CR). In: Ambio (ISSN 0044-7447), v. 23, no. 1, p. 87-90. 1994. A trend analysis of 81 series of precipitation data from the last 30 years (1960-1990) is presented. These series are from meteorological stations distributed throughout Costa Rica on the leeward and windward sides, both of which are affected by the trade-wind regime. Analysis of these data shows that over 75% of Costa Rica has experienced a precipitation decrease during this period. Most of the areas affected by this tred are located along the country from northwest to southeast. However, on the windward side there has been a positive trend in precipitation, suggesting a strengthened trade-wind regime. An analysis of data on Atlantic hurricane trajectories since 1900 shows that the the total number of hurricanes has increased, but there has been a reduction in the number crossing the Caribbean Basin. The passage of tropical cyclones in the Caribbean Basin accounts for around 70% of total precipitation in the Pacific region of Central America. These countries economies are highly dependent on agriculture, and on water resources for energy generation; thus changes in hurricane patterns and associated rainfall could have important economic consequences. Localización: Biblioteca OET: S8043. LC. Publicación no.: 066 Modelling land use dynamics by integrating biophysical and human dimensions (CLUE) Costa Rica 1973-1984 [Modelaje de la dinámica del uso de la tierra mediante la integración de las dimensiones biofísicas y humanas (CLUE) Costa Rica 1973-1984] / Veldkamp, A.; Fresco, L.O.; Zwerver, S. (ed.); Rompaey, R.A.V. (ed.); Kok, M.T. (ed.); Berk, M.M, (ed.). (Wageningen Agricultural University. Department of Environmental Sciences, Laboratory of Soil Science and Geology, P.O. Box 37, 6700 AA Wageningen, NL <E-mail: tom.veldkamp@agro.wau.nl> <E-mail: louise.fresco@agro.wau.nl>). In: Climate change research: evaluation and policy implications Amsterdam: Elsevier Science Publishers, 1995. p. 1413-1416. As a pilot study potential biophysical and human land use drivers in Costa Rica evaluated using multi-variate statistical methods in a nested scale analysis. The reconstructed land use drivers and their quantified effects on land use were applied within a dynamic framework CLUE (Conversion of Land Use and its Effects) to

model land use dynamics in Costa Rica from 1973 to 1984. Our pilot study demonstrates that its dynamics can be satisfactorily modelled as functions of biophysical and human drivers. Localización: Biblioteca OET: S6526. Publicación no.: 067 Gradient analysis of biomass in Costa Rica and a first estimate of total emissions of greenhouse gases from biomass burning / Helmer, E.H.; Brown, S. (USDA Forest Service. International Institute of Tropical Forestry, P.O. Box 25000, Río Piedras, PR 00928-5000, PR <E-mail: ehelmer/iitf@fs.fed.us>). , 1996. 25 p. Past efforts to estimate greenhouse gases (GHG) emissions from biomass burning generally have relied on global or regional data bases. Although the Central American country of Costa Rica is small in area (50 060 km²), it has a much better database than most regions and thereby provides an excellent "microcosm" for an analysis of GHG emissions by forest type. It has, for example, several forest formations for which data on forest structure and areas deforested are available. Between 1950 and 1984, the rate of deforestation in Costa Rica was one of the highest in the world at about 3.9% per year. Our objectives in this chapter are: 1) estimate biomass of stands undisturbed by human activity (as far as we can tell) as a function of environmental gradients in Costa Rica, and 2) estimate the release of GHGs to the atmosphere from knowing the spatial variation in deforestation rates in forests developed under differing climatic conditions. We estimate emissions simply by assuming 100% of aboveground biomass is burned eventually, an assumption recommended by the Intergovernmental Panel on Climate Change and Organization for Economic Cooperation and Development (IPCC/OECD) methodology for inventory of GHG. Localización: Biblioteca Centro Científico Tropical: C4.30. Publicación no.: 068 National inventory of sources and sinks of greenhouse gases in Costa Rica [Inventario nacional de fuentes y sumideros de gases de invernadero en Costa Rica] / Ministry of Environment and Energy. National Meteorological Institute, P.O. Box 7-3350, 1000 San José, CR. San José: Ministry of Environment and Energy / National Meteorological Institute, 1996. 51 p. Earth's atmosphere has been in constant change through time but nevertheless the faster pace of more recent times has been alarming: the atmosphere's composition has changed with and acceleration unknown in any other stage of human history. The sustained increase of greenhouse gases in the athmosphere, caused by human activities, is the main cause of alarm since we know with certitude that the affected radiative balance of the atmosphere will produce global climate changes. In June, 1992, in Rio de Janeiro, Brazil, 155 countries signed a Framework Convention on Climate Change, which main objective was to attain the stabilization of greenhouse effect gases concentrations in the atmosphere, at such a level to stop the dangerous anthropogenic interferences in the climate system. The signatory countries at the Convention got involved, among other objectives, in the perfomance of national inventories on the emissions of greenhouse gases and in the implementation of national programs aiming to provide measures towards the mitigation of climatic change. Costa Rica ratified the Convention on June 13, 1994 and as part of its compromise and as part of the National Program on Climate Change, the first inventory of emissions of greenhouse gases in the country was implemented. In order to make the results of the inventory able to be compared with those from other countries, it was carried out by following the "Guidelines for the Elaboration of National Inventories on Greenhouse Gases" as proposed by the IPCC/OECD (1994) and the reference year was 1990. The National Inventory on Emissions of Greenhouse Gases for Costa Rica, was elaborated as part of a larger project: "Country Studies, by Sources and Sinks of Greenhouse Gases Emissions". (GF/4102-92-42), implemented by the Climate Unit of the United Nations Program for the Environment (UNEP) and sponsored by the Global Environmental Fund (GEP). The evaluation was charged to the National Meteorological Institute, which in turn coordinated a team of professionals and technicians from various institutions. The inventory included six gases: carbon dioxide (CO2), carbon monoxide (CO), nitrous oxide (N2O), methane (CH4), nitrogen oxides (NOx), and non-methane volatile organic compounds (NMVOC), in five economic activity areas: Energy, Industrial Processes, Agriculture, Land Use Change and Forestry and Waste Management. The total emissions for greenhouse gases in Costa Rica for the year 1990 were estimated to be 4404.4 Gg, which is equivalent to 4 404 400 tons. To this total, the energy sector contributed with 2665.6 Gg (2 665 600 tons), Industrial Processes with 367.9 Gg (367 900 tons), Agriculture with 139.81 Gg (139 810 tons), Land Use Change and Forestry 1210.55 Gg (1 210 550 tons) and Waste Management with 20.5 Gg (20 500 tons). Localización: Biblioteca OET: AD 113. Publicación no.: 069 Clinton urges action on global warming [Clinton urge se tomen acciones en contra del calentamiento global] / Bennet, J. In: The New York Times (ISSN 0362-4331), May 10, 1997, Sec. A, p. 6, col. 41997. Drenched by a misting rain, President Clinton stood before the soaring forest here today to issue a hedged warning about global climate change and to declare that the world has much to learn from Costa Rica's environmental stewardship. While calling for reduction of greenhouse gases, Mr. Clinton stopped short of an explicit declaration that pollution was causing the global climate to change for the worse. "There is some doubt about what increased greenhouse gas emissions are doing to the climate," Mr. Clinton said, "but no one doubts that they'rechanging the climate, and no one doubts that the potential consequences can be very profound and severe." In keeping with the relentless solicitude he has shown his hosts on his first trip to

Latin America, Mr. Clinton did not talk about the environment in smog-bound Mexico City earlier this week. Instead, he waited until reaching Costa Rica, where one quarter of the land, he noted today, is protected by the Government. Mr. Clinton flew on to Barbados later this afternoon, for a summit meeting of Caribbean nations there on Saturday. Localización: Biblioteca OET: NBINA-3290. Publicación no.: 070 Potential impacts of climatic change on the productive capacity of Costa Rican forests: a case study [Impactos potenciales del cambio climático en la capacidad productiva de los bosques costarricenses: estudio de caso] / Tosi-Olin, J.A., Jr.; Watson-Céspedes, V.; Echeverría-Bonilla, J. (Centro Científico Tropical, P.O. Box 8-3870, 1000 San José, CR <E-mail: jtosi@cct.or.cr> <E-mail: vwatson@cct.or.cr> <E-mail: economia@cct.or.cr>). San José: Tropical Science Center, 1992. 79 p. In the context of present-day scientific concern with predicted climatic changes resulting from the current untoward generation and release of CO2 and other "greenhouse" gases, the Department of Sciences of the University of Virginia (UV) is undertaking a study of the possible effects of global warming on the Earth's forests. As an adjunct to the main UV study, larger-scale, regional and country level case studies have been included for corroboration and to facilitate analysis of the economic, social, and policy consequences of eventual global warming, should it occur. Costa Rica and Nicaragua have been selected for detailed analyses in the Tropical, Central American-Caribbean region. The Tropical Science Center, a not-for-profit Costa Rican research association was subcontracted by the University of Virginia to undertake detailed modelling and preliminary analyses of the implications of two potential climatic change scenarios on the forests of Costa Rica. Localización: Biblioteca Centro Científico Tropical. Publicación no.: 071 General equilibrium modelling of trade and the environment [Modelaje del equilibrio general de comercio y el ambiente] / Beghin, J.; Dessus, S.; Roland-Hurst, D.; van der Mensbrugghe, D. (<E-mail: beghin@iastate.edu> ). Paris: OECD Development Centre, 1996. 66 p. (Technical Papers OECD Development Centre; no. 116). The complete technical specification of a computable general equilibrium model is presented for six country case studies of the OECD Development Centre's programme on 'Sustainable Development: environment, resource use, technology and trade'. The six countries are Mexico, Costa Rica and Chile in Latin America, China, Indonesia and Vietnam in the Asia Pacific region. The model attempts to capture some of the key features relating to environmental emissions. These features include: linking emissions to the consumption of polluting inputs; including emissions generated by final demand consumption; integrating substitutability between polluting and non-polluting inputs; capturing important dynamic effects such as capital accumulation, population growth, productivity and technological improvements and vintage capital; and the impact of emissions taxes to limit the level of pollution. The first section provides an overview of the model and this is followed by a complete description of each block of the model. The third section provides a list of the differences of the data and model specification across country implementation. The final section presents concluding remarks. Localización: Non available. Publicación no.: 072 Greenhouse gas emission inventories: interim results from the U.S. Country Studies Program [Inventarios de emisiones de gases de efecto invernadero resultados provisionales del Programa de Estudios de Países de los EE.UU] / Braatz, B.V, (ed.).; Jallow, B.P, (ed.).; Molnar, S, (ed.).; Murdiyarso, D, (ed.).; Perdomo, M, (ed.).; Fitzgerald, J.F. (ICF Incorporated, Washington DC, US). In: Environmental Science and Technology Library 9 Dordrecht: Kluwer Academic Publishers, 1996. 387 p. ISBN: 0-7923-4142-2. Parties to the United Nations Framework Convention on Climate Change are required to conduct national inventories of anthropogenic greenhouse gas emissions and sinks using comparable methodologies. This book presents the results of preliminary national inventories prepared by countries participating in the US Country Studies Program which was set up to provide financial and technical assistance to 56 developing and transition countries for conducting national inventories. The gases included in the inventories are carbon dioxide, methane, nitrous oxide, carbon monoxide, nitrogen oxides, and non-methane volatile organic compounds. Preliminary national inventories are presented for the following countries: Ivory Coast, Gambia, Nigeria, Zimbabwe, Bangladesh, China, Mongolia, Philippines, Thailand, Bulgaria, Czech Republic, Estonia, Hungary, Kazakhstan, Slovakia, Ukraine, Bolivia, Costa Rica, Peru, and Venezuela. Localización: Non available. Publicación no.: 073 Fijación de carbono y diversidad biológica en el agroecosistema cafetero [Carbon fixation and biological diversity in the coffee agroecosystem] / Fournier-Origgi, L.A. (Universidad de Costa Rica. Escuela de Biología, San José, CR). In: Boletín de Promecafé (ISSN 1010-1527), no. 71, p. 7-13. 1996. Three coffee production systems are considered in terms of their contribution to maintaining biological diversity: (a) an agroforestry system in which coffee is grown with various timber and fruit shade trees, (b) a coffee plantation with shade trees (typically Inga and Erythrina spp.), and (c) a coffee plantation exposed

to the sun with intensive labour and fertilizer inputs. System (b) is considered to be the best option in agroecological and economic terms; this system has the highest potential level of CO2 fixation. Localización: Biblioteca OET: S4896. Biblioteca del MAG: Hb. Publicación no.: 074 Tropical land use change and soil emissions of nitrogen oxides [Cambio en el uso del suelo tropical y las emisiones de óxidos nitrosos del suelo] / Erickson, H.E.; Keller, M. (Universidad Metropolitana. Departamento de Ciencias y Tecnología, P.O.B. 21150, San Juan, PR 00928, US <E-mail: um_herickson@suagm.edu> <E-mail: michael.keller@unh.edu>). In: Soil Use and Management (ISSN 0266-0032), v. 13, Suppl. no. 4, p. 278-287. 1997. Increases in the emissions of globally important nitrogen (N) oxide gases have coincided with significant changes in land use in the tropics, Clearing of tropical forests and savannas for agriculture currently represents the most extensive alteration of land cover on the planet. Over the last several decades, N fertilizer use has increased globally and in China and the developing world, use has recently surpassed that in the developed world. The potential contribution of land-use change in the tropics to the increase in N oxides is great, yet only a few studies have measured N oxide emissions after tropical land conversion. Our summary of available research shows some conversions to pastures and a few management practices, especially those using N fertilizers, increase emissions beyond those found in undisturbed ecosystems. However, not all studies show unequivocal increases in emissions. Accordingly we call for a mechanistic understanding of the processes controlling trace gas fluxes to adequately predict under what conditions increased emissions may occur. More measurements are needed to build and test models that may improve management of N fertilizer use in tropical agricultural systems, Given the expected expansion of agriculture and increased use of N fertilizers in the tropics, increased emissions of N oxides from the tropics are likely. Localización: Biblioteca OET: S3382. Publicación no.: 075 A global inventory of nitric oxide emissions from soils [Inventario global de emisiones de óxido nítrico de suelos] / Davidson, E.A.; Kingerlee, W. (The Woods Hole Research Center, POB 296, Woods Hole, MA 02543-0296, US <E-mail: edavidson@whrc.org>). In: Nutrient Cycling in Agroecosystems (ISSN 1385-1314), v. 48, no. 1-2, p. 37-50. 1997. Over 60 published papers reporting field measurements of emissions of nitric oxide (NO) from soil are reviewed, and over 100 annual estimates of NO emissions were made for various types of ecosystems, including agricultural fields. These data were stratified by biome and the mean of each stratum was multiplied by an estimate of the biome area. A few strata were identified as clearly having low NO emissions: montane forests, swamps and marshes, tundra, and temperate forests that are not heavily affected by N deposition. The largest emissions were observed in tropical savanna/woodland, chaparral, and cultivated agriculture, but variation in NO emissions within these strata was also large. Although the stratification scheme fails to partition this within-stratum variation, it does clearly identify these biomes as globally important sources of NO and as areas where more research is needed to investigate within-biome variation in NO emissions. It is too early to tell whether differences in NO emissions between temperate and tropical agriculture are significant, but it is clear that agriculture is an important source of NO and that management practices affect NO emissions. The best current estimate of the global soil source of NO is 21 Tg N yr(-1). Adsorption of NO, onto plant canopy surfaces may reduce emissions to the atmosphere to as low as 13 Tg N yr(-1), although the absorption effect is probably smaller than this. An error term for the global estimate is difficult to determine, but it is at least +/-4 and perhaps as large at +/-10 Tg N yr(-1). Hence, only modest progress has been made in narrowing uncertainties in the estimate of the global soil source of NO, although some published lower estimates appear unlikely. This inventory reconfirms that the soil source of NO is similar in magnitude to fossil fuel emissions of NOx. Further narrowing of the uncertainty of the estimate of global soil NO emissions will require more sophisticated and carefully chosen stratification schemes to address variation within biomes based on soil fertility, soil texture, climate, and management and will require linking this type of inventory and stratification with mechanistic models. Localización: Biblioteca OET: S5911. NBINA-5185. Publicación no.: 076 Impact of human activity on NO soil fluxes [Impacto de la actividad humana en los flujos de óxido nítrico] / Sanhueza, E. (Instituto Venezolano de Investigaciones Científicas (IVIC). Laboratorio de Química Atmosférica, Apartado Postal 21827, Caracas 1020-A, VE <E-mail: esanhuez@quimica.ivic.ve>). In: Nutrient Cycling in Agroecosystems (ISSN 1385-1314), v. 48, no. 1/2, p. 61-68. 1997. Changes in land use driven by the increasing demand of food are affecting the fluxes of trace gases to the atmosphere. The more important human activities that affect NO soil fluxes are: deforestation, intensification of agricultural practices, and biomass burning. In this review emphasis is given to identifying the physicochemical and biological processes involved in the changes, and no attempt to quantify their contribution to global or regional NO budgets is made. Conversion of tropical forest to pasture is occurring very rapidly. An increase of the NO emission is observed immediately after deforestation (1-5 years) followed by a significant decrease (below forest levels) in old pastures and secondary successional forests. It seems that deforested tropical areas produce, in the long term, less NO than primary forests. The observed changes are not completely understood, but are most likely driven by the availability of exchangeable nitrogen and the bacteria' population. Soil plowing and fertilization are important factors that affect NO

fluxes in agricultural soils. Plowing increases soil porosity and aeration, as well increasing the surface area that is exposed to the atmosphere. These physical changes increase the production of soil nitrate, and the escape efficiency of NO from the soil, enhancing NO fluxes. The emission of NO from fertilized soils depends on many variables: type of fertilizer (i.e. ammonium, nitrate), the structure of the soil microbial community (e.g., populations of nitrifiers and denitrifiers), meteorogical conditions (e.g. soil moisture and temperature), and soil management(e.g. plowing). A combination of these factors should explain the large range reported for the fraction of N-fertilizer that is emitted as NO to the atmosphere. Measurements made in diverse ecosystems show that vegetation burning enhances NO soil emissions. However, it seems that different processes, which are not well understood, occur at the various sites; e.g., in the tropical savannah, enhanced emissions, from dry soils, are observed immediately after burning, whereas in Californian chaparral burned dry soils emit on average less than the unburned plots, and the fluxes only increase after soil wetting. Changes in the physical conditions of the soil surface and N availability are the most likely factors that explain the increased fluxes. Localización: Biblioteca OET: S5720. NBINA-5186. Publicación no.: 077 Fertilizer-induced nitric oxide emissions from agricultural soils [Emisiones de óxido nítrico inducidas por los fertilizantes de suelos agrícolas] / Veldkamp, E.; Keller, M. (Universität Göttingen. Institute of Soil Science, Büsgenweg 2, D-37077, DE <E-mail: eveldka@gwdg.de> <E-mail: michael.keller@unh.edu>). In: Nutrient Cycling in Agroecosystems (ISSN 1385-1314), v. 48, no. 1-2, p. 69-77. 1997. We summarize and evaluate 23 studies of the effect of fertilizer use on nitric oxide (NO) emission from agricultural soils. To quantify this effect we selected only field-scale studies with duration of at least one complete growing season and excluded studies with a legume as the principle crop. Only 6 studies met the established criteria, resulting in a total of 12 observations of soil/crop/fertilizer combinations, all in temperate areas. For these studies, the amount of NO emitted was linearly related to the amount of fertilizer applied (R² = 0.64) and about 0.5% of applied nitrogen was emitted as NO during the crop growing season. The available data are too limited to separate the effects of fertilizer type, soil type, or crop management. Localización: Biblioteca OET: S5242. Publicación no.: 078 Vienna Convention for the protection of the ozone layer: the Ozone Meeting in Costa Rica [Convención de Viena para la protección de la capa de ozono: La Reunión del Ozono en Costa Rica] / Karlaganis, G. (Swiss Agency for the Environment. Forests, Snow & Landscape Substances, Soil & Biotechnology Division, CH-3003 Bern, CH). In: Environmental Science and Pollution Research (ISSN 0944-1344), v. 4, no. 2, p. A 7-A 8. 1997. Localización: Non available. Publicación no.: 079 Banks, debt, and development / Umaña-Quesada, A. (Instituto Centroamericano de Administración de Empresas (INCAE), Barrio San José de Alajuela, CR). In: International Environmental Affairs (ISSN 1041-4665), v. 2, no. 2, p. 140-149. 1990. During the last few decades, humanity has become increasingly aware of our growing impact on the biosphere. Economic growth, industrialization, scientific and technological change and rapid increases in population have all contributed to environmental deterioration worldwide. The variety of threats to the earth's metabolism and its life-support systems are now well known and will be considered in detail during this conference. Perhaps the most serious of all these threats is the direct assault against life taking place in the tropical forests, which are located almost exclusively in developing countries. Within these forests live nearly two-thirds of all the plants and animals which share the planet with us. Nevertheless, each second that passes, the equivalent of an entire football field of tropical forest disappears, and with it, all the organisms that live in these ecosystems. We are extinguishing life on earth at a rate thousands of times greater than in any previous period during the evolution of life. The fate of the tropical forests will not be decided in the 21st century, but rather in the next decade, and with them may disappear a considerable component of the planet's biodiversity. Economic pressures are forcing rural populations in tropical countries onto a path of destructive short-term exploitation of precious timber species. Such exploitation is expanding ecological destruction, increasing pressures for climatic change, and limiting the development options of future generations. In most cases, however, there is still hope to redirect the development path toward a sustainable course; and we presented with a unique opportunity to reverse the destructive trends of the past. Appropriate economic incentives to tropical developing countries could significantly reduce deforestation and support a massive biomas buildup on a global scale. In addition to its positive influence on rural development and poverty in developing countries, such a program of re-greening the planet is increasingly recognized as the most effective way to curtail the potential impact of global climatic change. These economic incentives to tropical countries are critical to implement any strategy, and the analysis of present economic criteria with respect to environmental resources is a necessary first step. Localización: Biblioteca OET: I. Publicación no.: 080 Nitrogen oxide emissions from a banana plantation in the humid tropics [Emisiones de óxido de nitrógeno de una plantación bananera en los trópicos húmedos] / Veldkamp, E.;

Keller, M. (Universität Göttingen. Institute of Soil Sciences & Forest Nutritrion; Busgenweg 2, D-37077 Göttingen, DE <E-mail: eveldka@gwdg.de> <E-mail: michael.keller@unh.edu>). In: Journal of Geophysical Research: Atmosphere (ISSN 0148-0227), v. 102, no. D13, p. 15889-15898. 1997. Use of nitrogen fertilizer is thought to contribute significantly to the increase of atmospheric nitrous oxide (N2O) and nitric oxide (NO). While the current increase of fertilizer use is concentrated in tropical areas, nearly all studies of nitrogen oxide emissions have been conducted in agricultural systems in temperate areas. We measured N2O and NO fluxed from a fertilized banana plantation in the humid tropics of Costa Rica, where 360 kg Nha-1 yr-1 is applied. Using chamber techniques, we sampled an Andisol and an Inceptisol on a monthly basis. Twice on each soil type, we sampled intensively in time following fertilizer applications. There is a strong spatial and temporal dependence of nitrogen oxide emissions on place and time of fertilizer application. We find greater mean N2O and NO emissions fron the Andisol (31.4 ng N2O-N cm-2h-1 and 55.6 ng No-N cm-2h-1) than from the Inceptisol (9.3 ng N2O-N cm-2h-1 and 41.1 ng NO-N cm-2h-1) under the plants where fertilizer is typically applied. The percentages of applied fertilizer -N that are converted into nitrogen oxide ("yield") are between 1.26 and 2.91% for N2O and between 5.09 and 5.66% for NO depending on soil type. We consistently calculate higher nitrogen oxide yields based on intensive sampling versus monthly sampling. Temporal variation in nitrogen oxide emissions probably causes monthly sampling to underestimate mean annual fluxes. Our results suggest that in some tropical systems a higher percentage of applied nitrogen may be lost in gaseous from than in temperate agriculture. Current global estimates of N2O and NO sources from tropical agriculture are based on information from temperate areas and may cause an understimate of the contribution of tropical agriculture to the budgets of these trace gases. Localización: Biblioteca OET: S3253. Publicación no.: 081 Cambios del uso de la tierra e intercambios de gases atmosféricos en la región tropical húmeda: un estado en la zona atlántica de Costa Rica / Keller, M. (U.S. Department of Forest Service. International Institute of Tropical Forestry, Río Piedras, PR 00928-5000, US <E-mail: michael.keller@unh.edu>). San José: Organización para Estudios Tropicales, s.f. La deforestación en la región tropical húmeda es frecuentemente seguida por explotación de los terrenos deforestados para cultivos o pastizales. Estos sistemas de manejo causan cambios profundos en las propiedades químicas y físicas de los suelos. Como parte de la investigación de la OET en la Zona Atlántica de Costa Rica, se ha estudiado el intercambio entre los suelos y la atmósfera de ciertos gases: óxido nitroso (N2O), óxido nítrico (NO) y metano (CH4). El N2O) y el CH4, juegan un papel importante en el efecto de invernadero, mientras que el NO participa en las reacciones atmosféricas que producen ozono (O3) en la troposfera. Durante los últimos 3 años, se han analizado los intercambios suelo-atmósfera de N2O, NO y CH4 en sitios bajo distintos sistemas de manejo. Los sitios investigados incluyeron bosques maduros y jóvenes, potreros manejados y pastizales abandonados. Entre los sitios de potreros, se estudió varios con un historial distinto. Todos estos potreros fueron sembrados después de las talas de bosques maduros, con tiempos después de la tala de 2 hasta 25 años. Actualmente se inician investigaciones en terrenos de cultivos. La explotación de terrenos deforestados como potreros causa una inversión en la dirección del intercambio de CH4 entre los suelos y la atmósfera. Los suelos del bosques consumen 446 mg CH4/m²/año mientras que suelos de potreros producen 236 mg CH4/m²/año. Después de la deforestación la densidad aparente de los suelos aumenta rápidamente desde 0,65 hasta 0,80 g/cm3. Este aumento resulta de la presión del pisoteo del ganado lo que causa problemas de drenaje y una restricción de la difusión de gases. Ambos factores limitan el consumo aeróbico de CH4 y provocan la producción anaeróbica de CH4. Anualmente, los suelos del bosque emiten aproximadamente 5-10 ng de N/cm²/h de N2O. Las emisiones de N2O por los potreros jóvenes (2-10 años) exceden las emisiones de bosque por un factor 5 a 8 mientras que las emisiones de potreros antiguos son significativamente menores (½ a 1/3). Estos resultados coinciden con los de una investigación cerca de Manaus, Brasil en Oxisoles, donde se observa que el suelo de un potrero joven de 3 años emitió 3 veces más N2O que el suelo de un bosque adyacente. La emisión de NO por los suelos sigue un patrón similar al N2O. Así, las emisiones de potreros jóvenes excede las de los potreros antiguos aunque no hay ninguna diferencia significativa entre las emisiones de los potreros jóvenes (12 años) y las del bosque. El promedio anual de las emisiones de NO de los suelos del bosque excede los promedios de los potreros antiguos (12 años). Aunque la emisión de NO de los suelos del bosque fuese parecida a la de los suelos de los potreros jóvenes, probablemente los potreros emitirían más NO a la atmósfera porque tienen lugar reacciones que consumen NO en las copas más densas del bosque. Los procesos microbiológicos de nitrificación y desnitrificaciónproducen N2O y NO en los suelos. Por lo tanto, la rapidez del ciclo de N controla las emisiones de dichos gases. Se observó una correlación significativa entre los promedios por cada sitio de las emisiones de N2O y NO (r²=0,73; P0001). En los suelos de los potreros jóvenes, la descomposición rápida del material orgánico, originalmente del bosque, proporciona nutrimentos a los microorganismos nitrificadores y denitrificadores. El abono de cultivos con fertilizantes nitrogenados cambia drásticamente las emisiones de óxidos de N. Pocos días después de abonar con nitrato de amonio (33 kg-N/ha) se observó emisiones mayores a 250 ng N/cm²/h), y estos niveles altos se mantienen por un período que se extiende hasta 4 semanas después de la fertilización. La respuesta para NO fue menor (magnitud y duración). Estos resultados preliminares indican que el rendimiento de N2O de fertilizantes nitrogenados en suelos arcillosos en la zona tropical húmeda podría ser mucho mayor que en las condiciones

comunes en las zonas templadas. Estos resultados, sugieren que ambos, el manejo actual y la historia de manejo de un terreno, afectan el intercambio de gases atmosféricos. Así pues, el historial de manejo de los ecosistemas parece afectar críticamente y por largo plazo su estructura y funcionamiento, por lo que es necesario tomar esto en cuenta en estudios posteriores. El caso específico de la región estudiada sugiere que el balance global de N2O y otros gases podría ser drásticamente alterado si la rapidez de la deforestación tropical fuera controlada. Localización: Biblioteca OET: A. Publicación no.: 082 Forests and insects [Bosques e insectos] / Watt, A.D, (ed.).; Stork, N.E, (ed.).; Hunter, M.D. (Institute of Terrestrial Ecology. Edinburgh Research Station GB). , 406 p London: Chapman & Hall, 1997. ISBN: 0-412-79110-2. Most of the 22 chapters, by various authors, in this book were presented as papers during the 18th Symposium of the Royal Entomological Society in London, September 1995. They include: adaptations of phytophagous insects to life on trees, with particular reference to aphids; host specificity in forest insects; population dynamics of forest insects (are they governed by single or multiple factors?); the impact of parasitoids and predators on forest insect populations; herbivore-induced responses in trees; internal vs. external explanations; incorporating variation in plant chemistry into a spatially explicit ecology of phytophagous insects; forest structure and the spatial pattern of parasitoid attack; termites [Isoptera] as mediators of carbon fluxes in tropical forest (budgets for carbon dioxide and methane emissions); herbivory in forests (from centimetres to megametres); comparative analysis of patterns of invasion and spread of related lymantriids; threats to forestry by insect pests in Europe; forest pests in the tropics, current status and future threats; the impacts of climate change and pollution on forest pests; patterns of use of Saturniidae and Sphingidae by ichneumonid parasitoids in Costa Rican dry forest; impact of forest loss and regeneration on insect abundance and diversity; Coleoptera abundance and diversity in a boreal mixed-wood forest; overview of invertebrate responses to forest fragmentation; impact of forest and woodland structure on insect abundance and diversity; Ficus, a resource for arthropods in the tropics, with particular reference to New Guinea; arthropods of coastal old-growth Picea sitchensis forests, conservation of biodiversity with special reference to the Staphylinidae; conservation corridors and rain forest insects; and insect conservation. An index is provided. Localización: Biblioteca Conmemorativa Orton: 634.9617 F718. Publicación no.: 083 Decline of a tropical montane amphibian fauna [Una reducción en las poblaciones de anfibios en una localidad tropical ubicada en las montañas] / Lips, K.R. (Southern Illinois University. Department of Zoology, Carbondale, IL 62901-6501, US <E-mail: klips@zoology.siu.edu>). In: Conservation Biology (ISSN 0888-8892), v. 12, no. 1, p. 106-117. 1998. On the basis of surveys conducted between 1991 and 1996, I report a decline of the amphibian fauna at Las Tablas, Puntarenas Province, Costa Rica. I propose that the reduction in the abundance of Atelopus chiquiensis and Hyla calypsa, the presence of dead and dying individuals of six species of frogs and salamanders, and changes in population sex ratios of A. chiriquiensis and H. calypsa are evidence for "atypical" population fluctuations. Species with both aquatic eggs and aquatic larvae were most affected (e.g., Rana vibicaria, Hyla rivularis), whereas species with direct development or those that lack tadpoles, such as rainfrogs (Eleuthredactylus spp.) and some salamanders (e.g., Bolitoglossa minutula), do not seem to have declined in numbers. In light of this evidence and in comparison with other declines in tropical upland Australia, Brazil, and Costa Rica. I concluded that environmental contamination (biotic pathogens or chemicals) or a combination of factors (environmental contamination plus climate change) may be responsible for declines in the amphibian populations at this protected site. Localización: Biblioteca OET: S3560. Publicación no.: 084 Cambio climático en Centroamérica y agricultura / Ramírez-Obando, P. (MINAE. Instituto Meteorológico Nacional, Comité Nacional de Cambio Climático, POB Box 7-3350, 1000 San José, CR). Congreso Nacional Agronómico y de Recursos Naturales, IX. La agricultura de hoy para la Costa Rica del mañana, San José CR; 18-22 Oct 1993. San José: Colegio de Ingenieros Agrónomos de Costa Rica, 1993. [8] p. Localización: Biblioteca Conmemorativa Orton: 630.97286 C749 1993. Publicación no.: 085 El clima, su variabilidad y cambio y la deforestación en Costa Rica / Campos, M. (Comité Regional de Recursos Hidráulicos. Proyecto Centroamericano sobre Cambio Climático, San José, CR <E-mail: crrhcr@sol.racsa.co.cr>). Simposio Conservación del Bosque en Costa Rica. Memorias, Heredia CR30-31 Oct. 1997. In: Conservación del Bosque en Costa Rica San José: Academia Nacional de Ciencias, 1998. p. 169-181. ISBN: 9968-9845-1-5. Conclusiones: Es evidente que el bosque presenta una influencia importante dentro del balance global del planeta, y que procesos como la deforestación, conllevan a un acelerado deterioro ambiental; sin embargo, en lo que respecta al clima, el impacto de la deforestación sobre éste, debe estudiarse considerando los sistemas que constituyen el clima de la región en estudio. En el caso particular de Costa Rica, aunque aún se necesitan estudios más detallados, el estado del conocimiento del clima del país, sustentado en los factores y sistemas que lo componen, indican que la deforestación, en zonas como Guanacaste, no producirían un

efecto climático importante dado que la principal fuente de humedad y lluvia es el océano. Sin embargo, los cambios en el albedo y la evapotranspiración debido a la deforestación sí tendrán un impacto directo en lo que respecta a los microclimas de la región. Localización: Biblioteca OET: NBINA-1987. 333.7516 C755c. Publicación no.: 086 Interannual variability of annual streamflow and the Southern Oscillation in Costa Rica / George, R.K.; Waylen, P.R.; Laporte, S. (US Embassy. US Defense Attache Office, Santiago, CL <E-mail: prwaylen@geog.ufl.edu>). In: Hydrological Sciences Journal - Journal Des Sciences Hydrologiques (ISSN 0262-6667), v. 43, no. 3, p. 409-424. 1998. This study illustrates the association between annual and seasonal streamflow characteristics on six Costa Rican rivers and the Southern Oscillation Index (SOI). Annual discharge from rivers within the Pacific watershed are clearly positively associated with contemporary values of the SOI and experience significant reductions in both mean and variance in El Niño years. The considerable practical implications of this finding to a country in which over 60% of national electrical power comes from hydroelectric schemes is illustrated using quantile estimates from various models. Rivers draining towards the Caribbean show less clear and coherent patterns of associations. The observed associations with seasonal flows on some rivers appear to be the opposite of those on the Pacific, and may even vary during the course of a year at a site. The exact nature of the response seems to be closely related to the elevation of the gauge site. The larger the proportion of the basin at elevations above about 500-1000 m the greater the similarity to the Pacific pattern, suggesting that the marked topographic divide between the two coastal watersheds does not correspond to the divide in associations between streamflow and the SOI. Localización: Biblioteca OET: S4332. Publicación no.: 087 Responses of tropical trees to rainfall seasonality and its long-term changes [Respuestas de los árboles tropicales a la estacionalidad de las lluvias y sus cambios a largo plazo] / Borchert, R. (The University of Kansas. Division of Biological Sciences, 1200 Haworth Hall, Sunnyside Ave, Lawrence, KS 66045-7534, US <E-mail: borchert@ku.edu>). In: Climatic Change (ISSN 0165-0009), v. 39, no. 2-3, p. 381-393. 1998. Seasonality and physiognomy of tropical forests are mainly determined by the amount of annual rainfall and its seasonal distribution. Climatic change scenarios predict that global warming will result in reduced annual rainfall and longer dry seasons for some, but not all, tropical rainforests. Tropical trees can reduce the impact of seasonal drought by adaptive mechanisms such as leaf shedding or stem succulence and by utilization of soil water reserves, which enable the maintenance of an evergreen canopy during periods of low rainfall. Correlations between climate and responses of tropical trees are therefore poor and the responses of tropical rainforests to climatic changes are hard to predict. Predicted climate change is unlikely to affect the physiognomy of rainforests with high annual rainfall and low seasonality. Seasonal evergreen forests which depend on the use of soil water reserves will be replaced by more drought-tolerant semideciduous forests, once rainfall becomes insufficient to replenish soil water reserves regularly. As the limits of drought tolerance of tropical rainforests are not known, rate and extent of future changes cannot be predicted. Localización: Biblioteca OET: S3881. Publicación no.: 088 Estimating rainy season nitrous oxide and methane fluxes across forest and pasture landscapes in Costa Rica [Estimando los flujos de óxido nitroso y metano de la estación lluviosa a través del paisaje del bosque y potreros en Costa Rica] / Reiners, W.A.; Keller, M.; Gerow, K.G. (University of Wyoming. Department of Botany, Laramie, WY 82071, US <E-mail: reiners@uwyo.edu> <E-mail: michael.keller@unh.edu> <E-mail: gerow@uwyo.edu>). In: Water, Air and Soil Pollution (ISSN 0049-6979), v. 105, no. 1-2, p. 117-130. 1998. The objectives of this research were to estimate exchanges of CH4 and N2O, both radiatively active gases, between soil and atmosphere on hilltop, slope and swale hillslope positions of northeastern Costa Rica; and to assess the importance of accounting for topography in making areal estimates across hilly terrain. Emission rates from soils were measured during the rainy season on three hillslope positions of both actively grazed pastures and primary forests. Emission rates from pasture and forest sites were significantly different for both gases. Differences between slope positions, though notable, were not significantly different for CH4, but were significantly different for N2O. The forest landscape was partitioned with GIS methods into hilltop, slope and swale topographic positions. The calculated areas for each of these were multiplied by their respective emission rates to calculate overall flux from the entire forested area of 618 ha. Nitrous oxide flux ranged from 16,181 to 17,100 g N d(-1). Similarly, CH4 flux ranged from -6,201 to -6,658 g CH4 d(-1). Errors associated with both estimating mean emission rates for each hillslope position and judgmental errors in partitioning the landscape into hillslope positional classes are important to making landscape-scale estimates of flux. Localización: Biblioteca OET: S3870. NBINA-7135. Publicación no.: 089 GIS-based extrapolation of land use-related nitrous oxide flux in the Atlantic zone of Costa Rica [Extrapolación con base a sistemas de información geográfica del uso de la tierra en

relación con el flujo de óxido nitroso en la Zona Atlántica de Costa Rica] / Plant, R.A.J. (Agricultural University Wageningen. Laboratory of Soil Sciences & Geology, POB 37, NL-6700 AA Wageningen, NL <E-mail: rplant@gissrv.iend.wau.nl>). In: Water, Air and Soil Pollution (ISSN 0049-6979), v. 105, no. 1-2, p. 131-141. 1998. I estimated the aereal nitrous oxide (N2O) flux from 281,347 ha of Costa Rican lowland covered with primary and secondary forest, pastures and banana plantations by linking the DeNitrification-DeComposition (DNDC) model with a Geographic Information System (GIS). Generalized soil, texture and land use maps were overlaid to yield unique combinations of N2O flux control factors. Overlay patches were associated with the nearest of seven available meteorological stations. Monte Carlo-based sensitivity analysis was used to identify DNDC's key driving variables and required map attributes. Clay content, initial soil organic carbon (SOC), bulk density, and pH were selected as key driving variables. For 217 patch classes, DNDC simulations were carried out with climate data for seven different years. The estimated average areal flux was 6.8 kg N2O-N ha(-1) yr(-1). Possible applications of the GIS-DNDC interface presented include estimation of long-term areal flux dynamics from a changing land use mosaic, and prediction of areal fluxes resulting from alternative land use scenarios. Localización: Biblioteca OET: S3869. Publicación no.: 090 National inventory of greenhouse gas emissions: the case of Costa Rica [Inventario nacional de emisiones de gases de invernadero: el caso de Costa Rica] / Ramírez-Obando, P. (MINAE. Instituto Meteorológico Nacional, Comité Nacional de Cambio Climático, POB Box 7-3350, 1000 San José, CR). In: Revista de la Facultad de Ingeniería de la Universidad Central de Venezuela , v. 10, no. 1-2, p. 218-225. 1995. Costa Rica is assessing its first national emissions inventory by sources and sinks of greenhouse gases. The evaluation includes emissions of carbon dioxide and monoxide, nitrous oxide, methane, nitrogen oxides, and other non-methane volatile compds. in the energy, industry, agriculture activity, land use change, and waste management sectors. For the evaluation, the IPCC/OECD methodology is being used and 1990 as the base year, to make the results comparable with those presented by other countries. The results show a total emission of 5479.3 Gg. The energy sector contributes 48.6% to this total, land use with 41.7%, industrial processes with 6.7%, agriculture with 2.6%, and waste with 0.4%. Gas emissions are distributed as follows: CO2, 89.8%; CO, 6.0%; methane, 3.0%; and other gases, 1.83%. Localización: Non available. Publicación no.: 091 Effects of pasture management on N2O and NO emissions from soils in the humid tropics of Costa Rica [Efectos del manejo de los potreros en las emisiones de N2O y NO de suelos en los trópicos húmedos de Costa Rica] / Veldkamp, E.; Keller, M.; Núñez, M. (Universität Göttingen. Institute of Soil Science, Büsgenweg 2, D-37077 Göttingen, DE <E-mail: eveldka@gwdg.de> <E-mail: michael.keller@unh.edu>). In: Global Biogeochemical Cycles (ISSN 0886-6236), v. 12, no. 1, p. 71-79. 1998. We made monthly measurements of N2O and NO emissions from pastures with three different management systems on volcanic soils in northwestern Costa Rica: traditional (no N input from fertilizer or legumes), pastures with a grass-legume combination, and pastures fertilized with 300 kg N ha-1 yr-1. Average annual N2O emissions were 2.7 ng N cm² h-1 from the traditional pastures, 4.9 ng N cm² h-1 from the grass-legume pastures, and 25.8 ng N cm² h-1 from the fertilized pastures. Average annual NO emissions were 0.9, 1.3, and 5.3 ng N cm² h-1 from traditional, grass-legume and fertilized pastures, response. In a separate experiment the effects of ammonium, nitrate, and urea-based fertilizer mixtures on nitrogen oxide fluxes were compared. We measured nitrogen oxide fluxes following four different fertilization events. Nitrogen oxide fluxes were among the highest ever measured. The difference in soil water content between the fertilization events had a far greater effect on N2O and NO emissions than the effect of fertilizer composition. We conclude that the concept of "emission factors" for calculating N2O and NO emissions from different types of N fertilizer is flawed because environmental factors are more important than the type of N fertilizer. To estimate fertilizer-induced N2O emission in tropical agriculture, stratification according to soil moisture regime is more useful than stratification according to fertilizer composition. Localización: Biblioteca OET: S5243. NBINA-6583. Publicación no.: 092 Tests of null models for amphibian declines on a tropical mountain [Pruebas de modelos nulos para disminuciones de anfibios en una montaña tropical] / Pounds, J.A.; Fogden, M.P.L.; Savage, J.M.; Gorman, G.C. (Monteverde Cloud Forest Preserve. Tropical Science Center, Golden Toad Laboratory Conservation, Box 73, Santa Elena 5655 Puntarenas, CR <E-mail: goldtoad@racsa.co.cr> <E-mail: savy1@cox.net>). In: Conservation Biology (ISSN 0888-8892), v. 11, no. 6, p. 1307-1322. 1997. Many of the recent, widespread declines and disappearances of amphibian populations have taken place in seemingly undisturbed, montane habitats. The question of whether the observed patterns differ from those expected from natural population dynamics is the subject of an ongoing controversy with important implications for conservation. We examined this issue for the Monteverde region of Costa Rica's Cordillera de Tilarán, where a multi-species population crash in 1987 led to the disappearance of the endemic golden toad

(Bufo periglenes) and many other species. Focusing on long-term studies of other amphibian assemblages, we developed probabilistic null models for the number of disappearances. Tests of these models at Monteverde suggest that the patterns observed there are highly improbable in the context of normal demographic variability. Twenty species of frogs and toads (40% of the anuran fauna) were missing throughout our 1990-1994 surveys of a 30 km² area. Not all organisms in this area had declined accordingly: the relative frequency of absences was much greater for anurans than for breeding birds. Nevertheless, anuran habitats, most of which are protected within the Monteverde Cloud Forest Preserve, seemed unchanged, and none of the breeding-bird species known to be sensitive to deforestation was missing. Thus, only factors other than direct, obvious human impacts can explain the amphibian declines. Consistent with our tests of null models, analyses of recent population trends do not support the hypothesis that the 1987 crash was an extreme fluctuation from which populations are recovering. Surviving species for which baseline data are available stream-breeding glass frogs (Hyalinobatrachium fleischmanni and Centrolenella prosoblepon) and a pond breeding tree frog (Hyla pseudopuma)-remained far less abundant than they were before the crash and showed no increase during 1990-1994. We documented an increase only for one terrestrial-breeding rain frog (Eleutherodactylus diastema). Localización: Biblioteca OET: C. Publicación no.: 093 Economic value of the carbon sink services of Costa Rica's forestry plantations [Valor económico de los servicios de almacenamiento de carbono de las plantaciones forestales de Costa Rica] / Ramírez, O.A.; Gómez-Flores, M.; Sassa, K, (ed.). (Texas Tech University. Department of Agricultural and Applied Economics, Box 42132, Lubbock, TX 79409-2132, US <E-mail: octavio.ramirez@ttu.edu> <E-mail: mgomez@catie.ac.cr>). In: Environmental Forest Science, v. 54, p. 129-138. Dordrecht: Kluwer Academic Publishers, 1998. (Series: Forestry Sciences). ISBN: 0-7923-5280-7. It is estimated that the "average" hectare of plantation forestry in Costa Rica can sequester 7.7 metric tons of Carbon, or 28.2 tons of CO2 per year. Based on this estimate, it is calculated that the 128,000 hectares of forestry plantations reported have sequestered approximately 4.4 million metric tons of carbon to date (Figure 1). The average net amount of carbon that has remained scored in this area during the last 20 years is calculated at 750,000 metric tons, with a potential value of 7.5 to 15 million U.S. Dollars in government issued Carbon Bonds. In addition, the potential value of the average storage that is likely to occur during the next 20 years, of approximately 8.5 million tons, is estimated at between 84 and 168 million U.S. Dollars, as the prices paid for the bonds may vary widely. Localización: Non available. Publicación no.: 094 Posibles efectos de un calentamiento global en el cultivo de arroz de secano en el Pacífico Norte de Costa Rica [Possible effects of global warming on unirrigated rice in the North Pacific region of Costa Rica] / Villalobos-Flores, R.; Retana-Barrantes, J.A. (Instituto Meteorológico Nacional. Departamento de Agrometeorología, San José, CR <E-mail: rvilla@imn.ac.cr> <E-mail: jretana@imn.ac.cr>). In: Agronomía Costarricense (ISSN 0377-9424), v. 21, no. 2, p. 179-188. 1997. Rice is one of the most important crops in the world, a first necessity for more than half of the human population. However, it might have to be produced under uncertain conditions due to global warming. In Costa Rica, the greater concentration of sowed area is in the North Pacific (47%); this region has 42% of the labor force working in agricultural activities, therefore, a change in the climate of this zone, would increase the possibility of serious socioeconomic problems. A group of international scientists has developed a "Decision Support System for Agrotechnology Transfer" (DSSAT). It is a microcomputer software that uses databases of soils, crops and climate, with application programs to simulate growth and plant development. The DSSAT allows carrying out climatic changes in order to simulate the crop response to several environments. The objective of this work was to simulate the response of rice crop on unirrigated land in the North Pacific of Costa Rica, using several climatic scenarios that represent global warming characteristics, with the purpose of analyzing and quantifying the sensibility of the crop to different climatic elements. The outputs permit to infer that a strong relationship exists between temperature and duration of the sowing- flowering period of the rice crop cycle, and that changes in the climate of the region could modify the general pattern of growth, which could reduce yields. Also, there is an apparently different response the crop to the increase in temperature when maximal or minimal temperature are considered; for this reason, references to mean temperature would not be adequate. If this is correct, the DSSAT would constitute a valuable system of alert in agriculture and food production. Localización: Biblioteca OET: A. Publicación no.: 095 Effects of land use on regional nitrous oxide emissions in the humid tropics of Costa Rica: Extrapolating fluxes from field to regional scales [Efectos del uso de la tierra sobre las emisiones regionales de óxido nitroso en los trópicos húmedos de Costa Rica: Extrapolando los flujos de escalas de campo a regionales] / Plant, R.A.J. (Agricultural University Wageningen. Laboratory of Soil Sciences & Geology, POB 37, NL-6700 AA Wageningen, NL <E-mail: rplant@gissrv.iend.wau.nl>). Wageningen: Agricultural University Wageningen, 1999. 129 p. ISBN: 90-5808-001-3. Dissertation, Ph.D, Agricultural University Wageningen (The Netherlands).

The research was carried out in three steps resulting in the three parts of this thesis. Since most chapters are based on published and submitted papers, the reader may find some parts repetitive. Part I (Chapters 2 and 3) describes the results of model tests against field data. In Chapter 2, DNDC is tested against data from a chronosequence of soils below forest and forest-derived pastures. In Chapter 3, short-term measurements from fertilization experiments on a Costa Rican banana plantation comprise an additional benchmark against which DNDC is tested. Part II (Chapter 4) links field-level and land unit-scale modeling. In Chapter 4, effects of heterogeneous pasture management on N2O and NO emissions for one land unit are discussed. In Part Ill (Chapters 5 and 6), 1 describe the estimation of areal fluxes for land units across the Northern Atlantic Zone. In Chapter 5, a "classic" GIS-based extrapolation, whereby deterministic modeling is employed and spatial heterogeneity within land units is ignored, is presented. In Chapter 6, stochastic methods are used in concert with GIS-based extrapolation to fully account for spatial heterogeneity of both soils and management within land units. Chapter 7 summarizes and discusses key conclusions ensuing from this work. Localización: Biblioteca OET: Tesis 289. Publicación no.: 096 Modeling changes in soil nitrogen cycling induced by conversion of tropical forest to pasture [Cambios de modelaje en el reciclaje del nitrógeno del suelo inducidos por la conversión de bosques tropicales en potreros] / Plant, R.A.J.; Keller, M. (Agricultural University Wageningen. Laboratory of Soil Sciences & Geology, POB 37, NL-6700 AA Wageningen, NL <E-mail: rplant@gissrv.iend.wau.nl> <E-mail: michael.keller@unh.edu>). In: Effects of land use on regional nitrous oxide emissions in the humid tropics of Costa Rica: Extrapolating fluxes from field to regional scales Wageningen: Agricultural University Wageningen, 1999. p. 25-38. Dissertation, Ph.D, Agricultural University Wageningen (The Netherlands). We used the DeNitrification-DeComposition (DNDC) model to simulate the dynamics of soil carbon and nitrogen in 25-year chronosequences of Inceptisols and Andisols below forest that had been replaced by pasture. In order to simulate continuously grazed pasture, we modified DNDC by adding functions that simulate i) grazing, and ii) the steady input of organic matter through root turnover and the return of urine and feces to the pasture. We also added an explicit treatment for the immobilization of nitrogen. Results of simulations were compared to field observations of soil organic carbon stocks, nitrogen mineralization rates, nitrification rates, and evolution of nitrous oxide and nitric oxide. The DNDC formulation was found to be consistent with respect to annual carbon and nitrogen dynamics and annual nitrogen-oxide emissions. In contrast, simulated daily dynamics of nitrogen-oxide emission did not match field observations. Simulated rates and pathways of nitrogen loss in the chronosequences of Inceptisol and Andisol were similar. Considering that a rationale for DNDC is that an explicit description of short-term microbial processes is required to correctly estimate annual gas emissions, we examine possible causes for the model failure. We also consider better approaches for future tests of DNDC. Localización: Biblioteca OET: Tesis 289. Publicación no.: 097 Modeling nitrous oxide emissions from a Costa Rican banana plantation [Modelaje de las emisiones de óxido nitroso de plantaciones bananeras costarricenses] / Plant, R.A.J.; Veldkamp, E.; Li, C.S. (Agricultural University Wageningen. Laboratory of Soil Sciences & Geology, POB 37, NL-6700 AA Wageningen, NL <E-mail: rplant@gissrv.iend.wau.nl> <E-mail: eveldka@gwdg.de>). In: Effects of land use on regional nitrous oxide emissions in the humid tropics of Costa Rica: Extrapolating fluxes from field to regional scales Wageningen: Agricultural University Wageningen, 1999. p. 41-54. Dissertation, Ph.D, Agricultural University Wageningen (The; Netherlands). We applied the process-based DeNitrification-DeComposition (DNDC) model to estimate field-level nitrous oxide emissions from a nitrogen-fertilized banana plantation on a clayey Inceptisol and a loamy Andisol in Costa Rica. Simulated daily nitrous oxide fluxes were compared with data from monthly and frequent field sampling. Different parameterizations were used to represent fertilizer inputs below banana plants (10% of the plantation area) and crop residue additions between plants (90% of the plantation area). For both the Andisol and the Inceptisol, simulated below-plant fluxes matched better with frequently measured fluxes (R-square 0.53 - 0.60) than with monthly measured fluxes (R-square 0.00 - 0.42). Simulated between-plant fluxes matched better with monthly measured fluxes (R-square 0.44 - 0.78) than with frequently measured fluxes (R-square 0.00 - 0.16). Per soil type, annual N2O-N losses were calculated by integrating simulated below-plant and between-plant losses over space, assuming that 40% of the plantation area is affected by fertilization. Losses calculated for the Inceptisol and Andisol were 6 and 15 kg N2O-N ha-1 yr-1, respectively. Field-measured losses were 6 and 13 kg N2O-N ha-1 yr-1. In addition, three fertilization scenarios for Andisols were studied. When 360 kg N ha-1 yr-1 was applied in six rather than the typical thirteen equal splits, the below-plant N2O-N loss declined by 27%. With twenty-six equal splits, annual below-plant N2O-N losses increased most strongly with increasing amounts of fertilizer-N (100 - 800 kg ha-1 yr-1). Field-level simulation modeling plays a key role in regional analysis of land use-related N-oxide emissions. Localización: Biblioteca OET: Tesis 289. Publicación no.: 098 Modeling nitrogen oxide emissions from current and alternative pastures in Costa Rica [Modelaje de las emisiones de óxido nitroso de potreros actuales y alternativos en Costa Rica] /

Plant, R.A.J.; Bouman, B.A.M. (Agricultural University Wageningen. Laboratory of Soil Sciences & Geology, POB 37, NL-6700 AA Wageningen, NL <E-mail: rplant@gissrv.iend.wau.nl> <E-mail: b.bouman@cgiar.org>). In: Effects of land use on regional nitrous oxide emissions in the humid tropics of Costa Rica: Extrapolating fluxes from field to regional scales Wageningen: Agricultural University Wageningen, 1999. p. 55-72. Dissertation, Ph.D, Agricultural University Wageningen (The Netherlands). Emissions of nitrogen (N) oxide were simulated for one current pasture management system ("Natural") and two alternative systems ("Grass-Legume" and "Fertilized improved") relevant to the Northern Atlantic Zone of Costa Rica. Current forest-derived pastures deplete soil nitrogen stocks and therefore are unsustainable. Alternative management systems aim at a nitrogen use that is optimally adapted to the environment, hence they are sustainable. To produce frequency distributions of nitrogen oxide emissions, an expert system for generating technical coefficients of pastures was linked with a process-based simulation model. The expert model generated parameter sets representing different options for the three management systems. The simulation model was rerun for each parameter set. Simulated nitrous oxide-N losses twenty-five years after pasture establishment were 3-5 kg ha-1 yr-1 for natural pastures, 12-15 for grass-legume mixtures, and 7-28 for fertilized grasses. Losses of nitric oxide-N were 1-2 kg ha-1 yr-1 for natural pastures, 7-8 for grass-legume mixtures, and 3-16 for fertilized grasses. Stepwise multiple regression showed that nitrous oxide-N losses were explained by annual carbon input to the sod (R-square 0.997), and nitric oxide-N losses by attainable dry matter production (R-square 0.972). Carbon input and dry matter production were controlled by stocking rate and fertilizer level. Soil-atmosphere N-oxide emissions from pastures may increase by a factor 3-5 when natural pastures are converted to improved pastures. Such conversion may increase the sustainability of the pasture by stopping the decline of soil N. However, the change is not necessarily sustainable from a global perspective because it increases the emission of N-oxide greenhouse gases. Localización: Biblioteca OET: Tesis 289. Publicación no.: 099 GIS-based extrapolation of land use-related nitrous oxide flux in the Atlantic Zone of Costa Rica [Extrapolación con base a sistemas de información geográfica del flujo de óxido nitroso relacionado con el uso de la tierra en la Zona Atlántica de Costa Rica] / Plant, R.A.J. (Agricultural University Wageningen. Laboratory of Soil Sciences & Geology, POB 37, NL-6700 AA Wageningen, NL <E-mail: rplant@gissrv.iend.wau.nl>). In: Effects of land use on regional nitrous oxide emissions in the humid tropics of Costa Rica: Extrapolating fluxes from field to regional scales Wageningen: Agricultural University Wageningen, 1999. p. 73-84. Dissertation, Ph.D, Agricultural University Wageningen (The Netherlands). I estimated the regional nitrous oxide (N2O) flux from 281,347 ha of Costa Rican lowland, covered with primary and secondary forest, pastures, and banana plantations, by linking the DeNitrification-DeComposition (DNDC) model with a Geographic Information System (GIS). Generalized soil, texture, and land use maps were overlaid to yield unique combinations of N2O flux control factors. Overlay patches were associated with the nearest of seven available meteorological stations. Monte Carlo-based sensitivity analysis was used to identify DNDC'S key driving variables and required map attributes. Clay content, initial soil organic carbon (SOC), bulk density, and pH were selected as key driving variables. For 217 patch classes, DNDC simulations were carried out with climate data for seven different years. The estimated average regional flux was 6.8 kg N2O-N ha-1 yr-1. Possible applications of the GIS-DNDC interface presented include estimation of long-term regional flux dynamics from a changing land use mosaic, and prediction of regional fluxes resulting from alternative land use scenarios. Localización: Biblioteca OET: Tesis 289. Publicación no.: 100 Regional analysis of soil-atmosphere nitrous oxide emissions in the Northern Atlantic Zone of Costa Rica [Análisis regional de las emisiones de óxido nitroso del suelo a la atmósfera en la Zona Atlántica Norte de Costa Rica] / Plant, R.A.J. (Agricultural University Wageningen. Laboratory of Soil Sciences & Geology, POB 37, NL-6700 AA Wageningen, NL <E-mail: rplant@gissrv.iend.wau.nl>). In: Effects of land use on regional nitrous oxide emissions in the humid tropics of Costa Rica: Extrapolating fluxes from field to regional scales Wageningen: Agricultural University Wageningen, 1999. p. 85-106. Dissertation, Ph.D, Agricultural University Wageningen (The Netherlands). Regional analysis of greenhouse gas emissions is becoming increasingly important in answering questions related to climate change. Regional analysis typically employs a Geographic Information System and a mechanistic simulation model driven by deterministic inputs. For a region in Costa Rica (2817 km²), an analysis of nitrous oxide emissions was performed using both deterministic and stochastic descriptions of key driving variables. The stochastic representation accounted for soil and land use variability across non-georeferenced fields within 2472 georeferenced land units in eleven relevant classes. Using Monte Carlo integration, frequency distributions of field-scale fluxes simulated with a process-based model were obtained per land use class. Regional fluxes were calculated by summing expected values weighted by area. Stochastic incorporation of both soil and land use variability resulted in areal fluxes that were 14-22% lower than those estimated with deterministic model runs. This suggests non-linearity in the relationship between key model parameters and nitrous oxide fluxes. In addition, spatial flux patterns for land use in 1992 and two alternative land use scenarios were evaluated using stochastic inputs. With contemporary banana plantations and unfertilized natural grasses the regional nitrous oxide-N flux (standard deviation in

parenthesis) was 1.0 (0.4) Gg yr-1. Replacing natural grasses by sustainable grass-legume mixtures on relevant soil types increased the regional flux to 1.6 (0.5) Gg yr-1. When all natural grasses were replaced by fertilized improved species, the regional flux increased to 1.9 (1.2) Gg yr-1. Land use activities that are sustainable in terms of economic profit and soil fertility may be unsustainable when including N2O emission as an extra indicator. Due to formidable data requirements, the approach presented may not be widely applicable. However, regional analysis based on mechanistic modeling may provide valuable insights in the factors that affect emissions at scales relevant to policy making. Localización: Biblioteca OET: Tesis 289. Publicación no.: 101 Comportamiento de las variables meteorológicas (velocidad del viento y temperatura del aire) en el sistema Coffea arabica - Erythrina poeppigiana [Behavior of the meteorological variables (wind speed and air temperature) in an Erythrina poeppigiana - coffea arabica system] / Rodrígues-Rubí, J.A. Turrialba: CATIE, 1992. 77 p. Tesis, Mag. Sc, CATIE, Turrialba (Costa Rica). Se condujo un experimento de junio a agosto de 1992, en una finca cafetalera de Turrialba, Costa Rica, ubicada a 9° 55' latitud norte y 82° 39' longitud oeste, con el fin de evaluar el comportamiento de variables meteorológicas en un sistema agroforestal de café-poró. Las variables consideradas fueron velocidad del viento y temperatura del aire. Para la toma de datos se utilizaron termocuplas de tipo cobre constantan y anemómetros de tres copas. Los datos fueron almacenados en una central computarizada marca Campbell. Los sensores fueron colocados sobre una torre fija de 15 m de altura y un mástil móvil de 9 m de alto. El mástil fue colocado en diferentes posiciones dentro de una malla elemental, delimitada por cuatro árboles de poró, para cubrir las tres dimensiones del sistema. Se encontró además de las diferencias de temperatura del aire medidas a diferentes alturas, diferencias de temperatura del aire a nivel horizontal, éstas fueron provocadas por la influencia del follaje del poró, el cual determina las diferencias a nivel horizontal en el sistema y a nivel vertical. Las bajas velocidades del viento, características de la zona y la poca sensibilidad de los anemómetros a velocidades del viento inferiores a 0.5 m.s exponente -1, posiblemente no permitieron que se pusieran en evidencia las variaciones horizontales de la velocidad del viento dentro del sistema estudiado. De forma general se puede afirmar que las variaciones de temperatura en la parcela fueron facilmente explicadas por las leyes de transferencia de calor, y que el viento que llega a la parcela se reparte de manera relativamente homogénea dentro de la malla elemental en las condiciones del presente estudio. Localización: Biblioteca Conmemorativa Orton: Thesis R696cp. Publicación no.: 102 Soil nitrogen cycling and nitrogen oxide emissions along a pasture chronosequence in the humid tropics of Costa Rica [Ciclo del nitrógeno y emisiones de óxido nitroso a lo largo de una cronosecuencia de potreros en los trópicos húmedos de Costa Rica] / Veldkamp, E.; Davidson, E.A.; Erickson, H.E.; Keller, M.; Weitz, A.M. (Universität Göttingen. Institute of Soil Sciences & Forest Nutritrion; Busgenweg 2, D-37077 Göttingen, DE <E-mail: eveldka@gwdg.de> <E-mail: edavidson@whrc.org> <E-mail: um_herickson@suagm.edu> <E-mail: michael.keller@unh.edu> <E-mail: aweitz@bgc-jena.mpg.de>). In: Soil Biology and Biochemistry (ISSN 0038-0717), v. 31, no. 3, p. 387-394. 1999. Our objectives were: (1) to measure how N2O and NO emissions from a chronosequence of forested land converted to pastures in the humid tropics of Costa Rica had changed in 4 yr, and to relate these emissions to indices of N availability. We observed lower mean N2O (11.9 ng N cm² h(-1)) and NO (3.5 ng N cm² h(-1)) emissions from pastures in 1996 compared to 1992 (N2O, 39.9 ng N cm² h(-1); NO: 5.8 ng N cm² h(-1)). Even so, N2O emissions in recently formed pastures (13.8 ng N cm² h(-1)) were still higher than previously measured emissions from forests (7.0 ng N cm² h(-1)). Indices of N cycling, such as net N mineralization, nitrification potential, and extractable soil nitrate, decreased with pasture age, which we attributed to a decrease in substrate availability. Denitrification enzyme activity did not change significantly with pasture age, indicating that denitrification occurs at least sporadically at all sites and the presence of denitrifying enzymes is not as strongly linked to N availability as is the presence of nitrifying enzymes. There were no significant correlations between N2O and NO emissions and indices of N cycling. While this may indicate that the processes are not closely related, we believe that sampling of nitrogen oxide emissions in 1996 was inadvertently biased towards exceptionally dry soil conditions. This sampling bias limited the probability of observing large nitrogen oxide emissions associated with episodic denitrification. Results from chronosequence studies should be interpreted with caution especially for variables which depend on local weather conditions at time of measurement. Localización: Biblioteca OET: S5245. Publicación no.: 103 Potential effects of climate change on two neotropical amphibian assemblages [Efectos potenciales del cambio climático en dos gremios de anfibios tropicales] / Donnelly, M.A.; Crump, M.L. (Florida International University. Department of Biological Sciences, 3000 NE 151st St, N Miami, FL 33181, US <E-mail: donnelly@fiu.edu> <E-mail: peterf@nauvax.ucc.nau.edu>). In: Climatic Change (ISSN 0165-0009), v. 39, p. 541-561. 1998. Although anuran amphibians are diverse and conspicuous in many vertebrate communities, worldwide population declines have been observed. Climatic change is global factor that has been implicated in some of these declines. In this paper, we speculate on how Neotropical anurans might respond to changes in climate predicted by Hulme and Vine (1998). We focus on two distinct groups of Neotropical anurans: frogs that live

and oviposit in leaf litter and frogs that congregate at ponds to breed. Increased temperature, increased length of dry season, decreased soil moisture, and increased inter-annual rainfall variability will affect Neotropical frog strongly. We expect that these changes will directly affect frogs by changing reproductive success and breeding periodicity, and indirectly by altering the invertebrates prey base. The individual effects will likely translate into changes at the population and community levels. We also speculate on how climatic change will affect Neotropical amphibians that are restricted ecologically and/or geographically. We suggest directions for future research that will increase our ability to predict how amphibians in the New World tropics will respond to climatic change. Localización: Biblioteca OET: S4613. Publicación no.: 104 Estado del ambiente y los recursos naturales en Centroamérica 1998 / Rodríguez-Chacón, J.E. (comp.). (Universidad Nacional. Escuela de Ciencias Ambientales, Heredia, CR). San José: Comisión Centroamericana de Ambiente y Desarrollo, 1998. 179 p. ISBN: 9977-12-323-3. (No abstract). Localización: Biblioteca OET: 333.72 E79e. Biblioteca José Figueres F.: 333.72 E79e. Publicación no.: 105 Modeling nitrogen oxide emissions from current and alternative pastures in Costa Rica [Modelaje de las emisiones de óxido nitroso de potreros actuales y alternativos en Costa Rica] / Plant, R.A.J.; Bouman, B.A.M. (Agricultural University Wageningen. Laboratory Soil Sciences & Geology, POB 37, NL-6700 AA Wageningen, NL <E-mail: rplant@gissrv.iend.wau.nl> <E-mail: b.bouman@cgiar.org>). In: Journal of Environmental Quality (ISSN 0047-2425), v. 28, no. 3, p. 866-872. 1999. Emissions of nitrogen (N) oxide were simulated for one current, unsustainable pasture management system (Natural) and two alternative, sustainable systems (Grass-Legume and Fertilized Improved) relevant to the Northern Atlantic Zone (NAZ) of Costa Rica. To produce frequency distributions of N oxide emissions, an expert system for generating technical coefficients of pastures nas linked with a process-based simulation model. The expert model generated parameter sets representing different options for the three management systems. The simulation model was rerun for each parameter set. Simulated nitrous oxide (N2O)-N losses 25 yr after pasture establishment were 3 to 5 kg ha(-1) yr(-1) for natural pastures, 12 to 15 for grass-legume mixtures, and 7 to 28 for fertilized grasses. Losses of nitric oxide (NO)-N were 1 to 2 kg ha(-1) yr(-1) for natural pastures, 7 to 8 for grass-legume mixtures, and 3 to 16 for fertilized grasses. Stepwise multiple regression showed that N2O-N losses were explained by annual C input to the soil (R-2 = 0.997), and NO-N losses by attainable dry matter production (R-2 = 0.972), Carbon input and dry matter production were controlled by stocking rate and fertilizer level. Soil-atmosphere N oxide emissions from pastures may increase by a factor 3 to 5 when natural pastures are converted to improved pastures, Such conversion may increase the sustainability of the pasture by stopping the decline of soil N. However, the change is not necessarily sustainable from a global perspective because it increases the emission of N oxide greenhouse gases. Localización: Biblioteca OET: S6317. Publicación no.: 106 Biological response to climate change on a tropical mountain [Respuesta biológica al cambio climático en una montaña tropical] / Pounds, J.A.; Fogden, M.P.L.; Campbell, J.H. (Monteverde Cloud Forest Preserve. Tropical Science Center, Golden Toad Laboratory Conservation, Box 73, Santa Elena 5655 Puntarenas, CR <E-mail: goldtoad@racsa.co.cr>). In: Nature (ISSN 0028-0836), v. 398, no. 6728, p. 611-615. 1999. Recent warming has caused changes in species distribution and abundance (1-3), but the extent of the effects is unclear. Here we investigate whether such changes in highland forests at Monteverde, Costa Rica, are related to the increase in air temperatures that followed a step-like warming of tropical oceans in 1976 (refs 4, 5). Twenty of 50 species of anurans (frogs and toads) in a 30 km² study area, including the locally endemic golden toad (Bufo periglenes), disappeared following synchronous population crashed in 1987 (refs 6-8). Our results indicate that these crashes probably belong to a constellation of demographic changes that have altered communities of birds, reptiles and amphibians in the area and are linked to recent warming. The changes are all associated with patterns of dry-season mist frequency, which is negatively correlated with sea surface temperatures in the equatorial pacific and has declined dramatically since the mid-1970s. The biological and climatic patterns suggest that atmospheric warming has raised the average altitude at the base of the orographic cloud bank, as predicted by the lifting-cloud-base hypothesis (9,10). Localización: Biblioteca OET: S4809. Publicación no.: 107 Aporte de los sistemas silvopastoriles al secuestro de carbono en el suelo / López-Musalem, A. Turrialba: CATIE, 1998. 47 p. Tesis, Mag. Sc, Centro Agronómico Tropical de Investigación y Enseñanza, Turrialba (Costa Rica). La preocupación general por el aumento en la concentración de dióxido de carbono y su consecuente impacto en el clima, nos obligan a buscar mecanismos para mitigar sus efectos. Además de disminuir el uso de combustibles fósiles, que desde a mediados del siglo pasado es la principal fuente de CO2, es necesario manejar la vegetación terrestre, no solo para que disminuya su aporte, sino también para que secuestre la mayor cantidad posible de CO2, y fije el carbono en la biomasa y en el suelo. Los bosques, además de su riqueza biológica, representan un invaluable depósito de carbono que se debe proteger. La creación de

nuevas áreas arboladas como los bosques secundarios, las plantaciones y la agroforestería, ayudarían a liberar la presión hacia los bosques maduros, ofreciendo a la población recursos como alimento, material para vivienda, medicinas, energía barata, etc. En este artículo se resalta ese potencial y se propone que los sistemas silvopastoriles también se tomen en cuenta como sumideros de carbono, sobre todo por la extensión que actualmente ocupan en los trópicos. Localización: Biblioteca Conmemorativa Orton: Thesis L864ap. Publicación no.: 108 Why do tropical house wrens breed when they do? [¿Por qué los soterrey cucaracheros tropicales se reproducen cuando lo hacen?] / Young, B.E. (NatureServe, 1101 Wilson Blvd, 15th Floor, Arlington, VA, 22209, US <E-mail: bruce_young@natureserve.org>). The Association for Tropical Biology & The Organization for Tropical Studies Annual Meeting. Abstracts, San Juan PR; Jun 1-4, 1993. San Juan, PR: ATB/OTS, 1993. p. 168-169. I tested three hypotheses that could explain variation in the timing of breeding in populations of house wrens (Troglodytes aedon) at four sites in Costa Rica. The sites were located at 200 to 1500 m elevation on both sides and on top of the central mountain range, and had climates differing in temperature, the severity of the dry season, and total rainfall. For the first hypothesis, that breeding is timed to coincide with peaks in food availability, I monitored monthly arthropod abundance and wren clutch initiations at the four sites. Cross-correlation analysis showed that at three sites, wrens initiated clutches several months prior to when food levels were high. Indeed, breeding actually began when food levels were at their annual low. At the fourth site, food levels varied little throughout the year and house wrens nested nearly year round. These results indicate that sufficient food to produce eggs or feed nestlings may have been available throughout the year. Breeding appeared to be timed so that juvenile dispersal and molt occurred when food was predictably the most plentiful. The second hypothesis, that breeding is timed to avoid seasons when nest predation is high, was not supported because the rate of nest predation did not vary temporally. The third hypothesis, that breeding is timed to avoid climatic events that can increase the physiological costs of reproduction, was not supported at the three lower elevation sites. Clutch initiation at the highest site, however, did not commence until the early dry season wind and mist subsided. The termination of breeding was not correlated with climatic changes at any of the sites. Thus, reproduction in tropical house wrens seems generally to be timed to facilitate post-breeding activities, not activities associated with nesting itself. Localización: Este es el resumen completo. Publicación no.: 109 Estimation of methane (CH4) emission in the livestock from Costa Rica, 1990 and 1996 / Abarca-Monge, S.; Montenegro-Ballestero, J. (Estación Experimental Los Diamantes. Programa de Investigación para la Agricultura Sostenible (REPOSA) MAG/UAW/CATIE, Guápiles, CR <E-mail: jmonte@guayabo.sa.ucr.ac.cr>). Workshop on Measuring Methane Emission from Cattle Using SF6 Technique, Washington, DC US; 24-26 Feb. 1998. Turrialba: MAG, 1998. 12 p. Localización: Biblioteca Conmemorativa Orton: 363.7387 A118. Publicación no.: 110 Política comercial y medio ambiente en Costa Rica: aplicación de un modelo de equilibrio general computable / Rodríguez, A.G.; Abler, D.G.; Shortle, J.S. (Universidad de Costa Rica. Facultad de Ciencias Económicas. Instituto de Investigaciones en Ciencias Económicas, San José, CR <E-mail: d-abler@psu.edu>). San José: Universidad de Costa Rica, 1995. 43 p. (Documento de Trabajo - Universidad de Costa Rica. Facultad de Ciencias Económicas. Instituto de Investigaciones en Ciencias Económicas; no. 182). This study examines the environmental impacts of trade liberalization in Costa Rica. A CGE model is constructed which includes eight environmental indicators covering deforestation, pesticides, overfishing, hazardous wastes, inorganic wastes, organic wastes, greenhouse gases, and air pollution. Three trade liberalization scenarios are examined. Two sets of analyses are examined. Two sets of analyses are conducted for each scenario, one in which technologies do not change in response to trade liberalization and the other in which total factor productivity in each sector changes in response to changes in imports of machinery and equipment. To account for uncertainty regarding values of the model;s parameters, a Monte Carlo experiment is conducted for each policy option. The impacts of trade liberalization on the environmental indicators are generally negative in sign but small or moderate in magnitude, both when technology is constant and when technology is allowed to vary. Localización: Biblioteca Venezuela (IICA): E70 640. Publicación no.: 111 Simulating the effects of climate change on tropical montane cloud forests [Simulación de los efectos del cambio climático en los bosques nubosos tropicales montanos] / Still, C.J.; Foster, P.N.; Schneider, S.H. (Stanford University. Department of Biological Sciences, Stanford, CA 94305-5020, US). In: Nature (ISSN 0028-0836), v. 398, p. 608-610. 1999. Tropical montane cloud forests are unique among terrestrial ecosystems in that they are strongly linked to regular cycles of cloud formation. We have explored changes in atmospheric parameters from global climate model simulations of the Last Glacial Maximum and for doubled atmospheric carbon dioxide concentration (2 X CO2) conditions which are associated with the height of this cloud formation, and hence the occurrence of intact cloud forests. These parameters include vertical profiles of absolute and relative humidity surfaces, as

well as the warmth index, an empirical proxy of forest type. For the glacial simulations, the warmth index and absolute humidity suggest a downslope shift of cloud forests that agrees with the available palaeodata. For the 2 X CO2 escenario, the relative humidity surface is shifted upwards by hundreds of metres during the winter dry season when these forests typically rely most on the moisture from cloud contact. At the same time, an increase in the warmth index implies increased evapo-transpiration. This combination of reduced cloud contact and increased evapo-transpiration could have serious conservation implications, given that these ecosystems typically harbour a high proportion of endemic species and are often situated on mountain tops or ridge lines. Localización: Biblioteca OET: S4810. Publicación no.: 112 Aportes de la biodiversidad silvestre de las Áreas de Conservación a la economía nacional / Barrantes-Moreno, G.; Castro-Jiménez, E. (Servicios de Economía Ecológica para el Desarrollo, Apdo. 2028-3000, Heredia, CR <E-mail: gbarrant@una.ac.cr> <E-mail: ecastro@una.ac.cr> <E-mail: s.e.e.d@iname.com>). San José: SEED / INBIO, 1999. 55 p. Localización: Biblioteca OET: AD 250. Publicación no.: 113 Cuantificación del carbono almacenado en el suelo de un sistema silvopastoril en la zona Atlántica de Costa Rica [Quantification of carbon storage in the soil of silvopastoral system in the Atlantic zone of Costa Rica] / López-Musalem, A. (Av. Oaxaca No.31 1a. Sección, Juchitán Oax. C.P. 700000, MX). Turrialba: CATIE, 1998. 50 p. Tesis, Mag.Sc, Centro Agronómico Tropical de Investigación y Enseñanza, Turrialba (Costa Rica). Silvopastoral systems are considered potential carbon (C) sinks which might help to mitigate the effects of increasing global C emissions. In a case study in the Atlantic Zone of Costa Rica, a medium-low fertile Typic Tropfluvent soil stored 233 Mg C ha(-1) in the upper 50 cm under a Green Panic (Panicum maximum) pasture monoculture. In association with three different growth stages of natural regeneration of salmwood (Cordia alliodora; 3, 3-7,7 years) the soil stored 180-200 Mg C ha(-1). Soil C concentrations decreased with soil depth and distance from the tree. Variability of C distribution increased with soil depth and age of the stand. Localización: Biblioteca Conmemorativa Orton. Publicación no.: 114 Día de la Tierra 1998: secuestro de carbono bajo los mecanismos de implementación conjunta y de fondo de desarrollo limpio / Reifsnyder, D.A.; Dun, S. / WORLDNET, Washington, D.C, US. San José, 1998. 14 p. Localización: Biblioteca Conmemorativa Orton: AV 363.7 no. 7. Publicación no.: 115 Cuantificación del carbono almacenado en el suelo de un sistema silvopastoril en la zona Atlántica de Costa Rica [Quantification of carbon storage in the soil of silvopastoral system in the Atlantic zone of Costa Rica] / López-Musalem, A.; Schlönvoigt, A.M.; Ibrahim, M.a.; Kleinn, C.; Kanninen, M. (Av. Oaxaca No.31 1a. Sección, Juchitán Oax. C.P. 700000, MX <E-mail: ndrea_aschlonvoigt@yahoo.de> <E-mail: mibrahim@catie.ac.cr> <E-mail: ckleinn@gwdg.de> <E-mail: m.kanninen@cgiar.org>). In: Agroforestería en las Américas (ISSN 0304-2529), v. 6, no. 23, p. 51-53. 1999. Silvopastoral systems are considered potential carbon (C) sinks which might help to mitigate the effects of increasing global C emissions. In a case study in the Atlantic Zone of Costa Rica, a medium-low fertile Typic Tropfluvent soil stored 233 Mg C ha(-1) in the upper 50 cm under a Green Panic (Panicum maximum) pasture monoculture. In association with three different growth stages of natural regeneration of salmwood (Cordia alliodora; 3, 3-7,7 years) the soil stored 180-200 Mg C ha(-1). Soil C concentrations decreased with soil depth and distance from the tree. Variability of C distribution increased with soil depth and age of the stand. Localización: Biblioteca OET: A. Publicación no.: 116 Quantifying economic and biophysical sustainability trade-offs in tropical pastures / Bouman, B.A.M.; Plant, R.A.J.; Nieuwenhuyse, A. (International Rice Research Institute. Soil & Water Sciences Division, P.O. Box 3127, Makati City 1271, PH <E-mail: b.bouman@cgiar.org> <E-mail: andreas@mail.megalink.com> <E-mail: rplant@gissrv.iend.wau.nl>). In: Ecological Modelling (ISSN 0304-3800), v. 120, no. 1, p. 31-46. 1999. Sustainability of tropical pastures has various economic and biophysical dimensions and is affected by species composition, age and management. The sustainability of pastures in cattle ranching systems was analyzed in terms of economic viability, soil nitrogen stock change, CO2 loss/sequestration, N2O and NO emissions, pollution by herbicides, and nitrogen leaching loss, for a case study in the Northern Atlantic Zone of Costa Rica. Development scenarios were explored for the next 25 years based on degradation and yield decline of current pastures, and on possible introduction of grass-legumes and fertilized improved grass species. With degradation of current pastures, gross margin, soil nitrogen stock, nitrogen leaching and N2O and NO emissions are simulated to decrease in time, whereas CO2 emission and herbicide use increase. With the introduction of grass-legumes or fertilized grasses, the reverse takes place. The conversion of degraded pasture to grass-legumes or fertilized grasses is calculated to lead to a sequestration of CO2 of up to 50 ton

C ha(-1), which might be a potential mechanism in mitigating the greenhouse effect. Quantitative, exploratory studies point out the often conflicting nature of different dimensions of sustainability and show possible pathways of sustainable development. Localización: Biblioteca OET: S6405. Publicación no.: 117 Cuantificación del carbono almacenado en un sistema silvopastoril en la zona atlántica de Costa Rica / López-Musalem, A.; Schlönvoigt, A.M.; Ibrahim, M.A.; Kleinn, C.; Kanninen, M. (Av. Oaxaca No. 31 1a. Sección, Juchitán, Oax., C.P. 700000, MX <E-mail: andrea_schlonvoigt@yahoo.de> <E-mail: mibrahim@catie.ac.cr> <E-mail: ckleinn@gwdg.de> <E-mail: m.kanninen@cgiar.org>). Conferencia: 4a. Semana Científica, Turrialba CR6-9 Abr. 1999. In: Logros de la investigación para el nuevo milenio. Actas Turrialba: CATIE, 1999. p. 263-267. (Serie Técnica. Reuniones Técnicas (CATIE); no. 5). Silvopastoral systems are considered potential carbon (C) sinks which might help to mitigate the effects of increasing global C emissions. In a case study in the Atlantic Zone of Costa Rica, a medium-low fertile Typic Tropofluvent soil stored 233 t C ha-1 in the upper 50 cm under pure green Panic pasture (Panicum maximum Jacq.). In association with three different growth stages of natural regeneration of salmwood (Cordia alliodora Ruiz & Pav.) Oken; 3, 3-7, 7 years), the soil was less fertile and stored similar amounts of between 180-200 t C ha-1. C concentrations decreased with soil depth and distance from the tree. Variability of C distribution increased with soil depth and age of the stand. Localización: Biblioteca Conmemorativa Orton: CATIE ST RT-5. Publicación no.: 118 Assessing and monitoring carbon offset projects: the Costa Rican case [Evaluación y proyectos de compensación de almacenamiento de carbono: el caso costarricense] / Trines, E.P. (Societé Generale de Surveillance (SGS), Mill Street, Oxford OX2 0JX, GB). In: Commonwealth Forestry Review (ISSN 0010-3381), v. 77, no. 3, p. 214-218, 242. 1998. Projects wishing to generate Emission Reduction Units (ERUs) have to demonstrate carbon achievements by providing information on the size of the project's carbon pools and the changes to these pools. This paper outlines how the Protected Areas Project (PAP) in Costa Rica deals with this issue. The PAP covers 27 of the national parks and biological reserves and aims to protect the area from land use and further degradation by buying the land, transferring the ownership to the state, and actively protecting the entire area from encroachment and fire. The carbon achievements of the project are quantified using various assumptions for the required parameters. The scientific methodologies underlying these assumptions were assessed in the certification process conducted by SGS (Societe Generale de Surveillance), and values of the main parameters were verified. Specific emphasis was placed on the project's stratification using ecotypes, biomass estimates, determination of land cover, and deforestation rates. The outcome of the assessment overall was positive but some corrective action requests were raised to improve the availability and quality of the data sets used. This was reported to four independent peer reviewers who scrutinised the assessors' work and the report. After addressing the concerns articulated by the reviewers, SGS' professional judgement was approved. Localización: Biblioteca OET: NBINA-636. Publicación no.: 119 Climatic periodicity, phenology, and cambium activity in tropical dry forest trees [Periodicidad climática, fenología y actividad del cambium en árboles del bosque seco tropical] / Borchert, R. (The University of Kansas. Division of Biological Sciences, 1200 Haworth Hall, Sunnyside Ave, Lawrence, KS 66045-7534, US <E-mail: borchert@ku.edu>). In: IAWA Journal (ISSN 0928-1541), v. 20, no. 3, p. 239-247. 1999. The seasonal time course of vegetative phenology and cambium growth is compared for tree species from Central America and Asia growing in tropical climates with a long, severe dry season. Although the inhibition of plant growth by water stress is well established, responses to seasonal drought vary widely among such trees, and their annual development is not well synchronized by climatic seasonality. In deciduous trees growing at microsites with low soil moisture storage, phenology and cambium growth are well correlated with each other and with seasonal rainfall, and most trees have distinct annual rings. Phenology and cambium growth are progressively uncoupled from climatic seasonality in brevideciduous and evergreen trees growing at microsites with large soil water reserves which buffer trees against seasonal drought and thus may prevent the formation of distinct annual rings. There is some experimental evidence concerning the control of growth initiation in apical meristems and the cambium, but little is known about the mechanisms which arrest growth and determine qualitative changes in organ development and cambium cell differentiation. Localización: Biblioteca OET: S6466. Publicación no.: 120 In the heat of the night: warmer nights may be slowing tropical forest growth and raising carbon dioxide levels [En el calor de la noche: las noches calientes pueden estar disminuyendo el crecimiento del bosque y aumentando los niveles de dióxido de carbono] / Beardsley, T. In: Scientific American (ISSN 0036-8733), v. 279, no. 4, p. 20. 1998. Discusses unpublished research which asserts that increasing temperatures have slowed the growth of tropical trees at La Selva Biological Station in Costa Rica during the 1990s. Tropical forests adding to

greenhouse gases; Exacerbation of global warming; Details of research methods; Increase in the region's release of carbon dioxide; Causes of carbon excess; Rate of growth linked to average temperature; Impact of clearing tropical forests. Researchers have found evidence that global warming has slowed the growth of tropical trees, which may lead to ever higher carbon dioxide levels. Studies of forests in Costa Rica are discussed. Localización: Biblioteca OET: S7828. Publicación no.: 121 Your pollution, our forests [Su contaminación, nuestros bosques] / Anonymous. In: Economist (ISSN 0013-0613), v. 347, no. 8074, p. 36-38. 1998. The CTO or certified tradable offsets scheme of the Costa Rican government is being viewed skeptically around the world and by local environmental groups. Costa Rica will leave carbon-absorbing trees standing for a fee. CTO issued by the Costa Rican government to safeguard forests; Cost of CTO bonds; Amount of CTOs sold; Criticism of CTOs. Localización: Biblioteca OET: S7794. Publicación no.: 122 Desarrollo limpio en Costa Rica y Centroamérica / Tattenbach, F.; Pedroni, L. (Oficina Costarricense de Implementación Conjunta (OCIC), San José, CR <E-mail: crocic@sol.racsa.co.cr> <E-mail: lpedroni@catie.ac.cr>). In: Revista Forestal Centroamericana (ISSN 1021-0164), no. 27, p. 6-9. 1999. La inversión extranjera en actividades de implementación conjunta durante la fase piloto demuestra que a través de este mecanismo los intereses económicos del norte pueden converger con las necesidades de desarrollo del sur y proporcionar beneficios ambientales globales. La experiencia de Centroamérica abre grandes expectativas hacia el mecanismo de desarrollo limpio: a partir del año 2000, cuando se otorgarán créditos por las emisiones reducidas, la región podría beneficiarse de inversiones importantes por parte de entidades públicas y privadas de los países industrializados. Localización: Biblioteca OET: R. Publicación no.: 123 Implicaciones económicas del secuestro del CO2 en bosques naturales [Economic implications of the sequestration of CO2 in natural forests] / Ramírez, O.A.; Rodríguez-Sánchez, L.; Finegan, B.; Gómez-Flores, M. (Texas Tech University. Department of Agricultural and Applied Economics, Box 42132, Lubbock, TX 79409-2132, US <E-mail: octavio.ramirez@ttu.edu> <E-mail: bfinegan@catie.ac.cr> <E-mail: mgomez@catie.ac.cr>). In: Revista Forestal Centroamericana (ISSN 1021-0164), no. 27, p. 10-16. 1999. The check and the upper canopy treatment behaved similarly. The liberation treatment presents much lower carbon storage levels, even after 60 years, which imply an economic cost of approximately US$250/ha in comparison with the check or the canopy treatment. The liberation treatment shows a financial advantage due to a higher production of wood of high-value species during the first harvest. However, neither of the silvicultural treatments is justified from the environmental economics standpoint, when the value of the carbon storage service is considered. The liberation treatment is hindered by its strong negative impact on long-term carbon storage levels and the upper canopy treatment by its little effect on the commercial value of the harvested wood. The payment to farmers for the sustainable management of natural forests currently mandated by the Costa Rican Government, of US$360/ha is too low, even when it is only compared to the economic value of the environmental service of carbon storage provided. It does not appear to be sufficient to motivate the sustainable management of natural forests in the long run. Localización: Biblioteca OET: R. Publicación no.: 124 Estimación y valoración económica del almacenamiento de carbono [Economic value of the carbon sink services of Costa Rica's forestry plantations] / Ramírez, O.A.; Gómez-Flores, M. (Texas Tech University. Department of Agricultural and Applied Economics, Box 42132, Lubbock, TX 79409-2132, US <E-mail: octavio.ramirez@ttu.edu> <E-mail: mgomez@catie.ac.cr>). In: Revista Forestal Centroamericana (ISSN 1021-0164), no. 27, p. 17-22. 1999. It is estimated that the "average" hectare of plantation forestry in Costa Rica can sequester 7,7 metric tons of carbon, or 28,2 tons of C02 per year. Based on this estimate, it is calculated that the 142 600 hectares of forestry plantations reported until 1997 have sequestered approximately 6,3 million metric tons of carbon. The average amount of carbon that has remained stored in this area during the last 20 years is calculated at 1,5 million metric tons, with a potential value of 15 to 30 million U.S. dollars in government issued Carbon Bonds. In addition, the potential value of the average storage that is likely to occur during the next 20 years, of approximately 9,8 million tons, is estimated at between 98 and 196 million U.S. dollars, as the prices paid for the bonds may vary widely. Localización: Biblioteca OET: R.

Publicación no.: 125 Los arrecifes y comunidades coralinas de Bahía Culebra, Guanacaste, Costa Rica / Cortés-Núñez, J.; León-Soler, A.; Ruiz-Campos, E.; Jiménez-Centeno, C.E. (Universidad de Costa Rica. Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) y Escuela de Biología, San José, CR <E-mail: jcortes@biologia.ucr.ac.cr> <E-mail: aleonso@racsa.co.cr> <E-mail: ruizc@cariari.ucr.ac.cr> <E-mail: carlos.jimenez@zmt.uni-bremen.de> <E-mail: cjimenez@cariari.ucr.ac.cr>). In: Memoria. Jornadas de Investigación 1999 San José: Universidad de Costa Rica, Vicerrectoría de Investigación, 1999. p. 80. Bahía Culebra se localiza en el Golfo de Papagayo en el noroeste de Costa Rica. Esta es una región expuesta a afloramientos estacionales (diciembre a abril), resulta en la surgencia de aguas profundas, frías y ricas en nutrientes. El Golfo de Papagayo es una de las tres zonas de afloramiento costero del continente americano (las otras son: Estrecho de Tehuantepec y Golfo de Panamá). A primera vista estas condiciones oceanográficas no son conducentes al desarrollo de arrecifes coralinos, sin embargo, se han encontrado arrecifes coralinos verdaderos y comunidades coralinas creciendo sobre arena y sobre basaltos. Las tasas de crecimiento de los corales son tan altas como en otras regiones del Océano Pacífico Oriental (el Pacífico de América), o más altas. También se encuentran en la Bahía, algunos arrecifes de gran tamaño (vivos y muertos), algunos con colonias de hasta 10 m de diámetro. Desde 1995 se han estado monitoreando parámetros físicos (temperatura y salinidad del agua) y biológicos (dinámica de poblaciones de corales, desarrollo de tumores en corales, crecimiento de corales). En 1998 se inició la medición de tasas de sedimentación y en 1999 la determinación de concentraciones de nutrientes y de parámetros atmosféricos (temperatura, vientos, lluvia, brillo solar). Además, se han establecido nuevos sitios de estudio y foto-transectos permanentes, todo esto con la finalidad de elucidar la variabilidad ambiental y poder evaluar, a largo plazo, cambios debido a fenómenos naturales (e.g. El Niño, cambio climático) e impactos antropogénicos (e.g. sedimentación, eutroficación, extracción de organismos). Localización: Este es el resumen completo. Publicación no.: 126 Control on soil-atmosphere fluxes of nitrous oxide and methane: Effects of tropical deforestation [Control sobre los flujos de óxido nitroso y metano del suelo a la atmósfera: Efectos de la deforestación tropical] / Keller, M.; Zepp, R.G, (ed.). (U.S. Department of Forest Service. International Institute of Tropical Forestry, Río Piedras, PR 00928-5000, US <E-mail: michael.keller@unh.edu>). In: Climate Biosphere Interaction: Biogenic Emissions and Environmental Effects of Climate Change New York: John Wiley and Sons, 1994. p. 121-138. ISBN: 0-471-58943-3. Deforestation in the tropics is one of the most important changes to the Earth´s biology and surface processes occurring today (Clark, 1989). It is likely that only a small portion of tropical forests will survive beyond the early years of the next century. The replacement of tropical forests by agricultural and grazing systems and secondary vegetation causes myriad biophysical and biogeochemical changes which influence the fluxes of greenhouse gases. This chapter reviews measurements and models for fluxes of methane, nitrous oxide, and ozone from intact tropical forests and disturbed systems. Localización: Biblioteca OET: S5247. Publicación no.: 127 Model simulation of changes in N2O and NO emissions with conversion of tropical rain forests to pastures in the Costa Rican Atlantic Zone [Modelo de simulación de los cambios en las emisiones de N2O y NO con la conversión de bosques tropicales a potreros en la Zona Atlántica costarricense] / Liu, S.; Reiners, W.A.; Keller, M.; Schimel, D.S. (Raytheon Systems Company. EROS Data Center, Sioux Falls, S.D, US <E-mail: sliu@edcmail.cr.usgs.gov> <E-mail: reiners@uwyo.edu> <E-mail: michael.keller@unh.edu> <E-mail: schimel@ucar.edu>). In: Global Biogeochemical Cycles (ISSN 0866-6236), v. 13, no. 2, p. 663-677. 1999. Nitrous oxide (N20) and nitric oxide (NO) are among the trace gases of concern because of their importance in global climate and atmospheric chemistry. Modeling techniques are needed for simulating the spatial and temporal dynamics of N20 and NO emissions from soils into the atmosphere. In this study, we modified the ecosystem model CENTURY to simulate changes in N20 and NO soil emissions through the process of converting tropical moist forests to pastures in the Atlantic Lowlands of Costa Rica. Measurements of water-filled pore space (WFPS) and fluxes of N20 and NO from a chronosequence of pastures were used for calibration and testing of the model. It was found that the N20+ NO - WFPS and N20: NO WFPS relationships as developed from primary forests could be generalized to the chronosequence of pastures and other land use systems in the region. Modeled net increases (compared to primary forests) in total N20 and NO production after conversion from forest to pasture were 514 kg N ha(-1) during thefirst 15 years under normal field conditions. The nitrogen loss in the form of N20 and NO during the first 15 years could range from 401 to 548 kg N ha(-1), depending on the amounts of forest residue remaining on pasture sites. N20-N accounted for 90% ofthe gas fluxes, while NO-N accounted for 10%. Sensitivity analysis indicated that the impacts of forest-pasture conversion on N2O and NO emissions from soil into the atmosphere were complex, depending on the initial conditions of the forest-derived pastures, management practices, soil physical and chemical conditions and their changes over time, N availability, and climate. It is therefore important to incorporate the spatial and temporal heterogeneities of those controlling factors in estimating regional and global N20 and NO emissions from soils into the atmosphere. Localización: Biblioteca OET: S5238. NBINA-6919.

Publicación no.: 128 Economic value of the carbon sink services of Costa Rica's forestry plantations [Valor económico de los servicios de almacenamiento de carbono de las plantaciones forestales de Costa Rica] / Ramírez, O.A.; Gómez-Flores, M. (Texas Tech University. Department of Agricultural and Applied Economics, Box 42132, Lubbock, TX 79409-2132, US <E-mail: octavio.ramirez@ttu.edu> <E-mail: mgomez@catie.ac.cr>). IUFRO Division 8 "Forest Environment" Conference Proceedings, Kyoto JP19-23 October 1998. Kyoto: IUFRO, 1998. p. 243-244. ISBN: 4990-06-182-9. Forestry plantations have become an increasingly important part of Costa Rica´s rural economic development since 1964. During the last six years (1990-95), more than 16,000 ha have been planted per year, reaching a total of nearly 130,000 to date. This has required of an important investment from the public and private sectors, which has been only partially accounted for. It is estimated that the forestry plantations established up until 1995 a total investment value of nearly 188 million current (1996) U.S. dollars. Their inmediate consumption value is assessed at 41 million U.S. dollar, a full 2% of the value added from the agricultural sector and 0.35% of the Gross Domestic Product (GDP) of Costa Rica. The previous figures are approximately three times larger than the official estimates. Localización: Biblioteca OET: S5351. Publicación no.: 129 A framework for integrated biophysical and economic land use analysis at different scales [Un sistema para el análisis biofísico y económico integrado del uso de la tierra a diferentes escalas] / Bouman, B.A.M.; Jansen, H.G.P.; Schipper, R.A.; Nieuwenhuyse, A.; Hengsdijk, H.; Bouma, J. (International Rice Research Institute. Soil & Water Sciences Division, P.O. Box 3127, Makati City 1271, PH <E-mail: b.bouman@cgiar.org> <E-mail: h.hengsdijk@plant.wag-ur.nl> <E-mail: andreas@mail.megalink.com> <E-mail: johan.bouma@bodlan.beng.wau.nl>). In: Agriculture, Ecosystems and Environment (ISSN 0167-8809), v. 75, no. 1-2, p. 55-73. 1999. There is a general need for quantitative tools that can be used to support policy makers in regional rural development. Here, a framework for (sub-) regional land use analysis is presented that quantifies biophysical and economic sustainability trade-offs. The framework, called sustainable options for land use (SOLUS), was developed over a 10-year period of investigation in the Northern Atlantic Zone of Costa Rica and encompasses scale levels that range from field to region. SOLUS consists of technical coefficient generators to quantify inputs and outputs of production systems, a linear programming model that selects production systems by optimizing regional economic surplus, and a geographic information system. Biophysical and economic disciplines are integrated and various types of knowledge, ranging from empirical expert judgement to deterministic process models are synthesized in a systems-analytical manner. Economic sustainability indicators include economic surplus and labor employment, and biophysical ones include soil N, P and K balances, biocide use and its environmental impact, greenhouse gas emission and nitrogen leaching loss and volatilization. Land use scenarios can be implemented by varying properties of production inputs (e.g., prices), imposing sustainability restrictions in the optimization, and incorporating alternative production systems based on different technologies. Examples of application of SOLUS in the Northern Atlantic Zone of Costa Rica show that introduction of alternative technologies may result in situations that satisfy both economic as well as biophysical sustainability. On the other hand, negative trade-offs were found among different dimensions of biophysical sustainability themselves. Localización: Biblioteca OET: S5587. NBINA-5401. Publicación no.: 130 The Costa Rican experience with market instruments to mitigate climate change and conserve biodiversity [La experiencia costarricense con los instrumentos de mercado para mitigar el cambio climático y conservar la biodiversidad] / Castro-Salazar, R.; Tattenbach, F.; Gámez-Hernández, L.; Olson, N. (Ministerio del Ambiente y Energía. Barrio Francisco Peralta, Calle 25, Ave 8-10, San José, CR <E-mail: lgamez@una.ac.cr>). In: Environmental Monitoring and Assessment (ISSN 0167-6369), v. 61, no. 1, p. 75-92. 2000. Two decades of developing relevant legal and institutional regimes for the sustainable and nondestructive use of natural resources have framed Costa Rica's pioneer approach to mitigate climate change and conserve its rich biological diversity. This policy framework provides an appropriate context for the actual and proposed development of market instruments designed to attract capital investments for carbon sequestration and biodiversity conservation, and allows the establishment of mechanisms to use those funds to compensate owners for the environmental services provided by their land. As a developing economy, Costa Rica is striving to internalize the benefits from the environmental services it offers, as a cornerstone of its sustainable development strategy. Localización: Biblioteca OET: NBINA-6547. Publicación no.: 131 Valuing the environmental service of permanent forest stands to the global climate: The case of Costa Rica [Valoración del servicio ambiental de los bosques permanentes al sistema climático mundial: el caso de Costa Rica] / Castro-Salazar, R. (Ministerio del Ambiente y Energía. Barrio Francisco Peralta, Calle 25, Ave 8-10, San José, CR). Cambridge, MA: Harvard University, 1999. 134 p. Dissertation, D. Des, Harvard University Graduate School of Design, Cambridge, MA (USA). Like many tropical countries, Costa Rica is losing its forests: private landowners, cut down forests to grow crops and the government cannot afford to buy land for conservation. However, foreign countries can help, preserving tropical forest is their most cost-effective option for reducing carbon emissions. This thesis

investigates this possibility using Costa Rica's state-owned Wildlife Conservation Areas (WCAs) as a case study. Finding cost-effective ways to sequester carbon or reduce carbon emissions is important because reducing global warming is both urgent and costly: possibly 2% of the world's GDP. Deforestation increases carbon emissions into the atmosphere and contributes to global warming. Reducing deforestation and growing trees can help to sequester carbon, and reduce emissions. Various studies suggest that forest carbon sequestration may be a cost-effective way of reducing cost. According to the literature reducing emissions in the energy sector in industrialized countries will exceed $100 per ton. By contrast, the cost of sequestering carbon in US forests will cost from $10 to $100 per ton of carbon depending on the scale of the forestry projects and on the increasing opportunity cost of the land. The cost of sequestering carbon in permanent forests is even lower in Costa Rica than in the United States. The estimates developed in this thesis suggest that 92% of the carbon sequestered in the proposed expansion of the WCAs will cost less than $50 per ton. Moreover, some landowners in Costa Rica may be willing to preserve private natural forests or switch from traditional crops or cattle-raising to forest plantations if the price of sequestered carbon were to rise to as little, as $10 per ton. Therefore, using tropical forest as a carbon sink may have economic, ecological, and social benefits. Economically, it may reduce mitigation costs and facilitate capital transfer from industrialized to developing nations. Society benefits because forests are often located in the poorest rural areas; the ecological benefits come from keeping forest cover, especially primary forest, which is crucial to conserving tropical biodiversity. Localización: Biblioteca del INCAE: COS 333.75.09.728.6 C355. Publicación no.: 132 Implementación conjunta: un caso a nivel comunal en Costa Rica [Joint implementation: a case study at the community level in Costa Rica] / Segura-Bonilla, O. (Universidad Nacional. Centro Internacional de Política Económica para el Desarrollo Sostenible (CINPE), Heredia, CR <E-mail: osegura@una.ac.cr>). In: Revista Forestal Centroamericana (ISSN 1021-0164), no. 27, p. 36-40. 1999. A case study is presented of joint forest management at the community level in the community of Junquillal de Santa Cruz in Guanacaste Province, Costa Rica. The project started in 1997. The article discusses the advantages and disadvantages of joint management projects, describes the socioeconomic characteristics of Junquillal de Santa Cruz, the forest characteristics, forest management and products and services, forest protection certification and parallel benefits resulting from this, new management activities, problems and limitations, and lessons learned from the project. Localización: Biblioteca OET: R. Publicación no.: 133 Trade liberalization and the environment in Costa Rica [Liberalización del comercio y el ambiente en Costa Rica] / Abler, D.G.; Rodríguez, A.G.; Shortle, J.S. (Pennsylvania State University. Agricultural Economics, 207 Armsby Building, University Park, PA 16802-5600, US <E-mail: d-abler@psu.edu>). In: Environment and Development Economics (ISSN 1355-770X), v. 4, no. 3, p. 357-373. 1999. This study examines the environmental impacts of trade liberalization in Costa Rica. A CGE model is constructed which includes eight environmental indicators covering deforestation, pesticides, overfishing, hazardous wastes, inorganic wastes, organic wastes, greenhouse gases, and air pollution. Three trade liberalization scenarios are examined. Two sets of analyses are conducted for each scenario, one in which technologies do not change in response to trade liberalization and the other in which total factor productivity in each sector changes in response to changes in imports of machinery and equipment. To account for uncertainty regarding values of the model's parameters, a Monte Carlo experiment is conducted for each policy option. The impacts of trade liberalization on the environmental indicators are generally negative in sign but small or moderate in magnitude, both when technology is constant and when technology is allowed to vary. Localización: Biblioteca OET: S6248. NBINA-7802. Publicación no.: 134 Ecological footprints of Benin, Bhutan, Costa Rica and the Netherlands / van Vuuren, D.P.; Smeets, E.M.W. (National Institute of Public Health & Environment, POB 1, NL-3720 BA, Bilthoven, NL <E-mail: detlef.van.vuuren@rivm.nl>). In: Ecological Economics (ISSN 0921-8009), v. 34, no. 1, p. 115-130. 2000. The ecological footprint (EF) has received much attention as a potential indicator for sustainable development over the last years. In this article, the EF concept has been applied to Benin, Bhutan, Costa Rica and the Netherlands in 1980, 1987 and 1994. The results of the assessment are discussed and used to discuss the current potential and limitations of the EF as a sustainable development indicator. The originally defined methodology has been slightly adapted by the authors, who focus on individual components of the EF (land and carbon dioxide emissions) and use local yields instead of global averages. Although per capita and total land use differs among the four countries: available data suggest increasing land use in all four countries while per capita land use decreases. The EF for carbon dioxide emissions increases for all four countries in both per capita and absolute terms. Differences in productivity, aggregation (of different resources) and multi-functional land use have been shown to be important obstacles in EF application - depending on the assessment objective. However, despite the obstacles, the study concludes that the EF has

been successful in providing an interesting basis for discussion on environmental effects of consumption patterns, including those outside the national borders, and on equity concerning resource use. Localización: Biblioteca OET: S6904. NBINA-6876. Publicación no.: 135 Effects of climate change on biodiversity: A review and identification of key research issues [Efectos del cambio climático sobre la biodiversidad: Una revisión e identificación de los problemas importantes por investigar] / Kappelle, M.; van Vuuren, M.M.I.; Baas, P. (Utrecht University. Copernicus Institute for Sustainable Development and Innovation, Department of Science, Technology and Society, Padualaan 14, 3584 CH Utrecht, NL <E-mail: m.kappelle@chem.uu.nl>). In: Biodiversity and Conservation (ISSN 0960-3115), v. 8, no. 10, p. 1383-1397. 1999. Current knowledge of effects of climate change on biodiversity is briefly reviewed, and results are presented of a survey of biological research groups in the Netherlands, aimed at identifying key research issues in this field. In many areas of the world, biodiversity is being reduced by humankind through changes in land cover and use, pollution, invasions of exotic species and possibly climate change. Assessing the impact of climate change on biodiversity is difficult, because changes occur slowly and effects of climate change interact with other stress factors already imposed on the environment. Research issues identified by Dutch scientists can be grouped into: (i) spatial and temporal distributions of taxa; (ii) migration and dispersal potentials of taxa; (iii) genetic diversity and viability of (meta) populations of species; (iv) physiological tolerance of species; (v) disturbance of functional interactions between species; and (vi) ecosystem processes. Additional research should be done on direct effects of greenhouse gases, and on interactions between effects of climate change and habitat fragmentation. There are still many gaps in our knowledge of effects of climate change on biodiversity. An interdisciplinary research programme could possibly focus only on one or few of the identified research issues, and should generate input data for predictive models based on climate change scenarios. Localización: Biblioteca OET: S6909. NBINA-6880. Publicación no.: 136 Forest protection and reforestation in Costa Rica: evaluation of a clean development mechanism prototype [Protección forestal y reforestación en Costa Rica: evaluación de un prototipo de mecanismo de desarrollo limpio] / Subak, S. (Natural Resources Defense Council, 1200 New York Ave NW, Washington, DC 20005, US). In: Environmental Management (ISSN 0364-152X), v. 26, no. 3, p. 283-297. 2000. Costa Rica has recently established a program that provides funds for reforestation and forest protection on private lands, partly through the sale of carbon certificates to industrialized countries. Countries purchasing these carbon offsets hope one day to receive credit against their own commitments to limit emissions of greenhouse gases. Costa Rica has used the proceeds of the sale of carbon offsets to Norway to help finance this forest incentive program. Called the Private Forestry Project, which pays thousands of participants to reforest or protect forest on their lands. The Private Forestry Project is accompanied by a monitoring program conducted by Costa Rican forest engineers that seeks to determine net carbon storage accomplished on these lands each year. The Private Forestry Project, which is officially registered as an Activity implemented jointly. Is a possible model for bundled projects funded by the Clean Development Mechanism (CDM) established by the 1997 Kyoto Protocol to the UN Framework Convention on Climate Change. It also serves as an interesting example for the CDM because it was designed by a developing country host--not by an industrialized country investor. Accordingly, it reflects the particular "sustainable development" objectives of the host country or at least the host planners. Early experience in implementing the Private Forestry Project is evaluated in light of the main objectives of the CDM and its precursor-Activities Implemented Jointly it is concluded that the project appears to meet the criteria of global cost-effectiveness and financing from non-ODA sources. The sustainable development implications of the project are specific to the region and would not necessarily match the ideals of all investing and developing countries. The project may be seen to achieve additional greenhouse gas abatement when compared against some (although not all) baselines. Localización: Biblioteca OET: S6221. NBINA-7100. Publicación no.: 137 Regional analysis of soil-atmosphere nitrous oxide emissions in the Northern Atlantic Zone of Costa Rica [Análisis regional de las emisiones de óxido nitroso del suelo a la atmósfera en la Zona Atlántica norte de Costa Rica] / Plant, R.A.J. (Wageningen Agricultural University. Laboratory of Soil Sciences & Geology, P.O. Box 37, NL-6700 AA Wageningen, NL <E-mail: rplant@gissrv.iend.wau.nl>). In: Global Change Biology (ISSN 1354-1013), v. 6, no. 6, p. 639-653. 2000. Regional analysis of greenhouse gas emissions is becoming increasingly important in answering questions related to environmental change, and typically employs a Geographic Information System (GIS) linked with a process-based simulation model. For the Northern Atlantic Zone (NAZ) in Costa Rica (281 649 ha), a regional analysis of soil-atmosphere nitrous oxide fluxes from the dominant land-use types forest, cattle pastures, and banana plantations was performed with both deterministic and stochastic variable representations. The stochastic representation accounted for soil and land management variability across nongeoreferenced fields within 1572 georeferenced land units in 13 relevant classes. Per class, frequency distributions of held-scale fluxes were simulated with a process-based model and Monte Carlo methods. Stochastic incorporation of both soil and land use variability resulted in areal (i.e. Land unit-scale) fluxes that

were 14-22% lower than estimates based on averaged inputs. Soil heterogeneity was dominant. In addition, spatial flux patterns for current (1992) land use and two alternative land-use scenarios were evaluated using stochastic inputs. With current management, the regional nitrous oxide-N flux (standard deviation in parentheses) from agricultural land was 0.43 (0.13) Gg y(-1). Replacing natural grasses with mixtures of grasses and N-fixing species on relevant soil types and introducing different forms of banana plantation management (alternative I) increased the regional nux by 51% to 0.65 (0.22) Gg y(-1) When all natural grasses were replaced by fertilized improved species and allowing different forms of banana plantation management (alternative II), the regional flux increased by 126% to 0.97 (0.68) Gg y(-1). Using the revised IPCC methodology, the 1992 nitrous oxide emission from agriculture in the NAZ was estimated to be 0.32 Gg y(-1). Due to formidable data requirements, regional analysis may not easily be used to produce country-level estimates. However, regional analysis does provide a valuable benchmark against which the more straightforward IPCC methodology can be evaluated. Localización: Biblioteca OET: S6525. Publicación no.: 138 The Kyoto Protocol and payments for tropical forest: An interdisciplinary method for estimating carbon-offset supply and increasing the feasibility of a carbon market under the CDM [El Protocolo de Kyoto y los pagos por los servicios de los bosques tropicales: Un método interdisciplinario para estimar la compensación por el suministro de carbono e incremento de la factibilidad de un mercado del carbono bajo el Mecanismo de Desarrollo Limpio] / Pfaff, A.S.P.; Kerr, S.; Hughes, R.F.; Liu, S.; Sánchez-Azofeifa, G.A.; Schimel, D.S.; Tosi-Olin, J.A., Jr.; Watson-Céspedes, V. (Columbia University. School of International & Public Affairs, Room 1306, 420 W 118th St, New York, NY 10027, US <E-mail: ap196@columbia.edu> <E-mail: suzi.kerr@motu.org.nz> <E-mail: hughesf@terra.colorado.edu> <E-mail: sliu@edcmail.cr.usgs.gov> <E-mail: arturo.sanchez@ualberta.ca> <E-mail: schimel@ucar.edu> <E-mail: jtosi@cct.or.cr> <E-mail: vwatson@cct.or.cr> ). In: Ecological Economics (ISSN 0921-8009), v. 35, no. 2, p. 203-221. 2000. Protecting tropical forests under the Clean Development Mechanism (CDM) could reduce the cost of emissions limitations set in Kyoto. However, while society must soon decide whether or not to use tropical forest-based offsets, evidence regarding tropical carbon sinks is sparse. This paper presents a general method for constructing an integrated model (based on detailed historical, remote sensing and field data) that can produce land-use and carbon baselines, predict carbon sequestration supply to a carbon-offsets market and also help to evaluate optimal market rules. Creating such integrated models requires close collaboration between social and natural scientists. Our project combines varied disciplinary expertise (in economics, ecology and geography) with local knowledge in order to create high-quality, empirically grounded, integrated models for Costa Rica. Localización: Biblioteca OET: S6393. NBINA-4060. Publicación no.: 139 Almacenamiento de carbono y conservación de biodiversidad por medio de actividades forestales en el Área de Conservación Cordillera Volcánica Central, Costa Rica / CIFOR / CATIE. Turrialba, CR, Turrialba: CIFOR / CATIE, 2000. 71 p. (Serie Técnica (CATIE); no. 314). El Pago de Servicios Ambientals (PSA) se puso en marcha en Costa Rica en 1996 con la aprobación de la Ley Forestal No. 7575. Esta es una medida novedosa para valorar las actividades forestales por los servicios ambientales que prestan a la sociedad. La principal fuente de financiamiento del PSA es una parte de los impuestos a los combustibles, que llegó a recaudar US$38,4 millones en 1997, US$33,7 millones en 1998 y US$33,6 millones en 1999, aunque apenas 20, 15y 25de lo recaudado respectivamente ha sido transferido al Fondo Nacional de Financiamiento Forestal (FONAFIFO). Este mecanismo de financiamiento se debe asegurar y mejorar por parte de la sociedad civil en general, y buscarse otros como el pago por servicio de agua, debido a que constituye una de las decisiones más novedosas para que los propietarios de bosques y plantaciones capturen los beneficios de la protección y manejo sostenible de estos ecosistemas. El objetivo general de este estudio es analizar la capacidad y riesgos de las actividades forestales en la prestación de servicios ambientales, mediante la sistematización e integración de información científico-técnica e institucional existente para apoyar la toma de decisiones en el PSA por actividades forestales en fincas privadas del Area de Conservación Cordillera Volcánica Central (ACCVC). El estudio analizó las actividades forestales con PSA y los riesgos asociados a las mismas en conservación de biodiversidad y, fijación y almacenamiento de carbono, así como el impacto social y económico que generan. Se analizaron las actividades de protección de bosque, manejo de bosque, plantaciones forestales y pastos como actividad alternativa. La elaboración de un sistema de criterios e indicadores (C&I) y el análisis por medio de la lógica difusa, generó una base integrada y rápida para conocer la situación del PSA en las actividades forestales. Estos C&I consideraron las dimensiones biofísica, económica y social. La valoración fue realizada mediante consulta a 26 expertos y 37 propietarios de tierras que desarrollan actividades forestales en el ACCVC. En el ACCVC existen áreas geográficas con distintas potencialidades para el desarrollo de actividades forestales que pueden brindar servicios para la fijación y almacenamiento de carbono y la conservación de biodiversidad. En el área del ACCVC atendida por la Fundación para el Desarrollo de la Cordillera Volcánica Central (FUNDECOR) se da prioridad para el uso de los recursos del PSA a la protección de bosques (22 000 ha), seguida muy de lejos por el manejo de bosques (2 200 ha) y finalmente las plantaciones forestales (1 000 ha). El manejo técnico de bosque (incluyendo el secundario) representa un importante potencial para fijar y almacenar carbono, y contribuir a la conservación de la biodiversidad. La evaluación de los C&I puso

en evidencia aspectos que son vitales para el desarrollo de la actividad forestal con perspectiva a largo plazo. Entre aquellos que requieren atención se encuentran: En la dimensión social: mejorar la participación local en el proceso de toma de decisiones del PSAincrementar acciones educativas dirigidas a los niños y de capacitación a los propietarios, en aspectos de protección y manejo de bosques. En las áreas de protección de bosques (privadas), hacer esfuerzos para estudiar y poner en marcha algunas actividades productivas de bajo impacto ambiental que generen empleo. En la dimensión económica, la actividad de manejo de bosques presenta menor valoración por parte de los propietariosdebe por tanto prestarse atención para fortalecer la actividad. Los indicadores que requieren atención son la asistencia técnica efectiva, los requisitos y trámites para el manejo forestal, el conocimiento y acceso a mercados de la madera y otros productos del bosque, y el incremento de los ingresos a los propietarios. En la dimensión biofísica, establecer prioridades para la protección de bosques primarios o poco intervenidos que se encuentran en tierras privadas, áreas para el manejo del bosque secundario, y áreas para la recuperación y manejo de bosques muy intervenidos. El PSA podría convertirse en un mecanismo de política efectivo para potenciar la integración de la cadena productiva forestal, asegurar la aplicación en el campo de estándares de sostenibilidad, mediante la certificación forestal y la inserción de productos especializados en el mercado nacional e internacional. El reconocimiento por parte de la sociedad nacional al buen uso y manejo de los bosques privados, generan un nuevo escenario para el sector forestaleste es un acercamiento necesario entre dueños de bosques y la sociedad. La evaluación periódica de los C&I mostrará los avances y las proyecciones de este innovador mecanismo (PSA). Localización: Biblioteca OET: NBINA-4970. Publicación no.: 140 Adaptation to climate variability and change: methodological issues [Adaptación a la variabilidad y cambio en el clima: aspectos metodológicos] / Klein, R.J.T.; Maciver, D.C. (Postdam Institute for Climate Impact Research, P.O. Box 601203, 14412 Postdam, DE). In: Mitigation and Adaptation Strategies for Global Change (ISSN 1381-2386), v. 4, no. 3/4, p. 189-198. 1999. The Intergovernmental Panel on Climate Change (IPCC) convened a Workshop on Adaptation to Climate Variability and Change in Costa Rica in 1998 that involved more than 200 expects and incorporated views from many research communities. This paper summarizes the recommendations from the Workshop and profiles the contributions to the advancement of methodologies for adaptation science. Localización: Biblioteca OET: NBINA-6569. Publicación no.: 141 Revised rules of procedure for the IPCC process: an editorial essay / Anonymous. In: Climatic Change (ISSN 0165-0009), v. 46, p. 409-415. 2000. The Intergovernmental Panel on Climate Change (IPCC) held its fifteenth Plenary session in San José, Costa Rica in April, 1999. One major item on the agenda was the adoption of a revised set of rules of procedure for the Panel's work with its Third Assessment Report (TAR). The IPCC process is already a time-consuming and cumbersome process, and the new rules of procedure adopted at the fifteenth Plenary session adds further complexity and bureaucracy to the process. Localización: Biblioteca OET: NBINA-6572. Publicación no.: 142 Spatial and temporal variability of nitrogen oxide and methane fluxes from a fertilized tree plantation in Costa Rica [Variabilidad espacial y temporal de flujos de óxido nitroso y metano de una plantación forestal fertilizada en Costa Rica] / Weitz, A.M.; Keller, M.; Linder, E.; Crill, P.M. (University of New Hampshire. Institute of Study of Earth Oceans & Space, Complex Systems Research Center, Durham, NH 03824, US <E-mail: aweitz@bgc-jena.mpg.de> <E-mail: michael.keller@unh.edu> <E-mail: elinder@christa.unh.edu> <E-mail: patrick.crill@unh.edu>). In: Journal of Geophysical Research: Atmosphere (ISSN 0747-7309), v. 104, no. D23, p. 30097-30107. 1999. Nitric oxide (NO), nitrous oxide (N2O), and methane (CH4) are naturally produced and consumed by soil biogeochemical processes. Naturally high variation between trace gas fluxes may temporarily increase due to agricultural management. We studied spatial and temporal variability of fluxes in the context of a 3-year field experiment established to identify and quantify N2O fluxes and controlling factors using automated field measurements. We measured trace gas fluxes, soil temperature, and moisture from fertilized and unfertilized balsa (Ochroma lagopus) plantations. Combining spatial and temporal sampling we evaluate if automatically measured time series of N2O emissions are representative of overall mean fluxes from fertilized loam under balsa. Soil trace gas fluxes were measured manually at 36 randomly distributed sampling locations per plot. Mean plot emissions were evaluated against fluxes measured by seven chambers commonly used for routine bimonthly manual measurements and against N2O emissions measured by two automated chambers at 4.6-hour sampling intervals. Trace gas fluxes were highly variable over 40 x 40 m plots. Nitrogen oxide fluxes were mainly spatially independent. Fertilization increased nitrogen oxide emissions but did not introduce spatial dependency of flux data. Within about 6 weeks fluxes approached pre-fertilization level again. Given high spatial variation of nitrogen oxide fluxes we find that automatically measured N2O fluxes represent the nature of the flux response well and are in the range of fluxes indicated by spatial sampling. When soils were relatively dry fertilization inhibited CH4 uptake.

Localización: Biblioteca OET: S7773. Publicación no.: 143 Soil-atmosphere nitrogen oxide fluxes: Effects of root disturbance [Flujos de óxido de nitrógeno suelo-atmósfera: efectos de la perturbación de las raíces] / Keller, M.; Weitz, A.M.; Bryan, B.; Rivera, M.M.; Silver, W.L. (University of New Hampshire. Institute of Study of Earth Oceans & Space, Complex Systems Research Center, Durham, NH 03824, US <E-mail: michael.keller@unh.edu> <E-mail: aweitz@bgc-jena.mpg.de> <E-mail: wsilver@nature.berkeley.edu>). In: Journal of Geophysical Research: Atmosphere (ISSN 0747-7309), v. 105, no. D14, p. 17693-17698. 2000. Chambers are the most common method used to sample soil-atmosphere fluxes of trace gases. Working in tree plantations in Costa Rica and in subtropical forest in Puerto Rico, we performed controlled experiments in order to evaluate whether installation of the chamber bases into the soil affects the soil-atmosphere flux of nitrogen oxides. Installation of chambers severed roots. We found a short-term disturbance effect related to chamber installation. Fluxes of nitrogen oxides increased by as much as a factor of 4 during a period of about 1 month following chamber installation in the soil. Within 6 weeks of chamber base installation, fluxes fell to control levels. Given the timescale of disturbance and recovery, root mortality and decomposition is the most likely cause of the observed effect. Localización: Biblioteca OET: S7766. Publicación no.: 144 Isotopic variability of N2O emissions from tropical forest soils [Variabilidad isotópica de emisiones de N2O de suelos de bosques tropicales] / Pérez, T.; Trumbore, S.E.; Tyler, S.C.; Davidson, E.A.; Keller, M.; de Camargo, P.B. (University of California. Department of Earth System Sciences, Irvine, CA 92697, US <E-mail: tjperez@uci.edu> <E-mail: setrumbo@uci.edu> <E-mail: styler@uci.edu> <E-mail: eadavidson@whrc.org> <E-mail: michael.keller@unh.edu> <E-mail: pcamargo@mail.cena.usp.br>). In: Global Biogeochemical Cycles (ISSN 0886-6236), v. 14, no. 2, p. 525-535. 2000. We report measurements of the N-15 and O-18 signature of N2O emitted from tropical rain forest soils at the La Selva Biological Station in Costa Rica and in the Fazenda Vitoria in the State of Para, Brazil. The delta(15)N values ranged from -34 to 2 parts per thousand with respect to atmospheric N-2, while delta(18)O values had a smaller range, from -4 to 18 parts per thousand with respect to atmospheric O-2. We attribute these large variations to differences in microbial production, consumption, and transport of N2O. In general the delta(15)N of N2O emissions from an Oxisol soil in Brazil were consistently enriched by similar to 20 parts per thousand in N-15 compared to those from Ultisol and Inceptisol soils in Costa Rica. Denitrification is the most likely source of N2O in both locations during the rainy season, and the N-15 of nitrate was similar in both locations. We attribute the overall variability in emitted N-15 to differences in the ratio of N2O:N-2 escaping from the soil to the atmosphere, with a larger fraction of the N2O reduced to N-2 at the Brazilian sites. We found light delta(15)N-N2O values associated with high N2O emissions in a fertilized agricultural site in Costa Rica and in a "hot spot" of high emissions in the forest site in Brazil. This result suggests that the increase of substrate availability might increase the fractionation associated with N2O production. Overall, the Brazilian Oxisol soils had the most enriched delta(15)N-N2O emissions yet measured from soils. if these are more representative of tropical soil emissions than the Costa Rica emissions, then the globally averaged delta(15)N-N2O tropical rain forest soil source is more enriched than previously estimated. The large variations in isotopic signature for N2O emissions demonstrate the potential utility of stable isotopes as tools for understanding the processes of N2O production and consumption in soils. Localización: Biblioteca OET: S7988. NBINA-6920. Publicación no.: 145 Intensive field measurements of nitrous oxide emissions from a tropical agricultural soil [Mediciones intensivas de campo de emisiones de óxido nitroso de un suelo agrícola tropical] / Crill, P.M.; Keller, M.; Weitz, A.M.; Grauel, B.; Veldkamp, E. (University of New Hampshire. Institute of Study of Earth Oceans & Space, Complex Systems Research Center, Durham, NH 03824, US <E-mail: patrick.crill@unh.edu> <E-mail: michael.keller@unh.edu> <E-mail: aweitz@bgc-jena.mpg.de> <E-mail: eveldka@gwdg.de>). In: Global Biogeochemical Cycles (ISSN 0886-6236), v. 14, no. 1, p. 85-95. 2000. The amount of nitrous oxide (N2O) continues to increase in the atmosphere. Agricultural use of nitrogen fertilizers in the tropics is thought to be an important source of atmospheric N2O. High frequency, highly precise measurements of the N2O flux were made with an automated system deployed in N fertilized and unfertilized agricultural plots of papaya and corn in Costa Rica for an entire corn crop growth to harvest cycle. N2O fluxes were as high as 64 ng N-N2O cm² h(-1) from fertilized versus 12 ng N-N2O cm² h(-1) from unfertilized corn and 28 ng N-N2O cm² h(-1) from fertilized versus 4.6 ng N-N2O cm² h(-1) from unfertilized papaya. Fertilized corn released more N2O than fertilized papaya over the 125 days of the crop cycle, 1.83 kg N ha(-1) versus 1.37 kg N ha(-1). This represents a loss as N2O of 1.1 and 0.9% of the total N applied as ammonium nitrate to the corn and papaya, respectively. As has often been observed, N2O fluxes were highly variable. The fastest rates of emission were associated with fertilization and high soil moisture. A diurnal cycle in the fluxes was not evident probably due to the minimal day/night temperature fluctuations. Each chamber was measured between 509 and 523 times over the course of the experiment.

This allows us to evaluate the effect on constructed mean fluxes of lowered sampling frequencies. Sampling each collar about once a day throughout the crop cycle (25% of the data set) could result in a calculated mean flux from any individual chamber that can vary by as much as 20% even though the calculated mean would probably be within 10% of the mean of the complete data set. The uncertainty increases very rapidly at lower sampling frequencies. For example, if only 10% of the data set were used which would be the equivalent of sampling every other day, a very high sampling frequency in terms of manual measurements, the calculated mean flux could vary by as much as 40% or more at any given site. Localización: Biblioteca OET: S7109. NBINA-6921. Publicación no.: 146 Testing a conceptual model of soil emissions of nitrous and nitric oxides [Probando un modelo conceptual de emisiones de óxidos nitrosos y nítricos de los suelos] / Davidson, E.A.; Keller, M.; Erickson, H.E.; Verchot, L.V.; Veldkamp, E. (Woods Hole Research Center, POB 296, Woods Hole, MA 02543, US <E-mail: edavidson@whrc.org> <E-mail: michael.keller@unh.edu> <E-mail: aum_herickson@suagm.suagm.edu> <E-mail: l.verchot@cglar.org> <E-mail: eveldha@gwdg.de>). In: BioScience (ISSN 0006-3568), v. 50, no. 8, p. 667-680. 2000. In this article, we briefly review the disciplinary research on soil emissions of N2O and NO. We describe a mechanistically based conceptual model - the "hole-in-the-pipe" (HIP) model - that integrates the results of these disciplinary studies and that relates emissions of both nitrogen oxides to common soil processes. We then test the model predictions, using data from our recent studies in Costa Rica, Brazil, and Puerto Rico and additional data from the literature for forest ecosystems throughout the world. Localización: Biblioteca OET: NBINA-5998. S7221. Publicación no.: 147 Estimating historical changes in global land cover: Croplands from 1700 to 1992 / Ramankutty, N.; Foley, J.A. (University of Wisconsin. Institute of Environmental Studies, Climate, People & Environment Program, 1225 W Dayton St, Madison, WI 53706, US <E-mail: nramanku@students.wisc.edu> <E-mail: jfoley@facstaff.wisc.edu>). In: Global Biogeochemical Cycles (ISSN 0886-6236), v. 13, no. 4, p. 997-1027. 1999. Human activities over the last three centuries have significantly transformed the Earth's environment, primarily through the conversion of natural ecosystems to agriculture. This study presents a simple approach to derive geographically explicit changes in global croplands from 1700 to 1992. By calibrating a remotely sensed land cover classification data set against cropland inventory data, we derived a global representation of permanent croplands in 1992, at 5 min spatial resolution [Ramankutty and Foley, 1998]. To reconstruct historical croplands, we first compile an extensive database of historical cropland inventory data, at the national and subnational level, from a variety of sources. Then we use our 1992 cropland data within a simple land cover change model, along with the historical inventory data, to reconstruct global 5 min resolution data on permanent cropland areas from 1992 back to 1700. The reconstructed changes in historical croplands are consistent with the history of human settlement and patterns of economic development. By overlaying our historical cropland data set over a newly derived potential vegetation data set, we analyze our results in terms of the extent to which different natural vegetation types have been converted for agriculture. We further examine the extent to which croplands have been abandoned in different parts of the world. Our data sets could be used within global climate models and global ecosystem models to understand the impacts of land cover change on climate and on the cycling of carbon and water. Such an analysis is a crucial aid to sharpen our thinking about a sustainable future. Localización: Biblioteca OET: NBINA-6922. Publicación no.: 148 A climate of change [Un clima de cambio] / Figueres-Olsen, J.M. (Fundación Costa Rica para el Desarrollo Sostenible (Entebbe), Apartado Postal 557-2250, Tres Ríos de La Unión, CR <http://www.entebbe.com>). In: Our Planet: the Magazine of the United Nations Environment Program (ISSN 1013-7394), v. 11, no. 1, p. 5-6. 2000. Global climate change has ceased to be strictly an environmental threat, lurking in the future. Its potential impacts could well make it the greatest social and economic challenge that humanity will have to face in the coming century. The first is competition. An energy revolution is now in the making, with advanced new technologies such as fuel cells, photovoltaics, wind turbines and flywheels entering the market. The reason why we moved beyond the horse and buggy a hundred years ago was not because we ran out of hay. Similarly, there is no doubt that the planet still has impressive oil reserves. However, as was the case when the oil era first emerged, those industries that successfully incorporate the new technologies will be well positioned to succeed economically in the 21 st century. Localización: Non available. Publicación no.: 149 Gradient analysis of biomass in Costa Rica and a first estimate of countrywide emissions of greenhouse gases from biomass burning [Análisis de gradiente de biomasa en Costa Rica y primer estimado nacional de emisiones de gases de invernadero procedentes de la quema de biomasa] / Helmer, E.H.; Brown, S. (USDA Forest Service. International Institute of Tropical Forestry, P.O. Box 25000, Río Piedras, PR 00928-5000, PR <E-mail: ehelmer/iitf@fs.fed.us>).

In: Quantifying sustainable development: the future of tropical economies. Hall, C.A.S.; León-Pérez, C.; Leclerc, G. (eds.) San Diego, CA: Academic Press, 2000. p. 503-526. ISBN: 0-12-318860-1. Past efforts to estimate greenhouse gases (GHG) emissions from biomass burning generally have relied on global or regional data bases. Although the Central American country of Costa Rica is small in area (50 060 km²), it has a much better database than most regions and thereby provides an excellent "microcosma" for an analysis of GHG emissions by forest type. It has, for example, several forest formations for which data on forest structure and areas deforested are available. Between 1950 and 1984, the rate of deforestation in Costa Rica was one of the highest in the world at about 3.9% per year. Our objectives in thischapter are: 1) estimate biomass of stands undisturbed by human activity (as far as we can tell) as a function of environmental gradients in Costa Rica, and 2)estimate the release of GHGs to the atmosphere from knowing the spatial variation in deforestation rates in forests developed under differing climatic conditions. We estimate emissions simply by assuming 100% of aboveground biomass is burned eventually, an assumption recommended by the Intergovernmental Panel on Climate Change and Organization for Economic Cooperation and Development (IPCC/OECD) methodology for inventory of GHG. Localización: Biblioteca OET: 338.92797286 Q1. Publicación no.: 150 Ecology: The value of nature and the nature of value [Ecología: El valor de la naturaleza y la naturaleza del valor] / Daily, G.C.; Söderqvist, T.; Aniyar, S.; Arrow, K.; Dasgupta, P.; Ehrlich, P.R.; Folke, C.; Jansson, A.M.; Jansson, B.O.; Kautsky, N.; Levin, S.; Lubchenco, J.; Mäler, K.G.; Simpson, D.; Starrett, D.; Tilman, D.; Walker, B. (Stanford University. Department of Biological Sciences, Stanford, CA 94305, US <E-mail: gdaily@leland.stanford.edu> <E-mail: pre@stanford.edu>). In: Science (ISSN 0036-8075), v. 289, no. 5478, p. 395-396. 2000. (No abstract). Localización: Biblioteca OET: S7090. Publicación no.: 151 Geographic variation in soil organic carbon dynamics following land-use change in Costa Rica [Variación geográfica en la dinámica del carbono orgánico en el suelo luego del cambio en el uso de la tierra] / Powers, J.S. (University of Minnesota. Department of Soil, Water & Climate, St Paul, MN 55108, US <E-mail: powers@umn.edu>). Durham, NC: Duke University, 2001. 281 p. ISBN: 0-493-43112-8. Dissertation, Ph.D., Duke University, Graduate School and Department of Biology, Durham, NC (USA). Recent studies have suggested that the direction and magnitude of changes in soil carbon (C) pools following land-use change in the tropics depend upon initial site conditions, vegetation productivity, and management. Despite observations that soil C pools both increase and decrease following deforestation, global assessments of carbon dioxide fluxes due deforestation usually assume a single rate of loss. The goal of my dissertation was to understand how the response of the soil C pool to land-use change varies geographically for a 140,000-ha region in Costa Rica, and how to extrapolate site-specific changes in soil C pools to estimate regional C02 fluxes. I collected an extensive data set for 110 managed and forested sites in northeastern Costa Rica that included: soil C, indices of vegetation productivity, soil texture, mineralogy, elevation, topographic relief, and landcover history. Managed sites were paired with reference forest sites on similar soils and topography to estimate pre-conversion conditions. In this region, the direction and magnitude of the changes in soil C pools following conversion of mature forests to pasture varied as a function of non-crystalline clays in the low-elevation soils and %slope in the highelevation soils. The conversion of old pastures to intensively managed cash crops reduced soil C storage to a greater extent than the conversion of forest to pasture. Old pastures that had regenerated to secondary forests or tree plantations did not show increased soil C storage. As a whole, soils in this region have been a small source of carbon dioxide to the atmosphere over the past 50 years as managed lands have replaced native forests. Localización: Biblioteca OET: Tesis 374. NBINA-7784. Publicación no.: 152 Evaluating ultraviolet radiation exposure with satellite data at sites of amphibian declines in Central and South America [Evaluación de la exposición a la radiaci6n ultravioleta con datos de satélite en sitios de declinaciones de anfibios en Centro y Suramérica] / Middleton, E.M.; Herman, J.R.; Celarier, E.A.; Wilkinson, J.W.; Carey, C.; Rusin, R.J. (National Aeronautics and Space Administration (NASA). Goddard Space Flight CenterLaboratory for Terrestrial Physics (Code 923), Greenbelt, MD 207771, US <E-mail: betsym@ltpmail.gsfc.nasa.gov> <E-mail: careyc@spot.colorado.edu>). In: Conservation Biology (ISSN 0888-8892), v. 15, no. 4, p. 914-929. 2001. Many amphibian species have experienced substantial Population declines or have disappeared altogether during the last several decades at a number of amphibian survey sites in Central and South America. Our study addresses the use of trends in solar UV-B radiation exposure (280-320 nm) at these sites over the last two decades, derived from the Total Ozone Mapping Spectrometer satellite data. It is intended to demonstrate a role for satellite observations in determining whether UV-B radiation is a contributing factor in amphibian declines. We used these data to calculate the daily erythemal (sunburning) UV-B, or UV-Bery exposure at the latitude, longitude, and elevation of each of 20 survey sites. The annually averaged UV-Bery close, as well as the maximum values, have been increasing in both Central and South America, with higher levels reached at the Central American sites. The annually averaged UV-Bery exposure increased significantly from 1979-1998 at all 11 Central American sites we examined (r²= 0.60-0.79); p ¾ 0.015), with smaller but significant increases at five of the nine South American sites (r² = 0.24-0.42; p ¾ 0.05).

The number of days having the highest UV-B exposure (‗ 6.75 kJ/m²/day) increased in both regions from 40 days per year to approximately 58 days per year in 1998 (r² Localización: Biblioteca OET: S7272. Publicación no.: 153 Inventario nacional de fuentes y sumideros de gases de efecto invernadero en Costa Rica año 1996 / MINAE/IMN, San José, CR. San José: Ministerio del Ambiente y Energía / Instituto Meteorológico Nacional, 1996. 53 p. (Proyecto COS/95/G31). En junio de 1992, se llevó a cabo en Río de Janeiro, Brasil, la Convención Marco sobre Cambio Climático, en la cual los países firmantes se comprometieron entre otras cosas a realizar inventarios nacionales de emisiones de gases de efecto invernadero, a implementar programas que contengan medidas orientadas a mitigar el cambio climático y cooperar en los preparativos para la adaptación a los impactos del cambio climático. La Convención entró en vigencia en marzo de 1994 y sus compromisos se hicieron obligatorios para los firmantes. Costa Rica ratificó la Convención el 13 de junio de 1994 y en cumplimiento a los compromisos adquiridos realizó el primer inventario de emisiones de gases de efecto invernadero por fuentes y sumideros. La evaluación del primer inventario se realizó utilizando las guías para la elaboración de inventarios nacionales de gases de efecto invernadero del IPCC-OECI) y tomando como referencia el año 1990, con el fin de hacerlo comparable con otros países. Con los resultados de este inventario se inició un nuevo proyecto: Mejoramiento de la Capacidad Nacional para la Reducción de Emisiones de Gases de Efecto Invernadero, el cual fue financiado por el Fondo Global del Ambiente (GEF). Dentro de este proyecto se llevó a cabo la actualización del inventario de emisiones, para lo cual se utilizó la metodología revisada del IPCC-OECI) (IPCC, 1997), tomando como referencia para la evaluación, el año 1996. La evaluación del inventario estuvo a cargo del Instituto Meteorológico Nacional, que coordinó un grupo integrado por expertos de diferentes instituciones en las áreas de Energía, Procesos Industriales, Agricultura, Uso de la tierra y Manejo de Desechos. Se incluyeron en él los mismos seis gases evaluados en el inventario anterior: dióxido de carbono (CO2), metano (CH4), monóxido de carbono (CO), óxido nitroso (N2O), óxidos de nitrógeno (NOx) y otros hidrocarburos volátiles diferentes del metano (NMVOC). Además en algunos casos, se evaluó la emisión de dióxido de azufre (SO2), partículas y halocarburos (HFC). De acuerdo a la metodología del IPCC, el inventario se dividió en cinco áreas: Energía, Procesos Industriales, Agricultura, Uso de la tierra y silvicultura y Manejo de Desechos. Las emisiones totales de gases de efecto invernadero en el año 1996 tuvieron un valor neto equivalente a 4.047,7 Gg (4.047.700 toneladas). A este total el sector energía aportó 4.287,5 Gg (4.287.500 toneladas), procesos industriales 431,0 Gg (431.000 ton), agricultura 152,4 Gg (152.400 ton), cambio de uso de la tierra tiene una fijación neta de 864,6 Gg (-864.600 ton) y desechos 41,4Gg (41.400 ton). Valores detallados por sector y gas se pueden observar en el cuadro 1. Localización: Biblioteca OET: AD 389. Publicación no.: 154 Management effects on methane fluxes in humid tropical pasture soils [Efectos del manejo de los flujos de metano en suelos de pastos húmedos tropicales] / Veldkamp, E.; Weitz, A.M.; Keller, M. (Universität Göttingen. Institute of Soil Sciences & Forest Nutritrion; Busgenweg 2, D-37077 Göttingen, DE <E-mail: eveldka@gwdg.de> <E-mail: aweitz@bgc-jena.mpg.de>). In: Soil Biology and Biochemistry (ISSN 0038-0717), v. 33, no. 11, p. 1493-1499. 2001. Tropical ecosystems play an important role in the production and uptake of atmospheric methane (CH4). Our objective was to evaluate the long- and short-term effects of management on the CH4 fluxes in humid tropical pastures in Costa Rica. Using closed chambers, we measured CH4 fluxes on four replicates of three pastures with different management: fertilized, traditional and legume pastures. In experimental fertilizer applications, we also compared the short-term effects of ammonium, nitrate and urea fertilizers. In the course of one year, fertilized pastures showed net CH4 uptake (-0.34 mg CH4 m² day(-1)) while traditional (+0.69mg CH4 m² day(-1)) and legume pastures (+0.92 mg CH4 m² day(-1)) displayed net CH4 emissions. This difference was probably caused by the combined effect of lower soil water contents in the fertilized pastures and high nitrate concentrations, which may have inhibited production of CH4 in the fertilized pastures. CH4 uptake in the fertilized pasture was only about 25% of CH4 uptake in old-growth forest in the same area. In the fertilizer experiment, CH4 uptake was more reduced by ammonium sulfate (-0.24 mg CH4 m² day(-1)) and urea (-0.26 mg CH4 m² day(-1)) than by calcium nitrate (-0.62 mg CH4 m² day(-1)). We measured a short-term inhibition of CH4 uptake caused by NH4+ that lasted for less than 3 weeks. Addition of KCI led to an additional inhibiting 'salt' effect, which may be more long term than the inhibiting effect of NH4+. Localización: Biblioteca OET: NBINA-133. Publicación no.: 155 Primera comunicación nacional ante la Convención Marco de las Naciones Unidas sobre Cambio Climático / Costa Rica. Ministerio del Ambiente y Energía. Instituto Meteorológico Nacional, San José, CR. San José: MINAE / IMN, 2000. 101 p. (Proyecto COS/95/G31). Costa Rica has taken part in climate change activities for over a decade. it ratified the United Nations Framework Convention on Climate Change on October 13, 1994, and accordingly, it has conducted different initiatives. The First National Communication on Climate Change summarizes most of the activities carried out in the country in conformity with this commintment. Localización: Biblioteca OET: AD 398. Biblioteca Conmemorativa Orton: 574.5222 P953.

Publicación no.: 156 Climatic impact of tropical lowland deforestation on nearby montane cloud forests [Impacto climático de la deforestación de las tierras bajas tropicales en los bosques nubosos montanos vecinos] / Lawton, R.O.; Nair, U.S.; Pielke, R.A.; Welch, R.M. (University of Alabama. Department of Biological Sciences, Huntsville, AL 35899, US <E-mail: lawton@email.uah.edu>). In: Science (ISSN 0036-8075), v. 294, p. 584-587. 2001. Tropical montane cloud forests (TMCFs) depend on predictable, frequent, and prolonged immersion in cloud. Clearing upwind lowland forest alters surface energy budgets in ways that influence dry season cloud fields and thus the TMCF environment. Landsat and Geostationary Operational Environmental Satellite imagery show that deforested areas of Costa Rica's Caribbean lowlands remain relatively cloud-free when forested regions have well-developed dry season cumulus cloud fields. Further, regional atmospheric simulations show that cloud base heights are higher over pasture than over forest areas under reasonable dry season conditions. These results suggest that land use in tropical lowlands has seriour impacts on ecosystems in adjacent mountains. Localización: Biblioteca OET: S7349. NBINA-6744. Publicación no.: 157 Changes in reef community structure after fifteen years of natural disturbances in the Eastern Pacific (Costa Rica) [Cambios en la estructura de la comunidad de un arrecife después de quince años de perturbaciones naturales en el Pacífico oriental (Costa Rica)] / Guzmán-Espinal, H.M.; Cortés-Núñez, J. (Smithsonian Tropical Research Institute, Box 2072, Balboa, PA <E-mail: guzmanh@naos.si.edu> <E-mail: jcortes@biologia.ucr.ac.cr>). In: Bulletin of Marine Science (ISSN 0007-4977), v. 69, no. 1, p. 133-149. 2001. Eastern Pacific coral reefs have been severely disturbed by natural events during the past two decades. We have monitored changes in reef structure and reef recovery after ENSO 1982-83 (starting in 1984), at sixteen permanent plots in four different habitats at Caño Island, Costa Rica. Reefs were also severely affected by dinoflagellate blooms in 1985, and by warming events in 1987, 1990-95 and 1997-98. The 1982-83 event caused approximately 100% coral mortality in shallow reef zones at Caño Island, particularly of pocilloporid species. Coral recruitment may have coincided with putative larval pulses during the various ENSO events or shortly after, as deduced by the presence of sexual recruits during 1987-88 and widespread sexual recruitment in 1993-94. Mortality of juvenile and adult colonies during the 1997-98 ENSO warming was low (5%), suggesting that populations of massive and branching corals may have been more tolerant of elevated thermal stress than during previous events. Supporting this notion are the Reynolds SST comparative plots for 1982-83 and 1997-98, which indicate similar warming trends and temperature maxima at this locality. Reefs at Caño Island are recovering, with significant increases in the number of now sexual recruits. Although 1984 levels of coral cover have not yet been attained island-wide, 70% cover occurs in reef areas on the north side of the island. Other disturbances, such as phytoplankton blooms that affected Pocillopora spp. In all habitats, may have retarded reef regeneration, complicating the course of recovery after the 1982-83 ENSO warming disturbance. Localización: Biblioteca OET: S7580. NBINA-3973. Publicación no.: 158 Coral bleaching and mortality associated with the 1997-98 El Niño in an upwelling environment in the Eastern Pacific (Gulf of Papagayo, Costa Rica) [Decoloración de corales y mortalidad asociada con El Niño 1997-98 en un ambiente nutritivamente rico en el Pacífico oriental (Golfo de Papagayo, Costa Rica)] / Jiménez-Centeno, C.E.; Cortés-Núñez, J.; León-Campos, A.; Ruiz-Campos, E. (Universität Bremen. ZMT, Fahrenheitstr 6, D-28359 Bremen, DE <E-mail: carlos.jimenez@zmt.uni-bremen.de> <E-mail: cjimenez@cariari.ucr.ac.cr> <E-mail: jcortes @biologia.ucr.ac.cr> <E-mail: aleon@racsa.co.cr> <E-mail: ruizc@cariari.ucr.ac.cr>). In: Bulletin of Marine Science (ISSN 0007-4977), v. 69, no. 1, p. 151-169. 2001. Coincidental with the 1997-98 El Niño, overall coral bleaching (32.4% of all colonies) and mortality (5.7%) were observed on the Pacific coast of Costa Rica, in the seasonally cool waters of the Gulf of Papagayo and in the more thermally stable waters of Golfo Dulce, At a Pavona clavus reef (Culebra Bay, Gulf of Papagayo), mean seawater temperature at 7 m depth ranged from 0.2 °C to 3.9 °C warmer than in previous years for nearly all months during 1997 and 1998. Water column temperature to 25-30 m depth was above 29 °C for several days, which exceeded the long term average. Even though mortality was low for most coral species, it was severe ( 90% decrease in live cover) in a small population of Leptoseris papyracea known only at Culebra Bay. Pocillopora spp. Accounted for more than 60% and 80% of all bleached and dead colonies, respectively. Other coral species regained their normal pigmentation by the beginning of 1998 with little evidence of tissue mortality. The El Niño event of 1997-98 is considered the strongest on record by some measures, but coral mortality on the Pacific coast of Costa Rica was much less than in previous events, drawing attention to El Niño disturbance variability on local scales. Localización: Biblioteca OET: S7978. NBINA-3972. Publicación no.: 159 Population declines and priorities for amphibian conservation in Latin America [Disminuciones de la población y prioridades para la conservación de anfibios en Latinoamérica] / Young, B.E.; Lips, K.R.; Reaser, J.K.; Ibáñez, R.D.; Salas, A.W.; Cedeño, J.R.; Coloma, L.A.; Ron, S.R.; La Marca, E.; Meyer, J.R.; Muñoz, A.; Bolaños-Vives, F.; Chaves-Cordero, G.A.; Romo, D. (NatureServe, 1101

Wilson Blvd, 15th Floor, Arlington, VA, 22209, US <E-mail: bruce_young@natureserve.org> <E-mail: dbmcd@uwyo.edu> <E-mail: bolanosv@biologia.ucr.ac.cr>). In: Conservation Biology (ISSN 0888-8892), v. 15, no. 5, p. 1213-1223. 2001. Although dramatic amphibian population declines have been reported worldwide, our understanding of the extent of the declines in Latin America, where amphibian diversity is high, is limited to a few well-documented studies. To better understand the geographic extent of declines, their possible causes, and the measures needed to improve Latin American scientists' ability to research the phenomenon and make effective management recommendations, we convened three regional workshops with 88 Latin American herpetologists and conservationists. Population declines are widespread in Latin America. At least 13 countries have experienced declines, and in 40 cases species are now thought to be extinct or extirpated in a country where they once occurred. Declines or extinctions have affected 30 genera and nine families of amphibians, Most declines have occurred in remote highlands, above 500 m in elevation in Central America and above 1000 m in the Andes. Most documented declines occurred in the 1980s. Of the possible causes studied to date, climate change appears to be important at one site and chytrid fungal disease has been identified at sites in three countries. Although many monitoring studies are currently underway in a variety of habitats, most studies are recent and of short duration. In a signed resolution, workshop participants called for greater collaboration and communication among scientists working in Latin America to understand the geographic extent of population declines and the distribution of possible causal factors. In situ conservation is important to protect habitats, but captive-rearing programs for species subject to imminent extinction are also needed. Better understanding of the taxonomy and natural history of amphibians and more funding for research and monitoring are critical to developing a scientific basis for management action to arrest and reverse population declines. Localización: Biblioteca OET: S7559. NBINA-4755. Publicación no.: 160 N2O emissions from humid tropical agricultural soils: Effects of soil moisture, texture and nitrogen availability [Emisiones de N2O de suelos agrícolas del trópico húmedo: Efectos sobre la humedad del suelo, textura y disponibilidad de nitrógeno] / Weitz, A.M.; Linder, E.; Frolking, S.E.; Crill, P.M.; Keller, M. (Max-Planck-Institute for Biogeochemistry, 07701 Jena, DE <E-mail: aweitz@bgc-jena.mpg.de> <E-mail: elinder@christa.unh.edu> <E-mail: michael.keller@unh.edu>). In: Soil Biology and Biochemistry (ISSN 0038-0717), v. 33, no. 7/8, p. 1077-1093. 2001. We studied soil moisture dynamics and nitrous oxide (N2O) fluxes from agricultural soils in the humid tropics of Costa Rica. Using a split-plot design on two soils (clay, loam) we compared two crop types (annual, perennial) each unfertilized and fertilized. Both soils are of andic origin. Their properties include relatively low bulk density and high organic matter content, water retention capacity, and hydraulic conductivity. The top 2-3 cm of the soils consists of distinct small aggregates (dia. 0.5 cm). We measured a strong gradient of bulk density and moisture within the top 7 cm of the clay soil. Using automated sampling and analysis systems we measured N2O emissions at 4.6 h intervals, meteorological variables, soil moisture, and temperature at 0.5 h intervals. Mean daily soil moisture content at 5 cm depth ranged from 46% water filled pore space (WFPS) on clay in April 1995 to near saturation on loam during a wet period in February 1996. On both soils the aggregated surface layer always remained unsaturated. Soils emitted N2O throughout the year. Mean N2O fluxes were 1.04+-0.72 ng N2O-N cm-2 h-1 (mean ± standard deviation) from unfertilized loam under annual crops compared to 3.54 ± 4.31 ng N2O-N cm-2 h-1 from the fertilized plot (351 days measurement). Fertilization dominated the temporal variation of N2O emissions. Generally fluxes peaked shortly after fertilization and were increased for up to 6 weeks ('post fertilization flux'). Emissions continued at a lower rate ('background flux') after fertilization effects faded. Mean post-fertilization fluxes were 6.3 ± 6.5 ng N2O-N cm-2 h-1 while the background flux rate was 2.2+-1.8 ng N2O-N cm² h-1. Soil moisture dynamics affected N2O emissions. Post fertilization fluxes were highest from wet soils; fluxes from relatively dry soils increased only after rain events. N2O emissions were weakly affected by soil moisture during phases of low N availability. Statistical modeling confirmed N availability and soil moisture as the major controls on N2O flux. Our data suggest that small-scale differences in soil structure and moisture content cause very different biogeochemical environments within the top 7 cm of soils, which is important for net N2O fluxes from soils. Localización: Biblioteca OET: S7767. NBINA-135. Publicación no.: 161 Modeling trace gas emissions from agricultural ecosystems [Modelaje de emisiones de gases traza de ecosistemas agrícolas] / Li, C.S. (University of New Hampshire. Institute for the Study of Earth, Oceans, and Space, Durham, NH 03824, US). In: Nutrient Cycling in Agroecosystems (ISSN 1385-1314), v. 58, no. 1/3, p. 259-276. 2000. A computer simulation model was developed for predicting trace gas emissions from agricultural ecosystems. The denitrification-decomposition model consists of two components. The first component, consisting of the soil climate, crop growth, and decomposition submodels, predicts soil temperature, moisture, pH, Eh, and substrate concentration profiles based on ecological drivers (e.g., climate, soil, vegetation, and anthropogenic activity). The second component, consisting of the nitrification, denitrification, and fermentation submodels, predicts NH3, NO, N2O, and CH4 fluxes based on the soil environmental variables. Classical laws of physics, chemistry, or biology or empirical equations generated from laboratory observations were used in the model to parameterize each specific reaction. The entire model links trace gas

emissions to basic ecological drivers. Through validation against data sets of NO, N2O, CH4, and NH3 emissions measured at four agricultural sites (Jiangsu, China; Costa Rica; Texas, USA; and Henan, China, respectively), the model showed its ability to capture patterns and magnitudes of trace gas emissions. Localización: Biblioteca OET: NBINA-131. Publicación no.: 162 Global climatic change and Brazilian ecosystems [El cambio climático mundial y los ecosistemas brasileños] / Moreira, A.G.; Schwartzman, S.; Moreira, A.G. (ed.); Schwartzman, S. In: As mudancas climaticas globais e os ecossistemas brasileiros Brasilia: Instituto de Pesquisa Ambiental da Amazonia, 2000. 165 p. ISBN: 85-87413-02-3. This book is based on the papers and discussions of a conference held on 22-23 October 1998 in Brazil. Sections deal with Brazil within the international framework (including the Kyoto protocol, and greenhouse gas emissions in Brazil), carbon in Brazilian ecosystems (including the importance of cerrado in capturing carbon), experiences of carbon-fixing projects in Bolivia and Costa Rica, and society and climatic change (including the participation of NGOs in current discussions). Localización: Non available. Publicación no.: 163 Emisión de gases con efecto invernadero y fijación de carbono en el sistema de producción de café (Coffea arabica) en Costa Rica [Emission of gases with greenhouse and carbon fixation effects in the coffee production system (Coffea arabica) in Costa Rica] / Montenegro-Ballestero, J.; Abarca-Monge, S. (Ministerio de Agricultura y Ganadería. Dirección de Protección Fitosanitaria, Turrialba, CR <E-mail: jmonte@guayabo.sa.ucr.ac.cr>). XIX Simposio Latinoamericano de caficultura. Memoria, San José CR2-6 Octubre, 2000. In: Boletín de Promecafé (ISSN 1010-1527), no. 87/88, p. 59-68. 2000. The emission of gases with greenhouse and carbon fixation effects was studied in coffee in Costa Rica. Application of nitrogen fertilizer appeared to have a direct effect on the emission of nitrous oxide and carbon dioxide The main fluctuations in the emission of nitrous oxide occurred on the first days after application of nitrogen fertilizer. Emissions of nitrous oxide and carbon dioxide were lower in coffee ecosystems than in natural woodlands. The concentration of ammonium and nitrate in the soil was related to emission of nitrous oxide. Localización: Biblioteca Conmemorativa Orton. Publicación no.: 164 Short-term nitrous oxide profile dynamics and emissions response to water, nitrogen and carbon additions in two tropical soils / Nobre, A.D.; Keller, M.; Crill, P.M.; Harriss, R.C. (Instituto Nacional de Pesquisas, Avenida Andre Araujo, 2936, BR-69083000 Manaus, Amazonas, BR <E-mail: anobre27@yahoo.com> <E-mail: michael.keller@unh.edu>). In: Biology and Fertility of Soils (ISSN 0178-2762), v. 34, no. 5, p. 363-373. 2001. Tropical soils are potentially the highest and least studied nitrous oxide (N2O) production areas in the world. The effect of water, nitrate and glucose additions on profile concentrations and episodic emissions of N2O for two volcanic soils in Costa Rica was examined. Magnitudes of episodic N2O pulses, as well as overall N2O emissions, varied considerably and consistently, depending on soil texture, soil water content, and kind and availability of substrates. Emission pulses began within 30 min, peaking no later than 8 h after wetting. Production in the soil occurred mainly in the layer between 5 and 20 cm deep, but depended directly on the temporal dynamics of the water profile. Changes in soil NO3- were associated with soil N2O concentration changes. Depending on the treatments, one episodic N2O production event driven by one moderate rain could account for less than 15% to more than 90% of the total weekly production. Previous survey studies may have underestimated the contribution of N2O emissions from tropical soils. In order to improve budgets and models of N2O emissions. episodic emissions driven by rain events and amendments must be considered. Localización: Biblioteca OET: NBINA-84. Publicación no.: 165 Balance of emissions with greenhouse effect in silvopastoral systems in three life zones of Costa Rica [Balance de emisiones con efecto invernadero en sistemas silvopastoriles en tres zonas de vida de Costa Rica] / Montenegro-Ballestero, J.; Abarca-Monge, S.; Ibrahim, M.A, (comp.). (Ministerio de Agricultura y Ganadería. Dirección de Protección Fitosanitaria, Turrialba, CR <E-mail: jmonte@guayabo.sa.ucr.ac.cr>). International Symposium on Silvopastoral Systems and II Congress on Agroforestry and Livestock Production in Latin America, San José CR; 2-9 Abr. 2001. In: Silvopastoral systems for restoration of degraded tropical pasture ecosystems Turrialba: CATIE / GTZ / DANIDA / IUFRO / FAO, 2001. p. 107-111. (No abstract). Localización: Biblioteca Conmemorativa Orton: CATIE 631.58063 I61s 2001. Publicación no.: 166 El bosque como proceso fundamental de los servicios ambientales en Costa Rica / Bermúdez-Ramírez, F.; Garita-Cruz, D.; Rodríguez-Chacón, J.E. (Universidad Nacional. Instituto de Investigación y Servicios Forestales y Escuela de Ciencias Ambientales, Heredia, CR <E-mail: jrodr@una.ac.cr>). Heredia: Universidad Nacional, 2000. 113 p. Tesis, Lic. Ingeniería en Ciencias Forestales, Universidad Nacional, Facultad de Ciencias de la Tierra y el Mar, Heredia (Costa Rica). (No abstract). Localización: Biblioteca Conmemorativa Orton: Thesis B516.

Publicación no.: 167 Fijación de carbono por pastos tropicales en las sabanas de suelos ácidos neotropicales / Fisher, M.J.; Trujillo, W. Seminario Intensificación de la Ganadería en Centroamérica: Beneficios Económicos y Ambientales, Turrialba CR; 24-26 May. 1999. In: Intensificación de la ganadería en Centroamérica: beneficios económicos y ambientales. Pomareda-Benel, C.; Steinfeld, H. (eds.) Turrialba: CATIE / FAO / SIDE, 2000. p. 115-135. (No abstract). Localización: Biblioteca Conmemorativa Orton: 333.7414 I61. Publicación no.: 168 Fijación de carbono, emisión de metano y de óxido nitroso en sistemas de producción bovina en Costa Rica / Montenegro-Ballestero, J.; Abarca-Monge, S. (Ministerio de Agricultura y Ganadería. Dirección de Protección Fitosanitaria, Turrialba, CR <E-mail: jmonte@guayabo.sa.ucr.ac.cr>). Seminario Intensificación de la Ganadería en Centroamérica: Beneficios Económicos y Ambientales, Turrialba CR; 24-26 May. 1999. In: Intensificación de la ganadería en Centroamérica: beneficios económicos y ambientales. Pomareda-Benel, C.; Steinfeld, H. (eds.) Turrialba: CATIE / FAO / SIDE, 2000. p. 151-174. (No abstract). Localización: Biblioteca Conmemorativa Orton: 333.7414 I61. Publicación no.: 169 Dióxido de carbono (CO2) como un proceso fundamental de los servicios ambientales en Costa Rica / Bermúdez-Oconitrillo, R.; Díaz-Hernández, A.; Escribano-Montoya, J. Heredia: Universidad Nacional, 2000. 102 p. Tesis, Licenciatura en Ciencias Forestales, Universidad Nacional, Escuela de Ciencias Ambientales, Heredia (Costa Rica). (No abstract). Localización: Biblioteca Conmemorativa Orton: Thesis B516d. Publicación no.: 170 Fijación de carbono en plantaciones de melina (Gmelina arborea Roxb.), teca (Tectona grandis L.f:) y pochote (Bombacopsis quinata Jacq.) en los cantones de Hojancha y Nicoya, Guanacaste, Costa Rica / Cubero-Moya, J.A.; Rojas-Piedra, S.R. (Fondo Nacional de Financiamiento Forestal (FONAFIFO), Apdo. 594-2120, San José, CR <E-mail: jcubero@fonafifo.com>). Heredia: Universidad Nacional, 1999. 94 p. Tesis, Licenciatura en Ciencias Forestales, Universidad Nacional, Escuela de Ciencias Ambientales, Heredia (Costa Rica). (No abstract). Localización: Biblioteca OET: T470. Biblioteca Conmemorativa Orton: Thesis C962f. Publicación no.: 171 Soil hydraulic controls over nitrogen oxide emissions and nitrogen cycling in tropical agriculture [Controles hidráulicos del suelo sobre las emisiones de óxido de nitrógeno y el reciclaje del nitrógeno en la agricultura tropical] / Weitz, A.M. (Max-Planck-Institute for Biogeochemistry, 07701 Jena, DE <E-mail: aweitz@bgc-jena.mpg.de>). Durham, NH: University of New Hampshire, 2000. 136 p. ISBN: 0-599-74011-6. Dissertation, Ph.D., University of New Hampshire, Graduate School, Durham, NH (USA). Soils are the major natural source of nitrous oxide (N2O). Intensive land use increased atmospheric concentrations of this greenhouse gas. Soil microbes produce and consume nitrogen oxides (NO, N2O) during the processes of nitrification (aerobic) and denitrification (anaerobic). Micro-scale variability of controlling factors cause nitrification and denitrification to occur simultaneously in soils, resulting in high spatial variability of nitrogen oxide emissions. Fertilization increases nutrient availability and thus N2O fluxes. Forest soils in the humid tropics account for 20-50% of all N2O sources. Expansion and intensification of tropical agriculture is expected to increase atmospheric N2O concentrations. We measured N2O fluxes from secondary humid tropical forest soils at La Selva Biological Station in Costa Rica, followed fluxes during forest conversion and studied emissions from unfertilized and fertilized agricultural soils. We related fluxes to soil moisture dynamics and agricultural practice. Gases were measured using manual and automated chamber techniques. Soil moisture content was measured using manual (auger) and automated (Time Domain Reflectrometry; TDR) sampling techniques. A 3-phase-mixing model was found suitable to calibrate TDR technique for the studied soils. The field experiment was based on a split-plot design, comparing clay versus loam, each under fertilized and unfertilized annual and perennial crop. Soils feature relatively low bulk density, high hydraulic conductivity and high organic matter content. Mean soil moisture content was above 70% water-filled-pore-space (WFPS) in both soils and land uses. N2O was emitted throughout the year. Fluxes from forest soils showed no seasonality. Forest conversion caused fluxes to increase temporarily. Fertilization was the dominant source for temporal variability under agricultural use, differences in flux dynamics were large between individual post-fertilization phases. N2O-loss as % of applied fertilizer-N increased with soil moisture. Spatial variability was generally high, especially post-fertilization. Repeated fertilization increased mean and variation of fluxes. Emissions simulated by regression models and by the physically based Denitrification-Decomposition model matched field measured fluxes well. Both modeling techniques confirmed that nutrient availability and soil moisture content were the dominant flux controls. In aggregated soils differences in soil structure between the surface layer and soil at 0.05 m depth may affect moisture content and consequently soil N2O fluxes. Localización: Non available. Publicación no.: 172 Ecology and evolution of Phainoptila melanoxantha (Bombycillidae, aves) in the highlands of Costa Rica and western Panama [Ecología y evolución de Phainoptila melanoxantha (Bombycillidae, aves) en las tierras altas de Costa Rica y el occidente de Panamá] / Barrantes-Montero, G.

(Universidad de Costa Rica. Escuela de Biología, Museo de Zoología, San José, CR <E-mail: gbarrantes@biologia.ucr.ac.cr>). St. Louis, MO: University of Missouri, 2001. 175 p. ISBN: 0-599-99078-3. Dissertation, Ph.D., University of Missouri, International Center for Tropical Ecology, St. Louis, MO (USA). Composition of species in a community is the result of historical and ecological events operating at different temporal and spatial scales. Regional historical changes in geomorphology and climate generally promote dispersal and speciation when new habitats are created and connectivity between similar habitats change at regional and local scales. Biotic interactions, such as competition and predation are also important factors in determining species membership in a given community. In this study I examined the role of historical and ecological factors in determining species composition, and speciation of the highland avifauna of Costa Rica and western Panamá. Then I analysed the ecology and evolution of Phainoptila melanoxantha, a highland endemic species. In particular, I addressed aspects of diet, reproduction, population dynamics, and causes of genetic and morphological divergence of this species. I studied how historical (i.e, geological and climatic changes) and ecological (i.e., diet, altitudinal distribution) factors determined species composition and distribution in the region. Results of this study indicate that composition of this highland avifauna is the result of recurrent dispersal events from South and North America, and likely lowland species that adapted to gradual changes in climatic conditions. I studied the general aspects of P. melanoxantha ecology and population dynamics. The major goals were (1) - to describe habitat use, diet, and reproductive behavior of this species; and (2) - to analyse the dynamics (extinction - colonization events) of local populations of P. melanoxantha within the context of a metapopulation framework. Results indicated that P. melanoxantha inhabits mainly subalpine, elfin, and upper montane forests where it feeds on a large variety of fruit species with little overlap among mountain ran. The main goal in Chapter 3 was to assess the effect of gene flow and altitudinal changes in highland forests on the geographic distribution of haplotypes of P. melanoxantha, using mitochondrial DNA (mtDNA). Finally, I found that major haplotype divergence in the intraspecific phylogeny, as well as in the cladistic nested analysis were congruent with observed morphological discontinuities. I studied the effect of wind on shaping wing and tail morphology in the two subspecies of P. melanoxantha; P. m. melanoxantha and P. m. parkeri. Localización: Non available. Publicación no.: 173 Perception de l'environnement et des changements climatiques chez les leaders de groupes verts du Quebec et du Costa Rica [Percepción del ambiente y de los cambios climáticos de los líderes de grupos ambientalistas de Quebec y de Costa Rica] / Perron, B. (Université de Montréal. Département de Sociologie, C.P. 6128, succ. Centre.ville, Montréal (Quebec) H3C 3J7, CA <E-mail: benoit.perron@umontreal.ca>). Montreal: Université de Montreal, 2000. 250 p. ISBN: 0-612-52117-6. Dissertation, Ph.D., Université de Montreal, Graduate School, Montreal (Canada). Cette thèse, de nature exploratoire, s'inscrit dans ce qu'il est convenu d'appeler l'étude des dimensions humaines des changements environnementaux globaux. Elle vise d'abord à saisir les différents schémas attitudinaux de pensée "environnementale" qui animent les leaders de groupes verts, pour ensuite en arriver é une meilleure compréhension de la perception du phénoméne des changements climatiques chez ceux-ci. Trois études ont été réalisées afin d'atteindre ces objectifs généraux. Bien que ces études adoptent chacune un cadre théorique spécifique é leurs problématiques respectives, des approches générales s'en dégagent. D'une part, pour expliquer les attitudes environnementales, une approche psychosociologique, qui tient compte de déterminants l'structurels; sociodémographiques (âge, lieu, éducation, sexe, nationalité) et de déterminants cognitifs (attitudes gérales ne ciblant pas nécessairement l'environnement), est privilégiée. D'autre part, la sociologie des mouvements sociaux sert d'arriêre-plan conceptuel pour situer les sujets de recherche, c'est-à-dire les leaders de groupes verts. Au point de vue méthodologique, ces trois études utilisent le même questionnaire standardisé. La premiêre étude est réalisée auprês de leaders de groupes verts du Québec. Elle vise à en établir une typologie. Trois types de leaders émergent des analyses effectuées. Les "écologistes', plus radicaux, sont méfiants à l'égard de la science et de la technologie conventionnelle et acceptent que des sacrifices économiques soient faits pour améliorer la qualité de l'environnement. Ils sont plus jeunes que les autres et militent majoritairement à Montréal. Quant aux "environnementalistes nationalistes" et aux "environnementalistes de marché", ils se distinguent principalement par des positions divergentes à l'égard d'Hydro-Québec. Les premiers percoivent positivement cette société d'état, tandis que les seconds la voient d'un mauvais oeil et en favorisent la privatisation. La deuxiême étude cherche à voir si le problême global des changements climatiques constitue un dossier générateur d'une solidarité à l'intérieur du mouvement vert international. Elle est réalisée auprês de leaders de groupes verts du Québec et du Costa Rica afin d'incorporer une dimension Nord-Sud aux analyses. Les attitudes des répondants à l'égard d'aspects-clés des changements climatiques sont comparées en fonction de deux facteurs potentiellement discriminants: leur appartenance à un type d'orientation idéologique verte ("écologisme", "environnementalisme" ou "environnementalisme de marché") et leur nationalité. Enfin, la dernière étude cherche à découvrir les déterminants de l'appui à sept (7) politiques de protection du climat par les leaders de groupes verts du Québec et du Costa Rica. Localización: Non available. Publicación no.: 174 Save the clouds, too / Torres, A. In: Environment (ISSN 0013-9157), v. 44, no. 3, p. 4. 2002.

Deforestation affects more than the forest and its inhabitants-it also changes weather patterns by reducing the amount of water in the air for cloud formation. Researchers from the University of Alabama in Huntsville (UAH) have found that logging in Costa Rica's lowland forests is changing the region's weather. UAH scientists tracked the way clouds are formed in the lowlands and then swept into the mountains by strong winds. Normally, trees distribute water into the air through transpiration. This also cools the air, which keeps the cloud base low. The low-lying clouds are a vital source of water for the mountain forests during the annual dry season, but when trees are cut down, the air warms and pushes the clouds too high to provide enough water for the mountain forests. Ron Welch, chairman of UAH's atmospheric science department, says, "We're seeing that if you deforest the lowlands it impacts the environment several hundreds of kilometers away"-a discovery that may have serious implications for conservation efforts in Central America. The researchers found that in the last 25 years, Costa Rica's cloud base has risen, the dry season has become several weeks longer, and the amphibian population has diminished. In addition, UAH biologist Robert Lawton points out, "Reduced cloud interaction with the mountains might mean a substantially reduced supply of water". Localización: Biblioteca OET: NBINA-202. Publicación no.: 175 Tree cutting harms water supplies / Johnson, D. In: The Futurist (ISSN 0016-3317), v. 36, no. 2, p. 6-7. 2002. Heavy logging in the forests of Costa Rica's Caribbean lowlands is changing that country's weather patterns, according to scientists studying cloud formations there. "We're seeing that if you deforest the lowlands it impacts the environment several hundreds of kilometers away," reports Ron Welch, chairman of the Atmospheric Science Department at the University of Alabama in Huntsville (UAH). Using satellite and on-site data sources, UAH researchers have created models that track the way clouds are formed in Costa Rica's lowlands and then pushed into the mountains by strong trade winds. Low clouds are a vital source of water for the country's mountain forests during the annual dry season. Costa Rican lowland forests put water vapor into the air through transpiration, a process that is essential to the formation of dense, lowlying clouds. Trees also cool the air in this region, keeping the cloud base low. Cutting down the forests reduces the amount of water available for cloud formation and also warms the air. Warmer air drives the cloud layer to a higher altitude and trade winds carry the clouds into the mountains, but not at the low levels required to bring sufficient water to mountain forests. In the past 25 years Costa Rica's cloud base has risen, according to UAH researchers. During the same period the country's dry season has grown longer by several weeks and there has been a decline in the amphibian population. Altering the cloud forest may also bring unwelcome economic and social changes to the lowlands. Low clouds in Costa Rica are an essential water source for mountain forests during the dry season. In this valley near the Pacific coast, the clouds also provide enough water to support a regional dairy industry. A model of simulated cloud cross sections in Cordillera de Tilarán, Costa Rica. Above, the model shows smaller clouds at a higher altitude above a totally deforested lowland region. Below, the model reveals large, low-level clouds over a completely forested landscape. "There are some important potential hydrologic impacts. Dry season river flows might change. Reduced cloud interaction with the mountains might mean a substantially reduced supply of water for urban water systems, reduced water for irrigation, and reduced water for hydroelectric development," argues Robert Lawton, a biologist at UAH. Deforestation in Costa Rica could have a significant impact on the prospects of protecting Central America's biological "hot spots" fragmented regions that are especially rich in plant and animal life--extending from Guatemala to Panama. Ongoing research may help determine the range of climate effects related to Costa Rican deforestation. It could also guide conservation efforts and land-management practices in the future. "We have a chance here to develop a set of tools to allow us to look anywhere, from Cameroon to Fiji or Ecuador, and find out what might happen under various land-use scenarios," concludes Welch. Localización: Biblioteca OET: S7868. NBINA-201. Publicación no.: 176 Nitrous oxide, nitric oxide, and methane fluxes from soils following clearing and burning of tropical secondary forest [Flujos de óxido nitroso, óxido nítrico y metano de suelos luego de la tala y quema de bosques secundarios tropicales] / Weitz, A.M.; Veldkamp, E.; Keller, M.; Neff, J.C.; Crill, P.M. (University of New Hampshire. Institute for the Study of Earth, Oceans and Space, Durham, US <E-mail: aweitz@bgc-jena.mpg.de> <E-mail: eveldka@gwdg.de> <E-mail: michael.keller@unh.edu>). In: Journal of Geophysical Research: Atmosphere (ISSN 0148-0227), v. 103, no. D21, p. 28.047-28.058. 1998. Conversion of humid tropical forest to agriculture significantly alters trace gas emissions from soils. We report nitrous oxide (N2O), nitric oxide (NO), and methane (CH4) fluxes from secondary forest soils prior to and during deforestation, and throughout the first agricultural cropping. Annual average nitrogen oxide emissions from forest soils were 1.5 ng N cm² h-1 for N2O and 0.9 ng N cm² h-1 for NO. Forest clearing increased the level of extractable nitrate in soils and average nitrogen oxides fluxes (2.7 no N cm² h-1 for N2O, and 8.1 ng N cm² h-1 for NO). Immediately after biomass burning, short-term peaks of N2O and NO (123 ng N cm² h-1 for N2O, and 41 ng N cm² h-1 for NO) were superimposed on generally increased fluxes. Peak emissions declined within 3 days after burning. Postburn fluxes stayed higher than measured on adjacent forest sites for 3-4 months (averages for postbum fluxes were 17.5 ng N cm² h-1 for N2O, and 19.2 ng N cm² h-1 for NO). Increased N2O and NO emissions after clearing and until cropping were probably

due to a combination of increased rates of nitrogen cycling and higher gaseous diffusion in drying soils. Compared to emissions from young pastures in the region, fluxes of nitrogen oxides from unfertilized agricultural areas were low (3.9 ng N cm² h-1 for N2O and 3.4 ng cm² h-1 for NO), probably due to nitrogen uptake by fast growing corn plants and losses by leaching with draining soil water in the wet season. Variation in CH4 fluxes was high for all land use periods. Forest soils consumed an average of 1.0 mg CH4 cm² h-1, which slightly increased in drier soils after clearing (1.2 mg CH4 cm² d-1). Postburn CH4 consumption by soils was slightly reduced (0.8 mg CH4 cm² d-1) compared to forest soils. Unfertilized agricultural soils consumed less CH4 than forest soils. Localización: Biblioteca OET: S7768. Publicación no.: 177 Accelerated Pleistocene coral extinctions in the Caribbean basin shown by uranium-lead (U-Pb) dating [Extinciones aceleradas de corales durante el Pleistoceno en la cuenca del Caribe demostrado mediante datación con uranio-plomo (U-Pb)] / Getty, S.R.; Asmerom, Y.; Quinn, T.M.; Budd, A.F. (Colorado College. Department of Geology, Colorado Springs, CO 80903, US <E-mail: sgetty@coloradocollege.edu> <E-mail: ann-budd@uiowa.edu>). In: Geology (Boulder) (ISSN 0091-7613), v. 29, no. 7, p. 639-642. 2001. Ages of corals and shallow-marine sequences define rates of marine invertebrate evolution, tectonic uplift, and paleoclimate change, yet accurate ages are difficult to obtain prior to the Late Pleistocene. We report a new approach for combining uranium-lead (U-Pb) and uranium-series dating for the Middle Pleistocene corals from the Caribbean side of Costa Rica. Two corals have 230Th/238U in secular equil., small excesses in d234U, and 206Pb*/238U ages of 1.02±0.07 and 1.288±0.034 Myr. The latter coral age dates a recognized geomagnetic event to ~ 1.3 Myr, a time at which no polarity events had been identified. The new ages also show that the major coral extinction in the Caribbean Basin occurred shortly after 1.0-0.9 Ma, much more recently than previously thought. This coral extinction now coincides with the global change at 1.0-0.8 Ma to the current pattern of glacial-interglacial cycles and amplified changes in sea level. These factors may have provided a new, strong environmental mechanism for rapid habitat modification and coral extinction. Localización: Biblioteca OET: S8590. NBINA-1200. Publicación no.: 178 Late Holocene environment history and tephrostratigraphy in northwestern Costa Rica: a 4000 year record from Lago Cote [Historia y tefrostratigrafía del ambiente en el Holoceno Tardío en el noroeste de Costa Rica: un registro de 4000 años del Lago Cote] / Arford, M.R. (The University of Tennessee. Department of Geography, 304 Burchfiel Geography Building, Knoxville, TN 37996-09251420, US). Knoxville, TN: The University of Tennessee, 2001. 139 p. Thesis, M.Sc., The University of Tennessee, Graduate School, Knoxville, TN (USA). Paleoecological studies in the neotropics are revealing changes in past climate regimes and human use of the landscape that where previously unknown. Few paleoecology studies have been conducted in Costa Rica and, in most of these studies, strong evidence of prehistoric human impacts overwhelmed evidence of climate signals. Lago Cote, in the Cordillera de Tilarán, is the largest natural lake in Costa Rica (198 ha). Because of its size, Cote sediments reflect a more regional record of pollen and charcoal accumulation. The sediments also preserve tephra layers from past eruptions of nearby Arenal Volcano. In this thesis, I present an environmental history and tephrostratigraphy based on pollen, charcoal, and tephra preserved in 3.6 m sediment core from Lago Cote. High amounts of grass charcoal and grass pollen from the lower part of the core indicate a drier climate regime with frequent landscape fires from ~ 3900 cal. yr BP. After 2600 cal. yr BP, a dramatic decrease of grass pollen and charcoal reflects wetter conditions that limited landscape fires and agriculture. This climate change occurred simultaneously with an archaeological phase change documented in the nearby Arenal basin by the Proyecto Prehistórico Arenal. Small peaks in pollen of lower montane pollen taxa at the base of this zone may indicate forest regeneration. Comparison of Cote tephra to an earlier tephrochronology at the nearby El Tajo site was not straighforward. Cote tephras, analyzed by X-ray fluorescence, show differences in mineral composition when compared to the more proximal El Tajo tephras, and have lower levels of silicon dioxide than found at El Tajo. Because of major differences in tephra chemistries, visual comparison was a more effective way to compare tephra layers between the sites. Three tephra layers reported from El Tajo are not present in the Cote sediments, including the most recent Arenal Eruption in 1968. Two tephra layers in the lower part of the Cote core are not part of the El Tajo tephrochronology, and represent earlier eruptions from Arenal or the nearby and older Chato volcano. In the Cote sediments, peaks in Cecropia pollen follow at least two tephra layers, most likely indicating vegetation regeneration following eruptions of Arenal volcano. Localización: Biblioteca OET: Tesis 395. Publicación no.: 179 Joint implementation in Costa Rica: a case study at the community level [Realización conjunta en Costa Rica: un estudio de caso a nivel comunitario] / Segura-Bonilla, O.; Lindegaard, K. (Universidad Nacional. Centro Internacional en Política Económica para el Desarrollo Sostenible (CINPE), Heredia, CR <E-mail: osegura@una.ac.cr>). In: Journal of Sustainable Forestry (ISSN 1054-9811), v. 12, no. 1/2, p. 61-78. 2001. The policy of joint implementation (JI) is emerging as a new strategy for implementing global environmental aims, especially with regard to regulating the climate change process, where emission source and sink countries agree to develop a joint programme on a mixed argument of partnership and cost effectiveness.

Pros and cons have emerged during the development of this system. Costa Rica is the first country, together with Norway, to launch such a programme jointly, and Costa Rica is also the first country developing Carbon Tradable Offset bonds to be sold on the world market as a new commodity. The JI projects should be viewed from many angles and considered with respect to the issues of cost effectiveness, environmental effects, equity, linkage dynamics and the learning effects of the specific projects. A project in the community of Junquillal de Santa Cruz in northern Costa Rica is described to explore such questions and effects. Forestry projects are considered an especially complicated issue, in that the forest provides a whole range of services and products and, accordingly involves a wide range of actors and stakeholders. A JI programme in itself is not going to solve the problems at the community level. However, if accompanied by public and private initiatives, it definitely can generate an important change. Localización: Biblioteca OET: S9508. 333.750.97 C641. Publicación no.: 180 The effects of climate on the growth and physiology of tropical rainforest trees [Los efectos del clima en el crecimiento y fisiología de árboles del bosque lluvioso tropical] / O'Brien, J.J. (Florida International University. Department of Biological Sciences, Miami, FL 33199, US <E-mail: jjobrien@fs.fed.us>). Miami: Florida International University, 2001. 120 p. ISBN: 0-493-43978-1. Dissertation, Ph.D., Florida International University, Graduate School, Miami, FL (USA). Tropical rainforests account for more than a third of global net primary production and contain more than half of the global forest carbon. Though these forests are a disproportionately important component of the global carbon cycle, the relationship between rainforest productivity and climate remains poorly understood. Understanding the link between current climate and rainforest tree stem diameter increment, a major constituent of forest productivity, will. be crucial to efforts at modeling future climate and rainforest response to climate change. This work reports the physiological and stem growth responses to micrometeorological and phenological states of ten species of canopy trees in a Costa Rican wet tropical forest at sub-annual time intervals. I measured tree growth using band dendrometers and estimated leaf and reproductive phenological states monthly. Electronic data loggers recorded xylem sap flow (an indicator of photosynthetic rate) and weather at half-hour intervals. An analysis of xylem sap flow showed that physiological responses were independent of species, which allowed me to construct a general model of weather driven sap flow rates. This model predicted more than eighty percent of climate driven sap flow variation. Leaf phenology influenced growth in three of the ten species, with two of these species showing a link between leaf phenology and weather. A combination of rainfall, air temperature, and irradiance likely provided the cues that triggered leaf drop in Dipteryx panamensis and Lecythis ampla. Combining the results of the sap flow model, growth, and the climate measures showed tree growth was correlated to climate, though the majority of growth variation remained unexplained. Low variance in the environmental variables and growth rates likely contributed to the large amount of unexplained variation. A simple model that included previous growth increment and three meteorological variables explained from four to nearly fifty percent of the growth variation. Significant growth carryover existed in six of the ten species, and rainfall was positively correlated to growth in eight of the ten species. Minimum nighttime temperature was also correlated to higher growth rates in five of tile species and irradiance in two species. These results indicate that tropical rainforest tree trunks could act as carbon sinks if future climate becomes wetter and slightly warmer. Localización: Biblioteca OET: Tesis 393. Publicación no.: 181 Predicted regional impacts of climate change on the geographical distribution and diversity of tropical forests in Costa Rica [Predicción de impactos regionales causados por el cambio climático en la distribución geográfica y diversidad de los bosques tropicales en Costa Rica] / Enquist, C.A.F. (University of New Mexico. Department of Biology, Albuquerque, NM 87131-1091, US <E-mail: cafinn@unm.edu>). In: Journal of Biogeography (ISSN 0305-0270), v. 29, no. 4, p. 519-534. 2002. Aim: Spatial models generated in a geographical information system (GIS) are utilized to predict shifts in the distribution and diversity of tropical forests in Costa Rica in response to climate change. Location: Analyses were conducted using the Holdridge life zone classification system for the Central American country of Costa Rica. Methods: Mean annual precipitation and temperature ranges were varied to reflect different magnitudes of climate change and then used to predict the distributions of nineteen forest types (life zones). Holdridge et al.'s (1971) field survey data of species richness and endemism for ten Costa Rican life zones were also analyzed and considered in view of the climate change scenarios. Results: The scenarios indicated that shifts in the distribution of tropical forest life zones are likely to occur as a result of climatic changes. High elevation life zones were shown to be more sensitive to changes in temperature, while lower elevation life zones tended to be more sensitive to changes in precipitation. Regional life zone diversity was greatly reduced in an extreme wet and warm climate scenario. Three elevation-associated life zones (lower montane rain forest, montane rain forest, and premontane rain forest) ranked in the top four in percentage number of endemic species. The lowland seasonally dry forest life zone ranked second in this group, suggesting that this life zone has a unique species composition in comparison with other lowland Holdridge life zones. On the nineteen life zones, these four life zones displayed particular sensitivity to the climate changes modelled here. Main conclusions: Elevation-associated life zones may be particularly vulnerable to future climatic changes. This is also true of lowland seasonally dry forest. Geographical regions in Costa Rica that contain

these life zones are likely to warrant special management and conservation attention in the event of predicted climate change. Localización: Biblioteca OET: NBINA-6735. Publicación no.: 182 Potential effects of climate change on canopy communities in a tropical cloud forest: an experimental approach [Efectos potenciales del cambio climático en las comunidades del dosel en un bosque nuboso tropical: un enfoque experimental] / Nadkarni, N.M.; Solano, R. (The Evergreen State College, Olympia, WA 98505, US <E-mail: nadkarnn@evergreen.edu>). In: Oecologia (ISSN 0029-8549), v. 131, p. 580-586. 2002. Global climate change models predict reduced cloud water in tropical montane forests. To test the effects of reduced cloud water on epiphytes, plants that are tightly coupled to atmospheric inputs, we transplanted epiphytes and their arboreal soil from upper cloud forest trees to trees at slightly lower elevations that are naturally exposed to less cloud water. Control plants moved between trees within the upper site showed no transplantation effects, but experimental plants at lower sites had significantly higher leaf mortality, lower leaf production, and reduced longevity. After the epiphytes died, seedlings of terrestrial gap-colonizing tree species grew from the seed banks within the residual mats of arboreal soil. Greenhouse experiments confirmed that the death of epiphytes can result in radical compositional changes of canopy communities. Thus, tropical montane epiphyte communities constitute both a potentially powerful tool for detecting climate changes and a rich arena to study plant/soil/seed interactions under natural and manipulated conditions. This study also provides experimental evidence that the potential effects of global climate change on canopy and terrestrial communities can be significant for cloud forest biota. Results suggest there will be negative effects on the productivity and longevity of particular epiphytes and a subsequent emergence of an emerging terrestrial component into the canopy community from a previously suppressed seed bank. Localización: Biblioteca OET: S9442. NBINA-309. Publicación no.: 183 Climate change and forest management in the Western Hemisphere [Cambio climático y manejo forestal en el hemisferio occidental] / Dore, M.H.I. (Brock University, St. Catherines, Ontario, L2T 2M5, CA <E-mail: dore@brocku.ca>). In: Journal of Sustainable Forestry (ISSN 1054-9811), v. 12, no. 1/2, 191 p. 2001. After an introduction by the editor (pages 1-5), this special issue presents a collection of 8 papers on various aspects of forest policy in relation to climate change and to forest management in South, Central and North America. The papers are arranged in 3 parts. Part I, Integrated forest management, has 3 papers covering obstacles to comprehensive integration, forest management for timber production in relation to concern over biodiversity in Argentina and Costa Rica, and the impact of the regulation of climate change through new international initiatives such as policies designed to fulfil emission reduction targets by adopting bilateral policies (as exemplified by joint implementation in Costa Rica). Part II, Amazonia forests, has 2 papers addressing the role of the Brazilian rain forest in the global carbon cycle and the implications for the sustainable use of the rain forests. Part III, North American forests, has 3 papers focusing on the carbon cycle and the valuation of Canadian forests for carbon sequestration, the sustainable management of forests in British Columbia, and deforestation and land use change in Mexico. Localización: Non available. Publicación no.: 184 Emisión de gases con efecto invernadero y fijación de carbono en el sistema de producción de café (coffea arabica) en Costa Rica [Gas emission with the greenhouse effect and nitrogen fixation in the system of coffee (Coffea arabica) production in Costa Rica] / Montenegro-Ballestero, J.; Abarca-Monge, S. (Ministerio de Agricultura y Ganadería. Dirección de Protección Fitosanitaria, Turrialba, CR <E-mail: jmonte@guayabo.sa.ucr.ac.cr>). In: Boletín de Promecafé (ISSN 1010-1527), no. 89, p. 9-17. 2001. Investigations were conducted to determine the pattern of emission of N2O and CO2 in soils under coffee in Costa Rica, to determine a possible relationship between emissions and soil types, to determine the quantity of fixed nitrogen in soil under coffee. Data are presented on soil fertility under shaded coffee in Cartago and coffee fully exposed to the sun in Heredia, Costa Rica, in 1999, as well as total N2O and CO2 emissions, and N and C emissions in 1990, 1996 and 1997. Information is provided on materials and methods used in relation to crop management in the shade and full sun position, sampling of gas emissions, temperature and humidity of soil, N-NH4 and N-NO3 content in soil, soil density and soil fertility. Localización: Non available. Publicación no.: 185 Heads in the clouds [Cabezas en las nubes] / Holmes, B. (151 Wardour St, London, W1F 8WE, GB <E-mail: news@newscientist.com>). In: New Scientist (ISSN 0262-4079), v. 162, no. 2185, p. 32-36. 1999. The effects of global warming on the cloud forest ecosystems of Costa Rica are discussed. The author describes the depletion of the frog populations and the change in the bird and lizard fauna. One researcher, Alan Pounds, a conservation biologist affiliated with the University of Miami, Florida, set out to study why the frogs were disappearing from the Monteverde cloud forest. Twenty of the 50 frog species in his 30-square-kilometer study site vanished after a population collapse in 1987, and other population crashes followed in 1994 and 1998. The key to the mystery of what was causing these crashes was the steady increase from

1973 to 1998 in the number of dry days in each winter dry season, and the frequency of dry spells lasting five or more days. The solution to the one puzzle brought on another. During this same time there was a trend toward cooler days and warmer nights, making cloudier than usual conditions. This may support the idea that a fungal infection has killed frogs from Central America to Australia and that the climate change may be an underlying factor. Fungus is typically not infectious, but when an animal is stressed from some other factor, it is more likely to become infected. The findings at Monteverde also fit with the growing belief that the first effects of climate warming should be observed at high-elevation sites, particularly in the tropics. Localización: Biblioteca OET: S8317. Publicación no.: 186 Ecología y conservación de bosques neotropicales [Ecology and conservation of neotropical forests] / Guariguata-Urbano, M.R. (ed.); Kattan, G.H. (ed.). (Centro Agronómico Tropical de Investigación y Enseñanza. Unidad Manejo Bosques Naturales, Apdo. 7170, Turrialba, CR <E-mail: mguarigu@catie.ac.cr> <E-mail: gukattan@cali.cetcol.net.co>). Cartago: Libro Universitario Regional (EULAC-GTZ), 2002. 692 p. ISBN: 9968-801-11-9. El presente volumen ofrece una visión general del conocimiento actual sobre la ecología de los bosques húmedos y lluviosos del neotrópico. Nuestra intención ha sido la de seleccionar los temas más representativos para ilustrar la compleja dinámica de estos bosques, pero necesariamente se han quedado algunos temas importantes por fuera. Además, algunos capítulos presentan revisiones básicas, mientras que otros ofrecen un análisis quizás más profundo de un tema en particular. El libro está organizado en seis secciones. Las dos primeras secciones presentan una descripción básica del escenario sobre el cual se desarrolla el bosque neotropical. En la Sección I se describe la evolución del bosque, comenzando con los fenómenos geológicos y de cambio climático global que han dictado la distribución y estructura de este ecosistema a gran escala espacial y temporal, terminando con los factores históricos que han operado a escalas espacio-temporales menores. La Sección II discute algunos de los factores abióticos más importantes en la biología del bosque, como son la luz, el agua y los nutrimentos, y su interacción con la vegetación. En conjunto, estas dos secciones presentan una visión comprensiva de los factores que determinan los patrones de distribución, estructura y diversidad de los bosques húmedos y lluviosos neotropicales a múltiples niveles de organización biológica. La Sección III se enfoca principalmente a nivel de organismo y presenta algunos procesos ecofisiológicos esenciales como son la adquisición de carbono atmosférico por parte de las plantas y los patrones de flujo de agua a través de ellas, y examina en particular la ecofisiología de epífitas y hemiepífitas, las cuales constituyen una parte importante del bosque, en términos de diversidad de especies y en el control de ciertos procesos del ecosistema. En la Sección IV se enfatizan algunos aspectos de la dinámica poblacional de organismos como árboles y mamíferos, y cómo esta dinámica se traduce en patrones a nivel de comunidad. La Sección V se centra en las interacciones entre organismos que modulan algunos de los principales procesos bióticos del bosque neotropical, como son las interacciones entre microorganismos y plantas, la herbivoría y las defensas de las plantas, la polinización y la frugivoría. Estas interacciones representan la quintaesencia de este ecosistema y han sido tema de intenso estudio por varias décadas. Finalmente, el libro cierra con una sexta sección que explora ciertos aspectos de la interacción contemporánea entre la población humana y la ecología del bosque. El primer capítulo de esta sección ilustra las consecuencias de la fragmentación de los bosques sobre la diversidad biológica, mientras que el segundo describe cómo se recuperan la estructura y la función del bosque por medio de la sucesión secundaria luego de la deforestación. El último capítulo expone de manera resumida el desarrollo de una importante técnica de estudio, la teledetección, la cual puede ser de gran ayuda para evaluar, a gran escala, los procesos de deforestación y, a la vez, para intentar mitigar los efectos de esta deforestación. Localización: Biblioteca OET: 574.52642 E19ec. Publicación no.: 187 Geographic and vertical patterns of stable carbon isotopes in tropical rain forest soils of Costa Rica [Patrones geográficos y verticales de los isótopos estables del carbón en suelos de bosques lluviosos tropicales de Costa Rica] / Powers, J.S.; Schlesinger, W.H. (University of Minnesota. Department of Soil, Water & Climate, St Paul, MN 55108, US <E-mail: powers@umn.edu>). In: Geoderma (ISSN 0016-7061), v. 109, no. 1/2, p. 141-160. 2002. Understanding the natural variability in the stable carbon isotope composition of vegetation and soils can aid studies of soil carbon dynamics, and is a prerequisite for using C-13 as a natural tracer when vegetation communities change from one photosynthetic pathway to another (e.g. C4 pasture grasses replacing C3 forests). To examine the geographic and vertical patterns of delta(13)C under mature rain forest vegetation, we measured the isotopic composition of leaf litter, roots, and mineral soil profiles in 35 plots located in a 140,000-ha study region in northeastern Costa Rica. We hypothesized that soil carbon isotopic composition would be closely coupled to the signature of detrital inputs (the average delta(13)C of forest floor and fine-root biomass) and that the increase in delta(13)C with depth would be related to abiotic variables that influence soil carbon turnover rates. The correlations between surface soil isotopic composition (0-10 cm) and biophysical factors varied across the landscape. In multiple regression analyses, combinations of soil particle-size distribution and soil C/N ratio explained between 60% and 82% of the variation in surface soil isotopic composition for different regions in the landscape, but the isotopic composition of litter and roots did not explain any additional variation. The isotopic composition of litter, roots, and surface soils (0-20 cm) was fairly similar over large, regional gradients of elevation and edaphic properties (the range of variation was

2.6parts per thousand), but diverged considerably at depths below 20 cm (up to 5.8parts per thousand differences). These large regional differences in the isotopic composition of soil C at depth are attributed to variation in soil carbon turnover rates across the landscape. Localización: Biblioteca OET: NBINA-495. Publicación no.: 188 Evolution of the Organization for Tropical Studies [Evolución de la Organización para Estudios Tropicales] / Burlingame, L.J. (Franklin and Marshall College. Science, Technology, and Society Program; P.O. Box 3003, Lancaster, PA 17604, US <E-mail: leslie.burlingame@fandm.edu>). In: Revista de Biología Tropical (ISSN 0034-7744), v. 50, no. 2, p. 439-472. 2002. The Organization for Tropical Studies (OTS)/Organización para Estudios Tropicales (OET) has evolved in many ways since its founding in 1963 as a non-profit consortium offering graduate courses and facilitating research in tropical ecology in Costa Rica. By 2002, its international membership included about 65 institutions, including four from Costa Rica. It had developed three Costa Rican field stations (La Selva, Las Cruces, and Palo Verde) with excellent facilities for teaching and research, and itwas constructing a new Costa Rican office at the University of Costa Rica. Combinations of internal and external pressures influenced OTS to develop in new directions in the 1980s and 1990s. It became more diversified and more concerned with applied science in its traditional areas of graduate education and research facilitation. The Organization also evolved into new niches: more applied biology, professional education, environmental education and policy, conservation efforts, and an expanded geographic distribution to other Latin American countries. OTS was composed of changing combinations of people (Boards, members, staff) with evolving and competing priorities for limited financial resources. External environmental changes also shaped OTS's evolution. New problems of increased tropical deforestation, the emergence of the biodiversity "crisis" and conservation biology, global climate change, and calls for sustainable development affected OTS constituents and funding priorities of governments and foundations. Both internal and external pressures have in some cases demanded for OTS to improve its relationship with: Costa Rican biologists and their institutions, the Costa Rican government, and Costa Ricans living around the three OTS field stations. Localización: Biblioteca OET: S8485. NBINA-2263. Publicación no.: 189 Relationships among soil carbon distributions and biophysical factors at nested spatial scales in rain forests of northeastern Costa Rica [Relaciones entre la distribución del carbono del suelo y los factores biofísicos en escalas espaciales anidadas en bosques lluviosos del noreste de Costa Rica] / Powers, J.S.; Schlesinger, W.H. (University of Minnesota. Department of Soil, Water & Climate, St Paul, MN 55108, US <E-mail: powers@umn.edu>). In: Geoderma (ISSN 0016-7061), v. 109, no. 3-4, p. 165-190. 2002. Forested soils in the tropics contain a large carbon pool that may respond to global environmental changes such as climate warming and land-use change. A better understanding of the distribution of tropical soil carbon (C) pools is necessary in orderto manage soil C as well as to predict its potential responses to global change. The goals of this study were to quantify the relationships among soil C and environmental variables for 35 forest plots in a 140,000-ha landscape in northeastern Costa Rica,and to identify variables that can predict soil C storage at unsampled sites. The biophysical variables included indices of net primary productivity (forest floor mass, root biomass, and an index of productivity derived from satellite imagery), soil particle-size distribution and mineralogy, elevation, and slope. Soil carbon storage in these volcanic soils was relatively high, ranging from 51.1 to 138.6 Mg C ha(-1) in the top 30 cm of mineral soil. The relationships among forest soil C and biotic and abiotic variables were different for low-elevation (120 m) and high-elevation (120-800 m) sites, and elevation explained much of the variability in soil C concentrations. Soil particle-size distribution and mineralogical variables are correlated in this landscape and co-vary in predictable ways along the elevation gradient. Thus, elevation represents a weathering gradient with younger, allophanic soils at higher elevations and older soils with gibbsite, goethite, and kaolinite as dominant clay minerals in the lowlands. We propose two mechanisms of C stabilization: soil C concentrations and contents are positively correlated to the amount of noncrystalline clays (e.g. Allophane, imogolite, and ferrihydrite) in the high elevation soils, and positively correlated to aluminum in organo-metal complexes in the low elevation sites. The strong correlations among soil C concentrations, contents, and elevation (mediated through effects on soil mineralogy) indicate that it is possible to predict soil C in this landscape using variables that are easily mapped in a geographic information system. Localización: Biblioteca OET: NBINA-626. Publicación no.: 190 Los servicios ambientales de los bosques: el caso de cambio climático [The forests environmental services: The case of the climatic change] / Castro-Salazar, R. (Ministerio del Ambiente y Energía. Barrio Francisco Peralta, Calle 25, Ave 8-10, San José, CR). Cambridge, MS: PNUD, 2000. 142 p. Like many tropical countries, Costa Rica is losing its forests: private landowners, cut down forests to grow crops and the government cannot afford to buy land for conservation. However, foreign countries can help, preserving tropical forest is theirmost cost-effective option for reducing carbon emissions. This thesis investigates this possibility using Costa Rica's state-owned Wildlife Conservation Areas (WCAs) as a case study. Finding cost-effective ways to sequester carbon or reduce carbon emissions is important because reducing global warming is both urgent and costly: possibly 2% of the world's GDP. Deforestation increases

carbon emissions into the atmosphere and contributes to global warming. Reducing deforestation and growing trees can help to sequester carbon, and reduce emissions. Various studies suggest that forest carbon sequestration may be a cost-effective way of reducing cost. According to the literature reducing emissions in the energy sector in industrialized countries will exceed $100 per ton. By contrast, the cost of sequestering carbon in US forests will cost from $10 to $100 per ton of carbon depending on the scale of the forestry projects and on the increasing opportunity cost of the land. The cost of sequestering carbon in permanent forests is even lower in Costa Rica than in the United States. The estimates developed in this thesis suggest that 92% of the carbon sequestered in the proposed expansion of the WCAs will cost less than $50 per ton. Moreover, some landowners inCosta Rica may be willing to preserve private natural forests or switch from traditional crops or cattle-raising to forest plantations if the price of sequestered carbon were to rise to as little, as $10 per ton. Therefore, using tropical forest as a carbon sink may have economic, ecological, and social benefits. Economically, it may reduce mitigation costs and facilitate capital transfer from industrialized to developing nations. Society benefits because forests are often located in the poorest rural areas; the ecological benefits come from keeping forest cover, especially primary forest, which is crucial to conserving tropical biodiversity. Localización: Biblioteca Carlos Monge A.: 363.738.74 C355s. Biblioteca del INCAE: COS 333.75.09.728.6 C355E. Publicación no.: 191 Spatial and temporal dynamics of a Costa Rican tropical dry forest [Dinámica espacial y temporal de un bosque seco tropical costarricense] / Enquist, C.A.F. (University of New Mexico. Department of Biology, Albuquerque, NM 87131-1091, US <E-mail: cafinn@unm.edu>). Las Cruces, NM: The University of New Mexico, 2002. 55 p. ISBN: 0-493-55249-9. Dissertation, Ph.D., The University of New Mexico, Las Cruces, NM (USA). Long-term data from tropical dry forest communities are needed to understand the factors that influence tree species composition and forest dynamics, information critical to the conservation and management of this biome. The San Emilio tropical dry forest study area in the Area de Conservación Guanacaste (ACG), Sector Santa Rosa in northwestern Costa Rica offered the opportunity to investigate these unique tropical forests. Chapter two is a study that describes the tree species abundance, composition and biomass of the San Emilio tropical dry forest based on over 30,000 individual trees that were mapped and measured in 1976 and 1996. During the 20 years, total stem density per ha deceased by 27%, yielding a forest-wide annual mortality rate of 3.52%. However, forest-wide annual recruitment was lower (3.05%), signaling that the forest was not in a steady state but was in a transitional phase. Above-ground forest biomass decreased by 3.5%, most likely caused by a long-term decrease in rainfall. Chapter three investigates the effect of physical heterogeneity on the community dynamics of the San Emilio tropical dry forest. Analyses of vegetation surveys conducted in 1976 and 1996 showed that rates of change in stem density and biomass across the forest were related to variation in seasonal soil moisture and topography. The more xeric and highly variable areas showed the greatest change in stem density. The study suggests that the non-random heterogeneity found within the physical landscape of the San Emilio tropical dry forest contributed to local forest dynamics. Furthermore, on both spatial and temporal scales, these findings support previous work suggesting that neotropical dry forest dynamics are responsive to seasonal climates and the resulting microtopographic availability of soil moisture. Chapter four explores the effects of heterogeneity on tree species and plant functional groups found in the San Emilio forest. While responding to this physical heterogeneity, the spatial and temporal variability in species abundance patterns reflect a forest on a successional trajectory that maybe affected by shifts in regional climate. Localización: Biblioteca OET: NBINA-5619. Publicación no.: 192 Climatic impact of lowland deforestation on tropical montane cloud forests in Costa Rica [Impacto climático de la deforestación de las tierras bajas en los bosques nubosos montanos tropicales en Costa Rica] / Nair, U.S. Boulder, CO: Colorado State University, 2002. 129 p. ISBN: 0-493-68602-9. Dissertation, Ph.D., Colorado State University at Boulder (USA). Tropical montane cloud forests depend on predictable, frequent, and prolonged immersion in clouds. Recent studies have shown that there has been a reduction in dry season moisture input from direct interception of cloud water and wind blown mist at the lee edge of the Monteverde cloud forest, Costa Rica, since the mid 1970s. This reduction of moisture could be responsible for the population crashes of anurans observed in the region. It has been hypothesized that this behavior is a result of increases in cloud base height, linked to increased sea surface temperatures. This study presents a complementary hypothesis, that deforestation upstream of the Monteverde cloud forest preserve is responsible for the observed changes in cloud base height. An automated cumulus cloud classification scheme is used to extract monthly spatial maps of the frequency of occurrence of cumulus cloudiness over Costa Rica from GOES-8 visible channel satellite imagery. It is found that cumulus cloud formations in the morning hours over deforested regions are suppressed compared to forested areas. The degree of suppression appears to be associated with the extent of deforestation. This difference in cloud formation between forested and deforested areas is a clear signal of land-use change influencing the regional climate. The Regional Atmospheric Modeling System (RAMS) simulations are used to explore the differences in cloud field characteristics over the lowland pasture and forest surfaces. Statistically significant differences in cloud base height and cloud thickness are found between the forest and pasture simulations, clouds having higher base heights and being thinner over

pasture surfaces compared to forest surfaces. There are enhanced sensible heat fluxes over pasture surfaces compared to forest surfaces, while forest surfaces have higher latent heat fluxes. RAMS is also used to examine the impact of lowland deforestation on orographic cloud formation. Numerical modeling simulations of orographic cloud formation is examined for three types of deforestation scenarios where the most recent estimate of forest cover for the Costa Rican region is used. Numerical modeling suggests that deforestation shrinks the areal extent of the orographic cloud banks and elevates its base to higher altitudes. The increase in cloud base height is on the order of 200 m for complete deforestation and 100 m for partial deforestation. Increases in cloud base height of this magnitude may significantly impact the hydrology of the cloud forest regions. Deforestation results in a decrease of the orographic cloud cover, with the decrease being proportional to the amount of deforestation. The results from this study suggest that land use in tropical lowlands has serious impacts on ecosystemsin adjacent mountains. Deforestation in the Costa Rican lowlands may have a detrimental effect of increased frequency of mist free days upstream at Monteverde Cloud Forest Preserve. Localización: Non available. Publicación no.: 193 Geo Costa Rica: una perspectiva sobre el medio ambiente / MINAE / PNUMA, Apartado Postal 10104-1000, San José, CR E-mail: prensas.minae.go.cr. San José: Universidad de Costa Rica / Observatorio del Desarrollo, 2002. 162 p. ISBN: 9977-50-043-6. Introducción: La publicación de este primer informe GEO Costa Rica: una perspectiva ambiental por parte del Ministerio de Ambiente y Energía (MINAE) de la República de Costa Rica, responde a dos objetivos principales. En primer lugar, se busca establecer un mecanismo de rendición de cuentas ante la sociedad costarricense, en el campo de las políticas ambientales. En segundo lugar, responde a una recomendación del Foro de Ministros de Ambiente de América Latina y el Caribe para elaborar evaluaciones ambientales integradas de orden nacional y regional como instrumento en el proceso de diseño e implementación de políticas en este campo. Ante la decisión ministerial de elaborar el informe, el Programa de las Naciones Unidas para el Medio Ambiente (PNUMA), Oficina Regional para América Latina y el Caribe (ORPALC), en su calidad de organismo de coordinación técnica del Foro de Ministros, solicitó al Observatorio del Desarrollo de la Universidad de Costa Rica (OdD-UCR) colaborar con el MINAE brindando asesoramiento técnico y facilitando el proceso de elaboración del informe. El OdD es centro colaborador para Mesoamérica del PNUMA en el proyecto GEO (Global Environment Outlook), ocupado desde 1995 de la elaboración de evaluaciones ambientales integradas de ámbito global, regional y nacional. Las evaluaciones ambientales integradas propuestas por el PNUMA en su proyecto GEO suponen un análisis consultado sobre el estado del ambiente y las políticas de respuesta a este estado, incluyendo una consideraciónde las presiones que determinan el estado ambiental, y los impactos que resultan de ellas, tanto en el orden social como natural. El análisis se centra en los diferentes recursos que constituyen el acervo natural de un país o región: la tierra, los bosques, la biodiversidad, las aguas, las zonas costeras y marinas, así como la atmósfera. Se incluye igualmente una consideración específica de la situación ambiental en las áreas urbanas, así como el tema de los desastres (en lo relativo a sus causas e impactos relacionados con el ambiente natural) y, finalmente, el análisis especial de los impactos del estado del ambiente en la salud humana. También es fundamental en el enfoque GEO la elaboración de un conjunto de escenarios sobre tendencias previsibles odeseables en la evolución futura de la situación ambiental, que permita orientar la toma de decisiones en este campo. En este primer ejercicio para Costa Rica, la disponibilidad de recursos técnicos y financieros permitió una aproximación razonable en laaplicación del enfoque GEO. Partiendo de la finalidad de apoyar las funciones de rectoría del MINAE en el campo de la información y asistencia en la toma de decisiones, los objetivos específicos se centraron en establecer una "línea base" -es decir, un punto de referencia para evaluaciones posteriores- que contribuyera al establecimiento de un sistema nacional de información ambiental y un conjunto básico inicial de series estadísticas en este campo. Para acercarnos a estos objetivos, el proceso de elaboración del informe empezó por el establecimiento de un grupo de puntos focales temáticos dentro del MINAE, con el cometido de promover y facilitar las acciones necesarias -entre ellas, identificar las variables e indicadores fundamentales para la evaluación ambiental integrada, así como los expertos relevantes en la elaboración del análisis y, finalmente, acometiendo en buena medida la redacción inicial de informes temáticos que constituyen la base de esta publicación. El grupo de puntos focales logró desarrollar de manera muy satisfactoria las acciones encomendadas, convirtiéndose en el principal acervo humano para esfuerzos posteriores en este campo por parte del MINAE, y avanzando la finalidad de construcción de capacidades institucionales que anima al PNUMA con su proyecto GEO. La lista de punto focales del MINAE se encuentra en el apéndice de Reconocimientos. Un segundo paso importante en la elaboración del informe fue la convocatoria del grupo de expertos identificado por los puntos focales delMINAE, quienes contribuyeron a perfilar mejor los problemas existentes en el campo ambiental en el país, así como las variables más importantes para su análisis. El resultado de su trabajo se ha presentado en un primer informe técnico de avance, editado en octubre de 2001; la lista completa de personas que colaboraron en esta fase también se encuentra en el apéndice de Reconocimientos. Por su parte, al Observatorio del Desarrollo de la Universidad de Costa Rica le correspondió aportar insumos conceptuales y metodológicos, recopilar los datos necesarios y construir las series históricas correspondientes, así como coordinar la elaboración y edición de los informes. La revisión atenta de los borradores del informe por parte del equipo de ORPALC-PNUMA en México, así como por parte de la Ministra de Ambiente y Energía, Licda. Elizabeth Odio Benito, resultaron invaluables en esta fase final del proceso. El resultado de estos esfuerzos está a la vista. En el capítulo 1,

sobre el estado del ambiente, se pasa revista a la situación actual de los principales recursos naturales en el país: tierra, bosques, biodiversidad, agua, costas y mares, así como atmósfera. Las secciones inicialmente previstas sobre áreas urbanas y desastres no pudieron completarse y quedan pendientes para próximos esfuerzos. En el capítulo 2 se realiza un recuento de las principales acciones de política emprendidas en los últimos años en el país, con énfasis en los cuatro años correspondientes a la Administración Rodríguez Echeverría. Noobstante la amplitud del análisis presentado en este capítulo, las limitaciones de este primer ejercicio impidieron avanzar suficientemente en la valoración crítica de las políticas impulsadas, así como de la organización general de la gestión ambiental en el país (tanto pública como privada); queda ello pendiente también para el futuro. Finalmente, el ejercicio de elaboración de escenarios, contemplado inicialmente, no pudo intentarse, y pasa a formar parte de la agenda futura. Localización: Biblioteca OET: NBINA-6723. Publicación no.: 194 The carbon cycle and the value of forests as a carbon sink: a tropical case study [El ciclo del carbono y el valor de los bosques como almacenadores de carbono: estudio de caso tropical] / Ramírez, O.A.; Dore, M.H.I. ed.).; Guevara, R, (ed.). (Texas Tech University. Department of Agricultural and Applied Economics, Box 42132, Lubbock, TX 79409-2132, US <E-mail: octavio.ramirez@ttu.edu>). In: Sustainable forest management and global climate change: selected case studies from the Americas Cheltenham: Edward Elgar Publishing Ltd, 2000. p. 107-147. ISBN: 1-84064-161-4. This paper reviews the different types of carbon sink services provided by forests and addresses the issue of placing economic values on them. The concept of joint implementation is discussed in more detail and an example of its application is presented. Various methods to estimate the magnitude and economic value of the carbon sink services rendered by each of the three main types of tropical forests in Costa Rica: natural primary, naturally regenerating secondary, and artificial plantations are also presented and illustrated. Localización: Non available. Publicación no.: 195 Estimating the greenhouse gas benefits of forestry projects: a Costa Rican case study [Estimando los beneficios de los proyectos forestales de gases invernadero: estudio de caso costarricense] / Busch, C.B.; Sathaye, J.A.; Sánchez-Azofeifa, G.A. (Lawrence Energy Technologies Division. Environmental Energy Technologies Division, Energy Analysis Department, Berkeley, CA 94720, US <E-mail: arturo.sanchez@ualberta.ca>). Berkeley, CA: Ernest Orlando Lawrence Berkeley National Laboratory, 2000. 119 p. (LBNL; no. 42289). If the Clean Development Mechanism proposed under the Kyoto Protocol is to serve as an effective means for combating global climate change, it will depend upon reliable estimates of greenhouse gas benefits. This paper sketches the theoretical basis for estimating the greenhouse gas benefits of forestry projects and suggests lessons learned based on a case study of Costa Rica's Protected Areas Project, which is a 500,000 hectare effort to reduce deforestation and enhance reforestation. The Protected Areas Project in many senses advances the state of the art for Clean Development Mechanism-type forestry projects, as does the third-party verification work of SGS International Certification Services on the project. Nonetheless, sensitivity analysis shows that carbon benefit estimates for the project vary widely based on the imputed deforestation rate in the baseline scenario, e.g. the deforestation rate expected if the project were not implemented. This, along with a newly available national dataset that confirms other research showing a slower rate of deforestation in Costa Rica, suggests that the use of the 1979-1992 forest cover data originally as the basis for estimating carbon savings should be reconsidered. When the newly available data is substituted, carbon savings amount to 8.9 Mt (million tones) of carbon, down from the original estimate of 15.7 Mt. The primary general conclusion is that project developers should give more attention to the forecasting land use and land cover change scenarios underlying estimates of greenhouse gas benefits. Localización: Biblioteca OET: NBINA-6588. Publicación no.: 196 Arrecifes y ambientes de Bahía Culebra, Pacífico de Costa Rica: aspectos biológicos, económico-recreativos y de manejo [Coral reefs and environments of Culebra Bay, Pacific coast of Costa Rica: biology, economic and recreational considerations, management] / Jiménez-Centeno, C.E. (Universidad de Costa Rica. CIMAR y Escuela de Biología, San , CR <E-mail: carlos.jimenez@zmt.uni-bremen.de>). In: Revista de Biología Tropical (ISSN 0034-7744), v. 49, Suppl. 2, p. 215-231. 2001. The coral reefs (AC) and coral communities on basalts (CCB) or sand (CCA) of Bahia Culebra (Golfo de Papagayo, northern Pacific coast of Costa Rica), were compared with descriptors such as cover percentage, diversity, substrate topographical heterogeneity (I-H), associated organisms and frequency of recreational-commercial diving activities on them. Sea urchin abundance and IH were similar among the three reefal environments. The AC had higher coral cover (ca. 40%) and total live cover (50%). The CCB had higher macro and calcareous algae (5%) and sponges (2%). Associated organisms (2%) and general diversity (0.6) were higher in the CCA. Branching coral species (Pocillopora spp.) accounted for 40% of total coral cover in the reefs, followed by massive species (ca. 30%). In the CCB, branching species contributed ca. 80% and massive ca. 19%, whilst in the CCA ca. 68% and ca. 29% respectively. This differences could be related with the substrate consolidation and ample depth range of coral communities. Most of the recreational dives were conducted at the CCB; only occationally the CCA and AC are visited. Interviewed divers had a principal

interest on fish and it is precisely at the CCB where highest fish diversity and biomass are observed. Comercial divers tend to prefer the CCB because of their abundance and distribution in the bay. At the outer littoral of Bahia Culebra, diversity of all taxa and live coral cover zonal distribution are generally higher. In addition to these descriptors, indexes that indicate the regional value of a particular reef or coral community is recommended. Coastal infrastructure is mainly concentrated at three areas of the bay; one of them harbors a rare Leptoseris papyracea reef (the only reported so far in the eastern Pacific) and the solely Costa Rican living population of the free living coral Fungia (Cycloseris) curvata. A resort marina will be built over this reef. A protection plan for this and other reefal environments of Bahia Culebra is urgent and must include the monitoring of environmental variables and coral health. Localización: Biblioteca OET: R. Biblioteca Luis D. Tinoco: 570R. Publicación no.: 197 The United States Initiative on Joint Implementation: forest sector projects [La Iniciativa de los Estados Unidos sobre la Implementación Conjunta: proyectos del sector forestal] / Dixon, R.K.; Young, C.E.F.; Palo, M, (ed.).; Uusivuori, J, (ed.).; Mery, G. (U.S. Department of Energy. Office of Power Technologies, Deputy Assistant Secretary, 1000 Independence Avenue SW, Washington, DC 20585, US). In: World forests, markets and policies. Dordrecht: Kluwer Academic Publishers, 2001. p. 121-134. ISBN: 0-7923-7171-2. Flexible economic instruments, such as joint implementation (JI), the Clean Development Mechanism (CDM) and emissions trading, offer a concomitant means to facilitate economic, energy, and environmental security. The United States Initiative on JointImplementation (USIJI) was established as a pilot programme to facilitate voluntary project investments by US entities to reduce greenhouse gas (GHG) emissions worldwide. In addition to sharing the worldwide environmental and societal benefits of GHG emission reduction, the USA will gain improved market access, achieve lower cost of green technologies, and strengthen international credibility for its efforts in addressing a global threat. USIJI, working under guidelines established by the UN Framework Convention on Climate Change (FCCC), has developed a set of operational criteria for evaluating project proposals. To date, USIJI has received more than 150 project proposals, of which 36 have been accepted into the pilot programme. The 36 USIJI projects span four principal sectors: forestry, energy, waste and agriculture. This project portfolio includes a diverse set of forest sector conservation and carbon (C) sequestration practices and activities in 8 countries (Belize, Bolivia, Costa Rica, Ecuador, Honduras, Indonesia, Mexico and Russia). Preliminary estimates suggest that cumulative C sequestration potential of this project portfolio may exceed 75 Tg C. Methodological and technical issues concerning forest sector project baselines, boundaries and monitoring will need to be improved in the future. While the forest sector C offset industry is growing worldwide, human and institutional capacity building is required to realize meaningful, long-term environmental protection and economic security. In addition to the main paper by Dixon (pp. 121-132), their is a discussion of the subject by Young (pp. 133-134). Localización: Non available. Publicación no.: 198 Twenty years of change and development in a tropical dry forest, Guanacaste, Costa Rica [Veinte años de cambio y desarrollo en un bosque seco tropical, Guanacaste, Costa Rica] / Enquist, C.A.F. (University of New Mexico. Department of Biology, Albuquerque, NM 87131-1091, US <E-mail: cafinn@unm.edu>). Annual Meeting of the Ecological Society of America. 86th, Madison, WI USAugust 05-10, 2001. In: Ecological Society of America Annual Meeting Abstracts, v. 86, p. 86. 2001. (Abstract only). Localización: Non available. Publicación no.: 199 Los sistemas silvopastoriles y el calentamiento global: un balance de emisiones [Silvopastoral systems and global warming: a gas emission balance] / Montenegro-Ballestero, J.; Abarca-Monge, S. (Ministerio de Agricultura y Ganadería. Dirección de Protección Fitosanitaria, Turrialba, CR <E-mail: jmonte@guayabo.sa.ucr.ac.cr>). In: Agronomía Costarricense (ISSN 0377-9424), v. 26, no. 1, p. 17-24. 2002. A gas emission balance was carried out in SPS located in the Montano Low Forest (MLF), Wet Premontain Forest (WPF), and Tropical Wet Forest (TWF) of Costa Rica. The methane emission from cattle, N20 and CO2 emission from soil, temperature, humidity, carbon, ammonium and nitrate contents, and soil compaction were determined in SPS as well as in natural forest ecosystems. In the SPS located at the MLF and TWF emissions were higher than in natural ecosystems. In both, the N-NH4 soil concentration positively influenced the nitrous oxide gas emission. In the WPF ecosystem, the net emission showed a favorable N20 balance (-1.58 kg of N ha-1 year-1) for the SPS but the natural forest emitted less C (3.51 kg of C ha-1 year-1). The methane emission factor determined was 654 kg CH4 ha-1 year-1 in the WPF, 183 kg CH4 ha-1 year-1 in the TWF and 360 kg CH4 ha-1 year-1 in the MLF. The emission efficiency expressed as g of CH4 kg-1 of produced milk was MLF: 19, WPF: 22 and TWF: 31. The carbon in the soil was higher in the SPS than in the natural forest ecosystems. The annual amount of C per land unit in the arboreal component was higher in the SPS of the WPF and TWF than in the MLF. The lowest balance value (418 kg of C ha-1 year-1) was estimated for the SPS inthe TWF and the highest (3911 kg of C ha-1 year-1) for the SPS in the WPF; an intermediate range was estimated for the SPS located in the MLF (2418 kg of C ha-1 year-1). The total

emission of N20 was higher in the bovine production systems than in the natural ecosystem, with the exception of the SPS located in the WPF. The emission of carbon dioxide was always higher in the SPS. The total carbon amount stored in the soil profile was higher in the SPS. The balance indicated that all farms eva-luated act as originators of greenhouse gases, methane being the main gas affecting the final balance. Localización: Biblioteca OET: A. Publicación no.: 200 Estimating rainy season nitrous oxide and methane fluxes across forest and pasture landscapes in Costa Rica [Estimando los flujos de óxido nitroso y metano de la estación lluviosa a través del paisaje del bosque y potreros en Costa Rica] / Reiners, W.A.; Keller, M.; Gerow, K.G. (University of Wyoming. Department of Botany, Laramie, WY 82071, US <E-mail: reiners@uwyo.edu> <E-mail: michael.keller@unh.edu> <E-mail: gerow@uwyo.edu>). International Symposium on Ecosystem Behavior. Third, Villanova, PE, US; June 21-25, 1997. In: Biogeochemical investigations at watershed, landscape, and regional scales. Wieder, R.K; Novak, M; Cerny, J, (eds.) Dordrecht: Kluwer Academic Publishers, 1998. p. 117-130. ISBN: 0792351673. The objectives of this research were to estimate exchanges of CH4 and N2O, both radiatively active gases, between soil and atmosphere on hilltop, slope and swale hillslope positions of northeastern Costa Rica; and to assess the importance of accounting for topography in making areal estimates across hilly terrain. Emission rates from soils were measured during the rainy season on three hillslope positions of both actively grazed pastures and primary forests. Emission rates from pasture and forest sites were significantly different for both gases. Differences between slope positions, though notable, were not significantly different for CH4, but were significantly different for N2O. The forest landscape was partitioned with GIS methods into hilltop, slope and swale topographic positions. The calculated areas for each of these were multiplied by their respective emission rates to calculate overall flux from the entire forested area ofH4 flux ranged from -6,201 to -6,658 g CH4 d(-1). Errors associatedwith both estimating mean emission rates for each hillslope position and judgmental errors in partitioning the landscape into hillslope positional classes are important tomaking landscape-scale estimates of flux. Localización: Non available. Publicación no.: 201 Below-ground carbon dynamics as a function of climate variability in undisturbed soils of a neotropical rain forest [Dinámica del carbono en el suelo como una función de la variabilidad del clima en suelos no perturbados del bosque lluvioso neotropical] / Schwendenmann, L.C. (Universität Göttingen. Institute of Silviculture, Department of Tropical Silviculture; Busgenweg 1, D-37077 Göttingen, DE <E-mail: lscwen@gwdg.de>). (ISSN 0939-1347) Göttingen: Universität Göttingen / Forschungszentrum Waldökosysteme, 2002. 132 p. Dissertation, Dr., Universität Göttingen, Forschungszentrum Waldökosysteme, Göttingen (Germany). A través de un estudio llevado a cabo durante varios años se investigó el efecto de la temperatura y del contenido de agua en el suelo sobre la dinámica del carbono en un bosque húmedo tropical. La región de estudio, Estación Biológica La Selva, se ubica en la vertiente atlántica de Costa Rica. El clima está caracterizado por altas precipitaciones. Los suelos de la región son de origen volcánico. El experimento se llevó a cabo sobre viejas terrazas aluviales ('old alluvium') así como también sobre suelos residuales fuertemente meteorizados ('residual'). Los objetivos de la investigación fueron: (i) Cuantificación de la respiración del suelo en dos diferentes tipos de suelo, (ii) Cálculo de las tasas de producción de CO2 en diferentes profundidades de suelo, (iii) Investigación de la influencia de la temperatura y del contenido de agua en el suelo sobre la producción de CO2 y la respiración del suelo, (iv) Descripción de los procesos que influyen en la distribución vertical de la concentración de CO2 y (v) Cuantificación de la porción disuelta del carbono y del nitrógeno orgánico, así como la caracterización biológica y química en relación con la profundidad del suelo. Para esto fueron llevadas a cabo desde abril de 1998, en un total de 6 parcelasexperimentales, con intervalos de dos semanas, las siguientes mediciones. Para la caracterización de la respiración del suelo fueron instaladas en cada parcela experimental un total de 8 'cámaras de la respiración'. Se utilizó un aparato de gas infravermelho LiCor portátil para las mediciones de la respiración en el campo. Paralelamente se llevaron a cabo las mediciones de la temperatura y de la humedad del suelo. En cada parcela experimental se estableció una calicata de 3 hasta 4 m de profundidad. En diferentes profundidades se instalaron sondas para la toma de pruebas de gases, sensores de temperatura, instrumentos para medir humedad y lisímetros para sacar muestras de agua. Los coeficientes de difusión que dependen de la profundidad del suelo fueron estimados a través de fórmulas empíricas y comparados contra un perfil de Radon (222Rn). El cálculo de las tasas de producción de CO2 se llevó a cabo tomando como base los coeficientes de difusión estimados y los perfiles de CO2 medidos. Los resultadosmás importantes son: 1. La respiración del suelo (11 Mg ha-1 a-1) en los sitios experimentales sobre las viejas terrazas aluviales fue 20 % menor con respecto a los sitios ubicados sobre suelos residuales (14 Mg ha-1 a-1). La variabilidad espacial pudo ser aclarada a través del contenido de carbono en el suelo, la biomasa de raíces finas y la concentración de fosfato. La dinámica anual mostró dependencia del contenido de agua en el suelo. Bajas emisiones de CO2 fueron medidas tanto para bajas como para altas concentraciones de agua en el suelo. Las tasas más altas de respiración fueron determinadas para contenidos de agua entre 0.35 y 0.50 cm-3. La influencia de la temperatura del suelo sobre la respiración ha sido atribuida probablemente a la dependencia entre el contenido de agua en el suelo y la temperatura del suelo. 2. Las concentraciones de CO2 en las capas más cercanas a la superficie del suelo mostraron una fuerte variación temporal. Para

valores muy altos del contenido de agua subió el contenido de CO2 en el aire del suelo hasta en un 3 %. En las capas de suelo más profundas, el porcentaje de CO2 en el aire del suelo fue 10 %. Por debajo de 1 m de profundidad se disolvió el 90 % del contenido total de dióxido de carbono en el agua del suelo. 3. La producción de CO2 se concentra en los primeros 0.5 m del perfil del suelo (85 - 90 %) y estuvo influenciado por el contenido de agua en el suelo. La producción en capas de suelo más profundas estuvo correlacionada con el contenido de agua en el suelo y la radiación solar. En los sitios sobre las viejas terrazas aluviales (`old alluvium') se comprobó una fuerte dependencia de la temperatura del suelo en profundidades entre 2 - 3 m. 4. El registro del carbono orgánico disuelto es bajo ( 10 %) encomparación con las cantidades de carbono que se producen en forma de caída de hojarasca. A través de la alta capacidad de absorción de los suelos arcillosos se retiene en el suelo 80 % del DOC producido. Localización: Biblioteca OET: Tesis 413. Publicación no.: 202 Historical and future land use effects on N2O and NO emissions using an ensemble modeling approach: Costa Rica´s Caribbean lowlands as an example [Efectos del uso histórico y futuro en las emisiones de N2O y NO utilizando un enfoque de modelaje conjunto: Las tierras bajas caribeñas de Costa Rica como ejemplo] / Reiners, W.A.; Liu, S.; Gerow, K.G.; Keller, M.; Schimel, D.S. (University of Wyoming. Department of Botany, Laramie, WY 82071-3165, US <E-mail: reiners@uwyo.edu> <E-mail: sliu@edcmail.cr.usgs.gov> <E-mail: gerow@uwyo.edu> <E-mail: michael.keller@unh.edu> <E-mail: schimel@ucar.edu>). In: Global Biogeochemical Cycles (ISSN 0886-6236), v. 16, no. 4, p. 1068-1085. 2002. The humid tropical zone is a major source area for N2O and NO emissions to the atmosphere. Local emission rates vary widely with local conditions, particularly land use practices which swiftly change with expanding settlement and changing market conditions. The combination of wide variation in emission rates and rapidly changing land use make regional estimation and future prediction of biogenic trace gas emission particularly difficult. This study estimates contemporary, historical, and future N2O and NO emissions from 0.5 million ha of northeastern Costa Rica, a well-documented region in the wet tropics undergoing rapid agricultural development. Estimates were derived by linking spatially distributed environmental data with an ecosystem simulation model in an ensemble estimation approach that incorporates the variance and covariance of spatially distributed driving variables. Results include measures of variance for regional emissions. The formation and aging of pastures from forest provided most of the past temporal change in N2O and NO flux in this region; future changes will be controlled by the degree of nitrogen fertilizer application and extent of intensively managed croplands. Localización: Biblioteca OET: S9005. NBINA-6095. Publicación no.: 203 Spatial and temporal variation in soil CO2 efflux in an old-growth neotropical rain forest, La Selva, Costa Rica [Variación espacial y temporal en el flujo de CO2 en un bosque lluvioso neotropical de viejo crecimiento, La Selva, Costa Rica] / Schwendenmann, L.C.; Veldkamp, E.; Brenes, T.; O'Brien, J.J.; Mackensen, J. (Universität Göttingen. Institute of Silviculture, Department of Tropical Silviculture; Busgenweg 1, D-37077 Göttingen, DE <E-mail: lscwen@gwdg.de> <E-mail: eveldka@gwdg.de> <E-mail: jjobrien@fs.fed.us>). In: Biogeochemistry (ISSN 0168-2563), v. 64, p. 111-128. 2003. Our objectives were to quantify and compare soil CO2 efflux of two dominant soil types in an old-growth neotropical rain forest in the Atlantic zone of Costa Rica, and to evaluate the control of environmental factors on CO2 release. We measured soil CO2 efflux from eight permanent soil chambers on six Oxisol sites. Three sites were developed on old river terraces ('old alluvium') and the other three were developed on old lava flows ('residual'). At the same time we measured soil CO2 concentrations, soil water content and soil temperature at various depths in 6 soil shafts (3 m deep). Between 'old alluvium' sites, the two-year average CO, flux rates ranged from 117.3 to 128.9 mg C m(-2) h(-1). Significantly higher soil CO2 flux occurred on the `residual' sites (141.1 to 184.2 mg C m(-2) h(-1). Spatial differences in CO2 efflux were related to fine root biomass, soil carbon and phosphorus concentration but also to soil water content. Spatial variability in CO2 storage was high and the amount of CO2 stored in the upper and lower soil profile was different between `old alluvial' and `residual' sites. The major factor identified for explaining temporal variations in soil CO2 efflux was soil water content. During periods of high soil water content CO2 emission decreased, probably due to lower diffusion and CO2 production rates. During the 2-year study period inter-annual variation in soil CO2 efflux was not detected. Localización: Biblioteca OET: NBINA-921. Publicación no.: 204 Linking carbon inputs to sustainable agriculture in Canadian and Costa Rican agroforestry systems [Relación entre el aporte de carbono y la agricultura sustentable en sistemas agroforestales en Canadá y Costa Rica] / Oelbermann, M. (University of Waterloo. Department of Environment & Resource Studies, Waterloo, ON N2L 3G1, CA <E-mail: moelberm@fes.uwaterloo.ca>). Guelph, ON: University of Guelph, 2002. 208 p. ISBN: 0-612-71747-X. Dissertation, Ph.D., University of Guelph, Ontario (Canada). Alternative land management practices, including agroforestry, can rejuvenate marginal soils and increase soil C sequestration to help mitigate atmospheric CO2 emissions. The objective of this study was to quantify C inputs in temperate and tropical alley cropping systems. In Costa Rica 18, 9 and 3-year old Erythrina

poeppigiana (Walp.) O. F. Cook and G. sepium (Jacq.) Walp. were combined with maize and beans (Phaseolus vulgaris L.), and in Canada 12-year old hybrid poplar (Populus deltoides x nigra DN 177) was alley cropped with maize (Zea mays L.) and soybeans [(Glycine max L. (Merr.)]. The 18 and 9-year old tropical system, with either tree species, had an input of 2365 and 3960 kg C ha(-1) from maize and bean residues, where maize roots contributed approximately 14% of total residue C input and bean roots contributed 12%. Comparatively crop C input in Canada was 2118 kg C ha(-1) for maize and 826 kg C ha(-1) for soybeans, where roots contributed 10 to 14% of the total C inputs. A higher C inputfrom crop residues in the tropical biome results from two cropping seasons per year compared to a single crop in the temperate system. Carbon input from 18-year old tree prunings was 4003 kg C ha(-1), and 1038 and 1038 kg C ha(-1) for 9 and 3-year old trees. Annual C input from hybrid poplar prunings was 1407 kg C ha(-1) with an additional contribution of 816 kg C ha(-1) from autumnal litterfall within 3.5 m of the tree row. Soil organic C (SOC) ranged from 139, 101 to 96 Mg C ha(-1) for 18, 9 and 3-year old tropical systems, whereas the temperate system SOC pool was 125 Mg C ha(-1). The proportion of C derived from C4 plants to a 20 cm depth in tropical alley crops was 35% (18-yr) and 24% (9-yr), with similar values (23%) in the temperate system. These results suggest that the rate of SOC turnover in tropical soils (14 yrs) is greater than that of temperate soils (45 years). Localización: Biblioteca Conmemorativa Orton: Thesis O28. Publicación no.: 205 Ecosystem-level responses of carbon and energy from a tropical wet forest in Costa Rica [Respuestas a nivel de ecosistema del carbono y energía de un bosque húmedo tropical en Costa Rica] / Loescher, H.W. (Oregon State University. Department of Forest Sciences, 321 Richardson Hall, Corvallis, OR 97331, US <E-mail: hank.loescher@oregonstate.edu>). Gainesville, FL: University of Florida, 2002. 93 p. ISBN: 0-493-85051-1. Dissertation, Ph.D., University of Florida, Gainesville, FL (USA). Whether tropical forests are sources, sinks, or neutral with respect to their carbon balance with the atmosphere remains unclear. To address this issue, estimates of net ecosystem exchange of carbon and energy (NEE) were made for 3 years (1998 - 2000) using the eddy-covariance technique in a tropical wet forest in La Selva Biological Station, Costa Rica. Mean daytime NEE was ca. ± 18 µmol CO2 m-2 s-1 and mean nighttime NEE 4.6 µmol CO2 m-2 s-1 (efflux). However, because - 80% of the nighttime data in this forest were collected during laminar flow conditions ( 0.2 m-2 s-1), nighttime NEE was likely underestimated. Using an alternative analysis, mean nighttime NEE increased to 6.9 µmol CO2 m-2 s-1. Incident radiation accounted for - 51% of the variation in the daytime fluxes, with temperature and vapor pressure deficit together accounting for another - 20%. This forest was a slight negative carbon sink in 1998 (- 0.08 to - 1.42 t C ha-1 yr-1), a moderate sink in 1999 (-1.65 to - 3.21 t C ha(-1)), and a strong sink in 2000 (- 6.1 to - 8.1 t C ha(-1) ). This trend is interpreted as relating to the dissipation of warm-phase El Niño effects over the course of this study. The effects of net radiation (Rn), vapor pressure deficit (VPD), and surface conductances on energy balance and evapotranspiration (ET) were also determined for this forest. Sensible (H) and latent heat (lambda E) fluxes were estimated as the sum of above canopy eddy-covariance fluxes and changes in below-canopy heat profiles. Albedowas about 12% of incident radiation and did not differ seasonally. Rn was significantly different among years, explaining about 79% of the variation in each of the H and lambda E fluxes. The effects of VPD did not explain any additional variation in heatfluxes. Lambda E was always greater than H (when Rn exceeded 40 W m-2). The dimensionless decoupling coefficient, Omega; was always 0.5 and peaked at 0.7, suggesting that ET for this the forest was generally decoupled from physiological controls. Therewas better precision in estimating lambda E flux using the Priestly-Taylor model rather than using the more physiologically-based Penman-Monteith model. Annual ET was 54 - 66% of bulk precipitation and utilized 88 - 97% of available energy (R n). Localización: Biblioteca OET: NBINA-5634. Publicación no.: 206 El cambio climático y los humedales en Centroamérica: Implicaciones de la variación climática para los ecosistemas acuáticos y su manejo en la región / Rojas-Araya, M.; Campos, M.; Alpízar-Vaglio, E.; Bravo-Chacón, J.; Córdoba-Muñoz, R. (Unión Mundial para la Naturaleza (UICN). Oficina Regional para Mesoamérica, Apdo. Postal 146-2150 Moravia CR <E-mail: ealpizar@cedarena.org> <E-mail: jbravo@una.ac.cr> <E-mail: rocio.cordoba@orma.iucn.org>). San José: UICN, 2003. 40 p. ISBN: 9968-743-78-X. Introducción: Centroamérica está formada por un angosto istmo ubicado en el cinturón tropical, donde la interacción entre el predominante viento alisio y la compleja topografia hacen que se presenten contrastes climáticos importantes entre las vertientes Caribe y Pacífico. La región del Gran Caribe donde se localiza Centroamérica es una zona de interacciones climáticas entre los hemisferios norte y sur. En esta región la zona de convergencia intertropical, el movimiento de los ciclones tropicales, las ondas del este y el desplazmiento de los frentes fríos, son algunas manifestaciones climáticas que hacen que la zona sea climáticamente compleja. Otros factores de escalas inter-anuales como los eventos de El Niño y la Niña, hacen que los fenómenos climáticos puedan alcanzar niveles extremos, produciendo desastres y afectando las actividades productivas, los asentamientos humanos y los recursos naturales. El cambio en el clima que enfrenta hoy día el planeta, producto del aumento de las emisiones de gases de efecto invernadero, hace que los escenarios futuros y las proyecciones para el Istmo no sean muy favorables. Estudios regionales y nacionales referenciados en las comunicaciones nacionales ante el Convenio Marco de las Naciones Unidas sobre Cambio Climático (UN-FCCC) evidencian variaciones importantes en elementos del clima regional como

la temperatura, la precipitación, la nubosidad y la escorrentía. Los estudios hechos en Centroamérica demuestran la sensibilidad de los sistemas productivos y la fragilidad de los recursos naturales ante variaciones en el clima actual (PCCC, 1995; MARENA, 2000; MINAE-IMN, 2000). Las proyecciones globales indican que uno de los sistemas más afectados por la variabilidad climática y los eventos extremos son los ecosistemas de humedales. A pesar que no existen estudios específicos en Centroamérica que relacionen el cambio climático con los humedales, es de esperarse que bajo las condiciones descritas en los escenarios de cambio climático presentados en las comunicaciones nacionales, estos ecosistemas sufrirán alteraciones significativas, con sus consecuencias directas e indirectas en las poblaciones humanas que de ellos dependen para subsistir. Esto lo confirman estudios específicos hechos en Estados Unidos (LeRoy et. al., 2002), que permiten realizar comparaciones sobre los impactos en los ecosistemas de Centroamérica. En la mayoría de las regiones del planeta el cambio climático produce un aumento en la temperatura atmosférica, que a su vez causa un aumento en la temperatura del agua que tiende a alterar los procesos ecológicos y la distribución geográfica de las especies acuáticas. Para la región del Pacífico Centroamericano es de esperarse que la temperatura promedio anual sea aproximadamente 3 °C mayor que la actual. (MARENA, 2000; MINAE-IMN, 2000). A pesar de que algunas especies podrían adaptarse a las nuevas condiciones, las barreras que hoy día antepone el ser humano, limitan los correcdores de migración de las especies y aumenta la probabilidad de extinción y la pérdida neta de biodiversidad. Además de un incremento en la temperatura, se prevé que el cambio climático en la región también tendrá incidencia en el aumento del nivel medio del mar debido al calentamiento del océano, tanto por expansióntérmica o aumento de volumen por fusión de los hielos. El presente documento pretende hacer una breve descripción de la importancia de los humedales y documentar la experiencia regional sobre los riesgos del cambio climático en el agua y en el manejo de los humedales. De este modo, brinda recomendaciones que conduzcan a establecer un proceso de diálogo regional y de información a los actores, que permitan definir políticas para aumentar el nivel de preparación y adaptación al cambio climático, en función de los recursos hídricos y el manejo de los humedales. Localización: Biblioteca OET: AD 505. Publicación no.: 207 Nitrous oxide flux from dry tropical forests [Flujo de óxido nitroso de bosques seco tropicales] / Matson, P.A.; Vitousek, P.M.; Volkmann, C.; Maass, J.M.; García, G. (NASA. Ames Research Center, Moffett Field, CA 94035, US). Annual Meeting of the Ecological Society of America on Perspectives in Ecology: Past, Present, and Future. 75th, Snowbird, UT USJuly 29-August 2, 1990. In: Bulletin of the Ecological Society of America (ISSN 0012-9623), v. 71, no. 2 (Suppl.), p. 241-242. 1990. [Abstract only]. Fluxes of nitrous oxide were determined in several sites in drought-deciduous tropical forest, an extensive but little-studied biome. N2O-N fluxes from eight sites within intact Mexican forest averaged 0.91 ng cm-2 h-1 during the wet season; they were virtually absent in the dry season. Two subsistence maize fields yielded increasec soil N2O-N fluxes, while five pastures were more variable. Watering during the dry season caused a substantial but short-lived pulse of N2O. Similar fluxes were observed in less-intensive sampling of dry-forest sites in Hawaii and Costa Rica. Overall, N2O fluxes from soils of dry tropical forests appear to be similar to those from moist tropical forests during the wet season and very low during the dry season. Localización: Biblioteca OET: B. Publicación no.: 208 Carbon dynamics and land-use choices: Building a regional-scale multidisciplinary model [Dinámica del carbono y elecciones del uso de la tierra: construyendo un modelo multidisciplinario de escala regional] / Kerr, S.; Liu, S.P.; Pfaff, A.S.P.; Hughes, R.F. (Motu Economic and Public Policy Research, 19 Milne Terrace, Island Bay, Wellington, NZ <E-mail: suzi.kerr@motu.org.nz>). In: Journal of Environmental Management (ISSN 0301-4797), v. 69, no. 1, p. 25-37. 2003. Policy enabling tropical forests to approach their potential contribution to global-climate-change mitigation requires forecasts of land use and carbon storage on a large scale over long periods. In this paper, we present an integrated modeling methodology that addresses these needs. We model the dynamics of the human land-use system and of C pools contained in each ecosystem, as well as their interactions. The model is national scale, and is currently applied in a preliminary way to Costa Rica using data spanning a period of over 50 years. It combines an ecological process model, parameterized using field and other data, with an economic model, estimated using historical data to ensure a close link to actual behavior. These two models are linked so that ecological conditions affect land-use choices and vice versa. The integrated model predicts land use and its consequences for C storage for policy scenarios. These predictions can be used to create baselines, reward sequestration, and estimate thevalue in both environmental and economic terms of including C sequestration in tropical forests as part of the efforts to mitigate global climate change. The model can also be used to assess the benefits from costly activities to increase accuracy and thus reduce errors and their societal costs. Localización: Biblioteca OET: NBINA-1112. Publicación no.: 209 The social meaning of carbon dioxide emission trading: Institutional capacity building for a green market in Costa Rica [El significado social de la comercialización de la emisión de dióxido de carbono: Construyendo la capacidad institucional para un mercado verde en Costa Rica] /

Miranda-Quirós, M.; Dieperink, C.; Glasbergen, P. (Universidad Nacional. Centro Internacional en Política Económica para el Desarrollo Sostenible, P.O. Box 555-3000, Heredia, CR <E-mail: mmiranda@una.ac.cr>). In: Environment, Development and Sustainability (ISSN 1387-585X), v. 4, no. 1, p. 69-86. 2002. Forests offer good possibilities for the sequestration of carbon dioxide. This service can be commodified by the introduction of carbon (dioxide) credits, which can be traded on a carbon market. The premise of this paper is that the traditional economic view on the construction of these carbon markets is a too simplistic one, particularly, because it neglects the social meaning of a carbon market for developing countries. From their viewpoint as suppliers of carbon credits such a market has a broader meaning. It must be seen as a social mechanism for improving both the living conditions of local people and a more encompassing improvement of the environment than climate as such. What initially might be labelled as a carbon market might better be understood as a more encompassing 'green market'. The agreement between Costa Rica and Norway, officially known as the Reforestation Conservation Activities Implemented Jointly Project (RFCAIJP) represents a clear example of a green market. In this paper, we study the development, characteristics and benefits of that market, asking the question what lessons can be learned from this first practical experiences. More specifically we focus on the conditions that have made this type of agreement successful. Localización: Biblioteca OET: NBINA-6506. Publicación no.: 210 Impact of global changes on the reproductive biology of trees in tropical dry forests [Impacto de los cambios globales en la biología reproductiva de árboles en los bosques secos tropicales] / Bawa, K.S. (University of Massachusetts. Department of Biology, 100 Morrissey Blvd, Boston, MA 02125-3393, US <E-mail: kamal.bawa@umb.edu>). In: Biodiversity conservation in Costa Rica: learning the lessons in a seasonal dry forest. Frankie, G.W.; Mata-Jiménez, A.; Vinson, S.B., (eds.) Berkeley, CA: University of California Press, 2004. p. 38-47. ISBN: 0-520-24103-7. (No abstract). Localización: Biblioteca OET: 333.9516097286 b615. Publicación no.: 211 An ultrasonically silent night: the tropical dry forest without bats [Una noche ultrasónicamente silenciosa: el bosque tropical seco sin murciélagos] / LaVal, R.K. (Santa Elena de Monteverde, Apdo. 24-5655 Monteverde CR <E-mail: rlaval@racsa.co.cr>). In: Biodiversity conservation in Costa Rica: learning the lessons in a seasonal dry forest. Frankie, G.W.; Mata-Jiménez, A.; Vinson, S.B., (eds.) Berkeley, CA: University of California Press, 2004. p. 160-176. ISBN: 0-520-24103-7. (No abstract). Localización: Biblioteca OET: 333.9516097286 b615. Publicación no.: 212 A global problem for a global movement? An exploratory study of climate change perception by green groups' leaders from Quebec (Canada) and Costa Rica [¿Un problema global para un movimiento global? Estudio exploratorio de la percepción del cambio climático por parte de líderes de grupos ecologistas de Quebec (Canada) y Costa Rica] / Perron, B.; Vaillancourt, J.G.; Durand, C. (Université de Montréal. Départment of Sociologie, C.P. 6128, succ. Centre-ville, Montréal,Quebec H3C 3J7, CA <E-mail: benoit.perron@umontreal.ca> <E-mail: vaillje@poste.umontreal.ca>). In: Society and Natural Resources (ISSN 0894-1920), v. 14, p. 837-855. 2001. This article examines the possible unifying effect of climate change on leaders of green groups. The main goal is to identify ideological or North/South differences in attitudes on key aspects of climate change among them. Attitudinal data obtained with a standardized questionnaire administered to leaders from Quebec and Costa Rica are used to generate a typology. Three types of green orientations emerge: "ecologists," "mainstream environmentalism," anti "market environmentalism." General perceptions toward climate change and specific opinions about policy options related to global warming are compared on the basis of these orientations and of national origin. Results show that green leaders are divided on all measured attitudes concerning climate change. Most differences are explained hip diversity in ideological orientation, mainly by divergent viewpoints held by ecologists. The differences based on national origin are mainly explained by contrasted contextual features between Quebec and Costa Rica. The results do not provide convincing evidence of cognitive solidarity in the green movement concerning climate change. Localización: Biblioteca OET: S4077. Publicación no.: 213 Impact of global warming and locally changing climate on tropical cloud forest bats [Impacto del calentamiento global y los cambios climáticos locales sobre los murciélagos del bosque nuboso tropical] / Laval, R.K. (Santa Elena de Monteverde, Apdo. 24-5655 Monteverde CR <E-mail: rlaval@racsa.co.cr>). In: Journal of Mammalogy (ISSN 0022-2372), v. 85, no. 2, p. 237-244. 2004. Significant changes in local climate and correlated changes in non mammalian vertebrate populations have been documented in the Monteverde cloud forest in the Tilarán Mountains of northern Costa Rica, leading to the prediction that corroborative changes should occur in bat populations. Habitat changes resulting from development for ecotourism, including a 19% increase in forest, might also be expected to impact bat populations. Analysis of data collected between 1973 and 1999 in Monteverde supports the hypothesis, although changes are less dramatic than those shown for birds, reptiles, and amphibians in earlier studies. Capture rates did not change significantly during the 27 year sample period, but relative species abundance

increased, and at least 24 new species (of mostly lowland distribution) were recorded in the study area during the 1980s, 1990s, and through early 2002. These changes are likely a consequence of climatic change following global warming, forest clearing, and an increase in amount of secondary forest. This latter factor is a result of changes in land use due to development for tourism. Localización: Biblioteca OET: NBINA-1310. Publicación no.: 214 Estimating soil carbon fluxes following land-cover change: a test of some critical assumptions for a region in Costa Rica / Powers, J.S.; Read, J.M.; Denslow, J.S.; Guzmán, S.M. (University of Minnesota. Department of Soil, Water & Climate, St Paul, MN 55108, US <E-mail: powers@umn.edu> <E-mail: jaread@maxwell.syr.edu> <E-mail: julie.denslow@gte.net>). In: Global Change Biology (ISSN 1354-1013), v. 10, no. 2, p. 170-181. 2004. Changes in soil carbon storage that accompany land-cover change may have significant effects on the global carbon cycle. The objective of this work was to examine how assumptions about preconversion soil C storage and the effects of land-cover change influence estimates of regional soil C storage. We applied three models of land-cover change effects to two maps of preconversion soil C in a 140 000 ha area of northeastern Costa Rica. One preconversion soil C map was generated using values assigned to tropical wet forest from the literature, the second used values obtained from extensive field sampling. The first model of land-cover change effects used values that are typically applied in global assessments, the second and third models used field databut differed in how the data were aggregated (one was based on land-cover transitions and one was based on terrain attributes). Changes in regional soil C storage were estimated for each combination of model and preconversion soil C for three time periods defined by geo-referenced land-cover maps. The estimated regional soil C under forest vegetation (to 0.3 m) was higher in the map based on field data (10.03 Tg C) than in the map based on literature data (8.90 Tg C), although the range of values derived from propagating estimation errors was large (7.67-12.40 Tg C). Regional soil C storage declined through time due to forest clearing for pasture and crops. Estimated CO2 fluxes depended more on the model of land-cover change effects than on preconversion soil C. Cumulative soil C losses (1950-1996) under the literature model of land-cover effects exceeded estimates based on field data by factors of 3.8-8.0. In order to better constrain regional and global-scale assessments of carbon fluxes from soils in the tropics, future research should focus on methods for extrapolating regional-scale constraints on soil C dynamics to larger spatial and temporal scales. Localización: Biblioteca OET: S9649. NBINA-1400. Publicación no.: 215 Temperature effects on metamorphic rates in the tropical poison frog, Dendrobates auratus: Implications for global warming [Efectos de la temperatura sobre las tasas metamórficas en la rana tropical venenosa Dendrobates auratus: Implicaciones para el calentamiento global] / McRobert, S.P.; Korbeck, R.G., Jr. (Saint Joseph's University, Philadelphia, PA, US). National Meeting of the American Association for the Advancement of Science (AAAS) and Science Innovation Exposition. 166th, Washington, D.C., US; Feb. 17-22, 2000. p. A75. We examined the effects of temperature on developmental rate and survival in tadpoles of the poison frog Dendrobates auratus. Tadpoles reared at 26.2 and 29.4°C reached metamorphosis significantly faster, and had significantly higher rates of survival, than tadpoles raised at 22.3 and 30.9°C. Field studies showed that the mean temperature of bodies of water utilized by D. auratus tadpoles in La Suerte, Costa Rica was 26.2°C. Information such as this may aid efforts to maintain and breed tropical frog species in captivity. Localización: Non available. Publicación no.: 216 Decline of a tropical amphibian fauna [Disminución de la fauna tropical de anfibios] / Lips, K.R. (Southern Illinois University. Department of Zoology, Carbondale, IL 62901-6501, US <E-mail: klips@zoology.siu.edu>). National Meeting of the American Association for the Advancement of Science (AAAS) and Science Innovation Exposition. 166th, Washington, D.C., US; Feb. 17-22, 2000, p. A34. (No abstract). Localización: Non available. Publicación no.: 217 Something missing in fragile cloud forest: the clouds [Algo perdido en el frágil bosque nuboso: las nubes] / Yoon, C.K. In: The New York Times (ISSN 0362-4331), Nov. 20, 2001, Sec. F, p. 4. 2001. An article by R.O. Lawton and colleagues in a recent issue of Science 294:584-587. 2001, reports that the Monteverde cloud forest in the mountains of Costa Rica is under threat. Cloud forests, which are found throughout the Tropics, are usually rich in biodiversity and often provide a final refuge of biodiversity in places where the lowlands have been cleared and developed. Lawton and colleagues found that, in spite of Monteverde's tens of thousands of protected acres, the forest may be at risk because the clouds that bathe the mountains appear to be disappearing. Deforestation in the lowlands is raising the mountains' curtain of life-enriching fog and mist over the forest, leaving increasing areas of the forest without cloud cover. Researchers believe that the disappearance of the cloud, together with the effects of global warming, may explain some recent ecological changes observed in Monteverde. Localización: Biblioteca OET: NBINA-3305.

Publicación no.: 218 The potential negative impacts of global climate change on tropical montane cloud forests [Impactos negativos potenciales del cambio climático global sobre los bosques nubosos montanos] / Foster, P.N. (Stanford University. Department of Biological Sciences, Stanford, CA 94305-5020, US). In: Earth-Science Reviews (ISSN 0012-8252), v. 55, no. 1/2, p. 73-106. 2001. Nearly every aspect of the cloud forest is affected by regular cloud immersion, from the hydrological cycle to the species of plants and animals within the forest. Since the altitude band of cloud formation on tropical mountains is limited, the tropical montane cloud forest occurs in fragmented strips and has been likened to island archipelagoes. This isolation and uniqueness promotes explosive speciation, exceptionally high endemism, and a great sensitivity to climate. Global climate change threatens all ecosystems through temperature and rainfall changes, with a typical estimate for altitude shifts in the climatic optimum for mountain ecotones of hundreds of meters by the time of CO2 doubling. This alone suggests complete replacement of many of the narrow altitude range cloud forests by lower altitude ecosystems, as well as the expulsion of peak residing cloud forests into extinction. However, the cloud forest will also be affected by other climate changes, in particular changes in cloud formation. A number of global climate models suggest a reduction in low level cloudiness with the coming climate changes, and one site in particular, Monteverde, Costa Rica, appears to already be experiencing a reduction in cloud immersion. The coming climate changes appear very likely to upset the current dynamic equilibrium of the cloud forest. Results will include biodiversity loss, altitude shifts in species' ranges and subsequent community reshuffling, and possibly forest death. Difficulties for cloud forest species to survive in climate-induced migrations include no remaining location with a suitable climate, no pristine location to colonize, migration rates or establishment rates that cannot keep up with climate change rates and new species interactions. We review previous cloud forest species redistributions in the paleo-record in light of the coming changes. The characteristic epiphytes of the cloud forest play an important role in the light, hydrological and nutrient cycles of the cloud forest and are especially sensitive to atmospheric climate change, especially humidity, as the epiphytes can occupy incredibly small eco-niches from the canopy to crooks to trunks. Even slight shifts in climate can cause wilting or death to the epiphyte community. Similarly, recent cloud forest animal redistributions, notably frog and lizard disappearances, may be driven by climate changes. Death of animals or epiphytes may have cascading effects on the cloud forest web of life. Aside from changes in temperature, precipitation, and cloudiness, other climate changes may include increasing dry seasons, droughts, hurricanes and intense rain storms, all of which might increase damage to the cloud forest. Because cloud forest species occupy such small areas and tight ecological niches, they are not likely to colonize damaged regions. Fire, drought and plant invasions (especially non-native plants) are likely to increase the effects of any climate change damage in the cloud forest. As has frequently been suggested in the literature, all of the above factors combine to make the cloud forest a likely site for observing climate change effects in the near future. Localización: Biblioteca OET: NBINA-1499. Publicación no.: 219 Economic value of the carbon sink services of tropical secondary forests and its management implications [Valor económico de los servicios de almacenamiento de carbono de los bosques tropicales secundarios e implicaciones en su manejo] / Ramírez, O.A.; Carpio, C.E.; Ortiz, R.; Finegan, B. (Texas Tech University. Department of Agricultural and Applied Economics, Box 42132, Lubbock, TX 79409-2132, US <E-mail: octavio.ramirez@ttu.edu> <E-mail: bfinegan@catie.ac.cr>). In: Environmental and Resource Economics (ISSN 0924-6460), v. 21, no. 1, p. 23-46. 2002. This paper explores the economic feasibility of secondary forest regeneration and conservation as an alternative in the campaign addressing the problem of global warming. Detailed measurements of tropical secondary forests over time, in different ecological zones of Costa Rica, are used to evaluate carbon storage models. The paper addresses key issues in the international discussion about cross- and within-country compensation for carbon storage services and illustrates a method to compute/predict their economic value over time under a variety of scenarios. The procedure is applicable to other developing countries where secondary forest growth is increasingly important. Localización: Biblioteca OET: NBINA-1484. Publicación no.: 220 The environmental consequences of tax differentiation by vehicle age in Costa Rica [Consecuencias ambientales de la diferenciación de impuestos a los vehículos por su edad en Costa Rica] / Johnstone, N.; Echeverría-Bonilla, J.; Porras, I.T.; Mejías-Esquivel, R. (<E-mail: economia@cct.or.cr> <E-mail: ina.porras@iied.org> <E-mail: rmejias@cct.or.cr>). In: Journal of Environmental Planning and Management (ISSN 0964-0568), v. 44, no. 6, p. 803-814. 2001. This paper provides an overview of the potential environmental benefits in Costa Rica of increasing the relative tax rate on imported used cars. Analysis of this policy instrument has been chosen because Costa Rican fiscal policy has traditionally favoured the import of used cars. Moreover, a tax which differentiates between new and used cars can be a good proxy for taxes based directly upon emission levels. The results of the simulation reveal considerable environmental benefits in terms of nitrogen oxides, hydrocarbons and carbon monoxide emissions. Localización: Biblioteca OET: NBINA-1478.

Publicación no.: 221 Poblaciones de anfibios en declive ¿Un fenómeno global? / Márquez, R.; Lizana, M. In: Quercus (Revista de Observación, Estudio y Defensa de la Naturaleza) (ISSN 0212-0054), Cuaderno 94, p. 6-10. 1993. (No abstract). Localización: Non available. Publicación no.: 222 Diversity and composition of tropical soil nitrifiers across a plant diversity gradient and among land-use types [Diversidad y composición de los nitrificadores del suelo tropical a través de un gradiente de diversidad de plantas y entre diferentes tipos de uso del suelo] / Carney, K.M.; Matson, P.A.; Bohannan, B.J.M. (Smithsonian Environmental Research Center, POB 28, Edgewater, MD 21037, US <E-mail: karen.carney@gmail.com>). In: Ecology Letters (ISSN 1461-023X), v. 7, no. 8, p. 684-694. 2004. Ammonia-oxidizing bacteria (AOB) perform the rate-limiting step of nitrification, a key ecosystem process that in part determines the fate of nitrogen in ecosystems. However, little is known about the factors that determine soil AOB diversity or composition, especially in tropical systems. Using a set of study systems in Costa Rica, we examined whether plant diversity or land-use influenced AOB diversity or composition and whether AOB diversity or composition were associated with nitrification rates. We characterized the molecular diversity and composition of AOB via polymerase chain reaction amplification, cloning, and sequencing of 16S rDNA. We found that AOB diversity or composition did not change significantly across plant diversity treatments. In contrast, AOB differed among land-use types in some measures of diversity and in composition, and differences in AOB composition among land-use types were correlated with potential rates of nitrification. Our results suggest that anthropogenic changes of ecosystems can alter microbial communities in ways that may affect the processes they mediate. Localización: Biblioteca OET: NBINA-1546. Publicación no.: 223 The Forest in the Clouds: Nobody knew that tree cutting 30 miles away would jeopardize Costa Rica's delicate jewel [El bosque en las nubes: Nadie sabía que cortar árboles a 30 millas de distancia puede poner en peligro una delicada joya de Costa Rica] / Margolis, M. In: Newsweek (New York) (ISSN 0028-9604), Oct. 29, p. 58. 2001. When he first visited the wind-swept Monteverde cloud forest in the 1970s, University of Alabama biologist Robert O. Lawton "fell in love." No wonder. It is a luxuriant patch of tropical forest tucked away in the Tilarán mountain range, a great greenwall rising dramatically to 1,800 meters above the coastal lowlands of Costa Rica. Pilots recognize it by the permanent veil of cumulus clouds. Every year 70,000 tourists walk among the dripping forests, where relative humidity routinely reaches 100 percent, and marvel at the wealth of wildlife, from the ruby red-eyed tree frog to the sonorous blue-crowned motmot. Tourists for the most part tread lightly on the delicate cloud- forest habitat. But the nature they seek in the highlands is facing a threat from afar. Developers, ranchers and small farmers have for decades been steadily slashing and burning their way deep into the lowlands of Costa Rica, near the coasts. Today only 1,200 square kilometers, or 18 percent of the original lowland forest, remains untouched. Nobody ever suspected that cutting forests at sea level would influence weather patterns on Tilarán, 30 miles downwind, but it does. As Lawton and colleagues wrote in last week's Science magazine, the results could prove disastrous for this aerie in the clouds and the rich nature it supports. Scientists collected satellite images and field observations and then ran their data through a climate-change model from Colorado State University. Their initial findings are disturbing. As the trade winds pass over the now barren coastal forests, they pick up less moisture than they did when the forests were lush. When the hotter, drier air reaches the Tilarán mountains, it must climb higher before it yields enough moisture for clouds to form. Although the mountainside is still green, its life-giving mantle of clouds has been steadily shrinking. Just what this means for the ecology of the Monteverde preserve is still an open question. A lot is at stake. The dense, dripping cloud forest regulates temperatures and contributes to rainfall in the surrounding tropics. Its leafy canopy is home to an empire of animals and microorganisms, and more epiphytes--plants that live off other plants--than anywhere else on earth. Scientists are especially concerned over the fate of many cloud-forest birds, such as the resplendent quetzal, with its streaming tail feather, and the three- wattled bellbird, so named for its patented clanging call. Botanists have also cataloged 475 species of orchids. Environmental scientists first suspected something amiss in the late 1970s, when they observed a change in the habits of Monteverde wildlife. As clouds receded, birds and bats were forced to fly ever higher up the slopes. Scientists suspect that some reptiles have fled their old habitats altogether, leading to a general collapse of the reptile population. The splendid golden toad (Bufo periglenes), named after the male's bright gilded hue, has been declared extinct; it was unique to Monteverde. "Lose a cloud forest and you lose a whole family of species, some of which may be unique," says Lawton. It's not too late, he says, to restore the clouds. Slowing deforestation along the coasts and replanting cleared areas with fruit trees could help restore moisture to the air. It will take years of work before scientists know just how severe the damage will be to Monteverde. But by then, many more species may have gone by the wayside. Localización: Non available. Publicación no.: 224 Does conservation planning matter in a dynamic and uncertain world? [¿Importa la planificación de la conservación en un mundo dinámico e incierto?] / Meir, E.; Andelman, S.;

Possingham, H.P. (University of California at Santa Barbara. National Center of Ecology Analysis & Synth, Santa Barbara, CA 93101, US <E-mail: andelman@nceas.ucsb.edu>). In: Ecology Letters (ISSN 1461-023X), v. 7, no. 8, p. 615-622. 2004. Loss of biodiversity is one of the world's overriding environmental challenges. Reducing those losses by creating reserve networks is a cornerstone of global conservation and resource management. Historically, assembly of reserve networks has been adhoc, but recently the focus has shifted to identifying optimal reserve networks. We show that while comprehensive reserve network design is best when the entire network can be implemented immediately, when conservation investments must be staged over years, such solutions actually may be sub-optimal in the context of biodiversity loss and uncertainty. Simple decision rules, such as protecting the available site with the highest irreplaceability or with the highest species richness, may be more effectivewhen implementation occurs over many years. Localización: Biblioteca OET: NBINA-2027. Publicación no.: 225 Plant vulnerability to climate change [Vulnerabilidad de las plantas al cambio climático] / Berry, P. , 2004. 4 pp. (No abstract). Localización: Biblioteca OET: NBINA-1554. Publicación no.: 226 What are we learning from experiences with markets for environmental services in Costa Rica?: a review and critique of the literature [¿Qué hemos aprendido de experiencias con mercados para servicios ambientales en Costa Rica?: revisión y crítica de la literatura] / Rojas, M.; Aylward, B.A. (Eco-Asesores Integrados, Apartado 72-4400 Ciudad Quesada, CR <E-mail: manrique@racsa.co.cr> <E-mail: bruce@radel.com>, ). London: International Institute for Environment and Development, Environmental Economics Programme, 2003. 102 p. (Series: Markets for environmental services; no. 2). ISBN: 1843694557. Introduction: The use of markets and payments for environmental services is a topic gaining increasing attention amongst policy-makers and environment and development practitioners around the globe. Simply put, the term 'environmental services' can be taken to refer to the overall concept of natural systems providing a continuous flow of valuable goods and services to society. This is in contrast to similar services provided by man-made physical infrastructure and technological capital (i.e. water treatment, artificial fertilization, genetic modification) for which these environmental services are a substitute. The use of market mechanisms as a means of incorporating the economic value of these environmental services into the financial decision-making of producers and consumers is an additional tool that can be employed to resolve longstanding market failures that lead to less than desirable economic outcomes - i.e. having fewer environmental services and paying more for their man-made substitutes. In the developing world, Costa Rica has led efforts to experiment with the application of these mechanisms, many of which were simply ideas on paper just a few years ago. A survey of markets for environmental services by IIED highlights the formative role Costa Rica has played and provides a rich characterization of the economics of these initiatives in a global context (Landell-Mills and Porras 2002). As a complementary effort, this paper digs deeper into the literature regarding the Costa Rica experience in an effort to see what we are learning from the experience: how has technical, scientific and economic information on environmental services fed into these initiatives? To what extent are these initial experiences being monitored and evaluated? Is there a feedback loop that connects these experiences with learning about environment and development issues, particularly in the local context of policy-making within the country? The principal objective of the literature review is to identify and review documents and other material that address the following: 1. the local origins of the concept of payments and markets for environmental services and how they have developed over time, particularly in relation to the broader international development of the concept and local necessities/realities (historical and trend analysis); 2. the types of existing initiatives related to markets for environmental services, and who is participating in such initiatives (descriptive work); 3. the knowledge base that underpins market development, i.e. the extent to which markets are based on specific scientific and technical knowledge regarding the biophysical, economic and social relationships involved as opposed to general views on the subject (critical assessment); 4. the initiatives undertaken and underway to date with respect to the monitoring and evaluation of the experience with payments and markets for environmental services and to what extent (and with what results) the literature assesses these initiatives in terms of economic efficiency, environmental effectiveness, and social equity and/or poverty reduction. Where written material is not available or does not provide comprehensive coverage, interviews with those involved in these initiatives were used to supplement the documentary evidence. Given that IIED has undertaken a thorough review of the global literature on this topic and identified the examples emerging from Costa Rica, objectives 1 and 2 draw heavily on the existing IIED work by attempting to cross-check, confirm and, where possible, expand the coverage (in number and depth) of existing cases of markets and payments. The added value of the literature review will be in the deepening of the knowledge base and analysis of its content with respect to objectives 3 and 4. This in turn provides a basis for charting a way forward. The paper is organized to cover the objectives one by one. In the first chapter the local origins of the concept of markets and payments for environmental services in Costa Rica is explored. The paper then turns to the experiences (or market cases) gained so far in the country, providing in each of the succeeding chapters a description and review of each of the cases, an assessment of the role of knowledge in the development and formulation of the initiatives and a report on monitoring and evaluation underway to date. The paper concludes by

drawing out some of the lessons learned and making recommendations regarding practical steps that other countries, researchers and financing organizations might take to improve the process of launching such initiatives in the future. Localización: Biblioteca OET: NBINA-4513. Publicación no.: 227 Paleoclimate records from Central American cave calcite (Speleothem) deposits: results and progress [Registros paleoclimáticos de los depósitos de calcita de cuevas centroamericanas: resultados y progreso] / Lachniet, M.S.; Asmerom, Y.; Burns, S.J.; Patterson, W.P.; Seltzer, G.O.; Wurster, C.; Piperno, D. (Smithsonian Tropical Research Institute (STRI), Apartado 202, Balboa, PA <E-mail: matthew.lachniet@unlv.edu>). Tropical Forests: Past, Present, Future. The Association for Tropical Biology Annual Meeting. Smithsonian Tropical Research Institute, Panama City, PA; July 29-Aug. 3, 2002. Panamá City: The Association for Tropical Biology, 2002. p. 60. (Abstract only). We present paleoclimate proxy records from Central American speleothems that 1) constrain climate changes on millennial time scales, and 2) provide evidence for climate variability over decadal to centennial time scales. Stable isotope values in tropical precipitation reflect both the temperature of condensation and precipitation amount of an air mass, such that increased precipitation amount and decreased temperature result in lower delta ?18O values. Speleothems contain oxygen derived from precipitation, and if formed in isotopic equilibrium, provide a direct paleoprecipitation proxy record. Our speleothems from Costa Rica and Panamá, dated by precise U/Th methods, provide the first terrestrial stable isotopic records from the region. Stalagmite V1 from Costa Rica began growth before 10,140 yr BP and ceased about 5,200 yr BP. The oldest calcite has delta ?18O values 1), higher than the early and mid Holocene periods, suggesting some combination of cooler and/or drier conditions.During the early and mid Holocene, delta ?18O values vary by ?0.75?sigma, on decadal to centennial time scales, suggesting variations in dripwater delta ?18O values, which are related to precipitation amount associated with the Intertropical Convergence Zone. Additional records are being generated for Panamanian stalagmites, and hold promise for providing longer, more continuous paleoclimate records for the region. Localización: Biblioteca OET: AD 519. Publicación no.: 228 The geography of cloud formation and the biogeography of cloud forests: development of a quantitative approach [Geografía de la formación de nubes y la biogeografía de los bosques nubosos: desarrollo de un enfoque cuantitativo] / Lawton, R.O.; Nair, U.S.; Welch, R.M. (University of Alabama. Department of Biological Sciences, Huntsville, AL 35899, US <E-mail: lawton@email.uah.edu>). Tropical Forests: Past, Present, Future. The Association for Tropical Biology Annual Meeting. Smithsonian Tropical Research Institute, Panama City, PA; July 29-Aug. 3, 2002. Panamá City: The Association for Tropical Biology, 2002. p. 64. (Abstract only). Cloud forests, distinctive elements of montane vegetation throughout the tropics, are dependent upon predictable, frequent and prolonged immersion in cloud. Cloud forests are of interest in conservation and regional hydrological planning. However, we know little about how cloudy cloud forests are, or about the extent to which orographic cloud formation is influenced by natural climatic fluctuations, global warming, or regional land use. We present the initial steps, using ground observation, satellite imagery and atmospheric modeling, toward describing a quantitative geography of cloud forest cloudiness. Compiled data from GOES satellite imagery provides quantitative data on the proportion of time sites are covered by cloud. This approach reveals diurnal, seasonal, and between year variation in orographic cloud coverage at individual Central American cloud forest sites, and considerable between site variation as well. Such quantitative assessments of cloud cover and immersion should enhance between site comparisons in biogeographic and ecological analyses. Regional atmospheric modeling of the Cordillera de Tilarán and the associated lowlands of northern Costa Rica (with CSU RAMS) suggests that deforestation of lowland forests upwind of cloud forest sites can influence convective and orographic cloud formation, reducing cloud cover and raising the base of orographic cloud decks. Regional land use can thus interact with the natural geographic variation in cloud formation and exacerbate conservation problems in tropical mountains. Localización: Biblioteca OET: AD 519. Publicación no.: 229 Potential effects of climate change on canopy communities in a tropical cloud forest: an experimental approach [Efectos potenciales del cambio climático en las comunidades del dosel en un bosque nuboso tropical: un enfoque experimental] / Nadkarni, N.M.; Solano, R. (The Evergreen State College, Olympia, WA 98505, US <E-mail: nadkarnn@evergreen.edu>). Tropical Forests: Past, Present, Future. The Association for Tropical Biology Annual Meeting. Smithsonian Tropical Research Institute, Panama City, PA; July 29-Aug. 3, 2002. Panamá City: The Association for Tropical Biology, 2002. p. 79. (Abstract only). Global climate change models predict reduced cloud water in tropical montane forests. To test the effects of reduced cloud water on epiphytes, plants that are tightly coupled to atmospheric inputs, we transplanted epiphytes and their arboreal soil from upper cloud forest trees to trees at slightly lower elevations that are naturally exposed to less cloud water. Control plants moved between trees within the upper site showed no transplantation effects, but experimental plants at lower sites had significantly higher leaf mortality, lower leaf production, and reduced longevity. After the epiphytes died, seedlings of terrestrial gap-colonizing tree species grew from the seed banks within the residual mats of arboreal soil. Greenhouse experiments confirmed that the death of epiphytes can result in radical compositional changes of canopy

communities. Thus, tropical montane epiphyte communities constitute both a potentially powerful tool for detecting climate changes and a rich arena to study plant/soil/seed interactions under natural and manipulated conditions. This study also provides experimental evidence that the potential effects of global climate change on canopy and terrestrial communities can be significant for cloud forest biota. Results suggest there will be negative effects on the productivity and longevity of particular epiphytes and a subsequent emergence of an emerging terrestrial component into the canopy community from a previously suppressed seed bank. Localización: Biblioteca OET: AD 519. Publicación no.: 230 Biodiversity informatics, monitoring technologies and community science: challenges in the tropics [Informática sobre biodiversidad, tecnologías de monitoreo y ciencia comunitaria: retos en los trópicos] / Stevenson, R.D.; Haber, W.A.; Morris, R.A. (University of Massachusetts at Boston. Department of Biology, MA 02125, US <E-mail: robert.stevenson@umb.edu> <E-mail: whaber@racsa.co.cr>). Tropical Forests: Past, Present, Future. The Association for Tropical Biology Annual Meeting. Smithsonian Tropical Research Institute, Panama City, PA; July 29-Aug. 3, 2002. Panamá City: The Association for Tropical Biology, 2002. p. 112. (Abstract only). Two of the most important environmental problems facing humanity are global warming and loss of biodiversity. For the tropics, where biodiversity is high but changes in climate variables are expected to be relatively small, montane sites are likely to be the best locations for detecting change because change occurs over relatively short distances, facilitating field data collection. Climate variables to monitor include incident radiation, temperature, cloud cover patterns, precipitation, and extreme weather events. Biological variables to monitor include phenological data (migration events, flowering and fruiting times) and species distributions. New advances in microelectronics should greatly increase the spatial resolution of the climate measurements. We outline a general scheme for monitoring that includes a planning process, metadata standards, web based information systems to report and share data, a quality assurance plan, and an adaptive management plan. Special attention is paid to the limitations of statistical designs that can be used to detect change and to a citizen science component in which local communities can gather data and influence policy. A process is proposed to have the monitoring scheme certified by independent scientific organizations. This general scheme is applied to the Monteverde region with the goal of quantifying the relationship between the statistical power needed to detect change, the costs of monitoring, and the probability that a 20 year program can detect change. Localización: Biblioteca OET: AD 519. Publicación no.: 231 Characterization and dry deposition of carbonaceous aerosols in a wet tropical forest canopy [Caracterización y deposición de partículas secas de aerosoles carbonáceos en el dosel de un bosque tropical húmedo] / Loescher, H.W.; Bentz, J.A.; Oberbauer, S.F.; Ghosh, T.K.; Tompson, R.V.; Loyalka, S.K. (Oregon State University. Department of Forest Sciences, 321 Richardson Hall, Corvallis, OR 97331, US <E-mail: hank.loescher@oregonstate.edu> <E-mail: oberbaue@fiu.edu>). In: Journal of Geophysical Research: Atmosphere (ISSN 0148-0227), v. 109, no. D02309, doi:10.1029/2002jd003353. 2004. Carbon aerosol concentration was measured using an impactor on a 42 m tower over a wet tropical forest in La Selva Biological Station, northeast Costa Rica. Samples were collected at three different heights, 42, 21, and 2 m, for 2 months during the wet season in 1998. Winds originated from two directions, southeast from the Caribbean Sea and west from the continental isthmus. Concentrations were normalized by the fraction of dry sampling time during the collection. The distribution was negatively skewed for the range of aerodynamic diameter aerosols measured. The main size constituent was in the class 4.7-3.3 microm, accounting for ~0.70 microg C mol super(-1). No significant difference was found in the distribution of aerosol carbon with height, suggesting a well-mixed column of air, minimal resuspension, and that the source was from surrounding land use types. Functional relationships were developed to describe the loading of aerosols to the atmosphere and the removal by precipitation. Deposition was estimated using these relationships, combined with three different estimates of velocity deposition derived from (1) aerodynamic and canopy conductance, (2) aerodynamic and momentum conductance, and (3) traditional estimates of gravitational settling diffusion, impaction, and interception. Annual deposition estimates were 2.9, 5.0, and 9.6 kg ha(-1) yr(-1), respectively. Concentrations of carbon aerosols reported here are as much as two orders of magnitude higher than those reported elsewhere. Annual dry deposition estimates, however, were within the range of other estimates but were likely underestimated. Potential effects on deposition caused by seasonal burns and El Niño-Southern Oscillation are discussed. Localización: Biblioteca OET: NBINA-1653. Publicación no.: 232 Potencial de carbono y fijación de dióxido de carbono de la biomasa en pie por encima del suelo en los bosques de Costa Rica / Rodríguez, J.; Pratt, L. [Alajuela]: INCAE / CLADS, 1998. 69 p. (CEN; no. 762). En setiembre de 1996, la Universidad de Harvard y el Instituto Centroamericano de Administración de Empresas (INCAE) emprendieron un proyecto de tres años para proveer asesoría a las naciones de Centroamérica en la formulación de una estrategia competitiva que integre sus vastos recursos biológicos y su capital humano altamente emprendedor de manera innovadora, dentro del marco de la Alianza

Centroamericana para el Desarrollo Sostenible (ALIDES). En el área ambiental se le solicitaba asistir a los gobiernos centroamericanos en el análisis de las oportunidades y las restricciones para el desarrollo económico y, a partir de esto, diseñar e instrumentar nuevas estrategias que permitieran identificar y desarrollar oportunidades aprovechando su situación geográfica estratégica y su diversidad biológica, para así atraer mayor intercambio comercial e inversión, protegiendo al mismo tiempo el medio ambiente y su rica base de recursos naturales. Los esfuerzos de investigación dentro del desarrollo de mercados de mitigación de CO2, se deberían enfocar a: Desarrollar el concepto de Compensaciones Comerciales Certificadas de Gases con efecto de Invernadero (CCC), por medio de un mayor análisis de su mercado mundial, así como el uso de la tecnología para incrementar la aceptación del público de este mecanismo y demostrar su aplicación. Identificar cuellos de botella y eliminar obstáculos que inhiban la penetración al mercado de tecnologías para la reducción de emisiones y la expansión de la capacidad de captura de dióxido de carbono. Fortalecer los instrumentos financieros que regulan los CCC. Como parte de este estudio el Instituto Centroamericano de Administración de Empresas (INCAE) en conjunto con el Centro Latinoamericano para la Competitividad y el Desarrollo Sostenible, la Comisión Centroamericana de Ambiente y Desarrollo (CCAD) y el Harvard Institute for International Development tienen el placer de presentar los avances logrados en la investigación realizada para cuantificar la oferta potencial de compensaciones de carbono derivadas del recurso bosque centroamericano y, en este caso concreto, el potencial de carbono y fijación de dióxido de carbono en la República de Costa Rica, tomando como base los datos de uso del suelo estimados para 1996 y utilizando los años 2000, 2005, 2010, 2015 y 2020 como escenarios basados en las metas formuladas en el Documento "Perspectivas para el Desarrollo del Sector Forestal de Costa Rica hacia el 2020" presentado en el III Congreso Forestal Centroamericano, celebrado en San José de Costa Rica, en setiembre de 1997. Localización: Biblioteca OET: NBINA-1638.

Publicación no.: 233 Participación de la empresa privada en la conservación de la energía ante la apertura de un mercado global ambiental (el caso de INCSA) / Vega-Araya, E.E.; Pratt, L. [Alajuela]: INCAE / CLADS, 1999. 53 pp. (CEN; no. 717). Introducción: Ante los problemas relacionados con el cambio climático y el efecto invernadero, a partir de la Cumbre del Ambiente de Río de Janeiro en 1992, los países hablan de estabilizar y/o reducir las emisiones de gases de efecto invernadero. En Costa Rica se crea una Oficina de Cambio Climático adscrita al Instituto Meteorológico Nacional. Dicha oficina emite una directriz (solicitud) a todas las empresas con procesos productivos altamente contaminantes y consumidoras de energía de instalar aparatos de mediciones de emisiones y de estabilizar estas emisiones estables en el nivel de 1992. Por ser voluntaria, esta directriz no necesariamente se cumple en todas las empresas del país, y es necesario generar mecanismos de mercado para lograr este tipo de metas. En este trabajo se analizará la posibilidad que presenta uno de estos mecanismos de mercado para la solución del problema, desde la perspectiva de una empresa particular. El objetivo fundamental del caso es hacer el análisis de entorno con opciones de plantaciones forestales y/o bosques naturales, opciones de ahorro energético y ubicar esto desde la perspectiva de un gerente diseñando el futuro de una empresa altamente contaminadora, o altamente consumidora de energía. Se ha identificado una industria con un proceso productivo caracterizado por ser gran consumidor de energía y a su vez altamente contaminante, la Industria Cementera. En Costa Rica hay solamente dos empresas productoras de cemento que se reparten el mercado equitativamente.Se ha realizado este trabajo con una de ellas, la Industria Nacional de Cemento S.A. (INCSA), quienes amablemente han colaborado con este consultor suministrando información. Se han analizado las opciones que tiene la empresa ante la eventual apertura del Mercado Global Ambiental definido en el Protocolo de Kioto en diciembre de 1997, que en su artículo 12 define el Mecanismo de Desarrollo Limpio. Las opciones analizadas viables según el estado actual de la tecnología comercial para disminución del CO2 en la atmósfera son la de conservación energética (sustitución de combustibles fósiles por combustible no contaminante y/o reducción del uso de energía por unidad de cemento producida) y la de compensación de emisiones a través de fijación de CO2 con bosques y plantaciones forestales. También se podría aplicar proyectos como el uso de sistemas de absorción de gases de efecto invernadero (GEI) en procesos productivos (filtros), además de los citados en el párrafo anterior, pero dado el actual estado de la tecnología, aún no pueden competir comercialmente con las otras dos opciones, según estudios realizados en países desarrollados. Este tipo de proyectos no son analizados en el presente caso. Antes del análisis sugerido, se presenta información general sobre el entorno legal y económico relacionado con las posibilidades que ofrecería el Mercado Global Ambiental a la empresa privada. Localización: Biblioteca OET: NBINA-1631.

Publicación no.: 234 Estimación del costo marginal de los servicios fijación de carbono en Costa Rica / Sancho-Villalobos, F.; Pratt, L. [Alajuela]: INCAE / CLADS, 1999. 34 pp. (CEN; no. 704). Introducción: El estudio del tema del cambio climático implica una revisión de la influencia que ha tenido el hombre sobre uno de los sistemas que interactúan en el complejo funcionamiento de nuestro planeta. Lamentablemente, los niveles de este efecto ha alcanzado límites amenazantes, tanto para la vida del hombre como para la existencia de muchas otras especies. La humanidad enfrenta el dilema de actuar decididamente en el presente ante una amenaza que se proyecta dentro de varias décadas en el futuro, y que hoy en día sólo ha mostrado un ligero perfil de su peligro, cobrando un importante precio ambiental, social y económico. Sin embargo, el precio hasta hoy cobrado y las proyecciones que se han dibujado, demuestran que los grandes costos que implican las acciones para enfrentar el cambio climático, son de por sí, menores a los que enfrentará el planeta en el futuro si no se ejercen esas acciones. Este panorama es lo que ha generado la discusión en cuanto a la creación de un mercado de servicios de fijación y reducción de carbono. Se ha partido del concepto que este mercado no sólo significa una gran oportunidad para el mundo en desarrollo de proteger sus riquezas forestales y para permitirle un desarrollo realmente sostenible en lo ambiental y en uso de tecnologías limpias, sino que además se reconoce el potencial del mercado de carbono en favorecer el desarrollo social y económico, ya que implicará el flujo de recursos desde los países industriales, que más emisiones de gases de efecto invernadero producen, hacia los países en desarrollo, cuya competitividad en los servicios del bosque se considera como punto de partida. Este trabajo pretende identificar si Costa Rica realmente tiene una competitividad en los servicios del bosque que le permita aprovechar con éxito las oportunidades que abre el mercado de carbono. Este objetivo se trata de alcanzar con el uso de una metodología de apego científico suficiente, para que los resultados señalen si el país obtiene provecho máximo al estimular el uso de la tierra hacia la conservación, cubriendo el costo económico para los propietarios, sean privados o estatales. Si el comercio de Costa Rica lo hace con ese tipo de resultados estará en vía de que el mercado del carbono contribuya no sólo en loambiental, sino que también en lo económico y social, ya que crearía fuentes de trabajo alternativas a las que desplaza la conservación, pero igualmente remuneradas. Se evitará así la peligrosa tendencia de ofrecer los recursos naturales a precios bajos sin criterio económico, que reproduzca ese concepto erróneo de que son recursos gratuitos para la sociedad. El trabajo se dividió en dos partes, la primera ofrece el bagaje requerido para reconocer los factores que propician la aparición del mercado ambiental y que son lo suficientemente fuertes como para que los países en desarrollo apunten a aprovechar ese nuevo nicho. La segunda parte analiza el caso de Costa Rica, basándose en un proyecto de áreas protegidas vigentes. Se le aplican los criterios económicos con la información revelada en el proyecto base para identificar el costo del servicio ambiental para Costa Rica y el potencial de comercio internacional que se desprende. Localización: Biblioteca OET: NBINA-1630. Publicación no.: 235 The influence of plant diversity and land use on the composition and function of soil microbial communities [Influencia de la diversidad de plantas y el uso de la tierra en la composición y función de las comunidades microbianas del suelo] / Carney, K.M. (Smithsonian Environmental Research Center, POB 28, Edgewater, MD 21037, US <E-mail: karen.carney@gmail.com>). Stanford, CA: Stanford University, 2003. 105 pp. Dissertation, Ph.D., Stanford University, Stanford, CA (USA). Soil microbial communities mediate many critical ecosystem processes. Little is known, however, about the major factors that determine microbial community composition, and whether differences in microbial communities influence ecosystem process rates. Using an experimental system at La Selva Biological Station, Costa Rica, and a set of land use sites, I examined whether plant diversity, plant community composition, season, and land use influenced soil microbial communities and their functioning. This dissertation consisted of three main studies. In the first, I determined whether plant community composition, plant diversity, or season (i.e. wet versus dry) affected overall soil microbial community composition, as measured by phospholipid fatty acid analysis. I found that plant diversity significantly affected soil microbial community composition and that within a given plant diversity level, plant community composition affected microbial community composition. I found no strong seasonal trend in microbial community differences, although there were differences in composition across sampling dates. In the second study, I examined the effect of differences in overall microbial community composition on soil carbon cycling rates. I found that soil microbes that were compositionally distinct also differed in their abilities to decompose a suite of 24 labile carbon substrates (an assay termed "catabolic potential"). To determine whether differences in catabolic potential were indicative of a more real-world process (i.e. leaf litter decomposition), I conducted a factorial litter decomposition transplant experiment in the laboratory. My results suggest that microbial community composition has a significant influence over this process rate. In the third study, I used the same sites described above as well as two new land use types (i.e., forest and pasture) to explore patterns of diversity and function of a specific taxonomic and functional group: ammonia-oxidizing bacteria (AOB). I found no significant effect of plant diversity on either AOB diversity or composition, and no strong effect of land use on AOB diversity. However, I did find that land use affected AOB composition. Differences in composition were driven by the relative abundance of two genera: Nitrosospira and Nitrosomonas. Preliminary evidence suggests that these differences in composition may influence soil nitrification rates. Localización: Biblioteca OET: NBINA-5417. Publicación no.: 236 Centroamérica frente al cambio climático / Rojas, A.V.; Rodríguez, J.; Guzmán, J. San Salvador: FAO / Comisión Centroamericana de Ambiente y Desarrollo, San Salvador, 2003. 68 p. (Serie Centroamericana de Bosques y Cambio Climático). (No abstract).

Localización: Biblioteca Venezuela (IICA): P01 206. Publicación no.: 237 Costa Rica frente al cambio climático / Leiva, M.; Alfaro, M.; Hidalgo, M.; Méndez, A. San Salvador: FAO / Comisión Centroamericana de Ambiente y Desarrollo, San Salvador, 2003. 60 p. (Serie Centroamericana de Bosques y Cambio Climático). (No abstract). Localización: Biblioteca OET: NBINA-4181. Biblioteca Venezuela (IICA): P01 207. Publicación no.: 238 Mercados ambientales globales: estudios de caso / Castro-Salazar, R.; Pratt, L. San José: INCAE / PNUD, 1999. 100 pp. Hacia el petróleo verde en las Américas. El nuevo mercado mundial del carbono: el dilema de Costa Rica. Los bosques de Costa Rica y el mercado de créditos de reducción de carbono. Estudio de caso: puente en el Río Tempisque. Localización: Non available. Publicación no.: 239 Country case study on sources and sinks of greenhouse gases in Costa Rica. Final report / Costa Rica. Ministerio de Recursos Naturales, Energía y Minas. Instituto Meteorológico Nacional, San José, CR. Nairobi: UNEP, 1995. 100 pp. (No abstract). Localización: Non available. Publicación no.: 240 Arboreal ant species richness in primary forest, secondary forest, and pasture habitats of a tropical montane landscape [Riqueza de especies de hormigas arbóreas en hábitats de bosque primario, bosque secundario y potreros de un paisaje tropical montano] / Schonberg, L.A.; Longino, J.T.; Nadkarni, N.M.; Yanoviak, S.P.; Gering, J.C. (413 Rogers St NW, Olympia, WA 98502, US <E-mail: drummer@riseup.net> <E-mail: longinoj@evergreen.edu> <E-mail: nadkarnn@evergreen.edu> <E-mail: yanoviak@terra.com.pe>). In: Biotropica (ISSN 0006-3606), v. 36, no. 3, p. 402-409. 2004. Canopy invertebrates may reflect changes in tree structure and microhabitat that are brought about by human activities. We used the canopy fogging method to collect ants from tree crowns in primary forest, secondary forest, and pasture in a Neotropical cloud forest landscape. The total number of species collected was similar in primary forest (21) and pasture (20) habitats, but lower in secondary forest (9). Lower diversity in secondary forest was caused by lower species density (no. of species per sample). Rarefaction curves based on number of species occurrences suggest similar community species richness among the three habitats. This study has implications for conservation of tropical montane habitats in two ways. First, arboreal ant species density is reduced if secondary forest replaces primary forest, which increases the chance of extinction among rare species. Second, pasture trees may serve as repositories of primary forest ant communities due to similar tree structure. Localización: Biblioteca OET: B. NBINA-1777. Publicación no.: 241 Carbon sequestration in tropical and temperate agroforestry systems: a review with examples from Costa Rica and southern Canada [Captura del carbono en sistemas de agrosilvicultura tropicales y templados: una revisión con ejemplos de Costa Rica y el sur de Canadá] / Oelbermann, M.; Voroney, R.P.; Gordon, A.M. (University of Waterloo. Department of Environment & Resource Studies, Waterloo, ON N2L 3G1, CA <E-mail: moelberm@fes.uwaterloo.ca> <E-mail: pvoroney@uoguelph.ca> <E-mail: agordon@evb.uoguelph.ca>). In: Agriculture, Ecosystems and Environment (ISSN 0167-8809), v. 104, no. 3, p. 359-377. 2004. Deforestation in the tropics, and fossil fuel burning in temperate regions contribute to the largest flux of CO2 to the atmosphere. Therefore, land-use systems that increase the soil organic matter (SOM) pool and stabilize soil organic carbon (SOC) need to be implemented. Agroforestry systems have the potential to sequester atmospheric carbon (C) in trees and soil while maintaining sustainable productivity. The potential to sequester C in agroforestry systems in tropical and temperate regions is promising, but little information is available to date. The objective of this paper is to give an overview of the history of agroforestry and to outline differences in management practices between tropical and temperate systems. This review focuses on C inputs, SOC pools and SOC stabilization with highlights from Costa Rican and Canadian systems, and their role in C sequestration and trading. The potential to sequester C in aboveground components in agroforestry systems is estimated to be 2.1 x 10(-9) Mg Cyear-1 in tropical and 1.9 x 10(-9) Mg C year-1 in temperate biomes. However, the type of agroforestry systems and their capacity to sequester C vary globally. For example, alley cropping is an agroforestry practice where trees are integrated with crops, therefore storing C in the woody components of the trees and in the soil, with a continual addition of organic material from tree prunings and crop residues. Studies from Costa Rica have shown that a 10-year-old system with E. poeppigiana sequestered C at a rate of 0.4 Mg C ha-1 year-1 in coarse roots and 0.3 Mg C ha-1 year-1 in tree trunks. Tree branches and leaves are added to the soil as mulch, contributing 1.4 Mg C ha-1 year-1 in addition to 3.0 Mg ha-1 year-1 from crop residues. This resulted in an annual increase of the SOC pool by 0.6 Mg ha-1 year-1. Despite the two crop rotations in tropical agroforests, C input from crop residues is similar between the two biomes. The total organic matter input, however, is still greater in tropical systems due to the larger addition from tree prunings. This greater input does not necessarily increase the SOC pool significantly when compared to a temperate system of similar age as a result of faster turnover rates of the SOM pool. Localización: Biblioteca OET: NBINA-1765.

Publicación no.: 242 Quaternary geology and paleoclimate of Costa Rica: Evidence from glaciation, stable isotopes of surface waters, and a speleothem / Lachniet, M.S. (University of Nevada. Department of Geosciences, Las Vegas, NV 89154, US <E-mail: matthew.lachniet@unlv.edu>). Syracuse, N.Y., 2001. 140 pp. Dissertation, Ph.D., Syracuse University Graduate School, Syracuse, N.Y. (USA). Quaternary climates of the Caribbean Region are poorly known. This study investigates the terrestrial evidence of Costa Rican Quaternary paleoclimates via analysis of the Quaternary glaciation of the Costa Rican highlands to estimate temperature reductions associated with the last local glacial maximum, an analysis of the spatial and temporal variability in stable isotope values of Costa Rican surface waters and precipitation, and analysis of the stable isotope values of speleothems to estimate past variations in precipitation amount. The highest peaks of Costa Rica were glaciated during the late Quaternary, attesting to a significantly different climate in the Central American isthmus. New evidence of glacial extent comes from striated, grooved, and channeled bedrock in previously undocumented sites. During the last local glacial maximum, estimated as 12,000 14C yr BP, an ice cap 35 km² in extent covered the highest peaks of the Cordillera de Talamanca around Cerro Chirripó, 2 km² of ice existed around Cerro Kamuk, and 5 km² existed on Cerro de la Muerte. In Chirripó Park, the paleo equilibrium line altitude (ELA) was 3500 m. Cirque floor elevations around Cerro Kamuk of 3260 m suggest a lower paleo ELA there. The modern °C isotherm of 5000 m suggest a late Pleistocene ELA depression of 1500 m, associated with a temperature depression of 8 to 9°C. Analysis of a calcite speleothem from the Caribbean slope of Costa Rica provides direct evidence of past variations in precipitation amount on decadal time scales. delta18O calcite values prior to 10,140 yr BP are &sim;1&permil; higher than early Holocene values. These lower values may be explained by a temperature reduction of 5°C, decreased rainfall and relative humidity, or some combination of thetwo. To interpret the delta; 18O record preserved in this speleothem, a calibration study was undertaken to determine the spatial and temporal variation in stable isotopes in surface waters and precipitation delta18Owater values are most strongly correlated with precipitation amount and follow distinct regional trends. Deuterium excess values suggests that moisture recycling contributes to the moisture flux along the Nicaragua Trough. Localización: Non available. Publicación no.: 243 Diatom paleoecology of Laguna Zoncho, Costa Rica [Paleoecología de las diatómeas de la Laguna Zoncho, Costa Rica] / Haberyan, K.A.; Horn, S.P. (NW Missouri State University. Department of Biology, Maryville, MO 64468-2002, US <E-mail: khaber@mail.nwmissouri.edu> <E-mail: shorn@utk.edu>). In: Journal of Paleolimnology (ISSN 0921-2728), v. 33, no. 3, p. 361-369. 2005. We analyzed diatoms in a sediment profile from Laguna Zoncho in southern Pacific Costa Rica (lake elevation 1190 masl, depth 2.6 m, area 0.75 ha) spanning some 3240 cal yr. Diatoms are common in the profile, which we subdivide into three zones. Zone C (similar to 3240 - 1020 cal yr B. P.) is dominated by Staurosira construens var. venter and Aulacoseira spp.; during this time, the lake was dilute and circumneutral. Benthic and acidophilous taxa increase gradually in the upper section of this zone. Zone B (similar to 1020 - 460 cal yr B. P.) almost totally lacks Aulacoseira, and instead is dominated by combinations of Eunotia minor, Encyonema lunatum, Gomphonema gracile, and Pinnularia braunii. Previous pollen and charcoal analysis indicates that this zone falls within the peak of prehistoric agricultural activity at the lake, but diatoms may also reflect climate change. During this period, the lake was likely shallower and more acidic, but not eutrophic. Finally, Zone A (similar to 460 cal yr B. P. to AD 1997) begins near a 1.5-cm tephra layer from nearby Volcán Barú; diatom assemblages are dominated by Aulacoseira spp., and suggest deepening of the lake and return to conditions similar to Zone C. This was a time of indigenous population decline and forest recovery in the Zoncho region, probably reflecting the impact of European diseases on the native population, although climate change and impacts of the tephra deposition cannot be wholly discounted. Localización: Biblioteca OET: S10367. NBINA-2128. Publicación no.: 244 Amphibian population declines in Latin America: A synthesis [Disminución de las poblaciones de anfibios en Latinoamérica: una síntesis] / Lips, K.R.; Burrowes, P.A.; Mendelson, J.R., III.; Parra-Olea, G. (Southern Illinois University. Department of Zoology, Carbondale, IL 62901-6501, US <E-mail: klips@zoology.siu.edu>). In: Biotropica (ISSN 0006-3606), v. 37, no. 2, p. 222-226. 2005. The loss of global amphibian biodiversity has been well documented in recent years. The greatest information from Latin America came from countries such as Costa Rica, Panama, Ecuador, and Puerto Rico. The five papers in this special section illustrate the critical status of Latin American amphibians and further demonstrate certain commonalities of amphibian population declines within the region. These studies provide a framework by which future research and management could proceed in all tropical regions. Localización: Biblioteca OET: NBINA-2614. Publicación no.: 245 Payment for environmental services in Costa Rica: Carbon sequestration estimations of native tree plantations [Pago por servicios ambientales en Costa Rica: Estimaciones de captura de carbono de plantaciones forestales de árboles nativos] / Redondo-Brenes, A. (Yale University, New Haven, CT 06511, US <E-mail: alvaro.redondo@yale.edu>). In: Tropical Resources Bulletin, v. 24, p. 20-29. 2005. (No abstract). Localización: Biblioteca OET: S10594. NBINA-2473.

Publicación no.: 246 Potential carbon mitigation and income in developing countries from changes in use and management of agricultural and forest lands [Atenuación potencial del carbono e ingresos de paises en desarrollo a causa de los cambios en el uso y manejo de tierras agrícolas y forestales] / Niles, J.O.; Brown, S.; Pretty, J.; Ball, A.; Fay, J. (University of California. Energy and Resources Group, Berkeley, CA 94720, US <E-mail: joniles@socrates.berkeley.edu> <E-mail: sbrown@winrock.org> <E-mail: jpretty@essex.ac.uk> <E-mail: andrew@essex.ac.uk>). Essex: University of California / Winrock International / University of Essex, 2001. 26 pp. (Centre for Environment and Society; Occassional Paper no. 2001-04). The many opportunities for mitigating atmospheric carbon emissions in developing countries include implementing sustainable agricultural practices on existing lands, slowing tropical deforestation, and reforesting degraded lands. This new analysis shows that over the next ten years, forty-eight major tropical and subtropical developing countries have the potential to reduce the atmospheric carbon burden by about 2.2 billion tonnes of carbon. Given a central price of $10 tonne of carbon and a discount rate of 3%, this mitigation would generate a net present value of about $16.1 billion collectively for these countries. Achieving these potentials would require a significant global effort, covering more than fifty million hectares of land, to implement carbon-friendly practices in agriculture, forest, and previously forested lands. These estimates of host-country income potentials do not consider that outside financial investment may or may not be available. Our calculations also take no account of the additional benefits of carbon sequestration in forest soils undergoing reforestation, increased use of biomass, and reduced use of fossil fuel inputs and reduced agricultural emissions. In all events, realizing these incomes would necessitate substantially greater policy support and investment in sustainable land uses than is currently the case. Localización: Biblioteca OET: NBINA-2249. Publicación no.: 247 Modelación y proyección de tres usos del suelo forestales y agroforestales en Costa Rica: aplicación al Mecanismo de Desarrollo Limpio [Models and forecasting of three forest and agroforest land uses in Costa Rica: an application to the Clean Development Mechanism] / Venegas-Gamboa, I. Turrialba: CATIE, 2004. 99 pp. Thesis, Mag. Sc., Centro Agronómico Tropical de Investigación y Enseñanza (CATIE), Turrialba (Costa Rica). The Kyoto Protocol commits industrialized countries and economies in transition to cut their greenhouse gas emissions (GHG) to 5% below their 1990 levels by 2012 The Kyoto Protocol established the CDM (Clean Development Mechanism), which enables developed countries and economies in transition of the UNFCCC (United Nations Framework Convention on Climate Change) to meet their GHG reduction targets at lower cost through projects in developing countries. The Marrakesh conference established that the only eligible forest activities in the CDM are aforestation and reforestation. According to the CDM, forestry projects must demonstrate additionality in the reduction of carbon emissions Additionality is the difference between the carbon sequestration withthe project and without the project. The "without-project" scenario will be used as the baseline. Meanwhile, the baseline is a requisite for estimating the project additionality. The objective of this work is to model and to forecast the national baseline of three land uses and analyze their implication for Clean Development Mechanism projects in Costa Rica. In order to determine which types of land uses will be analyzed, criteria related to the Kyoto Protocol and the agreements of Marrakesh were taken into account as well as economic and environmental relevant criteria for agricultural activities. Forest plantations, coffee and secondary forest were selected. Data gathering was based on secondary information about land uses, land use changes and explicative variables of the three land uses A database was constructed with information for the period of 1970-2000. In order to complete the time series interpolation and extrapolation were used. In order to construct the models of land use change, two approaches were tested: the first was based in the tendency of the land use and the second one was based on the explicative variables of the land use. Finally, these approaches were compared. In the first approach, data was forecasted until the year 2012 (the end of the first commitment period of the Kyoto protocol) using two forecast methods STEPAR and EXPO Five curves were obtained for each use Outlier curves and those with the same shape were eliminated. With the resulting curves three new curves were obtained with the maximum, average and minimum values. In the second approach a linear regression model was constructed in order to explain the changes in each land use area. A regression analysis used the F test in order to obtain the significant explicative variables for each land use The explicative variables were extrapolated with the same methods as in the first approach Finally the model was applied with extrapolated variables in order to calculate future land uses areas. Localización: Biblioteca OET: NBINA-2401. Publicación no.: 248 Last glacial maximum equilibrium line altitudes in the circum-Caribbean (Mexico, Guatemala, Costa Rica, Colombia, and Venezuela) / Lachniet, M.S.; Vázquez-Selem, L. (University of Nevada. Department of Geosciences, Las Vegas, NV 89154, US <E-mail: matthew.lachniet@unlv.edu>). In: Quaternary International (ISSN 1040-6182), v. 138, p. 129-144. 2005. Equilibrium line altitude (ELA) estimates for Last Glacial Maximum (LGM) paleoglaciers in Mexico, Guatemala, Costa Rica, Colombia, and Venezuela were determined using the accumulation area balance ratio (AABR), accumulation area ratio (AAR), toe-to-headwall altitude ratio (THAR), and the maximum altitude of lateral moraine (MALM) methods. LGM glacial expansions are chronologically constrained in Mexico, the Merida Andes of Venezuela, the mountains around Bogota, Colombia, and the Ruiz-Tolima massif, Colombia. Undated glacial sites are tentatively correlated to dated sites on the basis of similar moraine morphology and weathering characteristics. LGM ELAs are 3400-3950 m in central Mexico, 3544 m for Guatemala, 3477 ± 13 m for Costa

Rica, 4104 ± 197 m for the Sierra Nevada de Santa Marta, Colombia, 3480 m for the Ruiz-Tolima region of Colombia, 3345 ± 130 m for the mountains around Bogota, Colombia, 4151 ± 181 m for the Sierra Nevada de Cocuy, Colombia, and 3576 ± 163 m for the Merida Andes of Venezuela. As the modern ELA and/or °C isotherm is found at 4900 ± 200 m, LGM ELA depression in the circum-Caribbean region was between 500 and 1625 m. Localización: Biblioteca OET: NBINA-2655. Publicación no.: 249 Deforestation and cloud forests in Costa Rica [Deforestación y los bosques nubosos en Costa Rica] / Lawton, R.O. (University of Alabama in Huntsville. Department of Biological Sciences, Huntsville, AL 35899, US <E-mail: lawton@email.uah.edu>). In: Environmental Review (ISSN 1080-644X), v. 9, no. 2, p. 1-8. 2002. Introduction: The Monteverde Forest Reserve in Costa Rica is a cloud forest ecosystem. Cloud forests receive a dependable and prolonged bath in clouds as trade winds push warm, moist air inland. Cloud forests in Central America are biological hotspots; that is, they support an unusual amount of biological diversity. However, deforestation not in Monteverde Reserve itself, but in lowland forests upwind has changed the conditions for cloud formation. Conversion of the lowland forests to pasture has resulted in drier, warmer air flowing into the cloud forests. This is our first indication that land use in tropical lowlands can have adverse effects on adjacent ecosystems. We spoke with Bob Lawton about his work in the cloud forests of Costa Rica. Localización: Biblioteca OET: NBINA-2248. Publicación no.: 250 The role of dissolved organic carbon, dissolved organic nitrogen, and dissolved inorganic nitrogen in a tropical wet forest ecosystem [El papel del carbón orgánico disuelto, el nitrógeno orgánico disuelto y el nitrógeno inorgánico disuelto en un ecosistema de bosque húmedo tropical] / Schwendenmann, L.C.; Veldkamp, E. (Universität Göttingen. Institute of Silviculture, Department of Tropical Silviculture; Busgenweg 1, D-37077 Göttingen, DE <E-mail: lscwen@gwdg.de> <E-mail: eveldka@gwdg.de>). In: Ecosystems (ISSN 1432-9840), v. 8, no. 4, p. 339-351. 2005. Although tropical wet forests play an important role in the global carbon (C) and nitrogen (N) cycles, little is known about the origin, composition, and fate of dissolved organic C (DOC) and N (DON) in these ecosystems. We quantified and characterized fluxes of DOC, DON, and dissolved inorganic N (DIN) in throughfall, litter leachate, and soil solution of an old-growth tropical wet forest to assess their contribution to C stabilization (DOC) and to N export (DON and DIN) from this ecosystem. We found that the forest canopy was a major source of DOC (232 kg C ha-¹ y-¹. Dissolved organic C fluxes decreased with soil depth from 277 kg C ha-¹ y-¹ below the litter layer to around 50 kg C kg C ha-¹ y-¹ between 0.75 and 3.5m depth. Laboratory experimentsto quantify biodegradable DOC and DON and to estimate the DOC sorption capacity of the soil, combined with chemical analyses of DOC, revealed that sorption was the dominant process controlling the observed DOC profiles in the soil. This sorption of DOC by the soil matrix has probably led to large soil organic C stores, especially below the rooting zone. Dissolved N fluxes in all strata were dominated by mineral N (mainly NO3(3)(-)). The dominance of NO3- relative to the total amount nitrate of N leaching from the soil shows that NO3- is dominant not only in forest ecosystems receiving large anthropogenic nitrogen inputs but also in this old-growth forest ecosystem, which is not N-limited. Localización: Biblioteca OET: NBINA-2703. Publicación no.: 251 Climate change and biodiversity: synercistic impacts [Cambio climático y biodiversidad: impactos sinergísticos] / Hannah, L.; Lovejoy, T.E, (eds.). In: Advances in Applied Biodiversity Science; no. 4 Washington, DC: Conservation International, 2003. 123 pp. ISBN: 1-881173-74-7. The chapters of this volume that follow focus on the synergistic and cascading impacts of climate change on biodiversity that occur when multiple factors interact. Researchers are working to understand these compound impacts using numeric computer models, field experimentation, and conceptual models framed by experts in multi-disciplinary assessment. The two chapters of this introductory section explore models and experimental methods that have been applied in research on the impacts of climate change on biotic interactions. Chapter 1 describes synergies and the models that may be used to simulate them. Because the models needed to directly simulate synergies are very complex, however, relatively few synergies have been successfully simulated. Instead, many synergies have been examined in conceptual models, through experimental manipulation, or by combining single-factor models. Chapter 2 explores these more fundamental approaches, which have been used to build understanding of synergies piece by piece. Chapters 1 and 2 lay the groundwork for Chapters 3-12, which draw on the methods described here and add others, such as conceptual models of fire or physiological effects of CO2, to paint a provocative, if partial, portrait of the synergistic effects of climate change on biodiversity. Localización: Biblioteca OET: NBINA-2715. Publicación no.: 252 Phytogeography of the bryophyte floras of oak forests and paramo of the Cordillera de Talamanca, Costa Rica [Fitogeografía de las floras de Briofitas de robledales y el páramo de la Cordillera de Talamanca, Costa Rica] / Holz, I.; Gradstein, S.R. (Universität Greifswald. Institute of Botany, Grimmer Str 88, D-17487 Greifswald, DE <E-mail: ingo.holz@uni-greifswald.de> <E-mail: sgradst@gwdg.de>). In: Journal of Biogeography (ISSN 0305-0270), v. 32, no. 9, p. 1591-1609. 2005. Aim: Central America is a biogeographically interesting area because of its location between the rich and very different biota of North and South America. We aim to assess phytogeographical patterns in the bryophyte floras of oak forests and paramo ofthe Cordillera de Talamanca, Costa Rica. Location: Tropical America, in particular the

montane area of Cordillera de Talamanca, Costa Rica. Methods: The analysis is based on a new critical inventory of the montane bryophyte flora of Cordillera de Talamanca. All species were assigned to phytogeographical elements on the basis of their currently known distribution. Absolute and percentage similarities were employed to evaluate floristic affinities. Results: A total of 401 species [191 hepatics (liverworts), one hornwort, 209 mosses] are recorded; of these, 251 species (128 hepatics, one hornwort, 122 mosses) occur in oak forests. Ninety-three per cent of all oak forest species are tropical in distribution, the remaining 7% are temperate (4%) and cosmopolitan (3%) species. The neotropical element includes almost 74% of the species, the wide tropical element (pantropical, amphi-atlantic, amphi-pacific) only 19%. A significant part of the neotropical species from oak forests are species with tropical Andean-centred ranges (27%). As compared with bryophyte species, vascular plant genera in the study region are represented by fewer neotropical, more temperate and more amphi-pacific taxa. Bryophyte floras of different microhabitats within the oak forest and epiphytic bryophyte floras on Quercus copeyensis in primary, early secondary and late secondary oak forest show a similar phytogeographical make-up to the total oak forest bryophyte flora. Comparison of oak forest and paramo reveals a greater affinity of the paramo bryophyte flora to temperate regions and the great importance of the paramo element in paramo. Surprisingly, oak forests have more Central American endemics than paramo. Main conclusions: (1) Providing first insights into the phytogeographical patterns of the bryophyte flora of oak forests and paramo, we are able to confirm general phytogeographical trends recorded from vascular plant genera of the study area although the latter were more rich in temperate taxa. (2) Andean-centred species are a conspicuous element in the bryophyte flora of Cordillera de Talamanca, reflecting the close historical connection between the montane bryophyte floras of Costa Rica and South America. (3) High percentages of Central American endemics in the bryophyte flora of the oak forests suggest the importance of climatic changes associated with Pleistocene glaciations for allopatric speciation. Localización: Biblioteca OET: NBINA-2786. Publicación no.: 253 Changing bee composition and frequency on a flowering legume, Andira inermis (Wright) Kunth ex DC. during El Niño and La Niña years (1997-1999) in Northwestern Costa Rica [Composición y frecuencia cambiante de abejas en una leguminosa florecida, Andira inermis (Wright) Kunth ex DC. durante los años de El Niño y La Niña (1997-1999) en el noroeste de Costa Rica] / Frankie, G.W.; Rizzardi, M.; Vinson, S.B.; Griswold, T.L.; Ronchi, P. (University of California. Department of Entomological Sciences, Berkeley, CA 94720, US <E-mail: frankie@nature.berkeley.edu> <E-mail: mar13@humboldt.edu> <E-mail: bvinson@neo.tamu.edu> <E-mail: tgris@biology.usu.edu> <E-mail: boraginaceae@hotmail.com>). In: Journal of the Kansas Entomological Society (ISSN 0022-8567), v. 78, no. 2, p. 100-117. 2005. In 1999, bees were sampled from several flowering individuals of the leguminous tree, Andira inermis (Papilionoideae), at two sites in northwestern Guanacaste Province of Costa Rica. One site, city outskirts of Liberia, was experiencing steady encroachment of human development, whereas the other was a moderately impacted cattle ranch/wildland area near the small town of Bagaces. A standardized method was employed to sample the bees, which had been used previously in 1996 in the same tree populationsat the same two sites (Frankie et al., 1997). Results of the 1999 samples were compared with those taken in 1996 to examine possible changes in bee diversity and abundance. During this three-year period, El Niño and La Niña climatic events had occurred back-to-back, and this combination of weather patterns provided an opportunity to evaluate possible short-term changes in the bee taxa that use A. inermis as one of their preferred host plants. Other bee host plants at both sites were also surveyed for seasonal flowering, the results of which formed a broader context for assessing the A. inermis bee samples. The comparison revealed the following. (1) The composition of bees had changed with reductions in large bees from 1996 to 1999; most noticeably someanthophorids and especially Centris and Epicharis. Africanized honey bees and smaller bee taxa remained about the same in composition and overall abundance. (2) During El Niño and La Niña years from mid 1997 through early 1999, the flowering of key resources for large bees, especially Byrsonima crassifolia, was substantially delayed (and sometimes reduced) to the point where building and provisioning of bee nests was likely reduced, which apparently led to declines in large bee taxa. Other possible causes of decline, including increasing agricultural development in the region, are also discussed. (3) Intertree variation in attraction of bees to A. inermis was documented in both 1999 and 1996, but persistence of this variable attraction on the same individual trees could be only partially evaluated in 1999. The flowering pattern(s) of individual A. inermis trees has proved to be highly variable within and between the two study sites. Localización: Biblioteca OET: NBINA-3315. Publicación no.: 254 Carbon storage in coffee agroecosystems of southern Costa Rica: potential applications for the clean development mechanism [Captura de carbono en agroecosistemas de café en el sur de Costa Rica: aplicaciones potenciales para el mecanismo de desarrollo limpio] / Polzot, C.L. Toronto: York University, 2004. 162 pp. Thesis, M.Sc. in Environmental Studies, York University, Toronto, Ontario (Canada). Climate change is one of the greatest environmental and economic threats facing the world today. Human activities, particularly the burning of fossil fuels and clearing of forests, have increased the level of greenhouse gases - the primary contributors to global warming - in the atmosphere. This accumulation is changing the Earth's weather patterns, resulting in higher global temperatures, rising sea levels and a potential shift in the distribution of the world's ecosystems. There is a growing need to develop strategies that will reduce current levels of greenhouse gases in the atmosphere and curtail future emissions. The Kyoto Protocol represents an international strategy: it establishes emission reduction targets for industrialized countries and incorporates a Clean

Development Mechanism for trading carbon credits generated by projects implemented in developing countries. Tree-based land-use systems, such as the shade-grown coffee agroecosystems of southern Costa Rica, sequester carbon dioxide from the atmosphere and store it in their biomass. Simultaneously, these agroecosystems provide additional products and services to local residents and reduce pressure on existing forests. Therefore, increasing tree cover in coffee production is a viable option for mitigating climate change that also provides social, economic and ecological benefits. The objective of this study is to generate aboveground carbon-stock inventory data for five coffee production systems in southern Costa Rica, which employ various degrees of structural complexity in their shade layer. The sites include coffee grown with poró (Erythrina poeppigiana), guaba (Inga sp.), banana (Musa spp.), eucalyptus (Eucalyptus deglupta) and diversified shade (primarily Terminalia amazonia and Cedrela odorata). An advanced secondary-forest site at the Los Cusingos Neotropical Bird Sanctuary is used as a control. The carbon-stock of shade trees, coffee bushes and leaf litter is calculated for each site, and the income that could be generated from a one-time payment for the environmental service provided by shade trees (carbon storage) is estimated. Results indicate the coffee production system that stores the most amount of carbon per hectare in its aboveground biomass is Diversified Shade (31.6 t C ha-¹), employing a variety of shade-tree species in three distinct layers. Conversely, the Inga sp. system - a shaded monoculture with low structural complexity in its shade layer - stores the least carbon (11.0 t C ha-¹). The carbon-stock of the other systems examined falls within this range and varies according to structural complexity, species composition and management practices. This study recommends that the shade layer in coffee agroecosystems be made more complex for increased carbon storage and maintenance of biodiversity, as previous papers suggest. In the case of southern Costa Rica, a carbon sequestration project implemented under the Clean Development Mechanism could provide farmers with an incentive to select management practicesthat favour higher carbon-stocks and biodiversity. Such an endeavour would have social, economic and environmental benefits and would provide an example that could be replicated in other small watersheds of Central America. Localización: Biblioteca OET: NBINA-2772. Publicación no.: 255 Energy dynamics and modeled evapotranspiration from a wet tropical forest in Costa Rica [Dinámica de la energía y modelo de evapotranspiración de un bosque húmedo tropical en Costa Rica] / Loescher, H.W.; Gholz, H.L.; Jacobs, J.M.; Oberbauer, S.F. (Oregon State University. Department of Forest Sciences, 321 Richardson Hall, Corvallis, OR 97331, US <E-mail: hank.loescher@oregonstate.edu> <E-mail: oberbaue@fiu.edu>). In: Journal of Hydrology (ISSN 0022-1694), v. 315, no. 1/4, p. 274-294. 2005. The effects of albedo, net radiation (Rn), vapor pressure deficit (VPD), and surface conductances on energy fluxes and evapotranspiration (ET) were determined for a wet tropical forest in NE Costa Rica from 1997 to 2000. Sensible heat fluxes (H) were estimated by the combination of eddy-covariance and the change in below-canopy heat profiles. Above-canopy latent heat fluxes (lambda E) were estimated by the residuals from Rn and H, and below canopy ?E fluxes. Surface reflectance (albedo) was about 12% of incident solar radiation and did not differ seasonally. Rn was significantly different among years and explained about 79% of the variation in H and lambda E fluxes. The effects of VPD did not explain any additional variation in heat fluxes lambda E fluxes were always greater than H fluxes when Rn 40 W m-². Understory heat fluxes were small and contributed little towards daily energy exchange, but may be significant when Rn is small. A dimensionless coefficient (Q) was used to determine the relative importance of aerodynamic conductance (ga) and bulk canopy conductance (gb) on lambda E flux. During the day, Q was 0.6 and peaked at 0.85 suggesting that the forest was decoupled from physiological controls, lambda E fluxes are more dependent on Rn than water availability, and ga exerts more control on AE fluxes than gb. Because of these results, both the Priestly-Taylor and the Penman-Monteith models performed well using only Rn. Because the canopy is wet about 32% of the time, there was better precision in estimating lambda E fluxes using the Priestly-Taylor model (with an empirically estimated alfa=1.24), when the canopy was wet. Annual ET were 1892, 2292 and 2230 mm for 1998, 1999 and 2000, respectively. Annual ET ranged from 54 to 66% of bulk precipitation. Using a Rutter-type model, interception losses were 17-18% of bulk precipitation. The overall amount of energy needed for annual ET accounted for about 88 to 97% of total Rn. Localización: Biblioteca OET: NBINA-2758. S10773. Publicación no.: 256 Global gap analysis: towards a representative network of protected areas [Análisis global de omisiones de conservación: hacia una red de áreas protegidas representativa] / Rodrigues, A.S.L.; Andelman, S.J.; Bakarr, M.I.; Boitani, L.; Brooks, T.M.; Cowling, R.M.; Fishpool, L.D.C.; Fonseca, G.A.B.; Gaston, K.J.; Hoffman, M.; Long, J.; Marquet, P.A.; Pilgrim, J.D.; Pressey, R.L.; Schipper, J.; Sechrest, W.; Stuart, S.N.; Underhill, L.G.; Waller, R.W.; Watts, M.E.J.; Xie, Y. Washington DC: Conservation International, 2003. 98 pp. (Advances in Applied Biodiversity Science; no. 5). The problem: Increasing human pressure on natural resources is transforming our planet's ecosystems and leading to irreversible biodiversity loss. The opportunity: Governments worldwide acknowledge the value of protected areas as conservation tools, and so set land aside for this purpose. An assessment of the completeness of the current global network of protected areas is a critical tool needed to strategically expand and strengthen the coverage of protected areas. The data: Four remarkable datasets have just become available that allow a first attempt at this assessment. The World Database on Protected Areas holds more than 100,000 spatial records of protected areas. Distribution maps produced through the IUCN Red List partnership now cover 11,171 species: 1,183 globally threatened birds, 4,734 mammals (978 threatened), and 5,254 amphibians (1,467 threatened). The analysis: This project overlaid species distribution maps onto protected area maps using Geographic

Information Systems to assess howwell each species is represented in protected areas. Assessment of the highest priority areas for consolidating and expanding the protected area network requires information on irreplaceability and threat. Irreplaceability measures how options for achieving species representation targets are reduced if a site is not conserved. Threat can be calculated as the number of threatened species present at a site, weighting those with higher extinction risk. Sites of exceptional irreplaceability and threat were identified as the most urgent conservation priorities. These include currently protected sites - priorities for strengthening the existing global network of protected areas - and unprotected sites - priorities for the expansion of the global network. Theresults: At least 1,310 species (831 at risk of extinction) are not protected in any part of their ranges. Amphibians, overall, are less well covered than birds or mammals. Areas identified as urgent (both for strengthening and for the expansion of the global network) are mainly concentrated in tropical forests, especially in areas of topographic complexity, and on islands. Proportionally, Asia is a higher priority for the expansion of the global network of protected areas, while the need for strengthening the existing network is mainly emphasized in Africa and South America. The percentage of area already protected in a given country does not inform how much more protection is needed - the level of endemism is a much better predictor. The implications: The current global network of protected areas is far from achieving a complete coverage of vertebrate species. The expansion of the global protected area network cannot be based on area targets (10 percent or otherwise): it must instead be based on biodiversity information. Many unprotected regions are highly irreplaceable and threatened - it is essential to ensure that they are adequately protected as soon as possible. Likewise, many existing protected areas urgently require increased investment. This analysis does not cover aquatic biodiversity, nor address issues of the persistence (only of the representation) of biodiversity. Nevertheless, expanding the global network of protected areas into the regions highlighted as urgent priorities in this global gap analysis would go a long way towards the conservation of bird, mammal, and amphibian species, and provide a first step towards a truly representative protected area system. Localización: Biblioteca OET: NBINA-2721. Publicación no.: 257 El impacto social de los mercados de carbono en Costa Rica: Estudio de campo de la Región Huetar Norte / Miranda-Quirós, M.; Porras, I.T.; Moreno-Díaz, M.L. (Universidad Nacional. Centro Internacional en Política Económica para el Desarrollo Sostenible, P.O. Box 555-3000, Heredia, CR <E-mail: mmiranda@una.ac.cr> <E-mail: ina.porras@iied.org>). Heredia: Universidad Nacional / CINPE / IIED, 2004. 58 pp. In this study the authors assess the impacts of the Payments for Environmental Services scheme in relation to reforestation activities as a source of carbon sinks. One of the aims is to test a methodology based on the five assets approach of the Sustainable Livelihoods framework. The study finds that the PES scheme has had important impacts on financial assets, not so much from the payments themselves, but from the expected income from timber sales. The payments have acted as a catalysing factor for reforestation activities, covering some of the upfront costs. Nevertheless high transaction costs for entering the scheme are noted as an obstacle. There have been important effects on human assets mainly in the form of transfer of knowledge on reforestation through technical assistance as well as learning through trial and error. The PES programme has had important impacts on social organisation encouraging alliances between NGOs and serving as a means to consolidate objectives, capacity and financial resources of some organisations working with groups of small landowners. Natural assets have benefited as the PES programme has contributed to the recovery of forest landscapes in the area. A side benefit of this has been promotion of the local tourist industry. The area of negative impact is for physical assets as the PES has contributed to greater use of existing infrastructure, roads, particularly and has not generated improvements. Localización: Biblioteca OET: NBINA-2734. Publicación no.: 258 Carbon and nitrogen geochemistry of sediments in the Central American convergent margin: Insights regarding subduction input fluxes, diagenesis, and paleoproductivity / Li, L.; Bebout, G.E. (Lehigh University. Department of Earth & Environmental Sciences, 31 Williams Dr, Bethlehem, PA 18015, US <E-mail: lol2@lehigh.edu>). In: Journal of Geophysical Research: Solid Earth (ISSN 0148-0227), v. 110, no. B11, Article B11202, doi:10.1029/2004JB003276. 2005. Carbon (C) and nitrogen (N) concentrations and isotopic compositions were determined for sediments from Ocean Drilling Program legs 170 and 205 offshore of Costa Rica, in an attempt to characterize C-N flux into the Central America (CA) convergent margin and identify signatures of diagenesis and changing productivity in this sediment section. Samples from sites 1039 and 1253 (outboard of the trench) contain 62 to 2382 ppm total nitrogen (TN) with delta(15)N(Air) values of +2.4 to +8.5 parts per thousand, 0.04-2.65 wt% total organic carbon (TOC) with delta(13)C(VPDB) values of -25.4 to -20.8 parts per thousand, and 1.1-87.3 wt% carbonate with delta(13)C values of +0.1 to +3.2 parts per thousand and delta(18)O(VSMOW) values of +21.3 to +34.2 parts per thousand. Total organic C and TN concentrations strongly depend on lithology, with carbonate-rich samples containing smaller amounts of both. Total organic C and TN concentrations and isotopic compositions also vary systematically within single units, perhaps reflecting small degrees of diagenetic alteration but mostly significant increase in productivity since the early Pliocene. Sediment subduction feeds 1.3 x 10(10) g yr(-1) N (mean delta(15)N = +5.7 parts per thousand), 1.4 x 10(11) g yr(-1) TOC (mean delta(13)C = -22.0 parts per thousand) and 1.5 x 10(12) g yr(-1) oxidized C (mean delta(13)C = +1.9 parts per thousand) into the 1100 km CA convergent margin. Incorporating possible inputs in altered oceanic crust (AOC) and by tectonic erosion, the C-N

inputs appear to be far larger than the arc outputs. A small part of this excess C and N is probably returning toward the surface by devolatilization, along structural heterogeneities in the forearc, and the remaining inventory is likely recycling into the deeper mantle. Localización: Biblioteca OET: NBINA-3197. Publicación no.: 259 Case of the dwindling cloud forest [El caso del bosque nuboso en disminución] / Holmes, B.; Fogden, M.P.L, (phot.).; Fogden, P, (phot.). (151 Wardour St, London, W1F 8WE, GB <E-mail: news@newscientist.com> <E-mail: goldtoad@racsa.co.cr> <E-mail: patriciafogden@hotmail.com>). In: International Wildlife (ISSN 0020-9112), v. 30, no. 4, p. 20-27. 2000. Something is amiss in Costa Rica's famous foggedin hilltops, and global climate change may be the cause. Localización: Biblioteca OET: NBINA-3256. Publicación no.: 260 Plant communities, soil microorganisms, and soil carbon cycling: Does altering the world belowground matter to ecosystem functioning? [Comunidades de plantas, microorganismos del suelo y ciclo del carbono del suelo: ¿Altera la materia mundial bajo tierra el funcionamiento del ecosistema?] / Carney, K.M.; Matson, P.A. (Smithsonian Environmental Research Center, POB 28, Edgewater, MD 21037, US <E-mail: karen.carney@gmail.com>). In: Ecosystems (ISSN 1432 9840), v. 8, no. 8, p. 928-940. 2005. Soil microorganisms mediate many critical ecosystem processes. Little is known, however, about the factors that determine soil microbial community composition, and whether microbial community composition influences process rates. Here, we investigated whether aboveground plant diversity affects soil microbial community composition, and whether differences in microbial communities in turn affect ecosystem process rates. Using an experimental system at La Selva Biological Station, Costa Rica, we found that plant diversity (plots contained 1, 3, 5, or 25 plant species) had a significant effect on microbial community composition (as determined by phospholipid fatty acid analysis). The different microbial communities had significantly different respiration responses to 24 labile carbon compounds. We then tested whether these differences in microbial composition and catabolic capabilities were indicative of the ability of distinct microbial communities to decompose different types of litter in a fully factorial laboratory litter transplant experiment. Both microbial biomass and microbial community composition appeared to play a role in litter decomposition rates. Our work suggests, however, that the more important mechanism through which changes in plant diversity affect soil microbial communities and their carbon cycling activities may be through alterations in their abundance rather than their community composition. Localización: Biblioteca OET: NBINA-3367. Publicación no.: 261 The effects of temperature on development and survival in tadpoles of the tropical poison frog Dendrobates auratus [Efectos de la temperatura sobre el desarrollo y sobrevivencia en renacuajos de la rana tropical venenosa Dendrobates auratus] / Korbeck, R.G., Jr.; McRobert, S.P. (Saint Joseph's University, Philadelphia, PA, US). In: Russian Journal of Herpetology (ISSN 1026-2296), v. 12, no. 1, p. 13-16. 2005. We examined the effects of temperature on developmental rate and survival in tadpoles of the poison frog Dendrobates auratus. Tadpoles reared at 26.2 and 29.4°C reached metamorphosis significantly faster, and had significantly higher rates of survival, than tadpoles raised at 22.3 and 30.9°C. Field studies showed that the mean temperature of bodies of water utilized by D. auratus tadpoles in La Suerte, Costa Rica was 26.2°C. Information such as this may aid efforts to maintain and breed tropical frog species in captivity. Localización: Biblioteca OET: NBINA-3365. Publicación no.: 262 Widespread amphibian extinctions from epidemic disease driven by global warming [Amplias extinciones de anfibios por enfermedad epidémica inducida por el calentamiento global] / Pounds, J.A.; Bustamante, M.R.; Coloma, L.A.; Consuegra, J.A.; Fogden, M.P.L.; Foster, P.N.; La Marca, E.; Masters, K.L.; Merino-Viteri, A.; Puschendorf, R.; Ron, S.R.; Sánchez-Azofeifa, G.A.; Still, C.J.; Young, B.E. (Monteverde Cloud Forest Preserve. Tropical Science Center, Golden Toad Laboratory Conservation, Box 73, Santa Elena 5655 Puntarenas, CR <E-mail: goldtoad@racsa.co.cr> <E-mail: amasters@racsa.co.cr> <E-mail: rpuschen@biologia.ucr.ac.cr> <E-mail: sron@puceuio.puce.edu.ec> <E-mail: arturo.sanchez@ualberta.ca> <E-mail: bruce_young@natureserve.org>). In: Nature (ISSN 0028-0836), v. 439, no. 7073, p. 161-167. 2006. As the Earth warms, many species are likely to disappear, often because of changing disease dynamics. Here we show that a recent mass extinction associated with pathogen outbreaks is tied to global warming. Seventeen years ago, in the mountains of Costa Rica, the Monteverde harlequin frog ( Atelopus sp.) vanished along with the golden toad ( Bufo periglenes). An estimated 67% of the 110 or so species of Atelopus, which are endemic to the American tropics, have met the same fate, and a pathogenic chytrid fungus (Batrachochytrium dendrobatidis) is implicated. Analysing the timing of losses in relation to changes in sea surface and air temperatures, we conclude with 'very high confidence' (99%, following the Intergovernmental Panel on Climate Change, IPCC) that large-scale warming is a key factor in the disappearances. We propose that temperatures at many highland localities are shifting towards the growth optimum of Batrachochytrium, thus encouraging outbreaks. With climate change promoting infectious disease and eroding biodiversity, the urgency of reducing greenhouse-gas concentrations is now undeniable.

Localización: Biblioteca OET: NBINA-3411. Publicación no.: 263 Geología, geomorfología y depósitos glaciares en los páramos de Costa Rica / Lachniet, M.S.; Seltzer, G.O.; Solís, L. (Smithsonian Tropical Research Institute (STRI), Apartado 202, Balboa, PA <E-mail: matthew.lachniet@unlv.edu>). In: Páramos de Costa Rica. Kappelle, M.; Horn, S.P. (eds.) Santo Domingo de Heredia: Editorial INBio, 2005. p. 129-146. ISBN: 9968-927-09-0. This article presents a brief summary of the glacial geology and superficial deposits in the Costa Rican páramos, primarily in the Chirripó National Park. As a result of their high elevation, the páramos have experienced strong climate changes duringthe Pleistocene, when mountain glaciers and ice covered the highest peaks around Cerros Chirripó, de la Muerte, and Kámuk. There are various glacial deposits such as subglacial and ablation tills, fluvio-glacial outwash and terraces, kame terraces, and moraines within the ice limit. Outside the ice limit, periglacial deposits like solifluction fans overlay outwash. Freeze-thaw processes have produced blockfields on some peaks and resulted in the fracturing of cobbles and boulders. In addition to these depositional forms, numerous erosive forms typical of mountain glaciation are present. Localización: Biblioteca OET: 581.753.097286 P222. Publicación no.: 264 Registros de sedimentos lacustres de la vegetación del Holoceno e historia del fuego en el páramo de Costa Rica / Horn, S.P.; League, B.L. (The University of Tennessee. Department of Geography, 304 Burchfiel Geography Building, Knoxville, TN 37996-09251420, US <E-mail: shorn@utk.edu>). In: Páramos de Costa Rica. Kappelle, M.; Horn, S.P. (eds.) Santo Domingo de Heredia: Editorial INBio, 2005. p. 253-273. ISBN: 9968-927-09-0. We examined pollen, pteridophyte (ferns and fern-allies) spores, and charcoal in a 5.6 m long sediment core from Lago de las Morrenas 1, and charcoal in a 1.1 m long sediment core from Lago Chirripó, to reconstruct postglacial vegetation and fire history in the Chirripó páramo. Lago de las Morrenas 1, the largest lake in the Valle de las Morrenas of Chirripó National Park, is presently surrounded by treeless páramo vegetation and has apparently been so since deglaciation approximately 10,000 radiocarbon years ago. Pollen spectra suggest no pronounced changes in vegetation since ice retreat. Pollen percentages for Poaceae and other páramo taxa decline upward, whereas percentages for certain subalpine, lower montane, and lowland forest taxa increase slightly; these changes may reflect the impact of prehistoric human activity as well as slight upslope migration of forest taxa owing to postglacial climatic warming. Cores from both lakes contain abundant microscopic charcoal (examined on microscope slide as well as macroscopic charcoal (quantified by sieving), indicating that fires set by people are lightning have repeatedly burned the Chirripó páramo. The microscopic charcoal record from Lago Chirripó spans the last 4,000 radiocarbon years and shows peaks in fire activity that generally match peaks in the corresponding section of the Lago de las Morrenas 1 microscopic charcoal record. The uppermost sections of both sediment cores show lower charcoal influx rates than some deeper sections, suggestingthat recent fire recurrence intervals in the Chirripó páramo are not unprecedented. A high-resolution analysis of macroscopic charcoal in contiguous 1-cm intervals of the Lago de las Morrenas 1 core confirms that fires burned within the lake watershed throughout the Holocene, and reveals variations in charcoal influx that mad signal Holocene climate variability. Localización: Biblioteca OET: 581.753.097286 P222. Publicación no.: 265 Distribución, impacto humano y conservación de los páramos neotropicales / Hofstede, R.G.M. (University of Amsterdam. Hugo de Vries Laboratory, Department of Systematics, Evolution and Paleobiology, Kruislaan 318, 1098 SM Amsterdam, NL <E-mail: grupoparamo@paramo.org>). In: Páramos de Costa Rica. Kappelle, M.; Horn, S.P. (eds.) Santo Domingo de Heredia: Editorial INBio, 2005. p. 701-724. ISBN: 9968-927-09-0. An outline of the geographic distribution of the paramos in the Neotropics, the impacts and threats which endanger their future, as well as initiatives aiming at the conservation of this ecosystem are presented. Localización: Biblioteca OET: 581.753.097286 P222. Publicación no.: 266 Climatic unpredictability and parasitism of caterpillars: Implications of global warming [El impredecible climático y el parasitismo de larvas de lepidópteros: consecuencias del calentamiento global] / Stireman, J.O.; Dyer, L.A.; Janzen, D.H.; Singer, M.S.; Lill, J.L.; Marquis, R.J.; Ricklefs, R.E.; Gentry, G.L.; Hallwachs, W.; Coley, P.D.; Barone, J.A.; Greeney, H.F.; Connahs, H.; Barbosa, P.; Morais, H.C.; Diniz, I.R. (Wright State University. Department of Biological Sciences, Dayton, OH 45435, US <E-mail: ldyer@tulane.edu> <E-mail: djanzaen@sas.upenn.edu> <E-mail: whallwac@sas.upenn.edu>). In: Proceedings of the National Academy of Sciences of the United States of America (ISSN 0027-8424), v. 102, no. 48, p. 17384-17387. 2005. Insect outbreaks are expected to increase in frequency and intensity with projected changes in global climate through direct effects of climate change on insect populations and through disruption of community interactions. Although there is much concern about mean changes in global climate, the impact of climatic variability itself on species interactions has been little explored. Here, we compare caterpillar-parasitoid interactions across a broad gradient of climatic variability and find that the combined data in 15 geographically dispersed databases show a decrease in levels of parasitism as climatic variability increases. The dominant contribution to this pattern by relatively specialized parasitoid wasps suggests that climatic variability impairs the ability of parasitoids to track host populations. Given the important role of parasitoids in regulating insect herbivore populations in natural and

managed systems, we predict an increase in the frequency and intensity of herbivore outbreaks through a disruption of enemy-herbivore dynamics as climates become more variable. Localización: Biblioteca OET: NBINA-3916. Publicación no.: 267 Climatic impact of land use change on the Mesoamerican Biological Corridor [Impacto climático del cambio de uso de la tierra en el Corredor Biológico Mesoamericano] / Ray, D.K. Huntsville, AL: The University of Alabama in Huntsville, 2005. 124 pp. ISBN: 0-542-16468-X. Dissertation, Ph.D., The University of Alabama in Huntsville (USA). The proposed Mesoamerican Biological Corridor (MBC) is an ambitious effort to stem and turn back the erosion of biodiversity in one of the world's biologically richest regions. Two broad categories of forests, based on their hydrometeorological dependence, are identified in Mesoamerica: (1) those requiring sufficient dry season rainfall; and (2) those requiring frequent immersion in clouds in the dry season (e.g., cloud forests). In the absence of a high-resolution rainfall data set, a statistical method is used to estimate rainfall from climatological cloud cover and rain gauge rainfall in northern Mesoamerica. Rainfall estimated from this method show deficits 25mm in the peak dry season month of March at several locations when compared to the climatologically occurring rainfall over forests. Numerical modeling analysis shows that future deforestation would lead to spatially widespread decreases in rainfall up to 100 mm at certain locations like those in the Peten region of Guatemala. Even forested corridor regions would suffer rainfall decreases. The data suggests that deforestation is locally intensifying the dry season, so that forest regeneration in some parts of the MBC, particularly in the central Peten of Guatemala, may not result in second-growth forest that is characteristic, but rather in forests more typical of drier conditions. New techniques for cloud forest mapping are developed and tested in Costa Rica that could be potentially useful for cloud forest biogeographers. Numerical modeling studies conducted for the Monteverde cloud forests of Costa Rica show that if the lowland and premontane regions were completely forested, the orographic cloud banks would have intersected the mountains at the lowest elevations, covered the largest land surface area, and remained longest on the ground in the montane regions. Deforestation has decreased the area immersed in orographic clouds in the montane regions by around 5-13% and raised the bases of the orographic cloud deck by about 25-75m in the afternoon. Results show that further deforestation in the lowland and premontane regions would lead to around 15% decrease in the cloud forest area immersed in orographic clouds and also raise the bases of the orographic cloud deck by up to 125 m in the afternoon. Localización: Biblioteca OET: NBINA-5411. Publicación no.: 268 Responses of natural communities to climate change in a highland tropical forest [Respuestas de comunidades naturales al cambio climático en un bosque tropical de altura] / Pounds, J.A.; Fogden, M.P.L.; Masters, K.L. (Monteverde Cloud Forest Preserve. Tropical Science Center, Golden Toad Laboratory Conservation, Box 73, Santa Elena 5655 Puntarenas, CR <E-mail: goldtoad@racsa.co.cr> <E-mail: amasters@racsa.co.cr>). In: Climate change and biodiversity. Lovejoy, T.E.; Hannah, L. [eds.] New Haven & London: Yale University Press, 2005. p. 70-74. ISBN: 0300104251. (No abstract). Localización: Non available. Publicación no.: 269 The dynamics of deforestation and the supply of carbon sequestration: illustrative results from Costa Rica [La dinámica de la deforestación y el suministro de la captura de carbono: resultados ilustrativos de Costa Rica] / Kerr, S.; Pfaff, A.S.P.; Sánchez-Azofeifa, G.A. (Motu Economic and Public Policy Research, 19 Milne Terrace, Island Bay, Wellington, NZ <E-mail: suzi.kerr@motu.org.nz> <E-mail: ap196@columbia.edu> <E-mail: arturo.sanchez@ualberta.ca>). In: Environment for growth in Central America: environmental management for sustainability and competitiveness. Panayotou, T. (ed.) Cambridge, MA: John F. Kennedy School of Government, Harvard University Press, 2001. 20 pp. (Harvard Studies in International Development Series). ISBN: 0674003594. Introduction: This chapter aims to contribute to the effective design of the rules that could allow lowcost carbon sequestration efforts in any number of tropical locations to replace high-cost emissions-reduction efforts in developed northern countries.2 The Clean Development Mechanism (CDM) of the Kyoto Protocol could potentially create such a market. This market could provide benefits for the tropical countries both directly, through profits from the sale of certified emissions credits (CERs), and indirectly, through side-benefits from forest protection, including biodiversity protection, watershed protection, and increased tourism potential. Creating the rules for such a market, however, involves considerable fixed costs. Participating in the market involves large costs on the part of the countries producing CERs. Can the market generate sufficient supply of CERs to justify the costs of its creation? What will the effect be of including tropical carbon sequestration on the global carbon price?The integrated analysis in this paper provides an illustration of a methodology that can be used to estimate the potential value of CERs from the protection of existing forest, and form a dynamic supply function. The model can also indicate which local characteristics are likely to contribute to high values from participation in the land-use component of the CDM. We use data from Costa Rica to estimate the model and simulate results. Localización: Biblioteca OET: NBINA-4075. Publicación no.: 270 How can carbon sequestration in tropical forests be rewarded? Evidence from Costa Rica [¿Cómo puede premiarse la captura del carbono en bosques tropicales? Testimonio de Costa Rica] / Kerr, S.; Pfaff, A.S.P.; Sánchez-Azofeifa, G.A.; Boscolo, M. (Motu Economic and Public Policy Research, 19 Milne

Terrace, Island Bay, Wellington, NZ <E-mail: suzi.kerr@motu.org.nz> <E-mail: ap196@columbia.edu> <E-mail: arturo.sanchez@ualberta.ca>). In: Environment for growth in Central America: environmental management for sustainability and competitiveness. Panayotou, T. (ed.) Cambridge, MA: John F. Kennedy School of Government, Harvard University Press, 2001. 40 pp. (Harvard Studies in International Development Series). ISBN: 0674003594. Introduction: As empirical evidence that human activities are affecting the global climate increases, so do efforts to identify and evaluate climate mitigation and adaptation options. Forest managers and policy makers around the world are increasingly participating in and following such efforts, since forestry activities (e.g., reforestation, slowing deforestation, or improved forest management) could in principle play an important role within the set of climate-change mitigation strategies. According to the last IPCC assessment (Watson et al. 1996), initiatives to slow deforestation, promote natural forest regeneration and create a global forestation program (plantations and agroforestry) have the potential to offset 12-15 percent of global fossil fuel carbon emissions from 1995 and 2050. More than two-thirds of such opportunities exist in the tropics. While the magnitude of these numbers indicates a potential role for land- and forestry-based projects as carbon sinks, questions have been raised over the feasibility of such projects as mitigation strategies, especially in developing countries. These questions stem from concerns about environmental integrity reflected in the requirements of Article 12 of the Kyoto Protocol, which clarifies the potential role of developing countries in climate-change mitigation. Their key role comes within the Clean Development Mechanism (CDM).2 Developing countries can contribute carbon offsets through the CDM only if these offsets are "additional" to what would have happened in the absence of the initiative, are real and long-term, and can be accurately measured, monitored, and verified. Localización: Biblioteca OET: NBINA-4076. Publicación no.: 271 Tropical forest dynamics and climate change [Dinámica del bosque tropical y cambio del clima] / Locatelli, B.; Karsenty, A. (CIRAD-Foret-CATIE, Global Change Group, Apdo 2, 7170 Turrialba, CR <E-mail: bruno.locatelli@cirad.fr> <E-mail: alain.karsenty@cirad.fr>). In: Beyond tropical deforestation: from tropical deforestation to forest cover dynamics and forest development. Babin, D. (ed.) Paris: United Nations Educational Scientific and Cultural Organization (UNESCO), 2004. p. 97-120. ISBN: 9231039415. This paper discusses the inclusion of tropical carbon sinks in the fight against climatic change. The possible impact of the Kyoto Protocol on tropical forest dynamics is also presented. Localización: Non available. Publicación no.: 272 Carbon storage in shade-grown coffee agroecosystems of southern Costa Rica: potential applications for the Clean Development Mechanism [Captura de carbono en agroecosistemas de cafetales bajo sombra en el sur de Costa Rica: aplicaciones potenciales para el Mecanismo de Desarrollo en Limpio] / Polzot, C.L (York University. Faculty of Environmental Studies, Toronto, ON MWJ 1P3, CA). Toronto: York University, 2004. 162 pp. Thesis, M.E.S., York University, Faculty of Environmental Studies, Toronto, ON (Canada). Climate change is one of the greatest environmental and economic threats facing the world today. Human activities, particularly the burning of fossil fuels and clearing of forests, have increased the level of greenhouse gases - the primary contributors to global warming - in the atmosphere. This accumulation is changing the Earth's weather patterns, resulting in higher global temperatures, rising sea levels and a potential shift in the distribution of the world's ecosystems. There is a growing need to develop strategies that will reduce current levels of greenhouse gases in the atmosphere and curtail future emissions. The Kyoto Protocol represents an international strategy: it establishes emission reduction targets for industrialized countries and incorporates a Clean Development Mechanism for trading carbon credits generated by projects implemented in developing countries. Tree-based land-use systems, such as the shade-grown coffee agroecosystems of southern Costa Rica, sequester carbon dioxide from the atmosphere and store it in their biomass. Simultaneously, these agroecosystems provide additional products and services to local residents and reduce pressure on existing forests. Therefore, increasing tree cover in coffee production is a viable option for mitigating climate change that also provides social, economic and ecological benefits. The objective of this study is to generate aboveground carbon-stock inventory data for five coffee production systems in southern Costa Rica, which employ various degrees of structural complexity in their shade layer. The sites include coffee grown with poró (Erythrina poeppigiana), guaba (Inga sp.), banana (Musa spp.), eucalyptus (Eucalyptus deglupta) and diversified shade (primarily Terminalia amazonia and Cedrela odorata). An advanced secondary-forest site at the Los Cusingos Neotropical Bird Sanctuary is used as a control. The carbon-stock of shade trees, coffee bushes and leaf litter is calculated for each site, and the income that could be generated from a one-time payment for the environmental service provided by shade trees (carbon storage) is estimated. Results indicate the coffee production system that stores the most amount of carbon per hectare in its aboveground biomass is Diversified Shade (31.6 t C ha-¹), employing a variety of shade-tree species in three distinct layers. Conversely, the Inga sp. system - a shaded monoculture with low structural complexity in its shade layer - stores the least carbon (11.0 t C ha-¹). The carbon-stock of the other systems examined falls within this range and varies according to structural complexity, species composition and management practices. This study recommends that the shade layer in coffee agroecosystems be made more complex for increased carbon storage and maintenance of biodiversity, as previous papers suggest. In the case of southern Costa Rica, a carbon sequestration project implemented under the Clean Development Mechanism could provide farmers with an incentive to select management practicesthat favour higher carbon-stocks and

biodiversity. Such an endeavour would have social, economic and environmental benefits and would provide an example that could be replicated in other small watersheds of Central America. Localización: Non available. Publicación no.: 273 Foraminifera and coccolithophorid assemblage changes in the Panama Basin during the last deglaciation: Response to sea-surface productivity induced by a transient climate change / Martínez, I.; Rincón, D.; Yokoyama, Y.; Barrows, T. (Universidad Eafit. Departamento de Geología, Area de Ciencias del Mar, Medellín 3300, CO <E-mail: jimartin@eafi.edu.co>). In: Palaeogeography, Palaeoclimatology, Palaeoecology (ISSN 0031-0182), v. 234, no. 1, p. 114-126. 2006. The responses of community assemblages of planktonic and benthonic foraminifera and coccolithophorids to transient climate change are explored for the uppermost 2 m of cores ODP677B (1.2° N; 83.74° W, 3461 m) and TR163-38 (1.34° S; 81.58° W, 2200 m),for the last similar to 40 ka. Results suggest that the deglaciation interval was a time of increased productivity and a major reorganization of planktonic trophic webs. The succession in dominance between the planktonic foraminifera species Globorotaliainflata, Globigerina bulloides, and Neogloboquadrina pachyderma denote four periods of oceanographic change: (1) advection (24-20 ka), (2) strong upwelling (20-15 ka), (3) weak upwelling (14-8 ka) and (4) oligotrophy (8 ka to present). Strong upwelling for the deglaciation interval is supported by the low Florisphaera profunda/other coccolithophorids ratio and the high percentage abundance of Gephyrocapsa oceanica. Benthonic foraminifera assemblage changes are different in both cores and suggest significant regional variations in surface productivity and/or oxygen content at the seafloor, and a decoupling between surface productivity and export production to the seafloor. This decoupling is evidenced by the inverse relationship between the percentage abundance of infaunal benthonic foraminifera and the percentage abundance of N. pachydermia. The terrigenous input of the Colombian Pacific rivers, particularly the San Juan River, is suggested as a possible mechanism. Finally, the Globorotalia cultratal Neogloboquadrina dutertrei ratio is used to reconstruct the past influence of the Costa Rica Dome-Panama Bight and cold tongue upwelling systems in the Panama Basin. A northern influence is suggested for the late Holocene (after 5 ka) and the last glacial (before 20 ka), whereas a southern influence is suggested for the 20-5 ka interval. There is a correspondence between our reconstructed northern and southern influences and previously proposed positions of the Intertropical Convergence Zone (ITCZ) after the Last Glacial Maximum (LGM). Localización: Biblioteca OET: NBINA-4668. Publicación no.: 274 Golden toads, null models, and climate change / Pounds, J.A. (Monteverde Cloud Forest Preserve. Tropical Science Center, Golden Toad Laboratory Conservation, Box 73, Santa Elena 5655 Puntarenas, CR <E-mail: goldtoad@racsa.co.cr>). In: Froglog [Newsletter of the IUCN/SSC Declining Amphibian Populations Task Force] (ISSN 1026-0269), no. 23, August, 2 pp. 1997. A decade after the 1987 population collapse that led to the disappearance of the endemic golden toad (Bufo periglenes), amphibians in the Monteverde region of Costa Rica's Cordillera de Tilaran show little sign of recovery. Twenty species of frogs and toads (40% of the anuran fauna) have been missing from a 30 km2 study area throughout the 1990s (Pounds et al., in press). In the debate over the significance of amphibian declines in undisturbed highland areas, arguments have hinged on standards of scientific proof and the absence of long-term demographic data for most species. Long-term data are essential to judge whether a particular population is in decline. Diverse tropical faunas, however, afford an approach that does not rely on these data. My co-workers and I asked whether the observed number of disappearances exceeds that expected for naturally fluctuating populations (Pounds et al., in press). To formulate null models that estimate the expected number of disappearances, we examined long-term studies of other amphibian assemblages. We chose studies that were conducted on spatial scales appropriate for comparison with Monteverde and that illustrated how unstable populations can be. From these studies, we estimated the probability that a single species would disappear in response to a natural disturbance such as a drought. Substituting this value in a binomial distribution, we calculated the likelihood that a particular number of species would disappear simultaneously. In light of the resultant probability distributions, the declines at Monteverde appear to go well beyond natural fluctuations. Even when we doubled our initial probability estimate, our conclusions were the same. We believe that the results confirm the naturalist's intuition; it is indeed extraordinary that so many populations would crash and disappear. A comparison with breeding birds in the same area puts the loss of anuran diversity in perspective (Pounds et al., in press). The relative frequency of absences for frogs and toads was much greater than that for breeding birds in general. It was similar to that for invasive open-country birds whose habitats had largely reverted from farmland to forest after being annexed to the Monteverde Cloud Forest Preserve. Amphibian habitats, however, seemed unchanged. Climate may have been a key factor in the declines (Pounds, in press). Although there is growing evidence that epidemic disease has been an important proximate cause of mortality, different pathogens have been implicated in declines on different continents. The patterns suggest the existence of a common denominator, and global warming could fill this role through various mechanisms. At Monteverde, there is a strong 24-year trend toward more severe dry seasons. Previousanalyses suggested that climate had played a role in the 1987 crash (Pounds and Crump 1994). They did not reveal major trends, however, because they focused on monthly and annual data rather than day-to-day patterns. Variability of daily precipitation has increased, leading to drier extremes, without affecting monthly or yearly averages. Days with no measurable precipitation have become more frequent and have increasingly coalesced into dry periods. The patterns suggest a change in the advective processes that account for most precipitation during the dry season. As moisture-laden trade winds

meet the windward (Caribbean) slope of the cordillera and flow upward, they cool adiabatically, producing a large orographic cloud bank. I hypothesize that atmospheric warming has raised the mean height at which condensation begins and thereby has increased the average altitude at the base of this cloud bank. Because higher clouds may pass over the cordillera with reduced turbulence and drag, they may be less likely to produce low-intensity precipitation (mist) before dissipating on the leeward (Pacific) side. Local temperature trends, viewed in relation to the modulating effects of clouds, are consistent with global warming and this condensation-height model. Biological patterns also follow the model's predictions. Many premontane breeding bird species have invaded lower-montane habitats, whereas some lower-montane species have retreated up the mountain slopes. In multiple regression analyses, patterns of daily precipitation during the dry season account for most of the year-to-year variation in the rate of invasion by premontane bird species. The same patterns are strongly correlated with abundance in highland populations of anoline lizards that have declined and disappeared. For both climate and biological responses, fluctuations in sea-surface temperature (i.e. the signal of El Nino) account for much of the variation superimposed on the long-term trends. The most extreme patterns of daily precipitation were associated with the 1986-87 warm episode, which immediately preceded the collapse of amphibian populations. The condensation-height model and evidence for it are summarized in an overview of the biology of Monteverde's amphibians and reptiles in relation to the declines (Pounds, in press). Supporting data and analyses are in a forthcoming paper (A. Pounds, M. Fogden, and J. Campbell, unpubl.), which will be presented in the BirdLife International/WWF workshop "Impacts of Climate Change on Flora and Fauna" in September at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado. Global warming is an important threat to highland biological communities. The Monteverde Cloud Forest Preserve announces the formation of the Monteverde Climate Panel, an interdisciplinary group that will focus on this problem. We also announce completion of the Golden Toad Laboratory for Conservation (GTLC), devoted to research, applied conservation, and education. Details will be given in a future issue of Froglog. Localización: Biblioteca OET: S10786. NBINA-4494. Publicación no.: 275 Laboratory production of vouchered reference charcoal from small wood samples and non-woody plant tissues / Orvis, K.H.; Lane, C.S.; Horn, S.P. (The University of Tennessee. Department of Geography, 304 Burchfiel Geography Building, Knoxville, TN 37996-09251420, US <E-mail: orvis@utk.edu> <E-mail: shorn@utk.edu>). In: Palynology (ISSN 0191-6122), v. 29, p. 1-11. 2005. Taxonomic identification of small fragments of burned plant tissue in lake sediment profiles can enhance reconstructions of past vegetation, fire regimes, and climate. Vouchered reference collections of charcoal prepared from both soft and woody plant tissues, analogous to modem pollen reference collections, will be required for making rigorous identifications and for knowing the level of certainty achieved. Published methods of laboratory production of charcoal may only poorly mimic pyrolysis as itoccurs in wildfires, and tend to require large volumes of plant material. We present a method for preparing reference charcoal from dried plant specimens that is simple, provides a high degree of control, yet requires only small tissue samples. Based on results of a series of experiments, we recommend placing dried samples in 25 cm(3) perforated-base porcelain Gooch filtering crucibles, surrounded by 250-500 mu m sand; saturating the sand with water and draining; and placing for eight to nine minutes ina furnace heated to 550 degrees C. The wet sand delays heating so that temperature rise is steep. Pyrolysis is brief and occurs under hypoxic conditions due to temporary oxygen flushing by water vapor. Using our method we achieved excellent results on both woody and soft tissues from a variety of plant taxa. Localización: Biblioteca OET: NBINA-4686. Publicación no.: 276 Squandering paradise? The importance and vulnerability of the world's protected areas [¿Despilfarro del paraíso? La importancia y vulnerabilidad de las áreas protegidas del mundo] / Carey, C.; Dudley, N.; Stolton, S. Gland: WWF-World Wide Fund For Nature, 2000. 233 pp. Protected areas are a vital component of any conservation strategy and also serve a host of other social, cultural and economic needs. Yet the quality of many protected areas is currently declining as a result of an onslaught of threats and pressures. Many more remain insecure and their long-term future in uncertain. This report explains why protected areas are important, looks at the trends and nature of the threats facing them and makes some predictions about the likelihood of losses. It is illustrated with a range of specially prepared case studies and examples. It ends with some proposals and a call for action in the lead-up to the World Parks Congress in 2002. Protected areas are the cornerstones of all national and regional conservation strategies. They act as refuges for those species that cannot survive in managed landscapes and as areas where natural ecological processes can continue unhampered by human interference. They are a vital resource for continuation of natural evolution and, in many parts of the world, for future ecological restoration. Human beings benefit directly from the genetic potential contained in the world's plants and animal species, a significant proportion of which are currently at risk. Most people also believe that we have an ethical obligation to prevent extinctions caused as a result of our own actions. Protected areas also play a number of key social and economic roles. Many indigenous and local peoples are given vital protection by protected areas, where theycan continue traditional lifestyles that are now often impossible elsewhere. A disproportionate amount of the world's drinking water comes from areas where natural forest has been preserved and protected areas also help to maintain healthy rivers systemsand smooth out the impacts of floods and soil erosion. Marine protected areas maintain coastal fisheries and in consequence are often supported by neighbouring communities. National parks and nature reserves are important 'green lungs',

providing space for people to relax, practice sports and experience nature and wilderness. They help to protect traditional cultural and spiritual values. In many countries, key national parks are regarded as part of the nation's 'ecological heritage areas' as important as, say, Chartres cathedral or the Taj Mahal. There is an assumption that once a protected area has been identified and declared, its values will be preserved. Sadly, this is not necessarily the case. The quality of protected areas and associated biological diversity can suffer in many ways, ranging from the removal of key species (such as poaching of elephants or great apes) through various types of more general ecological damage to, in extreme cases, almost total destruction. Even if protected areas themselves remain relatively intact, they can be badly affected as a result of isolation and fragmentation if land use in surrounding areas changes dramatically. The report identifies a wide range of threats, from the impacts of human settlement and illegal hunting and fishing through to more complex impacts such as air pollution and climate change. Three general trends can be identified. First, problems seldom come singly. If a protected area is under threat it is likely to be facing a whole range of different threats; it is quite unusual for a protected area to be perfectly secure except for one overwhelming problem. (There are rare exceptions, such as when a previously well-managed national park is subjected to mining or oil drilling). Secondly, protected areas only work in the long-term if they have the support of the people who live inside them or around them. The notion of a protected area as a pristine, empty wilderness is a myth in most places. Protected areas contain human populations - many belonging to communities resident for hundreds or even thousands of years. These communities need to agree with and participate in the management of the protected area. Third, many problems are beyond the control of individual protected area managers and their staff: a few poorly funded conservation personnel cannot address threats from pollution, drainage, highly organised poaching operations or war. Indeed, the underlying causes of the threats ? including such pervasive issues as poverty, over-consumption by a minority and the breakdown of the rule of law - are often far more significant than the concrete actions that actually do the damage within a national park or wilderness area. Localización: Biblioteca OET: NBINA-4506. Publicación no.: 277 High-resolution airborne profiles of CH4, O3, and water vapor near tropical Central America in late January to early February 2004 / Richard, E.C.; Tuck, A.F.; Aikin, K.C.; Kelly, K.K.; Herman, R.L.; Troy, R.F.; Hovde, S.J.; Rosenlof, K.H.; Thompson, T.L.; Ray, E.A. (University of Colorado. Atmospheric & Space Physics Laboratory, 1234 Innovat Dr, Boulder, CO 80303, US <E-mail: adrian.f.tuck@noaa.gov>). In: Journal of Geophysical Research: Atmosphere (ISSN 0747-7309), v. 111, no. D13, AR D13304. 2006. [1] High-resolution (1 Hz at true airspeeds near 200 m s(-1)) observations of methane, ozone, water vapor, and temperature taken between the surface and 18 km from the WB57F aircraft near San José, Costa Rica (10 °N, 84 °W), are used to examine processes influencing the maintenance of these profiles. There was a clearly defined thermal tropopause on each of the eight profiles, accompanied by structure on methane-ozone scatterplots on the five profiles having methane observations. There was a well-defined decrease in methane mixing ratio between approximately 12 and 15 km in each of these five profiles, 2 - 5 km beneath the thermal tropopause, correlated with sharp changes in water vapor and equivalent potential temperature. The methane observations are interpreted as meaning that air is recirculated between the lower stratosphere and the upper tropical troposphere. At the point on each vertical profile where the water vapor had its minimum value, the air was never saturated or apparently supersaturated, although apparent supersaturation with respect to ice was observed in vertically extensive, near-adiabatic layers with tops some 200 - 300 m below the water vapor minimum on all profiles. One of the profiles also exhibited apparent supersaturation above its water vapor minimum, near 18 km. We examine the decrease in water vapor to minimal values as a four-stage process in which its mixing ratio was lowered from similar to 10 to similar to 3 ppmv, consider the role of solar and thermal evaporation of the smaller ice particles in the final stage of the dehydration process, and correlate features separating near-adiabatic layers above 150 hPa pressure altitude with local sea surface temperatures. Localización: Biblioteca OET: NBINA-4687 Publicación no.: 278 Long-term CO2 production from deeply weathered soils of a tropical rain forest: evidence for a potential positive feedback to climate warming [Producción a largo plazo de CO2 de suelos profundamente mineralizados de una selva lluviosa tropical: evidencia para una regeneración positiva potencial al calentamiento climático] / Schwendenmann, L.C.; Veldkamp, E. (Universität Göttingen. Institute of Silviculture, Department of Tropical Silviculture; Busgenweg 1, D-37077 Göttingen, DE <E-mail: lscwen@gwdg.de> <E-mail: eveldka@gwdg.de>). In: Global Change Biology (ISSN 1354-1013), v. 12, no. 10, p. 1878-1893. 2006. Currently, it is unknown what role tropical forest soils will play in the future global carbon cycle under higher temperatures. Many tropical forests grow on deeply weathered soils and although it is generally accepted that soil carbon decomposition increases with higher temperatures, it is not known whether subsurface carbon pools are particularly responsive to increasing soil temperatures. Carbon dioxide (CO2) diffusing out of soils is an important flux in the global carbon. Although soil CO2 efflux has been the subject of many studies in recent years, it remains difficult to deduct controls of this flux because of the different sources that produce CO2 and because potential environmental controls like soil temperature and soil moisture often covary. Here, we report results of a 5-year study in which we measured soil CO2 production on two deeply weathered soil types at different depths in an old-growth tropical wet forest in Costa Rica. Three sites were developed on old river terraces (old alluvium) and the other three were developed on old lava flows (residual). Annual soil CO2 efflux varied between 2.8?3.6

lmolCO2-Cm_2 s_1 (old alluvium) and 3.4?3.9 lmolCO2-Cm_2 s_1 (residual). More than 75% of the CO2 was produced in the upper 0.5m (including litter layer) and less than 7% originated from the soil below 1m depth. This low contribution was explained by the lack of water stress in this tropical wet forest which has resulted in very low root biomass below 2m depth. In the top 0.5m CO2 production was positively correlated with both temperature and soil moisture; between 0.6 and 2m depth CO2 production correlated negatively with soil moisture in one soil and positively with photosynthetically active radiation in the other soil type. Below 2m soil CO2 production strongly increased with increasing temperature. In combination with reduced tree growth that has been shown for this ecosystem, this would be a strong positive feedback to ecosystem warming. Localización: Biblioteca OET: NBINA-4640. Publicación no.: 279 Lowland tree loss threatens cloud forests - Science News of the week - deforestation in Costa Rica affecting the environment [La pérdida de árboles de las tierras bajas amenaza a los bosques nubosos - Noticias de ciencia de la semana - la deforestación en Costa Rica que afecta el ambiente] / Perkins, S. In: Science News (ISSN 0036-8423), v. 160, no. 16, p. 245. 2001. Changes in regional climate brought about by large-scale deforestation in the eastern lowlands of Central America are affecting weather downwind in the mountains, imperiling ecosystems there. Satellite photos of the lowlands in the dry season show that clouds are absent or sparse over deforested areas but are thicker over the forests of neighboring Nicaragua. Localización: Biblioteca OET: NBINA-4589. Publicación no.: 280 Growth, productivity, aboveground biomass, and carbon sequestration of pure and mixed native tree plantations in the Caribbean lowlands of Costa Rica [Crecimiento, productividad, biomasa aérea y captura de carbono de plantaciones forestales puras y en mezcla de árboles nativos en las tierras bajas del Caribe de Costa Rica] / Redondo-Brenes, A.; Montagnini, F. (Yale University, New Haven, CT 06511, US <E-mail: alvaro.redondo@yale.edu> <E-mail: florencia.montagnini@yale.edu>). In: Forest Ecology and Management (ISSN 0378-1127), v. 232, no. 1/3, p. 168-178. 2006. In Costa Rica, reforestation programs with indigenous tree species area recent activity. Information is still scarce on long-term species performance and silvicultural management to ensure the success of tree plantings, especially for mixed stands. This study aims to estimate growth, aboveground biomass, and carbon sequestration of nine native tree species growing in mixed and pure plantings. The study was carried out at La Selva Biological Station in the Caribbean lowlands of Costa Rica. More than a half of the tree species studied (e.g. Calophyllum brasiliense, Jacaranda copaia, Terminalia amazonia, Hyeronima alchorneoides, Vochysia ferruginea, Balizia elegans) are distributed from Mexico-Guatemala to South America and a few have more limited distribution in Central America (e.g. Vochysia guatemalensis, Virola koschnyi, Dipteryx panamensis). The nine tree species are divided into three sets. The 3 members of each set were grown separately in pure plantations, and together in mixed plantation, giving 12 monocultures and 4 mixtures. Plantation 1 (13 years old) is composed of V. guatemalensis, C. brasiliense, and J. copaia. Plantation 2 (13 years old) is comprised of D. panamensis, T. amazonia and V. koschnyi. Plantation 3 (12 years old) is composed of H. alchorneoides, B. elegans, and V. ferruginea. Overall, all the species had good growth and productivity either in pure or mixed stands in comparison to other native and exotic species growing in similar ecological conditions. The exception was C. brasiliense in mixed stands, where it was suppressed by the fast-growing species V. guatemalensis and J. copaia. At the stand level, the mixed stands performed well for volume, basal area, aboveground biomass, and carbon sequestration, in comparison to other pure or mixed plantations of tropical timber species. Pure plantations of V. guatemalensis, V. ferruginea, V. koschnyi, J. copaia, and T. amazonia also presented good productivity. At the tree level, V. guatemalensis, J. copaia, T. amazonia, H. alchorneoides, and D. panamensis performed better in mixtures than in pure stands for diameter, height, aboveground biomass, and carbon sequestration estimations. Values for the former three species were significantly higher in mixed than in pure stands. C. brasiliense was the only species with significantly better growth in pure stands than in mixed stands, for the three-species combination examined. The results show that mixed plantings had similar or higher productivities for several of the variables examined, but conclusions, on relative productivities depend on the species and growth features, interactions among species, and the variables quantified. In addition, there is a need to continue monitoring over longer time-frames, and for further studies of the species interactions and site factors involved, in order to develop reforestation guidelines for a range of objectives and environmental settings. Localización: Biblioteca OET: NBINA-4751. Publicación no.: 281 Will buying tropical forest carbon benefit the poor? evidence from Costa Rica? [¿Beneficiará a los pobres la compra de carbono del bosque tropical? ¿evidencia de Costa Rica?] / Kerr, S.; Lipper. L.; Pfaff, A.S.P.; Cavatassi, R.; Davis, B.; Hendy, J.; Sánchez-Azofeifa, G.A. (Motu Economic and Public Policy Research, 19 Milne Terrace, Island Bay, Wellington, NZ <E-mail: suzi.kerr@motu.org.nz> <E-mail: ap196@columbia.edu> <E-mail: arturo.sanchez@ualberta.ca>). Wellington: Motu Economic and Public Policy Research, 2004. 39 pp. We review claims about the potential for carbon markets that link both payments for carbon services and poverty levels to ongoing rates of tropical deforestation. We then examine these effects empirically for Costa Rica during the 20th century using an econometric approach that addresses the irreversibilities in deforestation. We find significant effects of the relative returns to forest on deforestation rates. Thus, carbon payments would induce

conservation and also carbon sequestration, and if land users were poor could conserve forest while addressing rural poverty. We also give a weak result that the poorest areas would respond more to payment, i.e. if anything the impact is higher there, though there may well be no difference. If there is no difference, transaction costs and other practical issues could lead carbon payments policies not to be focused upon the many small poor land users. Nonetheless the poorest areas have much more forest per capita and could benefit. Localización: Biblioteca OET: NBINA-4720. Publicación no.: 282 Catastrophic population declines and extinctions in neotropical harlequin frogs (Bufonidae: Atelopus) [Catastrófica disminución y extinciones de la población en ranas arlequín (Bufonidae: Atelopus)] / La Marca, E.; Lips, K.R.; Lötters, S.; Puschendorf, R.; Ibáñez, R.D.; Rueda-Almonacid, J.V.; Schulte, R.; Marty, C.; Castro, F.; Manzanilla-Puppo, J.; García-Pérez, J.E.; Bolaños-Vives, F.; Chaves-Cordero, G.A.; Pounds, J.A.; Toral-C., E.; Young, B.E. (Universidad de Los Andes. Facultad de Ciencias Forestales y Ambientales, Laboratorio de Biogeografía, Apartado Postal 116, Mérida 5101-A, VE <E-mail: klips@zoology.siu.edu> <E-mail: rpuschen@biologia.ucr.ac.cr> <E-mail: bolanosv@biologia.ucr.ac.cr> <). In: Biotropica (ISSN 1744-7429), v. 37, no. 2, p. 190-201. 2005. We surveyed the population status of the Neotropical toad genus Atelopus, and document recent catastrophic declines that are more severe than previously reported for any amphibian genus. Of 113 species that have been described or are candidates for description, data indicate that in 42 species, population sizes have been reduced by at least half and only ten species have stable populations. The status of the remaining taxa is unknown. At least 30 species have been missing from all known localities for at least 8 yr and are feared extinct. Most of these species were last seen between 1984 and 1996. All species restricted to elevations of above 1000 m have declined and 75 percent have disappeared, while 58 percent of lowland species have declined and38 percent have disappeared. Habitat loss was not related to declines once we controlled for the effects of elevation. In fact, 22 species that occur in protected areas have disappeared. The fungal disease Batrachochytrium dendrobatidis has been documented from nine species that have declined, and may explain declines in higher elevation species that occur in undisturbed habitats. Climate change may also play a role, but other potential factors such as environmental contamination, trade, and introduced species are unlikely to have affected more than a handful of species.Widespread declines and extinctions in Atelopus may reflect population changes in other Neotropical amphibians that are more difficult to survey, and the loss of this trophic group may have cascading effects on other species in tropical ecosystems. Localización: Biblioteca OET: NBINA-4759. Publicación no.: 283 What role for tropical forests in climate change mitigation? The case of Costa Rica [¿Qué papel para los bosques tropicales en la mitigación del cambio climático? El caso de Costa Rica] / Boscolo, M.; Kerr, S.; Pfaff, A.S.P.; Sánchez-Azofeifa, G.A. (Harvard University. Harvard Institute for International Development, Cambridge, MA 02138-2902, US <E-mail: suzi.kerr@motu.org.nz> <E-mail: ap196@columbia.edu> <E-mail: arturo.sanchez@ualberta.ca>). Cambridge, MA: Harvard Institute for International Development, 1999. 43 pp. (Development Discussion Paper; no. 675). Land and forestry-based activities could in principle play important roles as climate change mitigation strategies. In practice, however, several questions have been raised about their feasibility. Therefore, understanding the processes and determinants of land use changes is critical. This paper aims to contribute to such understanding in the larger part of a larger project on sustainable development and economic growth. It begins with a dynamic model of land use. The model generates deforestation equations that are estimated from data in Costa Rica on land use, environment, and geography, and, in the case of geo-referenced information, from secondary data. Results suggest that susceptibility to deforestation depends on environmental, geographic and socioeconomic characteristics. Such results may be of use in establishing baselines. The next stage of this work will add variables such as land value in order to permit the analysis of the effects of payments for carbon sequestration. Even in its current state, the model?s results can be linked to carbon storage and accumulation functions in order to quantify the supply of carbon offsets by Costa Rica resulting from changes in land use. Localización: Biblioteca OET: NBINA-4772. Publicación no.: 284 What drives tropical deforestation? A meta-analysis of proximate and underlying causes of deforestation based on subnational case study evidence [¿Qué dirige la deforestación tropical? Un meta-análisis de las causas próximas y subyacentes de la deforestación con base a un estudio de caso subnacional] / Geist, H.; Lambin, E. (University of Louvain. Department of Geography, LUCC International Project Office, Place Louis Pasteur 3, 1348 Louvain-la-Neuve, BE lucc.ipo@geog.ucl.ac.be). (ISSN 1138-7424) Louvain-la-Neuve: University of Louvain, 2001. 136 pp. (LUCC Report Series; no. 4). To conclude this overview on proximate, underlying and other causes associated with tropical deforestation, we developed a preliminary scheme which depicts the relations between proximate and underlying causes as translated from the meta-analysis of subnational cases in a descriptive manner. Compared to another, most recent descriptive (but not quantified) scheme, striking similarities (e.g., grouping of natural causes at the proximate or direct level) and minor differences (e.g., formatting of cultural and technological factors) are obvious ? cf Figures 2 and 3. Considering our meta-anlysis to be the first study which relates underlying to proximate causes in a systematised manner, a summarisation of the quantified scheme of Figure 3 is provided in Figure 9 (inlay). To conclude the discussion of strengths and weaknesses of the methodology used (which certainly has implications for the conclusions drawn from the statistical results), we are aware of own

interpretation bias (variable grouping, coding, data exploration), while original author bias is minimal and selection bias (case study areas, not so agents) is limited. As compared to the methodological foundations of other case study comparisons ? see subchapters 1 and 2.1 ?, we feel that our standard criteria, i.e., to choose only ISI covered journal articles and to try a middle way between fine-scale local studies and crossnational data explorations, is unique and timely. This meta-analysis is the first study which, in a systematised manner, relates underlying to proximate causes for a very large number of case studies ? and, first time, quantifies the causative linkages (cf Figure 9). Localización: Biblioteca OET: NBINA-4786. Publicación no.: 285 Soil carbon dynamics and residue stabilization in a Costa Rican and southern Canadian Alley cropping system [Dinámica del carbono del suelo y estabilización del residuo en un sistema de cultivo por callejones costarricense y en el sur canadiense] / Oelbermann, M.; Voroney, R.P.; Thevathasan, N.V.; Gordon, A.M.; Kass, D.C.L.; Schlönvoigt, A.M. (University of Waterloo. Department of Environment & Resource Studies, Waterloo, ON N2L 3G1, CA <E-mail: moelberm@fes.uwaterloo.ca> <E-mail: pvoroney@uoguelph.ca> <E-mail: dclk9@hotmail.com> <E-mail: andrea_schloenvoigt@y). In: Agroforestry Systems (ISSN 0167-4366), v. 68, no. 1, p. 27-36. 2006. Agroforestry systems can play a major role in the sequestration of carbon (C) because of their higher input of organic material to the soil compared to sole crop agroecosystems. This study quantified C input in a 19-year old tropical alley cropping system with E. poeppigiana (Walp.) O.F Cook in Costa Rica and in a 13-year old hybrid poplar (Populus deltoides x nigra DN-177) alley cropping system in southern Canada. Changes in the level of the soil organic carbon (SOC) pool, residue decomposition rate, residue stabilization efficiency, and the annual rate of accumulation of SOC were also quantified in both systems. Carbon input from tree prunings in Costa Rica was 401 g C m² y-¹ compared to 117 g C m² y-¹ from litterfall at the Canadian site. In southern Canada, crop residue input from maize (Zea mays L.) was 212 g C m² y-¹, 83 g C m² y-¹ from soybeans (Glycine max L.) and 125 g C m² y-¹ for wheat (Triticum aestivum L.), and was not significantly different (p 0.05) from the sole crop. The averageyearly C input from crop residues in Costa Rica was significantly greater (p 0.05) in the alley crop for maize (134 g C m² y-¹) and Phaseolus vulgaris L. bean crops (35 g C m² y-¹) compared to the sole crop. The SOC pool was significantly greater (p 0.05) in the Costa Rican alley crop (9536 g m²) compared to its respective sole crop (6143 g m²) to a 20 cm depth, but no such difference was found for the southern Canadian system. Residue stabilization, defined as the efficiency of the stabilization ofadded residue (crop residues, tree prunings, litterfall) that is added to the soil C pool, is more efficient in southern Canada (31%) compared to the alley cropping system in Costa Rica (40%). This coincides with a lower organic matter decomposition rate(0.03 y-¹) to a 20 cm depth in Canada compared to the Costa Rican system (0.06 y-¹). However, the average annual accumulation rate of SOC is greater in Costa Rica (179 g m² y-¹) and is likely related to the greater input of organic material derived from tree prunings, compared to that in southern Canada (30 g m² y-¹) to a 20 cm depth. Localización: Biblioteca OET: NBINA-4857. Publicación no.: 286 Migración ambiental inducida por variabilidad climática: El caso del Corredor Centroamericano de la Sequía [Environmental migration induced by climatic variability: The case of the Central American Corridor of the Drought] / Vega-García, H. (Universidad Nacional. Escuela de Relaciones Internacionales, Centro de Ambiente y Desarrollo, Apdo 86-3000, Heredia, CR <E-mail: heidyv2002 @yahoo.com>). San José: Universidad Nacional / Centro Mesoamericano de Desarrollo Sostenible del Trópico Seco (CEMEDE), 2005. 66 pp. ISBN: 9968-9527-4-5. La migración es un fenómeno dinámico. Cada día en el mundo miles de personas se trasladan de un lugar a otro, en búsqueda de las mejores condiciones que les posibilite una calidad de vida satisfactoria. En algunas regiones, más que en otras, la migración se convierte en un mecanismo necesario y muchas veces inevitable. De forma tradicional, se ha estudiado que la migración obedece principalmente a razones socioeconómicas y políticas. Sin embargo, como se establece en la presente investigación, el análisis de un fenómeno tan importante no debe ser limitado por tal enfoque. En este sentido, a la luz de las corrientes académicas internacionales más novedosas, se plantea una nueva perspectiva para articular un entendimiento más integral de las causas de los flujos migratorios: la propuesta teórico-conceptual sobre la migración ambiental. Dicha propuesta adquiere relevancia al considerarse el caso particular del contexto centroamericano. Recientemente, gran parte de las zonas rurales de este espacio geográfico han sido afectadas por una serie de eventos ambientales, especialmente las sequías, que han generado la pérdida de las cosechas de productos de consumo básico. Tal situación se vio incrementada por el creciente desempleo debido a la crisis de los precios internacionales del café. Estas pérdidas agrícolas, así como el cierre de fincas cafetaleras, incidieron en el aumento de la inseguridad alimentaria, desencadenando hambrunas en casos extremos (caso de Matagalpa). En dicha coyuntura, se identificó que estos episodios de crisis alimentaria motivaron el desplazamiento de grupos humanos, dentro y entre los Estados centroamericanos. Por lo tanto, desde hace pocos años es innegable considerar que la migración en la región también es influenciada por factores ambientales. Sin embargo, el carácter reciente de este análisis pone en evidencia que aún existe gran desconocimiento de este fenómeno en los círculos académicos locales y en las esferas políticas de toma de decisiones. En suma, la migración ambiental centroamericana debe ser una preocupación fundamental, dado que la región presenta elementos de gran vulnerabilidad socioambiental, especialmente relacionados con eventos de variabilidad climática. A pesar de que incluso se ha logrado avanzar en el tema de la vulnerabilidad y se ha identificado un Corredor Centroamericano de la Sequía, aún no ha sido posible aproximarse al potencial que las condiciones

ambientales y el contexto socioeconómico en este espacio geográfico presentan para la migración ambiental. En este sentido, tampoco se han identificado escenarios presentes y futuros de migración ambiental regional; no se ha determinado un modelo de análisis y no se han generado propuestas de políticas públicas. Estos aspectos son los principales productos que pretende aportar esta investigación. Localización: Biblioteca OET: NBINA-4922. Publicación no.: 287 ¿Qué estamos aprendiendo de la experiencia con los mercados de servicios ambientales en Costa Rica? Revisión y crítica de la literatura / Rojas, M.; Aylward, B.A. (Eco-Asesores Integrados, Apartado 72-4400 Ciudad Quesada, CR <E-mail: manrique@racsa.co.cr> <E-mail: bruce@radel.com>). London: International Institute for Environment and Development, Environmental Economics Programme, 2003. 112 pp. (Series: Markets for environmental services; no. 2). ISBN: 1843694557. El uso de mercados y el pago de servicios ambientales es un tema que ha venido ganando terreno entre los hacedores de políticas, ambientalistas y desarrolladores alrededor del mundo. Visto desde una perspectiva simple el termino "servicios ambientales", se refiere al concepto de sistemas naturales que proveen un flujo continuo de bienes y servicios a la sociedad. Lo anterior contrasta con servicios similares brindados por infraestructura física hecha por el hombre y capital tecnológico (tratamiento de agua, fertilización artificial, ingeniería genética) para los que los servicios ambientales son un substituto. El uso de mecanismos de mercado como herramienta para incorporar el valor económico de los servicios ambientales a la toma de decisiones financieras de productores y consumidores es una herramienta adicional que podría ser utilizada para resolver las eternas fallas de mercado que conllevan a un bajo rendimiento económico- tener menos servicios ambientales y pagar más por sus sustitutos hechos por el hombre. En el mundo en vías de desarrollo, Costa Rica ha liderado esfuerzos para experimentar con la aplicación de esos mecanismos, muchos de los cuales eran simplemente ideas sobre papel años atrás. Una encuesta sobre mercados de servicios ambientales realizada por IIED evidencia el rol formativo que ha tenido Costa Rica y provee una rica caracterización de la economía de estas iniciativas en un contexto global (Landell-Mills and Porras 2002). Como una inciativa complementaria este documento profundiza en la literatura sobre la experiencia costarricense con el fin de visualizar lo que estamos aprendiendo de esa experiencia: ¿cómo ha calzado dentro de estas iniciativas la información técnica, científica y económica sobre servicios ambientales? ¿Qué alcance tienen el monitoreo y la evaluación de estas experiencias iniciales? Existe un retrocontrol que conecte estas experiencias con el aprendizaje ambiental y temas de desarrollo, particularmente en el contexto local de elaboración de políticas dentro del país. El principal objetivo de esta revisión bibliográfica es identificar y analizar documentos y otros materiales que estén dentro de la siguiente temática: 1. los orígenes locales del concepto de pago y mercado de servicios ambientales y como estos han evolucionado a través del tiempo, particularmente en relación con el amplio desarrollo internacional del concepto y con las necesidades / realidades locales; 2. el tipo de iniciativas existentes relacionadas con los mercados de servicios ambientales, y quien esta participando en estas actividades (trabajo descriptivo); 3. el conocimiento base que soporta el desarrollo de mercados, ej. el punto en el que se basan los mercados, un conocimiento técnico y científico que toma en cuenta la relación biofísica, económica y social que surge de los diferentes puntos de vista sobre el tema; 4. las iniciativas tomadas con respecto al monitoreo y evaluación de la experiencia con pagos y mercados de servicios ambientales y hasta donde y con que resultados la literatura toma estas iniciativas en términos de eficiencia económica, eficiencia ambiental, equidad social y/o reducción de la pobreza. En los casos en los que el material escrito no esta disponible o no brindaba una buena cobertura se realizaron entrevistas con las personas involucradas en estas iniciativas con el fin de completar la información requerida. Dado que el IIED ha realizado una revisión de la literatura global en este tema y que ha identificado ejemplos en Costa Rica, los objetivos uno y dos se cumplen con información existente del IIED. Además, se realiza un control cruzado confirmatorio y una expansión de la cobertura de los casos existentes de pago de servicios ambientales. El valor agregado de la revisión bibliografía esta en la profundización del conocimiento base y análisis de sus contenidos con respecto a los objetivos tres y cuatro. El documento esta organizado con el fin de cumplir con los objetivos uno a uno. En el primer capítulo se explora el concepto de mercado y pago de servicios ambientales en Costa Rica. Posteriormente, este escrito evalúa la experiencia ganada hasta el momento por el país, y brinda en los subsiguientes capítulos una descripción y un análisis de los casos, además de evidenciar el papel que tiene el conocimiento dentro del desarrollo y formulación de cada una de las iniciativas hasta la fecha. Finalmente se concluye con la presentación de las lecciones aprendidas y las recomendaciones prácticas sobre los pasos que otros países, investigadores y organizaciones financieras deberían tomar para mejorar el proceso de implementación de este tipo de actividades en el futuro. Localización: Biblioteca OET: NBINA-4513. Publicación no.: 288 Skeletal extension rates of Cenozoic Caribbean reef corals / Johnson, K.G.; Pérez, M.E. (Natural History Museum. Department of Palaeontology, Cromwell Road, London SW7 5BD, GB <E-mail: k.johnson@nhm.ac.uk>). In: Palaios (ISSN 0883-1351), v. 21, p. 262-271. 2006. There has been significant biological and environmental change in Caribbean coral reefs during the past 30 million years, including two periods of accelerated turnover of species in the zooxanthellate coral biota that may have been correlated with changes in regional sea-surface productivity during the Early Miocene and the Early Pleistocene. Skeletal extension rates measured on x-radiographs of 11 massive genera of fossil corals collected from Late Oligocene to Pleistocene units from across the Caribbean were analyzed to determine whether average coral growth responded to these regional environmental changes. The observed patterns were evaluated by

comparisons with records of Recent coral growth rates taken from published literature. These analyses suggest that there is significant variation in average growth rate among corals living in the Recent Indowest Pacific, eastern Pacific, and Caribbean, even when broad ranges of taxa and habitats are intermingled. When applied to fossils, a similar analysis suggests that rates of growth do not change overall through time. One exception is during the Late Miocene, when rates of growth were significantly lower than from other fossil units or for Recent colonies from the Caribbean. However, the Late Miocene colonies sampled for this study lived in relatively deep, turbid habitats, so the observed reduced growth rates may have resulted from local low availability of light. Similar facies were not sampled in other stratigraphic intervals, so there is no strong evidence for reduced regional average growth rates for Caribbean corals during the past 30 million years. Localización: Biblioteca OET: NBINA-4825. Publicación no.: 289 "Desarrollo" depredador globalizado / Delgado-Rodríguez, M. In: AMBIEN-TICO (ISSN 1409-214X), no. 147, p. 8-9. 2005. (No abstract). Localización: Biblioteca OET: NBINA-4832. Publicación no.: 290 Racha de huracanes revive debate sobre cambio climático / Manso, P. (MINAE. Instituto Meteorológico Nacional, POB Box 7-3350, 1000 San José, CR). In: AMBIEN-TICO (ISSN 1409-214X), no. 148, p. 7-8. 2006. Costa Rica fue el único país en Centroamérica que durante el siglo XX no fue afectado en forma directa por un ciclón tropical. Sin embargo, debido a la orografía del país, los efectos indirectos de los ciclones tropicales sobre la precipitación son tanto o más importantes que los efectos directos en periodos mayores de un día. Asimismo, por su frecuencia, trayectoria e intensidad, los ciclones tropicales del mar Caribe son los que en realidad más afectan a Costa Rica y en particular nuestra vertiente del Pacífico. La severidad del comportamiento climático durante la pasada temporada de ciclones tropicales tuvo grandes efectos en el país. Las pérdidas directas acumuladas superaron los 100.000 millones de colones solo en infraestructura pública y cultivos. Debido a los efectos indirectos de los ciclones tropicales en el Caribe y el golfo de México, entre septiembre y octubre se registró uno de los períodos atemporalados más extensos y severos en la historia climática de nuestra vertiente pacífica. Y se pronostica que la temporada de ciclones tropicales de este año estará por encima de lo normal. Localización: Biblioteca OET: NBINA-4837. Publicación no.: 291 Carbon isotope fractionation by methane-oxidizing bacteria in tropical rain forest soils [Fraccionamiento de isótopos del carbono mediante bacterias oxidantes del metano en suelos de bosques lluviosos tropicales] / Teh, Y.A.; Silver, W.L.; Conrad, M.E.; Borglin, S.E.; Carlson, C.M. (University of California at Berkeley. Department of Geography, 507 McCone Hall, Berkeley, CA 94720, US <E-mail: yit@nature.berkeley.edu> <E-mail: wsilver@nature.berkeley.edu>). In: Journal of Geophysical Research: Biogeosciences (ISSN 0148-0227), v. 111, no. G2, AR G02001. 2006. [1] Humid tropical forests have the potential to be significant sources or sinks of atmospheric methane (CH4), a radiatively important trace gas. Methane oxidation can consume a large fraction of the CH4 produced in tropical soils, although controls on this process are poorly understood. Using soil incubation experiments, we investigated the effects of CH4 and oxygen (O-2) concentrations on C isotope fractionation and CH4 oxidation in tropical rain forest soils. We also explored the effects of these environmental variables on the isotope fractionation factor for CH4 oxidation (a), which is widely used to evaluate the relative contributions of CH4 production and oxidation to the atmospheric CH4 pool. Methane oxidation was sensitive to CH4 at lower CH4 concentrations ( 850 ppmv) and insensitive to O-2 concentrations between 3 and 21%. Maximum rates of CH4 oxidation were between 8.2 ± 1.2 and 11.3 ±1.5 nmol CH4 hour-¹ g dry soil-¹. Measured values for a were sensitive to both CH4 oxidation rate and CH4 concentration. Alpha was inversely proportional to CH4 oxidation rate ( r² Localización: Biblioteca OET: NBINA-6449. Publicación no.: 292 La captura de carbono: un servicio ambiental en fincas cacaoteras indígenas / Somarriba-Chávez, E.; Quesada, F.; Villalobos, M. (CATIE. Area de Cuencas y Sistemas Agroforestales, Turrialba, CR <E-mail: esomarri@catie.ac.cr>). Turrialba: CATIE, 2006. 28 pp. (Serie técnica. Manual técnico / CATIE; no. 64). ISBN: 9977-57-425-1. Este manual se elaboró con el objetivo de servir como material de apoyo en procesos de educación e información sobre los servicios ambientales en pueblos indígenas y campesinos. Fue financiado por el Proyecto Captura de Carbono y Desarrollo de Mercados Ambientales en Cacaotales y otros Sistemas Agroforestales Indígenas en Talamanca, Grant TF052118, Banco Mundial. El proyecto Captura de Carbono fue financiado por el Banco Mundial al Gobierno de Costa Rica (MINAE), diseñado y ejecutado participativamente entre el CATIE, ACOMUITA, ADITIBRI, ADITICA, ACICAFOC y MINAE. � La Asociación Comisión de Mujeres Indígenas Bribrí de Talamanca (ACOMUITA) es la organización escogida por los gobiernos indígenas de la región de Talamanca para representar a los productores y administrar el Proyecto de Carbono. � La Asociación Coordinadora Indígena Campesina de Agroforestería Comunitaria de Centroamérica (ACICAFOC). Este organismo funciona como enlace entre las organizaciones indígenas de Centroamérica, que podrían interesarse en proyectos similares en sus respectivas regiones. � La Asociación de Desarrollo Integral de los Territorios Indígenas Bribrí (ADITIBRI), es el gobierno del pueblo Bribrí. � La Asociación de Desarrollo Integral de los Territorios Indígenas Cabécar (ADITICA), es el gobierno del pueblo Cabécar. � El Banco Mundial es el organismo que financió el Proyecto con fondos del gobierno de Japón (fideicomiso japonés). Grant TF052118. � El Ministerio de Ambiente y Energía (MINAE) y el

Fondo Nacional de Financiamiento Forestal (FONAFIFO) fomentan la preservación de los bosques pagando por servicios ambientales y se financian con el dinero recaudado mediante un impuesto a los combustibles y aportes de la cooperación internacional. � El Centro Agronómico Tropical de Investigación y Enseñanza (CATIE), es una asociación civil sin fines de lucro integrada por 13 países miembros de la región tropical de América Latina. Localización: Biblioteca OET: NBINA-4962. Publicación no.: 293 Implicaciones económicas del almacenamiento del CO2 en un bosque húmedo tropical en Costa Rica, bajo diferentes estrategias de intervención [Economic implications of CO2 storage on a tropical rain forest in Costa Rica, under different intervention strategies] / Rodríguez-Rubí, L.E. Turrialba: CATIE, 1997. 72 pp. Thesis, Mag. Sc. en Ciencias Agrícolas y Recursos Naturales, Centro Agronómico Tropical de Investigación y Enseñanza, Escuela de Posgrado, Turrialba (Costa Rica). The present study consisted on estimating carbon storage in a very humid tropical forest, under different interventions and management strategies and their economic implications through time. This study was carried out in a forest near a village called La Tirimbina, located in northern Costa Rica. The area is under silvicultural experimentation, on a random block design with three treatments. The experimental area consisted of 9 blocks measuring 1 hectare each, where three silvicultural models were placed. The first model or treatment one consisted of forest plots with utilization and a treatment two in the protection canopy treatment three was forest with utilization and a mixture of liberation and partial refinement. The estimation of stored carbon was done using real data from trees with a diameter equal to or more than 10 cm, according to diameter measurements made during six years from data based on the Natural Forest Management Department at CATIE, and on simulated data from 3 posterior utilizations from the seventh year. The analysis was done for a period of 60 year. For this, mathematical equations to predict biomass were used. The method used for the financial analyses with and without carbon valuation was the benefit-cost ratio, which permits to determine the financial rentability from each treatment. Three indicators were used: Net present value (NPV), Rate Internal Return (RIR) and the benefit cost analysis. Necessary information to develop the analysis was provided by the Natural Forest Management Department at CATIE, using market prices and unitary cost from year 1997. The amount of stored carbon through time didn't show considerable differences for treatments one and two, treatment three presented the smallest amount of stored carbon. The results of the financial analyses without carbon valuation indicated that treatment is the most profitable because it presented the highest NPV. However, results of the financial analyses with the carbon valuation as a environmental service indicate that the witness treatment is the one that presents the highest financial indicators (NPV, B/C) so, it is the most profitable. Localización: Biblioteca OET: NBINA-4971. Publicación no.: 294 Uncertainties in, and interpretation of, carbon flux estimates using the eddy covariance technique / Loescher, H.W.; Law, B.E.; Mahrt, L.; Hollinger, D.Y.; Campbell, J.; Wofsy, S.C. (Oregon State University. Department of Forest Sciences, 321 Richardson Hall, Corvallis, OR 97331, US <E-mail: hank.loescher@oregonstate.edu>). In: Journal of Geophysical Research: Atmosphere (ISSN 0148-0227), v. 111, no. D21S90, doi:10.1029/2005JD0069322006. [1] Whole ecosystem carbon dioxide (CO2) exchange estimated with the eddy covariance (EC) technique has been central to studies on the responses of terrestrial ecosystems to disturbance and intra-annual and interannual variations in climate, but challenges exist in understanding and reducing the uncertainty in estimates of net ecosystem exchange (NEE) of CO2. We review the potential uncertainties associated with the eddy covariance technique, including systematic errors from insensitivity to high-frequency turbulence, random errors from inadequate sample size associated with averaging period, vertical and horizontal advection issues, and selection criteria for removing periods of inadequate mixing from further analyses. We also discuss benefits andcaveats of using independent measurements to evaluate EC-derived NEE, such as comparisons of EC-derived annual NEE and allometric net ecosystem production estimates (NEP) and interpretation of nighttime NEE with scaled chamber-based estimates of ecosystem respiration. Localización: Biblioteca OET: NBINA-4935. Publicación no.: 295 Polychlorinated biphenyls and polybrominated diphenyl ethers in the North American atmosphere [Bifenilos policlorinados y difeniléteres polibromados en la atmósfera norteamericana] / Shen, L.; Wania, F.; Lei, Y.D.; Teixeira, C.; Muir, D.C.G.; Xiao, H. (University of Torono at Scarborough. Department of Chemistry and Department of Physical and Environmental Sciences, 1265 Military Trail, Toronto, ON M1C 1A4, CA <E-mail: frank.wania@utoronto.ca>). In: Environmental Pollution (ISSN 0269-7491), v. 144, no. 2, p. 434-444. 2006. To assess the spatial concentration variability of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in the atmosphere on a large continental scale, their annually integrated air concentrations were determined in 2000/2001 using XAD-based passive air samplers (PAS). The network included 40 stations in Canada, the United States, Mexico, Belize and Costa Rica, and covered 72 degrees of latitude and longitude. Total concentrations of PCB and PBDE congeners ranged from below the detection limit to 130 ng PAS(-¹) and 24 ng PAS(-¹), respectively. PCBs displayed a large variation between urban, rural and remote sites, whereas PBDEs did not follow such a pattern. Open burning of "Penta"-containing waste may have contributed to thePBDEs detected in the air samples from rural and remote areas. Air from the Canadian Arctic had a relatively higher percentage of

lighter PCB congeners than air sampled in the tropical region, which is interpreted as evidence for global fractionation. Localización: Biblioteca OET: NBINA-4959. Publicación no.: 296 Effects of poverty on deforestation: distinguishing behavior from location [Efectos de la pobreza en la deforestación: comportamiento notable según la localidad] / Kerr, S.; Lipper, L.; Pfaff, A.S.P.; Cavatassi, R.; Timmins, J.; Hendy, J.; Sánchez-Azofeifa, G.A.; Davis, B. (Motu Economic and Public Policy Research, 19 Milne Terrace, Island Bay, Wellington, NZ <E-mail: suzi.kerr@motu.org.nz> <E-mail: ap196@columbia.edu> <E-mail: arturo.sanchez@ualberta.ca>). Rome: FAO / Agricultural and Development Economics Division, 2004. 27 pp. (ESA Working Paper (FAO); no. 04-19). We summarize existing theoretical claims linking poverty to rates of deforestation and then examine this linkage empirically for Costa Rica during the 20th century using an econometric approach that addresses the irreversibilities in deforestation. Our data facilitate an empirical analysis of the implications for deforestation of where the poor live. Without controlling for this, impacts of poverty per se are confounded by richer areas being different from the areas inhabited by the poor, who we expect to find on more marginal lands, for instance less profitable lands. Controlling for locations? characteristics, we find that poorer areas are cleared more rapidly. This result suggests that poverty reduction aids forest conservation. Localización: Biblioteca OET: NBINA-5049. Publicación no.: 297 Seasonal variation in the stable isotopic composition of precipitation in the tropical montane forests of Monteverde, Costa Rica [Variación estacional en la composición de isótopos estables de la lluvia en el bosque montano tropical de Monteverde, Costa Rica] / Rhodes, A.L.; Guswa, A.J.; Newell, S.E. (Smith College. Department of Geology, Northampton, MA 01063, US <E-mail: arhodes@email.smith.edu>). In: Water Resources Research (ISSN 0043-1397), v. 42, no. 11, AR W11402. 2006. Climate and land use change may diminish orographic clouds over tropical montane forests, stressing biota and water resources during dry seasons. From 2003 to 2005 we measured the stable isotopic composition of precipitation and throughfall in Monteverde, Costa Rica, to distinguish convective, wet season rainfall associated with the Intertropical Convergence Zone (ITCZ) from dry season, orographic rain produced by northeasterly trade winds. While event-to-event fluctuations of delta O-18 and delta H-2 are high, monthly samples reveal a seasonal signal that may be used to trace water through the hydrologic cycle. Deuterium excess indicates that water evaporated from land is an important flux to the region during the transitional and dry seasons whenwinds from the Caribbean slope dominate. Following the shift to convective rainfall at the start of the wet season, when the western equatorial winds influence the Pacific slope of Costa Rica, d excess values become depressed. Yet as the wet season progresses, d excess begins to climb. These data suggest that several months of rain are needed following an acute dry season on the northern Pacific slope before a terrestrial evaporative signal is detected in wet season precipitation. The evaporative flux may result from a wet season expansion of surface water bodies and flooding of seasonal wetlands. Localización: Biblioteca OET: NBINA-5194. Publicación no.: 298 Arrecifes y comunidades coralinas de Bahía Culebra, Pacífico Norte de Costa Rica / Jiménez-Centeno, C.E. (Universität Bremen. ZMT, Fahrenheitstr 6, D-28359 Bremen, DE <E-mail: carlos.jimenez@zmt.uni-bremen.de> <E-mail: cjimenez@cariari.ucr.ac.cr>). San José, 1998. 218 pp. Tesis, M.Sc., Universidad de Costa Rica, San Pedro de Montes de Oca (Costa Rica). (No abstract). Localización: Biblioteca OET: Tesis 477. Biblioteca Luis D. Tinoco: TFG 17884. Publicación no.: 299 Tropical montane cloud forests: time for action / Bosques nublados tropicales montanos: tiempo para la acción / Forêts tropicales montagnardes de nuages: il est temps d'agir / Aldrich, M, (comp.).; Bubb, P, (comp.).; Hostettler, S, (comp.).; van de Wiel, H, (comp.). (WWF International Forests for Life, Avenue du Mont Blanc, CH-1196 Gland, CH <E-mail: maldrich@wwint.org> <E-mail: philip.bubb@unep-wcmc.org> <E-mail: cloudforest@iucn.org>). Gland: WWF International/IUCN The World Conservation Union, 2000. 32 pp. ISBN: 2-88085-245-5. Tropical Montane Cloud Forests (TMCFs) are beautiful evergreen forests, frequently enveloped in clouds and mist. Every tree trunk, branch and rock surface is covered in moss, ferns, orchids and other epiphytic plants. Although few cloud forests have been systematically explored, it is recognised that they are storehouses of biodiversity. And little by little their vital role as sources and providers of freshwater for millions of people is being unravelled and recognised. It is not surprising that with these almost magical properties, TMCFs possess strong spiritual and cultural values in many parts of the world. Yet cloud forests are seriously at risk. The majority of the TMCFs which remain are only fragments of their original extent. Rural poverty, insecurity of land tenure and policy failures underlie many of the threats to the world's cloud forests. Growing populations, unsustainable land uses and official development policies that ignore forest values all drive deforestation. Whilst some forest conservation projects exist in all regions with TMCF, many areas are not valued or protected at all. Sometimes only after the cloud forest has gone do local people and governments appreciate its unique functions. We have to act now, before it is too late. This informative and timely report has been produced in response to a perce ived lack of public and political awareness of the status and value of Tropical Montane Cloud Forests (TMCFs). Whilst a science

based publication, it has been written in terms that will also inform and stimulate concern among a non-scientific audience. Localización: Biblioteca OET: NBINA-5121. Publicación no.: 300 Wood and soil-atmosphere carbon dioxide fluxes from a tropical forest ecosystem [Flujos de dióxido de carbono de la madera y del suelo-atmósfera de un ecosistema de bosque tropical] / Lopes, E.C. Durham, NH: University of New Hampshire, 2005. 124 pp. ISBN: 0542312697. Dissertation, Ph.D., University of New Hampshire, Durham, NH (USA). Carbon cycling in tropical rainforests is an important component of the global carbon budget. A better understanding of controlling mechanisms and magnitude of CO 2 sources from tropical forests will improve our ability to predict future impacts of climate changes. The research presented in this dissertation has focused on determining the magnitude and characteristics of the CO2 flux from tropical wood and soil surfaces. Stem CO2 fluxes were measured in a tropical moist forest at Tapajós National Forest (TNF) in Brazil and in a tropical wet forest at La Selva Biological Station in Costa Rica (LS) using infrared gas analysis methods. Annual Stem CO2 fluxes for TNF and LS averaged 1.7 µmol m-2 s-1 and 4.5 µmol m-2 s-1, respectively. At TNF wood surface area was calculated (4161 m 2 ha-1 ) and wood CO2 flux extrapolated to ground area resulted in an annual flux of 259 g C m-2 yr-1 . Soil-atmosphere CO2 fluxes were measured at TNF using infrared gas analysis methods. Line sampling of soil CO2 fluxesmade on randomly placed 30 meters transects averaged 4.7 ± 0.2 µmol m-2 s-1 with higher rates during the wet season (4.9 ± 0.3 µmol m-2 s-1) than during the dry season (4.4 ± 0.2 µmol m-2 s-1). Fluxes were weakly correlated with precipitation and not correlated with soil moisture or temperature. Geostatistical analysis of grid sampling of soil CO2 fluxes indicated that they were not spatially dependent. Fluxes measured during wet season and dry season on grid sampling averaged 5.6 ± 0.2 µmol m-2 s-1 and 4.5 ± 0.1 µmol m-2 s-1, respectively. The estimated annual average of soil surface CO2 flux for the TNF was 1780 g C m-2 yr-1. Assuming that root and heterotrophic respiration each contribute about 50% of soil CO 2 efflux, then approximately 890g C m-2 yr-1 derive from each source. The estimated gross primary photosynthesis for the TNF is 3000 g C m-2 yr-1 (Miller et al., 2004). Therefore, estimated contribution of wood and root CO2 flux to the GPP are respectively 8.7% and 15%. Localización: Biblioteca OET: NBINA-5429. Publicación no.: 301 Caribbean and Pacific moisture sources on the Isthmus of Panama revealed from stalagmite and surface water delta O-18 gradients - art. no. L01708 / Lachniet, M.S.; Patterson, W.P.; Burns, S.J.; Asmerom, Y.; Polyak, V. (University of Nevada. Department of Geosciences, Las Vegas, NV 89154, US <E-mail: matthew.lachniet@unlv.edu>). In: Geophysical Research Letters (ISSN 0094-8276), v. 34, no. 1, p. 1708-1708. 2007. We test the hypothesis that the Pacific Ocean contributes moisture to the Intertropical Convergence Zone (ITCZ) over southern Central America, by spatial analysis of surface water delta O-18 values from Panama and Costa Rica. The delta O-18 values decrease with distance from the Caribbean Sea to the isthmian divide then gradually increase from the divide toward the Pacific slope, which suggests a contribution of both Caribbean and Pacific sourced moisture to the isthmus. We estimated the Pacific moisture contribution for Pacific slope regions of 22% to 64%. The delta O-18 values from stalagmites from five cave systems demonstrate decreasing delta O-18 values with distance from the Caribbean, implicating the Atlantic Basin as a dominant moisture source. Constraining modern moisture sources is important for the interpretation of stable isotopic proxy records of past rainfall, because of the combined influence of Pacific and Atlantic ocean-atmosphere phenomena on ITCZ rainfall over the Isthmus of Panama. Localización: Biblioteca OET: NBINA-5455. Publicación no.: 302 Seasonality and foliar nutrient dynamics of a tropical rain forest in Costa Rica [Estacionalidad y dinámica de los nutrimentos foliares de un bosque lluvioso tropical en Costa Rica] / Wood, T.E. (University of Virginia. Department of Environmental Sciences, P.O. Box 400123, Charlottesville, VA 22904, US <E-mail: tana@virginia.edu>). Charlottesville, VA: University of Virginia, 2006. 145 pp. Dissertation, Ph.D., University of Virginia, Graduate Faculty, Charlottesville, VA (USA). Through the examination of seasonal patterns of leaf litter nutrient cycling we may be better able to predict the response of tropical ecosystems to future environmental change. This work examines how seasonal variability in litter nutrient dynamics affects ecosystem function of a wet tropical forest in Costa Rica. I investigated the importance of litter nutrient dynamics through two experiments manipulating forest floor litter, and observations of nutrient resorption. The response to litter application was explained by the phosphorus (P) concentration of added litter. The response was not related to total P inputs, or to the concentration or inputs of nitrogen (N). The quality of leaf litter inputs is determined at the time of abscission via nutrient resorption (withdrawal of nutrients during senescence). Examination of foliar nutrient concentrations in nine common canopy tree species showed a mean resorption efficiency of 49% for P and 46% for N. Therefore, as much as 2.5 kg/ha/yr of P and 50 kg/ha/yr of N are recycled internally by the vegetation. Among these nine species, senesced leaf nutrient concentrations correlated positively with those of the green leaves. Therefore, variability in the quality of leaf litter inputs is likely a reflection of green leaff nutrient concentrations. Modeled shifts in the relative importance of these species at the stand-level indicate that a change in species dominance could have a major impact on stand-level nutrient economy by significantly altering annualinputs of leaf N and P to the forest floor. This effect was greatest when Vochysia ferruginea was dominant, resulting in significantly lower leaf N and P inputs to the forest floor. Green

and senesced leaff nutrient concentrations as well as nutrient resorption efficiency for the nine species were significantly higher in the wet versus the dry season. Low nutrient resorption during the dry season could reflect either incomplete resorption due to water stress or lower plant demand during this period. A more detailed evaluation of foliar N and P for two species (Pentaclethra macroloba and Laetia procera) showed that both green and senesced leaf nutrient concentrations as well as resorption efficiency changed significantly over the short-term (bi-weekly).This variability in foliar nutrients and resorption efficiency was not related to climate over the four-month study period (rainfall, light, temperature). It is possible that variability in nutrient resorption is driven by species-specific changes in phenological demands. This idea is supported by the different temporal patterns of foliar nutrients of P macroloba and L. procera. Results from this study demonstrate the dynamic nature of wet tropical forests. From the soil pool to the leaves of canopy trees, nutrients varied significantly both over the short-term (bi-weekly) and seasonally (wet and dry season). Species differed in their resorption efficiency, foliar nutrient concentrations, as well as their response to temporal variability in climate. Therefore, should land-use and climate change be accompanied by a shift in species dominance, both the pattern and magnitude of nutrients cycled in litterfall would likely change. With it, the functioning of tropical forests would be altered, as well as feedbacks on atmospheric carbon, water and energy balance. Localización: Biblioteca OET: NBINA-5389. Publicación no.: 303 Economic aid and the environment [Ayuda económica y el ambiente] / Repetto, R. In: EPA journal (ISSN 0145-1189), v. 16, no. 4, p. 20-22. 1990. Approximately 1/3 of the signatories of the Montreal Protocol on ozone depletion were developing countries lacking the resources to pay for its implementation. Germany announced at 25% reduction of carbon dioxide emissions by 2005, the Netherlands, the UK, and Japan promised similar steps. The southern hemisphere has to reduce emissions with improved technology from the northern hemisphere, as 45% of greenhouse gases are generated there. There is need to finance such initiatives: $20-50 billion a year is required by 2000 to help these countries. The world Resources Institute proposed a green investment fund for the environment or Ecovest. It was first proposed in Eastern Europe by the Nordic Environmental Finance Corporation (NEFCO) in 1990 with an initial capital of $47 million. The US Overseas Private Investment Corporation set up a $100 million for-profit Environmental Investment Fund for eastern Europe and the developing world for sustainable agriculture, forest management, eco-tourism, renewable energy, and pollution prevention. Debt-for-nature swaps between nongovernmental agencies and governments to purchase debt at discount have been paid in bonds for nature conservation in Bolivia, Ecuador, Costa Rica, the Philippines, Zambia, and Madagascar. $69 million of Costa Rica's debt was converted in 2 years to save parks, protected areas, and finance reforestation. The debts of some African countries have been written off by donor countries. The Bush Administration proposed to write off parts ofLatin America's $7 billion debt. The Global Environment Fund of the World Bank proposed to lend $300-400 million a year for environmental projects in developing countries and in eastern Europe. The main goals are to protect the ozone layer, prevent deforestation and desertification, and clean up pollution. Some companies finance reforestation in Guatemala to offset their own emissions. Localización: Biblioteca OET: NBINA-7028. Publicación no.: 304 Effects of the Younger Dryas cooling event on late quaternary montane oak forest in Costa Rica / Islebe, G.A.; Hooghiemstra, H. (El Colegio de la Frontera Sur (ECOSUR), Apartado 424, CP 77000, Chetumal, Quintana Roo, MX <E-mail: gerald@ecosur-qroo.mx> <E-mail: hooghiemstra@bio.uva.nl>). In: Ecology and conservation of neotropical montane oak forests. Kappelle, M. (ed.) Berlin-Heidelberg: Springer-Verlag, 2006. p. 29-38. (Ecological Studies Series; v. 185). ISBN: 978-3-540-28909-8. Climate change is expected to profoundly impact global vegetation types. Those changes can be best evaluated if we understand past climate change and its impact on vegetation types. From research by Martin (1964), we know that glacial times had impact on Costa Rican vegetation.Later paleoecological and palynological studies from the Cordillera de Talamanca include Hooghiemstra et al. (1992), Horn and Sanford (1992), Horn (1993), Islebe et al. (1996), Islebe and Hooghiemstra (1997), and Rodgers and Horn (1996). The Younger Dryas cooling event (11,000-10,000 14C years BP), the last stage of the Pleistocene, is of great interest as there is still an exciting discussion questioning if this event was global, or rather restricted to some regions of the northern hemisphere. To date, the effects of the Younger Dryas cooling have been observed in ice cores (Dansgaard et al. 1989), marine sediments (Kennett 1990), and terrestrial cores from different parts of the world (Peteet 1993, 1995). For Central America and northern South America, a Younger Dryas cooling event has been suggested for Guatemala (Leyden 1995), Costa Rica (Islebe et al. 1995), Colombia (van Geel and van der Hammen 1973; van der Hammen 1978; Kuhry et al. 1993; Hooghiemstra and van der Hammen 1995), Ecuador (Clapperton et al. 1997), and Peru (Thompson et al. 1995).However, the lack of bracketing radiocarbon dates (i.e., dates that delimit events by an upper and lower age boundary) is a problem in many paleorecords (Heine 1993; Van't Veer et al. 2000). In this chapter, we present data from the La Chonta bog area, located in the Cordillera de Talamanca. Hastenrath (1973) reported several glacier advances, and that at 10,000 years BP the deglaciation process had ended. Our study site is located at 2,310 m altitude and is today surrounded by montane oak forest.We consider this altitude as strategic to understand past vegetation changes. The objective of this chapter is to analyze the impact of the Late Glacial-Holocene transitional climatic conditions on montane oak forests. Localización: Biblioteca OET: NBINA-5514.

Publicación no.: 305 Arthropod assemblages in epiphyte mats of Costa Rican cloud forests [Comunidades de artrópodos en la maraña de epífitas de bosques nubosos costarricenses] / Yanoviak, S.P.; Nadkarni, N.M.; Solano, R. (Florida Medical Entomology Laboratory, 200 9th Street SE, Vero Beach, FL 32962, US <E-mail: yanoviak@terra.com.pe> <E-mail: nadkarnn@evergreen.edu>). In: Biotropica (ISSN 0006-3606), v. 39, no. 2, p. 202-210. 2007. Tropical cloud forests are functionally important ecosystems, but are severely threatened due to deforestation and fragmentation. Epiphyte mats, accumulations of live vegetation and dead organic matter on tree trunks and branches, are a conspicuous component of cloud forests and harbor diverse assemblages of meso- and microarthropods. We compared the morphospecies richness, composition, and abundance of arthropods in epiphyte mats between primary and secondary forests of Monteverde, Costa Rica, and at two nearby replicate sites. Epiphyte mats were thinner and less structurally diverse in secondary forest. We collected ca 36,000 micro- and mesoarthropods from epiphyte mats in the 2-yr study. Whereas arthropod morphospecies richness did not differ among forest types, arthropod abundance was significantly higher in secondary forest due to larger numbers of ants, especially Solenopsis spp. Arthropod assemblages showed a high degree of taxonomic overlap both within and between primary and secondary forests (Jaccard abundance-based similarity = 0.93-0.96). Although characteristics of the arthropod fauna proved to be similar among sites and between forest types, there was a significant temporal effect: arthropod morphospecies richness in epiphyte mats generally was lower in the dry season (February-May), when many taxa probably became dormant or sought shelter against desiccation in deeper portions of mats. Localización: Biblioteca OET: NBINA-5719. Publicación no.: 306 Simulation of nitrous oxide and nitric oxide emissions from tropical primary forests in the Costa Rican Atlantic Zone [Simulación de las emisiones de óxido nitroso y óxido nítrico de bosques primarios en la Zona Atlántica costarricense] / Liu, S.; Reiners, W.A.; Keller, M.; Schimel, D.S. (Raytheon Systems Company. EROS Data Center, Sioux Falls, SD 57198, US <E-mail: sliu@edcmail.cr.usgs.gov> <E-mail: reiners@uwyo.edu> <E-mail: michael.keller@unh.edu> <E-mail: schimel@ucar.edu>). In: Environmental Modeling and Assessment (ISSN 1364-8152), v. 15, p. 727-743. 2000. Nitrous oxide (N2O) and nitric oxide (NO) are important atmospheric trace gases participating in the regulation of global climate and environment. Predictive models on the emissions of N2O and NO emissions from soil into the atmosphere are required. We modified the CENTURY model (Soil Sci. Soc. Am. J., 51 (1987) 1173) to simulate the emissions of N2O and NO from tropical primary forests in the Atlantic Zone of Costa Rica at a monthly time step. Combined fluxes of N2O and NO were simulated as a function of gross N mineralization and water-filled pore space (WFPS). The coefficients for partitioning N2O from NO were derived from field measurements (Global Biogeochem. Cycles, 8 (1994) 399). The modified CENTURY was calibrated against observations of carbon stocks in various pools of forest ecosystems of the region, and measured WFPS and emission rates of N2O and NO from soil to the atmosphere. WFPS is an important factor regulating nutrient cycling and emissions of N2O and NO from soils making the accuracy of the WFPS prediction central to the modeling process. To do this, we modified the hydrologic submodel and developed a new method for the prediction of WFPS at the monthly scale from daily rainfall information. The new method is based on: (1) the relationship between monthly rainfall and the number of rainfall events, and (2) the relative cumulative frequency distribution of ranked daily rainfall events. The method is generic and should be applicable to other areas. Simulated monthly average WFPS was 0.68-0.02 - identical with the field measurement average of 0.68-0.02 from the annual cycle observed by Keller and Reiners (Global Biogeochem. Cycles, 8 (1994) 399). Simulated fluxes of N2O and NO were 52.0-9.4 mg-N m-² month-¹ and 6.5-0.7 mg-N m-² month-¹, respectively, compared with measured averages of 48.2-11.0 mg-N m-² month-¹ and 7.1-1.1 mg-N m-² month-¹. The simulated N2O/NO ratio was 11.2-1.9 compared with the measured value of 10.9-4.7. WFPS is the dominant determinant of the fraction of gross N mineralization that is emitted from the soil as N2O and NO. If WFPS were not limiting during part of the year, this fraction would be 4.2%. With some periods of lower WFPS, the realized fraction is 2.2%. Because of the strong relationships between N2O and NO emission rates and rainfall and its derivative, WFPS, these moisture variables can be used to scale up nitrogen trace gas fluxes from sites to larger spatial scales. Localización: Biblioteca OET: NBINA-5649. Publicación no.: 307 Propuesta metodológica para evaluar la adaptación de los productores a la variabilidad climática, principalmente la sequía, en cuencas hidrográficas en América Central [Methodological proposal to evaluate the farmer's adaptation to climate variability, specifically drought in Central America's watershed] / Benegas-Negri, L.A. Turrialba: CATIE, 2006. 145 pp. Tesis, Mag. Sc. en Manejo Integrado de Cuencas Hidrográficas, Centro Agronómico Tropical de Investigación y Enseñanza (CATIE), Turrialba (Costa Rica). Central America have drought continues zones exposed to natural disasters and food periodical scarcity but it has a responsal to this climate variability with people adaptation, aspect that was looking for evaluation. Therefore, was elaborated a standard to evaluate the farmer's adaptation to the climate varialibility, specifically drought in Central America's watershed, obtained through contributions of professionals of this region. It was obtained five principles, ten criteria, twenty six indicators and fifty one verifiers. This standard was applied in the watershed of the Aguas Calientes' river in Nicaragua, previous multicriteria evaluation of the acceptance level of the standard, which was mean. The general qualification indicates a low adaptation level to this condition. The analysis of drought adaptation strategies and technologies existing and the perception of climate variability were based in

surveys, interviews, workshops and field visits. It was prioritize the most vulnerable areas and the solution alternatives in a participative way. It was analyzed the financial feasibility of two crops (henequen and pitahaya) existing like adaptation to drought options. It was confirmed the vulnerability of this watershed, which most vulnerable areas are located in the middle and low stratums; and, in spite of that, in the middle zone there are not application of water harvest and storage strategies and plantation of fruit trees; and in the low zone there is exclusively the irrigation strategy, being insignificant the green manures and alive and died barriers, revealing the weaknesses of the most vulnerable zones. The henequen crop under the actual production system is untenable, but with the fiber transformation in thread, it's profitable. The pitahaya produced in patio present positive financial indicators with low capitalization of investments; however, this crop would be a good adaptation alternative if it has increased the density of plants maintaining the patio areas. Localización: Biblioteca OET: NBINA-5771. Publicación no.: 308 Protection fails to stem amphibian decline [La protección no puede prevenir la disminución de anfibios] / Williams, N. In: Current Biology (ISSN 0960-9822), v. 17, no. 10, p. 339-340. 2007. A long-term analysis of amphibian and reptiles in a Costa Rican nature reserves designated to protectect them reveals an alarming fall in numbers. Localización: Biblioteca OET: NBINA-6183. Publicación no.: 309 Análisis del sistema de pago por Servicios Ambientales en la rentabilidad de una plantación de Gmelina arborea, en la zona Huetar Norte, Costa Rica / Espinoza-Miranda, A. (Ministerio de Ambiente y Energía. Coordinadora de Educación Ambiental, San José, CR). In: Strucplan on Line, http://www.estrucplan.com.ar/Articulos/verarticuloss.asp?IDArticulo=1133, 14 p. 2007. Desde hace dos décadas Costa Rica se ha ocupado del campo ambiental, al igual que lo han hecho otros países y Organismos Internacionales, en busca de soluciones para incorporar un moderno concepto de compensación a los empresarios por los servicios ambientales que brinda el bosque y las plantaciones forestales a la sociedad. La problemática mayor del sector forestal está centrada en la tecnología y financiamiento de la sostenibilidad de los proyectos de reforestación, considerando que el retorno de la inversión se produce en el mediano y largo plazo, principalmente para garantizar un buen manejo silvicultural de las plantaciones. Por tal razón el Estado creó el Fondo Nacional de Financiamiento Forestal (FONAFIFO) con la finalidad de buscar alternativas de solución a la falta de financiamiento para el desarrollo de proyectos sostenibles que mejoren la calidad de vida de la sociedad costarricense. Es necesario por tanto evaluar hoy día el Sistema de pago por Servicios Ambientales, como principal fuente de financiamiento para asegurar el éxito en función de rentabilidad financiera de los proyectos de reforestación con especies maderables. En esta investigación se presenta la importancia del problema, se indica el problema principal, los objetivos: general y específicos, así como la conceptualización de las variables. Se desarrolla el marco teórico que abarca conceptos básicos utilizados en este estudio, los cuales de una u otra forma, han permitido conocer y permitirán aplicar los indicadores de laestructura de costos, la rentabilidad financiera de esta actividad. Los aspectos técnicos, involucran los términos en cuanto a la descripción de los sitios o fincas, especificaciones de las plantaciones, características de la especie, requisitos técnicosy legales para optar por el financiamiento, entre otros. Se hace referencia a la metodología empleada, las fuentes de información, la descripción de los instrumentos, su validez, alcances y limitaciones. Se analizan e interpretan los datos obtenidos con cada uno de los instrumentos aplicados en la investigación, incorporando el análisis estadístico y gráfico para su mayor comprensión. Finalmente, se presenta las conclusiones y recomendaciones por objetivo, además de una recomendación global que incluye todos los lineamientos expuestos y propone una solución financiera integrada del problema. Localización: Biblioteca OET: NBINA-6384. Publicación no.: 310 Manual para mejores prácticas de conservación de las tortugas marinas en Centroamérica / Chacón-Chaverri, D.; Valerín, N.; Cajiao-Jiménez, M.V.; Gamboa, H. (il.); Marín, G. (il.). (Asociación ANAI, Apdo 170-2070, San José, CR <E-mail: tortugas@racsa.co.cr> <E-mail: vcajiao@racsa.co.cr>). s.l.: PROARCA/CAPAS, 2000. 155 p. (No abstract). Localización: Biblioteca OET: NBINA-1645. Publicación no.: 311 Processes responsible for the nitrous oxide emission from a Costa Rican Andosol under a coffee agroforestry plantation [Procesos responsables para la emisión de óxido nitroso de un Andosol costarricense bajo una plantación agroforestal de café] / Hergoualc'h, K.; Skiba, U.; Harmand, J.M.; Oliver, R. (CATIE. Departamento de Agricultura y Agroforestería, 7170 Turrialba, CR <E-mail: hergoual@catie.ac.cr>). In: Biology and Fertility of Soils (ISSN 0178-2762), v. 43, p. 787-795. 2007. We used the inhibitor acetylene (C2H2) at partial pressures of 10 Pa and 10 kPa to inhibit autotrophic nitrification and the reduction of nitrous oxide (N2O) to N2, respectively. Soils (Andosol) from a Coffea arabica plantation shaded by Inga densiflora in Costa Rica were adjusted to 39, 58, 76 and 87% water-filled pore space (WFPS) and incubated for 6 days in the absence or presence of C2H2. Soil respiration, nitrification rates and N2O emissions by both processes were measured in relation to soil moisture conditions. At all WFPS studied, rates of N2O and N2 productions were small (4.8; 14.7; 23 and 239.6 ng N-N2O g-¹ d.w. d-¹ at 39, 58, 76 and 87% WFPS, respectively), and despite a low soil pH (4.7), N2O was mainly produced by nitrification, which was responsible for 85, 91, 84 and 87% of the total N2O emissions at 39, 58, 76 and 87% WFPS, respectively. At the three smaller values of WFPS, a linear relationship was established between WFPS, soil respiration, nitrification and

N2O released by nitrification; no N2 was produced by denitrification. At more anaerobic conditions achieved by a WFPS of 87%, a large rate of N2O production was measured during nitrification, and N2 production accounted for 84% of the gaseous N fluxes caused by denitrification. Localización: Biblioteca OET: NBINA-7073. Publicación no.: 312 Climate change implicated in amphibian and lizard declines [Cambio climático implicado en la disminución de anfibios y lagartijas] / Wake, D.B. (University of California. Museum of Vertebrate Zoology and Department of Integrative Biology, Berkeley, CA 94720-3160, US <E-mail: wakelab@berkeley.edu>). In: Proceedings of the National Academy of Sciences of the United States of America (ISSN 0027-8424), v. 104, no. 20, p. 8201-8202. 2007. The Tink Frog (Eleutherodactylus diastema), once a commonly encountered species with dense populations, is one of 17 species of amphibians and lizards that have experienced steep declines, on the order of 75%, over the past 35 years at the La Selva Biological Station in lowland northeastern Costa Rica. Localización: Biblioteca OET: NBINA-7204. Publicación no.: 313 Running hot and cold: Are rainforest sinks or taps for carbon? / Levy, S. (<E-mail: levyscan@sbcglobal.net>). In: Bioscience (ISSN 0006-3568), v. 57, no. 7, p. 552-557. 2007. Conventional wisdom has long held that tropical rainforests act as a sink for carbon dioxide, cleansing the atmosphere of a major greenhouse gas. However, biologists studying the forests of Costa Rica are finding that rising temperatures are causing trees to grow less and to pump out more casrbon dioxide, adding to an accelerating pattern of global warming. On a cloudy day, the rainforest seen from the top of the La Selva canopy research tower seems to go on forever. In fact, La Selva is the small tip of a peninsula of remnant habitat in a landscape heavily altered by human activities. Some researchers helieve this may make data from La Selva less relevant to conditions in Amazonia and other areas with large swaths of tropical forest. Localización: Biblioteca OET: NBINA-7306. Publicación no.: 314 New techniques for accurate measurement of water and water isotopes: Insights into the mechanisms that control the humidity of the upper troposphere and lower stratosphere [Nuevas técnicas para la medida exacta del agua y de los isótopos del agua: Entendimiento de los mecanismos que controlan la humedad de la troposfera superior y la estratosfera baja] / Sayres, D.S. Cambridge: Harvard University, 2006. 136 p. Dissertation, Ph.D., Harvard University, Cambridge, MA (USA). Elucidating the mechanisms that control stratospheric humidity is essential if global climate models are to accurately predict how changes in the boundary layer will effect ozone loss in the stratosphere. One method of testing which dehydration mechanisms are prominent in the tropical upper troposphere is using the isotopic ratio of water vapor, as the ratio records the dehydration history of the air parcel. Measurements of the isotopic ratio of water vapor in the overworld stratosphere, over the continental United States and Gulf of Mexico, show air that is enriched in HDO compared with previous remote measurements of tropical stratospheric air. It is concluded that the cause of this enrichment is evaporation of lofted ice as a result of deep convection that penetrates as high as 430 K. Based on a simple mixing model, it is shown that as much as 40% of water vapor in the midlatitude overworld is the result of convective ice lofting. During the recent CR-AVE mission, tropical profiles of HDO and H2O show that the tropical stratosphere over Costa Rica in wintertime is also enriched in HDO. However, measurements in the lower part of the TTL are consistent with convective air following a Rayleigh profile and detraining at 350 K and then rising without further depletion. It is proposed that the stratospheric air over Costa Rica is heavily influenced by middleworld air from the midlatitudes and is not the result of slow ascent in the tropics. The measurements used in this thesis were obtained using anew instrument that leverages advances in electronic design and laser development with the sensitivity obtained from cavity enhanced absorption spectroscopy to make accurate measurements of water isotopes. The Harvard Integrated Cavity Output Spectroscopy (ICOS) instrument uses a high-finesse optical cavity to produce kilometer pathlengths in a meter sized cell. The theory and application of ICOS as a tracer instrument are laid out in the context of making accurate measurements traceable to laboratory standards. Laboratory calibrations with two different water addition systems as well as cross-calibration with other water and water isotope instruments yield an accurate determination of molecular line strengths and line widths and a robust method for testing the ICOS fitting algorithm. Comparisons with other water and water isotope instruments were made during the AVE-WIIF campaign. ICOS shows good agreement in both H2O and HDO when compared to other instruments. However, a small bias is detected at low mixing ratios and pressures below 100 mbar. The cause of this bias is described as well as possible solutions. Accurate remote sensing measurements are also important for understanding the role of convection and other dehydration mechanisms. Comparisons made during the CRYSTAL-FACE mission use in situ ice water content (IWC) from the Harvard Total Water and Water Vapor instruments with remote measurements of radar reflectivities from the Cloud Radar System (CRS). A cloud model is used to assess the sampling error caused by comparing measurements that sample air parcels that are not spatially nor temporally collocated. The conclusion from the model, which is confirmed by the CRYSTAL-FACE data, is that measurements must be made within 2 kilometers of each other. Limiting the comparisons to times when in situ and remote measurements were within 2 kilometers of each other, IWC derived from CRS measurements is within 15% of the IWC measured in situ.

Localización: Biblioteca OET: NBINA-7459. Publicación no.: 315 Frog declines: Exploring connections among climate change, immunity and disease [Disminución de ranas: Explorando las conexiones entre el cambio climático, inmunidad y enfermedad] / Beecher, N.A. Bloomington: Indiana University, 2006. 112 p. Dissertation, Ph.D., Indiana University, Bloomington, IN (USA). Frog and toad populations have been declining drastically all over the world. For the past 20 years, marked declines have been recorded for 40% of the frog and toad species in the Monteverde Cloud Forest Preserve (MCFP), Costa Rica, where climate change and disease have been implicated. Our study explored possible connections between climate change, immunity and disease susceptibility, examining in particular how climate-induced changes in pond water levels may influence amphibian immune systems. Weexamined immune development and function (thymus growth, antibody production and skin graft rejection) in Meadow treefrogs (Hyla pseudopuma), a declining species in the MCFP, when tadpoles developed under various water regimes. During the wet seasons of 2001-2004, laboratory experiments were conducted in the MCFP by subjecting tadpoles to constant or declining water levels. Field studies also took place in man-made and natural forest ponds that experienced different rainfall and pond water retention patterns. Our studies suggested that development under shallow or highly variable water levels led to weaker immunity. Under these conditions, both tadpoles and young froglets were less able to reject foreign tissue, an important immune response involved ininitially fighting off infection. These data support the hypothesis that climate-induced changes in pond water can influence amphibian immune development as well as function. Collectively, these results may have important implications concerning climate change effects on amphibian populations, as well as the possible role of immunosuppression and increased disease susceptibility in species declines. Localización: Non available. Publicación no.: 316 An incentive mechanism for reducing emissions from conversion of intact and non-intact forests [Un mecanismo para incentivar la reducción de emisiones para la conversión de bosques intactos y no intactos] / Mollicone, D.; Achard, F.; Federici, S.E.; Grassi, H.D.; Belwared, G.; Raes, A.; Seufert, F.; Stibig, G.; Matteucci, H.J.; Schulze, G. (Commission of European Communities. Joint Research Centre, Institute of Environmal Sustainability, CCR, TP 440, I-21020 Ispra, IT <E-mail: dmolli@bgc-jena.mpg.de> <E-mail: frederic.achard@jrc.it>). In: Climatic Change (ISSN 0165-0009), v. 83, no. 4, p. 477-493. 2007. This paper presents a new accounting mechanism in the context of the UNFCCC issue on reducing emissions from deforestation in developing countries, including technical options for determining baselines of forest conversions. This proposal builds on the recent scientific achievements related to the estimation of tropical deforestation rates and to the assessment of 'Cyintact' forest areas. The distinction between 'Cyintact' and 'Cynon intact' forests used here arises from experience with satellite-based deforestation measurements and allows accounting for carbon losses from forest degradation. The proposed accounting system would use forest area conversion rates as input data. An optimal technical solution to set baselines would be to use historical average figures during the time period from 1990 to 2005. The system introduces two different schemes to account for preserved carbon: one for countries with high forest conversion rates where the desired outcome would be a reduction in their rates, and another for countries with low rates. A 'Cyglobal' baseline rate would be used to discriminate between these two country categories (high and low rates). For the hypothetical accounting period 2013-2017 and considering 72% of the total tropical forest domain for which data are available, the scenario of a 10% reduction of the high rates and of the preservation of low rates would result in approximately 1.6 billion tCO(2) of avoided emissions. The resulting benefits of this reduction would be shared between those high-rate countries which reduced deforestation and those low-rate countries which did not increase their deforestation over an agreed threshold (e.g., half of "global" baseline rate). Localización: Biblioteca OET: NBINA-7344. Publicación no.: 317 Efecto del cambio climático en la agricultura. Experiencias en Costa Rica / Villalobos-Flores, R.; Retana-Barrantes, J.A. (Instituto Meteorológico Nacional. Departamento de Agrometeorología, San José, CR <E-mail: rvilla@imn.ac.cr> <E-mail: jretana@imn.ac.cr>). [San José]: Roberto Villalobos & José. A. Retana, s.f. 2 p. La alteración de los patrones climáticos afectará indudablemente la producción y la productividad agrícola de diferentes maneras, dependiendo de los tipos de prácticas agrícolas, sistemas y período de producción, cultivos, variedades y zonas de impacto. Se estima que los principales efectos directos derivados de las variaciones en la temperatura y precipitación principalmente, serían la duración de los ciclos de cultivo, alteraciones fisiológicas por exposición a temperaturas fuera del umbral permitido, deficiencias hídricas y respuesta a nuevas concentraciones de CO2 atmosférico. Algunos efectos indirectos de los cambios esperados se producirían en las poblaciones de parásitos, plagas y enfermedades (migración, concentración, flujos poblacionales, incidencias, etc.) disponibilidad de nutrimentos en el suelo y planificación agrícola (fechas de siembra, laboreo, mercadeo, etc.). Una de las formas más utilizadas actualmente para estudiar el impacto de un cambio climático sobre los sistemas agrícolas ypecuarios, es evaluando escenarios futuristas de cambio en modelos computacionales de simulación de crecimiento de cultivos. Estos permiten analizar el comportamiento productivo durante todo el ciclo del cultivo bajo diferentes marcos climáticos, obteniendo resultados sobre los efectos de variaciones en la temperatura, la precipitación y la radiación solar, principalmente. La mayoría de estos estudios aplican variaciones en la

temperatura máxima, mínima o en la media y en la precipitación. Los rangos devariación de los elementos meteorológicos, son generados por Modelos de Circulación General (MCG). Si bien es cierto que existen desacuerdos entre los investigadores sobre la magnitud de cambio en estos elementos, la tendencia en las investigaciones agrícolas que utilizan escenarios climáticos derivados de los MCG es que sean del orden de 1 a 4°C en la temperatura, con un aumento o disminución en la lluvia diaria entre un 5 y un 15%. Con estos rangos de variación, las posibilidades de construcción de escenarios es grande, máxime que algunos modelos de simulación de crecimiento permiten manejar combinaciones de factores y factores aislados como tratamientos de estudio. Además de la temperatura y la precipitación, el otro elemento de cambio importante a evaluar es el contenido de CO2. Los MCG trabajan sobre el estimado de alcanzar el equilibrio climático ante una concentración de CO2 duplicada de la actual (323 ppm). Experimentos con altos contenidos de CO2 indican que el comportamiento estomático producido, podría generar una economía del agua consumida por las plantas, así como un efecto fertilizante en el caso de las leguminosas. Además, un incremento en la concentración del CO2, aumentaría directamente la taza de fotosíntesis y la producción de biomasa de las plantas C3, con cambios poco significativos en las plantas C4, como el maíz, sorgo y caña de azúcar. Localización: Biblioteca OET: NBINA-7188. Publicación no.: 318 Programa de asistencia holandés para estudios de cambio climático: Proyecto de evaluación del impacto del cambio climático sobre la producción agrícola de Costa Rica / Villalobos-Flores, R.; Retana-Barrantes, J.A. (Instituto Meteorológico Nacional. Departamento de Agrometeorología, San José, CR <E-mail: rvilla@imn.ac.cr> <E-mail: jretana@imn.ac.cr>). [San José]: Roberto Villalobos & José. A. Retana, s.f. 3 p. El objetivo general del proyecto fue estudiar el impacto de un cambio climático sobre los cultivos agrícolas de frijol, papa y café en las principales regiones de producción en Costa Rica. Específicamente se analizó el efecto de variaciones en la temperatura del aire y la precipitación sobre la fisiología general y los rendimientos del cultivo de frijol en la Región Huetar Norte y de los cultivos de café y papa en la Región Central de Costa Rica. Localización: Biblioteca OET: NBINA-7186. Publicación no.: 319 Measurements of trace gases in the tropical tropopause layer / Marcy, T.P.; Popp, P.J.; Gao, R.S.; Fahey, D.W.; Ray, E.A.; Richard, E.C.; Thompson, T.L.; Atlas, E.L.; Loewenstein, M.; Wofsy, S.C.; Park, S.; Weinstock, E.M.; Swartz, W.H.; Mahoney, M.J. (National Oceanic and Atmospheric Administration (NOAA). Chemical Sciences Division, Earth System Research Laboratory, Boulder, CO 80305, US <E-mail: tpmarcy@hotmail.com>). In: Atmospheric Environment (ISSN 1352-2310), v. 41, no. 34, p. 7253-7261. 2007. A unique dataset of airborne in situ observations of HCl, O3, HNO3, H2O, CO, CO2 and CH3Cl has been made in and near the tropical tropopause layer (TTL). A total of 16 profiles across the tropopause were obtained at latitudes between 10°N and 3°S from the NASA WB-57F high-altitude aircraft flying from Costa Rica. Few in situ measurements of these gases, particularly HCl and HNO3, have been reported for the TTL. The general features of the trace gas vertical profiles are consistent with the concept of the TTL as distinct from the lower troposphere and lower stratosphere. A combination of the tracer profiles and correlations with O3 is used to show that a measurable amount of stratospheric air is mixed into this region. The HCl measurements offer an important constraint on stratospheric mixing into the TTL because once the contribution from halocarbon decomposition is quantified, the remaining HCl (60% in this study) must have a stratospheric source. Stratospheric HCl in (60% in this study) must have a stratospheric source. Stratospheric HCl in the TTL brings with it a proportional amount of stratospheric O3. Quantifying the sources of O3 in the TTL is important because O3 is particularly effective as a greenhouse gas in the tropopause region. Localización: Biblioteca OET: NBINA-7405. Publicación no.: 320 Growth, carbon sequestration, and management of native tree plantations in humid regions of Costa Rica [Crecimiento, captura de carbono y manejo de plantaciones de árboles nativos en regiones húmedas de Costa Rica] / Redondo-Brenes, A. (Yale University. School of Forestry & Environmental Studies, 210 Prospect St, New Haven, CT 06511, US <E-mail: alvaro.redondo@yale.edu>). In: New Forests (ISSN 0169-4286), v. 34, no. 3, p. 253-268. 2007. The Costa Rican government has provided incentives for reforestation programs since 1986 and initiated a Payment for Environmental Services program in 1996. These incentives yielded native species reforestation programs throughout the country. This research aims to provide information about growth, carbon sequestration, and management of seven native tree species (Vochysia guatemalensis, Vochysia ferruginea, Hyeronima alchorneoides, Calophyllum brasiliense, Terminalia amazonia, Virola koschnyi, and Dipteryx panamensis) growing in small and medium- sized plantations in the Caribbean and Northern lowlands of Costa Rica. A total of 179 plots were evaluated in 32 farms. Overall, I found that V. guatemalensis, V. ferruginea, H. alchorneoides, and T. amazonia were the species with the fastest diameter, total height, and volume growth; and T. amazonia and D. panamensis sequestered more carbon. Moreover, I found that the plantations that had been thinned before this assessment had the best growth. The results of the present research enhance the criteria elaborated in previous research findings to improve species choices for reforestation and silvicultural management in Costa Rica and in other regions with similar ecological features. Furthermore, they support the concept that tropical plantations can serve diverse economic, social, and ecological functions that may ultimately help reduce atmospheric CO2 accumulation. The Costa Rican government has provided incentives for reforestation programs since 1986 and

initiated a Payment for Environmental Services program in 1996. These incentives yielded native species reforestation programs throughout the country. This research aims to provide information about growth, carbon sequestration, and management of seven native tree species (Vochysia guatemalensis, Vochysia ferruginea, Hyeronima alchorneoides, Calophyllum brasiliense, Terminalia amazonia, Virola koschnyi, and Dipteryx panamensis) growing in small and medium-sized plantations in the Caribbean and Northern lowlands of Costa Rica. A total of 179 plots were evaluated in 32 farms. Overall, I found that V. guatemalensis, V. ferruginea, H. alchorneoides, and T. amazonia were the species with the fastest diameter, total height, and volume growth; and T. amazonia and D. panamensis sequestered more carbon. Moreover, I found that the plantations that had been thinned before this assessment had the best growth. The results of the present research enhance the criteria elaborated in previous research findings to improve species choices for reforestation and silvicultural management in Costa Rica and in other regions with similar ecological features. Furthermore, they support the concept that tropical plantations can serve diverse economic, social, and ecological functions that may ultimately help reduce atmospheric CO2 accumulation. Localización: Biblioteca OET: NBINA-7404. Publicación no.: 321 The CO2 tracer clock for the tropical tropopause layer / Park, S.; Jiménez, R.; Daube, B.C.; Pfister, L.; Conway, T.J.; Gottlieb, E.W.; Chow, V.Y.; Curran, D.J.; Matross, D.M.; Bright, A.; Atlas, E.L.; Bui, T.P.; Gao, R.S.; Twohy, C.H.; Wofsy, S.C. (Harvard University. Department of Earth & Planetary Sciences, Cambridge, MA 02138, US <E-mail: swofsy@deas.harvard.edu>). In: Atmospheric Chemistry and Physics (ISSN 1680-7316), v. 7, no. 14, p. 3989-4000. 2007. Observations of CO2 were made in the upper troposphere and lower stratosphere in the deep tropics in order to determine the patterns of large-scale vertical transport and age of air in the Tropical Tropopause Layer (TTL). Flights aboard the NASA WB-57F aircraft over Central America and adjacent ocean areas took place in January and February, 2004 (Pre-AURA Validation Experiment, Pre-AVE) and 2006 (Costa Rica-AVE, CR-AVE), and for the same flight dates of 2006, aboard the Proteus aircraft from the surface to 15 km over Darwin, Australia (Tropical Warm Pool International Cloud Experiment, TWP-ICE). The data demonstrate that the TTL is composed of two layers with distinctive features: (1) the lower TTL, 350-360 K (potential temperature(theta); approximately 12-14 km), is subject to inputs of convective outflows, as indicated by layers of variable CO2 concentrations, with air parcels of zero age distributed throughout the layer; (2) the upper TTL, from theta=similar to 360 K to similar to 390 K (14-18 km), ascends slowly and ages uniformly, as shown by a linear decline in CO2 mixing ratio tightly correlated with altitude, associated with increasing age. This division is confirmed by ensemble trajectory analysis. The CO2 concentration at the level of 360 K was 380.0(±0.2) ppmv, indistinguishable from surface site values in the Intertropical Convergence Zone (ITCZ) for the flight dates. Values declined with altitude to 379.2(±0.2) ppmv at 390 K, implying that air in the upper TTL monotonically ages while ascending. In combination with the winter slope of the CO2 seasonal cycle (+10.8±0.4 ppmv/yr), the vertical gradient of -0.78±0.09) ppmv gives a mean age of 26(±3) days for the air at 390 K and a mean ascent rate of 1.5(±0.3) mm s-¹. The TTL near 360 K in the Southern Hemisphere over Australia is very close in CO2 composition to the TTL in the Northern Hemisphere over Costa Rica, with strong contrasts emerging at lower altitudes (360 K). Both Pre-AVE and CR-AVE CO2 observed unexpected input from deep convection over Amazonia deep into the TTL. The CO2 data confirm the operation of a highly accurate tracer clock in the TTL that provides a direct measure of the ascent rate of the TTL and of the age of air entering the stratosphere. Localización: Biblioteca OET: NBINA-7496. Publicación no.: 322 A stable isotope approach to neotropical cloud forest paleoclimatology [Un enfoque de isótopos estables para la paleoclimatología del bosque nuboso neotropical] / Anchukaitis, K.J. (The University of Arizona. Department of Geosciences and Laboratory of Tree-Ring Research, 105 Stadium, Tucson, AZ 85721, US <E-mail: kanchuka@ltrr.arizona.edu>). Tucson, AZ: The University of Arizona, 2007. 165 p. Dissertation, Ph.D., The University of Arizona, Department of Geosciences, Tucson (USA). Many tropical trees do not form reliable annual growth rings, making it a challenge to develop tree-ring width chronologies for application to paleoclimatology in these regions. Here, I seek to establish high-resolution proxy climate records from trees without rings from the Monteverde Cloud Forest in Costa Rica using stable isotope dendroclimatology. Neotropical cloud forest ecosystems are associated with a relatively narrow range of geographic and hydroclimatic conditions, and are potentially sensitive to climate variability and change at time scales from annual to centennial and longer. My approach takes advantage of seasonal changes in the delta18O of water sources used by trees over a year, a signature that is imparted to the radial growth and provides the necessary chronological control. A rapid wood extraction technique is evaluated and found to produce cellulose with delta18O values indistinguishable from conventional approaches, although its application to radiocarbon requires a statistical correction. Analyses of plantation-grown Ocotea tenera reveal coherent annual delta18O cycles up to 9h. The width of these cycles corresponds to observed basal growth increments. Interannual variability in delta18O at this site is correlated with wet season precipitation anomalies. At higher elevations within the orographic cloud bank, year-to-year changes in the amplitude of oxygen isotope cycles show a relationship with dry season climate. Longer delta18O chronologies from mature Pouteria (Sapotacae) reveal that dry season hydroclimatology is controlled at interannual time scales by variability in the eastern equatorial Pacific (ENSO) and the Western Hemisphere Warm Pool (WHWP), which are correlated with trade wind strength and local air temperature. A change in the late 1960s toward enhanced annual delta18O amplitude may reflect low frequency changes in the Atlantic and Pacific ocean-atmosphere system. This study establishes the basis for cloud

forest isotope dendroclimatology and demonstrates that the local climate of neotropical cloud forests is sensitive to interannual, and perhaps, multidecadal changes in important large-scale modes of climate variability. Localización: Biblioteca OET: NBINA-7386. Publicación no.: 323 Efecto de ENOS sobre la agricultura del arroz en la Región Chorotega y la agricultura del frijol en la Zona Norte de Costa Rica / Anónimo. San José: Instituto Meteorológico Nacional, s.f. 5 p. (No abstract). Localización: Biblioteca OET: NBINA-7486. Publicación no.: 324 Payment of environmental services in Costa Rica: Evaluating impact and possibilities [Pago por servicios ambientales en Costa Rica: Evaluando el impacto y posibilidades] / Russo-Andrade, R.O.; Candela, G. (Escuela de Agricultura de la Región Tropical Húmeda (EARTH), Apdo. Postal 4442-1000, San José, CR <E-mail: r-russo@ns.earth.ac.cr>). In: Tierra Tropical (ISSN 1659-2751), v. 2, no. 1, p. 1-13. 2006. Conclusions: Seen from the perspective of poor rural communities, the Costa Rican experience, offers several lessons, as pointed out by Rosa et al. (2004): First, it shows the importance of broad participation in the early stages of PES schemes to ensure their long-term legitimacy and sustainability. An accelerated institutionalization of PES schemes, without adequately including the interests of small producers and indigenous communities, generates restrictions that are difficult to overcome later.Second, without strong and representative organizations of small producers and indigenous communities, it is difficult to ensure participation that will result in truly inclusive schemes. Third, the global orientation, eligibility criteria, and operational rules largely determine the capacity for inclusion in the PES schemes. In some settings, greater inclusion requires seeing beyond the forest to link up with other productive activities that are central to livelihoods. Fourth, a broad focus on a wide range of practices for the provision of environmental services can be important for improving, diversifying, and strengthening the livelihood strategies of rural communities. The impact of PES schemes can be enhanced when they promote environmentally improved productive activities such as agro-forestry, agro-ecotourism, non-timber products, and sustainable agriculture. Fifth, the incorporation of local-level perspectives, priorities, and visions can empower local communities and promote participatory management. Finally, there are some issues on the program that would need some attention. One is the good will of the government expecting that PSE would help to alleviate poverty in small rural communities versus the facts of what actually happens. As mentioned, the recent surveys by Zbinden and Lee (2005) observed that the large farmers (not necessarily poor) are the real beneficiaries of the program. Moreover, an unpublished study by Hope et al. (2005) has investigated how the PES program may contribute to poverty reduction for small-scale land owners in the upper water catchment?s area of the northern Tilarán region of Costa Rica. Participation in the PES program is limited due to weak dissemination, disputed land claims, and inelastic commitment to compensation payment levels. Additionally, program design and impacts may be improved by clarification of resource claims and environmental service provision rights, and simplifying program goals to defensible biophysical and/or socio-economic criteria. The authors studied three livelihood groups representing the main activities in the area, two productive (coffee and livestock) and one in the service sector (ecotourism) and no group viewed PES as a significant factor. Even in the case that the region is only a part of the entire program, these issues should be taken into consideration in a reviewing process. Localización: Biblioteca OET: NBINA-7699. Publicación no.: 325 Zonas edafoclimáticas aptas para especies forestales bajo escenarios de cambio climático: un estudio de caso en Costa Rica / Cervi-F., A.P.; Imbach-Bartol, P.A.; Vallejo, A.; Tito, M.R.; Pérez, C.J. (Universidade de São Paulo. Escola Superior de Agricultura "Luis de Queiroz", Piracicaba, Sao Paulo, BR <E-mail: pimbach@catie.ac.cr>). Turrialba: CATIE, s.f. Climate variability and climate change may cause shifts in optimal sites for competitive production of different forest tree species. This study explored the variation of current optimal soil and climatic conditions for five forest species of commercial value in Costa Rica: Tectona grandis L. f., Gmelina arborea (L.) Roxb., Cordia alliodora (Ruiz & Pav.) Oken, Hyeronimia alchorneoides Allemao, and Vochysia guatemalensis (Donn. Sm.). The study consisted of developing a tool that could be used for planning and adequate site selection considering climatic variables, actual and future under climate change scenario for year 2100. A review of bioecological requirements of the above species was conducted; digital maps of soil type's distribution, climate parameters, etc., were collected from national institutions. Climate scenarios were derived from the I National Communication to the UNFCCC. Interviews were conducted to obtain actual locations of current plantations of the above species. The study showsthat current optimal areas for commercial plantations suffer geographical shifts under the climate change scenario used. Optimal areas for T. grandis, C. alliodora and H. alchorneoides, decrease by 19.5%, 13.7% and 30.8%, respectively. For G. arborea andV. guatemalensis, optima areas increase 4.5% and 21.1%, respectively. The study concludes that selection of appropriate plantation sites will require the consideration of climate change scenarios otherwise the competitiveness of timber production may be at stakes. Further efforts are needed to allocate digital positioning coordinates for forest plantation sites and trees used as seed sources. This will enable a better evaluation of the potential of current plantations and future site selection. Localización: Biblioteca OET: NBINA-7710.

Publicación no.: 326 The social impacts of carbon markets in Costa Rica: A case study of the Huetar Norte region [Los impactos sociales de los mercados del carbono en Costa Rica: Estudio de caso de la región Huetar Norte] / Miranda-Quirós, M.; Porras, I.T.; Moreno-Díaz, M.L. (Universidad Nacional. Centro Internacional en Política Económica para el Desarrollo Sostenible, P.O. Box 555-3000, Heredia, CR <E-mail: mmiranda@una.ac.cr> <E-mail: ina.porras@iied.org> <E-mail: mmoreno una.ac.cr>). London: International Institute for Environment and Development (IIED), 2004. 47 p. This study assesses the impacts of the payments for environmental services (PES) programme in Costa Rica in relation to reforestation activities for the establishment of carbon sinks. The methodology used is the Sustainable Livelihoods Approach (SLA)which is based on five assets: financial, human, social, physical and natural. The study shows that the PES programme has had a significant impact on financial assets, not so much through the payments themselves but from the income expected from timber sales. The payments have acted as a catalyst for reforestation programmes, covering some of the initial outlay. However, the high transaction costs and obstacles to joining the scheme can preclude access to the PES for some of the most vulnerable groups who are dependent on other government programmes for their survival (e.g., peasants in receipt of housing support). There have been important benefits in terms of human assets through the provision of technical assistance and through ?learning by doing?,particularly in relation to reforestation. The PES programme has had a considerable impact on social organisation, encouraging alliances between NGOs and providing the financial and human capital to consolidate objectives in organisations working with small producers. There has been a positive impact on the recovery of forest landscapes in the area, contributing to improvements in natural assets, which in turn has brought benefits for tourism. There have also been negative effects, particularly in relation to physical assets, including the deterioration of existing infrastructure such as roads and bridges, through increased use. Localización: Biblioteca OET: NBINA-7712. Publicación no.: 327 First direct landscape-scale measurement of tropical rain forest Leaf Area Index, a key driver of global primary productivity / Clark, D.B.; Olivas, P.C.; Oberbauer, S.F.; Clark, D.A.; Ryan, M.G. (Organization for Tropical Studies. La Selva Biological Station, Apdo 676, San Pedro de Montes de Oca 2050, CR <E-mail: dbclark@sloth.ots.ac.cr> <E-mail: daclark@sloth.ots.ac.cr> <E-mail: oberbaue@fiu.edu>). In: Ecology Letters (ISSN 1461-023X), v. 11, p. 163-172. 2008. Leaf Area Index (leaf area per unit ground area, LAI) is a key driver of forest productivity but has never previously been measured directly at the landscape scale in tropical rain forest (TRF). We used a modular tower and stratified random sampling to harvest all foliage from forest floor to canopy top in 55 vertical transects (4.6 m2) across 500 ha of old growth in Costa Rica. Landscape LAI was 6.00 ± 0.32 SEM. Trees, palms and lianas accounted for 89% of the total, and trees and lianas were 95% of the upper canopy. All vertical transects were organized into quantitatively defined strata, partially resolving the long-standing controversy over canopy stratification in TRF. Total LAI was strongly correlated with forest height up to 21 m, while the number of canopy strata increased with forest height across the full height range. These data are a benchmark for understanding the structure and functional composition of TRF canopies at landscape scales, and also provide insights for improving ecosystem models and remote sensing validation. Localización: Biblioteca OET: NBINA-7839. Publicación no.: 328 A new initiative to use carbon trading for tropical forest conservation [Una nueva iniciativa para utilizar el comercio del carbono para la conservación del bosque tropical] / Laurance, W.F. (Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, PA). In: Biotropica (ISSN 0006-3606), v. 39, no. 1, p. 20-24. 2007. An alliance of 15 Developing Countries known as the Coalition for Rainforest Nations, led by Papua-New Guinea and Costa Rica, has attempted to revive efforts to use carbon credits to slow deforestation. This paper discusses the main features of this initiative, reasons of its rapidly gaining political support, as well as the technical and political challenges that may lie ahead. Localización: Non available. Publicación no.: 329 Emisión de gases de efecto invernadero y agricultura orgánica / Castro, J.; Amador, M. (Corporación Educativa para el Desarrollo Costarricense (CEDECO), Apdo. 209-1009, San José, CR <E-mail: cedeco_pigi@racsa.co.cr>). San José: CEDECO, 2006. 62 p. La problemática de gases invernadero, calentamiento global y cambio climático han ganado terreno en varios ámbitos de discusión. En academias científicas, centros de investigación, alianzas políticas globales y sociedad civil se presta mayor atenciónal comportamiento del hombre en su entorno y como esto influencia las condiciones climáticas globales. El contexto mundial recalca la necesidad de generar alternativas de índole global para distribuir responsabilidades y compromisos de solución a la problemática. Surgen nuevas dinámicas de cooperación que dan cabida al reconocimiento de servicios ambientales globales. La Corporación Educativa para el Desarrollo Costarricense (CEDECO) en una ONG vinculada históricamente al acompañamiento de procesos deapoyo a la gestión de la agricultura orgánica. Con el apoyo y coordinación del Instituto Humanista de Cooperación con Países en Desarrollo de los Países Bajos (HIVOS) y la Federación Mundial de Movimientos de Agricultura Orgánica (IFOAM), asume en el año2003 una investigación novedosa sobre el papel que juegan las fincas orgánicas alrededor de la emisión de gases con efecto invernadero. El proyecto pretende, mediante la investigación científica, generar metodologías que permitan validar la Agricultura Orgánica en su capacidad para mitigar del cambio climático mediante la reducción de emisiones de gases de invernadero y el secuestro de

carbono. Procura introducir elementos para la retribución de servicios ambientales, balances energéticos y el reconocimiento de la producción de alimentos sanos desde la finca orgánica para la sociedad. Se investigan 15 fincas de pequeños y medianos productores orgánicos en diferentes regiones de Costa Rica. Incluye diferentes cultivos y estados de avance en la producción orgánica (convencionales, transición, certificados). Se da un alto valor a la participación y aporte de los productores orgánicos en la solución de un problema de pertinencia global. Las metodologías desarrolladas abarcan principalmente en papel de las fincas en la mitigación de emisiones de óxidos nitrosos desde suelos, el secuestro y conservación de carbono en suelos, la eficiencia energética de la producción orgánica y la ganadería orgánica como opción de mitigación de gases de invernadero. Paralelamente se ejecutan mediciones socioeconómicas valorando factores que influencian los productores en la toma de decisiones para el manejo de sus fincas. Finalmente, se genera un modelo matemático de interpretación. Este modelo está compuesto de variables socioeconómicas y biológicas en fincas. El modelo es una herramienta para orientar la toma de decisiones en una estrategia integral del abordaje de la mitigación del cambio climático mediante la Agricultura Orgánica en regiones específicas. El presente documento presenta el enfoque metodológico generado por CEDECO para explicar las variables que influencian el manejo en una finca orgánica y como éste da cabida a la menor emisión de gases, la fijación de carbono y la producción de alimentos orgánicosa la sociedad. Localización: Biblioteca OET: NBINA-8128