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Luděk Šefrna - One of the best experts on this subject based on the ideXlab platform.
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Climate in the Western Cordillera of the Central Andes over the last 4300 years
Quaternary Science Reviews, 2014Co-Authors: Zbyněk Engel, Grzegorz Skrzypek, Tomáš Chuman, Luděk Šefrna, Martin MihaljevičAbstract:Abstract The Distichia peat core obtained in the Carhuasanta valley near Nevado Mismi, Cordillera Chila, provides information on climatic and environmental conditions over the last ∼4300 years. The relative changes in the stable carbon isotope composition of plant remains preserved in the core reflect major temperature fluctuations in the Western Cordillera of the southern Peruvian Andes. These temperature variations can be additionally linked with the changes in precipitation patterns by analysing C% and C/N ratio in the core. Relatively warm and moist conditions prevailed from 4280 to 3040 cal. yrs BP (BC 2330–1090) with a short colder dry episode around 3850 cal. yrs BP (BC 1900). The most prominent climate changes recorded in the peat occurred between 3040 and 2750 cal. yrs BP (BC 1090–800) when the initial warming turned to a rapid cooling to temperatures at least 2 °C lower than the mean for the Late Holocene. Initially drier conditions within this event turned to a short wet phase after 2780 cal. yrs BP (BC 830) when the temperature increased again. This event coincides with significant changes in peat and ice core records in the Central Andes matching the timing of the global climate event around 2.8 cal. ka BP. Climatic conditions in the study area became relatively dry and stable after the event for about 800 years. Highly variable temperatures and humidity prevailed during the last 2000 years when an extended warm and relatively humid period occurred between 640 and 155 cal. yrs BP (AD 1310–1795) followed by predominantly colder and drier conditions. The established δ 13 C peat record represents the first continuous proxy for the temperature in the southern Peruvian Andes dated by the AMS 14 C. Distichia peat is wide spread in the Andes and the proposed approach can be applied elsewhere in high altitudes, where no other traditional climate proxies are available.
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Distichia peat a new stable isotope paleoclimate proxy for the andes
Earth and Planetary Science Letters, 2011Co-Authors: Grzegorz Skrzypek, Zbyněk Engel, Tomáš Chuman, Luděk ŠefrnaAbstract:article i nfo Global climate variability is a well-documented fact; however, the human contribution to climate change is now being vigorously debated. Therefore, a better understanding of past natural climate variability may help to establish the actual anthropogenic contribution to the observed climatic trend. A variety of high-resolution proxies now exist for documenting climate variability that has occurred in the northern hemisphere over the last 10 ka. In contrast, high-resolution paleoclimate records are more limited for regions such as high altitudes in the Andes/South America. However, many regions of the Andes contain a rich, but as yet overlooked, paleoclimate archive in the form of thick peat deposited in situ by the Distichia plant. In our study, based on altitudinal transect from the Peruvian Andes, we found a statistically significant and strong relationship between the stable carbon isotope composition of Distichia and air temperature (R=0.92 pb0.01). We also confirmed good preservation of relative differences in the original stable carbon isotope composition in peat derived from this plant. Our calibration showed that a decrease of ~0.97±0.23‰ in the stable carbon isotope composition of Distichia peat reflects a 1 °C increase in mean air temperature of the growing seasons. This relationship can be used as a new high-resolution proxy for reconstruction of paleotemperature variations over the past several thousand years in the Andes Mountains based on Distichia peat cores.
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Distichia peat — A new stable isotope paleoclimate proxy for the Andes
Earth and Planetary Science Letters, 2011Co-Authors: Grzegorz Skrzypek, Zbyněk Engel, Tomáš Chuman, Luděk ŠefrnaAbstract:article i nfo Global climate variability is a well-documented fact; however, the human contribution to climate change is now being vigorously debated. Therefore, a better understanding of past natural climate variability may help to establish the actual anthropogenic contribution to the observed climatic trend. A variety of high-resolution proxies now exist for documenting climate variability that has occurred in the northern hemisphere over the last 10 ka. In contrast, high-resolution paleoclimate records are more limited for regions such as high altitudes in the Andes/South America. However, many regions of the Andes contain a rich, but as yet overlooked, paleoclimate archive in the form of thick peat deposited in situ by the Distichia plant. In our study, based on altitudinal transect from the Peruvian Andes, we found a statistically significant and strong relationship between the stable carbon isotope composition of Distichia and air temperature (R=0.92 pb0.01). We also confirmed good preservation of relative differences in the original stable carbon isotope composition in peat derived from this plant. Our calibration showed that a decrease of ~0.97±0.23‰ in the stable carbon isotope composition of Distichia peat reflects a 1 °C increase in mean air temperature of the growing seasons. This relationship can be used as a new high-resolution proxy for reconstruction of paleotemperature variations over the past several thousand years in the Andes Mountains based on Distichia peat cores.
Grzegorz Skrzypek - One of the best experts on this subject based on the ideXlab platform.
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Climate in the Western Cordillera of the Central Andes over the last 4300 years
Quaternary Science Reviews, 2014Co-Authors: Zbyněk Engel, Grzegorz Skrzypek, Tomáš Chuman, Luděk Šefrna, Martin MihaljevičAbstract:Abstract The Distichia peat core obtained in the Carhuasanta valley near Nevado Mismi, Cordillera Chila, provides information on climatic and environmental conditions over the last ∼4300 years. The relative changes in the stable carbon isotope composition of plant remains preserved in the core reflect major temperature fluctuations in the Western Cordillera of the southern Peruvian Andes. These temperature variations can be additionally linked with the changes in precipitation patterns by analysing C% and C/N ratio in the core. Relatively warm and moist conditions prevailed from 4280 to 3040 cal. yrs BP (BC 2330–1090) with a short colder dry episode around 3850 cal. yrs BP (BC 1900). The most prominent climate changes recorded in the peat occurred between 3040 and 2750 cal. yrs BP (BC 1090–800) when the initial warming turned to a rapid cooling to temperatures at least 2 °C lower than the mean for the Late Holocene. Initially drier conditions within this event turned to a short wet phase after 2780 cal. yrs BP (BC 830) when the temperature increased again. This event coincides with significant changes in peat and ice core records in the Central Andes matching the timing of the global climate event around 2.8 cal. ka BP. Climatic conditions in the study area became relatively dry and stable after the event for about 800 years. Highly variable temperatures and humidity prevailed during the last 2000 years when an extended warm and relatively humid period occurred between 640 and 155 cal. yrs BP (AD 1310–1795) followed by predominantly colder and drier conditions. The established δ 13 C peat record represents the first continuous proxy for the temperature in the southern Peruvian Andes dated by the AMS 14 C. Distichia peat is wide spread in the Andes and the proposed approach can be applied elsewhere in high altitudes, where no other traditional climate proxies are available.
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Distichia peat a new stable isotope paleoclimate proxy for the andes
Earth and Planetary Science Letters, 2011Co-Authors: Grzegorz Skrzypek, Zbyněk Engel, Tomáš Chuman, Luděk ŠefrnaAbstract:article i nfo Global climate variability is a well-documented fact; however, the human contribution to climate change is now being vigorously debated. Therefore, a better understanding of past natural climate variability may help to establish the actual anthropogenic contribution to the observed climatic trend. A variety of high-resolution proxies now exist for documenting climate variability that has occurred in the northern hemisphere over the last 10 ka. In contrast, high-resolution paleoclimate records are more limited for regions such as high altitudes in the Andes/South America. However, many regions of the Andes contain a rich, but as yet overlooked, paleoclimate archive in the form of thick peat deposited in situ by the Distichia plant. In our study, based on altitudinal transect from the Peruvian Andes, we found a statistically significant and strong relationship between the stable carbon isotope composition of Distichia and air temperature (R=0.92 pb0.01). We also confirmed good preservation of relative differences in the original stable carbon isotope composition in peat derived from this plant. Our calibration showed that a decrease of ~0.97±0.23‰ in the stable carbon isotope composition of Distichia peat reflects a 1 °C increase in mean air temperature of the growing seasons. This relationship can be used as a new high-resolution proxy for reconstruction of paleotemperature variations over the past several thousand years in the Andes Mountains based on Distichia peat cores.
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Distichia peat — A new stable isotope paleoclimate proxy for the Andes
Earth and Planetary Science Letters, 2011Co-Authors: Grzegorz Skrzypek, Zbyněk Engel, Tomáš Chuman, Luděk ŠefrnaAbstract:article i nfo Global climate variability is a well-documented fact; however, the human contribution to climate change is now being vigorously debated. Therefore, a better understanding of past natural climate variability may help to establish the actual anthropogenic contribution to the observed climatic trend. A variety of high-resolution proxies now exist for documenting climate variability that has occurred in the northern hemisphere over the last 10 ka. In contrast, high-resolution paleoclimate records are more limited for regions such as high altitudes in the Andes/South America. However, many regions of the Andes contain a rich, but as yet overlooked, paleoclimate archive in the form of thick peat deposited in situ by the Distichia plant. In our study, based on altitudinal transect from the Peruvian Andes, we found a statistically significant and strong relationship between the stable carbon isotope composition of Distichia and air temperature (R=0.92 pb0.01). We also confirmed good preservation of relative differences in the original stable carbon isotope composition in peat derived from this plant. Our calibration showed that a decrease of ~0.97±0.23‰ in the stable carbon isotope composition of Distichia peat reflects a 1 °C increase in mean air temperature of the growing seasons. This relationship can be used as a new high-resolution proxy for reconstruction of paleotemperature variations over the past several thousand years in the Andes Mountains based on Distichia peat cores.
Zbyněk Engel - One of the best experts on this subject based on the ideXlab platform.
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Climate in the Western Cordillera of the Central Andes over the last 4300 years
Quaternary Science Reviews, 2014Co-Authors: Zbyněk Engel, Grzegorz Skrzypek, Tomáš Chuman, Luděk Šefrna, Martin MihaljevičAbstract:Abstract The Distichia peat core obtained in the Carhuasanta valley near Nevado Mismi, Cordillera Chila, provides information on climatic and environmental conditions over the last ∼4300 years. The relative changes in the stable carbon isotope composition of plant remains preserved in the core reflect major temperature fluctuations in the Western Cordillera of the southern Peruvian Andes. These temperature variations can be additionally linked with the changes in precipitation patterns by analysing C% and C/N ratio in the core. Relatively warm and moist conditions prevailed from 4280 to 3040 cal. yrs BP (BC 2330–1090) with a short colder dry episode around 3850 cal. yrs BP (BC 1900). The most prominent climate changes recorded in the peat occurred between 3040 and 2750 cal. yrs BP (BC 1090–800) when the initial warming turned to a rapid cooling to temperatures at least 2 °C lower than the mean for the Late Holocene. Initially drier conditions within this event turned to a short wet phase after 2780 cal. yrs BP (BC 830) when the temperature increased again. This event coincides with significant changes in peat and ice core records in the Central Andes matching the timing of the global climate event around 2.8 cal. ka BP. Climatic conditions in the study area became relatively dry and stable after the event for about 800 years. Highly variable temperatures and humidity prevailed during the last 2000 years when an extended warm and relatively humid period occurred between 640 and 155 cal. yrs BP (AD 1310–1795) followed by predominantly colder and drier conditions. The established δ 13 C peat record represents the first continuous proxy for the temperature in the southern Peruvian Andes dated by the AMS 14 C. Distichia peat is wide spread in the Andes and the proposed approach can be applied elsewhere in high altitudes, where no other traditional climate proxies are available.
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Distichia peat a new stable isotope paleoclimate proxy for the andes
Earth and Planetary Science Letters, 2011Co-Authors: Grzegorz Skrzypek, Zbyněk Engel, Tomáš Chuman, Luděk ŠefrnaAbstract:article i nfo Global climate variability is a well-documented fact; however, the human contribution to climate change is now being vigorously debated. Therefore, a better understanding of past natural climate variability may help to establish the actual anthropogenic contribution to the observed climatic trend. A variety of high-resolution proxies now exist for documenting climate variability that has occurred in the northern hemisphere over the last 10 ka. In contrast, high-resolution paleoclimate records are more limited for regions such as high altitudes in the Andes/South America. However, many regions of the Andes contain a rich, but as yet overlooked, paleoclimate archive in the form of thick peat deposited in situ by the Distichia plant. In our study, based on altitudinal transect from the Peruvian Andes, we found a statistically significant and strong relationship between the stable carbon isotope composition of Distichia and air temperature (R=0.92 pb0.01). We also confirmed good preservation of relative differences in the original stable carbon isotope composition in peat derived from this plant. Our calibration showed that a decrease of ~0.97±0.23‰ in the stable carbon isotope composition of Distichia peat reflects a 1 °C increase in mean air temperature of the growing seasons. This relationship can be used as a new high-resolution proxy for reconstruction of paleotemperature variations over the past several thousand years in the Andes Mountains based on Distichia peat cores.
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Distichia peat — A new stable isotope paleoclimate proxy for the Andes
Earth and Planetary Science Letters, 2011Co-Authors: Grzegorz Skrzypek, Zbyněk Engel, Tomáš Chuman, Luděk ŠefrnaAbstract:article i nfo Global climate variability is a well-documented fact; however, the human contribution to climate change is now being vigorously debated. Therefore, a better understanding of past natural climate variability may help to establish the actual anthropogenic contribution to the observed climatic trend. A variety of high-resolution proxies now exist for documenting climate variability that has occurred in the northern hemisphere over the last 10 ka. In contrast, high-resolution paleoclimate records are more limited for regions such as high altitudes in the Andes/South America. However, many regions of the Andes contain a rich, but as yet overlooked, paleoclimate archive in the form of thick peat deposited in situ by the Distichia plant. In our study, based on altitudinal transect from the Peruvian Andes, we found a statistically significant and strong relationship between the stable carbon isotope composition of Distichia and air temperature (R=0.92 pb0.01). We also confirmed good preservation of relative differences in the original stable carbon isotope composition in peat derived from this plant. Our calibration showed that a decrease of ~0.97±0.23‰ in the stable carbon isotope composition of Distichia peat reflects a 1 °C increase in mean air temperature of the growing seasons. This relationship can be used as a new high-resolution proxy for reconstruction of paleotemperature variations over the past several thousand years in the Andes Mountains based on Distichia peat cores.
Tomáš Chuman - One of the best experts on this subject based on the ideXlab platform.
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Climate in the Western Cordillera of the Central Andes over the last 4300 years
Quaternary Science Reviews, 2014Co-Authors: Zbyněk Engel, Grzegorz Skrzypek, Tomáš Chuman, Luděk Šefrna, Martin MihaljevičAbstract:Abstract The Distichia peat core obtained in the Carhuasanta valley near Nevado Mismi, Cordillera Chila, provides information on climatic and environmental conditions over the last ∼4300 years. The relative changes in the stable carbon isotope composition of plant remains preserved in the core reflect major temperature fluctuations in the Western Cordillera of the southern Peruvian Andes. These temperature variations can be additionally linked with the changes in precipitation patterns by analysing C% and C/N ratio in the core. Relatively warm and moist conditions prevailed from 4280 to 3040 cal. yrs BP (BC 2330–1090) with a short colder dry episode around 3850 cal. yrs BP (BC 1900). The most prominent climate changes recorded in the peat occurred between 3040 and 2750 cal. yrs BP (BC 1090–800) when the initial warming turned to a rapid cooling to temperatures at least 2 °C lower than the mean for the Late Holocene. Initially drier conditions within this event turned to a short wet phase after 2780 cal. yrs BP (BC 830) when the temperature increased again. This event coincides with significant changes in peat and ice core records in the Central Andes matching the timing of the global climate event around 2.8 cal. ka BP. Climatic conditions in the study area became relatively dry and stable after the event for about 800 years. Highly variable temperatures and humidity prevailed during the last 2000 years when an extended warm and relatively humid period occurred between 640 and 155 cal. yrs BP (AD 1310–1795) followed by predominantly colder and drier conditions. The established δ 13 C peat record represents the first continuous proxy for the temperature in the southern Peruvian Andes dated by the AMS 14 C. Distichia peat is wide spread in the Andes and the proposed approach can be applied elsewhere in high altitudes, where no other traditional climate proxies are available.
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Distichia peat a new stable isotope paleoclimate proxy for the andes
Earth and Planetary Science Letters, 2011Co-Authors: Grzegorz Skrzypek, Zbyněk Engel, Tomáš Chuman, Luděk ŠefrnaAbstract:article i nfo Global climate variability is a well-documented fact; however, the human contribution to climate change is now being vigorously debated. Therefore, a better understanding of past natural climate variability may help to establish the actual anthropogenic contribution to the observed climatic trend. A variety of high-resolution proxies now exist for documenting climate variability that has occurred in the northern hemisphere over the last 10 ka. In contrast, high-resolution paleoclimate records are more limited for regions such as high altitudes in the Andes/South America. However, many regions of the Andes contain a rich, but as yet overlooked, paleoclimate archive in the form of thick peat deposited in situ by the Distichia plant. In our study, based on altitudinal transect from the Peruvian Andes, we found a statistically significant and strong relationship between the stable carbon isotope composition of Distichia and air temperature (R=0.92 pb0.01). We also confirmed good preservation of relative differences in the original stable carbon isotope composition in peat derived from this plant. Our calibration showed that a decrease of ~0.97±0.23‰ in the stable carbon isotope composition of Distichia peat reflects a 1 °C increase in mean air temperature of the growing seasons. This relationship can be used as a new high-resolution proxy for reconstruction of paleotemperature variations over the past several thousand years in the Andes Mountains based on Distichia peat cores.
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Distichia peat — A new stable isotope paleoclimate proxy for the Andes
Earth and Planetary Science Letters, 2011Co-Authors: Grzegorz Skrzypek, Zbyněk Engel, Tomáš Chuman, Luděk ŠefrnaAbstract:article i nfo Global climate variability is a well-documented fact; however, the human contribution to climate change is now being vigorously debated. Therefore, a better understanding of past natural climate variability may help to establish the actual anthropogenic contribution to the observed climatic trend. A variety of high-resolution proxies now exist for documenting climate variability that has occurred in the northern hemisphere over the last 10 ka. In contrast, high-resolution paleoclimate records are more limited for regions such as high altitudes in the Andes/South America. However, many regions of the Andes contain a rich, but as yet overlooked, paleoclimate archive in the form of thick peat deposited in situ by the Distichia plant. In our study, based on altitudinal transect from the Peruvian Andes, we found a statistically significant and strong relationship between the stable carbon isotope composition of Distichia and air temperature (R=0.92 pb0.01). We also confirmed good preservation of relative differences in the original stable carbon isotope composition in peat derived from this plant. Our calibration showed that a decrease of ~0.97±0.23‰ in the stable carbon isotope composition of Distichia peat reflects a 1 °C increase in mean air temperature of the growing seasons. This relationship can be used as a new high-resolution proxy for reconstruction of paleotemperature variations over the past several thousand years in the Andes Mountains based on Distichia peat cores.
Anthelme Fabien - One of the best experts on this subject based on the ideXlab platform.
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Comunidades vegetales de los bofedales de la Cordillera Real (Bolivia) bajo el calentamiento global
Revista del Instituto de Ecología, 2015Co-Authors: Loza Herrera, Rosa Isela, Meneses R.i., Anthelme FabienAbstract:International audienceHigh-Andean wetlands (bofedales) are one of the most threatened ecosystems in the face of global warming. Given the close relationship between bofedales and water, it is expected that glacial retreat will cause their gradual shrinkage. With three proxies of climate change (bofedal area, glacier influence and elevation) we inferred how these changes may affect plant communities. The hypotheses were 1) that loss in the area of bofedales should reduce plant diversity - the glacier influence and elevation could affect this relationship through effect on environmental heterogeneity and diversity - and 2) glacial retreat may indirectly affect diversity through changes in dominant species. We measured ? and ? additive diversity of plants in 20 bofedales (>4.400 m) in the Cordillera Real (Bolivia). Sixty three species were found (species richness: 5-22 /plot 1 m2). Variations in bofedales área and glacial influence weren't correlated with vegetation changes whereas diversity reduced at higher elevation. In reference to our second hypothesis, leaves of Oxychloe andina were shown more resistant to drought stress because of its higher leaf dry mass content (LDMC) than the other cushions, indicating that the bofedales dominated by O. andina may be drier and the communities are dominated by species that also can be found in drier environments. In contrast, communities of Distichia spp. are less tolerant to water déficit. If glacial retreat reduces water availability in the coming decades, the bofedales of O. andina may be more abundant at the expense of Distichia spp. creating challenges for the biodiversity conservationLos humedales altoandinos (bofedales) son uno de los más amenazados frente al calentamiento global. Dada la estrecha relación entre bofedales y agua, el retroceso glacial podrá causar su contracción. Con tres proxis del cambio climático (área de bofedales, influencia glaciar y altitud) se infirió indirectamente cómo éstos pueden afectar a las comunidades vegetales. Las hipótesis fueron 1) que la reducción del área del bofedal podría afectar negativamente la diversidad de plantas - la influencia glaciar y la altitud podrían afectar ésta relación por su efectos en la heterogeneidad ambiental y la diversidad – y 2) que el retroceso glacial puede afectar indirectamente la diversidad a través de cambios en las especies dominantes. Se midió la diversidad α y β aditiva de plantas en 20 bofedales (>4.400 m) de la Cordillera Real (Bolivia). Se encontraron 63 especies (riqueza especifica: 5-22/cuadrante 1m²). Variaciones del área e influencia glacial no se relacionaron con cambios en la vegetación, pero la diversidad fue menor a mayor altitud. Las hojas de Oxychloe andina son más resistentes al estrés ambiental por su mayor masa foliar seca, a diferencia de Distichia spp., indicando que los bofedales dominados por O. andina son más secos. Además tienen más especies que también se pueden encontrar en las laderas. Mientras, las comunidades de Distichia spp. son menos tolerantes al déficit hídrico. Si el retroceso glacial reducirá el agua en las próximas décadas, el bofedal de O. andina podrá ser más abundante a expensas de los de Distichia spp., generando desafíos para la conservación. Oxychloe andina , Retroceso glacial
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Procesos ecológicos a múltiples escalas que afectan a las dinámicas de comunidades de plantas en los humedales altoandinos de Bolivia - Multi-scale ecological processes driving plant community dynamics in high-elevation peatlands of Bolivia
Revista del Instituto de Ecología, 2014Co-Authors: Munoz François, Anthelme Fabien, Raevel ValérieAbstract:National audienceProcesos ecológicos a múltiples escalas que afectan a las dinámicas de comunidades de plantas en los humedales altoandinos de Bolivia Multi-scale ecological processes driving plant community dynamics in high-elevation peatlands of Bolivia Resumen Algunas especies de plantas, dispuestas en forma de cojines, dominan y determinan el funcionamiento y la resiliencia de los humedales altoandinos (bofedales) frente al cambio climático y al derretimiento de los glaciares. Se tiene la hipótesis de que estas especies fundadoras influyen sobre el ambiente biótico y abiótico de las comunidades de plantas que habitan en los cojines. Se elaboró un esquema de meta-comunidad para investigar las dinámicas de las comunidades asociadas a dos especies de cojín dominantes, Oxychloe andina (OA) y Distichia muscoides (DM). En base a la composición funcional y florística, se propone un marco conceptual para evaluar la relativa influencia del filtro en base al nicho (en inglés: niche-based filtering) en contraste con los factores ambientales de OA y DM, la limitación de dispersión y la estocasticidad demográfica al conjunto de la comunidad. Los procesos del filtro en base al nicho pueden ser identificados mediante el análisis de la variación de los rasgos funcionales dentro y entre las comunidades y se selecciona un conjunto de especies relevantes para el análisis. Se propone un muestreo a múltiples escalas para abordar los efectos de la limitación de dispersión sobre las dinámicas de estos ecosistemas. Conjuntamente al supuesto básico del filtro en base al nicho, que básicamente diferencia las dinámicas de comunidad de los cojines de OA y DM, algunas covariantes ambientales también influyen de forma secundaria a la dinámica de comunidades en los cojines de OA. Palabras clave: Filtro en base al nicho, Interacciones entre plantas, Limitación de dispersión, Metacomunidades, Rasgos funcionales. Abstract A few dominant cushion plant species dominate and determine the functioning and resilience of high-elevation peatlands of Andes (bofedales), in the face of climate change and glacier melting. We hypothesize that these foundation species strongly influence the abiotic and biotic environment of plant communities inhabiting the cushions. We developed a metacommunity framework to investigate the dynamics of communities associated with two dominant cushion species, Oxychloe andina (OA) and Distichia muscoides (DM). Based on both taxonomical and functional composition, we propose a framework to assess the relative influence of niche-based filtering in contrasting OA and DM environments, dispersal limitation and demographic stochasticity to communit
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Métodos para estudiar el efecto del cambio climático sobre los bofedales y sus servicios ambientales inherentes
2014Co-Authors: Meneses R.i., Meneses R., Dangles Olivier, Garcia M.c., Naoki K., Anthelme FabienAbstract:Los bofedales son ecosistemas semi-acuáticos de la zona altoandina dominados por plantas en forma de cojín. Han sido y son usados para el pastoreo desde hace varias generaciones. Los herbívoros son conocidos por afectar la composición y riqueza de las especies en una comunidad vegetal. En bofedales el pastoreo, además de tener un efecto directo sobre la estructura de la comunidad, podría tener un efecto indirecto a través de cambios en las interacciones entre las especies dominantes (plantas en cojín) y sus especies acompañantes. En la Cordillera Real de Bolivia, los bofedales están formados principalmente por las plantas en cojín #Distichia muscoides$ y #Oxychloe andina$. Nuestro objetivo es proveer una lista de protocolos que permitirán identificar el impacto directo e indirecto de la herbivoría, a través de la modificación de los cojines expuestos al pastoreo y sobre la productividad y la biodiversidad de los bofedales. Discutimos métodos a nivel comunitario y poblacional, utilizando al mismo tiempo protocolos observacionales y experimentales. En particular explicamos en detalle un método experimental para excluir los herbívoros con cajas de exclusión en metal. Proponemos índices de rendimiento fisiológicos y morfológicos para seguir variaciones en plantas en cojín. (résumé d'auteur
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Métodos para estudiar el efecto del cambio climático sobre los bofedales y sus servicios ambientales inherentes
2014Co-Authors: Dangles Olivier, Meneses R., Munoz F., Anthelme FabienAbstract:Algunas especies de plantas, dispuestas en forma de cojines, dominan y determinan el funcionamiento y la resiliencia de los humedades altoandinos (bofedales) frente al cambio climático y al derretimiento de los glaciares. Se tiene la hipótesis de que estas especies fundadoras influyen sobre el ambiente biótico y abiótico de las comunidades de plantas que habitan en los cojines. Se elaboró un esquema de meta-comunidad para investigar las dinámicas de las comunidades asociadas a dos especies de cojín dominantes. #Oxychoe andina$ (OA) y #Distichia muscoides$ (DM). En base a la composición funcionaly florística, se propone un marco conceptual para evaluar la relativa influencia del filtro en base al nicho (en inglés: niche-based filtering) en contraste con los factores ambientales de OA y DM, la limitación de dispersión y la estocasticidad demográfica al conjunto de la comunidad. Los procesos del filtro en base al nicho pueden ser identificadas y se selecciona un conjunto de especies relevantes para el análisis. Se propone un muestreo a múltiples escalas para abordar los efectos de la limitación de dispersión sobre las dinámicas de estos ecosistemas. Conjuntamente al supuesto básico del filtro en base al nicho, que básicamente diferencia las dinámicas de comunidad de los cojines de OA y DM, algunas covariantes ambientales también influyen de forma secundaria a la dinámica de comunidades en los cojines de OA