99 research outputs found
Traditional Knowledge of Trees and Cultivated Plants in a Coastal Municipallity in Sao Paulo State, Brazil
Theoretical concepts of Historical Ecology were used to assess the traditional knowledge at one coastal region of São Paulo State, Pedro de Toledo Nucleus, at Serra do Mar State Park. Free listing exercises accessing semantic domains considered relevant to traditional knowledge were applied to local settlers. Forty-two interviews were carried out with adults (between 18 and 75 y.o.) regarding information on cultivated plants and trees that were part of the interviewees’ knowledge and data were analyzed through Smiths’ S, an index of data frequency. Results show that “cultivated plants” and “trees” are high psychological reality domains for that community. Methodological resources of cognitive anthropology which apply to the understanding of historical ecology showed to be high value multidisciplinary tools of easy and broad applicability on ecological studies.Os conceitos teóricos da Ecologia histórica foram utilizados para acessar o conhecimento tradicional em uma região litorânea do estado de São Paulo, Núcleo Pedro de Toledo, no Parque Estadual da Serra do Mar. Exercícios de listagem livre que acessam domínios semânticos considerados relevantes para o conhecimento tradicional foram aplicados aos moradores locais. Quarenta e duas entrevistas foram realizadas com adultos (entre 18 e 75 anos de idade) sobre as plantas cultivadas e árvores na região. Os conhecimentos e os dados dos entrevistados foram analisados através dos Smiths 'S, um índice de frequência de dados. Os resultados mostraram que as plantas cultivadas e árvores são domínios da realidade psicológica para essa comunidade. Recursos metodológicos da antropologia cognitiva que se aplicam para a compreensão da ecologia histórica mostraram-se de alto valor como ferramenta multidisciplinar e de fácil e ampla aplicabilidade em estudos ecológicos
CARACTERIZAÇÃO DA ARBORIZAÇÃO URBANA NO BAIRRO CENTRO DO MUNICÍPIO DE IBITINGA/SP
Na tentativa de minimizar os impactos gerados pela intensiva urbanização tornou-se comum a prática da arborização urbana, a fim de harmonizar esteticamente o ambiente das cidades. Este trabalho teve por objetivo avaliar os espécimes utilizados na arborização das ruas no bairro Centro do município de Ibitinga/SP. Para isto, foram realizados levantamentos quali-quantitativos em duas avenidas e 12 ruas, perfazendo uma área de 27 quarteirões. Foram amostrados 242 indivíduos, distribuídos em 22 espécies e 15 famílias botânicas. A maioria das espécies presente é exótica (63,64%) e as mais frequentes são Ligustrum lucidum (45,04%) e Licania tomentosa (26,45%). Os resultados apontam baixos valores de diversidade, elevados índices de pragas e alto registro de conflitos com a rede aérea. Verifica-se a necessidade de uma arborização mais diversificada bem como a seleção de espécies através de critérios técnicos na região estudada
Roads & SDGs, tradeoffs and synergies: learning from Brazil's Amazon in distinguishing frontiers
To inform the search for SDG synergies in infrastructure provision, and to reduce SDG tradeoffs, the authors show that road impacts on Brazilian Amazon forests have varied significantly across settings. Forest loss varied predictably with prior development – both prior roads and prior deforestation – and in a spatial pattern suggesting a synergy between forests and urban growth in such frontiers. Examining multiple roads investments, the authors estimate impact for settings of high, medium and low prior roads and deforestation. Census-tract observations are numerous for each setting and reveal a pattern, not consistent with endogeneity, that confirms our predictions for this kind of frontier. Impacts are: low after relatively high prior development; larger for medium prior development, at the forest margin; then low again for low prior development. For the latter setting, the authors note that in such isolated areas, interactions with conservation policies influence forest impacts over time. These Amazonian results suggest 'SDG strategic' locations of infrastructure, an idea they suggest for other frontiers while highlighting differences in those frontiers and their SDG opportunities
Interannual and spatial impacts of phenological transitions, growing season length, and spring and autumn temperatures on carbon sequestration: A North America flux data synthesis
Understanding feedbacks of ecosystem carbon sequestration to climate change is an urgent step in developing future ecosystem models. Using 187 site-years of flux data observed at 24 sites covering three plant functional types (i.e. evergreen forests (EF), deciduous forests (DF) and non-forest ecosystems (NF) (e.g., crop, grassland, wetland)) in North America, we present an analysis of both interannual and spatial relationships between annual net ecosystem production (NEP) and phenological indicators, including the flux-based carbon uptake period (CUP) and its transitions, degree-day-derived growing season length (GSL), and spring and autumn temperatures. Diverse responses were acquired between annul NEP and these indicators across PFTs. Forest ecosystems showed consistent patterns and sensitivities in the responses of annual NEP to CUP and its transitions both interannually and spatially. The NF ecosystems, on the contrary, exhibited different trends between interannual and spatial relationships. The impact of CUP onset on annual NEP in NF ecosystems was interannually negative but spatially positive. Generally, the GSL was observed to be a likely good indicator of annual NEP for all PFTs both interannually and spatially, although with relatively moderate correlations in NF sites. Both spring and autumn temperatures were positively correlated with annual NEP across sites while this potential was greatly reduced temporally with only negative impacts of autumn temperature on annual NEP in DF sites. Our analysis showed that DF ecosystems have the highest efficiency in accumulating NEP from warmer spring temperature and prolonged GSL, suggesting that future climate warming will favor deciduous species over evergreen species, and supporting the earlier observation that ecosystems with the greatest net carbon uptake have the longest GSL
Interannual and spatial impacts of phenological transitions, growing season length, and spring and autumn temperatures on carbon sequestration: A North America flux data synthesis
Understanding feedbacks of ecosystem carbon sequestration to climate change is an urgent step in developing future ecosystem models. Using 187 site-years of flux data observed at 24 sites covering three plant functional types (i.e. evergreen forests (EF), deciduous forests (DF) and non-forest ecosystems (NF) (e.g., crop, grassland, wetland)) in North America, we present an analysis of both interannual and spatial relationships between annual net ecosystem production (NEP) and phenological indicators, including the flux-based carbon uptake period (CUP) and its transitions, degree-day-derived growing season length (GSL), and spring and autumn temperatures. Diverse responses were acquired between annul NEP and these indicators across PFTs. Forest ecosystems showed consistent patterns and sensitivities in the responses of annual NEP to CUP and its transitions both interannually and spatially. The NF ecosystems, on the contrary, exhibited different trends between interannual and spatial relationships. The impact of CUP onset on annual NEP in NF ecosystems was interannually negative but spatially positive. Generally, the GSL was observed to be a likely good indicator of annual NEP for all PFTs both interannually and spatially, although with relatively moderate correlations in NF sites. Both spring and autumn temperatures were positively correlated with annual NEP across sites while this potential was greatly reduced temporally with only negative impacts of autumn temperature on annual NEP in DF sites. Our analysis showed that DF ecosystems have the highest efficiency in accumulating NEP from warmer spring temperature and prolonged GSL, suggesting that future climate warming will favor deciduous species over evergreen species, and supporting the earlier observation that ecosystems with the greatest net carbon uptake have the longest GSL
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Terrestrial biosphere models need better representation of vegetation phenology: results from the North American Carbon Program Site Synthesis
Phenology, by controlling the seasonal activity of vegetation on the land surface, plays a fundamental role in regulating photosynthesis and other ecosystem processes, as well as competitive interactions and feedbacks to the climate system. We conducted an analysis to evaluate the representation of phenology, and the associated seasonality of ecosystem-scale CO2 exchange, in 14 models participating in the North American Carbon Program Site Synthesis. Model predictions were evaluated using long-term measurements (emphasizing the period 2000-2006) from 10 forested sites within the AmeriFlux and Fluxnet-Canada networks. In deciduous forests, almost all models consistently predicted that the growing season started earlier, and ended later, than was actually observed; biases of 2 weeks or more were typical. For these sites, most models were also unable to explain more than a small fraction of the observed interannual variability in phenological transition dates. Finally, for deciduous forests, misrepresentation of the seasonal cycle resulted in over-prediction of gross ecosystem photosynthesis by +160 ± 145 g C m-2 y-1 during the spring transition period, and +75 ± 130 g C m-2 y-1 during the autumn transition period (13% and 8% annual productivity, respectively) compensating for the tendency of most models to under-predict the magnitude of peak summertime photosynthetic rates. Models did a better job of predicting the seasonality of CO2 exchange for evergreen forests. These results highlight the need for improved understanding of the environmental controls on vegetation phenology, and incorporation of this knowledge into better phenological models. Existing models are unlikely to predict future responses of phenology to climate change accurately, and therefore will misrepresent the seasonality and interannual variability of key biosphere-atmosphere feedbacks and interactions in coupled global climate models.Engineering and Applied SciencesOrganismic and Evolutionary Biolog
Causality guided machine learning model on wetland CH4 emissions across global wetlands
Wetland CH4 emissions are among the most uncertain components of the global CH4 budget. The complex nature of wetland CH4 processes makes it challenging to identify causal relationships for improving our understanding and predictability of CH4 emissions. In this study, we used the flux measurements of CH4 from eddy covariance towers (30 sites from 4 wetlands types: bog, fen, marsh, and wet tundra) to construct a causality-constrained machine learning (ML) framework to explain the regulative factors and to capture CH4 emissions at sub -seasonal scale. We found that soil temperature is the dominant factor for CH4 emissions in all studied wetland types. Ecosystem respiration (CO2) and gross primary productivity exert controls at bog, fen, and marsh sites with lagged responses of days to weeks. Integrating these asynchronous environmental and biological causal relationships in predictive models significantly improved model performance. More importantly, modeled CH4 emissions differed by up to a factor of 4 under a +1C warming scenario when causality constraints were considered. These results highlight the significant role of causality in modeling wetland CH(4 )emissions especially under future warming conditions, while traditional data-driven ML models may reproduce observations for the wrong reasons. Our proposed causality-guided model could benefit predictive modeling, large-scale upscaling, data gap-filling, and surrogate modeling of wetland CH4 emissions within earth system land models
Causality guided machine learning model on wetland CH4 emissions across global wetlands
Wetland CH4 emissions are among the most uncertain components of the global CH4 budget. The complex nature of wetland CH4 processes makes it challenging to identify causal relationships for improving our understanding and predictability of CH4 emissions. In this study, we used the flux measurements of CH4 from eddy covariance towers (30 sites from 4 wetlands types: bog, fen, marsh, and wet tundra) to construct a causality-constrained machine learning (ML) framework to explain the regulative factors and to capture CH4 emissions at sub -seasonal scale. We found that soil temperature is the dominant factor for CH4 emissions in all studied wetland types. Ecosystem respiration (CO2) and gross primary productivity exert controls at bog, fen, and marsh sites with lagged responses of days to weeks. Integrating these asynchronous environmental and biological causal relationships in predictive models significantly improved model performance. More importantly, modeled CH4 emissions differed by up to a factor of 4 under a +1C warming scenario when causality constraints were considered. These results highlight the significant role of causality in modeling wetland CH(4 )emissions especially under future warming conditions, while traditional data-driven ML models may reproduce observations for the wrong reasons. Our proposed causality-guided model could benefit predictive modeling, large-scale upscaling, data gap-filling, and surrogate modeling of wetland CH4 emissions within earth system land models.Peer reviewe
Causality guided machine learning model on wetland CH4 emissions across global wetlands
Wetland CH4 emissions are among the most uncertain components of the global CH4 budget. The complex nature of wetland CH4 processes makes it challenging to identify causal relationships for improving our understanding and predictability of CH4 emissions. In this study, we used the flux measurements of CH4 from eddy covariance towers (30 sites from 4 wetlands types: bog, fen, marsh, and wet tundra) to construct a causality-constrained machine learning (ML) framework to explain the regulative factors and to capture CH4 emissions at sub -seasonal scale. We found that soil temperature is the dominant factor for CH4 emissions in all studied wetland types. Ecosystem respiration (CO2) and gross primary productivity exert controls at bog, fen, and marsh sites with lagged responses of days to weeks. Integrating these asynchronous environmental and biological causal relationships in predictive models significantly improved model performance. More importantly, modeled CH4 emissions differed by up to a factor of 4 under a +1C warming scenario when causality constraints were considered. These results highlight the significant role of causality in modeling wetland CH(4 )emissions especially under future warming conditions, while traditional data-driven ML models may reproduce observations for the wrong reasons. Our proposed causality-guided model could benefit predictive modeling, large-scale upscaling, data gap-filling, and surrogate modeling of wetland CH4 emissions within earth system land models.Peer reviewe
Substantial hysteresis in emergent temperature sensitivity of global wetland CH4 emissions
Wetland methane (CH4) emissions (FCH4) are important in global carbon budgets and climate change assessments. Currently, FCH4 projections rely on prescribed static temperature sensitivity that varies among biogeochemical models. Meta-analyses have proposed a consistent FCH4 temperature dependence across spatial scales for use in models; however, site-level studies demonstrate that FCH4 are often controlled by factors beyond temperature. Here, we evaluate the relationship between FCH4 and temperature using observations from the FLUXNET-CH4 database. Measurements collected across the globe show substantial seasonal hysteresis between FCH4 and temperature, suggesting larger FCH4 sensitivity to temperature later in the frost-free season (about 77% of site-years). Results derived from a machine-learning model and several regression models highlight the importance of representing the large spatial and temporal variability within site-years and ecosystem types. Mechanistic advancements in biogeochemical model parameterization and detailed measurements in factors modulating CH4 production are thus needed to improve global CH4 budget assessments. Wetland methane emissions contribute to global warming, and are oversimplified in climate models. Here the authors use eddy covariance measurements from 48 global sites to demonstrate seasonal hysteresis in methane-temperature relationships and suggest the importance of microbial processes.Peer reviewe
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