Modelagem de competição por luz e atributos funcionais de plantas sob aumento de [CO2] na Floresta Amazônica
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Data
2021-04-26
Autores
Cardeli, Bárbara Rocha
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Universidade Estadual Paulista (Unesp)
Resumo
As emissões de carbono na atmosfera, desde o início da Era Industrial (1750), aumentaram 40%, de 278 ppm (partes por milhão) para 413.61 ppm em 2020 (NOAA, 2021), por conta, principalmente, das atividades humanas. Estudos mostram que a concentração de CO 2 na atmosfera determina o resultado da competição entre a vegetação. Vários modelos dinâmicos da biosfera terrestre (os chamados Modelos Dinâmicos de Vegetação Global) foram desenvolvidos para melhor compreender a resposta da vegetação às perturbações humanas, usando princípios ecofisiológicos para modelar a distribuição dos tipos funcionais das plantas. O objetivo deste estudo foi compreender como a competição ecológica relacionada às características funcionais das plantas altera a resposta das plantas tropicais da Amazônia sob mudanças nas condições ambientais, para isso será investigado (i) como a competição por luz está atualmente representada nos modelos de vegetação terrestre e (ii) como o funcionamento ecológico da Floresta Amazônica será afetado pelo aumento de CO 2 em uma versão do modelo que considera a competição pela luz, usando o modelo CAETÊ-DGVM (CArbon and Ecosystem functional Trait Evaluation model). Serão selecionados dois atributos funcionais, que estão intimamente relacionados à competição por luz para serem tomados como os novos atributos variantes do modelo: densidade da madeira e área foliar específica. A avaliação dos resultados demonstrou que a versão do CAETÊ com a competição por luz aumentou consideravelmente os níveis de NPP e biomassa na Amazônia, além de ter impactado o estabelecimento de diferentes estratégias de vida de planta em todo o bioma em relação à versão anterior. O aumento de CO 2 contribuiu para o aumento da produtividade mas assegurou os mesmos padrões de biomassa de um clima regular, levantando hipóteses acerca da influência do mesmo sob diferentes atributos funcionais além dos simulados. Os resultados deste estudo demonstram os efeitos do aumento do CO 2 e de outros fatores que agem como importantes filtros ambientais para o funcionamento e estruturação da comunidade.
Carbon emissions into the atmosphere, since the beginning of the Industrial Age (1750), increased 40%, from 278 ppm (parts per million) to 413.61 ppm in 2020 (NOAA, 2021), mainly due to human activities. Studies show that the concentration of CO2 in the atmosphere determines the result of competition between vegetation. Several dynamic models of the terrestrial biosphere (the so-called Dynamic Models of Global Vegetation) have been developed to better understand the response of vegetation to human disturbances, using ecophysiological principles to model the distribution of plant functional types. The objective of this study was to understand how the ecological competition related to the functional characteristics of the plants changes the response of tropical plants in the Amazon under changes in environmental conditions, for that purpose it will be investigated (i) how the competition for light is currently represented in terrestrial vegetation models and (ii) how the ecological functioning of the Amazon rainforest will be affected by the increase in CO2 in a version of the model that considers competition for light, using the CAETÊ-DGVM model (CArbon and Ecosystem functional Trait Evaluation model). Two functional traits will be selected, which are closely related to the competition for light to be taken as the new variant attributes of the model: wood density and specific leaf area. The evaluation of the results demonstrated that the CAETÊ version with the competition for light increased considerably the levels of NPP and biomass in the Amazon, in addition to having impacted the establishment of different plant life strategies in the entire biome to the previous version. The increase in CO2 contributed to the increase in productivity but ensured the same biomass patterns as in a regular climate, raising hypotheses about its influence under different functional attributes in addition to the simulated ones. The results of this study demonstrate the effects of the climate and other factors that act as important environmental filters for the functioning and structuring of the community.
Carbon emissions into the atmosphere, since the beginning of the Industrial Age (1750), increased 40%, from 278 ppm (parts per million) to 413.61 ppm in 2020 (NOAA, 2021), mainly due to human activities. Studies show that the concentration of CO2 in the atmosphere determines the result of competition between vegetation. Several dynamic models of the terrestrial biosphere (the so-called Dynamic Models of Global Vegetation) have been developed to better understand the response of vegetation to human disturbances, using ecophysiological principles to model the distribution of plant functional types. The objective of this study was to understand how the ecological competition related to the functional characteristics of the plants changes the response of tropical plants in the Amazon under changes in environmental conditions, for that purpose it will be investigated (i) how the competition for light is currently represented in terrestrial vegetation models and (ii) how the ecological functioning of the Amazon rainforest will be affected by the increase in CO2 in a version of the model that considers competition for light, using the CAETÊ-DGVM model (CArbon and Ecosystem functional Trait Evaluation model). Two functional traits will be selected, which are closely related to the competition for light to be taken as the new variant attributes of the model: wood density and specific leaf area. The evaluation of the results demonstrated that the CAETÊ version with the competition for light increased considerably the levels of NPP and biomass in the Amazon, in addition to having impacted the establishment of different plant life strategies in the entire biome to the previous version. The increase in CO2 contributed to the increase in productivity but ensured the same biomass patterns as in a regular climate, raising hypotheses about its influence under different functional attributes in addition to the simulated ones. The results of this study demonstrate the effects of the climate and other factors that act as important environmental filters for the functioning and structuring of the community.
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Palavras-chave
Ecologia global, Ecologia funcional, Modelagem de ecossistemas, Mudanças climáticas, Competição, Global ecology, Functional ecology, Ecosystem modelling, Climate change, Competition