Interação entre ecossistemas terrestres e a atmosfera na Amazônia: conexões biogeofísicas e biogeoquímicas

• Ano de defesa: 2006
• Autor(a) principal: Pereira, Marcos Paulo Santos
• Orientador(a): Costa, Marcos Heil
• Banca de defesa: Lima, Francisca Zenaide de , Grimm, Alice Marlene
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Meteorologia Agrícola
• Departamento: Agrometeorologia; Climatologia; Micrometeorologia
• País: BR
• Palavras-chave em Português: Climatologia; Modelagem; Desmatamento; Amazônia; Dióxido de carbono atmosférico; Ecologia das florestas tropicais
• Palavras-chave em Inglês: Climate; Modeling; Deforestation; Amazonia; Atmospheric carbon dioxide; Tropical forest ecology
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::METEOROLOGIA::CLIMATOLOGIA
• Link de acesso: http://locus.ufv.br/handle/123456789/5290

The Amazon is considered by many one of the most important areas of the planet, including extensive areas of tropical forest. However, the forest has been dramatically modified by the deforestation changes in the CO2 concentration night also affect the forest structure. This work aims at better understand the biosphere-atmosphere interaction in the Amazonian, including both the biogeophysical and the biogeochemical effects of this interaction. For this purpose, an atmosphere general circulation model (CCM3), coupled to the surface model (IBIS), was used. Seven simulations were run: control simulation (F), partial deforestation (D), radiative effects of CO2 (FR), radiative and ecological effects of CO2 (FRE), radiative and ecological effects of CO2 considering the feedback biogeochemical of the vegetation in the carbon cycle (FREB), partial deforestation with the radiative and ecological effects of CO2 (DRE), and partial deforestation with the radiative and ecological effects of CO2 considering the biogeochemical feedback of the vegetation in the carbon cycle (DREB). In these simulations, the effect of the deforestation modify the exchange of energy and water, with more significant changes in the dry season, showing an increase in the albedo in the deforested area, causing a decrease in the evapotranspiration and in the precipitation. The radiative effect of the increase in the CO2 concentration increased the availability of energy at the surface, increasing the sensible heat flux, temperature, and affecting the precipitation, but does not cause changes in the annual mean evapotranspiration. The increase of CO2 concentration alter the structure of the Amazonian forest, increasing LAI and the biomass of the Amazonian basin by 0.61 kg C.m-2, causing a decrease in the precipitation, evapotranspiration and in the latent and sensible heat fluxes. The biogeochemical effect of the vegetation growth, under conditions of total forest and partial deforestation, is noticed in a decrease in the atmospheric CO2 concentration, small changes in climate, showing a decrease in the radiation balance and temperature.