Sensitivity of the Amazon biome to high resolution climate change projections

Despite the reduction in deforestation rate in recent years, the impact of global warming by itself can cause changes in vegetation cover. The objective of this work was to investigate the possible changes on the major Brazilian biome, the Amazon Rainforest, under different climate change scenarios. The dynamic vegetation models may simulate changes in vegetation distribution and the biogeochemical processes due to climate change. Initially, the Inland dynamic vegetation model was forced with initial and boundary conditions provided by CFSR and the Eta regional climate model driven by the historical simulation of HadGEM2-ES. These simulations were validated using the Santarem tower data. In the second part, we assess the impact of a future climate change on the Amazon biome by applying the Inland model forced with regional climate change projections. The projections show that some areas of rainforest in the Amazon region are replaced by deciduous forest type and grassland in RCP4.5 scenario and only by grassland in RCP8.5 scenario at the end of this century. The model indicates a reduction of approximately 9% in the area of tropical forest in RCP4.5 scenario and a further reduction in the RCP8.5 scenario of about 50% in the eastern region of Amazon. Although the increase of CO sub(2) atmospheric concentration may favour the growth of trees, the projections of Eta-HadGEM2-ES show increase of temperature and reduction of rainfall in the Amazon region, which caused the forest degradation in these simulations.Original Abstract: Apesar da reducao na taxa de desmatamento nos ultimos anos, o impacto do aquecimento global por si so pode causar alteracoes na cobertura vegetal. O Objetivo deste trabalho foi investigar as possiveis alteracoes no maior bioma brasileiro, a Floresta Amazonica, levando em consideracao diferentes cenarios de mudancas climaticas. Os modelos de vegetacao dinamica permitem representar as mudancas na distribuicao de vegetacao bem como nos processos biogeoquimicos diante de mudancas no clima. Na primeira parte do trabalho, o modelo de vegetacao dinamica Inland foi forcado com condicoes iniciais e de contorno geradas a partir de dados de reanalise (CFSR) e pela regionalizacao da simulacao historica de um modelo global do sistema terrestre (HadGEM2-ES) com o modelo Eta. Estas simulacoes foram validadas utilizando os dados da torre de Santarem-K83. Na segunda parte, avaliou-se o impacto de uma futura mudanca climatica sobre o bioma floresta atrav