Assessment of climate change impacts on the biomass and carbon dynamics in the Amazon

Abstract

The Amazon rainforest has proven crucial in the global climate feedback, acting as a strong carbon sink. However, empirical data show a decrease in carbon sequestration associated with increased tree mortality, which, in turn, may be associated with the climate variability. Nevertheless, it have not been found in the literature studies that address tree mortality mapping in Amazon level and a spatiotemporal investigation of its association with extreme weather events. The project aims to develop a multi-scale methodology for estimating dead biomass across the Amazon using remote sensing data and spectral mixture modeling techniques. The objective is to evaluate the impact of climate change on the biomass and carbon balance in Amazon related to tree mortality. Quantification of dead biomass will be evaluated on the scaling of field data (inventory data from the Amazon Forest Inventory Network - RAINFOR) to high spatial resolution Landsat images and medium spatial resolution MODIS images. We intend to answer the following questions: (1) how accurately is it possible to quantify the dead biomass using remote sensed data and for how long after the mortality event the dead biomass signal remain detectable; (2) is there a significant difference in the amount of dead biomass between "normal" years and years of extreme drought, such as 2005 and 2010; (3) is there significant difference in tree mortality between secondary successions and primary forest areas; and (4) how did tree mortality dynamics went in the past few decades in Amazon.