Biosphere-atmosphere interaction - Phase 2: cerrados and land use changes

Abstract

The Brazillian savanna (Cerrado) is the primitive bioma covering from the Southeast Brazil to South/East borders of Amazonia, and its area has reduced to 20%, being concerned as one of the most threathened ecosystems worldwide. Whereas the Southeast Brasil was deforested in the 19th century, its current land use as agrosystems has little knowledge in terms of sustainability. As well, in Amazonia, escalating soybean production and logging occurs by several means due to increasing deforestation, thus threathening the savanna wetlands near Ilha do Bananal (the world largest fluvial island), a zone of abundant life and water resources. This project proposes to quantify the long term dynamics of water, energy and CO2 fluxes over dry Cerrado (in Southeast Brazil) and seasonally flooded Cerrados (ecotones) in Bananal Island, and over the agrosystems Sugar Cane and Eucaliptus. The main issues to be adressed are to characterize and compare the ecophysiological functionality, dependency of climate and water availability; patterns of CO2 sink and sources of the ecosystems. It will investigate the impact of land use changes on the hydrological and carbon cycle on the catchment (observationally) and regional (numerical models) scales. Ecological investigation will be pursued in paralell, namely those of studying the carbon exchanges and pathways on the water, C & N cycling using isotope studies. Physical-climate investigations will study the large scale climate variability and its influence on the surface fluxes (and v.v.). This proposal encompasses researchers and objectives of three different programs: (i) the Biota Fapesp Program, (ii) the Large Scale Biosphere-Atmosphere Interaction Experiment in Amazonia (LBA) and (iii) the La Plata River Basin Experiment (PLATEX/GEWEX). (AU)