Structure and Functioning of Meso and Micro-Scale Watersheds of the São Paulo State: Basis to Generate and Sustain Biodiversity

Abstract

The paradigm of this project is that biodiversity in a watershed is generated and preserved by interactions between the physical environment, biogeochemical processes and human actions. Therefore based on this statement, biodiversity can not be properly addressed without a comprehensive characterization of the structure and functioning of a watershed. The Biota-Fapesp programe open an unique opportunity to closely investigate the effects of landscape attributes and ecosystem biogeochemistry on the biodiversity, since this programe encompass several studies devoted to these topics. In this project we intend to address the biogeochemistry of meso-sca1e (103 to 104 km2) and micro-sca1e (101 to 102 km2) watersheds as subsidiary information to understand the results of ongoing biodiversity studies of the Biota-Fapesp programe. The link between environmental factors and biodiversity will be made: (1) by working in the same basins or sub-basins of the BIOT ASP Projects devoted to address aquatic biodiversity and (2) through specific parameters and analysis that link landscape attributes and ecosystem biogeochemistry with those related to biodiversity. At the meso-scale level our specific objective is to determine if chemical and physical attributes of rivers and atmospheric composition respond differentially across a gradient of anthropogenic impacts. The approach in this case will be to compare meso-sca1e basins with different degrees of human impacts. The specific scientific questions to be answered are: Question 1- What are the effects of the domestic sewage, industrial effluents and land-use on carbon, nitrogen and phosphorus distributions in rivers under different degrees of impact? In order to answer Question 1 we intend to compare key parameters of aquatic biogeochemistry among watersheds with different levels of human impact. Question 2 - What are the effects of urbanization, industrial activities, and land-use on the atmospheric composition in watersheds under different degrees of impact? In order to answer Question 2 we propose to compare the wet and dry deposition in the selected watersheds. At micro-sca1e we intend to address the biogeochemistry of small watersheds in order to answer the following scientific questions: Question 2: Is biodiversity related with some measurable chemical or biological variable in the water? Question 3: Is biodiversity related with some measurable landscape attribute of the watershed and specifically those of the riparian zone? Our approach to answer these questions is to compare micro-scale watersheds within a gradient of biodiversity. (AU)