Biogeochemical dynamics in meso-scale rivers of the Amazon Basin and their response to anthropogenic change

• Grant number: 99/01159-4
• Support Opportunities: Research Projects - Thematic Grants
• Start date: March 01, 2000
• End date: April 30, 2004
• Field of knowledge: Biological Sciences - Ecology - Ecosystems Ecology
• Principal Investigator: Reynaldo Luiz Victória
• Grantee: Reynaldo Luiz Victória
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Pesquisadores principais: Plínio Barbosa de Camargo
• Associated scholarship(s): 03/07676-8 - Development of automated processes employing flux analysis for the determination of total nitrogen and phosphorus dissolved in samples from the Amazon River, BP.IC; 02/08684-1 - The role of carboxylic acids of low molecular weight in the biogeochemical cycle of carbon in rivers of the Amazon basin, BP.PD; 02/00155-0 - System for geographical information and classification of the capacity of land use applied in the diagnosis of intensity of use of the hydrographic basin of the river Ji-Paraná, Rondônia, BP.DR; 00/09030-0 - Occupation and use of land in the hydrographic basin of the Ji-Paraná (Rondônia): socio-economic-agricultural survey, BP.IC; 99/12263-7 - Studies of hydrological and hydrogeochemical processes in the drainage basin of the river Piracicaba, BP.PD

Abstract

Very little is known about the biogeochemistry of micro and meso scale rivers in the amazon region. Even less is known about the possible changes in the biogeochemical cycles resulting from the conversion of pastures to forests, which is the most common land use change in the region. Therefore, the main objective of this proposal is to study and understand how the conversion of forests into pastures change the distribution of carbon and nutrients (nitrogen and phosphorous), the primary production and its limiting factors, and the biodiversity in micro and micro scales of tropical rivers in the Amazon. The major questions to be answered are: question 1 - how are the quantity and composition of the organic matter and nutrients that are delivered to and processed within a river changed when the watershed land cover is changed from forest to pasture ? question 2 - does the primary production and its limiting factors change with the changes in land cover, and what are the effects of such changes in the dynamics of the organic matter? question 3 - what are the changes in the benthonic macroinvertebrate fauna in small streams when land use changes from forest to pasture? question 4 - are there detectable and persistent changes in the storage and flux of organic matter, nutrients and associated elements when evolving from micro to meso scale basins, and how is it related to changes in land use? To answer these questions we propose to compare pristine and deforested watersheds, at two scales: rnicro scale (~10km2) at the Fazenda Nova Vida, and meso scale using the Ji-Paraná river (~104km2). Emphasis will be given to the spatial and temporal variations of carbon, nitrogen and phosphorous. Changes in primary production related to the conversion of forest into pastures and also its abiotic (light) and nutritional (nitrogen and phosphorous) limiting factors will be studied. As for the biodiversity, changes in the population of macroinvertebrates along land use change gradients will be addressed. Finally, patterns of biogeochemical signatures will be followed along the micro and meso scales to access their spatial and temporal variations. Considering that water is one of the major driving forces of the biogeochemical cycles in drainage basins, parallel studies of key hydrological processes within the watersheds will be also addressed. The following products are expected as results of this project: a) a georeferenced data base on the structural attributes of the studied watersheds; b) increased knowledge ... (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DE FÁTIMA FL RASERA‚ M.; BALLESTER‚ M.V.R.; KRUSCHE‚ A.V.; SALIMON‚ C.; MONTEBELO‚ L.A.; ALIN‚ S.R.; VICTORIA‚ R.L.; RICHEY‚ J.E.. Estimating the surface area of small rivers in the southwestern Amazon and their role in CO2 outgassing. Earth Interactions, v. 12, n. 6, p. 1-16, 2008. (99/01159-4, 03/13172-2)

BERNARDES‚ M.C.; MARTINELLI‚ L.A.; KRUSCHE‚ A.V.; GUDEMAN‚ J.; MOREIRA‚ M.; VICTORIA‚ R.L.; OMETTO‚ J.P.H.B.; BALLESTER‚ M.V.R.; AUFDENKAMPE‚ A.K.; RICHEY‚ J.E.; et al. Riverine organic matter composition as a function of land use changes‚ southwest Amazon. Ecological Applications, v. 14, n. sp4, p. 263-279, 2004. (99/01159-4)