From dry to flooded, from Cerrado to Forest : scaling the CO2 and H2O atmospheric fluxes across tropical ecosystems
Humberto
Ribeiro da
Rocha, USP, humberto@model.iag.usp.br
(Presenting)
A number of micrometeorological flux towers in South America have collected continuous data of climate, soil moisture, soil respiration and surface-atmosphere turbulent fluxes of heat, CO2 and H2O along the last years. A large heterogeneity of biomes, ranging from savanna to tropical forests, have been investigated in LBA and outside LBA in South America. Particularly in Amazonia, the terra-firme tropical forest sites have been studied with strong emphasys, as long as flooded or varzea-type areas have had less attention.
Ecosystem’s gross and net primary productivity depend partly on the input of energy, what is partly correlated with the latitude. Other local factors also influence the productivity and water control, e.g. the soil type, geomorphology and topography. They all help to define the biome type, and the feedbacks between the climate and the local factors. The aim of this work is to select a few biomes, among tropical terra-firme forest, dry Cerrado, flooded Cerrado, over different latitudes, for a comparison. It is attempted to separate how much variables like water use efficienty, CO2 and H2O fluxes, are influenced by climate, and, on the other hand, by other local conditions. It is believed that we can quantify how the climate control the extremes of variability across the biomes, whereas local factors contrain the variability within the sub-classes.
Submetido por Humberto Rocha em 18-MAR-2004
Tema Científico do LBA: CD (Armazenamento e Trocas de Carbono)