A Look at Amazon Basin Seasonal Dynamics with the Biophysical ...

CHARCOAL DEPOSITION FROM TROPICAL VEGETATION IN BRAZIL: ACOMPARISON IN DIFFERENT REGIONS AND TIME SCALE1 Cordeiro, R.C., 3,1 Turcq, B., 1,3 Sifeddine, A., 1 Albuquerque, A.L.S., 2,1 Simões-Filho, F.F.L.(1) PROFIX/CNPq/ Departamento de Geoquímica, Universidade Federal Fluminense, Outeiro S.João Batista, Niterói, R.J., Brazil.rcampello@yahoo.com, tel/fax: 55216207025(2) Institute de Recherche pour le development(3) Instituto de Radioproteção e Dosimetria. Conselho de Energia NuclearFires records were obtained through the charcoal particles flux analyses in lacustrine sediments (daPata Lake, São Gabriel da Cachoeira (AM); N4 Lake, Carajás, PA; Dom Helvécio Lake, ParqueEstadual do Vale do Rio Doce, MG; and Caracaranã Lake, RR), resevoir sediment (Alta Floresta,MT), and an anual cicle of atmospheric deposition (Porto Velho, RO). The deposition of charcoals inthe sediments results from local or regional burns, caused by dry climates, associated or not toanthropogenic action. The highest charcoal fluxes values were obtained in the period of intenseland use change in Alta Floresta and in sediments that represent the medium Holocene in Serra SulCarajás region. The lowest values were found Lagoa da Pata in São Gabriel da Cachoeira, apronounced humid region in Amazon and in Porto Velho region, atmospheric deposition in a humidseason. Paleofires The deposition of charcoals in the sediments results from local or regional burns,caused by dry climates, associated or not to anthropogenic action. Thus, the charcoal analysescould have also a great importance in evaluating the impact of dry climates and human in differenttropical ecosystems. Determination of fire frequencies and dimensions in key areas of SouthAmerica, is a first step to understand the global carbon transference between terrestrial andatmospheric systems.