Major Ions Fluxes in Rainfall and Throughfall at Tapajos National Forest . Belterra, Para State
Raimundo
Cosme de
Oliveira Jr., Embrapa Amazonia Oriental, cosme@cpatu.embrapa.br
(Presenting)
Michael
M.
Keller, US Forest Service, michael.keller@unh.edu
Patrick
Michael
Crill, Sweden, patrick.crill@unh.edu
William
Zamboni de
Melo, Universidade Federal Fluminense, zamboni@geoq.uff.br
Jadson
Dizencourt
Dias, LBA - TG-07, jadson@lbaeco.com.br
Kêmeson
Oliveira, LBA - TG-07, kemeson@lbaeco.com.br
Eráclito
Rodrigues de
Sousa Neto, LBA - TG-07, eraclito@lbaeco.com.br
Sérgio
N. da Silva
Albuquerque, LBA - TG-07, sergio@lbaeco.com.br
Joelma
Dezencourt
Dias, LBA TG-07, joelma@lbaeco.com.br
Cleuton
Pereira, LBA - TG-07, cleuton@lbaeco.com.br
The Tapajós National Forest –(FLONA Tapajós), an area of 600.000 ha of protected forest, is located 50km south Santarem (Pará, Brasil). The FLONA receives approximately 2000 mm.y-1 of rainfall and the forest is evergreen. The tropical forest nutrient cycle depends upon inputs from the atmosphere and from rock weathering. Internally, throughfall and stemflow transfer nutrients from the vegetation to the ground. Concentrations of the ions Cl-, NO3-2, PO4-2, SO4-2, Na+, NH4+, K+, Mg+2 and Ca+2 were analyzed using a Dionex DX-120 ion chromatograph. Ionic fluxes were calculated from volume-weighted concentrations. The fluxes in precipitation follow the sequence: NH4+ (7,1 kg.ha-1.y-1) > Ca+2 (6,31 kg.ha-1.y-1) > Na+ (6,11 kg.ha-1.y-1) > K+ (4,41 kg.ha-1.y-1) > Cl- (3,61 kg.ha-1.y-1) > SO4-2 (3,11 kg.ha-1.y-1) > NO3-2 (1,31 kg.ha-1.y-1) > PO4-2 (1,11 kg.ha-1.y-1) > Mg+2 (1,01 kg.ha-1.y-1). In the throughfall, the fluxes were in the sequence: NO3-2 (31,8 kg.ha-1.y-1) > K+ (27,6 kg.ha-1.y-1) > NH4+ (25,5 kg.ha-1.y-1) > Na+ (17,4 kg.ha-1.y-1) > SO4-2 (15,6 kg.ha-1.y-1) > Cl- (14,5 kg.ha-1.y-1) > Ca+2 (12,7 kg.ha-1.y-1) > Mg+2 (11,1 kg.ha-1.y-1) > PO4-2 (10,8 kg.ha-1.y-1).
Submetido por Raimundo Cosme Oliveira Jr. em 16-MAR-2004