Availability of Nutrients in Solutions in a Gallery Forest of Cerrado Biome
Lucilia
Parron, Embrapa e UnB, lucilia@tecnolink.com.br
(Presenting)
Mercedes
Maria Cunha
Bustamante, UnB, mercedes@unb.br
Daniel
Markewitz, University of Georgia, dmarke@smokey.forestry.uga.edu
Cesar
Prado, UPIS, cesarjardim@hotmail.com.br
Gallery forests represents 5% of the Cerrado biome (savannas of Central Brazil) but contains 1/3 of its biodiversity. They protect water quality, control soil erosion and are important corridors for the fauna. In Central Brazil, gallery forests are characterized by a high heterogeneity particularly due to topographic variations that determine important variations of the soils conditions. Our objective was to characterize the fluxes of nutrients in solutions in a gallery forest (atmospheric deposition, throughfall, litter leachate and soil solution). The experiment was established in a plot of 100 x 100 m in the Gallery Forest of the Corrego Pitoco, in the Reserva Ecologica do IBGE, DF (15°56'41''S and 47°56'07 ' 'W). Three sampling lines were established, parallel to the stream and 45 m apart to each other. The lines represent the wet community (near the stream), intermediate community and dry community (adjacent to a typical Cerrado area). The mean fluxes of NO3-, TOC, K+, Ca2+, Mg2+ and Cl- in throughfall were greater than in the atmospheric deposition, indicating that these elements are being leached from canopy. On the other hand, the fluxes of Ntotal, NH4+, Norganic, Ptotal, Na+ and SO42- were lower in throughfall than in the atmospheric deposition, indicating that these nutrients are being retained in the canopy. The Corganic, Ntotal, NO3-, NH4+, Norganic, K+, Ca2+, Mg2+ and Cl- fluxes in litter leachate were greater than in throughfall while Ptotal, SO42- and Na+ fluxes were lower, indicating that these nutrients are being retained in the litter. The fluxes in throughfall and litter leachate were in the order: Corganic > K+ > Ca2+ > Cl- > Mg2+ > Ntotal > SO42- > Na+ > Ptotal.
Submetido por Lucilia Parron em 25-MAR-2004
Tema Científico do LBA: SH (Hidrologia e Química das Águas)