Relação entre solo, vegetação e topografia em área de cerrado (Parque Estadual de Vassununga, SP): Como se expressa em mapeamentos?

Abstract

Relationships among vegetation, soil and topography maps were investigated in the Pé-de-Gigante Reserve (2137'30''S; 4737'30''W, SP). The studied area is the Paulicéia river basin, where soils are predominantly sandy and the vegetation includes a gradient of savanna physiognomies and patches of semideciduous forest, wet fields, and riparian forest. The cartographic material included: a) pre-existent vegetation map, b) topographic map based on 5 m contour curves, and c) a soil map based on chemical and physical soil features (soil samples collected at 54 sites at 0-5, 5-25, 40-60 e 80-100 cm depths) and aerial photographs (1988, 1:40.000). These maps were reclassified to generate secondary maps at different levels of detail, and overlayed through a geographic information system. Contingency tables were generated, and chi-squared values and Cramèr correlation coefficients were obtained to investigate the relationships between the maps. The semideciduous forest showed a strong correlation with the Oxissols; "campo cerrado" was associated to 620-650 m altitudes, probably due to sub-surface water dynamics. The refinement of the mapped information did not add to the interpretation of the relationships among soil, vegetation and topography, as the vegetation physiognomy does not respond directly nor independently to topography or to the usual soil classification.