Efeitos de solos e topografia sobre a distribuição de espécies arbóreas em um fragmento de floresta estacional semidecidual, em Luminárias, MG

Abstract

The objective of the present study was to analyze the correlations between tree species distribution and environmental variables in a fragment of tropical seasonal forest in Luminárias, SE Brazil. The fragment, locally known as "Mata do Galego", has an area of c. 77ha, and is located on the margin of the Ingaí River at the coordinates 21°29'S and 44°55'WG. The survey of the tree community, soils and topography was carried out through systematic sampling with 32 sample plots with 20 x 20m distributed on three transects which extended from the river margin to the forest edge. In these plots, all living individual trees with circumference at breast height (cbh) ≥ 15.5cm were recorded. Soil chemical and physical variables were obtained from the analysis of topsoil samples (0-20cm) taken from the center of each plot. Topographic variables were obtained from a topographic survey of the plots and adjacent areas. The survey recorded 2343 individuals belonging to 159 species, 109 genera, and 50 families. The gradient analysis; performed through principal components analysis (PCA), canonical correspondence analysis (CCA), and detrended correspondence analysis (DCA); indicated that the plots located near the forest edge and transitional to the montane grasslands are the most differentiated. Variables related to soil pH and texture produced the strongest correlations with the distribution of tree species.