Composição florística e estrutura fitossociológica de uma floresta ripária em Itutinga, MG, e comparação com outras áreas

Abstract

The floristic composition and phytosociological structure were investigated in an area of 7.55 ha of a riparian forest in Itutinga, State of Minas Gerais, Southeastern Brazil. This forest locates alongside a narrow creek, and is sharply bounded by montane grasslands. The phytosociological survey was done on 28 plots of 10 x 30 m where all individuals with diameter at the base of the trunk equal to or larger than 5 cm were recorded and had their diameter measured and height estimated. The floristic survey was based on specimens collected both in and outside the plots. The study area was compared with other forests of Sao Paulo and Minas Gerais States using multivariate analyses. The floristic survey recorded 162 species and 54 families. The forests with flora most similar to the study area were those in the same region (upper rio Grande). We suggest rainfall seasonality and altitude as the variables most strongly influencing the floristic differences among the forests compared. The phytosociological survey recorded 2145 individuals in 141 species. The highest structural similarities occurred with forests in Itutinga and Bom Sucesso, followed by Madre de Deus and Poco Bonito. We suggest differences and similarities in soil properties, topographic features and the occurrence of seasonal floods as the main variables influencing the pattern of similarity observed.