Leguminosae in an altitudinal gradient in the Atlantic Forest of Serra do Mar State Park, São Paulo, Brazil

Abstract

Studies on floristic and structural variations of forests in relation to altitude have contributed to the knowledge of patterns and causes of spatial distribution of plants in the Atlantic Forest. Geographical variables such as latitude, longitude and altitude result in different vegetation types, which limits newly established are not consensus. In the north coast of São Paulo state altitudes vary from the Restinga Forest, near the sea level, to the vegetation at the top of Cuscuzeiro Mountain at 1,279 m altitude. In order to evaluate the richness, taxonomic diversity, floristic similarity and the potential indicator of Leguminosae in the characterization of different vegetation types of Atlantic Forest on the northern coast of São Paulo, a matrix with the presence and absence of 142 species, in 15 different altitudinal belts was built. The greatest species richness was observed in the Restinga Forest (0-10 m), with 84 species, and in Montane Forest (500-1,200 m), with 69 species. The altitudinal belt with the highest number of tree species was 10-50 m, with 34 species. In the higher altitudes that number was significantly lower with six species of 1,100-1,200 m, and no species above this quota. The cluster analysis (Jaccard index) showed dissimilarity of the belts 0-10 m and 1,100-1,200 m in relation to the intermediate belts. The Lowland Forest and Submontane share the largest number of species (25). Some species characterize certain formations or have their preferred environment located at a specific elevation, as is the case of Abarema brachystachya and Inga subnuda (0-20 m), Inga lanceifolia, Inga mendoncaei and Ormosia minor (800-1,200 m). Distinguished for occupying all the phytophysiognomies: Abarema langsdorffii and Senna macranthera. Leguminosae, although well adapted to the first colonization and exploration of diverse environment, was poorly represented above 1,100 m altitude.