ANÁLISE FITOSSOCIOLÓGICA DE UM FRAGMENTO DE FLORESTA ESTACIONAL EM UMA CATENA DE SOLOS NO MORRO DO CERRITO, SANTA MARIA, RS PHYTOSOCIOLOGICAL ANALYSIS OF A FRAGMENT OF SEASONAL FOREST FOUND IN THE SOIL CATENA ON MORRO DO CERRITO IN SANTA MARIA, RS, BRAZIL

ABSTRACT This research took place in a semi-deciduous forest fragment in secondary succession stages on Morro do Cerrito in the municipality of Santa Maria, in the state of Rio Grande do Sul. The aim was to determine the floristic groups in the study area by quantifying the sociology of main species and their relationship with geomorphologic and pedological compartments. Permanent plots measuring 10m 2 were continuously allocated along the topographical gradient of the hill, beginning at the base and going to the top. All trees with a 5 cm diameter at breast height were measured. Analysis was performed by grouping divisive hierarchical method (Twinspan), having as variables the number of individuals of the species and characterized the sites of groups by testing in the field of geomorphological compartments and morphological and chemical analysis of soils. Three ecological groups were found evenly distributed along the gradient as a result of different successions and environmental conditions that were due mainly to the substrate, the soil classes, and landscape positions.