Floristic Characterization and Phytosociology of a Vegetation in a Caatinga Area in Brazil

The present study characterizes the floristic and phytosociological characters in the paraibano semiarid in Caatinga area. For the phytosociological survey 25, sample units with dimensions of 20 m x 20 m distributed randomly were used in order to collect the name of the species, the circumference at ground level (CFL), the circumference at breast height (CBH), the total height of the individuals and the state trees. The total surface of the area was 323.65 ha and 255.85 ha of shrub by arboreal vegetation what represent 79% of the area with vegetation, the remaining 21%, were classified as clean field, reservoirs, courses of water and highways, totaling 67.8 hectares. To the floristic composition 2.362 individuals were observed, which ones, 22 species belonged to 14 families. Considering the habit of the found species, 68% can be considered as arboreal and 32% as shrubby. The vegetation can be classified as a closed shrub-arboreal Caatinga. The most representative species and with the higher importance value (IV) in the area were Poincianella pyramidalis, Mimosa tenuiflora, Aspidosperma pyrifolium and Anadenanthera colubrina. The basal area average was 11.68 m²/ha. The species with higher basal area were P. pyramidalis, M. tenuiflora, A. colubrina and A. pyrifolium.