Composition and structure of a riverine forest in southern Brazil

Riverine vegetation occupies one of the most dynamic areas of a landscape, and has species that are specialized and adapted to grow in a variety of disturbances. A phytosociological survey was conducted that aimed to describe the floristic and phytosociological structure of the tree component in a riverine forest on the Jaguarão River, in southern Brazil. We sampled all of the trees with DBH ≥ 5cm in 25 plots of 10 × 10m (0.25ha). The study recorded 725 live trees belonging to 27 species, 24 genera and 16 botanical families. Myrtaceae and Salicaceae had the highest species richness. The species with the highest values of cover (VC) and importance (VI) were Sebastiania commersoniana, Allophylus edulis, Eugenia uniflora and Pouteria salicifolia, which accounted for more than 80% of the total abundance. The diversity (H’) was estimated as 1.84nats.ind.-1 and the evenness (J’) as 0.56. We also found a high proportion of zoochorous species from initial and intermediate successional stages, which are mostly from the west contingent and widely distributed across southeastern and southern Brazil