NATURAL REGENERATION MECHANISMS IN MIXED SUBTROPICAL WET FOREST REMNANT, RS, BRAZIL

This study aimed to characterize the mechanisms of natural regeneration in a Mixed Subtropical Wet Forest remnant. The study was conducted in the National Forest of Sao Francisco de Paula, RS, Brazil, using six conglomerates (I ha), with 16 plots (20 x 20 m) each, disregarding 10 m surround. The sampling of the seed rain (SR) was carried out in 96 circular collectors (1 m(2)), distributed in the center of each plot. The soil seed bank (SB) was sampled randomly in a distance of 3 m of each SR collector and the seedling bank (SeB) was sampled in plots of 2 x 2 m, located 4 m from SR collectors, counting the number of individuals (height >= 30 cm and diameter at breast height (DBH) < 1 cm) for each species. The regeneration mechanisms were evaluated through the floristic composition and horizontal structure. In SR, were sampled 81 species, 46 genera and 28 families, in SB, 103, 65 and 41, and in SeB, 88, 57 and 36, respectively The richness found and the presence of species with abundant fruiting and seed dispersal by animals, indicate the importance of seed rain as a strategic mechanism for the balance of flora and fauna in the ecosystem. The soil seed bank demonstrates potential for colonization and immediate restoration of vegetation after disturbances and the seedling bank is the main strategy for regeneration of many tree species that make up the current structure of the forest.