Rela？？o entre a presen？a de vegeta？？o herbácea e a regenera？？o natural de espécies lenhosas em pastagens abandonadas na Floresta Ombrófila Densa do Sul do Brasil

deforestation and conversion of forests to pasture is one of the most degrading activities impacting the atlantic rain forest. we analyzed pastures abandoned for 8, 14, 48, 50 and 96 months in antonina (paraná state; 25o19'15'' s; 45o24'24'' w) to verify if herb cover reduces the natural regeneration of the atlantic forest. we identified species and assessed shoot biomass of herbaceous species (in 24 1 m2 plots), and calculated the volume of all woody species (height > 1m; in 24 25 m2 plots). we collected 59 herbaceous species (1,062 individuals) most of which were allochthonous species (95%), including brachiaria decumbens and b. humidicola. we also sampled 104 woody species (2,234 individuals). there were significant floristic and structural changes in the community during the first four years since the pasture was abandoned. woody vegetation development was negatively related to herb species' biomass, suggesting that grasses (b. decumbens) inhibited forest regeneration. our results suggested that management, including brachiaria spp removal, is necessary for the restoration of abandoned pastures in the atlantic forest region.