Regeneração de espécies arbóreas sob a influência de Merostachys multiramea Hack. (Poaceae) em uma floresta subtropical

Abstract

The occurrence of bamboo species is common in several forest physiognomies, and the high abundance of these species may affect the regeneration of other ones. We evaluated bothtree species and Merostachys multiramea Hack. recruitment in a transition area between mixed Araucaria rain forest and seasonal semideciduous forests in southern Brazil. We compared the regeneration structure of the areas evaluated two and four years after flowering, fruiting and deathof M. multiramea. We randomly distributed 25 100 m2 sampling units, and surveyed all living culms of M. multiramea and tree saplings. We sampled 4,372 living bamboos and 2,918 tree saplings, belonging to 32 plant families and 75 species. Most species were classified as zoochorous and canopy light-demanding. On the other hand, plant abundance revealed a greater contribution of autochorous, understory and shade-tolerant trees. M. multiramea density was higher over the four years after the reproductive event (p<0.05), withtaller culms (p<0.01), but withthe same mean number of culms (p=0.46). A NPMANOVA revealed significant differences in composition and abundance between surveys, withhigher similarity among samplings two years after the reproductive event of M. multiramea. We also detected higher species richness over the study period, which was found to be directly associated withthe abundance of M. multiramea (p=0.002), but withlower evenness of abundance among regenerating species.