Dinâmica da metacomunidade de briófitas epifilas em florestas fragmentadas na Amazônia

Abstract

Studies of tropical plant communities which attempt to disentangle the principle mechanisms (connectivity and habitat quality) influencing their distributions across fragmented landscapes are scarce. Epiphyllous bryophytes, due to their spatially patchy distribution, high turnover and diversity of sexual systems, are an excellent model system with which to combine community and demographic data in light of life history traits to address what mechanisms control terrestrial plant distributions. In this work I studied a highly dynamic community, epiphyllous bryophyte, to investigate temporal changes in community structure in forest fragments and relate apparent changes with difference in life history traits in relation to more effective dispersers and physiological tolerance. By using baseline data on epiphyll assembly structure published from a study conducted at BDFFP over a decade ago, I sampled epiphyllous community in order to evaluate whether changes in species richness, abundance and composition have occurred in the intervening years. Based on previous results I test the following hypothesize: epiphyll community structure has changed in small (1- and 10-ha) to bias species presenting life history traits which favor increased dispersal capacity and physiological tolerance. For epiphyllous bryophytes we observed a degree of recovery in the abundance, species richness and composition in small fragments (1- and 10-ha), converging with 100 ha fragments and continuous forests. Positive changes in the epiphyllous community are related to adaptive life history traits related to species with greater dispersal capacity and physiological tolerance.