Functional diversity of plant communities at edge and interior of a submontane Atlantic Forest: greater functional than compositional stability

Abstract

We compared the functional diversity of community at edge and interior areas of an Atlantic forest fragment to test the hypothesis that higher functional diversity exists along edges - in consonance with their higher abundance and floristic diversity as compared to the interior of the forest. By considering a set of vegetative, reproductive and phenological traits and ecosystem service aspects of edge and interior environments, we defined plant functional groups using Cluster Analysis, followed by a silhouette width analysis, together with functional diversity indices of richness, divergence, evenness and dispersion. The main functional groups formed were similar between the edges and interior. Functional richness was the only index that demonstrated differences between edge and the interior. Alterations were perceived in relation to species richness and the Shannon index. Edge effects were not significant in the formation of functional groups. In contrast to our original hypothesis, similar groups were formed both along the edge in the interior - indicating that species played similar ecological roles in both environments, with similar responses to different environmental factors - so that forest edges were colonized by a series of different species that maintained diversity patterns similar to those found in the forest interior.

Key words:
artificial borders; Atlantic Forest; Chapada Diamantina; forest fragmentation; functional diversity