Diversidade beta e distribuição espacial de espermatófitas, anfíbios, aves e primatas em fragmentos florestais no Sudeste do Brasil

Abstract

Diversity analysis by partition is an approach employed in order to understand how communities structure themselves spatially and the factors that operate in the generation and maintenance of distribution patterns. We examined species diversity’s spatial structure regarding four taxonomic groups, with different dispersal abilities, in 16 localities (forest fragments) in the southern region of Minas Gerais state. Specifically, we tested: i) if the similarity in species composition would be negatively related to geographical distance between the fragments; ii) if beta diversity shown by each group could be negatively related to their dispersal abilities. Both the alpha diversity and the compositional similarity between localities were low. Beta diversity, for none of the groups, was not correlated with distance. Primates, followed by birds, showed higher tendency of forming similarity groupings, although in a manner that was independent from distance, as well as the lowest beta diversity relative values. Spermatophytes and amphibians did not define groupings and presented, relatively, the highest values of beta diversity. We interpreted such results as indications that groups with higher dispersal ability (primates and birds) tend to reach, in average, farther localities and, therefore, to define more similar groupings (low beta diversity). Groups with lower dispersal ability (spermatophytes and amphibians) showed the opposite tendency. Although most of the species presented occurrence restricted to few localities, contributing to the low similarity, beta and gamma diversities showed how much the localities are, respectively, different and complementary to each other in terms of species composition. Such features reinforce and justify, in some way, future conservation initiatives both in local and regional scope.