Processos locais e regionais que determinam a diversidade de formigas em Florestas Tropicais Secas Brasileiras

Abstract

Ecological processes operating at different temporal and spatial scales determine the distribution of diversity on the planet. At local scale, ecological processes such as interspecific interections, sum to abiotic conditions and resource (availability and variety) are more important. While at regional scale, historical processes, such speciation, extinction, and dispersion events are more important. 2. The present study aimed to understand how ecological processes determine ant community structure at different spatial scales. So, ant communities of Tropical Dry Forests (TDFs) (Cerrado, Cerrado-Caatinga transition and Caatinga) were evaluated, and the following hypotheses were tested: (i) the ant composition change along ecological succession gradient, and differs between FTSs inserted in different vegetation areas; (ii) the richness and density of trees determine the ant richness and beta diversity (β) in FTSs; and (iii) the richness and beta diversity (β) increase along ecological sucessional gradient in FTSs. 3. The FTSs studied have very different ant fauna with only eight species shared among them. FTS inserted in the transition was the richest in terms of species number, while the FTS inserted in the Cerrado showed the highest β diversity. Moreover, the richness and beta diversity of ants were positively affected by the wealth of trees in FTSs, only when regional scale was considered. 4. FTSs fragments inserted in different regions have different ant faunas, which possibly suffered strong influence of evolutionary history of each fragment, and ecological conditions of the vegetation domain in which they are inserted. Moreover, tree richness plays an important role as determinant of ants in FTSs at regional scale. We also emphasize the importance of conservation of transition regions, as they are key habitat that houses a wide number of species typical of more than one environment.