Análise da estrutura taxonômica, funcional e filogenética de comunidade de formigas em áreas savânicas e florestais do Cerrado.

Abstract

To understand how communities are organized is one of the most important questions in community studies. It is known that not just one, but several species characteristics can be used to answer such question. For this reason, lately there has been an increase in the number of studies in ecology that have opted for the use of taxonomic, functional and phylogenetic information in order to obtain knowledge about the organization of communities. Thus, in my first chapter, I compared the taxonomic and phylogenetic diversity of ant communities sampled in savanna and forest habitats in the Cerrado domain and in a disjunct area, in the Amazon basin. The alpha diversity analyses have shown that savanna and forest communities differ in terms of species composition. However, there were no differences in taxonomic and phylogenetic diversity. On the other hand, the beta diversity analyses demonstrated increases in taxonomic and phylogenetic dissimilarity between habitats as geographic and environmental distances increased. In the second chapter, I used the multiple diversity indices to understand the structure of ant communities along a vegetation gradient. Previous studies along the field-savanna-forest gradient in the region showed changes in the composition of ant species despite the little variation in taxonomic richness in most of this gradient. However, there are no studies that have assessed how the functional and phylogenetic diversity of ant communities varies due to changes in vegetation cover. To answer these questions, I analyzed the functional and phylogenetic diversity in a combined way, which allowed me to consider the dependence between these two information sources (functional and phylogenetic) to define the diversity of ant communities. In this way, I was able to identify whether both information sources are generating similar patterns or not. In general, I found that the communities sampled along this vegetation gradient did not show significant differences in terms of functional-phylogenetic diversity. However, the open savanna and semi-deciduous forest showed a tendency to differ from other habitats. When a greater importance to the functional distances was given, the open savanna and semideciduous forest showed the highest and lowest diversity, respectively. This result may indicate competition and habitat filtering as important ecological processes for the structure of these communities. However, according to the results of community structure, most of the observed values did not differ from the null models, which indicates a random structure pattern.