Estrutura de comunidade de aves em florestas seca e úmida no Nordeste da América do Sul

Abstract

In the past few years, many researches have been trying to explain biological diversity patterns as consequences of many processes involving species coexistence and community organization. Some phylogenetic and functional tools, as well as complex ecological networks, have been used for this purpose. Under this perspective, in this study we aimed to assess how bird assemblages are organized, considering both their ecology and history (First chapter) and the ecological interactions among organisms (Second chapter) in altitude forests of South America Northeast region. First, we selected 29 bird assemblages both in rain forest and in seasonally dry environments. We assessed the phylogenetic and functional structure of these assemblages in different scales through the net related index (NRI) and the nearest taxon index (NTI). Also, we verified which functional traits could have influenced the community assembly though a principal coordinate analysis (PCoA) and a phylogenetic principal component analysis (pPCA). We found that the rain forest-related bird assemblage differs from the seasonally dry forest-related assemblage regarding their phylogenetic and functional organization. Lastly, we analyzed the structural characteristics of the bird-food items networks of two altitude forests, one being a rain forest and the other a seasonally dry forest. Based on the networks characteristics found here, we observed that both networks were modular and not-nested, which points to a structural similarity between both forests. Nevertheless, differences regarding resource availability and seasonality may reveal particularities of each bird-food item network.