Avaliação das comunidades de formigas em uma área de extração madeireira

Abstract

This work presents a comparative study of ant fauna communities inhabiting in a primary tropical forest and two types of logging systems (Managed and Traditional) located in Paragominas, PA, Brazil. From each area, ants were sampled using pitfall traps (Majer & Delabie 1994) in six 200m transects separated from each other by 100m. Differences in ant fauna diversity in the three forest types were tested using índices of diversity (Shannon, Simpson and Fisher's Alpha) and richness estimates protocols (Colwell Coddington 1994). Species composition was evaluated through affinity analysis (Scheiner 1992) and indices of similarity (jaccard and Morisita-Horn). A total of 134 ant species belonging to seven subfamilies and 42 genera were identified in the entire area. From these, 90 species were found in Primary Forest, 90 in Managed logged forest and 84 in the Traditional logged Forest. Differences between habitats could be detected by comparing diversity and similarity indices in different transects/habitats. There were no differences in índices when absolute values were compared for each habitat. Results from richness estimate protocols indicate that ant fauna was similar between habitats and suggests that ant fauna diversity was underestimated. Periodic variations on pluviosity had a strong effect on diversity and richness estimates in the three forest types. The ant fauna composition was similar between habitats; however, a high mosaic diversity could be detected by using affinity analysis, suggesting that the ant community is composed of complex gradients. Thus differences in ant composition would be detectable at smaller scales.