Ground-dwelling ant diversity in Amazonian secondary forests and neighboring pastures

The expansion of livestock farming is one of the main causes of deforestation in the Brazilian Amazon. Intensive land use for beef production can cause changes, affecting native fauna composition and species richness. Ants are important organism of soil biota in tropical forests, mainly for their ecological attributes and their remarkable abundance. We investigated the effects of habitat loss by livestock farming on the richness and composition of ground-dwelling ants in the Brazilian Amazon. Ants were captured in five areas of secondary forests and pastures using pitfall traps for 48 h. Our results showed that the ant richness did not differ between habitats (p = 0.89). However, the species composition was different, resulting in two segregated clusters: one formed by forest areas and one by those of pasture. An indicator species analysis underscored the occurrence of three species that can be considered typical of the secondary forest, while a subset of four species from pasture, which probably tolerate land-use disturbance by livestock farming. Our results suggest the importance of maintaining secondary forests for biodiversity conservation and that livestock farming directly affects the taxonomic composition of ant species in the Amazonian biome.