Taxonomic and morphological diversity of the ground-dwelling ant fauna in Eastern Amazonian grasslands

Amazonian grassland ecosystems are poorly understood, highly threatened, and under-protected. This study combined taxonomic and trait-based diversity approaches to provide the first description of the diversity of the ground-dwelling ant fauna of grasslands in Eastern Amazonia. We surveyed two types of open vegetation habitats: campinarana (unique to Amazonia; five sites) and savanna (two sites). Of the 89 ground-dwelling ant species we collected from pitfall traps, a few species were characteristic of open vegetation habitats. We found significant differences among these sites in terms of their species richness, which was positively associated with vegetation complexity. Morphological diversity, via species richness, was positively related to flooding and negatively related to soil cover. In conclusion, we observed some characteristic ant species of open vegetation habitats in Amazonian grasslands, and morphologically rich, ground-dwelling ant fauna. Further, a trait-based approach improved our understanding of community organization in the Amazon, which is the most bio-diverse tropical biome on Earth.