Composition and species richness of ground-dwelling ants in tropical rainforest of Colombian inter-Andean valley

Tropical rainforests are characterized by having high structural complexity, stratification and species diversity. In Colombia tropical rainforests are critically endangered with only 24% remaining. We characterized the ant fauna associated with rainforest fragments and the surrounding landscape including: mature forests, flooded forests, gallery forests, live fences and pastures. Pitfall traps and mini - Winkler sacks were used to estimate ant diversity and relative abundance. We found 135 species from 41 genera, representing 15% of the species and 46% of the genera known for Colombia. The highest species richness was found in forest-covered sites, while richness and diversity was much lower in the most disturbed landscapes (F_5,66 = 168.98; P < 0.001). Species composition varied significantly between all habitat types (MRPP: A = 0.094; T = 5102; P < 0.001), being most similar between forest types and confirming that a loss of structural complexity has the greatest effect on ant communities. Across our study sites, 17 key species should the greatest response to the type of forest cover in the landscape. We conclude by discussing the value of conserving even small forest in this landscape due to their ability to retain high diversity of ants.