Effects of Treefall Gap Disturbances on Ant Assemblages in a Tropical Montane Cloud Forest

The study of gap dynamics and the effects of gaps on diversity has been at the center of tropical ecology for decades. While most studies have focused on the responses of plant species and communities to gap formation, in this study, we consider the effects of treefall gap disturbances on leaf litter ant assemblages in a Neotropical montane cloud forest. We sampled leaf litter ant assemblages and estimated a suite of abiotic parameters in 12 large (>80-m2) treefall gaps across a chronosequence and in 12 paired adjacent intact forest sites in the Monteverde Cloud Forest Preserve in Costa Rica. No species were more common in gaps than in intact forests, and in fact, species that were common in gaps were also among the most common in forests. The Chao2 estimate of species richness, however, was higher in gap sites than in intact forest sites. In addition, ant assemblages in gap sites did not become more similar to those in adjacent intact sites as gaps aged. In contrast to other studies, our work demonstrates that ant assemblages in the Monteverde Cloud Forest Preserve are weakly affected by the formation of treefall gaps. Together, these results indicate that treefall gap dynamics probably play little role in promoting ant diversity at more regional scales, or coexistence among species at more local scales.