Evaluating community effects of a Keystone Ant, Azteca sericeasur, on Inga micheliana leaf litter decomposition in a shaded coffee agro‐ecosystem

Abstract

AbstractOur research examined the effect of Azteca sericeasur, a keystone arboreal ant, on the decomposition of leaf litter of the shade tree, Inga micheliana, in coffee agro‐ecosystems. This interaction is important in understanding spatial heterogeneity in decomposition. We hypothesized that A. sericeasur could affect leaf litter decomposition by excluding other ants, which could release decomposers, like collembolans, from predation pressure. Determining the relative strengths of these interactions can illuminate the importance of A. sericeasur in decomposition and nutrient cycling processes. We assessed the ant and arthropod communities surrounding 10 pairs of trees, where each pair included one shade tree with an established A. sericeasur nest. Tuna baits were used in conjunction with pitfall traps to assess the ant and arthropod community, and litterbags with I. micheliana leaf litter were used to assess rates of decomposition. The species richness of ants did not change in proximity to A. sericeasur nests, though the ant communities were distinct. Abundance of Collembola and community composition of other invertebrates did not change in the presence of A. sericeasur nests, and there were no differences in leaf litter decomposition rates. This contradicts past studies that suggest A. sericeasur reduces ant species richness in its territory. We suggest that other ants may avoid A. sericeasur by moving within and beneath the leaf litter. Our results indicate that there is no net effect of A. sericeasur on leaf litter decomposition.