Seasonality of Epigaeic Ant Communities in a Brazilian Atlantic Rainforest

Abstract

In this study we assessed the leaf-litter ant community in the Cicuta Forest, a semi-deciduous forest located in the state of Rio de Janeiro, southeastern Brazil. Specifically, we tested the following hypotheses: (1) ant richness and diversity are higher in the rainy season, due to higher resource availability and better temperature and humidity conditions; and that (2) the structure of the ant community is influenced by climate seasonality. We collected 83 ant species of 35 genera and eight subfamilies. In total, 64 species were collected in the dry season and 73 species in the rainy season. Based on rarefaction curves with confidence intervals, we observed that species richness in the dry and rainy seasons did not differ significantly from each other. Diversity did not differ significantly (t = -1.20; P = 0.23) between the dry (3.43) and rainy seasons (3.52). Community structure did not differ between the dry and rainy seasons (NMDS followed by ANOSIM: r = 0.048, P < 0.001). We did not observe a significant effect of climate seasonality neither on ant species composition, richness, and diversity, nor on community structure. These results may be explained by the degree of isolation and degradation of this forest remnant. In short, our study contributes to knowledge on how seasonal variations affects ant communities.