Variação na sazonalidade e estratificação em uma área de transição Amazônia-Cerrado : influencia no brilho e tamanho de formigas (Hymenoptera : Formicidae)

Abstract

Understanding the distribution of species across the planet is crucial for developing conservation tactics, especially in ecotone areas such as the Amazon-Cerrado transition. Due to the marked seasonality in this ecotone, the environment functions as a filter for species. Thus, only adapted species can forage in different seasons or strata. Ants serve as excellent models for studying how this filter affects the community throughout the seasons, as their nests remain stable year-round, individuals occur in various strata, and they possess morphological and physiological characteristics enabling them to occupy these microhabitats. Two characteristics ensuring resistance to dry and hot environments are color and size. Therefore, to evaluate the distribution pattern of ants in soil and vegetation over two seasons (dry and rainy) and how this influences ant sizes and colors, ants were collected in the Xingu State Park-MT, an ecotone area. Ants were collected in both seasons using pitfall traps for soil and vegetation. Size and color (brightness) measurements were taken of the species collected in both stations and strata. In total, 2,659 occurrences of ants were recorded, distributed across 237 species, 53 genera, and 8 subfamilies. We observed that, generally, richness is greater in the dry season, especially in the soil. The component contributing most to beta diversity is species replacement (turnover). However, this is not temporally stable, as during the rainy season, ground ants typically climb vegetation, contributing to nesting. We also found larger ants in the vegetation and smaller ones in the soil, as well as darker individuals in the vegetation during the dry season. These findings help to understand how ant diversity behaves in response to environmental filters in Amazon-Cerrado transition areas.