Abstract

Ecological filters play a significant role in shaping communities by excluding species based on their morphological, physiological, and behavioral adaptations. Ants are excellent models for studying the effects of these filters, as their traits enable them to occupy a wide range of microhabitats. Individual characteristics, such as color and size, allow some species to overcome environmental filtering. In this study, we investigated how microhabitat and seasonality influence the distribution patterns of ants and how these patterns are shaped by the ants' size and color. The study was conducted in the highly diverse Amazon-Cerrado transition zone, where the regional species pool includes a mix of species from both phytophysiognomies as well as endemic species. We collected ants using pitfall traps placed in the soil and vegetation, and we measured the color and size of individuals from each species. In total, we recorded 2,659 ant occurrences, distributed across 236 species, 53 genera, and 8 subfamilies. Our results showed that ant species richness is higher during the dry season, particularly in the soil. Differences between strata and seasons were primarily driven by species turnover. However, this turnover was not consistent, as some soil-dwelling ants, particularly the large and light-colored ones, migrated to the vegetation during the rainy season, contributing to a nestedness pattern across seasons and strata. Furthermore, larger ants were consistently found in the vegetation, whereas smaller ants were more commonly observed in the soil. This indicates an interaction between biological and environmental filters in determining local communities, as the relaxation of environmental filters can allow ground-dwelling ants to forage on lower vegetation. These findings provide valuable insights into community assembly across different seasons and emphasize that a snapshot approach to community assessment may lead to incomplete conclusions about species richness and community dynamics.