Comunidade de formigas em áreas de Cerrado: Qual história elas nos contam sobre os últimos doze anos?

Abstract

How biological communities change over time and how these communities respond to disturbances are two long-standing and fundamental questions in ecology. The study of fire ecology in the Cerrado has become increasingly important, as the increase in the frequency and extent of fires can lead to a decline in biodiversity. Ants are frequently used as model organisms in studies on the effects of fire on fauna, as they are among the most diverse and abundant animal groups in terrestrial ecosystems and can be used as bioindicators of community changes. Studies on ant communities have been carried out in various parts of the Cerrado, including the Triângulo Mineiro region and southeastern Goiás—the region where the TMSG “site” is located, which has been part of the PELD (Long-Term Ecological Research Program) program since 2012. In particular, two conservation units have been monitored: REP, located in Uberlândia, and PESCAN, located in Caldas Novas. The present study evaluates the extent to which the diversity and composition of ground-dwelling ant communities changed over the past 12 years and whether the magnitude of these potential changes differs between the two conservation units. To do this, the study assessed temporal changes in the diversity and abundance of genera and selected species groups (fungus-growing ants, poneromorphs, and Cephalotes), determined the temporal dissimilarity in species composition within each reserve (assessing the relative importance of turnover and nestedness in the observed dissimilarity), and related changes in biodiversity patterns to possible temporal changes in vegetation and climate. Sampling was conducted in 2012 and 2023 at REP and in 2011 and again in 2023 at PESCAN. Pitfall traps were used, distributed across 10 points per transect (2 in REP and 3 in PESCAN). NDVI, temperature, and rainfall data were also collected. Analyses included the Bray-Curtis dissimilarity index, individual-based rarefaction curves, and the Sørensen index. The results of this study indicate a trend of decreasing genus richness in PESCAN and a high rate of turnover in both genera and species at REP, along with increased vegetation density in both areas, despite the fires at REP which may be responsible for the higher turnover rate observed in that reserve. Although ground-dwelling ants are generally resilient to the effects of fire, the results of this study indicate that temporal changes in communities do occur, particularly in areas affected by high-severity fires.