Urbanization is associated with ant species turnover without detectable changes in functional diversity in the Cerrado hotspot

Urbanization is one of the main anthropogenic pressures on biodiversity, altering patterns of richness, diversity, and composition of biological communities. Ants are particularly interesting for investigating urbanization effects on biodiversity because they are diverse, abundant, sensitive to environmental changes, and mediate multiple ecological functions. However, the response of taxonomic and functional structure to urbanization remains overlooked in tropical ecosystems such as the Brazilian Cerrado. Here, we investigated spatial variation of ant communities across a continuous urbanization gradient encompassing 30 areas within a huge Cerrado reserve in central-western Brazil. During the rainy season of 2025, we sampled ants using pitfall traps at five points along a 150-m transect placed in each area, totalling 150 samples. Additionally, we quantified urbanization by assessing human population density and the proportion of built-up area within a 1-km buffer around each area. We found no significant effect of urbanization on the richness or functional diversity of ants. Nevertheless, we observed shifts in species composition along the gradient, suggesting changes in community assembly with increasing urbanization. Further, beta-diversity partitioning revealed high spatial variation across the landscape, driven primarily by species turnover. Our findings suggest that large and well-preserved Cerrado fragments can sustain ant richness and functional diversity despite the urban pressure in their adjacencies. However, increasing urbanization along the edges of native vegetation fragments may, over the long term, compromise the ecological services supported by biological communities. We advocate the importance of conserving large, well-preserved native urban remains as they function as refuges for ant biodiversity in increasingly urbanized landscapes.