Habitat structure shapes ant diversity in Amazonian white-sand ecosystems.

This article investigates the taxonomic and functional diversity of ant assemblages in two types of Amazonian white-sand ecosystems (WSEs)—open white-sand campinas (WSC) and white-sand forests (WSF)—across two biogeographical regions in northern Brazil: Reserva de Desenvolvimento Sustentável do Rio Negro (RDS Rio Negro) and Parque Nacional do Viruá (Parna Viruá). The study found that arboreal ant alpha diversity was generally higher in structurally complex WSF than in WSC, while ground-dwelling ant diversity was similar across habitats but varied regionally, with lower diversity in WSC at Parna Viruá likely due to prolonged flooding. Species composition of arboreal ants differed more between regions than between habitats within regions, whereas ground-dwelling ants were influenced by both habitat and region. Functional traits related to vision, mobility, and prey manipulation were filtered mainly by habitat structure, highlighting that habitat complexity promotes greater arboreal ant diversity, while regional factors more strongly affect ground-dwelling ants. These findings underscore the importance of both local habitat structure and regional landscape history in shaping ant biodiversity in Amazonian white-sand ecosystems.