Forest loss and increased edge density reduce diversity and ecological functionality of dung beetle assemblages in the Tropical Atlantic Forest

Changes in native habitats that result from human actions compromise the composition and original configuration of landscapes, with negative effects on biodiversity and ecological processes. Dung beetles have been used in studies to assess the consequences of environmental modifications such as deforestation, being sensitive to natural heterogeneity and disturbance, have inter-specific response variability and reliability of disturbance response. Other criteria for their use include taxonomic and functional diversity, as well as their relationship with ecological functions. We conducted a survey in 16 Atlantic Forest remnants and compared dung beetle assemblages according to functional groups and assessed the influence of landscape attributes (forest cover and edge density) on richness, abundance, functional diversity, and ecological functions (dung removal and secondary seed dispersal). To relate the variables expressing dung beetle assemblages to forest cover and edge density, we used different types of models depending on the nature of the dependent variable. Increased edge density negatively affected species richness, abundance and FDiv of the total dung beetle assemblage, and abundance and FDiv of the tunneller assemblage. Yet, loss of forest cover negatively affected total dung removal for the total dung beetle assemblage and decreased FDiv and metatibia length for the tunnelers assemblage. We highlight the negative effects of deforestation on richness and abundance, functional diversity, and dung removal in dung beetle assemblages. Preserving forest remnants in forested landscapes ensures the critical ecological service that dung beetles provide to plant species.