Urbanization effects on dung beetle assemblages in a tropical city

The maintenance of forest fragments within urban landscapes is essential for human well-being, as the loss of biodiversity may result in a reduction of ecological services in cities. Conserving diverse functional groups within urban landscapes is essential, since it is directly related with the resilience of such ecosystems. Through the use of indicator groups, it is possible to draw predictions on how communities respond to increasing urbanization. The goal of our study was to assess how the increase of urban land cover affects the assemblage and functional groups of dung beetles (Scarabaeinae) that inhabit forest fragments in a tropical city. We sampled dung beetles in nine fragments embedded in the metropolitan region of Joao Pessoa, Brazil. Increasing urbanization negatively affected the abundance of coprophagous species, as well as the species richness, abundance and biomass of roller beetles. Assemblages from the most urbanized forest fragments were significantly different from the other fragments. According to the decomposition of beta diversity, species turnover was the main process shaping the dung beetle assemblages in Joao Pessoa. In this study we provide evidence that specific functional groups of dung beetles are affected by urbanization. Furthermore, as each functional group has different strategies to occupy habitats and use resources, urbanization has contrasting effects for each group. Our results confirm that dung beetles are highly sensitive to urbanization and that protected areas within cities are fundamental to conserve biodiversity and ecosystem services.