Decline of Ecological Functions Performed by Dung Beetles in Areas of Atlantic Forest and Contribution of Rollers and Tunnellers in Organic Matter Removal.

The feeding behavior of the Scarabaeinae subfamily has positive implications on ecosystem functioning. We characterize the necrophagous and coprophagous dung beetle assemblages, and we quantify the removal of swine carrion and domestic dog dung in two areas with different degrees of environmental disturbance in an Atlantic Forest remnant located in Florianopolis, SC, Brazil. The experiment was setup at eight sampling points in each area, by installing one control and two collection and removal assessment arenas for collecting necrophagous dung beetles while simultaneously evaluating the removal of carrion (50 g of rotting pork for 48 h). We used the same sample design with 50 g of domestic dog dung for evaluating the coprophagous dung beetle assemblage and dung removal. Our results indicated that necrophagous dung beetles were more sensitive to environmental disturbance owing to a lower richness and changes in species dominance, which resulted in a lower removal in the areas with greater disturbance and lower environmental quality (39.6% carrion removal) in relation to less disturbed areas (75.1% carrion removal). The dung beetle assemblages were similar in structure and removal rates between areas (80% of dung was removed). In assessing the influence of richness, abundance, and biomass of dung beetles on resource removal both for the whole assemblage and for each separate functional guild, only the abundance and biomass of rollers contributed significantly to dung removal. These results highlight the implications of environmental disturbances on the functions of dung beetles, which respond differently according to the resource they use.