Livestock management within legal reserves drives changes in dung beetle assemblage and functional composition in the Brazilian Cerrado

Legal reserves (LRs) are central to Brazil’s Forest Code, aiming to conserve biodiversity and ecosystem functions on private lands. However, in the Cerrado, the world’s largest and most biodiverse savanna, livestock incursions threaten these protected areas. We evaluated the effects of cattle presence on dung beetle assemblages by comparing a conserved savanna (Bacaba Park), an ungrazed LR savanna, and a cattle-grazed LR savanna. Species richness and abundance were highest in the conserved area and lowest in the cattle-grazed LR. Species composition differed markedly among sites, with only one species shared between conserved and cattle-grazed areas, indicating strong turnover and biotic homogenization. Functional guild analyses revealed sharp declines of large tunnellers and rollers in grazed areas, while small-bodied dwellers and rollers increased. These changes suggest that cattle grazing simplifies functional structure and may impair ecosystem services such as nutrient cycling, soil fertilization, and seed dispersal. The occurrence of the invasive African species Digitonthophagus gazella (Fabricius, 1787) exclusively in grazed areas further highlights risks to native assemblages. Our findings indicate that cattle access compromises the conservation role of Cerrado LRs, reinforcing the need for fencing, restoration, and stronger enforcement of the Forest Code.