What is the importance of open habitat in a predominantly closed forest to the dung beetle assemblage? The Atlantic Forest in Brazil is one of the most highly disturbed ecosystems and is mainly represented by fragmented areas. However, in places where human disturbances have ceased, certain areas are showing a natural regeneration pattern. The aim of the present study was to determine how the dung beetle assemblage responds to distinct habitat structures in a fragment of Atlantic Forest. For such, open and closed forest areas were sampled in a fragment of the Atlantic Forest in the northeastern region of Brazil. Pitfall traps baited with excrement and carrion were used to collect the beetles. A total of 7,267 individuals belonging to 35 species were captured. Canthon chalybaeus and C. mutabilis were restricted to open areas. Nearly 90% of the individuals of C. aff. simulans and Deltochilum aff. irroratum were identified in these areas. A higher percentage (> 50%) of Canthon staigi, Dichotomius aff. depressicolis and D. aff. sericeus occurred in closed areas. Abundance differed between areas, with higher values in closed areas. Richness was not influenced by the habitat structure. NMDS ordination exhibited the segregation of areas and ANOSIM confirmed that this variable explained the assemblage of dung beetle species. The findings of the present study validate that open areas are associated to more restrictive conditions, limiting a higher abundance of dung beetle. Although situated near preserved fragments, the studied open areas increase the heterogeneity of the general landscape
The Caatinga is a semiarid ecosystem that undergoes continual environmental disturbances through outdated production technologies and deregulated use of its natural landscapes. Bioindicators, such as dung beetles, are successfully used to understand processes of forest disturbance and subsequent regeneration. The aim of the present study was to evaluate the dung beetle assemblage of a region of the Caatinga with fragments at initial, intermediate, and late stages of regeneration. Sampling was conducted in forest remnants of northeastern Brazil between 2011 and 2013 during the dry and rainy seasons, using traps baited with dung and carrion. There were no differences in beetle richness and abundance according to stage of regeneration. However, there was higher abundance in carrion traps and during the rainy season, which also presented higher richness compared to the dry season. There was a difference in species composition among the fragments in late regeneration. Deltochilum irroratum (Laporte) and Canthon aff. simulans Martínez occurred predominantly in fragments with late regeneration. The harsh conditions and scarcity of resources in Caatinga during the dry season seem to be important factors that limit the activity of these beetles. As this ecosystem has high evapotranspiration rates, carrion, which is less ephemeral than dung, could be an important resource for the beetles, justifying the higher abundance attracted to this resource. Our results suggest that D. irroratum and C. aff. simulans have a strict distribution in conserved habitats and could be evaluated as indicator species of this ecosystem in future studies.