03187nas a2200205   4500008004100000245010700041210006900148300001200217490000700229520241600236653002602652653001702678653002502695653002702720653003402747100002002781700002002801700003502821856012502856       2006                        eng d00aRegional and local influence of grazing activity on the diversity of a semi-arid dung beetle community0 aRegional and local influence of grazing activity on the diversit  a111-1230 v123 aThis study analyses the effect of resource availability (i.e. sheep dung) on dung beetle communities in an arid region of Central Spain, both at regional and at local scales. A total of 18 sites within 600 km2 were sampled for the regional analysis and 16 sites within the 30 km2 of an Iberian municipality were sampled for the local ana- lysis. Spatial and environmental characteristics of sampling sites were also compiled at both scales, including measures of grazing activity (livestock density at regional scale, and two counts of rabbit and sheep dung at local scale). At a regional scale, any environmental or spatial variable can help to explain the variation in abundance. However, species richness was related to summer precipitation and composition was related to elevation. At local scale, abundance is not significantly related to any of the environmental variables, but species richness was related to the local amount of sheep dung (27% of variance). The amount of dung in a 2-km buffer around the site accounts for 27–32% of variance in abundance and 60–65% of variance in species richness. The presence of the flock with the highest sheep density explains 53% of abundance variability and 73% of species richness variance. A cluster analysis of localities identified two main groups, one characterized by a lower abundance and species richness that can be considered a nested subsample of the species-rich group. The mean and maximum amount of sheep dung in the sites separated by less than 2 km are the only significant explanatory variables able to discriminate both groups. These results suggest that grazing intensity (and the associated increase in the amount of trophic resources) is a key factor in determining local variation in the diversity and composition of dung beetle assemblages. However, dung beetle assem- blages are not spatially independent at the analysed resolution, and the amount of dung in the surroundings seems to be more important for locally collected species than the dung effectively found in the site. Although differences in the availability and quantity of trophic resources among nearby sites could be affecting the popula- tion dynamics and dispersion of dung beetles within a locality, sites with larger popu- lations, and greater species numbers would not be able to exercise enough influence as to bring about a complete local faunistic homogenization.10aResource availability10aScarabaeidae10asemi-arid ecosystems10asheep grazing activity10aspecies richness determinants1 aLobo, Jorge, M.1 aHortal, Joaquin1 aCabrero-Sanudo, Francisco-Jose  uhttps://scarabnet.myspecies.info/regional-and-local-influence-grazing-activity-diversity-semi-arid-dung-beetle-community