Esther Murciano
University of Granada, Spain
Title: Effects of changes in livestock management on dung beetle community structure of dung beetles in an arid environment of Southeastern Spain
Biography
Biography: Esther Murciano
Abstract
One of the major threats to biodiversity is habitat loss and degradation. Increasing industrialization and abandonment of traditional land uses are resulting in the loss of some anthropogenic habitats with high rates of species diversity. Variation in the community composition of dung Scarabaeid species was studied in an arid system in SE Iberian Peninsula, in which traditional livestock management has suffered profound changes due to the decline of grazing animals and the extensive use of antiparasitary pharmaceutical products over the past 15 years. The aims of this study were, a) to compare differences in dung availability between the springs of 1997-98 and 2012-13, and b) to assess differences in community structure by analysing variation in abundance (total, subfamily and species) and diversity (differences in the number of species by rarefaction). Standardized sampling protocols were used in order to allow temporal comparison of the data. Dung availability was assessed by census of fresh dung along a fixed transect of approx. 1 km in length and 2 meters wide, while sheep dung baited traps were used to assess the structure of the dung beetle community. The results show that the availability of excrements in 2012-13 decreased by approximately 80% as compared to 1997-98. Dung beetles abundance decreased significantly, especially species associated with arid environments (Onthophagus merdarius, Mecynodes leucopterus, Bodilus longispina); in contrast, some generalist detritivorous species (such as Calamosternus granarius) increased. There were also changes in diversity, with a reduction in species richness by 30% in 2012, although no significant variations in species richness was obtained in 2013, probably due to the much lower dung beetle abundances obtained last year. In conclusion, the reduced availability of excrements, probably acting synergistically with the ample use of antiparasitary pharmaceutical products, appears to be responsible for the profound changes in the structure of dung beetle communities observed in these areas.