Composition and Structure of Dung Beetle (Coleoptera: Aphodiidae, Geotrupidae, Scarabaeidae) Assemblages in Mountain Grasslands of the Southern Alps
Abstract
This study attempts to estimate the influence of local environmental conditions on dung beetle assemblages in a bioclimatic transition area. Dung beetle assemblages were monitored by monthly dung-baited pitfall trapping from July to October at five sites in the Southern Alps (Verdon Valley). The sites were characterized by both elevation (≈1,000, 1,500, and 2,000 m a.s.l., respectively) and exposure (north/south). Exposure had a noteworthy influence. In summer, Coprinae showed by far the highest numbers and biomass in the sites facing south regardless of elevation. In the north-facing sites, Aphodiinae dominated the assemblages. In autumn, the abundance of Coprinae decreased and, in turn, Aphodiinae became dominant in most assemblages. Species composition changed with assemblage structure and dynamics. When Coprinae were numerous, few species were predominant in the assemblages and diversity was negatively related with elevation. In the Southern Alps, the alternate predominance observed between Coprinae and Aphodiinae species, which develop at distinct elevation ranges, is analogous to the supramediterranean vegetation range, which characterizes Mediterranean mountains.
