Wildfire does not affect the dung beetle diversity of high-altitude Mediterranean habitats

Abstract

Wildfires represent an important factor in the disturbance in Mediterranean ecosystems, although the effects of wildfires on the insect communities of mountain environments remain largely unknown. This research investigated the effect of fire on dung beetles in a Mediterranean high-altitude area, located in Central Italy (1500 m elevation). Sampling in each of the three main vegetation types of the study area (conifer plantation, beechwood forest and grassland) used pitfall traps during Spring to Autumn. For each habitat, three burnt and three unburnt sites were sampled. We considered the following community structure parameters: abundance, richness, Shannon diversity and Simpson diversity. Effects of fire, habitat and sampling period were investigated using generalised mixed-effects models. Abundance, species richness and diversity were higher in the grassland than in the two forest habitats and June was the month with the lowest values because of the late emergence of insects at high altitudes. Fire negatively affected dung beetle abundance, but not diversity. Forest habitats were less favourable to dung beetle recolonisation than the secondary grassland. Thus, dung beetles are sensitive to vegetation type, but not to fire, possibly because of their high recolonisation capabilities and preference for open habitats.