Response of beetle communities five years after wildfire in mediterranean forest ecosystems

Abstract

Wildfires are one of the most important drivers of forest composition and biodiversity in the Mediterranean Basin. Many studies have demonstrated that fires can affect insect diversity by altering the functional traits of species groups. We examined the 5-year response of beetles to wildfires by assessing patterns of community composition across a gradient from forest interior to forest edge to burnt forest area in Southern Italy. Our objective was to characterize the relationship between distance from the forest edge and occurrence of beetle taxonomic assemblages. We analyzed the composition, similarity, and dominance of ground beetle communities in randomly selected plots located along the forest-to-burned-area gradient. We found a negative relationship between community similarity and distance from the forest edge; moreover, the composition of species assemblages (within each family) became increasingly similar with proximity to the forest edge. As the distance from the forest edge into the burned area became greater the dominance of few species increased, and species composition shifted toward habitat generalists. The results partially support the notion that the differences in beetle communities probably are driven by habitat changes caused by fires, especially for those taxa with many specialist species in feeding and oviposition habitats. Understanding the biological effects of wildfires is necessary prior to design management strategies and policies for counteracting the loss of biodiversity at the global, regional and national levels.