Long-term changes in surface-active beetle communities in a post-fire successional gradient in Pinus brutia forests

Abstract

Abstract: Fire is one of the most important ecological factors for many ecosystem types. Since prehistoric times, synergistic effects of fires and humans have led to changes in Eastern Mediterranean ecosystems. The effects of fire on different trophic levels, particularly regarding plants, have been examined intensively in fire-induced ecosystems. In this study, we aimed to study long-term changes in beetle community structure after fire in Pinus brutia Ten. forests. Five sites burned in different years and a control site unburned for at least 50 years were selected. Beetle sampling was conducted using four pit-fall traps in each of four transects in three replication plots at every successional site and in two plots at the control site. Microhabitat variables related to vegetation structure and litter layer were recorded and associated with abundances of beetles and feeding groups. The results showed that total, wood-eating, and predator beetles showed a decreasing trend of abundance along the successional gradient after fire. In contrast to these groups, herbivores tended to increase towards the late successional stages. Middle and late successional stages were important in terms of species richness, species diversity and evenness of beetle communities and feeding groups. The characteristics of vegetation and litter layer changed with successional gradient, playing a decisive role in the structure of beetle communities at successional sites. According to the data presented here, a mosaic structure consisting of different successional stages is very important to sustain high species diversity in beetle communities.