Post-industrial areas as successional habitats: Long-term changes of functional diversity in beetle communities

Abstract

Understanding succession is one of the main goals in ecosystem ecology, but very few studies regarding arthropods have actually examined this topic in sufficient detail. Missing are studies that examine the long-term trend of primary succession of arthropods in post-industrial habitats and also the functional consequences of primary succession on arthropods. We used epigeic beetles as a model group to investigate the process of primary succession of arthropods on spoil heaps for about 30 years of spontaneous development. For carabid beetles, we calculated indices of functional diversity (functional evenness, functional richness and functional divergence). To quantify functional diversity we used these functional traits: wing morphology, habitat preference and humidity dependence. Our results reveal that the main environmental factor determining the structure of beetle communities is spoil heap age, which is itself correlated with forest cover. The descriptive rank-abundance models that best fit our community structure were Gambin and Zipf – Mandelbrot. Abundances of brachypterous and forest species were positively correlated with successional age. Our results provide evidence that primary succession in post-industrial habitats differs from that in more natural habitats due to the rapid rate of successional changes and their attributes. In particular, abiotic factors are constitutive in comparison to interspecific competition during succession. The canonical correspondence analysis model identified that irregular disturbances are another important phenomenon of succession in post-industrial habitats. We assume that constant indices of functional evenness and richness reflect rapid colonization from surrounding habitats. Functional divergence was significantly correlated with increasing proportion of forest species.