Are power-line corridors an alternative habitat for carabid beetle (Coleoptera: Carabidae) and wolf spider (Araneae: Lycosidae) heathland specialists?

Abstract

Semi-natural habitats such as heathlands, are important for the conservation of biodiversity. Due to a significant decline in traditional management, e.g. burning and grazing, in combination with habitat loss, these ecosystems have become highly threatened. On the other hand, human activities create modern infrastructures, e.g. power-line corridors (PLCs), and they can function as an alternative habitat for species for which their semi-natural habitat has degraded. This study compared the species richness and species composition of carabid beetles and wolf spiders in PLCs, traditionally managed heathlands and former heathlands that are covered with coniferous forests. We also measured vegetation variables and used it to compare species richness of plant, abundances of species and Ellenberg indicator values in the different habitats. The results showed that species richness of carabid beetles in the traditionally managed heathland is significantly higher compared to the PLCs. The species composition of carabid beetles and wolf spiders were also significantly different in these two habitats, but there was no difference between the species composition of carabid beetles and wolf spiders in the PLCs and forests. This might be explained by the similar vegetation structure in the PLCs and the forests, such as the high abundance of trees and shrubs and low abundance of typical heathland plants. Our results showed that PLCs are not an alternative habitat for the carabid beetle and wolf spider heathland specialists. We discussed how the management could be changed in the PLCs in order to make them more valuable for these and other heathland species.