Changes in the habitat network of an endangered Pholidoptera transsylvanica, (Fischer Waldheim, 1853) metapopulation in the Aggtelek Karst (NE Hungary)

Abstract

The population of the endangered Pholidoptera transsylvanica bush-cricket in the Aggtelek Karst, Hungary lives in 39 habitat patches connected with several green corridors. For the long-term survival, insurance of gene-flow among subpopulations (hence the connectivity of the habitat network) would be essential. In the past few years we re-examined all the patches and corridors and our results were compared to the ones from a previous study. During the comparison we used indices applied for network analysis to characterize the relative importance of landscape elements, which tended to be decreasing due to the expansion of the habitat network. Node N5 (Nagy-Nyilas hayfield) was the most important in maintaining connectivity. We would like to draw attention to the fact that during the years between the researches several changes (such as forestation) have occurred which pose serious threats for the connectivity of the habitat network and, as a result, the long-term survival of the studied bush-cricket metapopulation. A potential solution for preventing the fragmentation of subpopulations is establishing new corridors or improving the existing ones, therefore we dealt with estimation of their possible effects.