The Impact of Restoration on Epigeic Arthropods in the Important European Forest Biotopes of the Danube Delta

Abstract

The floodplain forests of the Danube Delta are among the important European biotopes and are protected in Slovakia under Natura 2000. In order to preserve these biotopes, their restoration is underway, which also restores the original fauna. These biotopes are sensitive to environmental and ecological changes, which is also reflected in the spatial distribution of epigeic arthropods. Between the years 2020 and 2023, we investigated the impact of floodplain restoration on the population structure of epigeic arthropods in eight study areas (two control study areas and six study areas with ongoing biotope restoration). We placed five pitfall traps in a transect for each biotope. In total, we recorded 66,771 individuals belonging to 15 arthropod taxa. We found differences in the taxonomic structures between forest stands with management and forest stands without management (larger number of taxa) using spatial modelling. We also confirmed interannual changes in the taxa composition of epigeic arthropods and their abundance. Over the years of restoration, the number of individual epigeic arthropods decreased. In the years following revitalization, when succession took place, it subsequently increased. Overall, the restoration management of floodplain forests had a positive effect on epigeic arthropods, as well as on their number of individuals, which is important for the preservation of these important habitats in Europe.