Succession of ground beetle (Coleoptera: Carabidae) communities after windthrow disturbance in a montane Norway spruce forest in the Hrubý Jeseník Mts. (Czech Republic)

Wind disturbances are a key factor that is significantly involved in the life cycle of natural boreomontane coniferous forests. As most of these forests are currently intensively managed, we have limited knowledge on succession following natural disturbance. Succession in a Norway spruce stand after a windthrow event was studied using ground beetles as model bioindication taxa in the Hrubý Jeseník Mts. (Czech Republic). The study documented that the composition of ground beetle communities was significantly associated with stand age and its microclimatic parameters (particularly the minimal temperature and average and minimal humidity). Forest species including prey specialists, hygrophilous species, as well as habitat generalists were the most abundant in the mature stand, where the forest had the highest humidity and the least profound minimal temperatures. In contrast, open-habitat species, including euryoecious species and relict species of higher elevations, reached their highest abundances in clearing shortly after the windthrow. In clearing the humidity was lower and the temperature fluctuated significantly (the lowest minimal temperatures). Ground beetles, including forest species, were the least abundant in young stands (10 and 20 years after windthrow). We conclude that old stands are of particular importance because they harbour the highest abundance and diversity of ground beetles with various ecological requirements. Natural wind disturbances are important as well since they increase diversity by enabling the occurrence of many non-forest species. Hence, a mosaic of stands of different ages with a sufficient proportion of old stands should be maintained when managing montane coniferous forests.