Influence of deadwood on density of soil macro-arthropods in a managed oak-beech forest

In a 2-year study we investigated soil macro-arthropods (Opilionida, Araneida, Pseudoscorpionida, Isopoda, Diplopoda, Chilopoda, Coleoptera) in a forest where forestry management is nature oriented and includes the accumulation of about 10 m(3) deadwood per ha. We focused on soil arthropod density close to (c-CWD) or distant from coarse woody debris (d-CWD) in different locations of the forest stand (interior location versus edge zone) and in different seasons (summer versus winter). We found twice as many individuals of almost all taxa at c-CWD sites compared to d-CWD sites. The influence of CWD on most taxa of soil arthropods was more pronounced in the edge zone than in the interior location. In the edge zone c-CWD sites yielded significantly higher numbers of all taxa in both seasons. In the interior location seasonal effects occurred. For example, Pseudoscorpionida and Coleoptera-Larvae preferred c-CWD sites only in summer, whereas Araneida preferred c-CWD sites only in winter. A three-way ANOVA, regarding site, location and season as the main factors, emphasised the dominant influence of CWD on the density of all taxa. Consequently, CWD is an important structural component that serves as a habitat for many saprophagous species and thus locally improves the nutritional situation of a forest stand. CWD also may reduce the pest species problem because it harbours many zoophagous soil macro-arthropods as well. (C) 2004, Elsevier B.V. All rights reserved.