Annelids of beech forests on basaltic bedrock: findings from two forest reserves in Germany

The annelid communities (microannelids and earthworms) of woodruff beech forest in two Strict Forest Reserves on moderately base-rich soil (basaltic bedrock) were studied. For the Weiherskopf (Hesse) Strict Forest Reserve, a reference site that was under forest management was included in the investigation. While the investigations at Weiherskopf took place in 2014, the Nonnenstromberg (North Rhine-Westphalia) Strict Forest Reserve was studied already 1991/1993. Site conditions at Weiherskopf and Nonnenstromberg were similar in many respects, apart from the fact that at both Weiherskopf sites several heavy storms had caused extensive windthrow in 1990, resulting in different amounts of deadwood at the sites. Despite this, the species composition was similar at the studied sites (Sørensen Similarity Index between 0.73 and 0.83). At all three sites a species-rich annelid community was present, the majority of species indicating either slightly or moderately acid soil conditions. Among the microannelid species with the highest frequency were Hrabeiella periglandulata, Enchytronia parva and Buchholzia appendiculata. At all sites, the same humus form (F-mull) was developed, being closely linked to the presence of endogeic and anecic earthworms. Possible distinguishing features between annelid communities on basalt and calcareous bedrock respectively are discussed.