The Enchytraeidae of spruce forest plots of different exposure and acid deposition in a German mountain range

Enchytraeidae were studied at spruce forest sites (Harz, Germany) differing in their exposure and soil acidity affected by acid deposition. Total density ranged between 38 000 and 59 000 ind. m–2 and biomass between 0.5 and 1 g m–2 d.m. (annual means). Of the seven species recorded, Cognettia sphagnetorum, Marionina clavata, and Achaeta camerani were dominant. The site affected most by acidification had the highest densities and lowest species number. Population dynamics and vertical distributions were affected by climate. Field and laboratory data provide evidence for sexual reproduction in C. sphagnetorum. Substrate preference experiments showed this species to prefer spruce litter from the OL-Horizon to that from the OH-Horizon, and spruce litter to beech litter.