ENCHYTRAEIDS (OLIGOCHAETA) IN AN AUSTRIAN SPRUCE FOREST - ABUNDANCE, BIOMASS, VERTICAL-DISTRIBUTION AND REIMMIGRATION INTO DEFAUNATED MESOCOSMS

In an Austrian spruce forest, enchytraeid abundance, biomass, vertical distribution, dominance structure, and re-immigration into defaunated mesocosms were determined after an exposition period of eight months. With the exception of biomass, no significant differences compared wi th the control area were observed. In June 1992, the average enchytrae id abundance amounted to 30 274 [15 255 S.D.] individuals m(-2), the b iomass reached values of up to 8.99 [4.21 S.D.] g fresh mass m(-2). Fo ur species were found: Cognettia sphagnetorum made up about 90% of the enchytraeid fauna, with 83% occurring in the L+F-layer. Cognettia cla rae preferred the H-layer, where more mature worms were found. The bio mass of Mesenchytraeus pelicensis was greater in the L+F-layer. Marion ina clavata occurred in the forest soil in small numbers and showed no differences in colonization of the two horizons.