Organic landuse on Ritzerau Manor, Subproject: Earthworms

Spictureince 2001 earthworms are investigated as monitoring organisms in the broader research project ‘Organic landuse on Ritzerau Manor’. They should reflect changes in the soil fauna during the change from conventional to organic landuse. The earthworms are sampled on more than 80 sites at 6 sampling dates during the year, identified to species level, and the biomass is determined. In the meantime, data for 10 years are available.

picture Lumbricus terrestrisSince the beginning of the project, distinct changes in the species composition have been detected, while biomass has shown no changes. Endogeic species in fact decreased during the change of agricultural management; however, they were mainly influenced by the yearly weather conditions. Wet weather conditions had a positive effect, while dry weather conditions had a negative effect. In contrast, the anecic species, Lumbricus terrestris, was significantly preferred by the organic landuse. After 10 years, the density of the species is nearly 5 times as high as at the beginning of the management change and the spatial frequency is 3 times higher.