Earthworms and dehydrogenase activity of urban biotopes

Earthworm populations and biomass were determined on four urban sites, representing different stages of secondary succession. Moreover, dehydrogenase activity of the topsoils was measured on three of these sites. Formerly, the sites considered were used as garden, grassland or arable land. The soil properties of all sites investigated illustrate the former land use and in some cases the effects of succession. Higher densities of earthworms were found in biotopes, which were used for horticulture. Fewer individuals occur on former agricultural land (grassland and arable land). Biomass of earthworms and dehydrogenase activity decrease from ancient garden land to grassland and arable land. The results are discussed with special regard to the actual site characteristics, such as soil properties and litter quality.