Earthworms and microannelids as bioindicators in soil monitoring

Soil monitoring at permanent soil monitoring sites aims at detecting long-term changes in soil quality. Furthermore, the collected data serve as reference for assessing the soil conditions that develop under specific soil uses and pressures. A matter of particular interest is the biological soil condition that mirrors current ecosystem processes. Primarily earthworms are surveyed at soil monitoring sites as faunistic indicators of the biological soil condition. Additionally, also microannelids are investigated in several German federal states. They show a higher diversity than earthworms and therefore allow for more differentiation. Based on this reference an assessment procedure is presented using the example of a site with elevated heavy metal contents, showing the effect of airborne pollutants on the biological soil condition.