Floods and drought: Response of earthworms and potworms (Oligochaeta: Lumbricidae, Enchytraeidae) to hydrological extremes in wet grassland

The water holding capacity as well as the organic matter content of the soil are important factors for annelids in sites subjected to such hydrological extremes. To promote terrestrial annelids, controlled flooding should be kept short, especially in winters following natural summer floods. If possible, recovery times for annelids should be guarenteed, that is 2-3 months without inundations for enchytraeids and about half a year for earthworms. A microrelief with drier refuge sites can be judged as favourable for earthworms. An artificially raised groundwater table will favour annelids during drought periods.