MICROARTHROPOD BIOMASS-C DYNAMICS IN THE BELOWGROUND FOOD WEBS OF 2 ARABLE FARMING SYSTEMS

Microarthropod biomass-C dynamics in arable soil were observed in a 2 year sampling programme in a conventional and an integrated farming sy stem. The most abundant functional groups were omnivorous collembola, omnivorous non-cryptostigmatic mites and predatory mites. Management p ractice, especially soil fumigation, affected the short-term dynamics of most groups but no effects were observed on the mean annual biomass of these groups. In the food webs studied in the Netherlands (Lovinkh oeve) or in Sweden (Kjettslinge) and Georgia, USA (Horseshoe Bend), no relation between the biomass of the microarthropods and their main fo od source (primary decomposers) could be identified from the biomass a nnual means. The sampling results of the present study indicated that the microarthropod functional groups were able to recover rapidly from harsh management practices.