Short-term effects of cadmium, copper, nickel and zinc on soil nematodes from different feeding and life-history strategy groups

The effects of cadmium, copper, nickel and zinc on a nematode community were examined with a 'natural soil method'. Changes in the indigenous nematode community structure were studied 1-2 weeks after the addition of these metals (as sulphates) to soil collected from an agroecosystem The soil was acid and only contained a moderate quantity of organic matter as the main metal-binding constituent. As a result, its metal-binding capacity was rather low. The nematode community was found to be affected by increasing concentrations of Cu, Ni and Zn up to 1600 mg kg(-1), but not by Cd up to 160 mg kg(-1). EC(50) values for the reduction in population size of individual taxa showed a low intra-taxon variation for Cu, Ni and Zn. For these heavy metals, uptake and elimination processes as well as their final effect appear similar within the same taxon. Omnivorous and predatory nematodes, known to be K-strategists, were among the most sensitive taxa, and were already significantly affected by 100 mg kg(-1) Cu, Ni or Zn added to the soil. The relative abundance of the different life-history groups and, to a lesser extent, the different feeding groups indicated pollution-induced changes in the soil community. However, neither classification predicts the acute effects of Cu, Ni and Zn on different nematode genera in an adequate way.