INFLUENCE OF PERENNIAL RYEGRASS ON A COPPER AND ZINC AFFECTED TERRESTRIAL NEMATODE COMMUNITY

Effects of copper or zinc (0, 25, 50, 100, 200 and 400 mg kg(-1)) on s oil containing an indigenous nematode community were examined in a gre enhouse in the presence or absence of ryegrass (Lolium perenne L.). In creasing Cu and Zn additions had negative effects on the total abundan ce, average number of taxa, proportion of plant feeding nematodes, pro portion of omnivorous and carnivorous nematodes, nematode taxa from c- p groups 4 and 5 and the Maturity Index, both in the presence and abse nce of L. perenne. At intermediate Cu or Zn concentrations of 25-200 m g kg(-1), certain taxa had higher absolute abundances than in the cont rol, which indicated indirect effects. The effects of similar Cu or Zn additions were less extreme in the presence than in the absence of L. perenne. These results imply that the presence of vegetation influenc es the ecotoxicological effect of pollutants. The risk assessment of p ollutants could increase its realism by the inclusion of the response of communities of soil organisms in the presence of plants. (C) 1998 E lsevier Science B.V.