Species diversity and metal accumulation in oribatid mites (Acari, Oribatida) of forests affected by a metallurgical plant

A study was made of oribatid mite communities and their responses to metal contamination derived from the Kosogorsky metallurgical plant located in th e Tula District, Russia. Mite communities were sampled in three different s easons in four sites at different distances from the smelter. Concentration s of zinc, copper, cadmium, lead and iron were measured in ten mite species . The data show that the mite community as a whole is quite tolerant to the metal contamination caused by the Kosogorsky plant. At the polluted sites some species typical for nutrient-rich soils appeared, but community struct ure and species diversity were not seriously affected by metal contaminatio n. In general, oribatid mites accumulated metals to very high internal conc entrations. Average Cu, Cd, Pb and Fe concentrations did not differ signifi cantly between species, but Zn did, and its level was associated with the m ode of feeding of the species. Microphytophagous species, feeding exclusive ly on fungi, accumulated zinc in higher concentrations than other mites. Th is study illustrates the potential for bioindication by the little studied but species-rich group of soil oribatids.