Soil decomposer animal community in heavy-metal contaminated coniferous forest with and without liming

Responses of decomposer animals to heavy-metal contamination were studied near a Cu–Ni smelter in Finland. Samples were taken 0.5, 2 and 8 km from the smelter. In addition, plots fertilised with lime were sampled. Decomposer community in coniferous forest soil appeared to be quite resistant to heavy-metals. Only in the vicinity (0.5 km) of the smelter, were numbers of soil animals clearly decreased and their community structure strongly altered as compared to the control site (8 km). At the 2-km site, the community structure was only slightly changed. Most of the collembolan species were still found at the 0.5-km site. High metal sorption capacity of the humus, and heterogeneous distribution of the metals obviously mitigated the effects of metals. Thus, a more diverse and more abundant decomposer community is able to exist in contaminated forest soil than can be expected. Liming affected the decomposer animal community only at the control site where its impact on soil pH was the highest.