Arachnids (Aranei, Opiliones) in Meadows: Response to Pollution with Emissions from the Middle Ural Copper Smelter

Arachnids living in the herbaceous layer have been studied in 2006-2008 in secondary upland meadows along the gradient of pollution with emissions from the Middle Ural Copper Smelter (Revda, Sverdlovsk oblast). It has been shown that absolute abundance and general diversity decrease with increasing levels of technogenic pressure. Direct toxic effect of heavy metals is especially strong on taxa closely associated with soil and litter; this effect is the most likely cause of the absence of harvestmen near the smelter. The other groups of arachnids are more strongly affected by environmental changes (depletion of species diversity, simplification of architecture of the herbaceous layer, and modification of the hydrothermal regime of this layer) indirectly caused by pollution.