Application of Soil Oribatid Mites as Bioindicators in Impact Areas of theGas Industry in the West Siberian Tundra

Atmospheric emissions from gas pre-treatment centers of the Gazprom Dobycha Yamburg LLC influenced the community of oribatid mites in southern tundra ecosystems. It was evidenced by changing the ratio of the ecological groups of the oribatid mites rather than its total abundance. The euedaphic oribatid mites prevailed essentially in the mites community of more contaminated biotopes located closer to the source of atmospheric pollution. In the conditions of de- creasing pollution levels, the mites community structure was changed to predominance of litter-surface oribatid mites spe- cies, larger in size and typical for undisturbed natural communities. Level of pollution was evaluated on the basis of cu- mulative index of anthropogenic pollution load per unit of an ecosystem surface (IPLS). It was found that the best charac- teristic of bioindication of pollution is the ratio of litter-topsoil oribatid mites to euedaphic ones (RL/S). Very simple equa- tion with significantly high determination coefficient was obtained to describe this dependence: RL/S = 4.84 - Ln(IPLS).