Grassland Land Snail Communities after Reduction of Emissions from a Copper Smelter

The species structure of land snail communities inhabiting the meadow herb layer has been studied in the periods of relatively high emissions from the Middle Ural Copper Smelter (2006-2008) and after their almost complete reduction (2015-2017). No snails were found in the impact zone during these periods. In the background and buffer zones, their species richness during the second period decreased by a factor of two, and their abundance, by a factor of up to three, which was due to weather fluctuations (drought in 2016). The impact of drought was more distinct in the buffer zone, but two species (Discus ruderatus and Vitrina pellucida) appeared there and increased in abundance during the second period. The processes of recovery in land snail communities may be explained by normalization of soil pH and calcium content and also by an increase in the proportion of graminoids in the herb layer, which provided for stabilization of microclimatic conditions.