Role of environmental heterogeneity in species distribution of vascular plants in the periods of high and low emissions from copper smelter
M. R. TRUBINA, D. V. NESTERKOVA
Institute of Plant and Animal Ecology, Ural Branch, Russian Academy of Sciences, Yekaterinburg, Russia
Keywords: extinction, fragmentation, recolonization, dispersal, recovery, pollution, heavy metals, sulphur dioxide
Abstract
The environmental heterogeneity can significantly modify the rate of species extinction with an increase in anthropogenic load and the rate of recolonization of disturbed territories after decrease in load, but this issue is currently poorly understood. The distribution of fourteen species of the herb-dwarf shrub layer of forests on area of 1734 km2 in two natural regions of the eastern and western macroslope of the Urals during the periods of high (1995-1998) and low (2014-2016) emissions from the Middle Ural Copper Smelter has been analyzed. With an increase/decrease in load, the pattern of dynamics and the magnitude responses were species-specific, significantly depend on habitat conditions, but the main contribution to the space-temporal dynamics of species affected the load level. During the period of high emissions, the environmental heterogeneity slowed down the rate of decrease of area species distribution along a load gradient, but under very heavy pollution, the distribution has been decreased despite of habitats or species. After the reduction of emissions, the distribution of most species in the heavily polluted areas has changed little for 19 years, elimination and reduction in the distribution of the most sensitive species continued. Positive shifts have been revealed mainly in less polluted areas; the rates of recolonization varied in different habitats. Depending on habitat conditions, species response to increase/decrease in pressure can be "fast" (relatively high rates of change) and "slow" (lower rates of change and even continued decline in distribution despite of reductions in pressure).
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