Changes in the properties of soils and soil biota in the impact zone of the aerotechnogenic emissions from the Kandalaksha aluminum smelter

摘要

A comparative analysis of the changes in the properties of the soils and soil biota in the past ten years along the gradient of pollution with aerotechnogenic emission from the Kandalaksha aluminum smelter in response to a decrease in the emission volume has been performed. The concentrations of fluorine compounds (the priority pollutant) in the emissions and in the organic soil horizons in the impact zone significantly decreased in 2011 relative to 2001. The concentrations of Al decreased only in close vicinity to the smelter (up to 2 km). The concentrations of F, Ca, and Mg in the liquid phase were higher than those in the solid phase, and these elements migrated to greater distances from the source of the contamination (up to 15-20 km). The elements Si, Al, Fe, and P were contained mostly in the solid phase and were mainly deposited within the 5-km zone. The acidity of the litter near the smelter decreased by almost by two pH units in the nearest zone ( 2 km). The decrease in the amount of contaminants in the emissions resulted in the narrowing of the zone of the maximum soil contamination from 2.5 to 1.5 km from the emission source; the zones of strong and moderate contamination narrowed by 5 km. The regularities of the changes in the numbers and biomasses of the main groups of microorganisms in the soils of the permanent sampling plots did not change during the past ten years. The emissions inhibited the development of the fungal biota. The prokaryotic part of the soil microbiota and, particularly, the actinomycetes proved to be tolerant to the emitted contaminants. It was suggested that the changes in the structure of the fungal and actinomycetal communities should be used to monitor the state of the soil ecosystems affected by the emissions from the aluminum smelter.