ИСТИНА

As a country that accounts for almost a third of the Arctic with a population of more than 2.5 million people, it is especially important for Russia to resolve existing environmental problems in order to implement a comprehensive development program in high latitudes. Contamination of soils by heavy metals and metalloids (HMs) is one of the most common problems leading to land degradation. It is especially urgent in the Russian Federation northern regions, Arctic including. Consequences of the HMs contamination include deterioration of main soil ecosystem functions: provisioning, biodiversity conservation, climate regulation, water resources protection, and others. The fact that soils can be considered as almost non-renewable resources makes soil quality preservation an urgent problem, required to be maintained to achieve Sustainable Development Goals, specifically, № 2, № 13, № 15. Additionally, the quality of soils of the Arctic region is of high attention due to the problem of global Climate Change which poses a greater threat to the northern regions. Restoration of the vegetation cover, degraded due to the long-term pollutants’ exposure, is one of the mitigation actions because of the leading role of plants and well-functioning soils in the atmospheric carbon sequestration. Objects of presented study are soils of technogenic barrens developed in the vicinity of copper and nickel smelter, Severonikel, located in the north-western part of Russia, in the Kola Peninsula. Long-term exposure of HMs and sulfur dioxide resulted in destruction of plant communities in the closest area of the smelter, development of erosion processes, and loss of soil carbon. In this research we suggested a remediation based on the carbon pool regulation as an appropriate and highly promising strategy. We compared the application of different organic amendments, including peat and coal humates, peat-gel and biochar to the soils of the barren near the smelter at different stages of contamination. In short-term and long-term laboratory and field experiments we sowed non-tolerant to the HMs grass species, Deschampsia cespitosa and Festuca rubra. Evaluated chemical, physical and toxicological properties were used for the Multi-criteria analysis. Our results show the high potential of organic amendments for remediation of soils, contaminated by heavy metals in conditions of harsh Subarctic climate in terms of environmental, social and economic impacts.