Remediation of Technogenic Barren Soils in the Kola Subarctic: Current State and Long-Term Dynamics

摘要

Widespread industrial pollution and its serious ecological and economic consequences make it urgent to develop and refine approaches to remediation of soils as a key ecosystem component. The long-term impact of atmospheric emissions from nonferrous metallurgy enterprises in Monchegorsk (Murmansk region) resulted in the formation of technogenic barrens with contaminated and highly degraded soils near the pollution source. During long-term monitoring, the current status and dynamics of soil properties have been assessed on permanent control plots on barrens and in birch and willow plantations after remediation performed in 2003-2008 by two methods: chemophytostabilization and covering of contaminated soils by an artificially created fertile layer. The research data of 2011, 2015, and 2018 indicate the continuing acidification of soils and their contamination by heavy metals. Despite the reduction in emissions, the concentrations of available heavy metals in the topsoil of barrens and chemophytostabilized plots do not decrease, and the constructed layers accumulate nickel, copper, cobalt, iron, cadmium, lead, and manganese. The nutrient supply of soils is steadily improved only when a fertile layer is applied. According to the results of the multivariate analysis, the soils of barrens and remediation plots are clearly separated in the space of the first two principal components as the soil properties are improved during remediation, and the positions of chemophytostabilization plots reflect the unstable improvements. Recommendations for the development of a strategy and diversification of methods for remediation of technogenic barrens should take into account different levels of soil pollution and degradation in the vicinity of nonferrous metallurgy enterprises and the need to comply with technological requirements and perform supporting measures.