Airborne Heavy Metal Pollution and its Effects on Biomass of Ground Vegetation, Foliar Elemental Composition and Metabolic Profiling of Forest Plants in the Kola Peninsula (Russia)

In this work a quantitative estimation of biomass accumulation in the ground cover of pine forests of northern taiga in the background area of the Kola Peninsula (Russia) and in the territory of the buffer and impact zones of non-ferrous metallurgical plant, producing air emissions containing sulfur dioxide and polymetallic dust, was carried out. It was found that under the influence of airborne pollution in the first place the moss-lichen layer is destroyed with elimination of sensitive species of mosses and lichens; the structure of biomass changes and both the total stock of aboveground biomass and stocks of individual components decrease. The results of studying the elemental composition of dominant species of plants (Vaccinium myrtillus L., V. vitis-idaea L., V. uliginosum L., Empetrum hermaphroditum Hagerup), mosses (Pleurozium schreberi (Brid.) Mitt.) and lichens (Cladonia stellaris (Opiz) Pouza et V-zda) of northern taiga forests revealed an imbalance in their mineral nutrition. Using metabolomic analysis, the macroprofile of the component composition of the secondary metabolites in the leaves of 3 species of the Vaccinium genus was characterized, the specificity of the composition of metabolites in each studied species was revealed. Despite the reduction in atmospheric emissions by Severonickel Combine, the restoration of the ground cover in pine forests is inhibited (buffer zone) or it cannot even begin (impact zone) due to the high level of soil contamination with heavy metals. The mineral nutrition of higher plants, mosses and lichens is disturbed: as one approaches the source of pollution, the accumulation of heavy metals (Ni, Cu, Co, Fe) increases; their ratio changes; the content of micro- (Mn) and essential macroelements (Ca, Mg) decreases in the leaves of the dwarf shrubs and the moss. The changes in the metabolite profiles of the leaves of the genus Vaccinium are due to both the plant species and the level of airborne pollution.