The tree layer structure of forest communities of the Kola Peninsula central part formed when aerotechnogenic emissions reduced

This research provides an overview of the main component of forest ecosystems in northern Europe, the tree layer formed by the Scotch pine (Pinus sylvestris L .) species. The studied communities are located in the immediate vicinity of the largest plant in Europe, OAO Severonickel (Monchegorsk, Murmansk region). The main pollutants are polymetallic dust containing elements such as Cu, Ni and Co (which are by-products of processing and smelting non-ferrous ores) and sulfur dioxide - SO2 (which is formed during the primary processing of ores, the so-called “roasting”). The first permanent trial plots (PPPs) in this region were established in the early 1970s. Since the second half of the 1990s, the plant has significantly reduced the amount of aerotechnogenic emissions, as evidenced by the data noted by some researchers at that time. The cumulative nature of the accumulation (and release) of polymetallic dust led to the fact that, starting from the time the ore processing plant reduced its capacity, the concentration of metals contained in the soil and plant organs decreased to a certain level. We present the materials obtained in the course of field research in 2015-2018.