Features of restoration of disturbed pine forests (Pinus sylvestris L.) in the European north of Russia

The features of restoration of disturbed lichen-green-mossy pine forests (Pinus sylvestris L.) of III-IV age classes in deforestation and burning in the Kola North (Russia) were studied. It is established that the current trends in the formation of secondary pine forests are due to natural processes and intra-population relationships. In the central part of the Kola Peninsula, where a powerful metallurgical plant is located, the main cause of damage, weakening and even destruction of young pine forests is aerotechnogenic pollution of SO₂ with an admixture of heavy metals (Ni, Cu, Co, etc.). One of the first signs of deviation of the vital state of the common pine from the norm is dechromation of needles and its premature fall. This is the reason for the decrease in the life expectancy of needles on trees to 3-4 years in the area of intense pollution compared to 6-7 years in background stands. Atmospheric pollution suppresses growth processes, the vital structure of medium-aged lichen-green moss pine forests is noticeably deteriorating. The currently observed improvement in the condition of pine forests in areas of industrial atmospheric pollution on the Kola Peninsula (reduction in the damage of needles and an increase in their life expectancy on trees, intensification of growth processes, improvement of the living condition of individual trees and stands) indicate a positive reaction of Pinus sylvestris to a 6-8-fold reduction in the amount of atmospheric emissions of toxic substances since the beginning of the third millennium.