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The article presents the results that reveal the features of the state of the hypothalamic-pituitary-gonadal axis and the level of dopamine in apparently healthy men with different adaptive potential of the circulatory system, taking into account age and territory of residence. Material and methods. The study involved 155 men (90 residents of the European North (Arkhangelsk Oblast) and 65 residents of the Asian North (Yamalo-Nenets Autonomous Okrug)) aged 22–59 years. Serum hormone levels of the hypothalamic-pituitary- gonadal axis were determined by enzyme immunoassay and radioimmunoassay in vitro analysis. The adaptive potential was calculated according to R.M. Baevsky. Results and its discussion. The functional tension of the mechanisms of adaptation of the circulatory system in men of the European North and unsatisfactory adaptation in men of the Asian North were revealed. In the studied regions of the North, there are no people with good and satisfactory adaptation, and the group of people with a breakdown in adaptation was identified only in the Asian North in men aged 45–59 years, which allows us to classify these subjects as a risk group for developing cardiovascular diseases. In men of the European North, the unsatisfactory adaptation was combined with an increase in the levels of prolactin (at the age of 22–44 years) and follitropin (at the age of 45–59 years) and a decrease in the level of sex hormone-binding globulin (at the age of 22–44 years). A decrease in the levels of total and free testosterone can be attributed to the key markers of failure of adaptation in men of the Asian North aged of 45–59 years. When analyzing the data of the entire surveyed population of men aged 22–59 years, an increase in aromatase activity was noted against the background of a decrease in testosterone levels in men of the European North with the 4th degree of adaptive potential and in men of the Asian North with the 5th degree of adaptive potential, which can be considered as a compensatory reaction to preserve the function of the cardiovascular system.

In the European North of Russia, the need for scientifically based normative and reference materials for stands’ survey, including nonprincipal tree species, such as treelike willow, represented in the region mainly by sallow Salix carpea L., northern willow Salix borealis Fries, almond-leaved willow Salix triandra L., and their hybrids, was and remains relevant. Without maintaining a unified system of forest survey standards, it is impossible to conduct intensive forestry. Forest survey standards for a treelike willow were developed, taking into account the specifics of forest growing conditions of forest areas. The absence of forest survey standards for a treelike willow makes it difficult to improve the accuracy of accounting forest resources in the European North of Russia, to fulfill functions of protecting, safeguarding and restoring forest resources, and to increase the ecological functions of forests. The article presents new tables of volumes of willow tree stems in diameter and height in the north-taiga region. When developing the tables, the data of 42 sample plots were used, which were established in the Verkhnetoemsky and Arkhangelsk forestry districts of Arkhangelsk Oblast, on which 105 sample trees were measured. Tables of stem volumes by diameter and height of a treelike willow are used to determine the stock of stand, as well as to determine the volume of individual tree stems in the sample plots during the studies. The shape of willow stems were studied using sample trees using the old form factor. The height range with the appropriate diameter was taken from the sample plot data and the measured sample trees. Forest survey standards for a treelike willow in the north-taiga region of the European part of the Russian Federation previously have not been developed.

Assessment of forest regeneration using remote sensing data is a priority scientific research topic worldwide today. Threshold values for successful reforestation can be defined using multi­temporal satellite scenes and indices for analysis of vegetation on cutting and burned areas. The analysis of successful reforestation has practical value for Russian government organizations for transferring burned and cutting lands to forest cover land. The rate of reforestation depends on climate, soil conditions in the region of studies. Collection of field data and the studies were carried out in northern and middle taiga of Arkhangelsk Oblast. This territory belongs to boreal forest. Calculations of spectral indices for each research object were made using multi­temporal scenes for 20 years based on Google Earth Engine platform. Optimal spectral index was selected based on the analysis of collected data. The optimal threshold values of the index for transferring pixel of satellite imagery to forest cover land were found using this data. Optimal spectral index for transferring non­forest cover to forest cover land SWVI was selected. The optimal threshold value for transfer to forest cover land equals 80 % recovery of the index after a disturbance in forest cover. Method for transferring land to forest cover land was developed based on analysis of dynamic of the spectral index. The result was the spatial layer of transferring land to forest cover land in 2018 on the territory of Severodvinsk and Onega forestry district of Arkhangelsk Oblast.