The complex process of forming the language of Russian forest science remains an understudied and relevant area of research to this day. The relevance of studying terminological vocabulary is determined not only by its role in the system of scientific knowledge but also by its recognized authority in identifying scientific reflection of a certain period. This article examines one of the keys and at the same time controversial terms in the history of Russian forest science – “forest stand” (nasazhdenie) Based on retrospective analysis of diverse textual material, an attempt is made to reconstruct the initial stage of formation and transformation of the content of the term in Russian forestry. It is suggested that the term was introduced into scientific circulation and initially recorded in writing in P. Perelygin's work “Description of Forestry Rules” (1831) (Nachertanie pravil lesovodstva). The commonly used polysemous word “nasazhdenie” as a translation of the German forestry term “Bestand”, has been widely adopted within professional circles despite lacking formal lexicographic definition. The first dictionary entry for the term “nasazhdenie” appears towards the end of the nineteenth century in P. Verekha’s “A Sketch of Forestry Terminological dictionary” (Opyt lesovodstvennogo terminologicheskogo slovarya). Significant natural science works from the second half of the nineteenth century (by N. Annenkov, Kravchinsky, M. Tursky, A. Krauze et al.) are utilized to detail the debated aspects of interpreting the term within the Russian forest scientific discourse. By the beginning of the twentieth century, the term “nasazhdenie”, which had undoubtedly taken root, was more frequently employed than “lesonasazhdenie’. Scientists often regarded the nomination of the term as unsatisfactory, leading to attempts to find alternative names, among which the most common was “drevostoy”. There emerged a tendency toward ordering the semantic scope of the term, differentiating it from other concepts (group, quarter, plot), classifying characteristics of stands were highlighted, followed by their grouping into ‘types of stands”. These debates continued during the first half of the twentieth century and were linked with issues of forest typology.

Improving the effectiveness of additional professional education of employees of forest fire protection services and volunteers is a very relevant area of   research not only for the Khanty-Mansiysk Autonomous Okrug – Ugra, but also for all regions of Russia that have a forest fund. The purpose of the study is to examine the current state of affairs in the field of additional education of forest protection specialists and voluntary forest firefighters, to develop recommendations for improving the effectiveness of such additional education. The objectives of the study were: analysis of the amount of economic damage caused by forest fires in the autonomous region, the number of volunteers involved in the conservation, protection, reproduction of forests, the state of affairs for additional training of specialists and volunteers, the economic justification of the costs of developing a system of additional education for fire service workers. The principles of organization of additional education are formulated, the content of training modules is outlined, the amount of costs for organizing training is determined. The content of the fourth training module related to highlighting the results achieved in the work of fire services using statistical indicators is disclosed in detail. The main performance indicators of firefighters are: the average number of workers involved in one fire, the average area of   one fire at the time of detection. The actual values of these indicators are given, which indicated an increase in the performance of firefighters. The introduction of new educational technologies into the educational process and the return on costs are justified. The measures proposed in this study could logically supplement the existing system of forest protection measures approved in the strategic planning document for the development of the forestry complex – the Forest Plan of the Khanty-Mansi Autonomous Okrug for 2019-2028, and contribute to improving the efficiency of firefighters.

Due to climate change, the forest biomass acquires exceptional ecological significance at the planetary level. To evaluate it, easy-to-implement methods are needed, one of which is the method of allometric models. Since biomass is related to some dendrometric indices of the tree, multifactorial allometric models began to be developed, however, their verification for multicollinearity was usually not carried out, and the models were often unstable. The paper attempts to optimize the structure of a multifactorial model of biomass under the condition of multicollinearity of independent variables based on the most comprehensive author's database of tree biomass to date. For this purpose, 11,170 model trees with measured aboveground biomass were selected from the database for 12 forest-forming genera, of which only 1,514 trees had their root biomass measured. The multicollinearity of the tree's age, DBH, and height is analyzed. Based on the calculation of the variance inflation coefficient (VIF), it was found that when these three variables being included in the model, give not correct result under the condition of multi-collinearity for 12 genera. When analyzing VIF for two prognostic variables in different combinations, the lowest VIF values (< 5) were found for age and DBH, but only for 6 genera, the most represented by the number of measurements. It would seem that a model that includes a combination of these two variables with a minimum VIF is optimal in its structure. However, the low multicollinearity of variables does not ensure the optimality of the model structure. Regression analysis of the relationship of biomass with these two variables showed that age in some cases is not statistically significant, and its contribution to explaining the biomass variability was less than 7%. This means that the optimal model structure can be established as a result of some compromise between low multicollinearity and high contribution of variables to the explanation of biomass variability. After all, generic allometric models have been calculated to estimate the aboveground, underground, and total biomass by DBH for 12 genera, which, when used locally, can produce biased results. Thus, the issue of optimizing the structure of the biomass model remains open, and in each case the researcher has to find a “golden mean” between selecting independent variables with minimal multicollinearity, on the one hand, and between including the largest number of statistically significant independent variables in the model, on the other. 

The article considers the features of variation of anatomical characteristics and density of wood along the trunk in stands of Scots pine (Pinus sylvestris L.) on the territory of the Republic of Tatarstan, Russia. The objects of the study were forest plantations on former arable land with an average age of 55 years and natural stands aged 85 years on forest soils (the parent soils on the sites and the landscape conditions are similar). Trial areas were laid out on each of the objects, on which model trees were cut down from various diameter classes, and then buckled into segments of 10%. Further, the macrostructure of wood along the trunk height was studied on the selected discs, with the allocation of late and early xylem zones in annual growth width, and the basic density of wood was measured. The study showed that forest plantations on old arable soils formed a large average annual layer width along the trunk with a slightly increased proportion of early xylem relative to natural stands. At the same time, the increased proportion of early xylem in the annual layer width did not lead to the formation of significantly less dense wood in the plantation. The density of trunk wood in the most represented diameter classes (20-24 cm) in forest plantations and in natural stands is similar at a 95% confidence level. Given the superior productivity of the studied forest crops (255 m³/ha versus 210 m³/ha in natural stands), it can be concluded that in the Republic of Tatarstan the phytomass of such plantations significantly exceeds the natural stands on in similar landscapes by the age of 55 years. The aligned conditions at the site with forest plantations (old arable soils with constant mixing of the upper soil horizons and ordinary planting) led to less variability in annual growth rates along the trunk relative to a naturally formed stand, in which the influence of competition within the stand and the features of the microrelief areas occupied by individual trees led to large fluctuations in parameters. 

This paper examines the spread of invasive organisms that cause the weakening and death of elm and ash trees in the historic parks of St. Petersburg. The spread of the Dutch elm disease pathogen Ophiostoma novo-ulmi and the elm bark beetle Scolytus spp. has led to the widespread death of elms in St. Petersburg. The emergence of outbreaks caused by the fungus Hymenoscyphus fraxineus and, in particular, the spread of the emerald ash borer Agrilus planipennis are the cause of ash dieback in the Petrodvorets district. The main objects of study are Alexandria Park (144 hectares) and the Memorial to the Defense of the City in 1941–1944, part of the “Green Belt of Glory of Leningrad” complex. An analysis of the volumetric-spatial structure was conducted based on historical and archival data and field surveys. The degree of preservation of compositional integrity was determined using N.N. Gusev's scale for assessing the preservation of the historical (memorial) appearance of trees and shrubs. The death of elm and ash trees as a result of pest and pathogen activity was established. The species composition of the Alexandria Park plantings corresponds to the historical one by more than 50%, but their placement does not correspond to this historical pattern. At the memorial complex commemorating the defense of the city, the species composition corresponds to less than 50%, and the placement also does not correspond to the historical pattern. At all surveyed sites, measures are necessary to preserve the historical appearance of the cultural heritage site, namely, the restoration of the compositional structure. Adaptation of the plantings to the effects of invasive pathogens and pests is recommended for the territory of the memorial complex. Preserving the compositional structure of parks by replacing woody plant species with the most similar visual characteristics, while ash and elm trees are rapidly dying due to the spread of invasive pests and pathogens, is a key task in preserving St. Petersburg's historic parks. However, to avoid the permanent loss of key landscape components, this task must be accompanied by a search for ways to control the numbers and spread of invasive pathogens and pests. 

The article presents the results of a study of seven forest communities of the State Nature Complex Reserve of Republican Significance “Gornoye Zadelye” of the Mari El Republic: 1) Pinus sylvestris L. + Picea × fennica (Regel) Kom. ‒ Corylus avellana L. ‒ Oxalis acetosella L. + Mercurialis perennis L.; 2) Pinus sylvestris L. ‒ Carex rhizina Blytt ex Lindblom + Oxalis acetosella L.; 3) Tilia cordata Mill. ‒ Corylus avellana L. ‒ Stellaria holostea L.; 4) Sorbus aucuparia L. ‒ Rubus idaeus L. + Aegopodium podagraria L. + Equisetum pratense Ehrh.; 5) Alnus incana (L.) Moench ‒ Cirsium oleraceum (L.) Scop. + Urtica dioica L.; 6) Abies sibirica Ledeb. + Picea × fennica (Regel) Kom. ‒ Oxalis acetosella L. ‒ Rhytidiadelphus triquetrus (Hedw.) Warnst.; 7) Picea × fennica (Regel) Kom. ‒ Oxalis acetosella L. + Mercurialis perennis L. The characteristics of forest phytocenoses and phytoindication assessment of ecotopes are given according to soil scales and the illumination-shading scale of D.N. Tsyganov. The results showed that the soils of the studied phytocenoses are poor, poor/sufficiently supplied with nitrogen; acidic/slightly acidic/neutral; have dry forest-meadow/wet forestmeadow/damp forest-meadow moisture with relatively stable with slightly variable/moderately variable moisture; prefer semi-open spaces, light and shady forests. Rare plant species were found in the studied phytocenoses: Diplazium sibiricum (Turcz. ex Kunze) Sa. Kurata or (Turcz. ex Kunze) Jermy, Cystopteris sudetica A. Braun et Milde [Rhizomatopteris sudetica (A. Braun et Milde) A.P. Khokhr.], Hieracium sylvularum Jord. ex Boreau, Cypripedium calceolus L., Gymnocarpium robertianum (Hoffm.) Newman, Schizachne callosa (Turcz. ex Griseb.) Ohwi, Actaea erythrocarpa Fisch. and Epipactis atrorubens (Hoffm. ex Bernh.) Besser. The values of potential ecological valences and tolerance indices allow us to assess the adaptive abilities of rare species to environmental conditions. Almost all of them have a narrow distribution range on soil scales and are characterized as hemisthenovalent and stenovalent species, and in relation to a complex of factors they are hemisthenobionts and stenobionts, which emphasizes their vulnerability and the importance of protecting the forest ecosystems of this reserve. 

The structure of forest communities formed after catastrophic disturbances is determined by the nature of ongoing successions. The characteristics of forest phytocenoses recovery successions after catastrophic disturbances are largely determined by their initial stage. The increase in the number of various catastrophic disturbances determines the relevance of research aimed at studying the characteristics of forest restoration processes in clear cut areas in the Moscow region. The aim of the study was to examine the recovery processes of tree and shrub vegetation at the initial stages of demutation after catastrophic disturbances in pine stands in the near Moscow region. The article presents the results of a four-year study of secondary successions in clear cut areas after the 2017 windfall in pine stands on the territory of the Serebryanoborsky Experimental Forestry of the Moscow region. Taking into account natural regeneration, 46 circular survey plots of 10 m² each were laid out in the studied clear cut areas. There are 22 counting plots in felling area no. 1 and 24 plots in felling area no. 2. Only viable undergrowth was counted, divided into size categories. For each pine specimen, annual increments of the axial shoot in height were measured by whorls. The dynamics of the main forest-forming species for the period 2020–2023 are considered. In the sixth year after the windthrow, the share of Scots pine (Pinus sylvestris L.) does not exceed 30% of the total number of trees and shrubs. The number of trees and shrubs in the sixth year after clear sanitary felling in clear cut area no. 1 is 26.0 thousand pcs/ha, in the territory of clear cut area no. 2 – 29.2 thousand pcs/ha. The average age of the main species in clear cut area no. 1 is 3.6±0.1 years, and in clear cut area no. 2 – 4.5±0.1 years. Pine regenerates well at a distance of up to 60–70 m from the sources of seeding. The conducted studies show that in the type of forest growth conditions B₂ at the initial stages of secondary successions after catastrophic disturbances, the amount of natural pine regeneration is satisfactory, however, this species is significantly inferior in average height to small-leaved species, which complicates the successful formation of pine stands in the studied area.

The influence of regeneration felling on the younger generation of forests in the pine plantations of the Novichikhinsky forest district in the Altai Krai has been studied. The age of felling is 19-21 years; the intensity of felling varies from 30 to 60%. The regeneration felling was carried out by evenly thinning the older generations of pine trees. The taxation characteristics of stands and undergrowth before and after felling are given. The current height increases are determined. The number and stock of dead trees on the studied plots are estimated. The study shows that in the conditions of fresh forest and dry forest on gentle slopes, the felling allowed rejuvenating pine plantations and accumulating a sufficient amount of undergrowth in them for successful forest regeneration. In the conditions of the grassy forest, the regeneration felling negatively affected the undergrowth and the forest stand. The study proves that the younger generation in pine plantations subjected to regeneration felling is formed mainly due to pre-generation undergrowth. The study revealed that after regeneration felling in the conditions of fresh forest and dry forest on gentle slopes, the undergrowth of pine trees shows a similar growth dynamics in height. It has been established that after regeneration felling, the current height gains of the pregeneration undergrowth increase over a period of 10-14 years, after which they begin to decrease. It is recommended to carry out the final regeneration felling on three studied plots; on one plot, it is recommended to cut down single trees and take care of young ones; on another plot, measures are needed to promote natural regeneration and subsequent regeneration felling, or to carry out interlaced gradual felling and the creation of forest crops in the cut-down strips.

The article provides an assessment of the illumination under the canopy of the forests of the Arctic zone of the European North. The level of illumination under the canopy of a stand is a strategic regulator of the processes occurring in the forest biogeocenosis, valuable information necessary for forest management, especially in a changing climate. Proper regulation of illumination is recognized as the main way to control the restoration and development of forests. To do this, it is necessary to create a database on the illumination under the canopy of various plantings and the reaction of all components of the forest to it. The illumination under the canopy of the North taiga and tundra forests has not been sufficiently studied. The research was carried out during the growing season in pine forests, spruce forests and birch forests of Pechora (Komi Republic), Arkhangelsk and Pinezhsky (Arkhangelsk region) forest districts. The illumination was measured at a height of 1.3 m around noon. The difference between the light regime of tundra forests and North taiga forests is the high permeability of the canopy. The relative illumination at an altitude of 1.3 m under the canopy of various types of tundra forests and under different types of weather exceeds the same value in the North taiga forests by 3.6-5 times. As a result, higher levels of illumination are formed here. The high permeability of the canopy in tundra forests is due to the closeness of the crowns. With a relative abundance of trees similar to the Northern taiga forests, the crown closure are almost 2 times lower. The share of solar energy transmitted under the canopy in cloudy weather is 2-16% more than in sunny weather. The influence of the type of forest on the sub-ecological illumination is ambiguous. In addition to the type of weather, it is necessary to take into account the distance from the edge of the forest. In tundra forests, the proportion of birch in the composition of the stand affects the illumination.

Large herbivores are an active part of forest biogeocenoses, participating in trophic and topical activities, as a result of which they are considered key species, as they can make significant changes in the processes of landscape dynamics and functioning. The aim of the study is to identify long-term changes in tree and shrub vegetation (tree stand, young forest trees and undergrowth ) as a result of the impact of ungulates in the bison nursery of the Prioksko-Terrasny Reserve. The object of the study is the forest lands of the Prioksko-Terrasny Reserve. The materials for the study were the data of forest inventory descriptions for the territory of the nursery and adjacent areas for 1946 and 2016, visual route surveys. The study made it possible to assess numerically the impact of bison on the quantitative characteristics of the components of forest phytocenoses. In the bison nursery, from 1946 to 2015, there was a decrease in the forested area (from 92.4 to 83.2%) and the proportion of stands with a predominance of pine and aspen. A decrease in areas with distinct layers of young forest trees and undergrowth, as well as a decrease in their species diversity and density, was revealed. The most vulnerable were such forage species as spruce, buckthorn, rowan, and euonymus. In the conditions of suppression of natural regeneration by bison, in the coming decades, in places of tree loss in overmature stands, processes of formation of open landscapes with single trees and a further decrease in forested area will occur. Bison in the zone of coniferous-broadleaf forests have a strong impact on the composition and structure of plant communities. When reintroducing bison to different soil and climatic conditions, further research is required to monitor their impact on the components of forest biogeocenoses.

Water scarcity represents a critical global issue for many areas of activity, including agriculture and forest reclamation, both of which are pivotal for optimizing soil water regimes, mitigating erosion and enhancing soil organic matter content. For instance, forest reclamation activities require advanced technologies to improve water availability for transplanted seedlings. One such approach involves the application of superabsorbent polymers, commonly referred to as hydrogels. Hydrogels exhibit a broad spectrum of applications, spanning medicine, agriculture, construction, wastewater treatment, and land reclamation. Within the root zone, hydrogels function as moisture reservoirs, absorbing water and releasing it gradually over extended periods, thereby stabilizing the water balance in the rhizosphere. However, it is critical to acknowledge that once introduced into the soil, hydrogels persist for a duration dictated by their resistance to microbial degradation. Over time, they may lose their swelling capacity, potentially remaining in the soil in a degraded state, necessitating the periodic supplementation of new hydrogel doses. Given the continued utilization of hydrogels and their recurrent introduction into the environment, particularly into soils, it is imperative to evaluate their resistance to biodegradation. Considering that our current knowledge regarding hydrogel fragmentation in soils is limited and predominantly theoretical, it is essential to investigate specific environmental conditions and properties of the hydrogels themselves, that govern the fate of hydrogels in soil systems and their implications for ecosystem functionality.

The article discusses the use of deep learning neural networks to verify forest taxation indicators obtained during forest management. The authors have designed a technology for verifying forest management data based on the high-resolution optical satellite images processed applying neural networks. The initial data were images of the Melenkovskoye forestry district in the Vladimir region taken from Sentinel-2 satellites; atmospheric correction was performed with the Sen2Cor algorithm. The process of forest taxation interpretation of images was automated with the «Geotron. Forest Validation» software, a specialized geoinformation resource developed by the NC OMZ, FBU VNIILM and FGBU “Roslesinforg”. The TensorFlow and Keras libraries were used to train the neural network models; the training sample was based on the average pixel values within the boundaries of each plot for every channel. After training, the neural network determined forest characteristics for each section, and also gave the difference between the forest management documentation data and those calculated by the neural network; this allowed identifying deviations in the stock volume, forest density, and stands age. The model's operation demonstrated that a significant portion of inaccurate forest management data is typical for complex stands with several species in the composition, as well as for sparse maturing and mature stands with different species composition of the first tier. The study result showed that the accuracy of neural network training and operating directly depends on the of data amount, in particular, the number of sections for which training occurs. Acceptable results are obtained with a sections number exceeding 5,000 pieces. Considering this, the developed technology allows obtaining good results in validating forest management data on an area exceeding 10 thousand hectares, which is comparable to the average area of one forestry district in the central part of Russia.

The article is devoted to the inventory of larches (Larix Mill.), which was made by the authors in 2019–2020 on Elagin Island (S.M. Kirov Central Park of Culture and Leisure) to clarify the taxonomical composition of the collection, and was a continuation of a previously conducted comprehensive study of the park’s flora. The total number of larches is 974 specimens. These are mainly old-growth larches. L. sibirica (465 specimens) and L. decidua (384 specimens) prevail. L. archangelica (50 specimens) and L. czekanowskii (48 specimens) have the second place. These species have proven themselves well and successfully grow on the territory of park “Elagin Island”. In addition, in the park, there are some individual trees of the Czekanowskii larch, a natural hybrid between the Dahurian larch, or Gmelin's larch, and the Siberian larch (L. czekanowskii (L. dahurica × L. sibirica)) with horizontal, widely spreading branches; the bark of old trees has large adjacent oblong plates. The cones usually differ in size, even within the same shoot; there are forms with predominantly large cones and rounded, but naked scales (a form close to L. sibirica) or with small cones and truncated scales (a form close to L. dahurica). There are also cultivated hybrids of Sukachev, or Arkhangelsk larch, and European larch (L. archangelica × L. decidua) and European larch and Siberian larch (L. decidua × L. sibirica) with intermediate characteristics between the parental species.

The study was conducted in 2021-2024 in the North-West of Russia (Leningrad region, Gatchina district). The objects of the study were mature pine-spruce stands, with 6 to 8 units of pine and 1 to 3 units of European spruce (Pícea ábies), belonging to the Baltic-Belozersky taiga forest growth region of the Luga-Oredezh landscape in the Oredezh plateau area. Sample plots were laid out in forests that have not been affected by human economic activity for a long time. On 10 sample plots, 10x10 m squares were laid out, for which a continuous census of undergrowth was carried out, a geobotanical description of the living ground cover was made, soil pits were laid with subsequent agrochemical analysis of the upper horizons. Cartographic materials of parcel structure in 10x10 m squares allocated on the studied objects with marked trees of the main tree layer, undergrowth and underbrush have been compiled. The article reflects the distribution of spruce undergrowth by the main root parcels identified in pine-spruce forests. Agrochemical indicators have been determined: humus content, exchange and actual acidity indicators, degree of provision with mobile nitrogen. A correlation analysis of the relationship of agrochemical indicators with the number of spruce regeneration has been carried out, which showed their insignificant influence on the regeneration of European spruce, compared with the influence of plant elements. A significant influence of relief on the processes of natural regeneration by forming a moss layer has been revealed. The obtained results can be used for a more accurate assessment of the success of natural regeneration during forestry measures, for restoration and conservation of forests in the south of the Leningrad Region.

Experimental data on the composition of vegetation in forest areas subject to the complex influence of anthropogenic factors are presented. The object of the study is degrading spruce forests, the average age of which is about 80 years. Spruce forests grow on the southwestern outskirts of Petrozavodsk. It has been established that spruce forests growing along the federal highway Murmansk-St. Petersburg on the territory of the Republic of Karelia are destroyed with the formation of windows of different sizes in the place of decaying forest stands. The degradation of roadside spruce forests is aggravated under the influence of intense recreational load. The diameter of the windows varies from 10 to 80 m. It is shown that the windows are quickly overgrown with deciduous trees, represented mainly by birch, aspen, gray alder, rowan, and goat willow. The density of young growth reaches 2800 ind./ha. It is shown that the average height of young stands depends on the composition of tree species, the average age of the trees, the diameter of the window and ranges from 4 to 7 m. At the same time, under the canopy of the formed deciduous young stands, spruce regrowth appears. The total number of undergrowth can be 3100 ind./ha. Teenagers of the “viable” category predominate – from 62 to 94% of the total number. The average height of spruce undergrowth varies from 0.5 to 1.7 m. 22 species of vascular plants and at least 6 species of mosses were identified as part of the living ground cover. Eight species were identified as part of the undergrowth: red elderberry, common honeysuckle, goat willow, long-eared willow, brittle buckthorn, common rowan, red currant, and needle hips. The total number of undergrowth species reaches 1500 ind./ha. Of the herbaceous plants, the maximum coverage is Calamagrostis arundinacea (L.) Roth, – up to 13%, Oxalis acetosella L. – up to 31%, Vaccinium myrtillus L., – up to 36% and Dryopteris carthusiana (Vill.) H.P.Fuchs – up to 14%. In general, up to 32% of the area is covered with green mosses. The projected coverage with Polytrichum commune Hedw. on individual accounting sites is 62%.

The purpose of the study is a comparative assessment of the viability and prospects of further economic use of various representatives of the genus Larch in the Nizhny Novgorod region. To assess the viability and prospects of plants, 7 main indicators were adopted, which were determined by systematic visual observations of the general and seasonal development of plants and, at the same time, can characterize the condition and the possibility of the existence of these plants in these conditions. These are the following indicators: lignification of shoots; winter hardiness; preservation of the growth form; shoot-forming ability; height gain; generative development ability; methods of reproduction in culture. Representatives of the genus larch have complete lignification of the entire annual growth, annual shoots do not freeze during the winter period, and the form of growth in the culture remains. In addition, the studied species of larch have an annual increase in height and are capable of seed maturation. The study showed that European larch and Sukachev’s larch have the highest viability (100 points) in the Nizhny Novgorod region. The overall viability index of Japanese larch, broad-scaled larch and hanging larch is slightly lower (95 points), but they can also be attributed to the group of quite promising species. Daurian larch, Lyubarsky larch and Polish larch have a lower viability index (93 points). The conducted studies, which have shown the high viability of all introduced species of the genus Larch, determine great opportunities for carrying out full-scale introduction work, forming an assortment of species of this genus, replicating planting material to create landscaping plantings of larch in the territory of settlements of the Nizhny Novgorod region. The native species, Sukachev’s larch, deserves wider use in forestry, and the introducers of this genus are used in the creation of plantation and landscape crops, protective afforestation, and landscaping of settlements.

The article is devoted to comparison the phytomass of two tree species: lodgepole pine (Pinus contorta Dougl.), native to North America, and local Scots pine (Pinus sylvestris L.) in experimental plantations of the Syktyvkar, Koygorodsky, Kortkerossky and Ukhta areas of the Komi Republic, established in 2004–2006 on 4 sites of different forest categories. The studies were conducted from 2021 to 2023. Calculations of phytomass reserves were carried out using model trees for allometric equations. The weight of one tree in an absolutely dry state varies for Scots pine from 14 to 22 kg, for lodgepole pine – from 23 to 38 kg per tree. By the age of 20 years, the aboveground phytomass of lodgepole pine trees accumulates from 46 to 76 t/ha, and that of Scots pine from 30 to 44 t/ha of organic matter. It is shown that by trunk mass in experimental plantations planted on pine clearings and agricultural lands, lodgepole pine maximally exceeds Scots pine compared to other areas (reclaimed quarries). In general, the results of the study showed that the excess of aboveground phytomass of lodgepole pine plantations, compared to Scots pine, is from 25 to 45% in different areas. The structure of aboveground phytomass of the species studied has a similar pattern. The results obtained can be used to replenish the database on the productivity of forest crops and to assess carbon deposition by forest plantations in the middle taiga.

The research was conducted on Yagry Island in the Dvina Bay of the White Sea. It is a sandy island, which is almost completely overgrown with forest except for the northernmost part. Sample plots were laid out in two pine phytocenoses, where all vegetation layers were studied. One pine forest was formed the latest and is isolated from the general forest area (conditionally the first stage of succession). The other is about 10 years older and is located at a distance of about 1 km from the first (conditionally the second stage of succession). It has been established that significant changes in the species composition of living ground cover plants have occurred in the pine forests over the past 10 years. If, at the beginning of the pine's settlement, lightloving species prevailed in the ground cover, above all, cereals, after 10 years they disappeared (tufted hairgrass) or their cover significantly decreased (common bent). Shade-tolerant dominant species such as lingonberry in the grass-shrub layer and Schreber's pleurocium in the moss-lichen layer have significantly increased in the projective coverage. It is shown that the pine forests are of different ages in terms of age structure, the trees belong to two age classes. The parameters of pine trees have been determined. The average diameter of trees in 10 years increased by 0.8 cm, height by 0.7 m, and the number of trees, on the contrary, decreased by 72 pcs/ha. A high degree of synchronicity in the variation of radial increment over the years is shown. The synchronicity coefficient is 87%. The radial increase in absolute values at the first stage at the beginning of the settlement is about 1.5 times greater than at the second, but over time their values have equalized. It has been established that at the first stage of succession, the basic density is lower than at the second and the difference persists over the years. The basic density at the first stage of succession is 381 kg/m³, and at the second 5– 389 kg/m³, which is 55–11% lower than in the northern taiga. 

In the conditions of the Luga-Oredezhsky landscape of the Leningrad region, a study of the density of spruce wood was conducted.  The objects of the study were ripe relatively pure spruce forests growing on forest and postagrogenic lands. For spruce stands growing on old arable lands, there is a higher density of wood than for plantations on forest soils. The modeled graphs of the quadratic function make it possible to predict the density of wood by the height of the spruce trunk for similar growing conditions. The study revealed the different nature of the formation of the density of spruce wood in the height of the trunk at different levels of tree thickness. The differences are confirmed by a variance analysis of the data obtained. 

The object of the research is 8-year-old pine forest cultures in clearings in the true mosses type of forest in the territory of the West Siberian subtaiga-forest-steppe region. The aim of the research is to study the features of the structural and functional organization of pine forest plantations with different numbers of additional landings at the time of their transfer to the category of lands on which forests are located. The studies on the sample plots of forest plantations were carried out according to generally accepted methods, taking into account modern methodological requirements, with the laying out of sites measuring 50x50 m transect. The trees were additionally divided into groups by year of planting. It was found that in forest plantations with additional landings, the average diameters and heights of the trunks were significantly reduced compared to areas where additional landings were not made, but, in general, they met the established requirements, both in terms of the number and average height of trees of the main species. It has been shown that as a result of additional landings, the average age of pine forest plantations has decreased by 0.4–1.2 years. The presence of trees of different ages and sizes, as a result of the additional landings, determines a significant range of variation in trunk height. It has been established that in the absence of additional landings or a single additional planting, the distribution of trees by height is close to normal. In the presence of several additional landings, the distribution of pine trees by trunk height differs significantly from normal. Pine forest cultures with additional landings can be classified as single-aged young stands with regular placement of trees. 

Reduction of biodiversity in the process of forest management and the solution of the issue of species conservation are of particular relevance for the forests of the taiga zone, where clear-cutting is carried out over large areas. One of the possible ways to conserve species in the process of timber harvesting is the identification of key biotopes – areas with a high representation of floristic diversity, as well as the presence of single plant species in need of protection. The aim of the work was to verify the results of floristic studies conducted in key biotopes with temporary and permanent excess moisture preserved during clear-cutting 4-5 years ago. The Turing coefficient and the estimated indicator of the potential number of plants were used as tools for verifying the results of floristic studies, the determination of which is based on the calculation of the actual number of plant species found during the field survey, as well as the number of single and protected species within the boundaries of the sites. Carefully verified results of floristic studies, if sufficient and complete, can serve as a basis for formulating scientifically substantiated conclusions and practical recommendations. During the study of floristic diversity in key biotopes with excessive moisture 22-34 species were recorded, including herbaceous plants, mosses and lichens, among which 1-8 species are singletons, represented by single specimens, and 3 species have a protected status. The calculated Turing coefficients, ranging from 0.73 to 0.97, show that for all key biotopes the completeness of the survey is sufficient for interpreting the corresponding research conclusions. At the same time, the potential number of species growing in the areas may be somewhat higher compared to their actually recorded number. 

This study presents a detailed analysis of the soil microbial community in the Republic of Tatarstan, which has developed under the influence of different types of vegetation—mixed and pure pine communities—on former arable lands. Soil samples were collected from both the upper horizon and the previously cultivated layer, allowing for an assessment of changes in microbial structure depending on land use history. The research aims to identify relationships between various groups of microorganisms involved in the nitrogen cycle and organic matter decomposition, as well as their roles in soil fertility recovery processes. Correlation analysis using Pearson’s and Spearman’s coefficients revealed moderate to strong positive relationships among microorganisms. These connections indicate similar environmental conditions and participation in a common trophic chain. As a result of the study, several groups of samples were distinguished based on differing populations of nitrogen-fixing bacteria and actinomycetes, reflecting the dynamics of humus formation and changes in soil fertility levels. The work emphasizes the importance of microbial communities in soil selfremediation after cessation of agricultural use. The established relationships between microorganisms and their roles in ecosystem restoration open new avenues for further research, including studies on forest structure and agrochemical soil indicators. The obtained data will be utilized in future publications to deepen understanding of complex changes occurring in abandoned agricultural lands.

The article presents the results of research on the clonal micropropagation of the form of narrow-leaved blueberry (Vaccinium angustifolium Aiton) collected at the variety testing site of a plantation in the Arkhangelsk region. For clonal micropropagation of species, forms and varieties, it is necessary to select an individual protocol corresponding to the biological characteristics of the replicated species. For the initial treatment of plant material in vivo, the first 10 cm of annual growth of the donor plant were cut off. At the sterilization stage, when introducing into the in vitro culture, a 5% solution of “Lysoformin 3000” and a 5% solution of “Brilliant” were used to sterilize the explants of narrow-leaved blueberry at an exposure time of 5, 10 and 15 minutes. The largest proportion of healthy explants was recorded when using “Lysoformin 3000” solution for 15 minutes – 76.6%. At the stage of microreproduction proper, when hormones 2-ip (1.0-1.5 ml/l) and indolylacetic acid (0.1-0.2 ml/l) were added to the nutrient medium, the largest average number of formed buds and the highest values of the average length of micro-shoots of narrow-leaved blueberries were marked. The period between passages lasts 35 days. When replicating regenerants with segments containing 1 bud each, the reproduction coefficient is 3. In order to increase the amount of planting material yield, the upper part of the plant was cut off for further replication, and the rooted segment with two buds was moved to the vegetation plant for adaptation. The adaptation of micro-plants was carried out according to a proven technique in a vegetation installation for 16 days, which allows you to save the maximum number of adaptable plants.

The article reports the results of research on the growth of one-year-old curly birch seedlings produced through open pollination and growing in the Leningrad Region in the Gatchina permanent seed production stand (PSPS), training nursery of the Lisino Forest College (Shapki plantation), and arboretum of the St. Petersburg Forestry Research Institute (StPFRI). It is demonstrated that the seedlings’ parameters varied significantly depending on the seed collection year and method. Thus, the average height of seedlings in the StPFRI arboretum by the fall 2023 was 51.4 cm and their root collar diameter was 1.6 mm. In 2024, the average values of these parameters were the highest in seedlings grown from seeds collected in the Gatchina PSPS (20.5 cm and 2.5 mm, respectively) and the lowest in seedlings originating from the StPFRI arboretum (8.2 cm and 1.6 mm). Application of the BpCW1 molecular marker permitted detecting the seedlings with the ‘figured grain’ trait as early as in their first year, whereas this trait would normally have exterior manifestations only at 8 years of age or even later. PCR analysis revealed homo- or heterozygous (476 base pairs or 476/530 base pairs) amplification products characteristic of figured-grain curly birch plants in 43% of the analyzed seedlings, which is notably higher than accepted previously for seed progeny from open pollination. Our analysis of the growth parameters shows that the ‘non-figured’ plants had approximately 1.5-fold higher average height and diameter than the ‘figured’ plants irrespective of the seed provenance. However, these parameters are insufficient for differentiating between ‘figured’ and ‘non-figured’ plants considering the life-form polymorphism of curly birch. It is concluded that seeds from open pollination can be used to produce curly birch planting stock provided that the ‘figured grain’ trait is identified in them by the BpCW1 molecular marker, which is nearly unidentifiable at an early age using conventional methods based on the analysis of exterior (morphological) traits.

Invasive plants pose a significant threat to local ecosystems and agriculture, and their rapid spread necessitates the development of effective methods for detection and control, one of which is mapping based on remote sensing data. Geoinformation mapping of invasive plant species, particularly Sosnowsky’s hogweed (Heracleum sosnowskyi Manden.), is a pressing task for ecological monitoring. This study examines modern methods for analyzing remote sensing data to identify areas occupied by Sosnowsky’s hogweed. The research was conducted in the Leningrad Region, where the spread of this plant is a critical issue. The input data consisted of aerial photographs and open-source data from the Yandex.Maps cartographic service with ground sample distance of 3, 15, and 30 cm/pixel, which depicted territories overgrown with Sosnowsky’s hogweed. The objectives of the study were to develop an image processing technique for detecting Sosnowsky’s hogweed based on the use of automated classification algorithms. The data processing was performed using the QGIS geoinformation system and its additional plugins, «dzetsaka» and «Orfeo Toolbox». The accuracy of the research results was verified using data obtained through expert classification and manual vectorization. As a result, 24 classification maps were generated using different methods of automated classification. Accuracy analysis produced error matrices and tables showing the deviation in the areas occupied by Sosnowsky’s hogweed. Nevertheless, the accuracy assessment confirmed the high reliability of the presented classification methods. The algorithms developed in this study can be applied to detect and monitor Sosnowsky’s hogweed in the Leningrad Region.

The analysis of the reporting data of multi-operational forestry machines is an important and relevant area of research in the field of the timber industry, which makes it possible to competently regulate production and increase the efficiency of logging. This article examines the efficiency of multi-operational forestry machines in relation to the typical conditions of the North-Western Federal District. In the course of the study, the dimensional parameters of the grades harvested using felling, knot-cutting and bucking machines based on Caterpillar and Komatsu tracked excavators with a LogMax 6000 harvester head equipped with Parker Motomit IT 6.5 onboard computers and carrying out logging operations in the Leningrad Region and the Republic of Karelia were studied. The reporting data of logging operations in the Volkhov, Lodeynopolsky, Podporozhsky and Olonetsky forestry districts were analyzed.  To analyze and visualize reporting data from on-board computers of multi-operational forestry machines, a Python program has been compiled that allows processing data arrays from files downloaded from on-board computers in stm format, systematizing the data obtained, calculating statistical characteristics of the analyzed machine operation parameters, and visualizing them in the form of diagrams and graphs. It has been established that coniferous wood is mainly harvested in the considered forestry areas of the NorthWestern Federal District. In some cases (for example, in the Lodeynopolsky forestry), the harvesting of hardwoods, including illiquid and low-quality wood, prevails. In most forestry areas, sawn timber is harvested. The distribution of softwood bucking schemes varies significantly by region. The Volkhovsky district is distinguished by the harvesting of a significantly large proportion of trunks with several sawn grades, whereas in the Lodeynopolsky and Podporozhsky districts balance grades are more often produced.

This paper presents a rationale for developing a technical solution based on industrial all-terrain vehicles with ultra-low-pressure pneumatic tires. The implementation for the forestry industry consists of the design and manufacture of the studied TROM 25 wheeled timber picker. The values of the contour contact area of the tread contact patch of each measured wheel of the TROM 25 wheeled timber picker were measured. The maximum normal pressure on the soil of the TROM 25 wheeled timber picker( 8x8 wheel arrangement with Trom wheel equipment, 1960x900R38, and tire pressure of 50,000 Pa) were determined. The experimentally measured contact area of the TROM 25 wheeled timber picker (8x8 wheel arrangement with Trom wheel equipment, is indicated – 1960x900R38, and tire pressure is 50,000 Pa). A scientific innovation has been developed to determine the values of the contour contact area of the tread of each of the steering wheels, as well as to determine the contact patch of an ultra-low pressure pneumatic tire with the final support surface for forestry. The research resulted in the determination of the actual measured ground pressure of the TROM 25 wheeled timber picker, and recommendations for applying the results in real-world environmental and production conditions were provided.

Effective design of forest road networks is crucial for optimizing logging costs, forest management, and sustainable access to resources. Traditional approaches often suffer from high costs, labor intensity, and limited accuracy of initial data, especially in complex terrain and dense forests. This article presents a mathematical model for computer-aided design and optimization of forest road routes. The project area is discretized as a weighted graph, with nodes representing points on the digital terrain model (DEM) and arcs representing potential road segments. The model aims to minimize total construction cost, considering segment length, terrain, longitudinal slope (affecting earthwork volumes) via a special appreciation coefficient, and the need for culverts at watercourse crossings. Special attention is given to integrating highly detailed terrain data obtained through airborne laser scanning (LiDAR), including unmanned aerial vehicles (UAVs). LiDAR enables high-precision DEMs that penetrate the forest canopy, which is essential for accurate terrain modeling, identifying optimal corridors, obstacles (e.g., waterlogged or landslide-prone areas), and optimizing earthwork volumes. The article details the mathematical formulation as a shortest path problem on a graph, with a cost-minimizing objective function and constraints. Methods for extracting initial data from LiDAR point clouds are discussed: DEM creation, elevation extraction, slope calculation, and hydrographic network analysis using GIS. The developed model, utilizing optimal path algorithms (Dijkstra, A*), provides an objective, efficient, and economically justified choice of forest road routes, enhancing design quality. The authors also discuss prospects for further model development, including integrating soil type data.

This paper presents a review of the application of anti-corrosion coatings to protect forestry machinery load-bearing structures from corrosion. The material presented is based on research by domestic and international scientists in the field of metal and alloy corrosion protection methods, the application of various anti-corrosion coatings, and the automation of their application. The purpose of this paper is to review various types of anti-corrosion coatings that can be used to protect forestry machinery load-bearing structures from corrosion, as well as to highlight the technological features of coating application, taking into account the possibility of process automation in repair facilities. A classification of anti-corrosion coating types is presented. The article considers metallic, non-metallic, chemical, and alternative protective coatings, discusses the technological features of their use, and discusses the possibility of their application in forestry engineering. Images of the microstructures of the most typical representatives of various types of anti-corrosion coatings are presented. The images of the microstructures were obtained using a Leica DMI 5000 light optical microscope equipped with a Thixomet image analysis system. Special attention is paid to the automation of anticorrosion coating application. A classification scheme for the degree of automation in protective coating application is presented and its levels are discussed, taking into account the feasibility of implementation at forestry machinery manufacturing facilities. Based on the presented material, it is concluded that for load-bearing elements and some body parts of forestry machinery, a combination of a metallic coating applied by cold gas-dynamic spraying and a traditional paint coating is advisable. Partial automation is the most rational solution for applying protective coatings by cold gas-dynamic spraying in forestry repair facilities.

Further improvement of feller buncher machine designs is associated with comprehensive theoretical and experimental studies of their operating modes. Taking into account the large labor intensity of experimental studies it is necessary to pay more attention to the development of theoretical methods. The article deals with the vibration loading of the operator of a feller-buncher machine of limited load-carrying capacity during technological relocations. The dynamic model of the system “Operator – feller-buncher machine – subject of labor – tree” is developed, which allows to determine the operator's vibration load at the stage of machine design. The mathematical description is made in the form of Lagrange equation of the 2nd kind. The system of equations is solved with respect to the elastic deformation of the operator's seat backrest by Runge-Kutta method, using MathCAD programming environment. The character is shown graphically and the maximum values of vibration impact on the operator are determined when working in the modes of acceleration and stopping, as well as the results of vibration impact are given. The analysis of research results shows that the modes of acceleration and stopping are accompanied by a significant dynamic load both on the machine and on the operator. The level of vibration load of the operator is generally influenced by the rigidity of his seat, acceleration time when starting from the place, and the volume of transported trees.

The establishment of artificial plantations of tree and shrub species is done by sowing and planting. The most reliable and widespread method, due to better growth and development of seedlings and less need for maintenance, is planting. Forest planting is currently being done on large areas. This paper presents the results of a field study to determine the traction resistance of a forest planting machine and the quality of planting of seedlings depending on the distance between the rollers 130-165 mm for two different rollers, 400×100 mm and 310×35 mm. The strain gauge method was used in the experiment. The strain gauge equipment consisted of a multi-channel strain gauge station with a built-in generator to power the sensor. The ZET 058 strain gauge station allowed data collection from an S-shaped strain gauge that was mounted on the strain gauge linkage. Tensometric equipment allowed to determine that the resistance of the forest planting machine when installing 400×100 mm packer rollers is 1.3 times greater than when using 310×35 mm rollers. Moreover, when increasing the distance between the rollers from 130 to 165 mm, the resistance of the forest planting machine with 400×100 mm rollers decreases by 24.7%, and with 310×35 mm rollers decreases by 34%. The 400×100 mm rollers showed the best results on light soils. The average angle of inclination of seedlings during planting is 7.5°, the depth of root neck embedding is 2-3 cm, and the pulling force is 1.8-2.3 kg. All indicators lie within the optimal value. The obtained experimental data will contribute to the creation of new types of forest planting machine designs, which will further improve the quality of planting seedlings and increase the survival rate of planting material. 

The plastic ski is a high-tech multilayer composite and is assembled using the "sandwich" method: the wooden wedge is protected from below and from above by polymeric materials, which are fixed using adhesive materials ‒ prepregs. They have a structural purpose, are made on the basis of fibrous reinforcing fillers and polymeric binders of various nature. The aim of the work was to compare the performance characteristics of sports and running plastic skis manufactured using various types of prepregs developed at the Institute of Physical Chemistry of the National Academy of Sciences of Belarus. For the obtained skis based on prepreg tape and prepreg fleece, as well as unidirectional two-layer prepreg, the performance quality indicators (deflection, center of gravity position, rigidity of the middle part and bending strength, residual deflection, rigidity of the front and back parts) were determined. The obtained values of the experimental characteristics vary in a narrow range and do not exceed the standard values. The tests allowed to establish an equivalent effect on the performance of plastic skis for both samples based on a two-layer unidirectional prepreg and on a prepreg-tape – prepreg-fleece bond. The use of a two-layer unidirectional prepreg made it possible to double the productivity by simplifying the principle of assembling a ski package (complete wrapping) and the ability of one worker to service two presses. At the same time, it should be noted that the share of prepreg in the cost of a plastic ski is approximately up to 40%, replacing the prepreg-tape and prepreg-fleece bond with a two-layer unidirectional prepreg will lead to a decrease in the cost of the final product due to a 4-fold reduction in the price of the prepreg.

The article discusses the prospects for the use of surfactants in sulfate cooking. The presence of surfactants reduces the surface tension between the liquid and the wood chips, which promotes the rapid penetration of the liquor into the inner matrix of the chips and ensures selective delignification, reducing the amount of undercooked pulp and the content of extractives in the resulting pulp. Studies of the component composition of hardwood, which is a mixture of birch and aspen, showed that the content of extractive substances in it was 1.037%. Sulfate cooking was carried out according to the classical scheme and with additives of surfactants of the Dispersol brand. The consumption of surfactants for cooking was 0.1% of the weight of absolutely dry wood. As a result of the brews, technical sulfate pulp was obtained, the total yield of deciduous pulp was determined, the amount of the amount of undercooked pulp in the obtained pulp, and the pulp was analyzed for the content of residual lignin and extractives. Studies have shown that the addition of Dispersol brand surfactants to sulfate cooking solution has little effect on the yield of pulp and the content of residual lignin. The amount of undercooked pulp content of the obtained pulp, when surface-active substances of the Dispersol PCS 306 brand are added to the cooking solution, is reduced by 14% compared to cooking without additives. At the same time, the use of additives of surfactants in the cooking solution for sulfate cooking of hardwood makes it possible to reduce the content of extractives in the resulting pulp by 2-6 times. The presence of these surfactants in the cooking solution reduces the surface tension of the spent black liquor by 5-6%, but their low cooking consumption should not significantly affect the operation of the evaporators.