The article presents the history of the creation, development, and transformation of the Department of Wood Chemistry, both in terms of scientific achievements and the improvement of the educational process. It highlights the main areas of scientific research related to the chemical processing of wood. The article also includes the names of renowned scientists and professors who have contributed to the successful functioning of the Department of Wood Chemistry and the teaching of the discipline "Wood Chemistry" within the combined departments.

The article is dedicated to the memory of one of the leading teachers of the Faculty of Chemistry and Technology, now the Institute of Chemical Processing of Wood Biomass and Technosphere Safety, Obolenskaya Artemida Valentinovna. She was a co-author of numerous textbooks, educational and methodological manuals, and translated monographs.

The article presents the results of a study of the Picea abies root system in the middle taiga region using 3D scanning. A single 34-year-old tree 17 m high was selected for the study. The root system was exhumed as a 4×4 m square with a rootstock in the center. For 3D scanning, 360° digitalization was performed on three sides of the root system using an Artec Evo handheld 3D scanner. As a result of scanning, a 3D model of the root system was reconstructed with 251 individual roots with a diameter of 0,5 cm or Analysis of the 3D model showed that the total length of the root system was 18,408 cm, and the average length of one root was 74.5 cm. The root diameters varied from 0.5 to 18 cm, but 1–3 cm predominated. The morphometric structure of the root system included four main large roots with diameters of 14–22 cm, originating from the tree trunk and directed perpendicular to each other, to which the roots of the conditional 2nd and 3rd orders were adjacent. In the diagonal direction, areas of increased growth of roots of different orders were distinguished. In general, the obtained results correspond to the ideas about the root architectonics of this tree species.

The present study is devoted to the assessment of the impact of Populus tremula conservation on the dynamics of woody vegetation in 15-year-old clearcuts in wood sorrel-spruce forests of the Vologda region. The objective is to examine autogenous succession and natural regeneration. The methodology involved the establishment of 60 sample plots on clear-cuts and in adjacent forests with varying aspen preservation strategies, including single trees, clumps, and no preservation. A comprehensive analysis of stand structure, the vital state of tree components and undergrowth characteristics was conducted. The findings illustrate the beneficial impact of aspen conservation on the acceleration of reforestation processes and the establishment of favourable conditions for the growth of shade-tolerant species, particularly Picea abies. The greatest efficacy in maintaining tree diversity and optimizing microclimatic conditions was observed in the conservation of aspen in clumps. A decline in the vitality of aspen and spruce was observed with increasing post-exploitation periods, while trees in clusters exhibited higher vitality indices compared to single specimens. The undergrowth analysis revealed the dominance of soft-leaved species in the early stages of succession, with a subsequent increase in the proportion of shade-tolerant species. The findings confirm the importance of retention silviculture for biodiversity conservation and restoration of forest ecosystems after clear-cutting.

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 Norwegian 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 in forests that have not been affected by human economic activity for a long time. A continuous census of the main tree stand and undergrowth were carried out on 10 sample plots using a selective statistical method. A geobotanical description of the living ground cover was made. Cartographic materials of the parcel structure were compiled in 10´10 m squares allocated at the studied sites with the trees of the main tree layer, undergrowth and undergrowth indicated. For the first time in the study region, the relationship between the parcel structure and the processes of natural reforestation occurring in mature pine-spruce stands of the bilberry type of forest was studied. The article reflects the distribution of spruce undergrowth by the main native parcels identified in pine-spruce forests. A number of patterns were revealed that reflect the features of the formation of spruce regeneration with the main parcels in pine-spruce forests of the bilberry type. Recommendations are given for predicting the success of reforestation in the clearings of pine-spruce stands. The obtained results can be used for a more accurate assessment of the success of natural regeneration during forestry activities, for the restoration and preservation of forests in the south of the Leningrad Region.

The results of long-term studies on the abundance of raw materials plants are presented. The species composition and abundance of plants of resource value were studied in the pine forests of the Leningrad Region. The pine forests are characterized by a mixed composition of the stands. The average age of the pine forests is 70–140 years. The relative completeness of the stands is 0,6–0,8. The density of the stands is 548–782 specimens/ha. Under the canopy of tree stands, there is an undergrowth of pine and birch. The total number of undergrowth is 410–880 individuals per hectare. The undergrowth is represented by common juniper, common rowan, and common buckthorn. The total number of undergrowth does not exceed 570 individuals per hectare. The frequency of occurrence and the projective cover of each species in the living ground cover were determined on 10 m² plots. On each experimental plot, 30 to 48 counting plots were laid depending on the size of the experimental plot. It was found that the species composition and abundance depend on the characteristics of the phytocenosis and the growing conditions. The total number of species in the living ground cover is more than 50. The moss-lichen layer includes 4–6 species of lichens, 5 species of green mosses, 3 species of sphagnums, and cuckoo moss. It has been shown that 19 species of raw plant materials are suitable for industrial harvesting. The occurrence of such plants is at least 30%, the projective cover is from 5% and higher. In the blueberry pine forest and the grassy-marsh pine forest the maximum number of species in the living ground cover was identified, with 37 and 41 species, respectively. Of these, 33 species are raw materials in the blueberry pine forest and 36 species are raw materials in the grassy-marsh pine forest. Medicinal and technical plants predominate under the canopy of pine forests. The minimum number of species with raw material value is found in the lichen pine forest, which contains only 6 species. All groups of raw material plants in terms of their economic purpose are represented. The living ground cover includes 12 species of honey plants, 16 species of medicinal plants, 4 species of berry plants, 4 species of salad plants, 9 species of technical plants, and 6 species of forage plants. Many species of raw materials plants are poly-resource species.

The article is devoted to the use of the k-means machine learning method and vegetation indices for the classification of tree species based on UAV survey materials. Vegetation indices analyze the spectral characteristics of plants, which is especially useful for distinguishing similar tree species, as they exhibit different spectral signatures. The study was conducted on two forest plots with tree distributions of pine-birch and pine-spruce. Data were collected from five spectral sensors: Blue (470 nm), Green (560 nm), Red (665 nm), Far Red (720 nm), and Infrared (840 nm). Tree crown detection was performed using RGB images captured by spectral sensors and the DeepForest model. Within the boundaries of the detected crowns, spectral sensor data were processed to calculate the vegetation indices for each tree. Pixels for each tree from the matrix view were decomposed into a vector, sorted in ascending order. The following parameters were calculated from each vector: minimum, maximum, mean, median values, as well as the 25th and 75th percentiles and Shannon entropy. Dimensionality reduction via PCA and k-means clustering were then applied to differentiate tree types. The results showed that for pine and spruce, classification accuracy exceeded 80%, whereas for pine and birch, the metrics were less successful, possibly due to seasonal changes in the indices. In both cases, DVI proved to be the most effective indicator, demonstrating high efficiency for certain forest covers.

Currently, a large number of lands previously used in agriculture have been removed from active economic circulation, and the process of restoring native forest vegetation is underway in these areas. These areas of post-agrogenic lands are of interest for studying the patterns of formation of not only the wood stock, but also the density of wood. In the process of the study, a comprehensive assessment of pine stands growing on the former arable lands of the Republic of Tatarstan was carried out. The experiment was conducted in two directions: a series of objects on different types of post-agrogenic soils in four regions of the republic (young stands aged 10–15 years, including forest plantations), and an object on old arable soils (forest plantations aged 55 years) with a contrasting naturally formed stand (85 years in similar soil conditions on forest soils). Trial sites were laid out at the experimental objects, where vegetation was recorded and model pine trees were selected, followed by their felling. Using the obtained sets of wood discs from the models, their basic density was determined sectorially and then the average basic density of the trunk was calculated according to the diameter classes of the stand. Patterns of wood density formation in pine stands on post-agrogenic soils were determined and regression equations were proposed for the relationship of the basic density of wood at an altitude of 1.3 m from the soil level with the average basic density of the entire trunk in the study areas. The regression equations have a sufficient level of the coefficient of determination (R²) and can be used to determine the average density of the trunk wood and subsequently the stem phytomass of pine plantations growing on the post-agrogenic lands of the Republic of Tatarstan.

The study of two generations of spruce provenance trials established in the Leningrad Region allows us to trace the geographical variability of the species Picea abies (L.) Karst. and Picea obovata Ledeb. The first-generation culture object was created within the framework of the VNIILM program in 1977 on the territory of the Lyuban forestry, where cones were harvested to create second-generation provenance trials. The second generation is represented by semi-sib progenies on three objects that were established in 2006–2015 in the Gatchina and Kirov forestries and in the Lisinsky educational and experimental forestry (UOL). In the cultures of two generations, successful development of the offspring of Picea abies and a slow growth rate of P. obovata were established. The positive influence of the state of maternal climatypes on the preservation and growth of progenies was noted: the procurement of cones in plantations with a high bonitet class contributes to a more successful growth of progeny in both the first and second generations. Southern and western offspring with greater heat and moisture supply in the areas of original origins grow more intensively than northern and eastern ones, with less heat and moisture. The share of the influence of the maternal genotype in growth indicators reaches 56%. A direct relationship between the cone yield in mother plantations and the growth of daughter progenies was revealed. In 45-year-old crops, the most highly productive are the local Leningrad progeny and the progeny from the Pudozh forestry of the Republic of Karelia (550–580 m³/ha). In the second-generation objects, the highest selection significance is possessed by the climatype progeny from the Velikiye Luki forestry of the Pskov Region. Deliveries of spruce seeds to the Leningrad forest seed sub-district are possible from the Pskov, Tver, Moscow (north, northwest), Kaluga (center, north), Vitebsk (north, northeast) regions and the southern part of the Republic of Karelia, with coordinates limited to approximately 54°20′ – 61°40′ N and 27° – 39°E.

Forest fires are one of the main processes, both natural and anthropogenic, leading to large amounts of greenhouse gas emissions into the atmosphere. Forest fires lead to the complete or partial destruction of forest ecosystems. At the same time, there is a decrease in their absorption capacity, as well as greenhouse gas emissions due to the combustion of organic matter in the main pools of forest ecosystems. Forest fire protection activities can be one of the types of forest-climatic projects (FCP) within the framework of forest relations. In the process of implementing the FCP, a set of measures is being carried out aimed at preventing the occurrence of fires in forests, limiting their spread, reducing fire danger, increasing forest fire resistance and timely detection and extinguishing of forest fires. The article discusses the issues of determining the basic and design lines in the justification of the paintwork, two methods for quantifying the amount of greenhouse gas emissions reduction in the fight against forest fires. The first method is presented in the methodological guidelines approved by the decree of the Ministry of Natural resources and ecology of Russian Federation No. 371 dated 05/27/2022 and presented in the methodology for the implementation of climate project No. 0011 «Improved forestry management, including protection of forests from fires.» The second method is presented in the international standard VCS VM0015 «Methodology for preventing unplanned deforestation». The baseline was justified using the method of historical average changes. For this purpose, statistical data on the area of forest fires for the period from 2007 to 2022 were used. The forest climate project considers two scenarios for reducing the area of forest fires, by 30% and by 50% of the average annual area. The scenarios also take into account the need to reduce the area of forest fires in accordance with the Decree of the President of the Russian Federation on June 15, 2022. An assessment of the uncertainties and risks of the FCP was carried out. The results of the study provide quantitative estimates of the amount of possible reduction in greenhouse gas emissions as a result of forest fire control using two methods that have yielded different results. The carbon efficiency of the project was evaluated and the results obtained were compared with other estimates available in the scientific literature.

The relevance of the paper is defined by the need of improving activities in the sphere of forest regeneration and increasing the forest potential from the ecological and resource point of view. The goal of this study is to summarize experience in establishing Scots pine (Pinus sylvestris L.) plantations in the nemoral and subnemoral forest growth conditions of the Mari El Republic. Such plantations can provide a great amount of qualified wood in a shorter time than forest stands of the natural origin. For this paper, we used forest management documents containing the data on the taxation parameters of stands (over 45 thousands of strata) as well as the data of full-scale assessment performed at 15 research sites in the natural stands and Scots pine plantations growing in the fresh oakeries and ramens of the Mari El Republic. It is established that the forest species structure of oakeries and ramens in the Mari El Republic is far from optimal and needs to be radically changed. The highest productivity here is demonstrated by pine stands with the high point of the average annual increase in their stock occurring at the age of 45 to 55 years old and indicating their economic maturity. In order to increase the ecological and resource potential of forests in these forest growth conditions, it is appropriate to establish pure Scots pine plantations that can give the stock of stem wood more than 500 m³×ha^–1 by the age of 45 years old under the optimal conditions of their cultivation. In terms of basic density, their wood is as good as the wood grown in the pine forest conditions and amounts to about 460 kg×m^–3 at this age and achieves the maximum at the age of 90 to 120 years old. In the rich forest growth conditions, many pine trees are capable to live up to 200 years old and avoid any damage by trunk rots.

Protection of forests from fires is the most important function of forestry. The peculiarities of the constitutional and legal status of the Russian Federation, based on the principles of separation of powers, have seriously affected the organizational system of forest fire protection. The 2006 Forest Code of the Russian Federation, in terms of protecting forests from fires, was initially quite liberal, but subsequently it was amended to establish requirements for restrictions and standards. Serious differences in the climatic, forest-ecological and socio-economic conditions of the regions necessitate the introduction of forest fire zoning, as well as maneuvering of fire extinguishing resources, including a specially created federal reserve. The introduction of amendments to the Forest Code of the Russian Federation at the end of July 2023 was another serious step in the process of almost continuous improvement of forest legislation. The key changes include the norms related to the introduction of the concept of emergency response measures, a new approach to planning measures for fire protection of forests, and a number of others. The analysis of the changes revealed new contradictions and potential organizational and financial problems. The distribution of powers to extinguish forest fires between the federal and regional levels simplifies the issues of maneuvering resources, but generates a number of uncertainties, including the issue of responsibility for extinguishing forest fires on the part of federal and regional authorities. The authors propose a number of ways to improve legislative and managerial mechanisms for the effective prevention and control of forest fires, the key of which are the adjustment of the concept of forest fire zoning, as well as the introduction of mechanisms for assessing the quality (adequacy and expediency) of management decisions in the field of forest protection, including the choice of tactics and methods of extinguishing forest fires.

The research aim is to observe, evaluate and analyze the entire cycle of obtaining forest reproductive material using the example of the Scots pine (Pinus sylvestris L.) od the Negorelskaya cultivar, collecting a data bank, starting from a systematic study of the scientific landscape on the influence of spectral and morphometric indicators of individual seeds on the indicators of crops obtained from them to observation biometric parameters of the ontogenetic development of a seedling/sapling at the juvenile stage, taking into account the natural production conditions of growth and the time/age of transplantation. There are few studies containing information on the early growth of individual seedlings of Pinus sylvestris L. of the Negorelskaya cultivar according to the biometric indicator of the ratio of height to diameter of the root neck of seeds with known optometric brightness parameters. The object of the study were 494-day-old seedlings grown in the containers of a forest nursery, transplanted to a regenerated forest landscape in autumn without hardening (the first group: age from the moment of re-planting – 364 days) and in spring after 150 days of hardening (the second group: age – 214 days), as well as 497-daily container seedlings after 367 days of hardening, measured before transplanting. The null hypothesis was tested under the assumption that the average variants of the independent variable H/D ratio were not statistically differentiated in groups of seedlings with different transplant times. To clarify the degree of difference (or lack of difference), a multiple comparison based on the post-hoc Tukey test was used. The patterns of changes in the biometric ratio of the height of the seedling to the diameter of the root neck (H/D ratio) depending on six optometric parameters of the seed coat were visualized using a scatterplot and an approximating regression line of the second degree. In the future, by tracing the growth of seedlings of the Pinus sylvestris L. Negorelskaya cultivar in height and diameter during the second and subsequent growing seasons of the juvenile stage in the restored area of the forest landscape, it will be possible to more accurately determine the degree of intensification of the reforestation production of Pinus sylvestris L. of the Negorelskaya cultivar depending on the initial properties of the seed.

The article contains information on the structure and species composition of lawns, which are an integral part of urban landscapes. It is noted that the floral composition of lawns determines not only its appearance, but also its stability in different environmental conditions. The condition of lawns is influenced, first of all, by the conditions in which they develop. Special attention is paid to the species composition of uncultivated herbaceous plant species, which are of interest from the point of view of their further use in the creation of so-called "alternative" lawns. The assessment and comparative analysis of the species composition of lawns using examples of urban and suburban green spaces was conducted; the analysis of herbaceous plants by belonging to ecological-coenotic groups was made; the potential of the species diversity of herbaceous plants in this region for use in the preparation of herbal mixtures was assessed. The assessment of the lawn condition was carried out according to the "Methodology for assessing the ecological condition of public green spaces in St. Petersburg." The herbaceous cover was examined at 18 green space sites in the Petrogradsky district of St. Petersburg and Vsevolozhsk, Leningrad region, under different conditions of insolation, moisture, acidity and soil compaction, and relief features. According to the results of the study, attention should be paid to the fact that two invasive species have been identified on the lawns of both the city and the region, the number of which must be controlled. The species diversity of lawns and uncultivated species in the central districts of St. Petersburg is significantly less than in Vsevolozhsk, which is absolutely expected. The general list of identified species of herbaceous plants is dominated by representatives of the ecological and cenotic group "weeds" (68 species), many of which are indicators of soil compaction and acidification. And in order to optimize the species composition of lawns, first of all, species related to meadow (27 species) and forest (6 species) cenoses are of interest. Such species can form the basis of herb stands that develop in special conditions where there is no need for regular lawn mowing or in difficult conditions of insufficient lighting or humidity.

Forest policy as specific area of research is only beginning to take shape within the scientific and educational community of the Russian Federation. Among researchers and industry specialists, there are still no well-established scientific schools dedicated to this field, and the term itself is interpreted very broadly. This work is dedicated to analyzing the current situation of research in the field of forest policy in Russia. The tools used in this study include comparative analysis, as well as quantitative and qualitative sociological methods. The empirical basis consists of the results obtained from surveys of industry experts representing various interested groups: academic institutions, research institutes, non-profit organizations, government bodies, private forest management companies, and the forestry industry. The surveys were conducted between 2019 and 2022. Additionally, an analysis of various resources (literary sources and mass media) related to this field of knowledge was carried out. As a result of the research, information was collected and organized regarding scientists and authors of works, publications that disseminate research results in this area, and existing discussion platforms where information exchange and materials related to the topic take place. The understanding of the term «forest policy» by industry specialists was analyzed, and the obtained results were interpreted. The study identified key authors of scientific works associated with research and discussions in the field of forest policy within the professional community. The significant role of representatives from non-profit organizations in this process was highlighted. A list of Russian scientific journals publishing research results in this area, as well as discussion platforms, was compiled.

The main incentive for the introduction of robotic technologies at Russian enterprises of the timber industry complex (LPC) should be a significant increase in labor productivity. Robotic technologies help to maintain non-stop production, perform complex, labor-intensive and energy-consuming production operations 24 hours a day, improve working conditions in production. Meanwhile, robotization could help the industry to cope with the challenges that the domestic timber industry is facing today in the context of limited timber exports. An important topic is the reorientation of enterprises to deeper processing of wood in order to create a product with high added value. The exclusion of the possibility of human error, the speed and accuracy of the processes also testify for the need for investments in robotic technologies. Transport (mobile) robots (TR) can be used not only in factory conditions, but also in greenhouses, greenhouses, nurseries, where plantings are carried out on a regular basis. The increase in the efficiency of such systems is primarily due to an increase in the speed and accuracy of the mobile robot, for which it is necessary to take into account their dynamic characteristics. In this paper, the equations of motion of a transport robot are obtained, the undercarriage of which consists of 2 motor-wheel modules located on the transverse axis of the truck along its sides, and 2 weather vane wheels mounted in front of the truck along its sides. This arrangement of the traction wheels ensures high maneuverability of the vehicle up to turning around the central axis. Direct current electric motors are used as motor-wheel motors, which are powered by an on-board battery. The results obtained are of independent practical interest, and can also be used for mathematical modeling of vehicle movement along the highway, stability studies, etc.

The article presents a method for the automatic recognition of tree species based on the analysis of tree trunk images captured using unmanned aerial vehicles (UAVs). The authors employ convolutional neural networks (CNNs) to classify seven tree species: birch, spruce, pine, aspen, maple, oak, and larch. The study aims to overcome the limitations of traditional identification methods, such as subjective expert assessment and high labor intensity. The methodology includes data collection and preprocessing, image augmentation to increase variability, and model training using ResNet, EfficientNet, and MobileNet architectures. The results demonstrate the model’s high efficiency, with an average classification accuracy exceeding 90%. The best performance was achieved for oak (97,6%) and birch (95,4%), while visually similar species (spruce and pine) showed lower accuracy (around 85%), indicating the need for further optimization. An analysis of external factors revealed the significant impact of shooting angle and lighting conditions on classification accuracy. The proposed method can be applied in forestry for automated monitoring and resource management. To enhance performance, the authors recommend expanding the dataset, incorporating additional environmental parameters, and conducting cross-validation on independent datasets.

To collect or rake logging residues during timber harvesting or targeted removal of unwanted trees and shrubs, the technological process provides for a corresponding technological operation, which must be performed by specialized technical means under their common name «forest rakes». The relevance of the study is determined by the lack of modern scientific works evaluating such a key moment of achieving optimal productivity of forest rakes as identifying the volume of the logging residue pile formed by them. The purpose of the study is to develop a mathematical model for the formation of the volume of the logging residue pile in order to increase the efficiency of their raking by forest rakes. The object of the study was a forest rake with a broken profile of teeth of constant surface cross-section and the presence of safety devices, fixed to the front (mainly) or rear hitch of a Belarus-82.1 tractor. It has been revealed that the design parameters of forest rakes with a broken tooth profile (namely: the width and height of the rake, the lengths and angles of inclination of the upper and lower parts of the tooth), the parameters of logging residues raked by forest rakes (the largest size along the length or span of branches, the angle of internal friction, the sizes of the rollers of raked biomass on both sides of the forest rake) have a direct effect on the interaction of the forest rake with logging residues, forming the volume of the drag heap. It has been shown that the efficiency of raking logging residues by forest rakes largely depends on the productivity of their work, which depends on a set of influencing factors associated with the state of the removed (raked) and remaining (on the cleared territory) vegetation, the type of soil and terrain, the degree of pollution of the said territory. In order to increase the efficiency of raking forest rakes of logging residues, the authors of the study, based on the results of this work, proposed to identify the optimal values of their performance based on multifactor optimization of the design parameters of the forest rakes adopted in the study.

In the field of forestry and forest industry, when implementing environmentally friendly and nature conservation activities, there is a certain interest in the use of effective measures to prevent and extinguish forest fires. Annual forest fires deplete forest resources over an area of several thousand hectares throughout the country. In order to effectively localize forest fires and apply the latest, more rational measures to prevent them, it is necessary to implement appropriate technological solutions and use scientific developments in the field of innovative machines and devices that provide improved and technical characteristics. The article presents the results of the analysis of the dynamics of forest fires and the possibility of using innovative technical developments when carrying out work in fire-hazardous conditions in forest areas. It also presents the formed author's model of the course of the main measures to prevent and extinguish forest fires, consisting of three main blocks (prevention, control and monitoring, localization of forest fires). A comparative assessment of fire-fighting mechanized equipment was carried out, on the basis of which the main characteristics of typical forest fire-fighting machines and mechanisms used for fire-fighting work in forestry were analyzed in comparison with innovative technical means for the prevention and extinguishing of forest fires. The article contains the necessary calculations and an assessment of the efficiency of using typical and innovative technical means for the prevention and extinguishing of forest fires. Based on the results of the study, the most optimal and promising ground-based developments were determined, both on wheels, tracks, and on low-pressure tubeless tires.

The widespread introduction of digital technologies into human economic activities, including logging, is an actual development trend. When organizing the work of logging machines, it is necessary to take into account not only their technical characteristics, but also their ability to adapt to a single digital space. A review of domestic and foreign scientific and technical sources has shown that much attention is paid to the issues of improving the logging process, many researchers consider the digitalization of logging machine operation as one of the main activities. The development of artificial intelligence systems implies the creation of a set of logging machines that work autonomously, without human participation, both in timber harvesting and its removal. However, at the current stage of development, it is impossible to do without human participation, therefore, the considered solutions are aimed at improving the efficiency of the harvester operator, reducing his fatigue by automating some of the work performed, in particular, the introduction of machine vision, which allows automatic control of the safety of the logging process, presence in dangerous areas, determine the species of wood with the use of neural networks to reduce the mental load on the operator. An important aspect of improving the efficiency of logging is work planning with the use of an information system, which takes into account both the results of machine operation (diameter and number of assortments, their volume, species) and controls the technical condition of machines and technological equipment. The algorithm of the information system functioning should include specialized software that allows modeling and on its basis planning of operation modes of logging machines and equipment taking into account their technical condition and natural-production operating conditions. Solutions to transfer the necessary information to the company's server to take into account the peculiarities of logging machines operation due to the remoteness of harvesting areas from the cellular network coverage area are proposed in the paper.

The article considers the efficiency of using protective corrosion-resistant powder coatings applied to steel structural elements of forestry machines by cold gas-dynamic spraying (CGDS). To apply the protective coatings, 32 samples measuring 100×20×3 mm were made of Ст3сп steel. A low-pressure CGDS unit «Dimet-405» was used for spraying. The study considered 4 types of coating: copper-based – C-01-01; zinc – Z-00- 11; nickel – N3-00-02; aluminum with added zinc – A-80-13. For each type of powder coating, a morphological analysis of the particles was performed and the granulometric composition was determined. The resulting samples were tested under the following conditions: salt fog, salt fog and air, and sea water. The duration of corrosion tests was 720 hours. Based on the test results, the values of corrosion losses of the samples were determined. The obtained data were statistically processed. In addition, a metallographic analysis of the samples was carried out. The best corrosion resistance in all tests was shown by samples with zinc-based (Z-00-11) and aluminum-zinc (A-80-13) coatings. The results of the metallographic analysis showed that no steel corrosion centers were detected on the samples with zinc-based and aluminum-zinc coatings after the tests were completed, and the corrosion losses were caused by the thinning of the protective coatings as a result of exposure to an aggressive environment. At the same time, obvious steel corrosion centers were present on the remaining samples. The results of the study showed that composite coatings based on zinc and aluminum are the most preferable for steel structural elements of forestry machines.

Birch and aspen are the most common hardwoods in the Russian Federation. The disadvantages of these breeds include the pale color and featureless texture of the wood. One of the ways to refine such wood is to form an artificial texture. The artificial texture will provide an increase in the decorative properties of wood, which will expand the scope of its use, including for the production of finishing materials and interior items, which are subject to increased requirements in terms of aesthetic properties. In the presented work, the possibility of forming an artificial texture of birch and aspen wood due to its laser perforation followed by autoclave impregnation with a textile dye is investigated. The proposed method consists in laser-burning channels in wood according to a special scheme (depending on the texture design) through which local staining of wood occurs during autoclave impregnation. The texture is formed by alternating colored and unpainted areas over the entire thickness of the workpieces. In order to ensure the adjustable size of the local areas to be painted in wood, the paper examines the distribution features of the impregnation solution in laser-perforated wood. In the course of research, it was found that aspen wood, due to the different permeability of ripe wood and sapwood, is not suitable for controlled texture formation using the proposed technology. For birch wood, the possibility of controlled formation of artificial wood texture by laser perforation followed by its impregnation with textile dye has been confirmed. The dependences of the formation of the sizes of the colored zones adjacent to the laser perforations are obtained depending on the structural direction, pressure and duration of autoclave impregnation with the dye.

The aim of this study is to develop and validate a deep learning model architecture based on a convolutional artificial neural network for determining the proportion of bark in a digital image of cross-cut timber. The results were obtained using computer vision and deep learning methods. Reference documentation for the Faster R-CNN, RPN, Mask R-CNN, and Segment Anything artificial neural networks was used in developing the model architecture. The open-source Mask R-CNN and Segment Anything artificial neural network models were used in the software implementation of the model for research purposes (the Mask R-CNN model was integrated into a common stack with the Segment Anything (SAM) model, and the feature map generation functions were transferred to the Encoder block; the memory attention blocks of the SAM network were removed to optimize the solution in terms of the required amount of RAM). The model was trained and validated using the author's dataset of digital images of cross-cut timber, available in the repository. The measured Precision metric values during validation demonstrate that the proposed deep learning model architecture successfully solves the problem of segmentation and bark fraction determination in images. Experiments with the deep learning model allow us to evaluate the relationship between its architecture and the number of trainable parameters with the results of bark fraction determination in assortment images: stabilization of the Precision metric is observed when moving from a model with 38 million weights to a model with 217 million weights. Therefore, further research is warranted to determine the optimal number of trainable parameters that provides the best balance of accuracy and image processing performance.

The paper presents a study of the design of acoustic characteristics of a soundproof wooden panel. The growing need for effective noise control strategies in various applications, such as wooden house construction, has led to the development of innovative sound insulation materials. This study examines the incorporation of sound- absorbing elements into wooden panels to enhance their sound insulation properties. The theoretical basis for the use of acoustic cavities is based on the principle of acoustic resonators. In the presence of volumetric cavities in the structure, it becomes possible to create resonant phenomena that can significantly affect the sound pressure level and damping of sound waves. Resonation occurring at certain frequencies helps to reduce the intensity of sound, which improves the acoustic characteristics of the finished structure. The design process takes into account the choice of sound-absorbing elements and their integration into the construction of wooden panels. Various sound-absorbing materials such as porous absorbers, microperforated panels and resonant cavities are evaluated in terms of their sound absorption coefficients. The optimal configuration is determined by modeling and experimental measurements using standardized methods defined in GOST 27296-2012 «Buildings and structures. Methods for measuring the sound insulation of enclosing structures». The manufacturing technique involves the integration of sound-absorbing elements into the construction of a wooden panel while maintaining its structural integrity. The developed soundproof wooden panel offers a universal solution for noise reduction, opening up new opportunities in wooden house construction projects. The use of new types of wood slabs will significantly improve the construction technology and the level of acoustic comfort. To study the reduction of sound pressure, special sound-insulating wood panels with internal structural elements in the form of parabolic cavities that contribute to sound absorption were used. This study examines the introduction of sound absorption elements into wooden panels to improve their noise protection properties. By introducing parabolic recesses (or «sound pockets») into a wooden panel, its sound insulation properties can be significantly improved. These structural elements, made by milling, contribute to sound absorption and reduce the sound conductivity of the panel. Parabolic recesses reflect, absorb and disperse sound waves, reducing the transition of sound through the material, which helps to reduce noise levels and improve acoustic comfort in the room where this panel is installed.

The possibility of using ultrasound to determine the saw cut types of lumber is considered. Depending on the cutting pattern (set), lumber can be radially or tangentially sawn. The use of a certain type of lumber, the principles of their symmetrical arrangement in glued timber structures and other conditions depend on the requirements for finished products. Visual sorting of lumber by the direction of annual layers at the end in flow production is impractical, since it does not ensure the required level of labor productivity. A high degree of reliability in the diagnostics of solid wood is shown by the temporary shadow method of acoustic control. In the framework of the studies, a frequency of 2.5 MHz was used. When sounding wood, due to its anatomical structure, a number of features of the diagnostics itself arise, which allow expanding the possibilities of using the method. Such features include different speeds of ultrasound passage depending on the density of the wood, shifting the ultrasonic signal, the need for a reasonable selection of frequency, etc. During acoustic diagnostics, depending on the sawing option of lumber, different deviations of the ultrasonic signal are observed. The conducted studies show that the signal shift is most likely due to its movement along ribbon-like formations of parenchymatous cells, directed radially with respect to the wood growth layers – medullary rays. The results of the studies, the values of the signal shift angles depending on the type of lumber are given. Signal shift by an angle in the range from 25° to 53° relative to the emitter is typical for radial lumber, and signal shift by an angle of less than 25° determines tangential lumber.

The manufacture of end pieces of various shapes makes it possible to use rationally fine-grained wood in the form of segments of coniferous tops and segments of wood processing. Based on end blocks, highly artistic floors can be made according to individual projects in residential and public buildings. The technology of manufacturing wooden floor coverings from end checkers has a significant drawback, which is that the vertical edges of the checkers on pre-cut cylindrical blanks were carried out by contour pressing, which significantly complicates production. As part of this work, a method and equipment have been developed for producing prismatic end pieces by splitting. According to the proposed method, buckled round logs (blanks) are placed in a vertical feeder. Using a pusher, the workpiece is pushed longitudinally onto a square hollow body, the end cutting edge of which is made in the form of evenly alternating triangular teeth having two cutting edges symmetrically arranged at an angle of 45° relative to the feed velocity vector of the workpiece onto the body. On the outside of the housing there are longitudinal knives made flat and radially positioned relative to the axis of the housing. As a result of the advance of the workpiece through the body, an end piece having a cross-sectional profile corresponding to the internal cross-sectional profile of the hollow body is cut out and extruded. At the same time, with the help of longitudinal knives, the peripheral part of the timber is split into blanks in the form of a split hump. The high quality of the profile blanks is achieved by obtaining a given transverse profile of the workpiece at a greater length than its analogues. This is explained by the fact that when processing at the proposed installation, the tool being implemented with a smaller cutting angle cuts rather than splits the wood at the initial stage of implementation.

The recycling of MS-5B waste paper into a test liner and fluting at JSC Karavaevo is accompanied by the accumulation of waste. The inevitability of waste generation and the need for disposal at the landfill requires significant financial costs, therefore waste recycling is an urgent problem of waste paper recycling. The waste paper mixture was fractionated into plastics, fiber, wood, minerals, metals, rubber, and fabric. It has been established that the total content of plastic and fiber in waste is more than 71% and can be fully used as a binder in thermal compression technology. To determine the qualitative characteristics of polymer-sanded plates, quantitative parameters of consumer properties were determined for the specified geometric dimensions of polymer-sanded plates samples. The study shows the effect of the content of waste paper in the composition, as a binder, of polymer-sanded plates on their properties. The effect of additives of fractionated polypropylene in the composition of polymer-sanded plates containing waste paper as a binder is shown.

The properties of high-yield kraft pulp from aspen (Populus tremula L.) branches were compared in terms of its suitability as a raw material for the production of corrugated cardboard components. The high-yield pulp obtained from aspen branches by separate cooking using the kraft method in laboratory conditions according to the developed regime, compared to pulp from the trunk, has similar characteristics in terms of yield (60.2 and 61.8%) and kappa number (52 and 54 units). The obtained high-yield kraft pulp was characterized by a set of fundamental, deformation and strength properties. It was established that, having a 32% shorter fiber length (0.59 versus 0.86 mm) and 22% lower intrinsic fiber strength (zero breaking length 11.3 versus 14.5 km), 24.3% lower coarseness (14.3 versus 18.9 mg/m), it has a 2.3% higher (2.43 versus 2.37 MPa) magnitude of interfiber bonding forces, which are responsible for the elastic properties of paper. Pulp from aspen branches has a 15% lower breaking length, 24% lower tear resistance, 20% lower modulus of elasticity, 15% lower bending stiffness, and 11% lower tensile stiffness. However, the differences in the values of burst strength and compression strength do not exceed 3%. The differences are due to the difference in size (length and width), coarseness and own strength of the fibers, with the compensating effect of the surface condition and structure of the cell wall, which undergo changes as a result of hydromechanical action during refining, which is accompanied by the development of interfiber bonding forces and the ability to compact in a wet state. It is concluded that high-yield kraft pulp from wood waste in the form of aspen branches has high potential for use in cardboard composition, without requiring significant changes in technology, while having an environmental and economic effect.

The thermodynamic characterization of the true solubility at 25°C of amorphous and crystalline nanoscale modifications of ZrO₂ depending on the pH of the aqueous medium in the range of 0–14.7, taking into account the formation of mono- and polynuclear hydroxocomplexes of Zr(IV) and the dispersity of the solid phase, has been given for the first time. The average effective particle radius (r ≤ 25nm for αZrO₂) should be taken into account as a thermodynamic parameter in determining the solubility of zirconium dioxide in the nanostate. The true solubility of polymorphic modifications of ZrO₂ in aqueous slightly acidic and slightly alkaline media in the absence of fluoride and carbonate ions is very low (7×10^–10 – 10^–7 mol/L), decreases with calcination and is determined by strong neutral complexes Zr(OH)₄, prevailing at pH 2-13. Solubility in aqueous media depends markedly on the crystal structure (α-ZrO₂ < β-ZrO₂ < γ–ZrO₂), increases significantly with decreasing particle size of crystalline nanopowders and strongly (by about 4 orders of magnitude) in the transition from stable crystalline baddeleyite α-ZrO₂ to dry amorphous modification. In strongly acidic medium (1 M HClO₄) the solubility of crystalline modifications of ZrO₂ is 3-4 orders of magnitude higher than in water and is determined mainly by the complex Zr(OH)³⁺, and for amorphous powder ZrO₂ - by the complexes Zr₄(OH)₈⁸⁺ (pH 0), Zr₅(OH)₁₂⁸⁺ (pH 1) and Zr(OH)₂²⁺ (pH 2). The Zr(OH)₃⁺complex makes a minor contribution to the solubility of ZrO₂ at pH 0-2. Zr⁴⁺ aquacations determine the solubility of α- ZrO₂ at pH<0. At pH=1–15 polynuclear Zr(IV) hydroxocomplexes have no appreciable effect on the solubility of macrocrystalline ZrO₂ modifications. In strongly alkaline aqueous media (pH =13,5–14,7) the solubility of ZrO₂ is 2-3 orders of magnitude higher than in water and is determined mainly by the complex Zr(OH)₆^2–.

Over time, the negative impact of human activity on the environment increases. Among the industries, the pulp and paper industry stands out in particular: it has a significant negative impact on the environment. To reduce this negative impact, there is a system of discharge standards. The current system of standardization of wastewater discharges of pulp and paper mills involves the calculation of standards for permissible discharges for substances of hazard classes 1 and 2, as well as technological discharge standards. The values of the SDS largely depend on the calculated value of the dilution factor. The dilution factor of wastewater is calculated in accordance with the Methodology for developing the standard for permissible discharges of pollutants into water bodies for water users (hereinafter referred to as the Methodology). The analysis carried out in the work showed that the Methodology for the conditions of wastewater discharge through dispersive outlets used in pulp and paper industries does not contain methods for calculating the dilution factor for many hydrological and meteorological regimes. In a number of the methods provided, the applicability limits are incorrectly indicated. Thus, taking into account the identified shortcomings of the existing Methodology for calculating the dilution factor of wastewater, an improvement was proposed for the classification scheme of water bodies used in standardizing discharges by enterprises of the pulp and paper industry. The new scheme of the typology of water bodies provides the possibility of switching to the use of unified standard mathematical models that effectively simulate the processes of pollutant transfer in aquatic environments of various types. This made it possible to significantly improve the accuracy of calculating the standard values of wastewater discharges at pulp and paper mills. In addition, specific types of water bodies receiving wastewater from large domestic enterprises of the pulp and paper industry and cardboard and printing products were identified. The study showed that the most significant factors are the nature of the water body and the features of the wastewater discharge regime. Thus, each enterprise has the opportunity to choose an appropriate standardized mathematical model that provides an adequate description of the pollutant transfer process and an accurate assessment of the required level of wastewater dilution before they enter water bodies. This approach will ensure compliance with strict environmental standards and prevent further deterioration of the environment due to the production activities of pulp and paper industry enterprises.

The purpose of this study was to get plastic without resin (PWR) based on plant fillers of non-wood origin in the form of wheat husks and rice husks using piezothermal treatment in a sealed mold and to perform tests on the biodegradability of these materials in the soil, followed by an assessment of the level of chemical contamination of soils as a result of their destruction. PWR samples based on fractionated wheat husk and rice husk were produced. The samples were obtained by compression pressing in an airtight mold at a pressure of 40 MPa and a temperature of 170 °C, followed by its cooling without pressure relief to 40 °C. The physico-mechanical parameters of the samples were determined (density, modulus of elasticity when bending along the deflection of the disk sample, hardness after indentation of the ball, elasticity number, water absorption, swelling, wetting edge angle). After conducting studies of the physico-mechanical properties, the samples were subjected to biodegradability tests in relation to soil for 84 days. After the biodegradability tests were completed, the soil was examined for the level of chemical contamination with heavy metals. The results of the tests showed that plastic obtained from wheat and rice husks can be classified as a fully biodegradable material. During the destruction of these materials, inorganic compounds migrate into the soil environment, while the level of heavy metals does not exceed the established environmental and sanitary standards for the soil. According to the results of a comprehensive assessment of chemical contamination of soils by degradation products of a biodegradable composite material without a binder based on plant raw materials, the category of contamination of the studied soil was classified as "acceptable". Nevertheless, given the existing level of environmental pollution, when using the raw materials in question, an initial assessment of their quality is required, including the content of pollutants.

The research was conducted in three stages. At the first stage, the influence of the nature of the action of shortening and fibrillating grinding was determined, at the second stage – the optimal degree of grinding of the SFF, at the third – the optimal composition of the paper pulp by fiber. To solve the first task of the study, the range of the degree of grinding of the short-fiber fraction of 42 ... 51 °ShR with a step of 3 °ShR was selected. For shortening grinding, an NDM mill with a concentration of 3.5% during grinding was used, for fibrillating – a Yokro mill with a concentration of 6%. At the next stage, to determine the optimal degree of grinding of the SFF, laboratory samples were made from 100% SFF with a weight of 1 m² 120 g to determine the compression resistance at a short distance. The maximum increase in the SCT indicator (by 25%) was noted for samples with a grinding degree of 48 °ShR. With an increase in the degree of grinding of SFF by 8 °SR, a 10% increase in the SCT index is observed in the composition with LFF. The composition by fiber is LFF: KVF = 42: 58%. For the composition of 60% SFF and 40% LFF, the maximum values of resistance to planar compression and resistance to compression over a short distance were found, an increase of 10%. The maximum values of punching resistance are observed in samples of 65% SFF and 35% LFF, an increase of 4%. The optimal composition option should be considered to be 60% SFF and 40% LFF, since an increase of 10% was found for both indicators for this composition. Under production conditions, a pilot production of finished products with a composite composition of 65% SFF and 35% LFF and additional grinding of SFF was carried out. Pilot-industrial tests were conducted with an increase in the SCT index of 0.3 units, in addition, an additional favorable factor is that the variation in SCT and fluctuations in humidity across the width of the paper web with SFF refining are lower than without refining, i.e. the indicators have become more stable. The uniformity of humidity across the width and length of the paper web plays a huge role in the technological efficiency of processing raw materials in the production of corrugated cardboard.

Fish oil from natural salmon and trout of different habitats can differ significantly in the qualitative and quantitative composition of polyunsaturated fatty acids (PUFA). The aim of the study is to compare the composition of the investigated fish fat samples of different breeds and habitat by studying their composition by mass content of PUFA as factors of influence on the functioning of various life-support systems of the human body. The experimental results prove that salmon and trout fish oil samples have significant differences in the qualitative and quantitative composition of PUFAs. Omega-3 PUFAs predominate in salmon fat samples, their total content being 33,7%. In trout fat samples, omega-3 PUFAs account for only 13,3%. A distinctive feature of trout fat is its high content of omega-6 PUFAs and much higher content of omega-9 PUFAs. As for the influence of trout habitat, comparative analysis proves the undeniable advantage of fish oil from natural trout, where the mass fraction of Omega- 3, Omega-6 and Omega-9 acids is 13,3%, 19,9% and 56,7%, respectively (in «Aquaculture» – 8,9%, 15,9% and 47,7%, respectively). Thus, the results of comparative chromatographic analysis prove that the studied fish oil samples have a high content of triglycerides – the natural form of Omega-acids, which are the main type of energy to ensure the effective vital activity of the human body.