The characteristics of natural forest regeneration are examined using forestry units in the eastern Moscow Region as an example. These units are located in the Meshchera Lowland, which is characterized by its unique geological structure, soil conditions, vegetation characteristics, and history of economic development. A survey of forest regeneration of the main tree species was conducted on sample plots established in areas recovering from disturbances of varying ages. It was established that the predominant patterns of natural regeneration include the reforestation of clearings, burnt-out areas, and areas of dead and damaged forest stands with birch, aspen, and willow, followed by the development of spontaneous spruce seeding under the deciduous canopy; spruce self-seeding from preliminary regeneration in decaying dead spruce stands, under the canopy of overmature softwood and mixed-coniferous stands dominated by pine; pine self-seeding near forest walls, as well as in areas with light, dry soils and on microelevations. Data has been obtained on the unsatisfactory results of measures to promote natural regeneration by plowing furrows to increase the number of conifers in young stands. Based on regulatory requirements for ensuring the formation of forest stands that meet the intended purpose of protective forest categories, the main provisions of recommendations for the use of natural reforestation for forest reproduction in the Meshchera region of Moscow have been formulated. These recommendations include the goals, objectives, and standards for natural reforestation measures, as well as the transformation of softwood stands into deciduous-coniferous and coniferous-deciduous forests. Conclusions have been drawn regarding the feasibility of using natural forest regeneration to increase forest resilience to various adverse factors and the rational use of forestry resources.

This article presents the results of identifying and studying the lesser spotted eagle's nesting territories in the Pskov Region from 2017 to 2024. The aim of the study was to determine the structure of lesser spotted eagle nesting territories, identify factors limiting its reproduction in nature management conditions, and substantiate the necessary conservation measures for this species. Brief information on the lesser spotted eagle's phenotype and ecology in the study area, breeding success, and the size of the territory used by nesting birds for foraging are provided. The study showed that forest stands predominate over open spaces within a 2-km radius of lesser spotted eagle nesting territories, accounting for 57 to 81% of the territory. Nests are located within a 300- meter zone from the edge of fields. Fields and meadows predominate in the structure of the hunting territory, accounting for 54% to 92% of open habitat. lesser spotted eagle nesting is limited by a lack of hunting areas, primarily cultivated agricultural land. Inappropriate forest management practices are also a limiting factor. Birds abandon nests when clear-cut areas adjoin nesting trees, as well as when felling occurs near nests during the breeding season. For the conservation of the lesser spotted eagle in the study region, the most favorable habitat structure is one in which forest cover accounts for 55-60% and cultivated agricultural land accounts for 40-45%. This article provides recommendations for the designation of buffer zones and environmental management practices in lesser spotted eagle nesting areas.

The example of the Stieglitz estate in the Kramorskoye tract is used to examine a little-studied period in the formation of noble estates in the Yamburg district. The article describes the research methodology based on the study of archival, bibliographic, cartographic sources and field surveys with subsequent systematization of the obtained data. The article presents the results of historical, cartographic and archival research carried out with the involvement of a significant number of primary sources, most of which are introduced into scientific circulation for the first time. The historical periods of the formation of the Parusinka factory and residential area and the Stieglitz dachaestate are determined. The relevance of the study is due to the problems of restoring the historical appearance of estate parks, as part of the cultural heritage of our country, as well as their use in modern conditions.

The first discoveries of the invader in the Urals, the Cis-Urals, and the Volga region were made in the late 2010s. In the Udmurt Republic, P. proximus was first detected in 2019, in Perm Krai and Chelyabinsk Oblast in 2022, and in Sverdlovsk Oblast in 2023. According to the latest data, during a route survey in July 2024, P. proximus was discovered in forest stands along the Yekaterinburg-Serov and Yekaterinburg-Perm highways. In the Chelyabinsk Oblast, the invader was detected in all forestry sites with Siberian fir stands, as well as in a number of urban forests and parks, and regional and federal protected areas. These regions were almost certainly invided much earlier. As part of this study, we dated the invasion of P. proximus the Urals and Cis-Urals. In earliest total, data were obtained for 253 trees killed by the bark beetle, and 90 living trees, which were necessary for constructing a master chronology. Dating the mortality of the first trees colonized by the invader provided an idea of the time when P. proximus entered the surveyed area. The invasion of P. proximus most likely began in Udmurtia in the 2000s. The earliest tree mortality was recorded in the Chelyabinsk and Sverdlovsk Oblast in 2007. In Perm Krai, tree mortality was earliest recorded in two sites of the Dobryanskoye forestry (2011 and 2014). The invader arrived in Perm significantly later: fir dieback in urban forests began in 2018, 2021, and 2022. Since at least 2-3 years usually passe between the Polygraphus proximus arrival in a new area and the death of the first fir tree, this period should be taken into account when determining the date of invasion.

The vital structure of the edifying synusion of secondary lichen and moss-lichen pine forests of III-IV age classes in the central part of the Kola Peninsula (Murmansk region) has been studied. It has been established that in background areas the vital structure of the tree layer reflects natural successional processes during the restoration of communities after external disturbances (logging, fires). Against the background of the observed natural fluctuations in the vital state of the tree layer of P. sylvestris communities, significant changes in it were noted under the influence of atmospheric pollutants, from inhibition of tree growth and development to their death.

The relevance of the work is due to the need to develop scientifically sound zoning schemes, which is a fundamental task for implementing the principles of sustainable forest management. The article proposes the author's method of integrated resourceecological zoning, integrating the consistent application of factor, cluster and discriminant analysis. The methodology has been tested using the example of the Leningrad Region forest fund based on data from 19 forestry departments and 66 indicators, including taxation characteristics, data from the state forest register and climatic parameters. As a result of the factor analysis, four leading latent factors were identified and meaningfully interpreted, collectively explaining 64.3% of the total variance: “Forest management potential and productivity of forest lands” (23.5%), “Anthropogenic development and transformation of forest landscapes” (19.8%), “Stages of development of soft-leaved stands” (13.0%) and “Climatic severity and representation of marginal forest types” (8.0%). Based on the values of factor weights, the territory was typed using the k-means method, as a result of which 7 statistically significant and meaningfully interpreted clusters of forest areas were identified. The stability of the cluster structure was confirmed by discriminant analysis, which showed 100% classification accuracy. Canonical discriminant functions are constructed that allow assigning new objects to established types. The proposed methodology makes it possible to move from a continuous description of the forest fund to its discrete taxonomy and serves as the basis for the development of differentiated forest management models adapted to the specifics of the designated areas.

This article presents the results of a comprehensive study of a unique 73-year-old stand of Canadian hemlock (Tsuga canadensis) in the arboretum of the Main Botanical Garden of the Russian Academy of Sciences. The study included an assessment of biometric indicators, tree vitality, and mycobiota. It was established that the trees have reached average heights: 19.8 m and a diameter of 25.6 cm, confirming the species' ability to form tall stands in the conditions of Central European Russia. While 41% of the trees belong to categories 1 and 2 of health status, only 22% have a normally developed crown, and 31% have a normally developed trunk. Mycobiota analysis revealed the formation of a specific fungal complex, including both pathogenic and saprotrophic species. Over the observation period of 2023-2025, compared with the period 2006-2018, the number of dendrobiont fungi developing on the wood and roots of Canadian hemlock increased by 75%. This demonstrates the deep integration of the stand into the local mycobiome: the fungal community is becoming more diverse and functionally mature. It was assumed that the deterioration of the stand is due to high planting density, competition with native species, and the impact of fungal pathogens. The need for thinning to improve growing conditions and increase plant viability is substantiated. This study demonstrates the feasibility of successfully cultivating Canadian hemlock in the conditions of Central European Russia and has important implications for the introduction of rare tree species, as well as for understanding the processes of mycobiota formation in artificial stands.

The study of dependence between the elements of the structure of aboveground phytomass of pine and spruce trees grown under intensive technology by the age of 40 years in the conditions of the Leningrad region was carried out. On the basis of the data obtained on model trees the dependences of phytomass between trunk and crown parts of pine and spruce trees were modeled. Linear regression equations have been determined, which allow to apply them with a high degree of conditionality for calculation of ground phytomass in plantations grown in similar conditions.

The article analyzes and quantifies the results of forecasting the dynamics of the Leningrad Region forest fund using the EFISCEN model. A brief overview of the main simulation and other mathematical models used to predict the dynamics of the forest fund is given. The following five scenarios were used for modeling for the period from 1990 to 2020 using the EFISCEN model: ideal forest management, common forest management practices, a scenario aimed at achieving the highest possible sustainable level of forest management, a scenario involving the restoration of forestry production and timber harvesting in the late 1980s during the first 20 years and restoration scenario, but taking into account additional requirements of nature protection. The model's forecasting results were compared according to the following three indicators: the average growing stock of tree stands, the average wood stock increment of stands, and the volume of timber harvesting. The comparison was carried out with the actual values of these indicators according to the data of the State Forest Register on the state of forests of the Leningrad Region in 2021 in absolute and relative terms. To compare the quality of forecasting for 5 scenarios and determine the most accurate one, an index of discrepancy between the predicted modeling results and actual data was calculated for each scenario. The forecast turned out to be the most accurate according to scenario No. 2 – “Common forestry practice”. This result suggests that the most reliable forecasting method for a period of 30 years may be a simple extrapolation. The forecasts given by scenarios No. 1 – “Ideal forest management” and No. 3 – “The maximum possible sustainable level of forest management” – allow us to assess the potential of forestry in the Leningrad region. The simulation method, including the EFISCEN model, despite all its disadvantages, remains a useful tool for the scientific study of the dynamics of the forest sector in a changing environment

The article presents materials on the determination of a tree's vital state, taking into account the composition of the phytocenosis. The study object is the dendropark of the Botanical Garden of the St. Petersburg Forestry University. Five model trees were selected for scientific research – one Quercus robur L. and four Tilia cordata Mill. These tree species are present in almost all parks in St. Petersburg. The selected model specimens have comparable characteristics in terms of age and height. The height, trunk diameter, and age of the trees were measured. When visually assessing the condition of a tree, a scale was used that was recommended by the Rules for sanitary safety in forests, which were put into effect on January 1, 2021. Within a 6-meter radius around each model tree, the species composition and main characteristics of trees, undergrowth, understory, and living ground cover were determined. The survey was conducted in accordance with Russian Patent № 2852509. It has been established that the vital state of a tree correlates with the composition of the phytocenosis, and it depends on intensity of influence from neighboring trees.

This article examines the legal mechanisms governing the development of private forest ownership on agricultural lands in the Russian Federation, assesses the potential for integrating abandoned farmland into forestry use, and benchmarks possible reform trajectories against the experience of other boreal countries (Sweden, Finland, Norway, Canada, USA). The study draws on an analysis of Russian federal legislation, data from the FAO Global Forest Resources Assessment (FRA 2025), state land-use reports of Rosreestr, and a synthesis of domestic and international scientific literature. The findings confirm that the legal framework for afforestation on agricultural lands remains unresolved. The conflict between the Forest Code and the Land Code of the Russian Federation, compounded by subsequent amendments to Government Decree No. 1509, has precluded the emergence of a fully-fledged private forest ownership institution. At the same time, according to Rosreestr data, as of the beginning of 2025, 130.2 million hectares of agricultural land are in private ownership, of which, according to researchers' estimates, up to 76 million hectares are abandoned and are being intensively overgrown with tree and shrub vegetation. Potentially, such lands could be used for the establishment of highly productive plantation stands. The legal regulation of the use of agricultural lands for forestry purposes has the potential to resolve existing legal conflicts and become a driver for the development of the domestic forest complex. To achieve this, it is necessary to legislatively establish forestry as an independent type of land use on agricultural lands, create mechanisms for the inventory and registration of forest stands on such lands, and implement long-term regulatory instruments, including shortened rotation cycles (short rotations).

Rope installations have been used for a long time and belong not only to logging. There is a wealth of experience in the use of rope installations in the world and in Russia. The undoubted advantage of KTU is its loyalty to the terrain and soil conditions. The development of technology makes it possible to use rope installations at a different technological level, including when skidding wood in hard-to-reach cutting areas. During the construction and operation of linear objects. The article reflects the problems of transporting goods in inaccessible conditions using rope installations. The historical and technical analysis and review of modern scientific developments are carried out. General technological trends have been identified, promising directions for the development and use of rope systems have been assessed.

The work is devoted to the issue of the impact of the saturation of the cutting area with biodiversity objects on the productivity of logging equipment. The productivity of forest machines is the most important indicator of their work, determined by the amount of work performed by a machine or mechanism per unit of time. There are a number of scientific studies devoted to the study of the productivity of forest machinery, unfortunately, they do not pay attention to the impact of the saturation of the cutting area with biodiversity objects on the productivity of logging equipment. The purpose of this scientific study is to analyze the impact of the saturation of the cutting area with biodiversity objects on the productivity of logging equipment in the conditions of forestry in the North-West of the Russian Federation to determine its quantitative characteristics. The objectives of the study are formulated as follows: to analyze the modern regulatory and methodological framework for the conservation of biodiversity in the production of logging operations; to analyze the practice of conservation of biodiversity in the production of logging operations in the conditions of forestry in the North-West of the Russian Federation; Based on this analysis, to formulate proposals for determining the quantitative characteristics of the impact of the saturation of the cutting area with biodiversity objects on the productivity of logging equipment in the conditions of forestry in the North-West of the Russian Federation. The authors of this scientific study propose to concentrate all environmental protection actions that need to be carried out during logging operations into a new technological operation, which is proposed to be called "bio saving". The more a cutting area is saturated with biodiversity objects, the smaller these objects will be and the more scattered they will be across the cutting area, the more time the harvester operator will spend on bio saving, the greater the value of the bio saving time proposed by the authors of this scientific study. To understand the importance of this term in the harvester productivity calculation formula, it is enough to read the characteristics of such an important object of biological diversity as old-age trees of all breeds and imagine how much time the harvester operator will spend deciding whether this particular tree meets the above-mentioned characteristics or not.

This paper develops a mathematical model for optimizing two-echelon transport logistics in the forest industry, where the delivery process is divided into mainline transportation from an enterprise to hubs and subsequent distribution to consumers. The key feature of the model is the representation of the transport infrastructure as a weighted graph that includes not only departure, transshipment, and destination points, but also transit vertices representing road network nodes. This enables route cost calculation based on shortest paths in the graph, accounting for the real network topology, unlike simplified approaches using aggregated distances. The model is formalized as a mixed-integer linear programming problem (MILP) with balance constraints linking cargo volumes between echelons and vehicle capacity constraints. The model was tested on a transport graph of Primorsky Krai comprising approximately 150 vertices, 10 hubs, and 20 consumers. The optimal objective function value was 1619.0 cost units, with 15.3% attributed to the mainline echelon and 84.7% to the distribution echelon. Full demand satisfaction was achieved for all consumers (730.0 units). Second-echelon route costs ranged from 54.5 to 317.6, reflecting spatial heterogeneity in consumer distribution relative to hubs and the graph structure. The results confirm the model’s correctness and demonstrate coordinated route formation that explicitly accounts for transit infrastructure nodes. The proposed approach is applicable to transportation planning in forestry and other industries with spatially distributed infrastructure.

A simulation agent-based model of a feller-buncher for selective and gradual felling is developed, accounting for kinematic constraints of platform rotation and tree inaccessibility due to retained obstacles. The model is implemented in the AnyLogic environment. At the initialization stage, the user specifies cutting area boundaries by entering coordinates of turning points, which allows modeling sites of any geometric shape, as well as the machine trajectory, including main and strip skidding trails. A multi-agent structure is created, including harvested trees, retained trees, undergrowth, and an inaccessible trees category. The user specifies species composition, stem diameter, and the number of trees of each type. Tree distribution over the cutting area is random. Technical characteristics of the machine, including felling head reach, travel and rotation speeds, are also entered before simulation. An algorithm for trail clearance and a mechanism for assessing target tree accessibility from a working position are developed, providing for the transfer of inaccessible trees to a separate category with the possibility of their reassessment after a position change. Kinematic constraints of platform rotation are considered when pointing the felling head at a standing tree and when placing a felled tree into a bunch on the trail, including correction of the working position by reverse movement with vertical lifting of the tree when obstacles are detected. The model provides 2D and 3D visualization of the technological process. The practical significance lies in the ability to assess the real accessibility of timber stock at the logging design stage, considering kinematic constraints and the location of retained trees, which allows adjusting production standards before equipment enters the cutting area. The model provides a basis for subsequent assessment of time consumption and productivity.

The working processes of ploughshares and disk tillage tools for basic tillage in forest areas are analyzed. A new design of a resource-saving forest plow for extensive tillage in uncorrupted cuttings has been proposed, the spherical disc bodies of which are equipped with hyperboloid dumps to ensure the required quality of turnover of the blackened layer and its laying next to the furrow in the form of a continuous ribbon. Such a tool makes it possible to avoid the materially costly operation of uprooting stumps and, at the same time, reduce the negative impact on the soil and increase the survival rate of the planted plants. An equation is obtained for determining the angle of rise of the formation along the spherical working surface of the disk housing. The design and technological characteristics of the proposed plow are substantiated, in particular, the geometric parameters of additional working bodies – hyperbolic dumps. It has been established that in order to create a furrow 700 mm wide and 150 mm deep with an acceptable ridge of its bottom, ensure reliable overcoming of stumps with a tool and perform high-quality tillage of forest soil with minimizing energy loss, the proposed plow must have the following characteristics: diameter of a spherical disk – 710 mm; radius of curvature of a spherical disk – 1000 mm; angle of attack the disc case is 400; the angle of inclination to the vertical of the disc case is 00; the longitudinal distance between the centers of the spherical disc cases is 330 mm; the vertical distance between the centers of spherical disk housings is 300 mm; length of the hyperboloid blade – 240 mm; throat diameter of the hyperboloid blade – 26 mm; base radius of the hyperboloid blade – 37 mm.

Economically viable development of the main reserves of wood raw materials is often only possible if it is delivered from remote forest areas via a network of medium and small rivers. Due to shallow depths and short navigation periods, the use of existing vessels on them is generally impossible or economically impractical. The problem can be solved by using the proposed relatively cheap and simple shallow draft towing device, which is delivered to the timber place of departure by road transport. The work was carried out with the aim of obtaining the parameters of the propellers of the proposed device, which would reduce towing costs under the specified conditions. The absence of idle speed allows propellers to be designed specifically for towing mode, which increases their operating efficiency in this mode. In order to maximize the use of flow energy, it was decided to tow units having high resistance at a minimum speed that ensures their control. At this speed, efficient use of engine power and obtaining maximum thrust is achieved by using propellers with a particularly small pitch ratio. This involves increasing their diameter and rotation speed. In the case under consideration, the diameter of the propellers is limited by the depths along the route and, unlike ships, is not directly related to the hull draft. With a power of 125 kW, the most suitable engine for the proposed device, the use of one small diameter propeller (0.6-0.8 m) at a towing speed of 4.5 km/h suggests the occurrence of cavitation, insufficient strength, or low thrust. With two propellers, their diameter can be from 0.6 m, and the thrust increases significantly. For the proposed device, graphs and empirical formulas have been obtained, which make it possible to easily determine the parameters of propellers under various operating conditions in practice. Changing the propellers diameter from 0.6 to 1.0 m results in an increase in the total thrust from 15.0 to 21.3 kN.

At the moment there is great number of different models of harvester heads present on the market of technological equipment for woodcutting. Those harvester heads differ not only in their operational parameters, but also in constructive features of their systems and mechanisms. Even if the features that change the process of woodcutting fundamentally are not taken into consideration, there is plenty of those which have a serious influence on the effectiveness of the harvester head use. One of the constructive features of a harvester head is a type of gripping mechanism. The literature review showed that the science field of western countries a row of works on the topic is present, but there is few that focus on the differences of the types of gripping mechanisms. In the Russian science field studies on the topic are not present. The study is dedicated to the research of two types of gripping mechanisms – concentric and linear – and the determination of their possible differences, especially a calculation of feed force necessary for processing of a trunk of same diameter. The study examined the kinematic schemes of concentric and linear mechanisms and performed a static calculation of the forces acting on the processed tree trunk to establish possible differences in the force required for tree feeding, under certain assumptions (e.g., equality in the shape, size, and material of the feed rollers and delimbing knives, equality in the geometric and mechanical properties of the processed tree, etc.). The results showed that, under the adopted assumptions, it is impossible to assert specific differences in the feeding force between concentric and linear mechanisms of the harvester head's gripping device. However, when the tree diameter changes during processing with a harvester head featuring a concentric mechanism, the required feeding force follows a more complex relationship compared to processing with a harvester head equipped with a linear mechanism. These findings can aid in researching the harvester head's operation and understanding various dependencies related to harvester head characteristics. This will make the performance of such machinery more predictable and provide necessary justifications for applying specific design solutions when developing domestic equipment models.

This article examines issues of rational environmental management. It addresses the challenges of utilizing all wood biomass as raw material for producing process chips or chips for generating thermal energy and generator gas, as well as for a variety of promising chemical industries. The relevance of the study lies in the separation of wood chips not only by size but also by resin content, dividing them into fractions in an electrostatic field. The aim of the study is to develop an experimental setup for sorting wood particles with different resin contents in an electrostatic field. The objects of study in this article are the designs of devices for separating chips by various characteristics. A search method was used, including a review of existing sorting device designs, their analysis, comparison, generalization, and specification, identifying analogs and prototypes and their attendant shortcomings. Based on this, several promising areas of research in the field of wood chip sorting by resin content were identified. A schematic diagram of a separation unit for separating wood chips in an electrostatic field was developed, and the basis for its operation was presented. A full-scale experimental laboratory prototype of a separator for separating wood chips by resin content is presented. Its parametric dimensions are determined. A methodology for performing full-scale laboratory experiments on the separation of industrial chips and the results of an experiment on differentiating industrial chips by resin content are presented. The input parameters of the experimental laboratory setup, which completely separates wood chips by resin content fractions, are presented. Subsequent stages of research into the process of separating wood chips by resin content are outlined.

The possibility of using ultrasound to detect the presence and assess the condition of knots in wood is considered. Sorting lumber for defects or flaws is primarily done visually, which does not always allow for an accurate determination of the intended use of these semi-finished products with the required performance characteristics. Furthermore, visual assessment of the grade and condition of lumber is highly prone to making erroneous decisions, as some defects are hidden. The presence of hidden internal defects or flaws, including knots and cracks in the areas where they are located, can lead to further failure of either a single element or the entire structure. Ultrasonic diagnostics can be used to assess the presence and condition of these materials. The shadow method of acoustic testing demonstrates a high degree of reliability in the diagnostics of solid wood. A frequency of 2.5 MHz was used in the studies. Due to the anatomical structure of wood, several diagnostic features arise during the sounding process, which expand the scope of this method. These characteristics include the need to amplify the signal amplitude to pass through the wood, which indicates the presence or absence of defects and flaws, and allows for an assessment of their condition and the determination of their functional purpose. A defect-free zone, as well as a zone with healthy intergrown knots, requires signal amplification to 70 dB. Increasing the signal amplitude above 70 dB indicates the presence of a zone of internal stress concentration, as well as defects and flaws that significantly reduce the quality of the lumber.

The work is devoted to substantiating the choice of priority areas for the use of lowcommodity timber from the “SHELON” timber industry complex – one of the flagships of the timber processing industry in the North-West of the Russian Federation. In the process of logging, a significant amount of low-quality wood is formed at the enterprise in the form of fine grain, balance and technological raw materials, which are currently not being processed efficiently enough. The paper investigates and develops alternative rational directions for the effective processing of low-quality wood raw materials at the enterprises of the “SHELON” timber industry complex. During the research, the task of selecting and substantiating promising areas for processing existing low-quality wood raw materials was solved taking into account the analysis of logistical, technical, technological, environmental, energy, raw materials, economic factors, water resources. The following requirements for potentially manufactured finished products were taken into account: wood should make up the largest share of the finished product; the proposed product should, if possible, be made from all available wood species; the share of ingredients purchased on the side (adhesives, fillers, etc.) should be minimized; products should not be experimental and should have proven market advantages. prospects, possibly low production cost and high marginality; products should have an all-season demand. The following options for processing low-commodity wood are recommended: sawmilling using small-diameter roundwood; production of various building structural materials based on crushed wood and mineral binders; production of thermomechanical mass; production of various types of products based on pyrolysis processes; production of structural slab material (OSB slabs).

The purpose of the work is to obtain samples of packaging types of high-strength paper and cardboard due to the use of cellulose from technical hemp bonfire in a composition with MС-5Б waste paper. The technical hemp bonfire is comparable to hardwood in terms of its main components, but it has a high ash content. Natron cooking of cannabis fires was carried out under the following conditions: consumption of NaOH in units of Na2O – 18...30% of a.s.s., hydraulic module – 5:1, temperature rise to 170°C – 60 min, cooking time – 60 min. With an alkali consumption of 18% NaOH, cellulose contains up to 18.6% unwanted inclusions, and the mass fraction of lignin is 16.1%. At a consumption of 24% NaOH there is no unwanted inclusions, the yield corresponds to hard sulfate cellulose. With an alkali consumption of 30%, the yield is reduced to 43.2%. In further studies, cellulose obtained by the second cooking mode was used. Cardboard liner samples (cardboard for flat layers of corrugated cardboard) made of 100% waste paper and with 25% cellulose from the bonfire did not reach the required ring compression index for grades K-0 and K-1. At 40, 75 and 100% of the fires, the indicators correspond to the norms: fiber fires are tougher than waste paper. The analysis of the results of measuring the physico-mechanical parameters of paper samples for corrugation was as follows: with an increase in the proportion of pulp from the hemp bonfire, the strength of the paper increases, but over 50% the increase in the specific resistance to rupture stops, and the resistance to planar compression decreases. Optimal compositions – 50% waste paper + 50% bonfires (corresponds to the B-1 brand and cardboard not lower than K-0) and 25% waste paper + 75% bonfires (exceeds the requirements for the B-0 brand).

The article examines the possibility of obtaining a fibrous semi-finished product from cotton stalks of Uzbek origin (variety S-6524) using the soda pulping process. The effect of sodium hydroxide consumption on pulp yield, chemical composition, and physical and mechanical properties is established. The raw material consisted of unbarked cotton stalks, pre-cut to 4–5 cm, with a cellulose content of 49.4%, lignin 21.4%, and ash content 4.6%. Pulping was carried out at a NaOH charge of 10-50%, a liquor-to-solid ratio of 10:1, a temperature of 155 °C, and a cooking time of 120 minutes. Increasing alkali consumption leads to a decrease in pulp yield from 50 to 29% and a reduction in residual lignin from 20.3 to 9.6%. In the range of 17-40%, the content of extractives and ash changes insignificantly. A decrease in fiber length and width and an increase in fines content are observed with increasing alkali consumption. Maximum strength properties are achieved at a NaOH charge of 40%, while at 50% a sharp decrease occurs due to fiber degradation. At 17-20% NaOH, the pulp provides a balance of yield and strength properties. The obtained paper demonstrates tensile length 4350–4380 m, bursting strength 231–253 kPa, and tensile strength 4.17–4.35 kN/m. The results confirm the suitability of cotton stalks for packaging board production.

This review examines the current state of the biochemistry, chemistry, structure, and valorization of lignin, the second most abundant biopolymer on Earth after cellulose. The evolution of views on the formation of this polymer's macromolecules is noted. As it turns out, monolignols are highly flexible in their biosynthesis, allowing plants to replace monolignols when the functioning of one or more genes is disrupted, so the composition and quantity of lignin often change simultaneously. In addition to the canonical monolignols (coniferyl, sinapic, and coumaric alcohols), other compounds can participate in lignin biosynthesis. The supply of monolignols and polymerization conditions are carefully controlled within the cell, but this control should not be confused with the control of lignin polymer assembly. The most promising areas for the valorization of technical lignins are presented: lignin hydrogels, the use of lignin in medicine and pharmacology, 3D printing, carbon fibers, biofuels and biochar, lignin nanomaterials, composite materials and lignin derivatives, carbon quantum dots, a reagent for drilling fluids, and the synthesis of lignophenol-formaldehyde resins. In conclusion, the economic problems of lignin valorization are considered.

In the forming part of the paper machine, about 95-99% of the water contained in the paper pulp is removed. In addition to removing water, the paper web is formed in the mesh part, during which the structure of the paper web and its properties are predetermined. The study of the work of the forming part was carried out on a paper machine that produces paper for the production of corrugated cardboard. In the course of this study, the process of dehydration on a forming part during the production of paper with a mass of 1 m² equal to 100, 125 and 160 g was studied. Information about dehydration on the forming part was obtained using the FiberScanOne device from the Italian company Cristini. This device allows to measure the weight of paper pulp on a forming wire using a microwave sensor. The dehydration data was processed and calculated in specialized software – the Dragon program developed by Andritz. The study shows differences in the dynamics of the dewatering process during the production of paper with different weights of 1 m² on one machine. It was found that with an increase in the mass of 1 m², the dryness of the paper web decreases after passing through the forming part, as well as the displacement of the dry line in the direction of movement of the paper web. It is shown that with a decrease in the value of primary dehydration on the chest board box, there is an increase in the value of dehydration on the hydroplane box following it. It is also shown that with an increase in the mass of 1 m² of paper produced, the productivity of paper machine changes slightly. Thus, the productivity of the paper machine is the lowest in the production of paper with the highest and lowest mass of 1 m². In the production of paper with an average weight of 1m², the productivity of paper machine was the highest.