It is established that the post-fire restoration of the forest ecosystem has its own characteristics. As a result of a grass-roots forest fire, blueberry pine was replaced by blueberry birch. This is primarily due to forest conditions. The object of the study is a 2006 fire in the south of the Republic of Karelia. The species composition, condition and structure of the stand, undergrowth, undergrowth and living ground cover were established using the method of circular accounting sites. 15 years after the fire, a new stand was formed, its density exceeds 22 thousand copies / ha. Due to the high density of the young, the loss of birch reaches 23%. In total, 7 forest-forming breeds were identified in the young stock. Betula pendula Roth. – 73% and Alnus incana (L.) Moench predominate in number – 15%. Despite the large density of the main tier, the undergrowth also participates in the restoration of the forest ecosystem. The total number of plants in this component of the forest is about 17 thousand/ha. More than 95% of the number of undergrowth falls on Salix caprea L. and Sorbus aucuparia L.. In small numbers there are Prunus padus L., Viburnum opulus L and Juniperus communis L. The living ground cover is composed mainly of shade-tolerant species. Polytrichum commune HEDW., Avenella flexuosa (L.) DREJER and Oxalis acetosella L. predominate. Only these 3 species out of more than 26 identified as part of the living ground cover have a projective coverage of about 5%. The total projective coverage of the grass-shrub layer is about 50%. Plots without living ground cover (dead-cover parcels) occupy in general more than 29% of the area of the forest plot. The moss-lichen layer is represented by several types of mosses and lichens. According to the typology of V.N. Sukacheva formed birch can be attributed to the birch forests of the blueberry type of forest.

Залежные земли, не используемые для ведения сельского хозяйства, обладают высокими количественными показателями, отражающими реальное и потенциальное качество почв определяющих их экономическую ценность. Процесс оценки почв и установление их бонитета (качества) характеризует бонитировка. Экономическая оценка земли и бонитировка почв – две взаимосвязанные части единого земельно-оценочного процесса. Назначение бонитировки состоит в определении относительных достоинств почв по их плодородию. Экономическое признание качества земли, как главного средства производства должно обладать рядом особенностей, которые должны быть количественно соизмеримы и оценены. Большое значение в экономическом эффекте играет правильный выбор показателей. Они должны быть объективными, то есть отражать качество земли как средства производства и иметь определенное практическое значение. Таксировка продуктивности возводимых лесных насаждений на землях, выведенных из сельскохозяйственного оборота, аргументируется рентабельностью проведения культуртехнических работ. Основная цель расчета экономической целесообразности при мелиоративных мероприятиях выявить обоснованное решение ввода земель в активное сельскохозяйственное пользование, либо ускорить процесс выращивания древесины для получения фитомассы на постагрогенных землях, путем необходимых лесоводственных мероприятий, направленных на содействие возобновлению леса. Итогом расчета является планирование хозяйственной деятельности предприятия на ближайшие и отдаленные временные периоды в соответствии с потребностями рынка и возможностями получения необходимых ресурсов.

Growth stimulators accelerate seed germination, increase germination, have a positive effect on the development of the aboveground part and the root system of seedlings, increase survival during transplantation and contribute to better survival in extreme conditions. Currently, there are a large number of different substances with a growth-stimulating effect, but preference is given to environmentally friendly. Such stimulants include humic preparations. The aim of the study was to study the effect of humic preparations on laboratory germination of seeds, on the change in the number of cotyledons in shoots and the growth of seedlings of Pinus sylvestris. Pine seeds were soaked in solutions of preparations: Ecorost, Gumi, Humate + 7 iodine, Humate + 9 trace elements and in water (control). The germination of treated seeds was studied under laboratory conditions. We also took into account the number of cotyledons at each shoot in experimental versions and on control. In the greenhouse conditions of the Arkhangelsk region, the seedlings of Pinus sylvestris were watered with solutions of humic preparations Ecorost, Gumi, Humate +7. In the experiment on laboratory germination of Pinus sylvestris seeds, there were no significant differences between the control and experimental variants. According to the results of the evaluation of the structure of seedlings by the number of cotyledons, depending on the treatment of seeds with various humic preparations (Ecorost, Gumi, Humate +7, Humate + 9 trace elements), it was found that these preparations do not have an effect on the number of cotyledons in shoots of Pinus sylvestris. Seedlings of Pinus sylvestris of the first year of cultivation, fertilizing with humic preparation Humate + 7, were 0.3 cm higher than the control variant, which is not a significant indicator for the use of this substance in production. Preparations of Gumi and Ecorost showed a depressing effect on the growth of seedlings. All the tested preparations had no effect on the radial increase. Thus, the humic preparations tested in this study with the concentration selected by us do not affect the increase in seed germination, the growth of seedlings of Pinus sylvestris, or have a slight excess. Therefore, research in the field of application of specific humic preparations, their concentrations, soaking time, watering frequency, etc. to increase the efficiency of growing the planting material of Pinus sylvestris, should be continued.

Assessment of all aggregate properties of black pine as a species is important not only in general, but also for its varieties from isolated populations. The assortment of fairly stable and ornamental pine species in the region of the European part of the Russian Federation turns out to be very limited, but a place in it is given to Austrian black pine. Hence, the purpose of the study is to consider the features of the growth and condition of the Austrian black pine in the conditions of introduction in the foreststeppe region of the European part of the Russian Federation (Voronezh region). In relation to various diseases, it should be attributed to a very resistant species, which is confirmed by the corresponding category of sanitary condition at the site – I,1. Calculations show that the Austrian black pine on fertile soil surpasses the common pine in the characteristic conditions of the latter. As a result of differentiation of species by decorative features, we should give priority to black pine (24 points) with a slight preponderance over Scots pine (20 points). Taking into account the data obtained, we can recommend in terms of green building the location of the species in a cluster of three trees per planting place with a distance between trees in the cluster to 2.5 m, and between the clumps themselves – 5 m.

World statistics show a steady increase in greenhouse gas emissions in the planet's atmosphere. Сcontinuous growth of greenhouse gas markets occurred despite the financial crisis (2008) and the pandemic (2019–2022). Currently there are dozens of market mechanisms in the world that capture some 20% of greenhouse gas emissions. Despite obvious progress, the terms of the Paris climate agreement are far from being met. The current situation requires the global community to strengthen measures to combat climate change. New approaches are needed to develop marketbased instruments to achieve climate goals. The study explores the volumes and trends of using the market economic mechanisms abroad. These mechanisms are able to cover a significant part of greenhouse gas emissions. Russia has so far been passively involved in the development of global carbon markets, unlike its western and eastern neighbors. The study of the experience of these countries is necessary for the successful assertion of national Russian interests in the global carbon policy and markets. Carbon credits are traded on a mandatory and voluntary markets. They are divided into primary and secondary. Carbon markets reached $800 billion in 2021, more than international trade in grains or oil. Voluntary markets have surpassed the $800 million mark and continue to grow rapidly. It is expected that by 2030 their volume will be at least 100 billion US dollars. As part of the study, promising directions for the Russian carbon markets were highlighted, taking into account world experience and development trends.

The article is devoted to the last fundamental work of the outstanding Russian forester, professor of the Forestry Institute (Leningrad Forestry Engineering Academy) M.M. Orlov «Forests are water protection, protective and forest parks». The work was completed in January 1932, but was never published during the life of the author, or for several 10 years after his death. The article is based on materials kept in the Orlov family: letters, photographs, documents, typewritten copy of the work. The article contains information about the difficult period of the last year of prof. Orlov, when foresters were persecuted, defending the principles of constancy of forest management. Links to the letters of N.P. Anuchin, who tried to influence the publication of the book back in 1932. The chronology of events is shown, concerning the reasons for the non-publication of the book. The first publication took place half a century later, in an abridged version. For the first time in full, the work «Forests are water …» was published in 2019, as part of the multi-volume publication «Proceedings of prof. M.M. Orlov». An extensive review of the literature allowed prof. Orlov to globally present to the reader the importance of forests for humans, to give recommendations on the organization and technique of arranging of forests water protection, protective and forest parks; he proposes his own classification of forests according to the degree of their water protection. The book shows that prof. Orlov intuitively foresaw the course of the further development of forestry. Despite the past 90 years, it does not lose its significance in the 21st century.

In drained pine stands in the Sokolsky and Ustyuzhensky municipal districts of the Vologda Oblast, a study was made of the main macrostructural features of Scots pine wood, in particular, the study of the influence of hydrotechnical reclamation on its formation. The objects of study are drained and naturally swamped (control) pine plantations on peat deposits of oligotrophic and eutrophic types of waterlogging. Forest objects were selected in naturally swampy and drained pine forests with different distances between reclamation canals (80, 120 m, etc.), in which temporary trial plots were delimited. Forest taxation work was carried out, an estimate sheet was compiled, and features of the formation of wood in drained pine forests were revealed. The density of wood is determined and characterized by calculation according to the analysis of wood cores. The analysis of the basic parameters of the macrostructure of pine wood, such as the width of the annual ring, the width of the late layer of tracheids, the number of annual layers in one cm, and the growth of wood over 10 years, was carried out. The autocorrelation of pine wood increments, the dynamics of total radial increments of pine wood and extremums for five years of tree growth are calculated and analyzed. Mathematical processing of experimental data was performed using variational, correlation and regression types of statistical analysis. After the study, the positive influence of hydrotechnical engineering on the formation of Scots pine wood in the southern subzone of coniferous boreal forests was confirmed. The density of pine wood in soil with an oligotrophic type of peat deposit under conditions of artificial drainage is higher by 11% (450.8 kg / m3), relative to the situation in naturally swamped forest stands for the same time period. In intensively drained forest stands, the highest percentage of late wood was found, relative to other studied objects – 45%. The average width of the annual tree ring of wood was found to be the largest on peat with a transitional type of waterlogging after selective harvesting of wood near the reclamation canal (1.67 mm). The average value of the obtained auto-correlation of wood increments before reclamation is 0.14, after this indicator increased by 1.6 times.

The article presents a review of the literature about molecular and genetic mechanisms of birch and oak resistance to water and nitrogen deficiency. Analysis of the transcriptome activity of genes that respond to abiotic stresses makes it possible to carry out targeted selection for the purpose of effective reforestation, as well as the creation of forest plantations. The molecular genetic response to drought has been more studied in woody plants than nitrogen deficiency. Compared to Betula sp., the early response of Quercus sp. to drought is less intense and is expressed in the suppression of metabolic activity and activation of growth maintenance systems after stress. With prolonged exposure to drought, intensive сell wall remodeling is observed, associated with the biosynthesis of cellulose and lignin. Active processes of neutralization of reactive oxygen species and biosynthesis of antioxidants are observed. During the early response of Betula sp. drought, a high level of expression of genes associated with a decrease in water loss is observed. Drought protection also includes control of stomatal closure and activation of genes associated with the response to osmotic stress. Among candidate genes for response to drought in oak species, transcription factors, heat shock proteins, transporter proteins, etc. were identified. Based on the results of an analytical review of the literature, a list of differentially expressed genes (DEGs) identified in birch and oak in response to drought was compiled. If the molecular genetic mechanisms of drought resistance in woody plants have been studied to a sufficient extent, many candidate genes involved in the stress response have been identified and can be further recommended for targeted breeding, then the issue of adaptation of woody plants to nitrogen deficiency is poorly studied and seems to be very relevant for further research.

The structure, dynamics and regional features of artificial forest restoration on Sakhalin Island are analyzed. Over the past 75 years, forest crops have been created on the island as a whole on an area of 365885 hectares. The most large-scale reforestation work on Sakhalin was carried out in the 70-80s of the XX century, when the annual volume of forest crops reached 8-10 thousand hectares, which was due to the beginning of the functioning of two large basic nurseries. Due to the lack of their seeds, long-term forest crops on the island were grown from the inorainic scots pine, the total area of which eventually amounted to 113401 hectares. Especially actively forest crops of scots pine were created from 1968 to 1990 and reached 50-77% of the total volume of annual reforestation work in the region. However, due to the massive damage to pine crops by rodents and the negative impact of many natural factors, about 36% of their area died. For all other indigenous coniferous species (spruce, fir, larch) grown on Sakhalin, the death of forest crops was 3.7%. With the artificial reproduction of forests on Sakhalin, since the 80s, spruce has become significantly dominant over other species. As a result, the share of spruce crops for all the years of their cultivation on the island amounted to about half, and over the past 20 years – over 76% of the total area of forest crops. The share of forest crops of another dark coniferous species of the region – fir was extremely insignificant (2-3.5%). In general, artificial reproduction of forests on Sakhalin was carried out without taking into account the latitudinal differentiation of forest vegetation and the peculiarities of the biology of forest-forming species. The main reforestation work was first carried out in the southern regions, where the share of forest areas reaches 10-17%, and then in the middle part of Sakhalin. Meanwhile, very little attention is paid to the northern regions of the island (0.4-2.7%), where huge areas of unforested burns are currently concentrated.

Inefficiency of the «universal» traditional forestry model, which results in depletion of available forest resources for forestry industry, an overestimation of allowable cut in forestry regions by 2-3 times, and a decrease in area and share the most valuable and ecologically significant hardwoods and cedar pines, as well as an increase in the rate of intact primary forests loss. . The departments in charge, contrary to strategic governmental documents adopted in 2013–2018, do not take steps to stimulate transition to an intensive forestry model, which requires to charge fees based on a unit of leased area, and not the volume of cut wood; the transition of forest management to felling based on tree diameter instead on the tree age, etc. It is obvious that the transition to a model of intensive use and restoration of forests is more economically beneficial in regions with higher biological productivity of forest lands, with a greater density of forest roads and more developed infrastructure. The problem of spatial demarginalization of the country's forest complex seems to be an urgent task – the shift of forest resource base and processing infrastructure from the northern taiga of European Russia (ER) and Central and Eastern Siberia to secondary forests of coniferous-broad-leaved and southern taiga forests in ER with a developed and denser road network (6-7 km per 1000 ha and above). This position is confirmed by growth of investments in timber processing and production of wood-based panels, sheet materials, etc. by private companies.

The urgency of the issue of expanding the forest infrastructure in the Russian Federation is increasing every year and faces economic, environmental and operational problems due to the wide geography of our country. The presented research is aimed at a comprehensive solution of the voiced problems. The use of industrial waste mixed with soils and alkaline additives will reduce the shortage of road construction materials, and the disposal of significant amounts of waste will have a positive impact on the environmental component. The materials presented in the study comply with SUST in terms of their physical and mechanical characteristics. Primary recommendations on the use of catalysts in sludge-soil mixtures are given.

The research is devoted to the analysis of the main technical characteristics of wheeled narrow-grip feller buncher machines of frontal type by methods of stochastic mathematical modeling. The following parameters were analyzed: engine power, machine weight, ground pressure ground, power capacity, maximum diameter of trees to be cut and the weight of the feller head. As a result of static processing with Statgraphics 18 software, the laws of distribution of each of the investigated parameters. Also, a singlefactor and multifactor regression analysis. As a result of the one-factor regression analysis we received the dependences of the engine power of the engine, ground pressure and machine weight on the maximum possible diameter of the trees to be cut. The two-factor regression analysis made it possible to dependences of: engine power from the maximum diameter of trees to be cut of trees to be cut and the weight of the machine; the weight of the machine from the maximum diameter of trees to be cut and engine power; ground pressure from maximum diameter of trees to be cut and engine power. The obtained regression dependencies make it possible to approximate values of power, machine weight and ground pressure both at the stage of design development stage and when choosing a machine for operation depending on requirements to cutting diameter.

The object of the research is the methodology of determining the optimal location of pellet production facilities. The purpose of work is optimization of territorial location of new pellet manufactures in the given area by a criterion of a minimum of transport expenses for their raw material maintenance. As a result of the research, a mathematical model and an algorithm for finding an optimum location of the mill by the criterion of the raw material delivery load, taking into account the existing transport infrastructure of the region and estimated logging areas of forestries were developed. The realization of the posed optimization task of pellet mill location is carried out in MS EXCEL environment with the help of "Search for solution" subsystem and GIS-project of forest raw material base of Novgorod region. Significance of work consists in development of mathematical model and algorithm of optimization of territorial location of pellet manufactures. With the achieved volumes of harvesting and existing reserves of raw material sources in Novgorod region it is recommended to build one plant for pellet production with a capacity of 150 thousand tons in the town of Malaya Vishera. With the prospective volumes of harvesting in the Novgorod region equal to the estimated logging area and standard pellet production capacity of 100 thousand tons per year it is recommended to implement the first scenario – the construction of 8 plants in the following settlements: Chudovo, Neblochi, Lubytino, Pestovo, Krestsi, Demyansk, Staraya Russa and Soltsy. Existing pellet manufactures, except for located in settlement Marevo, are perspective for expansion of available capacities of pellet manufacture on raw materials supply.

Fuel briquettes from wood raw materials are widely used in the economy, briquettes are an environmentally friendly source of energy. The technological process of their production includes several operations, the main of which are transport, drying, grinding and direct briquetting (pressing) of raw materials. Nowadays researchers are studying the production of fuel briquettes not only from sawdust, but also from tree bark, branches and roots. This raises the question of assessing the efficiency of wooden biofuel production, including energy consumption. Our article is devoted to the development of an approach to the theoretical assessment of energy costs at the stage of pressing prepared raw wood materials. The study bases on the analysis of the results obtained earlier in the field of mathematical modeling of the pressing of strengthening wooded materials. As a basis, a non-linear equation for pressing a wood material is used, taking into account the increase in the plasticity limit of the briquette material. The calculations in the article are performed using the methods of approximate solution of differential equations in the Maple computer mathematics system. The estimation of power consumption and power parameters of pressing coniferous wood sawdust is carried out. The results of the calculations showed that the energy costs caused by pressing the briquette material are almost linearly related to the density of the formed briquette. To obtain a briquette from softwood sawdust with a density of 1 t/m3, the working body of the press does work of approximately 40 kJ; to obtain a briquette of 1.2 t/m3 – approximately 55 kJ. According to a theoretical estimate, the force of the working body at the end of the pressing process reaches 700 kN (70 tf).

The rational aerodynamic situation in the furnace of a pulverized coal boiler was determined experimentally and by calculation at different orientations in the space of the chamber of hot air flows from the rear blast supply unit. Numerical modeling of the processes of hydrodynamics and heat and mass transfer in the furnace space of a heat technological device was performed using the modern PHOENICS computer complex. The possibility of controlling the non-uniformity of energy carrier flows in the working chamber of a particular boiler unit, and hence the effective modes of its operation, is shown. Both experimental and calculated data obtained made it possible to determine not only the optimal spatial operating parameters of the rear blast supply unit and flow characteristics for two types of burners, but also to obtain a set of rational parameters of the rear blast unit when changing the operating mode of the boiler unit, for example, when new reductions in its load. The use of research results made it possible to practically eliminate emergency situations due to inefficient operation of the rear air curtains.

The analysis of industrial microchips of the outer layers and chips of the inner layer of particle boards with a fine-structured surface is carried out. In the workshop, the selection of a fine fraction of wood particles and its withdrawal from the process flow is not carried out. The studied chips had the following rock composition: aspen – 60%, birch – 20%, pine – 20%. The absolute moisture content of the chips is 2%. The fractional composition of wood particles and their linear dimensions are determined. The specific surface area was calculated for each fraction and for the chip mixture as a whole. A method has been developed for calculating the specific surface area, taking into account the content of bark and rot in wood raw materials, as well as the moisture content of dry chips. The average size of microchips: length 1.79 mm, width 0.35 mm, thickness 0.07 mm. The total surface of 1 kg of microchips is 120 m2. Of these, the largest area of about 81% are the surfaces of layers of wood particles, the shares of the side faces and ends of the microarray, respectively, 15 and 4%. With an average weighted basic density of wood raw materials of 427 kg/m3, the recommended dry resin distribution is 13.7%. At this rate, the calculated specific consumption of dry resin on the surface of wood particles of microchips is 1.14 g/m2. The microarray contains a significant amount of the smallest wood particles of a fraction of 0.5/0 mm – 22.8% of the total mass. The specific surface area of the particles of this fraction is 266 m2/kg, it occupies 50.6% of the total surface area of the microarray. The removal of fine particles of 0.5/0 mm fraction in the amount of 10% of the mass of the microchips allows to reduce the surface area of the microchips from 120 to 104 m3 or by 13.3%, and the surface area of this fraction from 50.6 to 36.4% of the total area of the microchips. With a resin consumption of 13.7%, the calculated specific consumption of dry resin on the surface of the microchip will be 1.32 g/m2. An increase in the specific consumption of resin from 1.14 to 1.32 g/m2 or by 15.8%. Average chip sizes of the inner layer: length 6.25 mm, width 0.88 mm, thickness 0.27 mm. The total surface of 1 kg of chips is 42.9 m2. Of these, the largest area of about 77% are the surfaces of wood particle layers, the shares of the side faces and ends of the microarray, respectively, 20 and 3%. The recommended consumption of dry resin is 10.2%. With this consumption, the even specific consumption of dry resin on the chip surface is 2.38 g/m2. The content of the smallest wood particles of 0.5/0 mm fraction is 5.2% of the total chip mass. The specific surface area of the particles of this fraction is 281 m2/kg, it occupies 34.1% of the total chip surface area of the inner layer. The removal of fine particles of 0.5/0 mm fraction in the amount of 5% of the chip mass reduces its surface area from 42.9 to 30.2 m2 or by 29.6%, and the surface area of this fraction from 34.1 to 2.0% of the total chip area. With a resin consumption of 10.2%, the calculated specific consumption of dry resin on the surface of the wood chips of the inner layer will be 3.38 g/m2. An increase in the specific resin consumption from 2.38 to 3.38 g/m2 or by 42.0%. With a mass fraction of the outer layers of 40%, the removal of 10% of the mass of microchips is 4% of the total flow of dry chips. The similar removal of 5% of small particles from the chips of the inner layer is 3% of the total flow. The sum of the removed fraction of 0.5/0 mm fraction particles is 7% of the total chip mass. Removal of a part of the smallest particles of 0.5/0 mm fraction from the general flow of dry chips leads to an effective increase in the specific consumption of resin over the surface of the remaining chips. When 7% of wood particles of this fraction are removed, the calculated specific resin consumption increases on the surface of the chipboard outer layers from 1.14 to 1.32 g/m2 or by 15.8%, and on the chip surface of the inner layer from 2.38 to 3.38 g/m2 or by 42.0%.

Mineral substances, in addition to their great physiological significance in the development of plants, have a significant effect on the processes of chemical and thermochemical processing of wood. In particular, this is important when carrying out acidic hydrolytic processes of the carbohydrate complex and associated processes of acid neutralization with ash elements of plant materials. The study of the behavior of ash elements of wood in the process of acid hydrolysis of wood was the goal of this work. It was shown in the work that the ash substances of birch wood are easily extracted with water and weak acid solutions at room temperature. At the same time, water-soluble substances make up 42.4%, and acid-soluble ones – 63.6% of the total ash content in wood. Analysis of the ability of ash substances of birch wood to neutralize acid showed that complete neutralization is – 72.5 mg-eq/kg dry weight (3.55 g of sulfuric acid per 1 kg of wood); after water extraction – 34.0 mEq/kg, and after extraction with acid solutions – 9.4-13.6 mEq/kg. When carrying out hemicellulose hydrolysis of birch wood, more than 85% of the mass of ash elements of the wood is removed, including more than 85% of calcium salts, 90% of magnesium salts, 90% of phosphorus and 63% of potassium. At the same time, the neutralizing ability of ash was 62.4 mg-eq/kg of dry weight (3.1 g of sulfuric acid per 1 kg of wood). The mode of low-acid hemicellulose hydrolysis of wood, selected on the basis of the data obtained, under the condition of 50% neutralization of sulfuric acid with ash elements (6.25 g/kg of dry raw materials). Showed significantly better indicators in terms of the rate of hydrolysis, the content of monosaccharides and the color of the extract in comparison with autohydrolysis.

The systems of hydrogen bonds (H-bonds) in natural natural birch bark and technical bleached eucalyptus cellulose have been compared by the methods of Fourier infrared spectroscopy. Study frequency intervals (wave numbers) of 3000–3700 cm–1 and 2700–3700 cm–1 contain the absorption region of hydroxyl groups of OH, whose frequencies in the order of 3400, 3300, 3200 cm–1 are most sensitive to the formation of H-bonds of cellulose. A distinctive feature of the study is that all measurements of IR-spectra of transmittance and mechanical influence were made on natural birch bark, elastic under longitudinal stretching. The decrease of transmittance far from absorption bands was due to scattering of radiation on natural heterogeneity of birch bark wood material, which due to high quality of cuttings turned out to be small enough to prevent detailed study of absorption spectra (absorptivity). To estimate parameters of H-bonds, we performed deconvolution of absorption bands of hydroxyl OH groups on 7 and 9 gauss contours in order to study the effect of methyl methylene on the regression coefficient R^ and study the nature of the interaction order in cellulosebearing raw material, the so-called characteristic «nose» for further research as it is not considered in this paper. In the following, only the parameters of the deconvolution contours related to hydroxyl groups were analyzed. It was assumed that each Gaussian deconvolution contour can be associated with a certain type of H-bond (hydrogen bond).The shift in the frequencies of the deconvolution components, i.e. the maxima of the Gaussian contours relative to the natural frequency of the hydroxyl group, not covered by the H-bond for this reason, was determined. Literature data on the correlation of H-bond energy with frequency shift were used to determine the H-bond energy. The relative density of H-bonds was estimated from the ratio of Gaussian deconvolution contour areas. The energies and densities were found to be different for all bond types. It was found that the densities of the strongest intermolecular hydrogen bonds, energies and bond lengths of the same order of magnitude of natural birch bark and technical bleached cellulose, when deconvolving the spectrum in the OH region without error are indicative and useful for comparative analysis with different species of hardwood and softwood cellulose, instead of the previously adopted high-tech bleached and unbleached condensed paper.

In the production of corrugated cardboard, corrugated paper and flat layer board are exposed to high temperatures. In this work, the influence of high temperature on the strength properties of cardboard and the morphological characteristics of fibers in cardboard during its cyclic use in the corrugation production process were researched. It has been established that the effect of temperature on cardboard during the corrugated production process significantly reduces the mechanical properties of cardboard during its cyclic processing. So, after the fifth cycle of cardboard processing, exposed to a temperature of 160 ± 5 C for 3 minutes, the tear resistance is 1.6 times lower, the bursting resistance is 2.7 times lower compared to cardboard samples that were not subjected to thermal treatment. In the first four cycles of processing, the destruction of the surface of the fibers probably occurs with a slight decrease in length (1–4%) and a low content of small pieces of cellulose. At the 5th cycle of processing, there is a significant reduction in the length of the fiber by 37%, an increase in coarseness, but it doesn’t lead to a critical decrease in the strength of the cardboard. In the course of the research, it was found that the length of small pieces of cellulose (objects <0.2 mm long) remained unchanged during cyclic use, and the area of the fines steadily increased. The morphological characteristics of cellulose fibers, depending on the cycle of use and temperature effect, changed significantly. The length of the fiber decreased, while the fibers flattened out, became wider and coarser. The number and area of small things increased with each processing cycle, the small things were combined into larger objects. At the same time, the fibers became less deformed, and their alignment took place.

In the cellulose production from birch wood by the neutral sulfite method liquors are formed. These liquors contain organic and mineral substances. At present, minerals content of the neutral sulfite liquors is not regenerated. Organic compounds especially carbohydrate oligomers are also not used anywhere. The only way currently available at the enterprises to utilize these liquors is to obtain lignosulfonates, which indicates the economic irrationality of the resource usage. The paper considered the possibility of separating lignin and lignosulfonate carbohydrates from neutral sulfite liquors by a biocatalytic method with the formation of simple sugars. Subsequently these simple sugars can be used for microbiological synthesis of lactic acid by the filamentous fungus Rhizopus oryzae F-1030. There are also wastes formed after the lactic acid separation, which also need to be disposed of. These wastes consist of the culture liquid based on the lignosulfonate enzyme lysate and the biomass of the fungus. As a possible way of their utilization, it is proposed to use the insoluble fraction of lignosulfonate lignin and the fungus R. oryzae F-1030 biomass, rich with chitin-glucan, to obtain feed additives for farm animals. These additives must have adsorption properties to mycotoxins. It was shown that the treatment of lignosulfonate with enzyme preparations Accellerase XC and Accellerase XY leads to an increase in the content of simple sugars in hydrolysates, which can be used by microorganisms as carbon sources. It was found that the fungus R. oryzae F-1030 synthesizes lactic acid at an average concentration of 42.0±4.0% per 1 g of assimilated RS during its cultivation on neutral sulfite lignosulfonate enzyme lysates. During this process, 1.8±0.2 g/dm³ of fungus dry biomass is also formed. It was proved the possibility of using neutral sulfite lignosulfonate lignin and the biomass of the fungus R. oryzae F-1030 in a 1:1 ratio to obtain a feed additive with an adsorption capacity for mycotoxins.