The study is devoted to revealing the peculiarities of spectral mapping of stands with participation and predominance of larch in the autumn period on the materials of Sentinel-2 imagery. The imaging range from 650.0 nm to 680.0 nm, corresponding to Sentinel-2 channel B4, was used to study the mapping of stands with larch participation and predominance. Phenological peculiarities of larch and associated hardwoods in the study area were used as a criterion for selecting the survey date. For field work, an area with larch participation and predominance was selected in the territory of 76 and 92 quarters of the Kepinsky district forestry of Arkhangelskoye lesnichestvo. For stand assessment, the method of constant radius circular plots (CRCP) was chosen. Geographical reference of the circular plots centers was carried out using a Garmin 62 GPS navigator. For the purposes of the study, 71 CRCPs were established. In October 2022 an unmanned aircraft survey was used to map larch crowns in the circular plots. Field survey materials were used to assess the accuracy of analytical larch identification based on detailed survey data. Phenological peculiarities of larch make it possible to identify this species on the detailed imagery materials with an accuracy of over 90%. A linear relationship between the increase in the spectral brightness of CRCP on the Sentinel-2 satellite image and the increase in the larch share was revealed. The complex of works carried out, including field work, the determination of individual larch crowns on a detailed survey and the analysis of their display on a satellite image, can be used to solve problems of determining the distribution area of larch in the Arkhangelsk region and the European North. The results of the study will contribute to the development of automated decryption methods.

Climate change observed in recent years combined with increasing anthropogenic pressures on forest ecosystems made it necessary to increase attention to protect forest from fires. Forest fires all over the world and in the Russian Federation lead to forest degradation, reduction of biological diversity and pollution of atmospheric air and soil. They often destroy economic facilities and create a real threat to the health and life of the population. The analysis of the actual fire rate of forest shows that in recent years the proportion of forest fires caused by landscape fires on former agricultural land and thunderstorms has increased. The latter explains the increase in the area covered by forest fires in hard to reach remote areas. Large forest fires, especially that one developing in control zones, lead to be being smoked in vast areas and often residents of megacities experience their negative impact for a long time. The problem of forest fires has long been international. During the period from 2001 to 2018 large forest fires occurred in Africa, Australia and South America, South America. This indicates the need to unite scientists of all countries in the world to solve the problem of minimizing the actual fire rate of forests and the damage caused by forest fires. In light of climate change and other factors influencing the occurrence and spread of fires it is important to develop and implement a strategy to reduce damage from wildfires.

Original data on the structure of mountain phytocenoses containing yew berry are presented. Yew grow on slopes of different exposures, with different slope steepnesses under the canopy of tree stands, which are dominated by eastern beech. The object of the study is phytocenoses in the forest fund of the Sunzhensky district forestry of the Prigorodny forestry of the Republic of North Ossetia – Alania. The experimental sites are located in the upper reaches of a river called Belaya Rechka. Altitude above sea level – from 950 to 1028 m. The composition and structure of phytocenoses was taken into account on test plots with a continuous count of trees. The number, composition and height structure of the vegetation of the lower tiers were taken into account on circular counting areas of 10 m². It has been shown that the number of Taxus baccata L. trees in the experimental plots varies widely – from 24 to 261 spc./ha. It is noted that on the northern microslopes, the number of yews is several times greater than on the southern slopes. The average height of yew at the study sites is 4.5–6.6 m, the average trunk diameter is from 6.4 to 13.6 cm. The young generation of yew is represented by plants of different heights in quantities from 98 to 306 spc./ha. In addition to yew, the undergrowth also includes beech, elm, linden, Norway maple and black alder. Four species were identified in the undergrowth: azalea, spindle tree, black elderberry and Caucasian blueberry. The total number of undergrowth species is 96–388 ind./ha. The species composition of the grass stand has been established, represented by 10–13 species. The results obtained can serve as a definite contribution to the study of the nature of the distribution and growth conditions of yew berry – a relict species of the Caucasus.

The aim of the work is to study the periodic growth of morphometric parameters second-age class Siberian and European spruce forest cultures after clearing. The objects of the research were areas of Siberian spruce (Picea obovata Ledeb.) and European spruce (Picea abies (L.) Karst.) forest cultures in forest types «spruce multiform grassy with green moss», «spruce-pine grassy» and «spruce-pine berry». For the first time in the southern taiga forests subzone on Middle Urals in three types of forest the growth of even-aged forest cultures of Siberian and European spruce is compared with the cutting of all self-seeding trees but without thinning forest cultures in rows and with thinning forest cultures in rows. Over a 12-year period the maximum trunk height growth for both tree spruce species was noted in the forest type «spruce multiform grassy with green moss» (on micro-raising) and «spruce-pine grassy» (on flat area), and the minimum one was noted in the forest type «spruce-pine berry» (on micro-depressions). In all forest types, the growth in trunk height is most pronounced in European spruce, but reliable differences with Siberian spruce are significant only in the forest type «spruce multiform grassy with green moss» in areas without thinning. The height of 31-year-old forest cultures of both spruce species in the forest types «spruce multiform grassy with green moss» and «spruce-pine grassy» in sections with thinning corresponded to the first capacity class, in the forest type «spruce-pine berry» – to the second capacity class. The periodic trunk diameter growth in both spruce species was significantly more in sections with thinning. The number of trees above the average diameter in sections with thinning in Siberian spruce is from 33 to 55% (without thinning – 20–42%), in European spruce – 36–46% (without thinning – 30–41%) of their total number. The volume of an average Siberian spruce tree wood in thinned sections compared to a section without thinning in the forest type «spruce multiform grassy with green moss» was 27% greater, in the forest type «spruce-pine grassy» – 42% greater, and in the forest type «spruce-pine berry» – 77% greater; for the European spruce, it was 14, 59, and 50% greater, respectively. It has been established that the cross-sectional area and volume of wood of an average tree of European spruce in all forests types are more than that of Siberian spruce. In the conditions of the southern taiga forests of the Sverdlovsk region, European spruce can be successfully introduced into forest cultures on a par with Siberian spruce.

The important role of forests for the conservation of biodiversity and maintaining the stability of other ecosystems is stated. The relevance of the problems of forest protection at World Heritage sites is substantiated for reasons of the need to ensure sustainable socio-economic development of territories. The consistency of the hypothesis of the existence of a significant potential of the world Heritage protection system for strengthening the legal protection regimes of forests in Russia and other countries is systematically argued. Proposals are formulated on the need to develop a categorical position of the World Heritage Committee on the use and protection of forests. Expert events conducted under the auspices of the world Heritage protection system bodies should be a necessary step towards its development. The expediency of holding such events in the Russian Federation on the territory of the World Heritage site «Lake Baikal» is substantiated. It is stated that it is necessary to develop a consolidated position on commercial timber harvesting and sanitary logging at World Heritage sites. The ways to improve forest protection by various means are proposed, among which the need to develop methodological recommendations at the international level on sustainable forest management practices at World Heritage sites, as well as specialized methodological guidelines on environmental impact assessment in the implementation of various types of forest management is highlighted.

The effectiveness of the use of a light-transforming shelter for vegetation structures, consisting of a spunbond with an organic photoluminophore integrated into its structure, was studied when rooting cuttings of woody species. The object of the study were stem cuttings of typical forms of common privet (Ligustrum vulgare L.), Hungarian lilac (Syringa josikaea J. Jacq. ex Rchb.), Forsythia × intermedia Zabel, Physocarpus opulifolius (L.) Maxim. and its varieties “Luteus”, “Diabolo” and “Summer Vine”, which are in an active physiological state corresponding to the phase of completion of linear growth of shoots. The mother plants were placed in the arboretum of the Nizhny Novgorod GATU. Shoots were simultaneously harvested from the peripheral zone of the middle tier of a well-lit section of the crown of plants located within the boundaries of a single experimental site with geographical coordinates 56°14'32.7"N 43°57'20.7"E and a height above sea level of 178 m. The organizational and methodological scheme of the work was based on the principles of a single logical difference, typicality, expediency and reliability of experience. The research was carried out using field stationary and laboratory methods. Synthetic covering materials with the inclusion of photoluminophores in their composition have been tested. The summer vegetation facilities were equipped with a fog-forming installation with an automatic water supply and control of environmental parameters. Coarse-grained river sand is used as a substrate in them. A specific reaction of cuttings to changes in the concentration of photoluminophore in the spunbond structure was revealed. The highest rates of callus formation were noted in the shelter variants with the highest concentration of phosphor and were found in Forsythia × intermedia – 77.00±4.64% and Hungarian lilac – 73.16±5.94%. It was recorded that these tree species under the conditions of introduction showed their regenerative ability in various ways when they were propagated by cuttings in summer vegetation structures using light-transforming shelters.

Sikang’s rhododendron (Rhododendron sikangense Fang) from family Ericaceae is cultivated at Peter the Great Botanic Garden of the V.L. Komarov Botanical Institute RAS at Saint-Petersburg since 2013 г. Its seeds were received directly from natural conditions of China, from highlands of Sichuan province, from elevation higher than 3700 m. This was the first introduction of this species during 3 centuries of arboriculture at this place. The first flowering and fruiting was observed in 2022, under the age of 9 years old. The species happened to be quite winter hardy during 10 years of observations (2014–2023), according to the Egbert Wolf’s scale. In conditions of Peter the Great Botanic Garden this is evergreen shrub or tree up to 0,81 m high on the age 10 years. Taking in mind its sizes in optimal conditions in the wild, it can reach 3–5 m high. It develops itself as very decorative shrub, especially during flowering season. The species is of interest for further cultivation and city planting of Saint-Petersburg. The task of the nearest future is to propagate the Sikang’s rhododendron and to introduce it to the city planting. For successful growing the right agrotechnics should be used. Such agrotechnical measures are developed and elaborated at Peter the Great Botanic Garden, using the experience of international practice.

Earth remote sensing data and GIS technology now provide a large amount of reliable information on the state of natural and man-made landscapes. Hunting resources and habitat are based on such landscapes and closely interrelated; the species composition and number of hunting resources depend to a large extent on the distribution of their habitat elements within the hunting grounds. A number of normative documents of the Russian Federation regulating the management of hunting and hunting activities reflect the fact that the most effective is inventoring the current state of the habitat of hunting animals on a single methodological basis, including monitoring using and analysing data from remote sensing of the Earth’s surface and aerial photography of hunting landscapes. The aim of this study was to develop an approach to typology classification of habitat elements of hunting resources based on the application of remote sensing data from the Earth (aerial photography with unmanned aircraft and space im-agery with Sentinel-2A), forest management materials, semi-automatic image classification algorithms and geo-information analysis of the resulting data. The study was conducted on a key ornithological area of international importance (KOA) NV-005 «Lake Il'men and adjoining marshy plain» with a total area of 190,950 ha, located in the Novgorod region. The software tools for data processing and analysis were QGis, a plugin of automated classification of images dzetsaka: classification tool with Pythonlibrary scikit-learn; “random forest” classification algorithm has been applied. As a result of this work, the schematic map of the habitat elements of hunting resources KOA NV-005 «Lake Il'men and adjoining marshy plain» and an attribute table with the distribution of the area of habitat elements of hunting resources according to the current regulatory requirements of regional hunting were formed. The accuracy of the automated classification and the reliability of the results obtained were assessed by using a built-in error matrix and Cohen’s Kappa coefficient calculation. The proposed approach can be effectively applied not only in hunting practices, but also in the monitoring of natural and human landscapes that include different land categories.

There is a high need to improve plantation forest cultivation technologies, including thinning, that ensures an increase in its economic efficiency and productivity of forest stands. The objective of the research is to assess the impact of different thinning options of 15-year-old artificially regenerated Scots pine (Pinus sylvestris L.) stands on the structural diversity of the forest stand in terms of tree growth patterns and their responses to climate fluctuations. The authors studied anexperimental site based in one of the Mari El forestries, 30 years after the thinning of the forest stand, the intensity of which varied from 25 to 80% by the number of trunks with the initial density of 10 thousand specimens/ha. The radial annual growth was measured on 60 trees (12 in each of the five experimental variants) with an error of ± 0.05 mm. The authors proved that the forest stand in all experimental variants was heterogeneous in the nature of tree growth, among which there are groups that are diametrically different from each other in terms of ecological requirements for environmental conditions. Early intensive dense forest stands thinning generated in the pine forests of the Mari El Republic did not have a significant impact on the diversity of their structure in terms of tree growth patterns. However, an increase in the radial growth of trees was traceable within the first eight years after thinning, later on its value in the control sections was higher. Coenopopulations of woody plants are self-regulating dynamic systems, the value of the current annual growth of trees in which is guided by the mechanism of stabilizing selection, based on the feedback among them. The specimens with a high growth rate normally will show a decrease in value in the following year, which ensures that this parameter is maintained within the framework of specific environmental conditions. Thus, we are concluding that the thinning of the tree stand has not had a significant impact on the way this mechanism works.

The article is devoted to a pre-project analysis of the state of plantings at the cultural heritage site of the Streshnev estate (Znamenskoye-Raek). Based on the Draft Application for inclusion in the list of UNESCO protected sites, the estate is of great historical and cultural interest. Existing methods for assessing the condition include historical and architectural analysis of the volumetric-spatial structure of the park and geobotanical studies of the species diversity of the plant community of the park area. This article analyzes the state of plantings in three interrelated areas: assessing the state of preservation of the planning structure of the park, assessing the state of the tree stand, which forms the basis of the volumetric-spatial structure of the estate complex, assessing the ground cover as a factor in the stability of the historical plant cenosis. The assessment of the safety of the planning structure was carried out on the basis of graphic materials published in the most complete monograph dedicated to the estate heritage of N.A. Lvov and field research conducted at the beginning of the 20th century. The assessment of the state of the tree stands and grass cover was carried out partly on the basis of guidelines for identifying and surveying historical parks and park landscapes on the territory of the OKN. Based on the initial survey, only partial preservation of the planning and volumetric-spatial structure of the park area was revealed. The state of the tree stand and ground cover allow us to conclude that there is a relatively high degree of sustainability of old-growth plantings due to the unprecedentedly high diversity of species composition of species naturally growing on the estate. Based on the survey, recommendations were made for the ongoing care of old-growth plantings, as well as methods for restoration work.

There is an acute shortage of relevant and reliable information about the state and dynamics of the country's forests. Forest plantations are actively exposed to a complex of unfavorable factors, under the influence of which they lose stability. Protection of forests from pests and forest diseases is ensured by systematic monitoring of its condition, timely identification of outbreaks of forest pests and diseases, their localization and elimination. An analysis of the sanitary state of plantings in the Central Federal District will reveal the main causes of weakening and death. The total area of forest disease foci in the constituent entities of the Central Federal District for 2022 was 134028.3 hectares. The largest share of the outbreak area falls on the Voronezh (22.0%), Tula (18.3%) and Moscow (12.1%) regions. The main plant diseases are: root sponge (33.7%), autumn honey fungus (26.3%), false aspen polypore (16.3%), false oak polypore (2.7%) and bacterial diseases of birch (2.8%). The volume of weakening and death of plantations from forest diseases indicates the imperfection of the existing forest protection system, the lack of a scientifically based system for carrying out forest management, the impossibility of carrying out preventive measures and preventing the emergence and development of disease foci over large areas.

This paper describes a simulation model of the wood supply in wood procurement. The developed simulation model of wood supply due to taking into account a large number of influencing factors allows us to obtain the correct estimates of the operational speed of timber trucks on a specific route at different time intervals. This makes it possible to evaluate the economic efficiency and compare different variants of transport flows to support decision-making regarding the planning of forest operations and allocation of timber warehouses, wood processing plants and transport infrastructure units.

The article presents the results of experimental studies of changes in the pressure of the vibration and tree clamping mechanisms of the gripping and cutting device at different stages of the technological process of thinning. The studies were conducted on an experimental sample of the gripping and cutting device with a vibration mechanism. As part of the experimental studies, the gripping and cutting device performed the main technological operations of logging, such as cutting and gripping a tree, separating a tree from a stump and dynamic stabilization in a vertical position during transportation. When performing technological operations, the parameters of the harvested trees varied in diameter at the cut site. Birch was chosen as the main harvested tree species. To identify the nature of the loads exerted, pressure changes in the lines of the drive hydraulic cylinder of the clamp lever and the hydraulic motor of the vibration mechanism were recorded using measuring sensors. The data obtained showed that when the vibration mechanism starts working, there is a surge in the amplitude and frequency of pressure oscillations in the lines of the vibration mechanisms and tree clamping, which is associated with the kinematics features of the gripping and cutting device design and strong swinging of the cantilever-mounted tree. It was also established that in the steady-state mode of operation of the vibration mechanism for trees from 10 to 16 cm at the cutting site there was a tendency to reduce the amplitude and frequency of pressure oscillations, which indicates to us the desire of the system to stabilize and smooth out dynamic parameters. Analysis of experimental data on harvesting trees of different diameters showed that the value of pressure in the main lines of the clamping and vibration mechanisms is within acceptable limits and with further improvement of the design of the gripping and cutting device with a vibration mechanism, there is a possibility of increasing the efficiency of dynamic stabilization of the tree in a vertical position.

The work is devoted to the study of one of the problems of interaction between forestry, the forestry industry and the hunting industry, which is characterized by special relevance in modern conditions. The relationship between these sectors of the economy and the need to coordinate economic activities are determined, among other things, by the fact that the use of forests (primarily for timber harvesting) and hunting (carrying out activities in the field of hunting) are carried out on the same territory of the forest fund. At the same time, as a result of logging operations during logging of ripe and overgrown forest stands, logging of forest maintenance, forest cultivation and other work, the habitat conditions of forest animals and birds may change significantly, which, in turn, will cause changes in the species composition, population dynamics and station distribution of forest fauna. This circumstance will have to be taken into account when conducting a hunting operation. The purpose of this study is to analyze the practice and regulatory and methodological foundations, as well as to justify the need to leave growing trees in cutting areas as an element of logging technology. In addition, when carrying out logging, it is necessary to design and implement measures to protect wildlife and their habitat. In this regard, the author suggests that activities related to biotechnical activities or pursuing biotechnical goals should be equated with activities for the protection of wildlife and their habitat. For example, leaving continuous logging of growing trees (and shrubs) in cutting areas for biotechnological purposes should certainly be attributed to measures to protect wildlife and their habitat.

The article discusses an innovative approach to assessing tree morphometric parameters using artificial intelligence (AI) and computer vision technologies. The main focus is on the development of a methodology for accurately measuring such characteristics as tree height, base and top diameters, trunk curvature, volume, and surface area. The authors emphasize that traditional measurement methods based on visual inspection and manual measurements have significant errors and require significant labor costs, while automated AI-based systems provide more accurate and reproducible results. Aerial photography from drones and ground photography were used to collect data, which provided comprehensive coverage of tree trunks from different angles. The resulting images were processed using computer vision algorithms, including convolutional neural networks (CNN), as well as 3D modeling methods based on point clouds. This made it possible to create detailed digital models of trees suitable for accurate analysis of their geometric parameters. The results of the study demonstrated the high accuracy of the proposed method: comparison with manual measurements showed minimal discrepancies. In addition, the authors conducted a correlation analysis that revealed the relationships between various tree parameters, which is important for assessing the quality of wood and planning logging. The developed methodology opens up new opportunities for sustainable forest management, allowing to minimize the negative impact on ecosystems and optimize forest management processes. The use of AI in forestry contributes to the transition to more accurate and environmentally friendly working methods, which is especially important in the context of growing demand for wood and the need to preserve biodiversity.

The efficiency of a saw frame is determined by the performance and operational reliability of the tool – a frame saw. During operation, a frame saw is exposed to complex effects of force and temperature factors, which must be taken into account when preparing the saw for operation. The ability of a saw to counteract the components of the cutting force is characterized by its rigidity and stability. To obtain a straight cut, it is necessary to ensure the standardized stability, the working rigidity of the blade. This is achieved by longitudinal tension of the saw. In practice, the tension stresses of the edges of the blade are increased by weakening its middle part. For this, the saw blade is subjected to rolling. It should be noted that rolling does not ensure the formation of a uniform stress field over the cross section of the blade, and is accompanied by a fracture of the metal along the rolling trace, which reduces the mechanical strength of the saw. The article discusses a new approach – to form residual stress fields in the saw blade by thermal action. The considered technology of preparing a frame saw for operation is based on the thermal method of creating stresses in the saw blade by pulsed induction heating of local longitudinally located strip sections without kinks along the entire crosssection. When heating, secondary thermoplastic residual deformations occur in the array of the strip section, which ensure the formation of residual thermoplastic stresses in the boundary zone of adjacent sections of the saw blade. This ensures the formation of normalized residual stress fields in the saw blade and an autonomous effect of compression of the middle part and tension of the rear and front edges of the saw blade appears, allowing to ensure a stable state of the frame saw in the cut with a normalized tension force of the frame saw blade between the grips. The paper provides a quantitative assessment of residual thermoplastic stresses. A new approach to the formation of normalized residual stresses in a frame saw blade by short-term concentrated thermal action on strip sections of the blade allows the formation of fields of residual thermoplastic stresses, increasing the transverse rigidity of the blade and the stability of the saw in the cut.

The aim of the study is refining the algorithm for binarization of digital images of cross-cut round timber for automated assessment of the bark ratio, as well as testing methodology for adjusting its parameters. The program implementation of the refined algorithm and calculations are performed in Python, the main functions used are implemented in the OpenCV library. The image binarization algorithm used to assess the bark ratio bases on the single threshold method. The method parameter settings are made for the author's images of cross-cut round timber. To obtain experimental data, cross-cut round timber was photographed from different angles. The sample intended for testing the proposed algorithm and software solution included 130 images of crosscut timber with a diameter of 20–30 cm; wood species – birch, spruce, alder. The photographing was performed in winter conditions, on a snow-covered background under natural light in the absence of direct sunlight. The resolution of the original images was 3024x4032 pixels (72 dpi). The algorithm proposed includes adjustment of the parameters of the single threshold binarization method basing on information about the photosensitivity, the brightness level of the image, and the exposure value; the method is called twice during the image processing. Heuristic dependencies are given for determining the threshold values of the single threshold method parameters for its two iterations performed sequentially when separating an object from the background and further segmenting the bark in the image. Examples of the results of determining the ratio of bark in images with an uneven contour and a dominant background, with a relatively smooth contour of a cross-cut in the image, as well as with a partially icy surface of a cut with an uneven contour, as well as a link to a repository with experimental images and the program solution implementing the proposed algorithm are given. Testing the method for adjusting the parameters and the algorithm taking into account various characteristics of the image and the object in it showed that the solution allows obtaining satisfactory results.

Cedar pines belong to the subgenus Strobus and are a economically valuable group of coniferous plants not only because of their wood, but also due to the useful components of their resin, the chemical composition of which is far from sufficiently studied. That is why, we carried out a comparative quantitative analysis of the composition of cedar pine resin taken from different trees of each species: Korean cedar pine (Pinus koraiensis Siebold & Zucc.), European cedar pine (P. cembra L.) and Siberian cedar (P. sibirica Du Tour), as well as Siberian dwarf pine (Pinus pumila (Pall.) Regel). To do this, we used the method of 1H- and 13C- NMR spectroscopy (allowing simultaneous detection of all soluble compounds in the samples). The study identified a total of 22 compounds, including 11 resin acids. The data obtained on the composition of the subgenus Strobus cedar pines’ resins testify to the presence of almost all the compounds typical for the subgenus Pinus two- and three-needle pines’ resins, except for pimaric and levopimaric acids; also terpinolene, β-phellandrene and p-cymene were not detected. The presence of labdane and cembrene diterpenes proved to be characteristic feature of the five-needle cedar pines resins. As it turned out, the European, Korean and Siberian cedar pines resins differ little from each other in composition and, at the same time, among labdonic acids, they contain only lambertian acid in noticeable quantities. The composition of dwarf cedar resin contains fewer compounds; in particular, lambertian acid is absent, but the main component is anticopalic acid. Worthy to point that the resins’ composition on the surface of Korean cedar cones is noticeably different from the same species analogs of the trees’ trunks, specifically in it the concentration of monoterpenes is approximately 3.5 times higher, and lambertianic acid is almost half as much, while there is quite a lot of levopimaric and neoabietic acids, but cembrene diterpenes are absent at all.

In order to expand the areas of application of disproportionated tall oil rosin with a low color value on the Gardner scale and to obtain the sizing compositions (cationic sizes) for paper and cardboard, the polyamidoamine and polyamidoamineepichlorohydrin resins have been synthesized. The synthesis of polyamidoamine resin based on disproportionated tall oil rosin, adipic acid, diethylenetriamine, and 2- aminoethanol was carried out in vacuum at 140–150 °C for 7 hours, the addition of epichlorohydrin to polyamidoamine and the preparation of polyamidoamineepichlorohydrin resin – at 40–60°C for 1 hour. It was found that 20% solutions of polyamidoamine and polyamidoamine-epichlorohydrin resins are stable when stored for 30 days at 20–24 °C, the dynamic viscosity at 25 °C was 105 and 114 mPa·s, respectively. The color of 50% solutions deteriorated slightly compared to the original disproportionated tall oil rosin not more 3 on the Gardner scale.

Potentiometric ion-selective electrodes based on chalcogenide glass membranes and films have important properties. The minimum detection limit of metal cations in aqueous solutions is 10^–7 mol/l, the reproducibility of the electrode function is within  10^–6–10^–1 mol/l. Glasses TlI-PbI₂-As₂Se₃ and HgI₂-PbI₂-As₂Se₃ were synthesized using reagents thallium iodide, mercury (II) iodide, lead iodide of chemically pure grade, arsenic triselenide of special purity grade. Glass synthesis was carried out at a maximum temperature of 1100 °C in evacuated quartz ampoules with a residual pressure of 10^–4 Pa. Upon reaching 1100 °C, the ampoules with the batch melt were kept under constant stirring for 4–6 hours, then the melt was quenched in water with ice. Films of the specified compositions were applied from glass solutions in n-butylamine. For the first time, chemical potentiometric sensors based on chalcogenide film membranes HgI₂PbI₂-As₂Se₃, TlI-PbI₂-As₂Se₃ were obtained for determining the content of thallium (I) and mercury (II) iodides in cationic form. It has been established that the electrode properties of potentiometric chemical sensors based on TlI-PbI₂-As₂Se₃, HgI₂-PbI₂As₂Se₃ films are determined mainly by the high content of thallium (I) and mercury (II) iodides in the chalcogenide membrane As₂Se₃, and to a lesser extent by the content of lead iodide. At a concentration of thallium (I) and mercury (II) iodides of 30–40 mol. % in membranes, the content of PbI₂ has virtually no effect on the electrode properties.

The purpose of the work is to assess the effect of cooking and dispersing additives on the yield, degree of delignification, quantitative and qualitative resin content during sulfate cooking of the hardwood composition. Birch and aspen wood chips were used for cooking (50:50); temperature rise to 175 °C – 40 min, cooking at 175 °C – 180 min; consumption of active alkali – 15% units of Na₂O from a.s.d.; sulfidity of white liquor – 25%; hydromodule – 4.0; consumption of cooking a dispersing additive of 0.8 kg per ton a.s.d. It was found that all additives reduce the content of extractive substances in cellulose by 1.25...2 times compared with the control cooking and cellulose does not contain encapsulated resin. It was found that the use of samples Sinalab 72151, Sinalab 74415 and (SINALAB® 8683) leads to an increase in yield (without non-testing) and a decrease in stiffness. The cellulose mass contains mainly coagulated and, in small quantities, dispersed resin. The samples are recommended for delignification of the hardwood composition as the most promising. It has been shown that the use of samples Sinalab 74415BX, Sinalab 72101, Sinalab 74418SR and Sinalab 74418 leads to an increase in yield, absence of non-steam, while increasing the hardness of cellulose with the exception of sample Sinalab PP10-3152. When using the Sinalab 74418 additive, cellulose contains only dispersed resin, and when using other additives, there is coagulated and dispersed resin in different ratios. To improve the results, it is necessary to select the conditions of impregnation, cooking and washing. The use of Sinalab 63602 and Sinalab 74393 samples during cooking leads to a decrease in lignin selectivity, but a high proportion of extractive substances removal is achieved. These additives are more effective to use when rinsing.

One of the most pressing problems of modern animal husbandry is to provide balanced diets for feeding farm animals. The current protein deficiency leads not only to overconsumption of feed, but also to a decrease in the productive potential of animals. The use of microbial biomass, in particular the biomass of basidiomycetes, is a promising direction for solving the problem of protein deficiency. The article is considered basidiomycetes as promising destructors of wood processing waste, namely, arabinogalactan, a natural polysaccharide with a branched structure. The work demonstrated the possibility of using arabinogalactan as a carbon source in nutrient media for cultivating yeast-like fungi Trichosporon moniliiforme. The presence of a β- galactosidase enzyme complex in T. moniliiforme, which is necessary for the breakdown of the arabinogalactan molecule, was confirmed. As a source of feed protein in the feed product, the most promising strain of yeast-like fungi is the strain T. moniliiforme H₃₇₆₃, which demonstrated the highest yield of biomass and reducing substances after cultivation on nutrient media with different concentrations of arabinogalactan. It was found that the increasing of the arabinogalactan concentration in the nutrient medium from 2% to 4% is corresponding to an increase in the yield of the feed product. A further increasing in the concentration of arabinogalactan to 6% does not provide a statistically significant increase in the yield of the feed product. Thus, it was shown the prospect for using yeast-like fungi of the strain T. moniliiforme H₃₇₆₃ for the microbiological destruction of arabinogalactan for obtaining a feed product, which will contain feed protein, reducing substances, β-galactosidase and intact arabinogalactan.

The structure and properties of lignin-phenol-formaldehyde resins prepared using technical sodium lignosulfonates were researched. At the first stage, highly alkaline resins were synthesized by replacing up to 40% of phenol with lignosulfonates; at the second stage, medium alkaline resins were synthesized with 30% phenol substituted by lignosulfonates, varying the duration of the polycondensation stage from 15 to 35 min. Based on the results of ¹³C NMR spectroscopy method it was suggested that highly alkaline resins contain predominantly phenol-formaldehyde oligomers of low molecular weight; the interaction of formaldehyde with lignosulfonates occurs mainly at the first stage of synthesis (at 55–60 °C). Highly alkaline lignin-phenolformaldehyde resins with 20% phenol replaced by lignosulfonates provide the highest physical and mechanical properties among all highly alkaline resins. However, boards manufactured using highly alkaline lignin-phenol-formaldehyde are significantly inferior to boards manufactured using industrial phenol-formaldehyde resin SFZh3014. Reducing the alkali content and increasing the duration of resin holding at 96– 98 °C (second stage) allows to significantly increase the molecular weight of phenolformaldehyde oligomers and improve the properties of lignin-phenol-formaldehyde resins-based particleboard. Phenol-formaldehyde oligomers of medium alkaline resins have a relatively high molecular weight. Particleboards based on medium alkaline resins synthesized with a second stage duration of 25 min meet all the requirements of the state standard. However, boards based on medium alkaline lignin-phenolformaldehyde resins are still inferior to boards based on SFZh-3014.