Intensive reforestation involves carrying out regular thinning, as well as performing multi-stage pruning for getting high-quality knot-free timber. At the same time, the productivity of work associated with its formation largely depends on the quantitative parameters of the crown: the number of living and dry branches in the whorl and interwhorl range, the diameters of the branches, the number of whorls, etc. Therefore, the study of crown architectonics is an important element of silvicultural and environmental research, since the economic impact largely determines the process of species competition in the forest ecosystem. Statistical analysis carried out on the basis of data on the size indicators of 223 living branches located in 104 interwhorl ranges, their share of the total number, including dry branches, as well as the weight indicators of the average by interwhorl spaces of Norway spruce tree branches, revealed the presence of significant differences in lengths, base diameters and weight of branches, as well as their life expectancy in trees of different growth classes. Thus, trees of the fourth growth class are characterized by comparatively smaller size and weight, as well as the lifespan of the branches. Using regression analysis, it was found that a logistic growth curve can be used to describe the age-related dynamics of the size indicators of interwhorl branches. The dynamics of weight indicators by moving from the top of the crown to the base of the tree is described with high accuracy by an exponential model, and the proportion of living branches – by the model of Gompertz. The identified patterns can be used in developing of methods for growing spruce trees, in particular, determining the intensity of pruning of branches aimed at minimizing their number in the stem wood, assessing the phytomass of trees and a number of other scientific and practical tasks.

Remote sensing data and geographic information systems are now an integral part of landscape research and monitoring. Hunting management is based on information about hunting resources and elements of their habitats, i.e. the natural and anthropogenic landscapes. The number of regulative documents of the Russian Federation reflecting modern requirements for the conduct and development of hunting industry, noted that an inventory of the current state of the hunting environment on a unified methodological basis, including monitoring using and analysis of remote sensing and aerial photography of hunting landscapes, is the most effective. The objective of this study was to form the methodological approach to the typological classification of elements of the habitat hunting resources on the basis of the application of an algorithm for the automated classification of satellite images and the geographic information processing of obtaining results from the State Forest Register. The test area of the study was the hunting farm of NP «Hunting farm «Olgino» plot 2 on the territory of the Malovishersky district of the Novgorod region with a total area of 7627.0 hectares. Satellite imagery from the Sentinel-2A L2A HSE, as well as forest inventory and management plans and State Forest Registry data from the WinPLP software complex, were used as source materials. The software included the QGis dzetsaka automated classification plugin of the QGIS i.e. the Classification tool with a classification algorithm based on the Gaussian Mixture Model (GMM) and the MapInfo Pro 17.0 GIS. The results of the processing of the satellite imagery were monitored and refined on the basis of data from the State Forest Register and forest inventory and management plan. As a result, a schematic map of the surveyed hunting farm and a table of the distribution of areas by elements of the habitat hunting resources in accordance with modern regulatory requirements were formed. The proposed approach can be used not only for typological assessment of hunting grounds, but also as a tool for landscape analysis in the practice of operational and retrospective monitoring of natural and anthropogenicmodified territories, including on specially protected natural areas, agricultural lands and forest lands.

This study presents the results of research on the growth, morphological diversity, and current condition of Curly birch (Betula pendula Roth var. carelica (Mercklin) Hämet-Ahti) plantations established in various years in Leningrad Oblast. The research focused on the largest plantations: «Okhta», «Shapki», Gatchina Seed Production Area (SPA), and Tikhvin Forest Seed Orchard (FSO), named after their respective geographic locations. It was shown that in the «Okhta» plantation, established in 1949 and expanded in 1957, less than 6% of the originally planted Curly birch trees have survived to the present day. This decline is presumably due to high planting density and the low competitive ability of Curly birch compared to other fast-growing deciduous species. In other plantations, primarily established in the 1970s, the survival rate of Curly birch was significantly higher. The highest average tree heights were recorded in the «Okhta» plantation and Tikhvin FSO-2 (19.1 m and 17.3 m, respectively), while the largest trunk diameters were found in the Gatchina SPA (averaging 28 cm at 1.3 m height and up to 62 cm at the base near the root collar). It was also noted that in the «Okhta» plantation, tall-stemmed growth forms predominated (88%), while in «Shapki», both high-stemmed (42.4%) and shrub-like forms (44.4%) were prevalent. In both Tikhvin FSO sites, high-stemmed (about 70%) and short-stemmed forms (about 20%) were roughly equally represented, whereas in the Gatchina SPA, all forms were almost equally distributed (34.6%, 39.9%, and 25.5% for high-stemmed, short-stemmed, and shrub-like forms, respectively). The observed characteristics of Curly birch plantations established in different years in Leningrad Oblast are primarily influenced by the duration of plantation establishment, the genetic traits of the original trees, competitive interactions during the early years of growth, and varying soil conditions at the plantation sites. It was demonstrated that by the first quarter of the 21st century, the primary Curly birch resources (more than 2,000 trees) are concentrated mainly in the Gatchina SPA and Tikhvin FSO and are in good condition. The accumulated experience in cultivating Curly birch in Leningrad Oblast indicates that with appropriate care measures, it is quite capable of growing and thriving, producing good growth and valuable figured wood in a wide range of soil conditions, from sandy to loamy soils. The study concludes that the creation of artificial plantationtype stands is the most promising method for reproducing Curly birch. In the future, these plantations may be used both for scientific research and practical applications.

The dynamics of annosum root rot development in Scots pine provenances of the 4th age-class in Serebryanoborskoe Experimental Forestry of Institute of Forest Science Russian Academy of Science (Moscow region) is analyzed. It is determined that for the period from 2014 to 2023 the rate of trees dieback caused by annosum root rot on the trial plots has increased many times, new pockets with affected trees have appeared. The pathological process began at the same time with the natural differentiation of trees, and the annosum root rot infected mainly suppressed pines, then the dieback spread to larger trees. An analysis of the spatial arrangement of disease pockets showed that one disease center could spread over two or more trial plots with different pine provenances, which suggests association of disease pockets with tree growth conditions including edaphic ones. However, some provenances, despite their proximity to the affected plots, retained resistance to the root rot. These are provenances from the Tver, Kaluga regions, Karelia, Latvia and the Mogilev region of Belarus. On these trial plots, monitoring of the condition of the plantings should be continued. Using the method of dendrochronological analysis, it was established that the greatest influence on the value of the radial growth index of trees is exerted by precipitation falling during the growing season and, in general, by the moisture availability during the growing season. After a drought, a sharp decrease in growth is observed in all climatypes, but a greater response of growth to precipitation deficit is observed in climatypes with a higher level of root rot damage. During 2014- 2023 the degree of influence of climatic factors on the magnitude of the radial growth of trees increased, which contributed to their weakening and increase the rate of trees dieback caused by annosum root rot.

The work deals with the results of studying the berry living resources of field layers cover on the gold and platinum polygons by a washing method, using the drags and hydromonitors on the territory of the Sverdlovsk Region north-west part, Russian Federation. It is based on the trial plot methods where laid on at landfills of various ages from 10 to 55 years. In total 19 objects were laid out. Of there 7 tests where laid out at reclamation landfills after the operation of the hydromonitor. After the drag’s work six trial plots were laid out on rellamated landfills and six – on reclaimed ones. The aboveground phytomass of berry plants of the field layers cover were taken for determining in absolutely dry state, as well it was determined there progressive coating and annual yields for 2019–2021. Berry plants were represented by five species: bilberry (blueberry) Vaccinium myrtillus L., bluebery Vaccinium uliginosum L., cowberry Vaccinium vitis-idaea L., strawberry Fragaria vesca L. and drumple Rubus saxatilis L. By increasing the age of the landfills establishment or ongoing reclamation, the reserves of berry plants living on the soil cover will increase. A correlation analysis has been carried out during which a close positive relationship at the above-ground phytomass of berry plants of living soil-cover in an absolutely dry state and the year of the succession (the occurrence of a polygon, or its reclamation). Corrections equations are derived at allow predictions changes the stocks of berry plants. The plants populations restored 45– 50 years after reclamation at the site of both gold and platinum-mining highly productive berry beds are formed by washing with a hydromonitors. Their average annual yield is 10,6–36,6 kg/ha, with projective coverage 37,2–55,6% and the above ground phytomass 530,6–645,2 kg/ha in absolutely dry state. At the site of the dredge polygons after 10–45 years of the primary succession of the soil cover, the berry beds are not formed. The projective cover of berry species on the field layer cover on them does not exceed 25,7 kg/ha the average annual fruit-yields is only 0,4–7,4 kg/ha and with the above-ground phytomass in on absolutely dry state-up to 159,0 kg/ha. The process of forming berry beds on reclaimed dredge-landfills proceeds much faster than in the absence of reclamation work.

In the development of forest-swamp complexes after drainage, ecosystem changes occur in all tiers of biogeocenosis, which requires their comprehensive study. We have studied the effect of a long (more than 80 years) drainage carried out in the shrub-sphagnum pine forest in the northern forest district (Arkhangelsk region), on the stand and the state of the lower tiers of biogeocenosis: natural renewal, living ground cover and properties of peat soil. Drainage reclamation was carried out in 1940 by hand, care felling (1976) was carried out on part of the area – clearing in order to regulate the density of planting and improve the growth conditions of trees of the main breed. The facility has been stationary since 1990. (Northern NIILH), in which 3 trial areas are laid – drained pine forest, drained pine forest with care cabins and nondrained control plantation. The study of the stand, natural renewal, living ground cover and soils was carried out according to generally accepted methods. On the drained area, soil and soil conditions positively affected the overall productivity of forest stands: the stand is characterized by high productivity, bonus class II, whereas on the non–drained trial area – Va. There are also significant differences in the stock of trunk wood (246 and 63 m³ /ha, respectively). Felling of care against the background of drainage reclamation slightly contributed to an increase in the productivity of the stand, primarily due to redistribution by species. Natural renewal in drained pine-birch plantations is weak, represented by birch (200 pcs./ha), which appeared after logging. In the living ground cover, as a result of drainage, the number of species decreased, their ecological and cenotic composition changed: xerophytic species completely disappeared, the proportion of mesophytes increased by 2 times. The similarity between non-drained and drained plantings is low, the Jacquard index is 0.153–0.233. Logging of care carried out against the background of drainage somewhat equalize the level of biodiversity and increase it, compared with the drained plantation. The type of shrub-sphagnum forest noted earlier and corresponding to the control planting has changed to blueberry (moist), in which a typical autotrophic moistening forest litter has formed. In peat deposits (upper layers): the degree of decomposition and the density of peat addition doubled, the total borehole decreased, but the borehole aeration increased. At the same time, the ash content and acidity of peat have changed slightly. The ecosystem of shrub-sphagnum pine during long-term drainage reclamation has undergone significant changes concerning the lower tiers of biogeocenosis towards their exit from the sphagnum group of forest types, which also causes an increase in the productivity of planting.

The purpose of the present paper is to assess an influence of necrotrophic and saprotrophic fungi species on the vital state of Quercus robur trees in its optimum range and north of natural distribution. To achieve this purpose, we have carried out a comprehensive analysis of stands formed in various growing conditions of Q. robur. Another object of our study was a complex of xylosaprotrophic fungi associated with the shoot system of Q. robur in forest and park ecosystems along the sublatitudinal[1]submeridional transect «Tula – Vyborg», reflecting the movement from the zone of the optimum range of this species to its periphery. A complex of key species of xylosaprotrophic fungi that determine the appearance of the shoot system of late generative and subsenile individuals of Q. robur has been identified: Colpoma quercinum, Vuilleminia comedens (promote a crown thinning), Daedalea quercina, Laetiporus sulphureus, Fomitiporia robusta (cause a trunk rot), Armillaria lutea (affects mainly the butt area of the tree). It has been shown that the adaptive potential of Quercus robur trees is determined by local soil and hydrological conditions. «Eutrophic» and «oligotrophic» ecades are distinguished, characterized by a trunk diameter (at a height of 1.3 m) of more and less than 50 cm, respectively. The studies carried out confirm the high resistance of trees of the «eutrophic» ecades to progressive crown dying and deterioration. The high correlation of crown necrosis with the rank by trunk diameter is explained by the constitutional difference between the «eutrophic» and «oligotrophic» ecades of Q. robur and the high resistance of eutrophic ecadas to stress effects. In the forest-steppe/broadleaf forest section of the transect, oak trees are weakly differentiated into two ecades and are generally suppressed by linden stands. In the subtaiga section, a motley picture of differentiation of oak trees by phytopathological condition is observed, whereas the «eutrophic» ecadas demonstrate a low phytosanitary condition score. In the southern taiga section, the continuous flow of generations of Q. robur is associated with anthropogenically transformed vegetation. The main purpose of park building north of the natural range of Q. robur is to maintain the drainage system and select «eutrophic» oak stands.

Due to the increasing relevance of work on the assessment of the carbon budget of forest-covered territories, today one of the main problems is the clarification of data on the reserves of deposited carbon by different forest components. The aim of the study is to assess the dynamics of phytomass input and carbon pool of above-ground litter in pine stands on the territory of the subtaiga-forest-steppe region of Central Siberia. Trial areas based on the modality of the stand species composition and forest growing conditions have been laid on the territory of the educational and experimental forestry belonging to Reshetnev Siberian State University of Science and Technology (SibGU), which is located in the suburban area of Krasnoyarsk city. The taxational description of the studied plantings was carried out, as well as collecting morphological information regarding the incoming tree litter for the growing season of 2022. The analysis and processing of the data obtained during the field and cameral periods were made, such as: the absolutely dry mass of each component of the litter fractions, the stocks of litter and carbon per area unit, the tree litter proportion from the mass of the forest litter and the growth stage of the tree litter accumulation. The results of the study showed that the share of the active fraction was 77.9%, while the inactive fraction was 22.1%; the predominance in the total mass was revealed in the needles of the common pine (Pinus predominance in the total mass was revealed in the needles of the common pine (Pinus sylvestris L.) up to 61%; the mass of deposited carbon of the litter varied on the sample areas from 1.0±0.12 t C ha^–1 to 1.6±0.26 t C ha^–1. Uneven accumulation in terms of components and duration of the process was also noted. The results obtained will be used to refine the data when assessing the carbon-depositing function of forests on the territory of the subtaiga-forest-steppe region of Central Siberia.

St. Petersburg City is a famous world center of landscape art and applied botanical science, where, since the 18th century, a variety of introduced trees and shrubs have been used for testing and landscaping. The sources of replenishment of the assortment of trees and shrubs in the city are mainly the activities of gardening farms. Therefore, researchers constantly note new taxa for the city green spaces. As a result of research conducted in 2019–2023. in 18 parks and gardens of St. Petersburg, three new species of woody plants for the city were identified: shrubs Spiraea × schinabecki Zabel (Shinabek's spirea) and Swida rugosa (Lam.) Rydb. (= Cornus rugosa Lam., wrinkled dogwood) and the tree Ulmus ‘Columella’ (hybrid elm cultivar Columella). The purpose of the study: to confirm the status of the finds as new taxa for the green spaces of St. Petersburg and to identify their distribution and, if possible, condition in botanical collections of Russia. These taxa are still used to a limited extent in landscaping Russian cities, although one of them, Swida rugosa, began to be tested in the second half of the 19th century in St. Petersburg – in the Botanical Garden of the Komarov Botanical Institute RAS. In the conditions of St. Petersburg, these three taxa have shown sufficient stability, are in satisfactory and good condition, decorative and can be used in the future for landscaping the city. And Swida rugosa, which is found in botanical gardens in the European part of Russia and Siberia, most likely can be used more widely in landscaping the populated areas of Russia in the southern forest zone. Spiraea × schinabecki is given for only two botanical garden. And Ulmus ‘Columella’ most likely has never been grown in Russian botanical gardens. However, due to the high resistance to Dutch elm disease, it definitely deserves widespread use in green spaces in Russian cities.

Due to climate change and the potential possibility of its stabilization with the help of managed forests and assessment of their carbon depositing capacity, the possibility of operational assessment of phytomass and organic carbon of forest cover is of particular relevance. Remote sensing of forests based on unmanned aerial vehicles made it possible to obtain the parameters of tree crowns from as close a distance as possible, which ensures high adequacy of models for assessing the phytomass of trees by crown diameter. Along with them, thousands of allometric models have been published to estimate the phytomass of trees by stem diameter. To combine them, it is necessary to know the interrelationships of the stem and crown diameters. When using the empirical data of 3,100 model trees for seven coniferous and 2,470 trees for sixteen deciduous species and genera (subgenera), 23 allometric models of crown diameter versus stem diameter and stem diameter versus crown diameter have been developed, significant at the level of t001 and higher. The first ones are designed to be combined with published models of phytomass of trees in connection with the crown diameter, and the second ones are designed to be combined with published models of phytomass in connection with the stem diameter. All genera were ranked both by crown diameter and stem diameter, followed by rank regression analysis, including the interdependence of two rank distributions of 23 genera. A negative relationship has been established between the rank distributions of genera by crown diameter and stem diameter, while the dependence of the empirical data of stem diameter on crown diameter is of positive relationship. Thus, the relationship of the crown diameter with the stem diameter can be either negative or positive, depending on a particular application and context.

Lack of moisture and high temperature lead to a decrease in crop yields. According to a number of researchers, the solution to this problem is implemented in an integrated approach, an important link of which is agroforestry. To study the effect of the ratio of agricultural land in the Krasnodar Territory on soil fertility in agroforestry landscapes, we conducted research in 2022. The research was conducted according to generally accepted methods. The condition of the lands of the agricultural landscapes of the districts was assessed according to literary sources and statistical data. The allocation of fertility zones was carried out according to the normalized vegetation index NDVI. The purpose of the research is to study the influence of the ratio of land in agroforestry landscapes on the productivity of crops in the Krasnodar Territory using the Agronomist Online program based on the Sky Scout service. As a result of the research, it was found that a higher percentage of the fertile zone category for all agroforestry areas belongs to the middle category and accounts for 46.09% of the total arable land area of the region. In the second agroforestry district of the Krasnodar Territory (Seversky district), there is a higher percentage of land with a high level of fertile land of 29.63%. In this area, there is also a higher percentage of arable land cover – 3.12. The analysis of the fertility of agroforestry landscapes revealed a linear dependence on all research options. A closer relationship between the yield of winter wheat (2010–2022) and the protective forest cover of arable land is noted for the Seversky district, the regression equation for which has the form y = 1.6622 x – 3307.9 with R2 = 0.5745. Thus, it follows from the presented research results that in order to increase productivity (fertility) in the Krasnodar Territory, it is necessary to additionally create protective forest plantations. The choice of the land ratio should be carried out using an adaptive landscape approach. This approach will contribute to obtaining additional agricultural products, as well as the formation of optimal forest cover, conservation, and improvement of the ecology of agricultural lands in the agro-industrial complex of the region.

The article focuses on studying the current condition of the soil and plantings in Yuzhno-Primorskiy Park in St. Petersburg. The park was created on reclaimed soils and is currently one of the largest elements of St. Petersburg's water-green framework. The authors tracked the dynamics of soil layer formation (based on data from 1974, 2004, and 2024). It was found that there is a gradual compaction of the lower reclaimed horizons, which negatively affects the hydrological conditions of the area. At the same time, the upper – filled – horizons are gradually increasing in thickness and retaining fertility due to continuous human activity. The species diversity of woody and shrub vegetation has changed insignificantly: some ornamental species, planted singly, have been lost; there has been an emergence of indigenous species that are resistant to adverse environmental conditions, primarily to soil compaction and excessive moisture. The condition of the plantings tends to deteriorate – an overall weakening of plants due to increased recreational load.

The article considers options for modernizing the design of the manipulator of a logging machine to implement a method of processing trees upside down by multistage bucking of trees in height, ending with the separation of the tree from the stump. The purpose of the research was to develop and analyze the design of a multi-link combined manipulator with the extension of the working body to a distance of more than 18 m. Manipulator designs were proposed with the modernization of the articulated truss by introducing additional links and the formation of pantograph mechanisms. The structural and kinematic schemes of two variants of multi-link combined manipulators are shown. Experimental models of the proposed designs of multi-link combined manipulators with a change in their length are presented. Photographs of physical models of experimental manipulators collected to prove the theoretical results are presented. Models of manipulators with scale of 1:10 were used for the experiment. For the possibility of quickly changing the position of the articulated truss structure and fixing it, a sliding rod with a stepped retainer (fixing step of 5 mm) was used, simulating the operation of the manipulator hydraulic cylinders. Based on the structural analyses of kinematic schemes of multi-link combined manipulators, a solution was found to the design of the articulated truss of the telescopic arm of the manipulator by adding additional levers forming pantographic mechanisms for extending movable sections. It is proved by mathematical calculations that the use of an articulated truss as a mechanism for extending movable sections creates conditions for increasing the output of the manipulator while maintaining a unified transport and energy module without the use of additional hydraulic cylinders and rope-block systems. Structural analysis has shown that the proposed structure of the manipulator with a pantograph mechanism for extending the movable sections of the telescopic handle is workable.

Limiting factors for the development of traditional solutions for the development of hard-to-reach logging sites are presented. Mathematical and software methods have been proposed for calculating the construction of routes for rope-skidding installations. Methods are proposed for solving the problem of laying out an acceptable optimal route using discrete programming methods under conditions of risk and uncertainty. Using a practical example in typical natural production conditions of the Northwestern Federal District of the Russian Federation (quarter 4, century 39 of the Primorsky district forestry of the Kurortny forestry of St. Petersburg), a mathematical model is built to solve a stochastic problem with quantile indicators.

The article considers the dynamic loading of the power plant of a feller-buncher machine with a platform leveling system during its pulling by the manipulator handle during timber harvesting on slopes. A mathematical model has been developed that allows determining the value of the additional dynamic torque acting on the machine’s power plant and the crankshaft rotation frequency at the design stage of the fellerbuncher. The mathematical description is written in the form of the Lagrange equation of the second kind. An example of calculating the mathematical model for the LP-19A feller-buncher is given. Graphs of changes in the additional dynamic torque at a pulling speed of 0.1, 0.2 and 0.3 s^–1, as well as depending on the slope angle (15, 30 and 45º) are presented. A graph of changes in the crankshaft rotation frequency reduction depending on the slope angle is presented. The analysis of the research results shows that the pulling of the feller-buncher machine equipped with the platform leveling system by the manipulator handle during timber harvesting on slopes is accompanied by a significantly less significant dynamic moment on the power plant than that of a machine with a “classic” layout. Thus, when pulling the feller-buncher machine on a slope with an angle of γ = 15º, the maximum value of the additional dynamic load on the power plant will be only 4.4 Nm. The level of dynamic loading of the power plant significantly depends on the angular velocities of the machine pulling used by the operator, as well as the value of the slope angle on which the work is carried out. The developed mathematical model allows us to study the loading of the feller-buncher machine power plants equipped with platform leveling systems during pulling during timber harvesting on slopes, both at the design stage of new machines and when improving the designs of serially produced models.

Laser heat treatment is an effective way to improve the mechanical properties and increase the wear resistance of metal parts. This article examined the features of choosing laser heat treatment modes for a plow share made of 65G steel. This type of steel belongs to carbon alloy steels with a high content of carbon, manganese and silicon. It is characterized by high hardness and strength, which makes it an excellent material for the manufacture of plow shares, which are subject to significant mechanical loads and friction with the soil. Laser heat treatment allows you to control temperature zones locally, which makes it possible to change the structure and properties of the material to achieve optimal characteristics. When processing plow shares with a laser, modes such as heating, hardening and tempering are used. The optimal choice of laser heat treatment modes for a plow share made of 65G steel will allow you to achieve the required mechanical properties and increase the wear resistance of the part. A comprehensive consideration of the material properties, geometry and technical capabilities of laser processing will allow us to determine the optimal parameters and achieve the desired results.

Cryolithozone forests belong to especially ecologically vulnerable forests. During logging operations, skidding operations have the greatest negative impact on the forest ecosystem. The most negative factor of skidding during the logging season is overconsolidation and destruction of forest soil structure on the skidding shafts and technological corridors. Intensive rutting leads not only to critical damage to the forest ecosystem, but also significantly reduces the efficiency of forest machines. At frosts of more than – 40° C forest machines cannot work due to frost brittleness of metal construction. Therefore, a significant volume of harvesting falls precisely on the moderately warm period of the year. Establishing the principles of the impact of the temperature of forest soil layers of the cryolithozone on their physical and mechanical properties provides more accurate assessments of these results of the relationship between forest machines and soil. The article presents the methodology, devices and data obtained in full-scale experimental studies to determine the influence of permafrost soil temperature. Reducing the unfavorable impact of forest machine drivers on the soil of harvesting areas is devoted to a very large number of theoretical and practical developments of domestic and foreign authors. It is expedient to point out a huge contribution to these theoretical and practical developments, which was made by the participants of the leading domestic sectoral scientific school «Innovative developments in the field of logging industry and forestry». Within the framework of this scientific school only for the last years more than ten candidate and doctoral dissertations on scientific specialty 05.21.01 «Technology and machines of logging and forestry», devoted to the issues of reducing environmental damage during logging, and, above all, to reducing the negative impact of forest machine drivers on the soil of harvesting areas, have been defended. However, the weak point of this theory is the lack of consideration of changes in the thermal regime of permafrost soil, which, by definition, is a multilayer system. Without taking into account the thermal regime of soil layers, the theoretical methods of assessing and predicting the impact of forest machine drivers on it are not accurate enough.

Methods of technical and computer vision are developing and being increasingly used in various civil industries. Computer vision tools may be used to improve passability and traffic safety of forest machinery by promptly recognizing isolated obstacles in the form of roots, stumps, hummocks, potholes, etc. The study tested methodology of an experiment to study capabilities of computer vision tools for recognizing isolated obstacles on forest roads. The experiments in were carried out for various versions of the YOLO artificial neural network (YOLOv8n.pt, YOLOv8s.pt, YOLOv8m.pt, YOLOv8l.pt), retrained on a large dataset of Road Damage Detection 2022. It was found that the experimental setup, including software and hardware, as well as the selected hyperparameters of the model training process, make it possible to obtain stable experimental data on the recognition and classification of road defects, including forest ones. The results of scoring the YOLO models during retraining and validation showed that the YOLOv8m.pt artificial neural network model should be recommended as a promising version for developing a technical solution for recognizing single obstacles on forest roads; however, the issue of regularizing the model weights should be additionally considered. Testing and expert evaluation of the results confirmed the preliminary conclusions about the promise of the YOLOv8m.pt version as basis for the technical solution. The expediency of using the numerical optimization method Adam with a minimization step of 0.00001 in further studies related to experiments with the models of the artificial neural network YOLOv9, YOLOv9v10 is noted for the purpose of compiling a more complete and systematic scientific understanding of the applicability of computer vision models for identifying isolated obstacles on forest roads.

Samples of plastic without resin (PWR) were produced using a wood filler with varying proportions of birch bark. The PWR samples were pressed in a sealed mold under a pressure of 40 MPa and at a temperature of 180 °C, followed by cooling without pressure release until reaching 40 °C. The resulting samples underwent testing for density, flexural strength, flexural modulus of elasticity, Brinell hardness, impact toughness, water absorption, and swelling after 24 hours. Additionally, biostability was assessed in soil for 90 days and in active soil for 105 days. Hydrophobicity was also evaluated based on the contact angle. Based on the test results, the optimal composition ratio for the press material was determined using birch sawdust with a 50% addition of birch bark. At this ratio, the material exhibited the following properties: density – 909 kg/m³, modulus of elasticity – 1566 MPa, flexural strength – 8.9MPa, Brinell hardness – 17 MPa, impact toughness – 3.818 kJ/m², water absorption in 24 hours – 32%, and swelling – 7%. A correlation was found between increased birch bark content in the press material and enhanced biostability, attributed to its high hydrophobicity and antiseptic properties.

High quality requirements for xylitol are due to its use in food and pharmaceutical industries. An important task in preparation of xylose solutions for hydrogenation is solution clarification, since xylitol is a white crystalline powder. For this purpose sorption and flocculation purification of the obtained solutions as well as membrane methods are used. The most commonly used sorption purification is activated carbon, the treatment of which is effective in reducing the color of the solutions obtained. The article considers the necessity of sorption purification of xylose hydrolysate and presents a comparative characterization of the efficiency of the process of clarification of pentose hydrolysate of birch wood by granulated active carbon (GAC) from cellolignin and BAU-A wood active carbon. The degree of clarification of hydrolysate when using GAC is higher than that of BAU-A and the required color is achieved when adding GAC in the amount of 17% of the CB of hydrolysate. The use of GAC for sorption purification of pentose hydrolysates allows to reduce the consumption of sorbents for clarification of hydrolysates in 1.3 times. The data on regeneration of spent GAC from cellolignin at different duration of treatment, as well as the results of efficiency of clarification of xylose solutions by regenerated GAC are presented. The regenerated GAC are suitable for sorption purification of hydrolysate. Sufficient duration of regeneration was 20 minutes. Organization of production of GAC from cellolignin will significantly reduce the cost of sorptive treatment of hydrolysate and increase the economic efficiency of xylitol production.

The results of the study of the initial woody greens –logging waste and the coniferous feed additive obtained from it are presented, the influence of the coniferous feed additive on the productivity and quality of dairy products, physiological and biochemical parameters of animals during the period of stress factors – increased air temperature and calving is determined. The purpose of the study is to study the composition of groups of substances and compounds of the acid fraction of the initial woody greens and coniferous feed additives manufactured under production conditions: the main indicators of productivity and quality of dairy products, zootechnical and physiological and biochemical parameters of farm animals under conditions of temperature stress and calving. An average sample of the initial woody greens, shoots with needles – logging waste, and a coniferous feed additive manufactured under production conditions by STC «Khiminvest» LLC have been studied. The feed additive was divided into solid and liquid parts. The initial woody greens and the solid part of the feed additive were extracted with propane-2-ol, the remainder was sequentially extracted with a hydrocarbon extractant (boiling range 40– 70 °C) and diethyl ether. The liquid part of the feed additive was similarly extracted with hydrocarbons and diethyl ether. The main groups of substances were determined in the hydrocarbon extract – the sum of resin and higher fatty acids, unsaponifiable substances, the content of chlorophyll derivatives and carotenoids. The composition of acid compounds was identified by GC-MS method. The results of the study showed that the compositions of the groups of substances of the original woody greens and the manufactured coniferous feed additive are similar. The parameters of the technological process for the manufacture of feed additives do not affect the nativity of the products obtained. The use of a coniferous feed additive during extremely high air temperatures (up to 42 0 C) in the shade and calving reduced the content of cortisol in the blood (by 1.7–5.9 per cent ), adrenaline by (4.7–8.4 per cent), urea (by 5.2–8.5 per cent ), increased the content of total protein (by 1.2–3.3 per cent) and glucose (by 6.2– 19.5 per cent) when compared with the control group of animals. The obtained research results allow us to positively assess the effect of coniferous feed additives on the physiological and biochemical processes of animals during heat stress and calving.

The recycling of MS-5B waste paper into a test liner and fluting at JSC Karavaevo is accompanied by the accumulation of waste, which is a complex mixture of substances of various types with variable mass composition. More than 1.2 million tons are delivered to the landfill per year, thus the specific content of waste per 1 ton of products is about 38 kg. The resulting waste must be disposed of at the landfill, which requires significant financial costs. Therefore, waste recycling has become an urgent problem of recycling waste paper. The waste mixture is fractionated into plastics, fiber, wood, minerals, metals, rubber and fabric. It has been established that the total content of plastic and fiber is more than 71% and can be used in full as a binder in thermal pressing technology. The technology of polymer-sanded plates based on waste paper of the MS-5B brand is considered. A polymer product (PI) was produced in the form of tiles with a size of 330´330´35 mm. With a tile weight of 3.3–3.5 kg/piece, the line capacity of 2 tons per shift (8 hours) turned out to be close to the calculated one when choosing equipment. The second option of the study is the production of PPIs. The compositions of the feedstock and sand were studied in the following ratios, %: 50/50; 40/60; 30/70. Currently, the operation of the equipment has been adjusted, the production modes of 2 types of products have been worked out: garden tiles 330´330´35 mm and road tiles 700´700´80 mm for roads and parking lots.

Avocado and pumpkin seed oils have different origin and methods of production and are characterized by similar content. The purpose of the study is the fatty acids composition research in order to evaluate their advantages and disadvantages and beneficial qualities of this oil’s usage as biologically active additives and the part of cosmetic. The oils are characterized by a high content of fatty acids of various types, both saturated and unsaturated. In the article the overview of information about avocado and pumpkin origin and production based on literary sources is included, the composition of avocado and pumpkin oils is described. The chromatographic method of analysis allows to evaluate the quantitative ratios of the components. The content of stearic, palmitic and myristic (fatty) acids was determined is 2 times higher in pumpkin seed oil compared to avocado oil, it means the advantages of avocado oil as a low-calorie product. The analysis revealed especially high content of «essential» unsaturated fatty acids: in pumpkin seed oil it is 80%, in avocado oil it is 87%. Therefore, these oils show the expediency of using as a therapeutic agent for external and internal use particularly to reduce the risk of cardiovascular diseases.

The industrial lactic acid production is based on microbiological fermentation of sugar-containing feedstock. Generally, the price on the substrate controls almost half the cost of the entire production. The use of pure individual sugars as a carbon source for the microbiological lactic acid synthesis leads to a significant rise in production expenses. Lignocellulosic biomass is one of the most common natural renewable sources of carbon, the use of which in biotechnological production as a carbohydrate-containing substrate is limited mostly due to the lack of cellulolytic enzymes in most strains of microorganisms used on industrial scale. The filamentous fungus Rhizopus orizae is an industrial lactic acid producing microorganism capable of metabolizing lignocellulose. The growth of microbial mass, substrate consumption rate and lactic acid yield are controlled by the metabolic activity of the producer cells, the latter depending on the cultivation mode. The microbiological lactic acid production regulation is carried out by changing such factors of nutrient medium as temperature, pH, nutrient concentration in the substrate and the final product concentration. The work involved the conditions’ selection for fungus R. oryzae F-1030 cultivation on neutral sulfite liquor, which made it possible to attain the optimal ratio of biomass and the synthesized lactic acid yield. It has been shown that the nutrient medium acidification is affected by the physiological maturity of the fungus. The level of reducing substances in the nutrient medium is controlled by the growth rate of the fungus R. oryzae F-1030 cells and the activity of its cellulolytic enzymes. There were no statistically significant differences in the amount of synthesized lactic acid and biomass growth depending on the mode of the fungus R. oryzae F-1030 cultivation on the neutral sulfite liquor after treatment with externally added enzymes. The growth of fungus R. oryzae F-1030 biomass is influenced by both the type of hydrolyzing agent (acid or enzyme) and the composition of the nutrient medium, in particular the presence of nitrogen, phosphorus, sulfur, and potassium salts. The batch cultivation mode was demonstrated as optimal for the fungus R. oryzae F-1030 to grow on the neutral sulfite liquor after acid hydrolysis.