The article presents data on the survey of forest plantations with the participation of Robinia pseudoacacia L., Crataegus laevigata (Poir.) DC., Gleditsia triacanthos L., Acer tataricum L., Acer negundo L., Pyrus communis ssp. pyraster (L.) Ehrh., Prunus cerasifera Ehrh., Quercus robur L., Amelanchier canadensis (L.) Medik., Pinus nigra ssp. pallasiana (Lamb.) Holmboe, Ulmus minor Mill., Ribes aureum Pursh, Morus alba L., Prunus armeniaca L., Pinus sylvestris L., Lonicera caprifolium L., Elaeagnus angustifolia L., Amorpha fruticosa L. from various habitats in order to select species and forms for the creation of a permanent forest seed base. It has been established that the main criteria for the selection of the gene pool are viability, drought, salt, frost resistance, height and rapid growth of the surveyed plantations. Despite the partial freezing of annual shoots of some species and forms, including the pyramidal and mast forms of Robinia pseudoacacia, they can also be used to create permanent forest seed bases (PFSB) and plantings of various types due to annual fruiting and sufficient growth. Groups of plants have been identified in relation to the main limiting environmental factors, of which Canadian serviceberry, Crimean pine, field elm, golden currant, desert false indigo, black locust, Tatarian maple, European wild pear, English oak, apricot, Russian olive and sea buckthorn are the most promising for creating PFSB in arid conditions. According to growth indicators, the maximum height was noted in Crimean pine, English oak, field elm, sea buckthorn, intensive growth of shoots – in honey locust. An improved scheme for the creation and use of breeding and seed-growing facilities for protective afforestation is proposed.

The downside of mining is the adverse human impact on the environment, which appears in the disruption of natural landscapes. Forest land reclamation plays a leading role in the restoration of post-technogenic lands. It was key to the creation of plantations for various purposes. It is possible to cultivate Forest Shelterbelts in agricultural areas. Forest Shelterbelts and effluent-regulating Forest Belts are created on specially lined dumps of more than 50 hectares: on clay and loam substrate – without preliminary application of the fertile layer, on sandy, sandy and chalk and chalk and marl substrates – after applying topsoil fertile layer. On the hydraulic dump called ‘Berezovy Log’ related to iron ore basin of the Kursk magnetic anomaly (KMA), in the conditions of two-component Technosols, were laid forest shelter belts and effluent-regulating forest belts using the following plant species: Populus balsamifera L., Fraxinus excelsior L., Robinia pseudoacacia L., Sorbus aucuparia L., Lonicera tatarica L., Quercus rubra L. Studies have shown that slope exposure has a large impact on the survival of plant species. Populus balsamifera L. is characterized better survival on the south-western plots, Sorbus aucuparia L. and Lonicera tatarica L. – on the west and south-west plots. Sorbus aucuparia L. is best survivable on the slopes of the north-west and western expositions, and Fraxinus excelsior L. – also on the slopes of the north-west exposition. Monitoring of previously created plantations on Technosols up to 43 years old allowed to assess the suitability of tested plant species to create Forest Shelterbelts on post-technogenic lands. The conclusions are made that only Robinia pseudoacacia L. can be used when growing forest shelter belts, as well as other types of protective forest plantations. Populus balsamifera L., although distinguished at a young age by high survival rate, does not form durable sustainable plantations, having at the age of 42 years of preservation of only 11%. It can not be recommended for forest reclamation of dumps, as well as Sorbus aucuparia L., which fell out completely by the age of 35. It is recommended to add Lonicera tatarica L., into Forest Shelterbelts according to the mixing schemes used on zonal soils.

The results of post-fire natural forest restoration on burned area up to 10 hectares of the south taiga zone of Western Siberia (e.g. Uvat forestry) and the subtaiga foreststeppe forest area (e.g. Iset forestry) are presented. Research data have shown that in 5–15 years after a wildfire according to the quantitative and qualitative indicators of main forest-forming species (pine, birch) regeneration there is a continuous forest restoration process. Pine natural regeneration is assessed as “normal” due to normative indicators. It was found that with the increasing distance from the forest border there is a common pattern of decreasing quantity of seedlings and undergrowth. It is proved that at a distance of 100 m from the forest border the number of seedlings and undergrowth in all height categories is by 1.5–2 times lower compared at a distance of 50 m from the forest border. There is a predominance of vital pine undergrowth – up to 60–100%. According to the indicator of pine undergrowth frequency, reforestation is going in the entire territory of the burnt area. In taiga conditions, there is a sufficient amount of large-sized viable aspen undergrowth in sufficient quantity (up to 2.0 thousand pcs / ha). This is the evidence of the successful reforestation of burned areas at this stage of development.

Morphometric parameters of 1-year-old pine needles of mountain pine (Pinus mugo Turra.) as an introduced species in the Nizhny Novgorod region were studied in comparison with the Scots pine (Pinus sylvestris L.), which belongs to the native dendroflora. The relevance of the work is due to the high demand for representatives of the genus Pine (Pinus L.) when creating artificial plantings for various purposes and structures, including attraction of plants from non-district populations for these purposes. The methodological approach provided for compliance with the principle of the only logical difference and meeting the basic requirements for the formulation of experience – typicality, suitability, expediency and reliability. The object of research was 5-year-old seedlings of Mountain pine and Scots pine, located at the experimental site of the Nizhny Novgorod State Agrotechnological University with geographical coordinates N56°19'43" E44°00'07" and an absolute height of 141 m. The research was carried out by field stationary and laboratory methods. The subject of the study was the ability of individuals of the compared species in the juvenile phase of ontogenesis to form a leaf apparatus during one growing season. The length of the needles was recorded with an electronic vernier caliper FinePower DC0220 with an accuracy of 0.01 mm, the weight was recorded on precision analytical scales Acculab Vicon VIC–300d3 with an accuracy of 0.001 g. The ANOVA was performed according to one-way and two-way schemes. Phenotypic differences in linear parameters and weight of 1-year-old needles were established both between the compared species and between individuals belonging to each of them. The length of the needles of Mountain pine ranged from 5.81±0.129 cm to 8.33± 0.101 cm, of Scots pine – from 3.50 ±0.040 cm to 5.60 ± 0.157 cm. This gave an excess of more over less in the first case by 2.52 cm or 1.43 times, in the second – by 2.10 cm or 1.6 times. The similarity of the morphometric characteristics of the needles of the native Scots pine and the introduced mountain pine indicates the fundamental similarity of their biology.

The typological characteristics of the stone birch forests (from Betula ermanii) of the south of the Koryak Highlands (Kamchatka Territory) located on the northern border of the range are given. The characteristic of the floral composition and structure of communities, habitat conditions and features of geographical distribution is given. The classification of biogeocenoses was carried out simultaneously on the basis of vegetation and soils; the characteristics of the organic and organo-mineral horizons of the soil, dominant species and indicator species were taken into account. In the study area, the typological diversity of stone birch forests is represented by 10 associations and 3 types of forests: Betuletum ermanii pinosum pumilae (stone birch forest with creeping cedar) Betuletum ermanii calamagrostidoso-alnosum fruticosae (stone birch forest with creeping alder), and Betuletum ermanii dryopteridosum (stone birch forest with fern). The stone birch forests of the Koryak Highlands differ from their Kamchatka counterparts in their depleted floral composition and significant development of the shrub layer with a predominance of large creeping shrubs.

Based on the results of studies in test cultures of 30–40-year-old Norway spruce plus trees, data on the influence of plantation density on the efficiency of comparative evaluation of families of plus trees were obtained. The inverse dependence of stand density on the average trunk diameter of the plantation was observed. At the same time, the density of the plantation does not have a significant effect on the level of diameter dependence on the family affiliation of the tree and does not significantly affect the results of comparative assessment of the growth rate of families of plus-trees in the progeny tests. The joint effect of planting density and plant family affiliation on growth rate is statistically insignificant, which confirms the possibility of analyzing the effect of plant family affiliation and planting density on biometric indices separately, without taking into account their joint influence. The actual distribution of trunk diameter is significantly different from the classical normal distribution of the trait. The value of the index of reliability of differences between families decreases at the age of bowing and intensive competition of plantations, remaining, nevertheless, within the limits of preservation of reliable values. Further growth and development of plantations after the end of intensive processes of self-expiration of the plantation (beginning of the second age class) leads to a repeated increase in differences between families of plus-trees. The influence of genetic factors (tree family identity) has a statistically significant effect on the growth rate of Norway spruce trees from at least the beginning of the second age class (20 years for conifers) up to the age of final evaluation of plus-tree families in progeny tests (40 years).

The article presents data on the species composition and abundance of raw materials growing under the canopy of spruce forests. The object of the study is spruce forests of different forest types in the Leningrad Region. The taxation of tree stands was carried out using the generally accepted method. The share of spruce in the composition of tree stands varies from 51 to 89%. The maximum number of undergrowth in the wood sorrel spruce forest is 1933 specimens/ha, in the bilberry spruce forest – 4241 specimens/ha and in the long-moss spruce forest – 3817 specimens/ha. The number of undergrowth species ranges from 320 to 2977 specimens/ha in the wood sorrel spruce forest, from 910 to 2700 specimens/ha in the bilberry spruce forest and from 430 to 612 specimens/ha in the long-moss spruce forest. The species composition, occurrence and projective cover of plants in the living ground cover were determined on circular survey plots using an original technique. At least 30 survey plots of 10 m² were laid out at each study site. In addition to the grassdwarf shrub and moss-lichen layers, the amount of undergrowth and undergrowth by species, as well as the height structure, were taken into account. The species composition of the living ground cover was compared using the Jaccard coefficient. The largest number of raw material species in the herbage was found under the canopy of wood sorrel spruce – from 24 to 29. The Jaccard coefficient as a whole for wood sorrel spruce forests – long-moss spruce forests is 0.37, i.e. the number of common species in the specified types of spruce forests is 37%. For bilberry spruce forests – long-moss spruce forests, the coefficient of community of species is 0.48. For wood sorrel spruce forests – bilberry spruce forests, the value of the Jaccard coefficient is 0.68. In the composition of the living ground cover under the canopy of spruce forests, plants from all raw material groups are found. Honey plants and medicinal plants predominate, regardless of the forest type. The results obtained can be used to adjust regulatory documentation on forest use and introduced into forestry training programs.

The city of Krasnoyarsk is a large industrial center of Siberia, characterized by a high level of air pollution. The green planting system of a modern city is designed to significantly improve the environmental situation, but an important condition in this case is the scientifically based selection of an assortment of woody vegetation suitable for landscaping the city of Krasnoyarsk and the cities of Central Siberia. To do this, it is necessary to have sufficient information about the ecological and biological state of woody plants, allowing one to assess the functional contribution of each species to changing the quality of the environment in the direction of its improvement. The purpose of the study was to study the morphometric parameters of annual shoots of some types of deciduous trees in the urbanized environment of Krasnoyarsk. The objects of the study were species of both local and introduced floras Betula pendula, Malus baccata, Tilia cordata and Padus maackii in plantings of various functional purposes. The biometric method for assessing the condition of trees involved measuring the size of annual segments of lateral shoots; number of leaves on annual segments of side shoots; wet and absolutely dry weight of leaves; leaf area. Research has shown that in the studied species in the technogenic environment of Krasnoyarsk, there is a decrease in all morphometric indicators, xerophytization of morphological structures, an increase in water deficiency, a decrease in the specific gravity of the leaf, a violation of assimilation processes, which increase with an increase in the level of technogenic loads. Based on the studies conducted on the degree of violation of the morphometric indicators of the annual shoot, the studied tree species can be arranged in the following sequence: Malus baccata > Tilia cordata > Padus maackii > Betula pendula. Thus, Malus baccata and Tilia cordata can be classified as unstable species in the technogenic environment of Krasnoyarsk. Species specificity was discovered in the optimization of the photosynthetic apparatus of the studied species to the conditions of the urbanized environment of Krasnoyarsk. An assessment of the state of the assimilation apparatus of the four dominant species in the plantings showed that Betula pendula has a relatively high adaptive potential, and Malus baccata has the lowest.

The article considers the prospects of plantation forest cultivation on lands disturbed as a result of the work of resource-extracting enterprises. Currently, one of the most important problems is the reduction of forest resources used in the wood processing industry. Restoration of forest stands on deforested areas will not only solve this problem, but also improve the ecological situation in the regions due to the restoration of degraded lands and the production of phytomass in the form of wood raw materials. The objects of the study were: forest ecosystems, including the characteristics of tree stands (fullness, age, growth; soils, light conditions, temperature); reclaimed lands; seedlings and cuttings of larch and other coniferous and deciduous species; natural and climatic factors. In this regard, the aim of the study was to determine the prospects for creating forest plantations, including on reclaimed areas disturbed by mining activities in the last century, to reduce their negative impact. The experimental studies conducted to develop a technology for creating forest plantations on reclaimed areas of the Kavalerovsky forestry in Primorsky Krai indicate that the highest rooting rates of poplar cuttings were found in the varieties Pioner, Volosistoplodny, Kitaysky, Marilandika, Brabantika-175, Stroyn in variants using the following bioactivators: succinic acid, huminol and rostivin. It was found that the condition of larch, pine, oak and maple seedlings was satisfactory. Experiments in the greenhouse of "DalNIILH" and in production conditions, on the reclaimed site of Kavalerovsky forestry (Primorsky Krai) allowed to identify the possibility of successful cultivation of plantation forest plantations, namely: planting cuttings of acclimatized poplar and seedlings of tree crops using the following bioactivators (biologically active substances): huminol, rostivin, rootin and succinic acid. The conducted studies allow to make a preliminary conclusion that when growing poplar cuttings on a plantation, it is possible to recommend the use of succinic acid and huminol.

The relevance of research on this issue today is of particular importance, because in connection with the current situation the issue of import substitution of products of harvesting and processing of oleoresin is quite acute. Oleoresin extraction is based, as a rule, on the exploitation of pine stands, and during its realization the trees with increased ability to produce oleoresin mass are of great interest. According to the current rules of oleoresin harvesting in the Russian Federation, the following forest stands can be transferred for exploitation: forest stands with the share of pine in the stand composition of not less than 40% of the total wood stock of the forest stand. In connection with the above-mentioned, the purpose of this study was to determine the resin productivity of pine in stands with different shares of pine (Pinus sylvestris L.). Experimental objects for the study were mature stands of pine with the share of its participation from 50 to 100% on permanent sample plots in the Leningrad region. To determine the resin productivity of pine trees, the micro-wounding method was used followed by flow measurement after 10 hours. The study showed that the influence of stand composition on pine resin productivity is not unambiguous. In some cases, no clear differences were found between pine-dominated stands and stands with a lower proportion of pine. Probably, the influence of quantitative representation of trees by size categories is a more significant factor in resin productivity in stands with a different proportion of pine. In general, there is a tendency for greater oleoresin extraction as the proportion of pine in the stand increases with increasing trunk diameter class. For the permanent sample plots, in pure pine stands, no differences in oleoresin extraction were found between the control section and the section with integrated management. However, a significant difference was observed between the other variants, which is related, as well as in mixed pine stands, to the different proportion of tree representation by size stages.

The study is devoted to the identification of the early stages of damage to Norway spruce tree stands by a bark beetle. The scale, intensity and dynamics of bark beetle damage are difficult to predict, and the negative consequences are comparable to the consequences of forest fires. From a practical point of view, it is of crucial importance to identify the initial stage of bark beetle damage, in which colonized trees do not yet show distinct symptoms of damage, and the needles retain their green color. The objective of the study was to study by methods of mathematical statistics changes in the vegetation indices NDVI and SWVI for Norway spruce stands, which in 3 years have gone from healthy to severely damaged, using as an example the sites of mass reproduction of bark beetle and other stem pests identified during a ground survey. The objects of the study were 12 sites of mass reproduction of bark beetles and other stem pests formed in 2021 on the territory of Vyborg and Gatchina districts of the Leningrad region in mature Norway spruce tree stands. During the ground work, the survey and mapping of damaged sites were carried out. With the help of the EO Browser mapping service, Sentinel-2B satellite survey materials for June-September 2020 (no damage), 2021 (early stages of damage) and 2022 (late stages of damage) were received on the territory of the damaged sites. Vegetation indices NDVI and SWVI were calculated on the basis of the received remote sensing materials. With the help of variance analysis, a reliable and significant decrease in the values of both indices was established by the years of damage, as well as by years and months. It is noted that when bark beetles damage plantings, the seasonal dynamics of index values changes. Reliable linear trends of decreasing of both index values by year and month are revealed. Analysis of the sensitivity coefficients and synchronicity of changes in vegetation indices by year and month showed that the decrease in index values occurs independently of external (random) factors, as well as well as not synchronously relative to each other. In practical terms, the revealed patterns of changes in the vegetation indices NDVI and SWVI can serve as a signal about the initial stage of damage to plantings and the basis for conducting ground surveys with the aim of early detection of damage and timely prevention of their spread.

Investigation of the periodic annual increment volume (PAIV) linden stand on a permanent research plot in the Republic of Bashkortostan, pursued three goals: 1) to evaluate the PAIV; 2) comparison of methods for estimating PAIV based on long-term observations and by single measurement; 3) to compare the PAIV of the studied stand with the data of existing yield tables. PAIV assessment is performed in several ways: i) by repeated measurements of the volume of the stand, taking into account mortality and ingrowth of trees over a 33-year period; ii) through of the percentage PAIV of ten felleed model trees and the volume of stand without bark; ii) along the straight line of the PAIV of model trees; iv) according to the elementary PAIV of trees of Prof. M.L. Dvoretsky; v) according to the method of simple percent increment of basal area, using information for the last 5 years from cores, and of simple percent increment of height of trees. The data obtained showed that P of the tree stand at the age of 57 years calculated using model trees (methods ii), iii) and iv)) were 9.86, 8.63 и 9.47 m3ha–1year–1 accordingly. At the age of 62-90 years they vary between 2.6 and 9.4 m3ha–1year–1. Method v) for estimating PAIV, based on the use of growth analysis on cores and the probabilistic rate of increase in height according to assortment tables taking into account the mortality of trees in the forest stand, can be safely used in the absence of the possibility of cutting down model trees and measuring height gain on growing trees. The PAIV values of the studied tree stand exceed the data from local yield tables and are comparable in value to German tables. It is concluded that further research is necessary using a larger volume of data to obtain statistically confirmed results of the influence of climate on the PAIV of linden plantings and adjustments to local yield tables.

In the course of the conducted studies, the forest databases at stand level for all categories of forest stands of the city of Yekaterinburg, namely, the federal, regional and municipal subdivision were modernized. The database includes a total of 22,098 forest units, including 9,245 forest units with some proportion of pine in their stands. The aboveground phytomass stocks of pine stands by the following fractions: tree stems, crowns and needles were calculated for all these forest stands on the basis of multifactor mathematical models. The tree stem models used the quality of growing conditions (mean height at 100 years), age and stock of tree stands as independent variables; and the crown tree models use the first two factors and mean area of tree feeding (density of tree). It was established that the total stock of aboveground phytomass of pine stands in absolutely dry condition on the territory of the municipal formation ‘Yekaterinburg city’ is 4,426.1 thousand tons. The pine stand phytomass per hectare in municipal urban forests averaged 114.7 t/ha, compared to 117.2 t/ha in regional subordinated forests and 123.4 t/ha in federal subordinated forests. These insignificant differences are explained by the peculiarities of the taxation structure of stands in urban forests under different subordinations. It is revealed that the total amount of carbon deposited in the aboveground phytomass of pine stands in the municipality is 2,114.2 thousand tons. 1,739.5 thousand tons of carbon (82.3% of the total) were accumulated in tree stems and 374.7 thousand tones (17.7%) in crowns. The mean carbon stock in aboveground phytomass of pine elements of stands per hectare is 57.9 t/ha. The minimum value of this indicator (54.8 t/ha) is typical for urban forests of regional subordination, and the maximum (58.9 t/ha) is for urban forests of federal subordination.

The reactions of Scots pine (Pinus sylvestris L.) to environmental changes after external disturbances (logging, fires, aerotechnogenic pollution) in the Kola North were studied. It was found that century-old pine trees-seed sources at a young age reacted quite clearly to a decrease in competition after external influences by increasing radial growth of wood (RP). Then there was a noticeable decrease in the intensity of RP, which is primarily due to the aggravation of competitive relationships in the emerging young community. The next period of growth and development of Scots pine, lasting more than 170 years, was characterized by the relative stability of the phytocenotic environment, which predetermined the stability of the RP. Then there was an external violation of the established community for years as a result of cutting down the stand. The remaining for felling seeds pines aged 250–270 years reacted quite actively by increasing the intensity of RP by 1.5– 2 times compared to the previous, long-term growth period. The established intensity of RP has not changed significantly for almost 50 years. However, in recent years overgrown pines have reacted to increased competition from the intensively developing young community of Scots pine by reducing RP. During the relative stabilization, periods of depression and RP expression associated with changes in weather conditions were observed in communities. In the surveyed forest communities exposed to industrial atmospheric pollution with sulfur dioxide in combination with heavy metals (Ni, Cu, Co, etc.), most of the century-old pines in the zone of intense pollution withered in 60-70s in the last century. In areas where average levels of industrial pollution were recorded, individual century-old pines in a depressed state are found among the young of Scots pine. Many of them dried up in the 90s of the last century, unable to withstand such a pronounced change in the environment. In conclusion, it should be emphasized that century-old pines (Pinus sylvestris) in conditions of Kola North they react quite vividly to environmental changes by increasing or decreasing the intensity of the RP of wood.

The article provides theoretical and practical data on the creation, composition and some parameters of productivity and reproduction of a bioresource collection of fast-growing woody plants using the example of the genus Betula L. The height growth of 10-year-old trees grown from seeds of open pollination of silver birch (13 families), downy b. (16 families), silver birch «Dalecarlica» (3 families), B. ermanii (1 family), B. lenta (3 families) was studied. Quantitative signs of the vegetative sphere of trees – height growth and generative – seed germination in different breeding categories of birch trees were revealed. The maximum value (7 m) for this indicator was observed in families C-3, C-4, C-31 and C-51 (highly selfsterile). In B. pubescens, the highest value of 7.1 m was found in the highly self-sterile form B-18. It has been established that for self-sterile forms of both local birch species, a promising breeding direction is the production of seeds and reproduction with a natural method of reproduction. Among those introduced to the Voronezh Region, the Dalecarlian birch is the most promising, in which even the average family height values exceeded the same indicator for local species, and individual trees of all three families were leaders in this respect among all studied species. Other birch species introduced to the Voronezh Region, B. ermanii and B. lenta, showed low values for this feature and are unpromising for the purposes of introduction in the Voronezh region. The germination of seeds of local birch species obtained by different pollination methods has been determined. A tendency to asymmetry in the distribution of germination scores during self-pollination (minimum values) and open pollination (maximum values) in a diploid species (silver birch) and relative symmetry in a tetraploid (polyploid) species (downy birch) was revealed.

The types of energies possessed by an elementary individual particle (EIР) in a volume of liquid under pressure are analyzed. It has been established that in addition to internal, kinetic and potential energy (in the field of gravitational forces), EIР has another additional type of energy. Moreover, the deeper the EIР is located in a resting liquid, that is, the greater the hydrostatic pressure, which is equal to the absolute pressure p of this EIР, the more work can be done when it rises, which means the more energy the EIР initially possesses. This type of energy possessed by any individual particle inside a liquid, depending on the absolute pressure p, is called baropotential energy. The introduction of the concept of baropotential energy makes it possible to formulate the first law of thermodynamics for open thermodynamic systems correctly and in a convenient form.

Forestry is one of the most important sectors of the Russian economy. But the main and important task of forestry is to manage and conserve forests. This is closely linked to the forest industry. Currently, in the wood harvesting and processing used modular objects (machines), which are design machines that serve as a basis for other techniques. The article considers the design of the mounted equipment and working parts of modern logging machines. Recommendations are given to increase the competitiveness of forest complex enterprises, namely by expanding the range of products produced or by creating new working bodies of logging machines in order to expand their technological capabilities. The development of new modular working units to increase the technological capabilities of logging machines is a priority in the forest industry. This leads to a reduction in the cost of work when extinguishing fires. When working on this topic, the authors used literature-patent search. The search resulted in replacement modular work units, which extend the functional capabilities of logging and forestry machines. The modular replacement work units for logging and forestry machines for forest fire fighting, as well as for fire prevention have been developed and proposed for consideration. The modular work units that are being developed, as well as new technology, make it possible to significantly reduce the workload of workers and save time and money when performing new operations. As a result of the work in preventing and extinguishing ground fires, these replacement modular working bodies expand the technological capabilities of serial logging machines based on harvesters, treelovingand forestry tractors.

Recommendations on the design of technological processes in machine-building industries are often fragmented and require generalization by product type (part, assembly unit, product as a whole) for the most typical conditions of industrial engineering. The use of modern automation systems for engineering calculations (CAD/CAE/CAM) also necessitates the formation of general system requirements, which determined the purpose and objectives of the presented work. The article discusses the methodological issues of forming the route of technological processes for manufacturing parts and assembling products in forestry engineering. The process of technology creation is divided into parts, the tasks of each stage and the most rational ways to solve them are formulated. The principles of forming the structure of the process, the sequence of transitions and technological operations are presented. Recommendations have been formed on the differentiation of the created object both by processing surfaces and the number of assembly units, taking into account the peculiarities of repair and small-scale production. The material is illustrated with examples of the design of processes formed in compliance with these recommendations (manufacturing technology of the saw blade of the gripping and shearing device of the felling machine). The efficiency of creating assembly processes can be significantly increased by the preliminary development of assembly schemes. The issue of improving the quality of work of a process engineer using modern CAD/CAM/CAE systems that ensure effective work with databases and structural elements of the technology tree is considered. The variants of the formation of assembly diagrams illustrated using the program «SOLIDWORKS», the Composer application are presented.

In the article, an algorithm was proposed and tested to find the optimal routes for the location of cable car trails when developing a cutting area with rope skidding installations, taking into account the technical limitations of rope skidding installations, such as the maximum distance between supports and the minimum radius of curvature. The algorithm is based on the construction of a visibility graph and the use of an annealing simulation method to optimize paths taking into account specified constraints. The given practical example showed the efficiency of the algorithm and its ability to find ways in real conditions. In the logging industry, the algorithm can be used to design hauls for any system of forest machines. Assistance to the forest engineer in the design of cutting areas will increase productivity, reduce the number of inconsistencies with the technological map.

The article considers the possibility of using the method of measuring the value of internal stresses in wood during drying process using standard control systems for the parameters of the drying agent. The hypothesis about the possibility of controlling the moisture content of the surface of lumber by sensors of the equilibrium moisture content of wood is put forward. The results of the experiment are presented to identify the speed and accuracy of achieving the values of the equilibrium moisture content of wood by samples.

The features of the formation of composite materials from crushed wood particles with minimal application of synthetic oligomeric compounds (glue) in relation to chipboard (chipboard) are considered. The process of forming adhesive compounds from wood particles was studied, in which, during tarring, glue droplets are applied with an incomplete coating of the particle surface. The degree of tarring was determined. Various types of adhesive joints were analyzed, dividing them into normal ones when the glue is on the microparticles of both surfaces to be glued, and weakened joints when the glue is only on one of them, as well as defects in the structure of the material that occur when microparticles contact without glue. Variants of the formation of types of adhesive joints when applying contacting particles were evaluated and it was found that Hc is only about 15%, and weakened ones – almost 50% of the total area of the contacted particles. The study showed that the tear strength of normal adhesive joints is 1,3…1,7 times higher than weakened ones, and that applying an excess of glue can increase the strength of weakened joints. The process of the behavior of a drop of glue on a substrate as a result of wetting of the substrate and absorption into the wood structure was studied. It is suggested to improve the quality by such techniques as heating the applied glue, modifying the nozzle design, reducing the interval between tarring and hot pressing operations.

Currently, the possibility of expanding the areas of application of cellulose is being actively investigated. Special attention is beginning to be paid to the products of cellulose destruction – powdered cellulose materials. The most common powdered cellulose materials are micro- and nanocelluloses. They have a number of unique characteristics that differ from cellulose, which leads to their use in such industries as construction, cosmetics, and pharmaceuticals. Powdered cellulose materials are considered as a material for flexible screens and 3D modeling. Along with this, there is growing interest in highly porous cellulose-based materials, in particular the production of aerogels from cellulose, recycled materials (waste paper) and cellulose destruction products (for example, microcrystalline cellulose). Cellulose aerogels belong to bioaerogels (the third class of aerogels) and represent a new category of sustainable and environmentally friendly materials. As part of this study, the possibility of obtaining aerogels from various cellulose materials was assessed. The structural and morphological characteristics and specific surface area of samples of powdered cellulose obtained by dry grinding in a planetary type ball mill with different durations were investigated. An aerogel was prepared and analyzed from samples of bleached softwood powdered cellulose. It is noted that such treatment does not allow developing the cellulose surface and obtaining an aerogel with the required characteristics. In order to improve the surface development of cellulose samples, they were subjected to sulfuric acid hydrolysis to release nanocellulose. The resulting nanocellulose samples were used to prepare aerogels. It was noted that nanocellulose-based aerogels have the necessary specific surface area and pore volume required for such materials.

Currently, the production of low molecular weight polymers (oligomers) has been mastered on an industrial scale, which have found their application in the production of paints and varnishes, as well as in composite compositions for various purposes. New compositions based on petrochemical waste and polystyrene have been developed and investigated for modifying wood-fiber boards in order to increase their hydrophobic properties and strength indicators. To modify the fiber-wood slabs, an oligomer-based composition prepared from polybutadiene by-products (50% styrene bound content, aluminosilicate catalyst, 160 °C, 24 h) in combination with secondary polystyrene was used. The molecular weight of the prepared oligomeric composition varied from 4000 to 7000, with an increase in the content of secondary polystyrene in the composite from 10 to 40%. The introduction of the oligomeric product into wood slabs was carried out in the form of a toluene solution with the addition of naphthenic siccative. Solvent was removed from impregnated samples of wood-fiber boards and high-temperature treatment of modified boards was carried out at a temperature of 160-165 °C. During high-temperature processing, additional distillation of solvent residues and other low-molecular fractions took place. This ensured the environmental friendliness of the modified plates obtained, and the presence of a siccative ensured the flow of the oligomer structuring processes with the formation of a wood-polymer frame. The oxidative processes occurring in this case provided an increase in the bond between wood fibers and oligomer molecules due to the intermolecular interaction between the polar groups of the woody substance and the modifier. This makes it possible to provide modified plates with increased physical and mechanical properties and significantly reduce their water absorption and swelling.

The aim of the study is to influence the concentration and nature of synthetic butadiene‒nitrile latexes on the physical and mechanical properties of a paper-like material based on mineral fibers. The methodology of the work consisted in the manufacture and testing of laboratory samples of asbestos cardboard castings obtained from the composition of the composition, wt. h.: 100 ‒ asbestos fiber grade M-4-20; 5‒60 ‒ butadiene-nitrile latexes BSNK, BN-30, SKN-40-1GP, SKN-40IH, BN-30K-2, BN-26NGP; for sizing M-4-20 grade asbestos fiber; 3‒6 ‒ aluminum sulfate as a coagulant. The mechanical and hydrophobic properties of the resulting material characterize the physico-mechanical parameters: breaking length (L, m); tear resistance (E, mN); penetration resistance (Po, kPa); absorbency with unilateral wetting (G, g/m²); capillary absorbency (B, mm); degree of sizing (C, s/mm). Results of the work: the strength properties of castings with butadiene-nitrile latexes, with the exception of BN-26NGP, are close to each other: L_max = 377‒516 m, at low concentrations (3 wt.h.) of coagulant. At a higher concentration (6 wt.h.) of aluminum sulfate, the strength is higher in samples with SCN-40-1GP (L_max = 427 m) and BN- 30K-2 (L_max = 559 m), which is explained by the presence of a third comonomer, methacrylic acid. For carboxyl-butadiene-nitrile latexes, carboxyl-containing monomer, which is more evenly part of the copolymer than butadiene or styrenebutadiene, increases the adhesion of the polymer to various substrates and creates a three-dimensional grid, in particular SKN-40-1GP. The latter property is realized by the formation of salt bonds when polyvalent metal oxides and polyamines are introduced into latex, as well as the participation of the polymer in a three-dimensional grid. Conclusions: the studied nitrile latexes can be used to produce asbestos cardboard with high strength and hydrophobic properties, according to which the best indicators were established for BN-30 and BSNК.