The paper considers a number of dependencies between morphometric indices of young pine trees formed on the lands, withdrawn from agricultural use. The work is based on materials of 16 sample areas, laid in accordance with the requirements of OST 56-69-83 ‘Forest inventory sample plots. Methods of laying’.

The aim of the work was to assess the dynamics of the objects on the basis of the method of relative growth, as well as growth as a function of age. Interrelationships between tree diameters and heights, the course of growth of treesby diameter and height, the degree of interdependence of average increments of indicators and their dynamics has been considered.

Literature data on the issue of constancy of ‘relative growth’ were analysed. We analysed allometric relationship between diameters and heights of young pine trees of different age and size. The peculiarities of the growth course of young pine trees formed on the lands withdrawn from agricultural use in terms of height and diameter at the height of 1.3 m and the root neck.

To understand the nature of changes in the degree of intercorrelation between individual characteristics of young pine trees, we calculated the values of average growths by trunk diameters, heights and crown diameters. It turned out that these indices are in a fairly close relationship, as evidenced by the values of paired correlation coefficients. The correlation coefficients between the average growth of trunk diameter and average growth in height, vary from 0.66 to 0.92 and the average is 0.82; the average between average growth of trunk diameter and crown diameter is 0.85 (they vary from 0.64 to 0.95); the average growth of height and crown diameter is 0.68 (they vary from 0.39 to 0.90). The last series of correlation coefficients has the highest variability of 23.0 %.

It turned out that with increasing age the degree of correlation between average growths decreases.

The morphometric parameters of 1-year-old needles of clones of plus-sized pine trees on the seed orchard in the Kovrovsky district forestry of Vladimir Oblast were studied. It was established in 2020 on a site that is a part of the coniferous-broadleaf forests zone and is classified as the coniferous-broadleaf (mixed) forests area of the European part of the Russian Federation. The purpose of the work is to evaluate the hereditary conditionality of the morphometric parameters of the needles of the plus-sised pine trees introduced into the specified forest–seed plantation of vegetative origin. The primary forestry information was obtained during the implementation of the stationary field method. In the experiment, each orthosis is presented in 3-fold repetition. Harvesting of 1-year-old and 2-year-old needles was carried out separately in the periphery of the middle belt of a well-lit area of the crown. The organizational scheme provided for the selection of accounting shoots from growing trees, from which 50 brachiblasts with a paired bundle of needles were separated. The number of registered samples was 15,000 pieces. The length was measured with a ruler with an accuracy of 1 mm, the diameter with a caliper with a division price of 0.1 mm. Statistical and variance analysis is performed according to traditional schemes. The average values of 1-year–old needles were determined: length varied from 3.63±0.023 cm to 9.91± 0.029 cm (a difference of 6.28 cm or 2.73 times); width varied from 1.12±0.016 mm to 2.15±0.006 mm (a difference of 1.03 mm or 1.93 times). The variability of the indicators was recorded, corresponding to an increased level in length (Cv = 27.89 %) within the boundaries of the site, and anaverage level in width (Cv = 18.79 %). It was noted that there are significant differences between the vegetative offspring of positive trees in the composition of a forest-seed plantation in terms of the morphology of the needles. A high degree of hereditary dependence of the phenotypic variability of its parameters was found: in length h2 ± mh 2 = 85.84±0.05 %; in width h2 ± mh 2 = 48.30±0.17 %.

The crown of a tree is important in studying the physiology of the forest canopy and modeling its dynamics, and the dependence of the radial growth of the stem on the morphometry of the crowns has been established. However, the relationship between the structural characteristics of the crown and the growth rings is poorly understood due to the high complexity of analyzing the crown structure using classical approaches. Terrestrial lidar scanning offers anew perspective for quantifying crown structure in 3D format, which can significantly contribute to understanding plant adaptations to the environment and their structural and functional responses. The purpose of this work was to develop predictive models of radial stem growth in relation to crown morphometry available for terrestrial lidar scanning. The research was carried out in the Aman-Karagaj forest in the conditions of the dry steppe of the Turgaj Depression, where 37 sample plots were established in pure Pinus sylvestris L. forests, on which 300 model trees were taken, including 190 in plantations and 110 in natural forests. The optimization of the model structure is performed according to the condition of multicollinearity of independent variables – crown diameter, crown length and crown ratio. It was found that with the same crown morphological structure, the cross-sectional stem area increment in natural stands is 38–46 % lower in relation to plantations, and the radial growth is 17–34 % lower, respectively. The models of stem cross-sectional area increment turned out to be more informative compared to the models of annual radial growth (65–73 % vs. 45–58 %), and the ontogenetic legacy of crown morphological structure is expressed to the greatest extent in increments over 10, but not over 5 years, which is confirmed by comparing the coefficients of determination (0.58–0.73 vs. 0.45–0.65).

The phenological observations results of natural origin European larch (Larix decidua Mill.) under the introduction conditions are presented. In the center of the Russian Plain, all larch species are the introducers, so studying their phenology will help determine how well they have adapted to the new conditions in the introduction area. The research was carried out in Nikolskaya lesnaya dacha (Nikolskaya forest estate), located in Moscow region northeastern part at the junction of two forest-growing areas – the spruce-deciduous forests of the Klin-Dmitrov ridge and the pine forests of Meshchera. The research subject was natural origin young (self-seeding and young growth) in B2 conditions in the territory of the near part of the Nikolskaya lesnaya dacha (Nikolskaya forest estate), formed from maternal plantations that have now stand age class VIII. The larch phenological observations program included the study of the main phenological phases (buds swelling, needles budding, needles separation, needles yellowing and needles falling), as well as apical shoots growth biometric measurements during the entire growing season of 2024. The presence ofevergreen needles in natural origin self-seeding European larch was noted. The studied seasonal development full cycle of natural origin young European larch shows that this tree species has acclimatized well to Moscow region north-east conditions, demonstrating a long growing season (194 days) and good growth rates. The data obtained should be used in the forestry care design for natural origin young European larch, which is advisable to perform in the May.

The survival rate and preservation of forest crops of Scots pine (Pinus sylvestris L.), Siberian spruce (Picea obovate Ledeb.), Sukachev larch (Larix sukaczewii Dylis) and Siberian cedar pine (Pinus sibirica Du Tour) in the reclaimed mined-out part of the Isetsky granite quarry located in the Middle Ural taiga forest region were analyzed. It has been experimentally established that the forestry direction is promising in the recultivation of mined-out granite quarries. Despite the low crop-producing power of the mixture of overburden rocks and granite screenings 25–30 cm thick, the created forest crops are characterized by high rates of survival and preservation in the first 2 years after creation. The worst survival rates for spring planting (79.9 %) are observed for forest crops of Siberian spruce created by 4-year-old seedlings. The best survival rates (92.0 %) were recorded when creating forest crops by 2-year-old seedlings of Sukachev larch. Autumn planting of seedlings showed an advantage over spring planting. Thus, the creation of forest crops in the second half of September ensured the survival of seedlings from 95.6 to 100 %. At the same time, significant differences in the seedlings survival with open and closed root systems were not recorded. Considering the importance of recultivation of disturbed lands, the research at the created station is planned to be continued in the direction of establishing the volume of carbon deposition in the components of the formed plantations.

The aim of the work is to study the dynamics of seed production and cone yield of the different species of spruce in the forest cultures of the second age class beginning. The objects of the research were 19-31-year-old cultures of Siberian spruce (Picea obovata Ledeb.) and European spruce (Picea abies (L.) Karst.) in three forest types in the southern taiga forests of the Middle Urals. Twelve years after the cutting of the all natural regeneration trees and thinning of the forest cultures, the greatest trunk growth in both species of spruce was noted in the forest type of spruce mixed grasses with green mosses and the smallest in the forest type of spruce-pine-berry. In all forest types the European spruce crown volume was larger than the Siberian spruce has. After clearing an increase of the fruit-bearing spruce trees proportion of both types was noted from the third year, and the cones yield increased with an increase in the size of the crown upper part.

In the year of the maximum number of fruit-bearing trees, their share with cones yield scores of 4.5.6 (together) in the forest type of spruce mixed grasses with green mosses was 41 % for Siberian spruce, 61 % in the forest type of spruce-pine grass, it was 63 % in the forest type of spruce-pine-berry; for European spruce, 45, 43 and 45 %, respectively.

The cone yield is significantly affected by weather conditions; prolonged drought in the summer months reduces the number of trees with generative organs and the cone yield. One Siberian spruce cone contained 84–223 seeds, whileone European spruce cone contained 116–273 seeds. The share of healthy seeds from them in the first spruce was 46– 62 % of all seeds, and in the second, 39–58 %. The total weight of healthy seeds of both spruce species in 30-year-old crops in 2015 was 4.0–6.5 kg/ha. Forest cultures of Siberian and European spruce have height which corresponds to I and II quality classes. It is possible to organize a permanent forest seed base here for the purpose of harvesting cones (seeds). A specific method of thinning for each forest type is proposed.

This article is devoted to assessing the severity of forest burns. The increasing number and frequency of forest fires necessitates studying average fire intensity indicators. A new relative indicator, termed the “degree of fire resistance”, is proposed. Normalization diagrams for the results of examining an ordered set of estimates P NBR r , characterizing the expected trends of changes P NBR post with increasing PrNBR are also proposed. Taking into account the introduced estimate in the form of an integral functional F and the introduced diagrams, a variational optimization problem for the functional F is constructed. The solution to the optimization problem showed that with a nearly linear decreasing relationship between P NBR post and P NBR r , the maximum value of F can be expected to be reached. A new average-integral indicator of forest fire severity is proposed. The ratio of known indicators PpostNBR and P NBR r is determined, at which the newly introduced indicator reaches its maximum.

Seasonal development of plants is the most important biological indicator of their relationship with the environment and is used to assess the adaptive capabilities of dendrointroducers.

The purpose of these studies is to identify differences in the timing of the onset of phenological phases of non– district trees and shrubs in urban systems when moving northward. The methodology of the work is based on generally accepted methods for detecting seasonal changes in tree species. The plants showed the duration of the growth period, the beginning and end of vegetation, the duration of foliage retention on trees and other phenological phases. The phase of bud swelling was taken as the beginning of the growing season, and the end of leaf fall was taken as the end. The timing of the onset of phenophases was compared for the Arkhangelsk and Vologda regions. The objects of research were non-district tree species of urban plantations. The research was conducted in 2002–2025. As a result, data on the rate of advance of each phenological phase when moving one degree north latitude were obtained.

The rate of advance of each phenophase at 1° latitude depends on the amount of heat required by the plant during this growing season. The greatest differences in the phenorhythms of dendrointroducers of the Arkhangelsk and Vologda agglomeration are manifested in the “beginning of flowering” phase – 3.5 days at 1° latitude, the smallest – in the “end of leaf fall” phase – 0.3 days at 1° latitude in the north direction.

These studies are part of the theoretical basis for introducing introductions to the North.

The object of the study is the technology of growing seedlings with a closed root system (CRS) and the analysis of the technological process of sowing seeds in cassettes in greenhouses of the Krasnoyarsk forestry with manual and automatic mulching of cassettes when sowing seeds for growing seedlings with a closed root system. The purpose of the research is to compare the technology of automatic and manual mulching, to determine the efficiency and reliability of the experimental sample of the precision seeding equipment complex for growing seedlings with a closed root system in comparison with manual sowing, and to identify possible improvements in the design and operation of the equipment. The main objectives included: determining the mechanical efficiency; developing corrective measures; drawing up a process map of the equipment operation.

Tests of the experimental sample were carried out in various operating modes. The tests included the evaluation of the following parameters: productivity was measured by the number of cassettes in which holes were formed per unit of time; the depth and location of the hole were estimated visually and using measuring instruments; the number and time of stops were recorded indicating the reasons; mechanical efficiency was determined by the stability of operation.

The article presents a study of vortex contact steps with axial and tangential swirlers of a distillation column used in technological lines of chemical processing of wood biomass. Mathematical processing of experimental data on the hydraulic resistance of the contact steps was carried out, with the obtaining of dependencies for determining the coefficient of hydraulic resistance of the contact steps.

Knowledge of the magnitude of hydraulic losses in the apparatus is also necessary when calculating the technological strapping schemes of the apparatus. Currently, there are numerous data in the domestic and foreign literature on the study of the laws governing changes in the hydraulic resistance of vortex apparatuses from operating and design parameters, with various types of vortices.

The results of experimental studies of the hydraulic resistance of vortex apparatuses with tangential vortices show that the hydraulic patterns in these apparatuses are similar to those in the apparatus with axial vortices.

Rectification is widely used in the following industries: in the technologies of complex wood processing; in the timber chemical industry in the production of consumer products; in the recovery of extraction solutions in the extraction of biologically active substances from plant raw materials; in the technology of chemical processing of wood in the production of ethanol; when processing increasing natural waste by gasification and using synthesis gas to produce a biopolymer at the stage of solvent regeneration (methylene chloride, sodium hypochlorite, hexane, etc.), where highly efficient and productive distillation columns are also in demand. For the most part, multicomponent mixtures are subject to rectification, as a rule, azeotropic, having a similar boiling point, which explains the use of multi-stage distillation columns for their separation. At the same time, various methods of rectification are used, such as azeotropic, extractive, molecular, fractional, partial.

The paper presents the results of studies of the physico-mechanical properties of a chipboard without the use of binders for various component ratios. Shavings obtained from plywood production waste (veneer flaps, pencils) with a moisture content of more than 100 % were used as a reinforcing component, and hydroactivated measles based on Pinus Sylvestris pine bark was used as a matrix. The ratio of bark/chip components by absolutely dry substance, wt. %, amounted to: 70/30; 60/40; 50/50; 40/60; 30/70. The introduction of chips in the amount of less than 40 percent of the mass into the composition of the plywood material leads to a decrease in the strength of the chipboard when bending, the introduction of chips in the amount of more than 60 percent into the sheet material leads to a decrease in the tensile strength perpendicular to the surface of the chipboard and an increase in the thickness of the swelling index. Physicomechanical parameters of chipboards with a thickness of 16 mm with a 50/50 % weight ratio of components (bark/chips). meeting the requirements of the standard for particle boards used in dry conditions are as follows: density is 750 kg/m3 , bending strength is 18.4 MPa, tensile strength perpendicular to a chipboard`s surface is 0.37 MPa. The produced boards can be used as an alternative to traditional particle boards based on formaldehyde resins in housing construction, building and furniture production.

The paper presents an analysis of the hydrodynamic effects during the flow of fibrous suspensions on the process of grinding fibrous vegetable semi-finished products using knife grinding machines.

In the working gap between the rotor and stator blades, the grinding process can be likened to the process of oiling rubbing metal surfaces. The flow of a fibrous suspension in the cells of the rotor and stator of the headset can be compared as the flow of a Newtonian fluid over the rough surface of a knife headset.