Vol 29, No 4 (2025)

The article presents results of studying the survival ability and growth of Scots pine (Pinus sylvestris L.) open communities created with planting material with root-balled and bare-root tree systems. The study establishes that, in conditions of the dry forest on gentle slopes, the survival rate of forest plantations created by various planting materials does not differ statistically. The study shows that in the conditions of the trial plot forest plantations are repeatedly supplemented. This leads to a postponement of the assignment of open forest plantations to the plots on which forests are located. It is recommended to increase the density of forest crop planting to 5–6 thousand pcs/ha, since the density of planting from 2,0 to 4,4 thousand pcs/ha does not allow the density of the Scots pine to exceed 2,5 thousand pcs/ha six years after planting. The growth progress graphs of artificial and natural trees growing in the trial plots were drawn. It is indicated that up to the age of eight years artificial forest plantations lag behind the trees of natural origin considering their height, but at older ages they are ahead of them in this indicator. It was revealed that there is no natural seeding of pine in seven of the eleven plots of open forest plantations; its number does not exceed 45 pcs/ha in three plots, and only in the plot adjacent to the forest edge, the number of self-seeding is 1,5 thousand pcs/ha. The average crown diameters and basic wood increment of pine trees of various origins have been determined. It is recommended not to use containerized root-balled seedlings in the Altai Region steppe zone in favor of bare root seedlings. 

The paper presents taxation indices of candidates for plus plantation and plus trees of Mongolian oak (Quercus mongolica Fish. ex Ledeb.) selected in the territory of the Verkhneussurian forest station of the Federal Research Centre for Biodiversity of the Far Eastern Branch of the Russian Academy of Sciences (Chuguevsky District, Primorsky Krai). The Mongolian oak trees were selected in accordance with the characteristics of the plus tree (according to age, straightness of stem, trunk purity and growth rate). An analysis of the size and shape of acorns was carried out, which allowed us to establish that they belong to the northern ecotype and have oval and rounded shapes. A low degree of variability in the morphometric characteristics of acorns has been established (coefficient of variation is up to 15 %). A comprehensive assessment of the seed progeny of candidates for plus trees at the initial stages of ontogenesis (oneand two-year-old plants) was carried out. A high level of variability in the height of annual seedlings and biennial plants in individual families and between individual trees has been determined (coefficient of variation up to 50 %). The highest level of variability in the height of two-year-old seedlings within families was observed in the offspring of trees no. 2, 001, 003. It was revealed that two-year-old seedlings actively formed lateral shoots and photosynthetic organs. There is a great variability in the number and length of shoots both in families and in the offspring of individual trees (the coefficient of variation is more than 50 %). The Mongolian oak plantation studied in the coniferous-broadleaved forest represents a unique genetically isolated population of seed origin. The selected trees are recommended to be regarded as plus trees.

The research data on the introduction of Siberian cedar in the conditions in the Voronezh forest-steppe region are presented. The complete correspondence of the life processes to the conditions of introduction has been determined, namely forest plantation density, orientation to the cardinal directions and soil fertility. It has been established that among individual trees of the same age state in cultures, the age state reveals their biological role but not the absolute age, which reflects the phenomenon of the bark state. According to the values of the complex evaluation index (CPC), among the groups of the phenomenon in the bark, the highest was found in smooth-barked trees (9,37 cm/cm2), which is due to their lag in development over time and is confirmed by underestimated indicators of all taxation indicators values. It was found that when determining the prospects for the development of a plantation, among the candidates for development, the most numerous was a group of trees with a platy bark (60,5 %), and the smallest was a group of trees with smooth bark (6,9 %). In general, 31,6 % of all observed trees can be attributed to candidates for development. According to the indicators that distinguish the group of candidate trees for development: trunk diameter (D_1,3), crown diameter (D_cr) with the corresponding crown projection area (S_к), growth (S_р) and trunk volume (V), the excess over the rest of the trees was: 34,7; 20; 42,1; 113,6 and 62,1 %, respectively. Attention is drawn to the fact that when recalculating the indicators for one tree, there is practically no individuals with male flowering among smooth-barked trees. It is recommended that in the future, when selecting trees individually, a complex evaluation index should be applied and the bark condition of the tree should be considered during selection care, where individuals for removal are selected from the smooth-barked group of trees.

The effect of soil drying and the humidity to which soil samples were moistened, as well as the mechanical effect of pastes on their viscosity, was studied. The purpose of the study was to explain the observed phenomena from the standpoint of physical and gel models of soils. The studies were carried out on samples taken from humus-accumulative horizons of chernozem, sod-podzolic and gray forest soils. The viscosity of the soil pastes was determined by using a vibrating viscometer, and a laser diffractometer was used to study the size of the soil particles in the pastes. It has been established that with an increase in the magnitude of mechanical effects on soil pastes, upon reaching its limit for each soil, an increase in the viscosity of soil pastes occurs, called rheopexy in colloidal chemistry. It has been shown that rheopexy is characterized by an increase in the particle size in soil pastes. It was found that the moisture content of the soil sample before the preparation of the paste affects the viscosity of pastes in a complex way: for the studied soil samples, two maximum viscosities of pastes are observed. One of them is close to the soil hydrological moisture constant of capillary rupture, and the second is close to the lowest moisture capacity.

The paper describes a methodology for obtaining heat-resistant organosoluble and hot-melt copolyimides for subsequent use as reinforcing binders in the technology of obtaining composite materials based on cellulosecontaining components of wood origin. It is shown that 3,6-diaminoacridine; 9,9-bis-(p-aminophenyl) fluorene, 2,2-bis-(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride and 3,3’,4,4’-tetracarboxydiphenyl oxide dianhydride can be used as raw materials for obtaining copolyimides in composite materials. An optimal method for synthesizing copolyimides of various compositions with a molecular weight of 20…180 kDa is presented. It is shown that in order to obtain wood-polymer composites with satisfactory properties, it is advisable to add wood dust with particles of an average diameter of 0,5...1,1 mm to the matrix of the obtained copolyimides, followed by obtaining the target product in the form of films that can be formed by casting from a solution. The solubility of the obtained polymeric materials in tetrahydrofuran, cyclohexanone, chloroform, dichloroethane, tetrachloroethane, dimethylformamide, dimethylacetamide, dimethylsulfoxide, toluene, nitromethane and acetonitrile was determined. Physicomechanical tests showed that the magnitude of the tensile stress at break of the obtained films was in the range from 140 MPa for a film 0,2 mm thick to 210 MPa for a film 0,5 mm thick, and the relative elongation at break was 5...36 %. Thermomechanical tests showed a sufficiently high heat resistance of the obtained copolyimides and composites based on them. It was established that the working temperature range of the obtained products was maintained without any damage to the shape and internal structure of the material up to a temperature of 300…320 °C. The synthesized copolymers and composites based on them can be used as heat-resistant materials.

The analysis of the current state of the process of extracting essential oil from pine showed the relevance of introducing periodic extraction technology using steam distillation at small enterprises of the forest industry complex, which allows effectively extracting the maximum number of valuable components. According to existing data, today the demand for essential oils in the pharmaceutical, cosmetic, food and agricultural markets has increased. The annual use of these biologically active substances from coniferous trees is growing at an average annual growth rate of 9,6 %. This also explains the high price of some substances. Thus, the price of 1 kg of essential oil is $ 113. The article presents a physical description of the process of extracting essential oils from non-woody parts (needles and bark) of pine. The equipment for extracting essential oil from pine needles and bark is provided. The methodology for conducting experimental studies and the process of extracting biologically active substances is presented. It was found that the maximum amount of essential oil was extracted at a steam temperature of 120 °C, duration of 150 minutes, and steam consumption to reach the operating temperature of 650 kg∙m³/h. The following dependencies were obtained: the yield of essential oil from pine needles and bark at different temperatures, changes in the density of essential oil during extraction, oil yield from the reduced steam consumption; the rate of essential oil extraction at different temperatures and the time it took for the extraction process to reach the operating temperature were determined. The maximum extraction of essential oils from needles was 0,9 %, and from bark — 2,5 %. The proposed method showed that the degree of essential oil extraction from needles is 82 %, and from bark 86 %.

The article is a comprehensive study on the control of soil compaction parameters during the construction of truck haul roads. The focus is on the interaction between the pneus and the compacted soil layer, which leads to deformations of both objects. The degree of these deformations depends on the physical and mechanical properties of the interacting bodies. Two schemes of deformation of pneus, which form the basis of sealing control, are considered in detail and analyzed. The analysis of the soil compaction process with pneus at both constant and variable tire air pressure, as well as how the deformation of the tire and the soil layer change with each passing tire. As a result, the logarithmic nature of the dependence of the deformation of the compacted layer and the bulk weight of the soil framework on the number of pneumatic passages was proved. The analysis showed that analytical dependencies were obtained characterizing the process of interaction between two contacting bodies, which can be used to control soil compaction. A method for measuring radial deformation of a pneumatic tire with additional determination of mechanical characteristics by accelerated methods is proposed. The proposed method opens the way to automation of soil compaction control and significantly improves the quality of excavation work. Thus, the results of the study can contribute to improving control methods and increasing the efficiency of construction processes related to soil compaction in forest road projects.

The complex of sanitary and health-improving measures in the forest is considered, which includes harvesting of waste wood with simultaneous quantitative and qualitative assessment of characteristics of waste wood in the whole forest area with a given accuracy in real time in the process of harvesting. The variant of waste wood harvesting with wood processing for wood chips in the forest is considered. The main machines carrying out harvesting on technological strips are specified, in particular mobile winch and chipper. With the use of natural data, mathematical model studies of estimation of the volume and quality of waste wood by simulation modelling methods based on the method of linear intersections have been carried out. It was found that at the volume of waste wood from 5 to 50 m³/ha the required total length of technological strips for the accuracy indicator P = 20 % is in the range from 500 to 6000 metres. It was determined that the errors between the true values of the waste wood volume and its estimates did not exceed 11,3 % in absolute value. It was found that the time to record and estimate the volume of waste wood decreases with increasing volume of waste wood in the plot. It was found that the main factors are the length of technological strips and the volume of waste wood on the plot. It was shown that the productivity of waste wood volume counting, and estimation increases as the volume of waste wood on the plot increases.