Forest biomass data provide an important contribution to the implementation of sustainable forest management, maintaining a positive carbon balance in the earth's atmosphere, as well as the supply of materials and renewable energy. When modeling data on forest biomass, the Biomass Conversion and Expansion Factor (BCEF) has become widespread as the ratio of dry biomass of its some fraction to the volume stock. The relevance of the BCEF application is determined, on the one hand, by the complexity of obtaining actual data on the stand biomass on sample plots, and, on the other hand, by the presence of huge arrays of data on volume stocks accumulated by traditional forest mensuration. The BCEF provides the interface of traditional tables and banks of forest inventory information on volume stocks with data on the stand biomass. There is no consensus on the patterns of changes in the BCEF in the geographical gradients of Eurasia. The purpose of our research was to develop models of BCEF of biomass of spruce stands (genus Picea L.) in geographical gradients of Eurasia using the author's database of 942 sample plots. As a result, models of BCEF of aboveground and underground biomass of spruce stands are proposed, designed to assess the stand biomass by the values of stand age and volume stock. Unlike previously published models, the proposed models are species-specific and differentiated by geographical coordinates of latitude and longitude. It was found that the BCEF of the aboveground and underground biomass fractions increases in the directions from south to north and from west to east. The age of the stands and their geographical location provide approximately equal contributions to the explanation of the variability of the BCEF of biomass. At the same time, the contribution of latitude is about three times greater than the contribution of longitude. The proposed BCEF models can be used to calculate the carbon pool in spruce stands according to forest inventory data. 

In recent decades, significant areas of abandoned agricultural land have appeared in the Russian Federation. On these lands stands of forests are being or have already been formed. According to various sources, they account for from 45 to 97 million ha. 

The purpose of this work was to determine the peculiarities of the diameter structure of pine stands formed on lands abandoned from agricultural use in Central Siberia.

The work is based on the materials of 18 sample plots, which were laid in compliance with the requirements of OST 56-69–83 ‘Sample forest inventory plots. Laying methods’. The average age of stands of sample plots lies within the range of 12–90 years. The density of stands ranged from 160 to 15 733 trees/ha. Apart from pine, the stands include birch, larch, spruce and fir. A total of 4 747 pine trees were measured.

The density of stands was taken as the main stratification feature along with the age group. As a result of data processing, we obtained series of distribution of number of trunks by diameter for different age and density groups.

The biodiversity and biological features of cultivated microscopic fungi living in peat mounds of the tundra woodlands of Western Taimyr are studied. The species composition and vertical distribution of the dominant psychrophilic species at different depths (0.1; 1; 2; 4 m) were determined; identical species were identified at different depths. The isolates were identified based on a combination of morphological, cultural, and molecular genetic features. The growth parameters of the dominant species in the range of 12–16 ºC and the activity of their redox and hydrolytic enzymes were studied. A collection of fast-growing psychrophilic strains with a radial growth rate from 5 to 24 mm/day at 12 ºC has been formed, which is of practical interest for screening producers of enzyme preparations effective at low temperatures.

The viability and fertility of pollen play a key role in the development of the plant organism. Pollen represents a critical stage in the plant life cycle, as the viability of pollen is crucial for the effective sexual reproduction of plants. Pollen quality is assessed based on its viability. In this study, the pollen of Siberian dwarf pine (Pinus pumila) collected from shrubs growing in the Far North was studied. In order to carry out breeding work to obtain new promising varieties, it is often necessary to preserve viable pollen. For these purposes, a study was conducted to determine the most optimal shelf life of viable pollen for further use. It has been found that Siberian dwarf pine pollen can maintain its viability for a long time with a slight loss of germination ability. Anomalies in the development of pollen grains were also revealed, which indicates the ecological situation of the places where the object of research grows.  

The research was carried out in pine plantations on Yagry Island in the Dvinsky Bay of the White Sea on the territory of the protected area “Sosnovy Bor of Yagry Island”. For the study, trial areas were laid out in typical pine forests for the island: blueberry, lingonberry and shrub-sphagnum. It has been established that in all types of forests, the predominant crown shapes are cone-shaped, ovate and spherical, and in shrubby-sphagnum pine forests and in blueberry and lingonberry pine forests, the cone-shaped crown prevails, accounting for 48 and 38 % of trees, respectively. Another important one is the ovoid shape in both cases, and the third one is spherical. The number of trees is decreasing by about 10 %. It is shown that the shape of acrons depends on age. As the age increases, the crown shape changes from cone-shaped to ovoid and then to spherical. Data on the relative height in different types of forest are presented. Their average value ranges from 48 to 70 cm/cm in different types of forests, and the weighted average value ranges from 47 to 64 cm/cm, while in pine forests on the mainland it is 116 cm/cm. The inverse dependence of the relative height on the diameter of the trees has been revealed, the correlation coefficients for different sample areas range from –0.76 to –0.86. It has been established that pine forests of different types are characterized as diverse in age. In the pine forests of the green moss group of forest types, trees from 20 to 160 years old are found, and in the shrubby sphagnum pine forests from 20 to 100 years old. 

The fat content in annual shoots of common ash was assessed. The objects of the study were trees located on the territory of the nature monument of regional importance Raspberry Ridge in the Nizhny Novgorod region. They are allocated according to the principle of typicality, their total number is 12. The test site had coordinates: 56°24'07"N 43°95'44" E. The work took into account the principle of the only logical difference and the key requirements: suitability, typicality and expediency of the experience. The study was conducted using field, stationary and laboratory methods. From each reference tree, 20 normally developed, intact annual shoots were selected in the periphery of a well-lit area of the middle tier of the crown. The primary sampling unit is represented by a one-time measurement of each of the tested parameters of all repetitions of the experiment. In our case, for each of the 12 tested trees, for each of the 8 tissues analyzed in them, accounting zones and their total index, 20 score fixes were performed. Accordingly, the volume of the database covered by the analysis amounted to 1920 data units. Cross sections were obtained from the central part of each shoot and examined using a Micmed-2 microscope using color histochemistry methods. The drug Sudan-III was used to detect fats. Their concentration in the tissues of the shoots was measured in conditional points on a scale that we developed. The variability of the fat content in the tissues of its shoots has been established. The amount of accumulated reserve nutrients in different tissues is not the same and has a significant variation in values between the accounting trees. The differences are most pronounced in the total fat content in the shoot tissues. The highest content was found in tree  No. 10 – 20.00± 0.68 points, and the lowest in tree No. 5 – 10.70± 0.63 points.

The competition of birch stands in low-mountain forests of the eastern macroslope of the Middle Urals in relation to the undergrowth of Siberian stone pine (Pinus sibirica Du Tour) is considered based on the microecosystem approach. The work was carried out using indices of light (Ilsc), root (Irsc) and integral competition of the stand (Irlsc) in post-fire berry-green moss birch forests of 13, 32 and 70 years of age, which are elements of one genetic  series of development of a potential Siberian stone pine forest. In a 13-year-old young birch forest with almost complete solar radiation and a weak relationship (R² = 0.23) with Ilsc, the main factor determining the growth and development of the Siberian stone pine undergrowth is the competition of the stand for soil nutrition, expressed by a relatively close (R² = 0.66) negative relationship of the average vertical growth of the undergrowth with Irsc. In a 32-year-old middleaged birch forest, a joint, almost identical, influence of the factors of light (R² = 0.62) and root (R² = 0.52) competition on the growth of the Siberian stone pine undergrowth is observed. In a mature 70-year-old birch forest, the main factor influencing the growth of Siberian stone pine undergrowth is light competition, expressed by a close (R² = 0.77) relationship with Ilsc, and no relationship was found with root competition. Such changes are probably related to the adaptive capacity and soil nutrition of the Siberian stone pine undergrowth characteristics and to changes in the degree  of saturation of the upper soil horizon with organic compounds formed during the decomposition of forest litter during the development of a post-fire birch forest.

The identification of yield dynamics of Siberian cedar pine in the conditions of introduction is useful for assessing the prospects of its introduction into local conditions and identifying high-yielding individuals. The paper presents the results of a study of the dynamics of seed bearing of Siberian cedar pine by year, as well as the individual variability of this indicator and correlative signs that allow the selection of high-yielding individuals. The research was carried out in the Chagrin cedar grove of the Vologda Oblast. In this plantation, the harvest of cones and seeds formed over a period of 11 years was recorded. In the absence of individual years without crop formation, which indicates the favorable climatic conditions of the area of introduction, the uneven formation of cones and seeds by the years of crop generation was revealed. The selection of model trees made it possible to identify instances of seed-bearing trees distinguished by a sufficiently high yield of cones and seeds. The average number of cones formed by maternal producers is most affected by the factor of individual variability. The year of crop generation also has an impact on the formation of cones in the crowns of trees, but noticeably lower. The effect of individual variability on the mass of the resulting seeds is somewhat less pronounced. Individual parameters of crown habitus are associated with reproductive ability. The width of the crown, unlike its length, is not related to yield. The most valuable correlative feature of seed productivity is the crown shape coefficient. The number of cones formed on trees and the weight of seeds depend significantly on the crown coefficient, i. e. on the ratio of its width to its length. When choosing seed trees for the collection of seeds necessary for the creation of high-yielding introduced crops and for the selection of plus trees, it is necessary to use such individuals of the crown shape coefficient, which is less than one.

The article discusses the project of organizing a forest nursery for the purpose of growing coniferous seedlings with a closed root system. Setting such a task in relation to the conditions of forest cultivation in the Khabarovsk Territory is important for involving local communities and organizations in the process of forest protection and restoration. The project of the organization is considered on the example of the forest nursery of IP Menshikov D. V., located at the address: Russian Federation, Khabarovsk Territory, Khabarovsk municipal district, Nekrasovka village, site 2. The plan of activity of the forest nursery by years, breeds, types and volumes of grown planting material is presented.. The needs for various materials for the effective operation of the forest nursery have been determined. Special attention is paid to the technology of growing planting material of cultivated coniferous species – Daurian larch, Korean pine, Ayan spruce.

The article presents the results of the ecological and geographical intraspecific variability of the characteristics and properties of the Scots pine, which is hereditary. The variability of breeding characteristics of populations of Scots pine growing in the ecological and geographical conditions of the forest-steppe zone of the Krasnoyarsk Territory on the territory of the experimental base “Pogorelsky Bor” is considered. 

The research area is located on the territory of the Krasnoyarsk forest-steppe and is an “island” of pine forests of cranberry-green and mixed-grass groups of forest types of II–III classes of bonit. 

The color of the cones showed a low diversity in color with slightly different shades: gray – green (35.5 %), gray (55 %), beige (8.3 %), gray-greenish with tan (1.7 %). According to the color of the seeds, the category of dark–colored seeds is mainly represented (72.5 %): dark brown (3.4 %), dark gray (24.2 %), dark brown (3.4 %), black (41.5 %) shades. The category of light-colored seeds is only 27.5 %. Seed quality indicators depend on morphological and phenological polymorphism. The analysis of the taxation indicators indicates a good linear growth of the Scots pine (the average height was 28.6 m, and the average diameter was 32.4 cm High rates of linear and radial growth indicate better productivity and, accordingly, good growing conditions for stands of Scots pine in the Pogorelsky forest. 

The paper presents the results of studies devoted to the study of the effect of the fine fraction of the crushed measles press mass on the physical and mechanical properties of plates without the use of binders. The crushing of Pinus sylvestris tree bark is carried out by its mechanical activation in a hydrodynamic dispersant, which ensures the production of a finely ground press mass. The analysis of scientific sources indicates that the fine fraction has a high specific surface area, has the ability to embed itself between larger particles of mass and act as a binding component in the composition of plates obtained without the use of binders. The influence of the fine fraction on the properties of the plates was assessed using the WRV water retention index. According to the conducted studies, the water-holding capacity of the measles press mass and the strength properties of the plates largely depend on the presence of fine particles in its composition. The degree of influence of the fine fraction was assessed by repeatedly rinsing the measles press mass with water at a ratio of weight and added water 1:15; 1:30; 1:45. When determining the properties of manufactured plates, it was found that with an increase in the proportion of water during washing, the properties of the plates deteriorate: the tensile strength perpendicular to the formation decreases by 0.59 MPa, the strength under static bending – by 13.2 MPa, the swelling in thickness increases by 18%. Thus, a decrease in the number of fine particles has a negative effect on the basic physical and mechanical properties of the plates. It has been experimentally confirmed that the fine fraction provides a high degree of contact of the crushed particles with each other, contributing to the formation of an integral plate frame.

The widespread use of forest planting machines when performing reforestation work, including for seedlings with a closed root system, is hampered by several factors: imperfect design of the forest planting machine and machine planting technology in general, low quality of work of existing machines, the occurrence of gaps during machine planting, and the cost of manual labor. when planting and straightening incorrectly planted plants. Based on this, the need to improve the technology of machine planting of seedlings with a closed root system is a pressing topic.

The object of study of this scientific work is a forest planting machine for growing seedlings with a closed root system. The subject of the study is the process of the operator inserting seedlings into the forest planting apparatus. The purpose of the work is to substantiate the operating speed of a forest planting machine for seedlings with a closed root system, taking into account the seedlings’ omissions during planting.

In the process of work, a study was carried out of the dependence of the passage of seedlings in the working body of the forest planting machine on the operating speed of the forest planting machine. During the study, the following results were obtained: a mathematical model was developed that describes the dependence of the probability of seedlings missing on the parameters of the planting apparatus, simulation modeling was performed based on the developed mathematical model using applied mathematical programs, the operating speed of the forest planting machine was justified based on the analysis of the results of simulation modeling, the relationship was determined storage capacity from the operating speed of the forest planting machine, a nomogram has been constructed for selecting the operating speed of the forest planting machine. Recommendations are given to reduce the omission  of seedlings with a closed root system during machine planting. 

To assess the quality of the stem wood of growing trees, a Resistograph device is used, the principle of which is to measure the resistance of wood to drilling. The results of the device are influenced by a number of factors, primarily the drilling depth and the degree of bluntness of the cutting edges. The purpose of the study is to assess the systematic measurement error of resistance to drilling of pine and spruce wood with a Resistograph device. The research was carried out in the Arkhangelsk forestry. Drilling was carried out sequentially in turn from the first tree to the next in the north-south direction and then returned to the first tree again, retreating from the previous drilling  up 1 cm. Drilling began at a height of 80 cm from the root neck. In total, 140 resistograms were analyzed for each tree species. The resistograms were smoothed by the standardized assessment method (z-score). The errors were estimated by calculating the differences between the values of the drilling resistance of the corresponding sections of wood or between successive drills for the same drilling interval for each tree. Regression analysis of the drilling resistances of spruce wood allowed us to obtain the following equations for estimating errors: with wear of the cutting edges,  R´ = 0,17х´ – 13,62, where х´ is the total length of drilling, cm; with increasing drilling depth, R´´ = 0,27х´´ + 8,56, where х´´ is the actual drilling depth, cm. According to the analysis of pine wood resistograms errors: when the cutting edges wear out, R´ = 0,15х´ + 23,67; when the drilling depth increases, R´´ = 0,92х´´ + 7,59. Therefore, to estimate the true value of the wood resistance to drilling with the Resistograph device, it is necessary to subtract the errors R´  and R´´ from the obtained value.

In this work, the assessment of the level of chemical pollution of soils as an indicator of the adverse impact on the environment by products of destruction of composite material (plastic) without resins (PWR) based on wood raw materials is carried out. Wood waste in the form of pine and birch sawdust was considered as unclaimed secondary plant raw materials. For the raw materials used, based on chemical analysis, the presence of heavy metals in it was found to be insignificant, the presence of which is due to the influence of external environmental conditions. The results of the assessment of the biodegradability of the studied PWR by marker morphological features showed that samples based on pine sawdust can be attributed to a fully biodegradable material, and based on birch sawdust – to a material with a moderate (partial) degree of biodegradability. According to the results of the exposure for 84 days in the soil of the PWR samples, migration of heavy metals and arsenic from the degradable biodegradable material into the soil substrate is observed. There were no exceedances of the maximum permissible concentration (MPC) for the contents of Class I pollutant elements (lead, cadmium, zinc, mercury, arsenic) and class II hazard (copper, nickel) in the soil after biodegradability tests. According to the total pollution indicator, the studied soil belongs to the category of "permissible" pollution. The performed studies have shown that the final choice of wood raw materials for the purpose of obtaining composite materials should be determined by the level of contamination of the raw plant raw materials used to produce composites, as well as the level of possible existing chemical contamination of the soils of the area intended for the use of products based on them.

The requirements for different types of paper depend on the field of its application. To obtain finished products with the necessary characteristics, it is important to take into account the properties of the fibrous mass. The milling of sulfate cellulose of coniferous and deciduous wood species was carried out on semi–industrial disc mills (grinding conditions: the concentration of fibrous mass was 1 and 12 %, the degree of grinding varied from 15...60 °C). The time for grinding the fibrous mass at a concentration of 12 % to a grinding degree of 60 °C was required for BSLC by 1.5 times; BSHC by 2.5 times, more than for grinding a mass of low concentration. The paper-forming properties  of the fibrous mass have been determined: the water retention capacity of BSLC increased by 151.4 and 131.4 %;  at BSHC by 138.5 and 115.4 %; fiber length at BSLC decreased by 35.8 and 47.7 %; at BSHC by 28.6 and 37.7 %.  The nature of changes in the mechanical properties of finished paper products depending on the degree of grinding and the nature of grinding is analyzed. It was found that with an increase in the degree of grinding of the fibrous mass from 15 to 60 °C, the following increase: the resistance to penetration of samples from BSLC by 4.6±0.4 times, from BSHC by 7.5±0.5 times; the breaking length of samples from BSLC by 2.5±0.3, from BSHC by 2.7 times. It was found out that the complexity of the process of grinding a mass of high concentration lies in the difficult movement of this mass in the grinding zone.