The relationships between heights and diameters at breast height of trees are widely used in determining of growing stock and assortment structure of stands. Numerous mathematical models are used to describe them. A comparative analysis of the accuracy of six models on the example of tree stands of Scots pine in the Training and Experimental Forestry of the Leningrad region showed the close accuracy of each of them. For different sample plots, however, the highest accuracy was showed by different models. This necessitates further research on this topic in order to identify the most applicable mathematical models for different tree species, ages and habitat conditions. In practice are often used the tables, compiled taking into account the ratios of heights and diameters at breast height in tree stands, the main of which are tables of volumes of trees by height ranks and assortment tables. Within the framework of the study, it was found that the actual relationships between tree heights and diameters at breast height differ from those given in the tables, which is due to the individual features of the stand structure and habitat conditions. For this reason, the height ranks, determined for individual diameter classes often differ from those found for the average tree stand height and diameter at breast height. This leads to discrepancies in the growing stocks of tree stands, found taking into account these two approaches, as well as the yield and cost of assortments in them. Although the differences are insignificant, they highlight the need for further research in order to improve the accuracy of determining the inventory parameters of tree stands.

There are 13 species and 1 hybrid of genus Larix Mill., represented by 124 trees, in collection of the Upper and the Lower dendrological gardens of Saint-Petersburg State Forest-Technical University, under the age from 25 till 200 years old. All of them are winter hardy and produce cones. Three species (L. archangelica, L. decidua, L. sibirica) give self-sowing. Totally there are 23 taxa which have been tested for the period of introduction. The largest amount of species were tested by E.L. Wolf. Some species (L. komarovii, L. maritima) were introduced here into general cultivation. There are trees of old age planted as early as in the XIX century (71). There are 9 of oldest trees cultivating since 1820 (L. archangelica, L. decidua, L. sibirica). The tallest tree is of L. sibirica: 34,0 m high, the most thick on trunk diameter is the tree of L. decidua: 102 см. The research confirm the importance of periodical biometrical measurements and uninterrupted monitoring of all collection. There are certain trees which deserve to be included into the data base on Champion trees on their sizes.

Collection fund of the Laboratory of Ornamental Plants (LOP) MBG RAS has been in existence since 1947. Currently, it includes ornamental perennials from 221 genera and 57 families (1039 species and varieties, as well as 5047 varieties and garden forms). The current policy of forming collections is mainly aimed at creating large and/or original collections. The purpose of the present work is to study the quantitative and qualitative characteristics of the modern collection fund LOP MBG RAS, as well as the structural features of large collections in its composition. The most widely used methods in the introduction studies are the ecological-phytocenotic method and the method of generic complexes. The structure of the species part of the collection fund of the LOP is dominated by representatives of the flora of Europe, Asia and North America, since these regions are traditionally considered the most promising donors of material for the introduction of ornamental plants. The predominant ecological groups in its composition are forest, steppe and meadow species. When forming varietal collections, various approaches are implemented. Domestic breeding achievements dominate the Syringa, Lilium and Phlox collections. The collection of the genus Paeonia is aimed at creating a sample of foreign varieties that represent the history of culture selection. The history of culture selection in the USSR is most fully presented on the basis of the Clematis collection. The main stages of microevolutionary development of culture are demonstrated by the example of the genera Astilbe and Iris. The aspect of preserving retro varieties is most fully implemented on the Hemerocallis collection. The selection of a promising assortment for the conditions of the region is the main direction of expanding the collection of the genus Rosa. The aspect of selecting the most promising early-flowering varieties in crops with late flowering dates is most successfully implemented for Dendranthema and Symphyotrichum. The Hosta and Tulipa collections are focused on the selection of a range that is promising for the conditions of the central part of Russia, reflecting the morphobiological diversity of the culture. For breeding purposes, the resources of the Dahlia, Astilbe, and Iris collections are used.

The main data for the stock of research results is the diameter of measurements and heights of trees. But measurements of the diameter at breast height are much easier to perform than measurements of heights, therefore, they are limited to measuring the heights of 15–25 trees. The aim of the study is to select the most adequate simple model based on the measurements of model trees in pine antiquities, which conveys the relationship between the height of trees and the diameter at breast height. The object of the study was pine stands of artificial origin on permanent test plots in the Forest Experimental Station Russian State Agararian University – Moscow Timiriazev Agricultural Academy. The work uses data from tree measurements on 17 permanent sample plots from 1934 to 2005. The age of the stands at the time of measurements was from 50 to 125 years. As a result of 77 enumerations, the data array amounted to 1157 observations. Both the fixed effects model and the mixed effects model adequately describe the relationship between heights and diameters of trees in pine stumps. But, as expected, the first model has worse quality metrics than the second. The mixed effects model more accurately predicts heights from the fixed effects model. The missing heights of a large number of trees on a site can be calculated accurately using mixed effects models, rather than using fixed effects models or using only a fixed portion (mean response) of the mixed effects model. The application of the developed model should be limited only in those conditions to which the experimental materials are applied.

Due to the global warming of the climate, the assessment of the carbon cycle in forest ecosystems has become particularly important. One method for determining deposited carbon is based on the use of biomass expansion factors (BEF) and State Forest Inventory (SFI) data. By combining BEF models with SFI data in two ecoregions of Russia – taiga and forest-steppe – it was found that over a 20–25-year period, accumulating the carbon deposition in the taiga zone is significantly less (5%) compared to the forest-steppe zone (39%). Despite the existing risks of natural disasters in the forest-steppe ecotone, there is a significant increase in carbon deposition over a quarter of a century. This was due to the high proportion of young stands at the beginning of the analyzed period, which have increased growth in relation to old stands. Comparable results were obtained by the same method in different ecoregions of the planet (from 8% in 5 years in China to 68% in 50 years in Japan). A comparison of the results obtained by the proposed method and the IIASA (Austria) method showed a minimal discrepancy (3%), which gives reason to consider the above estimates of carbon deposition close to reality. However, uncertainties remain related to the quality of the SFI data and the carbon deposition in the soil.

The processes of genesis of coniferous forests are widely investigating using molecular markers. Many studies are based on the analysis of microsatellite loci, which are acknowledged as the most reproducible and polymorphic co-dominant molecular markers. This study is aimed to establish the possibility of using microsatellite markers to determine differentiation between Norway and Siberian spruce (Picea abies and Picea obovata). Another task of this research was to assess the degree of genetic isolation of regional spruce population in the territory of European part of the Russian Federation. This study shows that using a large number of microsatellite markers allows to divide the sample of spruce collected from European part of Russia and Siberia in two genetic clusters, corresponding to Picea abies and Picea obovata. The microsatellite loci analyzed in the study can be used to assess genetic diversity and geographic origin of spruce trees and determine the origin of wood and planting material of Norway and Siberian spruce.

The content and ratio of plastid pigments in the conifers of representatives of different populations of Norway spruce introduced into the geographic test-cultures in the Nizhny Novgorod region were studied. A spectrophotometric method was used to identify quantitative estimates of the pigment composition of the leaf apparatus, ensuring the principle of a single logical difference and the basic requirements for the organization of the experiment. Field surveys of plantings and laboratory analyses of biological samples were carried out. The differences between representatives of Norway spruce populations that are remote from each other were revealed when they were grown together as part of geographical crops according to the complex of indicators of the pigment composition of annual needles. The highest content of chlorophyll-a (3.25±0.06 mg/g) was observed in the seed offspring of populations from the Pskov region, which is 1.26 times higher than the corresponding minimum (2.57±0.04 mg/g) recorded in representatives of populations from the Kaliningrad region. Similar scales of the ratio of estimates of the content of chlorophyll-b were recorded, despite the fact that the maximum values (1.37±0.05 mg/g and 1.37±0.06 mg/g) were observed in the origin from the Kostroma and Karelian regions, and the minimum values (1.07±0.03 mg/g and 1.09±0.03 mg/g) were observed in representatives of populations from the Arkhangelsk and Kaliningrad regions. The significance of differences between the populations of Norway spruce in all the considered indicators of pigment composition was confirmed. A similarity was found in the addition of three groups of populations that arose during factor and cluster analysis. The cluster density coefficients (the average Euclidean distance of its addition) of each of them were: 6,258 units of the Euclidean distance (for the first one); 4,374 units. (in the second); 7,818 units. (at the third) and 6,150 units. (total average distance). The average inter-cluster distance at the same time reached 20,414 units, which is fundamentally greater than the values of intra-cluster distances and allows us to recognize the correct allocation of clusters. The stable nature of the ratio of populations of Norway spruce with different geographical origin, according to the pigment composition of needles, is justified.

We studied the taxation indicators of forest crops of Sukhdev larch, laid in 1986 on the south-western border of the natural distribution of the species in the Sergachsky interdistrict forestry of the Nizhny Novgorod region. The coordinates of the first section are N 55.541378, E 45.471119; the second section is N 55.541388, E 45.471125. An assessment of the effectiveness of their creation in the specified region was obtained. The methodological basis of the working methods was the principle of the only logical difference. The work was carried out by the field stationary method. The characteristics of larch crops were given based on the results of a field survey. The test areas were laid in accordance with the current industry standard. The favorable forest conditions for the natural growth of Sukachev larch and the wide opportunities for the introduction of closely related species were confirmed. Unequal variability of taxation indicators was found. In particular, in terms of trunk diameter and height, it is insignificant and is mainly attributed to the low level: in the first section, 14.21% and 11.34%; in the second-17.11 and 9.16%, respectively. According to other signs, the variability is higher (more often the average and increased level) and in some cases reaches a high (trunk volume) and very high (crown asymmetry coefficient) level. Significant differences between forest crop plots were recorded in most of the taxation indicators, which were confirmed by the analysis of variance. The effect of their influence on the general background of the phenotypic variance is not the same. By the diameter of the trunk, it is minimal and amounted to 6.68±1.37%. The highest estimates were obtained for the distance to the first live knot – 30.42±1.05%. It is determined that the forest cultures of Sukachev larch, created in the Nizhny Novgorod region, reaching a height of 14-15 m by the age of 34, form plantings of the first class of bonitet.

For the first time for the region, the survival, growth and productivity of scots pine climates in 39-year-old provenance test of the state network (Plesetsk district of the Arkhangelsk region) were studied. Features of climate redistribution in the collection were traced, the best offspring were selected for use for reforestation within the test region. It has been established that northern offspring (northern and middle subzones of the boreal forest), differing in the I grade of age with high livability, in the II grade of age began the process of differentiation, which led to a decrease in the indicator by almost half. By the end of grade II of age, the offspring of provenance are equalized in height, while maintaining differences related to origin in diameter. The largest diameters of trunks have southern offspring, as well as from the northern subzone of mixed forests, which differ in the lowest rates of survival and quality of trunks. Direct dependence of H/D index with livability is established, which is connected with increase of provenance growth by diameter, increase of escape and curvature of trunks, formation of low-lowered crowns. It has been shown that in cultures of the II class of age, significant correlation of growth and livelihood indicators with the geographical coordinates and climatic characteristics of the places of the initial plantations remains, while with the reserve the connection is lost. Using the assessment approach, in units of standard deviation, the best climates in terms of productivity (reserve) were selected: local mold, Pinezhsky, Vologda, as well as climates from Karelia. The initial plantations of these offspring are included in the range, limited to 60–65 N, 36–44 E. For use in reforestation in the Arkhangelsk region, the use of seeds from plantations of the Urals and Siberia should be completely excluded. In the European part of the country, recommend the use of seeds harvested in three forested areas: South Karelian, Dvinsk-Mezensky and Verkhnedvinsky, limiting the movement of seeds for a distance of not more than 300 km.

The ruts formed after the passage of logging machinery during logging operations are one of the negative environmental consequences associated with disturbances of the soil and vegetation cover of deforestation, which determines their further renovation. The negative impact of the formation of ruts depends on the number of passes of machinery and is associated with soil and climatic conditions. We studied the effect of different number of passes (4, 8, 10) of a loaded Ponsse Buffalo King forvader on a skid trail that is not covered by felling residues. The experimental logging site of LLC Dvinlesprom is located in the watershed between of the Northern Dvina and Pinega (Arkhangelsk region, North Taiga forest region of the European part of the Russian Federation). The original site is represented by a blueberry spruce forest of the V class of bonity, which grows on podzolic soil on binomial deposits and is widely distributed in the region. We laid the permanent accounting pads (20  5 m) in 3 repetitions. We conducted a detailed study of the structure of the ruts, at the bottom of each rut, we opened the soil and made a description of the horizons/layers of the soil, took undisturbed soil samples from a depth of 0–10 and 10–20 cm to determine the soil bulk density and moisture content. It was found that the number of passes determines the depth more than the width of the ruts. We identified 6 types of disturbances of the soil cover on the structure of the soil at the bottom of the ruts, associated with mixing, shifting and removal of the gleying soil-forming parent soil to the day surface. We have given the types of the structure of the bottom of the ruts depending on the number of passes of the loaded forwarder, as well as the differences in the soil bulk density and moisture content. The soil bulk density in the thickness of 0–20 cm with an increase in the number of passes of the forwarder naturally increases to the values corresponding to the soil-forming parent soil. At the same time, the proportion of moisture in the thickness of 0–10 cm increases with an increase in the number of passes, and in the thickness of 10–20 cm decreases. Noticeable changes in the studied indicators are achieved with an eight-fold passage of a loaded forwarder, which allows us to consider this number as the maximum permissible passage on podzolic soils on binomial deposits in the north taiga forest area.

The research is devoted to finding an analytical mathematical model for determining the aiming time of a feller head on a growing tree. As the known parameters are used. The design dimensions of the technological equipment, taken from layout and kinematic diagrams of feller-buncher machines, the required stump height and the average distance between the trees of the windrow. The search for the required model can be briefly divided into several successive steps: finding the path that the hydraulic cylinder rod of the boom drive will take and by the known formula of speed of movement of the hydraulic cylinder piston is time to bring the boom to the tree; finding the way which the rod of the hydraulic cylinder of the arm drive; to find the path which the hydraulic cylinder rod of the tilt of the feller head; finding the path which the hydraulic cylinder rod for the arm actuator will take during the opening. The sum of the time for supplying each of the elements of technological equipment is the time required for the orientation, which is characteristic for a nonexperienced operator. In case of an experienced operator the time for setting the feller head to the tree is determined by the maximum time of one of the components.

In order to expand the field of application of tall oil fatty acids, a by-product of sulfate pulping (which mainly consist of unsaturated C18 acids), including the production of various synthetic products based on them, the corresponding ethylene glycol and dodecyl esters have been synthesized. The possibility of application the esters as pour point depressants for grades of universal fuel oil and marine ecological fuel has been studied. Fatty acids were esterified with 1-dodecanol and ethylene glycol in the presence of a p-toluenesulfonic acid as catalyst. The pour point of the fuels was determined manually according to the ASTM D97 standard. The pour point of ecological marine fuel decreased from +21 to 0 C when using 2% dodecyl ester of fatty acids as an additive. It was found that the synthesized esters of tall oil fatty acids reduce the pour point of residual fuels at a level comparable to the use of a commercially produced depressant additive, which makes it possible to expand the feedstock base of this type of additives and reduce import purchases, as well as to use more extensively tall oil fatty acids in organic synthesis.

The circular saws are widespread in sawmill and woodworking industry due to their high productivity, simplicity, design reliability, and low energy consumption. Thin saws are used to increase the effective yield of sawn timber. The insufficient rigidity and stability during operation of such saws limit their use. Slotted, roller, aerostatic and electromagnetic guides are applied to increase the bending stiffness of a circular saw. Most such guides create resistance to the rotation of the saw blade. Mechanical losses during the torque transmission from the motor to the saw blade is one of the circular saws disadvantages. Another disadvantage of thin circular saws is vibration of the circular saw blade during operation, which reduce the quality of wood processing, lead to the saw crashes and increased noise levels. It is proposed to use a linear induction arc-stator motor (LIASM), implementing the circular saw is the rotor, to increase the reliability of the cutting unit, stabilize the saw blade during operation, and reduce the oscillations of the saw blade. The experimental setup was created to analyze the developed mathematical model of a LIASM with a circular saw as a rotor. The aim of the work is the experimental evaluation of the mathematical model and the analysis of operating and mechanical LIASM characteristics, idling and short-circuit characteristics of the motor, the dependence of power and cos ϕ on slip. The influence of the saw blade electrical conductivity on the efficiency of the LIASM has been experimentally established. It was proposed to apply a material with high electrical conductivity (copper) on the side surfaces of the saw blade to increase the tractive effort of the drive. The carried-out experiment showed a significant increase in the tractive effort for a copper-coated saw blade. The experimentally established values of the magnetic induction in the air gap of the LIASM showed good coincidence with the calculated results from the developed mathematical model.

The problem of improving the rotary debarkers, which are used without fail in all timber processing technologies of the timber industry countries, is considered. Despite the sufficiently developed design, nevertheless, the main technological operations of the machine are not equipped with modern adaptive automatic control systems (ACS). Previously, developments based on a pneumatic hydraulic drive were proposed using automatic control based on fuzzy logic. In the proposed automatic control system, the stabilization of a given pressing force of the cutting tool – the debarker is performed. However, the given force depends on a number of technological parameters, which are characterized by uncertainty, and the problem of controlling the given clamping of the tool remains unsolved. Thus, the goal of the research was determined, which was to create an intelligent system for automatic control of a given pressure of the debarker staple lifter. The following tasks were solved: 1) development of an intelligent control scheme for the debarker; 2) development of a diagram of a generalized intelligent control system in the form of a neuro-fuzzy network; 3) setting the task of controlling the given clamping of the tool; 4) justification of the input and output variables of the problem (fuzzification); 5) development of a fuzzy system rule base; 6) execution of fuzzy conclusions for intermediate and final layers of the network in the Matlab environment; 7) implementation of the model of an intelligent system in the Matlab + Simulink environment. The results of the work are a model of an intelligent control system for the debarker and its software implementation in the Simulink environment for use in the practice of designing rotary debarkers.

The NMR method was used to analyze oleoresin composition of eight species of Pinus subgenus: Austrian black (P. nigra), Alleps (P. halepensis), mountain (P. montana), hard (P. rigida), Koch (P. kochiana Klotsch), Murray (P. murrayana Balf), common (P. sylvestris) and Pallas (P. nigra subsp. pallasiana) growing in different areas. In addition, the content of resin acids isolated in 1963 from the oleoresins of three species of pines belonging to the same subgenus: black Austrian, hooked (P. uncinata) and Kulunda (P. sylvestris ssp. Kulundensis) was studied. It was found that the oleoresin composition of the named pine species is well described by the presence of eight resin acids (abietic, dehydroabietic, isopimaric, levopimaric, neoabietic, palustrine, pimaric and sandaracopymaric) and nine monoterpenes (camphor, 3-caren, limonene, myrcene, α-pinene, β-pinene, terpinolen, β-felandreene, p-cymol). The quantitative content of these resin acids depends on many factors (pine species, time and place of oleoresin collection, and sample collection and storage conditions). In addition, isomerization and oxidation reactions are observed, leading to a redistribution of the composition. In the studied oleoresins, the content of monoterpenes differs greatly, being the lowest in Alleps pine and the highest in Scots pine.

The purpose of the study is to develop an algorithm for calculating technological indicators separately by types of products for an integrated pulp and paper mill when discharging wastewater after wastewater treatment at unified industrial wastewater treatment plants. A balance method was used for calculating the values of the masses of pollutants formed per ton of output from the pulp and paper mill based on the masses of pollutants formed in auxiliary technological processes, taking into account wastewater treatment at general industrial treatment facilities. Technological indicators are set separately for products rated for bleached or unbleached pulp. If the actual values of technological indicators exceed the values of technological indicators BAT, then it is necessary to develop water protection measures to achieve these indicators and, until they are reached, to pay for the negative impact on water bodies with a hundredfold increasing coefficient. An algorithm and functional dependencies for calculating technological indicators for pulp and paper mills producing products containing bleached and unbleached cellulose in the composition have been developed. The algorithm is considered on the example of a conventional pulp and paper mill, which produces primary unbleached and bleached fibrous semi-finished products, and full-cycle products. Primary unbleached fibrous semi-finished products include: coniferous and deciduous cellulose, ТМP, CТМP; primary fibrous bleached semi-finished products include: bleached softwood and hardwood pulp, BCTMP; full cycle products include: paper, cardboard and their processing products. The calculation algorithm consists of five stages: 1 – building a balance sheet for calculating technological indicators; 2 – calculation of technological indicators for primary fibrous semi-finished products, unbleached; 3 – calculation of technological indicators for primary fibrous semi-finished products bleached; 4 – calculation of technological indicators for full cycle products; 5 – calculation of the values of technological indicators for each type of product, taking into account cleaning at general production treatment facilities.

An approach to the development in the OMNeT ++ INET environment of the simplest simulation model of the infrastructure mode of Wi-Fi network operation is proposed, which allows a detailed analysis of the functioning of such networks, as well as to build and analyze the time diagram of the interaction of all network elements. The developed model can be used as a base for the formation of more complex models with an arbitrary number of mobile clients, allowing you to determine the required number of access points and their locations to ensure full coverage of the monitoring area of the forest area.

Assessing the prospects of using hybrid wood clones is one of the urgent tasks to improve the efficiency of plantation silviculture. One of the promising ways to solve this problem is the use of artificial neural networks (ANN). This research work is one of the few where ANN are used to solve such problems in forestry. Biometric data from 2018 hybrid aspen clones were taken to train neural networks and determine the potential use of hybrid wood clones for plantation silviculture. During this work, two ANNs were constructed where the architecture of the first network includes an input layer of 3 neurons, 1 hidden layer with 6 neurons and an output layer of 1 neuron, the architecture of the second network includes an input layer of 3 neurons, 2 hidden layers of 6 neurons and an output layer of 1 neuron, into which the normalized input biometric data were loaded for learning to determine the prospective use of hybrid wood species clones for plantation silviculture. Based on the results of this study, a comparison of the accuracy of ANN 1 and ANN 2 was made, which showed that ANN 1 was more accurate because its bias was 3,49% less than ANN 2. The results of this work confirmed the promise of using ANN to evaluate the use of hybrid wood clones for plantation reforestation. According to the evaluation of the calculated promisingness of ANN 1 for plantation silviculture, VTI, ESCH3 and ESCH5 hybrid wood clones were identified. The introduction of ANN in the forestry industry simplifies the evaluation of wood biometric results, especially for beginners, which provides a subsequent accurate assessment of the perspective of wood species.

The article presents for the first time an attempt to summarize the experience of teaching the Russian language and other philological disciplines in the First Forest Russian University from the beginning of the XIX century to the present. The historiography of linguistic education at SPbFTU relies not only on open information sources, but also on recently discovered departmental and state archival materials. The author's reference to the founded documents allows us to clarify not only certain stages in the history of teaching the Russian language, the main activities of teachers, but also to present the bright personalities of teachers who in different years taught Russian language to native and foreign students. Already in the first decades of the existence of the Forest Institute, much attention is paid to the actual language development and education. Students of the Forestry Institute study Russian, are engaged in writing business papers and rhetoric practice. The study of the Russian language in the XIX century is mainly subordinated to the pragmatics of teaching, but knowledge of the native language plays an equally important role for the general cultural level of the student. The change of the ideological paradigm, the removal of educational restrictions, the installation on the organization of the training of proletarian students after the revolution of 1917 also affects the humanitarian education of new students. A specialist of a new type, with a Marxist worldview, must be literate and have a broad outlook. Despite the urgent need for language education, for the practical teaching of the Russian language to students and postgraduates, there was no special department of the Russian language at the Forestry Academy (LTA) until the middle of the twentieth century. Awareness of the special role of the Russian language in professional training, in the formation of the world outlook of foreign students led to the creation of the Department of the Russian language in LTA only in September 1955. During the period that has elapsed since the formation of the department, the staffing table, the list of fixed disciplines, goals, tasks and requirements in the training of students have been repeatedly changed. However, teaching philological disciplines by the staff of the Russian Language Department at the Forestry University has always been associated with a broad context of human cultural development, with the strategic goal of raising the level of speech-thinking culture that ensures effective modern communication of a linguistic personality.