Lesnoy Zhurnal (Russian Forestry Journal)

Lesnoy Zhurnal (Russian Forestry Journal)

Basic info

  • Publisher: Northern (Arctic) Federal University named after M.V.Lomonosov
  • Country of publisher: russian federation
  • Platform/Host/Aggregator: Open journal system ojs
  • Date added to EuroPub: 2019/Sep/27

Subject and more

  • LCC Subject Category: Forestry, Technology
  • Publisher's keywords: Forestry, Technology, Machinery of logging, timber processing and chemical treatment of the wood biomass
  • Language of fulltext: english, russian
  • Time from submission to publication: weeks

Publication charges

  • Article Processing Charges (APCs): No
  • Submission charges: No
  • Waiver policy for charges? No

Open access & licensing

  • Type of License: CC BY
  • License terms
  • Open Access Statement: No
  • Year open access content began: 2001
  • Does the author retain unrestricted copyright? False
  • Does the author retain publishing rights? False

Best practice polices

  • Permanent article identifier: DOI
  • Content digitally archived in: eLIBRARY.RU
  • Deposit policy registered in:

This journal has '42' articles

Growth Indices of Siberian Pine of Different Geographical Origin Grafted on a Scots Pine Rootstock

Growth Indices of Siberian Pine of Different Geographical Origin Grafted on a Scots Pine Rootstock

Authors: R.N. Matveeva, О.F. Butorova, N.P. Bratilova, I.E. Shcherba, V.V. Komarnitsky
Year: 2020, Volume: 11, Number: 2
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Abstract

Forests dominated by Siberian pine (Pinus sibirica Du Tour) occupy about 40 mln ha in Russia. They fulfill soil- and water-protective roles, produce oxygen, and are the source of valuable nuts, wood, and other materials. The 36-year-old grafted trees of Siberian pine growing on a hybrid seed plantation in the suburban area of Krasnoyarsk region were the study object. A comparison of growth indices of 36-year-old ramets of Siberian pine of different geographical origin was the research purpose. Graftings were made on the Scots pine young growth in 1982. Grafting stocks were cut from plants grown from seeds harvested in 1960 in populations of different geographical origin. The location of the initial populations differs in latitude by 12°, longitude by 64° and altitude by 900 m above sea level. It has been found that the average height of 36-year-old grafted trees depending on geographical origin varies between 12.4 and 15.0 m; the trunk diameter – 29.7 and 40.9 cm; and the crown diameter – 6.4 and 7.6 m. Clones of Tomsk origin are characterized by the best growth. Clones of the northern populations (Komi and Sakha Republics) are characterized by the lowest height. The average diameter of scion exceeds the diameter of rootstock by 6.4–39.7 % depending on the graft geographical origin. Good graft intergrowth (the scion diameter is equal to the rootstock diameter) is observed in 10–27 % of trees. A relationship was found between the grafted trees: close, between trunk and crown diameter (r = 0.855); trunk diameter and crown volume (0.827); significant, between trunk diameter and crown length (0.520). It has been established that both the geographical origin and the clone belonging of scion influence on the growth intensity of the grafted trees and intergrouth of the grafted components. The obtained results can be used in creation of clonal plantations of the second generation.

Keywords: Siberian pine, plantation, geographical origin, graft, population, rootstock, scion, clone, ramet, variability
Growth and Development of Pollen Tubes in Common Juniper (Juniperus communis): The Role of the Tube Cell Nucleus

Growth and Development of Pollen Tubes in Common Juniper (Juniperus communis): The Role of the Tube Cell Nucleus

Authors: M.V. Surso, D.G. Chukhchin
Year: 2020, Volume: 15, Number: 2
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Abstract

In this work we have tried to explain the functional value of the tube cell nucleus and its relationship with the structures of the pollen tube on the example of juniper. Juniper pollen tubes were studied in vitro by the methods of light microscopy (transmitted light, fluorescence) and Fourier-transform infrared (FTIR) spectroscopy. A brief description of the growth and development processes of juniper pollen tubes is given. The experiments on the enzymatic destruction of the pollen tube wall revealed the relation between the generative nucleus and the protoplast associated with the tube cell nucleus. The generative nucleus is quite firmly connected with the protoplast of the tube cell nucleus by means of the surface tension of internal membranes. It was proven that the protoplast and the both nuclei save their integrity outside the tube body. That is, they retain their viability outside the tube body for some time after lysis the tube tip. However, both the generative nucleus and the tube cell nucleus cannot function independently outside the protoplast of the pollen tube. Microfibrils of the actin cytoskeleton are distributed irregularly inside the tube. Most of them are concentrated in the central part of the tube and associated with the tube cell nucleus and protoplast. Leucoplasts predominate in the composition of plastids. The majority of them are amyloplasts, the better part of which is concentrated around the tube cell nucleus and protoplast. Protoplast contains a large number of mitochondria. Lysosomes are distributed over the entire volume of the pollen tube more or less regularly. However, a significant part of lysosomes, especially in actively growing tubes, accumulates around the tube cell nucleus and near the tube tip. The use of deuterium as a marker allowed to establish the sequence of synthesis and localization of synthesized substances during the pollen tube growth. The increased deuterium content was observed in the zone of the protoplast associated with the tube cell nucleus. The obtained experimental data allowed to suggest that the tube cell nucleus likely controls the synthesis of organic substances and their distribution in the tube body. Probably, the tube cell nucleus promotes its polar growth and orients the growth of the tube tip in vivo in time and space.

Keywords: juniper, pollen tube, tube cell nucleus, infrared spectrometry, deuterium, enzymatic hydrolysis
The Effect of Long-Term Periodic Fertilization on the Structure of the Stand and the Ground Cover in the Cowberry Pine Forests of Middle Taiga (Republic of Karelia)

The Effect of Long-Term Periodic Fertilization on the Structure of the Stand and the Ground Cover in the Cowberry Pine Forests of Middle Taiga (Republic of Karelia)

Authors: N.V. Genikova, V.A. Kharitonov, A. M. Kryshen’
Year: 2020, Volume: 16, Number: 2
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Abstract

The results of research on studying the influence of after-effects of periodic nitrogen (N) and complex fertilizer (NPK) treatments on the structure of the tree layer and ground cover are reported. The study objects were pine plantations growing on poor sandy soils in the cowberry pine forests (Karelian taiga district and middle taiga). At the time of survey, the plantations were 53 years old; fertilizers were last applied 30 years ago. A geobotanical relevé was carried out, stand valuation characteristics were determined, and microphytocoenoses were mapped at each sample plot. The NPK fertilization resulted in an increase in the average diameter and height of the pine plantations with more intensive thinning of the stand in comparison to the control and nitrogen fertilizer treatments. The fertilizer and control treatments are the same according to the total number of species in the ground cover. At the same time, significant differences were observed in the ratio of projective covers of mosses and lichens. In all fertilized plots, the abundance of mosses was twice or even more higher than the abundance of lichens, whereas the moss cover at the control site was almost the same as the lichen cover, and locally even lower. This pattern is probably associated with the response of true mosses to elevated carbon and nitrogen content in upper soil horizons. The only stand valuation characteristic reliably and unambiguously correlating with the ground cover structure is the average diameter: the larger the value of the average diameter, the larger the projective cover of true mosses. Generally speaking, four-time mineral fertilization with 5 year intervals of pine plantations growing on sandy soils continue to exert an effect on the structure of the tree layer and ground cover even 30 years after the last treatment. In the fertilized sample plots, elevated nitrogen and carbon levels are observed only in the forest floor and the soil horizon directly underlying the floor. This is due to the fact that trace amounts of nitrogen are fixed in the phytocenosis and released back with litter fall only into the topmost soil horizons; influencing the structure of the moss-and-lichen layer towards the prevalence of true mosses (Pleurozium schreberi, Hylocomium splendens) over fruticose lichens of the genus Cladonia in the ground cover.

Keywords: mineral fertilizers, pine plantations, ground cover, species composition, sandy soils
Forest Plantations on the Drained Bottom of the Aral Sea

Forest Plantations on the Drained Bottom of the Aral Sea

Authors: N.J. Bakirov, A.Kh. Khamzaev, Z.B. Novitskiy
Year: 2020, Volume: 9, Number: 2
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Abstract

Information is provided on the current state of the drained bottom of the Aral Sea. It is noted that the Amu Darya and Syr Darya rivers dumped 55–60 km3 of water into the sea until 1966. The waters of Syr Darya ceased to flow into the open sea in 1973, and Amu Darya in 1966. This is largely responsible for the area of the drained bottom, which is about 6 mln ha today. It is necessary to carry out forest reclamation works in order to consolidate the drained bottom and prevent the occurrence of deflationary processes. The research purpose was to identify the types of bottom sediments according to their degree of forest suitability taking into account their mechanical and chemical composition and select woody-shrub plants for the reclamation development of the lands. The studies were carried out from 2006 till 2019. Soil was distinguished into 3 categories taking into account its granulometric texture: the first category is sandy and sandy loam soils; the second is shifting sands, and the third is salt wastelands. The role of forest plantations in reduction of deflationary processes has been established: the wind speed decreases by 20.5 % in the annual saxaul-saltwort plantation, by 34.6 % in the two-year plantation, and by 87.4 % in the five-year plantation. Natural grassland vegetation appears under the canopy of 4–5-year forest plantations, which results in a sharp decrease in wind speed and, thus, termination of soil deflation. It was determined that forest plantations reduce the blowing of salt, dust and sand and thereby contribute to the ecological recovery of the territory. The removal of chemical elements (such as chlorine, sulfur, calcium, magnesium and sodium) from the soil under the protection of forest plantations is significantly below than from an open surface. The research results are widely used by organizations involved in afforestation of the drained bottom of the Aral Sea, such as regional floristries of the Republic of Uzbekistan, which have already created about 400 ths ha of forest plantations. As a result conducting large-scale forestry and forest reclamation on the drained bottom of the Aral Sea will allow to consolidate it and thereby minimize the occurrence of deflationary processes, in other words will make it possible to improve the environmental situation in the Central Asia region.

Keywords: deflation of soils, forest plantations, drained bottom, Aral Sea, forest reclamation, wind, relief, selection of vegetation assortment, forest reclamation effectiveness
Assessment of Urban Forest Biological Productivity (Case Study of the Voronezh Upland Oak Forest)

Assessment of Urban Forest Biological Productivity (Case Study of the Voronezh Upland Oak Forest)

Authors: G.А. Odnoralov, Е.N. Tikhonova, I.V. Golyadkina, Т.А. Malinina
Year: 2020, Volume: 13, Number: 2
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Abstract

Fast-paced rates of urbanization reduce the area of forestlands. As a result, the volumes of photosynthesis, metabolic processes, oxygen production, carbon deposition and other processes are decreasing. All of this gives pause for thought about the existence of forests on the planet. The Voronezh upland oak forest with a total area of more than 7 ths ha is the central organizing element of the entire urban ecosystem of Voronezh. The forest stand is represented by coniferous crops along the left bank of the terraces above the flood-plain, as well as broad-leaved forest plantations extended over the riverside slopes of the watershed. The oak forest is a state nature reserve of regional significance and has the status of a specially protected natural area. One of the main functions of the nature reserve is lowering the level of anthropogenic impact on unique landscape systems and maintaining the ecological balance in the region. Through the example of the oak forest the basic forest types are characterized and their total biomass is calculated, the above-ground organic biomass is compared with the mass of soil humus and total biomass with the clay biomass. It was found that the total biomass reserves correlate with the mass of physical clay in the root layer. So, pine crops growing in habitats containing up to 900 t/ha of physical clay produce 121.57 t/ha of biomass; its double increase boosts the productivity of the forest to 288.92 t/ha. Herewith, in the first case, the yield class of pine crops ranges from the second to the third; in the second case it reaches the first class. The oak forest is losing its forest-growing potential, its sanitary and hygienic properties are deteriorating. As well as, there is a general decline in the economic value of the specially protected natural area in the context of ecosystem services.

Keywords: Voronezh upland oak forest, forest, biological productivity, biodiversity, phytomass, forest soils, urban green areas, urban ecosystem
The Density of Pine Wood in Drained Shrub-Sphagnum Pine Forests

The Density of Pine Wood in Drained Shrub-Sphagnum Pine Forests

Authors: O.N. Tyukavina
Year: 2020, Volume: 8, Number: 2
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Abstract

The density of wood is a key indicator of its quality. It is necessary to identify the factors affecting the density of wood for its effective and rational use. Knowledge of the features of wood formation in various forest growing conditions will allow to provide its well-targeted production for industrial use. Determination of pine wood density was carried out in the drained shrub-sphagnum pine forests of the Arkhangelsk forestry. Linear sample plots (20 m wide) were laid out near the drainage channel and in the interchannel space at a distance of 40 m from the channel. The distance between drainage channels is 100 m. Wood cores were selected at a height of 1.3 m on the trunk shady side and divided into parts 5 mm long. The conventional wood density was determined by the method of maximum humidity of the samples with a relatively small volume. The conventional wood density of pine in the drained shrub-sphagnum pine forests varied in the range from 0.390 g/cm3 to 0.697 g/cm3; near the drainage channel it was less in comparison with the interchannel space. The distance from the drainage channel in high-density plantations does not affect the conventional wood density. The density of pine wood in middle-aged plantations increases with increasing stand density. In mature and over-mature stands changes in the stand density do not affect the conventional wood density. The limiting values of the conventional wood density of pine are 0.486 g/cm3 with age increase and 0.532 g/cm3 with stand density increase. There is a tendency to increase the wood density with a decrease in the annual ring width. A significant correlation between the density of pine wood and the percentage of late wood was detected in middle-aged pine forests. A decrease in the wood density of the middle part of the trunk radius was found.

Keywords: drained shrubs-sphagnum pine forests, conventional wood density, stand density, hydromelioration, percentage of late wood
Lactic Acid Synthesis by Fungus Rhizopus oryzae F-1030 on Growth Media Based on Sulphite Liquors

Lactic Acid Synthesis by Fungus Rhizopus oryzae F-1030 on Growth Media Based on Sulphite Liquors

Authors: L.A. Mingazova, A.V. Kanarsky, E.V. Kryakunova, Z.A. Kanarskaya
Year: 2020, Volume: 13, Number: 2
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Abstract

Lactic acid is an industrially important product with an expanding consumer market. However, lactic acid production and isolation methods used at the present time are not effective enough, lead to the formation of large amounts of polluting waste and their recycling is economically unprofitable. At the same time, a half of the worldʼs lactic acid production is carried out by the microbiological method based on the fermentation of such costly sugarcontaining substrates as sucrose, molasses, treacle, sugar syrup, etc. These sugar-containing substrates usage significantly increases the final product cost. In order to solve the conomic and environmental problems of lactic acid production it is necessary to revise the current raw material source and put cheaper and readily available sources of carbohydrates, such as sulphite liquor formed during sulphite pulping, into the lactic acid production. In turn to enhance the economic efficiency of the Russian pulp and paper production it is necessary to use such paper production by-products as sulphite liquor to the fullest extent possible. Sulphite liquor is a chemical complex of inorganic and organic compounds such as monoand oligosaccharides. The article considers the dependence of the output of lactic acid synthesized on the sulphite liquor medium by the fingus R. oryzae F-1030 on the used method of cultivation. In case of the semicontinuous culture method, the culture liquid was replaced with the similar volume of the sterile growth medium with the fungus biomass saving when the sugars in the medium were depleted. In case of the batch culture method, the synthesized lactic acid was precipitated with calcium hydroxide and the reducing substances recovery in the culture liquid was achieved by adding concentrated sulphite liquor when the sugars in the medium were depleted. The study demonstrates that the largest amount of synthesized lactic acid is obtained when using the semicontinuous method for cultivation of the fingus on the sulphite liquor medium prepared according to the technology recommended in the industry during preparation growth media for yeast cultivation. If it is impossible to carry out a full industrial pre-treatment of sulphite liquor, it is recommended to use the batch culture method for the fungus in order to obtain more synthesized lactic acid.

Keywords: sulphite liquor, R. oryzae, semicontinuous culture method, batch culture method, lactic acid
Performance Assessment of the Drying Section of Machines for the Production of Tissue Paper Grades

Performance Assessment of the Drying Section of Machines for the Production of Tissue Paper Grades

Authors: D.A. Prokhorov, A.S. Smolin
Year: 2020, Volume: 10, Number: 2
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Abstract

The paper presents the method for assessment the performance of high-speed Yankee hoods in the production of tissue paper grades and the results of its use in working machine. The following parameters are found applying this method: paper web dryness, air pressure in the wet and dry ends of high-speed convective dryers and temperature of the air spilled out of the hoods. The methodology is based on the measurement of these characteristics during the operation of working equipment with further adjustment of the separate system units. Thermal imaging was carried out during the experiment. It has been found that blowing hot air on the front side of the hood and sucking in the cold air on the drive side leads to uneven moisture profile (measured on the paper machine roll) across the paper web width, a decrease in energy efficiency and the machine capacity. Performance indicator may be, for instance, the spilled air temperature, which on the studied machine is significantly different from the standard value and is 175 °C. The rationality of regular monitoring of air characteristics when changing processing modes is proved. The relevance of the cascade system is substantiated, where not only a direct cascade from the dry end to the wet end is possible, but also there is an opportunity to adjust the humidity of exhaust air by addition/reduction of part of it to/from the dry end. The direct effect of adjusting the humidity of exhaust air in the drying section on reduction of energy costs, as well as the effect of makeup air on the amount of infiltration and the air balance of the system are confirmed. A set of measures implemented within the framework of this methodology makes it possible to achieve energy saving in existing industries. The prospective saving potential of gas is 62 m3/h or 17 % of the current consumption and actual electricity consumption is 6.8 kWh or 4 % for the studied machine.

Keywords: paper machine, tissue paper grades, tissue, drying section, Yankee hood, energy consumption, cross-direction moisture profile, machine productivity
SOLVING THE PROBLEM OF REDUCING THE INFLUENCE OF LATERAL FORCE ON THE SAW BLADE STABILITY

SOLVING THE PROBLEM OF REDUCING THE INFLUENCE OF LATERAL FORCE ON THE SAW BLADE STABILITY

Authors: M.A. Blokhin, D.A. Podlesny, O.A. Rodionov
Year: 2020, Volume: 11, Number: 2
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Abstract

The accuracy of the thickness of lumber is one of the most important indicators of sawing. It is inextricably linked with saw stabilization in the plane of the greatest stiffness. The aim of the study is to eliminate the influence of lateral force on the saw blade and the thickness of the resulting lumber. The issue of eliminating the influence of lateral force in frame sawing and sawing on band saws belongs to the constructive decision in combination with the analytical one according to classical methods. Therefore, the most important issue in the development of a new machine is to identify the presence of a huge range of frequencies of natural and parametric oscillations of saw blades. Previously, these frequencies could not be analytically found to the full extent and, respectively, the tuning out the machine operating frequencies of the possible oscillation frequencies of saw blades could not be carried out. Due to the complexity and the science intensity of the problem solving, it is not conceivable without modern numerical methods of calculation. Among them are the finite element method, modern software of NX and ANSYS, as well as other original programs. One of such methods, which allow to reduce the influence of lateral force, is determination of stability of the plane form of bending by the Eulerʼs method. The technical solution presented by a fundamentally new saw block with a circular translational motion of the blades reduce dramatically the impact of lateral force on the accuracy of sawing in conjunction with a number of other advantages. At the same time, the issue of ensuring the dynamic stability of the blades both when sawing and at idling speed is solved. It is necessary to point out that with circular translational motion the tooth side cutting edges are under alternating load when scraping over the cut surface. Therefore, the tooth cutting element is a subject of increased strength requirements. The angles of their sharpening were adjusted in order to preserve the integrity of the corners of the teeth tips. The possibility of strengthening the teeth lateral cutting edges of saw blades made of steels of different grades was investigated. The reasons of wear and corrosion, both the elements of the saw module and its operating part (blade teeth) were studied and it was decided to supply the teeth with a hard alloy of the stellite type as the most optimal. However, this provision requires additional targeted field tests. Preliminary calculations showed that the daily productivity of a machine with circular translational motion of the blades (model M2005) in comparison with saw frames increases by 2–4 times; in comparison with band saw equipment of any class by 3–6 times; and in comparison with the circular saw equipment (for small and medium enterprises) by 2–4 times. Analyzing the design scheme and the dynamics of the saw modules, it is possible to find a number of advantages of the multi-saw unit presented as part of the machine. The simplicity and reliability of the design allows us to hope for high functional characteristics. Among those we should highlight the following: increasing the accuracy of sawn products due to the rigidity of short blades, increasing the productivity, improving the quality of treated surfaces, as well as reducing the energy consumption, relatively light weight and dynamic balance of the main units with increased mobility of equipment and the absence of a massive foundation.

Keywords: saw module, saw block, oscillation frequency, dynamic stability, lateral force, thickness variation
The Study of PLA-Based Wood-Polymer Composite Properties

The Study of PLA-Based Wood-Polymer Composite Properties

Authors: I.K. Govyadin, A.N. Chubinsky
Year: 2020, Volume: 17, Number: 2
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Abstract

The paper presents the study of wood-polymer filament for fused filament fabrication (FDM) printing. 3D printing is used in the manufacture of products of a complex shape, which means it can be an integral part of the production of hardscape, furniture decor, and childrenʼs toys. Additive manufacturing allow to switch over to zero waste production, as well as to use renewable biological raw materials. The use of wood-polymer composites in manufacture and inlay of furniture provides an opportunity to reduce the costs of the finished product. Filaments (1.7 mm diameter) were made of a filler/binder (wood flour/polylactide) mixture on a single screw extruder. As a result of studying the filament morphology, it was found that the filler is evenly distributed over the volume of the binder in the form of particles of a spherical or elongated shape with sizes from 0.2 to 1.2 μm. The size of the zones with an enhanced concentration of the filler particles vary between 2.7 and 9.8 μm. Voids were found in the wood-polymer filament sections obtained perpendicular to the filamentʼs length; the void shape is arbitrary; the void size ranges from 9.5 to 32.5 μm. The study of the filament sections in the crossed Nicols mode showed a mosaic pattern of birefringence. The size of aggregates of spherical particles with intense birefringence varies in the range from 4.5 to 55.1 μm. Probably, the particles of wood flour are the nucleation centre of crystallization of the binder (polylactide), which is manifested in the formation of the birefringence zones. The study of the temperature dependence of viscosity of the wood-polymer composite showed no significant differences WPC filaments in comparison with PLA filaments. The glass transition temperature was set to 58.19 °C and the melting point temperature was 214.00 °C, which confirms the similarity with PLA filaments. The results of water absorption tests showed that the water mass fraction in the samples increases significantly with the growth of the filler content in the material and the thickness of the printed layer. The results of measuring the contact angle of the test samples showed that water-dispersion varnishes partially wet the surface of the wood-polymer composite, creating the conditions for adhesive interaction. Determination of tensile strength and the tensile modulus of elasticity showed that at 100 % filling density the samples made of wood-polymer composition are inferior to the samples made of PLA, however, they exceed in comparison with the samples made of acrylonitrile butadiene styrene (ABS) plastic. The results of a thermal imaging study made it possible to detect a rapid decrease in the temperature of the model layers from the levels arising at the exit of the nozzle to the values of the model middle zone and to divide the thermal zones onto three levels and acknowledged the similarity with the samples made of PLA filaments.

Keywords: wood-polymer composition, FDM-printing, wood flour, polylactide, woodpolymer filament for FDM-printing, wood-polymer filament properties
Methodology for Sizing the External Borders of Cutting Areas when Their Development by Balloon Cable Systems

Methodology for Sizing the External Borders of Cutting Areas when Their Development by Balloon Cable Systems

Authors: A.V. Abuzov, P.B. Ryabukhin
Year: 2020, Volume: 20, Number: 2
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Abstract

Currently, the issue of introducing technologies that meet modern environmental requirements into the logging process is put into sharp relief in the forest industry. Such technologies can include air transport, in particular balloon installations, the introduction of which requires further research relating to the influence of weather and landscape conditions on the operation process. The article presents the results of practical and theoretical studies aimed at improving the functionality of balloon logging systems while processing forest areas of different configuration. It was found that the wind load influence is the crucial factor, which adversely affects the balloon as well as haulback line cables. We have developed a methodology and a computer program for determining the dimensions of the external borders of the operational forest area, which allow to install ground winches or border units of the cable system at a distance that provides access to previously inaccessible points of the forest area for the load-gripping mechanism. The output of the program can be represented in the tabular and the graphical forms, which makes it possible to manipulate the loads in the cables and, simultaneously, find the overall dimensions of the external borders of the site. The developed algorithm for determining the optimal dimensions of the external borders of the forest exploitation site allows to provide load distribution between the three haulback line cables of the balloon cable system. This will increase the handling and stability of the entire system, and, respectively, ensure the availability of the load gripping mechanism at any point of the processed forest exploitation site by eliminating non-operating zones.

Keywords: balloon logging, balloon cable system, cable tension, borders of a cutting area, perimeter of a cutting area
The Study of the Destruction Process of Frozen and Thawing Soils Exposed to the Skidding System

The Study of the Destruction Process of Frozen and Thawing Soils Exposed to the Skidding System

Authors: S.E. Rudov, V.Ya. Shapiro, I.V. Grigorev, O.A. Kunitskaya, O.I. Grigoreva
Year: 2020, Volume: 17, Number: 2
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Abstract

Wood logging in the forests of the cryolithozone is growing more urgent for the Russian Federation due to the depletion of available reserves of mature commercial forests in southern and Central Siberia, the Republic of Buryatia, and Khabarovsk Krai, while the development of woodworking enterprises in the Far Eastern Federal District. During the operation of modern forest machines, for instance wheeled forwarders, the issues of their efficiency, first of all, mobility and technological productivity in the specific production and geotechnical conditions are now becoming ever more relevant. These circumstances together with the necessity to minimize the anthropogenic load on the environment put forward the problem of optimizing the number of passes of the skidding system by one run into the most pressing ones. Special conditions for the operation of skidding systems take place in logging operations on frozen and thawing soils. In the first case, there is a sufficiently large volume of ice in the soil massif. The ice has a great impact on increasing the bearing capacity of the soil under the influence of the initial vertical load of the skidding system. In the second case, frozen soil is oversaturated with water when thawing; therefore, the natural bonds between the solid particles grow week, and the physical and mechanical properties of the soil lose their original values. The forwarder forms a rut in the immediate area of contact of the wheel with the soil. The larger the size of the area, the higher the force transferred to the soil for implementation of the necessary traction. We have developed the mathematical model of calculation of parameters of the destruction process of the thawing soil massif on the border with the permafrost zone. The model allows to make an assessment of hypothetical values of depth of the formed rut including engineering capabilities of forwarders and their maneuvering in the work environment at the design stage.

Keywords: frozen soil, logging, skidding system, soil compaction, soil deformation
Organic Carbon Stocks in the Forest Soils of Northern Mongolia

Organic Carbon Stocks in the Forest Soils of Northern Mongolia

Authors: М. Tungalag, S. Gerelbaatar, A.I. Lobanov
Year: 2020, Volume: 8, Number: 2
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Abstract

Soil organic carbon (SOC) stock and its variation on the regional and large spatial scales are critical for estimating the global SOC inventory and predicting further changes. This study was aimed at estimation of the SOC stock in the boreal forests of Northern Mongolia. The study was carried out in the forested areas of the Bulgan, Selenge and Tuv provinces using a completely randomized design. A total of 900 soil samples from 60 sampling points were collected for the laboratory analyses. At each point, a soil profile with a depth of more than 30 cm was laid out, and then soil samples were taken from three soil layers: 0–5, 5–15, and 15–30 cm of each profile. Therefore, the results of the assessment show a high difference of the SOC stock not only between the provinces, but also within each province. The higher SOC stocks were observed in the Selenge (123.5±14.85 t/ha), and lowest in the Tuv (51.23±7.8 t/ha) provinces. The estimated SOC stock in the studied regions was 93.77 t/ha on average. We found relatively less SOC stock in the boreal forests of Mongolia compared with the Asian part of Russia including Siberia and the Russian Far East. Such a less SOC stock may be caused by geographical distribution, where the Mongolian forests border the Central Asian dry steppe and frequent water deficit. However, we found that the accumulation of SOC stocks in the boreal forests of Mongolia is largely dependent on the mountain slopes and aspects combined with the distribution of precipitation across the country. Higher amount of SOC stocks were found in north-facing aspects and lower positions with low slopes of the mountains in lower altitude. Consequently, moisture supply basically determines the pattern of the SOC stock distribution in the northern boreal forests of Mongolia.

Keywords: forest soil, organic carbon, SOC stock, aspect, Northern Mongolia
Restoration of Spruce Forests: Theory, National Practice and Problem Solving

Restoration of Spruce Forests: Theory, National Practice and Problem Solving

Authors: N.N. Terinov, Е.M. Andreeva, S.V. Zalesov, N.A. Lyganskiy, A.G. Magasumova
Year: 2020, Volume: 15, Number: 3
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Abstract

Detailed analysis of standard and scientific literature on the problem of restoration of primary dark coniferous forests through the species succession is made for a long-term period. The forest formation theory developed by Professor B.P. Kolesnikov is behind the problem solution. According this theory the restoration of spruce forests occurs through the formation stage of short-term and long-term secondary soft-leaved plantations. The shortterm plantations are the most promising as they have the highest regeneration potential. It has been suggested that during the growth process of secondary soft-leaved forest stands on the site of primary spruce forests the plantation restores its structure and energy balance that were changed as a result of cuttings. Over this period accumulation of organic matter and nutrients, which had been removed from the ecosystem with cut trees, occurs in the soil. We shell underline that substantial improvement of water-physical properties, chemical composition of soil and its achievement of initial level of fertility is possible only after 40–60 years when secondary soft-leaved stands will grow in the place of pure spruce forests. It was concluded that succession of dark coniferous species to soft-leaved ones after clear cuttings is a massive and objective phenomenon; and from the point of view of improvement the forest site conditions it is positive. In this case it should be considered not only as a stage of restoration, but, perhaps, as a mechanism of preservation of primary dark coniferous forest plantations. The growing period of soft-leaved plantations is proposed to use in the forestry system as a restoration stage for the formation of productive dark coniferous plantations. A new method named transformation cutting was developed and patented specifically for spruce forests in order to solve this issue. Its essence lies in the fact that care of young generations of dark coniferous species is taken in the early stages of the secondary softleaved stand development. The entire process of formation of dark coniferous young growth or middle-aged forest stand finishes with cutting of upper soft-leaved storey at the tree age of 45–55 years, i.e. before they reach the cutting age of mature soft-leaved stands. The inclusion of this method in the system of forestry would require some changes and additions in inventory of forest fund, preparation of project documents, as well as technical and engineering support of the prescribed measures. For instance, it is necessary to start the valuation of secondary soft-leaved forest plantations with the middle-aged stand and determine the full valuation description of the stand by generations indicating the composition, age, height and number of tree species. The use of the developed method for dark coniferous forest plantations in forestry will allow to slow down the process of species succession and later on to balance deciduous and coniferous forests based on the ecological value of forest stands, forest site conditions and prospects for the development of a specific area.

Keywords: succession of species, soft-leaved plantations, transformation cutting, forming of spruce stands
Reconstruction of Stand History and Impact Evaluation of an Invasive Bark Beetle in Siberian Fir Forests with the Help of Spatial Structure Analysis

Reconstruction of Stand History and Impact Evaluation of an Invasive Bark Beetle in Siberian Fir Forests with the Help of Spatial Structure Analysis

Authors: N.M. Debkov, A. Gradel, A.A. Aleinikov
Year: 2020, Volume: 18, Number: 3
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Abstract

The most devastating insect invasion of forest ecosystems in Russia is the recent mass reproduction of the four-eyed fir bark beetle (Polygraphus proximus Blandf.) in southern Siberian fir (Abies sibirica Ledeb.) forests. The objective of our research was to study the spatial structure of fir forests and their change under the impact of the four-eyed fir bark beetle in its secondary (invasive) distribution range. We selected two fir stands located near the villages of Itatka and Malinovka in the Tomsk region. Both stands represent natural ripe succession forests on sites that previously experienced logging activities, which were triggered by settlement activities in the second half of the nineteenth century. We used Field-Map technology for gathering non-spatial and spatial stand data. The analysis showed that height, diameter and radial increment of fir trees, killed or severely weakened by attacks of the four-eyed fir bark beetle, were significantly lower than that of healthy individuals. The social status of fir trees, seriously attacked or already killed by Polygraphus proximus was indicated by the Ui index as moderately suppressed. In contrast to the distribution pattern of living firs, the pattern of dead or severally weakened firs killed by the four-eyed fir bark beetle was significantly clumped over short distances (sample plots (SP) Itatka and Malinovka). This finding coincides with visual observations in other stands, that dead trees are grouped to some extent. However, the hypothesis of spatial independence of the tree positions of living and dead firs was accepted for both plots.

Keywords: insect invasions, Polygraphus proximus Blandf., Abies sibirica Ledeb., tree mortality, spatio-temporal characteristics

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