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 '56' articles

Long-Term Growth Trends Analysis of Norway Spruce Stands in Relation to Possible Climate Change: Case Study of Leningrad Region

Long-Term Growth Trends Analysis of Norway Spruce Stands in Relation to Possible Climate Change: Case Study of Leningrad Region

Authors: A.S. Alekseev, S.K. Sharma
Year: 2020, Volume: 13, Number: 3
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Abstract

The Lisino training and experimental forest of the Saint-Petersburg State Forest Technical University was chosen as a study area. The forest is located in the central part of the Leningrad region and has a high level of protection as a forest of scientific and historical value. According to the official data, mean annual temperature in the region increased by 0.6 °C within 10 years as well as precipitation. The impact determination of changing climate conditions on Norway spruce trees growth was the aim of this study. Three most representative compartments dominated by Norway spruce (Picea abies (L.) Karst.) were selected for data collection. Core samples were taken by the Pressler increment borer from 107 dominant trees while climatic data were obtained from the nearest weather stations. Tree rings were measured and analyzed using WinDendro software while climate data were processed by Microsoft Excel. Tree ring data cover the time interval from 1848 to 2011, each ring was characterized by width, calendar year, age and diameter of the tree. Radial growth was analyzed within age and diameter classes. Annual rings widths were varied from 0.1 to 6 mm. There was a positive trend in age classes of 0-20, 21-40 and 41-60 years old. The growth was very slow in the age classes of 61-80, 81-100 and >100. Diameters are larger in the age classes of 20-40 and 41-60 as compare to the local diameter growth table which was developed in the 19th century. Diameters for age classes older than 41-60 years were less than prescribed by the diameter growth table. Annual rings width for all age classes also demonstrate cyclic dynamics, moreover, the decline in growth sometimes occurred in recent decades. Multiple regression was used for developing the response function of growth to changes in climatic conditions. There was revealed a high correlation (90 %) and low influence of vegetation period climate data on growth during 1848–2011 (0.08102 mm/°C and 0.00085 mm/mm). Likewise, analysis shows that growth is higher in young and middle-aged than mature and over mature stands. Overall, climate change impact has a positive effect on the radial growth of Norway spruce for the studied area, however, not for all age and diameter classes.

Keywords: Norway spruce, annual ring width, climate change, age classes, growth trend, temperature, precipitations
Diversity of Common Hazelnuts (Corylus avellana L.) and Occurrence Forecast of Its Forms in the North-Western Caucasus

Diversity of Common Hazelnuts (Corylus avellana L.) and Occurrence Forecast of Its Forms in the North-Western Caucasus

Authors: S.G. Biganova, Yu.I. Sukhorukikh, K.N. Kulik, А.K. Kulik
Year: 2020, Volume: 17, Number: 3
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Abstract

One of the most significant issues in common hazelnut biology and selection is the diversity (polymorphism) assessment of its fruits and the occurrence prediction of its forms with economically valuable features in natural populations, which are the source of the most valuable gene pool of the species. The research purpose is to identify the hazelnut diversity and to predict the occurrence of its forms in natural oak and fir forest formations of the studied region. For analysis, one nut was randomly selected from each plant of oak (297 pcs.) and fir (301 pcs.) forest formations. We studied the main economically valuable parameters of hazelnuts: kernel weight and yield, nut weight, fruit quality total score, nutshell strength and color, taste, indestructibility and presence of husk on a kernel. The significance of differences in entropy, its dispersion and degree of freedom, diversity by the Shannon index, variation coefficients, χ2 values, Pearson and Chuprov coefficients were determined by known methods. The index of distributed rank diversity (IRRR) was calculated from the ratio of the sum of the products of the relative entropy of a feature by its rank to the number of scales of this feature. The index of distributed rank diversity including share (IRRRD) for a single feature was defined as the product of the IRRR by the share of the feature of the corresponding scale. The forecast of the presence of hazelnut forms is made according to the law of parallelism. It was found that hazel has nuts with similar features in oak and fir forest formations. The conclusions on a greater variety of parameters of hazel fruits, growing in the composition of oak forest formation, in comparison with fir forest formation coincided completely with the Shannon index, IRRR, IRRRD and χ2. The occurrence of the most economically valuable forms in forest formations is predicted with varying frequency.

Keywords: common hazel, nuts, economically valuable indicators, diversity, Shannon index, coefficient of variation, index of distributed rank diversity, index of distributed rank diversity including share, diversity of forms, occurrence forecast
The Effect of Climatic Factors on the Seasonal Development of Coniferous Forest-Forming Species in the Taiga Zone (Karelia)

The Effect of Climatic Factors on the Seasonal Development of Coniferous Forest-Forming Species in the Taiga Zone (Karelia)

Authors: I.T. Kishchenko
Year: 2020, Volume: 11, Number: 3
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Abstract

Observations over the seasonal development of Scots pine (Pinus sylvestris L.), Siberian spruce (Picea obovata Ledeb.), Norway spruce (Picea abies (L.) Karst.) and Siberian larch (Larix sibirica Ledeb.) had been carried out for 15 years in South Karelia (taiga middle subzone). Phenological observations were taken after every 2-3 days. We recorded the time of such phenophases as swelling and bursting of vegetative buds, beginning and ending of shoot growth, isolation of wintering buds on the shoots, blooming, completion of growth, flowering and defoliation, corking of shoots. The research purpose is to study the similarities and differences in the seasonal development of the forest-forming species of Karelia affected by the main climatic factors. In order to establish the desired correlation we used methods of elementary statistics, correlation and regression analyzes. It was found that the starting dates of the majority of phenophases in the studied species largely depend on air temperature, and to a lesser extent on humidity, precipitation and solar radiation. The relationship between the starting dates of phenophases and the studied climatic factors is straightforward, and its strength depends on the biology of species and specificity of the phenophase itself. Features of development of conifers are largely determined by the state of the environment not only of the current year, but also the previous one. The increase in temperature and humidity, as well as in solar radiation in July of the previous year, significantly accelerate the phenological development of trees of the species studied. The studied species can be arranged according to the degree of resistance to climatic conditions of the taiga zone in the following order: Picea abies, Picea obovata, Pinus sylvestris, and Larix sibirica. It has been found that during the seasonal development Larix sibirica is the least demanding of air temperature, and the most demanding is Picea abies.

Keywords: taiga zone, conifers, spruce, pine, larch, climatic factors, seasonal development, phenology
Method for Transferring Non-Forest Cover to Forest Cover Land Using Landsat Imageries

Method for Transferring Non-Forest Cover to Forest Cover Land Using Landsat Imageries

Authors: A. Karpov, B. Waske
Year: 2020, Volume: 10, Number: 3
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Abstract

Satellite data becomes an important tool for monitoring global change in forest cover. Further development of remote sensing technologies creates opportunities for solving more complex problems requiring multi-time analysis of satellite data. Assessment of success reforestation after a disturbance in forest cover is such an important task. The traditional method of an assessment of successful reforestation is laying out the ground plots, which task requires significant time and resources. Fieldworks and transfer of land to forest cover land is carried out according to the method, which is developed by the Federal Agency for Forestry of Russia. This method has various criteria of success reforestation for every region. Arkhangelsk region, Vologda region and Republic of Karelia became the territories for research. Forest vegetation of this region belongs to the taiga zone and is divided into five groups: the area of pre-tundra forests and sparse taiga, northern taiga, middle taiga and south taiga. International forest classification relates this area to boreal forest. The task of transfer land to forest cover land can be optimized by using remote sensing data. This research shows analysis of recovery of the normalized difference vegetation index, the shortwave vegetation index and the normalized burn ratio in the framework of reforestation objects. Filed data was collected for every object and this data includes a number of young trees, average height and species composition. Processing of a considerable number of satellite imageries requires significant computing power because of the Google Earth Engine platform using for analysis data. The most suitable index was chosen in the analysis of the obtained data for the development of an automatic method for transfer land to forest cover land. The most suitable index for dividing lands on forest cover and nonforest cover lands is the shortwave vegetation index. Optimal threshold for transferring land is achievement of recovery index of 80 % from initial values before disturbance. The automatic method was developed using unsupervised classification and threshold values of recovery index.

Keywords: land management, forest management, reforestation, Landsat
Adaptive Forest Management: Case Study of Sessile Oak (Quercus petraea (Matt.) Leibl.) Forests on Ozren Mountain of the Republic of Srpska

Adaptive Forest Management: Case Study of Sessile Oak (Quercus petraea (Matt.) Leibl.) Forests on Ozren Mountain of the Republic of Srpska

Authors: Z. Govedar, M. Medarević
Year: 2020, Volume: 13, Number: 3
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Abstract

Adaptive management is a basic concept of managing forest ecosystems in the face of increased risks such as climate change. Therefore, there is a need to develop key theories and information on which adaptive forest management is based on. This paper deals with the overview of basic information on adaptive forest management, with particular reference to its importance in relation to examples of sessile oak forests drying and climate change in the Republic of Srpska, Bosnia and Herzegovina. Silviculture of sessile oak forests affected by acute and chronic drying of the trees should be based on the preservation of the complete set of stands and miscibility with black pine on shallow serpentinite and peridotite soils. The paper deals with the possibilities of adaptive management of sessile oak forests and concludes with a description of adaptive management activities.

Keywords: adaptive forest management, forest drying, sesile oak, climate change
Metal-Carbon Composites Based on Lignosulfonates

Metal-Carbon Composites Based on Lignosulfonates

Authors: O.S. Brovko, I.A. Palamarchuk, N.A. Gorshkova, A.D. Ivakhnov
Year: 2020, Volume: 10, Number: 3
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Abstract

The synthesis of the new nanostructured metal-carbon composites (NMCC) based on lignosulfonates was proposed. Obtaining and studying the properties of NMCC is a crucial task of modern materials chemistry due to the use of the materials based on them in various fields of science and technology as ion-selective electrodes and electrochemical cathodes, supercapacitors, magnetic sensors, information recording and storage devices, heterogeneous catalysts. The synthesis method, which allows the formation of particles of a certain shape and size, which subsequently determine the properties of the composite material (sorption, electrochemical, catalytic, magnetic and optical), acquires decisive importance in the production of the new materials. The research purpose is to study the influence of the synthesis conditions of NMCC based on carbon-containing organic raw materials (lignosulfonates, chitosan and polyethylene polyamine) and embedded metal on the structure and physico-chemical properties of the new materials. The feature of the developed approach is the colloid-chemical synthesis with subsequent carbonization, which allows to obtain a highly dispersed NMCC with the developed micro- and mesoporous structure, specific surface area up to 400 m2/g and a narrow particle size (30–65 nm) distribution. Metal binds to sodium lignosulfonate (LS) at the stage of chelate complex formation, which upon mutual coagulation with chitosan (CT) or polyethylene polyamine (PEPA) forms a water-insoluble compound (polymer metalorganic complex). The degree of extraction of Co(II) ions from aqueous solutions during the formation of the LS–Co–CТ metal complex is 78.6 % (LS : CТ mass ratio is 1 : 0.25) and the LS–Co–PEPA complex is 56.3 % (LS : PEPA mass ratio is 1 : 0.1). Centrifugation and washing with acetone followed by carbonization allow the metal to be fixed in the structure of the NMCC. The synthesis conditions, including the quantitative ratio of polymer components (LS : CT – 1 : 0.25 and LS : PEPA – 1 : 0.1), the duration of the formation of the chelate complex (1 h) and the metal-organic composite (1 h) and pH (4–6), were analyzed. The morphology of the NMCC was studied by electron microscopy, and the parameters of the porous structure were found by the method of low-temperature nitrogen adsorption. Carbon nanomaterials based on cheap starting polymers and obtained in the mild synthesis conditions are promising for practical use as effective sorbents and catalysts, as well as for environmental protection.

Keywords: lignosulfonate, chitosan, nanocomposite, carbon material, metal complex, polyethylene polyamine
Production and Use of Birch Activated Carbon for Drinking Water Post-Treatment

Production and Use of Birch Activated Carbon for Drinking Water Post-Treatment

Authors: Yu.L. Yur’ev
Year: 2020, Volume: 7, Number: 3
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Abstract

Pyrolysis of low-quality deciduous wood in the plants with low environmental hazard, located near the source of raw materials is one of the promising options for its processing. In the future, it will be possible to convert such charcoal into activated carbons for various purposes. The research purpose is to evaluate the usefulness of activated carbon derived from smalldiameter birch wood for the drinking water post-treatment, as well as to show the possibility of its regeneration. Commercial activated carbon BAU-A and crushed activated charcoal, obtained by steam activation of coal made of small-diameter birch wood in a rotary kiln with a z-shaped insert, were used as a filter medium in the columns. Water was supplied to the columns with activated carbon in such a way as to ensure the contact duration of water with coal for 8, 4, and 2 min. After three months of continuous operation, all carbon filters with 8-minute contact time retained sorption activity, and filters with 4-minute contact time were used for 80 %. Further on, water post-treatment tests were carried out with recovered carbons. It is found that post-treatment using birch activated carbon reduces the water permanganate oxidation by about 1 mg O2/dm3. The most complementary preferred contact time of coal charge with water is 4 min. The coal after regeneration is recyclable. It is shown that coal made of small-diameter birch wood using activation in a kiln with a z-shaped insert reduces the water oxidation in the same way as commercial coal BAU-A. Herewith, the use of cheaper raw materials (fine birch wood) and coal activation with low specific consumption of water steam (due to the organization of oscillating pressure) cut costs for the filter medium production and drinking water post-treatment.

Keywords: drinking water post-treatment, oxidability, sorption, activated carbon, smalldiameter birch wood
Experimental Evaluation of Strength of End Joints with Rectangular Pressed Fingers

Experimental Evaluation of Strength of End Joints with Rectangular Pressed Fingers

Authors: О.A. Rubleva, A.G. Gorokhovsky
Year: 2020, Volume: 15, Number: 3
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Abstract

End jointing of wooden blanks is widely distributed in the manufacture of wood products. The most commonly used splicing technology on finger joints with pointy fingers has a number of drawbacks, including the presence of waste and an expensive cutting tool. We proposed an alternative type of end jointing with multiple rectangular tenons made by pressing. Commercialization of the new splicing method requires confirmation of its high quality. The main quality indicator of adhesive joint is its strength. The aim of the study is an experimental evaluation of the bending strength and tensile strength of end joints with rectangular pressed fingers (case study of pine wood blanks). The joints of two types: A and B, with a pitch of 4.2 and 8.2 mm and depth of mortises of 10 and 20 mm, respectively, were studied. The strength of the samples was determined taking into account the requirements of the Russian State Standards GOST 15613.4 and GOST 15613.5. In order to evaluate the quality of joints, we used the indicator “relative strength”; it is the ratio of the joint strength to the solid wood strength. Statistical processing was carried out both by data groups, and for each size and each test type separately. This allowed us to establish the average values of strength for each individual group of samples, as well as to obtain a statistically valid joint evaluation of some indicators. Joints of type A with small fingers showed better results in tensile strength (59.5 %) compared to joints of type B (53.2 %). No statistically significant effect of the joint type was revealed, when processing the results of bending tests in the studied range. Therefore, the average bending strength (80.2 %) characterizes both types of joints. Moreover, the strength of these two types of joints with sufficient reliability can be characterized by the average tensile strength (56.4 %). At the same time, both types of joints correspond in strength to the standard requirements to the products with adhesive end joints. The test results vary in a relatively narrow range, which indicates a stable quality of adhesive joints with rectangular fingers made by pressing. This study demonstrates the possibility of using rectangular pressed fingers for the manufacture of joints based on them.

Keywords: finger joints, splicing, rectangular finger, wood pressing, bond strength of a joint
Determination of the Initial Stiffness of Unstretched Rolled Strip Saws

Determination of the Initial Stiffness of Unstretched Rolled Strip Saws

Authors: G.F. Prokofiev, A.M. Tyurin, M.Yu. Kabakova, O.L. Kovalenko
Year: 2020, Volume: 8, Number: 3
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Abstract

The paper presents the results of studies of the initial stiffness of rolled strip unstretched saws; theoretically obtained and experimentally confirmed. A mathematical model, that allows calculating the initial stiffness of unstretched strip saws, has been developed in order to justify the distance between the guides and the saw parameters for precise sawing. Experiments were performed for verifying the validity of the assumptions made in carrying out the theoretical research. The analysis of the research results and the following conclusions are made: theoretical and experimental values of the initial stiffness of rolled strip saws practically coincide (the difference does not exceed 2 %); the stiffness of the rolled saw according to the theoretical data exceeds the stiffness of the non-rolled saw by more than 80 %. According to the technological modes of RPI 6.1-00 “Preparation of Frame Saws” to ensure the required accuracy of wood sawing, the initial stiffness of the strip saw should be at least 60–70 N/mm. The obtained results allow us to determine the main parameters of unstretched strip saws providing this condition.

Keywords: accuracy of wood sawing, initial stiffness of strip saws, conditions for precise sawing, guides for saws, stress condition when rolling
Water Resistance of Wood-Based Panels Made without Binders

Water Resistance of Wood-Based Panels Made without Binders

Authors: V.N. Ermolin, M.A. Bayandin, S.N. Kazitsin, A.V. Namyatov, V.A. Ostryakova
Year: 2020, Volume: 8, Number: 3
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Abstract

Water resistance of medium density panels made of hydrodynamically treated sawdust without binders was studied. It is customary to use panel swelling through-thickness after soaking in water for 24 hours and residual strength under static bending as criteria for water resistance. The effect of the following operation conditions of hot pressing on water resistance of panels was studied: temperature of press boards, specific pressing time and molding compound humidity. It is found that an increase in the temperature of press boards and specific pressing time results in a decrease in panel swelling through-thickness. The smallest value of this parameter was recorded at the press pulp humidity of 210 %. In comparison, the effect of boiling in water within 1 hour on the properties of the panels made of mechanically activated, as well as particle boards, high density fiberboards (HDF) and medium density fiberboards (MDF) of dry process was studied. It was found that the particle boards and medium density fiberboards were completely broken. High density fiberboards retained their shape, but the static bending strength was 89.7 % of the initial one. The panels made of mechanically activated wood particles had the static bending strength loss of 18.2 % of the initial one (before boiling – 22.4 MPa, after boiling – 17.4 MPa). The cyclic tests conducted according to the state standard GOST R 56309–2014 and by the “soaking–freezing–drying” method allowed us to find that the moisture deformations of the panels made of mechanically activated wood particles are reversible. As a result of 3 test cycles, a decrease in the static bending strength of the boards was 29.2 %. At the same time, their dimensions had no considerable changes. The value of residual swelling through-thickness was 0.62 %. The obtained results show that the preliminary hydrodynamic treatment of wood wastes (sawdust) allows making eco-friendly boards that have permanent water resistance. They can become widely used, especially under severe temperature and moisture conditions of operation.

Keywords: mechanical activation, water resistance, swelling, wood-based panels without binders, hydrodynamic treatment, autohesion
Application of Ash-Polymer Mixtures in the Construction of Forest Roads

Application of Ash-Polymer Mixtures in the Construction of Forest Roads

Authors: А.N. Minaev, O.V. Zubova, D.M. Kulik, V.V. Siletskiy, V.I. Lugovov
Year: 2020, Volume: 11, Number: 3
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Abstract

The construction of forest roads is one of the priority issues of the forest industry. The underdeveloped forest road network does not allow the use of forest resources, which are situated too far from the civil roads because of lower profitability. Expanding the forest road infrastructure will allow to increase mobility as well as profitability of resource extraction. Forest roads are expensive. This is due to the high cost of road construction materials and long distance of their delivery. One of the latest ways of cost reduction of road construction materials is the use of industrial wastes. A study was carried out in order to obtain a pavement layer with high physical and mechanical properties and a relatively low cost from industrial wastes for the problem solving. Household high-pressure polyethylene is used as a binder in the mixture, and ash from incineration of sewage sludge is used as filler. A coagulation-condensation structure is formed due to the use of plastic in the mixture; herewith the material is characterized by high strength and frost resistance. The study has a scientific novelty as the issues of polyethylene adhesion with various fillers are poorly known. Recycled polymers (crushed polyethylene, fraction 1.5–2.5 mm) were used as a structure-forming component. Ash from the sewage sludge incineration obtained at the SUE «Vodokanal of St. Petersburg» was used as the filler material. According to the test results, a material with the following parameters was obtained: the compression resistance of 170.63–552.08 MPa, the elastic modulus of 322–1022 MPa, water absorption within 1 %; that allows using the material in the forest road construction. This material can be used as an application for reinforcing the pavement layer in the forest road construction on weak soils. The use of the obtained material in forest road construction will expand the forest road infrastructure by cost reduction. The studies of the Department of Industrial Transport of the Saint-Petersburg State Forest Technical University show that the high physical and mechanical parameters will increase the service life of forest roads and hence the time between overhauls. These aspects have a positive effect on the profitability of the forest road construction.

Keywords: household high-pressure polyethylene, ash from incineration of sewage sludge, construction of forest roads, road structure, road construction material
Substantiation of Fuel Consumption Rates of a Harvester

Substantiation of Fuel Consumption Rates of a Harvester

Authors: K.P. Rukomojnikov, V.O. Kuptcova
Year: 2020, Volume: 11, Number: 3
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Abstract

The research purpose was to substantiate the parameters of diesel fuel consumption during felling by the feller-delimber-slasher Silvatec 8266TH in the forest area of the Mari El Republic. The goal was achieved by conducting the experimental tests using the volumetric procedure of filling the machine tank at the end of the operating cycle. The experimental research was accompanied by fixation of the diameters and volumes of the trees cut down. After cutting down each of these groups of trees, the machine was stopped. The fuel tank was filled to the filler pipe. Each time the researchers fixed the fuel volume filled. Processing of the experimental data allowed us to obtain a regression model. This model characterizes the average fuel consumption for various tree diameters. Analysis of the obtained solution made it possible to find out that the average fuel consumption of a Silvatec 8266TH harvester working in the forest areas of the scientific and experimental forestry of the Volga State University of Technology depends on the average diameter of the cut trees. The multiple coefficient of determination (R2) of the resulting non-linear model was 0.73. The obtained mathematical dependence can be used by timber enterprises for the approximate rapid calculation of the consumption rates in the absence of running standards. Calculations can be carried out to substantiate the volume of the consumed fuel and to calculate the project cost of harvested products in the development of new forestry enterprises and new forest areas.

Keywords: feller-delimber-slasher, logging, regression model, fuel consumption rates, energy consumption, cut-to-length
Zonality of Forest Fuels and Their Pyrogenic Transformation in Pine Forests of Central Siberia

Zonality of Forest Fuels and Their Pyrogenic Transformation in Pine Forests of Central Siberia

Authors: G.A. Ivanova, V.A. Ivanov
Year: 2020, Volume: 18, Number: 4
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Abstract

Fires in the forests of Siberia occur annually and cause enormous damage to natural resources. Therefore, studies of the natural forest fire hazard, one of the components of which are forest fuels, are relevant. The research carried out on 53 sites in the pine forests growing along the Yenisei meridian transect revealed that surface fuel loads in pine stands of different zones of Central Siberia are defined by geographical latitude and increase from the forest-steppe zone to the northern taiga subzone. The largest forest fuel loads are concentrated in the pine stands of the northern and middle taiga. Their composition is dominated by loads of duff, the fraction of which in surface fuel loads increases from the forest-steppe zone (57.4 %) to the northern taiga zone (71.3 %). The obtained dynamic equations of the reserves of grass-shrub understory over the season may be applicable to grassy types of pine forests. Combustion of surface forest fuels in pine forests during surface fires of different intensity varies from 10.8 to 31.4 t/ha, which is from 26.1 to 74.1 % of their loads before the fire. The intensity of fires determines not only the number of burned forest fuels, but also their post-pyrogenic accumulation regardless of zonal and environmental conditions. The variation of fuel loads in forest areas is related to pyrogenic effects and the recovery period after the last fire, as well as to the mosaic distribution of living ground vegetation. Equations of accumulation of surface forest fuels after fires of different intensity that can be applied to pine forests of Central Siberia are developed. A change of dominants in the ground cover and a decrease in the productivity of the grass-shrub understory occurs in a long-term absence of fires in pine forests. The development of moss cover contributes to the decrease in litter reserves. The data obtained on the loads of surface forest fuels and their transformation during a fire provide the basis for understanding and simulation fire behavior, estimating emissions and impacts of fires on fuel loads, and can be used for improvement the existing global and regional models.

Keywords: forest fires, forest fuels, loads, surface forest fuels, fire intensity, pine forests, Central Siberia
Formation and Dynamics of the Biotope of Pine Plantations on Peat Soils after Irrigation Improvement

Formation and Dynamics of the Biotope of Pine Plantations on Peat Soils after Irrigation Improvement

Authors: B.V. Babikov, M.B. Subota
Year: 2020, Volume: 13, Number: 4
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Abstract

Wetlands in the Russian Forest Fund occupy more than 12 % of the country’s territory exceeding 100 mln ha. These are primarily afforested swamps with low-quality forest stands. A significant part of raised bogs is generally forestless. Meanwhile, about 60 % of the eutrophic and mesotrophic swamps are potentially rich. Here, only excess of water interferes with successful forest growth. The world forestry has accumulated wide experience in regulation of soil water retention through irrigation improvement and drainage. In Russia there are classic examples when stands of the 1st quality class grew in the large (several thousands of hectares) areas after irrigation improvement. One such case is the Kheynovskoye swamp with an area of over 2 ths. ha located in the Lisino training and experimental forest of the Saint-Petersburg State Forest Technical University and drained in 1847. However, there are enough cases of unsuccessful drainage. The better half of the drained swamps before drainage were grown over with forests. Irrigation improvement has turned around the growth conditions of all stands existed before drainage, but in poor eutrophic swamps forest growth is insufficient. The research purpose was to study brand new stands in the drained territory taking into account the whole formation cycle of the biotope and its change with time. In order to get that done, a pilot plot was laid out on a eutrophic-mesotrophic treeless peat, where drainage was carried out using a frequent network of small grooves (furrows). They were dug with the help of a double moldboard (trench digger) and directed into the channels of the drainage network, thus providing for constant water drainage. Forest plantations were laid out on the layers formed along the furrows with the participation of the author. We had been assessing changes in the stand condition each 5–10 years for almost 60 years. The studies have shown that in the first years after removal of excess water and better soil warming, sedimentation and depletion of peat occurred. At a depth of 0.4–0.5 m in 20 years after planting the trees, the depth of peat decreased by almost 2 times. The living ground cover has changed under the influence of drainage and the developed stand. The initial (swamp) type of soil formation was replaced with soddy soil. High-quality heavyproducing plantation was formed. When comparing the parameters of the created artificial plantation with the stands of natural origin according to the growth course tables, it was found that the stock of the created stands at the age of 50 is almost twice higher than the stock of natural stands. It can be assumed that when growing wood pulp for its intended purposes in 100 years two yields can be harvested. Changes in peat soil have taken place during the last 50 years. The carbon (C) content decreased and the total nitrogen (N) content increased due to the intensive decomposition of peat, as evidenced by the decrease in the ratio of C:N. Structure developed in peat soil. The beginning of podzol-forming is noticed. Probably, the actual and hydrolytic acidity have increased due to the needle litter.

Keywords: biotope, irrigation improvement, water balance, water supply, drainage rate
Performance Measurement of Blueberry Leaves and Fruits

Performance Measurement of Blueberry Leaves and Fruits

Authors: E.A. Flyurik, N.V. Bushkevich
Year: 2020, Volume: 13, Number: 4
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Abstract

The genus Vaccinium includes cowberries, cranberries and blueberries. Nowadays they are under large scale cultivation for the purposes of fruit production. In the Republic of Belarus bog blueberry (Vaccinium uliginosum L.) can be met in situ; among the cultivated plants the most prevalent varieties are highbush blueberry (Vaccinium corymbosum L.) and lowbush blueberry (Vaccinium angustifolium Ait.). Blueberry is rich in bioactive substances, such as organic acids, anthocyanins, pectin and tannins. The leaves and fruits of blueberries are a promising plant raw material for the food, cosmetic and pharmaceutical industries. It is useful for the production of herbal teas, juices, jams, preserves, shampoos, creams, infusions, extracts, etc. For the improved process of extracting leaves and fruits of blueberries, as well as quality estimation of extracts, it is necessary to know the basic technological properties of raw materials. During the study, the technological properties of various lowbush blueberry species were found. The properties of leaves are the following: bulk density – from 0.08±0.001 to 0.13±0.001 g/cm3; unit weight – from 1.20±0.003 to 2.10±0.001 g/cm3; bulk weight – from 0.09±0.001 to 0.14±0.003 g/cm3; porosity – from 0.04±0.001 to 0.06±0.002, void cross-section – from 0.89±0.001 to 0.95±0.001; absorption coefficient for water – from 4.99±0.10 to 6.09±0.10 cm3/g, 30 % ethanol – from 4.50±0.10 to 5.49±0.01 cm3/g, 50 % ethanol – from 4.25±0.05 to 5.03±0.05 cm3/g, 70 % ethanol – from 3.74±0.16 to 4.74±0.19 cm3/g and 96 % ethanol – from 2.75±0.15 to 3.49±0.09 cm3/g. The properties of fruits are the following: bulk density – from 0.57±0.001 to 0.69±0.001 g/cm3; unit weight – from 1.32±0.059 to 1.48±0.040 g/cm3; bulk weight – from 0.59±0.001 to 0.70±0.001 g/cm3; porosity – from 0.02±0.001 to 0.03±0.001; void cross-section – from 0.48±0.01 to 0.59±0.001; absorption coefficient for water – from 4.06±0.16 to 4.52±0.17 cm3/g, 30 % ethanol – from 3.38±0.05 to 4.06±0.02 cm3/g, 50 % ethanol – from 3.36±0.03 to 3.94±0.08 cm3/g, 70 % ethanol – from 2.86±0.09 to 3.74±0.07 cm3/g and 96 % ethanol – from 0.94±0.04 to 1.04±0.01 cm3/g. The obtained data allow to predict the optimal method and conditions of bioactive substances extraction from blueberry leaves and fruit. The data can also be used in the development of technological documentation which regulates the production process and the quality of the final product, as well as in the calculation of the process mass balance to ensure the appropriate level of profitability.

Keywords: technological properties, fruits and leaves of lowbush blueberry, Polovchanka, Motego, Yanka, hybrid Form 24

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