Russian Forestry Journal
ISSN (print): 0536-1036
Media registration certificate: ПИ № ФС 77 - 68484 от 27.01.2017
Founder: Northern (Arctic) Federal University named after M.V. Lomonosov
Editor-in-Chief: Melekhov Vladimir I. , Doctor of Sc., Full Professor
Frequency / Assess: Assess: 6 issues per year / Open
Included in: White List (3rd level),Higher Attestation Commission list, RISC
Lesnoy Zhurnal (Russian Forestry Journal) is the oldest naturalistic and forestry scientific periodical since 1833. Since 1958 it has been published in a series of the “Bulletin of Higher Educational Institutions”.
Lesnoy Zhurnal (Russian Forestry Journal) maintains good traditions and the main idea of the unity of forestry, science and practice, constantly expanding the themes and the range of issues. It publishes the research papers in all fields of forestry, reports on the manufacturing application of the results of completed studies, on the best practices in forestry and forest industries.
The founder and publisher is the Northern (Arctic) Federal University named after M.V. Lomonosov.
Lesnoy Zhurnal (Russian Forestry Journal) is registered in the Federal Service for Supervision of Communications, Information Technology and Mass Media (Roskomnadzor), certificate ПИ № ФС 77 - 68 484 от 27.01.2017.
The publication is registered in the International Center ISSN – ISSN 0536-1036.
Lesnoy Zhurnal (Russian Forestry Journal) is included in the List of peer-reviewed scientific publications of the State Commission for Academic Degrees and Titles.
The journal is reviewed by the Russian Institute for Scientific and Technical Information of the Russian Academy of Sciences (VINITI RAS), is indexed in the system of the Russian Science Citation Index.
Lesnoy Zhurnal (Russian Forestry Journal) meets the international standards and is included in the international databases Scopus, Emerging Sources Citation Index (Web of Science Core Collection), Russian Science Citation Index (RSCI) database on the Web of Science platform, DOAJ, Ulrich’s Periodical’s Directory, AGRIS, EBSCO, J-Gate, Chemical Abstracts Service, CABI Forest Science Database, Index Copernicus, China National Knowledge Infrastructure (CNKI), Norwegian Directorate for Higher Education and Skills, EuroPub, InfoBase Index, JournalTOCs, Scilit.
Full-text articles are placed in the electronic library systems: eLIBRARY.RU, KiberLeninka, Lan, IPR BOOKS.
The journal archive is presented in the NArFU electronic library since 1958.
Annually more than 100 original articles are published in 6 issues of the journal. Every article provides metadata (an abstract, keywords, references, an information about the authors) in Russian and English.
Subscriptional index: 70368
The International DOI indexes are assigned to all articles.
The journal does not have article submission / processing charges nor author’s remuneration.
We are grateful to our authors, reviewers and members of the Editorial Board for their cooperation, and to our readers – for their interest in the journal!
Currently, the journal publishes the materials in the following specialties groups:
2.6.11. Technology and Processing of Synthetic and Natural Polymers and Composites
4.1.6. Forest Science, Forestry, Forest Plantations, Land and Forest Reclamation, Landscaping, Forest Pyrology and Forest Inventory
4.3.4. Technologies, Machinery and Equipment in Forest Management and Wood Processing
The requirements and terms for the content publication in Lesnoy Zhurnal (Russian Forestry Journal) can be found at our website: http://lesnoizhurnal.narfu.ru/en/forAuthors.
Current Issue
No 6 (2025)
Forestry
Satellite Monitoring of the State of Serbian Spruce (Picea omorika (Panč.) Purk.) Stands in the Mount Veliki Stolac Area (Republic of Srpska)
Abstract
Multispectral satellite images of medium spatial resolution are the main source of data for remote sensing of stands, including the assessment of forest inventory and biological productivity parameters of stands, as well as changes in the vital status of species. The aim of this work has been to determine the effects of pyrogenic impact on one of the largest populations of Serbian spruce (Picea omorika (Panč.) Purk.) in the Mount Veliki Stolac area (the Republic of Srpska, 1,675 mabove sea level) using multi-temporal multispectral Sentinel-2 imagery. Serbian spruce (Picea omorika (Panč.) Purk.) is a relict, endangered tree species whose total population has been declining significantly over the past 100 years. Currently, the natural habitat of this species is limited to a fairly small area on the border of Serbia and Bosnia and Herzegovina. To analyze satellite data, a multi-stage method has been proposed that has allowed identifying the Serbian spruce population in the surveyed areas, determining the dynamics of changes in vital status over the past 10 years, and assessing the effects of the forest fire that occurred in this area in 2021. It has been revealed that approximately 50 % of Serbian spruce stands in the study area have been damaged, with the species predicted to die for 1/2 of these areas. The greatest damage has been caused to the stands in the central part of the northern slope of Mount Veliki Stolac. Average estimates of the areas of vital status for the recovery period are: healthy – 17.6 ha, weakened – 8.4 ha, damaged – 8.0 ha, drying out – 1.2 ha. The analysis of vegetation indices has shown the absence of significant trends towards natural regeneration of Serbian spruce. The analysis of images for 2024 allowsus to reasonably assume that the process of replacing Serbian spruce with deciduous species has begun, while no improvement in the vital status of the Serbian spruce population is expected. Thus, in order to preserve this population, it is necessary to carry out reforestation of this valuable relict species.
Russian Forestry Journal. 2025;(6):9-32
9-32
A Strategy for Adapting the Hydraulic System of Woody Plants to Various Tiers of the Floodplain Forest of the Enmyvaam River (Chukotka)
Abstract
The article examines the features of the anatomical structure of the hydraulic system of 17 species from 13 genera of 6 families of woody flowering plants, which belong to different tiers of the floodplain forest growing along the Enmyvaam River (hypoarctic tundra). It has been found that 1st-tier trees have the most advanced hydraulic system. It consists only of libriform fibers and vascular segments of a short-cylindrical, cylindrical fibrous shape with simple perforations, punctate alternate, closed, and close-set intervascular porosity, single-row, mostly homogeneous rays, apotracheal and paratracheal parenchyma. This is most likely due to the particularly intense water exchange regime in tall trees, whose crowns are more susceptible to harsh environmental influences. Shrubs and low-growing trees of the 2nd tier demonstrate the presence of both archaic and evolutionarily advanced features in approximately equal quantities in the stem wood. For example, in the genera Alnus and Sorbus, there is a combination of libriforms with fibrous and vascular tracheids; vessel segments with scalariform, reticulate, and simple perforations, apotracheal and paratracheal parenchyma, and heterogeneous and homogeneous palisade rays. As for the species of the genus Salix, they have a highly developed hydraulic system, similar to that of the 1st-tier plants. Small shrubs and dwarf shrubs of the 3rd tier, living in areas with excessive absolute and relative humidity and sometimes extremely low lighting, have the widest range of specific adaptive features acquired as a result of adaptation to the extreme conditions of high latitudes.
Russian Forestry Journal. 2025;(6):33-47
33-47
Comparative Ecological and Physiological Characteristics of the Response of Oak (Quercus robur L.) Seed Stands to Forest Growth Conditions
Abstract
A comprehensive retrospective ecological and physiological analysis of tabular data on the dry mass of stands of the genus Quercus aged from 10–20 to 140–200 years has been carried out in order to convert them into quantitative indices of the functioning of the root system, leaf apparatus, net primary productivity and carbon sequestration adapted to environmental conditions from the broad-leaved forests of Germany to the southeastern reaches of the Russian Plain. Ecological and physiological indices have been calculated for 1 conventional tree of average dry weight. Biological productivity has been determined by the relative increase in the average dry weight of a tree in adjacent ages. Quantitative indices of mineral productivity of the root system have been determined using the method by V.M. Lebedev (adapted by E.V. Lebedev to forest woody plants), and net photosynthetic productivity has been determined using the method by A.A. Nichiporovich. A negative relationship has been established between the net photosynthetic productivity, net primary production, biological productivity and plant age, and a positive one between mineral productivity, net photosynthetic productivity and biological productivity (r = 0.863…0.998 and 0.797…0.991). The relationship between the ratio of root potential to photosynthetic potential and plant age has turned out to be highly positive (r = 0.863…0.980), while the relationship between the ratio of root potential to the photosynthetic potential and mineral productivity, net productivity and biological productivity has been highly negative. The relationship between mineral productivity and plant age has been negative. A decrease in the absorption activity of the roots has activated a non-specific adaptive response affecting physiological, functional and morphological processes that enhance the supply of mineral nutrients to the aboveground organs, ensuring photosynthesis and stabilizing the biological productivity of the plant. Under these conditions, a transfer of metabolic processes at the organism level during the ontogeny to a mode of more efficient use of nitrogen during the formation of biomass to maintain homeostatic equilibrium in the biological system has been demonstrated.
Russian Forestry Journal. 2025;(6):48-59
48-59
The Influence of Soil Properties in Discrete Mounds on the Growth of Norway Spruce (Picea abies L. Karst.) Seedlings
Abstract
The aim of the study has been to identify the most significant soil factors of the root layer (water-physical and agrochemical) for ensuring the growth of Norway spruce. The research has been carried out in 5-year-old crops created at the mounds prepared by an excavator at the fresh cutting of blueberry-type forest in the Vilegodsky forestry of the Arkhangelsk Region. 2-year-old planting stock of Norway spruce with a closed root system (2.0 thousand pcs./ha) has been used. For 1 mound, 2–3 seedlings have been planted: in the centre, at the edge away from the hole, and at the edge near the hole formed during the preparation of the planting site. The main biometric parameters have been measured in seedlings (60 pcs.) and in similarly aged spruce undergrowth (40 pcs.) of the subsequent generation in the cutting strip. Multivariate statistics methods have been used to analyze the data. It has been determined that the most responsive to differences in growing conditions are plant height associated with growth, as well as the length of lateral roots. It has been found that, based on the similarity of water-physical and agrophysical properties in the root layer of spruce growing in the cutting strip, the central part of the planting site is closer. These conditions have also contributed to a better growth of seedlings in the centre, compared to the edges of the mound (near the hole and away from the hole). It has been established that the priority in ensuring the growth parameters of spruce in the 1st years of life largely belongs to water-physical properties, such as the mound height, porosity, solid body density, and moisture content, as well as the closely related density of soil structure and aeration porosity. At the same time, of the agrochemical indicators, only the content of potassium and phosphorus (at the trend level) have turned out to be significant. In practical terms, the results obtained make it possible to adjust the recommendations for discrete soil tillage with an excavator and the placement of planting material in planting sites. They will be useful in predicting the growth of planting material using rapid methods of soil research.
Russian Forestry Journal. 2025;(6):60-76
60-76
Peculiarities of the Response of Old-Growth Pine to Drainage of a Watershed Area in the Komi Republic
Abstract
The aim of the study is determined by the need to study the silvicultural efficiency of hydromelioration at sites with old-growth pine stands in the Komi Republic, where the total drainage area currently amounts to approximately 100 thousandha. The relevance of this work is related to the fact that as a result of the implementation of hydromelioration plans, significant areas of old-growth stands have accumulated in the republic. At such sites in commercial forests, the forest industry drainage field is focused on timber harvesting. At the same time, it is permissible to preserve drained standsup to the age of natural maturity in protective forests that perform sanitary, hygienic and aesthetic functions. When deciding on alternative options for using such stands for timber harvesting, it is advisable to assess their ability to adapt to the water regime on drained forest lands. The dynamics of radial increment of old-growth pine trees located at different distances from drainage channels has been studied. The increment is a fairly objective marker of the response of trees to changes in the water regime of soils after drainage, both positive and negative. It has been established that old-growth pine trees in the watershed area successfully adapt to changes in the water regime after drainage. The average increment in the totality of old-growth pine trees in the inter-channel space reaches its maximum at the beginning of the 5th five-year period after drainage. According to the forecast, the increment will reach values corresponding to the increment before drainage by the end of the 12th five-year period. All other things being equal, in the first 4 five-year periods after drainage in the inter-channel space, a positive relationship is observed between the increment and the distance of trees from the channels, and from the 5th five-year period, the negative direction of the relationship between these characteristics, typical for drained stands, is restored. The latter indicates the successful adaptation to the conditions after drainage in the watershed area not only of individual old-growth pine trees, but also of their totality in the inter-channel space at the hydromelioration site.
Russian Forestry Journal. 2025;(6):77-91
77-91
Frost Resistance of Containerized Scots Pine Seedlings in High Latitudes
Abstract
The technology for producing planting stock with a closed root system of the main forest-forming species using a multi-rotation cultivation mode is being improved. In forest nurseries of the middle taiga forest subzone of Russia with a short growing season, the introduction of such a regime is difficult due to the risk of seedlings being unprepared for transplantation to a planting area and low stress resistance. At the end of the growing season in November 2023, a comparative analysis of 1-year-old containerized seedlings of Pinus sylvestris L. was carried out under non-rotation (0rot) and 2-rotation (2rot) cultivation modes in northern latitudes. The experimental 1rotT variant has differed from the 1rot (1-rotation mode) by the use of a shade cloth. Morphometric parameters and the provision of basic mineral nutrients (N, P, and K) have been determined in seedlings. The dynamics of the index of damage to pine needle cell membranes by low temperatures in the autumn period during the transition of the plant from vegetation to dormancy has been studied. The morphometric parameters of the 2rot seedlings, with the exception of the stem diameter, have been lower than those of the seedlings of other variants and have not corresponded to the standard ones. The needles and stems of 2rot seedlings have differed from all variants in increased levels of nitrogen and potassium, as well as phosphorus in the stems compared to the 0rot and 1rotT variants. Unlike other variants, their needles have been bright green and they had not had an apical bud. The needles of seedlings of all cultivation modes in the 1st ten days of September have been resistant to low temperatures only down to –4 °C. The frost resistance of seedling needles has increased and in the 3rd ten-day period of October in all variants except 2rot the needles have not been damaged even at –25 °C. The 2rot seedlings have differed from other variants in their reduced frost resistance of needles from the 2nd ten-day period of September. Considering the possibility of frosts in the autumn period, there is a risk of damage to 2rot seedlings.
Russian Forestry Journal. 2025;(6):92-105
92-105
Sap Productivity of the High-Mountain Maple Stands in the North Caucasus
Abstract
The characteristics of maple syrup produced from Acer Trautvetteri Medw., growing on the northern macroslopes of the Caucasus, are presented in the article. The object of the study has been high-mountain maple stands at the lower limit of the vertical belt of their distribution. The geographical coordinates of the object are 42°56.352 N, 44° 29.677 E. The altitude above sea level is 1374–1398 m. The slope steepness is 30–35°, the slope is exposed to the north. The beginning of sap secretion is the 3rd ten-day period of April, the duration of sap production is 12–17 days. The tapping has been carried out using a closed method. It has been shown that maple stand sap productivity averages about 4 t/haper season. The main characteristics of maple sap and syrup have been determined by liquid chromatography in isocratic and gradient modes. The chemical composition of the syrup and the content of organic and inorganic components have been determined using a Maestro liquid chromatograph with spectrophotometric and refractometric detectors. The quantitative analysis of the elemental composition based on atomic absorption spectra has been carried out using a Contra AA 800 spectrometer with a flame and electrothermal atomizer. The sugar content in the sap has equaled 0.9–1.3 %. Maple sap syrup has been obtained by evaporation. The sugar content in the Trautvetter maple syrup has equaled 41 %, which is 12 % less than in the syrup produced in Canada. The proportion of glucose in the syrup is 1.7 %, the proportion of sucrose – 39.2 %. The content of Ca is 1286 mg/kg, the content of K – 9063 mg/kg. The elements such as Fe, Mn, Cu and Na in the syrup are present in small quantities – from 1 to 144 mg/kg. In terms of the content of identified chemical elements and organoleptic characteristics, syrup from the sap of the Trautvetter maple differs from syrup from the Canadian sugar maple. The data obtained contribute to solving the tasks of estimating the reserves of potential food resources of mountain forests in Russia. The results of the study can be used to update regulatory documents in the forestry sector and implemented into training programs for forestry specialists.
Russian Forestry Journal. 2025;(6):106-118
106-118
Technologies, Machinery and Equipment in Forest Management and Wood Processing
The Results of Experimental Studies of the Apparent Density of Wood
Abstract
The article presents the results of experimental studies of the apparent density of wood obtained under various operating modes of the pneumatic measurement system. A new technique and experimental unit have been used for the research to determine the apparent volume of porous bodies in an atmospheric air environment. For the experiments, samples of aspen, spruce, birch, pine and oak wood taken from the sapwood of tree stems have been used. The functional stability of the developed method for determining the apparent volume of porous bodies has been experimentally confirmed. Using the developed experimental unit, the apparent volumes have been measured and apparent densities of wood samples of various species have been calculated under conditions of overpressure and underpressure of the system operation. In the overpressure mode, the pneumatic system has operated at +70 and +90 kPa, and in the underpressure one at –70 and –90 kPa, respectively. It has been experimentally established that when operating the measurement system in the underpressure mode, the apparent density of wood is higher than in the overpressure mode. The values of apparent densities determined in the underpressure mode vary within the range of 1.361 to 1.434 g/cm3 for aspen, 1.151 to 1.348 g/cm3 for spruce, 1.356 to 1.402 g/cm3 for birch, 1.298 to 1.444 g/cm3 for pine and 0.99 to 1.147 g/cm3 for oak. The corresponding values of apparent densities determined in the overpressure mode have been 1.316 to 1.372 g/cm3 for aspen, 1.106 to 1.274 g/cm3 for spruce, 1.292 to 1.356 g/cm3 for birch, 1.285 to 1.412 g/cm3 for pine and 0.904 to 1.138 g/cm3 for oak. Thus, the hypothesis about the priority of applying the underpressure mode when determining the apparent volume of porous bodies in the atmospheric air environment has been confirmed. The magnitude of the largest deviation in the results between the highest and lowest values of apparent density when determined in different modes has been, respectively: for aspen – 6.83 %, for spruce – 8.54 %, for birch – 6.35 %, for pine – 6.82 % and for oak – 3.91 %. The magnitude of the largest deviation between the maximum values of apparent density and the generally accepted value of 1.46 g/cm3 have been, respectively: for aspen – 1.78 %, for spruce – 7.67 %, for birch – 3.97 %, for pine – 1.1 % and for oak – 21.44 %.
Russian Forestry Journal. 2025;(6):119-130
119-130
Synchronization of Log Cutting and Sawn Timber Drying Technologies
Abstract
The research is devoted to the synchronization of log cutting and sawn timber drying processes. It has been shown that, given the actual number of sawn timber sections produced by large-scale sawmilling during the technological period, the buffer storage units of drying stacks of boardsdo not ensure the uninterrupted operation of the tunnels. There is either an overflow of buffer storage units with stacks, or their absence when free space occurs in the tunnels. The methods used for calculating the buffer storage units of the stacks donot take into account the probabilistic nature of the characteristics of sawmills and drying shops. Theydo not provide a mathematical description of the relationships between the rate of incoming raw sawn timber stacks, the capacity of the buffer storage unit, as well as the number and capacity of drying tunnels. The aim of this work has been to find the patterns of accumulation of sawn timber stacks in front of drying tunnels and loading tunnels with stacks, with the establishment of the average waiting time for stacks in the storage unit under different characteristics of log sawing and sawn timber drying processes. The “stack storage unit – drying tunnels” system has been presented as a multi-channel queuing system with parallel operation of channels and waiting. The main initial indicators of the system are the rate of incoming raw sawn timber stacks to the storage unit in front of the drying tunnels and the intensity of sawn timber drying in 1 tunnel. The main output operational characteristics are the probability of a full tunnel load, the average number of stacks in the storage unit, and the time the stack remains in the storage unit. The general patterns of accumulation of board stacks and filling of drying tunnels in the conditions of large-scale production of sawn timber have been established. The examples of solving practical problems of synchronizing sawmilling and sawn timber drying have been presented. It has been shown that the obtained graphs and mathematical models make it possible to solve production problems: to analyze the influence of the type and size of the sawn raw material, the structure of the sawing patterns, the feed rates of the sawmill equipment, the operating modes of the sawmill, as well as the drying modes of the sawn timber on the choice of the number of tunnels and their capacity.
Russian Forestry Journal. 2025;(6):131-141
131-141
Technology of Wood Chemical Processing and Production of Wood-Polymer Composites
Comparative Analysis of Packaging Cardboard Obtained from Different Types of Cellulose Fibrous Raw Materials
Abstract
A comparative analysis of the properties of packaging cardboard types manufactured in laboratory conditions from cotton stalk cellulose with industrial samples of cardboard from recycled materials and high-yield semi-finished products produced at Russian paper mills has been presented in the article. The aim of the study has been to assess the possibility of using cotton waste as an additional or alternative raw material for the production of packaging cardboard, especially in cotton-producing countries. The use of cotton stalks as a raw material for the production of paper and cardboard not only solves the problem of agricultural waste, but also provides an opportunity to implement a circular economy model, according to which waste is recycled to produce high-margin materials. Samples of cardboard made from cotton stalk cellulose of 3 types from different manufacturers have been compared: linerboard made from primary fiber at the Arkhangelsk Pulp & Paper Mill; linerboard made from MS-5B waste paper at the Kamenskaya Paper & Board Mill and the “Mayak” Enterprise; linerboards made from eucalyptus waste paper at one of the Brazilian enterprises. To assess the structural characteristics of the samples, a microscopic analysis of the fiber has been carried out, which has made it possible to visualize the differences in the morphological structure of fibers of different nature. It has been established that the cellulose of cotton stalks is geometrically closer to that of eucalyptus waste paper fiber. The fiber length has been 0.75 mm, which is 40 % shorter than the fiber length of cardboard samples from the Kamenskaya Paper & Board Mill and the “Mayak” Enterprise and more than 2 times shorter than the average length of cellulose in the composition of cardboard from the Arkhangelsk Pulp & Paper Mill. The samples have been prepared for testing using standard methods in accordance with the requirements of GOST R 57207–2008. An analysis of the physical and mechanical characteristics of the materials, such as breaking length, bursting strength, etc., has been performed. Given the environmental and economic feasibility of recycling non-wood raw materials, the technology for producing cardboard from cotton stalks represents an important step towards creating more sustainable and competitive materials.
Russian Forestry Journal. 2025;(6):142-154
142-154
The Use of Cationites in the Modification of Kraft Lignin with Nitrous Acid
Abstract
Kraft lignin is the largest-tonnage technical lignin formed during kraft pulp cooking. According to statistics, approximately 70 mlnt of such waste are generated annually. Most of it is disposed of in the system of chemicals recovery and thermal energy generation. Approximately 10…20 % of kraft lignin can be used to obtain a variety of products, for example, in the production of polymers, low-molecular compounds, activated carbon production, rubber industry, etc. For this purpose, kraft lignin is subjected to various types of modifications, including chemical ones: periodate oxidation, halogenation, sulfonation, sulfomethylation, nitration, nitrosation, etc. This article presents a new method for modification of kraft lignin with nitrous acid in a water-dioxane medium using solid-phase catalysis. The cation-exchange resins in H-form containing sulfogroups (cationite KU-2-8 and wofatite) have been used as catalysts. The optimal reagent consumption has been determined to be 50 % sodium nitrite and 230 % cationite from kraft lignin. It has been shown that the developed method and the well-known one using sulfuric acid as a catalyst give similar results. The molecular and electronic spectra of modified kraft lignin have been studied. In the electronic spectra of modified kraft lignin, a new absorption band appears characteristic of the nitroso group in the region of 400…500 nmwith a maximum at 451 nm. By deconvolution, the electronic spectrum of modified kraft lignin is approximated by 6 Gaussians with an error of 2.5 %, while for the initial kraft lignin the spectrum can be described by 4 Gaussians with an error of 3.4 %. In contrast to the IR spectrum of kraft lignin, new absorption bands appear in the spectra of modified lignin at 615, 760, 1,330 and 1,550 cm–1, which are due to vibrations of NO bonds.
Russian Forestry Journal. 2025;(6):155-168
155-168
Barrier and Strength Properties of Agar-Agar Coated Sack Paper
Abstract
Samples of M78 sack paper coated with agar-agar (a biodegradable polymer obtained from brown and red algae) with a thickness of 15–70 μmhave been obtained. It has been shown that when agar-agar is applied to sack paper from an aqueous solution, a continuous elastic coating is formed, with part of the polymer penetrating into the volume of the paper, filling the interfiber space and, possibly, the macro- and micropores of the fibers themselves. As the thickness of the polymer coating grows, the drip absorbency of the material increases and then reaches a certain stable value (taking into account the experimental error). It has been found that the thickness of the agar-agar coating of 40 μmis sufficient to impart barrier properties to sack paper with respect to the action of moisture. In this case, the drip absorbency of coated paper will be equal to ~1000 s, and the absorbency at full immersion will be ~40 %. To evaluate the mechanical properties of pulp and paper materials, a method is proposed for determining the strength properties of the obtained samples, implying a comprehensive deformation of the samples, allowing for anisotropy to be neglected. It has been shown that the tangential stiffness values of sack paper coated with agar-agar is 15–20 % higher than that of the original paper. A mechanism for this strengthening has been developed, which consists in the following. When a load is applied to the paper material, its destruction occurs due to both the rupture of cellulose fibers and the separation of fibers from each other. If there is a lack of binder, the load is transferred from fiber to fiber only by means of friction force. In paper, the surface layer of which is impregnated with agar-agar, the load from fiber to fiber goes through the polymer, therefore the deformation and strength properties increase. The nature of cellulose fibers and agar-agar ensures the manifestation of good adhesion between them. It has been concluded that agar-agar coated sack paper is environmentally friendly, since both of its components are biodegradable.
Russian Forestry Journal. 2025;(6):169-178
169-178
Brief summaries and experience exchange
Calorific Value of the Degraded Stem Wood of Spruce Picea abies (L.)
Abstract
The popularity of bioenergy is increasing in the light of the development of the green economy and the desire to achieve carbon neutrality in production. In this regard, various types of energy raw materials, their properties and waste disposal possibilities are being considered. The purpose of the study has been to assess the calorific value of spruce wood damaged by wood-destroying fungi. An automated ABK-1B bomb calorimeter has been used to measure the calorific value of spruce stem wood. Separately, pellets have been pressed from wood, bark and knots and dried in a drying cabinet at a temperature of 105° C. The pellets have been burned in a completely dry state. The ash weight has been determined as the difference between the weight of the crucible with residues after combustion of the sample in a calorimeter bomb and the weight of the empty crucible. The calorific value of healthy spruce wood is 20,180–20,232 J/g. In the cross section of the spruce stem, the calorific value varies in the range from 18,900 to 21,700 J/g. The lowest values are typical for the pre-edge zone of the degraded wood. Wood damaged by corrosive rot has a lower heat capacity compared to healthy wood by 1.5–6.2 % (18,926–19,868 J/g). The calorific value of wood damaged by destructive rot exceeds that of healthy wood by 1.5–10.5 % (20,487–22,301 J/g). As the stage of destructive rot of spruce wood increases, its calorific value grows. The calorific value of pellets from degraded spruce wood can be estimated by their appearance. The yellow and mottled colors of the pressed raw material indicate a significantly lower calorific value compared to pellets of brown and orange colors. The ash content of degraded wood of different types is at the same level. The ash content of wood damaged by stage 3 corrosive rot is significantly higher than that of healthy wood and wood at previous stages of decomposition by 96–129 %. The calorific value of the bark of spruce stems damaged by rot is at the level of the calorific value of healthy wood, and the ash content is 3 times higher. The calorific value of a knot is 7 % higher than that of healthy wood, while the ash content remains at the same level.
Russian Forestry Journal. 2025;(6):179-188
179-188
Stimulation of Germination and Germination Energy of Scots Pine Seeds with Biochemical Preparations
Abstract
Currently, the task of obtaining high-quality planting stock used in reforestation remains urgent. Stimulating preparations are used to activate germination and seed germination energy. The aim of the work has been to study the effectiveness of using various stimulating preparations on the sowing qualities of Scots pine (Pinus sylvestris L.) seeds. The objects of the study have been Pinus sylvestris L. seeds soaked in solutions of preparations with a purported stimulating effect. The following preparations have been used: technical lingosulfonates, birch bark extracts, filtrate obtained by separating suberin from birch bark, Flavobacterin, Mizorin, condensate formed during the drying of sawn timber, and ash from the Eyjafjallajökull Volcano. In the experiments, several time options for soaking seeds have been adopted: 6, 12 and 24 hours. The highest germination and germination energy have been observed in seeds soaked for 24 hours. The indicators of the seed grain soaked for 6 and 12 hours have also increased compared to the control sample of dry seeds. The best germination has been observed in seeds treated with solutions of nitrosated and chlorinated lingosulfonates at a concentration of 10 % for 24 hours (95 %), the highest germination energy (86 %) has been observed in seeds soaked for 24 hours in an extract of birch bast fraction less than 1 mm (concentration 1:10,000) and filtrate from the separation of suberin from birch bark (concentration 1:10,000). In the control option, the seed germination has been equal to 80 %.
Russian Forestry Journal. 2025;(6):189-200
189-200