Home – Home – Jornals – Siberian Journal of Forest Science 2025 number 5

In the modern concept of forest science, forest vegetation zoning is recognized as the natural-historical basis of forestry zoning, and its purpose is to reflect the natural conditions and specific features of forests that are important for their complex multi-purpose use and increased productivity. The purpose of this article is to present the concept and map of forest vegetation zoning, created over more than 60 years by a team of researchers of the Institute of Forest Siberian Branch of the Russian Academy of Sciences. The stages of work on the map and the change of concepts and notions are noted - from a natural-territorial complex to an ecosystem and geosystem, from phytogeography and geobotany to the ecological-geographical direction in forestry. The map is based on forest fund inventory data from 1973-1990; the legend indicates the percentage of coniferous and deciduous formations (larch, pine, spruce, fir, birch, aspen, dwarf pine forests, stone birch, birch sparse forests, dwarf birch brakes and other formations) within each forest growth zone and subzone. In Siberia, as a part of the entire country, three longitudinal-climatic sectors are distinguished: West Siberian, Central Siberian and East Siberian, each with its own characteristics of forest growth zones and subzones, specific typological composition and productivity of stands. The region of the Mountains of Southern Siberia is distinguished separately, in which, according to the same criteria adopted for the plains and plateaus, 4 sectors of moisture-continentality are distinguished. The internal differentiation of this mountain region on a small scale cannot be shown on the map due to its small contours, but the principle of altitudinal zonal division is observed, published and briefly discussed. The methods and new approaches to compiling the published version of the map, which is part of the zoning map of the entire territory of the forest fund of the USSR, developed at the Institute of Forestry, are described. The published map can serve as a source of information as a starting point for monitoring the forest cover of Siberia, which has been conducted since the early 2000s on a new basis, using the state forest inventory of the country and remote sensing data. This is its historical, scientific and reference value.

For the first time, the phytopathogenic fungus Heterobasidion abietinum Niemelä & Коrhonena has been detected on coniferous trees Siberian pine ( Pinus sibirica Du Tour), Siberian fir ( Abies sibirica Ledeb.), and Siberian larch ( Larix sibirica Ledeb.) in southern Siberia, far from its previously established range. It is possible that its spread to the arboretum occurred due to the movement of planting material from European botanical gardens. Among other Heterobasidion species, H. parviporum Niemelä & Коrhonena is common in the dark coniferous forests of Siberia on Siberian spruce ( Picea obovata Ledeb.), Siberian pine and Siberian fir. In terms of phytopathogenicity and ability to colonize wood with well-developed resin ducts (especially Siberian spruce), H. abietinum is significantly inferior to H. parviporum . It has been established that the Siberian strains of H. abietinum and H. parviporum are closely related. A stable difference (with the formation of separate clades) only in the glyceraldehyde 3-phosphate dehydrogenase (GPD) gene. The vast areas of Siberian fir forests (about 13 million hectares), as well as regular outbreaks of mass insect infestations: (Siberian moth ( Dendrolimus sibiricus Tschetverikov), four-eyed fir bark beetle ( Polygraphus proximus Blandford), which lead to mass weakening and drying of Siberian fir, provide optimal conditions for the development of the low-pathogenic species H. abietinum . Forests that are not subjected to various types of stress are resistant to H. abietinum . Areas of forest dieback as a result of the phytopathogenic effect of H. abietinum has been established only in the conditions of an arboretum on soils after long-term agricultural use. Global climate change, accompanied by an increase in extreme weather events (droughts, storm winds, etc.), as well as an increase in anthropogenic impact (various types of logging and industrial pollution), creates conditions for a further increase in the aggressiveness of root pathogens, particularly H. abietinum .

The effect of mycocompost (the bioadditive) - pine sawdust partially destructured by a wood-destroying fungus culture - on the forest grey soil microbiocoenosis (Krasnoyarsk forest-steppe) was studied. Mycocompost variant was compared with the two ones: soil without bioadditives (control) and soil with addition of intact sawdust. In the trial areas (1 m²), a layer of turf was removed, bioadditives were applied in the amount of 1 % by weight to the top soil layer (10 cm), then the cut turf was returned to its place. During the first year an increase of the total number of soil microorganisms by 5-10 times was observed in all variants of the experiment including the control that was mainly related to the products of degradation of dead turf. Microbial processing of the both sawdust and mycocompost began in the second year of the experiment and was accompanied by a temporary decrease in soil pH, changes in the structure of soil microbocoenosis, a rise in the proportion of fungi and oligotrophic microorganisms, as well increase of availably nitrogen deficiency. The analysis of the data on soil microorganism number, structure of microbocoenosis, microbial respiration and biomass, mineralization velocity of organic matter, enzymatic activity, etc. showed that during two years in the variants with mycocompost and intact sawdust microbial utilization of bioadditives occurred gradually and did not cause imbalance of biological processes in grey forest soil. The mycocompost variant exceeded the control and sawdust ones in terms of the total number of soil microorganisms and biomass on average 2-3 times, did not cause stable soil acidification and provided better preservation of the introduced culture of Trichoderma harzianum Rifai. In combination with additional nitrogen supplementation, mycocompost can be used as a biofertilizer for poor forest soils.

The influence of spruce ( Picea obovata Ledeb.) stands on the change in morphological characteristics, physicochemical properties, state of organic matter, as well as the qualitative and quantitative composition of the microbiocenoses of cryogenic meadow-chernozem soil formed under meadow-steppe vegetation in Central Yakutia was studied. By means of the complex application of soil, microbiological, statistical research methods, all changes that occurred in the original cryogenic soil were identified and assessed. Thus, over a 45-year period of forest vegetation influence, the morphological profile of the original meadow-chernozem soil (Luvic Chernozems Sodic), which had the form: Аv, ca-Aca-ABca-Bcа-BCca-Cca, was transformed into the profile of cryogenic humus-carbonate soil (Calcic Cryosols Eutric), which was already characterized by the following structure: O-А0-A-ABca-Bса-BC-Cca. Over the noted period, a forb-green moss vegetation cover was formed on the surface of the forest soil, as a result of which the depth of seasonal thawing decreased. The physical-chemical properties, humus composition and the state of microbiocenoses of the studied cryogenic soils also changed significantly. Thus, in the meter-thick layer of these soils, the weighted average pH_H2O value decreased from 9.0 to 8.6, and the content of organic C and total N, respectively, increased from 0.79 to 1.72 % and from 0.03 to 0.13 %. At the same time, more mobile humus was formed in the humus profile of the cryogenic humus-carbonate soil, when the total amount of humic acids increased to 65.6-86.0 %, and the proportion of non-hydrolyzable residue decreased to 14.0-34.4 %. Also, this soil turned out to be the richest in microorganisms, where their total number was 2.4 ± 1.3×10⁶ CFU/g, while in the original soil it was only 5.8 ± 3.1×10⁵ CFU/g. Moreover, if actinomycetes (34 %) and micromycetes (29 %) were relatively predominant in the first soil, then oligonitrophilic bacteria (37 %) and ammonifiers (27 %) were predominant in the second.

The article presents the results of a sowing experiment (2016-2024) to assess the safety, growth and condition of seedlings/saplings of forest-swamp and forest-steppe ecotypes (origins) of Siberian larch ( Larix sibirica Ledeb.) planted in a forest area of Akademgorodok in Krasnoyarsk, and to assess the prospects for their use in urban greening. After transplantation from the sowing department in 2022, 6-year-old seedlings showed absolute survival. In the year of transplantation, during the initial examination, some of the young Siberian larch seedlings were found to be affected by hermes ( Adelges laricis Vall.) and larch bud midge ( Dasyneura laricis F. Low.), early yellowing, wilting and needle fall, which did not have a noticeable effect on survival. During the repeated examination, taking into account the degree of preservation of the needles, most of the seedlings of both forest-swamp and forest-steppe origin were characterized by satisfactory and good condition. The absolute growth of seedlings/saplings of the forest-steppe ecotype of Siberian larch was higher than that of the forest-swamp in the year of sowing seeds (2016) and in the year of transplanting young trees (2022). Statistically significant differences in growth between seedlings of forest-swamp and forest-steppe origin appeared when transplanting plants. In other years, greater growth was recorded in seedlings/saplings of the forest-swamp ecotype, compared to the forest-steppe. In 2024, seedlings of the forest-swamp ecotype of Siberian larch had a greater average height compared to the forest-steppe ecotype. Saplings of forest-swamp origin were distinguished by a wider range of height variability, while trees of forest-steppe origin had more even values of variation of this trait.

Environmental conditions of lava fields (moisture accumulation in porous basalts, and complex mesorelief) promote the naturalization of spruce ( Picea A. Dietr.), which forms stable phytocenoses here and acts as an edificator of plant communities. In contrast, larch ( Larix Mill.) occurs sporadically, which is due to its attachment to well-drained soils, making it less competitive in the conditions of lava fields. Dendroclimatic analysis of tree-ring chronologies of spruce and larch confirms the key role of atmospheric precipitation in the dynamics of wood vegetation. Trees, primarily spruce, in these conditions act as an edificator, modifying initial ecological niches and promoting their more active development by moss-grass vegetation. In the unusual ecological conditions of lava fields, hydrophilic and thermophilic spruce, compared to larch, shows greater dependence of radial increment on temperature conditions than on moisture availability.

The dynamics of quantitative and qualitative parameters of fir undergrowth in the indigenous South taiga fir forests of the Tomsk region, damaged by an invasive four-eyed fir bark beetle (Polygraphus proximus Blandford), has been studied. The observations were carried out twice - during the period of mass reproduction of the pest (2012-2016) and 10 years after the outbreak of reproduction (2023), on 8 test areas in phytocenoses, differing in the composition of stands, living ground cover, taxation indicators of the fir element of the mother canopy and the degree of damage. In 2012, the total number of live fir undergrowth in different phytocenoses was 500-6300 trees/ha, including the largest, most valuable, pre-renewal undergrowth of 325-1100 trees/ha. By 2023, the number of undergrowth Siberian fir ( Abies sibirica Ledeb . ) decreased by 1.5-8.5 times, mainly due to a decrease in the number of small undergrowth, and amounted to 167-4000 trees/ha, including large undergrowth 154-2500 trees/ha. The negative dynamics of the number of undergrowth is due to a complex of factors of a biogeocenotic, pathological and mechanical nature, as well as the transition of large undergrowth into a stand. The average height of small and medium-sized undergrowth changed slightly, in large undergrowth in most stands it increased by 1.2-1.7 times by 2023 and reached 4.5 m, the age of large undergrowth ranged from 14 to 36 years. A positive trend was noted in the vital condition of the undergrowth, due to the condition of large undergrowth, partially weakened during the period of mass reproduction of the beetle due to pest attacks and healthy in the post-outbreak period. The comprehensive characterization of fir undergrowth according to the studied parameters allowed us to assess the varying degrees of its success in restoring damaged stands.

Forms of Siberian stone pine ( Pinus sibirica Du Tour) (Siberian pine) with an annual reproductive cycle are unique natural models for studying reproductive processes, speciation and evolution of gymnosperms, as well as potential for genetic selection work aimed at obtaining high-yielding Siberian stone pine plantations. The study of the yield structure and seed productivity of Siberian stone pine trees with an annual cycle of female cone development showed that all growth characteristics of cones (linear dimensions, cone and seed weight) are significantly lower than in typical individuals, and morphogenetic characteristics (the number of seed scales) and the level of variability of yield structure characteristics are comparable to variability in Siberian stone pine populations as a whole. At the same time, for individual specimens with one-year development of reproductive structures, high seed productivity of female cones is characteristic (76.7 %). Selection and fixation in the offspring of traits that ensure stable yields of Siberian stone pine seeds are recognized as promising areas of breeding of Siberian stone pine. Species with one-year development of female cones are unique genotypes with the potential to obtain new varieties and forms.

The studies were carried out in two types of spruce forests: moist bilberry spruce and bilberry-sphagnum spruce forests. They cover the quantitative characteristics of precipitation in summer period and moisture consumption through transpiration by tree canopy of the studied stands. In moist bilberry spruce forest, trees evaporate about 304 mm of water against an average rainfall of 237 mm. In bilberry-sphagnum spruce forest, the values are 305 and 181 mm, respectively. According to the data of the meteorological station situated close to the area where the research was conducted, the air temperature has increased and precipitation has decreased, compared to the long-term annual average data, since 2003. The average sum of air temperatures for these years is by 3.7 °С above the norm, but precipitation is by 30 mm under the norm, which indicates climate warming in the study area. The soils of green moss spruce forests of the middle taiga subzone are characterized by a favorable moisture regime for plants. The moisture reserves in the root zone of the soil are 60-200 mm, so the trees do not experience a lack of moisture. Due to the fact that transpiration is a physiological process and is regulated not only by external factors, but also by the plant organism itself, it can exceed the amount of precipitation that falls in the form of rain. Water consumption for transpiration in each type of forest also depends on the composition of the forest stand, in particular on the admixture of deciduous species. Thus, the ratio of deciduous and coniferous species in the wet blueberry spruce forest was 97 : 3, in the blueberry-sphagnum spruce forest 99 : 1.

The experience of using terrestrial laser scanning LiDAR to assess the biometric characteristics of trees during the inventory of the artificial tree plantings in the «Bul’var Pobedy» (Boulevard of Victory) in the city of Petrozavodsk, Republic of Karelia, is discussed in the paper. The aim of the work was to conduct a comprehensive statistical analysis of LiDAR data in comparison with in-kind measurements of dendroparameters - tree height, crown and stem diameters at a height of 1.3 m, taking into account the species of trees. The results of the study showed the high efficiency of LiDAR technology for establishing the main dendroparameters. The best results were obtained for measuring stem diameter at a height of 1.3 m (91.5 % of reliable species), crown diameter (85.7 %) and tree height (92.9 %). The average relative error ranged from 5.0 % for stem diameter at a height of 1.3 m to 10.02 % for tree height. The most accurate measurement results are shown for a blue spruce ( Picea pungens Engelm.) and common ash ( Fraxinus excelsior L.), where all parameters were measured with high accuracy ( p > 0.05 in all cases). The stem diameter at 1.3 m turned out to be the most stable parameter with the lowest average error (4.99 %). This is explained by the relative simplicity of its measurement and lesser dependence on external factors. Measuring the crown diameter showed a higher average error (8.28 %). The obtained results of the study indicate the need to take into account tree species characteristics and crown density in the stand when scanning LiDAR and processing data.

The aim of the work was to study the pyrolysis of Siberian larch bark ( Larix sibirica Ledeb.) as a potential raw material for the production of torrefects and biochar. Based on the results of thermogravimetry and differential thermogravimetry (DTG), the kinetics of the pyrolysis process were analysed and its thermodynamic parameters were determined. The basic measurement data were analysed: stages of mass loss during heating, temperature intervals corresponding to them and mass loss rate. Taking into account the complexity of the structure and chemical composition of bark and the related appearance of the DTG peak in the thermogravimetric test, the ‘microstages’ of bark thermal decomposition were visualized by forth derivative of the DTG contour using the Savitsky-Golei differentiating filter. The dependence of the activation energy and the pre-exponential multiplier on the degree of conversion was calculated, using the isoconversion kinetic method of Ozawa-Flynn-Wall. The average value of activation energy is 283.7 kJ/mol when the degree of thermal conversion of bark (α) changes from 0.1 to 0.8. The obtained dependence E _a = f (α) was used to calculate thermodynamic parameters (Δ H , Δ G and Δ S ) and to determine the mechanism of reactions according to the Criado method characterising the bark pyrolysis process. The compensatory effect of thermodestruction was established. The mean values of Δ H , Δ G and Δ S are 294.7, 157.3, kJ/mol and 215.0 J/(mol × К), respectively. The conclusions formulate an integral evaluation of the obtained results, point out the area of their use and the subject of further research: analysis of physicochemical properties of torrefects and biochar obtained from larch bark.

The article presents the results of experiments conducted in order to establish the potential possibility of ignition of peat with 10 % moisture content from cigarette butts. The results showed that peat did not ignite from cigarette butts in the absence of wind. Wind velocity was the key factor that influenced the possibility of peat ignition from a cigarette butt. Ignition probability of cigarette butts was 10 % when the wind velocity was 1 m/s. As the wind velocity increased, ignition probability grew accordingly: 27 % of all experiments ended with peat ignition when the wind velocity was 1.5 m/s, and 50 % of experiments ended with peat ignition when the wind velocity was 2.5 m/s. During the process of peat ignition the cigarette filters burned completely, which prevents using filters as the evidence in order to investigate the cause of peat fires. The results showed that the arenation of the peat surface at the rate of 2.5 kg/m² prevented peat ignition from cigarette butts. Thus, the arenation of those drained peatlands sites where popular camping and smoking areas as well as hunting, fishing, mushroom and berries foraging routes are located can significantly reduce peatlands fire hazard and therefore can be used to develop fire prevention measures.