Home – Home – Jornals – Siberian Journal of Forest Science 2025 number 4

As part of long-term study conducted in Krasnoyarsk forest-steppe, the dynamics of the increment of major phytomass fractions (stems, roots, branches, needles) of young pine stands formed on former agricultural lands were analyzed. It was found that, in early ontogenesis, the maximum phytomass increment is characteristic for overstocked tree stands with an initial density of 40.7 thousand trees/ha. However, by the age of 17, these stands experience a decline in productivity due to intensified intraspecific competition for resources, which negatively affects photosynthesis efficiency. In contrast, in stands with lower density, including those with thinning treatments, phytomass increment shows a stable positive trend with increasing tree stands of 9-20 age. It was established that under natural competitive conditions, the proportion of stem fraction increment decreases with age, whereas in stands subjected to thinning, its contribution increases, reaching 62 % of total increment over a 20-year period. The obtained data emphasize the necessity of comprehensively considering all phytomass fractions when assessing the capacity of stands to absorb atmospheric carbon dioxide. Thus, accounting only for stem mass increment results in almost a twofold underestimation of the carbon sequestration potential of overstocked young pine stands. The study results should be taken into account when assessing the carbon balance of forest ecosystems in the context of international carbon trading. It has been shown that regulating the density and spatial structure of stands allows optimizing their functional purpose - from creating carbon farms focused on CO₂ sequestration to organizing industrial plantations prioritizing target assortments production. Thus, silvicultural practices, including thinning, serve as a key tool for managing the productivity and ecosystem services of forest stands.

The Arctic is one of the most climate-vulnerable regions of the planet, where the rate of temperature increase is twice as high as the global average. The rapid increase in temperature is largely due to the increasing concentration of greenhouse gases in the atmosphere. Forecasts indicate that the continuation of this trend may lead to a large-scale release of carbon accumulated in permafrost. The scale and duration of the expected effect are not obvious due to the poorly developed monitoring of greenhouse gases in the Russian Arctic: sporadic estimates of their atmospheric variations and exchange with ecosystems. The paper presents the results of studies of the dynamics of atmospheric greenhouse gases in the estuarine zone of the Yenisei River, indicating a stable annual increase in CO₂ (~1.9 million^-1/year) and CH₄ (~12.6 milliard^-1/year). The values of soil emissions of these gases for different types of tundra and vegetation on the western coast of the Taimyr Peninsula are presented, where it is shown that the highest values are typical for areas with vascular plant forms. Disturbances of the living ground cover by all-terrain vehicles lead, on average, to a threefold increase in methane emissions into the atmosphere.

The current state of the grass-shrub cover and soils of the forest area «Birch Grove», which belongs to the urban forests of the city of Krasnoyarsk and has been subjected to a strong anthropogenic impact over the past 30 years, is investigated. The main forms of recreation are walking, picnic, and physical culture. A detailed description of the vegetation of three types of forest is given: large-grass birch, forb birch with Scots pine ( Pinus sylvestris L.) and forb-sedge pine forest and their recreational characteristics. It was found that in the forb-sedge pine forest, which is most subject to recreation, there was a decrease in the degree of projective cover of the grass cover and the introduction of ruderal grass species under the forest canopy. It is shown that the largest stock of forest litter is characterized by less trampled large-grass birch, the smallest - forb-sedge pine forest. It was established that trampling led to the complete degradation of the forest litter and grass cover on the trails. A significant increase in the density of the composition and a decrease in the moisture content of the top layer of the trail soil was also noted. Water-physical and chemical analysis of dark gray and gray forest soils did not reveal a significant change in their parameters and deterioration of forest vegetation properties under the influence of recreation in forest types with stage 1 of digression. In sod-carbonate soil (a type of forest with the 2nd stage of digression), a significant increase in the density of composition, a decrease in the porosity of the root layer, alkalinization of the soil solution, as well as a weak accumulation of humus and biophilic elements were noted. A further increase in the recreational load on the Birch Grove forest area will lead to a more significant deterioration in the forest vegetation properties of soils, a decrease in the productivity of grass and tree layers.

The results of 18-year observations of cone production in clones from latitudinal and longitudinal ecotypes of the Siberian stone pine ( Pinus sibirica Du Tour) on geographical crops in the south of Tomsk Oblast are presented. With age, the number of female cones increased in trees of all ecotypes, and the pattern of differences between ecotypes changed. At the age of 10 years, the northern ecotypes and one of the eastern ecotypes formed the greatest number of cones. After 8-10 years, the central ecotypes from both transects had the most abundant cone production. By the age of 28 years, the southern ecotype became the leader in the cone number among the latitudinal ones, and among the longitudinal ecotypes, the western, local, and one of the eastern ones differed insignificantly. This trend remained unchanged until the end of the observation period for the longitudinal ecotypes, and among the latitudinal ecotypes, by the same time, the southern ecotype became the leader. The Siberian stone pine ecotypes were characterized by periodicity of cone crops. The degree of cone retention in all Siberian pine ecotypes was closely related to the date of the last spring frost and the sum of effective temperatures accumulated by this date; no significant correlations were found with other weather factors. Dangerous late frost led to a complete or partial loss of cone crop in all ecotypes. The later the frost and the higher the accumulated sum of effective temperatures, the greater the damage to the cone crop. At this time, cones were preserved more often in northern ecotypes than in others.

City parks are an integral part of the green infrastructure of Yekaterinburg, maintaining and regulating various ecosystem services. More than half of the city’s parks are created on the basis of natural plantings integrated into the urban environment during the construction of new districts. The purpose of the study is to identify the degree of Scots pine ( Pinus silvestris L.) participation in the formation of phytomass reserves of plantings of large parks in Yekaterinburg that arose during urbanization. The applied approach will reflect the level of anthropogenic transformation of the planting through the change in the stock of stem mass of Scots pine. The plantings of ten parks located in different parts of the city and created in different periods were studied: «Sem klyuchey» (Seven springs), «Zelenaya Roshcha» (Green grove), im. Chkalova (named after Chkalov), along the street of Chkalov, im. Agafonova (named after Agafonov), Kamvolny Kombinat (Worsted mill), Letniy «Uralmash» (Summer), Kompressorny Microrayon (Compressor microdistrict), plantings within the boundaries of the regional hospital and Park-stadion «Khimmash» (Park-stadium of chemical engineering plant). To assess the ecological efficiency of tree species, the indicator of the stem wood stock was chosen as the most accessible for working with growing trees. It is known that the stock closely correlates with the mass of the tree, which acts as an integrated indicator reflecting the participation of certain plant species in ecosystem services, primarily in carbon-depositing and oxygen-producing activities. In the course of the study, based on the tree inventory, the species composition, indicators of the sanitary condition of trees were determined, and the stock of stem mass was calculated. As a result of the study, it was established that there is a negative relationship between the share of introduced species in the massifs of large parks in Yekaterinburg, the stock of stem mass and the health condition of Scots pine.

It has been established that in the highlands of the Southern Urals, spruce trees are represented by single- and multi-stemmed forms of growth. Over the past two decades, the total number of spruce ( Picea A. Dietr.) trees in the upper tree-line ecotone has increased significantly, which indicates the continued colonization of relatively open spaces of the ecotone with woody vegetation. The nature of the dependence of the mass of the crowns as a whole and the mass of the needles on the diameter of the trunks is determined by the form of tree growth. Therefore, when evaluating these fractions of aboveground phytomass, the corresponding equations should be developed separately for single- and multi-stemmed trees. The form of the growth does not affect the dependence of the mass of trunks on their diameter. The total aboveground phytomass of spruce stands, and, consequently, the reserves of carbon deposited in them, increase significantly as the altitude above sea level decreases. During the period from 2002 to 2024, the aboveground phytomass of sparse tree stands and open forests increased at a higher rate than in the lower closed forest. In particular, it increased 2.2 times in sparse tree stands, 1.9 times in open forests, and only 1.2 times in closed forests. This situation is explained by the continued expansion of arboreal vegetation in the upper tree-line ecotone and the lower age of the stands formed there. The data we have obtained on the reserves of aboveground phytomass of spruce stands and carbon deposited in them can be used to assess and forecast the biosphere role (in particular, the carbon budget) of forests formed in previously treeless territories of highlands as a result of modern climate change.

The climate change observed on our planet recent decades most scientists explain by the increase in the atmosphere the share of greenhouse gases. One of them is carbon dioxide, which is released during volcanic eruptions, burning of coal, peat and oil products. Among the ways to minimize carbon dioxide in the atmospheric air it is possible to single out its deposition by plants during the growth process. We succeeded in analyzing the possibility of creating carbon farms on disturbed lands. These farms are created in the process of reclamation biological stage by planting the most productive in a given region forest crops of various species and forms of woody plants. Based on the materials of the trial plots, the accumulation of wood and carbon deposited in was analyzed on the example of disturbed in the process of mining and processing of resources these lands mineral as well as on gold dump. In particular, it was established that at the golden dump, the stock of only stem wood Scots pine ( Pinus sylvestris L.) in artificial plantations of 30-years age is 290 m³/ha, which corresponds 107.3 t/ha deposited carbon. The creation of carbon farms on chrysotile asbestos waste dumps ensures the deposition of 145 t/ha of carbon in the wood by the age of 42 years, which corresponds to 3.45 t/ha annually. When creating carbon farms on exhausted clay quarries, by the age of 40 years, the amount of carbon deposited in the wood is 142.67 t/ha, which corresponds to the annual deposition of only 3.57 t/ha of carbon from atmospheric air by the forest stand. The obtained data indicate the effectiveness of creating carbon farms on disturbed lands in the Middle Ural taiga forest region by planting Scots pine forest crops.

Toxic waste from tailings dumps, as a result of erosion processes, can cause significant environmental damage through the migration of pollutants. This leads to the degradation of forest ecosystems, since heavy metal and arsenic compounds are absorbed by plants and soil. The purpose of the work is to assess the state of natural forest vegetation near a man-made source and determine the resistance of forest species in the stand and undergrowth to heavy metal pollution. To assess the state of natural vegetation, 4 test plots were laid taking into account the vegetation on strip counts. According to chemical analysis data, migration of heavy metals from the soil and litter to tree needles is noted. According to the assessment of the state of forest stands, 55 % of all studied species can be classified as weakened and drying out. The article provides an inventory characteristic of tree species and undergrowth near the Vysokogorskiy tailings dump on the territory of the Kavalerovskiy forestry of Primorskiy Krai. The obtained data on the state of the forest stand and the chemical composition of the components of the forest ecosystem made it possible to determine the resistance of various forest species to the impact of unfavorable factors.

Scots pine ( Pinus sylvestris L.) sawdust is highly promising as a raw material for wood carbon sorbents. However, the prospect of using pine sawdust as adsorption materials to extract toxic metals from aqueous solutions depends heavily on the composition of active surface functional groups. The purpose of the study is to assess the sorption properties and the degree of change in the composition of oxygen-containing functional groups of carbon sorbents. The modification was made with solutions of one-, two- and polybasic carboxylic acids to promote large-scale woodworking waste as real alternative sorption materials. 1 % carboxylic acids of different basicity (acetic, succinic, tartaric, citric) were used as chemical modifiers for both initial sawdust and sawdust thermally treated at 300 ± 10 °C. Chemical modification was carried out at a temperature of 80 °C for 5 hours. To quantify functional groups in the composition of modified carbon sorbents, the Boehm titrimetric method was used. Impregnation of carboxylic acids of different basicity has increased the total acidity of the resulting carbon sorbents due to increasing in the number of hydroxyl groups in their composition, which were not previously present in initial pine sawdust. The sorption behavior of chemically and thermochemically modified carbon sorbents was investigated in relation to Cu (II) and Zn (II) ions and a positive effect of the modification has been established only in the case of copper extraction from aqueous solutions. The calculated thermodynamic parameters indicate the spontaneous physical sorption occurs without the formation of stable chemical bonds, and the sorption of Cu (II) ions on the original sawdust proceeds in accordance with the Dubinin-Radushkevich model, and extraction by modified samples occurs according to the Langmuir model. Pine sawdust sorbents modified chemically and thermochemically with 1 % citric acid (sorption capacity 16.96 and 12.20 mg/g, respectively) has shown good potential for effective extraction of copper iones.

First registered in Perm Krai in 2022, the invasive four-eyed fir bark beetle Polygraphus proximus has expanded its secondary range to almost 8,000 ha on the territory of 10 forestry districts of the region by the beginning of 2025. At the same time, the phytosanitary quarantine zone has grown to 1 million hectares. For dendrochronologic dating of tree mortality on the sites where initial foci was documented, the samples from five sites were analyzed: in Dobryanskoe forestry (2 sites) and in urban forests of the city of Perm (3 sites). In total, 131 tree-ring rows for 118 trees killed by the bark beetle and 60 rows for 40 live trees were used to construct a master chronology. Dating the dieback of the trees which appeared to have the earliest infestation signs of the beetle allowed us to define time when four-eyed fir bark beetle could first occur in Perm Krai. The earliest tree dieback was observed on the two sites in Dobryanskoe forestry (in 2011 and 2014 respectively). The invader penetrated the city of Perm significantly later: fir trees started to die in 2018, 2021, and 2022 on the studied city sites. Bearing in mind that the beetle requires at least 2-3 years to settle down in a new region, it can be assumed that four-eyed fir bark beetle arrived to Perm Krai no later than 2009.