Vol 28, No 5 (2024)

This study analyzes the regional characteristics of the trunk timber stock basic density in the bark of deciduous tree species growing in Eurasia. Being based on the data obtained from 2741 trees from six deciduous tree genera (species) growing in Eurasia, regression models of a mixed type have been developed for the trunk timber stock basic density, specific for clusters representing regions within the genus, species and origin of stands within the region. The structure of a mixed type model makes it possible to rank clusters according to the trunk timber stock basic bark density, provided that they are equal in age of trees (with the exception of the genera Betula and Populus, in which the age of the tree in the models is statistically insignificant). Two rankings were made according to the value of the trunk timber stock basic density in the bark, namely, the ranking of clusters within the genus (for European Beech — within the species) and species — specific ranking, according to which the maximum value is characterized by forest beech and the minimum is Black Poplar. The obtained models and the ranking of species by the value of the trunk timber stock basic density in the bark can be used to calculate the carbon pool in deciduous stands according to the forest inventory data.

The studies were conducted in different types of pine plantations in the North taiga region of the Arkhangelsk region, which are pure in composition or with a small admixture of other species. The measurement of meteorological factors was carried out at a height of 1,3 m and at the level of the grass-shrub layer. For this purpose, a luxmeter «TKA-Lux» was used, and measurements of air temperature, air humidity and wind speed were carried out using a meteorological meter MES-200. The taxational characteristics of the studied pine forests are given. The results of the analysis of variance on the effect of forest type on the meteorological factors under the forest canopy are presented. It has been established that, in general, the type of forest significantly affects almost all indicators of the microclimate. It was revealed that under the canopy of the forest, its climatic regime is composed, which accordingly affects all the lower tiers of vegetation and partly on the stand. The illumination and wind are higher in the shrub-sphagnum pine, and the air temperature is higher in the blueberry pine. The humidity of the air is the same. When comparing similar forest types of blueberry and blueberry moist pine forests, the meteorological factors are close (equal) with the exception of air humidity, it is higher in blueberry moist pine, it is shown that meteorological factors under the canopy of pine forests differ significantly from those in the open area. The strongest influence affects the illumination. It is smaller and makes up 21…22 % of the open area, the wind speed is 46…76 %, the air temperature is 92…97 %, but the humidity is higher and is 124…132 %. One tree in the stand with the existing density retains 12…21 lux of light. It is established that the parameters of meteorological factors change with altitude. From a height of 1.3 m, the wind speed to the ground cover level decreases by 10…40 %, illumination by 24 %, and the air temperature rises slightly to 1,3 °C.

Growth and development of annual seedlings of Siberian cedar pine (Pínus sibírica Du Tour) grown on mixtures using peat or coconut fiber with the addition of vermiculite, perlite in different proportions were analyzed. By the end of the first growing season (2021 year), the average weight of the above-ground part of seedlings averaged 1,1 ± 0,03 mg, and of roots was 0,4 ± 0,02 mg in the absolutely dry state. The influence of substrate composition on the growth of Siberian cedar pine seedlings with closed root system was established. Seedlings grown on pure peat overtook the seedlings of most of the used variants of mixtures in height. However, the plants grown on substrates where peat was the main component formed roots of significantly lower length and weight than on substrates based on coconut fiber. The sizes of annual seedlings in the variant with coconut fiber substrate mixed equally with vermiculite were characterized by significantly larger sizes of the above-ground parts by the end of the vegetation period compared to the peat mixture with the addition of agroperlite. Three-year observations (2021–2023 years) allow us to note the influence not only of the substrate composition, but also of the root ball size on the growth of Siberian pine seedlings. In the experiment with the use of 200 cm³ cups, seedlings grown on control peat substrate had the largest size in height by the end of the growing season than when using cassettes with a root ball volume of 85 cm³.

The main selection features of Scots pine (Pinus sylvestris L.) plus trees in the Novosibirsk region are considered. The ecological, environment-forming and economic significance of the breed is noted. The share of Scots pine in the composition of forest seed objects is presented, and the change for the period from 2008 to 2023 is determined. It has been established that in order to increase the productivity and quality of tree stands, it is necessary to carry out work on the selection of the best trees and a comprehensive assessment of their genetic potential with subsequent use for the procurement of high-quality seed raw materials. Between 2021 and 2023 a selection of plus trees was carried out on the territory of the Kolyvan forestry of the Orsko-Simansky forestry area and the Ordynsky forestry of the Karakansky forestry area of the Novosibirsk region. The objects of study during the selection were stands of Scots pine of age class III that were not affected by felling. It is characteristic that the excess of trunk diameter over the average for the stand in pine stands of age class III is more than 60 %. This is significantly higher than in older forest stands that have been repeatedly felled. Promising directions for the development of pine forest seed objects in the Novosibirsk region have been identified and proposed.

The issues of effectiveness of forestry measures aimed at reducing the burning of forests in regional forestry systems are considered. It has been established that in 2021, in the territories of most Federal Districts of the Russian Federation, there is a predominant decrease in the rate of carbon accumulation in the forest fund by 8...39 % compared to 2010. Based on the analysis of forest planning documents, the gradation of the subjects of the Federation according to the level of change in the carbon budget was performed. During the period under review, there were negative trends in reducing the carbon budget in forests in 62 regions of the Russian Federation. The largest number of critical regions are located in the Far Eastern Federal District, which is explained by its remoteness, poor development of transport and logistics, as well as significant reserves of forest resources compared to other federal districts. It was found that in critical regions during the analyzed period, carbon losses in the forest fund amounted to 335% in the Magadan Region, up to 235 % in the Nenets Autonomous Okrug and more than 180 % of the carbon budget in the Khabarovsk Territory. A list of the most significant measures aimed at reducing carbon emissions and losses in regional forestry systems has been identified. Measures to reduce the burning of forests are classified as key. The comprehensive implementation of such measures will lead to a reduction in greenhouse gas emissions from 264,4 to 142,4 million tons of CO₂-eq./the year until 2030 The necessary amount of financing for additional fire-fighting measures for the period 2024–2030 has been determined, amounting to 28,964,8 million rubles.

The paper analyzes the connection between the pollutants content (sulfur and heavy metals) in birch leaves and the vital state of the stand. It was found that metals such as cadmium, lead, copper and zinc have the greatest influence on the state of stands in the operating area of Karabashmed JSC. A positive correlation between the parameters of the vital state (defoliation, dechromation and the category of the state) and the content of these trace elements (correlation coefficients greater than 0,4…0,6) was revealed. An increase in the concentration of such heavy metals as cadmium, lead, zinc, copper and chromium in birch leaves in the trial plots closest to the pollution emission source by JSC «Karabashmed» was found.

Modification features in the structural and dimensional properties of kraft unbleached pulp obtained from Lodgepole pine (Pinus contorta var. latifolia Engelm) were identified and analyzed under laboratory standardized refining conditions of up to 60 SR at the Yokro mill. Measurements were carried out using an automatic fiber analyzer L&W Fiber Tester. Pulp fibers for board production (Kappa number 56), compared to pulp for subsequent bleaching and papermaking (Kappa number 25), are longer (2,1 mm versus 1,9 mm), wider (31,4 mm versus 30,1 µm), less curved (shape factor 89,2 versus 82,1) and have fewer fractures per 1 mm (0,28 versus 0,81). Lodgepole pine pulp has high resistance to refining and requires increased energy consumption for refining. The nature of changes in the fractional composition along the length, width and fiber shape factor, as well as the structural and dimensional properties of lodgepole pine cellulose depends fundamentally on the lignin content. Fibers with a low lignin content are more easily destroyed at defect sites, and the remaining fragments have increased straightness. As a result, the refining effect changes from predominant fibrillation and a slight increase in fines for cellulose fibers for cardboard, to predominant chopping of fibers, which passes mainly along the sections of the cell wall weakened by fractures, and the previously bent end sections of the fibers are torn off. At the same time, the rate of decrease in fiber length increases, and the direction of change in the structural and dimensional properties during refining changes, the content of fines, the number of breaks per fiber and the average length of the segment change in different directions. The differences in fiber properties measured on the automatic fiber analyzer L&W Fiber Tester are characterized in pulp samples with high (Kappa number 56) and low (Kappa number 25) lignin content. It has been shown that with a decrease in the lignin content in pulp, the average fiber length decreases from 2,1 to 1,9 mm, the average width from 31,4 to 30,1 µm, the form factor from 89,2 to 82,1 %, and the number of kinks per 1 mm increases from 0,28 to 0,81. It was revealed that the nature of the change in the fractional composition by length, width and fiber shape factor, as well as the structural and dimensional properties of pulp from lodgepole pine during refining depends fundamentally on the lignin content. It has been established that fibers with a low lignin content are more easily destroyed when refined at defect sites, and the remaining fragments have increased straightness. The change in the milling effect is shown from predominant fibrillation and a slight increase in fines for fibers with a high lignin content to predominant chopping of fibers with a low lignin content. With a decrease in lignin content, the rate of decrease in fiber length during refining increases, and the direction of change in structural and dimensional properties changes.