The provision of softwood plantations with undergrowth of Siberian Pine (Pinus sibirica Du Tour.) in Western Siberian north-taiga plain forest region was analyzed on the base of the forest management data. It was noted that there is Siberian Pine undergrowth only on the territory of the core Soviet forestry in Khanty-Mansiysk Autonomous Okrug – Yugra on the area of 25.6 thousand ha. It includes 24.6 thousand hectares where the amount of undergrowth is sufficient to ensure the formation of young Siberian pine on its basis. 

The main areas of softwood plantations with the presence of Siberian pine undergrowth are represented by derived stands formed on the site of felling and burned areas of cedar forests of the green-mossy and grass groups of forest types. The latter indicates a high potential productivity of young Siberian pine under the condition of preserving the undergrowth and the proper type of felling. The maximum number of Siberian pine undergrowth accumulated under the canopy of mature and overmature soffwood plantations with relative fullness in green-moss and grass groups of forest type is 0.7. And it is 0.5 in plantations of grass-moss groups of forest type. The latter is necessary to take in to account when choosing the type of felling and setting the intensity of thinning.

Yenisey Siberia, which includes Krasnoyarsk Krai and Khakassia, extends along the Yenisey and occupies the middle part of Siberia between 51º and 81º north latitude and 78º –113º east longitude. Krasnoyarsk Krai belongs to the large administrative regions of the country. In this regard, there are three climatic zones here from arctic to temperate, which leads to diverse climatic conditions and the specifics of agricultural production. The article gives features of the development of agriculture, describes natural risks that cannot be prevented, but can only be taken into account and adapted to them by the modern management system. The main part of natural risks is associated, first of all, with weather and climatic conditions: a short growing season, late spring and early autumn frosts, the presence of permafrost, floods, rainstorms, droughts, etc. Their extreme nature manifests itself in most regions lying north of 55– 56º N, reducing the production of certain types of agricultural products by 15–20 % or more. The natural landscape is subject to anthropogenic influence over time and is one of the components of environmental potential. Its current state differs to some extent from its original state. 

Characterization of the current ecological state of the landscape requires the study of anthropogenic layers on the natural background. A large burden of anthropogenic impact on the natural environment is associated with industrial forms of economic activity. Agricultural environmental management, like any anthropogenic activity associated with current and potential changes in natural ecological systems, is a risky type of environmental management; it is both a source and, less often, a recipient of risk. Examples are given of irrational plowing of unproductive lands, which led to dust storms, soil salinity, and loss of soil fertility. An expert assessment of land use risks and measures aimed at preventing risks in agricultural environmental management are provided.

The paper considers the biological features of growth and development of pine stands in Kolyvan forestry of the Novosibirsk Oblast. The correlation of indicators characterizing the productivity of pine stands is revealed. The distribution of forested area and reserves by age groups for the period from 1979 to 2021 is analyzed.

The research and analytical review of the data on the dynamics of pine plantations change by the main taxation indicators determining the features of growth and development of the stand have been carried out.

The character and structure of pine stands location on a certain territory of the forest management area was determined in order to assess the current state and forecast further target use for obtaining forest.

The regularities of age changes in the main taxation indices of common pine trees with a periodicity of about ten years have been revealed to assess the effectiveness of forest management measures.

The long-term analysis of the distribution of the area of plantations by age groups indicates a rather uneven distribution of individual groups. During the initial period of the study from 1979 to 1996, a significant share of the middle-aged group was established, with a decrease in the percentage of young stands and an increase in the share of mature and overmature stands. Since 2006, a tendency of increasing percentage of mature and overmature stands and a significant decrease in the group of young stands was noted. In 2021 the share of mature and overmature stands increased to 56%, there is no increase in the area occupied by young stands. Uneven distribution by age and area groups on lands covered with forest vegetation is observed.

In addition to changes associated with the transformation of forest area, changes in the area by age groups are also caused by the natural transition of plantations from one age group to another, the formation of natural young stands on non-forested and forested lands, and the conversion of unbroken forest crops into forested lands.

A transect with four test areas was laid on the territory of the Ergaki Natural Park, crossing the upper border of the forest during the transition from the mountain taiga to the goltsovo-tundra zone. At the altitude of more than 1,630 m above sea level, woody vegetation is represented by Pinus sibirica krummholz forms up to 1 m high. The line for trees with typical Siberian pine trunk shape runs between altitudes of 1,630 and 1,550 m above sea level, and the upper line is between 1,550 and 1,500. Below 1500 m, there is a mixed small-grass forest with a predominance of Pinus sibirica, and below 1450, there is a mixed large-grass forest with a predominance of Abies sibirica. During the study of the spatial and temporal variability of the pigment complex of Siberian pine needles in the conditions of the high-altitude zone of the Western Sayan, both general trends in the seasonal dynamics of chlorophylls and carotenoids and features of the pigment composition of the needles of Siberian pine trees growing at different heights above sea level were revealed. The high LHC/CPC ratio characteristic of plants of the upper sample area indicates their low productivity, and the low ratio of the amount of chlorophylls to carotenoids indicates stress resistance in relation to a combination of low temperature and high illumination. Natural selection above the forestline, apparently, is aimed at the survival not of highly productive Siberian pine individuals, but of stress-resistant slow-growing krummholz forms, which, by creating microcourtines, can become the basis for the emergence of stem forms of Siberian pine.

Methods are proposed for analyzing the susceptibility of forest stands to attack by forest insects based on Earth remote sensing data. As an indicator of the state of trees, it is proposed to use the indicator of the susceptibility of the vegetative vegetation index during the season (NDVI) to changes in the radiative temperature of the territory (LST), obtained from satellite data of the Terra/Aqua system. The indicator was calculated as the spectral response transfer function in the integral equation relating changes in NDVI and LST. 

The analysis was carried out for three experimental objects. In the first case, fir stands of the taiga zone of Krasnoyarsk Krai were studied. Those were territories that have been damaged by caterpillars of the Siberian silkmoth Dendrolimus sibiricus Tschetv since 2015 and adjacent undamaged areas. In the second case the object of the study  was mountain fir stands in the Ermakovsky District in the south of Krasnoyarsk Krai, damaged in 2013 by the black fir longhorned beetle Monochamus urussovi Fischer. Finally, the state of fir forests in the Birilyussky District of Krasnoyarsk Krai was examined in 2023, when no damage to the stands had yet been observed, but individuals of the Siberian silkmoth were found in pheromone traps. 

It was shown that the indicator of plant susceptibility in the studied sample areas changed significantly 2–3 years before the outbreak of the pest. The proposed indicator can be used to predict outbreaks of insect pests.

The article considers the prospects of growing Siberian cedar pine in the conditions of the Far North of Russia, which is one of the priority regions for exploration, restoration and development. In the context of climate change, the issues of reforestation and afforestation in the Far North are relevant, among them in connection with a complex of negative environmental factors, including those specific to this region. The unique ecological significance of the Far North in the issues of carbon sequestration is also noted. The high value in the forestry of the Russian Federation allows the authors to consider Siberian cedar pine as a promising species for cultivation in conditions of introduction, in territories beyond the northern boundary of the range. This species is distinguished by its extensive habitat, which enters the territory of the Far North, which, among other things, provides the genetic diversity of the species with northern and subalpine ecotypes. The authors propose to consider the prospects of growing Siberian cedar pine in the Far North, taking into account the use of close ecotypes as maternal forms for reproduction. The article presents hypotheses about successful acclimatization and successful production of improved planting material, characterized by a set of indicators of increased resistance to adverse factors in the Far North of Russia because of using innovative technologies and breeding methods.

High growth rates in height allow trees to dominate physically other plant forms in appropriate environmental conditions. However, the variation of the vertical components of the forest structure and their causes remain poorly understood. The height of the tree reflects the strategy of obtaining a carbon-depositing effect by trapping light, while the diameter of the stem is closely related to mechanical stability and plumbing ability. The interconnected tree height and stem diameter determine the growth strategy of tree species in accordance with the availability of terrestrial and underground resources for their life support. Usually, aboveground biomass is estimated using empirical equations that include the diameter of the stem at breast height as an independent variable, and in the absence of tree height data, estimates are biased. For such cases, auxiliary allometric models are being developed that describe the dependence of the tree height upon the stem diameter and vary due to the influence of climatic conditions of the area. The purpose of our study is to analyze changes in the height of trees and stands of some coniferous and deciduous species in the climatic gradients of Eurasia. The constructed models are adequate at the level of p < 0.001. Using the example of changes in the heights of trees and stands, the effect of the Liebig-Shelford limiting factor in transcontinental climatic gradients is confirmed. The results can be useful when assessing the biomass of trees and stands using their taxation indicators in relation to climate change.

An important indicator of the comfort level of urbanized areas is the provision of city residents with high-quality green areas. In large cities of Siberia, the complex natural environment is aggravated by technogenic loads; accordingly, the creation (reconstruction) of urban greening facilities must be carried out on the basis of an assessment of environmental risks, the manifestation of which leads to various degradation processes of green spaces. The limited assortment and quantitative lack of shrubs in city landscaping leads to the absence of an important shrub layer in the urban landscaping system. The insufficient representation of shrubs in city landscaping and poor knowledge of their growth and development do not allow their high-quality implementation on landscaping objects. During the research, an assortment of shrub plants was studied at 24 landscaping sites, represented by parks, squares, streets (avenues) and boulevards, located in 7 districts of the city of Krasnoyarsk, exposed to various external factors on their living condition. As of June 2023, the range of landscaping objects under study is represented by 24 types of shrubs. 10 species are widespread in urban plantings, but with different participation: Hungarian lilac, caragana tree, Tatarian honeysuckle, rugose rose, brilliant cotoneaster, viburnum-leaved bladdercarp, mountain ash, two-needle currant, white dogwood, common barberry. In two and one types of plantings there are 7 species of plants, 1/3 of the established landscaping assortment. Absolute occurrence was calculated to analyze the quantitative participation of shrubs in the structure of urban green spaces. As research results have shown, the occurrence of shrubs varies from 4.2 % to 16.7 % in 14 species (58 % of the composition). However, more than 25 % of objects have 10 plants (42 % of the studied composition). It is worth noting that rare species predominate in the landscaping of parks, are less often used in public gardens and minimally in the landscaping of streets. The greatest participation in landscaping falls on the Hungarian lilac; its use is noted in equal shares in squares and streets, and less in parks. Thus, increasing the proportion of shrubs in the city’s landscaping, which perform a protective as well as aesthetic function, will lead to an increase in the comfort of life in urbanized areas.

Currently, production waste in the form of hydrolyzed lignin and lignosulfonates from pulp and paper and hydrolysis industries is large-tonnage waste that requires solutions for their disposal and use as a secondary source of raw materials. Various solutions are proposed, one of which considers hydrolytic lignin as a component for the production of wood and composite materials. This study established the effect of an additive in the form of hydrolytic lignin to wood press raw materials on the physical and mechanical properties of plastic without resins (PWR), including water and biostability. It is shown that the introduction of hydrolyzed lignin into the press composition based on wood filler (wood flour) increases the water resistance of PWR obtained by hot pressing in closed molds. Rational values of obtaining PWR based on wood filler with the addition of 40 % by weight of hydrolyzed lignin with high performance properties have been determined. The dynamics of changes in the indicators of water resistance (water absorption and swelling) and biostability of PWR in relation to the soil for 90 days has been studied. It was found that when exposed to 90 days of PWR with hydrolyzed lignin in the aquatic environment and soil, there is a positive dynamics of a decrease in water resistance and weight loss. The results of microscopy and visual evaluation of the samples of PWR showed that the initial processes of destruction of the studied material proceed due to excessive water saturation of the wood filler with its subsequent destruction. The use of hydrolytic lignin for wood press raw materials can be considered as a hydrophobic and antiseptic additive for obtaining materials based on PWR.

In the present article the influence of methods of preliminary mechanoactivation of wood particles on the possibility of obtaining cellulose acetate is evaluated. The results of the study indicate the feasibility of using hydrodynamic mechanical activation of birch sawdust to increase the alpha-cellulose content in holocellulose. This is achieved by increasing the specific surface area of wood fibers through fibrillation and, as a consequence, intensifying the process of nitrate delignification.

Evaluation of the size and distribution of wood particles by sieve method, using an analytical sieving machine, showed that sawdust mechanically activated by hydrodynamic method was more effectively pulverized. During the study of the surface of wood particles by scanning electron microscopy, it was found that the morphological and anatomical structure of sawdust changed markedly during the hydrodynamic treatment process.

During the delignification process of hydrodynamically activated birch sawdust the degree of penetration of the reagent increases, as a result of which, mainly hydrolysis of secondary components occurs: lignin and beta-gammacellulose. As a result, with a yield of holocellulose of 31.4 %, a higher alpha-cellulose content of 82.8 % is observed.

In the case of acetylation by heterogeneous method, cellulose acetate corresponding to cellulose triacetate, well soluble in chloroform, with a bound acetic acid content of 60.3–61.1 % was obtained. In the case of acetylation by homogeneous method, cellulose diacetate was obtained, well soluble in acetone under stirring, with an increased content of bound acetic acid of 54.1–58 %. 

The article presents the results of research on improving the technology of tannin extracts from the bark of Siberian larch Larix sibirica Ledeb. The component composition of the studied raw materials is studied. It is shown that the wastes of mechanical debarking of larch wood can be transferred to the category of raw materials suitable for tanninextract production, if the process of extraction of tannins is carried out by aqueous solution of monoethanolamine with a concentration of 5 %, the duration of the process is 5 hours, at hydromodule 14. The concentration of extractive substances in the obtained extract is 41.5 g/l, and the benignity is 74.9 %. The research on tanning of leather fabric by dip-tanning method using tannin extract obtained from larch bark was carried out on the example of sheepskin of Zabaikal breed. The physical, mechanical and chemical parameters of the finished semi-finished product were studied, which meet the requirements according to GOST 4661–76.

As is known, the main raw material of the pulp and paper industry is usually coniferous and hardwood wood, but coniferous wood is most often used in technology. Taking into account the peculiarities of the physical and mechanical characteristics of finished products made of coniferous wood in comparison with hardwood, it is known that in comparison of these two types of wood, coniferous wood fibers are longer. And as you know, the length of the fibers is of great importance, both for the paper-forming properties of fibrous semi-finished products and the physical and mechanical characteristics of finished products of pulp and paper production. Given the need to use annual plants in pulp and paper production technology, it is naturally necessary to study the processes of fibrous semi-finished products from annual plants, in comparison with the grinding mechanism of fibrous semi-finished products from wood, and primarily from coniferous wood.

In the modern world, wood is widely used in various industries. Its most common use is associated with the pulp and paper industry, which annually consumes hundreds of millions of cubic meters of wood. Forest areas are shrinking on a global scale, and this reality is crucial for the global ecology. The shortage of wood for the paper industry has become a big problem, and for this reason it has become necessary to take into account other types of raw materials. Alternative sources of raw materials include waste paper and annual plants. Waste paper is the most important raw material for the paper industry, but only low-quality paper can be produced from it. Therefore, more and more research is aimed at improving the quality of secondary fiber by introducing additional components into its composition.

The research is carried out and the results are presented on the effect of the use of bacterial cellulose in a composition with waste paper of various brands on the change in the physical and mechanical characteristics of the finished product.