The aim of the work was to evaluate the influence of the six–toothed bark beetle (Ips sexdentatus Börner) on the state of Pinus sibirica Du Tour stands in dark coniferous forests in the south of Central Siberia. The object of research is an active bark beetle outbreak in dark coniferous plantations with a predominance of P. sibirica in the territory of the Mansky forestry district of the Krasnoyarsk Krai (Altai-Sayan mountain taiga forest region).

A forest pathology examination of plantings on three test areas was performed, followed by an integrated assessment of the sanitary condition of stands. The damage to cedar stands by a six-toothed bark beetle was revealed by visual signs using standard indicators, and statistical analysis of empirical tree diameter distribution series was used.

The vital condition of stands of all forest elements, including cedar, is severely weakened, and the degree of their disturbance in terms of current shrinkage is medium to severe. The damage to cedar stands in the bark beetle outbreak ranges from weak to strong, with a predominance of used trees, and the share of the trunk stock of inhabited trees is less than 10%. The six-toothed bark beetle invades trees of any size in proportion to their representation in the structure of the cedar element of the forest. In the part of cedar stands damaged by bark beetle, trees that have lost their viability predominate. According to the integral indicator, the average condition of damaged trees is shrunken or dead. The proportion of living trees in 2–3 categories was 13–19 %, which indicates an increase in the aggressiveness of the xylophagus. This is due to its high number against the background of a preliminary violation of the stability of plantations due to anthropogenic activity, negative changes in forest conditions.

The article considers the main features for the formation of agrolandscapes of forest-steppes in the southern part of Yenisei Siberia. The natural and ecological characteristics of the Minusinsk, Nazarovo, ChebakovoBalakhtinskaya, Sydo-Irbinskaya hollows are presented. An assessment of climatic conditions is presented based on such characteristics as annual precipitation, the sum of average daily air temperatures above 10 ° C, the duration of the frost-free period, the continentality coefficient, the hydrothermal coefficient, the average January temperature, the average monthly July temperature, the average annual; underlying rocks; soils, relief; vegetation, the possibility of using these natural resources for agricultural production of early and mid-season crops. For each region, forest cover is presented taking into account forest belts, ploughed area from the total area of the agrolandscape, meadows and steppes from the total territory.

A plot was created on the PTL-2 plantation using planting material of second generation from seeds collected on a hybrid seed plantation of vegetative origin. Pinus sibirica cuttings were prepared in the Geoschool of the Reshetnev Siberian State University Arboretum from trees of different geographic origin. A comparison of the growth and reproductive development indicators of 18-year-old seed progeny was carried out in the Biryusinsky, Ermakovsky, Komi, Sverlovsky, Tomsk, Tyumen and Yartsevo origin variants. The manifestation of geographic and individual variability  in height, trunk diameter, current shoot growth, needle length and the entry into the reproductive phase of development  is noted. The highest indicators for height, trunk diameter, current shoot growth and needle length were found in specimens of Pinus sibirica of Komi origin. In each variant, fast-growing specimens were identified, exceeding the average value for the experiment by 18.9–69.9 % in height and 23.7–76.3% in trunk diameter. The greatest excess  in height was demonstrated by specimens No. 14-14 Ermakovsky, No. 14a-14 Komi, No. 14-22 Tomsk, No. 15-25 Tyumen and No. 12-16 Yartsevo origin. The specimens with the longest needles are No. 14-14 Ermakovsky, No. 14a-14 Komi,  No. 12-38 Sverdlovsk, No. 14-22 Tomsk, No. 15-17 Tyumen and No. 12-16 Yartsevo origin. The specimens with early reproductive development include No. 13-34 Biryusinsky origin. The selected trees are planned to be propagated vegetatively for growing planting material and its use in creating plantations that differ in growth intensity, needle length and early reproductive development.

The biomass of forest stands plays an important role in the process of atmospheric carbon sequestration, however, the extent of carbon uptake by forests remains controversial, partly due to uncertainties in the assessment of forest biomass and its carbon content. Of the main forest-forming species in Eurasia, the five-needled pines (subgenus Haploxylon Pilg.) account for the smallest volume of empirical values of aboveground biomass in the existing database. These data were obtained on the territory of Siberia and the Far East, but there are no similar materials for the Urals. In the proposed study, based on the materials of 22 sample plots established in plantations and natural stands of Siberian pine (Pinus sibirica Du Tour) aged 17 to 118 years, a recursive system of regression models of aboveground biomass (t per ha) by component composition was developed, describing its dependence on the main taxation indicators of stands with coefficients of determination from 0.94 up to 0.99. Based on them, for the first time, a table of biological productivity by components of aboveground biomass was obtained for Pinus sibirica forests in the Urals. A comparison of the obtained table with previously compiled tables of biological productivity based on yield tables of modal and normal Pinus sibirica forests showed their significant discrepancies. Apparently, when assessing the biomass and carbon deposition capacity of Pinus sibirica forests in the Urals, a preference should be given to the proposed models and the table. Unlike the previously published tables, the suggested models and the table make their possible to combine with different sets of taxation indicators obtained by instrumental taxation, as well as when carrying out state accounting of Pinus sibirica forests.

Much attention is paid to the creation of plantation crops for special purposes, including Siberian pine for yield and stem productivity. In this regard, research aimed at studying the polymorphism of coniferous species, selecting valuable specimens for reproduction and cultivation of varietal planting material is relevant. The aim of the research was to study the variability and select seedlings of Siberian pine from the ramets of the plus tree No 100/64 growing on a hybrid-seed plantation (GSP) of the Department of Breeding and Landscaping of the Siberian State University named after M. F. Reshetnev, located on the territory of the Karaulny forestry of the Educational and Experimental Forestry. The mother plus tree, growing in the Kolyvansky forestry of the Novosibirsk region, was certified for seed productivity in 1977 and propagated by grafting in 1988. To study the variability of seed progeny, yield ramets No 7-18 and 22-17 were selected in 2017. In seedlings, biometric indicators were measured (height, current shoot growth, trunk diameter, length of primary, tufted needles, cotyledons), the number of primary needles and cotyledons was determined. A significant difference between ramets in the length of cotyledons, the height of seedlings, the current growth of the shoot, and the length of primary needles has been established. There is a significant relationship between the height, trunk diameter, growth and length of needles both at 5 and 7 years of age. Seedlings were selected according to the intensity of growth and the length of needles. The selected plants are recommended for the creation of forest seed plantations.

For Siberian stone pine, seed production and the possibility of selection based on seed production traits during introduction largely depend on growing conditions. We studied growth and seed production in introduced plantation-type crops with a planting density of 0.4 thousand pcs/ha. There was no competition for light between the trees in the crops, which contributed to the maximum development of the crown and generative organs. The studies showed that the plantation is characterized by high preservation and good condition of the trees. The trees develop a wide crown extending to the ground and enter the generative stage of development early. Most parameters of cones and seeds in the introduced population differ little from those in the species range, with the exception of the number of seeds in a cone, which is lower in the studied crops. That can be explained by the youth of the plantation, insufficient pollination and a high level of self-pollination. The most variable trait was the number of cones on a tree. This feature can be used in selection for early entry into the seed-bearing stage and high seed productivity. It was found that trees of different sexual types differed in the number of cones on the tree and the percentage of full-grained seeds in the cone. When conducting selection activities, preference should be given to trees with female sexualization and trees producing a relatively large number of generative organs of both sexes. It is advisable to leave trees of male sexualization in the plantation to ensure cross-pollination.

The object of the study was oak stands of natural origin, and the subject of the study was the complex ripeness of oak forests. Maturity was assessed by three indicators – average growth of large and medium-sized wood, seed yield, volume of absorbed carbon dioxide and released oxygen. The average growth of large plus medium-sized wood depends on the density of stands. Early technical maturity occurs in denser stands (100 years old) and later in sparser stands (160 years old). Seed yield is determined by weather factors during the flowering period and, consequently, is not related to age, but depends on stand density. Its age interval is 100–160 years. Maximum carbon dioxide uptake and oxygen release is also related to density. The greater the volume of wood, the more carbon dioxide is absorbed and oxygen is released by the stand. This indicator is associated with an age of 100–160 years. The inclusion of three additional factors expanded the concept of assessing the complex ripeness of oak woodlands. When assigning stands for harvesting, these data can be used to determine the biological and ecological losses in the oak formation. 

One of the key components of environmental protection potential of shrubs is the aesthetic effect in shaping the visual appearance of urban spaces. The variety of shapes, sizes and colors of shrubs allows creating compositions that make the city harmonious and stable at the psycho-emotional level. The “green” aesthetic effect is created due to the biodiversity of plant species (shrubs), their decorative properties (color and texture), volumetricspatial compositions, and the processes of their interaction with the surrounding natural and anthropogenic environment. The objects of the study are shrubs growing in plantings of the city of Krasnoyarsk for various functional purposes, located in 7 districts of the city, maintained by the Municipal Enterprise “Green Construction Management” (MP “GCM”) and the nursery of ornamental plants of the MP “GCM”: glossy cotoneaster, Hungarian lilac, Tatar honeysuckle, two-spined currant, tree-like caragana. The results of the analysis of the decorativeness of the studied shrub species showed that the total score of all the studied shrubs is within 31–47 points, which confirms the high decorativeness of these plant species; the order of decorativeness of shrubs by the total score is from high to low: Tatar honeysuckle – 42.30; Hungarian lilac – 40.79; tree caragana – 35.70; glossy cotoneaster – 35.61; two-spined currant – 34.40. The discrepancies in the values are not significant; each species has its own advantages that must be used when creating volumetric-spatial compositions.

Based on statistic reporting materials, literary and departmental materials as the results of the authors own research, there were analyzed the actual forest fire burning rates for the period from 2015 to 2024 for the Federal Districts of the Russian Federation. There are significant differences in the number of landscape fires in the specified districts and difficulties in establishing the total area covered by fire due to different accounting systems.

The burning indicators largely depend on the area of application of specific fire light forces and means as well as from the causes of forest fires. In Siberia and the Far East, the number of fires is lower than in the European Part of the country, but the area they cover is significantly greater. In addition there is a higher share of fires caused by lightning, that is by natural sources of fire. In recent years, the number of landscape fires and the area they cover in the Arctic circle have increased. That is explained by the climate change forwards increasing air temperature. The same reason explains the increase in the number of crown and plat fires.

The main direction for minimizing of forest fire risk indicators is the improvement of regulatory documents in the protection of forest from fires.

At present, the task of synchronizing the processes of sawing logs and drying sawn timber is complicated by the increasing number of simultaneously produced board thicknesses and the use of continuous drying chambers. To establish general synchronization patterns, expressions for the probability of full loading of drying tunnels, the capacity of the stack storage unit, and the waiting time of stacks in the storage unit, obtained in the authors' previous work, were used. The issues of synchronization of log sawing and lumber drying processes under conditions of large-flow sawmilling are considered. As a result, the mechanism of interrelations of full tunnel loading with the number of stacks in the storage unit is described. Dependences of the stack storage unit capacity and the waiting time of stacks in the storage unit on the tunnel capacity are obtained. It is proven that for synchronous operation of the sawmill and drying shops, drying tunnels must be supplemented with periodic chambers.

The development of biodegradable composite fertilizers with prolonged action is a promising direction in agriculture. Such fertilizers provide a gradual release of nutrients, which contributes to uniform nutrition of plants, reduce fertilizer losses and minimize negative impact on the environment. Composites consist of a polymer matrix (biodegradable polymers, zeolites, hydrogels), active components (nitrogen, phosphorus, potassium, microelements) and modifiers (water-retaining additives, biodegradable fillers), which allows regulating the rate of release of nutrients. Plasticized cellulose acetate (AC), which decomposes under the influence of microorganisms such as bacteria, fungi and actinomycetes, can be used as a polymer matrix. The study of AC biodegradation includes an analysis of the effect of soil moisture and the composition of the composites on the decomposition of the material. The inclusion of sodium polyacrylate (PAN) increases biodegradability due to its water-retaining properties, which facilitates accelerated penetration of microorganisms into the material. The work studies the fungal resistance of composites based on cellulose acetate, wood flour and PAN. Biostability was assessed based on the degree of mold damage to samples and weight loss after exposure to active soil. The data obtained confirm the influence of the composition of composites on their resistance to biological degradation. The results allow predicting the durability of composite fertilizers under real operating conditions and developing new effective compositions.