Vol 30, No 4 (2026)

The study is dedicated to methods for assessing the fire hazard of drained peatlands based on satellite monitoring data. A set of criteria is proposed to evaluate the fire hazard level in drained peatlands using retrospective satellite fire data. The sum of hotspots (SH) is identified as the main criterion. Additional criteria for ranking (sorting) drained peat bogs according to their fire hazard are proposed. A web tool and publicly available database have been developed for analyzing hotspots in the contours of most Russian drained bogs, dividing hotspots by year, season, and data from different satellites. For peat fire prevention projects planning and implementation it is recommended to select the most fire hazardous peatlands that cause great damage in case of peat fire based on the specified parameters in combination with other factors (population density, proximity to cities).

The composition, content and ratio of pigments are important characteristics of the functional state of plants. Changes in the pigment system of plants are a significant criterion for assessing the influence of environmental factors on them. The paper presents data on the content of photosynthetic pigments in the leaves of Vaccinium myrtillus L., growing in various ecological and cenotic conditions of the Southern Taiga subzone. Leaf samples collected in phytocenoses dominated by Vaccinium myrtillus L. in the grass-shrub layer, belonging to 5 types of plant communities, were analyzed. Chlorophyll a and b, carotenoid concentrations were determined in freshly collected raw materials using a spectrophotometric method. Among the types of habitats studied, the largest pigment stock, which provides a high intensity of photosynthesis, is characteristic of Vaccinium myrtillus L. growing in conditions of pine and spruce shrub-green moss (11,87 and 12,52 mg/g of dry mass, respectively). The lowest concentration of chlorophylls (5,22…7,65 mg/g of dry weight) was detected in phytocenoses with excessive moisture (pine forests, spruce forests, birch forests of shrub-green moss-sphagnum). As a result of the study, it was found that the ratio of chlorophylls a and b (К_a/b) varies from 1,17 to 1,83, and the value of the ratio of chlorophylls/carotenoids in the studied types of forest growing conditions ranges from 4,47 to 11,22. Carotenoids in the leaves of the species under study are contained, depending on the habitat, from 0,85 to 2,7 mg/g of dry matter. It was shown that the content of carotenoids positively correlates with the content of chlorophylls at the level of r = 0.62 (p < 0,01). The obtained results on the accumulation of carotenoids suggest that an increase in their proportion in shrub-green-moss pine trees is associated with an increase in the light-protective role of carotenoids in phytocenoses of this type. Whereas in spruce forests, the accumulation of pigment is due to the activation of its light-collecting function. It has been established that the pigment content in blueberry leaves depends on environmental factors (illumination, soil acidity).

The work is devoted to the application of a fundamentally new method of processing data from phenological observations. The proposed method analyzes the relationship of the onset of phenological phases with environmental factors, taking into account the rate of interphase transition, which strongly depends on the seasonal variability of these factors, primarily temperature. Describing the dynamics of seasonal development of plants, the coefficients of the interphase transition of trees are introduced, which characterize the rate of transformation of a tree from one phase to another. This makes it possible to establish the dependences of the onset of a specific phenophase on the influence of a limiting environmental factor when using linear and polynomial approximation. This method also makes it possible to eliminate the time interval of accumulation of positive temperatures from the calculation model and make comparisons regardless of the individual climatic conditions of the growing season. The application of the described technique is possible when conducting comparative phenological studies of similar taxa in order to identify differences in their response to limiting environmental factors. The proposed method for calculating phenological data is given and tested on the example of various species of the Larch genus. At the same time, the main factor under consideration affecting the seasonal development of species is the sum of positive temperatures. The obtained data are supposed to be used in the future for a detailed comparison of introduction of the studied species in the territory of the middle zone of the Russian Federation.

The predicted values of timber product using the ARIMA model has been considered. An algorithm for developing a prediction taking into account the industry and market specifics of the Russian Federation is presented. The process of using the ARIMA model in the Python programming environment is described in detail. The parameters of the ARIMA model are provided and interpreted, and a quality assessment of the price prediction based on it is given. The obtained pricing trends are evaluated, and the main economic factors influencing the research object are described.

The study results of the effect of cement activity on the hardening kinetics and wood-cement composite (arbolite) strength are presented. It has been established that in order to increase the wood-cement composite strength at the design age, it is possible to use highly effective cements during steaming. It was revealed by the relative strength index that the effect of highly effective cements on the arbolite hardening acceleration is observed only under prolonged conditions of temperature and humidity treatment. It has been established that a wood-cement composite made on cements of the same brand can acquire different strength at the age of 28 days when used for steaming cements of different efficiency. A sharp slowdown in composite hardening was observed with increased carbohydrate content, without reducing the maximum strength at the design age. An increase in the sensitivity of composite strength to a decrease in the number of extractives in the wood core was determined. The dependence of the final composite strength on the efficiency of the cement used is presented.

The necessity of developing modern models of equipment for cultivation forest soil, including those with an increased degree of moisture, has been determined. Soil cultivation in such conditions is carried out by creating microhills of the surface in the form of soil borders, ridges or turning of seams. The developed designs of woodland ploughs are presented, for which a study of their mass-inertia characteristics based on the designed 3D models was carried out. Using CAD, the mass distribution across the studied structures detail part was estimated, which made it possible, taking into account the overall dimensions, to find the location of the developed ploughs center of mass. In the CAD environment, a scheme for unitizing combined implements with basic tractors of drawbar category 3 and 1,4 tf was developed. In order to determine the necessary energy characteristics of the machine-tractor unit for the tools being developed, a theoretical study was conducted based on mathematical modeling of the ploughs working process. In this case, the value of the tractors nominal traction power is used as a classification parameter. By calculating a special coefficient, the ratio of the required traction power to the tractor rated traction power was estimated. Taking into account the parameters of the cultivated soil and the designed tools, a study was conducted to find the optimal value of the tractor traction power as part of a machine-tractor unit. As a result, for aggregation with forest ploughs that cultivation waterlogged soil with increased traction resistance by creating linear ridges or turning of seams along the edges of the furrow, it is recommended to use a tractor with a traction class of 3 tf or higher or a tractor with a traction class of 1,4 tf, respectively.

It is shown that in the canonical Jordan form of the expression F = (R + μI)(Q + νI) for the projectors R, Q the following symmetry with respect to the value ρ = μ(μ + 1)ν(ν + 1) is observed. For λ² ≠ ρ  if there are several cells J_k(λ), then there are exactly as many cells J_k(ρ/λ), where λ is the eigenvalue of the matrix F. For cells with λ Î σ = {μν, μ(ν + 1), (μ + 1)ν, (μ + 1)(ν + 1)} the symmetry is somewhat broken: if there is a cell J_k(λ) with k > 1, then there is necessarily a paired cell J_l(ρ/λ), where |k – l| ≤ 1. For λ² = ρ  and λ Ï σ  the cells J_k(λ) must have an even order.