Vol 28, No 3 (2024)

The study results of birch and spruce trees’ spatial location in southern taiga wood-sorrel-bilberry (oxalidosum-myrtillosum) birch forests concerning the stages of their development (maturation, maturity, consenescence) and the age generations of subordinate spruce crops are presented. The analysis was carried out on the basis of the survey data within 2,5×2,5 m plots, identified by provisional coordinates by the plans of 11 permanent sample plots. The type of tree placements was characterized by the following indicators: occurrence, average distance between trees, dispersion ratio to the average number of trees, Morisita, Fisher and Odum indices. The birch and spruce trees association, as well as spruce trees of different age generations were assessed. The occurrence rate of birch and spruce trees was determined according to the age development stages of birch forests. It has been established that during the transition from the stage of maturation to the stage of maturity the occurrence rate of the birch decreases from 64 to 18 %, for the spruce it ranges from 70…73 to 53 %. Regarding the type of spruce placement, it was found that from the stage of maturation to the stage of maturity it changes from contagious to accidental. During the consenescence stage, it becomes contagious again, which is connected with the emergence of a new spruce generation. For the trees of undergrowth and 2nd storey of spruce of different ages, the peculiarities of the dynamics of occurrence and type of placement were revealed. The latter changes from contagious to regular. The contagious type of placement is typical for most age groups of the subordinate spruce population. The exception is age groups of spruce trees over 80 years old; their placement is regular or random. It has been established that in order to identify the dominant aggregations of spruce trees and the trees associations of different age groups in the tree stands under survey, an analysis of placement on larger survey sites is necessary.

The topical issue of balanced sustainable development of regions, primarily those with large forest resources, is considered. Based on the comparative analysis of the efficiency of Russian and foreign forest resources use, the significant underestimation of forest land productivity on the territory of a particular region of the Russian Federation and the efficiency of their resource potential use across the entire spectrum of its utility, hence, its contribution to the country's GDP is shown. As one of the main reasons for this situation is identified as methodological, so the article outlines the conceptual framework for the integration of forest resource potential in the balanced socio-ecological-economic development of the region. In scientific terms, based on generalizations of previous research results and the latest scientific achievements, a new methodology based on modern approaches to large systems research and information technology is outlined. Presentation of the results of practical implementation of the proposed methodology in the form of application software is recommended to be used at all required levels of state strategic planning.

A comparative quantitative analysis of the natural regeneration of Siberian stone pine (Pinus sibirica Du Tour.) and the conditions for the formation of forests with its predominance on two test plots in burned areas of the green-moss forest type in the northern foothill-low mountain part of the Middle Urals is presented. It was found that in both test plots the amount of Siberian stone pine undergrowth ranges from 0,3 to 2,9 thousand ind./ha and, unlike anemochorous woody plants, does not depend on the distance up to 375 m from the peripheral tree stand (forest wall). Moreover, it positively correlated with changes in moss cover and negatively correlated with tall herbaceous cover and post-fire woody debris. On the test plot No. 1 (TP1), the abundant birch undergrowth (12,2...17,5 thousand ind./ha) of vegetative origin, 3 m high, is relatively evenly distributed throughout the burned area. Under its canopy, at a distance of up to 200 m from the forest wall, the number of spruce undergrowth (4,2 thousand ind./ha) is 4 times higher than that of Siberian stone pine (1,0 thousand ind./ha). At a distance of 200 m to 375 m from the forest wall, its quantity (0,7 thousand ind./ha) is 1,5–2 times lower than that of Siberian stone pine (1,2 thousand ind./ha). In test plot No. 2 (TP2), birch undergrowth (2,1 thousand ind./ha) of seed origin is distributed not further than 100 m from the forest wall. In this area, the number of spruce undergrowth (1,5 thousand ind./ha) is 3 times higher than that of Siberian stone pine (0,5 thousand ind./ha). On the other hand, at a distance of more than 100 m from the forest wall, its number (0,6 thousand ind//ha) is 3 times less than that of Siberian stone pine (1,7 thousand ind./ha). Rowan and willow bushes (1,8 thousand ind./ha) with a height of 3–4 m play the role of small-leaved canopy. Thus, with increasing distance from the periphery to the central part of the burned area, the quantitative ratio of undergrowth changes in favor of Siberian stone pine. It is planned to develop spruce forests with Siberian stone pine under the canopy of emerging birch forests at a distance of up to 200 m in TP1 and up to 100 m in TP2 from the peripheral seeding stands. In TP1, the development of the Siberian stone pine forest will take place classically under the canopy of a birch forest through a long-derived soft-leaved formation at a distance of over 200 m from the periphery. In TP2, at a distance of more than 100 m from the periphery, the pine forest is formed by a short-term shrub stage without the participation of small-leaved trees already in the young growth stage.

The article discusses the possibilities of using composted activated sludge wasted by Archangelsk pulp mill in order to grow seedlings of the main forest-forming species in a greenhouse complex. The effect of 3 year-aged activated sludge (biohumus «Arkhangelsk») on water-physical properties (density, true density, porosity, water absorption and total moisture capacity), as well as agrochemical parameters (content of nitrate and ammonia nitrogen, phosphorus and potassium, ash content, reaction of soil solution) is shown. The effect on the substrate properties of added composted activated sludge (the addition of sludge from 10 to 70 % by volume) in bog peat (the decomposition degree of 15 %) has been established. It is shown that all the properties of peat-based substrates and composted sludge are divided into three groups according to their significance: moisture content, agrophysical and agrochemical, of which the most priority water properties can be considered, on which the frequency of irrigation depends. It was found that with an increase in the proportion of silt in the composition of the substrate, the addition density and the true density of the substrate, the content of labile phosphorus and ash content naturally increase, but at the same time, silt reduces the porosity of the substrate and water accumulation, reduces the content of nitrate-nitrogen. According to the set of indicators, in comparison with the previously established optimal indicators and standards for growing pine and spruce seedlings, as well as with reference industrial production substrates, the most optimal is the addition to peat of 20 % of the composted waste of activated sludge wasted by Archangelsk pulp mill, subject to additional fertilization and toxicological examinations.

The purpose of the work is to analyze the legal and actual state of Moscow urban forests as a result of changes in forest legislation. The relevance of the work lies in the need for an overdue review of innovations in the Forestry Code, which are relevant in connection with the need to improve legislation in the field of forestry and forest protection. The importance of forests for the ecology, economy and social sphere requires the development of effective mechanisms and tools for managing forest resources, as well as protecting them from illegal logging and other forms of negative impact. The materials of the study, which are the basis, include the works of classics of forestry, ecology and environmental law, data from the analysis of recent legislative acts in the field of urban forests exploitation. The novelty of the research lies in the analysis of the latest changes made to the Forestry Code of the Russian Federation in August 2023. In the course of the research, the dialectical method, methods of analysis and synthesis, the unity of historical and logical, scientific abstraction, a systematic approach and others have been widely used, which have proven effeciency in understanding environmental issues. The amendments to the Forest Code are aimed at strengthening the legal framework for the sustainable use of forest resources, improving the efficiency of forestry, protecting forests and preserving their area. The results of the study were conclusions about the need to prevent the impact of negative factors, the allocation of areas protected from exposure, and the importance of monitoring the state of forests was also indicated.

The results of studies of deformations of wood-cement materials arising under the action of short-term loads are presented. For this purpose, the initial modulus of elasticity and the Poisson’s ratio of wood-cement materials were determined. It is established that the value of the initial modulus of elasticity ranges from 335...495 MPa, depending on the class of wood-cement material in compressive strength B0,35...B1, and the Poisson’s ratio is within 0,154...0,101. It is established that with an increase in the relative volume content of cement c2 from 0,50 to 0,58, the value of the initial modulus of elasticity increases and the shear modulus of the wood-cement material, and the Poisson’s ratio decreases. It was found that for heat-insulating wood-cement material, an increase in the relative volume content of filler (ash) c4 from 0 to 0,1, with constant consumption of binder and organic filler, also allows increasing the value of the initial modulus of elasticity and shear modulus. For wood-cement material with a filler made of wood chips (wool), the value of the initial modulus of elasticity was 134 MPa, and the Poisson’s ratio was 0,062. The coefficient of elasticity of wood-cement material, depending on the class, ranges from 0,60 to 0,75, and the coefficient of plasticity from 0,26 to 0,36. The obtained value of the ultimate compressibility of wood-cement material on average for the class of wood-cement material in terms of compressive strength B0,35, B0,75 and B1 is 2,55 mm/m. It is noted that the obtained values of the initial elastic modulus and Poisson coefficients of wood-cement materials are in good agreement with the data of previously performed work, however, they, as well as the strength of wood-cement materials, turned out to be 20...25 % lower than theoretical ones. It has been established that the conglomerate structure of wood-cement material determines the manifestation of both elastic and plastic properties associated with the formation and accumulation of microcracks, with the plastic properties of the gel component of cement stone. It is concluded that previously obtained analytical dependences can be used to predict creep deformations and shrinkage of wood-cement materials depending on the age of loading.

A study of the adsorption activity of four samples of initial and activated charcoal was carried out in relation to the purification from fusel group alcohols formed in the alcoholic beverage industry. One of the sorbents was active carbon obtained by activating birch charcoal in a rotary kiln with a zigzag insert. The increased interest in it is due to the fact that activation using this technology provides an increased yield and stable quality of the resulting active carbon. The values of the adsorption capacity of charcoal of different origin during the adsorption of alcohols of the fusel group were determined. The thermodynamic potentials of the sorption process are calculated. In the homologous series of alcohols, with an increase in the hydrocarbon radical by the –CH2– group, the adsorption capacity decreases, the values of the adsorption equilibrium constants increase, and for isomers the corresponding values are higher than for normal alcohols. The effectiveness of the use of active carbon obtained from industrial birch charcoal by its activation in a rotary kiln with a zigzag insert is shown.

Quality indicators of fuzzy regression models designed to study the dependencies between the qualitative characteristics of the educational process and to predict their values, as well as a model for recognizing fuzzy values of the output characteristics of regressions are presented. An algorithm for selecting a fuzzy regression model from linear and nonlinear models based on their quality indicators is given. An analysis of the degree of influence of input characteristics on the output characteristic is carried out. A fuzzy regression model has been constructed to predict the success of the dissertation defense when the applicant enters the PhD program and to study the dependencies between the applicant’s input characteristics and the output characteristic. An alternative approach to the construction of regression models based on non-numerical data of the educational process allows not to impose incorrect conditions on the initial data, considering them to be the values of random variables, and not to use incorrect arithmetic operations for the elements of ordinal scales.