Vol 27, No 5 (2023)

The subject of the research in this paper is the pricing system in the forest complex: essences and classifications of approaches to pricing are considered and analyzed. The purpose of the study is to analyze the currently existing pricing system efficiency in the forest industry, improve the system for assessing forest stands using the rental approach when harvesting timber in a leased forested area. These are the main ideas of the research. Pricing is one of the most important components of the forest industry, since the role of resource price formation is not only to provide the enterprise with revenue, but should also contribute to the effective implementation of the state policy for the forest fund reproduction. This proves the need to develop a methodology that solves the issue of natural resources efficient use. A computational experiment on calculating the cost of producing round timber when renting forests for the purpose of harvesting timber makes it possible to identify rent that contributes to a more rational use of the forest fund. In the field of forestry, various approaches to pricing are used such as comparative, costly, profitable, systemic, mathematical and rental ones. Pricing in the forest industry implies the presence of three economic components necessary for the implementation of an effective state policy, namely the social component, reproduction and innovation. A computational experiment on calculating the cost of a standing crop on a forest plot located on the territory of the Yambatorsky district forestry of the Mari-Turek forestry in the Mari El Republic showed that the natural rent makes up 27,6 %, and taking into account the standard profit, the rent totals 39,7 %. The relative value of the minimum payment rates for standing crop for the trial forest area is 1,5 % of the market value of the assortments. The result of the study is to develop measures aimed at improving the efficiency of the pricing system. The proposed approach to calculating the cost of standing crop as a whole will allow taking into account the main rent-forming factors and increasing the efficiency of forest management from the point of view of the state policy, as well as establishing equal economic opportunities for forest users.

Evaluation of the relationship between tree heights and diameters in the course of logging sites can be done through the use of tables of height categories or regression models. Models of mixed effects make it possible to improve the accuracy of forest inventory to a large extent. The purpose of the study is to develop a mixed effects model for describing the dependence of heights on the diameters of pine trees in the European part of Russia. In the course of study we used the data from measurements of 3 571 model pine trees growing on 201 trial plots from 13 regions of the European part of Russia from Karelia to the Samara region and from the Tver region to the Komi Republic. The paper analyzes 28 simple regression models of the dependence of height on diameter, selected according to literary sources. The selection of the best models was based on quality metrics accepted in statistics, such as the square root of the root mean square error (RMSE), the average percentage of absolute error (MAPE), the average absolute error (MAE), bias (Bias), coefficient of determination (R2), information criteria Akaike (AIC) and Bayesian (BIC). The two-parameter Neslund equation is recognized as the most simple and universal among the fixed effects models. To increase the predictive power of the Neslund equation, a separate trial plot was added as a random effect, which made it possible to significantly improve the quality metrics. It has been established that the height curves predicted by the obtained model are flexible and have a significant response to the initial ratios of the height and diameter of individual trees. The resulting model of mixed effects is an alternative to the tables of height categories used in the practice of forest accounting, which show only conditional relationships between the heights and diameters of trees. The introduction of industry standards developed on the basis of the model will improve the efficiency of accounting for wood resources in pine forests in the European part of Russia.

The article presents the results of a four-year study of the number of forest fires on the territory of 22 forestries in the Chelyabinsk region. It was revealed that the main cause of fires is the human factor such as careless handling of fire. The number and intensity of fires are somewhat dependent on the number of crown fires and weather conditions. Forest fires cause enormous economic and environmental damage to the environment. The damage from a forest fire consists of the loss of standing wood and the cost of extinguishing work, clearing and restoring burned areas, losses from the death of animals, moreover, the calculations have shown that the economic damage from fires can significantly exceed the cost of extinguishing them. Environmental damage from fires consists of the loss of natural resources, for example, valuable animals or rare plants, listed in the Red Book of the Chelyabinsk region of Russia, may be lost due to a forest fire. In order to carry out the most effective reforestation and afforestation, each of the 22 forest areas has developed forest management regulations for reforestation in accordance with the Order of the Ministry of Natural Resources and Ecology of the Russian Federation No. № 188 by 25.03.2019 making changes to it. The article presents an analysis of the forestry regulations on the example of the Krasnoarmeyskoye forestry of the Chelyabinsk region.

The article presents the study results of a linden plantations flowering index. Experimental methods, observations as well as forestry and taxation techniques were used in the course of the study. Circular test areas of a constant radius were laid to study the taxation indicators of linden plantations and to determine the linden flowering index. The test areas are laid within a radius of three kilometers from the apiaries located, since the active flight of honey bees is approximately this distance from the hives located. The trial areas are laid out in accordance with OST 56-69–83 «Trial forest management areas. Establishment method». The composition of plantings around two stationary and two transportable apiaries has been studied. The linden plantations flowering indices were determined. The results of the research are of practical interest mainly for beekeepers. The materials of scientific research are used in the educational process in the preparation of students in the «Forestry» science. The maximum flowering index is observed in incomplete (0,4…0,5) ripe and over-ripe stands with a predominance of small-leaved linden in the composition. It is this completeness of the stand that makes it possible to increase the width and length of the crown, thereby contributing to an increase in the number of flowers and, accordingly, the lime flowering index.

The article discusses the reasons for the low survival capacity of Siberian stone pine (Pinus sibirica Du Tour.) crops in the conditions of the West Siberian mid-taiga plain forest region. The field stage of research was performed in the autumn 2020 and the summer 2022. The survival capacity of forest crops was determined on rectangular trial plots covering 1–2 % of the total area of the surveyed plots. The article provides data on the location and description of the studied areas of Siberian stone pine crops, as well as data on the number of surviving plants and the survival capacity of seedlings in these plots. In the course of the research, it was found that the survival capacity of Siberian stone pine crops in the four studied plots was 7.8 (60.3 %) in 2020, and this figure decreased to 3.6 (39.8 %) in 2022. Along with many other possible causes of excessive death of Siberian stone pine seedlings, the most likely reasons for the poor survival capacity are soaking seedlings and suppressing them with unwanted herbaceous and woody vegetation. In the three study areas, it is recommended to write off forest crops and replant seedlings. In one of the studied crop plots, it is necessary to perform silvicultural maintenance in order to remove unwanted hardwoods and supplement forest crops with enlarged seedlings or seedlings of Siberian stone pine. To increase the survival capacity of Siberian stone pine crops, it is recommended to abandon soil cultivation methods in which the upper fertile soil layer is mixed with the underlying levels, as well as to perform agrotechnical and silvicultural maintenance in a timely manner.

The results of the analysis and applicability of sigmoid functions for studying the Scots pine crops growth on the territory of the North taiga region of the European part of the Russian Federation in the blueberry type growing conditions are presented. A computational procedure for finding models of forest crop growth progress is proposed. The growth progress model reflects the relationship between age and height of a tree and contains sigmoidal growth progress functions in its description. Sigmoid functions were selected for each of the five growth phases and development of the stand as a result of regression analysis. In general, the model of the Scots pine crops growth course in bilberry forests of the northern taiga region of the European part of the Russian Federation represents a system of equations based on the Weibull, Drakin-Vuevskii and Richards equations.

The analysis of fruits morphometric indices of various representatives of the genus Rosa L. growing in the SAFU dendrological garden is given. It is established that the largest fruits are produced by ramanas rose, ramanas «Plena» and cross roses. Indices of fruit parameters were determined, which are characterised by spherical, flattened and elongated shapes. It was found that the largest fruits mass has a ramanas rose and a Scotch rose, and the smallest fruits belong to a Michigan rose. It was observed that the highest percentage of seed content was found in a cinnamon rose, a blue rose and a hanging rose, while their fruits had the maximum number of seeds, except for the blue rose. It is shown that a rose de Mai and a cinnamon rose have the lightest seeds, while the seeds of a cinnamon rode have the highest quality (93.8 %). The minimum indicator of full-grained healthy seeds was observed in Scotch rose «Plena» (75 %).

A comparison of the visual and instrumental assessments of the horse chestnut foliar dechromation degree infested by the Ohrid miner (Cameraria ohridella) was carried out. The data of surveys of model trees for the period 2014–2022 in the Moscow region are compared. A statistically reliable regression relationship between the results of visual and instrumental assessment of dechromation in a long-term series of observations is shown. Instrumental monitoring of the leaves damages during the growing season was carried out based on the assessment of the NDVI vegetation index using the GreenSeeker Handheld® (Trimble) device. The seasonal dynamics of the NDVI index of foliage under Ohrid miner damage is presented on the example of the 2021 season. It is shown that the plants affected by the pest have a shorter growing season, and the average NDVI index for the season is 25…30 % lower than that of undamaged plants. In a nine-year series of observations, it was found that the transition of the NDVI index over the threshold value of 0.4 in plants affected by the Ohrid miner is observed on average 30…40 days earlier than in healthy plants. The possibility of assessing foliage dechromation based on the results of hyperspectral imaging without visualization using the Ocean Insight «Flame» spectrometer is considered. It is shown that the spectral characteristics of the reflectivity of healthy and damaged Ohrid miner leaves differ significantly, which was demonstrated by comparing the spectral brightness curves of reflection. Characteristic spectral zones in the visible and near infrared ranges have been identified, according to which the presence of leaf damage by a miner is successfully identified. It was found that in the near-infrared radiation area, the reflection of damaged leaves are significantly lower than that of healthy leaves, which indicates a decrease in the overall water content of chestnut leaf blades when damaged by pests. According to the results of multi- and hyperspectral surveys, it is possible to automatically determine the lesion of the horse chestnut foliage by the leaf-mining pest Cameraria ohridella.

The flora of Dagestan has been studied quite fully (numerous works by N.I. Kuznetsov, I.I. Tumadzhanov, Ya.I. Prokhanov, L.N. Chilikina, P.L. Lvov, etc.). At the same time, information about vegetation, including those related to arid light forests, is fragmentary and not systematized. In this article, we have made an attempt to assess the level of knowledge of woody vegetation in the arid territories of Dagestan; the results of many years of work on the altitudinal limits of their distribution, as well as the geobotanical description and classification of communities are presented. Arid light forests on the territory of Dagestan are formed by both coniferous and deciduous species. The former are represented by Juniperus oblonga M. Bieb., J. polycarpos C. Koch, J. sabina L. For Dagestan, we did not find them on the territory of the republic. Deciduous tree formations in the arid territories of Dagestan are mainly represented by the communities of the keep-tree (Paliurus spina-christi Mill.) and spirea (Spiraea hypericifolia L.). Other xerophilous tree species (Lonicera tatarica L., Cotinus coggygria Scop., some species of Rhamnus L. and Cotoneaster L., Rosa L., Celtis L., etc.) are included in other formations and do not form pure communities. Large natural massifs on the territory of Dagestan have been identified for Armeniaca vulgaris L. and species Berberis L. For the studied species of woody plants in arid territories, the habitats are marked, the areas and altitudinal limits are estimated, and the geobotanical characteristics of the communities with their participation are given.

The dependence of the macroelements content in the Silver birch (Betula pendula Roth) leaves on the vital state of the stand in the gradient of aerotechnogenic emissions by the Karabash Copper Smelting Plant was established. The content of macro- and microelements (nitrogen, phosphorus, potassium, magnesium, calcium, sulfur was studied, and NPK was calculated as the total content of nitrogen, phosphorus and potassium) in the leaves of a birch tree at different distances from the Karabashmed plant. The study showed that when air was polluted with sulfur dioxide, the total content of macronutrients in the leaves decreased. Severe damage to birch leaves by sulfur dioxide in the affected area of Karabashmed is indicated by an increased concentration of sulfur in the leaves — one and a half times more than on another sample area, as well as deterioration of the vital condition of the stand (the degree of defoliation and dechromation is 1.5–2 times higher, deterioration of the sanitary condition is 1.5 times more when in the others sites). With an increase in foliage dechromation, the potassium content decreases, the sulfur content increases; with a defoliation increase, the content of nitrogen, phosphorus and sodium decreases. The content of calcium and magnesium is not related either to defoliation, dechromation or the category of the tree condition.