No 4 (64) (2024)

Introduction. The size structure of a stand defines its internal diversity that facilitates sustainable development of a cenopopulation by providing materials for the natural selection of specimens and their targeted artificial selection with regard to their economically important characteristics. The aim of the study is to improve the methods of using the size structure parameters of Scots pine (Pinus sylvestris L.) even-aged stands in order to assess their current state and prospects for further development, as well as to identify cenopopulations valuable in terms of selective breeding. Materials and methods. The source material was collected from 300 permanent and temporary sample plots laid out in the even-aged pure pine stands varying in origin, age, density and growth conditions in the Republic of Mari El. On 17 permanent sample plots, circumference measurements were taken on all numbered trees and the estimation of their current diameter increment was performed periodically, every 5–10 years. The duration of observations at the stationary sites ranged from 10 to 40 years. The digital data obtained were processed on a PC using conventional methods of mathematical statistics. Results. The study determined the limits of variability and the key patterns of change in the values of a number of stand size structure parameters, each having its specific informative significance; relevant scores were developed for evaluating the current state and development prospects of the cenopopulations. The study has shown that a network of stationary sample plots is a reliable basis for gaining new knowledge about regularities in the dynamics of the stand size structure formation. Conclusion. For an adequate assessment of the current state of cenopopulations and determination of prospects for their further development, the values of size structure parameters must always be compared with a reference standard, which can be their values attributable either to regional modal stands or so-called “normal” stands.

Introduction. Varieties of blue honeysuckle (Lonicera caerulea L.) are a popular berry crop; their fruits have a sweet and sour desert taste and are of nutritional, dietary and medicinal value. The aim of the research is to determine fruit parameters for five varieties and four variety samples of honeysuckle, as well as the content of ascorbic acid and tannins in them in the conditions of the Republic of Mari El. The objects of the study are five varieties and four variety samples of blue honeysuckle grown in the Botanical Garden-Institute of Volga State University of Technology (Yoshkar-Ola, Republic of Mari El). Methods. The weight and size of fruits were studied in 2015 and 2017; the contents of the biochemical compounds were investigated in 2017. The quantitative content of ascorbic acid was determined by the titrimetric method using 2,6-dichlorophenolindophenolate of sodium, and the content of tannins was found by redox titration using a solution of indigo sulfonic acid and potassium permanganate. Results. The 'Chulymskaya' variety was found to have the largest fruits, while the 'Izyuminka' variety had the smallest ones. In excessively humid conditions of 2017, the 'Iolinka' variety produced fruits of greater size and weight than in the arid conditions of 2015, while the fruits of the other varieties were approximately the same or smaller. The fruit weight exhibited the greatest intervarietal variability, which was due to the impact of the varietal specificity factor; the length and diameter of the fruits were significantly affected by the factor of the year as well. In 2017, the ascorbic acid content in the fruits of the four varieties was 39.1–64.9 mg/100g and the content of tannins was 1.37–1.89%. The lowest content of these compounds was detected in the 'Iolinka' and 'Sinichka' varieties. The yield of air-dried fruits was inversely correlated with the weight of fruits, its values amounting to 10.8–13.7% of the weight of freshly harvested fruits. Conclusion. The fruits of the variety 'Chulymskaya' have good prospects for use as a source of ascorbic acid, while the fruits of ‘Sinyaya Ptitsa' are promising as a source of tannins. The results of the study can be applied in cultivating the studied varieties of honeysuckle for food and medicinal purposes.

Introduction. Thirty-five years after the Chernobyl accident, approximately 662 thousand hectares of forest plantations in the Russian Federation are growing in the areas affected by radioactive contamination, which requires ensuring radiation safety in forestry operations. The purpose of the study is to predict the radiation situation and external radiation doses to workers in forest plantations where the ¹³⁷Cs contamination density of soil varies within the range of 37–185 kBq/m². Objects and methods. The object of the study is a conditional district forestry that has an area of 10,000 hectares and includes 100 forest compartments. The density of soil pollution with ¹³⁷Cs was modeled in the range from 50 to 180 kBq/m². For the 2024 to 2084 period, forecast calculations of the density of soil pollution with ¹³⁷Cs were made along with the distribution of forest compartments according to the zones and subzones of radioactive contamination, the ambient dose equivalent rate of external gamma radiation, and the radiation dose to workers. Results. It has been established that by 2054, 7,700 hectares will be located on the territory of the district forestry with the ¹³⁷Cs contamination density of soil varying from 37 to 74 kBq/m². By 2084, around 80 per cent of the territory will have been categorized as conditionally uncontaminated, the density of soil contamination with ¹³⁷Cs ranging from 18 to 37 kBq/m². Conclusion. In the district forestry plantations, the inter-compartment interval of the ambient dose equivalent rate of external gamma radiation is predicted to decrease from 95–125 nSv/h in 2024 to 50–60 nSv per hour in 2054, and to 25–35 nSv per hour in 2084. The range of the external radiation dose to workers will decrease from 0.12–0.15 mSv per year in 2024 to 0.03–0.04 mSv per year in 2084, which is more than six times lower than the national Radiation Safety Standards NRB-99/2010. Radiometric control of by-use products is recommended at the ¹³⁷Cs contamination density of soil varying within the range of 18–37 kBq/m².

Introduction. Depending on the purpose, a distinction is made between "pure" birch bark and that with an admixture of bast. With an increase in the bast proportion in the birch bark composition, not only the grade of the bark but also its quality decreases. The necessity to separate the outer layer of birch bark from its inner layer is quite a complicated task that requires special devices. The conducted patent search and literature review revealed practical interest in the need to increase the volumes of harvesting high-quality birch bark. The purpose of the research is to modernize devices for separating birch bark layers in order to ensure high quality characteristics of the finished product. Objects and methods. The objects of the study are devices for separating birch bark from bast. The methods of literature survey and patent search for studying similar devices were employed. The advantages and disadvantages of existing design solutions were identified. Results and discussion. Analogs of the equipment, their advantages and disadvantages were determined. New design options were developed and proposals were made to modernize the existing technical solutions for separating bark layers. The authors used the principles of bark layer separation based on the interaction of impact mechanisms, electromagnetic vibrators, contacting vibrating plates and other mechanisms facilitating the deformation of the bark, destruction of the bast layer under the action of impact mechanisms and vibration loads and its separation. It is noted that changing the number of sequentially installed working units of the modernized equipment makes it possible to achieve the required quality of the separation of bark layers. Schematic diagrams of the equipment are presented, a brief description of its main units and their operation principle are given. Conclusion. Specialists and researchers of scientific and industrial organizations are invited to consider the proposed modernized design solutions for separating birch bark layers that allow for high quality characteristics of the finished products. This provides an opportunity to expand the range of existing equipment options available to production facility sections engaged in processing wood raw materials while increasing the efficiency of technological processes. The described technical solutions can contribute to the technical and economic development of the industry.