Home – Home – Jornals – Siberian Journal of Forest Science 2025 number 1

The interactions in the association of bark beetles, fungi, nematodes with the host tree is a multi-level system of transmission and trophic links that ensure the labile nature of disease scenarios leading to tree death. Transmission of phytopathogenic fungi and stem nematodes by bark beetles often acts as a key factor in the weakening and death of woody plants in forest and park plantations. Nevertheless, the nature of the interaction of various organisms in this four-component complex is species-specific and the role of transmission pathogens in the weakening and death of the host tree is far from always clear. To test this thesis, in our opinion, it is necessary to ensure a combination of field and experimental studies of the role of each infection agent - bark beetles, phytopathogenic fungi, and nematodes in weakening the tree with different sequences of colonization by members of the pathogenic association. Field studies should record seasonal changes in the dynamics of the number of pathogens in the tree and the vector in order to compile a model-diagram of infection. Experimental studies should test the scenarios of pathogen interaction in the vector-fungus, vector-nematode, nematode-fungus subsystems, as well as experiments on inoculation of fungi and nematodes into a plant, bypassing the vector and through the vector. Comparison of these data will make it possible to build a reliable regional predictive model of the infection scenario as a basis for developing practical measures to control diseases of woody plants. In 2023 and 2024, we began a series of studies to study the transmission of fungi and nematodes by bark beetles at different stages of the life cycle of two species of bark beetles, the most common in the taiga forests of the northwest of the European part of Russia - the European spruce bark beetle ( Ips typographus (Linnaeus, 1758)) (spruce ( Picea A. Dietr.)) and the Common pine shoot beetle ( Tomicus piniperda (Linnaeus, 1758)) (pine ( Pinus L.)). The results obtained show the high lability of the relationships between phytopathogens and bark beetles and the ambiguity of the role of bark beetles in the transmission of phytopathogenic fungi.

The article presents the results of a study of the variability of morphological features of vegetative organs (the number of needles in a bunch and the length of the needles) in intraspecific forms of Siberian larch ( Larix sibirica Ledeb.), differentiated by the color of young female cones into red-coned ( f. rubriflora Szaf.), green-coned ( f. viridiflora Szaf.) and pink-coned ( f. rosea Szaf.). The study was conducted over three years (2020-2022) in a cenopopulation of Siberian larch of artificial origin, created in an ecologically safe urbanized part of Krasnoyarsk - microdistrict of Akademgorodok. It was found that the variability of needle features in intraspecific forms of Siberian larch has an annual and form specificity. The variability of the number of needles in a bunch and the length of the needles in the red-coned, green-coned and pink-coned forms varies from average to high levels over the years. According to the average data for a three-year period, the red-coned form of trees is distinguished by the lowest values of the number of needles in a bunch and the length of the needles, the green-coned form is distinguished by the greatest length of the needles, and the pink-coned form is distinguished by the greatest number of needles in a bunch. The revealed morphological features of the needles can be considered as diagnostic features of intraspecific forms of Siberian larch with different colors of female cones, forming the population structure of the species in different growing conditions.

Modern methods of whole-genome sequencing have made it possible to develop a large number of DNA markers, both selectively neutral and functional. Microsatellite loci are the most informative, reproducible, relatively inexpensive and highly polymorphic among other genetic markers. Whole-genome sequencing significantly simplifies their search and development. The article is devoted to the development of new microsatellite markers for Scots pine ( Pinus sylvesrtis L.). Several thousand contigs containing microsatellite loci with tri-, tetra- and pentanucleotide motifs were selected in the draft genome assembly of Scots pine obtained by the authors. The search was specifically focused on loci with a repetitive motif length longer than two nucleotides, as the most reliable for genotyping even in a simple gel electrophoresis. A total of 39 primer pairs were tested. Of these, six loci with tri-, tetra- and pentanucleotide repeats were ultimately selected, which showed a high level of polymorphism, reliable genotyping, and were additionally tested in two populations from the Severo-Yeniseisky and Kuraginsky districts in Krasnoyarsk Region (East Siberia, Russia) and compared with other populations and marker sets according to published data. The developed markers can be used in the future in various population genetic studies and for identifying the origin of wood and plant material.

The article discusses an approach to regulating and automating cross-dating, which is an integral stage in obtaining tree-ring chronologies. The process of cross-dating the width of annual rings, although it is widely used and can be produced using software tools, is still not fully regulated and depends on subjective factors. The classical approach to cross-dating is based on the selection of one or more individual tree-ring chronologies (ITRC) as reference, and sequential dating of the remaining series relative to the selected ones. This approach has a number of restrictions. Our approach actually repeats the classical cross-dating technique, but with the only difference that the main bias is towards automating the process. In this case, all ITRCs can act as references and be dated among themselves, combining into separate selections based on the correlation level. Thus, upon completion of the process, we will have many selections of well-dated ITRCs, despite the fact that the selections themselves will most likely correlate poorly with each other. The initial selection will contain ITRCs that do not correlate with each other. Analysis of correlation links within the finished selections can reveal individual ITRCs that spoil the overall signal. Such chronologies should be removed one by one, repeating the analysis of links within the selection. The simplest solution is to evaluate the correlation of each ITRC with the generalized tree-ring chronologies (GTRC) and remove the least correlating ITRC, reconstruct the GTRC and repeat the process. Verification of the “automated cross-dating” method was carried out when creating the GTRCs Мuy 1510-2015AD; Muy1 107BC-2015AD and Muy2 3919-2053BC (Muya-Kuandinskaya Basin, Buryatia). The automated cross-dating method also made it possible to significantly improve the statistical marks and quality of the generalized tree-ring chronologies.

Article deals with topical issues of preserving protective forests, maintaining them in a state of constant effective fulfillment of their target functions taking into account regional specifics of natural, ecological and socio-economic conditions are considered. The aim of the work is to identify, taking into account the changing priorities of the attitude to forests in society, periodically aggravating for more than a century the problem of conservation of protective forests at the global, regional and local levels, the general principles of effective silvicultural maintenance of these forests in the country and the directions of their implementation by forest areas. To achieve this goal, on the basis of using historically developed system and priority method of silviculture, the reasons for the emergence and periodic aggravation of the problem of conservation of protective forests are considered. As well as applied variants of its solution, their validity and effectiveness, the existing silvicultural system for protective forests, its application in normative legal documents and in practice is assessed. The paper identifies the main principles of improving the systemic silvicultural support of maintenance, conservation of protective forests in the optimization of balanced ecological-resource forest management, determines the directions of implementation of common priority target silvicultural systems of maintenance, conservation of protective forests at the regional level, depending on the diversity of natural properties of forests, their division by intended purpose, accessibility for the implementation of silvicultural measures, as well as ecological and socio-economic conditions. As a result, a fundamental system of solving federal and regional issues of maintenance, conservation of protective forests and multi-purpose ecological-resource method of their use by silvicultural areas within the boundaries of certain territorial formations has been formed. The developed methodological provisions can be used in the development and implementation of research to create a scientifically based regulatory framework for the regulation and differentiated application of forestry measures in protective forests of the territories, allocated according to the taxons of their silvicultural zoning: silvicultural regions, districts and districts within the European-Ural part of the country, Siberia and the Far East, as well as the subjects of the Russian Federation.

The article presents the results of a 7-year study of the outbreak of Diplodia shoot blight, discovered in 2017 in young forest stands of Scots pine ( Pinus sylvestris L.) in the Moscow Oblast. The area covered by the disease at the peak of the epidemic was more than 2 thousand hectares. Previously, such a huge spread of Diplodia shoot blight with a high degree of damaged trees in forest stands of the Moscow Oblast had not been recorded. For the first time in the region, the symptoms of the disease and the periods of their development on pine in forest stands of different ages and origins have been described. New for the Moscow Oblast data on the complex development of the causative agent of Diplodia shoot blight ( Sphaeropsis sapinea (Fr.) Dyko & B. Sutton) and other pathogenic fungi that cause necrosis and cancer diseases of pine: Sclerophoma shoot blight ( Sclerophoma spp .) and Pine twisting rust ( Melampsora populnea (Pers.) P. Karst.) has been obtained. It was found that the highest level of the disease is usually observed in plantings aged from 3 to 6 years, afterwards a gradual weakening of the disease begins. The highest occurrence of disease and degree of crown damage were observed in forest plantations of different ages, pure in composition, in B2 type of growing conditions, as well as with a high level of anthropogenic impact. The density of forest plantations did not affect the degree of the disease development. The damage caused by Diplodia shoot blight included both the weakening of plants (up to complete death in isolated cases) as a result of the death of shoots immediately during the outbreak of the disease, and the subsequent deformation of trunks, formation of multi-topped (bushiness) crowns and the cankers, which reduced the resistance of young trees to snow and wind injury and can deteriorate the commercial qualities of the developing forest stands. Based on the results of measuring the growth of apical shoots, inhibition of plant growth due to damage by Diplodia shoot blight was revealed. The results of the study can be used for monitoring diseases in young pine stands and in projecting of a system of plant protection measures.

It has been established that the black grouse ( Lyrurus tetrix (Linnaeus)), when choosing a habitat, is primarily oriented to the presence of a wide variety of forage plants (at least 8-11 species) that can meet the needs of both adults and young at different stages of development. At the same time, the share of fodder plants in the total phytomass of the grass and shrub layer should be at least 55-77 %. In addition, the most important factor is the optimal protective properties of habitats - low and sparse herbage improves visibility and maneuverability, and the mosaic alternation of edges and glades provides shelter from raptors. The presence of tree canopy also provides protection from predators. We quantified the threshold values of forage plant reserves, light availability under the forest canopy, and stand characteristics (closeness, height, and diameter), which can maintain a viable black grouse population. Quantitative indicators of species diversity, proportion of forage plants, phytomass reserves, lighting and stand structure necessary to maintain a viable black grouse population were identified. It was found that in case of predominance of one of the factors (either only forage base or only protective conditions) optimal habitats of the species are not formed. The most attractive habitats are those with a mosaic combination of open and closed areas that provide all the ecological needs of the species. The results can be used to optimize black grouse forest habitats by preserving biotope mosaic, maintaining the necessary level of illumination, and enriching the forage base.

When studying the biological productivity of forests and developing standards for accounting for all components of biomass, it is necessary to know the laws of the dynamics of the wood density of growing trees as their key environmental characteristics that require the use of non-destructive methods. The pilodyn method, as one of the simplest and most accessible, is in demand in breeding programs, but the selection based on the density indicator obtained by the pilodyn tester was not effective for all tree species, and the density variability explained by this method varies in the range from 27 to 92 %. Qualimetry by the method of wood drilling resistance based on a resistograph, as a more sensitive device compared to a pilodyn tester, has also been widely used in breeding programs, but both methods are based on local probing, and its extrapolation to the entire tree gives biases of estimates. The use of the rigidimeter design does not have the drawback inherent in the two methods mentioned above. But, the method proved to be relatively time-consuming to perform multiple measurements. The acoustic method for assessing the modulus of elasticity and density of wood is sensitive to the presence of wood defects and allows you to remove the contradiction of selection targets aimed at simultaneously increasing the growth rate and density of wood. Radiation methods require the use of expensive equipment and successfully register the intra-ring density. The advantage of NIR-spectroscopy over all other methods is the ability to evaluate the chemistry of wood and the yield of cellulose, but it does not give a direct assessment and requires special calibration. Thus, any technique has its limitations, and it is important to be able to choose the technique that is most suitable for a particular.