Home – Home – Jornals – Siberian Journal of Forest Science 2024 number 1

The article provides original information about relict phenomena in the structure of the forest component of the mountain forest-steppe of Southern Siberia (SS). Larch (Siberian larch ( Larix sibirica Ledeb.)) shrub-grass forests are characteristic element of vegetation in the forest-steppe of the SS. The oldest are the Pliocene, the most thermophilic analogues of the modern forest-steppe, noted in the foothills of the Western Tannu-Ola ridge (Horlety) is a small-leaved larch, dwarf-gmelin wormwood with participation in the community of mountain-Asian elements of ancient Middle-earth. It is important to note that in the species composition of the relict larch forest, the role of characteristic boreal species such as spirea ( Spiraea media Schmidt), prickly wild rose ( Rosa acicularis Lindl.) is insignificant in comparison with typical elements of semiarid florocenotypes of the Ancient Middle Earth. Among them, participation in the shrub layer of the small-leaved honeysuckle community, an element of the Altai-Dzhungar-Tien Shan relict florocenotype of highland Asian shrubs, is especially significant in phylogenetic terms. In the conditions of Western Transbaikalia, in the spurs of the ridge Malyi Khamar-Daban (Inzagatuy tract) describes the relict larch forest with the participation of characteristic species of the periglacial Pleistocene complex. In the Quaternary period - especially the xerothermic phases of the Holocene, as mountains deglaciate and a relatively warm and temperate climate develops, conditions are created for the formation of a modern mountain forest-steppe in the conditions of the semi-humid climatic regime of the SS. For example, forb-iris-sedge larch, characterized by a rich species composition of herbaceous plants, along with a well-developed undergrowth. This is expressed in the processes of mesoxerophytization of vegetation with the development of floristic complexes of meadow steppes and hemiboreal forests in the structure of phytocoenocomplexes of mountain exposure forest-steppe from Altai to Transbaikalia.

The results of the study of the intraspecific variability of the morphological traits of Siberian larch ( Larix sibirica Ledeb.) cones in the south of Siberia (Tomsk Region, the Republics of Altai and Khakassia) are presented. Ecotypes (marsh, upland, forest-steppe, and steppe) and intraspecific forms, differentiated by the color of young female cones - red cone (f. rubriflora Szaf.), green cone (f. viridiflora Szaf.) and pink cone (f. rosea Szaf.) are considered. As a result of the study, a significant ecotopic variability of metric and qualitative traits of Siberian larch cones was established, caused by the heterogeneity of the ecological and geographical conditions of tree growth and probable interspecific hybridization. In the southern taiga subzone, in the process of hybridization with Sukachev’s larch ( Larix sukaczewii Dylis), plantations of Siberian larch (marsh and upland ecotypes) were formed with a predominance (up to 95 %) of large-cone and large-scale trees promising for forest seed production. In the forest-steppe and steppe ecotopes of Altai and Khakassia, the proportion of trees with small cones increases (up to 37 %), and the polyvariance of Siberian larch cenopopulations in terms of the quality of cones increases. When evaluating the shape variability of Siberian larch, it was shown that trees of the red cone form produce larger cones (length, 30.1 ± 0.7 mm; width, 23.7 ± 0.7 mm) with a large number of smaller scales. The green cone form is characterized by smaller cones (length 28.8 ± 0.8 mm, width 22.3 ± 0.8 mm) with fewer larger scales. The pink cone form has intermediate values of the traits under consideration. The predominance of large cones in red cones may have an adaptive character, associated with the formation of a larger number of cones with large seeds. The identified features of the ecotopic and form differentiation of Siberian larch should be taken into account when carrying out silvicultural, breeding and silvicultural activities in the south of Siberia.

The article deals with the issues of artificial reforestation on the burnt areas in the permafrost zone of East Siberia (Yakutia). Scientifically substantiated work on forest plantations in Yakutia has not been carried out before this work. The results of long-term observations of larch crops, which were carried out on the territory of the Megino-Kangalassky forestry of the Republic of Sakha (Yakutia), are summed up. Artificial reforestation was carried out with of Kayander larch ( Larix cajanderi Mayr) seedlings. The article also presents and analyzes all the experiences of creating forest plantations recorded in various sources, carried out in the republic in different years. An analysis of the growth and development of larch plantation is given, an estimate of survival rate for 8 years is given. In the first years after planting, seedlings adapt to new environmental conditions, starting from the third or fourth year after planting, there is an increasing growth of seedlings, and from 15-20 years, the growth of larch crops is intensified. The characteristics of the vegetation in the area of artificial reforestation and in the control are given. For twenty years, significant changes in the vegetation cover have been traced: from meadow-forb to forest vegetation. The materials of the article can be the basis for the development of the most promising technologies for reforestation in the permafrost zone and will make it possible to achieve high-quality reforestation during artificial and combined reforestation in the light of recent changes in forest legislation.

The article presents data on the effect of emissions from the Bratsk Aluminum Plant (BrAZ) on the photosynthetic apparatus of Siberian larch ( Larix sibirica Ledeb.). On the basis of data on the content of elements-pollutants (fluorine, sulphur, heavy, light metals and metalloids) in needle trees using cluster analysis the trees of critical, strong, moderate, low level of contamination, as well as background stands were identified in the surveyed area. It has been established that in the needles of trees with an increase in the level of pollution, the content of pigments decreases: chlorophyll a - by 68 %, chlorophyll b - by 72 %, carotenoids - by 67 % compared to the background level. The morphometric parameters of the assimilation organs of polluted trees (the length of auxiblasts of the second year of life, the mass of needles on them, and the length of needles) are reduced by 45-65 % compared to the background values; their minimum values are found at a critical level of pollution (on the territory of the BrAZ industrial zone). The presence of functional disorders of the photosynthetic apparatus of needles in conditions of pollution by emissions from an aluminum plant is evidenced by a change in the parameters of chlorophyll fluorescence: a decrease in the photochemical activity of photosystem II (F_v/F_m) by 7 %, the electron transport flow rate (ETR) - by 26 %, the quantum yield of photosystem II (Y(II) - by 35 %, as well as an increase in background fluorescence of chlorophyll F₀ by 26-35 % and non-photochemical quenching of chlorophyll fluorescence (NPQ) by 27 % compared to background values. The maximum negative impact of emissions on the photochemical processes of larch needles was recorded at the critical level of trees pollution.

The carbon depositing capacity of forest cover in the context of climate stabilization is determined by the productivity of its biomass, which, in turn, is formed under the influence of climate. The first attempts to build maps of forest productivity by stem volume and its growth were based on integrated climate indices without the use of statistical methods. When the taxation indicators of stands and climatic factors were included in the models as independent variables, the contribution of climatic factors to the explanation of the variability of production indicators was statistically insignificant due to the regional level of the models. With the release of multifactorial modeling of biomass to the Eurasian level, the explanatory ability of both taxation and climate variables has become statistically significant. However, the stability of such models was not evaluated and the multicollinearity of the defining variables was not checked. In our study, on the basis of the author’s database on the biomass of trees of forest-forming species of Eurasia and the WorldClim climate database, a conjugate analysis of monthly and average annual precipitation for the period from 1970 to 2000 was performed, the relationship of aboveground biomass of trees with their size, precipitation and temperature was revealed, and the multicollinearity of independent variables in models of biomass of forest-forming species was estimated. It has been established that multicollinearity of determining factors, including temperatures and precipitation, is not observed in the range of the main forest-forming species growing in Northern Eurasia from the subarctic to the southern temperate zones when developing climate-sensitive biomass models. But south of the 37th parallel, in the subtropical, subequatorial and equatorial zones of Eurasia, multicollinearity of temperatures and precipitation occurs when modeling the biomass of trees.

Populations of laurel poplar ( Populus laurifolia Ledeb . ) in the basins of the Tom and Chulyshman rivers, which are characterized by polymorphism in bark color, were studied. The most obvious morphological feature that marks these forms is the base of the leaf blade - rounded-wedge-shaped in gray bark and heart-shaped in white bark forms. The population of the river Chulyshman, differs from the plantations of the Tom’ basin by a sharp predominance of the ovate-triangular (75.5 %) shape of the leaf blade and the absence of elliptical leaves. There is a predominance of intrapopulation variability, which is typical for poplar. The interpopulation component in terms of quality features accounts for 11.8 %, in terms of phenotypes 23.8 %, which indicates the average differentiation of the studied plantations. The conducted studies have shown that the observed relationship between the blade morphology and form polymorphism is characteristic not only for the plantations of the river basin. Tom, but in general for laurel poplar. It has been established that polymorphism in different parts of the range is not an adaptation to moisture regimes, but probably reflects the distribution history of the species. The observed relationship between the populations of Tom and Chulyshman is explained by the evolution of the river system of the Altai-Sayan mountainous country. The Chulyshman River from the Oligocene to the Upper Pleistocene (30-40 thousand years ago) was part of a single river system, which also included sections of the Biya, Kondoma, and Tom. Considering that laurel poplar arose in the Neogene, and the formation of laurel poplar forests spread widely in the Middle Pleistocene, its white-bark and gray-bark forms probably populated this ancient river system even before the formation of Lake Teletskoe.

55-year-old crops of Scots pine ( Pinus sylvestris L.) the IB productivity class (bonitet) with a completeness of 0.94 on an area of 1.9 hectares, created according to the scheme 1.82 × 1.10 m, were studied. More than 2 thousand trees were located on this area and polygons of their nutrition were built around them in the «ArcMap-ArcView» program. The territory was divided into 24 test areas, with density fluctuations at the age of 30 years 1153-2207 trees/ha, a fullness of 0.84-1.03 and an average diameter of 19.1-23.0 cm. It was found that the density affects the intensity of the fall of trees by only 22 %, and 78 % of the factors of their fall are not related to the density. Therefore, increased density within these limits is not the main reason for the fall of trees. It was also found out that in the younger class of the tree’s feeding area, the probability of its falling off after 25 years is the greatest (58 %) and gradually decreases to 5-7 % by the senior classes. At the same time, the area of nutrition increased by 2.1 times or more did not guarantee the trees their complete safety by the age of 55, and in 9.6 % of cases they died for no apparent reason. The feeding areas of falling trees turned out to be almost functionally related to the frequencies of feeding areas at the age of 30 with a correlation of R = 0.95 ± 0.03, and this leads to the fact that their small feeding area (less than average) increases the probability of falling off by only 27 %. This is confirmed by S. N. Sennov’s research (1999, 2005) that despite intensive thinning at the age of 40, over the next 40 years trees died at any diameter, and the nature of the fall did not differ from the control. Therefore, from a forestry point of view, thinning felling in middle age is no longer effective. We need a much earlier optimization of the density of the stand at the age of 10-15 years.

In natural stands of Scots pine ( Pinus sylvestris L.) near Yekaterinburg city and in the city forest park the state of trees was studied at the edge of the tree stand and in its depth up to a distance of 225 m. On each of 16 transects there were studied 6 - 10 registration sites with a radius of 11.3 m and a distance between them of 25-33 m. For natural stands: 10 transects; 100 sites, in the forest park: 6 transects; 52 sites. The transects were located perpendicular to the edge of the stands. The relationship of the trunk diameter with foliation and branchiness, determined visually on a point scale in 2315 trees was determined. Most of the transects had south and southwest orientations. For relationships there were obtained nonlinear ratios. In them the coefficients of the variables depend on the distance to the edge of the stand. The relationship between the values of the coefficients and the factor of distance to the edge of stand is also non-linear, are described by polynomials of 4-5th degree. It is characterized by the presence of two maxima. Four zones are distinguished in natural stands (0-75 m, 100-125 m, 150-175 m, 200-225 m), characterized by different ratios of the development of trees assimilation apparatus ( for trees with the same diameters). In the forest park the width of the located between the maxima zone of decrease in the dependency of traits coefficient is greater than in natural stands. This is due to the shift of the first maximum closer, and the second - further from the edge of the stand by 25 m each. These features of the influence of urbanization are apparently explained by the influence of urban conditions on changes in the relationship between the diameter of the trunk and the development of the assimilation apparatus of trees.

The comparison of snow density in small open spaces adjacent to forest stands and under the canopy of spruce stands located on the macroslopes of the Middle Urals of the eastem end westem expositions was carried out. It was found that the density of snow in open spaces on the western macroslope is usually higher than on the eastem one. The forest canopy somewhat reduces the difference in the amount of snow density observed between forest clearings, but maintains a tendency of increased density on the western slope. On the western and eastern slopes, there is a higher variation in snow density under the canopy of stands than in forest clearings and a more significant variation under the crowns of spruce ( Picea A. Dietr.) than in the aisles. On the eastern slope, the dynamics of snow density in forest clearings over the years of observations has no indisputable connection with the sum of temperatures and precipitation of winter periods. On the western slope, when comparing between the observation seasons, the snow density in the forest clearing differs at a reliable significant level ( p < 0.05). The canopy of the forest can regulate the peculiarities of weather conditions, and most often, there is no statistically significant inter-seasonal dynamics of snow density on the permanent trial square of both slopes. A comparison of the snow density under the crowns and in the aisles showed that both on the eastern and western slopes the snow in the aisles is denser. Also, within the season, both on the eastern slope and on the western slope, the peculiarity of the canopy structure of the stand does not create conditions for the formation of snow density significantly different between the permanent trial square. Except for some years when differences are observed on the eastern slope between the density of snow on the permanent trial square with a predominance of the birch proportion in the composition formula and permanent trial square with pure spruce forests.

Naturalizing plants are characterized by both a reduction in the gene pool in comparison with the genetic diversity of the same species in the natural range, and the accumulation of new adaptive traits. Nanking cherry ( Prunus tomentosa Thunb.) on the one hand, it demonstrates instability to support in the conditions of Yekaterinburg, on the other hand, it shows a tendency to naturalize in the vicinity of Chelyabinsk. The study of the variability of plants in the places of naturalization of Nanking cherry by weight, fruit color, and peduncle length showed that the value of such populations for the selection of new selected forms is not inferior to the breeding garden laid from seedlings obtained from free pollination in varietal plantations of Nanking cherries. Only plants that have undergone natural selection in nature can be characterized by a higher adaptive potential. The range of variability in fruit weight for all studied plants in naturalization sites ranged from 0.57 to 2.16 g. In the breeding garden - from 0.62 to 2.20 g. Among the varieties, the highest average fruit weight in 2021 was noted for the Natalie variety 4.1 g, but in previous and subsequent years of observations did not reach such values. In the naturalizing populations, no plants with the maroon color of the fruit characteristic of the Damanka variety were found. In the breeding garden, such a fruit color was found, but the weight of the fruit is much less than that of the Damanka variety. The varieties, including some of which were obtained by introgressive hybridization with the species of Nanking cherry and louisiania vicinifolia ( Louiseania ulmifolia (Franch.) Pachom. sin. Prunus ulmifolia Franch.), did not show an increase in the length of the peduncle, characteristic of the species that took part in the creation of varieties. Plants with a longer peduncle length than those of existing varieties were found at individual centers of naturalization.

A method for separating clean plates of epicuticular wax has been proposed. The use of water, which can penetrate deeply into wax structures under the influence of van der Waals forces and expand upon freezing, allows to quickly obtain uncontaminated wax plates with a native structure without any third-party chemical impurities. Using scanning electron microscopy, images of blue spruce ( Picea pungens Engelm.) needle wax were obtained. Its morphological and structural characteristics have been determined. A distinctive feature is the presence of wax nanotubules with a characteristic diameter of ~150 nm and a length of 3-5 μm. Nanotubes lie on top of each other in stacks, forming a one-dimensional long-period lattice. Microscopic observations of the wax were made in reflected and transmitted light. It has been shown that the coating of blue spruce needles consists of microparticles of wax with a structural color. In a wide spectral range, individual particles change color from blue to red, as a result, large conglomerates of particles are white. Fluorescence spectra of needles with native wax cover and the same needles after wax removal were obtained. When comparing the width of fluorescence lines at half-height of blue spruce needles with and without wax, the influence of the wax layer on the lifetime of excited electrons in photosystem II was revealed, thereby establishing a connection between the wax cover and the process of photosynthesis. Using the matrix transfer method, transmission spectra were calculated for a lattice similar to a waxy structure, a chloroplast, and a combination of a waxy structure with a chloroplast. In the latter version, the long-wave zone of selective reflection is much wider than in individual cases. When examining a structure containing a chloroplast and epicuticular wax, there is a slight splitting of the stop zone, as if there were a defect, which contributes to a high concentration of energy at the site of splitting. Due to an increase in energy concentration, the density of photonic states at the corresponding wavelengths increases. This effect is important for photosynthesis because, according to Fermi’s golden rule, the rate of reaction is proportional to the density of photonic states. The calculation results are in good agreement with the experimental spectra.

The four-eyed fir bark beetle ( Polygraphus proximus Blandford) and the fungus ( Grosmannia aoshimae (Ohtaka, Masuya & Yamaoka) Masuya & Yamaoka) form an extremely aggressive invasive tandem affecting Siberian fir ( Abies sibirica Ledeb.) throughout almost its entire range. In spring 2023, the beetle and its fungal associate were first detected in fir plantings at the Botanical Garden, Ural Branch, Russian Academy of Sciences in the city of Yekaterinburg (Middle Urals). At the time of detection, the pest had destroyed and infested more than a third of the fir trees in the area accessible to visitors and had begun attacking the collection of fir species in the arboretum. The phytopathogen G. aoshimae was found in all beetle galleries. Fungi of the genus Geosmithia Pitt were frequently encountered also. The beetles first attacked Siberian fir trees with the smallest stem diameter. Beetles began exiting weakened trees infested in spring and infest live trees as early as late July - early August. From the fir collection, fir trees from the Balsamea section: Siberian fir, balsam fir ( A. balsamea (L.) Mill.), subalpine fir ( A. lasiocarpa (Hook) Nutt.), Frasier fir ( A. fraseri (Pursh) Poir.), Khingan fir ( A. nephrolepis (Trautv. ex Maxim.) Maxim.), Sakhalin fir ( A. sachalinensis F. Schmidt Mast.), were infested first. Firs of the section Grandis had traces of single attacks, and Manchurian fir ( Abies holophilla Maxim.) (the section Momi ) was not attacked by beetles at all. Traces of four-eyed fir bark beetle attacks were also found in the park-exhibition, 3.5 km far from the Botanical Garden, which indicates a wide distribution of the invasive bark beetle in the metropolis.