Home – Home – Jornals – Siberian Journal of Forest Science 2021 number 2

The article highlights the results of a paleobotanical study of peat deposits in different forest zones and types of habitats in the Western Sayan, where the Siberian stone pine Pinus sibirica Du Tour is currently the dominant species. Based on paleocarpological and radiocarbon analyzes, changes in vegetation, climate and landscapes from 8000 years ago to the present have been reconstructed. The material for the study was the macroremains of fossil plants. Changes in the species composition of macroremains of dominant plant species in each section made it possible to combine them into macrocomplexes, each of which characterizes a certain time and landscape-climatic regime. Carpograms were constructed for four sections, with a detailed characteristic of fossil macrocomplexes by species composition. When analyzing the morphological and anatomical physiognomy of each fossil object according to the degree of preservation, they were differentiated into two groups of plants - the local reflecting peculiarities of the habitat (facies) and the adjacent one characteristic of a larger territorial complex (paleolandscape). Their combination gives an idea of the change in the landscape situation in centuries of climate change. In each group, the edificator and dominants of past phytocenoses, fixed by macrocomplexes of fossils, were determined using the method of ecological-cenotic analysis. The dynamics of the composition and phytocenotic structure of plant communities, replacing each other in a thousand-year history, has been established. A quantitative assessment of the climatic situation is given, which determines their change in different climatic epochs. The repeated displacement of the upper forest boundary was established with conjugate changes in heat and atmospheric moisture, which manifested themselves simultaneously in the study areas. On the example of the Siberian stone pine formation, represented in different forest areas by three different climatic facies of the formation, it is shown that in each of them, with the trends of climate change common for the mountains (warming or cooling, as well as changes in atmospheric moisture), centuries-old changes of communities had their own specific features.

The article highlights the impact of ammunition at military ranges on the natural environment of disposal. The results of complex studies are presented (soil, vegetation, small mammals) for two sites: in the Krasnoyarsk forest-steppe (N. 1), where in 2013 the disposal of projectiles was completed and in Kansk subtaiga (N. 2), where the disposal of projectiles continue. The scientific novelty of the work lies in the interdisciplinary consideration of the issue using instrumental research methods and satellite data. It was found that under the influence of explosions, a belligerative landscape is formed, funnels are formed, which are filled with water. As a result of the removal of soil (soil and underlying parent rocks) during explosions, the structural organization and physical properties of soils change at a distance of up to 15 m from the edge of the funnel. The authors note that the formation of communities takes a long time and begins from the pioneer stage as result of shedding of the walls an erosional succession type occurs in the blast craters. The direct impact of explosions is manifested as internal hemorrhage and impaired kidney in small mammals. An indirect effect is manifested in a change in the biotope: loosening the soil and the formation of reservoirs at the bottom of the craters, contributes to the formation of local settlements of tundra voles Microtus oeconomus Pallas. According to the results of the research, the parameters and spatial confinedness of disturbed by the explosions habitats were determined, which is necessary for the organization and monitoring of this anthropogenic impact. This problem has been little studied and requires further research.

The magnetic susceptibility (MS) of three types of permafrost forest soils (pale-yellow, pale-brown, and podzolic) formed on permafrost soil-forming rocks in the cryoarid climate of Central Yakutia for the first time was studied. It is noted that the studied permafrost soils develop within various high-altitude geomorphological levels of the ancient alluvial Central Yakut plain and form a regular zonal series from bottom to top, that is, with an increase in the absolute height of the terrain: pale-yellow gray - pale-yellow typical and solodic - pale-yellow leached - pale-brown typical - pale-brown podzolized and podzolic soils. At the same time, in this series of zonal soils, the values of their volume (VMS) and specific (SMS) magnetic susceptibilities also naturally decrease, due to the increased intensity of eluvial soil processes, such as solodization and podzolization in the genesis of these soils. The weighted average values of the specific magnetic susceptibility calculated for 9 sections of the studied permafrost forest soils, taking into account individual values of SMS and the thickness of their genetic horizons, changed for pale-yellow soils in the range of 21.6-42.1, pale-brown - 3.9-12.4, podzolic - 1.8-5.7 × 10^-8 m³/kg. It is also established that based on certain values of the VMS of these soils, all the studied types of permafrost forest soils in Central Yakutia belong to the group of low-magnetic ones and differ in the values of volumetric magnetic susceptibility that do not exceed 100 × 10^-5 Si units. Among the studied pedons of zonal forest soils of Central Yakutia, various types of their magnetic profiles are noted, which are determined by the geographical and genetic features of these soils.

Studies of natural hybrid zones of Populus L. in Western Siberia have shown that the observed hybridization is asymmetric and introgressive. However, its phenotypic manifestation has not been sufficiently studied, which makes it difficult to create effective programs for the selection of valuable forms and subsequent selection work. The purpose of this study is to analyze the results of studying the populations of P. nigra L., P. laurifolia Ledeb. and P. irtyschensis Ch. Y. Yang in the Tom River basin, according to some qualitative anatomical and morphological characteristics, to show phenotypic manifestations of introgressive hybridization, to reveal its scale, direction and significance. Studies of a complex of qualitative morphological characters were carried out in 23 populations on 684 individuals. It was found that hybridization of P. laurifolia and P. nigra in the Tom River basin is not observed everywhere. Clusters of hybrids (foci of hybridization) stand out only in areas where the optimal combination of factors promoting hybridization develops. The morphological characters we selected allow us to reliably identify the parental taxa and P. irtyschensis . Additional use of the features of petiolar anatomy makes it possible to study the diversity of individuals within the identified taxa. The study of P. laurifolia in both mixed and pure (monospecific) plantations did not reveal any signs indicating the penetration of P. nigra genes into its gene pool. On the contrary, in the populations of P. nigra , phenotypic manifestations of introgression were found in both morphological and anatomical characteristics. It has been suggested that the asymmetric introgressive hybridization between two poplar species observed in the Tom River basin is apparently a fairly widespread phenomenon within the genus Populus . The studies performed demonstrate the adaptive role of introgression in the colonization of suboptimal habitats.

Deforestation and forest degradation in the forest-steppe zone is one of the most pressing issues in the world, involving territory of southern boreal forests in Northern Mongolia. The changes in forest cover between 1999 and 2016 and driving factors to deforestation and forest degradation in the Khustai nuruu mountains of the Northern Mongolia were analyzed. Forest monitoring was carried out in mature and over-mature flat-leaved birch Betula platyphilla Sukacz. forests with an admixture of aspen Populus tremula L. using the combined method of remote sensing and ground based field measurements. We found an accelerated deforestation trend between 2006 and 2009, which amounted to 463 ha (23.2 %) since deforestation in the Khustai nuruu mountains was started. Overall 17-year forest monitoring revealed that a total of 675 ha of forests were completely converted to non-forest area. As urgent measures to mitigate the effects and limit rapid deforestation in study area, it is recommended to improve the sustainable forest management via establishing optimum head of livestock and wild animals, strengthening prevention and control measures against pests, and reforestation on deforested areas using seedling of native tree species taken from forest nurseries in the region.

This article deals with the hygroscopic properties of the coniferous bark species in Siberia. Isotherms of moisture sorption in the bark of the Siberian larch Larix sibirica Ledeb., the Scotch pine Pinus sylvestris L. and the Siberian fir Abies sibirica Ledeb., when the relative vapor pressure changes from 0.1 to 0.8 at a temperature of (20.0 ± 1.5) °C practically coincided. Therefore, to analyze the sorption properties of the system bark-water vapor within the framework of the Brunauer-Emmet-Teller (BET), Guggenheim-Andersen-de Boer (GAB), Frenkel-Holsey-Hill (FHH), Zimm-Lundberg (ZL), Flory-Huggins (FH), and the theory of volume filling of micropores (MVF) used for «generalized isotherm» that approximates experimental data. The isotherms of moisture sorption by bark were used to quantify the most important hygroscopic characteristics. We used BET and GAB to calculate monolayer capacity ( u _m), specific inner surface area ( S _sp) and ZL equation to find water vapor content and relative pressure when water clusters start to form in the bark samples; FHH, FH model and MVF theory to obtain fractal dimension of «sorption surface», sorbent-sorbate interaction parameter and characteristic sorption energy (Е_с), respectively. Based on the precision methods of thermal analysis - thermogravimetry (TG), differential thermogravimetry (DTG) and differential scanning calorimetry (DSC), a fractional picture of thermal desorption of bound water and energy spent on its removal when heating samples at a constant rate. The values of u _m, S _sp indicate differences between these values obtained as a result BET models and the average value of the characteristic sorption energy E _с (MVF) indicates the absence or very small internal mechanical stresses in the cortex. From the analysis of the rate of nonisothermal drying according to the fourth derivative of the DTG circuit with respect to temperature, differences in the temperature ranges and thethermal desorption intensity of bound moisture by samples of bark of the Siberian larch, Scotch pine, and the Siberian fir were established; the heat of thermal desorption of bound water was 38.1, 38.0 and 45.6 kJ/mol Н₂О accordingly.

In the context of intensive replacement of natural forests by plantations, it is important to know how this replacement will affect the productivity of forests and their ability to mitigate the effects of climate change. The aim of our study was to establish: (1) how the ratio of biomass and volume of tree stems of two-needled pines (subgenus Pinus L.) of natural and artificial origin changes in temperature and precipitation gradients in Eurasia and (2) what contribution to the explanation of the variability of stem biomass is made by the tree’s forest inventory indices (stem age, diameter and volume), the origin of a stand (natural or artificial) and climatic factors (temperature and precipitation). To achieve this goal, a database of harvest data on the biomass of pine stems in the amount of 975 and 508 in natural and planted stands respectively, was formed. A positive relationship between the stem biomass and the average January temperature in conditions of sufficient moisture and its absence in dry conditions was established. The positive relation of stem biomass to precipitation in cold regions disappears as the transition to warm ones takes place. The stem biomass at the age of maturity in plantations is 15 % higher than in natural stands, and in young stands, on the contrary, it is less by 4 %. The contribution of inventory indices, the origin of stands and climatic factors to the explanation of stem biomass variability was 72, 10 and 18 %, respectively. The results obtained, tested on other tree species, can be useful in selecting tree species that are most tolerant to climate change.

Investigation was carried out in virgin spruce forests in the upper reaches of the Pechora river in middle taiga condition. It was show that spruce forests of different types are characterized by common features of the structure of stands and undergrowth. There was a large variability of trees in volume of stem and undergrowth height. Investigated stands formed a cyclical-multi-age type of age structure. The calculated data obtained using spatial statistics and analyses of point processes were presented. It was found that in spruce forests is expressed regardless of forest types, the group distribution of young individuals of woody plants, which passes into random distribution at more late stages of generation. The spatial relationships between woody plants tested using the cross-correlation function g_ij ( r ) show that the undergrowth is attracted to each other at distances of up to 1 meter. There were no spatial interrelation between the undergrowth and the trees. Trees demonstrated independent from each other placement in the area. The density of trees in the area and their phytosocial status are determining the intensity of competitive relations between woody plants in the indigenous spruce communities of the upper reaches of the Pechora River.

To date, various aspects of the formation of spruce forests as a result of felling of small-leaved stands with the preservation of the preliminary generation of spruce Picea A. Dietr. have been studied. One that is poorly studied is the question of the development and growth of spruce in connection with the parcel structure of the stands after such felling. The aim of this work is to study formation and growth of spruce forests in parcel structures with the same spruce density after felling a birch forest, but at different stages of age development. The studies were carried out in the sub-zone of the southern taiga (Rybinsk District of the Yaroslavl Oblast) at the Northern Experimental Station of the Institute of Forest Science, Russian Academy of Sciences. The study object is forest stand formed after cutting a 55-year-old birch forest. The felling was carried out using the technology of narrow strips with preservation of the preliminary generation of spruce. The analysis is based on the data of 20 years of observations on permanent sample plots in two groups of parcels: spruce in the young stand stage, spruce in the pole stand stage. The density of spruce in the groups of parcels after birch Betula L. felling is, respectively, 4.53 and 4.58 thousand trees per ha, and the average age is 25 and 33 years, respectively. The response of spruce to birch felling has been observed already in the first ten years. In the considered groups of parcels, the condition of the spruce improves and the growth of trees increases. In the poles, the growth increases more intensively than in the young. The timber stock of the upper layer (trees above 4 m per year of felling) in the first layer increases by almost 30, in the second - by 100 m³. In the pole stand, productivity of the stand increases from class V to class IV bonitet. In the second decade, the state of the population in young trees deteriorates as a result of increased intraspecific competition (the proportion of normal trees decreases from 55 to 40 %). In the pole, the opposite process was observed - the proportion of normal trees increased from 60 to 80 %. During this period, the growth of the wood stock in young stands was more intensive than in the pole ones. However, the wood stock in spruce forest, formed from the perch, reached almost 300 m³ per ha 20 years after felling. In spruce forest, formed from the young stand, wood stock was almost 3 times less. The bonitet of the perch has reached III, the young - IV class. When felling birch forests with preservation of the undergrowth and thin spruce for the fastest recovery of spruce stands, birch forests should be considered the most promising, under the canopy of which the preliminary generation is represented by a spruce pole stand 40 years old. Such stands should be assigned to the felling first.

The created forest plantations of 9424 hectares in the area of nutrition of mineral springs and around the resort towns of the Caucasian Mineral Waters excluded the pollution of ground and surface waters with fertilizers, created conditions for the growth of edible fungi, transferred the surface runoff to the soil, and prevented soil deflation. Soil solution from soils around Mashuk mountain, reaching hot mineral water, increases the formation of hydrogen sulfide by 6 times. The stands created conditions for the accumulation of iron, its migration to Lake Tambukan, which is necessary for the formation of healing mud. To normalize the natural conditions for the formation of healing waters, it is necessary to restore and preserve the native types of vegetation. It is revealed that native and preserved forests grew and grow on the slopes of the hydrographic system. The destroyed forests led to the formation of dangerous geological processes on the slopes and reduced the permeability of soils in the feeding area of the Tithonian stage. Protected are the indigenous subalpine meadows that covered and cover the watershed plateau-like surfaces in the upper reaches of the Berezovaya, Alikonovka and Dzhinalskiy ridge rivers. The Pasture Ridge is a barrier for broad-leaved species, and the upper (southern) climatic boundary of the oak Quercus L. does not exceed 940 m. To the south of the ridge, pine-small-leaved forests naturally grow. To normalize the nutritional conditions of the Tithonian stage it is necessary to restore planted and destroyed stands on the southern slope of the Kabardinsky ridge. Here, the flow (draining the underground waters of the Tithonian and Valanginian) should be directed outside the local underground drainage basin along one of the terraces created earlier for water infiltration by the rocks of the Tithonian. The absence of forest on three diapir mountains is explained by weakly expressed magmatogenic folds and the other forms of relief, as well as by the phytocenotic isolation of meadow and steppe vegetation.