Home – Home – Jornals – Atmospheric and Oceanic Optics 2024 number 10

The photoacoustic (PA) method is widely used in studies of the absorption of optical radiation by various media. As a rule, it is assumed that the PA signal is formed due to the relaxation of vibrationally excited molecules with a common characteristic time τ_VT. The kinetics of heat release in a PA cell at absorption of a laser radiation pulse in a mixture of two molecular gases with two independent channels of vibrational-translational relaxation with very different times is considered. An example of calculations of the kinetics of heat release for a mixture of H₂O and CO₂ at absorption of a CO₂ laser radiation pulse and variations in gas concentrations is presented. It is shown that it is necessary to take into account the relationship between the laser pulse duration and the characteristic times of vibrational-translational relaxation in the gas mixture under study.

In the Arctic, climate warming is occurring several times faster than in other regions of the globe. This сan be the result of strengthening feedbacks between climate and atmospheric composition. However, there are very few data on changes in the concentration of climatically active substances in this region. Therefore, to fill the gap in data on the vertical distribution of gas and aerosol composition of the air over the Russian Arctic, an airborne survey of the atmosphere and water surface over the all Russian seas of the Arctic Ocean was performed with use of the Tu-134 Optik aircraft laboratory in September 2020. This paper analyzes the spatial distribution of gas and aerosol composition in the Arctic troposphere. It is shown that during the experiment, the CO₂ mixing ratio changed from west to east in the opposite direction in the near-water and boundary layers compared to the free troposphere (FT), namely, it was increasing in the planetary boudary layer (PBL) and was decreasing in the FT. The methane content in the near-water layer decreased in the same direction. Concentrations of CO, NO _X , and SO₂ in the Russian Arctic were very low, which is typical for remote background areas. All aerosol fractions also showed a decrease in their content from west to east.

The results of experiments on determining the turbulence parameters of a stratified atmospheric boundary layer using remote sensing are presented. The height-time distributions and vertical profiles of the dissipation rate of kinetic energy of turbulence and the structural constant of turbulent fluctuations of temperature obtained from measurements of radial velocity with a coherent wind lidar and temperature with a microwave radiometer are compared with altitude variations in the parameters characterizing atmospheric stability. It is shown that the dissipation rate, which determines the intensity of wind turbulence, decreases in the boundary layer with altitude for all types of thermal stratification. The intensity of turbulent fluctuations of temperature depends to a greater extent on altitude variations in thermodynamic conditions in the atmosphere. If the thermal instability of the atmosphere at higher altitudes exceeds that in lower layers, then the structural constant of temperature fluctuations can not decrease but increase with altitude. In accordance with the altitude variation in the structural constant of temperature, the values of the structural constant of turbulent pulsations of the refractive index can also increase with altitude and differ from those predicted on the basis of known models.

Ozone is one of the important trace gases of the Earth's atmosphere. This study anal yses ground-based synergetic MW + IR method for remote measurements of ozone using ground-based instruments at Peterhof (SPbSU) - MW ozonometer and Bruker IFS-125HR Fourier transform infrared spectrometer. Numerical estimates of the errors and vertical resolution of remote measurements showed that uncertainties of remote ozone measurements at different altitudes vary from 5 to 20% or more. The vertical resolution of the MW + IR method varies from ~ 10 to ~ 12 km. These estimates demonstrate the potential for determining ozone in Peterhof using ground-based combined MW and IR measurements.

The operation of thermal power plants (TPP) is accompanied by the emission of various pollutants into the atmosphere, including nitrogen oxides. This paper presents the results of spectrometric measurements of the atmospheric NO₂ content carried out on circular routes around large urban TPPs of St. Petersburg. The spatial variability of tropospheric NO₂ content in the vicinity of a TPP, determined from experimental data using the DOAS (Differential Optical Absorption Spectroscopy) method, demonstrates increased values in the downwind side of smokestacks. The spatial distributions observed in the mobile DOAS measurements are confirmed by the results of numerical calculations of the NO₂ content field using the HYSPLIT (HYbrid Single-Particle Lagrangian Integrated Trajectories) model, taking into account a priori information on the volume of NO_x emissions from the main urban TPPs. Approximate estimates of NO_x emissions from the two largest TPPs in St. Petersburg, obtained on the basis of calculations of the total flow of NO₂ molecules through a closed loop of DOAS measurement routes, amounted to ~ 2 ÷ 3 thousand tons per year. These experimental data are important for determining the contribution of thermal power plants to anthropogenic atmospheric pollution.

The spatiotemporal distribution of the intensity of bioluminescence formed by hydrobionts in the Black Sea based on the data of expeditionary research conducted in June 2013 and September 2014 during the voyages of NIS “Professor Vodyanitskiy" (IBSS) was investigated. Comparison of this characteristic in the N-W and N-E parts of the Black Sea has been done. Satellite data on near-surface wind and geostrophic currents are used to explain the causes of spatiotemporal variations in the intensity of hydrobiont bioluminescence. It has been shown that in the vertical distribution of bioluminescence intensity, most stations had one maximum at the top part of the seasonal thermocline. At deep-sea stations in the north-western part of the sea located in the zone of weak vertical movements, two maxima were observed due to the development of heat-loving hydrobiont species in the upper maximum and cold-loving species in the lower one. The maximum values of the integral intensity of hydrobiont glow were observed in the divergence zone in the deep-water north-eastern part of the sea, which is explained by more active enrichment of waters with biogenic substances due to more intense upward movements. Obtained results can be utilized for more accurate assessment of the upper layer water bioproductivity in the Black Sea from satellite data.

Ecosystems of the fjell fields in the Khibiny Mountains (Kola Peninsula), were investigated, including vegetation, soils, soil algae and invertebrate fauna. We used EUNIS habitat typification (2013) to differentiation of habitats. The most common habitat types were: (1) Crustose-lichens (Rhizocarpon geographicum) rocks habitat type on eluvia of base-rich, alkaline and siliceous rocks (U5111); (2) The lichens-, sedges-and dwarf-shrubs-dominated turfs and cushions on gravelly and rocky slopes (U5112); (3) Sedge-, moss- and-lichens-dominated habitat type on rubble and stony mountain plateaus and peaks (U5113); (4) Biological soil crusts (BSCs) habitat type on fine-earth and gravelly polygons edges (U5114); (5) Late snow bed moss vegetation (U5115). Soils of the fjell fields were Leptosols. Content of soil organic C was very high (26-32 %) despite the thin soil profile, which had no illuvial-eluvial differentiation by the content of SiO2 и R2O3. The total flora includes 176 species of plants and lichens. Soil algae flora comprised 43 species, where green algae of Chlorophyceae prevailed. Among soil microarthropods prevailed Collembola, Oribatida and Mesostigmata, which were also typical for mountain tundra. The soil microbial activity, diversity and abundance of soil algae and invertebrates depend on habitat type, soil moisture, as well as soil organic matter contents and gets higher on wet substrata or in more complex vegetation.

The materials and performs a systematic analysis of the elemental composition of 110 species and 28 families of plants that form tree-shrub layers of forest phytocenoses and form the structure of urban landscaping in South Primorye in the article was summarizes. A high differentiation of the species composition in the accumulative abilities to the weight of the metal, especially Zn and Mn was noted. The most stable indicator among of the species was recorded on the Cu content. The types and families of high, low and background of heavy metals content are distinguished by the basis of the author’s indicator, i. e. “the relative intensity of accumulation (RIA)” of chemical elements. The low content of heavy metals is more typical for the main arboriflora composition. At the same time, about the half of the studied species is accumulated some metals above the background (average) exponents. The maximum of metals content (for the 5 times and high more than the background exponent) was recorded in the leaves (needles) of the concentrator species: Zn - Salix udensis, Populus maximowiczii, P. nigra, P. tremula, Syringa wolfii; Mn - Salix udensis, Sorbus pochuashanensis, Picea sp.; Fe - Crataegus pinnatifida. The high heavy metals content among the families is most typical for Hydrangeaceae and Salicaceae, the low content - for Fabaceae, Pinaceae, Tiliaceae and Aceraceae, the background level - for Rosaceae. The phytogeochemical systematics of the Far East arboriflora for species and family ranks on the basis research results was developed for the first time.

A study was conducted about the variation of levels of macro- and microelements in the soil and leaves of two species of the genus Nitraria L. in various habitats in Siberia. New data were obtained on the concentration variations of K, Na, Ca, Mg, Fe, Mn, Zn, Cu, Ni, Li, Sr, and Cd in leaves of N. schoberi L. and N. sibirica Pall. plants. It was found that the salinity of habitats of N. sibirica (up to 3.23 %) can exceed salinity of soils under N. schoberi (up to 0.5 %) by more than sixfold. Soils of N. schoberi habitats are characterized by lower contents of carbonates (1.0-3.8 %) and of physical clay (2-19 %) as compared to soils of N. sibirica habitats: 1.2-18.2 % and 9-40 %, respectively. An increase in the physical-clay content of soil positively correlated with the accumulation of Mg, Cu ( p ≤ 0.01), and Mn ( p ≤ 0.001) in the plant leaves. The degree of soil salinity was positively associated with the accumulation of Ca, Zn, Sr ( p ≤ 0.01), Mg ( p ≤ 0.05), and Cd ( p ≤ 0.001) in the plant leaves. An increase in concentration of mobile Na in soil positively correlated with concentrations of Ca, Cu ( p ≤ 0.01), and Zn ( p ≤ 0.001) in the leaves. In N. sibirica leaves, the concentration of K, Ca, Mg, Fe, Sr, Mn, Zn, and Cu was 1.5-3 times higher than that in N. schoberi leaves. Both species are capable of accumulating very high concentrations of Na (N. schoberi: up to 83,8 g/kg and N. sibirica: up to 77,2 g/kg). In the leaves of N. schoberi plants of immature age, K and Na levels were seven times higher than those in leaves of adult generative plants, whereas Mg and Ca levels were 3-5 times higher. This study should expand the understanding of mechanisms of Nitraria species’ adaptation to high-salinity conditions.

The accumulation features of heavy metals (Cu, Zn, Fe, Ni, Mn, Cd, Co, Pb) were studied in two annual halophytes, Sedobassia sedoides and Atriplex tatarica, growing naturally in contaminated soils (exceeding MAC values for Zn, Cd, Ni, Cu). The ability to accumulate heavy metals from the soil, evaluated as the ratio of metal concentration in the root to soil metal concentration (BF), was high and similar for both species, except for Ni and Cd. High values of BF and TF of Ni (ability to translocate the metal from the root to the shoot), as well as the positive correlation of translocation degree with the rate of Ni bioaccumulation in A. tatarica, make this species promising for soil phytostabilization. S. sedoides showed higher efficiency in the accumulation and translocation of Cd, as well as resistance to high/toxic concentrations of Cd in shoots, which makes this species promising for phytoremediation of Cd from soil. Both investigated plant species demonstrated the ability to accumulate Cu, Mn, and Fe in toxic concentrations.

The work summarizes the results of long-term field studies of 22 species of halophytic plants in the Elton region, belonging to 4 families and 14 genera. Plants were classified according to the ecological (salt-accumulating euhalophytes, salt-secreting crinohalophytes, salt-excluding glycohalophytes) and genetic (C3-type and C4-type of photosynthesis) system. The conditions of the abiotic environment (level of salinity and soil moisture) under which various groups of halophytic plants grew are shown. The composition of fatty acids of lipids in halophyte leaves was analyzed. It is concluded that the modulation of halophyte lipids, associated with changes in fatty acids composition depending on soil salinity and moisture, is one of the mechanisms of plant salt tolerance at the cellular level of organization.

Urbanization ongoing around the world leads to changes in ecosystems, and wildlife is forced to respond by adapting to this impact. First of all, plant communities change, which are actively being transformed inside and around the city what, with the stress of human presence, does not remain indifferent and for animals. For animals this often leads to decrease in biodiversity in the sites exposed to anthropogenic stress. However, for some mammalian species (especially small ones) what are more resistant to stress from human presence, urbanization has some advantages by creating modified habitats and reducing competition with natural forest species that are more sensitive to urbanogenic effects. For several years, we have been investigating the influence of the megalopolis located in the forest zone (Ekaterinburg city) on phytocenoses and communities of small mammals. The objects were two park-forests - areas of pine forest of the city outskirts, altered to varying degrees depending on the proximity to urban development, as well as the remains of a pine forest in the Central Park of Culture and Recreation. The forest phytocenoses were found have been changed through all park-forests area, especially strongly in places adjacent or close to buildings at the cost of weed vegetation and introduced plant species, as well as under the influence of recreation. In addition to the forest species, small mammals uncharacteristic for the forest of this zone were present at all sites. In outlying park-forest places where the anthropogenic load is much lower, forest mammal species are found in greater numbers, although and the presence of hemisynanthropic species, which in our forests include small wood mouse and striped field mouse, remains. In some cases, this might lead to an increase in community diversity indices. Naturally, the conditions of the plant environment affect the ability of rodents and shrews to form steady micropopulations and communities in the forest sites of the city, although and the disquiet factor plays a material role.

A statistical analysis of the variability in the amino acid composition of the mitochondrial protein CYTB of Asian mountain voles of the genus Alticola was carried out. Sequences (N = 36; 380 a. a.) were taken from GenBank along with accompanying information about their geographical location. The frequencies of amino acids for each sequence and the matrix of squared Euclidean distances between them were calculated, from which the principal components (PC) were calculated using the principal coordinate method. In the space of the first two PCs (Σλ = 76.89 %), all sequences are grouped according to their species, forming the East Siberian (A. strelzowi, A. olchonensis, A. semicanus, A. tuvinicus), southern (A. stracheyi, A. argentatus, A. albicaudus, A. stoliczkanus, A. barakshin) and the northeastern group (A. lemminus, A. macrotis). Mutational pressure in the PC1 direction leads to a change in the frequencies of Met, Gly, Ile → Ala, Thr, which strongly correlates with a large subset of AA indices and the average evolutionary rank of CYTB sequences (N = 362 with p-value < 0.01 taking into account multiple comparisons according to Bonferroni). In the PC2 direction, the frequencies Val, Phe → Leu change. This direction reveals significant correlations with latitude, altitude, 21 climatic variables of vole habitats and 54 AA indices.

Climate changes have led to an increase in fire rates throughout the entire range of larch (Larix sibirica, L. gmelinii, L. cajanderi). We tested the hypothesis that natural fires are an important factor that contributes to the functional stability and dominance of larch forests in the continuous permafrost zone. We included satellite imageries, on-ground surveys data, dendrochronological measurements and eco-climatic variables into analysis. We found that warming in the 21st century has led to an increase in the intensity and frequency of fires, moderate and extreme (>10,000 ha) burnt areas. The maximal burn areas and fire frequency observed in the northern and southern parts of the permafrost zone, respectively. The frequency of fires and burned areas are inverse exponentially dependent on precipitation, soil and ground cover moisture and atmospheric drought, and increase exponentially with air temperature increase. In the zone of continuous permafrost, larch successfully regenerates in burnt areas (up to 500+ thousand/ha of seedlings). In the zone of discontinues permafrost (southern part of the study area) the number of regeneration is 2-3 orders lower and regeneration represented mainly by hardwood species. The increasing fire frequency in the south of the larch range contributes to the partly transformation of the forested areas into grass and shrub communities. There is a high probability of larch retreat from its southern range during the process of continuous permafrost thawing. Gross primary productivity (GPP) in burned areas quickly (3-15 years) recovers to the pre-fire level. In combination with increasing GPP trends, that indicates carbon- sink role of larch forests increasing fire rate. In conditions of fire rate increase, it necessary to change firefighting strategy. It is necessary to realize (1) the impossibility of the total fires’ suppression and (2) the ecological significance of fires in the larch forests in cryolithozone, in which fires are the most important factor of supporting larch forests health and dominance. Alongside with that, periodic natural fires reduce the likelihood of catastrophic fires. It is necessary to focus the firefighting on the areas of the priority social, natural and economic importance, controlling burning outside these areas by monitoring methods.

Regularities of radial growth of pine (Pinus sylvestris L.) were studied within the southern taiga subzone of Western Siberia. The objects of the study were pine forests: uplands on sandy podzols and swamps under different conditions of water-mineral nutrition and pyrogenic influence. Using the methods of multivariate statistical analysis (cluster and discriminant analysis) based on the data of cyclic fluctuations in radial growth (increase, decrease or duplication of the subsequent one relative to the previous one), 4 clusters were identified. Swamp pine forests - eutrophic, oligo-mesotrophic, oligotrophic and upland pine forest. The final result of correctly classified objects is 100 %. The average width of growth rings in dry land conditions is 1.05 mm. In eutrophic swamp pine forests - 0.81 mm, oligo-mesotrophic - 0.57, oligotrophic - 0.39 mm. The main trend in the change in the width of tree rings over time (trend) is determined by a second-order parabola (p-level < 0.001). The signs and highly significant coefficients of the regression equations are postulated. In oligotrophic pine forests, the width of the rings increased annually on average by 0.80 mm with an annual average slowdown of 0.004 mm - an extreme of 190 years (inflection point). In oligo-mesotrophic ones - at 0.95 and 0.002 mm - the extremum is 340 years, in upland ones - at 4.27 and 0.068 mm - the extremum is 62 years. In eutrophic pine forests, according to the linear trend, the increase in the width of annual rings for 1 year averaged 0.715 mm. The relative frequencies of cyclic fluctuations in the increase and decrease of tree rings are characterized by equivalent ratios of their occurrence: 45-48 % in eutrophic and upland pine forests, 40-41 % in oligo-mesotrophic and oligotrophic ones. These equally possible episodes of recurrence can be considered one of the mechanisms for the formation of society through the probabilistic good neighborly relationships of trees in the interests of the whole. The frequency of occurrence of duplicate variants in eutrophic and upland pine forests is 7-9 %, increasing to 18-20 % in oligotophic and oligo-mesotrophic ones: the more severe the conditions, the higher the concordant onset.

Natural populations of Saposhnikovia divaricata (Turcz. ex Ledeb.) Schischk. has recently been subjected to severe anthropogenic impact due to biologically active substances with a wide spectrum of action detected in plants. The purpose of the study is to determine the state of natural populations of S. divaricata, to identify the biological features of the species that contribute to their stable ststus. 7 cenopopulations in the Republic of Buryatia have been studied, a description of phytocenoses and ontogenetic states of S. divaricata, demographic characteristics of cenopopulations, environmental and biological factors affecting the existence of this species have been identified. S. divaricata has a wide ecological amplitude, grows from tree communities to steppes and deposits. The share of participation in communities does not exceed 2 % of the total projective coverage. Most populations are characterized by a low density of individuals (5-48 individuals/ 100 m²) due to the destruction of plants (root extraction). One stable population without damage was found (density 209 individuals/100 m²) and one recovering population (113 individuals/100 m²). The height of generative plants varies significantly depending on the growing conditions from 35 to 100 cm. Environmental factors that negatively affect the stability of natural populations of S. divaricata have been identified: biotic (massive damage to seeds by invertebrates), anthropogenic (root harvesting, grazing). A number of biological features determine the strategy of the species in nature: a likely low stock of seeds in the soil and a spike in seedlings during dissemination; biological longevity of seeds for more than 5 years; early contractility of roots; dormant buds and renewal buds in the leaf axils of previous years are protected by remnants of leaf sheaths; when the apical bud is damaged, monopodial growth changes to sympodial (more often at the beginning of the virginal ontogenetic state); duration of the pregenerative period 10-12 years; monocarpicity, up to 50 % of generative individuals in the population they form pseudomutches, the percentage of fruit formation in a simple umbrella is 50-100 %.

The groupings of ground beetles of the lawn and the area with ruderal vegetation were studied on the territory of the PSU’s Botanical Garden in the period from April to November 2021 by the method of soil traps with a fixative (formalin 4 %). In total, 1,643 specimens of ground beetles were collected during the research period, 41 species from 14 genera belonging to 7 life forms and 5 ecological groups were registered. The absolute dominant is Pterostichus melanarius, and the subdominants in different seasons are such species as Bembidion properans, Calathus erratus, Amara aenea, Harpalus rufipes, Harpalus affinis and Harpalus tardus. The abundance, number of species and diversity indices of the ground beetle population vary significantly between sites and undergo changes depending on the season. On the lawn site, two peaks of abundance (May and August) were noted in the seasonal dynamics of ground beetles, whereas only May peak is expressed in ruderal vegetation. The quantitative ratios of ecological groups are dynamic throughout the season, but the common feature is the predominance of meadow-field species. On a site with ruderal vegetation, mixophytophages predominate over zoophages both in terms of the number of species and in number of individuals, zoophages predominate on the lawn both in terms of species diversity and the number of individuals.

Biomarkers of the presence of animals and humans - fecal stanols - are well preserved in the lake sediments. They are produced by intestinal microflora from sterols. Coprostanol and epicoprostanol are specific human stanols, since they are produced in the greatest quantities compared to animals. These stanols are used to reconstruct the population history of water bodies. In this work, fecal stanols were studied for the first time in the bottom sediments of Lake Zapovednoye, located in Evenkia (Siberia, Russia). The analysis was carried out using a gas chromatograph with a mass spectrometric detector. Along the entire core, there were no pronounced signals of coprostanol and epicoprostanol compared with other stanols, which indicates a negligible contribution of humans to the pool of fecal stanols. It is obvious that throughout the entire studied time interval (up to two and a half thousand years ago) there were no permanent settlements in the lake’s drainage basin, which is generally consistent with the extremely low population density of this region and unfavorable living conditions.

The gyrfalcon is a rare falcon with circumpolar distribution in low Arctic tundra. For the Russian Arctic islands and archipelagos, it is known as a occasional vagrant only. Here we report late summer observation of a young female gyrfalcon far beyond its main range. Our finding of gyrfalcon on Vize Island in 2020 is the northeasternmost record of this species in Eurasian Arctic. The falcon spent at least two weeks on the island and was able to adapt and mastered a new food resource - fledglings of0 kittiwakes. A young falcon took pre only in flight and often failed while attacking kittiwakes, but hunted 1-2 gulls daily, what covered its energetic demands in full. Under conditions of scarce food resources and few prey species available, being hunger the gyrfalcon could eat stale food, but necessarily obtained by itself. Any new data on the distribution of this rare species expands our understanding of its capabilities for dispersal and exploration of new habitats, adaptations to previously unknown trophic conditions and food plasticity.

The data obtained on the qualitative and quantitative composition of summer phyto- and zooplankton of two lakes of the Taimyr Peninsula indicate a higher trophic status of the water body, which is under pressure from hydrophilic birds. Compared to the background water body, statistically significantly higher phytoplankton abundance (134.6 ± 16.3 thousand cells/l vs. 60.4 ± 11.8 thousand cells/l), zooplankton biomass (134.6 ± 16.3 thousand cells/l vs. 60.4 ± 11.8 thousand cells/l), zooplankton biomass (349.0 ± 170.2 mg/l vs. 64.5 ± 19.5 mg/l), rotifer biomass (15.6 ± 3.5 mg/l vs. 1.6 ± 0.4 mg/l) and their dominance, as well as saprobic index (1.71 ± 0.09 vs. 1.48 ± 0.06). At the same time, specific features of community organization were revealed - higher species richness of phyto- and zooplankton; absence of Cyanobacteria in phytoplankton composition and statistically significantly higher abundance of Bacillariophyta (80.7 ± 11.8 thousand kl./l vs. 31.7 ± 6.5 thousand kl./l), number of species (4 vs. 2) and biomass (326.6 mg/l vs. 60.6 ± 18.8 mg/l) of paddle-bearing crustaceans, which may be determined by the peculiarities of hydrobionts reaction to the products of bird activity. This allows us to speak about the prospects of guanotrophication to improve the trophic status of water bodies without significant deterioration of environmental quality and biodiversity of hydrobiont communities.

A generalization of the available information in the reproductive ecology of widespread bivalve from the families Margaritiferidae and Unionidae during the most vulnerable period of reproduction in their complex life cycle has carried out. In the course of data analysis, the features of evolutionarily adaptive strategy of mollusks to various environmental conditions and relationships with fish are revealed. From a detailed review and analysis of the reproductive cycles of mollusks from the genera Margaritifera, Unio and Anodonta, it is revealed that in the boreal region from subarctic and temperate continentalal to subtropical climates the temperature is the main factor regulating all stages and timing of the reproductive process.

Phylogeographic and morphological analyzes of the whitefish Coregonus lavaretus of Europe, the level of polymorphism of the mtDNA nd1 gene indicate a relatively ancient origin of the populations inhabiting water bodies west of Jutland. It is suggested that these populations in Europe represent remnants of the primary wave of settlement by founders from Central Siberia (Lena River basin). In later waves of whitefish migrations from Siberia, synchronized in time with the events of repeated Lower Quaternary glaciations, whitefish settled west of the Urals from the lower reaches of large watercourses of Western Siberia (Ob River, Yenisei River), which evolved relatively independently of whitefish from Central Siberia. As a result of repeated events of settlement from disconnected periglacial refugia from the east and west, in the geographical space of Eastern Europe from the Baltic Sea to the Pechora River, whitefish haplotypes were greatly mixed. In addition to natural-historical reasons, the distribution of genetic variability in natural whitefish populations in Eastern Europe in recent decades has been influenced by fish hatchery activities for acclimatization and/or artificial maintenance of populations/species.

Species composition and fatty acid composition, seasonal dynamics of biomass, production and productivity of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) of the zoobenthos of the Ob River and its tributaries, the Inya River and the Tula River were studied. Total contents of EPA and DHA in all taxa of zoobenthos were relatively high, except of Trichoptera, Bivalvia and Gastropoda. Values of the EPA and DHA contents felt in the ranges reported in literature for the relevant taxa from various habitats, which confirms the hypothesis about the principal contribution of the phylogenetic factor to the contents of EPA and DHA of zoobenthos. As found, a similarity of the species composition between the Inya River and the Tula River was lower than that between the Ob River and each tributary, which may be due to different hydrological features and types of bottom sediments, as well as a drift of benthic invertebrates from the tributaries into the main channel. The Ob River, the Inya River and the Tula River had nearly similar values of zoobenthos production and EPA and DHA of productivity, while they differed from these parameters of the Yenisei River and its tributaries reported in literature, which had another species composition of benthic invertebrates. As found, the EPA and DHA productivity, i. e., the biochemical quality of the fish food under similar values of the production of zoobenthos, was determined by the species composition of zoobenthos, which depended on the complex of environmental factors.

The role of interspecific competition in biotic communities is poorly understood. The study deals with transformation of the Korean field mouse/stripped field mouse taxocene, which includes range expansion of the second one during global environmental change. The main goal is a comparative estimation of main intestine divisions’ length in these species to define their competitive asymmetry and to understand its role in the taxocene dynamics. We show that the assimilation carbohydrates prevailing in plant tissue is significantly more effective in the Korean field mouse intestine than in the stripped field mouse intestine, while their difference in the protein and lipid assimilation was low. We conclude that the Korean field mouse is the stronger trophic competitor in the taxocene, and the competition play an important role in its transformation. However, neither competition nor global change can directly influence range expansion of the stripped field mouse separately. A interactive mechanism of their influences on the Korean field mouse/stripped field mouse taxocene transformation is discussed.

Predators are an important factor in population dynamics and evolution. They not only kill their prey, but also induce adaptive changes in morphology, physiology and behavior. The relationship between the coat color of water voles, Arvicola amphibius (Linnaeus, 1758), and the predisposition to seizures in response to tactile stimuli was studied. Convulsive behavior is believed to have evolved in evolution as a reflex reaction that protects against sudden capture by a predator. It was found that among brown individuals the proportion of those prone to seizures was significantly higher than among dark brown and black individuals. A comparison of the frequencies of individuals of different color phenotypes in the natural population and in the prey of raptors using published data showed that black individuals are easier prey for predators. The occurrence of convulsive seizures when captured by a predator can disrupt the stereotypical hunting behavior of the predator and increase the likelihood of survival of brown individuals

The results of long-term observations are summed up, which made it possible to assess patterns and identify the reasons for changes in the numbers, current distribution and interspecific relationships of ungulates in the Ussuriysky Nature Reserve. A comparison of archival materials and data from the last decade shows that changes in the abundance and distribution of most ungulate species in the reserve are inextricably linked with the increase in the number of sika deer. After the introduction of this species into the territory over 70 years, its number increased from 25 to 1180 individuals, and the population density reached an average of 30 individuals/1 thousand hectares. Over the same period, the number of red deer in the Ussuriysky Nature Reserve decreased from 450 to 130 individuals, that is, more than three times. In the Suvorovsky forestry, there is currently a decrease in the number by about half (from 250-280 to 110 individuals); in the Komarovsky forestry, the number has decreased by about 10 times (from 180-200 to 15-20 individuals). The number and distribution of roe, musk deer and wild boar in the territory did not change so obviously. The current number of roe in the reserve is 170 individuals with a population density of 4 individuals/1 thousand hectares. The number of wild boars is about 200 individuals with a population density of 4-5 individuals/1 thousand hectares. The developed and applied accounting methodology made it possible to obtain reliable data on the number and distribution of ungulates throughout the Ussuriysky Nature Reserve. There are concerns about a further increase in the number of sika deer in connection with the implementation of biotechnical measures in the reserve.

We examined neuropteran assemblages of the Mordovia Nature Reserve collected in 2022 and 2023 using bait traps at the site of 2021 and 2010 fires and in areas not exposed to these fires. We found that the fires, in which almost all vegetation was destroyed, had different effects on different ecological groups of Neuroptera. Fires were favorable for chortobiont (herb-dwelling) species (e. g., Chrysopa abbreviata, Ch. walkeri, Ch. commata) and species preferring forest edges (e. g., Apertochrysa prasisa and A. ventralis) which increased their numbers. Such fires were, however, very unfavorable for dendrobiont (tree-dwelling) species, especially e. g., Nineta alpicola, N. vittata and Chrysotropia ciliata, which disappeared from burned areas or were unable to restore their numbers in this time.

Based on the well-known provisions of the general theory of systems, some key issues of successional transformations at the biogeocenotic (ecosystem), phytocenotic, microcenotic and population structural levels are considered on the example of post-fire successions in broad-leaved Korean Pine and dark coniferous Korean Pine forests of Sikhote-Alin. In research at the biogeocenotic level, long-term regime observations of individual environmental factors were used, as well as indicative methods based on the analysis of gradients of leading environmental factors by groups of indicator species, blocks of diagnostic species according to the Brown-Blanke ecological and floristic approach and regional ecological scales. The main attention at the phytocenotic level of the study of successions was paid to the issues of spatial structure, species and cenotypic composition of communities, dynamics of the number and productivity of communities. At the microcenotic level, the issues of transformation of the main elements of the mosaic of phytocenoses (synusions and microcenoses) and their equivalents in biogeocenoses (parcels) are considered. Ontogenetic states and the age structure of cenopopulations were established at the population level.

In dendroclimatic studies, there is a need for high-quality data series reflecting the state of the environment in the past. The construction of long-term tree-ring width (TRW) chronologies (in terms of the combined qualities of being one of the best sources of paleo-climatic information) is associated with the problem of finding a source of paleo wood, which will allow it to extend further into the past. The paper considers the prospect of extending the existing 2367-year TRW chronology (on the Siberian larch) due to the attraction of wood of Siberian pine, which is widely presented in collections collected on the premises of the Altai glaciers. The results of consideration of various parameters of annual rings, clearly and convincingly demonstrated that at the upper edge of the forest, the use of such parameter, as the delta of optical density of the annual ring will allow reliably to cross-date samples of different tree species and extend this TRW chronology to the past.

Changes in the soil hydrothermal regime caused by the permafrost layer melting, represent the most important environmental factor in the dynamics of vegetation cover in the permafrost zone. The impact of soil melting on the growth index (GI) of larch ( Larix spp.) and on the gross and net primary productivity (GPP, NPP) of vegetation in the Arctic region of Central Siberia (open woodlands, tundra and forest-tundra) was studied. The following hypotheses were tested: (1) gravimetric data make it possible to estimate the water mass dynamics in soils; (2) thawing of frozen soils stimulates the growth of woody plants and the productivity of vegetation. The work used dendrochronology methods, field data, satellite gravimetry (GRACE survey) and GPP (Terra/MODIS survey). Analysis of gravimetry data revealed a significant long-term trend in water mass decreasing in soils of the permafrost zone (R² = 0.68). The amount of water released during melting is estimated at 6.4 ± 2.3 kg/m^-2 per year. A close connection was found between larch GI and GPP with moisture anomalies in soils (r = - 0.7 and r = - 0.9, respectively). The increasing temperature of the root layer and the moisture deficiency in water vapor also have a positive effect on the GI of larch and the vegetation GPP value in general (r = 0.6 and r = 0.6…0.9, respectively). It was found that pyrogenic carbon losses are significantly (by two orders of magnitude) lower than the NPP value. In conditions of waterlogging of soils, typical for the Arctic, climate warming is accompanied by an improvement in the hydrothermal regime of vegetation growth, promotes an increase in vegetation productivity and the permafrost zone maintains the status of a carbon sink area.

Changes in the productivity of Pinus sylvestris L. were analyzed by remote sensing (gross and net primary production/photosynthesis) and dendrochronology (radial trunk growth) methods on two different-aged forest plots of ribbon pine forests in the dry steppe of Western Siberia. For both plots (young reforestation plantings and natural forest) a significant positive trend of primary production volume change over the period 2000-2023 was revealed. Differences in the set of climatic factors limiting stand primary production volume (spring and fall temperature and precipitation) and radial growth of pine were determined (last September temperatures are significant for pine of different ages, the sum of annual precipitation and Selyaninov hydrothermal coefficient of the growing season are also significant for young trees, and June temperature is also significant for mature forest). Correlations between the width of annual growth of model trees and primary stand production in June and early July for natural forest and in the second half of June for plantations were established. Calculations of the annual volume of carbon sequestration by trees based on tree-ring and biometric data showed that on average over the last 5 years, pine in the table fraction deposited from 525 g C/year (young plantings) to 565 g C/year (mature trees). The results of calculations of carbon sequestration volumes (for single-age pine plantations) are comparable in absolute terms and correlate with the values of primary stand production obtained remotely.

Fluctuation dynamics (studied for 9-27 years) of the abundance, density, age and spatial structure of Dactylorhiza maculata (L.) Soó population on Lake Dolgoe of the Volga-Kama Reserve reflects the mechanisms of maintaining the population at the southern border of the range. The data were stored into the database. Abiotic and biotic factors of transitional shrub-sedge sphagnum bogs are the most suitable for the conservation of a rare species, where boreal and arcto-boreal species are preserved, and favourable microsites are open and moist areas of the mire, with pH 4.1-4.5. The biodiversity of sphagnum mosses in the habitats of Dactylorhiza maculata is represented by 9 species, where the carpet species is Sphagnum angustifolium, and Sphagnum divinum appears in open and wet micro-areas, Sphagnum centrale appears in areas overgrown with open forest. A significant relationship of the species abundance with climatic factors revealed: positive relationship with precipitation, negative relationship with average temperatures of the growing season. The number of reproductive D. maculata does not depend on precipitation in moist microsites. Ontogenetic stages were reliably identified using the morphometric parameters of vegetative and reproductive plants: juvenile (j); immature (im); virginal (v); young reproductive (g1); mature reproductive (g2). The ontogenetic spectrum is 11.5: 17: 29: 42.5 (j: im: v: g), proportion of pre-reproductive individuals fluctuated between 57-66 % in the period of 9-27 years of study, due to a high percentage of fruit formation (up to 60 %). Spatial distribution of individuals predominantly is clustered, consisting of aggregations with a radius of 0.5-1.2 m, distributed randomly. The dynamics of spatial mosaics, accompanied by the migration of seeds and individuals of D. maculata to favourable microsites, is a natural compensatory resistance mechanism that ensures the dynamic balance of the population.

For the first time in Central Siberia, in the parks of Krasnoyarsk, on Pinus sylvestris L. trees of different ages with different phytopathological conditions, we identified the invasive species Diplodia sapinea (Fr.) P. Karst., which is a dangerous pathogen of coniferous trees. Pure cultures were isolated from pycnidia on cones; their morphological and molecular genetic characteristics correspond to the species D. sapinea. Siberian isolates are characterized by a high radial growth rate on nutrient media; are phytopathogenic against shoots of P. sylvestris and fruits of Granny Smith apples in vitro. They cause rapid and extensive necrotic lesions of the bark, shoot cambium and fruit pulp; exhibit high peroxidase and protease enzymatic activity. Siberian isolates of D. sapinea do not exceed the parameters of southern isolates in terms of morphological characteristics, enzyme activity and phytopathogenicity. Significant differences are shown with the Dp1-23 strain of Diplodia seriata De Not, isolated from pycnidia on the cones of Cupressus sempervirens L. For Siberian isolates of D. sapinea, high resistance to cold stress was established in the temperature range from -8 to -31 °C in a series of experiments on freezing and thawing of the mycelium. After activation, the radial rowth rate of isolates on PDA at 24 °C turned out to be higher than that of strains that were not subjected to freezing; relatively slow activation was noted at -16 °C compared to other temperatures. The presence of a long endophytic phase in a species first discovered in Central Siberia, high adaptive capabilities and phytopathogenicity pose a particular danger to its spread to a new territory and host plants, which requires special attention and study.

Plant communities sufficiently change microclimate under their canopy. To reveal the effects of different types of herbaceous communities on the soil thermal regime, phytomass and soil temperature were measured in four plant communities of the Central Forest State Nature Bioshpere Reserve and its surroundings (Tver` oblast`). The productivity of the studied communities ranged in the order: abandoned meadows (930 ± 53 g/m²) - managed meadows (1111 ± 40 g/m²) - Filipendula ulmaria communities (1357 ± 155 g/m²) - subruderal tallherb communities (1726 ± 188 g/m²). The belowground phytomass in the 0-5 cm layer ranged on average from 614 ± 102 g/m² in the subruderal community to 1756±448 g/m² in the Filipendula ulmaria community. The total phytomass was positively correlated with the soil pH (R = 0.814, p < 0.001, n = 16), as well as with nutrient availability indicator values (R = 0.528, p = 0.029). In all the communities the temperature maximum coincided with that of air temperature and occur in June-July. In winter, soils at 8 cm did not freeze, but some days surface temperatures dropped below zero. Soil water capacity was significantly negatively correlated with mean temperatures at the depth of 8 cm in July, August, and September. The links with soil surface temperature were similar, but less pronounced. Soil temperatures at the peak of the growing season and in the following months were not significantly correlated with aboveground phytomass values. Thus, in the forest zone even within relatively small area the phytomass of herbaceous communities differs greatly. Soil temperature under herbaceous vegetation canopy mostly depends on soil physical properties, but not on aboveground biomass.

An effective system of Rhododendron yedoense var. poukhanense (H. Lév.) Nakai. regeneration from seedling explant based on the use of thidiazuron (TDZ) for meristem proliferation was presented. In vitro germinated seedlings were used as explants. The duration of seed germination was 24 days. The total germination of the R. yedoense var. poukhanense seeds of was at the level of 77.5 %. The effects of 4-hour TDZ pulse treatment (7.5; 15.0; 30.0 µM) with further transferring to Anderson’s medium (AM) without TDZ and direct cultivation on AM supplemented with 1.0 µM TDZ on the morphogenic potential of seedlings were studied. R. yedoense var. poukhanense regenerants obtained both after pulse treatment and after cultivation on a TDZ-containing medium ware found to require an additional passage on hormone-free AM (AM0) for elongation and an increase in the number of shoots per explant. The highest number of shoots per explant was obtained after elongation with direct cultivation on AM with 1.0 µm TDZ and after 30.0 µm TDZ pulse treatment, on average 9.32 and 10.32, respectively. The maximum percentage of rooted plants (50 %) was obtained under the action of 4-hour pulse treatment with indolyl butyric acid followed by in vitro cultivation on AM0. The presented study demonstrates for the first time the effect of various types of TDZ treatment on the proliferation and development of shoots, and the developed technology made it possible to obtain rooted and acclimatized microshoots induced by TDZ pulse treatment. As a result, R. yedoense var. poukhanense was included in the in vitro collection for conservation and propagation for further practical use.

The article presents the results of application of the dendrochronological method of indicating the heliophysical and hydroclimatic signal on small time scales (from decades to centuries) in the lake basins of the Baikal rift zone. Three items were considered: dendroindication of climatic parameters in Cisbaikalia; dendroindication of the dynamics of the Lake Baikal level; and assessment of the hydroclimatic signal in the Khubsugul region. It has been found that the values of the width of annual rings is indicative of minima and maxima in the values of air and soil temperature, but the reconstructed series gives the smoothed values. The last cycle of the soil temperature increase may be a manifestation of an extreme climate warming, including soil warming. In the reconstructed series of the Lake Baikal level values, various cycles from 53 to 11 years were detected using the spectral Fourier analysis. Consequently, formerly observed periods of a low lake level were followed by a recovery to normal and then even high values. A high response in the larch growth to summer air temperatures (June-August) is observed in the Khubsugul region. Comparison of the indices of the annual rings width with fluctuations in solar activity suggests a connection between these characteristics.

The article presents the results of a comprehensive analysis of the relief and population dynamics of the key site - Akademgorodok of Irkutsk - in the downstream of the Irkutskaya HPP over the past five years. We used multi-temporal geo-images, including aerial photography, space images and topographic maps, free-access OSM databases, cadastral databases, as well as route observations. The analysis of such data allows us to promptly assess the dynamics of the relief morphology and changes in the structure of manifestation of exogenous processes and population density. Based on the data obtained, a change in the built-up area of the study territory, and a potential change in population density were noted. The results of the study show that changes in the morphotypes of development associated with an increase in population density and the load on infrastructure facilities, road network and engineering networks favorably affect the development of negative and dangerous geological processes, which increases the ecological and geomorphological tension in this particular place. It is obvious that as a result of illiterate planning of urban environment, without calculation of anthropogenic load, unfavorable conditions affecting the stability of the geomorphosystem may arise.

The article examines the formation of academic geography in Altai from first travelers-explorers up to classical geographical research created and developed by the scientists from the Siberian Branch of the Russian Academy of Sciences. The methodological basis of these studies is the landscape approach implemented through a system of methods such as the landscape indication developed by the Institute for Water and Environmental Problems SB RAS and the landscape-hydrological analysis developed by the V.B. Sochava Institute of Geography SB RAS. Currently, the above-mentioned and other methods of landscape studies are successfully applied in landscape and territorial planning both in Altai and in the Baikal region. It is shown that the combination of landscape indication methods and landscape-hydrological analysis reliably reflects the reality that in turn allows solving complex economic problems. We have successfully used these methods during the joint research on expert assessment of the project for the construction of the Main Channel for the transfer of water resources of the Ob-Irtysh basin along the Tobol ancient riverbed into the Aral Sea basin, as well as IWEP SB RAS projects dealing with the environmental support of the Katunskaya and Krapivinskaya HPP construction, natural reclamation assessment of the territory of Altai Krai, justification of the development of agricultural nature management systems in the zone of intensive land use of Siberia, and detection of climate risk sources and peculiarities of their manifestation for ensuring climate security. Time has confirmed the validity of the conclusions obtained during the conducted research.

The article highlights the results of the Complex Expedition to Study Historical Waterways of Russia, organized by the S.I. Vavilov Institute for the History of Natural Science and Technology of the RAS with the participation of the staff members of the Lomonosov Moscow State University. The purpose of the expedition was to conduct a comprehensive historical and geographical study, which helped to identify previously unknown data on the history of the development and study of the territory of waterways and individual natural objects, clarify some facts of the construction of the water system, and compile retrospective reconstructions of changes in the natural environment. A special role in the scientific research of the expedition, in the development of methodology, preparation and implementation of field work, with the further publication of articles and monographs belonged to V.A. Snytko, who actively participated not only in the scientific, but also in the field part of the expedition work. Using the results of many years of research, the creation of a unified geoinformation system was initiated, including certified hydraulic engineering facilities and structures, interesting natural formations and a complex of landscape, environmental and hydrochemical characteristics of the waterways themselves. The common dominant uniting these elements into a system is no longer only the waterway itself, but a cultural and historical landscape complex that takes into account all aspects of human activity and natural formations. The geoinformation base on the historical waterways of the European part of the territory of Russia, including hydrological and hydrochemical, landscape, archival and cartographic sources on the history of water systems, served as the basis for the creation of an appropriate website and for the beginning of the formation of the virtual museum “Historical Waterways”.

The article highlights the significant contribution of V.A. Snytko to the study of matter movement by aeolian processes in the steppe and forest-steppe geosystems of Siberia. The scientist paid much attention to the Baikal region. Based on the analysis of the hydrothermal environment and special experiments, he established that the intensity of aeolian migration of matter is a reflection of the climatic situation, and an indicator of the state of landscapes and the degree of their technogenic transformation. In each studied landscape, V.A. Snytko took into consideration the wind regime prevailing in areas of active deflation and accumulation of aeolian deposits. Together with Polish researchers, he carried out a typification of aeolian tracts. The established morphological and dynamic features of modern aeolian migration of matter are important for the purposes of geographical forecasting. The great role of aeolian processes in the spatial differentiation of matter is noted. It is shown that anthropogenic use of the sandy shores of Lake Baikal led to their degradation and disrupted the course of aeolian processes. As a result of many years of research, the features of the transformation of the functioning of aeolian geosystems have been identified. It has been noted that all Baikal geosystems require careful handling. The results of the research are reported in numerous articles, collections and monographs.