Home – Home – Jornals – Russian Geology and Geophysics 2024 number 9

We discuss the rocks of the Larba granulite block in the Ilikan zone of the Dzhugdzhur-Stanovoi superterrane. The Larba block is dominated by basic schists and garnet-biotite-orthopyroxene and garnet-biotite-cordierite-sillimanite gneisses (metabasites and metapelites). Calculation of temperatures and pressures of mineral formation was carried out by multi-equilibrium geothermobarometry, which makes it possible to evaluate the degree of equilibrium of mineral compositions along with P - T parameters. The P - T estimates have shown metamorphism of aluminous gneisses under moderate-pressure granulite facies conditions (7-8 kbar, 800-850 °C). Orthopyroxene granulites formed under granulite-amphibolite transition facies conditions. The mineral compositions and parageneses in highly ferrous metabasites permitted estimation of the conditions of metamorphism, P = 4-5 kbar and T = 630-700 °C, and show no influence of earlier granulite facies metamorphism. The bimodal P-T distribution for most samples of aluminous gneisses most probably reflects progressive and near-peak conditions of granulite metamorphism. The time of enderbite magmatism is determined from the upper intercept of discordia with concordia at 2546 ± 52 Ma and should be verified. The age of metamorphic rims over enderbite zircon is 1882 ± 11 Ma. The model Nd age of enderbites, t _Nd(DM) = 2.57-2.58 Ga, is close to the age of the core of enderbite zircon and differs significantly from the model Nd age of the host metamorphic rocks (2.8-3.0 Ga). The Paleoproterozoic metamorphism of the Larba block rocks regionally coincides with the third stage of collisional granitoid magmatism of the southeastern Siberian craton and records the formation of this structure.

We have studied the isotopic composition of Nd, Sr, and Pb in Permo-Triassic subalkaline dolerites and Late Cretaceous basanites of the northern part of the Minusa depression. The wide variations in the primary isotope parameters of dolerites (ɛ_Nd = 6.6-8.5, ⁸⁷Sr/⁸⁶Sr = 0.7031-0.7061, ²⁰⁶Pb/²⁰⁴Pb = 18.13-18.72, ²⁰⁷Pb/²⁰⁴Pb = 15.51-15.55, ²⁰⁸Pb/²⁰⁴Pb = 37.88-38.07) and basanites (ε_Nd = 5.3-9, ⁸⁷Sr/⁸⁶Sr = 0.7026-0.7054, ²⁰⁶Pb/²⁰⁴Pb = 18.63-19.09, ²⁰⁷Pb/²⁰⁴Pb = 15.54-15.56, ²⁰⁸Pb/²⁰⁴Pb = 38.40-39.01) indicate both heterogeneity of mantle mafic melts and their partial crust contamination. Doleritic magma was presumably generated predominantly from a substance from a moderately depleted mantle source, which is similar in isotopic composition to the PREMA component of sublithospheric plumes. The basanitic magma might have formed through the melting of the material of the subcontinental lithospheric mantle modified as a result of plume activity in the Paleozoic-early Mesozoic. The similar isotopic compositions of Pb in basanites and the derivates of the enriched lithospheric mantle (EM 2 type) are due to the mixing of different substances of the SCLM substratum.

The absorption spectrum of the ¹⁴N¹⁷O molecule in the range 5200-5550 cm^-1 was recorded for the first time using a Bruker IFS-125M Fourier spectrometer with a spectral resolution of 0.0056 cm^-1. An analysis of the spectrum made it possible to detect 83 vibrational-rotational lines of the 3-0 band of the main transitions in the X ²P electronic state of the ¹⁴N¹⁷O molecule. For 29 resolved doublets, the positions and relative intensities of each component of a doublet are determined. The spectroscopic Λ-parameters are found. For the remaining 25 unresolved doublets, the positions and relative intensities of the doublet center are also determined. The maximum of the rotational quantum number J was 24.5. The found experimental line positions in the 3-0 band confirmed the calculated data given in the ExoMol database. The frequencies of registered transitions weighted in accordance with experimental uncertainties have been processed, and the spectroscopic constants for the vibrational state v = 3 have been determined. With the found spectroscopic constants, predictive calculations were made of the rotational energy term values up to J = 30.5 in the vibrational state v = 3 and, accordingly, the transition frequencies of the 3-0 vibrational band for ²Π_1/2 and ²Π_3/2 electronic states. The calculations performed showed agreement with the data given in the ExoMol database, within the error specified.

Accurate measurements of the concentration of nitrous oxide, a potent greenhouse gas, in the Earth's atmosphere are important for modeling the radiation balance of our planet. The work presents the measured broadening and shift coefficients of N₂O lines by air pressure at room temperature for 82 rovibrational transitions in the (00⁰2) ← (00⁰0) band; the rotational quantum number m varies from 3 to 54. The measurements were carried out on an IFS-125M Fourier transform spectrometer with a spectral resolution of 0.0056 cm^-1. The calculated line-broadening and shift coefficients were obtained using a semi-classical method modified by introducing a correction factor in the calculation scheme. Our parameters are compared with those presented in the literature and in modern spectroscopic databases. A vibrational dependence of the line half-widths for the ν₃ stretching vibration was revealed.

For five isotopologues of the SO₂ molecule: ³²S¹⁶O₂, ³⁴S¹⁶O₂,³³S¹⁶O₂, ³²S¹⁸O₂, ³²S¹⁶O¹⁸O, parameters of the effective vibrational Hamiltonian are derived from fitting to the available experimental data and with the use of the basic relations of the isotope substitution theory. Vibrational constants obtained from the fit reproduce the experimental vibrational energy levels within 0.025 cm^-1 for symmetric isotopologues. The found vibrational energy levels are compared with the variational calculation data, and the quantum numbers for 93 vibrational states are corrected.

To determinate the type of atmospheric turbulence (Kolmogorov, coherent, etc.) in operational mode, a new technique has been developed based on algorithm for spectral analysis of sequential overlapping samples from a continuously replenished population of meteorological measurement data. The samples are formed by the sliding time window. Criterion for turbulence type is the slope of inertial interval of the temperature fluctuation spectrum near the maximum, which is equal to “-5/3" under Kolmogorov turbulence and “-8/3" under coherent turbulence. The slope is calculated from the linear regression equation at the initial part of the spectrum, the length of which is set by the level of decrease by one order of magnitude from the maximum. It is shown that such slopes of the spectra for the recorded meteosituations under urban conditions are distributed lognormally. It is found that the proportion of non-Kolmogorov turbulence in more than 5 million calculated spectra is much larger than expected and amounts to 75-97% depending on the estimation rigor. It is shown that sequences of spectra with the same slope correspond to regions of turbulence of the same type. Boundaries of the regions are defined with accuracy of the sliding window shift step. The size of the regions is estimated based on information about wind speed and registration duration. It is shown that under comparable conditions the extent of the regions can significantly exceed the one for an ordinary single sample. To accelerate the post processing of large datasets, the algorithm uses the Message Passing Interface (MPI) for a computing cluster with an arbitrary number of nodes. The field of application of the technique in astronomical practice is the evaluation and registration of the sizes of spatial regions of “strong" and “weak" turbulence along optical path, in which the intensity of turbulence is in fixed intervals, as well as the sizes of regions with fixed temperature stratification.

The purpose of the study is to describe the seasonal variability of optically active components in the Sea of Azov based on continuous information obtained from the combined MODIS-Aqua/Terra satellite observation product and a three-dimensional hydrodynamic model. The paper discusses the results of testing a method for restoring missing data in remote sensing images using the results of three-dimensional hydrodynamic simulation. The method has been tested for four main bio-optical parameters: the concentration of chlorophyll- a and pheopigments (TChl), indicators of light absorption by phytoplankton pigments ( a _ph(678)) and non-living organic matter ( a _CDM (438)), and indicator of backscattering of light ( b _bp(438)). The results obtained from the combined product were compared with in situ observations carried out in April-May 2019 on the SRV Professor Vodyanitsky. The deviation of the average TChl values according to MODIS and simulation data relative to in situ observations was 1.8 and 2.2 mg × m^-3, respectively. Analysis of the calculated series of main bio-optical parameters obtained through regular assimilation of MODIS data into a hydrodynamic model made it possible to establish their seasonal variability for the central part of the Azov Sea in 2019. Among the studied bio-optical parameters, a clear seasonal variability of TChl stands out with an average annual value of 2.98 ± 1.22 mg × m^-3. Changes in a _CDM(438) and b _bp(438) are characterized by two periods of greatest values: spring (March-May) and autumn (August-October), with corresponding annual averages of 0.42 ± 0.15 and 0.10 ± 0.03 m^-1. Maximal changes in a _ph(678) are observed from July to October with an annual average of 0.04 ± 0.03 m^-1. The proposed method takes advantage of remote sensing data, which expand the capabilities of operational oceanological monitoring, and simulation data, which allow filling information gaps in these data. The results provide complete continuous data sets on the distribution of basic bio-optical indicators, which are crucial in predicting the ecological state of sea basins.

Comparison of results of satellite measurements by results of independent measurements is an esencial and necessary component of validation of satellite data, justifying their use for scientific and practical tasks. The work compares the results of spectrometric measurements of the NO₂ content in the atmosphere by the Ozone Monitoring Instrument (OMI) in 2004-2020 with the results of ground-based twilight zenith measurements at 14 stations of the Network for the Detection of Atmospheric Composition Change (NDACC). Latitudinal distributions of quantitative characteristics of the comparison have been obtained, including the NO₂ contents, their differences, and correlation and linear regression coefficients between the satellite and ground-based data. Criteria for validation of interannual and long-term changes in NO₂ derived from the OMI data with the help of ground-based measurements are proposed. The latitudinal - hemispheric and regional - features of the correspondence between the satellite and ground-based data have been revealed. Significantly new results have been obtained on the dependence of the comparison characteristics on the level of pollution of the lower troposphere with nitrogen oxides and on the time scale of NO₂ variations: day-to-day, seasonal and interannual. The results will be useful in analysis of NO₂ variability based on OMI data. The continuation of this work may be a comparison of the results of the analysis of interannual variations and long-term NO₂ trends obtained on the basis of the OMI and ground-based measurement data.

This work is devoted to the issues of remote monitoring of atmospheric gas concentrations using the example of carbon monoxide over the oil and gas producing territories of the Khanty-Mansi Autonomous Okrug with a high concentration of fuel combustion sources. The analysis of the variability of carbon monoxide (CO) content in the atmosphere over an oil-polluted area in the Khanty-Mansi Autonomous Okrug is performed based on satellite sensing data (Terra/MOPITT). The daily and seasonal dynamics of the integral content and surface concentration of CO are studied. The average CO content (integral and surface) in the oil-polluted area exceeds similar values in the background area, both in general for the warm period of the year and for most months. There are no significant differences in the CO content above the background and contaminated areas, which may be due to the mixing of air masses; however, the average CO content (integral and ground level) in the contaminated area exceeds similar values in the background area, which is explained by the presence of stationary CO sources in the former, including flare units.

According to the IPCC-2021 Report on climate change, the atmospheric CO₂ and CH₄ concentrations have increased by around a quarter for the last 50 years. The CO₂ and CH₄ radiative forcing due to their concentration growth was calculated for mid-latitudes. The vertical profiles of temperature and humidity were taken from the ECMWF ERA-5 European reanalysis data. An impact of overlapping of H₂O absorption bands with CO₂ and CH₄ bands on the radiative forcing calculation results in the troposphere and stratosphere of mid-latitudes with different water vapor content was investigated by statistical methods. It was shown that absolute value of the CO₂ radiative forcing in the troposphere increases with the atmospheric water vapor content, whereas the CH₄ radiative forcing does not depend on the atmospheric total column water vapor.

This paper presents the results of an experiment on remote sensing of a smoke plume over a model fire with the use of a specialized lidar based on the backscatter enhancement effect and detecting optical turbulence. Burning was 1.600 m away, and the area of the model fire varied from 1, 9 and 25 m². It was found that during combustion, the lidar recorded an increase in the echo signal in the main receiving channel, which registers aerosol scattering and the turbulent component, relative to an echo signal in the additional receiving channel, which registers only the aerosol. The width of the smoke plume did not exceed 20 m, an increase in the main echo signal was observed immediately after the plume in the distance range up to 300 m. In this experiment, a plume of warm smoke acted as a phase screen that changed the coherent structure of the laser beam. After the completion of intensive combustion, the temperature inside the plume rapidly decreased and the lidar recorded only the aerosol content. The appearance of two signs in the echo signal - an increase in the aerosol concentration and turbulence intensity - clearly indicates a source of burning. The lidar estimation of the values of the structural characteristic of the refractive index C_n² at an altitude of 10 m above the combustion focus was compared with the data of the ultrasonic meteorological station AMK-03 at an altitude of 3 m and results of simulation of a grass-roots fire published earlier.

The laser fragmentation/laser-induced fluorescence (LF/LIF) method is well known for its efficiency in detecting complex chemical compounds based on the fluorescence of their characteristic fragments. The method is applied, for example, to measuring the local content of nitrous acid and hydroxyl radicals in the atmosphere, visualization of intermediate stages of combustion processes, remote detection of substances in the gaseous state in the atmosphere and condensed state on surfaces, etc. We present for the first time the results of the experimental study of a possibility of remote excitation of LIF of characteristic photofragments of a substance in an aerosol state in the atmosphere. The organophosphorus compound triethyl phosphate (TEP) was used as the test substance. It has been shown that synchronized two-pulse laser irradiation of TEP aerosol particles and their PO-fragments (phosphorus oxide molecules) makes it possible to increase the efficiency of the LF/LIF process by approximately seven times compared to single-pulse laser exposure. It has been established that the process of formation of PO-fragments of TEP aerosol under the laser irradiation at a wavelength of 266 nm has a decaying exponential character with a characteristic time of 192.6 ± 20.2 ns. In terms of the nature of the time dependence of the formation of photofragments, the results obtained are fundamentally different from similar measurements for other compounds in gaseous and condensed states and motivate further research that will contribute to the development of the LF/LIF method.

To monitor objects of man-made origin, the issues of reducing the errors of pointing an optoelectronic system (OES) of a space survey at an object, which are associated with the influence of mechanical factors on the design of a pivoting device, are considered. To reduce these errors, the calibration of the optical sensors of the OES by stars is used. Mathematical methods of processing measurements are used to increase their accuracy, or interpolation methods are used to determine intermediate values between measured calibration points. The work uses spline approximation to find corrections to the readings of optical sensors of the azimuthal and elevation axes.

Erebus volcano is the southernmost active volcano on Earth, whose volcanogenic emissions include components that play a significant role in catalytic cycles of stratospheric ozone depletion. High cyclones contribute to the rise of gas emissions from Erebus volcano (including HCl and SO₂) from the troposphere to the altitudinal range of ozone hole formation, from 14 to 22 km in the stratosphere. The paper considers the integral content of HCl and ClONO₂ for the period 1992-2023 and analyzes the variability of the frequency of high cyclone occurrence for the period 1980-2022 based on the ERA5 reanalysis data. It is revealed that the maximal frequency of occurrence of high cyclones over Erebus volcano is usually observed in July. The analysis of the integrated HCl content at different stations showed that the values over the Antarctic are much higher than over the Arctic and approximately twice as high as at midlatitude stations. The effect of HCl accumulation in the stratosphere is shown: the correlation coefficient between 5-year average frequencies of occurrence of high cyclones and 5-year average values of ozone hole area with a 4-year shift of the series of the ozone hole area ahead relative to the series of the frequency of occurrence of high cyclones, calculated for the period from 1980 to 2022, amounts 0.78.

Aiming at the problem that the coefficient matrix of multivariate errors-in-variables (MEIV) model contains constant columns, the MEIV model is extended to partial multivariate errors-in-variables (P-MEIV), and the new algorithm of P-MEIV model is proposed based on the principle of partial errors-in-variables (PEIV) model and indirect adjustment. The algorithm is simple and easy to implement. An example of coordinate transformation is used for verifying, and the results are compared with the existing MEIV model algorithm, which shows the effectiveness of the proposed algorithm. Finally, the P-MEIV algorithm is applied to the multi-point grey model (MGM(1,N)) of settlement monitoring. The results show that the P-MEIV model proposed in this paper can better consider the influence of monitoring point errors, and the estimated results are in good agreement with the actual situation.

A unitoid is a square matrix that can be brought to diagonal form by a congruence transformation. Among different diagonal forms of a unitoid A, there is only one, up to the order adopted for the principal diagonal, whose nonzero diagonal entries all have the modulus 1. It is called the congruence canonical form of A, while the arguments of the nonzero diagonal entries are called the canonical angles of A. If A is nonsingular then its canonical angles are closely related to the arguments of the eigenvalues of the matrix A^-∗A, called the cosquare of A. Although the definition of a unitoid reminds the notion of a diagonalizable matrix in the similarity theory, the analogy between these two matrix classes is misleading. We show that the Jordan block J_n(1), which is regarded as an antipode of diagonalizability in the similarity theory, is a unitoid. Moreover, its cosquare C_n(1) has n distinct unimodular eigenvalues. Then we immerse J_n(1) in the family of the Jordan blocks J_n(λ), where λ is varying in the range (0,2]. At some point to the left of 1, J_n(λ) is not a unitoid any longer. Wediscuss this moment in detail in order to comprehend how it can happen. Similar moments with even smaller λ are discussed, and certain remarkable facts about the eigenvalues of cosquares and their condition numbers are pointed out.

The study of the spread of greenhouse gases in space and time, as well as the assessment of fluxes from the Earth's surface of these gases using a data assimilation system is an urgent task of monitoring the state of the environment. One of the approaches to estimating greenhouse gas fluxes is an approach based on the assumption that fluxes are constant in a given subdomain and over a given time interval (on the order of a week). This is due to both the need for an effective implementation of the algorithm and the properties of the observational data used in such problems. Modern problems of estimating greenhouse gas fluxes from the Earth's surface have a large dimension, therefore, a variant is usually considered in which the estimated variable is fluxes, and the transport and diffusion model is included in the observation operator. At the same time, there is a problem of using large assimilation windows, within which the flow values are estimated at several time intervals. The paper considers an algorithm for estimating fluxes based on observations from a given time interval. The algorithm is a variant of the ensemble smoothing algorithm, widely used in such problems. It is shown that when using the assimilation window, in which the flow values are estimated for several time intervals, the algorithm can become unstable, while the observability condition is violated.

This paper considers a new class of nonlinear second degree integro-differential Volterra equations with a convolution kernel. We derive some sufficient conditions to establish the existence and uniqueness of solutions by using the Schauder fixed point theorem. Moreover, the Nystrőm method is applied to obtain an approximate solution of the proposed Volterra equation. Numerical examples are given to validate the adduced results.

Variable order fractional operators can be used in various physical and biological applications where rates of change of the quantity of interest may depend on space and/or time. In this paper, we propose an explicit finite difference approximation for a space-time Riesz-Caputo variable order fractional wave equation with initial and boundary conditions in a finite domain. The proposed scheme is conditionally stable and has global truncation error O(τ²+h²). We also present a numerical experiment to verify the efficiency of the proposed scheme.

In this paper we study the technology of calculating difference problems with internal boundary conditions of flow balance constructed by means of one-sided multipoint difference analogs of first derivatives of arbitrary order of accuracy. The proposed technology is equally suitable for any type of differential equations to be solved and admits a uniform realization at any order of accuracy. It, unlike approximations based on the continued system of equations, does not lead to complications in splitting multidimensional problems into one-dimensional ones. Sufficient conditions of solvability and stability of the realization of algorithms by the run method for boundary conditions of arbitrary order of accuracy are formulated. The proof is based on the reduction of multipoint boundary conditions to a form that does not violate the tridiagonal structure of matrices, and the establishment of the conditions of diagonal dominance in the transformed matrix rows corresponding to the external and internal boundary conditions.

The paper considers an implementation of an adaptive computational grid constructing algorithm inside the numerical solution of the one-dimensional forward magnetotelluric sounding problem (the Tikhonov-Cagniard problem). The numerical solution of the problem is realized by the method of local integral equations, which was proposed by authors earlier. An adaptive computational grid construction is based on geometrical principles, which conduct approximation of the electrical conductivity function via optimization of its’ piecewise-constant interpolant. Numerical experiments are carried out to study and illustrate the effectiveness of the combined method. Approbation was realized on the Kato-Kikuchi model with known exact solution.

An analysis of the ecological characteristics of cyanobacteria in Svalbard has been carried out. Two groups of habitats have been identified: aquatic and terrestrial. The main factor determining the development of cyanobacteria is considered to be the degree of water saturation. The variability of habitats can be represented as a gradient of moisture from typically aquatic to dry terrestrial habitats. Based on the number of findings and species richness, it can be concluded that the most favorable habitats for cyanobacteria in Svalbard are 1) rocky communities in conditions of sufficient moisture, 2) exposed soil surfaces on which biological soil crusts form, 3) slow, well-warmed streams, and 4) specific over-moistened habitats such as seepages. Using the example of the analysis of the ecological characteristics of species growing in the archipelago, it is shown that the concept of eurybiont properties of cyanobacteria is not tenable. The greatest plasticity is exhibited by Nostoc commune Vauch. ex Born. et Flah., Microcoleus autumnalis (Trev. ex Gom.) Strunecky et al., Calothrix parietina Thur. ex Born. et Flah., Oscillatoria tenuis C. Ag. ex Gom., Pseudanabaena frigida (Fritsch) Anagn. All of cyanobacterial species, including those mentioned above, have obvious ecological preferences. Analysis of the substrate specificity of cyanobacteria demonstrates that the greatest number of species are found in soil, rocky substrates, and moss-like environments.

A comprehensive paleoecological study of permafrost peat deposits from three locations of the middle reaches of the Yuribey River in the subzone of modern subarctic shrub tundra of the Yamal Peninsula has been carried out. Based on the results of palynological and carpological methods and radiocarbon dating data, the changes in regional and local vegetation and climatic conditions of Central Yamal in the Late Glacial and Postglacial periods are reconstructed. It was found that in this area shrubby tundra with Betula nana were widespread in climatic conditions close to modern ones in the Younger Dryas about 12.6-11.7 cal. ka BP. The penetration of tree species (Betula sect. Betula, Picea obovata, Larix sibirica) and their accompanying boreal herbaceous plants began due to improved climatic conditions in the Early Holocene warming about 10.2-9.7 cal. ka BP. The most favorable conditions for the growth of tree-shaped birch, larch and spruce in the territory of Central Yamal existed in the Early and Middle Holocene in the range of 10.2-4.4 cal. ka BP. At that time, sparse woodlands or even closed forests were common, the climate was much warmer than the modern one. Forest vegetation degraded and open landscapes with tundra communities formed at the end of the Middle Holocene (4.5-4.4 cal. ka BP). The climatic conditions have become close to modern ones.

The paper examines the influence of several fire characteristics including fire energy release, seasonality and duration on the number of wildfires resulting in tree stands mortality in Siberia between 2002 and 2022. Fire energy release was assessed using Fire Radiative Power (FRP), measured using MODIS data. To assess the degree of forest stands disturbance and to identify fires resulted in the forest stand mortality, a global forest cover change product generated from Landsat satellite data was used. Siberia experienced an increase in both total burned area and the area of stand replacing fires between 2002 and 2022. At the same time, an increase in the fire radiative power was also observed. The total values of fire radiative power for stand replacing fires (390.2 (σ = 80.5) MW/km²) were significantly higher ( p < 0.01) comparing to fires that did not result in the tree stands mortality (291.8 (σ = 74.7) MW/km²). Fire radiative power in dark coniferous forests was 20-25% higher comparing to FRP in mixed forests with a predominance of deciduous stands. Stand replacing fires were mainly observed in the late summer with the peak occurring in July - first half of August, while non-stand replacing fires were observed throughout the entire fire season. Stand replacing fires were also characterized by a longer duration (average duration 4.8 (σ = 1.0) days) compared to non-stand replacing fires (3.9 (σ = 0.7) days).

The questions of changes in the life status of Larix gmelinii along the gradient of urbanized ecotypes are considered on the basis of population analysis and morphometric approach. L. gmelinii growing under different conditions differed in a number of size and growth characteristics of photosynthetic activity. The maximum values were noted in plants growing in public gardens and on city streets under conditions of high insolation. The vitality structure of the populations of the species in the vegetative ontogenetic state changed from depressive to equilibrium, the population quality index changed from 0.2 to 0.333. When examining the landscaping of transport highways of the city, local populations of L. gmelinii in the generative ontogenetic state were of a prosperous type, the population quality index varied slightly from 0.47 to 0.49. The plasticity of the species, the high viability of L. gmelinii, due to resistance to air pollution, unpretentiousness to soil conditions of growth, transplantation, allow larch to be widely used for landscaping urban areas.

The results of studies of bottom biocenoses in three types of littoral zone (rocky biotope, gravel-sand biotope and surf zone with thickets of higher aquatic vegetation) of Lake Onego in 2013 and 2014 are presented. Our results show that among the three types of coastal zone, the maximum values of macrozoobenthos biomass were noted in the rocky littoral zone (3.4-6.6 g/m²), the minimum values in the sandy zone (0.1-0.2 g/m²). The invasive species Gmelinoides fasciatus (Stebbing 1899) (CRUSTACEA: AMPHIPODA) has successfully naturalized in all types of littoral zones of the reservoir in recent decades. On the rocky type of biotope, G. fasciatus dominates both in numbers and biomass.

This study is focused on soil nematode communities in under-crown areas of tree plants introduced to and cultivated for a long time in the botanical garden on Is. Bolshoy Solovetsky (Arkhangelsk Region, Russia). Soil nematode communities of natural forests (pine-, spruce-, birch stands) were studied as the control. The study has demonstrated that the taxonomic diversity and abundance of nematodes, as well as the share of plant parasites in the trophic structure of nematode communities in the soil under introduced trees were higher compared to natural forests. The ecological indices (structure index SI, enrichment index EI) changed non-uniformly and so had poor performance as tools for evaluating the consequences of the plant introductions for the soil ecosystem. Correlation analysis revealed a significant positive relationship between the content of carbon and nitrogen in soil and the absolute and relative abundance and the taxonomic diversity of plant parasites, as well as a significant negative relationships between C: N and fungal feeders, also between the soil pH and the taxonomic diversity of nematodes and the relative abundance of bacterial feeders and EI. The entomopathogenic nematode Steinernema affine Bovien revealed on the island has been reported for the first time in Russia.

For the first time, information is provided about the algae of Lake Azas, part of the water area of which belongs to the Azas State Nature Reserve. 171 species and intraspecific taxa have been identified, which belong to 72 genera, 50 families and 8 divisions. It has been established that the basis of the algal flora consists of diatoms and blue-green algae. 14 dominants were identified, 9 of which belong to the Bacillariophyta department. An ecological and geographical analysis of algae in the reserved part of the lake was carried out. It was established that the algal flora of the water body is represented by benthic species with a predominance of indifferent forms in relation to the algae and active reaction of the environment. In all studied biotopes, 123 species were identified - indicators of water saprobity. The predominance of betamezosaprobionts and oligosaprobionts was noted. Geographically, cosmopolitan and boreal species dominated.

In pine and birch-aspen forests that are typical for forest-steppe Ob region in Novosibirsk area we conducted a study of earthworm populations (Lumbricidae) with taking into account forest mosaic. A detailed analysis of the structure of earthworm complexes made it possible to identify concrete species and living forms that are biotopically distributed to both a certain type of forest and a forest microsite. Asian species mainly predominate in pine forests, cosmopolitans in birch-aspen forests. Differences in the population of forest microsites in terms of earthworm population density and biomass are more pronounced in the forest gaps than in the spaces under tree crown and between tree crown, especially in pine forests. Studying the population of earthworms in the deadwood we revealed the characteristic features of complexes structure for each type of forest: in pine forests incomplete deadwood earthworm complexes complement soil ones, in birch-aspen forests, deadwood is a specific microsite with a full-complete earthworm complex.

The ¹³C-NMR spectra and elemental composition of lipids of gray forest soils (Greyic Phaeozems), dispersed carbonate chernozems (Haplic Chernozem Hypocalcic) and chestnut soils (Kastanazems) of Western Transbaikalia were determined. The contribution of carbon contained in lipids to the total reserves of organic carbon is calculated. For the first time, the work presents the characteristics of the lipid fraction of organic matter in cold soils of Western Transbaikalia. An analysis of the spectra was carried out, including the assignment of signals from ethoxy groups, phenol derivatives and alkene fragments, as well as an indication of the ranges of chemical shifts characteristic of certain types of carbon nuclei. A comparison was made of the content of various types of structural elements in the studied lipids. The results obtained showed that the main part of lipids consists of esters and fatty acids. Carbon atoms in the molecular structure of lipids are predominantly represented by aliphatic chains. Analysis of the composition of lipids showed that the content of carbon atoms is 65-73 %, and hydrogen - 8-10 %. The high concentration of oxygen atoms in lipids indicates that functional groups containing oxygen are concentrated in the aliphatic part of the lipids. The share of lipid carbon in the total reserve of organic carbon is 6.5 % for chestnut soils, 5.8 % for gray forest soils, 4.1 % for dispersed carbonate chernozems.

The abundance and morphogenetic indicators of the Adonis villosa Ledeb., a vulnerable species in the Altai Republic (AR), have been studied. For the first time, genetic differentiation in six cenopopulations (CP) of A. villosa using ISSR markers and variability of morphometric characters in individuals from four CPs in the AR were revealed. Similarities in the variability of morphometric characters in the studied CPs were revealed, as well as a decrease in the number of mature generative individuals by 1.5-14.0 times over the period from 2017 to 2023. The genetic structure was studied using 6 primers: M 9, UBC 834, UBC 830, UBC 857, UBC 840, UBC 811. Of these, UBC-857 turned out to be the most informative. In representatives of the six studied CPs, we identified four variants in the distribution of ISSR markers, and a high similarity in the distribution of ISSR markers between the A. villosa CPs (88-99 %) was found. Intrapopulation similarity among individuals of this species is also high and reached 97 %. The probable reasons for this phenomenon are the small number of mature generative individuals in the CP (no more than 10) and their spatial isolation. In Northern Altai, A. villosa individuals have a homogeneous genetic structure, which leads to the vulnerability of this species. This species requires a special approach to conservation in natural conditions and culture.

Trophic relationships of bats (Chiroptera) with Lake Baikal biota were assessed based on microscopic studies Myotis petax feces (n=22). From 82 to 86 % of samples maintained fragments of exoskeletons of caddis flies (Trichoptera) and dipterans (Diptera). These taxa include mainly aquatic and semi-aquatic species. Many species from these taxa are endemic to Lake Baikal. Terrestrial insects were found in studied samples less frequently (Hymenoptera - 41 %, Neuroptera - 27 %, Heteroptera - 9 %). The morphological analysis revealed fragments of Baikal amphipods in two fecal samples of M. pretax. Further molecular studies will allow the detection of greater invertebrate taxa diversity in fecal samples of bats feeding near Lake Baikal.

The observed increase in temperature, caused by increasing concentrations of climate-active (greenhouse) gases in the atmosphere, primarily carbon dioxide (CO₂) and methane (CH₄), may be responsible for the projected release of carbon accumulated over millennia in large areas of northern latitudes. The scale and duration of the expected effect remains an open question, due to the sporadic nature of quantitative estimates of carbon flows. The work reflects the current status, directions and main results of long-term instrumental studies of carbon flows in the ecosystems of the middle taiga subzone of Central Siberia, on the basis of the Middle Yenisei experimental station of V. N. Sukachev Institute of Forest, Siberian Branch of the Russian Academy of Sciences (ZOTTO observatory). The dynamics of CO₂ and CH₄ concentrations in the atmosphere from 2009 to 2020 are presented. The values of net ecosystem exchange of CO₂ for forest-swamp complexes are given, indicating that they act as a sink (sink) of atmospheric CO₂. For representative ecosystems, an assessment of soil CO₂ emission fluxes and the seasonal variation in the values of photosynthetic carbon assimilation by dominants of the subordinate vegetation layer are presented. The patterns of behavior of dissolved forms of carbon in the waters of streams draining oligotrophic and eutrophic swamps in the study area were revealed, and the values of CO₂ emission from the water surface were presented.

The phenology, productivity, intensity of gas exchange and resistance to biotic factors in climatic ecotypes of Siberian stone pine ( Рinus sibirica Du Tour) from latitudinal (from the West Siberian forest tundra to the low mountains of the Western Sayan) and longitude (from the Urals to the Northern Baikal region) profiles were studied in the 30-year clone archive at the scientific field station «Kedr» of the Institute for Monitoring of Climatic and Ecological Systems, Siberian Branch of the Russian Academy of Sciences. It has been established that Siberian stone pine is characterized by a high level of hereditarily determined ecological and geographical differentiation in productivity and resistance to biotic factors (pests and fungi diseases) when growing vegetative progeny in the south of the forest zone. The main factor of differences between ecotypes is the heat supply of the growing season in their places of origin. It increases significantly more from north to south than from east to west. Therefore, the differences between latitudinal ecotypes are much greater than between longitudinal ecotypes. The intensity of respiration depends more than the intensity of photosynthesis on the climate in which a given population was formed. Ecotypes from cold habitats have significantly higher respiration costs. This is an important factor in reducing their productivity in warmer climates. Being weakened by the imbalance between photosynthesis and respiration, they are damaged by pests and diseases which becomes an important factor in further reducing productivity. In conditions of global warming, ecotypes from warmer climates are not inferior to the local ecotype in terms of resistance to biotic factors and surpass it in productivity. Therefore, they are recommended to be actively used for breeding.

Quantitative assessments of the carbon balance of terrestrial landscapes and, specifically the permafrost zone, where the most significant warming trends are observed, require taking into account the export of terrigenous carbon beyond their boundaries with lateral flow. The paper presents the results of long-term monitoring of intraseasonal and interannual fluctuations in the concentrations of dissolved organic (DOC) and inorganic (DIC) carbon in the hydrographic network of the Central Siberian Plateau, carried out on the basis of the Evenkian field station of the V. N. Sukachev Institute of Forest, Siberian Branch, Russian Academy of Sciences (Tura settlement). Research is being carried out on more than 100 streams and rivers of various orders in the middle reaches of the Lower Tunguska River (62-66°N, 96-102°E) based on regular measurements of the concentrations of all forms of carbon, as well as quasi-continuous monitoring of the physical and chemical parameters using specific sensors and automatic loggers. It has been shown that the main limiting factors of lateral carbon flux within the Central Siberian Plateau at present are: 1) stocks of potentially mobilizeable organic carbon in terrestrial landscapes and 2) amount of precipitation in a sharply continental climate. An increase in the DOC flux is predicted both as a result of thawing of C-rich frozen deposits and an increase in the productivity of plant cover, and inorganic carbon - as a result of increased rates of silicate rock weathering and sequestration of atmospheric CO₂. Negative predictions of DOC behaviour are associated with an increase in the depth of infiltration of solutes with an increase in the seasonally thawed soil layer, which determines the sorption of DOC in the soil column and its microbiological destruction. An increase in the area and intensity of fires as a result of climate warming determines a significant transformation of the lateral carbon flux. At the same time, the observed reduction in river flow as a result of an increase in the pyrogenic factor will determine the overall decrease in the transport of terrigenous carbon from terrestrial landscapes.

The interaction of the main forest-forming species of Siberia: Siberian spruce ( Picea obovata Ledeb.), bush birch ( Betula fruticosa Pall.), Scots pine ( Pinus sylvestris L.), aspen ( Populus tremula L.), Siberian larch ( Larix sibirica Ledeb.), and Siberian stone pine ( Pinus sibirica Du Tour) with agro-gray soil is considered. The study is carried out in a special long-term experiment with forest crops, initiated by prof. N. V. Orlovskiy in 1968-69 in the southern taiga on the territory of the Kemchug Upland. It was revealed that biological characteristics and successional position of tree species significantly influence all components of the phytocenosis. The biggest changes were recorded under the canopy of early successional coniferous (larch) and small-leaved (birch and aspen) species, while late successional species - spruce and cedar - at this stage significantly limit the development of subordinate layers. Over the 45-year period of growth of forest crops, the soil profile is formed due to the differentiation of the arable substrate of the soil-forming species into genetic horizons. The influence of the forest canopy on planted agro-gray soil occurs gradually and intensifies with the growth and development of crops, the formation of a litter horizon and covers all soil properties. Active modern soil formation affects the mineral soil layer 0-10 (13) cm. Vertical flows of matter and energy entering the soil in the process of increasing capacity and intensity of the biological cycle are the main factor in the formation of the soil profile. The development of soil under forest crops under the conditions of a long-term zonal experiment was noted.

Two lime tree species: European - small-leaved lime ( Tilia cordata Mill.) and Far Eastern - amur lime ( Tilia amurensis Rupr.) grow in the arboretum of V. N. Sukachev Institute of Forest, Siberian Branch, Russian Academy of Sciences experimental station «Pogorelskiy Bor». Small-leaved lime tree has 9-16 m in height and 10-36.5 cm in diameter, amur lime tree has 11.5-14.5 m and 7.5-21.5 cm, accordingly. Plants of both species are characterized by high winter hardiness, they are not damaged with spring frosts and rarely attacked by pests. The lime trees begin blooming in the middle of July when the sum of effective temperatures reaches about 800 degrees/day (42.2-43.0 % of the total t _ef > 5 for the year). They continue blooming during 10-17 days. A fruits - lime-capsules ripen in September. The small-leaved lime tree capsules were 5.7 mm in length, 4.4 mm in width and 23.6 g in weight per 1000 pieces, its seeds were 4.0 mm, 3.0 mm and 14.5 g, accordingly. Sizes of amur lime tree capsules and seeds were similar - 5.3 mm, 3.9 mm and 23.8 g for the first ones and 3.9 mm 2.6 mm and 16.1 for the second ones. The part of empty seeds in small-leaved lime tree was 70 % but the part of such seeds in amur lime tree was 30 %. At the same time, the good quality of seed samples of both species did not exceed 30 %. On the territory of the arboretum there is natural regeneration of lime tree, including self-seeding. It is the most abundant at a distance of 50-100 m from the mother plants, where its density is 25-41 pieces per square meter.

The structure of the carbon pool in the middle-aged and mature pine stands of the Krasnoyarsk forest-steppe during care logging has been studied. The basis for calculations is data on the dynamics of the volume stocks of the stands. In accordance with the method of conversion coefficients, the phytomass of fractions (stem, bark, branches and needles) was calculated, which was then converted into carbon stocks. It has been established that the main contribution to the carbon pool of pine stands is made by stem wood. In medium-aged pine stands, the proportion of stems in the bark is 66-70 % of the total phytomass, and for mature stands this value is in the range of 76-80 %. The contribution of roots in medium-aged stands is about 20 %, and in mature stands 14-16 %. Branches and needles account for about 6.5 and 5.5 %, respectively, and in mature stands - 4.5-6.0 and 1.5-1.8 %. Felling residues account for about 13 % in medium-aged stands, and about 9 % in mature stands. In medium-aged and mature stands, when felling with an intensity of 15-20 %, it takes about 10 years to restore the carbon pool to the pre-cutting level. Felling residues in quantities proportional to the intensity of logging remain at the logging sites, and the carbon deposited in these fractions is an integral part of the ecosystem pool. In order to obtain the greatest increase in the phytomass of pine stands and minimize carbon losses during felling, selective logging using modern technologies for clearing felling areas and processing logging waste is most appropriate. It is possible to increase carbon absorption and minimize carbon dioxide emissions during felling of forest care by determining the intensity of optimal thinning of the tree stand.

The experience of a long-term study of the population dynamics of phyllophagous insects in Krasnoturansky pine forest (the southern part of Krasnoyarsk Krai) is discussed in the paper. Over the course of 40 years (1978-2016), regular counts of the abundance of five species of phyllophages were carried out in five landscape structures. Based on the data obtained, models of population dynamics of these species were proposed. The models were based on the idea of the existence of positive and negative feedbacks in populations. This approach made it possible to ignore the impact of parasites on insects. For calculations, an autoregressive (AR) model was proposed, according to which the current density linearly depends on the densities of previous years. The model coefficients were calculated using data from long-term surveys. It has been shown that most populations are characterized by the influence of the density of the past season on the current density in the form of a positive feedback and the influence on the current density of the density of the previous season in the form of a negative feedback. The characteristics of the stability of population dynamics of individual species in various habitats are considered. Stability margin indicators, widely used in control theory, were used as stability characteristics. It has been shown that the margin of resistance for sawflies (Tenthredinidae Latreille) is slightly greater than for other groups of species, which is consistent with the smaller dispersion of the population sizes of these species during long-term censuses. The use of AR models and characteristics of the stock of stability made it possible to classify landscape structures on the territory of the Krasnoturansky forest according to the risks of outbreaks of mass reproduction in these landscapes.

A review of the contents, processes of writing and reconstitution from manuscript materials of V. P. Grechkin’s monograph «Lesopathological characterization of the forests of the USSR by separate natural and geographical zones» is presented. Edited by Yu. I. Gninenko. In 3 volumes. VNIILM, 2019-2021.