Caucasus Mountains Research Articles

Selected Active Galactic Nuclei from SRG/eROSITA Survey: Optical and IR Observations in 2021 and 2022 with the 2.5-m Telescope at the Caucasian Mountain Observatory of SAI MSU

Selected Active Galactic Nuclei from SRG/eROSITA Survey: Optical and IR Observations in 2021 and 2022 with the 2.5-m Telescope at the Caucasian Mountain Observatory of SAI MSU

The wool carder bee Pseudoanthidium alpinum (Morawitz, 1873): identity of the enigmatic type species of the genus Pseudoanthidium (Hymenoptera: Megachilidae: Anthidiini)

Pseudoanthidium Friese is a species-rich genus of wool carder bees (Anthidiini) in the Old World. Pseudoanthidium alpinum (Morawitz, 1873), originally described from the Caucasus Mountains, was chosen as the type species of the genus, although it was insufficiently known. A genetic analysis of the mitochondrial cytochrome c oxidase I (COI) gene (barcoding gene) of new material now allowed the unequivocal assignment of males and females to each other and proved the conspecifity of material from Spain, Greece and Georgia. It turned out that the males with their specialized hairs and combs on the metasomal sterna correspond to the characteristics of Pseudoanthidium s. str., but females with their fully exposed, protruding clypeal apex to the subgenus Royanthidium Pasteels, 1969. A similar combination of male and female characters was also found in three other species of Pseudoanthidium. As the protruding clypeal apex is thus found in both subgenera, this trait proves to be inappropriate for subgeneric classification and indicates that the definition of the subgenus Royanthidium needs to be revised.

Stable isotopes of oxygen and hydrogen in precipitation and river water in Georgia

Abstract The article presents the first comprehensive evaluation of the isotopic composition of precipitation and runoff in Georgia. It is based on data from the monitoring of δ18O and δ2H in monthly precipitation at eleven precipitation stations and monthly runoff from five large, mostly nested catchments in Georgia, collected between the years 2013 and 2022. The data represent different climatic and altitudinal conditions ranging from the wet western part of Georgia affected by the Black Sea to the dry eastern part of the county presumably affected also by the air masses from the Caspian Sea. Specific conditions affecting the isotopic composition of precipitation and river water seem to occur close to the main ridge of the Greater Caucasus Mountains. We defined the National Meteoric Water Line (NMWL) and the National River Water Line (NRWL) for Georgia as well as the Local Meteoric Water Lines (LMWLs) and River Water Lines (RWLs) for individual precipitation stations and river gauges and investigated their slopes and intercepts. Altitude gradients of δ18O and δ2H in the rivers were similar to those in precipitation (–0.16‰ and –1.2‰ per 100 m of altitude for δ18O and δ2H, respectively). The rivers were supplied from precipitation of the colder part of the year (November/December to March/April) while the isotopic composition of precipitation in the remaining warmer part of the year was clearly detached from that of the rivers. The isotopic signal in precipitation was dampened in the rivers by a factor of 5–6. The scaled line-conditioned excess (lc-excess*) did not indicate any significant deviations of river waters from meteorological conditions in the catchments.

Long-Term Trends of Astroclimatic Parameters above the Terskol Observatory

Astroclimatic conditions characterize the quality of an astronomical site. The Terskol Observatory was founded over 42 years ago in 1980. The astronomical site (coordinates 43°16′29″ N, 42°30′03″ E) is located about 10 km from Mt. Elbrus in the northern Caucasus Mountains. The paper presents the results of an analysis of long-term variations from 1980 to 2022 of astroclimatic parameters such as total cloud cover, precipitable water vapor, and wind speed at a level of 200 hPa above the Terskol Observatory using atmospheric ERA5 Reanalysis data from the European Center for Medium-Range Weather Forecast. The probability distributions and seasonal variations of the astroclimatic parameters are also presented. Long-term trends of the astroclimatic parameters are studied with statistically significant trend analysis methods using the Mann–Kendall test and the Sen’s slope test to estimate the magnitude of the changes. The results show non-significant decreases of annual average 200-hPa wind speed and increases in precipitable water vapor, but significant (99 per cent confidence level) long-term decreasing of total cloud cover above the Terskol Observatory.

Lopuh i imperskoe soznanie v povesti L.N. Tolstogo «Hadzhi-Murat»

Lev Tolstoy’s last novella Hadji Murat is set against the backdrop of the fierce war between Russia and the Caucasus Mountains' people in the mid-nineteenth century, and focuses on Murat's life after defection to Russia. Tolstoy explores the relationship between the burdock flower and Russian ethnic, historical, and cultural factors.

Genetic Structure of Aedes (Stegomyia) albopictus Populations in Russia.

Aedes (Stegomyia) albopictus was found for the first time in 2011 on the Black Sea coast in Russia, and during 2011-2019, the species expanded over two climate zones Cfa and Csa. Here, we studied the sequence diversity of the mitochondrial cytochrome c oxidase I (COI) gene, 1317-1433bp in length. In total, 131 specimens of Ae. albopictus sampled from 21 locations in Russia and Abkhazia were examined. Two of the six identified mitochondrial haplotypes were detected for the first time. Four COI haplotypes were shared by at least two studied local populations. The most prevalent H1 and H2 haplotypes dominated in all the sampled localities in the Cfa zone. The H3 haplotype was prevalent in the Csa zone. Other haplotypes were rare. Phylogenetic analyses, spatial isolation and limited gene flow revealed that the samples from the Csa zone differed significantly from those from the Cfa zone. Two spatially isolated genetic lineages exist in Ae. albopictus population in southern region of Russia. One lineage obtained on the seacoast and inland (in valleys of the Caucasus Mountains and steppe zone) is widely distributed worldwide including Mediterranean populations. This confirms the hypothesis that the emergence of Ae. albopictus population in southern region of Russia may be associated with the terrestrial spread of mosquitoes from the well-established European population due to human activity. The other lineage, discovered in Novorossiysk, a maritime port, is similar to Ae. albopictus from the USA and Japan, suggesting the independent introduction of these mosquitoes.

First record of Bacillicladium lobatum (Chaetothyriales) in Caucasus (second finding in the world)

First record of Bacillicladium lobatum (Chaetothyriales) in Caucasus (second finding in the world)

Regional Impact of Snow‐Darkening on Snow Pack and the Atmosphere During a Severe Saharan Dust Deposition Event in Eurasia

AbstractLight‐absorbing impurities such as mineral dust can play a major role in reducing the albedo of snow surfaces. Particularly in spring, deposited dust particles lead to increased snow melt and trigger further feedbacks at the land surface and in the atmosphere. Quantifying the extent of dust‐induced variations is difficult due to high variability in the spatial distribution of mineral dust and snow. We present an extension of a fully coupled atmospheric and land surface model system to address the impact of mineral dust on the snow albedo across Eurasia. We evaluated the short‐term effects of Saharan dust in a case study. To obtain robust results, we performed an ensemble simulation followed by statistical analysis. Mountainous regions showed a strong impact of dust deposition on snow depth. We found a mean significant reduction of −1.4 cm in the Caucasus Mountains after 1 week. However, areas with flat terrain near the snow line also showed strong effects despite lower dust concentrations. Here, the feedback to dust deposition was more pronounced as increase in surface temperature and air temperature. In the region surrounding the snow line, we found an average significant surface warming of 0.9 K after 1 week. This study shows that the impact of mineral dust deposition depends on several factors. Primarily, these are altitude, slope, snow depth, and snow cover fraction. Especially in complex terrain, it is therefore necessary to use fully coupled models to investigate the effects of mineral dust on snow pack and the atmosphere.

Contribution of microbial activity and vegetation cover to the spatial distribution of soil respiration in mountains.

The patterns of change in bioclimatic conditions determine the vegetation cover and soil properties along the altitudinal gradient. Together, these factors control the spatial variability of soil respiration (RS) in mountainous areas. The underlying mechanisms, which are poorly understood, shape the resulting surface CO2 flux in these ecosystems. We aimed to investigate the spatial variability of RS and its drivers on the northeastern slope of the Northwest Caucasus Mountains, Russia (1,260-2,480 m a.s.l.), in mixed, fir, and deciduous forests, as well as subalpine and alpine meadows. RS was measured simultaneously in each ecosystem at 12 randomly distributed points using the closed static chamber technique. After the measurements, topsoil samples (0-10 cm) were collected under each chamber (n = 60). Several soil physicochemical, microbial, and vegetation indices were assessed as potential drivers of RS. We tested two hypotheses: (i) the spatial variability of RS is higher in forests than in grasslands; and (ii) the spatial variability of RS in forests is mainly due to soil microbial activity, whereas in grasslands, it is mainly due to vegetation characteristics. Unexpectedly, RS variability was lower in forests than in grasslands, ranging from 1.3-6.5 versus 3.4-12.7 μmol CO2 m-1 s-1, respectively. Spatial variability of RS in forests was related to microbial functioning through chitinase activity (50% explained variance), whereas in grasslands it was related to vegetation structure, namely graminoid abundance (27% explained variance). Apparently, the chitinase dependence of RS variability in forests may be related to soil N limitation. This was confirmed by low N content and high C:N ratio compared to grassland soils. The greater sensitivity of grassland RS to vegetation structure may be related to the essential root C allocation for some grasses. Thus, the first hypothesis concerning the higher spatial variability of RS in forests than in grasslands was not confirmed, whereas the second hypothesis concerning the crucial role of soil microorganisms in forests and vegetation in grasslands as drivers of RS spatial variability was confirmed.

Culture — the brdge that could not be blown up

Not so long ago one of the main and traditional problems of Russia has been that culture was not considered to be a subject of political life. Before the bill "About Culture” each region in the country used to live in different cultural context and to understand aspects of culture in different manners. At the edges of 20th–21st cc. the understanding of the problems of Russia-Caucasian social and cultural communication actualized. North Caucasian region is a complicated system of very many cultures. It was a contact zone and at the same time a kind of a barrier among civilizations and empires in The Mediteranian region, South-Western Asia and Eastern Europe. The today culture of North Caucasian region has been formed as a result of the dialogue among Caucasian mountain, Islam and Russian civilizations and cultures, and also the processes of modernization during 20th-21-st centuries. The problem of preserving of cultural traditions is a central one in "ases of state culturally politics" (2014). Cultural bridges among the peoples and countries should be kept even in times of war conflicts and military actions.

The farther, the closer: geographic proximity and niche overlap versus genetic divergence in Caucasian rock lizards

Abstract Caucasian rock lizards (Darevskia) are a speciose group with 42 described species from the Caucasus Mountain region. We selected 11 species from Georgia and adjacent territories to explore whether their distribution depends on the distribution of congeneric taxa. We estimated two measures for each species pair: (1) niche overlap between all pairs of the studied species; (2) the extent of contact between the ranges of individual species. We then calculated the correlation between these measurements and the time of divergence between the species. The results showed that in sympatric and parapatric (but not allopatric) species, there is a highly significant correlation between the divergence time and the extent of the contact, as well as between the divergence time and the overlap of suitable habitats. The ranges of the evolutionarily closest species have the smallest extent of contact. Species separated later have overlapping ranges, although are separated by altitude. The most distant species, irrespective of their phenotype, are commonly found in the same location. We suggest that a gradual increase in the contact extent is compensated for by increasing the effectiveness of other mechanisms of niche shift or behavioural isolation and hence the frequency of potentially deleterious interspecific contacts is kept low.

Refinement of the motion model of the Linus satellite of the asteroid (22) Kalliope

The aim of this article is to analyze the dynamics of the Linus satellite of the asteroid (22) Kalliope. New results have been obtained, and now they are being published. New observations of the satellite were made at the Caucasus Mountain Observatory of the SAI from October 2021 to March 2022. The obtained astrometric results are presented in the article. Based on the updated set of observations, the parameters of the satellite’s orbit were re-determined. An increase in the accuracy of ephemeris with the addition of new observations is shown. A new attempt was made to determine the precession of the satellite’s orbit caused by the compression of a rapidly rotating asteroid. The goal was to determine the dynamic compression of the central body. The entire observation interval is divided into groups. From the observations of each group the position of the axis of the satellite’s orbit was found. Changing the position of the axis gives the desired precession. Studies on several examples show that the position of the axis from such groups of observations is determined very unreliably. The reason lies in the strong correlation between the determined parameters with limited observational accuracy. Ways of studying precession are outlined by joint determination of dynamic parameters on the basis of all available observations.

The Catalog of Resolved Spectroscopic Binaries: Development and Description

Resolved spectroscopic binaries are unique among other types of binaries. They provide the only possibility (aside from trigonometric parallaxes) to accurately determine distances to objects, which is one of the most important characteristics in astronomy. Such binaries are not numerous, but an exhaustive catalog of them still does not exist. The authors have developed a pilot version of a new catalog of resolved spectroscopic binaries. It contains information about orbital elements, component masses, parallaxes, and other parameters for 107 stars. Thus, the catalog represents the most extensive list of resolved spectroscopic binaries known to date. A preliminary analysis of the distributions of the stellar parameters of the objects in the catalog has been carried out, as well as a comparison of the trigonometric parallaxes from Gaia DR3 with the orbital parallaxes. The article is partly based on a report presented at the conference “Modern Stellar Astronomy-2022,” which was held at the Caucasian Mountain Observatory of the Astronomical institute of Lomonosov Moscow State University on November 8–10, 2022.

The Catalog of Resolved Spectroscopic Binaries: Development and Description

Resolved spectroscopic binaries are unique among other types of binaries. They provide the only possibility (aside from trigonometric parallaxes) to accurately determine distances to objects, which is one of the most important characteristics in astronomy. Such binaries are not numerous, but an exhaustive catalog of them still does not exist. The authors have developed a pilot version of a new catalog of resolved spectroscopic binaries. It contains information about orbital elements, component masses, parallaxes, and other parameters for 107 stars. Thus, the catalog represents the most extensive list of resolved spectroscopic binaries known to date. A preliminary analysis of the distributions of the stellar parameters of the objects in the catalog has been carried out, as well as a comparison of the trigonometric parallaxes from Gaia DR3 with the orbital parallaxes. The article is partly based on a report presented at the conference “Modern Stellar Astronomy-2022,” which was held at the Caucasian Mountain Observatory of the Astronomical institute of Lomonosov Moscow State University on November 8–10, 2022.

Mass Computations of the Brightness of Stars in an Arbitrary Spectral Band

The problem of calculating the brightness of an array of stars in an arbitrary photometric band, which is not the standard band of astronomical photometry, is considered from their multicolor photometry in some other photometric system. A similar problem is to transfer photometric measurements of stars from one multicolor photometric system to another. This task includes methods for calculating and comparing magnitudes, as well as merging photometric catalogs. The questions of choice of various zero-points of photometry and reduction of measurements for the atmosphere are considered. The issues of reducing the error of the proposed methods are discussed. The article is partly based on a report presented at the conference “Modern Stellar Astronomy-2022”, held at the Caucasian Mountain Observatory of the Sternberg State Astronomical Institute, Moscow State University, in November 8–10, 2022.

Evaluation of Leucopis hennigrata (Diptera: Chamaemyiidae) as a classical biological control agent of Adelges nordmannianae (Hemiptera: Adelgidae) in northern Europe

The silver fly Leucopis hennigrata McAlpine is a predator of the silver fir wooly adelgid, Adelges nordmannianae (Eckstein), a pest in the European production of Christmas trees. While the fly is known to be a common native predator of the adelgid in Georgia, Turkey, and central Europe, it is absent from northern Europe, where the Christmas tree production is an important industry. Therefore, L. hennigrata has been suggested as a classical biological control agent of Ad. nordmannianae in northern Europe. Here, we evaluated the fly’s suitability as a classical biological control agent in terms of (1) differences between Asian and European populations, (2) its abundance relative to other predators of Ad. nordmannianae, (3) larval feeding efficacy, as well as (4) the physiological and (5) ecological prey preference of the fly. The results showed that despite genetic divergence between Western Asian and Central European populations, L. hennigrata is a dominant natural enemy of Ad. nordmannianae in Switzerland, the Pontic mountains in northern Turkey, and in the Greater and Lesser Caucasus mountains. Larvae of L. hennigrata killed on average 57–117 eggs in 24 h, depending on their size, the number of eggs offered to them, and possibly some environmental factors. In no-choice tests, adult flies oviposited on twigs containing different non-target adelgid, aphid, and scale insect species. Larvae of L. hennigrata were observed to feed on several of them. However, only the non-target species Mindarus abietinus Koch supported development of a single specimen to the adult stage. During field surveys in Switzerland and Georgia, L. hennigrata was never found on any sampled non-target species. Based on our findings, we conclude that L. hennigrata is a suitable classical biological control agent because it (1) is already present in countries that neighbor northern Europe, (2) is a dominant natural enemy of the pest in Switzerland, (3) is an efficient predator of the pest’s eggs, and (4) seems to be specific to Ad. nordmannianae in its ecological range.

Spectroscopic searches for evolutionary orbital period changes in WR + OB binaries: the case of CQ Cep and CX Cep

ABSTRACT We present the results of spectroscopic observations of two eclipsing WR + OB-type systems – CQ Cep and CX Cep – performed in 2020–2023 with a low-resolution slit spectrograph TDS (λλ = 3660–7410 Å, R = 1300–2500) on 2.5-m telescope of the SAI MSU Caucasian Mountain Observatory. For CQ Cep, the radial velocity curves of a WN6 star are constructed, the problem of visibility of spectroscopic traces of an OB star is discussed, and the components’ mass ratio q ∼ 0.6 is estimated. For CX Cep, the radial velocity curves are constructed for both the WN5 and O5 components enabling their masses and circular orbit elements to be refined. The comparison of the radial velocity curves of these systems obtained in different epochs allowed us to derive the orbital period change rate $\dot{P}$ by the spectroscopic method, which is found to be in good agreement with estimates obtained by comparing the moments of primary eclipse minima: $\dot{P} = -0.0151\pm 0.0013$ s yr−1 for CQ Cep and $\dot{P} = 0.054\pm 0.009$ s yr−1 for CX Cep. The prospects of applicability of the spectroscopic dynamical method for studying the orbital evolution of Galactic WR + OB binaries and related objects are considered. We also discuss the effect of finite sizes of stars with stellar wind mass-loss in close binary systems on their orbital evolution.

The Eurasian shrew and vole tick Ixodes trianguliceps: geographical distribution, climate preference, and pathogens detected

The Eurasian shrew and vole tick Ixodes trianguliceps Birula lives in the nests and burrows of its small mammalian hosts and is—along with larvae and nymphs of Ixodes ricinus or Ixodes persulcatus—one of the most commonly collected tick species from these hosts in its Eurasian range. Ixodes trianguliceps is a proven vector of Babesia microti. In this study, up-to-date maps depicting the geographical distribution and the climate preference of I. trianguliceps are presented. A dataset was compiled, resulting in 1161 georeferenced locations in Eurasia. This data set covers the entire range of I. trianguliceps for the first time. The distribution area between 8^circ W–105^circ E and 40–69^circ N extends from Northern Spain to Western Siberia. To investigate the climate adaptation of I. trianguliceps, the georeferenced locations were superimposed on a high-resolution map of the Köppen–Geiger climate classification. The Köppen profile for I. trianguliceps, i.e., a frequency distribution of the tick occurrence under different climates, shows two peaks related to the following climates: warm temperate with precipitation all year round (Cfb), and boreal with warm or cold summers and precipitation all year round (Dfb, Dfc). Almost 97% of all known I. trianguliceps locations are related to these climates. Thus, I. trianguliceps prefers climates with warm or cold summers without dry periods. Cold winters do not limit the distribution of this nidicolous tick species, which has been recorded in the European Alps and the Caucasus Mountains up to altitudes of 2400 m. Conversely, I. trianguliceps does not occur in the Mediterranean area with its hot and dry summers.

Preservation of the Alanian cultural heritage in the context of globalization

The article deals with the problems of preserving the Ossetian cultural heritage in the context of globalization. The purpose of this article is to analyze the main challenges to the Ossetian culture and practical recommendations aimed at preserving it. Special attention is given to the objects of cultural and natural heritage located in the territories of both North Ossetia-Alania and the Republic of South Ossetia. The methodology is based on a generalization of empirical data and comparative analysis related to cultural heritage in a state that does not have a generally recognized status. Particular importance is attached to a number of important documentary sources, in particular, UNESCO conventions and declarations, along with expert assessments. The novelty of the study is due to considering, indeed, for the first time, the problem of cooperation between the international organization that deals with the preservation of cultural heritage on the global scale, viz. UNESCO, and the state only partially recognized. The author comes to the conclusion that the Ossetian culture, on the whole, successfully resists the challenges of globalization: the national way of life, language and traditions are preserved despite the division of the ethnos by the Caucasus mountain range. However, there is a problem of preserving tangible cultural heritage on the territory of South Ossetia due to existing geopolitical situation that has resulted in the republic remaining underrepresented on the international platforms.

Comparison of Instabilities of Annular Perturbations on the Background of Pulsating 2D and 3D Self-Gravitating Models

The problem of gravitational instability of the observed annular (ring-like) structural perturbation modes on the background of a nonlinearly pulsating spherical model based on the well-known equilibrium Camm ball is studied. Nonstationary analogues of dispersion relations for the perturbation modes under consideration within this model are obtained. Critical diagrams of the initial virial ratio versus the model rotation parameter are constructed for each case. A comparative analysis of the increments of gravitational instability of annular perturbation modes on the background of spherical and disk-shaped nonlinearly pulsating models is also performed. An analysis of the results shows that the annular perturbation modes are predominantly more unstable in a nonstationary disk than in a spherical nonequilibrium model, regardless of the rotation parameters and the initial virial ratio of the systems. The article is partly based on a report presented at the conference “Modern Stellar Astronomy-2022” held at the Caucasian Mountain Observatory of the Sternberg Astronomical Institute of Lomonosov Moscow State University, November 8–10, 2022.