Home – Home – Jornals – Contemporary Problems of Ecology 2022 number 1

The relationship between climate warming and processes occurring in communities and populations of terrestrial small mammals, reptiles, amphibians, and arthropods is considered. The studies were conduct-ed at the Yenisei ecological station “Mirnoe” of the A. N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences. The dynamics of climatic changes are shown on the basis of data from seven weather stations located along an almost thousand-kilometer stretch of the Yenisei River valley. The maximum temperature increase for the period from 1972 to 2020 was noted in the spring months, and the more northern the station is, the stronger these changes are manifested. In the XXI century cyclic type of small mammal population dynamics, which was noted for this area earlier, changed to fluctuating one. The number of small mammals in tenth century was lower than in XX century. At the same time, a significant decrease was noted mainly for species whose origin is connected with Siberia. Some new species were recorded for the first time in the territory of the Yenisei ecological station. The banc vole (<i>Clethrionomys glareolus</i>) and the taiga mite (<i>Ixodes persulcatus</i>) appeared on the right bank of the Yenisei, and the gray toad (<i>Bufo bufo</i>) appeared on both banks.

The results of continuous monitoring of the Naroch lakes system, which includes eutrophic Lake Batorino, mesotrophic Lake Myastro and oligo-mesotrophic Lake Naroch, were used to study the question of what factors most affect the long-term dynamics of the state of the lake ecosystem that is under variable load of biogenic elements. The set of continuous series of seasonal mean values of eight parameters of each ecosystem for 1978-2015 was analyzed by methods of singular spectrum analysis (SSA) and principal component analysis (PCA). The third principal component (F3) which contributed 8,2 %, 9,8 % and 13,3 % respectively to the dynamics of ecosystems of Lake Batorino, Myastro and Naroch turned out to be connected with biomasses of phyto- and zooplankton, as well as with the parameters characterizing processes of destruction and biochemical decomposition of organic matter. Comparison of statistical relationships and periods of the dominant cyclic components of the principal components F3 and associated parameters of ecosystems allowed us to conclude that the interpretation of the third main factor under conditions of variable load of biogenic elements depends on the characteristics of a particular ecosystem. For ecosystems that are not deficient in nutrients, it can be interpreted as the transfer of created primary organic matter to consumers of the next trophic level, related to the structure of the food chain in the ecosystem. For an ecosystem in which the process of primary production formation is limited by the available amount of nutrients, it is this available amount of nutrients that is the third main factor affecting its long-term dynamics.

The succession of bird communities in the hemiboreal forests of the Eastern upper Volga region was traced by the method of multidimensional nonmetric scaling (nMDS).Comparison of data on the species composition and bird population density of managed forests, intact forests, and forest reserves. Analysis of the impact of natural and anthropogenic disturbances of various intensity on common and rare species, as well on the stability of hemiboreal ornithocenoses in space and time.

The population of spiders in the intermontane depressions of Southeastern Altai and Tuva was studied using a numerical approach. It has been established that the population is very small in number and taxonomically poor. On the catenas of the Chuya Hollow, subarid species predominated, while in the Kurai Hollow, located in the valley of the large Chuya River, polyzonal species predominated. In Tuva, the driest conditions of the catena on the Tannu-Ola ridge (Uvs-Nur depression, western sector) determined the predominance of subarid faunal elements, as in the Chuya depression. For the same reason, these two catenas were distinguished by the largest proportion of representatives of the Central Palaearctic fauna. On the catenas near lakes Khadyn (Ulug-Khem depression) and Tore-Khol (Uvs-Nur depression, eastern sector), where accumulative positions were characterized by high humidity, the share of subboreal humid species was high. Western Palaearctic species predominated on the catenas in the Kurai steppe and near Lake Khadyn. On the catena near Lake Tore-Khol, there is no dominance of species with any one longitudinal type of range. The dynamic density of spiders was usually highest in the lower catena positions. Under extremely arid conditions, at all catena positions in the Chuya and Uvs-Nur (Tannu-Ola) depressions, the maximum dynamic density was noted at the uppermost positions. The spiders belonging to the families Lycosidae and Gnaphosidae are the most numerous and diverse in the population of spiders in the mountain basins of Southeastern Altai and Tuva. In the isolated conditions of individual hollows, specific spider faunas are formed. Only the transit and accumulative positions on the catena in the Kurai depression are similar in terms of population structure.

The aim of this study is to identify ecological and phytocenotic features and factors of differentiation of plant communities with Heracleum sosnowskyi Manden. in the Kursk region. This region is located on the southern border of the secondary area of this species in the European part of Russia. Plant communi-ties with Heracleum sosnowskyi in the study area are represented by 4 syntaxons. To identify of ecological patterns of their organization, we used the analysis of the composition of differential species and species with the greatest activity, the identification of differences in the ecological regimes of their habitats, and the ordination analysis of relevйs. Each syntaxon differs from the others in a number of environmental factors and is characterized by a group of species with similar environmental requirements. Рredominance of ruderal and eurytopic species in communities and increase of similarity of their floristic composition are manifestations of the negative impact of the distribution of Heracleum sosnowskyi on the vegetation cover. The greatest similarity of coenofloras is found between the derivative communities Heracleum sosnowskyi [Agropyretalia intermedio – repentis] and the association Urtico dioicae – Heracleetum sosnowskyi. Their phytocoenoses represent successive stages of vegetation cover change under the influence of the invader. As a result of the spread of hogweed, the strongest changes occurred in the aboriginal communities, in place of which the phytocenoses of these syntaxons were formed. In communities where Heracleum sosnowskyi forms variants of associations Rudbeckio laciniatae – Solidaginetum canadensis and Chelidonio – Aceretum negundi, the floristic composition and ecological conditions changed slightly compared to typical communities of these syntaxons due to the presence of other invasive species.

The round goby is a small demersal fish considered one of the top invasive fish species. Having settled far beyond its native Ponto-Caspian region, the round goby currently inhabit the basins of the Baltic and North Seas, as well as the Great Lakes of North America. Since 2005, the species has been increasingly occurred in the eastern part of the Baltic Sea - the Gulf of Finland, where one of its northernmost populations was founded. The study is focused on studying the morphological differentiation of the round goby from geographically distant parts of the Gulf of Finland in order to assess the heterogeneity of this population and to suggest the most probable ways of the species penetration and dispersal there. Four samples were compared in 5 meristic and 35 morphometric traits. The traits characterized the number of finrays and rows of scales along the body, the shape of the body and head, and the position and shape of the fins. The comparison was carried out using indices, parametric and nonparametric tests, factorial, cluster analysis and multivariate scaling. Round goby samples collected at a distance of 40 to 270 km significantly differed in body shape, position and size of fins, while other characters were less prominently different between locations. The round goby from the western part of the gulf was the most different from goby of its eastern part, where morphological differentiation between locations was also observed. The results of the study assume the existence of separate round goby populations in the Gulf of Finland, with development of morphological features, associated with local habitat conditions, and the limited migrations of the species within the gulf. On the basis of the results obtained, we suggested independent introduction of the round goby into the western and eastern parts of the Gulf of Finland of the Baltic Sea.

The effect of PEG‑induced drought on the growth, the efficiency of photosystems I and II, and the
accumulation of proline, sodium and potassium ions in plant shoots of two populations of the intermediate
C3-C4 xerohalophyte Sedobassia sedoides was studied. The heterogeneity of plant response to osmotic stress
was revealed, both between populations and within each of them. The relationshi ps between the factors involved
in the adaptive mechanisms of plants from different populations under osmotic stress was determined.
Presumably, the intraspecific variability of S. sedoides plants in the mechanisms of drought tolerance is
associated with the different expression of the C4 photosynthetic syndrome in different populations and soil
conditions, in particular, with the water-salt balance of soil.

This study was conducted to examine the diversity and community structure of saproxylic beetles inhabiting silver birch ( Betula pendula Roth) in the State Nature Reserve “Voroninsky”. Beetles were caught using interception traps that were located on the trunks of birch trees in different decomposition stages. The result of this study showed that a total 1806 individuals of saproxylic beetles, belonging to 96 species and 37 families were sampled. The largest number of species is found in the families Staphylinidae, Tenebrionidae and Mycetophagidae. The largest number of specimens is found in the families Throscidae, Tenebrionidae, Staphylinidae, Lycidae, and Pyrochroidae. Most of the species are facultative inhabitants of the birch tree and are able to develop on other types of trees. More than a third of all the collected specimens belong to six species Lygistopterus sanguineus , Aulonothroscus brevicollis , Schizotus pectinicornis , Mycetochara flavipes , Trixagus dermestoides and Mesosa myops . The species composition and trophic structure of the complex of beetles at different stages of wood decomposition in the surveyed habitat is characterized by high similarity, but the distribution of species and quantitative abundance at different destruction stages differ. In general, complexes of saproxylic beetles at decomposition stages II and III are more taxonomically diverse, which shows the importance of dead wood for maintaining the species diversity of forest communities. Almost all trophic groups were observed at all decomposition stages, only necrophagous ones were found at decomposition stage III. In terms of species and number abundance, mycetophagous ones prevail at all decomposition stages, saproxylophagous ones take a noticeable part in the composition of the complex at the last decomposition stages. The dominant complex includes both mycetophages and saproxylophages ones. The composition of the dominant complexes of different habitats differs at stage I of wood destruction. The analysis reveals connectedness in time to certain stages of wood destruction in 37 species and 5 families. The least pronounced connectedness is at decomposition stage I; the subsequent decomposition stages are preferred by a greater number of species.

Comparative analysis of the size-mass and biochemical parameters (total lipid content and their fractional and fatty acid composition) of eggs of wild and cultured producers of the Ob muksun showed significant differences between them. Wild eggs is characterized by smaller size (by 7 %) and weight (by 15 %), higher fat content (by 13 %) and the level of diacylglycerols (by 33 %), and lower phospholipid content (by 30 %) in comparison with factory eggs. At the same time, factory eggs differs from wild eggs by a higher level of physiologically significant docosahexaenoic 22:6n-3 (1.8 times) and linoleic 18:2n-6 (7.1 times) acids, but a relatively lower level of eicosapentaenoic 20:5n-3 (in 1.5 times) and arachidonic 20:4n-6 (4.2 times), respectively. Such changes in the fatty acid status led to a decrease in the commercial eggs of n-3/n-6 ratio (by 52 %), palmitic 16:0/ oleic 18:1n-9 (32 %) and α-linolenic 18:3n-3/18:2n-6 (by 45 %), and to an increase of 22:6n-3/20:5n-3 (by 63 %). In addition, in the eggs of factory muksun, 68 % of the total lipids are 4 acids - 16:0, 18:1n-9, 22:6n-3 and 18:2n-6, in wild eggs the share of these acids was 47 %. The established differences in the size-mass parameters, the total lipid content and their fractional and fatty acid composition of wild and hatchery eggs of the Ob muksun are most likely associated with a different diet and habitat conditions of the sexually mature fish in captivity and nature.

Trophic position of fish is one of the most important factors controlling the accumulation of potentially toxic elements and compounds in fish tissues, primarily via the spectrum of fish nutrition. In this study, the content of potentially toxic transition metals (Cu, Zn, Mn, Pb, Cd) and radiocesium (¹³⁷Cs) in the edible tissues (muscles and liver) of two representatives of the fish-eating ichthyofauna of the Yenisei River, northern pike ( Esox lucius ) and burbot ( Lota lota ), have been comparatively studied relatively to the size of the fish. A significant decrease in the content of radiocesium and zinc in the muscles of pike, and zinc in the liver of pike with an increase in body size was recorded in juvenile pikes with a body weight ( W ) of less than 0.35 kg. For larger sexually mature pikes, no significant size dependences of the accumulation of metals in tissues were found. A positive correlation was found between the content of ¹³⁷Cs, Cu, Zn and Mn in muscles and the size of burbot in the W range from 0.42 to 1.62 kg. The tissues of one-sized burbots and pikes significantly ( p < 0.05) differed in the concentration of metals in their tissues: concentrations of Zn and Mn were 1.6-2.2 times higher in muscle of burbot; concentration of Pb was 1.8 times higher in muscle of pike; Cu was twice higher in liver of burbot; Zn and Mn were 4.7 and 1.6 times higher in liver of pike, respectively. The revealed differences may be due to the differing food spectra of pike and burbot. Concentrations of Cu, Zn, and Mn in liver of pike were 3-7 times higher than in muscle; concentration of Cu in liver of burbot was 5 times higher than in muscle. Pb and Cd tended to be higher in liver than muscle for both fish species. Despite the revealed size-dependences, the concentrations of potentially toxic metals and radiocesium in the muscles and liver of fish were below the permissible concentrations for food. The results obtained can be used to assess environmental risks for the population consuming fish, as well as to plan long-term environmental monitoring of rivers using representatives of fish-eating fish fauna.