Home – Home – Jornals – Contemporary Problems of Ecology 2025 number 1

As a result of a spill and leakage of diesel fuel from storage tanks in Norilsk, oil products entered adjacent water bodies, reaching Lake Pyasino. The objects of the study were nesting and migrating geese, their organs and tissues. An aerial survey was conducted in 2021-2023, and counts in aggregations were made using photographs. For monitoring and establishment of sampling sites, the territory was divided into 4606 squares (1 km²), of which 1205 sites (149 impact sites and 1056 control sites) were identified. After their ranking and species richness analysis, 5 most contaminated and 7 control sites were identified. Nesting birds showed the greatest changes in liver, lungs and heart. Brown-colored foreign particles were present in the blood, diffusely distributed throughout the circulatory system and noted in the blood in all organs under study. At the same time in all groups of birds a pronounced invasion in the organs under study was detected. The studied birds showed disorders of hematopoiesis, venous hemorrhage, edema and hemorrhages in lungs, bronchopneumonia, hypertrophy of cardiomyocytes, fatty dystrophies in parenchyma, focal necroses in liver. The presence of brown-colored foreign particles was observed in the blood. With prolonged exposure to a toxicant there is a transition of the organism from a stress state to a shock state. In this case, free kinins, which are vasoactive polypeptides, play a significant role. Thus, after chronic exposure to petroleum products, pronounced pathologies of internal organs characterized by disorders of hepatobiliary, cardiovascular and respiratory systems were observed. The hypothesis that oil product spills during accidents, as well as their residual presence after territory cleanup are toxic for both nesting and migratory birds of the wetland complex was confirmed. However, pathohistological changes in the liver, lungs and heart are more pronounced in nesting species.

Fire-derived charcoal (charcoal) is a common product of post-fire forest ecosystems. Its role in a litter decomposition is still poorly understood, even less is known about the relationship between charcoal and soil fauna. In a field “litterbag” experiment using physical exclusion of fauna by means of mesh different sizes, the influence of charcoal on microbial activity indices at the early stage of oak leaf decomposition in conditions of faunal community complexity was studied. The response of microorganisms to charcoal addition and faunal community complexity was evaluated using the substrate-induced respiration method in terms of microbial respiration coefficient (BR/SIR) (basal respiration / substrate-induced respiration), microbial metabolic coefficient (qCO₂), and microbial biomass carbon (M_BC). When the faunal community complexity increased from microfauna to mesofauna, regardless of the presence of charcoal, microbial biomass increased by 40 %. In the control treatment, a 21 % decrease in qCO₂ and BR/SIR was observed with access of mesofauna compared to access of microfauna alone. In the charcoal treatment, the decrease in qCO₂ and BR/SIR in the presence of mesofauna was twice as pronounced and amounted to 44 % (p < 0.05), and an acceleration of mass loss by 17 % was also observed. In our study, the decrease in qCO₂ in the presence of mesofauna and its even greater decrease in the charcoal-mesofauna treatment were due to an increase in microbial biomass, but not to an increase in BR. Further complication of the faunal community (access of macrofauna) did not lead to significant changes in microbial activity indices irrespective of charcoal adding.

The paper aims at the dynamics of vegetation and soil properties formed by the primary succession (for about 30 years) in the middle taiga subzone of the European North-East of Russia. By the end of the third decade, the post-technogenic territory practically finished the process of grass-to-forest community replacement with the formation of a dense tree layer, development of soil ground cover dominated with forest and forest edge species. Forest ecosystem means differentiation of separate groups of woody plants (parcels) with the formation of litter: deciduous-coniferous litter in pine parcel and deciduous-grass litter in birch parcel. The grass-to-forest community replacement is accompanied by transition from humus-impregnated humus pelozems to eluviated humic- impregnated pelozems. At the tree stand development stage, soil morphological structure and chemical properties are determined by the parcel structure of forest community. Differences in C_org. and content of biogenic elements in litter and organic-mineral soil horizon are caused by different composition of plant communities in parcels and, consequently, different mineralisation rates of plant residues. By the end of the third succession decade, the upper 0-20-cm soil layer accumulates up to 24.5 t organic carbon /ha in pine parcel and 28.7 t organic carbon/ha in birch parcel.

Our aim was to investigate levels of biologically active compounds and antiradical activity in water-ethanol extracts from the leaves of Siberian species of the genus Caragana [ C. spinosa (L.) DC., C. arborescens Lam., C. bungei Ledeb., C. microphylla (Pall.) Lam., C. frutex (L.) C. Koch, and C. pygmaea (L.) DC.] as a source of medicinal raw material and for chemotaxonomy of these species. The profile of biologically active compounds and antiradical activity of C. frutex are reported for the first time. The leaves of C. spinosa have a high content of catechins (4.88 mg/g). It was shown that the highest concentration of secondary metabolites (tannins, flavonols, and saponins) and high antiradical activity are present in forest-steppe species: C. frutex and C. arborescens . Among all the assayed populations, the highest variation was observed for catechins, and the lowest for saponins. High interpopulation variation of biochemical traits in C. pygmaea was noted (coefficients of variation (%): catechins 119.91, flavonols 74.19, tannins 44.45, and saponins 44.09). Among the analyzed Caragana populations, a correlation was demonstrated between the antiradical activity and levels flavonols (r = -0.61), tannins (r = -0.52), and saponins (r = -0.51). The chlorophyll a /chlorophyll b ratio ranged from 2.3 to 3.8 among the populations, with a median value of 3.0, indicating near-optimal conditions for plant growth. Correlation analysis revealed a positive association between total chlorophyll and carotenoid levels (r = 0.64). The level of pectins among the studied Caragana species varied from 0.7 to 21.7 mg/g, and that of protopectins from 9.0 to 114.0 mg/g. The present paper illustrates substantial antioxidant potential of water-ethanol extracts from Caragana leaves, consistently with high concentrations of phenolic compounds and saponins, and this association was confirmed by correlation analysis. Our results point to potential uses of Siberian Caragana species in nutraceutical and pharmaceutical products and thus offer good industrial applications.

As a result of many years of research in the Barabinsk forest-steppe, the peculiarities of ecology and biology of the damselfly Enallagma cyathigerum were revealed. The species lives in all permanent reservoirs - rivers, river channels, lakes and ponds, where its most numerous populations have been identified, and also inhabits temporary reservoirs, surviving in them during periods of drying out due to the egg phase. Biotopic preferences were found in the choice of habitat: the larvae live only in non-reed hydrocenoses, which is associated with the ecological standards of the species. In the last 20 years, there has been a decrease in the number of E. cyathigerum, despite the increase in humidity in the region, which we associate with the consequences of climate warming - weather disasters in the summer, an increase in air temperature and, accordingly, water in reservoirs, leading to a deterioration in the hydrology of reservoirs and suffocation of aquatic organisms. A study of the development of E. cyathigerum on Kargat River and Fadikha Lake in 2004-2006 revealed a one-year life cycle of a species that has a different population structure on a river and lake associated with their different hydrological and temperature regimes. The species population on the Kargat River was unified in all 3 years, on Lake Fadikha in high-water 2004 it was unified, and in low-water 2006 it was divided into 2 seasonal groups - summer with wintering larvae and summer-autumn with wintering eggs. Such a complication of the population structure on Lake Fadikha in 2006 was the result of an increase in water temperature (as a result of an increase in the average daily air temperature and a decrease in the water level in the lake), and is a kind of “adjustment” of the species to the deterioration of habitat conditions in the low-water period: eggs are present in the lake almost all year round (wintering and non-wintering) and the larvae have different ages, and imagoes fly on land from spring to autumn. This adaptive feature of E. cyathigerum may partly explain its relatively high abundance, eurybiont and large range - almost the entire Palearctic.

Based on the results of computer modeling of the Altai-Sayan endemic species Euphorbia pilosa L. (Euphorbiaceae) distribution in Western Siberia, where the main part of its range is located, areas of accumulation of species registration points were identified that largely coincide with the climatic optima of the forecast model. A set of variables with a high contribution to the forecast model was established, including the long-term average monthly precipitation in August (14.1 %), the amount of precipitation in October (13.4 %), the seasonality of surface air temperature (11.4 %) and the long-term average monthly precipitation in May (10.7 %). The contribution of climatic variables characterizing the amount of precipitation significantly, more than twice, exceeds the contribution of climatic variables characterizing surface air temperature. In contrast, the total contribution of bioclimatic indicators is noticeably, more than 1.5 times, higher for air temperature indicators than for precipitation indicators (18.7 % versus 8.6 %). According to the forecast model, one of the well-defined climatic optimums is located at the northern limit of the species distribution in Western Siberia, in the vicinity of Tomsk. To identify the ecological features of the range within the Tomsk climatic optimum, a model site characterized by the highest predicted values of the probability of the species presence was selected. Using the method of latitudinal and longitudinal bands, sites with a relatively high number of species registration points were identified, and sites with the most favorable climate were determined based on the values of the probability of the species presence indicator. The obtained results are correlated with the possible impact of anthropogenic load within the boundaries of the Tomsk urban agglomeration, where deforestation in areas allocated for gardening associations and societies, construction of linear suburban and suburban infrastructure facilities (highways, railways, etc.) leads to changes of the phytocenotic confinement of the species and fragmentation of parts of its range at the northern limit of distribution in Western Siberia.

The influence of ground lichens Flavocetraria cucullata and Certraria laevigata on chemical, biochemical and microbiological characteristics of permafrost soils of Central Yakutia was studied. It was revealed that the values of the content of organic carbon, exchangeable cations and anions, and pH did not depend on the presence or absence of lichens on the soil surface. It was revealed that the main secondary metabolites of F. cucullata were usnic, lichesteric, protolichesteric and allo-protolichesteric acids, and C. laevigata - fumarprotocetraric acid. Chromatographic analysis of soils revealed the presence of only usnic acid in humus samples under F. cucullata and adjacent areas without vegetation. It was shown that as F. cucullata moved away from the place of growth, there was a decrease in the content of usnic acid and an increase in the content of specific compounds that could be biomarkers of fungi in the soil. Analysis of fungi and bacteria in soils, performed using the cultural approach, showed an abundance of fast-growing micromycetes and bacteria. According to the metagenomic analysis, the taxonomic diversity of fungi in soils was incomparably higher than according to the cultural studies, and mycorrhizal basidiomycetes were the predominant ecological group. Ectomycorrhizal basidiomycetes are primarily susceptible to the effect of lichen F. cucullata. The allelopathic effect of C. laevigata on the soil microbiome is much less pronounced. It is assumed that usnic acid synthesized by F. cucullata diffusely spreads and accumulates in the soil, selectively suppressing the growth of ectomycorrhizal basidiomycetes.

The state of urban forests of natural origin, which is the most important component of improving the ecological environment of a large city (Irkutsk, Eastern Siberia), has been studied. The condition of forests was assessed based on a set of parameters of trees, soil, and herbaceous cover. The impact of aerotechnogenic pollution on forests is shown, it was determined by the accumulation of heavy metals in the assimilation organs of forest-forming species (Pinus sylvestris, Larix sibirica, Betula pendula) and horizons of soil profiles, as well as by the amount of suspended particles of solid aerosol (Particulate Matter, PMx) adsorbed by needles/leaves. The degree of recreational load in urban forests was judged by the violation of the morphological, physical and pedochemical properties of the forest litter and upper soil horizons. A number of negative changes in the parameters of trees have been identified - the level of crown defoliation can reach 50-65 %; the photosynthetic volume of the crowns decreases by more than 2 times; photosynthesis productivity decreases (maximum) by 35-48 % compared to the background; other physiological and biochemical parameters of pine, larch, and birch also change. The herbaceous cover in the forests is sparse, the projective cover averages 60 %, the share of ruderal species averages 44 %. Negative processes were also found in the soil - destruction of forest litter, decrease in aeration, moisture content, violation of acid-base, cation exchange, humification properties. The results indicate that most of the surveyed urban forests are polluted and subjected to recreational pressure. When summarizing the data obtained from field and laboratory studies, a complex of correlating highly sensitive indicators characterizing the state of urban forest biogeocenoses was identified.

The results of an anatomical description of a cross section of a shoot of Juniperus oblonga M.Bieb are presented., affected by Arceuthobium oxycedri. The anatomical structure of a healthy shoot of J. oblonga was compared with the description of the stem of J. communis L. according to literature data, and distinctive features in the structure were noted. It was noted that shoots of J. oblonga are affected by A. oxycedri up to 12 years of age. The depth of penetration of the haustorium depends on the age of the affected shoot; when young shoots are affected, the connection of the haustorium with the xylem is detected up to the perimedullary part of the pith. The haustorium is pointed towards the center of the stem and expanded towards the crustal part and joins the xylem obliquely towards the apex of the stem. At the base of the arceutobium shoot, at the site of its penetration into the juniper bark, “root cups” are formed. n the shoots of J. oblonga affected by A. oxycedri, in the places of penetration of haustoria, the shoot xylem grows, which is the result of activation and synchronization of the work of the cambium of the host plant and the haustorium of the semi-parasite. The growth of xylem occurs due to an increase in the number of layers of the early spring part of the xylem of the stem. The connection of the xylem and phloem of the juniper stem with the conducting system of the hemiparasite is carried out through disjunctive fragments of the haustorium. Each above-ground shoot of Arceutobium has its own haustorial system, not connected with other shoots, which enters the bark part of the stem and rests on the “root cup”. By eight to twelve years of life of the juniper stem, the ectophytic part of the semi-parasite system is destroyed, only “root cups” remain on the surface of the juniper bark, and excessive thickening of the shoot stops.