Home – Home – Jornals – Contemporary Problems of Ecology 2021 number 1

Climatic fluctuations are among the most important factors causing changes in terrestrial and aquatic ecosystems. The review considers the main mechanisms of the influence of climate change on the structure and functioning of ecosystems of water bodies and shows the need to consider these mechanisms when developing a strategy for the conservation of biological resources of aquatic ecosystems. Climatic fluctuations affect aquatic ecosystems through changes in temperature, surface runoff of nutrients and other substances and their relationships, the intensity of water mixing during the circulation period and other mechanisms. Additional nutrients that come in rainy periods from the catchment and directly with precipitation stimulate the development of primary producers and cause the risk of further eutrophication of water bodies. An increase in temperature promotes the development of potentially toxic phytoplankton species and exacerbates the problem of “green tides,” the massive development of multicellular algae in the coastal zone. Organic substances coming from the catchment area during wet periods stimulate a “microbial loop” in aquatic ecosystems. In shallow lakes, climate fluctuations can cause food web dynamics and a change in ecological regime. Climate-induced changes in the composition of producer communities often lead to weakened pelagic-benthic relationships in aquatic ecosystems. Climate-induced changes in the composition of phytoplankton often lead to weakening of pelagic-benthic coupling in aquatic ecosystems. In some cases, climate change has contributed to invasions of alien species. The natural dynamics of ecosystems due to climate fluctuations deserve close attention and require the development of special adaptive management of aquatic biological resources. In some cases, it is necessary to apply more severe measures for the protection and restoration of water bodies, which would take into account adverse changes in the natural background that occur with long-term changes in natural factors.

Results of continuous monitoring of the Naroch lake system, which include the eutrophic lake Batorino, mesotrophic lake Myastro and oligo-mesotrophic lake Naroch, had been used to study the question of what factors most affect the long-term dynamics of the lake ecosystem, which are under a variable nutrient loading. The set of continuous series of average seasonal values of eight parameters from each ecosystem in 1978-2015 was analyzed using the methods SSA and PCA. The second principal component (F2), which contribution to the dynamics of lake ecosystems Myastro, Batorino and Naroch were 15.3 %, 20.5 % and 22.1 %, respectively, was associated with only three parameters that reflect the processes of formation and decomposition of organic matter. Comparison of the periods of the dominant cyclical components of the principal component F2 and related ecosystem parameters allowed us to interpret the second main factor behind these components as the activity of solar radiation.

The article presents the results of study species and trophic structure of macrozoobenthos community in the littoral zone mesotrophic Obsterno Lake (Republic of Belarus) having different macrophyte beds ( Chara , reeds, lily). The results of ANOVA shown the influence of studied biotopes on the number of species and Shennon index. The number of species increased from summer to autumn, but Shennon index was minimal in the middle of summer. The significant differences in species abundance between biotopes obtained for oligochaetes, chironomids, active filter feeders, and predators. There no differences for Ephemeroptera and Trichoptera . The mean values of species similarity for the studied period were 68.9, 74.1, and 70.0 percent for reeds, lily, and Chara , respectively. The trophic similarity between groups were 66.3, 54.1, and 69.7 percent. The significant differences between species and trophic similarity pointed out only for the lily beds. The values of variability species structure during studied period are higher than trophic structure, i. e. trophic structure is more stable to compare with species stru

The body shape variability of perch populations in the mountain and semi-mountain reaches of the Loz’va river basin and adjacent lakes Prostaptur and Elesinskoe (Northern Urals) was investigated by geometric morphometrics using box truss method. 23 distances between homologous landmarks were used to describe the body shape variability of fish. About 33 % of the total shape variance in perch is due to the perch inhabiting the gradient of the locations along the river. The spatial variability of the perch body shape in different river reaches 1.3 times exceeded the scale in shape variability which is associated with river and lakes habitats and 1.6 times exceeded the scale of the morphological shift in perch in the lake Prostaptur. A low intra-group diversity of body shape was identified for the perch population in the lakes with a periodic oxygen-deficient in water. The perch from the river with their strong turbulence of mountain currents, variable water-levels of the watercourse and water flow paths have an increased intra-group body shape diversity. It may indirectly indicate some ontogeny change in the individuals from the mountain river, related to the formation of a wide range of ontogenetic trajectories and suggests a greater perch adaptation to periodic low dissolved oxygen in the lakes than to changes in the hydrodynamic regime of the mountain river.

One of the possible consequences of climate change is a change in the demographic dynamics of phyllophagous insects. For a retrospective analysis of this dynamics, tree rings are used, especially in regions with limited documentary data. Due to the complex nature of the factors determining tree growth, in order to more clearly identify pest-induced defoliation in tree-ring chronologies one suppress the climatic signal expressed directly or indirectly (through chronologies of non-host tree species). However, in the South Siberia, the choice of non-host species is hampered by the wide distribution of polyphages, like gypsy moth ( Lymantria dispar Linnaeus) and Siberian silk moth ( Dendrolimus sibiricus Tsch.). Therefore, the analysis of pest outbreaks in larch forests of the Republic of Tuva low mountains was started by removing the climatic response based on instrumental data, identifying depressions in the residual time-series of individual trees’ radial growth at several sites, and comparing them with available actual data on forest damage by phyllofages. Dendroclimatic analysis showed that the model including the precipitation-to-maximum-temperature ratio for June-September of the previous season and June of the current year, i. e. the degree of aridity during the previous and current growing season, describes 43.7 % of the regional variation in the growth of Siberian larch ( Larix sibirica Ledeb.). After removal of this component, several periods of larch growth depression were revealed during confirmed outbreaks of the Siberian silk moth, gypsy moth, and larch tortrix ( Zeiraphera diniana Gn.). Use of documented data over 1998-2016 allowed to clarify the threshold values of the portion of affected trees for intensities of the growth depression ranging 1-1.5 standard deviations, providing the required reliability of the outbreak reconstruction. The dependence of the spatio-temporal patterns of growth depression on the pest species was revealed, reflecting their migration in the affected area. It has been shown that growth depressions may be delayed compared with the actual damage by pests due to the long recovery after recurrent defoliation.

As a result of the analysis of all data on the number and distribution of small mammals in Western Siberia over the past 120 years, it was found that 20 of their 28 species, recorded in the Northern taiga, form their communities. In the communities of small mammals of the Northern taiga, a similar structure of dominance is generally preserved. The main dominant species: red vole, medium and common shrews predominate almost everywhere. Other 6 codominant species (small and tundra shrews, and housekeeper’s, dark, red and red-gray voles) dominate only in certain areas. The remaining 11 species, both widely and narrowly distributed, make up a small part of the communities. The increase in the species richness of communities in the Eastern direction (from 15 to 19 species) is determined by the increase in the number of Siberian species. In General, in the studied area of the Northern taiga, the largest contribution to small mammal communities is made by representatives of the Siberian type of fauna, with the exception of the Western part of the subzone, where European species predominate.

We sampled ground beetles Pterostichus montanus in 1988-2014 at different altitude plots of Barguzin ridge (N 54°30′; E 109°50′) - the coast (500 m a. s. l.), low mountains - 720 m, middle mountains - 1004 m and high mountains - 1667 m. Morphological measurements included six traits - the length and the width of elytra, pronotum and head in males and females separately. Sample size was 968 individuals. Altitude and sex affected significantly beetles size: the latter was smallest at the coast, at the other altitudes beetles did not differ in size. Sexual size dimorphism (SSD) was female-biased and its value was the highest in elytra and head width. Mean values of SSD by all six traits were the lowest on the low mountains populations. Reduced regression models coefficients were positive in all cases. Then body size variation in males and females had similar direction at all altitudes. But Intercepts were negative in majority of cases and linear regression coefficients more than 1. Thus, males were more sensitive to environment impact practically by all traits.

Artemisia gmelinii Web. ex Stechm. is a shrub, mesoxerophyte, pan-Asian area. A. gmelinii has found application in folk medicine. The composition essential oil has been studied for plants growing in different parts of the area. This article demonstrated on the composition of essential oils of plants growing of the Рriolkhonian flora (Lake Baikal), in particular in Aya Bay. Raw materials were collected during expeditionary work in 2019. Essential oil was obtained by hydrodistillation from air-dried raw materials in the year of collection. Oil analysis was performed by chromatography-mass spectrometry. Data on the composition of the essential oil for visualization were processed using the principal component analysis. The γ-amorphous, isochumbertiol B, caryophyllide oxide, caryophylla-4 (12), 8 (13) -diene-5α-ol, ylangenol, caryophyllylene and cabrevia oxide B are dominant components of the essential oil of plants from Aya Bay. Based on our own and published data we show that the component composition of essential oils is the result of the action of abiotic and biotic environmental factors and and ensures the best adaptation of plants to growing conditions. On the other hand, regardless of the place of plant growth, the directions of biosynthesis of the constituent essential oils are preserved, which makes it possible to distinguish various chemotypes of essential oils. The composition of the essential oils can be divided into two chemotypes: the “Indian” is characterized by a high content of irregular monoterpenoids in the composition and the “Siberian” - of monoterpenoids such as Menthane terpenoids. Among the plants of the “Siberian” chemotype, there is a tendency to the formation of two lines - the western with a prevalence of camphor terpenoids (camphor, borneol, etc.). In the eastern (alpine) sector of the range, the accumulation of sesquiterpenic compounds in essential oils.

The features of the composition and structure of soil microarthropod communities formed on ash dumps of combined heat and power (CHP) plants at the initial stages of their self-restoration under conditions of varying degrees of conservation were studied. The investigation was carried out in 2017 in Novosibirsk (55°00′ с. ш., 83°04′ в. д.) at the ash dump of CHPP no.5 consisting of two sections - non-reclaimed (S 1) and reclaimed by covering ash and slag with potentially fertile soil (S2). A plot in a birch forest adjacent to the ash dump was used as a control. The collection of material was carried out in the ash dump zones of different degrees of moisture (three plots in both S1 and S2) and in the control (in total, 7 plots). Microarthropod communities included mites (Mesostigmata, Oribatida, Prostigmata) and springtails (Collembola). The microarthropod abundance on the territory of both sections of the ash dump was significantly lower than in the control, while no significant differences were found between the ash dump sections. The influence of reclamation was revealed only for the mites. The representatives of Oribatida appeared to be the most sensitive. There were no significant differences in the proportion of the different groups in the community on S1. On S2 and under control, Oribatida took the lead. Using the example of Oribatida and Mesostigmata model groups, it was shown that the mite communities formed at the ash dump were species-poor and consisted of widely distributed species with a high degree of dominance of some of them. Oribatida appeared to be a good bioindicator for assessing the soil state while restoration succession at ash dumps of CHP plants.

The article presents an analysis of the influence of technogenic pollution on the content of the main groups of biologically active substances (flavonoids, anthocyanins, oxycinnamic acids, procyanidins, tannins, carotenoids, ascorbic and free organic acids) in the fruits and leaves of the representative of the natural flora of Donetsk region Crataegus fallacina Klokov. The content of heavy metals such as cadmium, lead, mercury in the soil (mobile forms) and plant materials was determined, and the environmental safety of the raw materials was evaluated. It was revealed that a significant increase in the content of tannins in the leaves of C. fallacina , as well as a decrease in the content of procynidins in the fruits in anthropogenic conditions, can be recommended for screening the degree of impact of an urbanized environment on plants. The conformity of the raw materials of C. fallacina to the requirements of the regulatory documents for the content of active substances was evaluated. It was shown that this raw material has a high antioxidant activity, which increases in conditions of pollution.