Home – Home – Jornals – Contemporary Problems of Ecology 2023 number 3

Knowledge of the age structure of plant populations is important for assessing the current state and predicting the population dynamics and related components of phytocenoses, since the load on the environment is different for different age groups. According to the scheme of age periodization of plant ontogenesis proposed by T. A. Rabotnov and A. A. Uranov, about a dozen main ontogenetic states are distinguished. Accordingly, each population sample represents an ordered row of frequencies of these states - the so-called ontogenetic spectrum. However, there are ambiguous interpretations of the role of some ontogenetic states in the classification of cenopopopulations, as well as statistical problems of estimating the profiles of ontogenetic spectra. A unification of approaches to typification of the age structure and indices of plant cenopopulations, based on the reduction of the ontogenetic spectrum to a standard scale of development periods - pregenerative, generative, and postgenerative, is proposed. From these perpespectives, classical types of cenopopopulations (invasive, regressive, invasive-regressive, and normal), different variants of normal cenopopopulations, age structure indices, and possible irregularity of the period scale are considered.

The review is devoted to the current environmental problem - a reduction of greenhouse gases (GHGs) in the atmosphere. A significant proportion of carbon is known to be deposited in the soil cover. Measures are being discussed in a many countries to promote carbon sequestration depending on the land use, because soils and forests, along with the world’s oceans, are the main stores of CO₂. Different land use issues (virgin lands, arable land, pasture and forest lands) are covered in connection with the problem of greenhouse gas emissions. Data on the land cultivation: zero; standard with and without plant residues; using biochar; microalgae are given. A comparative analysis using biomarkers on a pasture with mixed herbage, arable land with rapeseed, soil under willow have been considered in order to determine microorganisms assimilating carbon from rhizosphere deposits of various plants. Some sources evident the hydrolysable lipids constitute a high share of the soil organic carbon (SOC) accumulation in forests, in contrast to phenols of lignin. The former substances are actively accumulated with the decreasing of soil pH, increasing of reactive iron, aluminum, and lignin oxidation. SOC is higher in a silt and clay fractions as compared to the sandy ones due to it absorbance in aggregates. Hence, it was proposed to use the finely dispersed mineral fraction as a key element to determine carbon stabilization in most soils. Carbonates play an important role in carbon sequestration, accounting for approximately 40 % of carbon stored in the world soils. They are the main component of carbon storage in arid regions. Attention to the radical improvement of pastures is given - inversion treatment (FIT). The methodical issues to detect SOC by remote distance (RD) technique are given. Reflected shortwave radiation in the upper atmosphere (TOA) practice has shown a great potential for climate mitigation through the cultivation of a cover crop with high albedo and a lack of chlorophyll.

Climate change contributes to increased attention on factors determined the dynamics of biogeochemical processes in active layer of biosphere (seasonally thawing/freezing soils) on the border with permafrost. There are geological, geomorphic, weather conditions associated with atmospheric precipitations, which determine the differences in the segregation and depth of permafrost thawing in different regions. Research area is Bureya River Basin with intermittent distribution of permafrost within unique landscape units - marshes. It is formed in swampy, poorly drained areas, where the active soil layer is in contact with permafrost, and has a direct impact on the quality of surface waters. The results of the study include the information about composition of water in different order tributaries by hydrochemical parameters; spectral characteristics of soluble organic matters (OM) in water extracts of soils from different horizons of the active layer; assessment of the activity of microbial complexes in relation to humic substances depending on the permafrost depth. The heterogeneity of landscapes is an important factor influencing the transport of OM into watercourses. Microbial complexes of the active layer involved in the transformation of humic substances played a decisive role in changing the composition of soluble OM. It was experimentally shown that temperature influences the qualitative composition of humic metabolism products, including the ratio between aliphatic, aromatic fragments and chromophore groups responsible for the color of natural waters.

Changes in the timing of bird migration can be tracked if there is data on the timing of bird migration collected from the same methodology. The bird ringing is a source of such data. Combination of two methods of registration migratory birds - observation and catch - provide more accurate data about first meeting of migratory species in the study area. The article deals with three parameters of spring migration: the first registration, the median of span and the last registration of the species (average values for 2015-2018) for 48 species of migratory birds according to capture and observation data around Baikal Bird Ringing Station (the south-east coast of lake Baikal). Comparison of the timing of the beginning of spring migration of 17 bird species in some areas of Baikal (Irkutsk region, southeastern and northeastern coasts of Baikal) showed that 13 species of birds arrive on the southeastern coast of Baikal 2-20 days earlier. Determined that changes in date of the first record are insignificant for 13 species of birds (±3 days). These species are most perspective for long-term monitoring of climate and population changes.

The article presents a generalization of the results of studying the long-term history of paleofires in the world and on the territory of Russia specifically. Perspective and reliable methods for reconstructing the local and regional dynamics of paleofires - micro- and macro-charcoal analyzes, are considered. In the article, we analyze approaches to the study of paleofires, methods of processing and identifying micro- and macroscopic charcoal particles, including the state-of-the-art software tools for their identification (“The Charcoal Quantification Tool”, “WinSEEDLETM”) and analysis (“CharAnalysis”) based on a review of world and Russian scientific achievements. In addition, the possibilities of modern international paleofire databases (Global Charcoal Database, Reading Palaeofire Database), which contain up-to-date information on local and regional paleofire data in the Holocene, are considered here. The results of the study of paleofires globally and on the territory of Russia in particular are analyzed and possible research directions along with fire reconstruction issues are highlighted. The review of Russian publications has shown that the central and south part of the East European Plain, as well as the southeast of Western Siberia, are the most studied regions in terms of reconstructing the dynamics of paleofires. Few similar studies were carried out in the Urals Mts., Eastern Siberia and the Far East, but most of the regions of Russia remain unstudied in this regard. In recent years, Russian researchers are mainly focused on the study of local fire dynamics based on the use of macro-charcoal analysis. The analysis of international paleofire databases (Global Charcoal Database, Reading Palaeofire Database) shows that these data need to be radically revised in relation to key sites in Russia. The authors present a generalized map-scheme of Russia indicating the key areas where paleofire dynamics were reconstructed using micro- or macro-charcoal analyzes.

In this study firstly reports the founding of the liver fluke O. felineus into the ide Leuciscus idus in the Chany Lakes system in the south of Western Siberia. The Prevalence O. felineus among the ide at the mouth of the Chulym river inflowing to Chany Lake was 1.6 ± 1.57 % in 2019 and 4 ± 2.29 % in 2020 and 5.3 ± 5.1 % in Lake Bolshie Chany. Trematode O. felineus were registered in ide during the period of water level rise and a decreasing in the water mineralization. Four other studied by us cyprinid species (roach, bream, golden carp, silver carp) the infection with opisthorchids did not found. Earlier, in the Chany lakes system and in the estuarine of inflowing rivers the Kargat and Chulym rivers, the trematode O. felineus, the causative agent of diseases of the liver and bile ducts of humans and piscivorous mammals, was not registered in cyprinids. The relationship between the prevalence of the liver fluke O. felineus in the reservoirs of the Chany Lakes system with cyclic fluctuations in the water level and the associated changes in hydrochemical parameters and general water mineralization as well as the zoonotic risk to consumers is considered, since the ide is used as food by the population.

The ecological, morphological, physiological and biochemical characteristics of representatives of the genus Galium (Rubiaceae) have been studied. The objects of study are the hybrid (notovid) Galium × affrenum (Klokov) Ostapko (=notovid) and its parent species G. ruthenicum Willd. and G. octonarium (Klokov) Pobed. s. l. G. × affrenum habitually is closer to G. ruthenicum, but he differs in the color of the flower. Using the method of artificial neural networks, it was shown that, according to the physiological and biochemical characteristics, the notovid is closer to the parent species G. octonarium. The leaf biomass of G. × affrenum is characterized by an increased content and greater variability in the concentration of photosynthetic pigments and lipid metabolism, which may be the key to its greater stability and viability.

The aim of the study was to develop an approach to the quantitative assessment of interspecific relationships nature in soil micromycetes. The studies were carried out in the northern forest-steppe of West Siberia by conventional and author’s methods. It has been established, that during 2020-2022 the phytopathogenic mycocenosis of underground and generative organs of cultivated and wild-growing cereals was characterized by stability: the main phytopathogens were Bipolaris sorokiniana Sacc. Shom. and Fusarium Link. fungi, whose occurrence was close to 100 %. The total number of micromycete species on underground organs was 13, on generative organs - 8. The biological diversity of fungi was maximal in humid conditions, a change in the dominance of the moisture-loving F. poae (Peck.) Wollenw. by drought-resistant F. oxysporum Schltdl. was revealed. The coefficients of the species composition commonality of Fusarium root rot pathogens reflected the degree of the weather factors contrast during vegetation. The succession of Fusarium fungi in the system of plant organs according to the phases of vegetation was revealed, The quantitative parameters of their realized ecological niches overlapping were also determined. The study of pairwise interspecific relationships of micromycetes by the method of counter cultures, thanks to the development of a new original scale for the quantitative assessment of the interaction of species, made it possible to identify the most competitive species. Competition was expressed in a decrease in the rate of radial growth of colonies (up to 2.5 times), significant morphological deviations from pure cultures (up to 7 characters out of 10), in the formation of a lysis zone more than 7 mm wide (maximum 12 mm), and also in a change in the intensity of sporulation both in the direction of stimulation (up to a maximum of 20 times) and oppression (up to a maximum of 30 times). Within the studied combinations, competitive relations were identified in 46.4 % of cases, and neutral - in 53.6 %.

The resistance of Populus alba × P. bolleana No.7, P. alba × P. bolleana No.12 и P. davidiana × P. bolleana cv. Baichen 1 to osmotic stress in vitro has been investigated. Hybrid No. 7 was shown to tolerate up to 250 mM d-mannitol, whereas Baichen 1 variety only up to 50 mM d-mannitol in the nutrient medium after a 30-day culture period. Hybrid No. 12 remained viable at d-mannitol concentrations up to 150 mM. The use of d-mannitol significantly reduced the parameters of the leaf blade (length, width, leaf area) only in hybrid No. 7, for the rest of the samples the differences were insignificant (p < 0.05). The introduction of the osmotic component led to a decrease in the fresh and dry weight of all the studied samples by 1.7-2.2 times, while the water content of the tissues remained practically unchanged. The results of this study were confirmed by micromorphological parameters (stomatal apparatus and pubescence) in relation to drought tolerance. Poplar Baichen 1 was characterized by the weakest pubescence and the highest density of stomata (155.44 pieces/mm²), poplar No. 7 - the most dense pubescence and the smallest number of stomata per unit area (127.75 pieces/mm²). No direct relationship was found between the impact of osmotic stress and the number and size of stomata in the studied samples. We have shown that the studied poplar hybrids have different resistance to osmotic stress under in vitro conditions. More drought-tolerant hybrid No. 7 can be recommended for landscaping urban areas with increased anthropogenic pressure.

Monitoring studies of the impact of various types of industrial pollution on ecosystems using the histomorphological method have been carried out. The stages of formation and development of changes in the main body systems in mouse-like rodents living near the rivers of the industrial district of Norilsk are noted. Despite the external well-being, numerous structural, morphological pathologies were found in the organs and tissues of the examined mice living in contaminated areas. Disorders in the organs of hematopoiesis, an imbalance of the organs of the endocrine system, may be the result of a breakdown of stabilizing mechanisms, or accelerated depletion of the reserve capabilities of the studied systems.

The changes in the specific growth rate, fluorescent, cytometric and morphological parameters of the green microalgae Dunaliella salina were evaluated when copper ions were added to the culture medium at a concentration of 0-3750 µg/L. The growth rate is the most sensitive parameter of algae to the action of copper, its decrease was noted at the concentration of the pollutant above 150 µg/L, the death of the culture - at 1500 µg/L and above. The number of algae cells in the stationary phase of growth naturally decreases with an increase in the copper content in the medium from 150 to 3750 µg/L. It was found that copper does not affect the efficiency of the photosynthetic apparatus of algae at concentrations that do not lead to the death of the culture. A decrease in the values of the maximum quantum yield of fluorescence, non-photochemical quenching of fluorescence and the maximum relative electronic transport rate below the optimal values can be used as an indicator of the lethal effect of the studied pollutant on D. salina. At a copper concentration of 750 µg/L and above, it was noted: an increase in cell volume, an increase in the number of spherical cells, deformation and perforation of the plasmalemma, the predominance of deformed cells of irregular shape, a twofold decrease in the intracellular content of chlorophyll a and the specific yield of fluorescence per chlorophyll a.

Artemisia jacutica Drob. is an East Siberian endemic, biennial plant. It is distributed within the Republic of Sakha-Yakutia and the South of Central Siberia. The typical habitats are saline mesic and semi-dry meadows, steppes, salt marsh, abandoned fields and ruderal habitats. The south-eastern border of the species area of distribution is located in Buryatia. The essential oils were obtained by hydrodistillation from air-dry raw materials in the year of collection. The composition of the essential oils was analyzed by chromato-mass spectrometry. The main component of the essential oils of A. jacutica was chamazulene, which showed anti-inflammatory effect. According to the literature and own data it was found that the formation of essential oils’ composition was influenced by climatic conditions, which, obviously, provided the best adaptation of plants to environmental conditions. Climatic conditions determined the composition of essential oils of A. jacutica, resulting to the formation of two chemotypes - “Buryat” and “Yakut”. It has been established that the formation of these chemotypes generates due to differences in the level of heat and moisture supply of habitats, which is expressed by the hydrothermal coefficient (HTC). The temperature-humidity extremeness coefficient calculated on the basis of annual data influenced the ratio of components in the essential oils in a greater degree. Climatic factors (air temperature, precipitation, etc.) and their integral characteristics affected the content of individual components in the essential oils directly or in combination with each other, enhancing or diluting the influence of each other.

Here, we present the results of long-term monitoring (2002-2017) of epiphytic lichen Hypogymnia physodes in the influence zone of the Middle Timan Bauxite Mine (Komi Republic). The main environmental pollutant in this area is dust with a predominance of Al and Fe. Three periods of the reaction of lichen to dust pollution are identified: shock, maximum changes, and adaptation. Dust pollution significantly decreased the projective cover of the species under study, increased the frequency of thallus necrosis and decreased thallus linear dimensions. In ten years after we started our monitoring studies, the vital state parameters of H. physodes began to stabilize and then to improve due to adaptation of the lichen to chronic environmental pollution with dust. The study of changes in the content of main pollutants showed that, during the mine operation, they accumulate in the thalli of the lichen H. physodes in the following order: Al > Fe > Ni > Cu > Pb.