Home – Home – Jornals – Contemporary Problems of Ecology 2021 number 5

During the study, the structural adaptations of the desiccation-resistant homosporous fern Ceterach officinarum Willd were revealed at the organ and cellular-tissue levels. Among them, the main role is played by features that contribute to the maintenance of cell hydration. Xero-heliomorphic signs at the organ level: nanism, area reduction and leatheriness of fronds; dense cover of trichomes and scales. At the cellular-tissue level, water is retained due to the relatively thick blade of fronds, their small cells, a large number of cells per unit area and pycnomorphy, high values of the specific surface area of the fronds (UPW), dorsiventrality of the mesophyll, a relatively dense network of veins per unit area of the frond. Biochemical and functional - by increasing the concentration of osmotically active substances, lowering osmotic pressure, accumulation of water-retaining chemical compounds (catechins and tannins); on the phytocenotic - due to facultative bryophily. Sciomorphic features: at the cellular-tissue level - hypostomaticity, a relatively small number of stomata per unit area of frond, tortuous seams of epidermal cells, minimal values of the ratio of cell surface to volume. Mesomorphic features: differentiation of the mesophyll into columnar and spongy tissue, a thin cuticle layer on the surface of the epidermis, the presence of stomata in the lower epidermis. Another adaptation mechanism that determines the rhythm of fern development is the ability to inactivate life processes and fall into cryptobiosis under conditions of water stress and high temperatures. Unlike poikilohydric ectohydric bryophytes, the sporophytes of this fern, resistant to dehydration, can withstand drying out (and are, to this extent, poikilohydric), but are endohydric. In a word, the poikilohydricity of fern sporophytes is realized on a different structural basis, which is more evolutionarily advanced in comparison with thalloid plants. However, the frequent state of cryptobiosis, especially under conditions of alternating wet and long dry seasons, leads to an imbalance in carbon metabolism. Apparently, poikilohydricity is not the most perfect and productive way to combat drought.

The paper presents an overview of ontogeny of 11 life forms on the example of 16 species of boreal willows belonging to two ecological groups - alluvial and non-alluvial. At the intraspecific level, among the studied species, the greatest variety of life forms was found in alluvial species, and the smallest in non-alluvial species. In the species studied, polyvariety of evolution was revealed: structural and dynamic. As part of the structural polyvariety, morphological (as a result of which two or more (up to 4) life forms are formed in the adult state), dimensional (expressed in changing the size and life state of an individual within one ontogenetic state) are distinguished. Dynamic polyvariety is associated with different duration of pre-generative and generative periods of ontogeny. In all alluvial and most non-alluvial species, the predominance of the generative period of ontogeny over the generative one is observed. In individuals of two life forms of non-alluvial species, the pre-generative period prevails during ontogeny. Alluvial species have mastered a narrower range of environmental conditions compared to non-alluvial ones. At the intraspecific level, among the studied species, the greatest variety of life forms was found in alluvial species (2-4 life forms in each species), and the smallest in non-alluvial species (1-3 life forms in each species). Alluvial species are characterized by the presence of a small number of long shoots, a large number of shoots of medium length and a smaller number of short ones, which determines their high height compared to non-alluvial ones.

The ecological and geographical regularities of the spatial differentiation of the fauna of birds and mammals of the seas of northeastern Russia were studied at the end of the winter period of 1987-1988. The aerial surveys covered the Bering, Chukchi, East Siberian Seas, and the eastern part of the Laptev Sea. Mammals are ecologically associated with open sea areas, sea ice, continental and island coasts, and mainland tundra. Wintering flocks of birds form species of inland mountain streams, species common circumpolarly in the Holarctic tundra, marine species of the continental and island coasts of the North Pacific and the Arctic Ocean, including high-latitude endemics. 7 species of mammals and 23 species of birds have been registered. There are 22 bird species recorded exclusively in the Bering Sea (24 % of the marine avifauna of the Russian Far East). In terms of the number of species represented ( n = 9), auks prevail, which are very characteristic of the avifauna of the subpolar marine areas of the Palaearctic. Mammals have been regularly recorded in both the Arctic Ocean and the Pacific research sector. The winter fauna of mammals in the seas of northeastern Russia, in which the number of species is dominated by pinnipeds and cetaceans, makes up 23 % of the total mammalian fauna of this region. In the Bering Sea, 3 areas of concentration of wintering birds have been identified: in the southeast of Chukotka, southeast of Cape Navarin, south of about. St. Lawrence. The maximum density of the bird population (21.8 ind./km²) is in young ice and ice of primary education - where there are many forage polynyas. The population of birds of all types of ice is numerically dominated by fulmar, thin-billed and thick-billed guillemots. Most of the marine mammals were observed on the openings in the contact zones of different types of ice or in the ice openings of autumn formation. Polar bears form clusters near the island. Wrangel, beluga whales - to the east and northeast of Cape Navarin, walruses - to the south of it. The stability of winter spatial groups of walrus and polar bears in the Arctic Ocean, which annually demonstrated similar levels of abundance, has been established. Winter aerial surveys showed that beluga whales and humpback whales are not found north of the Bering Strait, and polar bears are almost never found outside the Arctic Basin.

Data on the seasonal development of 78 species of perennial plants in the Western Siberia forest-steppe due to changes in the regional climate are summarized over a 20-year period 1996-2015. It is shown that the meteorological indicators of the warm season in Novosibirsk have undergone noticeable changes: the average daily air temperature has increased by 0.16 °C, the growing season has extended by 12 days, and the period of active vegetation of plants at temperatures above 10 °C - by 8 days. Correlations of the dates of regrowth and flowering in perennials with the date of snowfall, the dates when the average daily air temperatures exceed 5 °C and 10 °C, and the sums of these temperatures were revealed. Using linear phenological trends, a delay within 2-6 days of the spring regrowth and an advance in the flowering by 2-10 days, except for early summer species, were established. A reduction of the prefloral period duration from 5 to 24 days indicated an acceleration in the rate of seasonal development in perennials against the background of the identified meteorological trends. The change in the duration of vegetation period was significant in spring-summer-fall green species and spring-summer-winter green species - 10 and 12 days, respectively. Low values of the coefficient of determination for most of the trends R ² < 0.06 showed changes in the phenology were mainly due to interannual variability.

The results of the study of biological and ecological features of the invasive species Elaeagnus angustifolia L. in the territory of the South Urals are given. The species is actively naturalized mainly in river floodplains and around other reservoirs. It is included in the Black Book of flora of Central Russia, Siberia, “black lists” of the Middle Volga region, Voronezh, Orenburg and other regions. The total number in the investigated coenopulations is estimated at 18-20 thousand individuals. The species is naturalized in various types of phytocoenoses - from steeped meadows to halophytic communities. Most of the investigated coenopulations are located in an arid climate, with little precipitation. The northernmost coenopopulations are in more favorable natural and climatic conditions. DCA-ordination of communities revealed leading environmental factors: continental climate, humidification, soil acidity, rich soils with nitrogen, moisture variability. Individuals of E. angustifolia vary in height from 2 to 8 m. Tall plants are noted mainly on unsalted habitats with sufficient humidification. Lower plants are found in saline or dry habitats. The study of reproductive biology revealed that the greatest indicators for the parameters of fruits are observed in the coenopulations Aslykul, Izobilnoye, Sol-Iletsk, the minimum - in the coenopulation Tatar Kargala. Regression analysis of the dependence of the bone fraction on the fetal mass shows that with an increase in fetal mass, a decrease in the bone fraction is observed. The naturalization of E. angustifolia in river floodplains negatively affects the growth, development and resumption of native forest-forming species, which leads to irreversible consequences of the degeneration of floodplain forests.

The investigation of belowground plant production and its determining factors is critical for better understanding carbon turnover in the biosphere. The measurement of fine root production is a methodical and difficult task. To reveal factors determining fine root production in mountain ecosystems, we introduced a new modification of ingrowth method with the use of filter balls (tea strainers). We studied root production in 16 communities from upper forest to subnival belts in the range of 2184-3069 m a. s. l. in the Teberda Reserve, Northwestern Caucasus, Russia. The filter balls were filled with sifted soil (without roots or stones) and buried in the soil 7-8 cm deep. The mass of root ingrowth was measured after two months of incubation under natural conditions. Mixed-effect models were applied to test the relationships between root mass, elevation, soil moisture, organic matter content, and pH. The highest root production was observed in an alpine snowbed (247 mg per filter ball in 60 days), the lowest was in forest and subnival communities (3-20 mg per filter ball in 60 days). The communities with woody dominants had lower production than herb communities. It increased with soil moisture, which was the most important factor. In herb communities the production of roots tended to decrease with the elevation. Soil organic matter as a separate factor had a positive relationship with root production in herb communities. There were no links between root ingrowth and soil pH. The method introduced presently both allows for the comparison of plant communities by their root production and reveals factors determining it.

The morphological and physiological biochemical features of calciphytes Hedysarum grandiflorum Pall. and Hedysarum gmelinii Ledeb are investigated. Plants H . gmelinii grown on a more moisturized and saline soil substrate. The leaf parameters of plants H . grandiflorum were characterized by a greater thickness, an area and contained significantly more water compared to the leaves of H . gmelinii . The leaf mass per unit area of H . gmelinii is 1.5 times higher than that of H . grandiflorum . Pigment foundation of H . grandiflorum is more enriched with chlorophylls. The level of lipid peroxidation in H . grandiflorum plant cells lower more than twice compare with H . gmelinii . The activity of enzymes catalase, peroxidase, polyphenolxidase on the contrary it was higher in H . grandiflorum . In addition, H . grandiflorum leaf lipids were distinguished by a greater saturation of fatty acids (SFA) (46.0 % of the amount of SFA) than H . gmelinii (31.5 %), but the concentration of α-linolenic acid in the leaves of H . gmelinii 1.5 times higher than H . grandiflorum . It was concluded that the existence of calciphyte plants in peculiar soil-climatic conditions imposes specific morphological and physiological and biochemical features even among closely related species H . grandiflorum and H . gmelinii .

The results of a seven-year study of two populations of the rare orchid Cypripedium calceolus L. located in different ecotopes (in the forest and in the swamp) on the territory of the Komi Republic are presented. It was revealed that the size of the shoots of this species is influenced by the weather conditions of both the current and previous growing seasons, while the specifics of the action of weather factors depending on the growing conditions are noted. The number of generative shoots in the studied populations is positively associated with the temperature and humidity of August of the previous growing season, and frosts have an additional effect on their number. The number of shoots in different growing conditions during the study period changed synchronously and was positively associated (as well as the number of juvenile plants) with the weather (temperature and precipitation) at the beginning of the growing season. At the same time, the population of C. calceolus , growing in different ecotopes, differed in a number of characteristics: the spatial placement of shoots, their size, the number of flowers per shoot, etc. This indicates that all population parameters are strongly influenced by the local conditions of the site. In a more shaded habitat (forest), the population of C. calceolus remained stable during the seven years of study, whereas in the swamp the population was more dynamic. There was an increase in its number and active seed renewal. Despite the different seed productivity of the fruit in the two populations, the actual seed productivity of the generative shoot was the same in the same years of research.

The assessment and reliable prediction of the productivity of grassland communities are largely determined by the approaches and methods used. The use of information on the species composition of the plant community and its functional structure in determining the primary production expands the possibilities of using modern information databases of geobotanical data. Selection of practically significant functional groups of species (graminoids, motley grasses, legumes) in composition of grassland communities of hayfields and pastures and determination of dominant species allows to include indicators of biodiversity in the procedure of agricultural lands productivity estimation. The experience in predicting the amount of aboveground phytomass of grassland ecosystems using the data on the functional composition and projective cover of species is discussed. The conducted cluster analysis confirms the assumption of the relationship between community biodiversity and its productivity. Based on the main provisions of the dominance hypothesis, by building a statistical linear model, the possibility of predicting the value of aboveground biomass from the data on the species composition of communities and the abundance of the dominant functional groups of plants, which act as universal evaluation criteria, was tested. The predictive statistical model is constructed on the basis of processing of the experimental data received from 32 sample geobotanical areas. The model shows the relationship between the value of the predicted biomass for the community and the abundance of the main functional groups of plants, the way they are used and the result of assigning community to the classification categories of the EVC and EUNIS systems. The applied classifications, based on species lists and indicators of the projective cover of species, bring a component of biodiversity in the further evaluation of community productivity. The use of the developed linear regression model makes it possible to estimate the productivity of grassland communities similar in species composition and belonging to the same classification categories with a sufficiently high degree of reliability without direct collection of data on the produced biomass. The model makes it possible to take into account the contribution of plant species composition to the provision of productive ecosystem services, providing the development of an accessible technique for their evaluation.

According to the results of bird counts carried out in 140 habitats over 12 years, in the period from 1982 to 2002 drawn up hierarchical classification and a structural graph of the similarity of ornithocomplexes in the plain southwestern part of Western Siberia and Northern Kazakhstan have been compiled. The hierarchical classification contains 10 types of bird populations. The similarity graph is built at the level of types and is represented by three rows (trends). One row consists of bird complexes of residential and recreational areas, the second from wetlands and the third from forest, forest-field and steppe habitats. The given characteristics of taxa of classifications contain information on the three most numerous bird species (leaders in abundance), their share in the community, population density, and also on the background species richness. Based on the assessment of the degree of coincidence of the similarity of bird communities and environmental factors, a hierarchy of the impact of the main anthropogenic and natural factors determining the formation of the bird population has been established.

N the northern spurs of the Manchurian-Korean Mountains (Primorsky Territory), an assembly of dung beetles from sheep dung was studied. Data on the species composition, population dynamics, number and biomass of dung beetles are presented. Comparison of assemblages of dung beetles of the inhabitants of sheep dung of the northern spurs of the Manchurian-Korean Mountains and the South Sikhote-Alin Mountains shows that despite the fact that both groups were formed on the base of one local fauna and have the same number of species, but the taxonomic structure and dynamic (seasonal) aspects are quite different. Differences in the species composition and composition of trophodynamic groups are due to the peculiarities of the geographic location, different weather and climatic conditions, grazing regime and differences in the composition of grazed animals, historical factors of the formation and dynamics of beetle assemblages. Weather conditions, as a factor influencing the rehydration of sheep droppings, determines the dynamic processes in assemblages and limits the penetration of certain species into the Sikhote-Alin Mountain system. A small size of sheep excrements, which are both trophic and topical resources, determines a high transformation rate of the substrate and the distribution of species according to a hypothesis of niche interception. The overlapping of niches in species from the same trophodynamic groups leads to a shift in the timing of the imaginal activity of certain species

We present the results of study on the number of indicator bacterial groups of the nitrogen cycle in plankton and epilithon of the littoral zone Lake Baikal in the spring and autumn periods from 2017 to 2019. The number of ammonifying bacteria (AB) in the lake waters varied from 25 to 6.0 × 10⁵ cells/ml; in epilithic biofilms - from 3.5 × 10³ to 9.5 × 10⁶ cells/cm². The stations subject to anthropogenic impact showed a high number of AB as evidence of active mineralization of nitrogen-containing organic compounds. The maximum number of AB in the water column and the biofilms from stony substrates was detected in June 2017 in the water area of the Severobaikalsk town. The average annual number of AB in the water column was (5.0 ± 2.8) × 10² cells/ml in June and (6.0 ± 1.3) × 10² cells/ml in September. In epilithic biofilms, it was an order of magnitude lower in June than in September, (3.4 ± 1.2) × 10⁴ cells/cm² and (2.6 ± 1.4) × 10⁵ cells/cm², respectively. The number of denitrifying bacteria (DB) in water varied from 0 to 60 cells/ml; in epilithic biofilms - from 6 to 2.5 × 10³ cells/cm². Throughout the study period, the highest number of DB in epilithon was detected in June at the station near Elokhin Cape. The average annual number of DB in the water column was 13 ± 4 cells/ml in June and 7 ± 6 cells/ml in September; in epilithic biofilms - (7.9 ± 2.4) × 10² cells/cm² in June and (4.8 ± 0.5) × 10² cells/cm² in September. The number of planktonic AMB positively correlates with the concentration of ammonium ions; the number of DB directly depends on the nitrate concentration and inversely depends on nitrites at some stations.

To reveal changes in plant mineral nutrition causing leaves’ chlorosis and parthenocarpy in the blue honeysuckle plants of Siberian origin, grown on plantations in Heilongjiang Province, China, we compared macro- and trace elements’ composition in two counties in China and two districts in the south of the West Siberian plain. It was found that massive leaves’ chlorosis and dying-off, as well as hormonal changes resulting in parthenocarpal fruits, may be associated with soil acidity (рН_KCl 4.0-4.5) on some of the study sites in the Heilongjiang Province, as such high acidity increased plant available Al, Fe and Mn concentrations to phytotoxic levels. The blue honeysuckle plants grown on such study sites had specific patterns of Al, Fe, Mn, Cu and Zn distribution throughout their organs, as well as accumulation of toxic concentrations of Al, Fe, Mn in leaves, resulting in aberrant P/Al, Ca/Al, Mg/Al, P/Fe, P/Mn, Cu/Fe and Cu/Mn ratios, which are vitally important for plants.

Data on the state of stands and undergrowth of the main forest-forming species at the Karadag Nature Reserve in oak forests of downy oak (Quercus pubescens) and sessile oak (Q. petraea) under conditions of super-high density of European roe deer (Capreolus capreolus) are presented. The exponential growth in number of roe deer in the reserve, which has been observed since its creation (1979), led to an increase in its number by 2016 to 750 individuals and a density of up to 437 individuals per 1000 ha, which is 10 times higher than the norm. At the same time the level of damaged sessile oak undergrowth increased from 7.6 to 88.9 %, and downy oak - from 8.4 to 83.7 %. A decrease to an absolute minimum in number of mid and complete absence of big undergrowth of both sessile oak and pubescent oak took place. Alignment of tree species in abundance (estimated by the Berger-Parker index) is 1.20 for sessile oak stands and 1.18 for downy oak stands, and undergrowth in these stands is 3.0 and 1.6 respectively. At the Primorskoye Forestry located next to the reserve, relatively favorable in terms of the density of roe deer (37 individuals per 1 thousand ha), damage to the undergrowth of the main species was 5.5 % in sessile oak groves and 7.2 % in downy oak groves. Alignment of tree species in oak forests at the Primorskoye Forestry in abundance is 1.25 for sessile oak and 1.54 for downy oak, and for undergrowth - 2.15 and 2.11 respectively. Being based on the totality of the obtained data it was concluded that even under conditions of a super-high density of ungulates oak forests of the Karadag Reserve retain the possibility of renewal due to an increase in the density of small undergrowth (sessile oak groves) and alignment of undergrowth (downy oak groves). Regarding to the renewal of the main species the excessive number of roe deer in the reserve plays a negative role, and respectively biodiversity in terms of the alignment of tree species undergrowth in terms of abundance it plays a positive role.