Home – Home – Jornals – Contemporary Problems of Ecology 2019 number 5

The review considers the phenomenon of phylogenetic immobilization, which was first described by I. I. Schmalhausen and consists in a loss of evolutionary plasticity as a result of stabilizing selection and deleterious mutations with habitat-specific fitness effects. Examples of immobilization are described and their classification proposed. Stability of the environment and morphological conservatism are considered as factors in immobilization. The issues under discussion include the role of the immobilization concept in solving problems of the theory of evolution, the possibility of taking advantage of immobilization in breeding, and the problem of preserving taxa having a lower evolutionary plasticity.

The composition and ecological-geographical features of the rarest endemic species of vascular plants of Siberia, including 50 species, known so far only from the classical location (the so-called stenoendemics) are considered. Their share is about 1 % of the flora of vascular plants of Siberia. For the first time, according to the floristic zoning, the composition of the chorological groups of the stenoendemics of Siberia has been established. The zones of concentration of their ranges are determined. The largest number of species studied (23) is concentrated in the Altaic Siberian ecoregion. A significant number of stenoendemic species are also represented in the Baikal Siberian (10) and West Siberian (8) regions. It has been quantitatively proved that the conditions for the existence of stenoendemics are most favorable in Southern Siberia. The mountain systems of Altai and Sayan provide the most diverse spectra of habitats for the successful implementation of microevolutionary processes, as well as the level of isolation sufficient to isolate new species. To determine the environmental conditions conducive to the processes of speciation, the grouping of the studied species according to their belonging to floristic complexes was carried out. More than a third of the studied species of the Altaic Siberian ecoregion (9 out of 23) are confined to the high-mountain floristic complex. Stenoendemics of the forest floristic complex are concentrated in the Altaic Siberian and West Siberian ecoregions and form a grouping comparable in value to the types of the high-mountain floristic complex. In the Baikal Siberia, species of the steppe floristic complex predominate, which is due to the diversity of the steppe areas and their insular character. It has been established that the level of state protection of the studied species is unacceptably low, since none of them are listed in the Red Book of the Russian Federation. To assess the degree of study and the prospects for further research on endemic species, a methodology for their ranking by quantitative indicators has been developed and tested. The recommendations presented in the article should be the basis for consideration of questions on the inclusion of the studied endemic species of vascular plants of Siberia into the lists of rare and endangered plants of the Russian Federation.

On the basis of an investigation of epiphytic ferns and taking into account the literature data, information on ecological classifications of vascular epiphytes is summarized and a multiple ecological classification is proposed, in which vascular epiphytes are grouped into 3 blocks of morpho-functional types (MFT): facultative epiphytes (protoephiphytes), obligate epiphytes (holoepiphytes) and hemiepiphytes, and obligate epiphytes (holoepiphytes) and hemi-epiphytes and hemi-epiphytes and hemiepiphytes and obligate epiphytes (holoepiphytes) and hemi-epiphytes. The main criterion underlying this division is the degree of specialization of plants to the epiphytic way of life. Each group includes several subgroups diverged on the basis of presence of special morphological structures providing epiphytes with nutrients and water under conditions of their deficit as well as life in the conditions of low irradiation and high hydrature. Within the subgroups, the variants are distinguished and inside them - preadaptive and adaptive mechanisms used by the epiphytes in order to cope with the specific environment. Physiofunctional types with specialization to epiphytic mode of life are distinguished as well.

The features of the distribution of climate-forming factors in Siberia are considered. The study area is represented by three regions: the West Siberian plain, the Central Siberia and the mountain systems of Southern Siberia. Climate and environmental resources (air and soil temperature and snow cover) in each region are estimated. A detailed analysis of the temperature along the soil profiles (to a depth of 0.8 m) was made. Vertical soil profiles are grouped according to the degree of summer heating and winter cooling. Differentiation of the territory of Siberia is made on the basis of soil temperatures. The paper proposes a new approach to the assessment of integrated climate and environmental resources for a large area. The generalization of the revealed regularities for the Siberia region is presented.

His study analyzes the present distribution of the Tuva mountain voles based on literary data, museum collections, and the own materials. The bioclimatic model of potential species distribution has been constructed using 25 localities which were identified as the presence of Tuva mountain vole in the territory of Russia and Mongolia. It is shown that the species range of the Tuva voles consists of three large isolated parts: the northern one, located mainly in Khakassia; southern, located in Tuva and the adjacent territory of Mongolia; small area on the northern shore of Lake Khuvsgul in Mongolia. The examination of habitats of the Tuva mountain voles in the territory of Khakassia showed that in recent decades there has been a significant decrease in the number of inhabited sites, which indicates a significant decline of population and intensification of fragmentation of the northern part of the range of the Tuva mountain vole.

Data on the population dynamics and dominance structure in the community of shrews in the surroundings of Magadan (2011-2018) are represented. In general, the even-toothed shrew (S. isodon) and the Laxmann’s shrew (S. caecutiens) dominated in the catch; species of secondary abundance were the slender shrew (S. gracillimus), the Siberian large-toothed shrew (S. daphaenodon), the Kamchatka shrew (S. camtschaticus) and the least shrew (S. minutissimus). Increases and decreases of number of all species coincided to varying degrees, and the differences in the dominance structure between years were relatively small. Only the status of the Laxmann’s shrew, characterized by the largest amplitude of number fluctuations, and the slender shrew, the abundance of which has increased recently in the region, has varied. The role of some factors in the regulation of the number of animals is discussed.

The results of studying the structural and functional characteristics of phytoplankton in the coastal region of the Black Sea with the help of flow cytometry are presented. Data of the seasonal variability of the biomass of three algal groups (Synechococcus, pico-eukaryotic phytoplankton, nano-phytoplankton), chlorophyll a content, percentage of living cells, and fluorescence FDA (diacetate fluorescein), which characterizes the functional state of algae were obtained. A significantly positive relationship between the values (biomass, autofluorescence of chlorophyll), determined on the flow cytometer and the total content of chlorophyll a , calculated using standard methods, was revealed. Influence of environmental factors such as temperature, illumination and content of nutrients in the medium on biomass and fluorescence of the FDA of three isolated groups of algae is shown. It was noted that the nitrate content and temperature had no significant effect on the abundance of pico and nano-phytoplankton, while a reliable relationship was established between the biomass of nano-phytoplankton and the concentrations of dissolved forms of mineral phosphorus. An inverse statistically significant correlation was established between the intensity of light and the biomass of pico-eukaryotic phytoplankton. It was noted that the abiotic environmental factors considered in the study did not significantly affect the FDA fluorescence value, except for temperature: in the warm period of the year in the Black Sea the picophytoplankton are most active, while the cold period of the year s favorable for the development of nanophytoplankton.

The growth and reproduction parameters in progeny of abundant (Lymnaea stagnalis) and rare (Stagnicola corvus) pulmonate species originated from the specimens captured in water bodies with the different forms and levels of anthropogenic pollution were determined in the reproduction experiment by cross-fertilization (CF) and self-fertilization (SF). It has been shown that SF leads to increasing of pre-reproductive age, fertility decline, decreasing amount of breeding individuals and growth rate of population numbers. Increasing of waterbodies’ pollution level leads to decrease of ability to SF in L. stagnalis. S. corvus as compared with L. stagnalis is characterized by reduced ability to SF. It could be one of the most crucial reasons for low abundance of S. corvus in nature.

Forest disturbances induced by the clear-cutting (CC) leads to the transformation of the natural biogeochemical processes, which determining main greenhouse gas fluxes (principally CO₂) between forest ecosystems and the atmosphere. Effects of clear-cutting on CO₂ exchange substantially vary depending on local environmental and climate conditions. This study is focused on estimation of net ecosystem exchange of СО₂ (NEE), gross primary production (GPP), total ecosystem respiration (TER) and soil respiration in southern taiga in European Russia. The results are based on continious eddy covariance measurements during the 2 growing seasons (2016 and 2017). The research showed that the clear-cut was a consistent source of CO₂ for the atmosphere during the first years following harvest (NEE since May to october is 553.3 2016 and 193.3 g С∙m^-2 in 2017). Interannual variability of the cumulative NEE, of GPP (777.5 g С∙m^-2 in 2016 and 1020.5 g С∙m^-2) and decrease in TER (1330.95 g С∙m^-2 in 2016 and 1213.7 g С∙m^-2 in 2017). The results of chamber measurements showed, that soil respiration in the midday hours in summer changed between 3.6 ± 0.7 and 11.8 ± 3.0 μmol∙m^-2∙s^-1 in 2016 and between 6.0±1.3 and 14.8±3.5 μmol∙m^-2∙s^-1 in 2017 at the different plots within the clear-cut site. The estimates of the cumulative GPP at the clear-cut in southern taiga of European Russia exceed the GPP rates obtained previously in the other clear-cut forest ecosystems, located in boreal and sub-boreal ecozones.

The article is devoted to the ecological problem of effective urban landscaping and increasing the role of green plantings in environment stabilizing. The paper summarizes the material on the complex bio-ecological assessment of functionally different urban green areas of Vladivostok. There are six types of urban plantings: ordinary plantings, squares, intra-quarter gardening, old city public gardens, city parks, intra-urban recreational forests. The questions of specificity of their species composition, conditions of growth and the intensity of influencing anthropogenic press are considered. It is noted almost fourfold increase of environmental stress in following series: city parks → intra-quarter gardening → intra-urban recreational forests → old city public gardens → ordinary plantings → squares. The greatest attention is paid to the comparative analysis of tree-shrub species and plantations accumulation of heavy metals - the main markers of technogenic pollution of the urban environment. The correlation regularities in the accumulation of heavy metals by plants in the conditions of Vladivostok urban ecosystems were found out and the geochemical association of the main metal-pollutants was established: Fe_4.1 Zn_2.0 Pb_1.9 Cu_1.4 Ni_1.3. It is shown that the intensity of heavy metals transformation by green plantings increases 3 times in a ranked series: intra-urban recreational forest → city parks → old city public gardens → intra-quarter gardening → squares → ordinary plantings. On the basis of the conducted researches and attraction of the received earlier results the complex assessment of a functional condition of city green plantings is performed. For its practical solution the author offers the functional status index (IFS) of plantings as an integral indicator of ecological condition of vegetation and soils of green plantings, their ability of heavy metals transformation in the conditions of the urbanized environment. The high functional status of ordinary plantings and squares, caused mainly by the active accumulation of heavy metals by soils and plants, is noted. This index is one and a half times lower for old city gardens and intra-urban recreational forests. In conclusion, the author recommends using the obtained results in the organization of a rational system of urban landscaping and differentiated measures of care for plantations of various functional purposes.