Data on the dynamics of the ontogenetic structure of two cоenopopulations (CP) of Dracocephalum fruticulosum located in various ecological and cenotic conditions of Tuva are presented. The changes in the type of the ontogenetic spectrum and the density index of individuals were analyzed. A sharp decrease in density was revealed in both CP during 18 years. The monomodality of the ontogenetic spectrum was established during all the years of our study. There was a change in the type of the cenopopulations, namely, from transient to aging in CP 1 and from transient to mature in CP 2. The calculated demographic indicators and the rate of development reflect the unidirectional dynamics of the CP structure, namely, a successive type in CP 1, and a wave-fluctuation type in CPU 2. CP analysis showed significant vulnerability of demographic indicators. Changes in the coenopopulations are due to different causes: overgrowth of Selaginella sanguinolenta communities in CP 1, anthropogenic impact (grazing) in CP 2, weak seed setting and germination.

The paper is devoted to the resource capacity of habitats of the Eurasian beaver (Castor fiber L.), an invasive species. Insufficient forage supply is a deterrent to the expansion of the range of this species, which has been actively settling in Eurasia in recent decades. Complexes of herbaceous wetland plants (macrophytes) under certain conditions can be a significant source of feed for these animals. However, at the edge of the range, which is currently limited to the forest-steppe zone in the south, the lack of development of aquatic macrophytes could lead to containment of the settlement of this species. It is shown that the conducted studies are important from the viewpoint of forecasting the stability of populations of the Eurasian beaver in the forest-steppe zone, assessing changes in their structure and abundance, and determining the limits of possible expansion of the species' range.

The results of our study of the dynamics of fresh subor (B2), a widespread type of forest ecosystems in the central part of the Volga Upland, are presented. The study was carried out on the territory of the Upper Sura section of the Privolzhskaya Forest-Steppe Nature Reserve. The course of the process was studied in the age series identified in homogeneous forest conditions based on the principles of dynamic classification of forest types. As a result of processing the forest inventory data, the average values of forest stand taxation indicators were obtained for each age class. At the same time, analysis of changes in all the components of plantations was carried out. On its basis, the age series was divided into separate periods and phases. Trends in the share of participation of each forest-forming species in the forest stand at different age stages were described by nonlinear equations. The study showed the resulting age series to be a series of transformation of forest communities. Violation of the course of the forest formation process led to a large-scale change of indigenous plantations to derivative ones. After the beginning of the use of clear-cutting fellings, the area occupied by deciduous trees (primarily birch) has been constantly growing. The largescale use of intermediate-use, sanitary and voluntary-selective cuttings resulted in the formation of sparse pine stands. At the same time, transformation of the lower tiers of communities took place. These factors caused deterioration of the conditions for natural pine regeneration (Pinus sylvestris L.). As a result, by now the possibility of forming pine forest stands through natural regeneration is almost completely excluded.

The results of our bacterioplankton study (total abundance; saprophytic, hydrocarbon oxidizing and phenol resistant bacteria; total microbial number, and coliform bacteria) in an urbanized tributary of Lake Onego in 2015 are presented. The lower reaches of the Lososinka River flow across the territory of Petrozavodsk city (Karelia) and receive 14 untreated drains of the urban storm sewers. Differences in the temporal abundance dynamics of bacteria which are the indicators of oil pollution, sanitary condition and saprobity were found in the reference and urban parts of the river. These changes are not related to the hydrological and temperature regime of the river and reflect the influence of the pollutant drainage from the urban area on the formation of the river bacterial community. A significant increase in all studied indicators of the quantitative development of bacterioplankton in the urban part of the river as compared to the reference part was revealed. The number of heterotrophic bacteria of various ecological-trophic groups decreases in the lake water by 8–16 times due to dilution, as early as 500 m from the mouth of the river. A significant decrease in the numbers of hydrocarbon oxidizing bacteria in the river water and an increase in sanitary-indicative microorganisms are shown to occur over four years. The Lososinka River on the territory of the Petrozavodsk city is assessed as polluted with oil products and organic matter of fecal origin and unsuitable for recreation according by the level of indicator bacteria.

The paper presents the results of our long-term monitoring of the family of larks (Alauda arvensis L., Melanocorypha calandra L., M. leucoptera Pallas, M. yeltoniensis J. R. Forster and Calandrella rufescens Vieillot) in the semi-desert zone of the Saratov Trans-Volga region. Bird censuses were carried out at 4 key sites on permanent routes during the nesting period, the total length of the census transects was 792 km. Statistical indicators of population dynamics were calculated, namely: the growth rates (T_np.) and average density values (ind. / 100 ha) of each lark species. A statistical multivariate factor analysis (F-test) was carried out, with the help of which we were able to reveal the influence of a whole range of factors on the lark density dynamics. Changes in habitat conditions at the key areas (F_crit. = 1.30, p = 0.003), as well as weather factors (F_crit. = 1.39, p = 0.004) of particular years, have a significant impact on the density dynamics of larks. Evaluation of the variance showed heterogeneity of the sample (St = 0.119, p = 0.006), therefore, the average densities of larks differs significantly from each other. Thus, the structure of the lark community and the annual density of each species are the result of the environmental conditions of the habitats at each key site, and the weather conditions of particular years.

The use of microalgae Chlorella kessleri VKPM A1-11 ARM (RF, NPO Algobiotechnology) for environmental and energy purposes is considered. The results of our study of the use of C. kessleri microalgae biomass as a biosorbent to purify model wastewater from Cu2+ ions under static conditions are presented. Biosorption is a promising technology for the treatment of industrial effluents containing various heavy metal compounds, but the issues of economic benefits of using biosorbents, their environmental safety and the cost of disposal of used sorbents are subject to much discussion. The paper proposes to dispose the used biosorbent formed after wastewater treatment from copper as an additional fuel. The copper concentration in the filtrate was determined by colorimetric analysis with sodium diethyldithiocarbamate. The cleaning efficiency and sorption capacity of the dry mass of C. kessleri were obtained by calculation. The maximum sorption capacity for Cu2+ ions was 4.2 mg/g. The purification efficiency reached 87% at the initial concentration of Cu2+ ions being 97 mg/l. Tests to estimate the specific heat of combustion of C. kessleri biomass and used biosorbents based thereon were carried out by the calorimetric method using a bomb calorimeter. The specific heats of combustion were 22,125 kJ/kg and 21,674 kJ/kg, respectively. A comparison of these values with traditional energy carriers is given. A technological scheme has been developed for a waste-free cycle of using C. kessleri to treat wastewater from industrial enterprises with the production of several valuable resources as end products, such as purified water, energy resources, fertilizers, and recycled metals. The obtained results of our study can be applied in technologies for post-treatment of wastewater from various industrial enterprises using biological non-waste resources.

A comparative interspecific assessment of the leukocyte profile of young Elaphe dione, Natrix natrix and N. tessellata is given. Juvenile snakes were obtained in captivity from females captured, being pregnant, from Volga populations. Eosinophils and basophils predominated in the blood of young E. dione, the total content of mononuclear cells (agranulocytes) was lower compared to the young of N. tessellata and N. natrix. At the same time, the species of the genus Natrix differed in the content of all three types of mononuclear cells, namely: the proportion of azurophils and monocytes was higher in N. tessellata, and that of lymphocytes was higher in N. natrix. The main contribution to the balance of mononuclear cells was made by lymphocytes. The leukocyte composition of young snakes had no pronounced lymphocytic profile, the contribution of the specific reactivity of the organism to the overall adaptive response of the body of young snakes to environmental conditions was small. According to the content of lymphocytes, the studied species were arranged in descending order in the following row: N. natrix (Me – 60.00, IQR – 2.50) → N. tessellata (52.00, 6.00) → E. dione (40.00, 5.00). The increased value of the leukocyte shift index in E. dione young testified to the predominant role of granulocytes in the immune response with some lag of lymphocyte-monocyte cells and later activation of the effector link of the immune response (lymphocytes) compared with young of N. natrix and N. tessellata. While the specific reaction of the immune system decreased, a compensator activation of the nonspecific protective blood system was observed in the organism of E. dione. The increase in the content of granulocytes in the blood of young snakes was a characteristic indicator of an increase in environmental stress, assessed by the integral leukocyte index (the ratio of heterophiles and lymphocytes). Integral leukocyte indices reflected an imbalance of the adaptive response of the blood system in young snakes kept in captivity in relation to adult males and females from natural populations.

Lead (plumbum, Pb) is a toxic element of the first hazard class. Global soil pollution with Pb leads to severe consequences for the environment and human health. Mobile Pb forms represent a special environmental danger. To immobilize Pb in soils, various materials (meliorants) are used which can convert it into some form poorly soluble in water and weak acids. The search for safe natural materials for the rehabilitation of contaminated soils is of great practical importance. Glauconite-containing phosphorite tailings (PT) are promising reclamation materials. The main component of PT, glauconite, is a natural sorbent capable of binding heavy metals. The composition of PT also includes small-fraction phosphorites, clay and calcareous components, and quartz. The effect of PT on lead mobility in soil was studied in laboratory conditions. Four variants of loamy soil with various chemical structures were used. The lead content in different soil samples did not differ statistically significantly from each other. The effect of PT on lead mobility was evaluated in comparison with limestone. The meliorants were introduced in a dosage of 1 g / kg. The use of PT led to active Pb immobilization in acidic organic–depleted soils, while lime did so in neutral highly humus soils. Mathematical processing of our experimental results suggests that the formation of sedentary complexes with organic matter and adsorption of lead on glauconite serves the predominant mechanism of binding Pb in soil when using lime and PT, respectively. The introduction of PT causes a decrease in the Pb mobility, as well as the enrichment of the soil with phosphorus, potassium, sulfur, calcium and trace elements contained in this meliorant. This is important for restoring the fertility of degraded lands.

In most passerine species, an individual bird sings multiple song types to be combined into non-random song sequences. Because of this non-randomness, stereotype sequences of several or even dozens of song types appear in the vocalization of some species. Passerine birds acquire songs through some learning process while imitating other individuals. Song sharing is well known in songbirds and is a consequence of the song learning. Apparently, above the song type level, transitions between song types may be also shared. However, we still do not know exactly, how long are those song sequencies a bird can memorize? We analyze song sequence sharing in Radde’s warbler. Each song of this species consists of a dozen of short notes and lasts 1 s. In many males, the identity of the next song type in a sequence can be predicted on the basis of the previous song type (linear syntax). We found that males can share (i.e. memorize) song sequences from no more than 5 song types. Individual repertoires included up to 40 song types. Therefore, the ability of memorizing song sequences are rather limited in Radde’s warbler, as shared song sequences were rather short in comparison with the total size of the repertoire.