The position of the Sicista strandi population from the southwestern periphery of its range (the mountainous Caucasus, the vicinity of the Ekiptsoko cordon, Zol’sky district of Kabardino-Balkaria, the adjacent territory with terra typica of the species) in the species structure was investigated on the basis of a comparative analysis of the nucleotide sequences of a fragment of the gene of nu-clear DNA in this population and in representatives of the species from a number of localities from the Russian Plain for the first time. It was established that according to this molecular feature, the studied Caucasian population belongs to the southern grouping of the species, covering, in addition to the Caucasus, samples from the basins of the Lower (Rostov region) and Middle Don (Lugansk region) and presumably from the Lower Volga region, and differs from samples from the northern parts of the range in the Central Chernozem Zone (Kursk and Belgorod region). In the S. strandi population from the southwestern periphery of the range, a number of environmental and biological characteristics (biotopic confinement, population composition, abundance, diurnal, seasonal activity, reproduction, and nutrition) considered in a comparative aspect in connection with the genetic differentiation of the species were studied for the first time. 

Currently, there is an acute problem of pollution of the hydrosphere, which results in a drop in the stability of ecosystems, destruction of the signaling links of biocenoses, and food pyramid violation. This paper presents the results of our monitoring the current state of phytoplankton communities and water quality of the Peipus-Pskov Lake, a large transboundary reservoir located in the northwest of the Pskov region. During the growing season of 2022, 221 phytoplankton taxa with ranks below the genus from 8 divisions were identified. The average abundance of phytoplankton over the entire period of our study was 11.6 million cells/L, the average biomass was 1.6 g/m³. An ecological and geographical analysis was carried out, according to which widespread freshwater planktonic forms of microalgae predominated in the lake, preferring stagnant-flowing weakly alkaline waters. According to the Sjörensen–Chekanovsky index, the degree of commonality of the species composition of the planktonic algal floras in the Pskov and Peipsi Lakes was 73.2%. Saprobiological analysis showed that the waters of the study area in 2022 were slightly polluted (class II of water quality).

The results of our 12-year study of a population of the rare orchid Cypripedium guttatum Sw. on the northern border of its range, on the territory of the Komi Republic (north-east of European Russia) are presented. Our research has shown that weather factors (temperature and precipitation) have an impact on the seasonal development of shoots and plant size. The number of shoots is influenced by the weather conditions of the previous growing season, namely: the temperature of the first decade of August influences positively while early autumn frosts and the amount of precipitation of the entire period do negatively. A negative correlation was found between the number of flowering shoots and the temperature of the second decade of July of the previous growing season and a positive relationship between the number of juvenile plants and the precipitation of August of the previous growing season. Fruit set was quite low (17.1%), which is typical for this species. The pollination efficiency of C. guttatum was negatively affected by the high temperature during its flowering (the second decade of June). One box contained an average of 4065 seeds. The real seed productivity per shoot varied from 1989 to 7064 pcs., it is associated with precipitation in the second decade of July of the current growing season. The high number of the population studied (25 thousand shoots), the correspondence of the ontogenetic spectrum to the basic one of the species, the annual presence of juvenile plants of seed origin indicates its stable condition. 

Article 36 of the Federal Law on Hunting and Conservation of Hunting Resources of 24.07.2009 No. 209-FZ (in the edition of the Federal Law of 22.12.2020 No. 455-FZ) stipulates that the accounting of hunting animals, in respect of which, in accordance with the above Federal Law, the limit of extraction and the quota of their extraction are established, is carried out on the basis of scientifically substantiated methods. Currently recommended by the authorized federal executive body and posted on the information and telecommunication network “Internet” on the official website of the authorized federal executive body is the Methodology of accounting for the number of hunting resources by the method of winter route counting, approved by the order of FGBU “Federal Research Center for Hunting” from November 14, 2022 no. 74. One of the main differences of the mentioned methodology is the algorithm of determining the minimum necessary total length of counting routes from the total area of hunting grounds located within the boundaries of the relevant hunting farms. However, in the open press there are no data on the conducted scientific studies justifying such an approach to determining the necessary length of survey routes. This was the basis for the present study. On the example of moose counting for some hunting farms of Saratov region the possibility of objective determination of the minimum necessary total length of counting routes depending on the total area of hunting grounds located within the boundaries of these farms was checked. The results of the study showed that such an approach in planning the volume of survey work is fundamentally flawed and cannot be considered scientifically justified, and since it takes the central place in the considered Methodology of counting the number of hunting resources by the method of winter route counting, the latter is scientifically unjustified. Consequently, its placement in the information and telecommunication network “Internet” on the official website of the authorized federal executive body contradicts the current legislation of the Russian Federation in the field of hunting and conservation of hunting resources. 

The results of our studies of the great bustard population in the Saratov and Volgograd Trans-Volga region are presented. For the first time in this territory, censuses of the numbers of bustards were carried out in their lek areas in the spring for 3 years. This made it possible to obtain more reliable data on the numbers of individuals of this species, as well as on the demographic structure in the model area and compare them with those obtained during autumn population counts. In our opinion, as a result of agriculture intensification, the nesting habitats of the bustard have been sharply reduced, which was caused by changes in the structure of crop areas and the massive use of pesticides. In the absence of necessary protection measures, this has led to a reduction in the numbers of birds in the Saratov Trans-Volga region by almost 10 times over 20 years. This trend is observed throughout almost the entire world range of the great bustard, where there are no long-term effective measures aimed at preserving the natural habitats of the species. In the Trans-Volga region, the number of lek areas has decreased by approx. half and the numbers of individuals of the species in the remaining leks have decreased. The demographic structure of the bustard population when studied in lek areas shows a significant predominance of males over females, which contradicts the stability of the population. Due to the reduction in the number of habitats suitable for bustards to nest, the success of their reproduction has significantly decreased. Spring treatment of crop areas with pesticides by ground and aerial methods coincides with the nesting period of birds, which is a powerful factor of disturbance and leads to the loss of clutches. Females whose clutches have been preserved, have the problem of acute food shortage after their chicks hatched, which also leads to elimination of some part of the broods. 

Clostridia are one of the largest genera of eubacteria living in water, soil, the intestines of humans and animals. The genus Clostridium includes both pathogenic and non-pathogenic species. Representatives of this genus occupy a leading position among all types of bacteria in producing a variety of toxins. Due to their ability to form spores, these microorganisms can survive in the most unfavorable conditions. Antibiotic-resistant Clostridia, which are released to the environment as part of farm animal manure, are of particular environmental danger. We have studied the influence of various treatment methods (aeration, acidification, and surfactant application) of the liquid fraction of pig manure effluents (ME) on the species composition and the numbers of Clostridia. Cl. septicum and Cl. perfringens were found to occupy a dominant position in the ME of manure storage baths. Both species are actively involved in the ammonification of organic compounds, releasing a wide range of volatile substances with an unpleasant odor into the environment. Most of the Clostridia were detected in biofilms formed on the surface of ME under anaerobic conditions. Such conditions are formed during storage of the liquid fraction in closed lagoons, which increases the environmental risks of the release of undesirable microorganisms into the environment. Round-the-clock aeration and acidification of ME to pH 5.5 reduce the numbers of Clostridia. Such conditions contribute to the formation of microorganism consortia with fungi to occupy a dominant position. Cl. difficile (32.52%), Cl. putrificum (31.62%) and Cl. septicum (30.72%) predominated in biofilms of acidified ME, whilst only Cl. difficile (69.98–95.26%) did in options with surfactants added. The largest relative numbers of pathogenic Cl. difficile (95.26%) were observed in the option with the addition of a cationic surfactant (benzalkonium chloride). 

clarification. In the course of our specially organized expedition, tissue samples of the common hamster were collected in 12 regions of Russia and Kazakhstan, including areas at the potential border of the ranges of phylogroups “A” and “E” (“Europe”). Analysis of the nucleotide sequences of the cytb gene of the captured animals has shown that the boundary between these phylogroups runs between Turinsk and Yekaterinburg, further between Chelyabinsk and Kurgan, between Omsk and Tatarsk, and turns to the south, leaving the village of Turgai and the town of Temirtau in the west and the village of Bayanaul in the east. The structure of territorial genetic clades belonging to phylogroups “A” and “E” and the history of their formation were also analyzed. Most of the detected territorial clades were formed during the Late Pleistocene and Holocene. The population dynamics of phylogroups “A” and “E” was analyzed and its decline was shown in 8 of the 12 surveyed regions. 

Cenopopulations of three rare and protected plants of the Saratov region (Gladiolus tenuis, Iris halophila, and Dactylorrhiza incarnata) were found in the tract “Bolshiye Mochazhiny”. These species are protected in neighboring regions as well – the Tambov, Voronezh, Penza regions and others. The species are of high ornamental value, which is another factor besides the narrow ecological amplitude of the plants. G. tenuis, I. halophila, and D. incarnata are demanding to moisture and soil fertility, have high numbers, and create aspects. In the cenopopulations of the studied plants a process of self-renewal proceeds, which is not hampered by anthropogenic factors, as the tract is far from settlements and is swampy in some places. The morphometric indices of the rare species correspond to their biology. The ontogenetic status of the species cenopopulations is characterized by a single-vertex spectrum with a high proportion of individuals of generative fractions: 49.4% for G. tenuis, 40.0% for D. incarnate, and 62.2% for I. halophila, respectively. According to T. A. Rabotnov’s classification, the cenopopopulations of the studied species are normal incomplete-membered. According to L. A. Zhivotovsky’s delta–omega classification, the cenopopulations of G. tenuis and D. incarnata are old; while that of I. halophile is aging. The studied cenopopulations of rare plants are stable in time and space. It is necessary to declare the tract “Bolshiye Mochazhiny” a natural monument of regional importance.