bluuebunny/crossref_metadata_2025_split huggingface dataset:
Water deficiency of little-leaf linden poly-metallic contamination
Authors: Kh Giniyatullin R , Zaitsev G A 
Published: July 2021

Abstract
A high level of environmental pollution identifies Sterlitamak industrial center (PreUral, Russia). Among human-made emissions, particulate matter (including heavy metals), nitrogen dioxide, ammonia and formaldehyde dominate. We studied the water regime of little-leaf linden (Tilia cordata Mill.) trees in habitats with diverse pollution levels from 2010 to 2018. There have been significant changes in the indicators of water deficiency of linden leaves under pollution conditions. Regardless of the category of life state, the linden trees had a slight water deficit under control, while the healthy and weakened linden trees had a high-water deficit under pollution conditions. The results point that under polluted conditions, as the temperature increases and the air’s relative humidity decreases, the water consumption of linden leaves increases. The maximum water deficiency is in the daytime (13-15 hours). At night, the flow of water is not covered by the inflow, so the following day, the morning begins with some water lack. Thus, in a polluted environment, significant changes in the water deficit of the linden trees are associated with reduced soil moisture, increased transpiration, and worsened of stand life states.
Vertical Distribution and Migration of Algae under Thermal Stratification in Small Water Bodies of the Forest-Steppe Volga Region
Authors: Gorokhova O G 
Published: July 2021

Abstract
In this article the author presents some study results of taxonomic composition, distribution and migrations of algae under thermal stratification in small water bodies of the forest-steppe Volga region. The author considers the main factors influencing the formation of heterogeneity of the structure of algocoenoses: vertical temperature gradients, water density and the content of basic biogenic substances. The composition of vertically migrating common species is discovered. The nature of species distribution during the day is shown, when samples are taken with an interval of 3 hours. The predominance of mobile mixotrophic phytoflagel-lates is a feature of the taxonomic composition of algae in water bodies with a pronounced vertical heterogeneity of populations of dominant species. The clearest picture of distribution and migration in plankton is demonstrated by Pandorina morum, Mallomonas caudata, Dinobryon divergens, Cryptomonas curvata, and a number of other large-cell flagellar forms. Of the species without active movement, vertical distribution was constantly observed in Westella botry-oides, Botryococcus braunii, Dictyosphaerium pulchellum, Koliella longiseta, Woronichinia naegeliana, and some species of the genus Anabaena. The author notes the connection between the maximums of the abundance of some common species with changes in the content of nutrients within the photic zone. Vertical heterogeneity of taxonomic and quantitative indicators in algocoenoses is considered as an adaptive strategy to the heterogeneity of the habitat in highly eutrophic water bodies with a high density of algae in plankton.
Floristry and plant biogeography of the Eastern part of the Volga Upland
Authors: Gafurova M M , Ivanova A V , Yu Istomina E 
Published: July 2021

Abstract
Analysis of taxonomic indicators traditionally leads the overall analysis of flora. In this case, first of all, it is necessary to consider the range of families. The triad of leading families deserves special attention, according to the third member of which it is customary to distinguish the type of flora. The type of flora characterizes the corresponding territory within which a floristic “zone” is distinguished. According to the published data on the floras of the administrative units of the Volga basin, we have previously outlined the boundaries within the territory of the Middle and partly the Lower Volga region, on which the Fabaceae-type of flora is revealed. At the same time, the Upper Volga region is represented by Rosaceae-type floras. However, these selected administrative units are too large to outline more specific boundaries.In this article, we propose a similar analysis based on the data of the floras of physical-geographical regions with an area of 2.3–9.7 thousand km2. For the analysis, we selected six areas belonging to the forest-steppe province of the Volga Upland, which is part of the Middle Volga region. We found that the border of the floristic zones (Fabaceae and Rosaceae) runs along the considered area of the Volga Upland. With respect to physical-geographical regions the border runs on one side between Korsun-Sengileevsky and Sredne-Sviyazhsky areas, on the other, between Zasursky and Tsivil-Kubninsky areas. Within the studied territory, the border is determined by the occurrence of representatives of the genera Alchemilla and Potentilla (for Rosaceae), as well as Vicia and Astragalus (for Fabaceae) The prevalence in the number of the common lady’s mantles is more noticeable to the northwest. The genera Carex, Galium, Viola, Potentilla, Artemisia, Salix, Vicia, and Veronica are leading in the frequency of occurrence in the head part of the spectra of floras in the territory under consideration.
Taxonomic structure as an indicator of anthropogenic transformation of flora: The Case Of the southern part of the Melekess-Stavropol region (Samara Trans-Volga region)
Authors: Ivanova A V , Kozlovskaya O V 
Published: July 2021

Abstract
The results of anthropogenic impact can be traced on different components of the ecosystem. The vegetation cover is the basic component. Higher vascular plants make up an essential part of it. The flora of Samara Oblast can be characterized as the flora of legumes, since the Fabaceae family ranks third in the spectrum of families. However, not all territories in its composition have similar characteristics. Earlier, we analyzed the features of the flora of the Low Trans-Volga province using the example of the Melekess-Stavropol region. Its territory has a low-lying flat relief and significant economic development. As a result of human economic activity, most of the territory has been plowed and deforested. The flora of the southern part of the area is distinguished by the abundance of representatives of the Brassicaceae and Rosaceae families. The family Fabaceae is represented here by a relatively small number of species. Within the framework of this study, we consider local floras of various sizes corresponding to the middle part of the Melekess-Stavropol physical-geographical region (Suskan group) and the southern part (Togliatti group). Each of these groups, considered when taking into account the forest massifs in its composition, which, among other things, have a small area, exhibits the Rosaceae type of flora. At the same time, the indigenous fraction of the Suskan floristic group, excluding forest flora, shows the Cyperaceae type. The Rosaceae-type of flora can be considered as corresponding to the natural conditions of the studied area. The abundance of the Brassicaceae family can be explained by a significant anthropogenic transformation of the territory, which manifests itself, in particular, as an adventitization of the flora.
First finding of spirurid larva (Chromadorea, Spirurida) in the common European viper Vipera berus (Linnaeus, 1758) of the Russian fauna
Authors: Kirillov A A , Yu Kirillova N 
Published: July 2021

Abstract
The National park “Smolny” (Republic of Mordovia, Russia) is located in the Basin of Alatyr River, a second-order tributary of the Volga River. Favorable conditions are created for the development of helminths and infecting reptiles with them in floodplain biotopes. In 2018–2020 in this Protected Area we examined 25 individuals of the common viper Vipera berus (Linnaeus, 1758) by the method of complete helminthological dissection. We studied only road-killed vipers and reptiles killed by local residents. In total, eight species of helminths were registered in vipers: Leptophallus nigrovenosus, Telorchis assula, Alaria alata, larvae, Rhabdias fuscovenosa, Oswaldocruzia filiformis, Physocephalus sexalatus, larvae, Physaloptera clausa, larvae and Agamospirura minuta, larvae. Larva of spirurid nematodes Ph. sexalatus, Ph. clausa and A. minuta were recorded in the common viper for the first time in Russia. We found these nematode juveniles in walls and lining of stomach and intestine of snakes. We gave original drawings and morphological descriptions of these nematodes. Vipera berus was noted as a new host for Physaloptera clausa. Currently the helminth fauna of Vipera berus of the Russian fauna includes 15 species. Helminth infection of Vipera berus strongly depends on habitat and, especially, on the diet features. Snakes that live in dry habitats and feed on mouse-like rodents, as a rule, are weakly infested by helminths. Conversely, helminth infection is higher in vipers living in near-water habitats and feeding tailless amphibians. Participation of paratenic hosts in the helminth life cycles plays an important role in the distribution and preservation of parasites in the wild, and increases the invasion probability of the final hosts.
Integrative assessment of anthropogenic transformation of the flora in the Uzyukovo forest massif (Low Trans-Volga region)
Authors: Kozlovskaya O V , Ivanova A V , Ilyina V N , Kozlovskaya T N , Belyaeva Yu V 
Published: July 2021

Abstract
The authors give a physical and geographical description of the Uzyukovo district forestry (Low Zavolzhye) in the Novo-Buyansky forestry of Samara forest management with a forested area of about 8.5 thousand hectares. An inventory of the species composition of the flora of the Uzyukovo district forestry revealed about 400 species of vascular plants. We carried out a comprehensive ecological analysis of floristic fractions: taxonomic, biomorphic, phytocoenotic, and geographical. Comprehensive ecological analysis as a whole reflects the confinement of flora to the forest-steppe zone. The results of a comprehensive ecological analysis are supported by a physicochemical analysis of the soil cover of the Uzyukovo forest massif. The tendencies of anthropogenic dynamics of flora are considered, the degree of anthropogenic disturbance of floristic complexes is revealed by means of soil analysis, analysis of the adventive component and the preservation of rare species of flora. In the adventive flora of the Uzyukovsky forest massif, 98 species of plants, mainly woody, have been identified. The authors provide a list of rare species in need of conservation, of which 2 species are included in the Red Data Book of the Russian Federation and 21 species in the Red Data Book of Samara Region. Under the influence of anthropogenic factors, on the one hand, ecological-floristic complexes are enriched with eurytopic weed species, and on the other, the number of anthropophobic rare species is reduced, which is steadily leading to the unification of the flora. In this regard, the authors recommend assigning the Uzyukovsky forest massif the status of a regional natural monument and regularly carrying out environmental monitoring.
Distribution of picoplankton and detritus in the lower course of the Kama River
Authors: Krasnova E S , Umanskaya M V 
Published: July 2021

AbstractThe distribution of picoplankton and detritus in the lower course of the Kama River in 2009, 2012, 2016 and 2020 was analyzed. The abundance (1.5-6.7 × 106cells mL−1) and biomass (25-173ug C L−1) of picoplankton corresponds to the mesotrophic level. The abundance and biomass of the heterotrophic picoplankton increases from spring to autumn, the autotrophic picoplankton has maximum in August. The amount (17-1367 × 103particles mL−1) and mass (0.1-62 μg C L−1) of picodetritus varies greatly from station to station without clear patterns, but basically its mass is higher at coastal stations. Heterotrophic picoplankton prevails in picoseston structure; the average APP and picodetritis contributions are comparable, with little excess of picodetritus. The structure of the picoseston varies significantly depending on the season and the riverbed or the coastal location of the station. The amount of nanodetritus is very high (up to 229 × 103particles mL−1and 662 μg C L−1), and it varies slightly both in space and in time. Its mass is almost always several times higher than the biomass of picoceston Most likely, nanodetritus is one of the main factors affecting the plankton of the lower course of the Kama River.
The current state of the steppe vegetation classification system in the Volga region
Authors: Lysenko T M 
Published: July 2021

Abstract
Steppe vegetation in the Volga region is one of the predominant types of vegetation. At present, it has survived only in areas inconvenient for human economic and recreational activities. Its research is necessary to understand the structure and composition of zonal vegetation and distribution patterns to predict changes in the modern vegetation cover. The relevance of studying the steppe vegetation of the Volga region is also due to the creation of the project “Vegetation of Russia”. We studied the steppe vegetation of the Volga region in the period from 2011 to 2020 from the standpoint of the J. Braun-Blanquet approach. Field studies covered all the diversity of the steppe vegetation represented in the region-herb-rich grass steppes, herb-grass steppes, grass steppes and desert and their psammophytic, petrophytic and halophytic edaphic variants within Ulyanovsk, Penza, Samara, Saratov, and Volgograd Oblasts, the western part of Orenburg Oblast and the northern part of Astrakhan Oblast. The syntaxonomic analysis of our own materials and literature data made it possible to establish 65 associations, 47 subassociations and 2 variants. They are assigned to the class Festuco-Brometea, the orders Festucetalia valesiacae, Helictotricho-Stipetalia, Tanaceto achilleifolii-Stipetalia lessingianae and the alliances Festucion valesiacae, Agropyrion pectinati, Centaureion sumensis, Stipion korshinskyi and Tanaceto achilleifolii-Stipion lessingianae.
Freshwater mollusks of the Priplotinny Ples Reach, the Kuibyshev Reservoir (middle Volga River, Russia)
Authors: Mikhailov R A 
Published: July 2021

Abstract
In September 2020, the fauna of mollusks was studied at the Priplotinny Ples Reach of the Kuibyshev Reservoir, the Volga River, Russia. In total, 23 taxa were registered, including four invasive species. Extrapolating of the species richness, taking into account the sampling effort, allowed to assess the estimated species pool according to the Chao 2 algorithm. Bivalve mollusks predominated in the studied area. The mollusks Dreissena (Pontodreissena) bugensis and Dreissena (Dreissena) polymorpha have been found most frequently at the study sites. Both abundance and biomass varied in wide range, as 391 ± 325 ind. m−2 and 256.693 ± 228.355 g m−2, respectively. The complex of dominant species was mainly represented by alien mollusks. The type of bottom sediment was a significant ecological factor (p ≤ 0.05) that determined the distribution of mollusks at the Priplotinny Ples Reach. The water quality of the study area was assessed by bioindication method according to the composition and structure of the mollusk fauna, formed mainly by species of European and European-West Siberian ranges.
Primary signs of internal organ diseases in carp in case of standard condition violations in fish farming ponds
Authors: Mineev A K , Mineeva O V 
Published: July 2021

Abstract
Hematological and histopathological study results of adult carp from a private fish farm are presented. Abnormalities in the main hematological parameters (blood elements ratio, leukocyte formula, erythropoiesis level, possible pathologies of erythrocytes) were not revealed. One third of the examined fish were found to have abnormalities in the tissues of gills, liver, and heart muscle in the form of minor focal formations (detachment of the gill epithelium, dissection of myofibrils, disorders of glycogen metabolism, foci of necrosis and infiltration) which indicates the initial stage of the pathological process. Kidneys, gonads, and somatic muscle fibers showed no signs of pathology. The main factors determining the primary signs of internal organ diseases are water quality (water saturated with magnesium, calcium, and iron salts, increased hardness) and an unbalanced diet (primarily, an insufficient amount of raw protein) that does not meet the standards adopted in fish farming. The registered initial signs of the pathological process in the gills, liver and heart muscle can be leveled by improving the carp keeping conditions.
Influence of Chloride- and Soda-Dominated Salinity on Physiological and Biochemical Aspects of Halophytes with Different Strategies of Salt Metabolism
Authors: Nesterov V N , Bogdanova E S 
Published: July 2021

Abstract
The authors study the effect of NaCl and NaHCO3 at concentrations of 1 M on the physiological and biochemical state of Salicornia perennans and Artemisia santonica for 24 hours. In our experiment, we evaluated: the accumulation of Na in the aerial part of plants, the stress index is lipid peroxidation (LPO); the state of membranes – by the composition and content of lipids and proteins, the level of photosynthetic pigments. The euhalophyte S. perennans accumulated Na on average 30% more than the glycohalophyte A. santonica. The addition of NaCl and NaHCO3 to the root environment promoted an increase in LPO in S. perennans by 2.4 times as compared to the control. In the case of A. santonica, LPO concentration increased by 1.2 times, but only when NaHCO3 was added to the soil. In addition, NaCl and NaHCO3 negatively affected plant lipids and proteins. Thus, in S. perennans plants, NaCl contributed to a decrease in phosphlipids by 34%, and NaHCO3 in glycolipids by 22% in comparison with the control. The quantitative content of the sum of water-soluble and membrane-bound proteins in the studied plants decreased by 10–36%. Chloride and soda-dominated salinity caused a decrease in the proportion of chlorophyll a and carotenoids only in S. perennans. The authors concluded that the response of the photosynthetic system and membrane complexes to various types of salinity in euhalophyte and glycohalophyte was different.
Analyzing Water Conservation Indicators in Russia
Authors: Rashoyan I I 
Published: July 2021

Abstract
The authors collected and analyzed statistical indicators of the use and pollution of water resources in Russia for the time period 2009-2019. The authors studied the dynamics of statistical data on water withdrawal from natural water reservoirs for practical use, as well as on discharge of polluted sewage, and also differentiated the data obtained by the main types of economic activity (industries). Some conclusions are made on the effectiveness of the implementation of measures for the protection of water resources for each type of activity. The article highlights the industries using water resources most efficiently over the past 10 years and systematically implementing measures to reduce the discharge of polluted wastewater into surface water bodies. The study shows in which industries the efficiency of water purification and water use activities has decreased for the same period. The results of the analysis can be used to optimize and manage measures for the use and conservation of water resources for certain types of economic activities.
Monitoring research and care for nature technologies in biosphere reserves UNESCO
Authors: Roshchevskiy Yu K , Vekhnik V A 
Published: July 2021

Abstract
In biosphere reserves UNESCO, we propose to distinguish scientific research studying the unknown qualities of the biota from technological design aimed at restoring and caring for the ecosystems of a reserve. In primary or climax ecosystems, we propose to use technological methods that prevent anthropogenic transformation. In secondary and degraded ecosystems at different levels, we propose artificial restoring of the lost functions of ecosystems. Examples of monitoring studies in ecosystems with varying degrees of disturbance in the Middle-Volga Integrated Biosphere Reserve are considered.
Effect of cadmium on the mesophyll parameters, pigments, and lipid profile of the photosynthetic apparatus of Suaeda salsa
Authors: Rozentsvet O A 
Published: July 2021

Abstract
Halophytes were found to accumulate HM ions in their tissues; therefore, they are potentially useful for remediation of soil contaminated by salt or HM. In this study, we evaluated the effect of Cd2+ on the characteristics of mesophyll, pigments, and lipid profile of the photosynthetic organelles of the halophyte Suaeda salsa. Seeds were sprouted in distilled water for 1–3 days and then sown in containers with sand. Plants were watered with Robinson’s nutrient solution. After 3 months, plants were divided into two groups: experimental and control. In the experimental group, soil was treated with 200 µM Cd(NO3)2 for 24 hours. Our findings suggest that Cd2+ causes changes in the anatomical structure of the leaf and the ultrastructure of the photosynthetic organelles in S. salsa due to alterations in the composition of lipids and fatty acids.
Interannual and intra-annual changes in the Volga River water discharge in the alignment of the Zhigulevsk hydroelectric complex
Authors: Seleznev V A 
Published: July 2021

Abstract
Interannual and intra-annual changes in river water flow play a decisive role in the formation of water quality and the functioning of aquatic ecosystems. For a quantitative assessment of long-term and seasonal changes in the water flow of the Volga River, an analysis of water discharge in the outlet section of the Kuibyshev reservoir (Zhigulevsky hydroelectric complex) for the period 1958-2019 was carried out. Almost the entire water flow of the Volga River passes through the bottom spillways of the hydroelectric power station and the overflow dam of the Zhigulevsky hydroelectric complex. The results of time series analysis showed that the average annual water discharge was 7,7 × 103 m3/s, the highest water discharge was 10,4 × 103 m3/s, and the lowest water discharge was 5,3 × 103 m3/s. Over a long-term observation period (61 years), it was established that the water content of the river is characterized by a change in low water and high-water periods. Statistical analysis revealed a positive trend for an increase in the average annual water discharge of the Volga River by 700 m3/s. Extremely low-water (1996, 1977, 1976, 1975, 1973, 1967) and extremely high-water (1994, 1991, 1990, 1981, 1979, 1966) years have been identified. The regulation of water flow at the Zhigulevsky hydroelectric complex has formed the seasonal variability of water discharge, which is characteristic of technical water bodies. Within the year, three periods are distinguished: winter low-water period (December-March), spring high water (April-June), and summer-autumn low-water period (July-November). The highest water discharges were observed during the spring flood (8,7-19,6 × 103 m3/s). During the winter and summer-autumn low-water period, the water discharge was 5,5-6,5 × 103 m3/s. The amplitude of fluctuations in the average monthly water discharge for the entire observation period was 2,1-33,5 × 103 m3/s.