Polycyclic Aromatic Hydrocarbons in Betula nаnа (Betulaceae, Magnoliópsida) under the Impact of a Thermal Power Plant

The content of polycyclic aromatic hydrocarbons (PAH) in Betula nаnа L. and soil organogenic horizons was studied at a control site and sites affected by a thermal power station (TPS) at distances of 0.5, 1.0, and 1.5 km from the source of pollution. The PAH distribution over the vegetative organs of dwarf birch was irregular. The qualitative composition of PAH in different organs of dwarf birch was similar. No significant changes in the PAH content in dwarf birch organs and at the surface of these organs at different distances from the TPS were revealed.

About the Border between Two Phylogroups of the Common Hamster (Cricetus cricetus) (Cricetinae, Rodentia)

The Common hamster (Cricetus cricetus) is the rodent with one of the largest range (6 million km2). There were four phylogenetic lineages earlier recovered in Western Europe, Ukraine and Bryansk Province of Russia: “North”, “Рannonia”, E1 and E0. E1 was previously reported from South-Eastern Poland and Western Ukraine and never been found in sympatry with “Pannonia” although the closest distance between them was estimated as 20 km. The question is whether the sympatry of E1 and E0 phylogroups exists?

Number of Small Mammals in Fields, Stacks and Ricks in the South of the Central Black-Earth Region

The results of studies conducted by the sanitary and epidemiological service in the Voronezh region from 1959 till 2013 were analyzed. Records of small mammals (SM) were carried out by snap traps with wire hooks for baiting. Standard bait (black bread pieces flavored with sunflower oil) was used. Traps were placed in lines. The numbers of SM were calculated as a percentage of animals fallen into 100 traps per day. The data obtained were analyzed using conventional statistical methods, including the method of standard deviations.

Biodiagnosis of Soil with a Low Level of Anthropogenic Impact (with the typical Urban Settlement Stepnoe, Saratov Region, as an example)

With the urban-type settlement Stepnoe as an example, biodiagnosis of the soil of a settlement with low technogenic impact was conducted. In the course of our work, 30 soil samples were plated onto solid nutrition media to evaluate the following: the total numbers of heterotrophic microorganisms - on meat peptone agar, the numbers of hydrocarbon-oxidizing and iron-oxidizing microorganisms - on their corresponding selective media, and the activity of several soil redox and hydrolytic enzymes (dehydro-genases, catalases, peroxidases, and invertases) were also studied.

Population Dynamics Factors of Ungulates and Wolves of the Saratov Region in the 21st Century

The paper is devoted to studying of the relations between the formation of “private” hunting grounds, the increase in the density of ungulates and the decline in the numbers of wolves, and the role of other factors determining the abundance of these game animals.

Gamma Radiation Effect of Partnogenetic Artemia (Branchiopoda, Anostraca) Cysts on Nauplius Hatching and Postnauplius Survival under Different Salinity

The effect of gamma radiation doses of 0, 2.5, 5.5 and 7.5 Gy received by Artemia cysts on the hatching of nauplii and post-nauplial survival of crustaceans was studied at salinities of 0, 9, 18, 36, 54, 62, 78 and 88 g/L. Under the same salinities, the above parameters were also estimated without irradiation. It has been found that the rate of nauplii hatching from cysts primarily depends on salinity, the coefficient of determination being 90%.

Structure Transformation of the Anuran Amphibian Spawning Communities in Floodplain Lakes of the Medveditsa River Valley (Saratov Region) under Conditions of Long-Term Reduction of Water Content

The structure of spawning taxocenoses of anuran amphibians in five floodplain lakes of the Medveditsa river valley in 2009-2018 is analysed. Two near-terrace lakes (Lebyazhye and Koblovo) and three lakes of the central floodplain (Sadok, Kruglen’koye, and Cherepashie) were used as model ones. The degradation of the populations of the three most numerous species, a decrease in the dominance degree of the common spadefoot toad were established.

Phytoplankton of the Plain River Usa (the Kuibyshev Reservoir Basin)

Data on the status of summer phytoplankton of the Usa river and its tributaries are given. 184 taxa of algae with a rank lower than the genus from 7 divisions were recorded in algoflora, with Bacillariophyta (43-57% of the composition) and Chlorophyta (23-47%) predominating in the rivers. The abundance range in algocenoses was 0.02 - 5.2 mln cells/L, that of biomass was 0.01 - 1.8 mg/L; the content of chlorophyll-a was 0.01 - 3.1 µg/L.

Bacterioneuston Abundance and Physicochemical Properties of the Surface Microlayer of Lake Baikal

The aquatic surface microlayer is located at the atmosphere-hydrosphere boundary and occupies 70% of Earth's surface, covering all water bodies. The depth of the surface microlayer is about 50 μm. A special microbial community called neuston is formed there. The total bacterial abundance in the surface microlayer (SML) and underlying waters (UW) of Lake Baikal was studied using epifluorescence microscopy. Physico-chemical features of the surface microlayer of Lake Baikal were revealed for the first time.

Estimation of the Toxicity of a Metal/Carbon Nanocomposite of Copper by Biotesting

The toxic effect of a metal/carbon copper nanocomposite (Me/C Cu NC) on higher plant seeds and the bacterial sensor “Ecolum-8” was evaluated. A significant inhibitory effect of 0.1% nanomaterial on the seedlings of radish seeds was established. Some stimulating effect on the development of the roots of this culture was found at a concen-tration of 1 • 10–8%, but it was insignificant (by 11.3%).