Статьи

DEVELOPMENT OF THE SYSTEMATIC APPROACH TO STUDYING AGRICULTURAL LAND AND AGROLANDSCAPE MANAGEMENT

Methodological foundations of agrolandscape-environmental studies and management of agricultural land were developed. They are based on the concept of conservation and reproduction of land and other natural resources used in agriculture, soil fertility, the productive longevity of agro-ecosystems and agro-landscapes (All-Russian Williams Fodder Research Institute); the concept of the ecological frame of agricultural landscapes and ecologo-economic balance (Moscow State University, Institute of Geography Russian Academy of Sciences).

INFLUENCE OF NATURAL AND CLIMATIC FACTORS ON THE NUMBERS OF SAIGAS (SAIGA TATARICA PALL.) (BOVIDAE, ARTIODACTYLA) BETWEEN THE VOLGA AND URAL RIVERS

Characteristics of the Uralian saiga habitats are discussed. Periods of high and low abundance of the animals that alternate depending on the productivity of plant communities and territorial humidity (the number of watering-places) due to climate changes are shown. After the occurring periodic mass death of saigas, their population is quickly restored to its previous level, according to the existing feed and water resources.

PHYSIOLOGICAL AND BIOCHEMICAL ASPECTS OF HALOPHYTE ECOLOGY

Physiological and biochemical features of euhalophytes, сrinohalophytes and glycohalophytes growing in natural conditions in the Elton Lake area were studied. The water content in tissues, lipid peroxidation intensity, and membrane permeability were found to determine the differentiation of plants by their salt accumulation strategy. The concentration of pigments and their ratio are related to the mesostructure of leaves and dependent on the salt accumulation strategy and living form. The membrane complex is connected with the cell structure and photosynthetic apparatus.

STATISTICAL ANALYSIS OF THE DISTURBANCE FACTOR INFLUENCE ON THE SPATIAL STRUCTURE FORMATION OF THE GREAT BUSTARD (OTIS TARDA L.) (OTIDIDAE, AVES) POPULATION IN THE TRANS-VOLGA REGION

The paper examines the influence of the location of settlements, railroads and highways on the spatial structure of the Otis tarda population in the Trans-Volga region studied on a model area of 12,000 km2, located in the southern part of the Saratov Trans-Volga region in 1998 – 2016.

SOIL STATUS ASSESSMENT IN URBAN AREAS BY CHEMICAL AND ENVIRONMENTAL TOXICOLOGICAL METHODS

The ecological status of soils in an urbosystem was assessed in terms of the total content of heavy metals, their mobile forms, petroleum products, integrated toxicity, and soil catalase activity. Parts of the functional transport areas of the city have turned out to be the most disadvantaged areas. A tendency of suppression of the ciliate motor activity and the growth indicators of watercress, reduction of the catalase activity in urban soils are observed.

INFLUENCE OF MACROPHYTE DEVELOPMENT IN THE ZOOPLANKTON STRUCTURE FORMATION IN THE LOWER REACHES OF THE VOLGA RIVER DELTA

The cattail, reed and bur-reed association is the cenosis-forming ones for a part of the mouth of the Kutum duct of the kultuk area of the Volga river delta. The insular area of the avandelta is characterized by reed–mace associations. The terrestrial and aquatic vegetation begins to grow massively in late May. The aquatic vegetation begins to die since the end of July whereas the terrestrial vegetation, on the contrary, reaches its maximum in this period.

PHYTOPROTECTIVE EFFECT OF AMMONIUM HUMATE AT HIGH COPPER CONCENTRATIONS IN THE ENVIRONMENT

The influence of ammonium humate obtained from peat on the wheat plant tolerance to high CuSO4 concentrations (100, 250, 500, and 1000 μM/l) was studied. Seeds were germinated on cop-per sulphate solution with and without the humate. Then the plants were grown on Hoagland’s solution in an artificial climate chamber. The humate protective action coefficient was estimated in two ways, namely: by dry weight changes and by copper ion content in comparison with the plants grown without humate.

GENETIC DIVERSITY IN POPULATIONS OF THE SILVER CRUCIAN CARP CARASSIUS AURATUS GIBELIO (CYPRINIDAE, CYPRINIFORMES) AS DEPENDS ON REPRODUCTION TYPE AND RESERVOIR SIZE

The paper presents data on the polymorphism of the interior simple sequence repeats of DNA in the silver crucian carp Carassius auratus gibelio from waterbodies in the Western Siberia. The proportion of the polymorphic ISSR-PCR bands in the silver crucian carp populations from different lakes varied from 40 to 70%, the rate of Nei’s gene diversity being 0.16 – 0.25. Genetic diversity indicators were lower in the populations primarily presented by females, as compared with bisexual ones.

MERCURY CONTENT AND ANTIOXIDANT SYSTEM IN INSECTIVOROUS (INSECTIVORA, MAMMALIA) AND RODENTS (RODENTIA, MAMMALIA) OF VARIOUS ECOGENESIS

The present study was aimed at analyzing the total mercury in the tissues of mammals adapted to the semi-aquatic or subterranean lifestyle and at analyzing the possible role of their antioxidant system in heavy metal detoxification. The water shrew (Neomys fodiens Pennant, 1771), European mole (Talpa europaea Linnaeus 1758), muskrat (Ondatra zibethicus Linnaeus, 1766), and water vole (Arvicola terrestris Linnaeus, 1758) were the species under study.

FLORISTIC RICHNESS OF PHYSICAL-GEOGRAPHICAL AREAS AND A FLORISTIC SUBDIVISION SCHEME OF THE MIDDLE-VOLGA REGION

A scheme of floristic division of the Middle-Volga region has been compiled for the first time on the basis of available material and our analysis of the distribution of plants over the physical-geographical regions of the Middle Volga and identification of their floristic similarity. A brief description of each floristic region is given. The species of vascular plants determining the specificity of these regions are listed.

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