Regularities of the Growth of Pedunculate Oak (QUERCUS ROBUR L., 1753) in the Protective Plantings of the Steppe and Forest-steppe of the Volga Upland

The purpose of the study is to establish the regularities of the growth of pedunculate Oak in protective forest stands on erosion-prone slopes in the conditions of the steppe and forest-steppe of the Volga Upland. Studies have established a regular decrease in the height of the petiolate oak on the southern chernozem and gray forest soil by 6.9-11.3% with an increase in the slope of the slope by 2 times, which is associated with a drop in soil fertility as a result of increased erosion. The index of oak growth intensity with an increase in the slope slope increases on both types of soils by 21.4-38.5%, and the productivity of cambium decreases by 14.1-23.6%. The same trends in the dynamics of taxation indicators are characteristic of the accompanying species of petiolate oak-holly maple and small-leaved linden. The coefficients of determination of the relationship of growth in the height of the pedunculate oak from the indicator of growth intensity and productivity of cambium are 0.95-0.98, which indicates a close interdependence.

Impact of environmental conditions on the vitality structure of the cenopopulations of the dominant tree tier in the forests of the southern part of the Volga Upland

The vitality structure of cenopulations of woody plants is formed under the influence of ecological, cenotic and anthropogenic influences. The study of the nature and degree of influence of the ecological parameters of the habitat will make it possible to predict the formation of the vitality structure of woody plants. The objects of study are individuals of the generative age state of three species of woody plants: Quercus robur, Tilia cordata, Acer platanoides. Environmental conditions of habitat were assessed by using range ecological scales. Vitality was assessed by three key determinative morphometric parameters. Correlation analysis was carried out to establish the impact of environmental conditions on the indicators of the vitality of cenopopulations. Both direct and inverse relationships (with a correlation coefficient of 0.5 and above) between ecological conditions and vitality of the studied species were noted. The vitality of Tilia cordata is more influenced compared to other studied species.

FEATURES OF ACCUMULATION OF HEAVY METALS IN LANDSCAPES SURA-SVIAZHSKY WATERSHED PRIVOLZHSKY HILLS

The data of the study of the concentrations of some metals (Cd, Cr, Cu, Fe, Mn, Pb, Zn) on the territory of the Sura-Sviyazhsky interfluve of the Volga Upland are presented. In the study area, the processes of accumulation of iron and copper are taking place. The maximum concentrations were registered in the illuvial horizon of the Prisursky GPP - 884 mg / kg. Iron is a typomorphic element for the studied area. In addition to accumulation processes, iron comes from parent rocks. Copper concentrations are also significant - up to 2.39 mg / kg, registered near the city of Alatyr.

Regional features of birth rate and mortality in the Lower Volga region in the famine of 1932-1933s

The paper is exploring the problem of the vital rate data in the Lower Volga region during the famine of 1932-1933. Despite the ample quantity of papers presenting this problem the estimations and indicators differ even in the papers of the same authors and valuation methods are not always reliable. The birth rate of the Lower Volga region was 76223 while the mortality was 184570 during the 1933 famine peak by our estimate. However, there are no vital rate data on the Kalmykia in the central statistical administration archives and the registration of 15,2 thousand deaths were not ascertained identically. The real losses from the famine of 1932-1933 in the Lower Volga region (excluding Kalmykia) are estimated at 175 thousand maximum and birth rate losses are 147 thousand in 1932-1934. The mortality of the Lower Volga region had clear geographical distribution and location. The high mortality regions were allocated on the Volga Upland and abutting the Oka-Don plain eastern frontier and on the Medium Syrt frontier in Saratov Krai. The allocation of high mortality regions to the Volga River is interpreted as associating with regions containing major cities and towns with high mortality neighborhoods to the Volga. Stalingrad Krai is defined as a region with lower mortality and gradual slow in its increase with a low peak displaced to July 1933. In 1933 the Lower Volga mortality dynamics was from north to south epidemic; whereas in the south there was time to assume the measures as opposed to northern regions. Some Lower Volga regions in 1933 were characterized by a catastrophic low birth rate and high mortality and at the same time by high birth rate and low mortality and positive vital rate data. The distribution of high mortality regions was determined by the character of local authorities activities and local conditions including geographical description (orthometric height), that requires background study.

Features of the Soil Cover of the Semi-Desert Ecotone in the South of the Volga Upland

The semi-desert ecotone of the south of the Volga Upland is part of the zonal macroecotone bordering the Eastern European steppes from the southeast. Under strained hydrothermal conditions, the microrelief plays a decisive role in the redistribution of atmospheric moisture. This article contains materials from 10-year studies of the soil and landscape cover of the contact zone of the south of the Volga Upland and the northern end of Ergeni. The so-called three-membered complex described 100 years ago by N.A. Dimo and B.A. Keller is not traced in the soil cover. The methodology of landscape-catenary sections was used by laying soil-geomorphological profiles and drilling wells with subsequent sampling of soils at 5 test sites. The soil cover of the watersheds of the sites is represented by complexes of light chestnut low-humic weakly alkalinized medium- and heavy-loam soils. A smaller area is occupied by meadow-chestnut soils of cavities and solonets. The structure of the soil cover of the slopes includes combinations and variations that transform into mesocatenes. In the mesocatene of balkas, zonal light chestnut turn into metamorphosed meadow-chestnut soils or drift dark-colored soils of the bottom of balkas. The semi-desert ecotone is almost completely located within the boundaries of the spread of light chestnut soils in Volgograd region. The structure of the soil cover of the ecotone is dominated by a twofold complex, where zonal light chestnut soils in combination with meadow-chestnut soils of cavities and solonets.

Zoning of Catchments of Small Rivers in the South of the Volga Upland by the Water Protection Role of Forests

The article presents the results of the spatial distribution analysis of protective forest plantations within the catchment basins of in the south of the Volga Upland (within the Volgograd region). The data obtained are important for planning agroforestry and land reclamation. The interpretation of 133 reservoirs using satellite images and large-scale (Scale – 1:100 000) isolinear mapping of forest cover in the key areas allowed us to find that for the majority of catchments the low forest cover of the central part of the basin, caused by agricultural land use, is typical. The main environment protection function is performed by large forests of natural (growing in floodplains, uplands and steppe ravines) and artificial origin (forest shelterbelts), localized near the source (in watersheds) and the mouths of small rivers. Depending on the type of plantations and their presence or absence near the source or mouth of the river 6 types of forest cover of catchments in the south of the Volga Upland have been identified: I – river source and mouth have maxima (relative to the rest of the catchment basin) of natural forest cover; II – the source has a maximum of artificial forest cover, the mouth has a maximum of natural forest cover; III – there are no plantations at the source, there is a maximum of natural forest cover at the mouth; IV – there is a maximum of natural forest cover at the source, there are no plantations at the mouth; V – there is a maximum of artificial forest cover at the source, there are no plantations at the mouth; VI – there are no plantations at the source and mouth. It is found that the largest area within the south of the Volga upland is occupied by catchments of the III type (38.3 %), the relief of which is characterized by the predominance of gentle slopes, which have been exposed to the greatest extent to plowing and destruction of natural forest vegetation. Together with catchments of the IV–VI types, having no afforestation in the lower stream, about 59.2 % of plantations of the south of the Volga Upland are not protected from the processes of water erosion and deflation.

The influence of solar activity on the formation of plant phytomass in dry steppe conditions

The main mechanism for the formation of yield is the process of transpiration, the driving force of which is the radiation balance and photosynthetically active radiation (PAR). The larger the area of the plant surface that receives the luminous flux of solar energy, the more active the action of the photosynthetic process. The formation of organic matter depends on the formed aboveground phytomass of plants. The aim of the study is to find the optimal ratio between the emitted flux of solar energy and the area of the assimilation apparatus for further determining the phytoproductivity of plants. The object is located in the steppe zone of the central part of the Volgograd region (southern part of the Volga Upland, 48°38′52″ N, 44°26′14″ E). Modern methods of mathematical processing of experimental data were applied. The duration of the growing season of plants and the amount of light exposure affect the optical density coefficient (Kod). As a result, the coefficient (KPAR ) should be close to 1 unit for use 2.5% sunlight radiation (PAR).

FLORISTIC RESEARCH WITHIN THE FRAMEWORK OF THE PROJECT OF THE RUSSIAN GEOGRAPHICAL SOCIETY «ENVIRONMENTAL-FLORISTIC ASPECTS OF THE MIDDLE RIVER POOLS OF THE CENTRAL PART OF THE VOLGA UPLAND»

The article presents the results of ecological and floristic studies within the framework of expeditions of the project of the Russian Geographical Society «Ecological and floristic aspects of the middle river basins of the central part of the Volga Upland»