Vol 9, No 4 (2019)

The state and development of vegetation cover is an important criterion for the improvement of the ecological environment of arid regions; therefore, the study of the ecological water use of vegetation has become a pressing problem in ecology and hydrology. This study covered eight counties in the central and southern parts of Ningxia Hui Autonomous Region, which are located from north to south in an arid region in northwestern China. The purpose of the study was to assess the potential evaporation and environmental water consumption of local vegetation based on meteorological data, vegetation-distribution data, data on the state of water resources, etc. This study can help us to understand and assimilate patterns in the spatiotemporal distribution of ecological water consumption and can provide a basis for the planning and cultivation of forest–meadow vegetation in a region. First, the models of Thornthwaite and Penman-Monteith were used to calculate ecological water consumption. Comparison of the calculation results showed that the data obtained from the Penman-Monteith model were more acceptable, since the model uses a number of meteorological variables and geographic location factors. At the same time, the Jensen formula and the regional soil characteristics curve were used in the calculation of the ecological water consumption to determine the factor for soil moisture correction. Second, the potential evaporation and ecological water consumption of local vegetation was estimated month by month based on precipitation. The spatial and temporal variability of potential values was analyzed on this basis. The results showed that th epotential evaporation tends to increase from month to month from January to July and decrease from August to December. Regarding the spatial distribution, the potential evaporation gradually increases from south to north. The spatial variability of the balance between precipitation and the ecological water consumption of vegetation was analyzed; the results showed that the ecological reserves of water in the central region are more substantial than in the southern region, and the largest reserves of water were found in Yanchi, the northernmost district of the central arid region. Conversely, the ecological water consumption in forests was excessive throughout the growing season in the southernmost district of Jingyuan. In addition, the spatiotemporal variability of the relationship between precipitation-dependent ecological water consumption and water resources is discussed. The results showed that there is still enough space for the regional distribution of vegetation in Yanchi, Tongxin, and Haiyuan in the central arid region and relatively dry districts, such as Yuanzhou, Siji and Pengyang in the southern highlands. More land for an increase in vegetation was observed in the Longde districts and Jingyuan, located in the south of a highland where there is a relatively high amount of precipitation.

The article describes patterns in the spatial organization of landscapes and vegetation on the Abrau Peninsula within the Utrish State Nature Reserve and the adjacent territory. The use of ecological and topological profiling and large-scale mapping of the vegetation and landscapes made it possible to evaluate the spatial diversity of unique sub-Mediterranean ecosystems with respect to geological and geomorphological conditions, including the elevation, exposure and steepness of the slopes, as well as climate and sea effects. The specificity of the environmental conditions at different altitudes is reflected in the structure of phytocenotic diversity, which leads to the formation of two altitudinal sub-belts of the coastal belt and a change in typological composition of forest, woodlands, and shrub communities at different levels of phytocatenas.

The dynamics of the botanical diversity of plain forbs–bunchgrass steppes is analyzed for the period of 2008–2018 based on materials from the biomonitoring of plant cover at the Tumentsogt experimental station (Eastern Mongolia) as part of the scientific program of an integrated Russian–Mongolian biological expedition. Eight permanent test plots of 100 m² were laid along the transect on the plain between hills in the northeastern part of the experimental station. We analyzed the correlation between the main parameters of the plant communities (the species composition, richness, and saturation; the height and abundance of species; and the density of grass stands) with the meteorological conditions (the heat supply and the amount and distribution of precipitation during the growing period). A combined analysis of phytocenotic and climatic data was performed with nonparametric multidimensional scaling of indirect ordination. Ecotopic fluctuations caused by changes in the amount and regime of precipitation in different years, as well as by the dynamics of the temperature regime, were studied. The species saturation of communities was maximal in years with low ombrothermic indices and lowest in years with high indices. The floristic composition of communities of three–feather-grass steppes includes a flora-cenotic core composed of 23 permanent perennial steppe and forest–steppe species, which provides a relative stability of ecosystems under changing environmental conditions. The dynamics of steppe ecosystems of the East Mongolian steppes is phytocyclic.

This paper provides a medical–environmental and biogeographical assessment of potential natural hazards in the Ile-Balkhash State Nature Reserve (Republic of Kazakhstan) with consideration of the tourism activities planned there. The exposure factors were analyzed for allergenic and poisonous plants and natural disease foci. The medical–geographical risks are caused by the existence of five natural foci of nosological entities in the reserve, among which tularemia and brucellosis have high morbidity levels in the region. The mammals inhabiting the reserve act as carries of natural-focal diseases, and a large number of poisonous and allergenically active plants grow there. This indicates that the presence of the corresponding risks require regular medical and environmental monitoring. The presented methodological scheme used to assess natural hazards may also be applied to other arid areas and regions.

Various types of arid soils that formed under the environmental conditions of the ultracontinental climate at the northern boundary of the steppe distribution in central Asia have been studied. The survey results for the surface horizons of the steppe soils and the soils of the contact forest–steppe zone according to the color characteristics and the humus properties are reported. The dominant cryo-humus accumulation in the soils of the steppe ecosystem and the light-humus soils of the contact zone are determined according to the Munsell scale and the CIE-L*a*b* color system. The ratio of labile and bioinert fractions of the humus compounds may serve as diagnostic parameters. Cluster analysis is performed based on 25 parameters of the soil humus horizons. The first cluster unites the steppe soils with the cryo-humus accumulation, while the second cluster involves soils with light-humus accumulation. Soils with the AK–BCA–Cca profile are classified at the current survey stage as cryo-humus soils. The obtained data can be used to correct the status of cryo-arid soils in the soil classification system.