Molecular methods were used to study variation in the taxonomic structure of bacterial, archaeal, and fungal communities in soil samples taken along a salinity gradient from a solonchak in the vicinity of Lake Akkol' (Shingirlau, Kazakhstan). Soils from arable fields located 195 km from the solonchak served as the control. Total DNA was isolated from every sample and analyzed by T RFLP and real time PCR. Saliniza tion was found to be the main ecological factor determining the structure of soil microbial community in the study region. The values of Simpson's index characterizing the diversity of this community proved to be sim ilar in all the samples, which, however, significantly differed in the taxonomic composition of microorgan isms. A significantly increased content of archaea was revealed in the sample with the highest salinity. The results of this study show that the structure of soil microbial community reflects specific features of a given soil and can be used as an indicator of its ecological state.

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A retrospective analysis of river bed deformation over a 34-year period has been carried out for the first time for the Ural River in West Kazakhstan, in different environmental conditions. Horizontal shifts of the Ural riverbed have been defined according to space shots made in 2012. Erosion risk, as a result of horizontal displacement of the river bed has been determined in West Kazakhstan. A geomorphologic description of the Ural River bed and floodplain, and the dynamics of channel processes in the river within West Kazakhstan are given. The probable pattern of channel realignments for the Ural River has been determined. The paper describes the results of map compilation and related data consolidation with respect to the horizontal river bed shifts in West Kazakhstan, and includes a review of characteristics of the hydrologic and hydrochemical regimes of the river. The main river bed types, which are typical of flat terrain, are also discussed. West Kazakhstan is a region where there is medium-level ecologic stress on the river beds and floodplains.

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