The analysis of landscape differentiation of the low-mountain Maima basin was performed due to the field studies for different periods as well as the remote sensing data. The formation of modern landscapes of the basin depends on regional features related to geographical location of landscapes on the periphery of the mountain region (mainly in its low-mountain part) and local factors as well. Structural-lithological and geomorphological heterogeneity, high-altitude along with climatic background parameters determine the development of the landscape structure of the territory. The basin map represents the peculiarities of current landscapes arrangement at the local level (groups of stows, their spatial modifications) and atregional one (subtypes of landscapes). In the forest-steppe area, slopes (4-10 and 10-20) of the southern, western and eastern aspects with grass-forb real and steppe meadows dominate. Sub-taiga landscapes are represented by terraced slopes (10-20) of northern and northeastern aspects with birch-pine and pine-birch forests. Among the chern-taiga landscapes, the slopes (10-20) of the eastern and western aspects with birch-aspen-fir forests prevail. Modified and transformed landscapes occupy about 30 % of the basin area due to the largest agglomeration (Gorno- Altaisk, Maima and Kyzyl-Ozek) in the Russian Altai. Secondary grasslands occupy 20 % of the basin area that is mainly related with anthropogenic modifications (deforestation, grasslands). The share of perennial plantations and arable land accounts for 2 %; built – up areas-about 4 %.

The stable water isotopes in snow (primarily 18O and 2H) are widely used for tracing hydrological and ecological processes. However, isotopic signatures of snow can be significantly modified by topography and land cover. This study assesses spatial and temporal variability of the bulk snowpack isotopic composition (δ18O, δ2H, d-excess) between forested (pine and birch) and open areas in the West Siberian forest steppes. Isotopic samples were collected over the peak snow accumulation in 2017–2019. The snow isotopic composition within forested areas differed from open steppes, mainly in reducing d-excess (1.6‰ on average). We did not find a significant effect of canopy interception on snow enrichment in heavier isotopes. Snowpack in the pine forests was even lighter by 3.6‰ for δ2H compared to open areas, probably, due to low energy inputs and interception capacity. Additionally, snow depth significantly influenced the isotopic composition spatial variability. As snow depth increased, δ18O and δ2H values decreased due to conservation within the snowpack and less influence of sublimation and moisture exchange with the soil. However, this pattern was only evident in winters with below-average snow depth. Therefore, taking into account snow depth spatial and seasonal variability is advisable when applying the isotopic methods.

The paper presents results of snow route measurements carried out during two winter seasons (2014/15 and 2015/16) over the period of maximum snow accumulation. The region of investigation was mainly the lowmountain basin of the river Maima (North, NorthEast Altai). Meteorological conditions for these periods (amounts of precipitation and mean monthly temperatures) were compared with climatic data (1985-2016). The results obtained allowed establishing a relationship between the spatial and temporal variability of the snow depth, density and SWE (snow-water equivalent) and the weather conditions, orographic features (exposure and steepness of slopes), and characteristics of the underlying surface. The winter of 2014/15 was warm and moderately snowy season, while the winter of 2015/16 was warm but with small amount of snow. At the subtype level of the landscapes the maximum values of the snow cover thickness and the snow storage were observed in the chern-taiga landscapes, and the smallest ones-in the sub-taiga part of the basin area. The maximum snow storages (SWE) are characteristic for the secondary small-leaved forests and meadows, where these values exceed similar ones under the indigenous fir trees by 30%.