Change of feed stocks in southern subarctic tundra of Yamal

The relevance of the research is related to the need to monitor the resource potential of the vegetation in the southern subarctic tundra. The Yamal tundra has been experiencing a high grazing pressure since 1990. As a result of the increase in the number of private farms and the number of domesticated reindeer in Yamal, pasture degradation occurs (trampling of forage mass, shredding vegetation, disappearance of lichen cover, increased soil deflation). Purpose of the research is compare the forage stocks of reindeer pastures in the southern subarctic tundra of Yamal in 2017–2018 and in the 1990s. In the course of the study, estimates of the amount and structure of forage stocks in plant communities of the southern subarctic tundra of the Yamal Peninsula was assessed in the vicinity of the Payutayakha river. The stock of aboveground phytomass was determined by the mowing method. In 2017, degraded areas of the tundra were studied, and in 2018 undisturbed and intact areas were investigated. Scientific novelty. The data obtained are compared with the estimates published for the southern subarctic tundra in the 1990s. Results. Forage stocks in degraded areas, compared to stocks in the southern subarctic tundra in the 1990s, decreased 14 times; while in on undisturbed areas they decreased 3 times. In the structure of forage stocks in 2017–2018, compared to the situation at the end of the 20th century, the proportions of shrubs, lichens and grasses has decreased; the proportion of dwarf shrubs in degraded areas increased 4 times, while in undisturbed areas it increased 6 times. The study confirms the existence of overgrazing and a shortage of forage resources on pastures in the zone of the southern subarctic tundra of Yamal.

Production potential of the Kabardino-Balkarian Republic pasture ecosystems

The pasture digression of meadows followed by soil deflation is one of the pressing environmental problems. This problem is typical for mountain pastures that are constantly in economic circulation. The article presents the results of a geobotanical survey of the Zolsky pastures on the territory of the Kabardino-Balkarian Republic in 2018-2020. The results of a geobotanical survey show that the pasture phytocenoses are characterized by high floristic diversity due to the heterogeneity of edaphic and orographic factors. The flora of the pastures is represented by postwood moist sedgy-and-tussock-grass, mesophilic woodreed-and-agrostidinic grass, cereal forb, forbs cereal mesophilic and subalpine meadows, low sedgy meadow steppes. The average yield for the pasture period varies from 7.2 to 16.6 centners/ha of dry eaten mass. The consequence of prolonged pasturage and excessive pasture load was a decrease in alpha and beta diversity, the formation of low-productive secondary plant communities of non-food, poisonous and weed grasses, the destruction of sod and soil outcropping. Restoration of degraded pasture ecosystems is possible on the basis of ecological intensification, which provides for the regulation of pasture loads, adherence to grazing terms, phytomelioration using perennial grasses, and short-term isolation of pastures from grazing. This will prevent erosion processes, increase biodiversity, productivity, forage value of grass stand and stability of pasture ecosystems.

Morphometric analysis of the Crimean river basins relief by using GIS

It is planned to develop projects of basin nature management for the Crimean peninsula. The characteristics of the relief within the river basins is an important stage in the pre-project justification. ArcGIS 10.5 is used for research. The tools of the subset “hydrology”, “Surface”, “Zonal”, “Algebra of maps” made it possible to create morphometric characteristics of the relief, and their visual representation in the GIS environment made it possible to establish spatial patterns and substantiate soil-water conservation measures. Shuttle radar topographic mission with a resolution of 3 arc seconds is selected as input data. Its resolution is consistent with the scale of the study. The morphometric analysis of the relief of 1534 different-order basin structures showed that the height of 64 % of the 3–6-order basins does not exceed 300 m; for them, five steps of vertical dissection of plain territories have been identified. 37 % of the basins are vertically divided into high-mountainous areas. In the plain part of Crimea, where deflationary processes are developed, the average slope steepness is 1°, basins with transversely straight longitudinal-straight slopes prevail, the linear boundaries on which can be rectilinear. In the foothill areas under conditions of agricultural use, soil deflation is added to the processes of water erosion caused by the presence of long slopes with a steepness of more than 3° with the values of the relief factor (LS) exceeding 2, and in some agricultural basins the average value of the relief factor is close to the critical value—4.3. Transversely convex slopes prevail in these territories, here it is necessary to design contour linear boundaries. The density of the river network is on average—0.11 km/km2 in the mountainous part of Crimea, but due to climatic, geomorphological and soil conditions, the redistribution of sediments occurs in the upper link of the erosion network (more developed on the territory of the peninsula). the density of the river network does not exceed 0.2 km/km2 in the flat part of the Crimea. Morphometric analysis of the relief allows describing the hydrogeomorphology of the river basin, identifying the causes of erosion, and substantiating the functioning of ecosystems.

MODERN NEGATIVE RELIEF-FORMING PROCESSES OF THE KINGARGA RIVER BASIN (REPUBLIC OF BURYATIA)

The article analyzes the current adverse relief-forming processes in the Kyngarga river basin. The most dangerous for natural and man-made complexes are fluvial processes represented by mudflows. The processes of swamp formation as well as areas of water erosion development and soil deflation are leading by occupied area in basin, which adversely affect human activities.

Gross chemical composition of dark gray podzolized soils of Small Polissya and its transformation caused by human impact

Dark gray podzolized soils (Phaeozems Albic (PHad), WRB, 1998) are typical for the natural area of Pasmove Pobuzhia physiographic oblast of the Small Polissya. The investigation of the transformation of the gross chemical composition of dark gray podzolized soils of Small Polissya due to erosion processes conducted for the first time, confirming the relevance of the research. Standard methods of research were used in the investigation of the gross chemical composition of dark gray podzolized soils. The research results have been worked out according to the methodology of Y. Arynushkina and N. Myakina. According to the research, SiO2 dominated in all genetic soil horizons. Its content in the humus-accumulative horizon is 82.06 % by weight of calcined soil, decreasing to 74.45 % in soil rock. Different distribution of silica in the soil profile indicates the poor process of podzolic soil development. Among oxides in the soil profile dominates Al2O3, it contents in the humus-accumulative horizon is 8,10 %. A slight accumulation of Aluminium oxides was found in horizon confirming weak profile differentiation by eluvial-alluvial type. Content of Fe2O3 oxides in the soil profile is low variadic in the arable layer and the content is 2.30 %. Oxides of CaO content ranges from 0,75 % in the horizon He to 6,17 % in soil rock, and the content of oxides MgO, respectively, from 0.65 % to 1.06 %. Gross content of iron oxides, titanium, manganese, sodium, potassium, phosphorus and sulfur in the soil genetic horizons ranges from 0,04 % to 2,39 %. The estimated ratio between the major oxides and their profile distribution also confirm weak profile differentiation of dark gray podzolized soils. The content of the constitutional water of humus He horizon of dark gray podzolized soils is 1.57 %. Increase of constitutional water in the middle of the profile may be caused by increasing of internally soil deflation processes. This is also confirmed by the growth of silica coefficient changes of the soil at the same depth. In eroded dark gray podzolized soils of the arable layer the content of SiO2 is decreasing, reaching values of 79,63–80,84 % in strongly eroded. The content of other oxides tends to increase as well as decrease comparing to non-eroded soil. The correlation between wash out level and molar magnitude ratios The correlation between wash out level and molar magnitude ratios is being observed in eroded soils. With erodation increase the ratio of SiO2: Al2O3 and SiO2: R2O3 is being narrowed, which indicates accumulation in arable horizons of aluminium, including oxides in general, compared with non-eroded types. The content of the constitutional water increases and expands the coefficient of the silica changes, indicating the strengthening of internally soil deflation processes in the arable layer of erosion-degraded dark gray podzolized soils compared to non-eroded types. Key words: dark gray podzolized soils, gross chemical composition, oxides, degradation.