Restoration of the Soil and Vegetation in Sandy Land with Different Stages of Deflation

The aim of this work is to reveal the features of fallow sandy lands with different stages of deflation. The virgin soil-vegetation cover was the reference point: plots with light and strong deflation were compared with it. The soil deflation stages were determined by the presence or absence of layers characteristic of the backgroundsoils of the territory. The restoration of vegetation depends on the activity of wind erosion, the properties of the soils and substrata emerging on the soil surface. Studies have shown that the soil properties of deflated plots contradict the background and classical schemes of fallow land recovery. Keywords: Trasbaikalia, Barguzin Depression, sandy lands, plant-soil cover, soil deflation, vegetation restoratio

Bush Encroachment of Forest-steppe Landscapes in the Mongolian Part of the Lake Baikal Basin

The character of competitive relationships between woody and shrub vegetation in the southern (Mongolian) part of the Lake Baikal basin was studied via model polygons. Depending on the environmental conditions, native forests are being replaced by different types of shrubs. The main factors contributing to these changesare the aridization of the climate and human activity. It is shown that the current state of shrub communities and their progressive dynamics along the southern border of boreal forests in Mongolia allow us to consider them stable cenoses, which prevent a natural renewal of coniferous (pine, larch) forests in this region. However, some shrub species may be considered indicators of ecotopes’ suitability for natural or artificial reforestation because their ecological requirements are similar to those of forest trees. Keywords: Lake Baikal basin, ecotone area, destruction of forests, bush encroachmen

Restoration of the Soil and Vegetation in Sandy Land with Different Stages of Deflation

The aim of this work is to reveal the features of fallow sandy lands with different stages of deflation. The virgin soil-vegetation cover was the reference point: plots with light and strong deflation were compared with it. The soil deflation stages were determined by the presence or absence of layers characteristic of the backgroundsoils of the territory. The restoration of vegetation depends on the activity of wind erosion, the properties of the soils and substrata emerging on the soil surface. Studies have shown that the soil properties of deflated plots contradict the background and classical schemes of fallow land recovery. Keywords: Trasbaikalia, Barguzin Depression, sandy lands, plant-soil cover, soil deflation, vegetation restoratio

The properties and the mineralogical composition of dark-humus quazi-glei solonchak solonetzic cryoturbed cryosols of Barguzin hollow (Buryatia)

Morphological, physical-chemical properties, texture, salt composition mineralogical composition of the particle-size fractions 5 mkm of dark-humus quasigleyic solonchakous solonetzic cryoturbated deeply permafrost loamy-sandy soil developed from alluvial sediments (Salic Mollic Reductaquic Turbic Cryosol (Eutric, Loamic, Calcaric, Fluvic, Sodic)) are presented. The soil is situated at the northern-eastern part of Barguzin Depression in the impact zone of dumping of nitrogen siliceous thermal underground waters of Kuldur type (Kuchiger springs). The soil forms from materials of disintegration of high-content-potassium calcareous-alkali granites of Barguzin complex of Angara-Vitim Batholith. It was found soil salinity of weak to very strong degree, presumably sulfate-sodium with gypsum. There is a net of gypsum filaments in the solum that is observed by morphological analysis. Low amount of rectorite was found in clay fraction of undisturbed layers of alluvium at the depth of 54-145 cm in the studied soil profile. Regular structure of rectorite comprised mica (A) and smectite (B) packets with alternation motive ABAB… is transformed into irregular structure of mica-smectite interstratifications by impact of soluble sodium salts and cryoturbation of soil material in soil horizons at the depth of 0-54 cm formed from the alluvium. Regional peculiarity of studied soil is small shear of quartz in silt and sand fractions that is a result of mineral composition of biotite and amphibole-biotite granites and granitoids. Irregular mica-smectite interstratifications with high shear (>50%) of smectite packets are destroyed by impact of sodium sulfate and hydrocarbonates hydrogenic accumulation in the solum and are partially illuviated into middle part of soil profile with formation of humus-clay cutans on the lateral sides of aggregates by infiltration of rain waters. Existence of humus-clay cutans is an evidence of weak degree of solonetzic process

THE ROLE OF THE DEMUTATIONAL PROCESSES IN THE TRANSFORMATION OF THE PLANT-SOIL COVER OF THE FALLOW LAND IN BAIKAL BASIN

In the article the features of demutational processes in fallow lands are considered on the example of key plots with soils of light granulometric composition in Transbaikalia. There is a «failure » of the classical scheme for the restoration of fallow land on alkaline sands. There is a development of biological crusts, which prepare the substrate for the settlement of higher vegetation. A record decrease in the humus and fine earth content (particles less than 0,05 mm in diameter) is noted in the surface horizons of the fallow land, which is 0,45 % in the Barguzin basin and 0,38 % in Ust-Kiran. During the process of restoration, in Ust-Kiran key plot, the stage of weedy and annual species of polynyas and motley grass has already been passed, and at present the vegetative composition is represented by a small mosaic of mono-dominant parcels. In the «Upper Kuitun» key plot, overgrowing of deposits by higher vegetation is prevented by the moss-lichen cover formed on the soil surface. The process of so-called «soil sequestration», which discovered in the ecosystems of this site, not only leads to a special type of degradation of pasture vegetation, but contributes to the depletion of its water potential.Исследования выполнены в рамках темы № АААА–А17–117011810038–7, а также при финансовой поддержке гранта РФФИ № 17-29-05019