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Landscapes stability

Landscape stability is one of the most important parameters determining the state of the environment and changes occurring in it under the influence of natural and anthropogenic factors. The nature of landscape changes depends on the location in the geographical environment, their properties, and type and extent of the anthropogenic impact. Of particular importance is the estimation of landscapes stability of the Baikal basin, which is an environmentally critical area.

Landscape stability is a property of a geosystem to maintain its structure and the mode of functioning under changing conditions of its environment [Protection of landscapes..., 1982]. An assessment and mapping of landscapes stability are made according to the complex of natural and anthropogenic factors of influence. The natural factor is mainly determined by the influence of climate (indicators of heat-moisture supply) and the properties of lithological-and-geomorphological basis. The anthropogenic influencing factor is associated with the background nature management, which is based on spatially extensive use of natural resources, and lands, closely related to the zonal-belt features of natural landscapes. The background types of nature management in the study area include agriculture, mainly in steppe landscapes, forestry in taiga landscapes, as well as recreation.

Stability is considered in relation to landscapes of two levels: regional (geoms) and topological (groups of facies). A landscape map, compiled by the authors on the basis of landscape maps of the territory under consideration [Landscapes..., 1977; Landscapes..., 1990], was used for its mapping.

Stability of landscapes of the regional level – geoms – is determined based on the level of natural ecological potential of a landscape (EPL), the main indicator of which is the index of biological effectiveness of climate (TK) according to N.N. Ivanov [Ecological..., 2007, Ecological..., 2007]. Characterization and comparative assessment of this indicator is based on the ratio of heat and moisture, on which the biological productivity of a landscape and ecological capacity primarily depend. At the same time, the influence of latitudinal and altitudinal zonality on their distribution is traced. A single and continuous process of moisture and heat exchange not only forms the spatial differentiation and a type of a landscape, but also determines its stability. Landscapes with high values of TK and EPL are the most stable, while low values ​​of these parameters characterize unstable landscapes.

Twenty-two geoms are represented in the landscape structure of the territory under consideration. Mountain terrain predominates in the catchment area of ​​Lake Baikal. Therefore, this territory is characterized by the altitudinal belt differentiation of landscapes, which determines the degree of their stability.

At the regional level, according to the values ​​of these indicators, landscapes are subdivided into five ecological groups of geoms, to which the corresponding values ​​of stability, ranged on a five-point scale, are assigned. These values ​​are considered as the starting point, or background stability.

A geom unites groups of facies similar in structural-dynamic characteristics [Sochava, 1978]. This taxonomic unit is important in generalization of geotopological works. Inside a geom, stability was readjusted in respect of groups of facies with different dynamic categories. A set of variable states of these categories includes indigenous, pseudo-indigenous, serial and derivative geosystems under one epifacie. The highest natural and anthropogenic stability characterizes indigenous landscapes with well-established intrasystemic and external relations; many of them are notable for durability. Pseudo-indigenous landscapes, unlike indigenous ones, are modified as a result of hypertrophy of one of the components of the system. Serial facies in most cases are nondurable, quickly alternating with each other spontaneous geosystems, formed under the significant hypertrophy influence of various natural factors. In a range of transformation of geosystems they are characterized by the greatest variability and are prone to damage, and therefore they are classified as landscapes unstable to anthropogenic impacts. Derivative landscapes are variable states of geosystems caused by human influence. They are characterized by different degrees of stability.

The highest values ​​of stability, considered as the initial point corresponding to the background rate of stability of a geom, are set for indigenous facies. Further on, the initial point is reduced to three gradations, namely, for pseudo-indigenous, serial and derivative facies. For pseudo-indigenous facies a decrease in the stability by 1 point in relation to the initial point is possible; for serial facies it can amount to 1-2 points. For derivative facies deviations from the norm can reach 1-2 points towards an increase or decrease in the stability depending on the type of succession, namely, progressive stabilizing or digressive destabilizing.

To assess the anthropogenic stability of landscapes an analysis was made of disturbances of natural environment, arising under the influence of various types of human activities related to the background land use. According to the predominant nature of the background land use, the following types of functional load on the environment were distinguished: agricultural arable and grazing (mainly for steppe and forest-steppe landscapes), and forestry (for taiga landscapes) and recreation.

Stability of arable lands was largely determined by the intensity of erosion loss, soil deflation and pesticide pollution, and natural self-purification potential of soils. Stability of natural-forage lands was determined in respect of plant communities to grazing and haymaking and was assessed according to the degree of degradation of hayfields and pastures, susceptibility to erosion and deflation, and recoverability of vegetation and soils.

The most significant impact on the state of forests is made by commercial logging using the clear felling approach. Stability of forest landscapes was determined according to the degree of disturbance of forests by felling and fires, recreation, and agricultural use. Reforestation is influenced by changing temperature conditions, hydrophysical properties of soils, evolving erosion and cryogenic processes, deflation and waterlogging in felled and burnt areas. An important criterion for stability, i.e. forest bonitet, is an indicator of productivity and environmental growth conditions, evaluated by richness (trophicity) and moisture content of soil. Environmental factors, spontaneous and associated with the human activity, prevent natural reforestation; their progressive successions do not reach the original state. Such landscapes fall in the category of the most unstable.

Recreational stability is assessed referring to the mass recreation and tourist-excursion activities. Indicators of the degree of recreational digression of landscapes, depending on the type and intensity of recreational influence, sensitivity and recoverability of landscapes, which together define their recreational potential, served as stability criteria. Stability of landscapes is a key indicator, based on which the regulation of recreational loads is made.

The compiled map reflects the territorial diversity of landscape stability, characteristics of which is presented in the table.

The lowest and low (I-II points) stability characterize goletz and sub-goletz landscapes presented in major mountain ranges in the north-eastern and south-western parts of the territory. In the north-east, they are goletz and sub-goletz landscapes of the Baikalsky, Verkhne-Angarsky, Barguzinsky, and Ikatsky ridges in the framing of the Severo-Baikalskaya, Verkhne-Angarskaya and Barguzinskaya depressions. In the Khovsgol region and in Southern Cisbaikalia they include the Eastern Sayan mountain structures. In the south-west, alpine meadows, and subalpinotype and subgoletz landscapes of the Khangai and Khentei uplands are characterized by low stability.

Ecological potential of these landscapes is very low; TK is less than 8. The structure of geoms is dominated by serial groups of facies. They are characterized by severe climatic conditions and dissected mountainous terrain, active development of exogenous geological processes, and lack of heat and excess of moisture. The same values ​​of stability are assigned to steppe landscapes of depressions and valley bottoms, characterized by the excess of heat together with the lack of moisture, with manifestations of cryomorphism, waterlogging, water erosion and deflation, and soil salinization.

In general, the Baikal basin is dominated by moderately stable and stable landscapes (III-IV points), distributed mainly in the central part of the territory. They are characterized by medium and relatively high ecological potential; the index of biological effectiveness of climate amounts to 8-16. Pseudo-indigenous geosystems with a relatively stable landscape structure predominate.

Landscapes of reduced development of mountain-taiga and taiga intermountain depressions and valleys, having dispersed distributional pattern and occurring in the Selenga-Vitim interfluve and to the north of the Khangai upland, are referred to the stability of III points.

The stability of III points also characterizes piedmont and plain relatively dry and arid steppes. They are located in the Barguzinskaya depression, in hollows of the Trans-Baikal type, to the north of the Khangai upland, and in the surroundings of the Khentei upland.

The group of geoms with the stability of IV points includes mountain-taiga landscapes of restrictive and optimal development, taiga piedmont landscapes of intermontane depressions and valleys of restrictive development, mountain low-bunchgrass and forbs-bunchgrass, and mountain dry steppes. The main areas of development of taiga landscapes of this stability group are low- and middle mountains to the south of the Eastern Sayan, the Primorsky ridge, Selenginskoe middle mountains, Vitimskoe plateau, Olekminsky Stanovik, Khentei-Chikoy upland, and others. Mountain steppes with IV points of stability are most commonly found in the Selenge-Orkhon interfluve.

Landscapes with the highest ecological potential for the region, and TK amounting to 16-20, are classified as the most stable (V points). In the Russian part of the territory, they are landscapes of piedmont and intermountain depressions of optimal development, as well as piedmont subtaiga landscapes. They are found in the Verkhne-Angarskaya and Barguzinskaya depressions, in the Selenga river delta, and in depressions of the Trans-Baikal type. In Mongolia they are represented by mountain subtaiga landscapes, the large area of which is middle and low mountains lying to the north of the Khangai upland in the central part of the basin of the Selenge and Orkhon rivers. The structure of geoms is dominated by pseudo-indigenous and indigenous geosystems. They are the nuclei of the ecological stability and reproduction of the environment [Mikheev, 2001]. In the landscape structure of the region their distribution area is in the transition zone between taiga and steppe landscapes with low background stability.

The conducted mapping of landscape stability is the basis for the assessment of the anthropogenic impact on the environment, and for substantiation of environmentally acceptable nature management in the Baikal basin.

References

Landscapes of the south of Eastern Siberia (map, scale 1:1500000). (1977). V.S. Mikheev and V.A. Ryashin. Moscow: GUGK, , 4 sheets.

Landscapes (map, scale 1:3000000) (1990). in National Atlas. Mongolian People's Republic. Ulaanbaatar–Moscow, pp. 83-85.

Mikheev, V.S. (2001). Landscape synthesis of geographic knowledge. Novosibirsk: Nauka, 216 p.

Protection of Landscapes. Explanatory Dictionary. (1982). Moscow: Progress, 272 p.

Sochava, V.B. (1978). Introduction to the Theory of Geosystems. Novosibirsk: Nauka, 320 p.

Ecological potential of landscapes (map, scale 1:15000000). (2007). In National Atlas of Russia. Vol 2: Nature and Ecology. Moscow: PKO “Kartografiya”, p. 417.

Ecologo-geographical map (scale 1:15000000). (2007). In National Atlas of Russia. Vol. 2: Nature and Ecology. Moscow: PKO “Kartografiya”, pp. 454-456.

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Physical-geographical regionalization

and the landscape-typological structure (40-41)

The materials presented uniformly consider physical-geographical regionalization and the landscape-typological structure of the Baikal basin. Map compilation was based on the idea of geosystems classification and the resultant works, including cartographic works on physical-geographical differentiation of the territory in the Russian Federation and Mongolia, which are presented below.

The boundaries of physical-geographical structures (individual and typological) were integrally positioned on the same topographic base in the Mapinfo environment and verified according to the Landsat 7 multispectral satellite images (2000).

The physical-geographical regionalization map reflects individual heterogeneous regional natural formations. The featured physical-geographical regions and provinces characterize the territories with a similar geographical location, manifestation of morphotectonic geological and geomorphological features, latitudinal, vertical and bioclimatic zonation. Physical-geographical regions, countries and provinces are comparable across different research. Mountain areas of North Asian mountain megalocation on the edge sphere of the continent (Baikal-Dzhugdzhurskaya and South-Siberian-Khangai-Khentei) and their contact with the Central Asian desert-steppe region of the Central continental megalocation are presented within this territory. Intraregional differentiation into provinces is related to the specific manifestations of altitudinal differences and geological and geomorphological features in mosaics of geosystem types and their mobile components of soils and vegetation. The map shows three physical-geographical areas and 12 provinces.

Landscape-typological structure shows the features of spatial mosaic of individual physical-geographical units, their internal structure of relatively homogeneous combinations of physical-geographical conditions. In accordance with the small scale, 39 geom groups are shown on the map. The geoms are distinguished according to the indicators of topological order, but generalized to the regional level [Sochava, 1978]. They combine topogeosystems of the certain zone or belt (within a physical-geographical region) characterized by similar structural features of soil cover, vegetation and hydrothermal regime. The vegetational component of a geom is adequate to a formation, soil one is close to the subtype of soils, and the climate regime is close to the modification of climate of a subzone, which arose under the influence of the structural properties of other components.

Geosystems specific to North and Central Asia form the regional classification range. Their location, interpenetration and uniqueness of landscape situations in the Baikal basin are presented. Regional interpretation of landscape-typological units (geom groups on the geasystem map) characterizes their latitudinal and altitudinal differences, as well as shows their relation to various regional and typological complexes of natural conditions that may be disclosed in detail on a larger display scale of landscape structures and geosystem components.

Multiscale mosaic character of the natural-territorial structure determines the landscape complexity of the territory, the local "contrasts" of economic use, and specificity of different local options of development.

References

Sochava, V.B. (1978). Introduction to the Theory of Geosystems. Novosibirsk: Nauka . Sib. Otd., 320 p.

Sochava, V.B. and Timofeev, D.A. (1968). Physical-geographical regions of North Asia. In: Reports of the Institute of Geography of Siberia and the Far East, vol. 19, pp. 3-19.

Preobrazhensky, V.S., Fadeev, N.V., Mukhina, L.I., and Tomilov, G.M. (1959). Types of locality and natural zoning of the Buryat ASSR. Moscow: Izd-vo AN SSSR, 219 p.

Landscapes of the south of Eastern Siberia. 1:1500000 Map; Physical-geographical regionalization. 1:8 000 000 Map. (1977). Mikheev, V.S., Ryashin, V.A. with the participation of Bogoyavlenskaya, N.G., Vetrova, S.D., Dmitrienko, L.S., Zhitlukhina, T.I., Kosmakova, O.P., Krotova, V.M., Smirnova, D.A. Ed. by V.B. Sochava. Moscow: GUGK, 1977.

Mikheev, V.S. (1990). Physical-geographical regionalization. In: Nature and environment protection in the Baikal watershed basin. Novosibirsk: Nauka. Sib. Otd., pp. 21-29.

Mikheev, V.S. and Ryashin, V.A. (1967). Landscapes; Physical-geographical regionalization. In: Atlas of Transbaikalia. Moscow-Irkutsk: GUGK, pp.70-71, p. 76, text pp.172-173.

Batjargal, B., Mikheev, V.S., and Erdenechimeg, Zh. (1989). Landscapes (map 39, text p.103). Physical-geographical regionalization (map 45, text p.104). In: Atlas of Lake Khovsgol. Moscow: GUGK.

Fadeeva, N.V., Smirnova, E.V., and Tulgaa, Kh. (1989). Landscapes and natural zoning in the atlas of the MPR. In: The National Atlas of the Mongolian People's Republic (problematic and scientific content). Novosibirsk: Nauka. Sib. Otd., pp. 109-125.

Dash, D., Smirnova, E.L., Tulgaa, Kh., and Fadeeva, N.V. (1990). Landscapes and natural zoning. Maps 145, 146 (scale 1:3 000 000) text p. 83. In: The National Atlas of the MPR. GUGK SSSR, GUGK MPR.

Open full size

Physical-geographical regionalization

and the landscape-typological structure

The materials presented uniformly consider physical-geographical regionalization and the landscape-typological structure of the Baikal basin. Map compilation was based on the idea of geosystems classification and the resultant works, including cartographic works on physical-geographical differentiation of the territory in the Russian Federation and Mongolia, which are presented below.

The boundaries of physical-geographical structures (individual and typological) were integrally positioned on the same topographic base in the Mapinfo environment and verified according to the Landsat 7 multispectral satellite images (2000).

The physical-geographical regionalization map reflects individual heterogeneous regional natural formations. The featured physical-geographical regions and provinces characterize the territories with a similar geographical location, manifestation of morphotectonic geological and geomorphological features, latitudinal, vertical and bioclimatic zonation. Physical-geographical regions, countries and provinces are comparable across different research. Mountain areas of North Asian mountain megalocation on the edge sphere of the continent (Baikal-Dzhugdzhurskaya and South-Siberian-Khangai-Khentei) and their contact with the Central Asian desert-steppe region of the Central continental megalocation are presented within this territory. Intraregional differentiation into provinces is related to the specific manifestations of altitudinal differences and geological and geomorphological features in mosaics of geosystem types and their mobile components of soils and vegetation. The map shows three physical-geographical areas and 12 provinces.

Landscape-typological structure shows the features of spatial mosaic of individual physical-geographical units, their internal structure of relatively homogeneous combinations of physical-geographical conditions. In accordance with the small scale, 39 geom groups are shown on the map. The geoms are distinguished according to the indicators of topological order, but generalized to the regional level [Sochava, 1978]. They combine topogeosystems of the certain zone or belt (within a physical-geographical region) characterized by similar structural features of soil cover, vegetation and hydrothermal regime. The vegetational component of a geom is adequate to a formation, soil one is close to the subtype of soils, and the climate regime is close to the modification of climate of a subzone, which arose under the influence of the structural properties of other components.

Geosystems specific to North and Central Asia form the regional classification range. Their location, interpenetration and uniqueness of landscape situations in the Baikal basin are presented. Regional interpretation of landscape-typological units (geom groups on the geasystem map) characterizes their latitudinal and altitudinal differences, as well as shows their relation to various regional and typological complexes of natural conditions that may be disclosed in detail on a larger display scale of landscape structures and geosystem components.

Multiscale mosaic character of the natural-territorial structure determines the landscape complexity of the territory, the local "contrasts" of economic use, and specificity of different local options of development.

References

Sochava, V.B. (1978). Introduction to the Theory of Geosystems. Novosibirsk: Nauka . Sib. Otd., 320 p.

Sochava, V.B. and Timofeev, D.A. (1968). Physical-geographical regions of North Asia. In: Reports of the Institute of Geography of Siberia and the Far East, vol. 19, pp. 3-19.

Preobrazhensky, V.S., Fadeev, N.V., Mukhina, L.I., and Tomilov, G.M. (1959). Types of locality and natural zoning of the Buryat ASSR. Moscow: Izd-vo AN SSSR, 219 p.

Landscapes of the south of Eastern Siberia. 1:1500000 Map; Physical-geographical regionalization. 1:8 000 000 Map. (1977). Mikheev, V.S., Ryashin, V.A. with the participation of Bogoyavlenskaya, N.G., Vetrova, S.D., Dmitrienko, L.S., Zhitlukhina, T.I., Kosmakova, O.P., Krotova, V.M., Smirnova, D.A. Ed. by V.B. Sochava. Moscow: GUGK, 1977.

Mikheev, V.S. (1990). Physical-geographical regionalization. In: Nature and environment protection in the Baikal watershed basin. Novosibirsk: Nauka. Sib. Otd., pp. 21-29.

Mikheev, V.S. and Ryashin, V.A. (1967). Landscapes; Physical-geographical regionalization. In: Atlas of Transbaikalia. Moscow-Irkutsk: GUGK, pp.70-71, p. 76, text pp.172-173.

Batjargal, B., Mikheev, V.S., and Erdenechimeg, Zh. (1989). Landscapes (map 39, text p.103). Physical-geographical regionalization (map 45, text p.104). In: Atlas of Lake Khovsgol. Moscow: GUGK.

Fadeeva, N.V., Smirnova, E.V., and Tulgaa, Kh. (1989). Landscapes and natural zoning in the atlas of the MPR. In: The National Atlas of the Mongolian People's Republic (problematic and scientific content). Novosibirsk: Nauka. Sib. Otd., pp. 109-125.

Dash, D., Smirnova, E.L., Tulgaa, Kh., and Fadeeva, N.V. (1990). Landscapes and natural zoning. Maps 145, 146 (scale 1:3 000 000) text p. 83. In: The National Atlas of the MPR. GUGK SSSR, GUGK MPR.

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Ichthyofauna

Ichthyofauna of Lake Baikal and its basin comprises 67 species and subspecies including 6 naturalized ones. Within the bounds of the lake 57 species and subspecies are registered. Out of this number 34 are endemic golomyanka-goby fishes (Cottoidei) (Table) [The freshwater fish atlas…, 2003; Fishes of…, 2007; Fishes of the Mongolian…, 1983; Sideleva, 2003]. A certain conventionality in the assessment of the fish population composition according to species and subspecies should be highlighted. In terms of biodiversity such accounting is to an extent justified, but such characterization is insufficient for the assessment of ecosystem’s operation. For instance, omul which occupies a 350-meter water column comprises 3 morphoecological fish groups with various morphological diagnoses, behavior, rates of growth, deposition of fat and breeding grounds. The same can be noted in the case of cisco (3 morphogroups) and black and white graylings.  These are young “endemic” forms. Their age is within the limits of the Holocene, but they are new stable structural-functional formations “in the bioenergetic sense equivalent” to species [Reshetnikov, 1980]. With them considered the total fish composition of the basin increases to 71, and 61 in Lake Baikal. The results of immigration of various fish species in Lake Baikal for naturalization carried out in the 20^th century testify to the fact that zones of life in the lake and its food supplies are quite rigidly fixed. Out of 33 species and intraspecific forms tested for immigration only the Amur carp, catfish, sleeper and Caspian bream survived in the lake (mostly in its “peripheries”), while peled survived in the lakes of the watershed basin. Rejection of non-Baikal fish species by Lake Baikal was also reflected in the analysis of the causes of “unmixing” of the Baikal fauna with the life around the lake.

According to current concepts [Vereshchagin, 1935; Kozhov, 1962; Taliev, 1955, etc.], Baikal’s ichthyofauna is divided into two ecologically and genetically diverse complexes: European-Siberian and native Baikal ones. In the recent years the “neoendemics” or new young endemic offshoots of widely spread species have been registered [Timoshkin, 1995].

The faunal classification by G.V. Nikol’sky (1953, 1980) is usually used in the course of analysis of fish distribution according to their biotope [Kozhov, 1960]. Despite some shortcomings [Sychevskaya, 1983] this classification is rather appropriate for reflecting the ecological specificities of the faunal complexes in the conditions of one and the same water body. It enables to observe their rigid differentiation in Lake Baikal [Mamontov, 1977; Sorokin, Sorokina, 1988].

The ichthyogeographic complexes

Lake Baikal

1. System of lakes, sors, bays and near-delta shallow waters of Lake Baikal. Inhabits the boreal plain complex – limnophiles of the coastal-sor fish group (roach, perch, pike, orfe, crucian carp, etc.) occupy the entire system of interconnected lakes, bays and sors of Lake Baikal to a depth of 10-50 m. Sturgeon is the only exception for particular distribution to depths of 180 m. In Baikal it occupies an area of limnorheophiles. The lakes near Lake Baikal (Kotokel’, Dukhovoe, and Barmashovoe) can also be included here. Their ichthyofauna composition and productivity are dependent on a degree of their connection with Lake Baikal. The highest productivity occurs with the maximum, but not complete, disjunction with Baikal. Lake Kotokel’, one of the most productive lakes, is inhabited by 15 fish species (catfish, carp, bream, roach-bream hybrid, roach, dace, nerfling, crucian carp, river perch, sand sculpin, and stoneloach).  Lake Barmashovoe, previously uninhabited by fish, is now inhabited by river perch, roach, dace, and pike, which migrated there from sor-lake Arangatuy during water level increase on Lake Baikal [Fishes of…, 2007].

2. Coastal zone of open Baikal- the boreal piedmont complex - limnorheophiles of littoral and partially sublittoral areas (taimen, grayling, lenok, minnow, loach, etc.) occupy Baikal coastal open waters to a depth of 20-70 m, rarely up to 100 m.

3. Abyssal zone. Arctic freshwater complex (cisco, lawyer, omul) populate the slope and pelagic zone to a depth of up to 350 m — the Baikal autochthonous complex. It includes endemic Baikal scorpion fish: bullheads, deep dwelling Baikal sculpins and Baikal oilfish (golomyanka) that took the entire water column of the lake with the greatest diversity of benthic forms at depths of 600-700 m.

Due to the fact of high capacity of proper Baikal conditions qualitative changes in fish caused quantitative expression: higher environmental capacity corresponds to the density of endemic fish population (about 65 % of the fish biomass of the lake). This complex becomes the main one ensuring successful existence of the first three, including the Baikal seal, owing to fish diet [Sideleva, 2003].

A complex set of species of different faunal assemblages and goby fish has led to a number of features in the structure of the fish community of Lake Baikal. According to the nature of habitat and behavior of species the Baikal communities include features of ocean ecotone communities, and according to the type of population dynamics (explosive nature) and to the composition they correspond to the Siberian biocoenoses [Mamontov, 1977].

By the abundance of fish Baikal belongs to the golomyanka-goby fish type of a water body [Koryakov, 1972]. Success in assimilating the biotic and abiotic environment of Baikal by fish species of this complex lies primarily in their original biological qualities – absence of a swim bladder (and therefore availability to the deep-dwelling habitation), increased fertility, protection of spawn, occupation of all zones for spawning within the open Baikal, and finally, removal of the embryonic development of eggs in golomyankas in pelagic zone - in the body of a female, functioning as spawning substrate [Chernyaev, 1973, 1974]. These issues are important in theoretical and practical investigations of fish fauna and its rational use.

Increase in the number of individuals in a behavior homogeneous group leads to their increased consumption, and in the future to an increase in the population, group or other biological heterogeneity, reducing predation pressure on certain groups. This developmental pattern became widespread among Baikal slow-moving benthic organisms. The development of variability of morphological characters, color and behavior accelerated their speciation. Among 34 endemics, 28 (82.5 %) are typically benthic forms.

Necessity of multivariancy of individuals in a population of the pelagic fish group weakens due to the formation of a high population size of the few species with small size of their body. This vector of species evolution became possible on the basis of the pelagic larval-fry stage which contributed to dispersal and acquisition of the entire littoral zone for spawning. They include sand sculpin and yellowfin Baikal sculpin. These species occupied biotopes from the shore area to a depth of 500-700 m. Further oecizing of Lake Baikal was feasible due to vivaparity of Baikal oilfish [Taliev, 1955; Chernyaev, 1973]. As a result it became possible to disseminate fry within the confines of general currents facilitating its dispersal in the water area and to settle practically the entire water column. By the number and rate of reproduction, pelagic species prevail over other species so much that they are used in the diet of Baikal seals (nerpa) and almost all the fish of the lake, including cannibalism of gobies themselves on their own fry. This leads to the populating of Lake Baikal by fish of the common Siberian complex and the entire Lake Baikal’s ecosystem stability in time.

River and lake systems of the basin reflect the interchange of mountain and plain spaces. They are inhabited by interpenetrating species of the boreal piedmont, boreal plain and Arctic freshwater complex of the Arctic province. The contemporary Arctic ichthyofauna is a derivate of a more thermophilic Neogen Euro-Siberian ichthyofauna that existed in the temperate zone of Eurasia. Its modern distribution is defined by a sharp differentiation of landscape and drainage system following the Alpine orogeny at the boundary of the Pliocene and the Pleistocene accompanied by a more pronounced delimitations of climatic zones [Sychevskaya, 1983].

Water bodies of the watershed area are inhabited by 33 species, including 27 species in the Selenga river (20 local species, two Baikal endemics, six natiralized species and dwarf Altai osman that has recently penetrated the Selenga river basin), and nine species in Lake Khovsgol, including the endemic Kosogol grayling and naturalized Baikal omul. The endemic Baikal-Lena grayling was detected in the fluviolacustrine system of northern mountain streams, while in the Upper Kichera lakes an isolated population of coastal-pelagic omul and homotypical ichthyocenoses formed by the Baikal-Lena grayling and Arctic char (Verkhneuyakchinskie lakes) (Table) [Fishes of Lake…, 2007].

4. Lower and upper courses of the Selenga river – packings and spawning migrations of omul, sturgeon and Siberian whitefish, habitation and spawning of Siberian whitefish, graylings, lenok, burbot, taimen, dace, roach, pike, etc.

5. Large tributaries of the Selenga river and of Lake Baikal – packings and migration of omul, lenok, grayling, taimen, burbot, dace, carp, bream, dwarf osman, etc.

6. Large and medium mountain streams and drainage high altitude lakes – habitation of grayling, lenok, taimen, common minnow, spined loach, Siberian stone loach, dace, perch, roach and pike. The Upper Kichera lakes, Kulinda and Verkhnekicherskoe – habitation of omul, pike, burbot, Siberian stone loach, grayling, sand sculpin, stone sculpin, and common minnow. Svetlinskoe lake – habitation of three species: Arctic char, common minnow and Siberian stone loach. Lake Frolikha – 11 species, including lenok, Arctic char, grayling, pike, roach, perch, burbot, lake minnow and common minnow, spined loach, sand sculpin and stone sculpin. The Verkhneyakchinskie lakes (the Yakchai river) – habitation of Arctic char (small and dwarf) in one lake and one species of Baikal-Lena grayling in the other.

7. Small streams and creeks of the medium-altitude mountain belt – possible habitation of minnows and temporary entries of grayling for spawning.

8. Lake system of the hollows – water bodies diversified in size, hydroclimatic conditions and fish composition. A cluster analysis of interrelationship of fish species was carried out in order to characterize Transbaikalian ichthyocenoses [Biodiversity…, 1999]. Two fish complexes determine the ichthyocenoses structure of the lakes: 1 – roach, perch and pike; 2 – lenok and grayling. Other fish species have subdominant value and build up the distinctness of communities. The first complex is connected with the lake limnogenesis processes, while the second – with the tectonic processes, specific for the Baikal type intermontane hollows. The Eravna lakes: in the Shchuchye lake (one of the Eravna lakes) there are peled, perch, roach and pike. Fishes from this lake underwent a thorough study of their productional characteristics. The results were used for the analysis of fishes in the water bodies of the Eravna-Kharginsk lake system. The Gusino-Ubukinskaya group, small water bodies (roach-perch lake Shchuch’e, crucian carp lakes Kamyshovoe, Krugloe, Chernoe, and perch-dace Abramovskoe lake). The total of 10 species registered: Amur sleeper, sand sculpin, spined loach, perch, burbot, lake minnow, crucian carp, dace, roach, peled and omul. Lake Gusinoe is the largest one. It is inhabited by 22 species: taimen, lenok, carp, bream, Amur catfish and Amur sleeper and farmed omul and peled. The Ivano-Arakhlei lakes (Arakhlei, Shaksha, Undugun, and Irgen) are inhabited by 16 species. Mostly they are pike, roach, dace, crucian carp, European cisco, peled and omul.

9. Meander lakes of the Verkhneangarskaya and Barguzinskaya hollows. The major lake complexes host 15 to 20 species, such as roach, perch, pike, nerfling, crucian carp, tench, carp, catfish, bream and others. There are about 7000 lakes in the Upper Angara and Kichera basins. The largest one is the eutrophic Irkana lake hosting nine species, such as roach, perch, pike, crucian carp, dace, nerfling, lake minnow, burbot and tench. The Barguzin basin lakes (4918 lakes) are inhabited by 19 fish species. In the upper course (mesotrophic) lakes there are taimen, lenok, grayling, common minnow, burbot, sand sculpin, Siberian spined loach and stoneloach. In the middle course (eutrophic) lakes there are pike, roach, perch, nerfling, crucian carp, bream, burbot, catfish, tench, carp, lake minnow, etc. In the lower course eutrophic lakes there are pike, roach, perch, dace, nerfling, crucian carp, catfish and lake minnow.

10. Ichthyocenosis of Lake Khovsgol. Nine species. The species composition has been forming since the post-glacial period. In 1957 the Baikal omul was introduced. Nowadays the water body is characterized as the lenok-grayling type of water bodies [Tugarina, 2002; Fishes…, 1983]. The majority of fishes inhabit coastal areas (grayling dwells at depths down to 25 meters, burbot – down to 30 meters) with the highest concentration in the bay and the mouth of the Khankh-Gol river. In 1957 10 million Baikal omul eggs were additionally incubated in the mouth of the Ikh- Khankh-Gol river by Professor A. Dashidorzhi of the Mongolian University. The first omul was detected in the mouth of the Ikh-Khankh-Gol river in 1971. Beyond the bay area omul has not yet been detected. Lenok inhabits the depths of 7 to 12 meters. Habitation limits in the open littoral of the western shore are confined to the 25-30 meter isobaths. The generative river form of grayling inhabits the area from the edge of water to the 25-30 meter isobaths while the generative lake form reaches down to the 80-100 meter isobaths. The roach habitation zone is limited to depths of down to 15 meters. Minnow inhabits the shore edge down to the depth of 1-1.5 meters while stoneloach – down to 1-1.3 meters. These are usually backwaters. Siberian spine loach inhabits the areas with sand and slimy ground down to the depths of 3 to 5 meters. Perch is common in the littoral at the depths down to 10-15 meters. Burbot is common everywhere within the depths of down to 40 and rarely 70 meters. All deep tributaries of Lake Khovsgol are mainly used as spawning grounds of lenok, grayling, burbot, etc. The meander lakes of the Ikh-Khoroo-Gol and Egiin-Gol rivers as well as the Ongolik Bay are the spawning grounds of perch, roach and minnow.

11. Near water-divide and water-divide areas. Small fishless lakes.

12. Territories with ulterior river net and closed drainage areas are located beyond the limits of the ichthyogeographic complexes.

References:

The freshwater fish atlas of Russia : 2 vols. (2003). / ed. Yu.S. Reshetnikov, Moscow: Nauka, Vol. 1 379 p., vol 2. 253 p.

Korsunov, V.M., Pronin, N.M., Gonchikov, G.G. et al. (1999). Biodiversity of the Baikal Siberia, Novosibirsk: Nauka, 350 p.

Vereshchagin, G.Yu. (1935). The two typobiological complexes of Baikal. Trudy Limnologicheskoi stantsii, vol. 6., pp. 199-212.

Kozhov, M.M. (1962). Biology of Lake Baikal, Moscow: Izd-vo AN SSSR,  315 p.

Koryakov, E.A. (1972). The pelagic gobies of Baikal, Moscow: Nauka, 1972, 155 p.

Mamontov, A.M. (1977). Ichthyocenoses, their dynamics and production. Limnology of the coastal-sor zone of Baikal, ed. by corr. member of the Academy of Sciences of the USSR N.A. Florensov. Novosibirsk: Nauka, pp. 263-288.

Nikol’skiy, G.V. (1953). On the biological specifics of the faunal complexes and the significance of their analysis for zoogeography, Moscow-Leningrad, pp. 65-76. .

Nikol’skiy, G.V. (1980). The species structure and tendencies of fish variability, Moscow: Pishchevaya promyshlennost’, 183 p.

Pronin, N.M., Matveev, A.M., Samusenok, V.P. et al., Fishes of Lake Baikal and its basin, Ulan-Ude: Izd-vo BNTs SO RAN, 2007, 284 p.

Reshetnikov Yu.S. (1983). The ecology and classification of the Coregonidae, Moscow: Nauka, 301 p.

Fishes of the Mongolian Peoples’ Republic. (1983). Moscow: Nauka, 277 p.

Sideleva, V.G. (2003). The endemic fish of Lake Baikal, Backhuys Publishers, Leiden, 270 p.

Sorokin, V.N., Sorokina, A.A., (1988). Biology of the commercial fishes of Baikal, Novosibirsk: Nauka, 214 p.

Sychevskaya, E.K. (1983). History of formation of Mongolia’s ichthyofauna and problem of faunal complexes, Fishes of the Mongolian Peoples’ Republic, Moscow: Nauka, pp. 225-249.

Taliev, D.N. (1955). Bullheads (Cottoidei) of Baikal, Moscow-Leningrad: Izd-vo AN SSSR, 602 p.

Timoshkin, O.A. (1995). Biodiversity of Baikal faunas: contemporary level of knowledge survey and study prospects, Atlas and field guide of Baikal pelagobionts, Novosibirsk: Nauka. Sib. Otd-nie, pp. 25-52.

Tugarina, P. Ya. (2002). Fish ecology of Lake Khubsugul and their fishery potential, Irkutsk: Izd-vo Irkutskogo gos. un-ta, 209 p.

Chernyaev, Zh.A. (1973). On the genesis of the Baikal bullheads (Cottoidei), Zool. zhurn., vol. 52, #3, pp. 452-453, .

Chernyaev, Zh.A. (1974). The Morphoecological peculiarities of reproduction and development of big Baikal oilfish Comephorus baicalensis (Pallas), Vopr. ikhtiologii, 14(6), p. 990-1003.

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Taxonomic diversity of soil biotic communities

Cartographic analysis of the spatial distribution of taxonomic diversity of invertebrate communities was carried out on the basis of the vegetation map of the Baikal basin.

The object of the analysis is the species (taxonomic) diversity of terrestrial invertebrates, forming community and having systemic and functional relationships. The main focus is on the mesopopulation (supraspecific taxonomic level), i.e. on relatively large invertebrates inhabiting soil and its surface.

The data were obtained as a result of a detailed study of the quantitative characteristics of invertebrate communities on key testing areas in taiga, mountain taiga and steppe geosystems of the Baikal basin. Numerous published and cartographic materials, information on soil cover and vegetation state were analyzed, and data on the heat and moisture supply to soils are taken into account. A method of soil-zoological and biogeocenotic studies with the application of the comparative-geographical approach was used in formulating and carrying out the work. Opportunities of landscape indication, based on theoretical concepts about the relation and interdependence of all natural components within a certain genetically homogeneous space, were used to compile map models of distribution of soil-biotic communities.

The structure of the animal population corresponding to the specific range of edaphic conditions ensuring normal functioning of soil organisms, was interpreted from the standpoint of the landscape-typological approach, i.e. correlation and subsequent identification (experimentally) of soil invertebrates in specific conditions of their habitat.

Spatial patterns of change in species diversity in gradients of environmental factors such as altitudinal zonality, temperature regime and moisture content of soil were identified on the most well-studied model groups of invertebrates in the Baikal region, namely, the representatives of the Lumbricidae, Carabidae, Staphylinidae, and Elateridae families.

As a result of a unified research methodology the communities of terrestrial invertebrates were united into four groups: alpine, taiga and forest, forest-steppe and steppe, and meadow and hydrophilic. Five categories of diversity of the structure were identified in each group according to the number of taxonomic units in a community: 1 - very low diversity (less than 5 taxa), 2 - low (6-10 taxa), 3 - medium (11-15 taxa), 4 - high (16-20 taxa), and 5 - very high (more than 20 taxa).

On the basis of the structural-dynamic analysis of differences in habitats and corresponding invertebrate complexes on the macrogeographical level, two main types of community structure are distinguished: mesothermohygrophile with a relatively small fraction of insects and a large fraction of annelids, and xeroresistant with significant participation of the class of insects. The first type includes zoocomplexes of taiga, forest and meadow biogeocenoses, represented mainly by moisture-loving forms, and the second one includes zoocomplexes of steppificated, steppes and radically anthropogenically disturbed biogeocenoses, dominated by insects with relatively short development cycles and largely adapted to moisture deficit. This corresponds to two main types of natural environment: of excess moisture - taiga with humid climate, and insufficient moisture - steppe with semihumid climate.

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Soil-ecological zoning

The principles of “Soil-ecological zoning of Irkutsk oblast” [Kuzmin, 2004], “Soil zoning of the Baikal region” [Kuzmin, 1993], and “Soil-geographical zoning of Mongolia” [Dorzhgotov, 2010], the map of the soil cover, information on soils, their connections with the natural conditions, obtained as a result of the in-house long-term research, and materials on geology, topography, and other natural components were used when developing the zoning.

In the map of the soil-ecological zoning, nine provinces are singled out, reflecting the peculiarity of the surface topography, since the ratio of the heat and moisture balance, which serves as the basis for zoning, manifests itself against the background of the complex orography. Here bioclimatic factors play a key role. Twenty-eight districts are distinguished in the provinces according to the lithologic-geomorphological features. From the standpoint of the structural approach, the districts are regarded as territories with a specific regular change of several types of the soil cover structure, associated with the features of terrain and parent rocks.

The complex of all natural conditions that influence the formation of the soil cover is taken into consideration in the soil-ecological zoning. Connections of soils with other components of the landscape are identified. It is necessary to consider regional features of the soil cover when planning the distribution of agricultural production, while knowledge of the interrelations of soils with the natural conditions is essential to develop the measures aimed at avoidance of negative consequences of the anthropogenic impact.

The maps of soil cover can be used as independent scientific works, characterizing the soil cover of the area, which is an important component of the landscape, as a starting material for the soil (land) resources accounting, as a support material for planning the chemicalization of the agricultural production, agroforestal and erosion control measures, development of forest resources, environmental protection, as a basis for various types of zoning, and as a manual for students of higher education institutions.

References

Dorjgotov, D. and Batkhishig, O. (2009). Soils. Soil-geographical zoning of Mongolia, in National Atlas of Mongolia, Ulaanbaatar, pp. 120-122.

Dorjgotov, D. (1976). Soil classification of Mongolia.Ulaanbaatar, 170 p.

Dorjgotov, D. (2003). Soils of Mongolia.Ulaanbaatar, 370 p.

Classification and Diagnostics of Soils of Russia. (2013). Authors and compilers: Shishov, L.L., Tonkonogov, V.D., Lebedeva, I.I., and Gerasimova, M.I. Moscow: V.V. Dokuchaev Soil Science Institute RAAS,  http://soils.narod.ru/obekt/obekt.html.

Kuzmin, V.A. (2004). The soil cover. Soil-ecological zoning of Irkutsk oblast, in Atlas of Irkutsk Oblast, pp. 40-41.

Kuzmin, V.A. ( 1993). Soil zoning, in Atlas of Baikal, p. 130.

Ubugunov, L.L., Ubugunova, V.I., Badmaev, N.B., Gyninova, A.B., Ubugunov, V.L., and Balsanova, L.D. (2012). Soils of Buryatia: diversity, taxonomy and classification, in  Bulletin of the V.R. Filippov Buryat State Academy of Agriculture, no. 2, pp. 45-52.

Shishov, L.L., Tonkonogov, V.D., Lebedeva, I.I., and Gerasimova, M.I. (2004). Classification and diagnostics of soils of Russia. Smolensk: Izd-vo Oikumena, 342 p.

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Soil stability

A qualitative assessment of the soil stability (i.e. the resistance to external effects and the ability to restore the disturbed properties) was made with regard to the external and internal factors. In general, the stability decreases from low graded surfaces or gentle slopes with an increase in an altitude and steepness of slopes. In the same direction a change from loamy deposits to stony deposits with small thickness of the loose mass takes place, and heat supply changes for the worse. In total, four large subdivisions of soils were distinguished according to different degrees of stability: low, medium, medium and above medium, and moderate. Their characteristic is given in the legend to the map of the soil stability to the anthropogenic impact.

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Soils

Soil associations are presented in the contours on the map. Combinations of soils, united in a contour, are associated with the altitudinal and expositional differentiation, and are determined by the character of mesorelief (combinations) and microrelief (complexes), and by the heterogeneity of the soil-forming material (mosaic). The predominant soil is the first in the legend, followed by accompanying and occurring soils. Most soils are distinguished at the type level, rarely at the subtype level.

The great extension of the territory of the Baikal basin from south to north determines latitudinal variations of the thermal factor and the associated vegetation and soil cover. In addition to these basic regular patterns, the influence of exposure and meridional arid mountain zonality is manifested here. The role of permafrost and heterogeneity of parent rocks, complicated and insufficiently clear evolution of landscapes in the past, and their changing as a result of the human impact are essential.

Within the mountain taiga, independent contours are distinguished in the south-western and north-eastern parts of Cisbaikalia. They are represented by combinations of soils with the eluvial-illuvial and undifferentiated profile. The Baikalsky Ridge and the North-Baikal Highland are dominated by podzols and podburs, involving peat-podburs and sod-podzols. They are characterized by a thin profile, which averages 30 cm in podzols of the highland, while in the mountains of Cisbaikalia it is about 40 cm. Thickness of the profile of podburs, which can be regarded as being in the early stage of soil formation, is even less.

Soils of piedmont dry steppes of Cisbaikalia are common in the Priolkhonie region and on Olkhon Island. Formation of dry steppe landscapes with chestnut soils is due to the arid mountain zonality (location in the rain shadow). The lack of atmospheric moistening is compounded here by a high water penetration capacity of woody-loamy soils. The territory is similar to that of the dry steppe of Kazakhstan in the nature of moistening, and to the middle taiga of Yakutia in heat supply. A consequence of the extreme soil-climatic conditions is a low biological productivity. Agroecosystems here are in a state of crisis; the vegetation and soil cover undergoes degradation.

In the high-mountain part of the Khamar-Daban, Muisky, Verkhne-Angarsky and Barguzinsky ridges the basic soils are petrozems, peat-lithozems, and coarse humus lithozems. Coarse humus, humic and humic-dark-humus soils are formed under the sub-alpine meadows. On the northern slopes, in relatively low relief elements, and in areas composed of parent rocks of heavier particle-size distribution, gley podburs are formed.

Cryo-lithozems, petrozems and cryo-carbo-lithozems accompany nival dissected landscapes of the Khangai region of Mongolia. Cryozems (coarse humus) and peat-cryozems are developed in the sub-goletz altitudinal belt, locating in a relatively narrow band near the forest line. In soils of taiga massifs permafrost areas are of frequent occurrence; moreover, seasonal frost is longstanding, and cryoturbation phenomena and solifluction are usual.

The structure of the soil cover of the mountain-taiga zone of Transbaikalia is heterogeneous and is largely associated with the manifestation of vertical zonality, slope exposure, and permafrost. The main soil background is comprised of podburs, podzols, sod-podzols, sod-podburs, gray-humus, humic, humic-dark-humus soils and coarse humus burozems. The main background of the soil cover of taiga territories of Mongolia includes cryozems, podburs and dark-humus soils. Soils of podzolic type are rare here. In the upper part of the taiga belt, cryozems and podburs are formed; higher there are peat-lithozems. In mountainous taiga there occur steppe "islands" with chernozem-like soils. They can be found on steep parts of the southern slopes, facing the broad areas of intermontane depressions.

The natural-climatic zone of forest-steppe is dominated by gray metamorphic soils, which are formed on the foothill areas of depressions and on the northern slopes of hills inside intermontane lows or at the bottom part of the forested slopes of ridges, facing the steppe depressions. These soils occupy the largest areas in the forest-steppe of the southern part of the Trans-Baikal middle mountains. In the forest-steppe landscape belt of Mongolia of light-coniferous and mixed subshrub and herbaceous facies there occur dark-humus metamorphosed soils, located mainly along the southern slopes of ridges and hills. Gray humus soils formed under woody communities with forbs on carbonate rocks. This combination of soils, characteristic of different environmental conditions, is the main feature of the soil cover at the junction of taiga and steppe.

In steppe landscapes of Transbaikalia the main background of the soil cover is comprised of chernozems. They are formed under meadow and true steppes. The main massifs of these soils are located in the Tugnui-Sukhara basin: on the Tugnuisky ridge and on the southern slopes of the Zagansky ridge, on the northern slopes of the Kudarinskaya range and the Small Khamar-Daban, Monostoisky, and Borgoisky ridges. In the more northern part of the territory, chernozems are formed in individual spots on the north-western slopes of the Unegeteisky ridge and along the Uda and Itantsa river valleys.

The soil cover of dry steppe is dominated by chestnut soils. They occupy vast tracts in the Udinskaya, Priselenginskaya, and Borgoiskaya steppes, and wide gently sloping terraces in the valleys of large rivers; they are common on the southern slopes of the ridges. On the watersheds of high ridges there occur soils of the lithozem group. Humus psammozems are formed on aeolian sand deposits of the dry steppe zone, especially in the Selenga-Chikoy and Chikoy-Khilok interfluves, and on pine-forest sands.

Soils of the river valleys of Cisbaikalia and Transbaikalia are represented mainly by alluvial humic-gley, peat-gley, dark-humus, gray-humus, and dark-humus quasi-gley soils. In the structure of the soil cover of the floodplains of the upper and middle reaches of the rivers stratified alluvial soils are of frequent occurrence. In the steppe and especially in the dry steppe zones of Transbaikalia solonchaks and less frequently solonetzic soils are formed in the river floodplains. They occupy mostly lacustrine depressions and lower parts of gentle slopes, generally adjacent to the river floodplains, where there is a zone of accumulation of waters of the valley runoff enriched with soluble salts or a discharge of mineralized groundwaters. The most common types of salinization of solonchaks and solonetzic soils are sulfate-soda, soda-sulfate, sulfate, and chloride-sulphate. Large massifs of saline soils are widespread in the Borgoiskaya steppe and lacustrine lows of Lakes Verkhnee Beloe and Nizhnee Beloe. Their proportion in the Ivolginskaya depression is quite substantial. Solonetzic soils and solonchaks also occur in lacustrine depressions of the Bichursky district and the Tugnuiskaya steppe. In the Selenga river delta, in the Barguzin river valley, and in some other regions relatively large massifs are covered with bogs, where mainly peat eutrophic and peat eutrophic gley soils develop.

Soils of waterlogged meadows and lacustrine-boggy complexes of Mongolia are widespread in the near-shore zone of Lakes Khovsgol and Doot-Nur, in the Dzhargalant-Gol and Mungaral-Gol interfluve, in the northern and southern part of the Darkhatskaya depression, and along river valleys. Alluvial dark-humus soils are formed in river floodplains on elevated areas, in deltas, and on alluvial fans of temporary streams. Alluvial humic gley soils are formed under the conditions of additional inflow of moisture. In elevated locations of the riverbed floodplain of mountain rivers on sandy-gravel deposits gray-humus alluvial and stratified soils were formed. Alluvial peat-gley (peat-mineral) soils are formed in relatively low locations of river floodplains with the conditions of long-term surface and subsurface moistening, as well as on the edges of water bodies overgrown with bog vegetation. Humus-hydrometamorphic seasonally freezing for a long time soils are formed in the central floodplain of the rivers. In the lacustrine part of the depressions humic-hydrometamorphic (silty-humic) cryogenic soils are developed.

In the territory of Mongolia a series of relatively small contours of saline soils occurring in different parts of the country was distinguished. Processes of erosion and deflation are widespread, which is due to the shower precipitation pattern, and periodic occurrence of dust storms and strong winds, especially in spring when soil is dry and vegetation grows poorly.

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Forest cover

Forest cover is a parameter reflecting the ratio of the total forested area (on forest lands and lands of other categories where forests are located) to the area of the municipality (district or aimak). Forest cover is an important indicator characterizing the forest availability, and, consequently, the ecological security and the features of the socio-economic development of a territory.

Average forest cover of the Baikal basin within the Russian territory is 62.5 %. Forest cover fluctuates here from 26.4 % in Kyakhtinsky district, located in the steppe part of the Republic of Buryatia, to 82-89 % in Krasnochikoysky, Petrovsk-Zabaikalsky, Uletovsky, and Khiloksky districts of Zabaikalsky krai. In Mongolia, the average forest cover is significantly lower than in the Russian part of the basin amounting to 11.5 %, and it ranges from 0.75 % (Uverkhangay aimak) to 35.0 % (Darkhan aimak).

Over the last decade (2000-2010) a decrease in forest cover in the most developed parts of the Baikal watershed basin is registered. This is associated with the reduction of forested lands due to areas, subjected to fire, cutting, and insect pests.

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Legend to the “Vegetation” map

GOLETZ (HIGH-MOUNTAIN) VEGETATION

MOUNTAIN TUNDRAS

PAN-ATLANTIC PHRATRY OF FORMATIONS

South-Siberian formations

1. Stony tundras with the predominance of crustose lichens (species of genera Cetraria Ach., Cladonia Hill ex P. Browne, and Alectoria Ach.), in places with clumps of fruticose lichens and with sparse vegetation groups of Hierochloë alpina (Sw.) Roem. et Schult., Luzula confusa Lindeb., Saussurea congesta Turcz., on stony placers, comprised of granitoids in the upper parts of the goletz zone, combined with subshrub (Rhododendron aureum Georgi, Ledum palustre L., Dryas oxyodonta Juz.)-lichen (Alectoria ochroleuca (Hoffm.) A.Massal., Cetraria islandica (L.) Ach.) tundras on flat tracts, covered with fine detritus of shale rocks or gneiss with mountain arctic-tundra primitive soils

2. Moss-lichen (Aulacomnium turgidum (Wahlenb.) Schwägr., Dicranum elongatum Schleich. ex Schwägr., Cetraria cucullata (Bellardi) Ach.) tundras on stony sunlit slopes, combined with alpine-type small meadows (Ptilagrostis mongholica (Turcz. ex Trin.) Griseb., Festuca sphagnicola B.Keller, Kobresia myosuroides (Vill.) Fiori) on rubble-silt talus fans in places of deep snow banks

3. Mountain avens (Dryas oxyodonta Juz., D. punctata Juz.)-lichen (Flavocetraria cucullata (Bellardi) Kärnefelt et A.Thell) tundras on stony-rock-debris mountain ranges and convex sodded tracts with fine skeleton substrates, combined with crowberry (Empetrum sibiricum V.N.Vassil)-yernik (Betula rotundifolia Spach) communities on flat uplands with loose fine earth and in wide hollows of mountain slopes

4. Grass (Festuca ovina L., Carex ensifolia Turcz. ex Gorodk., Pedicularis oederi Vahl.)-lichen (Cladonia alpestris (L.) Rabench.) tundras often with shrubs (Betula rotundifolia Spach., Rhododendron aureum Georgi, Salix glauca L.) on gentle slopes and well drained flat tracts with mountain-tundra humic gley soils, combined with subshrub (Empetrum sibiricum V.N.Vassil, Dryas oxyodonta Juz.)-moss (Cetraria laevigata Rass., Cladonia stellaris (Opiz) Pouzar et Vězda) tundras on concave tracts with peaty-gley soils

North-Mongolian formations

5. Lichen (species of genera Cladonia Hill ex P. Browne, Cetraria Ach., Alectoria Ach., Stereocaulon Schreb.) and moss (species of genera Aulacomnium Schwägr., Polythrichum Hedw., and others) tundras on mountain-tundra underdeveloped and destructive soils among stony placers and taluses in the goletz zone, combined with sedge, kobresia (Kobresia myosuroides (Vill.) Fiori, K. sibirica (Turcz. ex Ledeb.) Boeck.)-sedge (Carex melanantha C.A.Mey, C. macrogyna Turcz. ex Steud) and subshrub (Dryas oxyodonta Juz, Arctous alpina (L.) Niedenzu, Rhododendron aureum Georgi)-lichen (Cetraria laevigata Rass., Cladonia stellaris (Opiz) Pouzar et Vězda) tundras in high-mountain rigions on semi-sodded stony slopes with mountain-tundra humic-peaty-gley soils and on convex mountain slopes with mountain-tundra soddy and humic-soddy soils

PAN-PACIFIC phratry of formations

Baikal-Dzhugdzhur formations

6. Stony tundras with the sparse lichen cover (Alectoria ochroleuca (Hoffm.) Mass., реже with Cetraria nivalis (L.) Ach., C.cucullata (Bell.) Ach.) and singly occurring vegetation groups (Potentilla elegans Cham. et Schlecht., Sibbaldia procumbens L.) in the upper parts of the goletz zone with mountain arctic-tundra primitive soils

7. Lichen (Cetraria nivalis (L.) Ach., C.islandica (L.) Ach., C.chrysantha Tuck., C.cucullata (Bell.) Ach.) tundras in the upper parts of goletz plateaus on convex land forms with ledges of crystalline rocks, combined with mountain avens (Dryas punctata Juz., D. Incise Juz.)-lichen rock debris tundras on dry slopes with gravelly peaty-loamy soils

8. Grass (Calamagrostis lapponica (Wahlenb.) Hartm., Carex globularis L., C. ensifolia Turcz. ex V.I. Krecz. , Hierochloe alpina (Sw.) Roem. et Schult.)-lichen (Cladonia alpestris (L.) Rabench., C. sylvatica (L.) Hoffm., C. rangiferina (L.) Web.) dry tundras in the middle and lower parts of the goletz zone and in the subgoletz zone on slopes and placers with fine-earth peaty substrates, combined with subshrub (Empetrum sibiricum V.N.Vassil, Cassiope ericoides (Pallas) D.Don.)-Cladonia tundras and tracts of kobresia (Kobresia myosuroides (Vill.) Fiori) heathlands and high-mountain fescue (Festuca lenensis Drob.) steppes on flat summits and gentle concave slopes with mountain tundra-meadow soils

9. Subshrub (Ledum decumbens Small.)-moss (Drepanocladus uncinatus (Hedw.) Warnst., Racomitrium canescens (Hedw.) Brid.)-lichen (Cetraria islandica (L.) Ach., Cladonia rangiferina (L.) Web.) tundras on slopes with mountain-tundra humic-carbonate soils, combined with wet tundras (Carex tristis M. Bieb., Ledum palustre L., Aulacomnium turgidum (Wahl.) Schwaegr.) and nival small meadows (Bistorta vivipara (L.) Delarbe, Allium malyschevii N.V.Friesen) in saddles and microdepressions with mountain tundra-meadow soils

10. Subshrub (Vaccinium myrtilus L.)-bergenia (Bergenia crassifolia (L.) Fritsch)-lichen (Stereocaulon paschale (L.) Fr., Cladonia alpestris (L.) Rabench., C.rangiferina (L.) Web.) tundras (heathlands), in places with golden rhododendron, Siberian dwarf pine and Middendorff’s dwarf birch on summit surfaces and convex stony slopes with mountain-meadow light loamy gravelly soils, combined with nival small meadows on flat and concave slopes with mountain-meadow loamy soils

11. Tundras turned to meadows (Festuca ovina L., Lycopodium alpinum L., Hierochloe alpina Roem. et Schult.) on sodded tracts of stony and rocky slopes, combined with alpine-type  small meadows (Anemone sibirica L., Oxytropis kusnetzovii Kryl.) on concave and flat surfaces with soddy mountain-meadow light loamy soils, as well as dwarf Siberian mountain pine (Pinus pumila (Pallas) Regel) and yernik (Betula divaricata Ledeb.) vegetation on stony slopes with gravelly weakly-humic soils

MOUNTAIN (ALPINE-TYPE) MEADOWS AND HEATHLANDS

ALTAI-TIAN-SHAN PHRATRY OF FORMATIONS

South-Siberian formations

12. Alpine-type (Trollius sajanensis (Malyschev) Sipliv., Aquilegia glandulosa Fischer ex Link) and subalpine-type (Geranium albiflorum Ledeb., Saussurea latifolia Ledeb.) meadows on flat sodded tracts on bottoms of kars and on gently sloping plots with mountain tundra-meadow soils, combined with shrubs vegetation (Betula rotundifolia Spach, Duschekia  fruticosa (Rupr.) Pouzar, Salix glauca L.) on flat and concave slopes with mountain-tundra peaty-gley soils

North-Mongolian formations

13. High-mountain cryophyte meadows and heathlands (Cerastium pseudosibiricum J.Mayer, Dryadanthe tetrandra (Bunge) Juz., Valeriana petrophylla Bunge) in the transition area from the goletz to subgoletz zone on valley bottoms and at the foot of slopes with mountain tundra-meadow soils, combined with sedge-kobresia, kobresia-sedge and waterlogged sedge (Carex macrogina Turcz. ex Steud., C. orbicularis Boott, C. bigelowii Torr.) meadows on mountain-meadow soddy-humic gleyic and cryogenic-meadow peaty-humic-gleyic soils

14. Kobresia (Kobresia bellardii (All.) Degl.) and sedge (Carex rupestris All., C. stenocarpa Turcz.)-kobresia meadows and heathlands on flat summits of ranges, gentle slopes of all aspects, and in bottoms of non-waterlogged hollows with mountain tundra-meadow soils, combined with stony-rock-debris placers and patches of high-mountain steppes (Kobresia simpliciuscula Mack., Ptilagrostis mongolica Griseb., Festuca supina Schur., F. brevifolia R. Br., F. sphagnicola B. Keller) on concave slopes and in wide bottoms of intermontane depressions with tundra-meadow rich humus soils           

TAIGA (BOREAL) VEGETATION

SUBGOLETZ SPARSE FORESTS AND SHRUBS VEGETATION

URAL-SIBERIAN PHRATRY OF FORMATIONS

South-Siberian formations

Dark-coniferous (Pinus sibirica Du Tour, Abies sibirica Ledeb.,

Picea obovata Ledeb.) sparse forests

15. Spruce Siberian dwarf pine (Pinus pumila (Pallas) Regel) moss (Pleurozium schreberi (Brid.) Mitt., Ptilium crista-castrensis (Hedw.) De Not.)-lichen (Cladonia mitis Sandst, Cetraria islsndica (L.) Ach., Stereocaulon paschale (L.) Hoffm.) sparse forests on flat saddles, concave surfaces and slopes to river valleys with mountain cryogenic-taiga soils, combined with stony tundras and placers on convex tracts with mountain-tundra soils

16. Siberian stone pine and larch (Larix sibirica Ledeb.)-Siberian stone pine yernik (Betula rotundifolia Spasch) subshrub (Vaccinium vitis-idaea L., V. uliginosum L.)-moss (Dicranum scoparium Hedw., Pleurozium achreberi (Brid.) Mitt.)-lichen (Cladonia turgida Hoffm., C.uliginosa (Ahti) Ahti) sparse forests on stony slopes and plateau-like rocky surfaces with mountain cryogenic-taiga soils, combined with grass-shrubs vegetation in microdepressions and sodded tracts with mountain-tundra soils

17. Siberian stone pine with spruce and larch (Larix sibirica Ledeb.) dwarf Siberian mountain pine (Pinus pumila (Pallas) Regel) cowberry (Vaccinium vitis-idaea L., Ledum palustre L.)-true-moss (Pleurozium schreberi (Brid.) Mitt., Hylocomium splendens (Hedw.) B.S.G.) sparse forests on convex watersheds and steep slopes of different aspects with shallow rank nonpodzolized soils, combined with Siberian stone pine cowberry forests on gentle and planate tracts with cryogenic-taiga soils

18. Fir and spruce-fir sparse forests, in places with lanate birch (Betula lanata (Regel) V.N.Vassil.), with golden rhododendron (Rhododendron aureum Georgi) and dwarf Siberian mountain pine (Pinus pumila (Pall.) Regel) tall-grass (Pteridium aquilinum (L.) Kuhn., Dryopteris fragrans (L.) Schott, Athyriium filix-femina (L.) Roth, Anemone baicalensis Turcz., Bupleurum multinerve DC.) on stony slopes with mountain podzolic gravelly-sandy-loamy shallow soils, combined with tracts of subalpine-type meadows (Geranium krylovii Tzvelev, Aconitum baicalense Turcz. ex Rapaics, Carex aterrima Hoppe) in near-brooks habitats with mountain tundra-meadow soils

Light-coniferous (Larix sibirica Ledeb.) sparse forests

19. Larch and Siberian stone pine-larch yernik (Betula rotundifolia Spach, B. exilis Sukaczev, Salix glauca L.) grass (Festuca ovina L., Bistorta elliptica (Willd. ex Spreng.) Kom., Artemisia dolosa Krasch.)-moss (Hylocomium splendens (Hedw.) Bruch et al., Rhytidium rugosum (Hedw.) Kindb.), in places with lichens (Cladonia alpestris (L.) Rabenh., C.rangiferina (L.) Web.), sparse forests on steep slopes, aprons and high river terraces with cryogenic-taiga peaty-gleyic soils, combined with larch marsh tea-cowberry sparse forests on less steep slopes with the same soils and patches of grass-lichen-moss tundras on convex well drained surfaces with mountain arctic-tundra sandy and sandy-loamy shallow soils

ANGARIDE PHRATRY OF FORMATIONS

Baikal-Dzhugdzhur formations

Light-coniferous (Larix dahurica Laws.) sparse forests

20. Larch sparse forests with dwarf Siberian mountain pine (Pinus pumila (Pal.) Regel), dwarf birch (Betula divaricata Ledeb.), in places with Duschekia (Duschekia fruticosa (Rupr.) Pouzar) moss (Dicranum elonganum Schleich. ex Schwaegr., Aulacomnium turgidum (Wahl.) Schwaegr., Rhytidium rugosum (Hedw.) Kindb.)-lichen (Cladonia alpestris (L.) Rabench.) on planate surfaces and gentle stony slopes with mountain cryogenic-taiga surface-ferruginized soils, combined with shrubs (Benula nana L.) vegetation on convex and flat surfaces with fine skeleton soils and patches of alpine-type small meadows (Anemone sibirica L., Aquilegia glandulosa Fisch. ex Link, Festuca altaica Trin.) on sodded tracts on bottoms of kars and concave slopes with mountain-meadow soddy-humic light loamy soils

BERINGIAN phratry of formations

Baikal-Dzhugdzhur formations

Dwarf Siberian mountain pine (Pinus pumila (Pallas) Regel) vegetation

21. Dwarf Siberian mountain pine vegetation with singly occurring trees (Larix dahurica Laws., Pinus sibirica Du Tour., Betula lanata (Regel) V.N.Vassil.) on slopes with coarse stony substrates and stony-rank immature soils, combined with subshrub (Cassiope ericoides (Pall.) D.Don, Ribes fragrans Pall.) and meadow (Festuca altaica Trin., Dracocephalum grandiflorum L., Aquilegia glandulosa Fisch. ex Link) communities in microrelief lows with mountain tundra-meadow soils

MOUNTAIN-TAIGA FORESTS

URAL-SIBERIAN PHRATRY OF FORMATIONS

Middle-Siberian formations

Dark-coniferous (Abies sibirica Ledeb., Pinus sibirica Du Tour, and Picea obovata Ledeb.) forests

22. Fir-Siberian stone pine subshrub (Ledum palustre L., Vaccinium vitis-idaea L., Vaccinium uliginosum L.)-grass (Pyrola rotundifolia L., Linnaea borealis L., Carex macroura Meinsh., in places with tall grass - Valeriana alternifolia Ledeb., Silene amoena L., Brachypodium pinnatum (L.) Beauv., Trollius asiaticus L., Pulmonaria mollis Wulfen ex Hornem.)-true-moss (Pleurozium schreberi (Brid.) Mitt., Hylocomium splendens Bruch et al.) forests on summits and slopes of  high watersheds with coarse-skeleton soddy-podzolic soils

22d. Larch-pine with Siberian stone pine and fir subshrub-grass-true-moss anthropogenic series

Light-coniferous (Larix sibirica Ledeb.) forests

23. Larch and pine-larch cowberry-forb (Saussurea controversa D.C., Polygala sibirica L., Scabiosa ochroleuca L., Carex macroura Meinsh., Calamagrostis arundinacea (L.) Roth.) forests on slopes of different steepness with soddy-forest weakly podzolic or soddy-carbonate leached soils

24. Larch with the inclusion of Siberian stone pine and spruce, in places with undergrowth of yernik (Betula fruticosa Pallas) subshrub (Ledum palustre L., Vaccinium uliginosum L.)-moss forests in the lower parts of slopes of different aspects, in weakly waterlogged river terraces, drained creek valleys and in river valleys with podzolic deeply-freezing or seasonally-cryogenic soils

South-Siberian formations

Dark-coniferous (Abies sibirica Ledeb., Picea obovata Ledeb.,

Pinus sibirica Du Tour) forests

25. Siberian stone pine-fir bilberry (Vaccinium myrtillus L.)-grass (Equisetum sylvaticum L., Moneses uniflora (L.) A. Gray, Trientalis europaea L., Carex iljinii V. Krecz.)-true-moss (Hylocomium splendens (Hedw.) B.S.G., Polytrichum commune Hedw.) forests in interfluves on heads of watersheds and upper parts of slopes with podzolic sandy-loamy and light loamy soils

25a. Aspen-birch with fir and Siberian stone pine bilberry-grass-true-moss

anthropogenic series

25c. Larch with Siberian stone pine, fir, birch bilberry-grass-

true-moss anthropogenic series

26. Siberian stone pine-fir with spruce and larch (Larix sibirica Ledeb.) bilberry (Vaccinium myrtillus L.)-bergenia (Bergenia crassifolia (L.) Fritsch)-true-moss (Hylocomium splendens (Hedw.) B.S.G., Polytrichum commune Hedw.) forests in the upper parts of the forest zone on convex surfaces, steep stony shady slopes and slopes to river valleys with weakly podzolic gravelly soils

27. Fir-Siberian stone pine with spruce bilberry-small grass (Mitella nuda L., Trientalis europaea L., Stellaria bungeana Fenzl.)-true-moss (Pleurozium schreberi (Brid.) Mitt., Ptilium crista-castrensis (Hegw.) De Not.), in places with bergenia (Bergenia crassifolia (L.) Fritsch), forests on convex surfaces and steep stony slopes with shallow gravelly-loamy moistened soils

27a. Aspen-birch with Siberian stone pine and fir bilberry-small grass-

true-moss anthropogenic series

27c. Pine-larch with Siberian stone pine, fir, birch, aspen bilberry-

small grass-true-moss anthropogenic series

28. Siberian stone pine with undergrowth of golden rhododendron (Rhododendron aureum Georgi) bilberry-cowberry-true-moss (Pleurozium schreberi (Brid.) Mitt., Dicranum congestum Brid.), in places with bergenia, forests on mountain ranges and their slopes with humic weakly podzolized moderately loamy soils

28а. Siberian stone pine-birch with undergrowth of golden rhododendron

bilberry-cowberry-true-moss anthropogenic series

28c. Larch with Siberian stone pine with undergrowth of golden rhododendron

bilberry-cowberry-true-moss anthropogenic series

29. Siberian stone pine with larch (Larix sibirica Ledeb.) (in places with fir and spruce) subshrub (Vaccinium myrtillus L., Ledum palustre L.)-grass (Bergenia crassifolia (L.) Tritsch, Carex iljinii V. Krecz. in places with tall grass)-true-moss forests on gentle shady slopes, saddles, and in intermontane depressions with cryogenic-taiga peaty-gley and peaty-weakly podzolic soils

30. Siberian stone pine with the inclusion of spruce and larch marsh tea-cowberry-true-moss (Pleurozium schreberi (Brid.) Mitt.) forests in the middle and the upper parts of steep sunlit slopes with soddy-forest brown-colored shallow fresh soils, in places combined with bergenia Siberian stone pine woodlands, on narrow crests of watersheds and their steep stony slopes with podzolic coarse-skeleton soils

30c. Larch with Siberian stone pine Marsh tea-cowberry-true-moss,

in places with bergenia, anthropogenic series

31. Siberian stone pine-spruce with larch, in places fir-spruce with Duschekia and wild ash in the underwood, subshrub (Vaccinium vitis-idaea L., V.myrtilus L., Rubus arcticus L.)-grass (Linnaea borealis L., Pyrola rotundifolia L., Equisetum palustre L., Goodyera repens (L.) R. Br., Lusula parviflora (Ehrh.) Desv.)-true-moss (Pleurozium schreberi (Brid.) Mitt., Polytrichum commune Hedw.) forests in the lower parts of gentle undulating shady slopes, intermontane depressions and on slopes to river valleys with loamy and peaty-humic wet soils

32. Spruce with larch, in places with poplar (Populus suaveolens Fischer, P. laurifolia Ledeb.), grass (Сalamagrostis arundinacea (L.) Roth, C. langsdorffii (Link) Trin., Delfinium elatum L., Viola uniflora L., Vicia cracca L., Orthilia secunda L. Garcke., Sanguisorba officinalis L.)-subshrub (Vaccinium vitis-idaea L., V. uliginosum L.) forests in waterlogged valleys of brooks and rivers with peat-bog deeply freezing soils

33. Poplar (Populus suaveolens Fischer)-fir with spruce tall-grass (Solidago dahurica Kitag., Calamagrostis obtusata Trin, Hieracium umbellatum L., Agrostis stolonifera L.) forests along rivers on channel deposits, in creek valleys, wide concave depressions with deep sandy-loamy-humic soils

33а. Fir-birch with poplar and spruce tall-grass anthropogenic series

Light-coniferous (Larix sibirica Ledeb, Pinus sylvestris L.) forests

34. Larch with undergrowth of small-leaved rhododendron (Rhododendron parvifolium Adams) and round-leaved birch (Betula rotundifolia Spach)-grass (Pedicularis verticillata L., Delfinium crassifolium Schrad. ex Spreng., Carex amgunensis F.Schmidt)-moss (Rhytidium rugosum (Hedw.) Kindb) forests on planate surfaces, rather steep sunlit slopes and on slopes of mountain valleys with soddy-carbonate leached soils

35. Siberian stone pine-larch and larch with Siberian stone pine cowberry (Vaccinium vitis-idaea L., Ledum palustre L., Calamagrostis lapponica (Wahlenb.) Hartm.) forests on gentle slopes and aprons of different aspects, as well as on terraces of different levels with soddy-forest weakly podzolic loamy and sandy-loamy fresh soils

35а. Larch-birch cowberry anthropogenic series

36. Larch and pine-larch with undergrowth of rhododendron (Rhododendron dauricum L., реже Rh. ledebouri Pojark.) marsh tea-cowberry-true-moss forests on planate surfaces and slopes of different aspects with weakly podzolic sandy-loamy cryogenic soils

36а. Birch with larch and pine with undergrowth of Daurian rhododendron

marsh tea-cowberry-true-moss anthropogenic series

37. Pine and larch-pine with undergrowth of Daurian rhododendron (Rhododendron dauricum L.) and fruticose Duschekia (Duschekia fruticosa (Rupr.) Pouzar) grass (Geum aleppicum Jacq., Crepis praemorsa (L.) Tausch, Euphorbia jenisseiensis Baikov., Crepis praemorsa (L.) Tausch, Anemone crinita Juz., Saussurea controversa D.C.) forests on gentle slopes in the middle and lower parts of the forest zone, in intermontane depressions, and on slopes of different aspects to river valleys with soddy weakly podzolic soils

37а. Birch with larch and pine with undergrowth of rhododendron and

Duschekia grass anthropogenic series

North-Mongolian formations

Light-coniferous (Larix sibirica Ledeb., Pinus sylvestris L.) forests

38. Siberian stone pine-larch grass (Linnaea borealis L., Vicia baicalensis (Turcz.) B.Fedtsch., Calamagrostis obtusata Trin.)-subshrub (Vaccinium vitis-idaea L., V. uliginosum L.)-true-moss (Hylocomium splendens (Hedw.) B.S.G., Pleurozium schreberi (Brid.) Mitt.) forests in the upper parts of the forest zone on planate surfaces and the upper parts of slopes with peaty-weakly podzolic cryogenic soils

39. Larch with Siberian stone pine subshrub (Ledum palustre L., Vaccinium vitis-idaea L.)-bergenia (Bergenia crassifolia Trisch)-true-moss (Hylocomium splendens (Hedw.) Bruch et al., Pleurozium schreberi (Brid.) Mitt. ) forests on shady slopes, aprons, high terraces with soddy deeply-cryogenic shallow soils

40. Larch with spruce, Siberian stone pine, less often fir with undergrowth of rhododendron (Rhododendron dahuricum L.), cowberry-true-moss (Pleurozium schreberi (Brid.) Mitt.) forests on steep stony slopes often to river valleys with soddy shallow rank soils

41. Larch forb-Rhytidium and sedge-Rhytidium (Festuca altaica Trin., Carex amgunensis Fr. Schmidt, Pedicularis verticillata L., Delphinium crassifolium Schrader ex Sprengel, Rhytidium rugosum (Hedw.) Kindb.) forests of the middle and lower parts of shady slopes with soddy nonpodzolized, humic and peaty soils

42. Larch (in places with pine) with undergrowth of Daurian rhododendron cowberry-grass (Сarex iljinii V.I.Krecz., Maianthemum bifolium (L.)F.W.Schmidt, Equisetum arvense L.) forests in the middle and lower parts of predominantly shady slopes and on slopes to river valleys with soddy taiga deeply-cryogenic deep soils

43. Pine, in places birch-pine, with undergrowth of Daurian rhododendron forb с and cowberry-forb (Pyrola chlorantha Swartz, Maianthemum bifolium (L.) F.W. Schmidt, Trientalis europaea L.) forests on mountain slopes with soddy-forest, in places with weakly podzolic soils

ANGARIDE PHRATRY OF FORMATIONS

Baikal-Dzhugdzhur formations

Light-coniferous (Larix dahurica Laws., Pinus sylvestris L.) forests

44. Larch with undergrowth of dwarf Siberian mountain pine and golden rhododendron (Rhododendron aureum Georgi) small grass (Carex iljinii V. Krecz., Linnaea borealis L., Calamagrostis obtusata Trin.)-moss (Pleurozium schreberi (Brid.) Mitt.)-lichen (Cladonia alpestris (L.) Rabench, C. mitis Sandst.) forests in the upper parts of the forest zone and subgoletz on convex surfaces and steep slopes of different aspects with peaty-humic acid длительно cryogenic loamy soils

45. Larch, in places sparse, with undergrowth of dwarf Siberian mountain pine (Pinus pumila (Pallas) Regel), marsh tea (Ledum palustre L.)-true-moss (Pleurozium schreberi (Brid.) Mitt., Polytrichum commune Hedw.) forests in the upper parts of the forest zone on watershed surfaces and stony slopes of different steepness and aspects, often on slopes of river valleys with loamy stony soils 

46. Larch with undergrowth of yernik (Betula  middendorffii Trautv. et Mey.) and Duschekia (Duschekia fruticosa (Rupr.) Pouzar) subshrub (Vaccinium vitis-idaea L., Ledum palustre L.)-true-moss (Pleurozium schreberi (Brid.) Mitt.) forests in the middle and lower parts of stony slopes of different aspects, on watershed surfaces and on slopes to river valleys with loamy cryogenic soils, in places with crystalline rock debris

47. Larch with undergrowth of Duschekia (Duschekia fruticosa (Rupr.) Pouzar) cowberry-grass (Vaccinium vitis-idaea L., Calamagrostis lapponica Hartm., Carex cespitosa L., Equisetum palustre L.) forests in the middle and lower parts of gentle predominantly shady slopes with soddy-podzolic soils

47a. Birch with undergrowth of Duschekia cowberry-grass anthropogenic series

48. Larch subshrub (Vaccinium uliginosum L., Ledum palustre L.)-moss (Pleurozium schreberi (Brid.) Mitt., Polytrichum commune Hedw.) forests on weakly waterlogged river terraces and aprons of slopes with peaty-gley alluvial cryogenic soils

49. Larch with undergrowth of Daurian rhododendron (Rhododendron dahuricum L.) grass-cowberry-true-moss (Pleurozium schreberi (Brid.) Mitt., Vaccinium vitis-idaea L., Carex iljinii V.I. Krecz., C. globularis L., Linnaea borealis L.) forests on planate surfaces, in the middle and lower parts of slopes and drained tracts of valleys with soddy-podzolic soils

50. Larch with undergrowth of yernik (Betula middendorfii Trautv. et Mey., B. exilis Sukaczev) forests, in places sparse, on waterlogged tracts of above-floodplain terraces and mountain creek valleys with peaty-slimy-gley soils, combined with spruce-larch and larch-spruce forests in the lower parts of gentle slopes of different aspects with peat wet soils

51. Larch with undergrowth of yernik (Betula fruticosa Pall., B. middendorffii Trautv. et Mey.) waterlogged forests in the middle and lower parts of gentle and concave slopes and valleys of rivers and brooks with peaty-bog soils, combined with yerniks vegetation and grass-moss (Tomenthypnum nitens (Hedw.) Loeske, Tuidium abietinum (Schwaegr.) Dr. Sch. et Gmb., Rhytidium rugosum (Hedw.) Kindb., Carex dioica L., C. limosa L., Caltha palustris L., Equisetum fluviatila L., Cicuta virosa L., Epilobium palustre L.) bogs in waterlogged floodplains of streams and gentle slopes to river valleys with peat sphagnous-bog shallow wet soils

52. Larch-pine with undergrowth of Daurian rhododendron (Rhododendron dahuricum L.) cowberry (Vaccinium vitis-idaea L.)-forb (Calamagrostis arundinacea (L.) Roth, Geranium pseudosibiricum J. Meyer, Viola uniflora L.) forests in the upper and middle parts of slopes of different aspects with moderately podzolic soils

53. Larch-pine with undergrowth of Duschekia (Duschekia fruticosa (Rupr.) Pouzar) and Middendorff's birches (Betula middendorffii Trautv. et Mey., B. exilis Sukaczev) bilberry (Vaccinium myrtillus L. with the inclusion of V. vitis-idaea L., Ledum palustre L.)-true-moss (Pleurozium schreberi (Brid.) Mitt.) forests on flat summits of low ranges and on their slopes with moderately podzolic heavy loamy soils

54. Larch-spruce (Picea obovata Ledeb.) with Chosenia (Chosenia arbutifolia (Pall.) A.K.Skvortsov) and poplar (Populus suaveolens Fischer) subshrub (Vaccinium vitis-idaea L., V. uliginosum L., Ledum palustre L.)-forb (Galium boreale L., Veratrum lobelianum Bernh., Trollius asiaticus L., Thalictrum minus L, Linnaea borealis L., Maianthemum bifolium (L.) F.W.Schmidt.)-true-moss (Hylocomium splendens (Hedw.) Bruch et al., Pleurozium schreberi (Brid.) Mitt., Dicranum undulatum Schrad. ex Drid., Ptilium crista-castrensis (Hegw.) De Not) forests on pebble-beds along river channels and on floodplains with soddy-podzolic sandy-loamy soils

PIEDMONT-DEPRESSION FORESTS

URAL-SIBERIAN PHRATRY OF FORMATIONS

South-Siberian formations

Light-coniferous (Larix sibirica Ledeb, Pinus sylvestris L.) forests

55. Larch and pine-larch small reed-forb (Calamagrostis arundinacea (L.) Roth, C. epigeios (L.) Roth s. str., C. langsdorffii (Link) Tzvelev, Serratula coronata L., Euphorbia borealis Baikov., Stellaria graminea L., Carex pallida C.A.Meyer) forests in the lower parts of southern slopes with soddy forest soils, in places combined with steppizated grass larch woods and tracts of steppes, on sunlit low slopes and planate surfaces with rank and stony soils

56. Pine with undergrowth of spiraea (Spiraea media Franz Schmidt), cotoneaster (Cotoneaster melanocarpus Fisch. ex Blytt.), prickly wild rose (Rosa acicularis Lindley) grass (Pulsatilla patens (L.) Miller, Artemisia desertorum Sprengel.) steppizated forests on sunlit slopes with sandy skeleton-stony soils, combined with steppe formations on the upper parts of waterless creek valleys with sandy-loamy soils and tracts of blown sands

56a. Pine-birch grass series of anthropogenic transformation.

57.Pine and larch-pine cowberry-bearberry (Arctostaphylos uva-ursi (L.) Sprengel) with patches of lichens (Cladonia alpestris (L.) Rabench., C. amaurocreae (Flörke) Schaer, Cladonia rangiferina (L.) Web.) forests on gentle sandy sunlit slopes and planate surfaces with rank shallow soils

ANGARIDE PHRATRY OF FORMATIONS

Baikal-Dzhugdzhur formations

Light-coniferous (Larix dahurica Laws.) forests

58. Larch with undergrowth of fruticose willows (Salix lanata L., S. rosmarinifolia L., S. pyrolifolia Ledeb.) sedge (Carex diandra Schrank, C. meyeriana Kunth, C. capitata L., C. irriqua (Wahlenb.) Hiitonen)-moss (Aulacomnium palustre (Hedw.) Schwägr.,  Sphagnum warnstorfii Russow, Sph. teres (Schimp.) Engstr., Tomenthypnum nitens (Hedw.) Loeske) waterlogged forests in lower tracts of valleys with peaty cryogenic soils

SUBTAIGA (PIEDMONT) FORESTS

URAL-SIBERIAN PHRATRY OF FORMATIONS

Middle-Siberian formations

Light-coniferous (Pinus sylvestris L., Larix sibirica Ledeb.) forests

59. Pine and larch-pine with undergrowth of rhododendron (Rhododendron dauricum L.) cowberry-grass (Vaccinium vitis idaea L., Pulsatilla patens (L.) Mill., Aquilegia sibirica Lam., Limnas steleri Trin., Cypripedium guttatum Sw., Vicia cracca L., Trifolium lupinaster L.) forests on planate surfaces and sunlit slopes with soddy forest and podzolic sandy and sandy-loamy soils, combined with cowberry-bearberry (Arctostaphylos uva-ursi (L.) Spreng.) forests on dry sandy terraces and low slopes with sandy well-heated soils

60. Pine and larch-pine grass (Saussurea propinqua Iljin, Latthyrus humilis (Ser.) Spreng., Maianthemum bifolium (L.) F.W.Schmidt, Aegopodium alpestre Ledeb., Carex pediformis C.A.M.)-cowberry forests on flat lows and slopes of different aspects with soddy-forest weakly podzolic soils, combined with gramineous (Brachypodium pinnatum (L.) Beauv., Calamagrostis arundinacea (L.) Roth)-forb (Zigadenus sibiricus (L.) A.Gray, Euphorbia borealis Baikov., Stellaria graminea L., Euphorbia jenisseiensis Baikov., Cirsium serratuloides (L.) Hill.) forests on planate surfaces and gentle low slopes often to river valleys with soddy-forest and soddy-carbonate soils

61. Pine and larch-pine with undergrowth of Duschekia (Duschekia fruticosa (Rupr.) Pouzar) cowberry-forb (Vaccinium vitis-idaea L., Calamagrostis arundinacea (L.) Roth., Viola uniflora L., Galium boreale L., Trollius asiaticus L., Sanguisorba officinalis L.) often with marsh tea (Ledum palustre L.) and whortleberry (Vaccinium uliginosum L.) forests in the lower parts and on aprons of slopes, as well as along river banks with peaty-podzolic sandy-loamy soils

61b. Birch-aspen with pine and larch cowberry-forb with

marsh tea and whortleberry anthropogenic series

YERNIKS, BOGS AND MEADOWS

URAL-SIBERIAN PHRATRY OF FORMATIONS

Middle-Siberian formations

62. Subshrub (Vaccinium uliginosum L., Chamedaphne calyculata (L.) Moench)–sedge (Carex meyeriana Kunth)-hypnum (Drepanocladus vernicosus Warnst., D. sendtneri (H.Muell.) Warnst., Meesia triquetra (Richter) Aongstr.) bogs on overmoistened tracts are often enclosed by peat bogs, combined with marsh tea-moss pine forests, in floodplain depressions with peaty wet soils and sedge meadows in interior deltas on more drained tracts of bogs with silt deposits and light loamy soils

ANGARIDE PHRATRY OF FORMATIONS

Baikal-Dzhugdzhur formations

63. Yernik (Betula fruticosa Pallas, B. exilis Sukaczev) vegetation with singly occurring larch (Larix gmelinii (Rupr.) Rupr.) and birch trees (Betula platyphylla Sukaczev) in valleys and floodplains of rivers and brooks and lower tracts with peaty soils, combined with grass bogs in low floodplains and sedge-small reed meadows on river banks, along-channel natural levees and on gentle slopes to river valleys with loamy moist soils

64. Sphagnum (Sphagnum warnstorffii Russ., S. teres (Schimp.) Aongstr. ex Hartm.) oligotrophic bogs in river floodplains, on gentle poorly drained slopes of ouvals, in saddles, in the upper reaches of brooks and creek valleys, on low flat watersheds and summits of столовых возвышенностей with overmoistened soils and permafrost, combined with willow (Salis viminalis L., S.rosmarinifolia L., S.triandra L.) vegetation in the along-channel parts of rivers with грубыми sandy отложениями

65. Small reed-sedge and sedge (Carex pseudocuraica Fr. Schmidt, C. wiluica Meinsh., C. enervis C.A.M.)-small reed (Calamagrostis langsdorffii Trin.) valley overmoistened meadows on peaty-gley cryogenic soils, in places combined with shrubs vegetation (Rosa acicularis Lindl., Spiraea salicifolia L., Betula exilis Sukaczev, Salis rosmarinifolia L.) on summits of along-channel natural levees and low ridges of the central floodplains with sandy-loamy and loamy soils

FOREST-STEPPE COMPLEXES

Mountain

URAL-SIBERIAN PHRATRY OF FORMATIONS

North-Mongolian formations

Light-coniferous (Larix sibirica Ledeb., Pinus sylvestris L.) steppizated forests

with tracts of steppes

66. Complex of larch (Larix sibirica Ledeb.) and birch (Betula platyphylla Sukaczev)-larch grass (Calamagrostis obtusata Trin., Carex amgunensis Fr. Schmidt, Iris ruthenica Ker-Gawler s str., Paeonia anomala L., Lilium pumilum Delile, Anemone crinita Juz.) steppizated forests and forb-sedge-oat-grass steppes predominantly on shady slopes with meadow-forest глубоко cryogenic soils

67. Complex of pine (Pinus sylvestris L.) and birch (Betula platyphylla Sukaczev)-pine xerophytic-forb (Festuca lenensis Drob., Artemisia frigida Willd., A. laciniata Drob., Oxytropis oligantha Bunge, O. chionophylla Schrenk) steppizated forests and shrubs (Ulmus pumila L., Cotoneaster melanocarpus Fisch. ex Blytt) vegetation on planate surfaces, mountain slopes and river terraces with weakly podzolic sandy soils  

Piedmont

URAL-SIBERIAN PHRATRY OF FORMATIONS

Middle-Siberian formations

Light-coniferous (Pinus sylvestris L.) forests with tracts of steppes

68. Complex of pine steppizated sparse-grass (Scabiosa ochroleuca L., Dracocephalum nutans L., Silene nutans L., Elymus gmelinii (Ledeb.) Tzvelev, Calamagrostis epigeios (L.) Rhot.) forests and steppe formations on convex surfaces, dry pine-forest terraces, lower watersheds and their gentle slopes with fine sandy-loamy or loamy soils

STEPPE VEGETATION

STEPPES OF MOUNTAINS

MONGOLIAN-CHINESE PHRATRY OF FORMATIONS

DRY STEPPES

South-Siberian formations

69. Kobresia (Kobresia myosuroides (Vill.) Fiori, K. humilis Meadow.)-fescue (Festuca lenensis Drobow) high-mountain steppes on convex surfaces and stony-rock debris slopes with mountain steppe carbonate-free soils, combined with moss-lichen and lichen-moss tundras on flat lows with tundra peaty-gley soils   

North-Mongolian formations

70. Forb-bunchgrass (Festuca lenensis Drobow, F. sibirica Hackel ex Boss., Poa attenuata Trin., Koeleria cristata subsp. mongolica Tzvelev, Carex pediformis C.A.Meyer, Stellera chamaejasme L., Alyssum lenense Adams, Oxytropis nitens Turcz., Phlojodicarpus sibiricus Koso-Pol.,) with shrubs (Cotoneaster melanocarpus Fisch. ex Blytt., Ribes pulchellum Turcz., Pentaphylloides parvifolia (Fischer ex Lehm.) Sojak) steppes on high planate tracts and in the upper parts of slopes of different aspects with mountain chernozems and dark-chestnut soils, combined with forb-fescue and sedge-fescue steppe communities on gravelly-stony and stony-rock debris slopes

71. Forb-Leymus-feather-grass (Stipa capillata L., S. krylovii Roshev., Leymus chinensis (Trin.) Tzvelev, Bupleurum scorzonerifolium Willd., Galium verum L., Aconogonon angustifolium (Pallas) Hara, Oxytropis filiformis DC., Astragalus melilotoides Pallas) steppes on high plains, on sunlit slopes, in steppizated river valleys on low ridges and pebble-beds with dark-chestnut light loamy soils with the feaures of meadow soils in combination with birch (Betula platyphtlla Sukaczev) and aspen (Populus tremula L.) grass (Fragaria orientalis Losinsk., Geranium pseudosibiricum J.Meyer, Campanula glomerata L. s.str., Valeriana dubia Bunge, Vicia unijuga A. Br.) steppizated forests on northern slopes with soddy-forest and meadow-forest deeply cryogenic soils

Central-Asian formations

72. Forb-fescue and forb (Rhinactinidia eremophylla (Bunge) Novopokr. s. str., Peucedanum morisonii Besser ex Sprengel, Dracocephalum foetidum Bunge, Oxytropis oligantha Bunge, Saussurea sajanensis Gudoschn., Potentilla fragarioides L.)-wheatgrass (Agropyron cristatum (L.) Beauv.)-fescue (Festuca lenensis Drobow) steppes on summits of watersheds and ranges with parent rock outcrops and in the upper parts slopes with mountain steppe carbonate-free soils, combined with kobresia and sedge steppes in depressions, along river valleys and creek valleys with clay soils

73. Forb (Carex pediformis C.A.Mey, Aster alpinus L., Artemisia frigida Willd., Galium verum L.)-gramineous (Festuca valesiaca Gaudin s. str., Poa attenuate Trin. s. str.) steppes on stony slopes of different aspects, comprised of quartz-clay sandstones, combined with forb-Koeleria and fescue-Leymus steppe groups on dry slopes with light-chestnut and rank soils

74. Forb (Serratula centauroides L. s. str., Astragalus brevifolius Ltdeb., Cleistogenes squarrosa (Nrin.) Keng, Asterothamnus heteropappoides Novopokr., Vincetoxicum sibiricum (L.) Decne)-gramineous (Agropyron criststum (L.) Beauv.)-feather-grass (Stipa glareosa P. Smirnov, S. krylovii Roshev) with shrubs (Krascheninnikowia ceratoides (L.) Gueldenst., Caragana bungei Ledeb.) desert steppes on rock debris slopes, among rocks, in intermontane valleys and slopes with sandy-loamy and rank-sandy-loamy soils

MEADOW STEPPES

North-Mongolian formations

75. Rich-forb-sedge-bluegrass (Poa attenuate Trin., P. altaica Trin., Festuca lenensis Drobov, Carex pediformis C.A.Mey, Filifolium sibiricum (L.) Kitam., Scabiosa comosa Fisch. ex Roem.et Schult.) meadow steppes, combined with forb-gramineous meadow-steppe communities on planate surfaces, gentle sunlit slopes and in intermontane valleys with mountain chernozems and dark-chestnut  soils

STEPPES OF FOOTHILLS, PLATEAUS AND HUMMOCKS

TRANS-VOLGA-Kazakhstan PHRATRY OF FORMATIONS

MEADOW STEPPES

Middle-Siberian formations

76. Complex of saz (Leymus paboanus (Claus) Pilger, Achnatherum splendens (Trin.) Nevski) and Nitraria-sagebrush steppes with halophytic (Plantago cornuti Gounan, Limonium gmelinii (Willd.) Kuntze) meadows on shores of salt lakes, in the near-terrace part of steppe valleys, saline bottoms of waterless creek valleys and microdepressions with meadow carbonate alkali soils

MONGOLIAN-CHINESE PHRATRY OF FORMATIONS

DRY STEPPES

Central-Asian formations

77. Feather-grass (Stipa krylovii Roshev., S. baikalensis Roshev., S. grandis P.Smirn.) steppes on planate tracts, gentle slopes, piedmont aprons with sandy-loamy soils, as well as on solonetzic heavy-textured soils and on deluvium of limestones and carbonate rocks, combined with wheatgrass, Leymus and leistogenes communities, in places with patches of allium polyrrhizum steppes in the same habitats with light-textured soils

78. Leymus (Leymus chinensis Tzvel.) steppes on planate and hilly tracts with sandy or solonetzic soils, combined with Koeleria-fescue communities and patches of halophytic (Puccinelia tenuiflora Krecz., P. macranthera Norlindh.) meadows on gentle sunlit slopes and on bottoms waterless creek valleys with sandy and sandy-loamy soils

79. Filifolium (Filifolium sibiricum (L.) Kitam.) steppes on slopes and plateau-like summit surfaces, comprised of quartz-clay sandstones, combined with steppe shrubs vegetation and steppizated meadows in the upper parts gentle slopes with drift sandy and sandy-loamy soils

80. Pea shrub (Caragana microphylla Lam., C. stenophylla Pojark.)-Leymus-feather-grass (Stipa baikalensis Roshev., S. grandis P.Smirn.), in places feather-grass-pea shrub steppes on gentle slopes and ouvals with loose chestnut and light sandy-loamy soils, combined with feather-grass and cleistogenes communities on sandy slopes and high above-floodplain terraces

81. Forb-feather-grass (Stipa klemenzii Roshev., S. sibirica (L.) Lam., Artemisia frigida Willd., A. scoparia Waldst.end Kit., Cymbaria dahurica L., Veronica pinnata L., and others) and gramineous-feather-grass (Stipa krylovii Roshev., Agropyron cristatum (L.) Beauv., Festuca valesiaca Gaudin, Cleistogenes squarrosa (Trin.) Keng, Leymus chinensi (Trin.) Tzvelev), in places shrub (Caragana microphylla (Pall.) Lam., C. Bungei Ledeb., C. pigmaea (L.) DC.,   C. stenophylla Pojark. On rare occasions - Spiraea hypericifolia L.) steppes on planate surfaces and gentle slopes of hummocks and hills with light sandy-loamy and light loamy soils, combined with forb-fescue, Leymus and cleistogenes steppe communities on rocky and stony surfaces

MEADOW STEPPES

South-Siberian formations

82. Wheatgrass, feather-grass-wheatgrass (Agropyron cristatum (L.) Beauv., Stipa krylovii Roshev.) in places forb-fescue-wheatgrass (Agropyron cristatum, Festuca lenensis, Artemisia argirophylla, Oxytropis chionophylla) with kobresia (Kobresia humilis) steppes on steep stony sunlit slopes, on aprons of mountains and in wide lows with light-textured soils, combined with Koeleria and tall-grass (Serratula centauroides L., Scabiosa comosa Fischer ex Roemer et Schultes) steppes on gentle slopes and bottoms of depressions with good soil moistening with sandy-loamy and steppe carbonate-free soils

83. Fescue (Festuca lenensis Drobov) and bluegrass (Poa botrioides (Griseb.) Roschev) in places mixed small-bunchgrass with forbs (Kobresia filifolia, Oxytropis oligantha, O. chionophylla, Saussurea saichanensis, Potentilla nivea) steppes on slopes and on bottoms of depressions with dark-chestnut and steppe carbonate-free soils, combined with steppe shrubs vegetation (Cotoneaster melanocarpus Fisch. ex Blytt, Spiraea media, S.pubescens, Ribes diacantha), kobresia (Cobresia filifolia (Turcz.) Clarke) and sedge meadows (Carex pediformis C.A.Meyer) on stony slopes and rocks with clay soils

84. Pea shrub (Caragana micriphylla Lam., C. pygmaea D C.)-wild rye (Leymus secalinus (Georgi) Tzvelev)-wheatgrass (Agropyrum michnoi Roshev.) steppes on blown sands and sandy soils, combined with thyme and fescue communities, as well as elm (Ulmus pumila L.) woods on slopes, rocks and cliffs with arid sandy-stony soils

85. Sagebrush (Artemisia frigida Willd.) and low-grass (Chamaerhodes altaica Bge., Arctogeron gramineum D C., Arenaria capillaries Poir., and others) lithophilous steppes on steep sunlit slopes and planate surfaces with stony-rank soils, combined with fescue and petrophyte-forb-small-bunchgrass (Stipa krylovii, Festuca lenensis, Agropyron cristatum, Krylovia eremophylla, Agropyron cristatum, Allium eduardii, Potentilla sericea, Arenaria meyeri Peucedanum histris, Dracocephalum foetidum) groups on rocks and taluses

MEADOWS AND HYDROPHILOUS COMMUNITIES

TRANS-VOLGA-Kazakhstan PHRATRY OF FORMATIONS

Middle-Siberian formations

86. Sedge (Carex enervis C.A.Meyer)-gramineous (Hordeum brevisubulatum (Trin.) Link)-forb (Iris biglumis Vahl) alkaline meadows in the near-terrace and central parts of floodplains with saline soils, comprised of fine fractions of alluvium

87. Sedge-gramineous predominantly alkaline meadows (Hordeum brevisubulatum (Trin.) Link., Agrostis mongolica Roshev., Puccinellia tenuiflora (Griseb.) Scribner et Merr.) in kettle depressions of salt lakes, on natural levees and along-channel floodplains, comprised of alluvium of coarse fractions, combined with sedge bogs and willow stands (Salix dahurica Turcz., S. rossica Nas.) in lower tracts of floodplains with waterlogged peaty soils

MONGOLIAN-CHINESE PHRATRY OF FORMATIONS

South-Siberian formations

88. Low-grass partially steppizated meadows (Agrostis trinii Turcz., Carex pediformis C.A.M., Kobresia filifolia Meinsc.) in river valleys on flat and wide low ridges, as well as on bottoms of creek valleys with floodplain-meadow sandy-loamy and loamy soils, combined with yernik (Betula gmelinii Bge.) vegetation on sides of ravines and banks of streams and kobresia-fescue steppes on higher tracts of floodplains with pebble and sand deposits

89. Gramineous (Leymus chinensis Tzvel., Carum buriaticum Turcz., Coeleria cristata (L.) Pers.s.str., Cleistogenes squarrosa (Trin.) Keng, Agropyron repens) and forb (Geranium pretense, Sanguisorba officinalis, Valeriana oficinalos, Trifolium lupinaster, Orostachys spinosa, Thymus dahuricus)-gramineous steppizated meadows with poplar (Populus suaveolens Fish.) and willow shrubs (Salix rorida Laksch.) in river floodplains and on along-channel pebble-beds with saline soils

90. Grass (Leymus secalinus Tzve, Poa pretensis L., Elytrigia repens (L.) Nevski, Agrostis mongolica Roshev., Bromus sekalinus L, Sanguisorba officinalis L., Medicago falcata L.) meadows with shrubs (Salix microstachya Turcz., Hippophae rhamnoides L., Ulmus pumila L.) and sigly occuring poplar trees (Populus laurifolia Ledeb.) on sufficiently moistened tracts of large rivers and in the mouths of small rivers with loose peaty soils

91. Reed (Phragmites communis Trin.), small reed (Calamagrostis langsdorffii Trin.), sedge (Carex orthostachys C.A.Mey.) and horsetail hydrophilous communities in the along-channel zones of rivers on newly formed alluvium with cryogenic floodplain waterlogged soils   

92. Waterlogged sedge (Carex lithophila (Turcz.) Hämet-Ahti, C. schmidtii Meinsh., C. cespitosa L.) and gramineous-forb (Ranunculus sceleratus L., R. propinquus C.A.Mey, Rumex gmelinii Turcz. ex Ledeb., Stachys aspera Michaux, Calamagrostis langsdorffii Trin., C. neglecta (Ehrh.) Gaertner) meadows in floodplain, often flooded lows on meadow-bog cryogenic soils, combined with shrubs vegetation (Salix kochiana Trautv., S. viminalis L.) and waterlogged larch (Larix sibirica Ledeb.) forests in river valleys with gleyed slightly peaty soils with close occurence of permafrost

93. Sedge (Carex cespitosa L., C. karoi Freyn, C. orthostachys C.A.M., C. rynchophysa C.A.M.) meadows, combined with shrubs (Salix viminalis L., S. rhamnifolia Pall., Caragana spinosa (L.) DC.) and spruce (Picea obovata Ledeb.) (along the Tesiin-Gol river) forests on edges of lakes and in river valleys with loamy soils

Central-Asian formations

94. Iris (Iris biglumis Vahl.) meadows on river terraces and along-channel tracts with loamy soils, combined with Leymus steppes and solonchak communities in floodplains and kettle depressions of salt lakes with well-drained alluvial sandy soils

95. Forb-gramineous (Elytrigia repens (L.) Nevski, Geranium pretense L., Sanguisorba afficinalis L.) meadows along river valleys with cryogenic soddy-gley and meadow-bog soils, combined with shrubs (Salix pentandra L., S. arbuscula L., Dasiphora fruticosa (L.) Rydb., Betula fruticosa Pall.) (along the Tesiin-Gol river – Populus laurifolia Ledeb.) along rivers and lower parts of slopes with boggy moistened peaty-meadow soils

96. Halophytic-forb (Halerpestes salsuginosa (Pallas ex Gejrgi) Greene, Iris biglumis Vahl.), halophytic-gramineous (Achnatherum splendens (Trin.) Nevski) and sedge (Carex enervis C.A.M., C. duriuscula C.A.M.) meadows, in places with the inclusion of willow stands (Salix ledebouriana Traunv.), on edges of solonchak depressions, lakes, terraces and along banks of steppe rivers and brooks with meadow-solonchak soils, combined with alkaligrass (Puccinellia tenuiflora (Griseb.), Scribn. Et Merr., P. Hauptiana V.I.Krecz.) and saltwort (Salsola corniculata (C.A.Meyer) Bunge, s. str.) meadows on solonchaks, on bottoms of saline lowlands and around intermittent lakes with meadow-solonchak-like soils in the steppe and forest-steppe zones, predominantly in the east and in the central part of Mongolia.

Vegetation

The map “Vegetation” is an overview-reference geobotanical map. All available different-scale cartographic materials on the vegetation of southern East Siberia of the Russian Federation, literary and archival sources, and forest inventory data were used when compiling the map. For the territory of Northern Mongolia, basic cartographic and literary materials on the vegetation of this region of Central Asia were involved. For the entire area of the Baikal basin modern satellite images from the Internet resources (Google Earth) were used. Their processing was carried out with the use of GIS technologies.

When creating the legend to the vegetation map of the Baikal region, well-tested geographical-genetic and structural-dynamic principles of a multi-dimensional and multi-stage vegetation classification, developed by Academician V.B. Sochava, were applied. Accordingly, the legend of the map has a multi-stage structure.

All higher subdivisions of vegetation in the map legend are united by specific taxa of plant communities, typed according to the flora-coenotic and dynamic features of their structure. When typing an epitaxon principle was followed, according to which on the basis of structural-dynamic and topological similarity indigenous communities are joined together with derivatives into common epitaxa. The lowest unit of indigenous communities being mapped is a class-group of associations. On the total the map legend contains 96 numbers of epitaxa of indigenous and derivative vegetation. Each taxon singled out in the legend has a detailed floristic, structural-coenotic and ecological-topological characteristics. Due to the complexity of the spatial structure of the vegetation cover, combinations and complexes of plant communities, which are the most characteristic of a particular type of vegetation or area, are almost universally used.

The highest level of the legend is formed by the following vegetation types: goletz (alpine), taiga (boreal) and steppe, communities of which form the modern vegetation cover of the Baikal basin. Each type of vegetation is presented by its set of communities of genetically close phratries of formations and their regional groups of formations.

Taiga (boreal) vegetation covers the main areas of the Baikal basin both in the plains and high plateaus, and in the mountains, forming a mountain-taiga altitudinal belt and a belt of subgoletz sparse forests. According to the landscape features of the region, taiga (boreal) vegetation is represented in the legend and in the map by several groups of formations, namely: subgoletz sparse forests with thickets of shrubs, mostly of Siberian dwarf pine, mountain-taiga forests, piedmont-hollow forests, and forests of plains and plateaus.

The first three groups represent an altitudinal-belt structure of vegetation of mountain ranges. Altitudinal-belt groups of formations of taiga (forest) vegetation are represented by communities of different origin and territorial confinedness.

In the contact zones of the taiga and steppe (in the form of islands) vegetation forest-steppe complexes are formed; they are mostly of expositional-conditional nature. Southern warm and dry slopes of mountains and hills are occupied, as a rule, by steppe groups, while northern and eastern cold slopes are covered with forest taiga and in some places steppificated communities. In accordance with the terrain features, these complexes are represented by three groups, namely: mountain, of plains and plateaus, and piedmont ones.

Steppe vegetation occupies large areas in the south of the Baikal basin and in northern Mongolia. Here there is an important biogeographical barrier that separates two large flora-coeno-genetic groups of western North Kazakhstan and eastern Central Asia steppes, representing Trans-Volga-Kazakhstan and Mongolian-Chinese phratries of formations, respectively.

Two groups of formations are clearly distinguished; they are mountain steppes and steppes of foothills, elevated plains and hummocks. In each of them, large ecological-morphological groups – meadow and dry steppes – are distinguished according to the nature of steppe vegetation. For each of these groups within the respective phratries of formations independent regional steppe complexes are identified, namely: Southern Siberian, northern Mongolian and Central Asian formations. The main areas, both in the mountains and on the plains and hummocks, are occupied by dry steppes of the Mongolian-Chinese phratrie of formations.

In general, the map reveals in details the spatial flora-coenotic structure of the vegetation cover of the Baikal basin in its evolutionary-genetic and dynamic dependence. Regional-geographical features of the coenotic diversity are well identified, taking into account their zonal-subzonal or altitudinal development conditions.

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Permafrost

Permafrost occurs in abundance within the Baikal basin. According to the extent of spreading, thickness of a permafrost section and its temperature, the following five types of areas of permafrost distribution are distinguished: 1) continuous and discontinuous, 2) insular, 3) sparsely insular, 4) sporadic, and 5) without permafrost.

Continuous and discontinuous permafrost is developed on all relief features in the mid- and high-mountain and goletz areas. Unfrozen rocks occur only under large rivers, lakes and in the zones of tectonic faults with the discharge of subsurface water, along the fissures of exogenous weathering, as well as on sands, gravels and karsted rocks. The permafrost thickness reaches 100-300 m, and up to 500-600 m on watersheds. The average annual temperature ranges from -0.5 ºC to -3 ºC. Frost mounds, thermokarst, frost weathering, aufeis formation, kurum (rock stream) formation, and solifluction should be mentioned among the prevailing cryogenic processes and phenomena.

Insular permafrost. The permafrost thickness reaches 50-80 m. Islands of permafrost occur on all relief elements, but usually only in wet, waterlogged or shaded areas, and in mountains above abs. alt. of 1000-1200 m. Sand massifs and karsted rocks are usually unfrozen. The average annual temperature of permafrost ranges from -0.2 ºC to -1ºC. Thermokarst, frost mounds, aufeis formation, solifluction, and frost fracturing of soil are distinguished among the prevailing cryogenic processes and phenomena.

Sparsely insular permafrost occurs in waterlogged areas in valley bottoms, and at the bottom parts of northern slopes of hills, composed of peaty (from the surface) clay rocks. The permafrost thickness reaches 20-30 m. The average annual temperature of permafrost ranges from -0.1ºC to -0.5ºC.

Sporadic permafrost. Individual islands and lenses of permafrost occur only in wet lowlands, composed of peaty (from the surface) clay loams and sandy loams. The permafrost thickness reaches 10-15 m. The average annual temperature of permafrost varies from 0ºC to -0.2ºC. Seasonal frost mounds, relic thermokarst, and frost fracturing of soil are distinguished among the prevailing cryogenic processes and phenomena.

The area of only seasonal soil freezing has become of widespread occurrence in the Angara river valley and the Selenga river delta. Permafrost patches and neoformations are possible when developing a territory, composed of clay rocks. The depth of winter freezing of rocks ranges from 2-2.5 m in clay loams to 2.5-3 m in sands. Ground heaving, frost fracturing of soil, and relic thermokarst should be mentioned among the prevailing cryogenic processes and phenomena.

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Groundwater

The map is based on generalizing materials of the Institute of the Earth's Crust, and the Geological Surveys of Buryatia, Chita and Irkutsk using hydrogeological maps of 1:5000000 [Atlas..., 1983] and 1:4500000 scales [National Atlas ..., 1990].

During mapping the method of mapping the main aquifers (hydrogeological formations) was applied. Aquifers are distinguished according to structural and hydrogeological features, the prevailing type of water-ermeability, and reservoir properties of rocks.

In the Baikal basin pore-edge waters, confined to loose unconsolidated sediments of Mesozoic and Cenozoic age, have a wide distribution, as well as crack waters in all lithified metamorphic, igneous and sedimentary rocks of different ages from the Archaean to the end of the Paleozoic - Mesozoic inclusive.

Hydrogeologically, the Baikal basin is a complex system of artesian basins and hydrogeological massifs. Artesian basins occupy intermontane depressions composed of loose rocks of the sedimentary cover and crystalline basement rocks. They are characterized by pore-edge waters of the zone of active water exchange and crack waters, often pressure waters, and foundation waters. Hydrogeological massifs are composed with crystalline rocks of mountain- folded frame and can accommodate crack waters of exogenous fissuring. Thickness of the zone of active water exchange does not exceed 100-150 m.

Most watered are karst carbonate rocks, as well as zones of tectonic dislocations, intersecting the cropping-out foundation or spread along the contacts of sedimentary-metamorphic rocks with igneous and metamorphic rocks. They are often traced by upward unloading both of cold and thermal waters.

References

Atlas of hydrogeological and engineering-geological maps of the USSR. Scale 1:5000000. (1983).

National Atlas of the Mongolian People's Republic, scale 1:4500000. (1990).

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Floods

The aim of the flood map is to give an insight into distribution of flooding risk on the territory, and level of its danger to human activity and facilities of national economy. The map was compiled on the basis of reference materials of the national water resource inventory [Long-term…, 1986; Resources …, 1973], data on the flooding damage, and archival and cartographic materials.

Flood hazard is characterized by their genesis, recurrence, impact, damage, possibility and appropriateness of forecasting a dangerous situation. T.A. Borisova determined the integral risk of floods from the territorial assessment of risk caused by floods [Borisova, 2013] using private maps of disturbances of land of different categories and population (based on the estimation of physical, economic and social risks). Flood danger for the rivers of Southern Baikal flowing from the Khamar-Daban Ridge is determined through an expertise as there are no appropriate calculated data.

Severe floods take place at the Selenga, Khilok, Uda, Upper Angara, and Barguzin rivers. The depth of floodplain inundation does not exceed 0.5-1 m during common floods and reaches 1.8-3 m during severe floods. The height of the water layer increases downstream the rivers: for example, its height at the Selenga river near the settlement of Ust-Kyakhta is 1 m and near the city of Ulan-Ude increases up to 3 m. The longest floods (30-90 days) are observed in the valley of the Selenga river and downstream the  river. Shorter floods (up to 25 days) are recorded in the basins of the Barguzin, Upper Angara, Uda, Dzhida, and other rivers. The duration of floods at small rivers, flowing directly to Lake Baikal, is, as a rule, 3-7 days.

The increase of water levels and flow rates in the rivers under study are observed during spring floods caused by thawing of snow cover and glaciers and during summer rain floods. High water floods are not characteristic of rivers located in the southern part. Spring floods are observed in the rivers of the Selenga basin, as well as in the streams running from the Khamar-Daban and Primorsky Ridges. The rivers with spring-summer floods are located in the northern part of the territory (Upper Angara, Barguzin, Turka, Tyya, Rel, Goudzhekit, and others).

Breakup of the ice is often accompanied by ice jams resulting in sharp short-term water level increases. Such local floods are confined to certain areas of narrowing riverbeds or river oxbows. Areas where ice jams are most likely to occur are noted on the Selenga River (Omulyovka Mountain – village of Voznesenovka – Mostovoy sidetrack – settlement of Reid, etc.).

Rain floods usually start from the decrease of spring flood and are observed during the entire summer period. The highest water levels are usually recorded in July-August. The highest intensity of the water level increase is registered at the rivers of the Selenga basin. For instance, during the highest flood in 70 years on the Dzhida River (19/1) it was 4.5 m per day (Khamney level gauge) and 2.79 m per day (Dzhida level gauge). Besides, rapid water level increases of a number of mountain stream tributaries (Khamney, Kurba, Ona, etc.) are associated with their location in the permafrost zone which considerably decreases the infiltration capacity of the soils. Fluctuations of water levels in the Selenga river and in the lower reaches of its tributaries are smoother, which is attributed to the spreading of floods and regulatory influence of the plains. However, the damage from the floods in this area is the most severe as the floodplains are the deepest and flooding is the longest. Moreover, this territory is highly developed economically and densely populated.

Maxima of rain floods on the territory under study significantly prevail over the maxima of spring floods in both absolute value and their number of the total annual maxima [Kichigina, 2000]. The first ones are the most dangerous for the flood formation. The exception is some rivers in the northern regions (Upper Angara, Barguzin, Rel, and Tyya) where the spring flood is the main water regime phase. The map represents the distribution of cross-sections with the dominance of rain flood maxima and with comparable contribution of spring and rain flood maxima. Rain floods cause huge damage as they are widely spread, repeat many times and have a high rate of formation. They can flood both separate small basins and vast territories. Their timely and precise forecast is, as a rule, low. For example, the destructive rain flood that happened in July of 1966 caused a 3 m water increase in the Tuul river, and for several hours the city of Ulaanbaatar submerged and 130 people drowned.  Only for the Republic of Buryatia the damages in the Selenga river basin amounted to about 1.4 billion roubles in 1971, 0.7 billion roubles in 1973 and 40 billion roubles in 1993 (based on current prices). In Mongolia the damages are considerably lower due to the specific settlement patterns and the unique features of the economic use of alluvial lands.

On the southern coast of Lake Baikal (from the Mysovka River mouth to the Angara River outlet), on the south-eastern slope of the Baikal Ridge and in a number of the Selenga River tributaries, floods are often aggravated by mud flows [Makarov, 2012]. Mud floods are caused by heavy rains at the sites with significant slope steepness and easily washed-away loose soil. Mud flow processes mostly develop in the near-mouth areas of the rivers of the northern slope of the Khamar-Daban Ridge and along the Circum-Baikal railway. Mud flows have very destructive force, and they are able to cause significant damages. The increase of water level in such small rivers as the Pokhabikha, Tiganchikha and others can be caused by thawing of ice crust formed as a result of freezing of their river beds.

In general the rivers in the Baikal basin are related to high flood probability ones. Small floods on certain rivers are registered almost annually. Recurrence of severe floods over the period from 1936 to 2012 amounts to 5-12%. According to statistics the most severe last century’s floods were registered in 1932, 1936, 1971, 1973, 1993 and 1998.

The height of the water level on the floodplain and the duration of high water stand are important characteristics. The height depends on both severity of a flood and hydrological and morphological properties of a river. During floods on the Selenga river near the village of Ust’-Kyakhta is comes to 1-2 meters; in the conditions of a narrowing valley and a sufficient stream supply by the Dzhida and Chikoy rivers near the village of Novoselenginsk it sharply rises and may exceed 4 meters. By the city of Ulan-Ude it drops down to 2.2 meters and to 1 meter in the vast delta.

The duration of high water stand varies. Long-term water floods on a floodplain (25-40 days) are observed in the valley of the Selenga river and in the lower course of the Chikoy river. Shorter-term floods (up to 25 days) are registered in the basins of the Barguzin, Upper Angara, Uda and Dzhida and other rivers. On small mountain streams floods usually do not exceed 3-7 days.

3 to 5% of the basin’s territory is exposed to recurrent floods. However, these are largely the most developed and settled lands. For instance, within the Russian part of the Selenga river basin about 4.000 sq km of inundated landscapes may be exposed to flooding; 231.600 hectares or 9.5% are agricultural lands. On the rivers of the northern part (the Barguzin, the Upper Angara) almost 2.000 sq km are flooded, a quarter of them agricultural lands.

The list of settlements on the territory of the Baikal basin, which are at risk of flooding, was compiled using summarized archival and reference data. In total, 75 settlements were included into the flood zone. The settlements with the highest risk of flooding are marked on the map.

References

Borisova, T.A. (2013). Natural-anthropogenic risks in the Lake Baikal basin. Chief Ed. A. Tulokhonov, Novosibirsk: Akad. Izd-vo “Geo”, 2013, 126 p.

Kichigina, N.V. (2000). Genetic and statistic analysis of maximal flow of rivers in South-East Siberia. In: Natural and socio-economic conditions of Siberian regions. Novosibirsk: Izd-vo SO RAN, pp. 19-22.

Makarov, S.A. (2012). Mud flows in Cisbaikalia. Irkutsk: Izd-vo Instituta geografii im. V.B. Sochavy SO RAN, 111 p.

Long-term data on regime and resources of surface land waters. (1986). Leningrad: Gidrometeoizdat, issue 13, 346 p.; issue 14, 282 p.

Surface water resources of the USSR. (1973). Leningrad: Gidrometeoizdat, 1972, vol. 16, issue 2, 586 p.; vol. 16, issue 3, 400 p.

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Self-clarification condition of surface water

The map "Self-clarification conditions of surface waters" reflects the potential of natural waters of the territory to neutralize the introduction of pollutants into water bodies and to restore the original properties and composition of water. The self-clarification capacity of water bodies is formed by chemical, physical and biological processes; the dominant role here is played by dilution and oxidation.

The process of dilution of pollutants with the waters of rivers and water bodies is directly dependent on the amount of water mass, and it can be characterized by the influx of water into a reservoir and the water flow rates in rivers during the minimum runoff (the largest environmental stress conditions). Given the lack of material on the inflow for the majority of the lakes, the evaluation of diluting ability was carried out according to the average annual water volume in the reservoirs.

The oxidation of organic substances depends on the amount of oxygen from the atmosphere, and is determined by the conditions of mixing and temperature control of water bodies. The amount of oxygen required for oxidation of the process is specified as the biochemical oxygen demand (BOD₅ and COD) and standardized for various substances at the water temperature of 20ºC. Because of insufficient data on BOD₅ and COD, the oxidative reactions intensity was assessed indirectly based on the average temperature within the warm period and the intensity of water overturn.

The water overturn in the reservoirs is influenced by the differences of density and dynamic parameters, such as churning, wind-induced surges, etc. The data on churning observations (as well as the inflow observation) for the waters of the Baikal region are not sufficient, that is responsible for indirect assessment of dynamic performance. Here, morphometric parameters are used as an indicator of overturn intensity, namely: the ratio of depth and area of the mirror, which characterizes the potential churning power. In watercourses the channel slopes are criterial for the overturn degree; the flow velocity depends on them.

As a result, the assessment criteria of self-clarification conditions of surface waters are temperature, flow rate and volume of water, stream slopes and morphometric parameters of reservoirs. According to the regional dimension of the territory the analysis was performed for medium and large catchment areas of the rivers (4 – 6^th according to Strahler’s stream order) and lakes.

The parameterization of these characteristics is carried out with the help of statistical methods and comparative analyzes with the development of special scales and matrices. The inventory data on more than 200 waterways and 12 lakes and reservoirs of the Baikal basin was used for the map construction [Long-term…, 1986; Surface water resources..., 1972, 1973]. For most rivers on the territory the overturn intensity was determined for sections according to a longitudinal gradient. The range of slopes is divided into four groups: from the minimum values (0-2 ‰) for plain areas to the maximum (over 15 ‰) in the mountainous areas. The water temperature during the warm period was calculated as the average for four months (June - September), as on the rivers of the region's the water temperature transition over 0 °C is registered in May and October. The temperature scale is divided into three intervals - less than 10, 10 to 15, and above 15ºC. The water volume required to dilute pollutants was determined on the basis of the minimum 30-day river flow rates (seven gradations - from less than 10 to more than 800 m³/s) and the average annual water amount in water bodies (four gradations - from less than 10 to more than 500 m³).

Determination of the self-clarification conditions of rivers and water bodies was carried out in stages. Primarily, transformation of pollutant by biochemical processes was estimated, and then pollutant dilution conditions were analyzed. As a result, four categories of self-clarification degrees of water bodies were defined.

On the map the self-clarification conditions of water bodies are shown with colored along-channel linear curves and with shadings. The most favorable self-clarification conditions within the Baikal basin develop in some areas of the Selenga river. Most of the water bodies of the territory are classified as having satisfactory conditions.

The self-clarification capacity can be regarded as the criterion of sustainability (preservation of properties) of aquatic ecosystems to anthropogenic impact, and the map can be considered an element of environmental potential assessment of the area.

References

Long-term data on the regime and surface water resources. The Baikal basin. (1986). Vol. 1, no. 14, Leningrad: Gidrometeoizdat, 361 p.

Surface water resources of the USSR. (1972). Vol. 16, no. 3. Leningrad: Gidrometizdat, 595 p.

Surface water resources of the USSR. (1973). Vol.16, no. 3, Gidrometeoizdat, 400 p.

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Flow

The map “Mean annual flow” reflects the formation patterns of the water regime of the territory, which are determined by the properties of landscapes to transform atmospheric moisture into the runoff.

For a water body basin, the surface runoff is the total amount of water loss from the watershed landscapes. The runoff rate from landscape complexes is determined by solving the inverse problem, i.e. identification of the connection of flow rate at the main stream station of a catchment with the runoff from landscapes, occupying its area, and is calculated based on the equation Q_j = ∑q_i f_ij, where j is the index of the river basin, Q_j is its runoff, L/s; q_i is a modification of flow from the i-th landscape complex, L/s km²; f_ij is an area of the j-th basin occupied by the i-th landscape, km². Long-term average runoff data for small and medium-sized rivers of theLake Baikal basin were used in calculations for the map construction [Long-term…, 1986, http://www.r-arcticnet.sr.unh.edu]. Characteristics of landscape components were obtained on the basis of the materials on landscape of the Baikal region [Landscapes…, 1977, Natural..., 2009, Landscapes…, 1990, Lysanova et al., 2009]. In accordance with the regional dimension, generalization degree is chosen at the geom level, and their average annual flow moduli are determined. The territory on the map is divided into regions according to five gradations of the module - from less than 1 to more than 10 L/s km².

The catchment area of the lake covers a variety of landscape zones and altitudinal belts, which makes a great contrast between the runoff rates. The highest annual flow moduli are formed within the goletz and mountain-taiga landscapes. Steppe and forest-steppe areas are distinguished by the minimum runoff rates, and in the desert regions of Mongolia (the Selenga river basin) flow formation almost does not take place.

The maps of minimum and maximum flow were compiled based on the typological landscape classification represented on the map [Landscapes…, 1977]. In the course of investigation, landscapes of different types were generalized by identifying the most hydrologically informative properties (morphological characteristics, vegetation structure, altitudinal zonation, etc.). As a result, more than 200 landscapes were combined into sixteen types of natural complexes, and runoff rates were determined for them. The moduli of maximum snow runoff and minimum summer runoff were calculated as described above.

Areas with the highest runoff of floods are confined to the mountain ranges and systems with goletz open woodlands and mountain-taiga landscapes. The main areas, distinguished by formation of frequent and high floods are the Baikalsky Range on the north-eastern end of the lake; Barguzinsky Range, located in the south-eastern part of the catchment, and the Khamar-Daban, covering the south-western shore of Lake Baikal. The values of the maximum flow modification are shown in three gradations on the map, namely: less than 25, 25-70, and more than 100 L/s km².

Features of formation of the minimum summer runoff in the Baikal basin are associated with the regime of atmospheric moisture, as well as with the effects of altitude and exposition. The calculations and analysis of the minimum summer runoff have shown a relatively high water yield in the low-flow period from high-mountain taiga landscapes and extremely low river flow formation in the central areas of the Selenga river catchment and in Priolkhonie, which are covered with light coniferous landscapes and steppe complexes on slopes and plains. The map shows the value of the minimum flow in three gradations, namely: less than 1.5, 3.0-5.0, and more than 5.0 L/s km².

Landscape-hydrological mapping based on the quantitative characteristics of water yield of landscape complexes objectively reflects the hydrological organization of the territory.

References

Kuznetsova T.I. (2009). Map "Natural landscapes of the Baikal region and their use: purpose, structure, and content”.  T.I. Kuznetsova, A.R. Batuev, and A.V. Bardash. Geodeziya i kartografiya, , no 9, pp. 18-28.

Landscapes of southern East Siberia [Maps]: [physical map] (1977) / compiled and prep. for printing by factory no. 4 GUGK in 1976, authors: V.S. Mikheev and V.A. Ryashin. 1: 1 500 000, Moscow: GUGK, 1 map (4 sheets): col.

Landscapes [Maps] [physical map] / The National Atlas of the Mongolian People's Republic. / comp .and prep to print by GUGK in 1989, authors: B.M. Ishmuratov, K.N. Misevich, I.L. Savelyeva, et al.

Lysanova, G.I., Semenov, Yu.M., Shekhovtsov, A.I., and Sorokovoy, A.A. (2013). Geosystems of the Republic of Tuva. Geografiya i prirodnye resursy, no. 3, pp. 181-185.

Long-term data on the regime and surface water resources. The Baikal basin. (1986). Vol. 1, no. 14, Leningrad: Gidrometeoizdat, 361 p.

A Regional, Electronic, Hydrographic Data Network For the Arctic Region. URL: http://www.r-arcticnet.sr.unh.edu