Even in ancient times, many geographers and naturalists noticed a strange pattern: as you climb the mountains, the composition of the soil, vegetation, wildlife, and climatic conditions change. This pattern was defined as altitudinal zonation.
general characteristics
Altitudinal zone or altitudinal zonation represents a natural change in natural conditions in the mountains as their absolute height increases. The first who was able to classify and describe these changes in detail was the German scientist Alexander von Humboldt.
When climbing a mountain, the following changes occur:
- decrease in air temperature by approximately 6C per kilometer;
- reduction of air pressure;
- increase in intensity solar radiation;
- change in precipitation.
There are some similarities between altitudinal zones and latitudinal zones. This concerns the placement of soils, vegetation, and climatic features. However, some altitudinal zones do not have exact latitudinal analogues. For example, the polar night is characteristic of the tundra natural zone on the plain, but at the same time this phenomenon is not typical for the mountain tundra belt.
The formation of areas of altitudinal zonation is influenced by the following factors :
- The height of the mountain system. The higher the mountains and the closer they are to the equator, the more diverse the altitudinal zones will be. This is one of the main reasons for the emergence of altitudinal zonation. The most complete range of altitudinal zonation is presented in the mountains located in the tropics and on the equator. Typical representatives of such mountain systems are the Himalayas and the Andes.
Rice. 1. Himalayas.
- Geographical position. The number of altitudinal zones, as well as their height above sea level, are largely determined by the geographic latitudinal mountain system. The distance of the mountains from the seas and oceans also has a significant influence. Thus, when moving from north to south, there is a natural increase in the number of altitudinal zones. The lower zone will always correspond to the latitudinal zone of the area.
- Climate . In mountain conditions, humidity, temperature, pressure, and solar radiation levels change. In accordance with this, the composition of the flora and fauna changes.
- Relief . Depending on the topography of the mountain range, its evenness, dissection and other factors, the distribution of snow cover, the accumulation or removal of weathering products, and the development of vegetation occur.
- Location of mountain slopes . The position of mountain slopes relative to the movement of air masses, sunlight, has a significant impact on the distribution of moisture, heat, and the development of soil cover.
Rice. 2. Mountain slopes.
Altitudinal areas
The change of natural complexes in mountainous areas occurs in exactly the same way as on the plain. However, mountains are characterized by a sharper and more contrasting change of zones.
There are two main altitudinal groups:
- Primorskaya . Mountain forest belts in this group are located in the lowlands, while alpine meadows are concentrated in the highlands. A typical example is the mountain ranges of the Western Caucasus, where at the foot of the mountains there is a mountain-forest strip (coniferous and broadleaf forests), above is the alpine zone, and even higher is the nival zone.
Rice. 3. Mountains of the Western Caucasus.
- Continental . In the foothills of this group there is usually a desert-steppe strip, and in the highlands there is a mountain-meadow belt. The continental group is represented by the mountains of the Tien Shan and the Urals, in which there is a natural change of belts from deserts (foothills) to mountain steppes in the highlands. Above them there is also a nival belt.
The nival altitude zone is the highest point of any mountain, covered with eternal snow and ice. Those areas where there is no snow are subject to severe frost weathering, which leads to the appearance of rubble and large stones. Vegetable and animal world The nival belt is characterized by extreme scarcity.
1. Geographical location.
2. Geological structure and relief.
3. Climate and water.
4. Soils, flora and fauna.
Geographical position
Altai-Sayan Mountain country located in the center of Asia and occupies the western part of the mountains Southern Siberia. The country's borders are determined by faults and displacement of block structures during tectonic movements. The border with the West Siberian Plain passes along fault ledges 300-500 m high. In the northeast, the border with the Central Siberian Plateau. In the southeast, the country borders on the Baikal mountainous country along a rift zone - the Tuva graben. In the southwest the border passes with Kazakhstan and Mongolia. The country includes: mountain systems and intermountain basins - Altai, Salair Ridge, Kuznetsk Alatau, Western and Eastern Sayans, Tuva Highlands, as well as the Tuva, Minusinsk, Kuznetsk basins, etc.
Geological structure and relief
Altai-Sayan folded-block geostructures frame the Siberian platform from the southwest. The most ancient mountain-building movements occurred at the end of the Proterozoic. As a result, the Sayano-Baikal fold belt was created in the east. At the beginning of the Paleozoic, the structures of the Caledonian folding (Sayan and most of Altai). The last folding, the Hercynian, appeared in the west of the country. By the beginning of the Cenozoic, the structures were severely destroyed and experienced new tectonic movements in the Cenozoic: faults and volcanoes formed, high elevations (up to 3000 m) and intermountain basins were created. These processes led to the formation of folded-block mountains, highlands and intermountain basins. The country experienced ancient glaciations, so the relief preserved glacial forms (karas, troughs, moraine hills, etc.). Erosion landforms are also widespread. External (exogenous) processes determined the morphological zonation: the first zone – highlands with nival-glacial forms (peaks of Altai, Sayan, etc.); the second belt is the ancient peneplain, these are high mountain ranges with a leveled surface; the third belt is erosion-denudation lowlands. The direction of the country's mountain ranges is different. Altai has the shape of a fan facing northwest. The highest peak is Mount Belukha (4500 m). The Kuznetsk Alatau and the Salair ridge extend from southeast to northwest, parallel to each other. The Western Sayan has a northeastern direction and runs almost perpendicular to the Eastern Sayan. Average heights are 1000-3000 m. The Western Sayan slopes steeply to the Minusinsk and Tuva basins. The Eastern Sayan is a watershed between the basins of the Angara and Yenisei rivers.
Climate and water
The climate of the country is sharply continental, with very cold winter and warm (in hollows) summers. The climate is influenced by continental air of temperate latitudes, mountainous terrain and westerly transport of air masses, which is most pronounced on windward slopes. The Tuva Basin has the most continental climate. In winter, the country's climate is influenced by the Asian High. Average January temperatures vary from -18˚C in the Altai foothills to -30˚C in the Tuva Basin. Temperature inversions are characteristic. On the windward slopes of Altai and Sayan, up to 2 meters of snow falls. Average July temperatures range from +12˚C+14˚C in the mountains and up to +20˚C in the foothills and basins. During the year, precipitation ranges from 250 mm in the basins to 2000 mm in the mountains on windward slopes.
The river network is well developed. In the Altai-Sayan country are the sources of the Ob and Yenisei rivers and many of their tributaries. All rivers are mountainous in nature. The feeding is mixed snow, rain, and for some rivers also glacial. High water from May to July. The warm period accounts for up to 80-90% of the annual runoff. Most large rivers: Biya, Katun, Chulyshman, Big Yenisei, Small Yenisei, etc. There are many lakes in Altai, most of which are located in ancient glacial carts. But the largest lake, Teletskoye, is of tectonic origin. It is mountainous and lies at an altitude of 436 m above sea level. The length of the lake is 78 km, the average width is 3.2 km. Maximum depth 325 m (the second deepest in Russia), many rivers flow into it (Chulyshman and others), and the Biya River flows out. This mountainous country has developed modern glaciation. The largest number of glaciers is in Altai - about 1500 (area 910 km2). In the Sayan Mountains, glaciation is less common, only in the east. The height of the snow line rises from 2300 m in the west to 3000 m in the east.
Soils, flora and fauna
Altitudinal zonation is clearly visible in the distribution of soil and vegetation cover. At the foothills of Altai, the Salair Ridge, the latitudinal extent of the Russian steppes ends and the steppes extend onto the slopes of the ridges, up to 500 m, and into intermountain basins. There are steppes at the foothills of Altai and the Salair Ridge, but they are especially widespread in the Tuva Basin. The soils are predominantly chernozem; in the east, in areas of dry steppes, they are chestnut. Foothill steppes – forb-turf-grass; from forbs (geranium, iris, anemone, etc.) and from cereals (feather grass, fescue, tonkonogo); there are shrubs (honeysuckle, rose hips, caragana, bean grass, meadowsweet, etc.). In the mountain steppes, edelweiss, astragalus, sweetgrass, etc. appear. The Tuvan steppes are drier - small-grass-grass with the presence of tansy, snakeweed, wheatgrass, wormwood, and sweetgrass. Forests cover the slopes of the mountains, they give way to steppes and rise to a height of 1800-2400 m. On the most humid slopes they grow spruce-fir forests with an admixture of aspen on mountain sulfur forest soils, as well as on mountain podzolic soils. Sometimes they contain cedar. On the inner slopes of mountains with a more continental climate, larch forests grow with an admixture of pine and cedar on podzolic soils, and in permafrost areas - on permafrost-taiga podburs. These forests rise the highest on the mountain slopes up to 2000-2500 m. Above the forests there is a high-mountain belt of shrubs (erniks) - dwarf birch, juniper and cedar shrubs, willow trees, red currants, honeysuckle. Even higher are subalpine meadows on mountain meadow soils. Grasses (orch grass, bluegrass, oats), umbellifers, knotweed, etc. grow here. Subalpine meadows gradually turn into low-grass alpine meadows, consisting of brightly colored flowers: Siberian columbine, lights, pansies, anemones, poppies, buttercups, gentians, etc. Mountain peaks cover mountain tundras (made up of mosses and lichens on tundra-mountain soils) and rocky placers; in some places there are glaciers.
The fauna is characterized by great diversity. This is due to the diversity of modern landscapes from mountains to plains, the history of their formation and the border position of two zoogeographic regions: European-Siberian and Central Asian. Therefore, the fauna consists of taiga, steppe and mountain-tundra species. Taiga fauna predominates in the north and west of the country. This Brown bear, wolverine, lynx, wolf, fox, weasel, sable, chipmunk, squirrel, flying squirrel, ermine, otter, mountain hare, elk, deer, musk deer. Among the birds - wood grouse, hazel grouse, nutcracker, deaf cuckoo, bee-eater, woodpeckers, owls, falcons, etc. The steppe fauna gravitates to the south, intermountain basins, especially Tuva. Numerous ground squirrels, Mongolian marmot, pikas, jerboa, tolai hare, corsac fox, manul cat, and gazelle antelope live there. Birds include the red duck, demoiselle crane, Mongolian bustard, sajja, Mongolian auklet, etc. The argali live in the high mountain areas ( Mountain sheep), Mountain goat, reindeer(mountain subspecies), snow leopard (leopard), Altai vole, pika; Birds include snowcock, mountain turkey, ptarmigan, mountain pipit, Altai finch, red-billed jackdaw, etc.
Nine nature reserves have been created within the country: Stolby, Altai, Katunsky, Sayano-Shushensky, etc.
A natural change in processes and phenomena with altitude in the mountains. It is caused by changes in density, pressure, temperature, moisture and dust content of air. Atmospheric pressure decreases in the troposphere by 133 n/m2 (1 mmHg for every 11-15 m of altitude); at 5.5 km it is approximately half as low as at sea level. Half of all water vapor is concentrated below 1.5-2 km, and the dust content in the air quickly decreases upward. For these reasons, the intensity of solar radiation in the mountains increases with altitude, and the return of long-wave radiation from the surface of mountain slopes into the atmosphere and the influx of counter radiation from the atmosphere decrease. Under the conditions of absorption and release of radiation and vertical exchange of air created in the atmosphere, the air temperature, as a rule, decreases within the troposphere by an average of 5-6 ° C for each kilometer of altitude. The conditions for condensation of water vapor are such that the number of clouds, concentrated mainly in the lower kilometers of the troposphere, increases to a certain height. This leads to the existence of the belt maximum precipitation and to their decrease by more high levels.
The set of altitudinal belts of a macroslope (slope) of a mountainous country or a specific slope of a separate ridge is usually called a set or spectrum of belts. In each spectrum, the basic landscape is the foothills of the mountains, close to the conditions of the horizontal natural zone in which the given mountainous country is located. The combination of numerous factors influencing the structure of the high-altitude spectrum causes a complex differentiation of the types of altitude spectra. Even within one zone, the spectra of V. p. are often heterogeneous; for example, they become richer as the height of the mountains increases.
Altitudinal zonation in Altai.
Complex geological history, sharply delineated relief, contrasting climatic conditions and diverse soils predetermined the formation in Altai of a unique set and mosaic of vegetation cover.
The main patterns in the distribution of vegetation are associated with altitudinal zones, the identification of which is due to changes in climatic indicators with altitude. Currently, among the works published by researchers on altitudinal zonation (zoning), there is no unity in the identification of zones.
In works on altitudinal zonation by G.N. Ogureeva (1980), there are six identified zones: steppe, forest-steppe, forest, subalpine, alpine-tundra, nival.
I.Yu. Koropachinsky (1975), also distinguishes for the entire Altai Sayan region: steppe, forest-steppe, forest, subalpine, alpine, nival.
A.V. Kuminova (1960), gives a complex system of vegetation zonation for Western, Northern, Central and South-Eastern Altai.
According to V.V. Rudsky, it is advisable to adhere to the following scheme of altitudinal zones: steppe, forest-steppe, forest, high-mountain, nival.
Let's give brief description vertical belts.
1. Steppe belt.
It has a very limited distribution in Northern Altai within Altai Territory, and is also represented by the island steppes of the Central and desert steppes Southern Altai. Here, plant formations of the semi-desert type are found in fragments, which do not form an independent vegetation belt.
Their existence is explained by a lack of moisture, as well as drying winds - hair dryers, the maximum of which is observed in winter and autumn.
2. Forest-steppe belt.
It is also a small belt bordering the steppe regions and associated with the increasing ruggedness of the terrain and the appearance of forest phytocenoses along the northern slopes of the ridges. In addition to larch, the forest element of the forest-steppe complex consists of birch and pine, and steppe vegetation is represented by formations of meadow steppes. IN vegetation cover steppe grassy and forest formations occupy the same areas. Their differentiation is associated with exposure differences in lighting and moisture conditions.
Thus, on the southern slopes, steppe communities develop, consisting of xeropetrophilous species of herbaceous plants and some shrubs, among which meadowsweet can be distinguished. At the same heights, but on the slopes of northern exposure, forest formations with the participation of birch, aspen, pine, and larch are common.
3. Forest belt.
It has two sub-belts: taiga and light-coniferous forests.
Light coniferous with a predominance of larch, occupies significant areas in the basin of the middle Katun, on the Terektinsky and Kuraisky ridges. In virgin larch forests, a sparse shrub undergrowth and a rich and varied herbaceous cover develop. The subtaiga subbelt includes primarily park larch forests located along river valleys, foothill trails and on gentle slopes. They were once widespread in Altai, but due to economic development they underwent a significant reduction, especially around settlements and along river valleys.
Pine forests distributed mainly along river valleys (Katun, Chulyshman). Here you can highlight areas of park pine forests with a well-developed grass stand, in which cereals predominate.
The taiga subbelt occupies the largest area. Within its boundaries, the black taiga, which is widespread in the western foothills of Altai and in the North-Eastern Altai (Lake Teletskoye basin), is of significant interest.
In the tree layer, along with fir, Siberian pine (cedar) can also dominate.
The herbaceous layer consists of large-grass and tall-grass species.
The taiga forests themselves are very diverse in Altai.
The leading position is occupied by the polydominant dark coniferous taiga, where the main cenose-forming species are three species: Siberian fir, common spruce and Siberian pine (cedar). Along with polydominance, the leading role may belong to one of the three above-mentioned species. Then associations of fir dark-coniferous taiga are formed, confined mainly to the middle part of the mountain slopes, cedar taiga, gravitating mainly to the upper parts of the forest belt, and spruce taiga occupies river valleys. Unlike the black taiga, the dark coniferous taiga is characterized by good development ground cover, consisting of mosses and lichens, the presence of a shrub and subshrub layer and weak development of the herbaceous layer. The upper boundary of the taiga subbelt lies within the altitude range from 1600-1800 to 1700-2465m ( upper limit forests). It is characterized by cedar-larch and cedar forests with an admixture of fir and developed shrub and grass-shrub layers.
4. Alpine belt.
In a simplified form, the high-mountain belt can be divided into two sub-belts: subalpine and alpine-tundra.*
The subalpine sub-belt is represented by subalpine meadows and thickets of shrubs (erniks), alternating with cedar and larch woodlands.
The Alpine-tundra subbelt is characterized by a complex of South Siberian alpine-type formations, widespread in absolute altitudes 2000-3500m. it is most typically represented on the ridges of Western and Central Altai; as you move south and east, the area of alpine meadows decreases.
A.V. Kuminova (1960) distinguishes four formations of alpine meadows: large-grass, small-grass, grass-sedge and cobresia.
Largest areas the subbelt is occupied by tundra, represented by meadow, moss-lichen, shrub and rocky formations.
5. Nival belt.
More homogeneous throughout its entire length due to the almost complete absence of vegetation and the presence of modern and traces of ancient glaciation.
It is mainly located at altitudes above 3000m.
A special intrazonal plant formation is formed by swamps, widespread everywhere and at different altitudes, but mainly on flat watershed spaces (for example, the Tyugurk swamps on the Terektinsky ridge), flat depressions in the relief of plateaus (Chulyshmanskoe, Ukok), and in the bottoms of trough valleys. Large tracts of swamps were formed as a result of overgrowth and siltation of high-mountain lakes.
V.P. Sedelnikov (1988) in work throughout the Altai-Sayan mountainous region distinguishes three types of altitudinal zones in the highlands.
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Altitudinal zonality in the mountains.
Altitudinal zonality or altitudinal zonation is a consistent change of natural zones and landscapes with increasing altitude above sea level.
Altitudinal zone or altitudinal zone– more or less homogeneous natural conditions band. May be intermittent.
Altitudinal zonation (zonation). Characteristic.
Altitudinal zonation (altitudinal zonation) is caused by climate change in the mountains with increasing altitude.
As you climb the mountains:
The air temperature decreases by an average of 6 degrees Celsius for every kilometer,
Air pressure decreases
Solar radiation is becoming more and more intense,
The amount of precipitation changes.
Vegetation.
The vegetation of the subalpine altitudinal zone is represented by subalpine meadows, consisting mainly of cereal and forb tall grasses, and small areas of park forests and crooked woods. The vegetation of subalpine meadows is very rich, with haymaking in some regions globe gives up to 30 c/ha of hay.
Mountain meadow altitudinal belt
The term is used to combine the alpine and subalpine belts.
General characteristics.
The wettest altitude zone. The mountain-forest altitudinal zone is represented mainly by forest landscapes. Reaches greatest development in tropical and equatorial latitudes, however, it is also found in arid regions of the planet. In the latter case, the forest does not grow as a continuous mass, but alternates with the steppe, forming a forest-steppe natural zone.
Boundaries of the mountain-forest altitudinal zone.
Below it borders on the desert-steppe belt, on top – on the subalpine or mountain-tundra belt.
Vegetation.
Very rich. The types of vegetation that form mountain forests depend on latitude, continental climate and other factors.
General characteristics.
The desert-steppe altitudinal zone is characteristic of desert, semi-desert and steppe natural zones of the tropics, subtropics and temperate climate zone. Partly represented in the zone of savannas and woodlands of subequatorial belts.
In temperate and subtropical zones the development of mountain steppes occurs with 350-500 mm of precipitation per year, mountain semi-deserts - with 250-350 mm, mountain deserts - with precipitation amounts of less than 250 mm per year. In tropical or subequatorial climate these values will be 100-200 mm larger.
The Altai-Sayan mountainous country is located in the center of Asia and occupies the western part of the mountains of Southern Siberia. The country includes mountain systems and intermountain basins - Altai, Salair Ridge, Kuznetsk Alatau, Western and Eastern Sayans, East Tuva Highlands, Kuznetsk, Minusinsk, Tuva and other basins.
The boundaries of the Altai-Sayan mountainous country are determined by faults and displacement of block structures as a result of repeated tectonic movements. The border with the West Siberian Plain passes along fault ledges 300-500 m high; in the northeast - along ledges 400-500 m to the Central Siberian Plateau. In the southeast, the Eastern Sayan borders on the Baikal mountainous country in the Baikal rift zone along the Tunkinsky graben. In the southwest and south, the territory adjoins the state border of Russia with Kazakhstan, Mongolia and, for a very short distance, with China.
The basis for separating this territory into an independent physical-geographical country is the following:
The Altai-Sayan mountainous country is a large block structure with a complex mountain-basin topography. It is characterized by the dominance of mid-altitude and high-mountain folded-block mountain systems, separated by large and small basins. Modern look The relief reflects the structures of Paleozoic folded belts, raised by recent tectonic movements to 500-1000 m in intermountain basins and up to 3000 m in the mountains.
Continental continentals predominate here all year round. air masses and in the conditions of mountain-basin relief they create a continental climate, and in intermountain basins a sharply continental climate. The influence of western circulation is actively manifested on windward slopes and ridges from an altitude of 2000 m. This is reflected in the formation of the natural appearance of forest and high-mountain belts.
A single structure of altitudinal zonation, expressed as a forest-meadow type with char and glaciers. The forest belt (taiga) predominates. Treeless belts form steppes, alpine meadows and mountain tundras.
The largest researchers of Siberia repeatedly visited certain parts of Altai, Sayan and intermountain basins (P.S. Pallas, P.A. Chikhachev, V.V. Sapozhnikov, V.A. Obruchev, S.B. Obruchev
and many others). They compiled the first descriptions of the nature of the Altai-Sayan country. Ranges, highlands, mountain systems, plants and other geographical features are named after them. The diversity of the geological structure, the wealth of minerals, turbulent rivers, snow-glacier peaks, vegetation, and animals have long attracted the attention of various nature researchers. Extensive work was carried out by scientists from Tomsk University. The first systematic studies of vegetation were carried out in late XIX- early 20th century Professor P.N. Krylov. He compiled a summary of the flora of Altai, identified and described altitudinal vegetation zones, and studied endemism and relict phenomena. At the same time, Professor V.V. carried out work on the flora and vegetation of Altai. Sapozhnikov. He was the first to climb in 1898 to a snow-covered saddle between the two peaks of Mount Belukha and reached a height of 4050 m. In 1914, the brothers B.V. and M.V. The Tronovs conquered the highest peak of Siberia - Belukha. They studied the glaciers of Altai for many years.
Cartographic and complex geographical works in Eastern Sayan in the 20s. XX century carried out by brothers N.V. and V.V. La-maquinas. Later, numerous expeditions led by C.B. explored the Eastern Sayan and Tuva Highlands. Obruchev. Over the years, many “white spots” have been erased from the maps Altai-Sayan country. During the Great Patriotic War exploration of the territory continued: research was carried out for the railway route through the Minusinsk Basin and the Eastern Sayan. In subsequent years, research into the nature and natural resources of the Altai-Sayan mountainous country continued. Much attention was paid to the knowledge and development of mineral resources, the study of glaciers and their importance in watering the territory, and the structure of altitudinal zones. Botanists studied vegetation, especially treeless areas - steppe intermountain basins and highlands, and continue to complement the general works of P.N. Krylov, as well as the works of K.A. Soboleva on the vegetation of Tuva and A.V. Kuminova in Altai.
Geological structure, history and relief
On the map and especially on the orographic diagram (Fig. 38) of the Altai-Sayan country, the main directions of the ridges and the position of the intermountain basins are visible. The pattern of different mountain structures that make up the country is different. So, Altai has the shape of a fan, turned to the west and northwest. This determines the free invasion of air masses from the north-west, as well as the penetration of steppe complexes into the internal parts of Altai. Kuznetsky Alatau And Salair ridge stretched from southeast to northwest parallel to each other.
In the Sayan Mountains and Tuva, two directions of mountain systems predominate - northwestern and northeastern. West And Eastern Sayan, Western And Eastern Tannu-Ola They approach each other at an angle. They seem to form an arc, convexly facing north. The central ridges of the entire arc rise to 2500-3000 m, to the north and south the heights decrease to 900 m.
Western Sayan drops off abruptly towards Minusinskaya And Tuva basins. The ridge is cut through by a narrow, rapids valley of the Yenisei. Eastern Sayan extends from the northwest, from the left bank of the river. Yenisei, to the southeast, to Tunkinsky graben. It is located between the Central Siberian plateau, intermountain basins - Minusinsk and Chulym-Yenisei And East Tuva Highlands. The Eastern Sayan serves as a watershed between the basins of the Angara and Yenisei rivers. Its greatest height is Mt. Munku-Sardyk(3491 m) is located in the southeastern part. At the junction of the Western and Eastern Sayans, a mountain junction with a peak was formed Grandiose(2922 m).
Altai-Sayan folded-block geostructures frame the Siberian platform from the southwest. They are classified as a large heterogeneous tectonic structure created in different eras and periods. The most ancient mountain-building movements occurred at the end of the Riphean - the beginning of the Cambrian. As a result, the Baikal fold belt was created in the east of the Sayan Mountains. The structures of the Caledonian folding were added to it in the mid-Cambrian - early Devonian: they formed the Sayan Mountains and a significant part of the Altai. The last folding (from the end of the Devonian) - a certain Hertsian, or Variscan, appeared in the west of the country.
At the end of the Caledonian orogeny due to the movement earth's crust and the emergence of faults, large intermountain depressions and troughs (Chulym-Yenisei, Minusinsk, Tuva) were formed on a folded foundation of different ages. Depressions continued to form into the Hercynian fold, for example the Kuznetsk trough, located between Salair and Kuznetsk Alatau. The folded complexes are penetrated by Paleozoic granitoids. In the Mesozoic, almost the entire territory was dry land. In the process of its denudation, the most ancient surfaces of alignment with the weathering crust were created.
In the Cenozoic, the destroyed Altai-Sayan structures experienced new tectonic movements, expressed in a smooth arched uplift, the formation of faults and the emergence of volcanoes (for example, the Oka group). Blocky vertical and horizontal displacements occurred along the faults: some areas rose by 1000-3000 m, while others sank or lagged behind in uplift, creating intermountain basins and valleys.
As a result of neotectonic movements, revived folded-block mountains, highlands and intermountain basins were formed on the folded Paleozoic belts. These morphostructures were changed external processes, since the rise of the territory caused increased erosion, climate cooling, and the development of glaciation. Almost all mountains experienced ancient two or three times glaciation. The relief preserves the forms created by glaciers: ridges, troughs, sharp ridges and carlings, moraine ridges, hilly-moraine and outwash plains. In a drier climate in the foothills, loess deposits formed on watersheds and in valleys (for example, in the area between the Biya and Katun rivers).
External processes created complex and different age erosion-denudation and nival-glacial morphosculptures. Being at different levels, they determined the morphological zonality. The first zone is glacial-nival highlands with cirques, cirques, troughs, carlings (for example, the upper parts of the Katunsky, Chuisky, Chikhacheva ridges - in Altai and the Sayansky, Tunkinsky, Mount Munku-Sardyk - in the Sayans). The second belt is an ancient peneplain. These are high mountain ranges with leveled surfaces and steep, often stepped slopes. Individual remnants rise above the surface of the peneplain in the form of flat domes or narrow ridges, composed of the hardest rocks. The peneplain contains remains of an ancient weakly incised river network and traces of glacial accumulation. The watersheds are not clearly expressed, in most cases they are flat and swampy (the flat surfaces of the watersheds of the Terektinsky Range in Altai or numerous “Belogory” in the Sayan Mountains). The third belt - erosion-denudation low and middle mountains - has heights from 500 to 1800-2000 m. These are smoothed rounded forms of low ridges, widespread in the western and northern parts of Altai, as well as in the north of the Sayan Mountains.
Climate and water
The climate of the Altai-Sayan mountainous country is sharply continental. It is characterized by very cold winters and cool summers. Its formation is significantly influenced by western air masses, which are responsible for the bulk of precipitation, as well as continental air of temperate latitudes in the foothills of the Altai and Sayan Mountains. Orographic conditions that determine sharp climatic contrasts (uneven precipitation over the territory, vertical climatic zones, temperature inversions, development of mountain-valley winds, hair dryers) are important. The influence of western circulation is more pronounced on windward slopes and ridges above 2000 m. This is reflected in the formation of various natural complexes of forest and high-mountain belts, as well as modern mountain-valley glaciation. Noticeable differences in climate can be observed in certain parts of the country. Altai and Kuznetsk Alatau, to a greater extent than the Sayan Mountains and the Tuva Highlands, are influenced by western air masses and are located further from the center of the Asian anticyclone. Therefore, the climate of Altai and Kuznetsk Alatau is less continental (less amplitude of annual temperatures and more precipitation). The greatest continental climate is achieved in closed basins, especially in Tuva.
The winter weather pattern determines the Asian maximum. Average January temperatures vary widely: from -16...-18°C in the foothills of Altai, to -34°C in the Tuva Basin. In winter, weak southwesterly winds blow; sometimes they roll over ridges, turn into hair dryers and contribute to an increase in temperature. On mountain slopes, winter temperatures are slightly higher, which is associated with temperature inversions. The greatest amount of snow falls on the windward slopes of Altai and Sayan (up to 150-200 cm).
Summer in the mountains is cool, with increased westerly transport, cyclonic activity and precipitation; in the west of the Katunsky ridge - up to 2500 mm, in the basins - about 200-300 mm, and the minimum is less than 200 mm (in the Chuya and Khemchinskaya basins). The average July temperature in the mountains is about 10-14°C or more, in the foothills and intermountain basins - up to 19-20°C. Annual quantity precipitation in the highest ridges reaches 1200-2500 mm.
Climatic conditions and ancient glacial topography of the highlands contribute to the development modern glaciation. The largest number of glaciers is concentrated in Altai - about 1,500 glaciers are known there with a total area of 910 km 2. In the Sayan Mountains, only the highest massifs of the Eastern Sayan and the Eastern Sayan Highlands are glaciated. The height of the snow line in the west of the country reaches 2300 m, and to the east it rises in Altai to 3500 m (in the Chikhachev Range) and in the Sayan Mountains to 2940 m (on Mount Munku-Sardyk).
In the Altai-Sayan mountainous country are the sources rivers Ob and Yenisei and their numerous tributaries. All rivers are mountainous in nature. Due to the diversity of runoff formation conditions, surface runoff varies in different parts of the country. The highest flow is typical for the Central Altai and Kuznetsk Alatau ridges. The sources of river nutrition are melted snow waters and summer-autumn rains, and in glacial regions glacier feeding plays a significant role. The flow of most rivers during the warm period is up to 80-90% of the annual one.
There are many lakes in Altai, most of which are located in ancient glacial carts. The largest lake in Altai - Teletskoye- has a tectonic origin.
Soils, vegetation and fauna
The soils and vegetation of the region in their distribution are subject to a clearly defined altitudinal zonation. At the foothills of Altai and the Salair Ridge, the latitudinal extent of the steppe and forest-steppe natural zones of the Russian plains ends. The steppes from Western Siberia extend onto the slopes of ridges and into intermountain basins. On the slopes, steppe and forest-steppe rise to a height of 500-700 m. Under the steppes they form under different conditions of relief, heat and moisture black soils and chestnut soil: in the foothills of the northwestern and northern Altai there are ordinary chernozems, and to the north, in the foothills of the Salair Ridge and Kuznetsk Alatau, there are leached chernozems. The intermountain basins are characterized by leached, ordinary, southern and mountain chernozems, and in the driest places - mountain chestnut soils.
The mountains are covered primarily with taiga spruce-fir, as well as larch, larch-cedar and pine forests. On the most humid slopes of the west and north of the Altai and Sayan Mountains under fir-aspen forests (black taiga) mountainous gray forest soils. On the interior ridges with a more continental climate under larch and pine forests Podzolic, brown-taiga and acidic non-podzolized soils predominate. In the Sayan Mountains and Tuva, where permafrost is widespread, permafrost soils are formed - taiga podburs, which are often found east of the Yenisei.
Significant areas are occupied by a high-mountain belt consisting of shrubs (erniks), subalpine and alpine meadows, mountain tundra, and in some places stone deposits and glaciers. It is located at various heights. The lowest position of the lower boundary of the high-mountain belt is in the northern part of the Kuznetsk Alatau (only at an altitude of 1100-1150 m. To the south and southeast of the country, this boundary rises higher and higher. For example, in Tuva, on the Sangilen highlands, it already reaches 2100-2300 m.
The nature of the Altai-Sayan mountainous country naturally changes both in the meridional and latitudinal directions.
This pattern can be traced in all altitudinal zones. Thus, significant differences in the high-mountain belt are observed between Altai, Sayan Mountains and the East Tuva Highlands. In the west (Altai), in conditions of excessive moisture, heavy snow cover and low temperatures widespread subalpine and alpine meadows with a variety of species composition. Mountain meadow soils were formed under the meadow vegetation. In the east (Sayan Mountains, Tuva Highlands), where the continental climate is more pronounced, alpine and subalpine meadows are confined only to low-moistened areas of the highlands, and the steep slopes are dominated by mountain tundra, represented by communities of bushy lichens on mountain-tundra light, slightly humus-rich soils, herbaceous-lichen communities on mountain-tundra peaty soils, herbaceous-dryad communities on mountain-tundra turf soils. All tundras of the Altai-Sayan mountainous country are close in floristic composition and appearance to the northern lowland tundras. This is apparently due to the history of the development of natural zones and altitudinal zones North Asia in the Quaternary period.
Animal world The Altai-Sayan country is characterized by great diversity. This is due to the diversity of modern geographical landscapes (from steppes to high-mountain tundra and glaciers), the history of their formation, as well as the border position of the country between two large zoogeographical subregions of the Palearctic region: European-Siberian and Central Asian. The fauna consists of taiga, mountain tundra and steppe species, among the latter there are animals of the Central Asian subregion.
Within the Altai-Sayan mountainous country there are now nine reserves. Reserve " Pillars» was created in 1925. It is located in the northern low-mountain spurs of the Eastern Sayan, not far from Krasnoyarsk. The syenite rocks “Grandfather”, “Berkut”, “Perya” and others, destroyed by denudation processes, and overgrown with larch and pine, are protected there. Altaic The reserve was organized in 1932, but then was closed and reopened several times. It is located in the North-Eastern Altai, covers part of the water area of Lake Teletskoye, and occupies a significant area on the watershed of the Ob and Yenisei basins in the middle and high mountains of Altai.
Sayano-Shushensky The biosphere reserve is located on the left bank of the Yenisei near a deep-water narrow reservoir. The typical landscapes of the Western Sayan are protected here.
In the upper reaches of the Katun River, one of the sources of the Ob, in 1991, a Katunsky reserve. It covers middle and high mountains with absolute elevations of up to 4000 m.
In the central part Kuznetsk Alatau there is a reserve of the same name. It protects natural complexes of all altitude zones from steppe to alpine meadows and high-mountain tundra.
Reserve Azas located in the Todzha Basin on the basis of a beaver reserve. It was created to preserve the mountain-taiga and goltsy-tundra landscapes characteristic of the East Tuva Highlands and the Eastern Sayan, and the only Upper Yisei population of beavers.
On the northern slope of the Western Sayan in the basins of the Maly and Bolshoy Abakan rivers there is a nature reserve Small Abakan, created in 1993. Its territory is dominated by mountain taiga forests, but in the upper parts of the mountains there are also mountain tundras and fragments of mountain meadows. In the Abakan River basin there is another reserve - Chazy, where steppe and forest-steppe landscapes are protected. On the southern outskirts of Tuva in the basin of Lake Ubsunur on the border with Mongolia there is a nature reserve Ubsunur basin.
Natural resources
The natural resources of the Altai-Sayan country are rich and varied. Large mineral reserves are concentrated here. In the Kuznetsk Basin there is the largest coalfield. Thick layers of coal (9-50 m) lie here at shallow depths. In many open-pit mines, mining is carried out using open-pit mining. Jurassic brown coals are developed in the Chulym-Yenisei and Tuva basins. In Gornaya Shoria, iron deposits are associated with intrusions. ore Polymetallic ores Altai (Zmeinogorsk deposit) are also associated with Paleozoic intrusions. In the Eastern and Western Sayans, among the Precambrian sediments, ferruginous quartzites are contained. High-quality deposits are concentrated in the Botogolsky ridge. graphite And nepheline syenites. Numerous sulfur and carbon dioxide springs emerge in fault zones.
A significant part of the mountains is covered with large tracts of ripe and overmature forests, consisting of valuable tree species: larch, pine, spruce, fir, cedar, etc. They are also important industrial and hunting grounds. Squirrel, sable, ermine, marten, weasel and deer are caught here. The muskrat and American mink have been acclimatized and the beaver population is being restored. The main places of squirrel and sable production are located in the Eastern Sayan and the East Tuva Highlands.
The rivers of the Altai-Sayan country have huge reserves of hydropower. The Krasnoyarsk and Sayano-Shushenskaya hydroelectric power stations were built on the Yenisei. There is a project to build a cascade of dams on the Katun River. But after a deep analysis and broad discussion, it turned out that when the valley is flooded, the ecosystems of unique and valuable territories will be destroyed Gorny Altai. When drawing up the project, the environmental problems of the region were poorly taken into account. A number of rivers are used for timber rafting. The Yenisei and Biya are navigable.
The agroclimatic resources of the Altai-Sayan country are favorable for the development of agriculture. Agriculture is concentrated mainly in the northern and western foothills, as well as in the intermountain basins. Spring wheat, oats, millet, sunflowers, and potatoes are grown here. Throughout the territory, natural conditions are favorable for cattle breeding. In the spring, cattle are grazed on steppe pastures and in hollows, and in the summer they are driven to the mountain meadows of the forest and alpine zones. In winter, livestock graze on mountain slopes with a predominantly southern exposure, since it is warmer there than in the basins, and the low snow cover allows the animals to easily obtain food.
Mountain areas
Altai is a large mountainous region located in the western part of the country. In the north and northwest it borders on the Kuznetsk Alatau, the Salair Ridge, Mountain Shoria and the West Siberian Plain. In the east, Altai adjoins the Western Sayan and Tuva. Altai is divided into Central, Northwestern, Northeastern and Eastern.
Eastern Altai is formed by ridges of various strikes: northeastern, northern and northwestern with maximum heights of more than 3000 m (Sailugem, Shapshalsky, etc.). The Central Altai includes the main mountain ranges - the Katunsky ridge with Mount Belukha (4506 m), the North Chuysky and South Chuysky ridges, etc. To the west, the ridges drop to 2600 m (Kholzun). Between the ridges there are intermountain depressions - Uimonskaya, Abayskaya, Kuraiskaya, Chuiskaya - and the Ukok plateau. All of them are cut through by river valleys. Northwestern Altai consists of medium-altitude ridges fan-shaped from the ridges of Central Altai - Terektinsky and Listvyag. North-Eastern Altai is located between the North Chuysky and Terektinsky ridges in the south, the Salair ridge and Kuznetsk Alatau in the north. The ridges are separated by deep valleys and the Chulyshman Highlands, through which the Chulyshman River flows, flowing into Lake Teletskoye.
Altai is composed mainly of Paleozoic sedimentary, igneous and metamorphic rocks. The most ancient rocks are Precambrian. These are crystalline schists that occur in the axial parts of the anticlinoriums (Katunsky,
Terektinsky, etc.). The Cambrian is represented by a thick sequence of crystalline limestones, shales, basic volcanic rocks, tuffs and is distributed in the cores of anticlines in the northeastern part of Altai. Ordovician and Silurian deposits, consisting of green sandy-shale strata and conglomerates, are widespread in the basins of the Chulyshman and Katun rivers. The northeastern part of Altai was created by the Caledonian fold. In the rest of the Altai, folded structures appeared during the Hercynian folding. They are composed of Paleozoic strata.
In the Mesozoic, Altai was subject to denudation processes; An extensive peneplain surface formed. Intense recent tectonic movements caused the arched rise of the territory, the formation of horsts and grabens. This, in turn, led to increased erosion. The lines of young faults have a predominantly latitudinal strike; hot springs with a water temperature of 31-42°C are confined to them. The height and width of the raised horsts are different: the narrowest and raised blocks are in the southern part of Altai, and towards the north they become wider and lower. As a result of the movements, the surface of the peneplain ended up at different levels - from 500 to 3500 m.
The first Quaternary glaciation reached its greatest thickness in Altai and covered significant areas of mountains and intermountain depressions - the Chuya and Kurai steppes, onto which glacial tongues emerged along river valleys. During the interglacial period, tectonic block movements along old and new fault lines again manifested themselves: grabens of Lake Teletskoye were formed, and movements of the northern ledge of Altai over the Priob Plateau resumed. In connection with the change in the bases of erosion, there was an increase in the activity of rivers, a restructuring of the hydrographic network and the erosion of moraine deposits of the first glaciation. The last glaciation was of the valley and cirque types. After the retreat of the glaciers, in the upper reaches of the valleys there remained many cirques, dammed lakes, and hanging valleys, on which numerous waterfalls formed, especially in the Chulyshman valley and along the shores of Lake Teletskoye.
Large intermountain basins are typical for Altai. They extend between the ridges, while the height of the bottoms of the depressions increases to the east. The height of the ridges over the depressions reaches 2000-3500 m. For example, the slopes of the Terektinsky and Katunsky ridges rise above the Uimon depression with almost vertical walls.
Intermountain depressions are of tectonic origin, but they have been modified by the activity of rivers, glaciers and lakes. Their bottoms are filled with moraines, fluvioglacial, alluvial and lacustrine sediments. Modern rivers have cut through these deposits, forming a series of terraces. Steppes formed on the terraces: Chui, Kurai - in the valley of the Chui River; Uimonskaya - in the Katun Valley. The steppes are located at different altitudes: the highest of them is Chuyskaya (1750 m), along its edges rise the slopes of ridges, the relative height of which is 2000 m and higher.
The climate of Altai is continental. It differs from the climate of the West Siberian Plain in its greater mildness: winters are warmer, summers are cooler, and there is more precipitation. Arctic air masses, highly transformed, reach the northern spurs of the mountains, penetrate through the valleys into the interior regions and have a cooling effect on weather types. Western circulation is often decisive in the formation of weather types from an altitude of 2000-2200 m. The main amount of moisture falls from air masses coming from the Atlantic Ocean (up to 80%). They are distributed unevenly. In the west of Altai, the amount of precipitation reaches 1500 mm per year or more, for example, on the Katunsky ridge - up to 2500 mm, and in the southeast of Altai - up to 200-300 mm. The greatest number of them falls during the warm period of the year.
Winter in Altai is cold, with little snow in the foothills and intermountain basins and heavy snow in the mountains. The spur of the Asian High passes through Altai. Cold air stagnates in the basins; windless, cloudless, severely frosty and even severely frosty weather with temperature inversion develops there. Thus, at an altitude of 450 m the average February temperature is -22.3°С, and at an altitude of 1000 m - only -12.5°С. In the Chui steppe, the average January temperature is -31.7°C, the absolute minimum reaches -60.2°C. The height of the snow cover is only 7 cm. Permafrost is developed at a depth of 1 m. It is much warmer in the northern and northwestern foothills. The average January temperature is about -16°C, the absolute minimum reaches -50°C. This is due to the activity of cyclones. Therefore, moderately frosty and significantly frosty weather prevails in the north and north-west of Altai.
Summer in Altai is much cooler and shorter than on the neighboring plains. In closed intermountain valleys and on high plateaus in July, night frosts, temperature drops to -5°C, snowfalls and ice formation on lakes and swamps are possible.
The average July temperature in the foothills reaches 19°C, and at an altitude of 2000 m 8-10°C. On some ridges there is a snow line already at an altitude of 2300 m.
In the Northwestern and Northern Altai, cloudy and rainy weather prevails, so the warming process is weakened. The average July temperature is 18.4°C. The maximum temperature in Chemal reaches 37.5°C. In the intermountain basins of Central Altai due to great height The area is cloudy and rainy, and dry weather is rare. These plains are quite humid and have an average July temperature of 15.8°C.
Large centers of modern glaciation are concentrated in the high ridges of Central and South-Eastern Altai. There are individual glaciers on lower ridges, for example on the Kholzun, Kuraisky ridges, etc. The largest number of glaciers are concentrated on the Katunsky ridge. Glaciers descend through deep valleys to an altitude of 1930-1850 m.
In Altai, there are several main types of glaciers - valley, cirque, hanging and flat-top glaciers. The main area of glaciation is concentrated on the northern slopes. On the northern slope of the Katunsky ridge, the glaciation area is 170 km 2, and on the southern slope it is only 62 km 2. On the South Chuya Ridge, 90% of the glaciated area is on the northern slope.
The river network in Altai is well developed. The rivers originate on flat watersheds, often swampy (the headwaters of the Bashkausa River), from the edges of glaciers (the Katun and Argut rivers), and from lakes (the Biya River). Watersheds do not always correspond to the highest parts of the ridges, since many of them are cut by rivers. An example is the gorge of the Arguta River (a tributary of the Katun), separating the Katunsky and South Chuysky ridges. All Altai rivers belong to the Ob basin (Katun, Biya, Chulyshman, etc.), and only small ones flowing from the eastern slopes of the Korbu and Abakan ridges belong to the Yenisei basin.
The rivers are mainly fed by snow and rain. The rivers of the Altai highlands are fed by snow and glaciers. They are characterized by summer high water with a maximum in early July, and low and long winter low water. The rivers of the Altai mountain-forest belt are characterized by spring-summer floods (70% of the annual flow) with a maximum at the end of May, summer and autumn floods, which sometimes exceed the flood. Rivers freeze in winter. The duration of freeze-up is six months. In rapids, the current persists until mid-winter. Through non-freezing rapids, water comes to the surface of the ice, forming ice dams.
In Altai there are many lakes of various sizes and origins. The largest of them is tectonic Lake Teletskoe. It is located among the ridges at an altitude of 436 m above sea level. Its basin consists of two parts: meridional - southern and latitudinal - northern. The length of the lake is 78 km, the average width is 3.2 km. The shores are almost vertical and often rise to 2000 m. In many places near the shore, the depth immediately drops to 40 m. The maximum depth is 325 m. In terms of depth, Lake Teletskoye ranks second in Russia (after Lake Baikal). Its tectonic basin was processed by an ancient glacier. The lake is flowing: a lot flows into it mountain rivers, but Chulyshman brings the most water. The Biya River flows out of it and carries out the bulk of the incoming water. The water temperature on the surface of the lake is low (14-16°C), which is explained by the significant depth and mixing of water due to strong wind activity. There are two types of winds over the lake - “Verkhovka” and “Nizovka”. The first blows from the mouth of Chulyshman to the source of the Biya. This is a foehn-type wind: it brings clear and warm weather with low relative humidity (up to 30%) and with strong waves the waves reach 1.2 m. “Nizovka” blows from Biya to the mouth of Chulyshman. This is a less constant wind; it is associated with cooling, the formation of fogs and heavy precipitation. The lake is rich in fish. Telets whitefish, Siberian grayling, perch, pike, and burbot are of commercial importance.
The flora of Altai consists of 1840 species. It includes alpine, forest and steppe forms. There are 212 known endemic species, accounting for 11.5%. In the northwestern and northern foothills, the plain steppes turn into mountain steppes and forest-steppes. The mountain slopes are dominated by a forest belt, which is replaced on the highest ridges by a belt of subalpine, alpine meadows and mountain tundra, above which on many high peaks glaciers are located. In the northern and western parts of Altai, the boundaries of all zones are lower than in the southern and eastern ones. Extremely? in the northeast, the mountain forests of Altai merge with the taiga of Gornot Shoria and the Salair Ridge.
The steppes are located at different altitudinal levels and in a variety of morphological and climatic conditions, so they differ sharply from each other and are divided into steppes of hilly foothills and mountain steppes. The steppes of the hilly foothills stretch in a continuous strip along the northwestern and northern foothills of Altai. These are forb-turf-grass and forb steppes, consisting of grasses (feather grass, fescue, tonkonogo) and forbs (anemone, geranium, iris, etc.). But with the rise of the foothills and increased precipitation, many bushes of honeysuckle, meadowsweet, rose hips, and bean appear. Under the steppes, ordinary chernozems and mountain chernozems are developed mainly on loess-like loams. In the forest-steppe they are interspersed with mountain forest gray soils. The steppes are used as pastures, but some of them are plowed.
Mountain steppes are found in separate spots along valleys, basins and plateaus. Their climate is more continental: due to the stagnation of cold air in winter, the temperature is very low, summer is warm and humid. The parent rocks also significantly influence the appearance of the steppes: fluvioglacial and lacustrine sediments predominate. Rainwater quickly penetrates into deeper horizons, and the steppe remains dry. Therefore, xerophytic vegetation develops there on southern chernozems and chestnut soils, and in some places on salt marshes. In the steppes, subalpine meadow species appear, such as edelweiss, astragalus, and jasmine.
In the southeastern part of Altai, high-mountain steppes are developed at altitudes of 1500-2200 m. Brown and chestnut carbonate soils and even salt marshes (on the floodplains of the Chui steppe) are formed under a very sparse grass cover. The vegetation cover is formed by pebble feather grass, astragalus, holly grass, caragana, etc. The lowest steppes are plowed under grain crops.
Altai forests are formed mainly by coniferous species: larch, spruce, pine, fir and cedar. The most common is larch, which occupies almost all mountain slopes in the central regions of Altai, often rising to the upper border of forests, where, together with cedar, it forms larch-cedar forests. Sometimes larch descends along river valleys into the forest-steppe and steppe. Above 700 m, the forest belt is dominated by light larch forests. They have a park-like character: the trees grow sparsely, the sun's rays penetrate freely. Therefore, these forests have abundant grass cover, consisting of irises, lights, anemones and many other plants. Pine grows in the foothills and climbs the slopes to a height of 700 m.
In the marginal parts of the mountains, the slopes are covered with aspen-fir forests, the so-called black taiga. In the upper parts of the 19 to B40U forest belt there are cedar forests. Cedar climbs the slopes of mountains often higher than others coniferous trees, forming the upper boundary of the forest belts
Under the forests, a variety of mountain taiga podzolic, mountain brown forest and gray forest soils are developed. The forest belt in the direction from north to south and from west to east, due to decreasing precipitation and increasing dry air, is reduced and rises into the mountains. The upper limit of forests in Northwestern Altai is at an altitude of 1700-1800 m, in Central Altai - 2000 m, in the south and east - 2300-2400 m. The highest forests rise in the Chui ranges, up to 2300-2465 m. At the upper limit The forests include shrubs of dwarf birch with an admixture of junipers, willows, honeysuckle, and red currants among individual trees. Thickets of bushes alternate with tall grass. The height of plants of cereal-forb subalpine meadows reaches 1 m. Meadow plants are cereals (urchin grass, oats, bluegrass) and large-leaved dicotyledons (knotweed, umbelliferae). They are replaced by short-grass alpine meadows, the grasses of which are distinguished by large and brightly colored flowers: Siberian catchment with blue flowers, lights, or frying, orange, pansies from yellow to dark blue, white anemones, poppies, buttercups, gentians with dense blue goblet-shaped flowers. Under subalpine meadows, weakly humused soddy or cryptopodzolic soils are formed, and under alpine meadows - mountain meadow soils. Subalpine and alpine meadows reach 2800-3000 m. These rich meadows are used as mountain pastures.
Mountain tundras rise above the alpine meadows, bordered by eternal snow and glaciers. The tundra is characterized by an alternation of gravelly or rocky soil, devoid of a soil layer, and low areas with loamy soil, on which low-growing birch and gray willow grow. Their surface is covered with a continuous moss carpet. Occasionally flowering plants are common among mosses and lichens. Dryad tundras are located in places where winds are weaker and more snow accumulates in winter.
The fauna of Altai is also diverse. In terms of zoogeography, its southeastern part stands out, which is classified as the Central Asian subregion. In the high-mountain steppes (Chuyskaya, Kuraiskaya, Ukok plateau), the fauna, unlike the rest of Altai, has Mongolian features. Among the mammals that live here are the gazelle antelope, mountain sheep (argali), snow leopard, or snow leopard, jumping jerboa, Mongolian marmot, Daurian and Mongolian pika; Among the birds, the Indian goose, Mongolian buzzard, Mongolian bustard, and sajja are occasionally encountered. Argali, gazelle, snow leopard and bustard are included in the Red Books. Altai mountain sheep at the beginning of the 19th century. was everywhere in the Altai-Sayan country. Currently, it has become rare, is endangered and lives in alpine cobresia meadows and mountain tundra of the Sailyugem and Chikhacheva ranges (this is the northern limit of its range).
Reindeer live on the Chulyshman Highlands. The most common rodents in the highlands are the Altai highland vole - an endemic of Altai, the Altai pika, and the marmot; among birds - the Altai snowcock, or Altai mountain turkey, is endemic to Altai, listed in the Red Books. She flies poorly and avoids the forest. In the rocky tundra (up to an altitude of 3000 m) there is a white partridge, and in the alpine and subalpine meadows there are mountain pipit, Altai finch, red-billed jackdaw, etc.
The northeastern part of Altai differs from other areas in the predominance of taiga fauna. Its typical representatives of mammals are the weasel, wolverine, bear, otter, sable, wolf, fox, deer, musk deer, mountain hare, squirrel, chipmunk, flying squirrel, ermine, Altai mole. The most common birds in the northern forests of Altai are capercaillie, hazel grouse, deaf cuckoo, and nutcracker. In the rest of Altai, the fauna consists of representatives of steppe, taiga and high-mountain species. Numerous ground squirrels, red ducks, and demoiselle cranes are typical for steppe and forest-steppe landscapes.
Tuva Basin and Tuva Highlands located south of the Western and Eastern Sayans in the center of Asia; They are characterized by exceptional isolation. In the Tuva Basin, in the city of Kyzyl, is the center of Asia.
The territory was formed during the Archean-Proterozoic and Caledonian folding. Cenozoic faults and block movements of the ancient peneplain of the East Tuva Highlands, the Tuva Basin and the Tannu-Ola ridges largely determined the features of the modern relief. Young faults occurred mainly along Caledonian and Precambrian lines: in the southeastern part of the highlands, relief forms are subordinated to meridional directions, and in the northern and western parts - predominantly latitudinal. These fault lines also determined the directions of the main river valleys.
In the Neogene-Quaternary time, after the outpouring of basalts, the entire Sayano-Tuva Plateau and the Tannu-Ola ridges began to rise. Young tectonic movements of Tannu-Ola and subsidence of neighboring basins are evidenced by dislocations of Paleogene-Neogene sediments, straight fault sections of ancient denudation plains on the southern slope of the ridge, hot springs along fault lines, frequent earthquakes and young erosional forms. Neotectonic movements created revived folded-block highlands with intermountain basins. The morphostructures are composed of Precambrian and Lower Paleozoic rocks (Cambrian, Ordovician, Silurian), there are outcrops of Devonian and Carboniferous rocks, and Jurassic deposits are common in the central part of the Tuva Basin.
Among the mineral resources, deposits of gold, coal, and rock salt are known here. In the lakes of the basin, self-sedating table salt and Glauber's salt are formed. Numerous outcrops of mineral sulfur and carbon dioxide springs are associated with tectonic fissures in many areas.
The East Tuva Highlands consists of plateaus, mountain ranges and basins. The highlands are composed mainly of Precambrian rocks, intruded by ancient and young intrusions. A large plateau within its boundaries is the Biy-Khemskoye, located north of the latitudinal section of the valley of the Biy-Khem (Big Yenisei) River. The plateau is elevated in the eastern part to 2300-2500 m. To the west, the surface gradually decreases to 1500 m. To the south of the Biy-Khem plateau stretches the Academician Obruchev ridge, which is the watershed of the Biy-Khem and Ka-Khem (Small Yenisei) rivers. In the east, its heights reach 2895 m. The ridge is strongly dissected by glacial and river erosion. Its lowest areas have plateau-like, sometimes swampy watershed surfaces.
In the East Tuva Highlands, intermountain basins lie between the ridges and plateaus: the largest of them is the Todzhinskaya. In the interfluves and in the valleys, traces of ancient glaciation are visible everywhere, expressed by accumulative forms and big amount lakes plowed by glaciers and dammed by moraine. In the northeastern part of the East Tuva Highlands, glaciers descended from ridges and plateaus, merging into two powerful tongues (up to 200 km long) - along the Biy-Khem valley and along the Todzha depression. Glaciers more than 30 km wide descended to the west, their ends lay at an altitude of 800-1000 m.
The Tuva basin is limited in the south by the northern steep slopes of the Tannu-Ola ridges, and in the southwest by the spurs of Altai and the Tsagan-Shibetu ridge, behind which is the largest high-mountain massif of Tuva - Mungun-Taiga (3970 m), formed by the intrusion of granites. In its highest parts, modern glaciation has developed. The Tuva Basin consists of several basins and small ridges and plateaus separating them. It is cut through by the Yenisei and its left tributary - the Khemchik River. The heights in the Yenisei valley are about 600-750 m, along the outskirts of the basin - 800-900 m, and on the ridges and plateaus - up to 1800-2500 m. Within the basin, along the foothills, small hills and gently sloping trains are common, which are composed of crushed stone-sandy loam deposits . Deluvial-alluvial plains occupying the central parts of the basins are widespread. On the sandy terraces of the rivers, aeolian forms are developed, created by the prevailing northwestern winds.
The Western Tannu-Ola (with altitudes of about 3000 m) and Eastern Tannu-Ola (about 2500 m) ridges separate the Tuva Basin from the drainless Ubsunur Basin. East of Tannu-Ola is the Sangilen Highlands. The watershed between the Northern basin passes through all these mountain systems. Arctic Ocean and the drainage region of Central Asia. The ridges and highlands are composed of various rocks of the Proterozoic and Lower Paleozoic (thick strata of sandstones, shales and conglomerates, limestones, as well as effusive and intrusive granitoids). Their watershed surfaces are partially swamped, sharp ridges rise in places and well-preserved glacial landforms - troughs, cirques, cirques. The bottom of the Ubsunur basin is covered with gravelly and sandy deposits, above which rise individual ridges, hills and hills composed of granites. The flat surface of the basin is dissected by rivers flowing from the Tannu-Ola ridges.
The climate of the Tuva Basin and the Tuva Highlands is sharply continental with large temperature amplitudes, severe winters with temperature inversions, warm summers, a small amount of uneven precipitation and very dry air.
Winter is long, cold and dry. Winter weather types are formed under the influence of the Asian High. In winter, the entire territory is filled with cold continental air of temperate latitudes, which accumulates and stagnates for a long time in the basins. It promotes strong cooling and the development of temperature inversions. For example, in Kyzyl (altitude 640 m) the average temperature in January is -32.2°С, and at an altitude of 1500 m it is -22°С, at an altitude of 2000 m -19°С. There are no thaws for three months (December-February). The snow cover here is insignificant, its height is 10-20 cm. The average January temperature in the Tuva Basin reaches -32°C, and the absolute minimum in Kyzyl is -58°C. Severe frosts contribute to deep freezing of the soil and its slow thawing in the spring. Therefore, permafrost remains there.
Summer in the mountains is short and cool, on the East Tuva Highlands it is cold and rainy, and in the basins, where the air warms up intensely, it is warm and even hot. In the steppes of Tuva, the average July temperature is 19-20°C, with a maximum reaching 36.9°C. In July, temperatures can drop to 3-6°C. In elevated areas the climate is more moderate; there are frosts at all times. summer months, the growing season is sharply decreasing. Hairdryers often appear. In the foothills the average July temperature is 19°C, and on the mountain slopes 14-16°C. From the foothills to the passes, the summer period is shortened by 40 days. In summer, cyclonic activity (along the polar front) and the westerly transport of air masses intensify, bringing the bulk of precipitation mainly in the form of showers. The highest annual precipitation (400 mm or more) reaches the East Tuva Highlands, where it often rains in the summer. In Kyzyl, precipitation falls annually to 200 mm, in the Ubsunur depression - less than 200 mm. In the basins, their western parts are the driest, since air masses descend here along the slopes of the ridges and hair dryers are formed.
The river network of the East Tuva Highlands is dense, which is primarily due to the dissected topography. Almost all rivers belong to the Yenisei basin; a small number of small rivers flowing from the southern slopes of Tannu-Ola and Sangilen are directed into the endorheic basin. The rivers of the upper Yenisei basin flow in deep valleys and cut through ridges, forming winding gorges up to 100-200 m deep. The rivers are fed mainly by rain and snowmelt; groundwater and glacial feeding are insignificant. The flood in most of them begins in mid-April. Snow melts at different altitudes at different times, so rivers remain high-water for a long time.
Lakes in Tuva are common at the headwaters of rivers, on watersheds, in river valleys and basins. There are many of them, but their sizes are small. A large number of moraine lakes are concentrated in the Todzha depression. Rivers and lakes are rich in fish; taimen, lenok, grayling, etc. are common in them.
The mountain slopes are covered with larch and larch-cedar forests, under which mountain gray forest soils, mountain podburs, taiga permafrost and mountain taiga podzolic soils are formed. Huge forested areas consist mainly of ripe and overmature trees and have large reserves of wood and hunting and fishing resources. In the fur trade, squirrel and sable occupy the first place. The forests are home to red deer, reindeer, roe deer, musk deer, and elk, the latter widespread in the basins of the Big and Small Yenisei. The mountain goat is found in the high mountain zone.
About V of the territory of Tuva is occupied by steppes. Almost the entire western part of the Tuva Basin is covered with them; they stretch in a wide strip along the right bank of the Khemchik River and move into the eastern part of the basin - into the lower reaches of the Big and Small Yenisei.
In the Tuva Basin, small-grass (serpentine-chamomile) and tansy steppes dominate, and in the Ubsunur Basin, along with steppes, semi-deserts on dark chestnut and light chestnut soils are also common. Isolated steppe areas are common in the mountains, on dry rocky slopes and plateaus.
According to the species composition, the Tuvan steppes are divided into two types: 1) grass-wormwood on chestnut soils, consisting of cold wormwood, crested and creeping wheatgrass, common grass and eastern feather grass. In some areas, shrub thickets of dwarf caragana are common; 2) stony-gravelly on rocky and gravelly light chestnut soils. They consist of pebble feather grass, wheatgrass, snake grass, wormwood, and holly grass. In the moist areas of river valleys, grass-legume and grass-forb meadows dominate. Along the floodplains stretch a narrow strip of coastal forests, or urems, consisting of poplar, birch, aspen, and alder.
The fauna of the steppes, forest-steppes and Urem is especially diverse, as Siberian and Mongolian species live there. In the Ubsunur Basin, the inhabitants of the Mongolian semi-deserts and steppes predominate: the corsac fox, the gazelle, the tolai hare, the Daurian pika, the roundhead, the Mongolian foot-and-mouth disease, etc. In the Tuva Basin, Siberian species predominate, since many Mongolian species do not cross the Tannu-ridges. Ola.
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