The soil and vegetation cover of Western Siberia is distinguished by two main features: classically pronounced zoning and a high degree of hydromorphism. Within the plain there are tundra, forest-tundra, forest (peat-bog), forest-steppe and steppe zones with their characteristic soils and vegetation.

Zonal types of soils - tundra-gley, podzolic, soddy-podzolic, chernozems and dark chestnut soils - are associated with relatively drained territories, which make up from 23.7 to 74.7% of the zone area. In Western Siberia, not only in the tundra and forest-tundra, as is the case in Russian, but also in the forest-bog and forest steppe zones ax large areas (about 1/3) are occupied by semi-hydromorphic soils. They are formed under conditions of close occurrence of groundwater and periods, a clear waterlogging of the entire soil profile or its lower part, which causes the development of gleying processes. Such soils are gley-podzolic and swamp-podzolic, developed under coniferous forests, as well as meadow-chernozem soils, widespread in the forest-steppe zone. The soddy-podzolic soils of Western Siberia also differ from their European counterparts in the presence of signs of gleying, while the chernozems and dark chestnut soils differ in solonetzization.

Waterlogged territories are occupied by hydromorphic soils, among which peaty-bog and peat-bog soils dominate in the northern part of the plain, and in the southern part along with them, solonetzes, solods are common, and solonchaks are also found. Despite the similarity of the dominant types of vegetation and their zonal distribution, there are very significant differences between the vegetation of Western Siberia and the Russian Plain. They are associated not only with the wide distribution of swamps, but also with the peculiarities of the formation of flora, as well as with an increase in continentality and the severity of the climate. This is clearly seen in the composition of the main forest-forming species. Along with spruce and pine forests, cedar and larch forests are widespread here, and fir forests are also found. Larch, and not spruce, as on the Russian Plain, goes to the northern limit of the distribution of woody vegetation in Western Siberia. Birch and aspen here form not only secondary, but also primary forests. In Western Siberia, there are practically no broad-leaved species, only linden is found in the undergrowth up to the Parabel and Tara rivers. Mixed forests here are represented by pine-birch.

Large areas are occupied in Western Siberia by floodplain vegetation, represented mainly by meadows and, to a lesser extent, shrubs. It accounts for about 4% of the plain area. In connection with the wide development of hydromorphism in the distribution of soils and vegetation in Western Siberia, a much greater role than on the Russian Plain is played by the nature and density of the division of the territory, which determine the degree of its fitness. For each zone, a combination of zonal soils and vegetation, typical of trained areas, with certain types of hydromorphic complexes is typical.

The fauna of Western Siberia has many features in common with the Russian Plain. Both plains are part of the European-Siberian zoogeographic subregion of the Palearctic. In Western Siberia, there are about 500 species of vertebrates, including 80 species of wild mammals, 350 species of birds, 7 species of amphibians and about 60 species of fish. Whitefish, bream, carp, carp, pike-perch have been introduced into the reservoirs of the plain. Muskrat, American mink, muskrat are acclimatized. The stock of sable and river beaver, almost destroyed before the revolution, has been restored. On the vast territory of Western Siberia, the animal world noticeably changes from place to place, primarily depending on zonal conditions and the associated availability of food and shelter. However, taiga animals penetrate along ribbon forests and aspen-birch pegs to the south almost to the borders of the plain, and on the lakes of the forest-steppe and steppe zones there are some inhabitants of polar water bodies (for example, the gull-gull), and the white partridge nests in the swamps. The uniformity of the relief of Western Siberia and the considerable extent of the territory from the coast of the Arctic Ocean deep into the mainland creates ideal conditions for the manifestation of latitudinal zonality and its inevitable consequence - gradual transitions in the form of subzones (Sochava, 1980). Zoning is represented by a clear change of zones and subzones in the direction from north to south. Within the plain there are tundra, forest-tundra, forest (forest-swamp), forest-steppe and steppe zones.

Unlike the Russian Plain, there are no zones of mixed and deciduous forests, semi-deserts and deserts, the zones have a clear latitudinal strike, and their boundaries are somewhat shifted to the north. Within the zones, relatively small changes in natural conditions are observed due to changes in the lithogenic base, so provincial differences in Western Siberia are less pronounced than in the Russian Plain. The tundra zone stretches from the coast of the Kara Sea almost to the Arctic Circle in the west and to Dudinka in the east. It occupies all three peninsulas. The more southerly position of the zone boundary in the west is due to the cooling effect of the deeply incised Gulf of Ob - this "ice bag" that slowly warms up in summer.

The length from north to south is 500-650 km. The tundra is characterized by a sharp change in insolation according to the seasons of the year. During the warm period, the sun does not fall below the horizon for about three months (at 70 ° N - 73 days), and in winter the polar night lasts almost the same amount. Winter lasts from October to mid-May. In January-March, average monthly temperatures are almost the same - from -21--23°С in the west to -29°С in the east. Minimum temperatures reach -- 50--55°C. The severity of the climate is increased by strong winds, which, at fairly low temperatures, create more severe weather. Therefore, the winter on the coast of the Kara Sea is more severe, although less cold, than in Central Yakutia. The windiest month is December with an average wind speed of 7-9 m/s. The highest wind speeds (30-40 m/s), turning into a storm and causing a snowstorm, are due to the entry of cyclones. The number of days with snowstorms, carrying very fine, dust-like snow (blizzard), in the west is 120 days, in the east - 80-90 days a year. The snow cover lies for about 9 months. Under influence strong winds snow moves, so its thickness is uneven. Convex relief elements are often devoid of snow throughout the winter. There is a long and deep freezing of the soil.

Under steep slopes, in hollows and valleys, snow faces are formed with very dense snow, which persists until July, and sometimes until new snow, which are sources of river nutrition, especially in the second half of summer. Summer lasts from 40 days in the west to 30 days in the east. The warmest month is August. Its average temperatures are + 6--8°C and only in the extreme south + 10--11°C. Frosts and snowfall are possible throughout the summer. There are also hot days in the tundra (up to + 20--28 ° С), associated with the inflow of warmed continental air with increased meridional transport air masses. During the warm period, more than half of the annual precipitation falls (up to 150-220 mm) with a maximum in August (40-50 mm).

Precipitation falls in the form of prolonged drizzling rain. The ubiquitous permafrost plays a large landscape-forming role in the tundra zone. The active layer (seasonal thawing horizon) reaches 20–25 cm in the north, increasing to 80–90 cm on the sands near the southern boundary. The thawing of the upper horizon is accompanied by solifluction processes, leading to a smoothing of the relief. Permafrost landforms are widespread in the tundra: patches-medallions, polygons, thermokarst basins, peat mounds and bulgunnyakhs. Erosion forms are not typical for the tundra, since erosion processes occur during a very short summer. Do not contribute to the development of erosion processes and features of the relief of the tundra zone - the predominance of flat marine accumulative plains. The plains descend to the coast in a series of terraces. There are many swampy areas on the lower terrace, which are flooded during surge winds. sea ​​waters. In the interior regions of the peninsulas, there are more elevated areas with ancient glacial relief. The relative heights on them are 15-20 m. Many interfluve spaces are not at all developed by river erosion and are not drained. There are many thermokarst lakes in the tundra. Often a chain of lakes turns out to be strung on a winding, slightly incised river bed. The rivers are fed by melted snow and rain waters and have a summer flood. The surface of the tundra in large areas is waterlogged and waterlogged. The peculiarities of the climate and the youth of the zone are the cause of the poverty of the floristic composition of the tundra.

Only about 300 species of higher plants are found here. Under conditions of heat deficiency, even small fluctuations in the heat supply of plants, in changes in the ratio of heat and moisture determine the spatial distribution different types tundra. In the most northern regions and the hilltops are dominated by patchy tundra with arctic tundra soils. Loamy patches up to 1.5 m in diameter form here on the surface bare of snow. They are separated from each other by narrow strips of vegetation confined to frost cracks. Lichens and flowering plants settle here, which are better than mosses to endure the comparative dryness of soils and sharp fluctuations in temperature on a surface insufficiently protected by snow and vegetation. On dry elevated places with loamy soils, on sandy and gravelly substrates, lichen tundras develop. They are dominated by fruticose lichens of cladonia, alectoria, cetraria, and others. There are few herbaceous plants, shrubs, and mosses in them. With immoderate deer grazing, the predominance in these tundras passes to the worse eaten cetraria and mosses. Moss tundras with tundra-gley soils are confined to clay soils and moist areas with loams. A continuous small-hummocky and thin cover of gypsum mosses gives them a monotonous appearance. In addition to mosses, two to three dozen species of herbaceous plants grow in these tundras (partridge grass, crowberry, arctic bluegrass, cotton grass, a number of sedges, etc.) and rare shrubs of small creeping dwarf birch and some arctic willows. In the southern part of the zone, the role of shrubs increases both in the composition of the moss tundra and in the form of thickets of tundra shrubs of birch, willow, alder (shrub tundra) on podzolized tundra soils.

In waterlogged depressions, hypnum swamps are common, on well-warmed slopes and in river valleys - tundra meadows, consisting of brightly flowering buttercups, lights, valerian and other plants. The animals are dominated by local mammals (reindeer, arctic fox, Ob and ungulate lemmings, voles) and migratory birds (especially many sandpipers and geese). Of the birds, only white and tundra partridges and snowy owls remain in the tundra for the winter. The tundra zone of Western Siberia is divided into three subzones according to the characteristics of nature. The arctic tundra subzone is characterized by particularly harsh conditions with the dominance of polygonal tundra, whose plants have a height of only 3–5 cm. Shrubs in this subzone reach a height of 30-50 cm, and cotton grass is the most typical of herbaceous plants. And, finally, the southern subzone is the shrub tundra subzone. Under optimal conditions of existence, shrubs here reach a height of 0.5--1.5 m. In the south of the subzone, on the slopes of the valleys, a creeping form of Siberian larch is found. Its branches are flattened at the very surface of the earth, and a thin twisted trunk rarely rises above 1.5-2.0 m. In all tundra subzones, zonal natural complexes of trained areas are combined with mineral hypnum swamps and thermokarst lakes.

Tundra is the least populated zone of Western Siberia. Most of the population is concentrated on the shores of sea bays and rivers and is engaged in fishing. In areas remote from the coast, the main occupation of the indigenous population is reindeer herding and hunting for arctic fox and birds (partridges, geese, ducks). Western Siberia is the second reindeer breeding region of our country after Chukotka and one of the largest in the world. Reindeer pastures occupy about 2/3 of the territory of the zone. On a limited scale, early ripening vegetables and potatoes are grown here, mainly in greenhouses. Gas production is rapidly developing in the tundra zone, which is carried out, as a rule, on a rotational basis.

The forest-tundra zone stretches in a narrow strip (50-200 km), gradually expanding to the east, from the foothills of the Urals to the Yenisei. It is located near the Arctic Circle East of the river. Taz, the southern boundary of the zone deviates to the north approximately as far as Igarka. Compared with the Russian Plain and Central Siberia, the forest-tundra zone of Western Siberia differs more southern position due to the cooling effect of the Gulf of Ob, large swampiness and the development of large hilly peat bogs. The climate of the forest-tundra is more continental than in the tundra. Average annual temperature amplitudes here reach 40°. Winter in the forest-tundra is more severe and snowy, lasting about 7-8 months. Average January temperatures are 25...30°C.

During winter, there are from 45 to 60 days with an average daily temperature below -25 ° C. Minimum temperatures reach 55-60 ° C. The thickness of the snow cover at the end of winter is 50 - 70 cm. Summer is warmer and longer than in the tundra. The average temperature in July varies from 10 to 14°C. The forest-tundra is characterized by an abundance of surface water and intense swamping of the territory. Relief-forming processes here preserve many features of the tundra zone. Permafrost favors the spread of thermokarst relief and greatly limits the development of erosion processes. The forest-tundra zone is crossed by the transit rivers Ob and Yenisei with their lower reaches. Nadym, Pur and Taz.

The territory of the zone was in the post-glacial period and continues to be the scene of a continuous struggle between forest and tundra. Both the tundra and the forest are at the limit of development here. For tree species this is the northern limit, for many tundra plants it is the southern limit. Larch woodlands choose the most favorable places within the forest-tundra. In the northern part of the zone, sparse forests occupy 10-20% of the territory, in the south - up to 40-45% The height of the trees here rarely exceeds 6-8 m. Under the sparse forests, gley-podzolic soils are common, and in the eastern part of the zone gley-permafrost-taiga soils. Depending on the composition of soils, the ground cover in light forests changes. On light sandy soils, lichen sparse forests develop, on heavier and cold clay soils, swampy sparse forests with moss cover, swamp shrubs and grasses develop. Dry hilltops, marshy depressions, and poorly dissected interfluve spaces are occupied by shrub and moss-lichen tundras on tundra gley soils and swamps. In addition to the lowland bogs characteristic of the tundra zone, sphagnum bogs are also found here; in the southern relic large-hilly. In the valleys of large rivers, large areas are occupied by water meadows.

The forest-tundra is distinguished by a great diversity and richness of the animal population. Reindeer and arctic foxes migrate here for the winter from the tundra. Along with typical tundra animals, there are widespread stoats, white hare, as well as forest dwellers such as wolverine, brown bear, and squirrel. The forest-tundra is characterized by a more complex zonal structure compared to the tundra. It combines forest tundra, marsh and lake PTCs. The formation of one or another of them (depends on the depth of the permafrost and on the nature of the snow cover. The most drained areas are usually occupied by forest complexes, convex, subject to winds and deep freezing - by tundra, shallow depressions by hilly swamps, and thermokarst basins - often by lakes.

The main areas of economy in the forest-tundra zone, as in the tundra, are reindeer herding, fishing and hunting. Reindeer husbandry is based on the seasonal use of the zone's pastures. Here reindeer are grazed in the cold season, and in the tundra - in the warm season. Agriculture is somewhat more developed than in the tundra. The cultivation of early ripening vegetables and potatoes is carried out both indoors and outdoors. open field. Population growth in the forest-tundra zone is associated with the intensive exploitation of gas fields and the further development of geological exploration.

The forest-bog zone is the most extensive of the natural zones of Western Siberia. For 1100-1200 km it extends from the Arctic Circle to almost 56 ° N. sh. Its southern border runs approximately from the Iset valley (the left tributary of the Tobol) to Novosibirsk. A specific feature of the zone is the almost equal ratio of forests on podzolic and podzolic-gley soils and sphagnum bogs on peat-bog soils and peat, which is why it was called forest-bog, and not forest.

The climate of the zone is continental with cold snowy winters and moderately warm and cool humid summers. The continentality of the climate increases from west to east. Annual amplitude average monthly temperatures is 36 - 40 ° - in the western part and 40 - 45 ° - in the eastern part, the amplitude of extreme temperatures is 84 and 94 °, respectively. Winter is moderately severe and cloudy. Average January temperatures vary from 18°C ​​in the southwest to 26-28°C in the east and northeast. The number of days with an average daily temperature below - 25°C is 30 - 35, the absolute minimum reaches 55 .. 60 °C. The winter type of weather is predominantly anticyclonic. The passage of cyclones creates unsettled weather. More often they pass in the northern part, where, in connection with this, more winter precipitation falls. In winter, up to 12% of the annual precipitation falls. The thickness of the snow cover reaches 60-100 cm, and the duration of occurrence is from 150 days in the south to 200 days in the north.

Summer is quite warm in the southern part and cool in the northern part. Average temperatures in July vary from + 13--14°С in the north of the zone to + 18--19°С in the south. The duration of the growing season varies from 95 days near the northern border to 160 days in the south, and the sum of active temperatures, respectively, is from 800 to 1800-1900 °. In summer, about half of the annual precipitation falls. Rains are not uncommon in the second half of summer, delaying the ripening of agricultural crops and making harvesting difficult. The amount of precipitation over the entire area of ​​the zone exceeds evaporation. Only in the extreme south does the moisture coefficient approach unity.

Most of the territory of the zone is located at altitudes of less than 100 m. Only within the Upper Taz Upland, the heights increase to 285 m, and in the Cis-Urals - up to 400 m. In the northern part of the zone, hilly-moraine, rather dissected plains alternate with more flattened water-glacial and . Permafrost is common here, thermokarst depressions are common, with a diameter of tens and hundreds of meters and a depth of up to 10-15 m. In the north of the zone, the largest surface runoff (up to 250 mm) is observed. The southern part of the zone is characterized by a flatter relief of alluvial and alluvial-lacustrine plains. The river valleys are slightly incised, the channels strongly meander. Only the most major rivers have an incision of up to 30 - 40 m. Many rivers or their segments have inherited the ancient hollows of the runoff (Ket, Tavda, the upper reaches of the Konda, Vakha, Tyma, etc.). The modern erosional ravine-gully network is well developed only on the Verkhnetazovsky and North Sosvinskaya uplands, Chulym-Yenisei, Turinskaya and Tavdinsky plains, as well as on steep slopes. river valleys. The rivers of the zone are fed by snow, rain, and bog-soil and have a long spring-summer flood. Groundwater is abundant and close to the surface. The territory of the zone is heavily swamped (Table 2). Here there are huge areas of such water-saturated swamps as ridge-hollow, ridge-lake and swamp. In the central part of the forest-bog zone, climatic conditions are optimal for peat accumulation, which occurs equally intensively both in relief depressions and in elevated interfluves. The predominant type of swamps are ridge-hollow sphagnum peatlands.

The location of the dominant types of vegetation - forests and swamps, is primarily affected by the degree of drainage of the territory. To the low hills and ridges of the interfluves, to the slopes and terraces of the river valleys, there are forests on podzolic and soddy-podzolic soils. In conditions of stagnant moisture, swamps form. An intermediate position between them is occupied by swampy forests on gley-podzolic and marsh-podzolic soils. In the forest-bog zone, two main types of natural complexes - forest and swamp - are adjacent and conjugated with each other. Their relationships are a powerful source of restructuring of the intrazonal structure and determine the main trend in the evolution of the nature of this zone. Bog complexes are especially active and aggressive. They constantly increase their size and advance on the surrounding territories. This is due not only to the fact that swamps conserve moisture, but also to the fact that swampy forests (natural complexes of a semi-hydromorphic type) are favorable for the development of phytocenoses with a moss (especially sphagnum) cover.

Excess moisture and limited thermal resources contribute to the accumulation of dead organic matter. This leads to the formation of peat horizons of soils and peatlands, which, in turn, begin to retain moisture. Thus, not only the self-development of peat bogs, but also the development of swampy forests leads to a reduction in the area of ​​forest complexes. The dominant type of forests in Western Siberia are dark coniferous forests of spruce, fir and cedar. Along with them, common pine forests and larch from Siberian larch, pine-birch and small-leaved axes new birch forests. In the direction from north to south within the zone, the composition of the forest - forming rocks and the prevailing types of swamps - is changing, which is associated with climate change. On this basis, the forest-bog zone of Western Siberia is divided into four subzones: northern taiga, middle taiga, southern taiga and small-leaved forests.

The northern taiga subzone is characterized by a wide distribution of permafrost and the predominance of treeless, large-hilly sphagnum bogs over forests, forming vast massifs. Forests here occupy about a third of the territory, are characterized by great sparseness and short stature (8-10 m). Larch forests on podzolic illuvial-humus soils on sandy soils predominate among them. Wetter habitats on loamy and clayey soils are occupied by spruce-birch-larch and spruce forests on gley-podzolic and gley-frozen-taiga soils.

In the middle taiga subzone, forests occupy more than half of the territory. 60% of the forest area is occupied by pine forests confined to sandy ridges, plateaus and riverine ridges. There are especially many of them in the western, Ural part of the subzone. About a third of the forest area is occupied in the subzone by dark coniferous forests of spruce and cedar with an admixture of fir (urmana). Swampy dark coniferous taiga with long moss and sphagnum cover on bog-podzolic soils is most common in the central and eastern parts of the subzone. Extensive watershed spaces are occupied by ridge-hollow sphagnum bogs. Their surface is often overgrown with small pine, gnarled birch and shrubs (bog rosemary, Cassandra, podbel, dwarf birch).

The southern taiga subzone is characterized by significantly less swampiness and the predominance of dark coniferous forests of fir, cedar, and spruce on podzolic and soddy-podzolic soils. Dominance in the dark coniferous forests of Siberian fir is a typical sign of the southern taiga. Pine forests are found on gravelly soils in the Ural part of the subzone and on river terraces. On poorly drained interfluves, ridge-hollow sphagnum and pine-sphagnum bogs are common. To the south, the areas of transitional and sedge-grass bogs increase.

The subzone of small-leaved forests stretches in a narrow strip (from 50 to 200 km) along the southern margin of the forest-bog zone. The basis of the vegetation cover of the subzone is formed by aspen-birch forests on soddy-podzolic gray forest and peculiar secondary podzolic soils. Aspen-birch forests alternate with birch-pine forests on sandy soils, with grassy, ​​rarely sphagnum bogs and meadows. Large areas in the subzone are occupied by arable land. This subzone is the most densely populated and developed.

Among the animals of the forest-bog zone, there are typical "Europeans" (pine marten, European mink), representatives of the East Siberian taiga (sable) and species closely associated with water bodies (otter, water rat, West Siberian beaver). Mammals are typical brown bear, wolverine, lynx, marten, otter, badger, squirrel, etc. There are many different birds, whose life is usually closely connected with the coniferous forest.But there are few songbirds among them, so the taiga is distinguished by silence and gloom.In the gloomy purely coniferous taiga, animals keep less, preferring secondary, birch - aspen forests.

Many inhabitants of the zone are valuable fur animals (sable, squirrel, muskrat, water rat, etc.). The forest-bog zone has a variety of natural resources and is a territory of intensive development. The main oil deposits are concentrated here, large-scale industrial harvesting of timber and other forest products is being carried out, meat and dairy animal husbandry and vegetable growing are being developed around cities and workers' settlements. As in northern zones, the indigenous population is engaged in fur harvesting and fishing. In the vast expanses of the forest-bog zone, noticeable internal differences are observed not only in the transition from one subzone to another, but also depending on the nature of the lithogenic base from province to province. In all subzones, the most significant differences are observed between the provinces of better-drained upland plains and especially marshy lowlands.

The Sredneobskaya province occupies the central part of the West Siberian Plain, crossed by the middle course of the Ob and its numerous tributaries. It is confined to the synek Lisa of the same name, which experienced significant subsidence (up to 100–150 m) in the Neogene-Quaternary, and is a flat lacustrine-alluvial plain composed of sandy and sandy-argillaceous rocks. A significant part of it is occupied by a floodplain (up to 25–35 km wide) and 2–3 terraces above the floodplain of the Ob 15–40 m high. -20 m. Their slope is negligible. Within the floodplains, river channels form extremely complex meanders, alternating with oxbow lakes and channels. The left-bank part of the Ob is quite strongly dissected by numerous valleys (Salym, Yugan, Demyanka and their tributaries) and is better drained. A more intense cut of the left tributaries is apparently associated with the uplift of the Vasyugan swell, which runs along the southern margin of the province. There are a huge number of lakes on the right bank of the Ob.

The climate of the province is typical for the middle taiga of Western Siberia. The river is fed by late melting snow, rain and swamp waters. Most of the rivers originate from swamps. The high water level on the rivers lasts for almost three months. The province is very different a high degree swamps. In a significant part of the Surgut lowland, it reaches 70--90%. The largest swamps here occupy areas of up to several thousand km. In fact, the entire lowland is a huge swamp system, traversed by narrow forest belts along slightly incised rivers. The left bank of the Ob is less swampy: from 50--70% in some places to 30--35% in the rest of the territory. Ridge-hollow, lake-ridge-hollow and lake-ridge bogs dominate in the province. Pine lichen forests are widespread on sandy podzolic illuvial-ferruginous soils of the right bank. Along with white-moss forests and sphagnum forests, marshy dark coniferous forests on bog-podzolic soils are found in the province, along river valleys and on the slopes of ridges there are pure cedar forests on podzolic soils. Secondary aspen-birch forests are widespread in the burnt areas. On floodplains, large areas are occupied by grass and sedge water meadows on alluvial soils.

The province is intensively developed and settled in recent decades, since the largest oil fields of Western Siberia are located within its boundaries. Here are the young, rapidly growing cities of Surgut and Nizhnevartovsk. The Chulym-Yenisei province occupies the southeastern part of the forest-bog zone. In tectonic terms, the province is heterogeneous. It is located within several tectonic structures of the peripheral part of the plate, the largest of which is the Chulym syneclise with a basement subsidence depth of up to 3000 m. In the Neogene-Quaternary, the territory experienced a significant uplift.

Different intensity of tectonic movements caused the presence of two altitudinal levels in the relief: 200--350 and 150--180 m. The highest intensity of uplift was reached in the south and southeast. Ridge erosional plains are common here, gradually turning to the northwest into gently ridged and wavy ones. The bedrocks of the Paleogene and Cretaceous age are overlain within their limits by a thin cover of Quaternary loess-like loams, sands, and clays, and in some places come directly to the surface. The lower level is dominated by flat alluvial plains composed of fairly thick strata of Quaternary sandy-argillaceous deposits. The territory of the province is dissected by the valleys of the Chulym, Keti, lower reaches of the Tom, incised at 40-60 m. The climate of the province is marked by a significant continentality. The average temperature in January is - 19--22 ° C, July 4 - 17.5 ... + 18.5 ° C. The annual amount of precipitation is 450-600 mm. The thickness of the snow cover reaches 50-70 cm.

The soil and vegetation cover of the province is dominated by dark coniferous southern taiga forests and pine forests on soddy-podzolic and gley-podzolic soils. To the south, they are gradually replaced by small-leaved ones on gray forest soils, often gleyic. In the extreme south, forests alternate with meadow steppes on leached chernozems. The western and northern parts of the province (the lower altitudinal step) are distinguished by relatively high swampiness (up to 30%) of watershed plains and river terraces. In the rest of the territory with a dissected erosional relief, the swampiness is less than 10%.

The Chulym-Yenisei province is one of the most developed and inhabited provinces of the forest-bog zone. Settlements confined to the valleys of the rivers Ob, Yenisei, Chulym, Keti and the lower reaches of the Tom. Forestry is carried out in the province, brown coal is mined in the southern part. The main areas of arable land are also concentrated here. The forest-steppe zone stretches in a narrow strip (150-300 km) from the Urals to the foothills of the Salair Ridge and Altai, the southern border of the zone runs along the river. Uy - to the left tributary of the Tobol, south of Petropavlovsk to Omsk and further to Barnaul. The forest-steppe zone of Western Siberia is characterized by a complex combination of aspen-birch copses and steppe, now plowed areas with sedge-tussock bogs and solonchak meadows. It is distinguished from the forest-steppe of the Russian Plain not only by its more northern position, but also by its strong salinity, the widespread development of swamps and many lakes.

The climate of the zone is continental with severe windy and little snow winters and hot dry summers. The average January temperature is 17--20 °C, the absolute minimum is 54 °C. Up to 25-30 days during the winter it happens with snowstorms in the western part of the zone and up to 45-49 days in the eastern part. The snow cover lies for 150-165 days. Its thickness at the end of winter reaches 30-40 cm, and on convex relief elements - less than 20 cm, so crops often freeze on them. In late March - mid-April, snow melts quickly. The air temperature rises rapidly, but in May (and in the eastern part until mid-June) there are often night frosts.

In summer, dry muds of weather prevail (dry windy-arid and moderately dry) with frequent winds. The average temperature in July is -j-18--20 0С, the maximum rises to +39--41 °С. The duration of the growing season is 150-160 days. The sum of temperatures for the period with an average daily temperature above 10 is 1800--2000. In summer, about 200 mm of precipitation falls, and most of them fall in the first half of summer, when evaporation is especially intense. Sometimes there are showers, during which up to 80 mm of precipitation can fall per day. In connection with the intensification of the meridional transport of air masses, every 3rd-4th year in the forest-steppes of Western Siberia is dry.

The annual amount of precipitation (400-500 mm) is less than evaporation, so the surface runoff is small. Suffusion-subsidence processes play an important role in the formation of the relief. Their development is favored by the flat relief and the predominance of loess-like loams among the surface deposits. The wide distribution of drainless depressions, closed basins, depressions and saucers is a characteristic feature of the relief of the West Siberian forest-steppe. Equally typical for the zone is a ridge-hollow relief with relative heights up to 40–60 m. These landforms, like most modern river valleys, have a common strike from the northeast to the southwest.

The river valleys are incised by only 10–15 m. -50 m/km2, and in the eastern part increases to 70-130 m/km2. The main source of river nutrition is melted snow water. With a friendly melting of snow, the flood on the rivers is short. In summer, the flow is very small, supported mainly by groundwater. The waters of some small rivers are saline at this time and cannot be used for water supply. Many rivers dry up. Transit rivers are Ob, Irtysh, Ishim and Tobol. Of these, only the Ob and the Irtysh remain full of water in the summer.

In the forest-steppe there are many shallow lakes with gently sloping shores, confined to suffusion-subsidence basins and depressions. Among them are fresh, brackish and salty. The composition of salts is dominated by soda lakes. Silts (mud) and waters of highly mineralized lakes are used for medicinal purposes. Due to the poor drainage of the surface, groundwater is shallow and often causes swamping in relief depressions. Since the thickness of the Quaternary deposits is small, and the primary Paleogene and Neogene strata are saline, groundwater is often saline. In the northern part of the zone, and where the thickness of the Quaternary deposits is significant, the upper horizons contain fresh groundwater.

The soil and vegetation cover of the zone is highly variegated due to poor drainage and the development of salinization and waterlogging processes, which are difficult to combine in space. On the drained interfluves and slopes under the meadow steppes, the most fertile soils were formed - fat chernozems. The humus content in them reaches 10–12% with a humus horizon thickness of about 50 cm. . To the south, fat chernozems are gradually replaced by ordinary ones. However, chernozems account for about 10% of the land area. On poorly drained interfluve plains and river terraces, with a shallow occurrence of fresh groundwater, the proportion of meadow species in the herbage increases and meadow-chernozem soils are formed. Virgin meadow steppes and steppe meadows have been preserved only in small areas.

Forest cover varies from 20-25% in the northern part of the zone to 4-5% in the south. The forests are mainly represented by aspen-birch groves and confined to depressions with malt or solonetsous soils. The warty birch predominates in the forests, well adapted to alkaline soils. Downy birch and aspen settle along the wettest parts of the pegs. Pine forests on soddy-podzolic and podzolic soils are common on sandy soils above the floodplain terraces. In complex with chernozems and meadow-chernozem soils, solonetzes and solonchaks are also combined, confined to depressions and other depressions of the relief with a sparse herbage of solonetz meadows from licorice, askitsa, large plantain, astragalus, and solonchak meadows with saltwort and other halophytes.

Among the forest pegs and plowed steppe massifs, there are widespread large-grass bogs (reed, sedge-reed, large sedge) lowland bogs that appear on the site of overgrown lakes (zaimishches) in the northern subzone of the forest-steppe. In addition to them, there are convex sphagnum peat bogs overgrown with oppressed pine and birch - ryams. River floodplains are covered with large-grass meadows. On the terraces there are solonchak meadows with solonchak barley and butlachka. The fauna of the forest-steppe consists of the inhabitants of forests and steppes. The most typical rodents are ground squirrels, hamsters, ground hare, voles. Foxes, weasels, white polecats, ermines, black grouses, white and gray partridges are common in the pegs. Elk, teleutka squirrel, roe deer, hares - hare and hare acclimatized here are found in the forests. Gray ducks, geese, gulls, coots, and whooper and mute swans nest on the lakes. There are many birds of prey on the banks. The water rat and muskrat also live in reservoirs. Many of the reservoirs are rich in fish, including acclimatized bream and pike perch.

Introduction

Two species grow on the territory of Siberia: Siberian spruce (P. obovata) and Ayan spruce (P. ajanensis). Depending on growing conditions and other natural factors, the tree has a number of morphobiological forms. Outwardly, they mainly differ in the color of the needles. It can be green, silver, golden or bluish-gray. The last of these varieties is considered the rarest.

The emergence of similarities and differences environment affects the process of realization of inherited traits, in particular, genetics finds out in spruces.

The importance of genetics is great for agriculture and forestry. It serves as a theoretical basis for the selection of agricultural plants and animals. The task of breeding is to change the hereditary properties of plants and animals, to create varieties and breeds that allow you to get the maximum amount of products of the best quality and meet the needs of agricultural production.

Genetics is of great importance for both medical and agricultural immunology. Specific knowledge in this area makes it possible to conduct a directed fight against hereditary diseases and pathogens of agricultural plants and animals.

Natural characteristics of Siberia

Territories of Siberia. Natural zones of Siberia

The territory of Siberia is traditionally divided into two parts: Western Siberia and Eastern Siberia. Western Siberia includes: Tyumen Region, Altai Territory, Kemerovo Region. To Eastern Siberia belong: the Taimyr Territory, the regions of Tungus, Yakutia, Transbaikalia, the Irkutsk Region and the Republic of Buryatia.

Western Siberia is a lot of lakes and rivers, with small areas of taiga. The Tyumen Region is located on the West Siberian Plain. The Yamal and Gydan Peninsulas in Siberia are completely covered with tundra vegetation. Their height above sea level is only 10 - 20 meters. To the south of Siberia, the height of the territories rises to 100 - 150 meters. On the West Siberian Plain is the Siberian Uval Upland. Its height is about 285 meters above sea level. Further there is a large swampy valley of the Ob River. These places are rich in oil and natural gas.

About 700 thousand years ago there were glaciers on the territory of Western Siberia. northern part Western Siberia was often flooded by the sea. Here lived: big-horned deer, woolly rhinos and mammoths, whose tusks are still found on the territory of Yamal and the Gydan Peninsula. As a result of global cooling in Western Siberia, a region of permafrost has turned out. In the northern regions, the ground was frozen to 450 meters. Only under the reservoirs the earth did not freeze. In the more southern regions of Western Siberia, permafrost has become two-layered: ancient permafrost, located at a depth of 150-400 meters, and modern permafrost.

Between these layers there is an area of ​​thawed soil. Such soils are very fragile for construction work.

There are several natural zones on the territory of Western Siberia. After the dark coniferous forests, there are small-leaved aspen-birch forests. They are replaced by forest-steppe, where both meadow herbaceous plants and birches grow. To the south of Western Siberia, the number of tree species decreases. Near the border with Kazakhstan, the landscape is an endless vast steppe. A large amount of land has been plowed up for growing agricultural products. Due to the fact that there are enough areas for pastures, animal husbandry is developed here.

In the southern part of Western Siberia, there are plains and lowlands in the area of ​​the Tobol, Irtysh and Ob rivers. In some places there are hills. This entire area is swampy. The Vasyugan plain is a continuous swamp, occupying vast territories. In the east of Western Siberia, the foothills of the Salair Ridge begin, and then the ridges of the Kuznetsk Altai. Altai mountains are the highest in Southern Siberia. They have an unusual relief. Mountain ranges come out of one center and diverge in different directions, like the rays of the sun.

The Putorana Plateau is located in the southern part of the Taimyr Territory. It is the highest part of the Central Siberian Plateau. The plateau is composed of layers of sandstone and igneous rocks. Numerous small valleys are lakes. Bolshoi Khantaysky is the largest lake with an area of ​​882 square kilometers. The deepest place of the lake reaches 420 meters.

Most of Central Siberia is located on the Central Siberian Plateau.

In almost 3 million square meters. km, flat flat terrain with small low ridges and continental climate contributed to the pronounced geographical zonality of its landscapes from the northern cold tundra to the warm southern steppes. The main territory here is occupied by forest-marsh dark coniferous taiga rugged landscapes.

On the coast and islands of the Kara Sea, the bays of the Ob, Baidaratskaya and Gydanskaya bays, on the Yamal and Gydan Peninsulas north of the Arctic Circle, there is a natural ecosystem of the northern cold tundra. A feature of the tundra is the widespread swampiness on permafrost soils and the complete absence of forests.

At first glance, it seems that the tundra does not caress the eye with lush vegetation and bright colors. But a person who looks closely at her harsh beauty cannot but be fascinated. Vibrant patches of growing plants in every hue from emerald green to olive, red, bright yellow and brown are seen everywhere.

The climate of the tundra is very severe, the long winter polar night is a serious test for animals and plants living in the tundra. Average January temperatures in the tundra are -22oC, -24oC. The absolute minimum can drop here to -51оС, -54оС. Cold northern winds further cool the flat area.

Summers are cool and very short, which led to a short growing season. Average temperatures in summer fluctuate from 0oC to +8oC, the maximum temperature on hot days can rise to +32oC, +34oC. The tundra blooms profusely and amicably, against the backdrop of solid moss, islands of partridge grass turn white in large lawns, forget-me-not and polar poppy, veronica and cyanosis, buttercups and yarrow bloom in carpets. Plants of the northern tundra spaces are most often undersized and creeping, propagated by rhizomes. Tree forms are also undersized, grow here dwarf species birches and willows.

The main food of numerous birds in the tundra is a huge number of mosquitoes and midges, there are so many of them that they can obscure the sun. Very prolific pied mice became food for predators and large birds. For the winter, they hide in deep snow, while feeding on the roots of plants. Reindeer, arctic foxes, hares, polar partridges and owls became characteristic animals for the tundra.

forest tundra

A forest-tundra zone stretches along the Arctic Circle from Salekhard to a narrow strip. This is, first of all, a transitional zone between the vast expanses of the tundra and the vast expanses of taiga in the south. Here the climatic conditions are milder, and among the tundra at first stunted trees rarely appear with a characteristic flag-shaped crown shape formed by the prevailing winds. To the south, there are more and more trees, and the forest-tundra ecosystem turns into typical taiga forests.

Taiga

The largest area of ​​up to 1,850 thousand square meters. km, located in a wide strip in Western Siberia, is occupied by s. They are located along the middle reaches of the Ob and the lower reaches of the Irtysh. Main coniferous trees taiga West Siberian forests are fir and spruce, cedar, pine and larch with an admixture of birch, aspen and alder. Boundless taiga wilds stretch here through colossal swamps and lowlands for thousands of kilometers. Urmans grow on more elevated areas - dense cedars, spruce and fir forests.


Under the dense palmate branches of trees in the Siberian taiga it is always damp, cool and gloomy. There are very few shrubs and grasses here, the ground is covered with a solid carpet of emerald green fluffy mosses and moisture-loving lichens. In the taiga there are a lot of windbreaks and dead trees dried on the vine with hanging tufts of gray lichens. In damp places, fern grows abundantly, fallen trees are covered with thick green moss. Broken branches hang intertwining on the trees, further obscuring the space between the trees.

The climate in the taiga is temperate continental with average January temperatures of -16oC, -24oC. The absolute minimum in vast taiga areas can drop to -48oC, -50oC. Cold northern winds already cool down the vast flat taiga space. Summer in the taiga is quite cool, the average temperature in July is +16oC and the absolute maximum is +38oC, +41oC. The main precipitation falls in the summer.

In the cool gloomy taiga forest, conditions are created for insufficient evaporation and therefore in the Siberian taiga zone the world's largest array of swampy ecosystems is located. In the crowns of the trees, the cheerful chirping of birds is heard, among which the gentle voices of warblers stand out. Down in the dusk it is very quiet, dark and damp.

The rays of the sun practically do not penetrate here. Only clouds of midges curl in the motionless frozen air. Yes, sometimes a woodpecker sits down with a sharp cry and knocks on dead trees, and a capercaillie will fall off a dry branch with a noise. Sometimes a squirrel will look curiously from behind the trunk and a striped chipmunk will flash by. But you can walk through the taiga wilds for tens of kilometers, and not see a single bird, not meet a single animal.

Only along the rivers, where alder and willow forests, birch forests with an admixture of mountain ash grow more sun, life is in full swing. Doves coo, warblers and warblers fumble in the bushes, magpies chirp loudly and cuckoos call. The chirping of birds stops only when a hawk appears nearby. Broods of capercaillie and hazel grouse come to the thickets of cranberries, lingonberries and blueberries, and the bear also comes here to “fatten”.

Moose graze in the lowland swampy taiga with abundant moisture-loving vegetation and young growth. deciduous trees. In hot weather, moose, in order to escape from the midges, climb into the water up to the very muzzle. During the long winter, the taiga is covered with deep snow for many months. He hangs with a hat from wide spruce paws, sprinkles unsteady swamps. Foxes, squirrels and ermines feast on the gifts of the generous forest.

mixed forests

In mixed forests, stretching in Western Siberia in a narrow strip from Yekaterinburg to, it is noticeably warmer. Average temperatures in January here range from +16oC to +18oC. The absolute maximum temperature can rise from +38°C to +40°C. With sufficient moisture in mixed forests, bushes and grasses grow violently in the undergrowth.

Mixed forests are more elegant and lighter, sometimes they consist of one type of tree, spruce or birch, aspen or pine. But more often in the forest stand are found conifers mixed with broadleaf. A mixed forest always consists of two tiers, pines and maples, candle-shaped firs and spruces, grow high towards the light, viburnum and walnut, wild apple trees and cherries grow below.

In the undergrowth there are a lot of berry bushes, raspberries, currants, wild roses, acacias and spireas. Below are whole clump thickets of oak veronica and lily of the valley, wild strawberries and stone berries. In the forest clearings, daisies turn white in a cloud, buttercups turn yellow, forget-me-nots are found.

The fauna of the mixed forest is richer than that of the taiga. Here you will no longer meet sables and a column, appear red deer, pine martens, minks, black ferrets and wild boars. In the crowns of trees, whistling melodiously, the oriole builds a nest. In spring, the forests ring with the voices of birds, finches, thrushes, siskins sing, wild pigeons coo. Lots of hedgehogs and badgers, hares and foxes. large forest predators are wolves, wolverines and brown bears.

forest-steppe

From Chelyabinsk to the upper reaches, a forest-steppe zone stretches in a wide strip across Western Siberia. This is also a transition zone from mixed forest to steppe, characterized by a more comfortable climate and sufficient annual moisture. Forests are gradually thinning out, remaining patches and birch groves along rivers and natural lake reservoirs.

Steppe

In the very south of the plain, partly in the Omsk region, partly in the zone of dry steppes is located. This is an absolutely flat area with low manes covered with grassy vegetation and lack of moisture. It is the adaptability to endure the lack of moisture that distinguishes steppe vegetation from meadow grasses.

The steppe is characterized by a continental climate with a short cold winter and long dry hot summers. Average winter temperatures in the steppe range from -14°C to -16°C. The absolute minimum in the steppe can drop to -49oC. In summer, average temperatures rise to +18°C, absolute to +40°C. The steppe is moistened only in spring with precipitation and snowmelt. In summer, little cages fall, up to 400 mm/year, which, with high evaporation, creates conditions for soil salinization and the formation of solonchaks.

The steppe landscapes are dominated by grass meadows with birch and aspen-birch cleft forests, feather grass rich herb, fescue-feather grass, fescue with halophytic wormwood and sagebrush nitrate communities, wormwood-fescue, quinoa and camphorosm plant communities on chestnut and, accordingly, dark chestnut soils.

The brightly flowering steppe is especially beautiful in May and on a bright sunny June day in the morning. All the flowers turned their corollas strewn with sparkling dew drops towards the sun and opened their buds to the maximum. In an hour, another picture will change dramatically, under the rays of the rising bright sun, the flowers close the corollas by noon, and the steppe will fade.

The air above the steppe is filled with the buzzing and chirping of countless insects, bees, bumblebees, grasshoppers. Silently, but very beautifully, butterflies of various colors flutter, gophers whistle. And above, spreading its wings, a hawk looks out for prey.

Large expanses of steppes on fertile soils in Western Siberia have been plowed up. It was here in the steppes of East Kazakhstan that the virgin lands came, developed and plowed the steppes, built villages and roads. And today the steppes of Western Siberia are the breadbasket of the country.

North-Eastern Siberia is located east of the Lena valleys and the lower reaches of the Aldan, from the Verkhoyansk Range to the shores of the Bering Sea and is washed by the seas of the Arctic and Pacific Oceans in the north and south. It is located in the eastern and western hemispheres. The extreme eastern point of Russia and all of Eurasia - Cape Dezhnev - is located on the Chukotka Peninsula.

The geographical position in the subpolar and polar latitudes near the cold seas and the dissected relief with a semi-circular orographic barrier from the south, west and east and a slope to the north predetermined the harsh natural conditions of the country with bright, unusually contrasting physical and geographical processes, typical only for this territory.

North-Eastern Siberia is a country of young and ancient structures expressed by mountain systems, ridges, highlands, plateaus, coastal and intermountain plains. The relief combines ancient glacial forms and modern mountain glaciers, deep terraced valleys with numerous thermokarst lakes. The subarctic climate prevails, almost continuous permafrost, fossil ice and giant icing - taryns are developed. Here, many rivers freeze to the bottom in winter, and in some valleys, on the contrary, sub-frost warm waters come out and feed non-freezing watercourses all winter. Sparse larch taiga and thickets of Siberian dwarf pine are widespread. Large areas are occupied by plain and mountain tundra. There are areas of steppe vegetation up to the north of the Chukotka Peninsula. All these are specific features of the nature of the Northeast as an independent physical and geographical country.

Geological structure

Northeastern Siberia belongs to the area of ​​Mesozoic folding. The direction of the Mesozoic structures was significantly influenced by ancient massifs - Paleozoic and pre-Paleozoic - located within the Northeast and in neighboring territories. The intensity and direction of tectonic processes in the Mesozoic time depended on their stability, tectonic activity and configuration. In the west, the Northeast borders on the Siberian Precambrian platform, eastern edge which had a decisive influence on the direction and intensity of folds in the Verkhoyansk anticline zone. Mesozoic folding structures were formed in the Early Cretaceous as a result of the collision of the ancient Siberian continent with the microcontinents of Chukotka and Omolon.

On the territory of the Northeast there are rocks of different ages, but Mesozoic and Cenozoic are especially widespread. The protrusions of the pre-Riphean base are composed of gneisses, granite-gneisses, crystalline schists and marbled limestones and are overlain by Paleozoic and Mesozoic deposits. They are located in the northeastern and southeastern parts of the Chukotka Peninsula (Chukotka Massif), in the upper reaches of the Omolon River (Omolon Massif), on the Taigonos Peninsula (Taigonossky Massif) and in the basin of the Okhota River (Okhotsk Massif). In the central part of the North-East is the Kolyma massif. It lies at the base of the Alazeya and Yukagir plateaus, the Kolyma and Abyi lowlands. Its pre-Riphean basement is overlain by Paleozoic and Mesozoic marine and continental deposits. Outcrops of Mesozoic granitoids are developed along the edges of the Kolyma massif.

Between the ancient massifs and the Siberian platform, there are geostructures of the Mesozoic folding. Mesozoic folded areas and ancient massifs are bordered from the south and east by the Okhotsk-Chukotka volcanogenic belt. Its length is about 2500 km, width - 250-300 km. All rocks within it are broken through and overlain by dislocated volcanogenic formations of the Lower and Upper Cretaceous, the thickness of which reaches several thousand meters. Cenozoic effusive rocks are poorly developed and distributed mainly off the coast of the Sea of ​​Okhotsk. The emergence of the Okhotsk-Chukotka belt is apparently associated with the subsidence and fragmentation of the marginal part of the Mesozoic land in connection with the movements of the continental Eurasian, North American and Pacific oceanic lithospheric plates.

Mesozoic-Cenozoic magmatism covered vast territories of the North-East of Siberia. The metallogeny of this region is associated with it - numerous deposits of tin, tungsten, gold, molybdenum and other metals.

After the completion of folding, the uplifted territory of the Northeast was subjected to erosion. In the Upper Mesozoic and Paleogene, there apparently was a hot climate. This is confirmed by the composition of plant remains (broad-leaved and evergreen forms) of the Upper Mesozoic and Paleogene deposits, the coal content of these deposits, and the presence of a weathering crust of the lateritic type.

In the Neogene, under conditions of tectonic quiescence, the formation of alignment surfaces takes place. The subsequent tectonic uplifts led to the dismemberment of the alignment surfaces, their displacement to different heights, and sometimes to deformation. The marginal mountain structures and the highlands of Chersky rose most intensively, and some coasts sank below sea level. Traces of marine transgressions are known in the mouths of the rivers of the eastern part of the Chukotka Peninsula. At this time, the northern shallow part of the Sea of ​​Okhotsk sank, the land of Beringia, the New Siberian Islands separated from the mainland.

Volcanic eruptions occurred along the faults. The volcanoes are confined to a band of tectonic faults stretching from the Momo-Selennyakh depression to the Kolyma valley. The depression arose as a rift zone at the site of the Eurasian Plate and the Chukotka-Alaska block of the North American Plate moving apart. It extends, apparently, from the Arctic Ocean from the rift of the Gakkel Ridge to young depressions that cut through the Chersky Highlands. This is one of the seismic zones of Russia.

The uplift and subsidence of individual land areas led to increased erosion-accumulation activity: rivers deeply eroded mountain systems and created terraces. In their alluvial strata there are placer deposits of gold, tin and other minerals. In the river valleys of the North-East, there are up to ten terraces from 2-5 to 400 m high. Terraces up to 35-40 m high were formed in the post-glacial period. Interceptions of rivers are associated with the change in erosion bases.

Thus, in the development of the relief of the Northeast after the Mesozoic mountain building, two periods can be outlined: 1) the formation of widespread leveling surfaces (peneplains); 2) the development of intense newest tectonic processes that caused splits, deformation and displacement of ancient alignment surfaces, volcanism, violent erosion processes. At this time, the formation of the main types of morphostructures occurs: 1) fold-block areas of ancient median massifs (Alazeya and Yukagir plateaus, Suntar-Khayata, etc.); 2) mountains revived by the latest arch-block uplifts and depressions of the rift zone (Momo-Selennyakh depression); 3) folded and blocky-folded Mesozoic structures (mountains Verkhoyansk, Sette-Daban, Anyui, etc., Yansk and Elga plateaus, Oymyakon highlands); 4) stratal-accumulative, sloping plains created mainly by subsidence (Yano-Indigirskaya and Kolyma lowlands); 5) fold-block ridges and plateaus on the sedimentary-volcanic complex (the Anadyr Plateau, the Kolyma Highlands, the ridges - Yudomsky, Dzhugdzhur, etc.). As you can see, neotectonic movements determined the main plan of the modern relief.

By the beginning of the Quaternary glaciation the territory had a dissected relief with significant contrasts in heights. This had a significant impact on the development various types glaciation. On the plains and in the mountains of the Northeast, traces of several ancient glaciations are known. Many researchers have been and are studying the ancient glaciation of this territory, but there is still no consensus on the number and types of glaciation, the size of ice sheets, their relationship with the glaciations of Siberia and all of Eurasia.

According to V.N. Saksa (1948), three glaciations existed in the mountains and on the plains: maximum, Zyryansk and Sartan. In the work of D.M. Kolosov (1947) it is said that two types of ancient glaciation existed in the territory of the North-East - mountain and plain cover.

Glaciations developed differently on different forms of relief, and therefore several types of mountain glaciation were formed. Glaciation of mountain ranges was expressed in the development valley glaciers with ice gathering in cirques and through valleys on passes (the length of glaciers reached 300-350 km). On separate mountain domes formed ice caps, from which valley glaciers departed along the radii. On the plateaus developed huge pass ice fields combined with valley glaciers of dissected plateaus. On the highlands, glaciation took on a diverse character: ice collections formed on the tops of mountain ranges and massifs, glaciers descended along the slopes of the ridges and then emerged on the surface of the plateau base, and even lower valley glaciers descended to the edge of the plateau base. At the same time, under the influence of climate in different parts of the mountains, the same types of mountain glaciation reached different stages of development. Glaciation of the outer edge of mountain structures, which is under oceanic influence, developed to the maximum. On the same slopes of the mountains, modern glaciation of the southern parts of the Chersky and Verkhoyansk mountain systems also develops.

For the northern plains, one glaciation is assumed, which was preserved as a relic of the Lower Quaternary ice sheet until the end of the Pleistocene. The reason for this is that there were no conditions for a complete interglacial. Several glacial and interglacial epochs have been noted in mountain structures. Their number has not yet been established. There is an opinion about a double glaciation, and many authors reject the existence of glaciation on the northern plains east of the Lena. However, a number of authors (Groswald M.G., Kotlyakov V.M. et al., 1989) convincingly prove the spread of the Zyryansk ice sheet on the Yano-Indigirskaya and Kolyma lowlands. Glaciers, in their opinion, descended south of the New Siberian Islands and the East Siberian Sea.

In the mountains of the Northeast, glaciation, depending on the relief, had a different character: semi-cover, valley-reticulate, valley-car and car. During their maximum development, the glaciers came out onto the foothill plains and shelves. The glaciation was synchronous with the glaciations throughout Siberia and, apparently, was caused by global climate fluctuations.

The morphological and geological activity of glaciers and their melt waters in a cold continental climate and permafrost determined the main types of morphosculpture and Quaternary deposits throughout the territory. The mountains are dominated by relic cryogenic-glacial denudation morphosculptures with erosion processing and Upper Pleistocene glacial deposits, above which colluvial accumulations of different ages are distributed along the mountain slopes. The plains are covered with lacustrine-alluvial deposits with cryogenic and erosive landforms.

Relief

For the North-East of Russia, unlike other physical and geographical countries of Siberia, sharp orographic contrasts are characteristic: medium-altitude mountain systems predominate, along with them there are plateaus, highlands and lowlands.

In the west, the Verkhoyansk mountain system serves as the country's orographic barrier. To the south of Verkhoyansk, the Sette-Daban and Yudomsky ridges extend, separated by the Yudomo-Mai highlands, and further along the coast of the Sea of ​​Okhotsk, the Dzhugdzhur ridge passes. The eastern part of the Verkhoyansk Mountains in the north-western direction stretches for 1800 km, the Chersky ridge.

Between the Chaun Bay and the Sea of ​​Okhotsk there is a medium-altitude mountain system, consisting of numerous, differently oriented ridges. All this marginal system of mountains and highlands forms the eastern and southern orographic barriers for the interior regions of the Northeast. The main Pacific-Arctic watershed passes through them, on which the maximum heights of about 2000 m are concentrated. Between the mountains there are deep tectonic basins that go to the sea or are separated from it by a mountain barrier. The intermountain basins are lowered by 1000-1600 m in relation to the watersheds. The Eastern Chaun Bay, and the Chukchi Highland with heights of 1600-1843 m extends to the shores of the Bering Strait. It also serves as a watershed of two oceans.

In the interior regions of the North-East there are large highlands and plateaus: Yukagirskoe, Alazeiskoe, Oymyakonskoe, etc. The lowlands occupy coastal territories or enter the intermountain spaces to the south as narrow "bays".

Thus, the Northeast is a huge amphitheater, tilted towards the Arctic Ocean. A complex combination of large landforms is predetermined by the long history of the development of this largest peninsula of Eurasia, located in the contact zones of the main continental and oceanic lithospheric plates of the Earth (Eurasian, North American and Pacific).

Climate

The climate of the North-East of Siberia is sharply continental. Many factors influence its formation. A large extent of the territory from north to south between 73 and 55 ° N. latitude. predetermines the uneven arrival of solar heat: a large amount of solar insolation in summer and its almost complete absence in most of the territory in winter. The structure of the relief and the cold water areas surrounding the territory determine the free penetration of cold continental arctic air masses of the Arctic Ocean. Sea air comes from the Pacific Ocean temperate latitudes, which brings the main amount of precipitation, but its entry into the territory is limited by coastal ridges. The climate is influenced by the Asian maximum, the Aleutian minimum, as well as circulation processes on the Arctic front.

The North-East is located in three latitudinal climatic zones: arctic, subarctic and temperate. Most of the territory is located in the subarctic zone.

harsh winter The northeast of Siberia lasts about seven months. To the north of the Arctic Circle comes the polar night. On the Arctic coast, it lasts from mid-November to the end of January. At this time, the Arctic Northeast does not receive solar heat, and south of the Arctic Circle, the sun is low above the horizon and sends little heat and light, so the radiation balance is negative from October to March.

The northeast becomes very cold in winter, and an area of ​​high pressure forms there, which is the northeast spur of the Asian High. The mountainous relief also contributes to the strong cooling of the territory. Cold and dry arctic air is formed here. The Arctic front runs along the coast of the Sea of ​​Okhotsk. Therefore, the anticyclone type of weather with a predominance of calm and very low temperatures is typical for intermountain basins and valleys. Isotherms of the coldest month -40...-45°C outline many intermountain basins. In the areas of Verkhoyansk and Oymyakon, the average temperature in January is about -50°C. The absolute minimum temperature reaches -71°С in Oymyakon, and -68°С in Verkhoyansk. The interior regions of the Northeast are characterized by temperature inversions. For every 100 m rise, winter temperatures rise here by 2°C. For example, in the basin of the upper part of the Indigirka on the Oymyakon highland and on the adjacent slope of the Suntar-Khayata ridge average temperature January at an altitude of 777 m is -48°С, at an altitude of 1350 m it is already -36.7°С, and at an altitude of 1700 m it is only -29.5°С.

To the east of the Omolon valley, winter temperatures increase: an isotherm of -20°C passes through the eastern part of the Chukchi Peninsula. On the coastal plains in winter it is warmer than in the Verkhoyansk region, by about 12-13°C. In the mountains, tundra and on the coast of the Sea of ​​Okhotsk, low temperatures are combined with strong winds. Cyclonic activity is manifested on the Okhotsk coast and Chukotka in connection with the development of the Arctic front.

In the interior regions of the Northeast, all types of frosty weather are formed in winter, but weather with increased frostiness (heavy, hard and extremely frosty) prevails. On the coast, the weather is more common moderately and significantly frosty. The windy and frosty weather characteristic of these areas creates a significant severity of winter in coastal areas.

A stable snow cover lasts 220-260 days, its height is about 30 cm on the coast of the Laptev Sea and in the Verkhoyansk region; to the east and south, it increases to 60-70 cm, on the windward slopes of the mountains of the Okhotsk-Chukotka arc it reaches 1-1.5 m. During the period of maximum snow accumulation (March-April), avalanches descend in all mountains. The areas with significant avalanche danger include the Verkhoyansk and Chersky mountain systems. There, in many places, avalanches are widespread and descend all year round. Favorable conditions for avalanches are a sufficient amount of precipitation in the mountains and its redistribution under the influence of strong winds (the creation of multi-meter snow walls and snow cornices), intense solar insolation in summer, which contributes to the recrystallization of snow into firn, slight cloudiness and forest cover on the slopes, as well as the distribution clay shales, the moistened surface of which contributes to the sliding of avalanches.

Summer the influx of solar heat increases. The territory is filled mainly with continental air of temperate latitudes. The Arctic front passes over the northern coastal lowlands. Summer in most of the territory is moderately cool, and in the tundra it is cloudy, cold, with a very short frost-free period. In the mountains from a height of 1000-1200 m, there is no frost-free period, strong winds prevail and temporary snow cover can form in all summer months. The average July temperature in most of the territory is about 10°С, in Verkhoyansk 15°С. However, on some days the temperature can rise up to 35°C in the inner intermountain basins. With the invasion of arctic air masses, warm weather can be replaced by cold snaps, and then the average daily temperature drops below 10°C. In the coastal lowlands, summers are cooler than in the interior. The weather is changeable, with strong winds. The sum of active temperatures reaches a maximum in the basins, but at the same time it is only 600-800°C.

The following types of weather are typical for the summer period: cloudy and rainy, with daytime cloudiness with strong heating of the underlying surface; with night cloudiness (typical for coastal areas). In July, up to 10-12 days in the basins, there is little cloudy dry weather. Many mountainous regions are characterized by frosty weather during the period of advective cooling.

Summer precipitation is highly variable from year to year. There are dry years and wet, rainy years. So, in Verkhoyansk for 40 years of observations, the minimum amount of precipitation was 3 mm, and the maximum 60-80 mm.

The distribution of annual precipitation over the territory is determined by atmospheric circulation and topography. The Pacific Basin receives a lot of precipitation when southerly and southeasterly air currents predominate. Therefore, the largest number of them (up to 700 mm per year) is received by the eastern slopes of the mountains of the Taigonos Peninsula and the southern slopes of the Okhotsk-Kolyma watershed. In the basin of the Arctic Ocean, precipitation falls with the arrival of northwestern air masses.

The greatest number of them is received by the western slopes of the Verkhoyansk mountain system and Suntar-Khayat (718 mm at an altitude of 2063 m), in the mountain system of the Chersky ridge - 500-400 mm. Intermountain basins and plateaus, as well as the coast of the East Siberian Sea, receive the least amount of precipitation per year - about 200 mm (in Oymyakon - 179 mm). The maximum precipitation falls on a short warm period of the year - July and August.

Modern glaciation and permafrost

Modern glaciation developed in many mountain systems: the Suntar-Khayat, Verkhoyansk, Chersky (Ulakhan-Chistai) ridges and the Chukchi Highlands. The total area of ​​glaciation formed by glaciers and large snowfields is about 400 km2. The number of glaciers is more than 650. The largest center of glaciation is the Suntar-Khayata ridge, where there are more than 200 glaciers with a total area of ​​approximately 201 km2. The largest number of glaciers is concentrated in the mountains of the Indigirka basin. This is due to the high altitude of the mountains, the dissection of the relief and the abundance of snow.

The formation of glaciation is greatly influenced by moist air masses coming from the Pacific Ocean and its seas. Therefore, this entire territory is assigned to the glaciological region of predominantly Pacific nutrition.

The snow line in the Indigirka basin runs at an altitude of 2350-2400 m, on the Suntar-Khayat glaciers it reaches about 2200-2450 m. The ends of the glaciers are in the Indigirka basin at an altitude of about 2000 m. Numerous snowfields are located at various levels. The most common are car and valley glaciers. The length of the glaciers is up to 8 km. There are many hanging glaciers on the steep, steep slopes of the mountains. The glaciers are currently shrinking. This is evidenced by the division of large glaciers into smaller ones and the retreat of glacier tongues from the terminal moraine to a distance of 400-500 m. However, some glaciers advance, overlap even the terminal moraine and descend below it.

The modern harsh climate favors conservation and development permafrost(underground glaciation). Almost the entire Northeast is covered with low-discontinuity (practically continuous) permafrost, and only small areas of the coast of the Sea of ​​Okhotsk have patches of permafrost among the thawed soil. The thickness of frozen soil reaches 200-600 m. The greatest freezing of soil with minimum temperatures is in the middle part of the country, in its mountainous region - from Lena to Kolyma. There, the permafrost thickness is up to 300 m under the valleys and 300-600 m in the mountains. The thickness of the active layer is determined by the exposure of slopes, vegetation, local hydrological and climatic conditions.

Water

Rivers from the territory of the North-East they flow into the Arctic and Pacific Oceans. The watershed between them runs along the Dzhugdzhur, Suntar-Khayat, Kolyma Uplands, Anadyr Plateau and Chukotka Highlands, therefore, the watershed is close to the Pacific Ocean. The largest rivers - Kolyma and Indigirka - flow into the East Siberian Sea.

River Kolyma begins on the slopes of the southern ranges of the Chersky mountain system, has a length of 2130 km and a basin area of ​​​​about 643 thousand km 2. Its main tributary - the Omolon River - has a length of 1114 km. The flood of the rivers of the entire basin occurs in June, which is associated with the melting of snow. The water level is high at this time, since there is much more snow in its basin than in the Yana and Indigirka basins. The high level is partly due to ice jams. The formation of powerful floods is associated with heavy rains, especially in early summer. The winter runoff of the river is negligible. The average annual water consumption is 4100 m 3 / s.

River Indigirka originates on the slopes of the Suntar-Khayat ridge, flows through the Oymyakon highland, cuts through mountain system Chersky through deep gorges and goes into the Momo-Selennyakh depression. There it receives a large tributary - the Moma River and, going around the Momsky Range, goes to the Abyskaya lowland, and then to the Yano-Indigirskaya. The length of the river is 1726 km, the basin area is about 360 thousand km2. Its main tributaries are the Seleniekh and Moma rivers. The Indigirka is fed by snow and rain waters, melting snowfields and glaciers. The rise of water and the main runoff (about 85%) occurs in spring and summer. In winter, the river is shallow and in some places on the plain it freezes to the bottom. Average annual flow is 1850 m 3 / s.

River Yana begins in the Verkhoyansk mountains and flows into the Laptev Sea. Its length is 879 km, the area of ​​the basin is 238 thousand km2. In places it flows through wide ancient valleys filled with alluvium. In coastal cliffs there are outcrops of fossil ice. Ice intrusions - hydrolaccoliths - are widespread in lacustrine-alluvial deposits. The spring flood is weakly expressed, since an insignificant amount of snow falls in the Yana basin. Flood usually occurs in summer when it rains. The average annual water consumption is about 1000 m 3 /s.

The rivers Kolyma, Indigirka and Yana at their confluence form vast low-lying marshy deltas with numerous small lakes. In deltas, buried ice occurs at a shallow depth from the surface. The area of ​​the Yana delta is 528 km 2 , the Indigirka  7700 km 2 . In the mountains, the rivers have predominantly narrow valleys, rapid current, thresholds. In the lower reaches, all the valleys are wide, the rivers flow through the vast marshy lake lowlands.

The rivers of the North-East freeze in October and break up in late May - early June. The water temperature reaches 10°C, but in some places in June-August it can rise to 20°C. In many areas in the lower reaches, the rivers freeze to the bottom in winter. An interesting and important feature of the winter regime of the rivers of the Northeast  wide distribution of ice(in Yakut - taryns).

Ice is a complex geographical concept. It develops under a combination of hydrological, climatic, permafrost and other conditions. But the icing itself affects the morphology, the nature of the deposits, the microclimate and vegetation of the valley, and also creates its own natural complex.

The ice floes of the Northeast are among the largest in the world. Some of them occupy areas over 100 km2. Their most intense formation occurs in tectonically mobile areas, where they are associated with places of rock disturbances caused by faults. Frosts grow throughout the winter, filling riverbeds and floodplains, especially in the mountainous areas of the Yana, Indigirka and Kolyma basins. The largest of them - Momskaya ice - is located on the river Moma and has an area of ​​150 km2. Almost all large ground icings are fed by subpermafrost waters that emerge along the lines of tectonic faults. Powerful ascending springs in places of tectonic fracturing overcome the cooled layer of soil, come to the surface, form ice and feed them all winter even at frosts of -40°C and below. In summer, large ice fields remain for a long time, and some remain for the next winter.

The ice floes contain a large amount of water, which in summer enters the rivers and is an additional source of their nutrition. In winter, polynyas form on some mountain rivers. Their occurrence is also associated with the outflows of warm subpermafrost waters. Fog and frost form over them and ice floes. The sources of subpermafrost waters, especially in winter, are of great practical importance for the water supply of the population and the mining industry.

All major rivers of the Northeast are navigable in their lower reaches: the Kolyma - from the mouth of the Bakhapchi River (Sinegorye village), the Indigirka - below the mouth of the Moma River, and along the Yana ships go from Verkhoyansk. The duration of navigation on them is 110-120 days. The rivers are rich in valuable species of fish - nelma, muksun, whitefish, sturgeon, grayling, etc.

Lakes. In the lowlands, especially in the lower reaches of the Yana, Indigirka, Alazeya and Kolyma, there are a lot of lakes and swamps. Most lake basins are of thermokarst origin. They are associated with the thawing of permafrost and ground ice. The lakes freeze in September - early October and are covered with thick ice (up to 2-3 m) for a long winter, which leads to the frequent formation of kills and the death of the ichthyofauna. The melting of ice occurs in May and early June, and floating ice on large lakes occurs in July.

Soils, vegetation and wildlife

A variety of physical and geographical conditions (mountainous and flat terrain, low air and soil temperatures, different amounts of precipitation, a small thickness of the active layer, excessive moisture) contribute to the formation of a motley soil cover. Severe climatic conditions and permafrost retard the development of chemical and biological weathering processes, and therefore soil formation is slow. The soil profile is thin (10-30 cm), cartilaginous, with a low content of humus, peaty and moist. Common in the lowlands tundra-gley, humus-peat-bog and gley-taiga permafrost soils. On floodplains of river valleys developed floodplain humus-soddy, permafrost-gley or permafrost-marsh soils. In the floodplains of tundra rivers, permafrost occurs at a shallow depth, sometimes layers of ice protrude in coastal cliffs. The soil cover is poorly developed.

In the mountains under the forests prevail mountain podburs, taiga permafrost soils, among which on gentle slopes are found, gley-taiga permafrost. On the southern slopes, permafrost-taiga soils with slight podzolization are common. In the mountains of the Okhotsk coast dominate mountain podzolic soil. In the mountain tundra, underdeveloped coarse skeletal structures are formed. mountain tundra soils, passing into stony placers.

Vegetation North-East of Siberia consists of representatives three floras: Okhotsk-Kamchatka, East Siberian and Chukchi. The most diverse in terms of species composition is the Okhotsk-Kamchatka flora, which occupies the coast of the Sea of ​​Okhotsk. Most of the mountains are covered with sparse northern taiga forests and mountain tundra. The lowlands are occupied by tundra, turning into forest-tundra.

The history of the development of the Northeast and adjacent territories (the ancient lands of Beringia, Okhotia and Eoarctic, connecting the Northeast with Alaska), as well as the climate predetermined the modern appearance of the vegetation cover of the tundra, forest tundra and taiga, therefore, in terms of species composition, they differ from similar zones of neighboring territories Siberia.

On the far north, on the coastal lowland, located tundra. Lichen tundras are not typical for it, since clay soils are strongly waterlogged and marsh-peat and peat-gley soils predominate. The tussock-hypnum-sphagnum tundra dominates here. Its surface is formed by dense tufts of cotton grass. The height of the herbage is up to 30-50 cm. The tussock tundra occupies approximately 30-50% of the area of ​​tundra groups. Uneven thawing and freezing of the soil leads to deformation of the soil, rupture of the soil and the formation of bare spots around the tussocks (0.5-1 m in diameter), in the cracks of which mosses, lichens, saxifrage, creeping polar willow huddle.

South streak is coming forest-tundra. It is formed by shrubs of alder, willow, birch, which alternate with tufts of cotton grass and with individual specimens of the oppressed Cajander larch.

All the rest of the plains and lower parts of the mountains covered larch forests on gley-taiga abominable soils and mountain taiga podburs. The main forest-forming tree species is Cajander larch. Of the deciduous species in the floodplain forests, there are fragrant poplar and relic Korean willow Chozenia. Pine and spruce are distributed only on the southern slopes of the mountains of the Verkhoyansk Range and rise into the mountains only up to a height of 500 m.

In the undergrowth of larch forests, elfin cedar, shrubby alder, bluecurrant, or wild grouse, thickets of birches - Middendorf and lean; the ground cover consists of lingonberry shrubs, crowberries and lichens. There are few lichens on the northern slopes; mosses dominate there. The highest larch forests grow on the slopes of the southern exposure. On the slopes of the northern exposure, forest-tundra is predominantly distributed.

On the slopes of the southern exposure of valleys and high terraces, steppe plots. They are known in the wide valleys of the Yana (between the mouths of its tributaries the Dulgalakh and the Adycha), the Indigirka (in the mouth parts of the Moma, etc.), and the Kolyma, as well as in the Chukchi tundra. The vegetation of the steppes on the slopes consists of steppe sedge, bluegrass, tipa, couch grass, herbs - veronica, cinquefoil. Under the steppes, thin gravelly soils, close to chestnut ones, have formed. On the floodplain terraces there are grass-forb steppes, developing in drained areas, and sedge-grass-forb steppes, located in the most low places. Among the steppe vegetation, local species are distinguished, genetically related mainly to the vegetation of the mountainous regions of the South and Central Siberia, other species came along the river valleys from Central Asia during the warm interglacial period, and species that have survived from the “tundra-steppe” past of the Beringian North.

The predominance of mountainous terrain within the Northeast determines altitudinal zonality in the placement of vegetation. The nature of the mountains is extremely diverse. It determines the structure of the zonality of each system, while maintaining the general type of altitudinal belts, which are characteristic only for the North-East of Siberia. They are clearly shown on maps of soils and vegetation, as well as on the altitudinal zonality diagram. Altitudinal zonality in the lower parts of the slopes begins with light coniferous taiga (except for the Kharaulakh Mountains and the Chukotka Highlands), but it does not rise high into the mountains: in the Chersky ridge system - up to 650 m, and in the Dzhugdzhur ridge - about 950 m. Above the taiga, a closed shrub belt forms cedar elfin up to 2 m high with an admixture of dwarf dwarf birch.

Northeast  one of the main places of growth cedar dwarf a nut-bearing plant that has adapted to the harsh subarctic climate and thin gravelly soils. Its life forms are different: bushes 2–2.5 m high grow along the river valleys, and single-trunked trees spread on the summit plateaus and hills. With the onset of frost, all branches are pressed to the ground, and they are covered with snow. In spring, the warm rays of the sun “raise” them. Elfin nuts are small, thin-shelled and very nutritious. They contain up to 50-60% oil, a large amount of protein, vitamins of group B, and young shoots of the plant are rich in vitamin C. On the slopes of hills and ridges, dwarf elfin is an important flow regulator. Dwarfs are favorite places for many animals of all altitude zones; they find shelter and abundant food here.

At the upper limits of the belt, the elfin gradually thins out, more and more pressed to the ground and is gradually replaced by mountain tundra with stony placers. Above 800-1200 m, tundra and cold deserts dominate with many snowfields. The tundra also descends in separate patches into lower belts - elfin cedar and larch woodlands.

There is no such combination of altitudinal belts in any of the mountain systems of Russia. The proximity of the cold Sea of ​​Okhotsk determined the decrease in altitudinal belts in the coastal ridges, and even at the foot of the mountains of the Taigonos Peninsula, cedar tundras give way to hummocky ones - analogues of the northern lowland tundras (this occurs at the latitude of southern Timan and the north of Lake Onega).

Animal world Northeast Siberia belongs to the Arctic and European-Siberian subregions of the Paleoarctic region. The fauna consists of tundra and taiga forms. However, many animal species typical of the taiga do not inhabit the eastern Verkhoyansk Mountains. The fauna of the Chukchi Peninsula is very similar to the fauna of Alaska, since the Bering Strait was formed only at the end of the Ice Age. Zoogeographers believe that the tundra fauna formed on the territory of Beringia. The elk of the Northeast is close to the elk North America. White-tailed goose breeds on the Chukchi Peninsula, and winters off the rocky coasts of Alaska and the Aleutian Islands. Endemic to the Northeast and Alaska are guillemots. Dalliya (black pike) from the salmon order is found in small rivers, lakes and swamps of the Chukchi Peninsula and in northwestern Alaska. This is the most frost-resistant breed of fish. In winter, when water bodies freeze, it burrows into the ground and hibernates there in a frozen state. In the spring, the dallium thaws and continues to live normally.

Mountain-tundra animal species penetrate far to the south along the loaches, into the forest zone. Of these, the most typical is the endemic yellow-bellied lemming, which does not penetrate east of the Indigirka. Next to them, in the mountain tundra of the North-East, animals of open spaces of Central Asian origin live. They penetrated here in the xerothermal period and are now preserved here. These include, for example, the black-capped marmot (tarbagan). In the cold season (eight to nine months), he falls asleep in burrows located in permafrost. For the same long period, the Kolyma ground squirrel, an inhabitant of the forest zone, also falls asleep. Up to the Lena Delta, a mountain finch penetrated through open high-mountain landscapes. Of the predators in the taiga, there are a bear, a fox, an ermine. Sometimes there are lynx and wolverine. The sable was almost completely destroyed. But now it has been restored and in the basins of the Kolyma, Oloy, Yana and on the Koni Peninsula there are separate centers of its habitat.

Of the ungulates, wild reindeer is widespread in the taiga and tundra, and elk in the taiga. Musk deer are found on the rocky forest slopes of the mountains. The bighorn sheep (Chukotian subspecies) lives in the mountain tundra. It lives at altitudes from 300-400 to 1500-1700 m and prefers rocks when choosing sludge. Of the rodents in the mountain forests, the squirrel is common, which is the main food animal. In the past, the Asian river beaver lived in the basins of the Kolyma and Omolon, the northern limit of its distribution was about 65 ° N. At present, small rodents are diverse - the red-backed vole, the root vole, the wood lemming, and the northern pika. The white hare is common in the thickets of river valleys.

Of the birds, it should be noted the stone capercaillie, hazel grouse, scura, kukshu, nutcracker and tundra partridge living on stone placers. A very beautiful bird - the pink gull was called the pearl of the Arctic. Lesser swan, white-tailed goose, handsome Siberian Crane - white crane, white-billed loon, falcons - saker falcon, gyrfalcon and salmon, hawks - white-tailed eagle and golden eagle have become rare.

Mountain regions and provinces

In the Northeast, natural complexes of plains and mountains are developed. The lowlands are represented by natural zones of tundra, forest-tundra and sparse taiga. On the territory of the plains, two physical-geographical provinces are distinguished: the tundra and forest-tundra Yano-Indigiro-Kolyma and the Abyis-Kolyma northern taiga. The rest of the territory is occupied by mountains and is subdivided into mountainous regions.

The Yano-Indigira-Kolyma province is located along the Arctic coast within the Yana-Indigira and Kolyma lowlands.

Zoning is manifested in the distribution of vegetation and soils. The coast is occupied by arctic tundra on gley, peaty-gley and marsh soils. To the south, they are replaced by typical moss-lichen, which pass into the forest-tundra with gley-frozen soils. A specific feature of the Northeast is the absence of a shrub tundra subzone. Within the zone of their distribution, larch woodlands also appear, which is due to the sharp continentality of the climate. Larch sparse forests and shrub tundra alternate with areas of sedge-cotton grass hummocky tundra.

The Yano-Kolyma tundra are the main nesting places for many waterfowl, and among them are the pink gull and the Siberian Crane. The pink gull builds nests on hummocks of sedge-cotton grass tundra and on islands near small lakes and channels. After nesting (late July - early August), adults and young birds disperse to the north, northwest and northeast. The area of ​​winter roaming of the pink gull extends from the Bering Strait to southern islands Kuril ridge. The main nesting sites of the Siberian Crane are low-lying, highly humid, lake-lake tundras between Yana and Alazeya. For wintering, birds fly to Southeast China.

Abysko-Kolyma province is confined to the largest intermountain depression. The surface of the watersheds here is covered with sparse larch forests, sedge-cotton grass bogs and lakes. Along the river valleys, swampy meadows, thickets of shrubs are developed, and in drier areas - forests of larch, fragrant poplar and chosenia.

Verkhoyansk region occupies a western marginal position. The altitudinal zonality of the soil and vegetation cover is most fully expressed on the Suntar-Khayata and Setta-Daban ridges. The lower belt here is represented by northern taiga sparse larch forests that rise along the northern slopes up to 1200-1300 m, and up to 600-800 m along the southern slopes. Lichens predominate in the ground cover; the dwarf shrub layer is formed by lingonberries, crowberries and wild rosemary. Developed dwarf birch from Middendorf's birch. Along the river valleys on sand and pebble deposits, gallery forests of fragrant poplar and chosenia stretch with an admixture of larch, birch, aspen and Siberian mountain ash.

Above the upper boundary of the larch crooked forest, thickets of dwarf dwarf, shrubby alder and dwarf pine dominate in combination with lichen-shrub tundra. The next belt is mountain-tundra with taryns. Its upper boundary should be drawn at the ends of the glaciers (1800-2100 m). Above are high-altitude deserts with glaciers and snowfields. Avalanches come down in autumn, winter and spring.

Anyui-Chukotka region stretches from the lower reaches of the Kolyma to the Bering Strait for almost 1500 km.

The tundra of Chukotka differs from other tundras of the Arctic coast of Russia in that its main part is mountain tundra with stony placers, rocks and thickets of bushes, while the coastal part is flat tundra grassy-shrub and tussocky with cotton grass vaginal and wild rosemary.

The flora of vascular plants of the Chukchi tundra contains about 930 species and subspecies. This is the richest flora of the Arctic region. Chukotka was part of Megaberingia, and this had a significant impact on the composition of the flora of its plant communities. On the southern slopes of the ridges and terraces above the floodplain, mountain-steppe vegetation has been preserved - the remains of the Beringian tundra-steppe landscapes. North American plant species grow there: among the dryad tundras on limestones, there are Mackenzie's kopek, a dense cat's foot, and in willow-herbaceous communities - balsam poplar and edible viburnum. In the nival tundra, the Egalik primrose is common. In the steppe areas, Lena fescue is common. B.A. Yurtsev calls it the emblem of the steppe complexes of the North-East of Siberia. Once upon a time, horses, bison, saiga and other herbivores lived in the tundra and steppes of Beringia. Now the problem of the sunken Beringia attracts the attention of various specialists.

In Chukotka, near the Beringian coasts, thermal springs emerge with temperatures ranging from 15 to 77°C. They create favorable conditions for the development of lush and diverse vegetation. There are up to 274 plant species here. In severe climatic conditions, the flora near hot springs has a subarctic and temperate character with a predominance of arcto-alpine elements - mountain shrub-moss communities. Cassiopeia, diapensia, loiselaria, phyllodoce, Kamchatka rhododendron, etc. grow among them, as well as mountain-tundra Asian-American or Beringian species - anemone, chrysanthemum, primrose, saxifrage, sedge, etc.

Anthropogenic impact on nature

The nature of the Northeast is experiencing a significant anthropogenic impact due to the operation of off-road vehicles (all-terrain vehicles), construction, geological surveys and mining, deer grazing and frequent fires.

Fur farming and fur trade for squirrel, arctic fox, ermine, white hare, and muskrat are developed on the territory. Plain and mountain tundra and forest tundra serve as good pastures for reindeer. One of the main foods reindeer in winter - bushy lichen-cladonia (reindeer moss). The restoration of its reserves takes five to seven years. Due to anthropogenic impact, the pasture fund is decreasing, therefore, strict observance of the pasture load and careful attitude of the entire population to reindeer pastures are necessary.

The main commercial fish - vendace, muksun, nelma, omul, whitefish, etc. - are concentrated in the lower sections of the Yana, Indigirka and Kolyma rivers. In warm areas of the valleys of the Yana, Indigirka, Kolyma and other rivers, early varieties of cabbage, potatoes and other vegetables are grown with special agricultural technology.

Active development of the territory contributed to the change in natural landscapes, reduction in the number and ranges of many species of animals and plants, for example, the Chukchi bighorn sheep, the Siberian Crane and the Spatula, nesting only in Russia, Berdov's sandpiper, the real slipper, etc.

The nature of the North-East is very vulnerable, therefore, with increased human activity, entire natural complexes (ecosystems) die. For example, when developing alluvial deposits, significant areas of floodplains are completely destroyed, on which a wide variety of animals and plants are concentrated. On the territory of this vast physical and geographical country, there is so far only one nature reserve - Magadansky, several complex and branch reserves (waterfowl nesting) and natural monuments, and among them - a buffer zone for the location of mammoth fauna.

Scientists propose to create a number of protected areas here, for example, the Buordakh natural park with the basins of the left tributaries of the Moma and Mount Pobeda. Among the unique geographical objects of this region are the world's largest icing Ulakhan-Taryn (Momskaya), which does not completely melt every year, and in the valley on the rubbly slopes of the southern exposure - the Yakut mountain steppes, turning into steppe alpine lawns and mountain tundra. It is also proposed to create the Central Yakut Reserve as a biosphere reserve, where the Chukotka bighorn sheep has been preserved on the rocky shores of Lake Elgygytgyn, where there are places for calving of wild reindeer - the only large population in the entire North-East. Here, poplar-chozenia valley forests are at the limit of distribution, and steppe areas have been preserved.

Eastern Siberia occupies an impressive area - more than 4 million square meters. km. The diversity of local landscapes is due to the large extent of the region from north to south in the Asian territory of the Russian Federation. The natural zones of Eastern Siberia are represented by arctic deserts, forests and steppes, but the taiga zone occupies the largest area.

Climate

The climatic features of Eastern Siberia are due to its geographical location:

• great distance from the Atlantic Ocean;
• isolation from the Pacific Ocean;
• location at high latitudes.

The climate of this region is sharply continental, consistently severe. Its characteristic feature is significant daily and seasonal temperature fluctuations, low cloud cover and insufficient moisture level.

On the Far North region in winter time the polar night reigns, when the sun does not appear above the horizon for two months. But with the onset of summer, the sun, on the contrary, shines constantly, even at midnight, for several weeks.

Rice. 1. Polar night.

Continental air currents cool very quickly in the ground layers, which leads to incredibly low temperatures in winter. -60 degrees Celsius and prevailing arctic winds are not uncommon for Eastern Siberian winters.

Summer is quite cold, the air temperature in July rarely exceeds +15 degrees. In addition, it is very short, and the growing season in these parts is 2-2.5 months.

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Vegetable world

Due to the large extent in the meridional direction, the nature of Eastern Siberia, as well as the natural zones of Central Siberia, lies in three climatic zones:

• arctic;
• subarctic;
• moderate.

The predominant territory of Eastern Siberia is occupied by taiga. Fir, larch, pine, cedar grow here.

Rich taiga forests with a length of several thousand kilometers make up almost half of all forest resources in the Russian Federation.

Rice. 2. Endless taiga forests of Eastern Siberia.

Also, an impressive part of the region is occupied by the tundra zone. Poor soils, excess moisture and low temperatures create not the most Better conditions for vegetation development. Dwarf trees, saxifrage, cotton grass, poppy grow here.

Animal world

Almost all areas of Eastern Siberia are not distinguished by a great variety of fauna. The main reason for this is the poor development of plants, the lack of food in the right quantities and permafrost.

Of the large predators, the brown bear, wolverine, and lynx should be distinguished. There are also foxes, deer, elks, sables, ermines, ferrets, badgers. Due to the constantly cold soils, very few rodents live in this region. The world of birds, on the contrary, is very diverse. Capercaillie, woodpecker, crossbill, goose, nutcracker, crow, sandpiper and many other species of birds live here.

Rice. 3. Wolverine.

What have we learned?

Eastern Siberia occupies a very large territory. Thanks to geographical location its natural zonality is pronounced. The largest area is occupied by two zones: taiga and tundra. Eastern Siberia is especially valued for its impressive forests of coniferous trees.

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