West Siberian taiga. Natural zones of Western Siberia and their characteristics

Lesson number 49: "Natural areas of the West Siberian Plain»

LESSON TYPE: combined.

TASKS:

Educational: to acquaint with the natural zones of the West Siberian Plain. To form an idea of ​​the main features of the plain zones: climate, temperature regime, precipitation, humidity, flora and fauna.

Developing: continue the formation of skills for determining the FGP, the ability to work with thematic maps atlas, establish causes and effects between the components of nature, the ability to generalize and draw conclusions.

Educational: formation positive image Western Siberia and the value attitude to this region.

EQUIPMENT: Maps of Russia (physical, natural zones), presentation, textbook “Geography: nature of Russia. Grade 8", contour map.

LESSON PLAN:

1. Organizational part - 2-3 minutes.

2. Frontal survey - 8-10 min.

3. Learning new material - 20-26 min

4. Fixing the material - 3-5 minutes

4. Message homework - 3 min.

5. Completion of the lesson - 1-2 minutes.

DURING THE CLASSES.

1. Organizing time

Greetings. Checking students' readiness for the lesson.

Hello guys! I am very glad to see you. Sit down.

2. Checking homework, setting the goal of the lesson.

Dear Guys! Before we start studying new topic let's remember what we talked about in the last lesson. (We determined the geographical location, climate, inland waters, relief of Western Siberia).

Front poll:

What is the area of ​​the West Siberian Plain? (2.6 million km2)

What are the boundaries of the plain? (Clearly defined natural boundaries)

What objects represent natural boundaries? Show them on the map hanging in the classroom (North is the coastline Kara Sea; in the south - the foot of the Kazakh uplands, Altai, Salair Ridge and Kuznetsk Alatau; in the west - the eastern foothills of the Urals, in the east - the valley of the Yenisei River)

What is the relief of the West Siberian Plain? (Flat, falling towards the center)

How did such a relief form? (The relief was formed by loose deposits of rivers and ancient glacial sediments, which covered the Paleozoic plate with a sedimentary cover. main reason– horizontal layering of sedimentary layers. Glaciation also affected the relief)

Tell us about glaciation: did it affect only the relief? (No. Glaciation affected not only the relief, but also the flora and fauna of the West Siberian Plain. When the glacier retreated, the north of the plain was conquered by tundra and taiga, although before there were broadleaf forests in which mammoths, giant deer lived. According to the remains of trunks in the swamps, it can be judged that the forest boundary was located several hundred kilometers to the north than at present).

What is the climate like in the West Siberian Plain? (The climate is continental and quite severe)

Let's remember what 4 reasons formed the harsh climate. (The first is the position predominantly in temperate latitudes ah determined the small amount of solar radiation received by the territory. The second is the distance from the Atlantic and Pacific oceans. The third is the flatness of the territory, which allows cold masses of Arctic air to freely penetrate far to the south from the "ice bag" - the Kara Sea, and warm air masses from Kazakhstan and Central Asia - far to the north. Fourth - mountains along the periphery, fenced off from the Atlantic air masses from the west and Central Asian from the southeast)

How does continentality change in the West Siberian Plain? (Increases when moving from north to south). What is it expressed in? (In an increase in the annual temperature amplitude, a decrease in the amount of precipitation, a reduction in the duration of spring and autumn - the transitional seasons of the year)

Tell us about the features of the sediments of the West Siberian Plain. (At the junction of air masses of temperate latitudes with tropical ones, cyclones arise that bring rain. At the beginning of summer, this front acts in the south - the steppe zone receives moisture. In July, hot air dominates the entire south of the plain. In August, the front reaches the tundra, where 250 mm falls In winter, at the junction of moderate and Arctic air masses, cyclones of the Arctic front act.This softens frosts in the north, but due to high humidity and strong winds the harshness of the climate is also manifested at lower frosts)

What pattern can be traced in the placement surface water? (Dependence on the relief and on the zonal ratio of heat and moisture.

What is the largest river? (Ob with a tributary of the Irtysh) Show it on the map.

What is the swampiness in the territory of the West Siberian Plain? (Wetland area - 800t. km2) Give an example. Show on the map. (Vasyuganye)

Causes of swamp formation. (The presence of excessive moisture flat relief, permafrost, low temperatures air, the ability of peat to retain water.

Goals: (Slide 2)

3. Actualization of knowledge.

Guys, earlier you studied the zonality of Russia as a whole. On what principles is it formed? (by climate)

4. Learning new material.

Guys, and now I will tell you about the natural zones of the West Siberian Plain. The large length of the plain from north to south allows several latitudinal zones to fit in - from the tundra in the north to the steppes in the south.

On the map, determine which of the natural zones occupies the largest area in the West Siberian Ravpipe. (Taiga forest-bog zone).

The vast size of the West Siberian Plain and the flat relief make it especially good to trace the latitudinal changes in natural landscapes. Main distinguishing featuretundra - the severity of the climate. Adapting to harsh conditions, tundra plants prepare wintering buds from autumn. Thanks to this, in the spring they are rapidly covered with leaves and flowers, and then bear fruit. In the tundra there are many different plant foods, so many herbivorous birds nest here.(Slide 3)

Taiga forest swamp zone - the most extensive of the natural zones of the plain (its area is 1.5 million km 2 ). In the taiga - the kingdom of spruce-fir, larch-cedar-pine forests with lichens and shrubs. The northern part is dominated by larch-cedar and pine forests. In the middle part of the zone dominated by taiga of pine, cedar, spruce and fir. Aspen and birch forests are widespread at the site of forest fires. The southern part of the taiga is birch-aspen small-leaved forests. The fauna of the taiga is rich: “Europeans” are also found in it, such as mink and pine marten, and "Eastern Iberian", such as sable. The chipmunk, the squirrel, the badger and the owner of the taiga, the bear, live in the taiga. Birds feed on the seeds of forest trees and shrubs - capercaillie, hazel grouse, woodpeckers, turtle doves. The fauna of the taiga river valleys is the most diverse. Here you can meet a white hare, a mole, a wolf and a fox. Taiga oxbows and lakes abound various types ducks, waders. Common cranes, snipe and great snipe nest in swamps. The most typical swampy areas of the taiga on the flat interfluves of the Ob and Irtysh are calledUrmans.

In notebooks, we write down the definition of "urmana" in the dictionary.

The taiga of Western Siberia is formed by spruce and cedar, larch and fir, pine and aspen-birch forests.

Animal world West Siberian taiga has many general types with the European taiga. Everywhere in the taiga live: brown bear, lynx, wolverine, squirrel, ermine.(Slide 4)

West Siberianforest-steppe stretches in a narrow strip from the Urals to the foothillsSalairsky ridge. The abundance of lake basins is a feature of this zone. The shores of the lakes are low, partly swampy or overgrown with pine forests. In the Kulunda pine forests, along with steppe species - oatmeal, field pipit, jerboa - taiga species live: flying squirrel, capercaillie.

In the forest-steppe and steppe zones can be grown on fertile soils good harvests cereals and vegetables.

The picturesque landscapes of the south of the plain - birch groves, elevated areas - manes and lakes - are potential recreational resources of the territory.

Manes are sandy ridges from 3 to 10 m high, less often up to 30 m, covered with pine forests. They bring great diversity to the treeless flat landscapes of the south of Western Siberia. In some places, the ridged terrain is full of lakes, which makes the area even more attractive.

In notebooks, we will write down the definition of “mane” in the dictionary.

Let's look at page 204 figure 120. It is called "The structure of the crests of Western Siberia". What do you see in the picture? (The components of the crests are the underlying clay, then alluvial sandy loam, birch forest-steppe, steppe on chernozems).

Kolki are groves of birches and aspens, turning green, like oases, among the lack of water of the surrounding steppe plains. These are quiet, poetic corners, full of shade and freshness, bright colors and the singing of birds.

In notebooks, we will write down the definition of “splits” in the dictionary.

(Slide 5)

Steppe occupies small areas in the south of Western Siberia, there is little rainfall here from 300-350 mm, grassy, ​​with fertile chernozem and chestnut soils, can produce high yields of wheat, corn, sunflower, vegetables (but often the lack of moisture and dust storms at the beginning of summer).(Slide 6)

5. Fixing the material .

Let's open the atlas and look at natural areas.(Slide 7)

What natural areas are located on the territory of the plain? (Tundra, taiga forest-bog zone, forest-steppe, steppe)

Which zone occupies the largest area? (Taiga forest swamp zone)

6. Summing up and results of the lesson.

7. Homework.

§41, questions after the textbook.(Slide 8)

Throughout Central Siberia There are 3 zones: tundra, forest-tundra and taiga. The taiga is most fully represented, occupying 70% of the area. The Central Siberian Plateau includes only the forest-tundra and taiga.

The forest-tundra stretches in a narrow strip (up to 50-70 km); the boundary of the zone runs along the northern ledge of the Central Siberian Plateau.
The climate of the zone was assigned to B.P. Alisov to subarctic with a predominance of continental air of temperate latitudes in the cold period and transformed arctic air in summer. The combination of the polar position with continentality with insignificant radiation and the dominance of anticyclone weather determines the severity of the winter period, which lasts about 8 months, from October to May. Snow cover lasts 250-260 days. Its thickness is 30-50 cm, slightly increasing towards the west. In summer, the soil and the surface layer of air warms up intensively. average temperature July is 12-13оС.

Sufficiently high temperatures during the growing season, a decrease in the strength of winter winds, favor the growth of not only herbaceous and shrubby vegetation, but also trees. From tree species Dahurian larch dominates here. The vegetation cover of the forest-tundra is dominated by shrub thickets of birch, alder, and willow. Trees are scattered in individual specimens or groups.
The taiga zone stretches from north to south for more than 2000 km from the northern edge of the Central Siberian Plateau.

The specific features of the Central Siberian taiga, which sharply distinguish it from the taiga of Western Siberia, are sharply continental climate and the almost universal distribution of permafrost, slight waterlogging, the dominance of monotonous deciduous taiga and permafrost-taiga soils.
The climate of the zone is sharply continental, with severe winters with little snow and moderately warm and cool, moderately humid summers. Cold winter with persistent and severe frosts lasts 7-8 months. On the western slopes of the Central Siberian Plateau, the greatest amount of precipitation falls, which contributes to the formation of snow cover up to 70-80 cm thick. The relief and features of atmospheric circulation determine the variegated distribution of precipitation in the zone.

The zonal soils of the taiga are permafrost-taiga. In the central part of the taiga, the density of the tree layer and the height of the trees increase. In the undergrowth, in addition to shrubs, birch, there are bird cherry, mountain ash, elderberry, juniper, honeysuckle. The grass-moss cover is typically taiga. Acid permafrost-taiga soils develop under the forests. In the southern taiga, the diversity of coniferous forests is increasing. In the space of the taiga zone, intrazonal differences associated with the nature of the lithogenic base are clearly traced.

The increase in the severity of winter and the decrease in the thickness of snow cover from west to east have the greatest influence on the distribution of forests across the territory. In this regard, dark coniferous spruce-cedar forests predominate in the Yenisei part. To the east, they are replaced by dark coniferous-larch and pine-larch.

Natural zones of Western Siberia

Western Siberia covers five natural zones: tundra, forest-tundra, forest, forest-steppe and steppe. Perhaps nowhere on the globe does the zonality of natural phenomena manifest itself with the same regularity as on the West Siberian Plain.

The tundra, which occupies the northernmost part of the Tyumen region (the Yamal and Gydansky peninsulas) and has an area of ​​about 160 thousand km 2, does not have forests. Lichen and moss tundras of Western Siberia are found in combination with hypnum-grass and lichen-sphagnum, as well as large-hilly swampy massifs.

The forest-tundra zone extends to the south of the tundra in a strip of about 100-150 km. As a transitional zone between tundra and taiga, it is a mosaic combination of areas of light forests, swamps, and thickets of shrubs. The northern limit of woody vegetation is represented by sparse crooked larch forests, occupying areas along river valleys.

The forest (taiga, forest-bog) zone covers the space between 66o and 56oS. a strip of about 1000 km. It includes the northern and middle parts of the Tyumen region, the Tomsk region, the northern part of the Omsk and Novosibirsk regions, occupying about 62% of the territory of Western Siberia. The forest zone of the West Siberian Plain is divided into subzones of the northern, middle, southern taiga and birch-aspen forests. The main type of forests in the zone are dark coniferous forests with a predominance of Siberian spruce, Siberian fir and Siberian pine (cedar). Dark coniferous forests are almost always found in ribbons along river valleys, where they find the conditions for the drainage they need. On watersheds, they are confined only to hilly, high places, and flat areas are occupied mainly by swamps. Essential element landscapes of the taiga - swamps of lowland, transitional and riding type. The forest cover of Western Siberia is only 30.5% and is a consequence of the weak dissection and associated poor drainage of the entire territory of the region, which contributes to the development of not forest-forming, but swamp-forming processes throughout the entire area of ​​the taiga zone. The West Siberian Plain is characterized by exceptional watering and swampiness, its middle and northern parts are among the most waterlogged areas on the earth's surface. The world's largest swamps (Vasyugan) are located in the southern taiga. Along with the dark coniferous taiga on the West Siberian Plain, there are pine forests confined to the sandy deposits of ancient alluvial plains and to sandy terraces along river valleys. In addition, within the forest zone, pine is a characteristic tree of sphagnum bogs and forms peculiar associations of sphagnum pine forests on waterlogged soils.

The forest-steppe zone adjacent to the subzone of deciduous forests of the forest zone is characterized by the presence of both forest and steppe plant communities, as well as swamps (ryams), solonchaks and meadows. The woody vegetation of the forest-steppe zone is represented by birch and aspen-birch forests, which occur in islands or in the form of pegs, usually confined to saucer-shaped depressions, while the main background is formed by meadow and forb-cereal steppe. Only in the Tobol and Ob region of this zone are natural insular pine forests common. A characteristic feature of the forest-steppe of Western Siberia is the crested-hollow relief and the abundance of saline drainless lakes.

The steppe zone covers southern part Omsk and the southwestern part of the Novosibirsk regions, as well as the western part Altai Territory. It includes the Kulundinskaya, Aleiskaya and Biyskaya steppes. Ribbon pine forests grow along the ancient glacier water runoffs within the zone.
The significant height of the mountains of Western Siberia determines the development of altitudinal zonation here. In the vegetation cover of the mountains of Western Siberia, the leading position is occupied by forests covering most of the area of ​​the Salair Ridge and Kuznetsk Alatau and about 50% of the territory of Altai.

Natural areas of Eastern Siberia

Due to its great length from north to south, Eastern Siberia is characterized by a variety of landscapes from arctic deserts to steppes. However, the taiga zone occupies the largest area. Nowhere in Russia does the taiga reach as far north or descend as far south as in Eastern Siberia. The width of the forest zone in some places exceeds 2 thousand kilometers.

The spread of taiga vegetation north of the Arctic Circle (the tundra is located in neighboring Western Siberia at this latitude) is facilitated by a relatively warm summer. In turn, low winter temperatures do not allow the growth of deciduous trees, and therefore the taiga is spreading to the south. In these latitudes, there were broad-leaved forests on the East European Plain, and steppes in Western Siberia.
The main forest-forming species of Eastern Siberia is larch. The tree, dropping needles for the winter, is able to withstand severe frosts. In addition, larch wood is extremely dense, contains little moisture and does not crack along the grain even at very low temperatures.
In the Baikal region, larch is mixed with Siberian pine, which is mistakenly called cedar.

Coniferous forests also cover most of the slopes of the mountains in the south of Eastern Siberia. On the mountain slopes, in addition to light coniferous larch-pine forests, there are dark coniferous spruce-fir forests. Dry intermountain basins are occupied by steppe vegetation.

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 Asian territory. 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 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.

In the Far North of the region 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.

From large predators brown bear, wolverine, lynx should be distinguished. There are also foxes, deer, elks, sables, ermines, ferrets, badgers. IN this region because of the constantly cold soils, there are very few rodents. 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 natural zoning its pronounced. The largest area is occupied by two zones: taiga and tundra. Eastern Siberia is especially valued for its impressive woodlands coniferous trees.

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1. Geographic location.

2. Geological structure.

3. Relief.

4. Climate.

5. Water and permafrost.

6. Soils, flora and fauna.

7. Natural areas.

Geographical position

Central Siberia is located between the Yenisei River and the western foot of the Verkhoyansk Range. In the north it is washed by the Laptev and Kara seas, in the south it borders on the Eastern Sayan, the Baikal ridge, the Patom and Aldan highlands. The greatest length from north to south is 2800 km (or 25˚), from west to east 2500 km (at the latitude of Yakutsk). The area of ​​this country is about 4 million km2. Most of the country lies on the Siberian platform, in the north the North Siberian lowland and the Taimyr Peninsula. Unlike Western Siberia, the borders of Central Siberia are not clearly drawn on maps. Taimyr and especially the Aldan Highlands are controversial. Scientific research Central Siberia began in the XVIII century: the Great Northern Expedition. A great contribution to the study of this country was made in the 19th century by A.F. Middendorf.

Geological structure

The tectonic basis of Central Siberia is the ancient Siberian platform. At the same time, its Aldan Shield is not included in Central Siberia. The basement of the Siberian Platform is composed of Archean and Proterozoic folded complexes and has a dissected surface. In the area of ​​the shields, the basement rocks (gneisses, quartzites, granites, marbles) come to the surface. The Yenisei Ridge belongs to the Baikal folding. The foundation has deflections: Tungussky, Khatangsky, Angara-Lensky, Vilyuysky. These depressions are filled with rocks of the sedimentary cover, the thickness in places is up to 8-12 km. The formation of the cover began in the Early Paleozoic with marine transgression. Then almost the entire territory became dry land. In the Late Paleozoic, the lacustrine-marsh regime dominated, at which time coal strata were being formed. By the beginning of the Mesozoic, fissure magmatism began to appear, the foundation experienced faults and movements. This process led to the formation of traps. Traps are associated with igneous intrusions, basalt (lava) sheets and explosion pipes (ring structures). At the end of the Mesozoic, almost all of Central Siberia was an area of ​​demolition (at that time the Putorana Plateau rose) and active denudation. In the Cenozoic, the country slowly rose, which led to erosion processes and the formation of a river network. Neotectonic movements led to the uplift of the Byrranga, Putorana, Anabar and Yenisei massifs. IN Quaternary glaciation was developed on the Putorano Plateau. There was also glaciation in Taimyr, but vast areas of Central Siberia were in the conditions of the periglacial regime. The cold climate contributed to the formation of permafrost and underground ice.

Relief

The main orographic structure of the country is the Central Siberian Plateau. It is characterized by a significant elevation and contrast of the relief. The heights range from 200 m to 1700 m, and the average height of the plateau is 500-700 m. The surface is close to flat, but with deep incised river valleys. highest height plateaus in the region of the Putorana Plateau (1700 m). To the east of the plateau lies the Vilyui and Central Yakut plains. The Lena-Aldan Plateau is located in the extreme southeast, and the Yenisei Ridge (remnant mountains) is located in the southwest, the average heights here are 600-700 m. far north the Byrranga mountains stretch, these are low-mountain blocky massifs with a leveled surface (800-1000m). The morphostructures of Central Siberia can be divided into 4 groups: 1) Plateaus, ridges, low mountains - Anabar plateau, Yenisei ridge, Byrranga mountains. 2) Layered uplands and plateaus - the Angara and Prilenskoye plateaus, the Anagar-Lena plain. 3) Volcanic plateaus - Putorana, Central Tunguska, Vilyui. 4) Accumulative - Central Yakut and North Siberian lowlands. Almost the entire territory of Central Siberia is characterized by cryogenic landforms: thermokarst, solifluction, mounds, hydrolaccoliths, etc. In mountainous areas, kurums (placers of stones) are characteristic. River valleys have big number terraces (6-9). In places in the south of the country there is karst.

Climate

The climate is sharply continental, which is due to the remoteness from the Atlantic and the isolation of mountain barriers from the Pacific Ocean. highest degree reaches continentality in central Yakutia. Annual amplitudes average temperatures around 60˚C (extreme almost 100˚C). There is little rainfall and the winter is very cold. The total solar radiation varies within the country from 65kcal/cm2 (northern Taimyr) to 110 kcal/cm2 (Irkutsk). In winter, the Asian maximum dominates, to the northwest the pressure decreases. Therefore, almost throughout the entire territory, except for the northwest, the weather regime is anticyclonic: clear, calm and frosty. Winter lasts 5-7 months. During this time, the surface is strongly cooled, temperature inversions, which is facilitated by the relief. Cyclones dominate only in Taimyr. The lowest average January temperatures are observed in the Central Yakut lowland and the northeast of the Central Siberian Plateau -42˚-45˚C. In the lowlands, the absolute minimum is -68˚C. To the north and west, the temperature rises to -30˚C. There is little precipitation in winter, 20-25% of the annual amount (100-150 mm), and in Central Yakutia - 50 mm. Thus, the thickness of the snow cover in Central Yakutia is no more than 30 cm by the end of winter. To the periphery of the country, the thickness of snow increases to 50 cm, and in the Yenisei part to 80 cm. Spring is short and friendly (May). In summer, pressure over Central Siberia decreases. From the North Arctic Ocean rush air masses, but the arctic air quickly transforms and turns into temperate continental. July isotherms take a sublatitudinal direction and change from +2˚C at Cape Chelyuskin, +12˚C near the ledge of the Central Siberian Plateau and up to +18˚C in Central Yakutia, +19˚C in Irkutsk. In summer, precipitation is 2-3 times more than in winter, especially in the second half of summer. Autumn is short (September). In total, precipitation falls from 600 mm in the pre-Denisei part of Central Siberia (on the Putorana Plateau, Tunguska Plateau about 1000 mm) to 350-300 mm in Central Yakutia. In Central Yakutia in the lower reaches of the Aldan and Vilyui k1.

Water and permafrost

The rivers of Central Siberia are full of water, there are lakes, permafrost is everywhere, in the north there are swamps. The river network is well developed. Permafrost contributes to the increase in river runoff. According to the nature of the flow, the rivers of Central Siberia occupy an intermediate position between mountainous and flat ones. Most of the basins of the Yenisei and Lena rivers (Lower Tunguska, Podkamennaya Tunguska, Angara; Vilyui, Aldan, Amga, and others) are located in Central Siberia. Olenyok, Anabar, Khatanga, Pyasina and others flow directly into the sea. According to the water regime, all rivers belong to the East Siberian type. Feeding is mixed, with the leading role of snow feed, the role of rain feed is not significant, and ground runoff gives only 5-10% (due to permafrost). The freeze-up is powerful and long, the flood is very high. In the lower reaches of the Lena, the water rise in May exceeds 10 m, on the Yenisei - 15 m, on Lower Tunguska up to 30 m. In winter, low water on the rivers. The formation of ice on many rivers does not begin from above, but from the bottom, and then the ice rises to the surface. Ice formation begins in October, and only Angara freezes in December. Ice thickness on the rivers is 1-3 meters. Small rivers freeze to the bottom. Ice forms on many rivers in winter, which leads to the formation of ice fields in the river valleys. the largest river is Lena, its length is 4400 km, the basin area is 2490 thousand km2. The source of the Lena is on the western slope of the Baikal Range, the river flows into the Laptev Sea, forming a huge delta (32 thousand km2). There are fewer lakes in Central Siberia than in Western Siberia. Most of the lakes are located in the North Siberian Lowland and the Central Yakutsk Lowland, here are predominantly thermokarst lakes. Large tectonic and glacial-tectonic lakes are located on the Putorana plateau: Khantayskoe, Lama, etc. The largest lake is Taimyr (area 4560 km2, maximum depth- 26 m). Permafrost is widespread almost everywhere in Central Siberia. Its formation took place in ice age, for several thousand years. Permafrost is a relic formation, but even now modern climatic conditions in some places contribute to the formation of permafrost. The southern border of continuous permafrost runs from Igarka, Nizhnyaya Tunguska and in the Lena valley near the mouth of the Olekma. The thickness of frozen soils here is 300-600 m (maximum 800-1200 m). South of this boundary, permafrost has an insular character (taliks). In some places there are underground ice, hydrolaccoliths (ice intrusions). Permafrost contributes to the development of cryogenic landforms and hinders erosion processes. About 75% of Central Siberia is occupied by East Siberian artesian basin, which lies under the permafrost in bedrock.

Soils, flora and fauna

Soils are developed mainly on the eluvium of bedrocks, so they are stony and gravelly. Soils are formed on permafrost. In the far north, arctotundra soils are common, which are replaced by tundra-gley soils. In the forest zone, taiga-frozen soils are formed, in which there is no soil profile. Due to permafrost, the soil regime is non-leaching, which prevents the removal chemical elements outside the soil profile. The taiga-frozen soils are characterized by gleying, weak aeration, and the absence of clear genetic horizons. The reaction of soils is acidic, but in places where pale permafrost-taiga soils are developed, their reaction is neutral. In the south, where the permafrost is discontinuous, soddy-podzolic soils develop. On the Central Yakut lowland there are saline soils: solods, solonetzes.

Vegetation, like soils, is subject to latitudinal zonality. On the coast of the sea there are arctic deserts, to the south there are typical tundras and shrub tundras made of dwarf birch, willow, etc. Due to the severity of the climate, the floristic composition is not rich. Of the tree species, Dahurian larch dominates; it is characteristic of both the forest-tundra and the taiga, where they form light coniferous forests. In the south, pine is added to it, and in the west, cedar, spruce. Larch forests along the river valley reach Taimyr (almost 73˚N) - this is the northernmost distribution of forests on the globe. In some places in the south of Central Yakutia there are areas with meadow-steppe vegetation (they are a relic of the xerothermal period and now exist due to the dry climate).

The fauna of Central Siberia is characterized by greater antiquity than the fauna of Western Siberia. A complex of taiga animals is widely represented here, but a number of European-Siberian species (marten, mink, hare, hedgehog, mole, etc.) are absent. To the east of the Yenisei are typical eastern elk, reindeer, bighorn sheep, musk deer, Siberian weasel, northern pika, long-tailed ground squirrel, black-capped marmot, stone capercaillie, black crow, rock pigeon, etc. As in the West Siberian taiga, sable, chipmunk, squirrel, ermine, fox, arctic fox, wolf, wolverine, Brown bear and etc.

natural areas

Natural zones in comparison with Western Siberia in Central Siberia are mixed to the north. This applies primarily northern zones. Forests occupy up to 70% of the country's territory, reaching in the south almost to state border. On the coast Arctic seas a narrow band is formed Arctic deserts with polygonal arctic soils. More than 70% of the surface is occupied by bare soils. Of the plants, mosses and lichens, dryad (partridge grass), cotton grass, and sedges predominate. To the south, typical tundras are common, and even to the south, shrubs. The southern border of the tundra reaches Lake Pyasino, the valley of the Kheta River and the north of the Anabar Plateau. The width of the zone is 100-600 km. Unlike the tundras of Western Siberia, there are fewer swamps here, and the climate is more continental. Arctic continental air masses dominate throughout the year. Precipitation varies from 450 mm in the northwest of the zone to 250 mm in the southeast of the tundra. Cyclones reach only the lower reaches of the Khatanga, they do not penetrate to the east. Winter lasts about 8 months. Most cold month- January (on the coast - February). Average winter temperatures are -30˚-35˚C. The snow cover lies for about 9 months. Summer lasts 2 months. July temperatures vary from +1˚C at Cape Chelyuskin to +10˚C at the southern boundary of the zone. Humidification is excessive. Evaporation is only 50 mm per year. There are many lakes, all rivers are full of water. Permafrost thickness is 600-800 m. Cryogenic landforms prevail. The soils are tundra-gley. In the vegetation cover, in addition to mosses and lichens, dryads, cassiopeia, and polar poppies grow; to the south, shrubs - skinny birch, undersized willows. Of the animals, lemmings, voles, arctic foxes, reindeer live, in the mountains - bighorn sheep, partridges, plantains, many geese, ducks, loons, eiders, gulls, waders, etc. arrive in the summer.

The forest tundra extends along the southern margin of the North Siberian Lowland, in a strip of 70-100 km, but some authors combine this zone with the subzone of northern sparse forests (tundro forest) in the north of the Central Siberian Plateau. Within such boundaries, the forest-tundra extends to the Arctic Circle, and in some places to the south of it. The climate is subarctic continental. Winter is very severe and lasts 8 months. Winter temperatures 5-7˚C lower than in the tundra. Summer is warmer +11˚+12˚C. Soils are permafrost-tundra and tundra-peat. In this zone, woody vegetation joins the typical tundra vegetation.

Dahurian larch dominates, Siberian larch in the west. In addition, skinny birch, shrubby alder and willow, wild rosemary grow well. The animal world has both tundra and taiga species.

The taiga stretches from north to south for more than 2000 km, occupying the entire Central Siberian Plateau and reaching the borders of the country in the south. The climate is sharply continental. Amplitude average monthly temperatures 50-60˚C, and extreme up to 102˚C (Yakutsk). Winter 6-7 months. Average January temperatures range from -25˚C in the southwest to -45˚C in the east. Characterized by temperature inversions. In winter, an anticyclone dominates. Spring is short. Summer, due to the elevation of the territory, is cooler than at the same latitudes in Western Siberia. Average July temperatures are +16˚C+18˚C. In summer, cyclonic activity is manifested, but less actively than in Western Siberia. The annual amount of precipitation varies from 800 m on the elevated slopes of the relief to 300 mm on the plains. Permafrost is ubiquitous, and, accordingly, permafrost relief is widespread. Erosive relief is less developed, lateral erosion prevails over deep erosion. The river network is well developed and the rivers are full of water. Food is mostly snowy. There are relatively few lakes and swamps. Acid permafrost-taiga soils predominate. The light-coniferous taiga of larch dominates, in places with an undergrowth of mountain ash, willow, birch, alder, bird cherry, juniper, honeysuckle, etc. In the south of the taiga, pine, cedar, spruce, fir and pure pine forests appear, with a well-developed undergrowth of shrubs. Numerous patches of alas - grass-sedge meadows are interspersed in the taiga massifs. In the extreme south of Central Siberia, forest-steppe is found in places, which is an alternation pine forests with areas of meadow steppes on leached chernozems. On plateaus and plateaus, taiga is replaced by mountain tundra. The fauna of the forests of Central Siberia is typically taiga: brown bear, wolverine, wolf, lynx, fox, sable, ermine, weasel, Siberian weasel, chipmunk, squirrel, hare, muskrat, voles, shrews. Of the ungulates, elk is everywhere, less often musk deer, in the north of the taiga - reindeer, in the south - deer and roe deer. Of the birds - stone capercaillie, hazel grouse, woodpeckers, owls, blackbirds, scops, nightjars, lentils, flycatchers, waterfowl in reservoirs. Most birds arrive only in the summer. Reserves have been created on the territory of Central Siberia: Taimyr, Ust-Lensky, Central Siberian, Putoransky.

"Deserts and semi-deserts in Russia" - Semi-deserts are poor fresh water. Geographical position. large areas occupied by orchards and vineyards. Baskunchak field table salt is in Astrakhan region near the town of Bogdo. Unlike the tundra and taiga, the zone does not form a continuous latitudinal band. Without irrigation, agriculture is almost impossible.

"East European Plain" - Tectonics and mineral resources of Russia. The height of some hills and plateaus reaches 600-1000 meters. Russian plain. Satellite view. Glaciation left its mark on the formation of the relief of the East European Plain. Independent work. Lesson plan: The East European Plain almost completely coincides with the East European Platform.

"West Siberian Plain" - The sources of the river begin in glaciers, are replenished below with melted snow waters. In the Sokolovsko-Sarbaisky, Kacharsky deposits, iron ore. Many minerals are found in the West Siberian Plain. The length of the Irtysh in Kazakhstan is 1400 km. Minerals. Geological structure.

"Territory of the Russian Plain" - Journey through the territory of the Russian Plain. Complete tasks using cards, textbook, additional material. How are the rivers distributed over the territory of this plain? K a r e l and I. Why are there so many wonderful corners of nature in this area? Journey across the Russian Plain. Homework. Neighborhood of Pskov.

"Siberian Plain" - Flat low-lying district. Neither yar, nor fall. Sit straight, freely, without straining. Excess moisture. ? ? ? ? Flood on the rivers. Features of the climate of the West Siberian Plain. How can a person protect himself from annoying insects? Young plate, sedimentary rocks. Protecting people from annoying insects.