Characteristic of the nature of the East European Plain. Features of the nature of the Russian East European Plain

The East European (Russian) Plain is one of the largest plains in the world by area; It extends from the coast of the Baltic Sea to the Ural Mountains, from the Barents and White Seas to the Azov and Caspian Seas.

The East European Plain has the highest density of rural population, large cities and many small towns and urban-type settlements, and a variety of natural resources. The plain has long been developed by man.

Relief and geological structure

The East European Elevated Plain consists of hills with heights of 200-300 m above sea level and lowlands along which large rivers flow. The average height of the plain is 170 m, and the highest - 479 m - is on the Bugulminsko-Belebeevskaya Upland in the Ural part. The maximum elevation of the Timan Ridge is somewhat lower (471 m).

According to the characteristics of the orographic pattern within the East European Plain, three stripes are clearly distinguished: central, northern and southern. A strip of alternating large uplands and lowlands passes through the central part of the plain: the Central Russian, Volga, Bugulminsko-Belebeevskaya uplands and General Syrt are separated by the Oka-Don lowland and the Low Trans-Volga region, along which the Don and Volga rivers flow, carrying their waters to the south.

To the north of this strip, low plains predominate, on the surface of which smaller hills are scattered here and there in garlands and individually. From west to east-northeast, the Smolensk-Moscow, Valdai Uplands and Northern Uvals stretch here, replacing each other. They mainly serve as watersheds between the Arctic, Atlantic and internal (drainless Aral-Caspian) basins. From the Northern Uvals the territory descends to the White and Barents Seas. This part of the Russian Plain A.A. Borzov called it northern slope. Large rivers flow along it - Onega, Northern Dvina, Pechora with numerous high-water tributaries.

The southern part of the East European Plain is occupied by lowlands, of which only the Caspian is located on Russian territory.

The East European Plain has a typical platform topography, which is predetermined by the tectonic features of the platform: the heterogeneity of its structure (the presence of deep faults, ring structures, aulacogens, anteclises, syneclises and other smaller structures) with the unequal manifestation of recent tectonic movements.

Almost all large hills and lowlands of the plain are of tectonic origin, with a significant part inherited from the structure of the crystalline basement. In the process of a long and complex development path, they formed as a single territory in morphostructural, orographic and genetic terms.

At the base of the East European Plain lie the Russian plate with a Precambrian crystalline foundation and in the south the northern edge of the Scythian plate with a Paleozoic folded foundation. These include syneclises - areas of deep foundation (Moscow, Pechora, Caspian, Glazovskaya), anteclises - areas of shallow foundation (Voronezh, Volgo-Ural), aulacogens - deep tectonic ditches, in the place of which syneclises subsequently arose (Kresttsovsky, So-ligalichsky, Moskovsky, etc.), protrusions of the Baikal foundation - Timan.

The Moscow syneclise is one of the oldest and most complex internal structures of the Russian plate with a deep crystalline foundation. It is based on the Central Russian and Moscow aulacogens, filled with thick strata of the Riphean and is expressed in relief by fairly large uplands - Valdai, Smolensk-Moscow and lowlands - Upper Volga, North Dvina.

The Pechora syneclise is located wedge-shaped in the northeast of the Russian Plate, between the Timan Ridge and the Urals. Its uneven block foundation is lowered to varying depths - up to 5000-6000 m in the east. The syneclise is filled with a thick layer of Paleozoic rocks, overlain by Meso-Cenozoic sediments.

In the center of the Russian plate there are two large anteclises - the Voronezh and the Volga-Ural, separated by the Pachelma aulacogen.

The Caspian marginal syneclise is a vast area of deep (up to 18-20 km) subsidence of the crystalline basement and belongs to the structures of ancient origin; the syneclise is limited on almost all sides by flexures and faults and has angular outlines.

The southern part of the East European Plain is located on the Scythian epi-Hercynian plate, lying between the southern edge of the Russian plate and the alpine folded structures of the Caucasus.

Modern relief, which has undergone a long and complex history, turns out to be in most cases inherited and dependent on the nature of the ancient structure and manifestations of neotectonic movements.

Neotectonic movements on the East European Plain manifested themselves with different intensity and direction: in most of the territory they are expressed by weak and moderate uplifts, weak mobility, and the Caspian and Pechora lowlands experience weak subsidence (Fig. 6).

The development of the morphostructure of the northwestern plain is associated with the movements of the marginal part of the Baltic shield and the Moscow syneclise, therefore monoclinal (sloping) strata plains are developed here, expressed in orography in the form of hills (Valdai, Smolensk-Moscow, Belorussian, Northern Uvaly, etc.), and strata plains occupying a lower position (Verkhnevolzhskaya, Meshcherskaya). The central part of the Russian Plain was influenced by intense uplifts of the Voronezh and Volga-Ural anteclises, as well as subsidence of neighboring aulacogens and troughs. These processes contributed to the formation of layered, stepwise uplands (Central Russian and Volga) and the layered Oka-Don plain. The eastern part developed in connection with the movements of the Urals and the edge of the Russian plate, so a mosaic of morphostructures is observed here. In the north and south, accumulative lowlands of the marginal syneclises of the plate (Pechora and Caspian) are developed. Between them alternate stratified-tiered uplands (Bugulminsko-Belebeevskaya, Obshchiy Syrt), monoclinal-stratified uplands (Verkhnekamskaya) and the intraplatform folded Timan Ridge.

During the Quaternary, climate cooling in the northern hemisphere contributed to the spread of glaciation.

There are three glaciations on the East European Plain: Oka, Dnieper with the Moscow stage and Valdai. Glaciers and fluvioglacial waters created two types of plains - moraine and outwash.

The southern border of the maximum distribution of the Dnieper cover glaciation crossed the Central Russian Upland in the Tula region, then descended along the Don valley - to the mouth of the Khopr and Medveditsa, crossed the Volga Upland, then the Volga near the mouth of the Sura River, then went to the upper reaches of the Vyatka and Kama and crossed the Urals in area 60° N. Then came the Valdai glaciation. The edge of the Valdai ice sheet was located 60 km north of Minsk and went northeast, reaching Nyandoma.

Natural processes of the Neogene-Quaternary time and modern climatic conditions on the territory of the East European Plain determined various types of morphosculptures, which are zonal in their distribution: on the coast of the seas of the Arctic Ocean, marine and moraine plains with cryogenic relief forms are common. To the south lie moraine plains, transformed at various stages by erosion and periglacial processes. Along the southern periphery of the Moscow glaciation there is a strip of outwash plains, interrupted by remnant elevated plains covered with loess-like loams, dissected by ravines and ravines. To the south there is a strip of fluvial ancient and modern landforms on highlands and lowlands. On the coast of the Azov and Caspian Seas there are Neogene-Quaternary plains with erosional, depression-subsidence and aeolian relief.

The long geological history of the largest geostructure - the ancient platform - predetermined the accumulation of various minerals on the East European Plain. The richest deposits of iron ore (Kursk magnetic anomaly) are concentrated in the foundation of the platform. Associated with the sedimentary cover of the platform are deposits of coal (eastern part of Donbass, Moscow basin), oil and gas in Paleozoic and Mesozoic deposits (Ural-Volga basin), and oil shale (near Syzran). Building materials (songs, gravel, clays, limestones) are widely used. Brown iron ores (near Lipetsk), bauxites (near Tikhvin), phosphorites (in a number of areas) and salts (Caspian region) are also associated with the sedimentary cover.

Climate

The climate of the East European Plain is influenced by its position in temperate and high latitudes, as well as neighboring territories (Western Europe and Northern Asia) and the Atlantic and Arctic oceans. The total solar radiation per year in the north of the plain, in the Pechora basin, reaches 2700 mJ/m2 (65 kcal/cm2), and in the south, in the Caspian lowland, 4800-5050 mJ/m2 (115-120 kcal/cm2). The distribution of radiation across the plain changes dramatically with the seasons. In winter, radiation is much less than in summer, and more than 60% of it is reflected by snow cover. In January, the total solar radiation at the latitude Kaliningrad - Moscow - Perm is 50 mJ/m2 (about 1 kcal/cm2), and in the southeast of the Caspian lowland it is about 120 mJ/m2 (3 kcal/cm2). Radiation reaches its greatest value in summer and July; its total values in the north of the plain are about 550 mJ/m2 (13 kcal/cm2), and in the south - 700 mJ/m2 (17 kcal/cm2). All year round, westerly transport of air masses dominates over the East European Plain. Atlantic air brings coolness and precipitation in summer, and warmth and precipitation in winter. When moving east, it transforms: in summer it becomes warmer and drier in the ground layer, and in winter - colder, but also loses moisture

During the warm period of the year, from April, cyclonic activity occurs along the lines of the Arctic and polar fronts, shifting to the north. Cyclonic weather is most typical for the northwest of the plain, so cool sea air from temperate latitudes often flows into these areas from the Atlantic. It lowers the temperature, but at the same time it heats up from the underlying surface and is additionally saturated with moisture due to evaporation from the moistened surface.

The position of January isotherms in the northern half of the East European Plain is submeridional, which is associated with greater frequency of occurrence in the western regions of the Atlantic air and its lesser transformation. The average January temperature in the Kaliningrad region is -4°C, in the western part of the compact territory of Russia about -10°C, and in the northeast -20°C. In the southern part of the country, isotherms deviate to the southeast, amounting to -5...-6°C in the area of the lower reaches of the Don and Volga.

In summer, almost everywhere on the plain, the most important factor in the distribution of temperature is solar radiation, so isotherms, unlike in winter, are located mainly in accordance with geographic latitude. In the far north of the plain, the average July temperature rises to 8°C, which is associated with the transformation of air coming from the Arctic. The average July isotherm of 20°C goes through Voronezh to Cheboksary, approximately coinciding with the border between forest and forest-steppe, and the Caspian lowland is crossed by an isotherm of 24°C.

The distribution of precipitation over the territory of the East European Plain depends primarily on circulation factors (westerly transport of air masses, the position of the Arctic and polar fronts and cyclonic activity). Especially many cyclones move from west to east between 55-60° N. latitude. (Valdai and Smolensk-Moscow uplands). This strip is the most humidified part of the Russian Plain: the annual precipitation here reaches 700-800 mm in the west and 600-700 mm in the east.

Relief has an important influence on the increase in annual precipitation: on the western slopes of the hills, 150-200 mm more precipitation falls than on the underlying lowlands. In the southern part of the plain, maximum precipitation occurs in June, and in the middle zone - in July.

The degree of moisture in an area is determined by the ratio of heat and moisture. It is expressed in various quantities: a) the moisture coefficient, which on the East European Plain varies from 0.35 in the Caspian Lowland to 1.33 or more in the Pechora Lowland; b) the dryness index, which varies from 3 in the deserts of the Caspian lowland to 0.45 in the tundra of the Pechora lowland; c) average annual difference in precipitation and evaporation (mm). In the northern part of the plain, moisture is excessive, since precipitation exceeds evaporation by 200 mm or more. In the band of transitional moisture from the upper reaches of the Dniester, Don and Kama rivers, the amount of precipitation is approximately equal to evaporation, and the further south of this band, the more evaporation exceeds precipitation (from 100 to 700 mm), i.e., moisture becomes insufficient.

Differences in the climate of the East European Plain affect the nature of vegetation and the presence of fairly clearly defined soil and plant zonation.

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Transnistrian State University named after. T.G. Shevchenko

Faculty of Natural Geography

Department of Physical Geography and Environmental Management.

on the topic: Comprehensive physical and geographical characteristics of natural zones of the Russian Plain

Completed by: Varanitsa A.

Teacher: Doga E.F.

Tiraspol 2013.

Introduction

Tundra and forest-tundra zone

Taiga zone

Forest-steppe zone

Steppe zone

Semi-desert and desert zones

Conclusion

Bibliography

Application

Introduction

The Russian (East European) Plain is one of the largest plains on our planet (the second largest after the Amazon Plain in Western America). It is located in the eastern part of Europe. Since most of it is located within the borders of the Russian Federation, the East European Plain is sometimes called the Russian Plain. In the northwestern part it is limited by the mountains of Scandinavia, in the southwestern part by the Sudetes and other mountains of central Europe, in the southeastern part by the Caucasus, and in the east by the Urals. From the north, the Russian Plain is washed by the waters of the White and Barents Seas, and from the south by the Black, Azov and Caspian Seas.

The length of the plain from north to south is more than 2.5 thousand kilometers, and from west to east - 1 thousand kilometers. Almost the entire length of the East European Plain is dominated by gently sloping terrain. The majority of Russia's population and most of the country's large cities are concentrated within the territory of the East European Plain. It was here that the Russian state was formed many centuries ago, which later became the largest country in the world by its territory. A significant part of Russia's natural resources is also concentrated here.

The East European Plain almost completely coincides with the East European Platform. This circumstance explains its flat terrain, as well as the absence of significant natural phenomena associated with the movement of the earth’s crust (earthquakes, volcanic eruptions). Small hilly areas within the East European Plain arose as a result of faults and other complex tectonic processes. The height of some hills and plateaus reaches 600-1000 meters. In ancient times, the Baltic shield of the East European Platform was at the center of glaciation, as evidenced by some forms of glacial relief. On the East European Plain there are almost all types of natural zones found in Russia. The Russian Plain has clearly defined natural zones: tundra and forest-tundra, zone of mixed and broad-leaved forests, forest-steppe, steppe, semi-desert and desert.

Tundra and forest-tundra zone

The youngest landscape zone on the Russian Plain is tundra. It was formed only after the death of the Valdai glacier.

Some, albeit not particularly significant, fluctuations in the boundaries of landscape zones were observed in post-glacial times. In particular, there is a lot of evidence suggesting that during the climatic optimum (Atlantic period) most of the continental tundra of the Russian Plain was captured by taiga and forest-tundra.

Tundra and forest-tundra are two independent landscape zones. However, the forest-tundra on the Russian Plain is presented as a narrow strip that has not yet been sufficiently studied, therefore, for convenience of description, it is combined here with the tundra zone.

The tundra and forest-tundra zones include the Arctic islands: Franz Josef Land, Novaya Zemlya, Vaigach, Kolguev and the Barents Sea coast on the mainland.

The southern border of the forest-tundra on the mainland passes near the Arctic Circle, and the northern island of the Franz Josef Land archipelago lies at a latitude of 81045 "N. This geographical position determines the small amount of total solar radiation in the tundra. And although in the summer, during a continuous polar day, solar radiation reaches more or less significant sizes, but the overwhelming majority of it goes not to warm the soil and air, but to evaporate moisture. Therefore, the air temperature in the tundra and forest-tundra is low even in summer: the average July temperature in the forest-tundra is about 12 °, and on Franz Land -Joseph it is close to zero.

The severity of summer in the tundra and forest-tundra increases due to the fact that their territory is washed by the waters of the Barents and White Seas, which absorb a lot of heat, which is spent on melting ice and heating water. But in winter, the seas “heat” the territory of the tundra and forest-tundra and prevent a sharp cooling of the air. The latter is especially noticeable on the Murmansk coast, where the Barents Sea does not freeze even in winter. The average January temperature on the Murmansk coast is above -10°, and only in the north of Novaya Zemlya and Franz Josef Land does it drop below -20°.

In addition to the seas, the weakening of the climate continuity of the European tundras is strongly influenced by active cyclonic activity. It is associated with the passage of the Arctic front over the Barents Sea. In winter, warm masses of Atlantic air come here with cyclones, causing unstable weather with heavy precipitation. The annual precipitation in European tundras is 300--400 mm; this is much more than the annual precipitation in the tundra of Siberia.

Tundra and forest-tundra are young landscapes. Their territory was freed from continental ice later than other areas. Here, traces of the presence of the glacier are clearly visible in the relief, and the north of Novaya Zemlya and a large part of the Franz Josef Land archipelago are still hidden under ice.

The formation of tundra and forest-tundra landscapes occurs under conditions of prevailing frost weathering; the activity of the biological components of the landscape - vegetation, fauna and microorganisms in the soil - is not very active. It intensifies to the south - in typical tundra and forest-tundra. In the Arctic deserts of Franz Josef Land, the tundra landscape is in the first stages of formation: lichens, mosses and flowering plants clinging to the soil grow in separate clumps, most often along frost-cut cracks in the rocks. In the typical tundra subzone there is a fully formed landscape well adapted to the cold climate of the North with developed moss-lichen, shrub and shrub cover.

In landscape terms, the tundra zone is divided into three subzones. The Arctic desert subzone includes Franz Josef Land and northern Novaya Zemlya. The natural conditions of the subzone are characterized by exceptional severity. The average temperature of the warmest month - July - is below 4.5°. The soils of Arctic deserts are polygonal, skeletal, with sparse and in some places completely disappearing plant cover. We believe, just like L. S. Berg and I. M. Ivanov, that this subzone can be considered as an independent ice zone; The landscape feature of this zone throughout the year is ice and snow. The name “ice zone” conveys the essence of the landscape of the extreme latitudes of the Arctic more fully than the “Arctic zone,” as some researchers propose to call it.

The arctic tundra subzone is widespread in the south of Novaya Zemlya, Vaygach Island and the coast of Baydaratskaya Bay. The average July temperature here is 5-6°. The vegetation, as in the previous subzone, is very poor; only a few species of low-growing grasses and shrubs rise above the moss-lichen ground cover. The subzone is heavily swamped, with peaty-gley soils and hypnotic bogs predominating.

Typical tundra is characteristic of the entire continental coast of the Barents Sea. The average July temperature there reaches 6-10°. In the north of the subzone, moss and lichen tundras are predominantly developed; in the south, shrub tundras with thickets of polar willow and polar birch grow. Unlike the two previous subzones, sphagnum bogs here acquire landscape significance.

The vegetation cover of a typical tundra is often very similar to the corresponding tiers of the taiga - moss-lichen and shrub. Looking at some areas of moss-lichen tundra, dotted with blueberries or lingonberries, you can’t help but think that coniferous forests were once rustling here. There is nothing surprising in such an assumption. Between the tundra and the moss-lichen and shrub cover of the taiga there is not only a physiognomic similarity, but also a genetic commonality. During the post-glacial climatic optimum, forests, most likely of the forest-tundra open forest type, covered almost the entire continental tundra of the Russian Plain. Later, due to climate cooling, the forests retreated to the south, and the moss-lichen and shrub layers, in a modified form, became part of the tundra vegetation cover.

L. S. Berg believed that the advance of the tundra into the forest, caused by climate cooling, continues to this day. G.I. Tanfilyev also assumed that the tundra was encroaching on the forest, but he saw the reason for this, unlike L.S. Berg, not in the cooling of the climate, but in the fact that huge snowdrifts were blowing up on the edges of the forest, the melting of which leads to waterlogging soil and death of tree species.

A different view on the relationship between the tundra and forest was held by V. R. Williams. In his opinion, the young tundra landscape over time, regardless of general climate changes, evolves into a forest landscape, and therefore, at present, it is not the tundra that is advancing on the forest, but the forests on the tundra.

Observations over the last two decades show that in nature there is an encroachment of forests onto the tundra. The process of forest encroachment on the tundra is not local, but universal; it has been noted in the tundras of the Russian Plain, Eastern and Northeastern Siberia, and North America. Now it is difficult to say whether the encroachment of forests on the tundra is the result of a directed climate change towards warming, or whether it is a consequence of short-term, periodic climate fluctuations and soon the encroachment of forests on the tundra may stop or be replaced by the opposite process - the encroachment of tundra on the forest.

In addition to climate, the relationship between the tundra and forest is influenced by other factors that should not be forgotten. In particular, in tundras that have recently been freed from a glacier, the erosive dissection of the relief increases, and this improves drainage and increases the forest suitability of the tundra, and promotes the movement of forests to the north. Another important factor is human activity. For many centuries, people have destroyed forests in the forest-tundra. Many northern island forests have disappeared without a trace under the influence of human activity. It is precisely such artificially deforested areas that are primarily captured by the forest as it moves north. Therefore, in the case of the protection of northern forests and moderate use of forest-tundra for pastures, it is possible to expand the forest area, not associated with changes in any natural components of the landscape.

Regardless of the reasons causing the forest to encroach on the tundra, this process is of great economic importance. It creates favorable conditions for afforestation of the forest-tundra and southern regions of the tundra. Successful experiments in afforestation in the tundra have already been carried out in the area of the cities of Naryan-Mar and Vorkuta and along the Pechora railway. Afforestation of the tundra will improve its microclimate and increase the productivity of northern meadows and pastures.

Taiga zone

Taiga is a zone of coniferous forests on podzolic soils. In the southwest it borders on the mixed forest zone, in the southeast on the forest-steppe zone. Its southern border passes through Leningrad, Novgorod, Yaroslavl, Gorky, and Kazan.

Over vast areas - from the White Sea to the Volga - the taiga landscape is relatively monotonous. Everywhere there are coniferous forests of spruce on loam and pine on sand. These tree species are joined east of Onega by Sukachev larch (Larix Sukaczewii), east of Kostroma by fir (Abies sibirica) and in the Cis-Urals by cedar (Pinus sibirica). Everywhere in the taiga there are poor podzolic soils, constantly alternating with bog-podzolic and bog soils. Like any other type of landscape, taiga is largely a product of climate. This latter is characterized by low summer temperatures and the predominance of precipitation over evaporation. The average July temperature (at sea level) ranges from 12° in the north to 20° in the south. Precipitation in the middle part of the taiga is 500-600 mm per year, and evaporation there does not exceed 400 mm.

With a positive moisture balance, groundwater in the taiga comes to the surface or lies in close proximity to it. This in turn leads to waterlogging of the area. Taiga is a zone dominated not only by coniferous forests, but also by swamps, including upland swamps, covered with sphagnum.

The complex of animals characteristic of taiga forests on the Russian Plain has been greatly modified by humans. Among the surviving typical inhabitants of the taiga there are bear, marten, lynx, wolverine, ermine, squirrel, chipmunk, mountain hare, elk; Birds include wood grouse, hazel grouse, woodpeckers, crossbills, and various species of waders. At the same time, species of southern origin have already penetrated into the taiga through fields and clearings: the hedgehog, the brown hare, the black polecat, the common vole, the forest mouse, the field mouse and the little one, and the black grouse.

The taiga of the Russian Plain has three features that distinguish it from other taiga regions of Russia. It has a temperate continental humid climate with active cyclonic activity. In this respect, it differs sharply from the taiga of Eastern Siberia. The predominance of dark spruce forests is the second feature of the taiga of the Russian Plain. And in this respect, it is the complete opposite of the light larch taiga of Eastern Siberia. Finally, moderate swampiness distinguishes it both from the East Siberian taiga, which is poor in swamps, and from the heavily swampy, drainage-free West Siberian taiga.

In the taiga of the Russian Plain, moving from north to south, zonal changes in the landscape are observed, making it possible to distinguish three subzones in it: northern, typical and southern taiga.

The northern taiga subzone is located between the forest-tundra and 64° N. w. Summer in the northern taiga is short and cold (average July temperature is from 14 to 16°); Noteworthy is the high percentage of swampy areas, low growth and sparse forests. An admixture of birch is common in spruce forests; swamp-tundra species are found in the grass and shrub cover. In addition to green moss spruce forests, long-moss spruce forests, sphagnum spruce forests and lichen spruce forests are common in the northern taiga. There are few typical podzolic soils in the northern taiga. The podzol formation process here is constantly complicated by the swamp-tundra process, and therefore gley-podzolic soils with surface gley dominate on the loams.

Subzone of typical (middle) taiga. The average July temperature reaches 10-18°C. The taiga of this subzone is characterized by a closed forest stand, the absence of birch as a permanent admixture with spruce, and the dominance of the spruce-blueberry association in the group of green-moss spruce forests. In the south of the typical taiga, the first representatives of broad-leaved species appear. The podzol-forming process finds optimal conditions for its development in the subzone; Typical strongly podzolic soils become dominant in this subzone.

In the southern taiga subzone, the average July temperature exceeds 18°. Coniferous forests find the most favorable conditions for their growth. Instead of spruce-blueberry forests, spruce-sorrel forests are becoming a common association. A new type of coniferous forest appears - complex (shrub) spruce and pine forests, containing in the shrub layer and undergrowth linden, elm, hazel (Corylusavellana), warty euonymus (Evonymus verrucosus) and other species characteristic of broad-leaved forest. The area of swamps in the southern taiga is decreasing, and the sod process is intensifying in soil formation, leading to the formation of sod-podzolic soils. Along with zonal differences in the taiga of the Russian Plain, provincial landscape features are clearly expressed. These latter are due to the heterogeneity of the geological-geomorphological and longitudinal-climatic conditions of the zone.

The west of the taiga is part of the Baltic crystalline shield with surface occurrence of up to Cambrian crystalline rocks, the east is a tectonic basin filled with sedimentary Paleozoic and Mesozoic. Dissected hills alternate in the taiga with swampy lowlands. The northwest of the taiga bears fresh traces of the Valdai glaciation: hilly moraine landscapes, sandy, outwash plains, and an endless number of lakes. In the central and northeastern parts of the taiga, which were covered by the Dnieper glacier, moraine landscapes were greatly processed and modified, and the extreme southeast of the zone was completely deprived of ice cover.

Longitudinal and climatic differences are superimposed on the geological and geomorphological differences in the taiga of the Russian Plain. The climate of the eastern taiga is much more continental than the west. The average January temperature in the southwest of the zone is about -6°, and in the northeast it is below -20°; The annual amount of precipitation also changes accordingly - from 600 mm in the west to 500 mm in the east.

Zone of mixed and deciduous forests

Mixed forests are an independent type of landscape, the main feature of which is the presence in zonal conditions of coniferous and broad-leaved forests on soddy-podzolic soils.

In the northeast, mixed forests border with taiga along the line: Leningrad - Novgorod - Yaroslavl - Gorky. In the southeast they are replaced by forest-steppe along the line: Lutsk - Zhitomir - Kyiv - Kaluga - Ryazan - Gorky. In the west, outside the USSR, mixed forests are gradually turning into European broad-leaved forests.

The position of mixed forests in the southwest of the forest region of Russia and their relative proximity to the warm Atlantic Ocean enhance the western features in the landscape of this zone. The western character of the mixed forest zone is reflected primarily in climatic conditions. This zone does not experience either severe frosts or deep snow cover in winter. The average January temperature in the west of the zone is above -5°, in the east about -12°. Frequent thaws in winter prevent the formation of deep snow cover. Therefore, the southwest of the zone in terms of the duration of snow cover (less than 100 days) and its height (below 30 cm) resembles the steppes and semi-deserts of the Volga region. Western climate features are further expressed in the abundance of precipitation. In most of the zone, their annual number exceeds 600 mm, and in some places (east of Riga) even 800 mm.

The soddy-podzolic soils in the west of the zone already have some characteristics that bring them closer to the brown forest soils of Western Europe. Thus, in the west of Belarus, podzolic soils have a yellow-fawn color, and in the Kaliningrad region more or less typical brown forest soils are described. The western influence on the vegetation of the mixed forest zone is very noticeable. Broad-leaved forests are of Western origin, with characteristic shrub and herbaceous species. In the Baltics, such typical Western Europeans as yew (Taxus baccata) and ivy (Hedera helix) are known. The very composition of coniferous species in the landscape zone of mixed forests is different than in the taiga: European spruce and pine are common here and there are no Siberian coniferous species at all - Siberian spruce, Siberian fir, Sukachev larch.

The location of coniferous and broad-leaved species is subject to a certain pattern: broad-leaved forests prefer to grow on loamy, well-drained soils, most often on southern slopes and the tops of low hills.

Like vegetation, the fauna of mixed forests is rich in Western species and depleted in taiga-Siberian species. Typical Western species include the European subspecies of roe deer, wild boar, wild forest cat, several species of dormouse, mink, and pine marten; of birds - green and middle woodpeckers, finch. An ancient inhabitant of broad-leaved forests, the bison, has been preserved in Belovezhskaya Pushcha. The heterogeneity of geological and geomorphological conditions brings great diversity to the landscape of mixed forests. Moving from the northwest to the southeast, in the zone of mixed forests you can find traces of a glacier of the most varied preservation - from fresh terminal moraine ridges of the Valdai glaciation in the west to secondary moraine plains and erosional relief in the area of the Dnieper glaciation in the east. The west of the mixed forest zone is called the “lake belt” due to the abundance of moraine lakes. In the east of the zone, watershed lakes are found as a rare exception.

The role of the glacier in the formation of the relief of the zone was greatly exaggerated for a long time, considering that all its elevations, such as the Valdai, Smolensk-Moscow, Lithuanian-Belarusian, and others, are of glacial-accumulative origin. In reality, all these hills are composed of bedrock and are only covered on the surface by a moraine of relatively small thickness. The origin of the main elevations of the zone is due to tectonics and partly to ancient erosion.

The vertical differentiation of landscapes in the mixed forest zone is much more pronounced than in the taiga zone. Its sharpness is due not only to large fluctuations in relative heights, but also to two more circumstances: geological differences between highlands and lowlands and the position of the southern border of the zone at the main landscape boundary of the Russian Plain. Many lowlands in the mixed forest zone belong to the “Polesie type” - they have passed the stage of a periglacial reservoir and are composed of fluvio-glacial sands. Poorly drained, even on the border with the forest-steppe they are swampy and covered with pine forests, reminiscent of the taiga in their landscape. Examples of them are Polesie and Meshchera. The hills are composed of loamy moraine, which in the south of the zone is covered with cover and loess-like loams. With good drainage and a moisture balance close to neutral, fertile soddy-podzolic and even gray forest soils are formed on the loamy soils of the uplands in the south of the zone. Accordingly, the vegetation also takes on a southern character: swamps disappear, the role of broad-leaved species in the tree stand increases, and the first representatives of the northern steppes appear.

Forest-steppe zone

Forest-steppe is a zonal landscape of the temperate zone, characterized by the alternation of closed, predominantly deciduous forests on gray forest (forest-steppe) soils and grassy steppes on chernozems, now mostly plowed.

The northern border of the forest-steppe, coinciding with the main landscape boundary of the Russian Plain, is well defined climatically: near it there is a change from a positive moisture balance to a negative one. This is the first zone on the Russian Plain, moving from north to south, in which evaporation begins to exceed the annual amount of precipitation. Botanically and pedologically, the northern border of the forest-steppe is marked by the southern border of spruce and the northern limit of the continuous distribution of gray forest (forest-steppe) soils. From west to east it goes as follows: Lutsk - Zhitomir - Kyiv - Karachev - Kaluga - Ryazan - Gorky - Kazan - the right bank of the Kama and Belaya rivers to the Ural ridge.

In the south, where the last large forest islands disappear on the watersheds, the forest-steppe turns into the steppe zone. It is difficult to establish the exact southern border of the forest-steppe, since many forest islands near it have long been cut down by humans. Approximately the southern border of the forest-steppe on the Russian Plain coincides with the southern border of the distribution of medium-humus (ordinary) chernozems and passes through the following places: the southern outskirts of Codri in Moldova - Dnepropetrovsk - the Samara valley - northeast of Stalino - North. Donets, from the mouth of Kalitva to Oskol - Don, from the mouth of Chernaya Kalitva to Podgornaya, - the valley of the Podgornaya River on the Kalach Upland - Volga, north of Kamyshin - General Syrt, south of the Samara valley.

The southern border of the forest-steppe is located near the climatic “Voeikov axis”. Therefore, in the north of the forest-steppe, humid westerly winds predominate in winter and summer, and cyclones are relatively frequent; in the south of the zone, the westerly transport weakens, in winter the role of eastern winds increases, and the frequency of cyclones decreases. In this regard, the annual amount of precipitation in the forest-steppe quickly decreases from 500-600 mm in the north to 300-400 mm in the south. In contrast to precipitation, summer temperatures increase in a southerly direction: the average July temperature at sea level varies from 20° in the north of the zone to 22.5° in the south. With this ratio of precipitation and temperature, the moisture balance in the forest-steppe, although negative, is not so much as to impede the development of vegetation.

The unfavorable side of the forest-steppe climate for vegetation is the instability of moisture, the alternation of wet years with dry ones. In the forest-steppe, for the first time, when moving from north to south, the need for special agrotechnical measures to combat drought and hot winds arises. The forest-steppe zone was not covered by a glacier, with the exception of the Dnieper and Oka-Don lowlands. Instead of moraine and fluvioglacial sands, loess and loess-like loams are common as subsoils. On these carbonate rocks, with discontinuous and inconsistent soil wetting under the cover of forb steppes, fertile chernozems were formed: podzolized and leached chernozems in the north, typical thick chernozems in the center and medium-humus (ordinary) chernozems in the south. Only in the far north of the zone and under forested areas in the south do chernozems give way to gray forest (forest-steppe) soils.

The soils of the forest-steppe change not only from north to south, but also from west to east. In the west, in the Ukrainian part of the forest-steppe, chernozems are distinguished by their great thickness and low humus content; in the Central Russian and Trans-Volga forest-steppe, on the contrary, the chernozems are thin, but rich in humus. The reason for these differences in soils in the west and east of the zone is twofold - increased continental climate and an increase in the clay fraction in the subsoils in the east of the zone.

In contrast to the podzols of the forested north, the forest-steppe soils do not suffer from excess moisture. The swampiness of lands in the forest-steppe is negligible. The economic value of forest-steppe soils in the south of the zone is in some places reduced by salinization processes, leading to the formation of malts and solonetzes. But the real disaster for forest-steppe soils is not salinization, but erosion.

Erosion processes in the forest-steppe zone are very active. There are many reasons that activate erosion processes in the forest-steppe: the presence of loose, easily eroded loess-like soils, the rainy nature of summer precipitation, a high degree of plowing of the territory, etc. The soils of the forest-steppe uplands are especially strongly eroded, where the density of the gully-beam network in some places exceeds 1.0 km per 1 km2 of area, and washed away soils in some areas occupy up to one third or more of the land fund. In the Kursk region, from fields located on slopes with a steepness of 4 - 6 °, only during snowmelt, 25-60 tons of fine soil per 1 hectare are washed away. Soils on steep slopes with southern and south-eastern exposure are most susceptible to erosion; soils on gentler slopes with northern exposure are least eroded.

The fight against soil erosion in the forest-steppe is as urgent and important a government task as the fight against droughts and hot winds.

In the forest-steppe, the connection between vegetation and soils with relief and subsoils is more clearly visible than anywhere else. All the uplands of the forest-steppe zone are more forested and covered with more leached soils than the adjacent lowlands. This is reflected in the vertical differentiation of the forest-steppe landscape, which is also noticeable when comparing watersheds with river valleys. To verify this, just look at the diagram of the placement of soils and vegetation depending on the relief, developed by G. I. Tanfilyev and B. A. Keller for the territory of the Central Russian forest-steppe. The floodplain of each river is occupied by meadows, sedge forests, oak forests and black alder forests in near-terrace depressions. The lower floodplain terraces, composed of sand, are covered with pine; in the inter-dune depressions there are patches of sphagnum bogs with cranberries. The pine forest on the border with the steppe terraces above the floodplain turns into a subbora, and then into a mixed-grass steppe on chernozems with aspen bushes on the malts in the depressions. The flat plains, once occupied by mixed-grass steppes, but now completely plowed, also have the same steppe character. Plakor ends with a high, dissected right bank of the river, lost under the greenery of a mountain oak forest.

The fauna of the forest-steppe is a motley mixture of forest and steppe species. In the forests there are elk, marten, squirrel, dormice, capercaillie, hazel grouse, black grouse, in the steppes and in open places - ground squirrels, European in the west of Ukraine and in Moldova, speckled - from the Moldavian SSR to the Volga, reddish - in the Volga region, the common dwarf, the ground hare (a large jerboa), the marmot (baibak), which is now close to complete extinction, the steppe polecat, various species of mouse-like rodents are numerous, the most common birds are the bustard and the little bustard, which have now become very rare in the forest-steppe of the Russian Plain. River beaver and muskrat are found along the river floodplains.

Over the centuries, human activity in the forest-steppe has not been in favor of the spread of forest animals. And although many steppe species also suffered greatly as a result of the economic development of the zone, in general the proportion of the steppe element in the modern animal world of the forest-steppe has undoubtedly increased compared to its amount in the animal world of the virgin forest-steppe. There are major differences between the northern and southern forest-steppe landscapes. This allows us to distinguish three subzones in the forest-steppe of the Russian Plain: northern, typical and southern” forest-steppe. The northern forest-steppe is developed on gray forest (forest-steppe) soils and podzolized chernozems and in the past was almost entirely covered with broad-leaved forests. Many botanists consider it a subzone of deciduous forests of the forest zone. However, the presence of islands of mixed-grass steppe speaks in favor of the forest-steppe, rather than forest, nature of this territory, which in its landscape is completely alien to the broad-leaved forests of Western Europe.

In a typical forest-steppe in the past, forest and mixed-grass steppe alternated, occupying approximately the same areas. The soils of a typical forest-steppe are leached and typical (thick) chernozems with islands of gray forest soils and podzolized chernozems under forests.

The southern forest-steppe on medium-humus (ordinary) chernozems is characterized by the dominance of cereal steppes and the presence of isolated forest islands on watersheds. Grass steppes predominated here over forests even before human intervention.

In the virgin state, differences between subzones in the forest-steppe appeared sharply. Nowadays, as a result of deforestation and plowing of the steppes, the differences between them have been greatly smoothed out, and cultivated fields have become the predominant landscape in all subzones.

Steppe zone

The most important features of the steppe landscape zone are a dry continental climate, treeless watersheds, and the predominance of herbaceous, predominantly cereal vegetation on chernozems and dark chestnut soils. As a type of vegetation, the steppe is also known in other landscape zones - in forest-steppe and semi-deserts.

The steppe zone, located south of the forest-steppe, goes to the Black and Azov seas. In the southeast it borders on a semi-desert zone. The border with the semi-desert runs along the west of Ergeniy, the north-eastern coast of the Tsimlyansk reservoir, goes to the Volga north of Stalingrad, from here it goes along the Volga valley to Saratov and, before reaching it, sharply turns east to the city of Uralsk.

The landscape of the steppe zone represents a single interconnected geographical complex. Many outstanding researchers have studied the steppes as a geographical complex. The development of Russian geobotany and soil science is largely associated with the development of issues of treeless steppes and the origin of chernozem.

The dry, continental climate plays an important role in the formation of the steppe geographical complex. With sunnier and hotter summers than in the forest-steppe, there is less precipitation, which entails a sharply negative moisture balance. In the south of the zone, evaporation is approximately twice the annual amount of precipitation. Droughts and hot winds, which were characteristic of the forest-steppe, are even more pronounced in the steppes. In the north of the steppe zone, in the city of Kalach (Voronezh region), in 1954, for 15 days (from June 25 to July 10), the maximum air temperature ranged from 33 to 39.4 °, with a minimum relative humidity of 27 up to 41%. Dry winds sometimes develop into black dust storms. In some years, black dust storms can also be observed in winter, when there is little snow.

The predominance of evaporation over precipitation leads to a decrease in surface runoff in the steppes, the vast majority of which also falls during the spring snowmelt period. As a result, the own river network in the steppes is few and low in water. Groundwater, lying at great Depth, is hard, sometimes salty, and not always suitable for drinking purposes.

The steppe zone is one of the oldest on the Russian Plain. As a type of landscape, it took shape in the Pliocene; in the Quaternary period, unlike the zones located to the north, it was not covered by a glacier at all. The relief of the zone is mature, erosive, with deep asymmetrical river valleys, large ravines and a developed network of ravines. The formation of erosional relief in most areas began from the end of the Paleogene, in places, for example in the Black Sea lowland, from the end of the Neogene.

Despite the antiquity of the steppe landscape, modern soils in the steppes are young post-glacial formations. Their youth is confirmed by the fact that the mother rock for them is loess and loess-like rocks, the accumulation of which occurred during the glaciation era.

The concept of steppes is always associated with the idea of chernozems. However, it should be borne in mind that the most fertile subtypes of chernozems, as well as the main area of distribution of chernozems in general, are not in the steppe landscape zone, but in the forest-steppe. In the steppe zone, only low-humus (southern) and in some cases medium-humus (ordinary) chernozems are known. In the south of the steppes, chernozems give way to dark chestnut soils that show signs of solonetsity. Solonetzes, rare in the north of the steppes, are common in the south of the zone and thereby reduce the economic value of the soil.

The cereal steppes of the western Russian Plain, like forbs, are almost completely plowed. They were preserved only in the southeast of the zone, in the Volga region, mainly in the form of old fallow lands used as pastures and pastures. However, here too, the proportion of virgin steppe lands has sharply decreased since 1953 due to increased plowing.

Plowed territory, loess-like soils, heavy rainfall in summer and rapid snowmelt in spring - all this creates conditions in the steppes that are favorable for the development of erosion and soil loss. In terms of the distribution and intensity of modern erosion processes and soil loss, the steppe zone is only slightly inferior to the forest-steppe.

There are many western species in the flora and fauna of the steppes of the Russian Plain. Such are, for example, the Ukrainian feather grass (Stipa ucrainica) and the coastal brome (Bromus riparius) among plants, the common mole rat and the speckled ground squirrel among animals. In the floodplain and ravine forests of the zone, east to the Ural Valley, oak is found together with its broad-leaved companions.

Another landscape feature of the southern Russian steppes is the presence of thickets of steppe shrubs, the so-called dereznyaks. They were also known in the forest-steppe, but were especially characteristic of the steppe zone. Steppe cherry, blackthorn, bobwhite, wolfberry (chiliga), and meadowsweet form impenetrable thickets on the slopes of the steppe and along the edges of the forest. This distinguishes the southern Russian steppes from the western Siberian steppes, which are almost devoid of forests.

As in the forest-steppe, in the steppe zone the arrangement of soils, vegetation and fauna is in close relationship with the terrain. This circumstance allows us to distinguish several types of terrain on the territory of the forest-steppe and steppe south of the Russian Plain - typological landscape complexes of great economic interest.

The floodplain type of terrain is best expressed in the valleys of large rivers in the lowlands. Water meadows, as well as floodplain sedge forests, oak groves and black alder forests are of great economic importance. There are many lowland swamps and oxbow lakes on the floodplains. Fertile floodplain lands produce high yields of corn, vegetables and other valuable crops.

The floodplain-terrace type consists of two or three, and sometimes more, terraces above the floodplain, usually located on the low-lying left banks of large rivers. The upper terraces, covered with loess-like rocks, differ little in their landscape from watersheds. The first and second terraces are composed of sands and sandy loams; their surface, reworked by the wind, has a hilly relief. The area of terraced sands along the Lower Dnieper, Don and North is especially large. Donets. In the forest-steppe, pine forests grow on the lower terraces above the floodplain. Large areas of sand are secured by plantings of pine, shellweed and grass crops. The upland type corresponds to flat watersheds with a sparse network of shallow drainage troughs and gullies. The soil cover and vegetation are characterized by homogeneity and constancy; they experience certain disturbances only in connection with the presence of steppe depressions on the plains. With a few exceptions, the plakoras are completely plowed. Their landscape is enlivened by shelterbelts, ponds and aspen bushes in the forest-steppe.

The remnant-watershed type differs from the previous one in the presence of mounds and hills of remnant-denudation origin on the watersheds. The rocky slopes of hillocks and hills are unsuitable for plowing and are used primarily as pastures. This type of terrain is known in the High Trans-Volga region, the Donetsk Ridge, the Volga and Azov uplands.

The riverine type is developed along riverine, predominantly right-bank sections of watersheds with a dense gully-beam network and washed away soils. Soils, vegetation, and riverine microclimates are extremely diverse. Very characteristic of it are ravine forests, to which mountain oak forests are added in the forest-steppe. The majority of finds of rare relict plants in the south of the Russian Plain are associated with the riverine type of terrain. The dissected relief complicates the economic development of riverine areas and requires anti-erosion measures. Zonal differences are clearly visible in the landscape of the steppe zone. An expression of zonal differences is the existence of two subzones: northern steppes on chernozems and southern steppes on dark chestnut soils.

Semi-desert and desert zones

natural zone forest-steppe tundra

The semi-desert zone enters the Russian Plain only in the southeast, occupying the Ergeni Upland and the northern half of the Caspian Lowland. Its southern border west of the Volga runs at a distance of about 150 km from the coast of the Caspian Sea; in the Volga-Ural interfluve it moves even further from the sea and passes here along the line: Lake Baskunchak - Lake Aralsor - the mouths of the Small and Bolshoi Uzeni - the Ural River south of Kalmykov.

The location in the southeast of the Russian Plain in the depths of the Eurasian continent determines the sharply continental, dry climate of this zone. Summer in semi-deserts is sultry and sunny. The average temperature in July reaches 23-25°; in the city of Novouzensk, during the warm period, there are 85 days of dry winds. Winter is as cold as on the Kola Peninsula: the average January temperature is --7--8° in the southwest of the zone and --13--14° in its northeast. The snow cover is thin - from 10 to 30 cm. The total annual amount of precipitation is 300-200 mm; this is three to four times less than the evaporation value. For example, in the city of Novouzensk the annual precipitation is 250 mm, and evaporation is 910 mm.

The surface flow in the semi-desert is negligible, so its own river network is not developed. Groundwater is saline and most of it is not suitable for drinking.

In addition to climate, the geological and geomorphological features of the territory have the strongest impact on the landscape of the zone - low absolute height, flatness, weak erosional dissection, the presence of saline bedrock and Quaternary rocks. There are few ravines and gullies in the zone. Instead of these erosional forms, closed basin-depression forms are widespread - steppe depressions, estuaries, soras, etc. Their genesis is different - from suffusion-subsidence to karst and tectonic (some estuaries).

The continental climate, flat terrain and saline soils contribute to the accumulation of salts in semi-desert soils, including easily soluble ones. Solonetz soils are as characteristic of semi-deserts as light chestnut soils, which are zonal here. Lack of moisture and soil salinity lead to a patchy, clump-like distribution of vegetation. The abundance of depression-depression forms causes extraordinary diversity and complexity of plant and soil cover. With a lack of moisture, even the most insignificant depressions - 10 - 20 cm deep - lead to sudden changes in soil and vegetation. We can say that a semi-desert is a zone of complexes in which a grassy steppe in depressions, a wormwood-hodgepodge desert on solonetzes, and a fescue-chamomile semi-desert proper on light chestnut soils are closely intertwined.

In the fauna of semi-deserts, an outstanding role belongs to rodents. Among them, in terms of abundance and impact on the landscape, ground squirrels stand out, represented here by two species - the small ground squirrel, which lives on loamy plains, and the yellow ground squirrel, which inhabits the sands. The occurrence of gophers is very high. In some places, up to 740-750 gopher burrows can be counted on one hectare. The discharges of gophers create the tubercular microrelief characteristic of the Caspian region, which further enhances the complexity of the soil and vegetation cover.

In addition to gophers, common rodents in the semi-desert are jerboas, gerbils, voles, steppe pieds, and mice. The saiga antelope, which previously inhabited the steppe and forest-steppe zones of the Russian Plain, is found within the zone. Here and there a wild boar is found in the reed thickets of river valleys. The most common predators are the wolf, corsac fox, and steppe polecat.

The composition of birds (steppe eagle, harrier, larks), reptiles and insects is also quite diverse.

Most of the semi-desert zone is used as pasture. Estuary and irrigated agriculture is developed in some places.

The southern third of the Caspian lowland belongs to the desert zone. Due to the small size of the territory and the uniformity of geological and geomorphological conditions, the desert zone on the Russian Plain belongs to one landscape province - the province of sandy and clayey-salt deserts of the Caspian region. The features of dryness and continental climate, characteristic of the southeast of the Russian Plain, reach their maximum in the desert zone. The annual amount of precipitation in deserts is less than 200 mm. In the city of Astrakhan, on average, 170 mm of precipitation falls per year, with an evaporation rate of 936 mm. The winter is exceptionally light-snowy, even at the end of it the snow cover does not reach 10 cm. For this reason, the Caspian desert, especially west of the Volga (Black Lands), where the winter is warmer, is a good winter pasture.

Surface flow in deserts is so insignificant (less than 0.5 l/sec) that not a single local river crosses the territory of the province.

Geologically, the territory of the Caspian desert is very young; Its coastal parts turned into dry land quite recently. Unlike the semi-desert, the desert zone in the Quaternary was flooded by all three transgressions of the Caspian Sea, including the Khazar one. Almost the entire territory of the province lies below sea level.

Huge areas in the desert are occupied by sands of marine (late Khvalynian Sea) and alluvial-deltaic origin. The area of the Volga-Ural sands alone is about 50 thousand km3.

On the coast of the Caspian Sea and especially near the Volga delta and to the west of it, Baer mounds are found. More precisely, these are low (6-20 m) and long (from several hundred meters to 5-6 km) sand ridges, mainly in a latitudinal direction. First described by Academician K. M. Baer, the mounds then more than once served as the object of special study. A variety of hypotheses have been put forward regarding their genesis - aeolian, tectonic, water-erosion, water-accumulative and many others. Most likely, their formation should be associated with the accumulation and movement of sediments by the waters of ancient sea basins retreating to the south. Later, some of the mounds underwent aeolian reworking. Brown desert-steppe soils appear in the soil cover of deserts, and salt marshes stretch in a wide strip along the shores of the Caspian Sea. Vegetation is closely dependent on soils. On saline clayey soils, wormwood-solyanka groups are present. The vegetation of sandy deserts, characterized by shallow fresh groundwater, looks more diverse. It is formed by grass-wormwood groups with the participation of bluegrass (Poa bulbosa), Siberian wheatgrass (Agropyrum sibiricum), twig grass, and milkweed. In the north-west of the Volga-Ural sands in the Urda sands, rich in fresh water, small groves of poplar and aspen have survived, and orchards and melons are planted.

Deserts are used as pastures and hayfields. In the wide Volga-Akhtuba floodplain, horticulture, vegetable gardening and melon growing are developed. The area of floodplain land used for agriculture is still small and can be successfully increased many times over.

Conclusion

So, based on the work done, we can say that on the territory of the Russian Plain there are almost all types of natural zones found on the territory of Russia.

Based on the above, the question arises, “why is there a complete set of natural zones on the Russian Plain?” All this happens due to the length of the plain from north to south of more than 2.5 thousand kilometers, and from west to east - 1 thousand kilometers. Consequently, climatic zones and natural zones change from the tundra in the north to the desert in the south.

These zones gradually replace each other from north to south. For example, off the coast of the Barents Sea, the subtropical zone is dominated by tundra. To the south, in the temperate zone, a strip of forests begins, which stretches from Polesie to the Urals. It includes both coniferous taiga and mixed forests, which in the west gradually turn into deciduous ones. To the south begins the transition zone of the forest-steppe, and beyond it the steppe zone. A small strip of deserts and semi-deserts begins on the territory of the Caspian lowland.

Examining the natural zones of the Russian plain, we can say that between the zones there are large differences in climate, relief, soil composition, differences in flora and fauna, etc. For example, if in the taiga the average July temperature (at sea level) ranges from 12° in the north to 20° in the south, then in the forest-steppe the average July temperature at sea level varies from 20° in the north of the zone to 22.5° in the south.

Bibliography

1. Physical geography of Russia. At 2 o'clock Rakovskaya E.M., Davydova M.I. M.: 2001, Part 1 - 288 p., Part 2 - 304 p.

2. 10. Berg L. S. Geographical zones of the Soviet Union, vol. 1, ed. 3. M., 1947; t. 2. M., 1952.

3. Vegetation map of the USSR (for higher educational institutions), 1: 4,000,000. M., 1955.

4. Atlas of the USSR - M.: GUGK, 1983-1986.

5. Physico-geographical atlas of the world (FGAM) - M. GUGK 1964.

6. Alpatiev A. M., Arkhangelsky A. M. et al. Physical geography of the USSR, part III. M., 1976.

Application

Scheme of natural zones of the Russian Plain

Tundra and forest-tundra zone.

Taiga zone

Zone of mixed and deciduous forests

Steppe zone.

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Theory of formation, age and tectonic structure of the plain

At the base of the Russian Platform lies an ancient (more than 1.5 billion years old) folded crystalline foundation, protruding only in the areas of the Baltic and Ukrainian shields. On the rest of its surface, as a covering, there is a thick layer of sedimentary rocks dating from the Proterozoic to the Cenozoic. The platform thickness varies from 35 to 55 km.

As a result of the shields coming to the surface, the Central Russian Upland and the Khibiny Mountains were formed. Not far from the Tsimlyansk Reservoir there is a significant geological anomaly, the so-called Main East European Fault.

The influence of the glacier on the relief of the plain

In ancient times, the northern end of the plain was covered by a powerful glacier.

As a result of its destructive movement in the Quaternary period, hills were formed:

Privolzhskaya.
Valdai.
Timan Ridge.
Northern Uvaly.

In the southern direction, the movement of the glacier left moraine traces, which were subsequently erased by erosion factors and waters from the melting of the Dnieper glaciers.

Relief

The East European Plain has a relief typical of platform ones with a characteristic alternation of hills and lowlands. The highest part of the plain is the northeastern part, where the average absolute height is 400 m. The platform is lowering towards the coastal zone of the Arctic Ocean. To the south, a series of hills alternate with lowlands.

Main elevations:

Central Russian.
Privolzhskaya.
Bugulminsko-Belebeevskaya.
Valdai.
Smolensk-Moscow.

From the east they are adjacent to the Meshcherskaya and Upper Volga lowlands. Further to the south, the height of the plain decreases and here its relief is represented by the Oka-Don and Caspian lowlands. Here, the main relief-forming work was done by modern factors - rivers and winds. Therefore, the surface of the earth is wavy with small hills.

Prevailing altitudes

The Russian platform has average absolute heights of 100-300 m. Its highest point (479 m) is located near Bugulma. In the south, the Caspian Lowland is located at levels of 10-18 m below the free surface of the ocean.

Climate and natural areas

In foreign geographical studies, information on the Sarmatian Plain is presented in an extremely confusing manner. Domestic popular science articles also suffer from their fragmented nature. The reason is that the wrong research and description methodology is used.

It is extremely inappropriate to separate the following factors from each other:

geological structure;
relief;
natural areas;
climatic features.

All of them are inevitably in close interaction and influence each other, as well as the formation of hydrology, flora and fauna. The Russian Plain is so large that it is located simultaneously in 4 climatic and 8 natural zones.

Climate zones:

arctic;
subarctic;
moderate;
subtropical.

Natural areas:

arctic deserts;
tundra;
taiga;
forests;
forest-steppe;
steppes;
semi-deserts;
deserts.

From the Rybachy Peninsula to Yamal along the coast lies the Arctic desert. Winters in this zone are long and abnormally frosty. The thermometer scale drops below -50°C. Summer temperatures barely reach + 10°C. On average, temperatures throughout the year range from -10 to 0°C. Precipitation (light drizzle and snow charges) is more frequent in the warm season.

The annual precipitation rate is 140 - 160 mm. The summer season corresponds to the polar day, the winter season to the polar night.

To the south, the desert turns into tundra and forest-tundra. Here the climate is slightly milder; the average January temperature ranges from -10°C to -40°C, and in July reaches +11 - +14°C. There is also more precipitation - 150 - 300 mm, but evaporation is low, which leads to swampiness of large areas.

The taiga-forest zone occupies the largest part of the East European Plain (almost 700 thousand sq. km or about 60%). In this natural enclave, the climatic conditions can be described as moderate continental. This is due to the influence of Arctic and Atlantic air masses.

Winter here is long: from 5 to 6 months, depending on the distance from the Arctic. On average, the winter temperature scale is at -10°C – -10°C. When Arctic anticyclones invade (1 – 1 time per season), frosts reach anomalous levels of -30°C – -40°C. The thickness of the snow cover in the middle zone is 40–90 cm.

The spring period begins at the end of March, snow melting is unstable and can continue until mid-April. Return frosts end in the first ten days of June. The average duration of summer is 3 months.

Summer temperatures are low and average +19°C, but with the arrival of the Siberian and Central Asian anticyclones it becomes hot: the thermometer exceeds +19°C. Precipitation falls quite often in summer; the total summer norm is around 150 mm. This is about a third of the annual norm.

Autumn is usually quite short and rainy. The temperature rarely goes above +9 - +11°C. Precipitation in the form of wet snow begins at the end of October. From the beginning of November, autumn begins to turn into winter. In the area of the 50th parallel, broad-leaved forests begin to give way to forest-steppes. They occupy about a quarter of the Russian Plain (150 thousand sq. km).

The climate type is also temperate, however, in this natural zone it is already much milder. Winter comes at the very end of November with the establishment of permanent snow cover. Winter cold fluctuates from -9°C to -15°C. Temperatures rarely reach low values. The snow cover can be up to 40 cm and completely disappears in March.

Spring is warm and short: it begins in April, and by the end of May summer weather has already set in. With the arrival of summer, precipitation increases significantly and in the first two months more than 60% of the annual average falls (from 300 to 600 mm). The temperature regime is much warmer than in the forests: the night temperature is +19°C, and during the day it soars to +36°C.

Summer ends in the second half of September.

Autumn lasts more than 2 months with fairly comfortable temperatures: the thermometer scale drops to zero only in mid-November. Further south are the Russian steppes. In addition, the steppe zone is also present on the Crimean Peninsula. In relation to the previous natural zones, they occupy a very small territory.

The zone is located in the temperate zone, however, much warmer than all the previous ones. The duration of the seasons when there are no negative temperatures is six months or more. Winter lasts from December to March. In April, the warm spring weather is already stable. From mid-May the temperature rises to +30°C. Long and warm summers set in.

The thermometer rarely drops below +30°C. Summer turns into autumn only at the beginning of October. Moreover, above-zero temperatures last until mid-November; the transition to winter weather usually occurs in mid-December. There is little precipitation: only 150–300 mm falls during the year.

The East European Plain in its southeastern part covers 2 natural zones that are not quite typical for Russia: semi-deserts and deserts.

They are fragmentarily wedged into the following areas:

Kalmykia.
Astrakhan.
Volgogradskaya.
Rostov region.

These 2 natural enclaves are very similar to each other; they can only be divided very conditionally. The climate here is sharply continental and arid. The temperature regime and precipitation level are almost no different from the steppe zone. In deserts the amount of precipitation is 160 – 110 mm per year.

Dry subtropics are located in the Novorossiysk region and on the Crimean peninsula. The climate here is dry and hot. Winters are very warm and with high humidity. Precipitation amounts to more than 700 mm per year.

The comparative analysis in the table shows how diverse the climate of the Russian deserts is:

Name	Average temperature °C		Annual difference	Precipitation per year (mm)	Evaporation (mm)
Name	January	July	Annual difference	Precipitation per year (mm)	Evaporation (mm)
Arctic deserts	— 30	+ 9	39	140	100
Tundra	-15	+11	37	300	100
Taiga-forest zone	-15	+19	34	750	600
Forest-steppe	-11	+15	37	600	800
Steppe	-9	+30	39	300	900
Semi-deserts	— 15	+ 15	40	300	1500
Deserts	— 9	+ 19	37	100	1000
Dry subtropics	+ 4	+ 19	15	700	1300

The groundwater

The Russian Plain has a high supply of groundwater, which is contained in the East European platform artesian region. It, in turn, is divided into smaller basins of 1st and 2nd orders. The main source of groundwater is atmospheric precipitation due to its infiltration into depth. There is also seepage of water from surface bodies of water.

Another method of replenishing groundwater is very unique: at positive temperatures, the steam in the air has a more elastic structure than in the soil. Entering the ground, it reaches a zone of constant temperature and condenses. This condensate is the basis for the formation of groundwater in semi-deserts and deserts.

Fresh waters are located at depths of up to 100 m, and below that their mineralization begins. The groundwater of the Russian Platform is characterized by high levels of iron, manganese and fluorine.

Rivers

Consideration of the issue of lowland rivers should always follow groundwater: by their nature they are bodies of water with mixed nutrition. The initial basis is groundwater, and a significant part is snow water with powerful floods.

According to their ownership, the rivers of the Russian Plain are divided into basins:

Atlantic.
Arctic Ocean.
Caspian Sea.

In accordance with the relief of the plate, the main elevations are the watershed:

Central Russian.
Valdai.
Privolzhskaya.

The main rivers of the Russian Plain are:

Name	Length (km)	Basin area (thousand sq. km)	Annual flow (km 3)
Volga	3530	1360	154
Dnieper	1101	504	53,5
Don	1870	411	17,7
Northern Dvina	744	350	110
Pechora	1809	311	130
Neva	74	181	78,9
Kama	1805	507	117

Lakes

Lake beds of the plain are represented by 5 types:

glacial;
moraine;
floodplain;
karst;
estuarine

By lens size, the largest lakes in the plain are:

Caspian Sea.
Ladoga.
Onega.

The hydrology of the largest plain is not limited to rivers and lakes. Other bodies of water include swamps, ponds and reservoirs.

Flora

The East European Plain with its rich set of natural zones makes the flora of the region unique. All the vegetation characteristic of Russia is present here. The only exceptions may be plants from the high mountain regions of the Caucasus and some samples of the flora of the Primorsky Territory. The region with the poorest vegetation is the Arctic desert and tundra.

Mosses, lichens, and small shrubs, adapted to life in the extreme conditions of the subarctic climate, form the basis of fragmentary plant covers. With the transition to the forest-tundra, sparse forests and herbaceous plants appear, and mosses already cover the entire surface of the earth. They form the basis of the reindeer's diet.

The taiga zone is represented by a full range of coniferous species:

pine;
larch;
fir.

The zone of mixed and deciduous forests, as well as the forest-steppe, are very similar in terms of plant life (including conifers).

In different proportions, but each zone has the same plants:

Linden;
ash;
poplar;
maple;
aspen.

In addition to tree crops from the taiga to the forest-steppe, Russian nature is rich in shrubs, both flowering and berry-bearing. A countless family of mushrooms hides in forests and shelterbelts throughout the warm season. The grass covers are represented by meadow and oak forest forbs.

The steppe zone has significant differences in vegetation: the basis is the zonal distribution of meadow steppe and forb or feather grass steppe. Half a thousand species of herbaceous (flowering and non-flowering) plants fill the steppe. The Don Valley is famous for its huge water meadows. Semi-deserts have much sparse vegetation.

Mainly feather grass and fescue. In addition, there are a number of subshrubs such as wormwood. Herbaceous plants are represented by a small set of species that have adapted to seasonal existence: either they complete a full life cycle in one summer, or they are bulbous and persist until the next season (tulips, for example).

And in the dry subtropics, low-growing deciduous and evergreen shrubs grow. In deserts, only plants with a developed root system survive, which is able to hold them in weak soils and reach groundwater.

Fauna

The fauna of the Russian Platform is as diverse as the vegetation. There are no exotic species here, however, given the enormous size of the territory and the numerous natural zones on it, the richness of the fauna here is the most unique in the world.

Many authors really want to present the real issue in an exotic light: attempts to link the habitats of walruses and polar bears to the Russian Plain are not very justified. These animals mostly live much further east, and on the islands adjacent to the north of the Russian Plate their population is quite insignificant.

But in the vastness from the Arctic to the subtropics, the true owners of the continent live in abundance:

Various small predators and rodents are represented in huge numbers.

Feathered inhabitants, including migratory ones, number more than 100 species, of which the indigenous inhabitants are:

owl;
duck;
martin;
crow;
bustard;
heron;
nightingale;
partridge;
capercaillie;
black grouse;
sparrow.

Traditionally, coastal sea waters and lowland rivers are rich in fish resources, the most popular of which are:

roach;
sturgeon;
pike;
trout;
cod;
flounder;
gudgeon;
crucian carp;
zander;
burbot;
perch;
rudd;
sterlet.

It is impossible to give an exact answer on how many species of insects live within the plain due to their lack of knowledge. It is estimated that there are about 90,000 species.

Of these, several species are clearly classified as exotic:

arctic bumblebee;
tarantula;
scorpion.

The order of invertebrates on the Russian plain is not very large:

viper;
runner;
copperhead;
Cottonmouth;
monitor lizard

In total, the flora of the East European Plain includes more than 100 species of mammals, about 100 species of birds, 15 invertebrates, almost 100 thousand species of insects and more than fifty fish.

Minerals

Due to its geological structure, the East European Plain has a specific composition of fossil raw materials. Here is the world's largest (more than 50% of world reserves) iron ore basin. Its capacity is estimated at 100 billion tons or more.

Less significant minerals within the ancient geological plate are:

There are diamond deposits in the Arkhangelsk region.

Regions

Of the 85 subjects of the Federation, 53 are located on the Russian Plain.

These are territorial entities that are part of the Federal Districts:

Central.
Northwestern.
Southern.
Privolzhsky.
North Caucasian.

Large cities located on the plain and their features

The main historical stages of Russian history are associated with cities located on the territory of the Russian Plain. Each of them made their worthy contribution to the development of the state.

You can classify them by size, then the most significant will be:

City	Population (million people)	Add. information
Volgograd	1	It has existed since 1579. It ranks third in Russia in terms of area.
Voronezh	1	Laid down in 1586. This is where the history of the Russian Navy begins.
Ufa	1,1	Capital of Bashkortostan. The most spacious city with a population of over a million (about 700 sq. m per inhabitant).
Rostov-on-Don	1,1	The first name was Azov (a fortress built by decree of Empress Elizabeth Petrovna in 1749)
Samara	1,16	Known since 1367. Soviet name Kuibyshev - since 1941 it has been a reserve capital.
Kazan	1,2	The cultural capital of Muslims in Russia.
Nizhny Novgorod	1,3	Built in 1221. The militia of Minin and Pozharsky was formed here. Nowadays it is a large industrial center.
Saint Petersburg	5,2	It has existed since 1703. The northern capital of Russia. From 1712 to 1918 it was the true capital. The northernmost city in the world with a population of over a million.
Moscow	12	Historical capital.

Ecological situation and specially protected natural areas

The cities located on the Russian Plain are mostly industrial centers. They emit heavy metal compounds and acid-containing substances into the atmosphere, and discharge untreated waste. This aggravates the environmental situation.

To be specific, the main sources of environmental disaster are:

Cherepovets.
Dzerzhinsk.
Lipetsk.
Moscow.

If the first three are the largest industrial centers and their emissions are caused by production factors, then the capital suffers an environmental disaster just from the huge number of cars. There are more than 5 million vehicles registered here alone.

In addition to damage to nature from industrial facilities, human intervention leads to the destruction of the flora and fauna of the Russian Plain. In order to preserve natural enclaves in their pristine condition and restore the habitats of wild animals, a number of specially protected sites are being created.

For example:

Reserves.
Bashkir.
Bogdinsko-Baskunchaksky.
Volzhsko-Kama.
Zhigulevsky.
Crimean.
Mordovian.
Volga forest-steppe.
Rostovsky.
Biosphere reserves.
Astrakhan.
Bryansk forest.
Voronezh.
Darwinian.
Oksky.
Prioksko-Terrasny.
Central Forest.
Central Black Earth.
National parks.
Bashkiria.
Valdai.
Kalevalsky.
Curonian Spit.
Elk Island.
Meshchersky.
Onega Pomerania.
Lake Pleshcheyevo.
Smolensk Poozerie.

The largest plain of the continent was called Sarmatian, as European geography stated, implying that it belonged to the Eastern race. And this time the Europeans were right: the lion's share of the plain is occupied by Russia. And all its riches and attractions give a special color to life on these lands.

Article format: Lozinsky Oleg

Video about the East European Plain

East European Plain, features, geography:

Tundra and forest-tundra zones- humid, moderately cold - occupy the coast of the Barents Sea on the moraine-marine plain in the subarctic climate zone. Tundra covers the entire Kanin Peninsula south to 67° N. Next, the border goes to Naryan-Mar and the Polar Urals. To the south there is a narrow strip (30-40 km) of forest-tundra.

European tundra and forest-tundra are warmer and wetter than Asian ones. Frequent winter cyclones originating on the Barents Sea branch of the Arctic front, associated with the trough of the Icelandic low, bring quite warm sea air from the Atlantic and the non-freezing part of the Barents Sea. This is reflected in the distribution of winter temperatures (the average January temperature on the Kanin Peninsula is -10°C, and on the Yugorsky Peninsula -20°C), annual precipitation (about 600 mm in the west of the tundra, and 500 mm in the east), and the highest perennial temperatures permafrost (from 0 to -3°C).

In the European tundra, only two subzones are expressed: typical, moss-lichen, and southern, or shrub. Typical tundra is especially widely represented in the area from the Timan Ridge to the Urals. Among the moss tundras, there are both dry moss hypnotic and damp swampy moss tundras with a cover of hygrophilic mosses. In addition to mosses and lichens, there are herbaceous plants: arctic bluegrass, alpine bluegrass, sedges, arctic pike, alpine basilisk; Shrubs include wild rosemary, dryad (partridge grass), polar and net willow, and blueberry. The southern subzone is characterized by a predominance of shrub (dwarf birch and willow) and shrub communities in the vegetation cover in combination with moss, sphagnum and lichen-sphagnum bogs.

Along the southern edge of the tundra there is a transition zone of forest-tundra. The forests here are open woodlands consisting of Siberian spruce 5-8 m high, joined by birch and Sukachev larch. Low-lying areas are occupied by swamps or dense thickets of bushes - small willows and birch dwarf. Lots of crowberries, blueberries, blueberries, herbs, lichens. In the north of the forest-tundra, open spaces are common, which are characterized by single scattered oppressed crooked trees. Tall forests penetrate deep into the territory only along river valleys due to the warming influence of river waters and protection from strong winds. In the south of the forest-tundra, in open birch forests, bird cherry appears with the latest flowering on the plain (June 30) and mountain ash (blooms around July 5).

Rice. 26. Borders of zones and provinces of the Russian Plain

Physiographic provinces: tundra zone - 1 - Kaninsko-Pechora; forest-tundra zone - 2 - Mezensko-Bolshezemelskaya; taiga zone - 3 - Pechora, 4 - Timan, 5 - North Dvina, 6 - Northern Uvalov, 7 - Tikhvinsko-Vepsovskaya, 8 - Ladoga, 9 - Unzhinsko-Vetluzhskaya, 10 - Vyatsko-Kama; zone of mixed and broad-leaved forests - 11 - Baltic, 12 - Valdai, 13 - Smolensk-Moscow, 14 - Bryansk Polesie, 15 - Central Russian, 16 - Meshcherskaya; forest-steppe zone - 17 - Central Russian, 18 - Oka-Don, 19 - Volga region, 20 - Low Trans-Volga region, 21 - High Trans-Volga region; steppe zone - 22 - Azov-Don, 23 - Volga-Ergeninsky, 24 - Low Trans-Volga region, 25 - General Syrt; semi-desert zone - 26 - Caspian; desert zone - 27 - Caspian

Mossy tundras contain large reserves of green fodder and serve as a valuable food source for reindeer husbandry.

The fauna of the tundra is monotonous and characterized by a poverty of forms. Typical mammals are the domestic reindeer and the polar wolf. Rodents are represented by pieds - the Ob lemming. The arctic fox is widespread everywhere. It enters the forest-tundra and even the northern taiga. Ermine and mountain hare are often found in river valleys. A common animal in the forest-tundra is the wolverine, but in the summer it goes into the tundra to the shores of the Barents Sea.

In the Kaninskaya and Malozemelnaya tundras, European species are found - pine marten and European mink, as well as acclimatized muskrat. Many birds nest in the tundra - common eider, snow bunting, tundra swan. Among them there are also rare ones listed in the Red Books - the little swan, the lesser white-fronted lesser white-fronted eagle (the duck family), the white-tailed eagle, the gyrfalcon, and the peregrine falcon. Among the game animals of the tundra and forest-tundra, the arctic fox and ermine are of great importance, and among the fish - salmon, whitefish, pike, perch and char. The subsoil of these zones is rich in oil, gas and coal.

The taiga zone extends south of the forest-tundra. Its southern border runs along the line St. Petersburg - Novgorod - Yaroslavl - Nizhny Novgorod - Kazan. In the southwest, the taiga merges with the zone of mixed and broad-leaved forests, and in the southeast - with the forest-steppe zone.

The taiga of the Russian Plain differs from the Siberian one in its geographical location and history of development of the territory, and they determined the modern appearance of its nature. The close position to the Atlantic Ocean and the warmest sector of the Arctic predetermined the development of Pleistocene multiple glaciations, a temperate continental climate, promoting the settlement of both more heat-loving European plants and animals and more cold-loving Siberian ones across the plain. The European taiga receives more precipitation than the West Siberian taiga. Their annual quantity on the plains is more than 600 mm, and on the hills - up to 800 mm. The entire zone of excess moisture, since precipitation exceeds evaporation by 200 mm. There are many lakes in the Onega and Volga basins, and the eastern part of the taiga is poor in lakes, but rich in swamps.

Podzolic soils are developed on moraine and fluvioglacial deposits of the taiga. The flat topography of the northern part of the forest zone, as well as the water-resistant properties of the soils, contribute to severe swampiness and the development of bog-podzolic peaty and peaty-gley soils east of the Northern Dvina. Typical podzolic soils are characteristic of the middle part of the taiga. The podzol formation process is weakened in the north, where low temperatures and waterlogging prevent the formation of podzol, as well as in the south due to a decrease in moisture content.

The European taiga is characterized by dark coniferous spruce forests: only here are Norway spruce (common spruce) and Siberian spruce found together. Norway spruce moves east only to the Urals, while Siberian spruce enters the Kola Peninsula and eastern Karelia. Siberian fir, Sukachev larch and Siberian cedar crossed the Urals to the west. There are many pine forests along the river valleys and outwash. A secondary role in forests belongs to deciduous trees: birch, aspen, alder. Lots of sphagnum bogs. Dry and floodplain meadows are widespread in the zone.

Typical animals for the taiga are reindeer, wolverine, lynx, wolf, squirrel, and white hare. The Siberian weasel and the Siberian rodent, the chipmunk, came to the northeast of the taiga and settled west to the Northern Dvina and the White Sea. Mink, otter, and water shrew live along the river banks. There are many birds in the taiga. Capercaillie and hazel grouse are found everywhere, and ptarmigan are found in moss swamps. The three-toed woodpecker is typical of spruce forests. Bee-eater, bullfinch, and kuksha are common. Some of them fly to more southern places for the winter and live in the mixed forest zone. In the meadows and swamps there are snipe and woodcock, geese, ducks, corncrakes, lapwings, etc. Among the reptiles, the viper and viviparous lizard are ubiquitous, and the gray toad is common. Newts are found in stagnant bodies of water.

The European taiga is divided into three subzones: northern, middle and southern. The northern taiga is characterized by excessive moisture. In its western part the winters are snowy and moderately cold, while in the eastern part the winters are cold and quite snowy. The forests here are low-growing and sparse of spruce and pine (green moss, long moss, sphagnum and lichen). The agroclimatic characteristics are as follows: the depth of soil freezing is 120 cm, the duration of the growing season is 65 days, the sum of active temperatures is 800-1200°C, i.e. This is the territory of early vegetable crops with reduced heat requirements.

The middle taiga is characterized by excessive moisture, moderately cold and cold snowy winters. Here, blueberry spruce forests predominate (from European and Siberian spruce). Agroclimatic parameters are as follows: duration of the growing season - 100 days, soil freezing depth - 70 cm, the sum of active temperatures is 1200-1500‰С, which corresponds to the early crops of the temperate zone (gray bread, legumes, potatoes, flax and other crops).

The southern taiga is also quite humid, but has significant differences in winter temperatures (the average January temperature in the west is -6°C, in the east -13°C), the depth of soil freezing in the west is 30 cm, in the east 60 cm or more. The sum of active temperatures is 1900-2400°C. Spruce, sorrel, shrub and pine forests grow here. In the south of the taiga, elm, linden, hazel and euonymus appear. Mid-early crops are cultivated: wheat, later varieties of legumes, sugar beets.

Within the taiga, not only subzonal, but also provincial differences are clearly expressed. As an example of taiga provinces, consider Pechora.

Pechora province is located in the extreme northeast of the zone. It occupies the southern most elevated part of the Pechora Lowland, confined to the syneclise of the same name. The bedrock here is sandy-clayey deposits of the Triassic, Jurassic and Cretaceous, overlain by a thick (up to 100 m) thickness of Quaternary fluvioglacial, lacustrine-alluvial and lacustrine-glacial deposits. In the interfluves there are moraine spots here and there.

Flat or undulating interfluve plains are located at altitudes of more than 150 m, but only rarely in the very south do they rise above 200 m. In some places there are hills - the remains of terminal moraine ridges, kama and eskers. The lowland is drained by the Pechora and its numerous tributaries, the largest of which are the Izhma and Usa. The interfluve plains are swampy, the valley areas are better drained, so they are less swampy.

The climate of the province is the most severe and continental compared to other taiga provinces. Winter is harsh, long and snowy. The average January temperature is -18...-20°C. Here the highest snow cover depth on the Russian Plain is observed - 70-90 cm. Summer is cool, with cloudy, often rainy weather. The average temperature in July is 14-16°C; annual precipitation is 600-800 mm, gradually increasing to the east, approaching the Urals. The rivers of the province are full of water. The large thickness of the snow cover determines their high floods, which occur in May. There are many lakes in the lowlands. They are often found among swamps.

The Pechora province lies in the northern taiga subzone, only its extreme south falls into the middle taiga. The vegetation cover is dominated by sparse spruce and pine forests. Siberian conifers are common in the tree stand: cedar, fir, larch. Forests are usually swampy. Gleyic-podzolic soils develop under them. Only in the valley areas and on the slopes of the hills do not swampy spruce forests grow. In the northern part, primary birch forests are quite widespread and are also largely swampy. There are a lot of swamps in the province. Hilly ones predominate, and in the southern part - sphagnum ridge-hollows. Floodplain meadows with high grass stand are developed along the rivers. The taiga is home to European and Siberian animal species.

The province is rich in oil and gas deposits. The population of the taiga is engaged in fur farming.

The zone of mixed and deciduous forests is located in the western part of the plain between the taiga and forest-steppe and extends from the western borders of Russia to the confluence of the Oka and the Volga. The territory of the zone is open to the Atlantic Ocean and its impact on the climate is decisive.

The zone is characterized by a mild, moderately warm climate. The relief exhibits a combination of hills (200 m or more) and lowlands. The strata plains are overlain by moraine, lacustrine-alluvial, fluvioglacial and loess rocks. Within the zone, under conditions of a moderately humid and moderately warm Atlantic-continental climate, soddy-podzolic and gray forest soils are formed.

Large high-water rivers of the East European Plain begin here - the Volga, Dnieper, Western Dvina, etc. Groundwater lies close to the surface. With dissected topography, clay-sand deposits and sufficient moisture, this contributes to the development of swamps and lakes.

The climate of the zone is favorable for the growth of coniferous tree species along with broad-leaved trees. Depending on the relief conditions and the degree of moisture, meadows and swamps are also formed. European coniferous-deciduous forests are heterogeneous. Among the broad-leaved species in the zone, linden, ash, elm, and oak are common. As you move east, due to the increasing continentality of the climate, the southern border of the zone shifts significantly to the north, the role of spruce and fir increases, while the role of broad-leaved species decreases. The most widespread of the broad-leaved species in the zone is linden, which forms the second tier in mixed forests. They have a well-developed undergrowth with a predominance of hazel, honeysuckle, and euonymus. In the grass cover, taiga representatives - wood sorrel, woodruff - are combined with elements of oak forests, among which the role of black grass, hoof grass, woodruff, etc. is significant.

The natural complexes of the zone change to the south, as the climate becomes warmer, the amount of precipitation approaches evaporation, dominance passes to broad-leaved species, and coniferous trees become rare. In these forests the main role belongs to linden and oak.

Here, as in the taiga, upland and floodplain meadows are developed on alluvial soils. Transitional and lowland swamps predominate. There are few sphagnum bogs.

In historical times, the zone of mixed and deciduous forests was home to many wild animals and birds. Currently, they are pushed into the least populated areas or completely exterminated and are only preserved and restored in nature reserves. Nowadays, the typical animals of the zone are wild boar, elk, bison, black or forest polecat, badger, etc. In recent decades, the number of wild boar, river beaver and elk has increased significantly. The border of the wild boar's range has advanced to the northeast and southeast in some places up to 600 km or more. Coniferous-deciduous forests are characterized by animal species characteristic of Eurasia, but mostly close in origin to the species of Western broad-leaved and mixed forests, for example, European roe deer, European red deer, European mink, marten, dormouse, European forest cat, muskrat. Red deer, sika deer, and muskrat are acclimatized. Of the reptiles in mixed forests, the sand lizard and grass snake are common.

Rice. 27. Geological structure of the Valdai Hills

The zone of coniferous-deciduous forests has long been densely populated and developed, so its nature has been greatly changed by human activity. For example, forests occupy only 30% of the zone's territory; the most convenient areas are plowed or used for pastures; In the fauna there was a change in the species composition - the tarpans and European aurochs that once lived in the forests completely disappeared. Marten, wolverine, muskrat, golden eagle, osprey, white-tailed eagle, white and gray partridge have become rare. Much work was carried out to restore the river beaver, bison, red deer, increase the number of elk, acclimatize the raccoon dog, American mink and muskrat. Many species of animals and plants are taken under protection. Nature reserves have been created in the zone to protect the most typical natural complexes and especially rare animals and plants. Among them is the Prioksko-Terrasny biosphere reserve, which protects the natural complexes of the center of the zone, which played a large role in the restoration of bison brought from Belovezhskaya Pushcha and the Caucasus in the dense coniferous-deciduous forests.

The Valdai province extends from the upper reaches of the Lovat and Western Dvina rivers north-northeast to Lake Onega. It consists of hills Valdai(341 m), Tikhvinskaya(280 m) and Vepsovskaya(304 m), separated by depressions about 100 m above sea level. In the west, the hills end abruptly with a picturesque Valdai-Onega ledge(up to 150-200 m) to Priilmenskaya lowland. In the east, the hills gradually turn into adjacent low-lying plains.

The province is located on the western flank of the Moscow syneclise, so the thickness of sedimentary rocks composing the cover occurs monoclinally. The Valdai-Onega ledge is usually considered as a Carboniferous cliff (cuesta ledge), fixing the boundary of the distribution of Carboniferous rocks, represented by limestones, dolomites and marls. The province is located in the marginal part of the Valdai glaciation, therefore, within its boundaries there is a well-preserved glacial-accumulative hilly-moraine relief with terminal moraine ridges (Torzhokskaya, Vyshnevolotskaya, Lesnaya, etc.) and numerous moraine lakes along the basins ( Seliger, Volgo, Valdai, Velyo and etc.). This strip of young picturesque landscapes is called Poozerie. The thickness of the moraine that covered the pre-glacial relief varies from 1-2 m to 100 meters or more. The carbonate rocks underlying the moraine determine the development of karst relief forms where the thickness of Quaternary sediments is small - within the carbon ledge itself and in the valleys of the rivers cutting through it. Karst forms are represented by saucers, ponoras, basins, as well as cavities, caverns, and caves.

The sources of the Volga, Dnieper and Western Dvina lie on the Valdai Upland. Many rivers flow in the depressions of glacial melt water, and their valleys are not yet fully formed. Short rivers connect numerous lakes, forming single water systems.

The province's climate is humid with cool summers. The average temperature in July is only 16°C, and the average daily temperature rarely rises above 20°C. Winter is moderately cold. The average January temperature is -9...-10°C. Cyclones that often come here cause thaws. The annual precipitation is more than 800 mm, which is the maximum for the Russian Plain. The maximum occurs in summer.

The province is characterized by an extraordinary diversity of soil and vegetation cover, which is due to the frequent change of soil-forming rocks and relief forms. Moraine hills and ridges are covered with broad-leaved spruce forests on sod-podzolic and podzolic soils. Pine forests predominate on outwash plains, lakeside sands and sandy hills. On limestones, dolomites and carbonate moraine, dark-colored humus-carbonate soils are common, on which spruce-broadleaf forests grow, dominated by oak, with linden, ash and elm in the second tier.

Scattered among the forests are damp meadows and pine-sphagnum lowland grass and convex ridge-hollow bogs with cloudberries and cranberries. They are confined to the bottoms of wide valleys, lake shores, and sometimes flat watersheds.

A significant part of the province’s area has long been greatly altered by man, but in some places slightly altered areas still remain. Here in 1931 the Central Forest Reserve was created, which now has biosphere status. Its territory is covered with spruce and spruce-broadleaf forests, typical of the province.

The Meshchera province is located between the Klyazma and Oka rivers. In the north it is limited by the slopes of the Smolensk-Moscow Upland, in the east by the Oka-Tsninsky rampart. The typical landscape of Meshchera is a gently undulating alluvial-outwash forest plain 80-150 m above sea level with lakes and swamps. Along the edges of Meshchera there are moraine-erosive uplifts with average heights of 150-200 m. This type of landscape is called woodland. Woodland landscapes formed at the edge of the Pleistocene ice sheet, in depressions of the pre-glacial relief, along which glacial melt waters drained. Elevated remnants or “loess islands” - opoles - have also been preserved here. On the East European Plain within Russia, the Polesie type of landscapes forms an entire belt consisting of Bryansk-Zhizdra, Meshchersky, Mokshinsky, Balakhninsky, Vetluzhsky, Kama-Vyatsky and others Polesiy.

Meshchera is confined to the pre-glacial tectonic trough. At its base lie Carboniferous limestones, overlain by Jurassic and Cretaceous sandy-clayey deposits. Quaternary deposits consist of eroded moraine, preserved in the highest areas of the pre-glacial relief ( Egoryevskoe plateau, Oksko-Tsninsky shaft etc.), and large thicknesses of sand and loam of water-glacial and alluvial origin. In the central part of Meshchera there is a lowland with peat bogs and lakes (Svyatoe, Velikoye, etc.). Around it stretch wide strips of sandy plains with dunes. Rivers flow slowly in flat, swampy lowlands and drain them poorly.

The climate of Meshchera is moderately humid with cold, snowy and long winters. The average January temperature is -11...-12°C. Snow lies for up to 150-160 days with a maximum snow cover height of 50-55 cm. Winter weather types are unstable - with frosts and thaws. Due to the significant amount of snow, the flood on the Meshchera rivers is prolonged. Summers are warm with maximum precipitation. The average July temperature is 18.5-19°C. The annual precipitation (about 600 mm) exceeds evaporation, so the territory is excessively moist.

The main area of Meshchera is covered with pine forests, in some places with an admixture of oak and swamps. Spruce and birch forests are less common. Under the forests, soddy-podzolic and soddy-podzolic gley soils were formed on sands and sandy-clayey deposits. Light lichen forests are common on sandy ridges, hills and dunes; in the interfluves along the slopes of the valleys, spruce-pine forests with an admixture of oak, maple and linden dominate; on the moraine outcrops grow mixed forests of spruce, oak and linden, with an undergrowth of hazel and a thick herbaceous cover of nymph, hoofed grass, and lily of the valley; There are wet oak forests on the floodplains.

Swamps occupy about 35% of the surface of Meshchera. The main types of bogs are lowland and transitional, among which are sphagnum-sedge, hypno-sedge, sedge and birch-sedge. Raised bogs are less common, but they form large massifs and contain thick peat layers (up to 8 m) of high quality. The Shaturskaya thermal power plant operates on the Meshchersky peat.

Diverse landscapes are located in the south of Meshchera in the wide Oka valley and the strongly meandering valley of the Pra River, as well as in their interfluve. Created there in 1935 Oksky Reserve.

The forest-steppe zone, moderately humid and moderately warm, is located in the south of the Atlantic-continental climate region of the temperate zone of the East European Plain. Its southern border runs approximately south of Voronezh, Saratov, rises along the Volga valley to the north and runs along the Samara valley. The European forest-steppe is characterized by the main natural features of the entire zone, but at the same time it differs in its natural appearance from the forest-steppe of the West Siberian Plain, since it has differences in geographical location and the history of the formation of the territory. The forest-steppe extends from southwest to northeast, i.e. occupies the southernmost position in the west of the plain. This determined its bioclimatic features: its western part, up to the Voronezh meridian, has a semi-humid climate and richer vegetation, while the eastern part is semi-arid with depleted vegetation cover.

Winter in the east is colder and snowier, with an average temperature of -12°...-16°C. Summer in the European forest-steppe can be moderately warm with sufficient moisture. Then the vegetation and soils receive a lot of moisture, groundwater is replenished with a sufficient amount of moisture, its level rises and becomes accessible to plant roots in many places, and the flow of spring water in ravines, gullies and river valleys increases. In such a summer, steppe, forest and cultivated vegetation develops luxuriantly (abundantly). Summer can be hot with droughts and dry winds. This type of weather has a detrimental effect on the development of natural and cultivated vegetation. An important bioclimatic zero band of the ratio of precipitation and evaporation passes through the forest-steppe zone: to the north of it there is 100-200 mm more precipitation than evaporation, and to the south there is 100-200 mm less evaporation.

The East European forest-steppe formed on highlands and lowlands in the regional region of the Dnieper glaciation, covered with loess-like loams. The relief is characterized by erosional dissection, which creates a certain diversity of soil cover. The soils of watershed elevated areas under oak groves are characterized by significant podzolization. Along high river terraces with loess-like covers, tongues of degraded and leached chernozems extend to the north. The most typical for the northern part of the zone are gray forest soils, slightly podzolized, developed on loess-like loams. Leached and podzolized chernozems are typical for the southern strip of forest-steppe. Gray forest soils are developed in small areas along watersheds. Of the intrazonal soils, common in depressions - steppe saucers, malt is characteristic.

The natural vegetation of the forest-steppe has hardly been preserved. The forests here are found in small islands. Forest-steppe Russian Plain oak, which distinguishes it from the more eastern regions of Russia. The main forest-forming species in the European forest-steppe is pedunculate oak, to which Norway and Tatarian maples, elm and ash are mixed; in the shrubby undergrowth - hazel, warty euonymus, honeysuckle, etc. In the floodplains of rivers, in well-drained areas, oak forests are also found, and on the terraces - mixed oak-pine forests of Scots pine, pedunculate oak, etc.

Steppe areas in the forest-steppe, once covered primarily with forbs (V.V. Alekhin called them northern colorful forbs), have been plowed. Small patches of virgin steppes remain along ravines and ravine slopes, inconvenient for plowing, as well as in nature reserves.

The fauna of the zone consists of inhabitants of forests and steppes. There are no species of our own here. Due to the intense plowing of the zone, the animal world is now dominated by animals of open spaces and human companions.

Five provinces are distinguished within the forest-steppe zone.

The Central Russian province is located on the hill of the same name in the westernmost part of the zone. The northern border of the province runs approximately along the sublatitudinal segment of the Oka River. The upland was formed within the Voronezh anteclise, which is characterized by uplifts over a long history of geological development, including the modern era. Just south of the Kursk-Voronezh latitude, the basement rocks come closest to the surface (100-200 m). The largest iron ore deposit of the Kursk magnetic anomaly is associated with Precambrian crystalline rocks (gneisses and granites). The basement rocks here are overlain by Upper Cretaceous strata with a predominance of chalk, and in places sandy-clay deposits of the Paleogene and Miocene.

In the north, the gentle slope of the Voronezh anteclise is covered with Devonian limestones, sandstones and clays. They are exposed by rivers in the Don and Oka basins, where they form picturesque indigenous banks. To the north, the Devonian layers submerge and Carboniferous limestones come to the surface, among which lies the clay-coal-bearing strata of the Moscow Basin, which belongs to the Lower Carboniferous. It is associated with deposits of brown coal, as well as sedimentary iron ores. At watersheds, Carboniferous rocks are overlain by sandy-clayey Jurassic and Cretaceous strata, which are washed away near rivers.

Quaternary deposits include brown carbonate loess-like loams, as well as reddish-brown clays. Loess-like loams in the south turn into loess of different ages. Their power is different. On watersheds they are often completely absent or reach 2-3 m; on the slopes of river valleys and ravines their thickness is 10-12 m.

In the Neogene-Quaternary, the entire territory experienced uplifts of up to 200 m, which determined the formation of a step-tier plain here with a height of up to 293 m above sea level and its intense erosional dissection.

Lithology has a great influence on the formation of the relief of various parts of the hill. Its northern part, up to the Orel parallel, where limestones are widely represented, is sharply dissected by deep river valleys. On the slopes of the valleys, solid layers of limestone form steep and rocky walls, cornices, and cliffs. Limestones contribute to the creation of small canyon-like valleys and the development of karst forms. In the middle and southern parts of the territory, where loose strata are developed, wide terraced valleys with sloping slopes predominate. Sharper relief forms are confined to places where writing chalk is distributed. Such a deeply dissected relief with a large amplitude of relative heights is observed near Belgorod. The depth of the incision here reaches 150-125 m. In the loess layer, ravines with steep walls arose. Landslides form on slopes of all forms of erosion.

Throughout the heights, various erosion forms are developed - valleys, ravines, ravines, represented by several types. Karst landforms are also common here. Therefore, the Central Russian Upland can be classified as a region of classic gully-beam relief in combination with limestone and chalk karst.

The elevated, dissected topography of the province affects its climate. Summers here are cool, and the annual precipitation is slightly higher than in the adjacent lowlands. The average July temperature is 19°C in the northwest and 23°C in the southeast. Maximum precipitation falls in July (60-70 mm). But summer can also be dry. Winter is moderately cold: the average January temperature is -8...-10°C. The absolute minimum is -35...-40°C. The maximum height of snow cover reaches 30-45 cm in the third ten days of February. The annual amount is about 600 mm on the western slope, and up to 500 mm on the eastern slope. Precipitation gradually decreases from northwest to southeast.

The province's dense river network dissects its surface in all directions. The Oka begins almost in the center and heads north with numerous tributaries (Zhizdra, Zusha, Upa, Tarusa). The rivers of the western part carry their waters to the Dnieper. The Don flows along the eastern edge of the hill and receives the waters of the Beautiful Sword, Sosna, Seversky Donets and Oskol. In summer, many small rivers dry up and their valleys look like ancient ravines.

The Central Russian province is dominated by gray forest soils, as well as leached and podzolized chernozems. The vegetation of the province has been greatly modified by humans. Before human intervention, almost the entire northwestern part of the hill was covered with oak forests. Nowadays only small tracts of forests remain (Tula abatis). In the southwestern part of the hill, on the Vorskla River, centuries-old oak forests have been preserved. These forests consist of English oak with small-leaved linden, ash, maple, birch and aspen. In the subzone of typical oak forest-steppe, modern forests are represented by ravine oak groves, which to this day have survived only in a few places and in small areas.

In the south of the hill, within the outcrops of chalk deposits, pine forests of chalk pine are developed, which are also preserved in a few places (the Oskol area, the right bank of the Potudan, etc.). They are called chalk pine forests. These are ancient, pre-glacial forests of the Central Russian Upland.

Remains of the former steppe vegetation are preserved on steep steep slopes of valleys, in deep winding ravines and ravines. Forest-steppe reserves were formed in these surviving areas: Central Chernozemny named after. V.V. Alekhina, Galichya Mountain, Forest on Vorskla.

At the end of the last century, botanists discovered the most interesting steep cliff of the Don River - Galichya Mountain. Scientists consider the vegetation of steep cliffs to be the most valuable for science. Here ancient species were preserved from pre-glacial and post-glacial times. These are relict plants. Among them, especially interesting are the shrubs of tertiary forests - the Sofia wolfberry and the representative of mountain alpine meadows - the hairy wolfberry.

The steppe zone extends from the southern border of the forest-steppe zone to the Kuma-Manych depression in the south. It reaches its greatest width at 42° east. To the east it becomes narrower and shifts sharply to the north. The steppe zone is located on the southern erosion-accumulative loess plains.

The climate of the steppes is not humid enough, with warm summers and cold winters. Winter in the Trans-Volga steppes is especially harsh for these latitudes. The average January temperature here is -14...-16°C. The Azov steppes are distinguished by milder winters with an average January temperature of -4...-6°C. Summer temperatures in the steppe zone are +21...+23°C everywhere, and the sum of temperatures for the period with an average daily temperature above +10°C reaches 2800-3000°. There is not enough moisture in the steppes. During the year, the western steppes of Russia receive 500 mm of precipitation, and the Middle Volga region - about 400 mm. At high air temperatures in the steppes, evaporation exceeds the amount of precipitation by 200-400 mm, which leads to insufficient moisture. Dry winds are frequent here; in the east, their total duration is 20-30 days.

The northern steppes are less warm, but more humid than the southern ones. Therefore, the steppe zone is divided into two subzones: northern and southern. In the northern steppe, ordinary and southern chernozems were formed under forb-fescue-feather grass vegetation. In the southern, drier steppes, under turf-grass steppes with Ukrainian feather grass, hair grass and fescue, dark chestnut and chestnut soils are common. Their distinctive feature is varying degrees of solonetzity.

Western European species grow among the steppe plants, some of them are classified as tertiary relicts, for example, the bluish china is a Balkan relict, and the pollenhead grandiflora is an endangered European-Mediterranean species. Some endemic relics have been preserved - Taliev's cornflower, Don serpuha, Don gorse, feather grass.

In the steppe zone, woody vegetation is found only in river floodplains. In the floodplain of the Don, for example, poplar, sedge, willow, alder, oak, aspen, elm, maple, willow, etc. grow.

Among the animals of the steppes, rodents predominate: ground squirrels, shrews - mole voles, field mice, hamsters. They are hunted by ferrets, foxes, weasels and feathered predators - eagles, hawks, falcons. Among the birds, larks and steppe harrier are also common, but bustards and little bustards are rare. Many insects of the steppes have become very rare in nature, therefore they are included in the Red Books, for example, the steppe grasshopper, the steppe bumblebee, the alpine longhorned beetle, Apollo butterflies, Mnemosyne, the solitary bear, several pigeons, etc. Therefore, insect micro-reserves began to be organized. One of the first such reserves was created in the Voronezh region among fields on an area of 1 hectare. Beneficial insects, including plant pollinators, are protected here.

The steppes of the East European Plain have long been developed by humans, the most fertile soils have been plowed; chernozems on which wheat, barley, corn, legumes, industrial and melon crops are grown. Thousands of kilometers of protective state forest belts stretch across the steppe zone. The largest forest plantations in the steppe extend from Saratov to Volgograd, then to Elista. Near-valley Don forest strips have been created from Voronezh to Rostov. Protective afforestation is carried out in the sands in the basins of the lower Don.

Since the last century, ponds have been created in ravines and gullies and the banks of reservoirs have been planted with greenery.

Semi-desert and desert zones within Russia are located in the southwestern part of the Caspian lowland and on the Ergeni upland. They adjoin the coast of the Caspian Sea, adjacent to the semi-deserts and deserts of Kazakhstan in the east and Eastern Ciscaucasia in the southwest. Arid landscapes of the Caspian region began to form on low-lying sea plains after the retreat of the Khvalynsk Sea about 20 thousand years ago.

The climate of semi-deserts and deserts is moderately dry and very warm with an annual precipitation of 300-400 mm. Evaporation exceeds precipitation by 400-700 mm. Winters are quite cold, with negative temperatures prevailing. The average January temperature in the southwest is -7°C, and in the northeast -11°C. In winter, a snow cover is formed, the height of which reaches 10-15 cm. The snow remains for 60-80 days. In the extreme south of the Caspian lowland, stable snow cover does not form every year. It usually forms 15-30 days after the average daily temperature passes through 0°C. This contributes to seasonal freezing of the soil to a depth of 80 cm (about the same amount as in the middle taiga).

The semi-desert and desert of the Caspian lowland are distinguished by an abundance of salt lakes, salt marshes and solonetzes. Therefore, light chestnut solonetzic soils are developed there, the absorption complex of which contains sodium. The thickness of humus horizons is 30-40 cm, and the humus content is only 1.3%. In the north of the semi-desert zone, vegetation of the wormwood-grass type is developed with the dominance of feather grass (tyrsa) and Lessing, as well as Tauric wormwood and Lerch. To the south, the number of cereals decreases, wormwood begins to predominate and the number of saltworts increases. The low-growing grass cover consists of white and black wormwood, fescue, thin-legged grass, xerophytic feather grass, and isen shrub (Kochia prostrata). In spring, tulips, buttercups, and rhubarb appear. White wormwood grows on slightly saline loams. Clayey, more saline soils are covered with black wormwood. On the salt licks, in addition to black wormwood, biyurgun and kermek saltworts and tamarix shrubs grow. In the Astrakhan Trans-Volga region, sands are common, which are characterized by the grass grass, or kiyak, which is a sand fixer. There is Siberian wheatgrass, which is of great nutritional value. Willow, white poplar, sedge, aspen, oleaster, and rose hips grow in wet hollows. Oak is found in the Volga floodplain.

For the fauna of semi-deserts and deserts, ground squirrels and many jerboas are common, of which the small one, the ground hare, and the woolly-footed hare are typical. There are numerous gerbils - combed, southern, or midday, inhabiting mainly sands. Common species include ermine, weasel, steppe ferret, badger, wolf, common fox and small corsac fox, and many reptiles. Lesser larks are typical of semi-desert birds. The white-winged lark nests along the outskirts of the salt licks. Sea plover and shelducks are common on self-propelled lakes. The Volga delta is characterized by the great cormorant. Among the geese that nest in the delta are the gray goose and the white heron. Sultan's chicken and pheasant are occasionally found. The mustachioed tit is common in the coastal area.

Some species of plants and animals are included in the Red Books. For example, a rare endemic - Regel's bow, Taliev's cornflower, giant mole rat, bandage, bustard, little bustard, etc.

Characteristic of the nature of the East European Plain. Features of the nature of the Russian East European Plain

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Introduction

Tundra and forest-tundra zone

The youngest landscape zone on the Russian Plain is tundra. It was formed only after the death of the Valdai glacier.

Tundra and forest-tundra are two independent landscape zones. However, the forest-tundra on the Russian Plain is presented as a narrow strip that has not yet been sufficiently studied, therefore, for convenience of description, it is combined here with the tundra zone.

The tundra and forest-tundra zones include the Arctic islands: Franz Josef Land, Novaya Zemlya, Vaigach, Kolguev and the Barents Sea coast on the mainland.

Taiga zone

Taiga is a zone of coniferous forests on podzolic soils. In the southwest it borders on the mixed forest zone, in the southeast on the forest-steppe zone. Its southern border passes through Leningrad, Novgorod, Yaroslavl, Gorky, and Kazan.

With a positive moisture balance, groundwater in the taiga comes to the surface or lies in close proximity to it. This in turn leads to waterlogging of the area. Taiga is a zone dominated not only by coniferous forests, but also by swamps, including upland swamps, covered with sphagnum.

In the taiga of the Russian Plain, moving from north to south, zonal changes in the landscape are observed, making it possible to distinguish three subzones in it: northern, typical and southern taiga.

Zone of mixed and deciduous forests

Mixed forests are an independent type of landscape, the main feature of which is the presence in zonal conditions of coniferous and broad-leaved forests on soddy-podzolic soils.

The location of coniferous and broad-leaved species is subject to a certain pattern: broad-leaved forests prefer to grow on loamy, well-drained soils, most often on southern slopes and the tops of low hills.

Forest-steppe zone

Forest-steppe is a zonal landscape of the temperate zone, characterized by the alternation of closed, predominantly deciduous forests on gray forest (forest-steppe) soils and grassy steppes on chernozems, now mostly plowed.

The fight against soil erosion in the forest-steppe is as urgent and important a government task as the fight against droughts and hot winds.

In a typical forest-steppe in the past, forest and mixed-grass steppe alternated, occupying approximately the same areas. The soils of a typical forest-steppe are leached and typical (thick) chernozems with islands of gray forest soils and podzolized chernozems under forests.

The southern forest-steppe on medium-humus (ordinary) chernozems is characterized by the dominance of cereal steppes and the presence of isolated forest islands on watersheds. Grass steppes predominated here over forests even before human intervention.

In the virgin state, differences between subzones in the forest-steppe appeared sharply. Nowadays, as a result of deforestation and plowing of the steppes, the differences between them have been greatly smoothed out, and cultivated fields have become the predominant landscape in all subzones.

Steppe zone

Despite the antiquity of the steppe landscape, modern soils in the steppes are young post-glacial formations. Their youth is confirmed by the fact that the mother rock for them is loess and loess-like rocks, the accumulation of which occurred during the glaciation era.

Semi-desert and desert zones

natural zone forest-steppe tundra

The surface flow in the semi-desert is negligible, so its own river network is not developed. Groundwater is saline and most of it is not suitable for drinking.

The composition of birds (steppe eagle, harrier, larks), reptiles and insects is also quite diverse.

Most of the semi-desert zone is used as pasture. Estuary and irrigated agriculture is developed in some places.

Surface flow in deserts is so insignificant (less than 0.5 l/sec) that not a single local river crosses the territory of the province.

Huge areas in the desert are occupied by sands of marine (late Khvalynian Sea) and alluvial-deltaic origin. The area of ​​the Volga-Ural sands alone is about 50 thousand km3.

Deserts are used as pastures and hayfields. In the wide Volga-Akhtuba floodplain, horticulture, vegetable gardening and melon growing are developed. The area of ​​floodplain land used for agriculture is still small and can be successfully increased many times over.

Conclusion

So, based on the work done, we can say that on the territory of the Russian Plain there are almost all types of natural zones found on the territory of Russia.

Bibliography

1. Physical geography of Russia. At 2 o'clock Rakovskaya E.M., Davydova M.I. M.: 2001, Part 1 - 288 p., Part 2 - 304 p.

2. 10. Berg L. S. Geographical zones of the Soviet Union, vol. 1, ed. 3. M., 1947; t. 2. M., 1952.

3. Vegetation map of the USSR (for higher educational institutions), 1: 4,000,000. M., 1955.

4. Atlas of the USSR - M.: GUGK, 1983-1986.

5. Physico-geographical atlas of the world (FGAM) - M. GUGK 1964.

6. Alpatiev A. M., Arkhangelsky A. M. et al. Physical geography of the USSR, part III. M., 1976.

Application

Scheme of natural zones of the Russian Plain

Tundra and forest-tundra zone.

Taiga zone

Zone of mixed and deciduous forests

Steppe zone.

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Video about the East European Plain

Huge areas in the desert are occupied by sands of marine (late Khvalynian Sea) and alluvial-deltaic origin. The area of the Volga-Ural sands alone is about 50 thousand km3.

Deserts are used as pastures and hayfields. In the wide Volga-Akhtuba floodplain, horticulture, vegetable gardening and melon growing are developed. The area of floodplain land used for agriculture is still small and can be successfully increased many times over.