What kind of soil is in the East European Plain. East European Plain - main characteristics

To better understand the environmental problems of the Russian Plain, it is necessary to consider in detail what natural resources this geographic area has and what makes it remarkable.

Features of the Russian Plain

First of all, we will answer the question of where the Russian Plain is located. The East European Plain is located on the Eurasian continent and ranks second in area in the world after the Amazon Plain. The second name of the East European Plain is Russian. This is due to the fact that a significant part of it is occupied by the state of Russia. It is in this territory that most of the country's population is concentrated and the largest cities are located.

The length of the plain from north to south is almost 2.5 thousand km, and from east to west - about 3 thousand km. Almost the entire territory of the Russian Plain has a flat topography with a slight slope - no more than 5 degrees. This is mainly due to the fact that the plain almost completely coincides with the East European Platform. Destructive natural phenomena (earthquakes) are not felt here and, as a result, there are no destructive natural phenomena.

The average height of the plain is about 200 m above sea level. It reaches its maximum height on the Bugulma-Belebeevskaya Upland - 479 m. The Russian Plain can be conditionally divided into three stripes: northern, central and southern. On its territory there are a number of hills: the Central Russian Plain, the Smolensk-Moscow Upland - and lowlands: the Polesie, Oka-Don Plain, etc.

The Russian Plain is rich in resources. There are all types of minerals here: ore, non-metallic, combustible. A special place is occupied by the extraction of iron ore, oil and gas.

1. Ore

Kursk iron ore Deposits: Lebedinskoye, Mikhailovskoye, Stoilenskoye, Yakovlevskoye. The ore of these developed deposits has a high iron content - 41.5%.

2. Nonmetallic

• Bauxite. Deposits: Vislovskoe. The alumina content in the rock reaches 70%.
• Chalk, marl, fine-grained sand. Deposits: Volskoye, Tashlinskoye, Dyatkovskoye, etc.
• Brown coal. Swimming pools: Donetsk, Podmoskovny, Pechora.
• Diamonds. Deposits of the Arkhangelsk region.

3. Flammable

• Oil and gas. Oil and gas bearing areas: Timan-Pechora and Volga-Ural.
• Oil shale. Deposits: Kashpirovskoye, Obseshyrtskoye.

Minerals of the Russian Plain are mined in various ways, which has a negative impact on the environment. Contamination of soil, water and atmosphere occurs.

The influence of human activity on the nature of the East European Plain

The environmental problems of the Russian Plain are largely related to human activity: the development of mineral deposits, the construction of cities, roads, emissions from large enterprises, their use of huge volumes of water, the reserves of which do not have time to be replenished, and are also polluted.

Below we will consider all of the Russian Plain. The table will show what problems exist and where they are located. Possible methods of struggle are presented.

Climate of the Russian Plain

The climate of the East European Plain is temperate continental. Continentality increases as you move inland. The average temperature of the plain in the coldest month (January) is -8 degrees in the west and -12 degrees in the east. In the warmest month (July), the average temperature in the northwest is +18 degrees, in the southeast +21 degrees.

The greatest amount of precipitation falls in the warm season - approximately 60-70% of the annual amount. There is more precipitation over the higher elevations than over the lowlands. The annual precipitation in the western part is 800 mm per year, in the eastern part - 600 mm.

On the Russian Plain there are several natural zones: steppes and semi-deserts, forest-steppes, taiga, tundra (when moving from south to north).

The forest resources of the plain are represented mainly by coniferous species - pine and spruce. Previously, forests were actively cut down and used in the wood processing industry. Currently, forests have recreational, water-regulating and water-protection significance.

Flora and fauna of the East European Plain

Due to small climatic differences, pronounced soil and plant zonation can be observed on the territory of the Russian Plain. Northern soddy-podzolic soils to the south are replaced by more fertile chernozems, which affects the nature of vegetation.

Flora and fauna have suffered significantly due to human activities. Many plant species have disappeared. Of the fauna, the greatest damage was caused to fur-bearing animals, which have always been a desirable object of hunting. The mink, muskrat, raccoon dog, and beaver are endangered. Such large ungulates as the tarpan have been exterminated forever, and the saiga and bison have almost disappeared.

To preserve certain species of animals and plants, nature reserves were created: Oksky, Galichya Gora, Central Chernozemny named after. V.V. Alekhina, Forest on Vorskla, etc.

Rivers and seas of the East European Plain

Where the Russian Plain is located, there are many rivers and lakes. The main rivers that play a major role in human economic activity are the Volga, Oka and Don.

The Volga is the largest river in Europe. The Volga-Kama hydro-industrial complex is located on it, which includes a dam, a hydroelectric power station and a reservoir. The length of the Volga is 3631 km. Many of its tributaries are used by the economy for irrigation.

Don also plays a significant role in industrial activities. Its length is 1870 km. The Volga-Don shipping canal and the Tsimlyansk reservoir are especially important.

In addition to these large rivers, the following flow on the plain: Khoper, Voronezh, Bityug, Northern Onega, Kem and others.

In addition to rivers, the Russian Plain includes the Barents, White, Black, and Caspian.

The Nord Stream gas pipeline runs along the bottom of the Baltic Sea. This affects the ecological situation of the hydrological object. During the construction of the gas pipeline, water became clogged and many species of fish decreased in number.

In the Baltic, Barents, and Caspian Seas, some minerals are extracted, which, in turn, has an adverse effect on the waters. Some industrial waste leaks into the seas.

In the Barents and Black Seas, several types of fish are caught on an industrial scale: cod, herring, flounder, haddock, halibut, catfish, anchovy, pike perch, mackerel, etc.

Fishing, mainly sturgeon, is carried out in the Caspian Sea. Due to favorable natural conditions, there are many sanatoriums and tourist centers on the seashore. There are shipping routes along the Black Sea. Petroleum products are exported from Russian ports.

Groundwater of the Russian Plain

In addition to surface water, people use underground water, which, due to irrational use, has an adverse effect on soils - subsidence is formed, etc. There are three large artesian basins on the plain: the Caspian, Central Russian and East Russian. They serve as a source of water supply for a vast area.

The Russian Plain is one of the largest plains on the planet. It is located in the eastern part of Europe, which is why its second name is the East European Plain. Since most of it is located on the territory of the Russian Federation, it is also called the Russian Plain. Its length from north to south is more than 2.5 thousand kilometers.

Relief of the Russian Plain

This plain is dominated by gently sloping terrain. There are many natural resources of Russia here. Hilly areas on the Russian Plain arose as a result of faults. The height of some hills reaches 1000 meters.

The height of the Russian Plain is approximately 170 meters above sea level, but there are some areas that are 30 meters below sea level. As a result of the passage of the glacier, many lakes and valleys arose in this area, and some tectonic depressions expanded.

Rivers

The rivers flowing along the East European Plain belong to the basins of two oceans: the Arctic and the Atlantic, while others flow into the Caspian Sea and are not connected with the world ocean. The longest river, the Volga, flows through this plain.

Natural areas

On the Russian Plain there are all types of natural zones as in Russia. There are no earthquakes or volcanic eruptions in this area. Tremors are quite possible, but they do not cause harm.

The most dangerous natural phenomena on the East European Plain are tornadoes and floods. The main environmental problem is soil and atmosphere pollution due to industrial waste. There are many industrial enterprises in this area.

Flora and fauna of the Russian Plain

On the Russian Plain there are three main groups of animals: arctic, forest and steppe. Forest animals are more common. Eastern species - lemmings (tundra); chipmunk (taiga); marmots and gophers (steppes); saiga antelope (Caspian deserts and semi-deserts). Western species - pine marten, mink, forest cat, wild boar, garden dormouse, forest dormouse, hazel dormouse, black polecat (mixed and broad-leaved forests).

The fauna of the East European Plain is greater than that of any other part of Russia. Due to hunting and changes in the habitat of animals, many fur-bearing animals suffered for their valuable fur, and ungulates for their meat. River beaver and squirrel were trade items among the Eastern Slavs.

Almost until the 19th century, the wild forest horse, the tarpan, lived in mixed and deciduous forests. Bison are protected in the Belovezhskaya Pushcha Nature Reserve. Beavers have begun to be successfully bred in the Voronezh Nature Reserve. The Askania-Nova steppe reserve is home to a variety of animals from Africa, Asia and Australia.

In the Voronezh regions, an elk appeared and the previously exterminated wild boar was restored. The Astrakhan Nature Reserve was created in the Volga delta to protect waterfowl. Despite the negative influence of humans, the fauna of the Russian Plain is still great.

Climate

The climatic conditions of the chernozem distribution zone are characterized by increasing continentality from west to east. In the southwest of the East European Plain, the average annual temperature is 8-10 C. Winter in the western regions of the zone is relatively warm and mild, to the east it becomes more severe and with little snow. Also, from west to east, the number of frost-free days and annual precipitation decrease.

However, during the warm period, the climatic contrasts of different regions are smoothed out.

Water mode

The yield of agricultural crops in the chernozem zone is determined primarily by the content of moisture available to plants in the soil. This is an area of ​​insufficient moisture. Even in the forest-steppe, the probability of dry and semi-arid years is about 40%.

Therefore, throughout the history of the study of chernozems, special attention was paid to the study of their water regime.

A. A. Izmailsky, G. N. Vysotsky, P. A. Kostychev, S. I. Dolgov, A. F. Bolshakov, A. A. Rode, E. A. Afanasyeva and others studied the water regime of chernozems.

Studying the water regime of ordinary chernozems, G.N. Vysotsky established that 2 periods can be distinguished in the dynamics of moisture in chernozems:

1) drying out of the soil, covering the summer and the first half of autumn, when moisture is intensively consumed by plants and evaporates due to the dominance of ascending flows over descending ones;

2) soaking, starting in the second half of autumn, interrupted by frosts and continuing in the spring due to warm waters and spring precipitation.

These periods in the water regime of chernozems and its features are characteristic of all chernozems, however, the duration and timing of drying and wetting will be different for each subtype. They are determined primarily by the amount of precipitation, its distribution in time and temperature. The general pattern is a decrease in the depth of soil wetting from podzolized and leached chernozems to southern chernozems and an increase in soil drying in the same direction as the drying period lengthens.

Summer precipitation only moistens the arable layer. The moisture reserve in the lower horizons of chernozems is created by precipitation of the cold period (late autumn precipitation, melt water). In subzones, the moisture content of chernozem soils largely depends on the topography and mechanical composition of the soil. Light loamy and sandy loamy chernozems are soaked to great depths. On convex relief elements and slopes, moisture consumption increases due to surface runoff and evaporation; in depressions, especially concave and semi-closed ones, surface water accumulates and evaporation is weakened, which determines deeper soil wetting. In closed depressions it can reach groundwater.

The water regime of steppe chernozems differs from that of steppe zone chernozems. Podzolized, leached and typical chernozems are characterized by periodically leaching water regime.

The lower horizons of the soil-ground layer of forest-steppe chernozems, deeper than the layer of maximum wetting, always contain a certain amount of available moisture, which can serve as a moisture reserve in dry years.

The water regime is much more intense in the steppe zone (ordinary and southern chernozems), which are classified as arid and semi-arid. The chernozems of the steppe zone have a non-percolative water regime: in the lower part of their soil layer a constant horizon is formed with a moisture content not exceeding the wilting moisture content.

To obtain average yields of agricultural crops, the meter layer of soil before sowing must contain at least 1000 t/ha of available moisture. Therefore, all agrotechnical measures should be aimed at maximizing the restoration of the reserves of moisture useful for plants in the entire root layer of the soil by the spring of next year.

On arable chernozems, compared to virgin soils, a significant loss of water is possible due to snow drift and surface runoff of melt water. Blowing away snow leads to deep freezing of soils, so they later freeze. A sharp decrease in the water permeability of unthawed soil layers is accompanied by large losses of moisture from surface runoff.

Plant cover and fauna

Chernozems are soils of herbaceous formations confined to the steppe and forest-steppe zones. The characteristic humus profile is due to the influence of herbaceous vegetation with its powerful, rapidly dying root system.

The natural vegetation of the forest-steppe zone in the past was characterized by alternating forest areas with meadow steppes. Forest areas, partially preserved to this day, are located along watersheds, ravines and river terraces, and are represented by broad-leaved forests, mainly oak. Along the sandy terraces there are pine forests. The vegetation of the meadow steppes included feather grass, fescue, steppe oats, brome, sage, commonweed, yellow alfalfa, bluebell and many others.

The vegetation of the steppe zone consisted of forb-feather grass and fescue-feather grass steppes.

Among the former, the main background consisted of narrow-leaved turf grasses - feather grass, fescue, steppe oats, and others with a wide participation of forbs - sage, clover, bluebells, etc.

Fescue-feather grass steppes were characterized by less powerful and diverse vegetation, the main representatives of which were low-stemmed feather grass, tyrsa, fescue, wheatgrass, and sedges. The less powerful general character of the vegetation of the fescue-feather grass steppes, the widespread participation of ephemerals and ephemeroids in the herbage - mortuk, bulbous bluegrass, tulips, alyssum, as well as wormwood - is a consequence of a noticeable deficiency of moisture here.

The main features of the biological cycle of steppe and meadow-steppe herbaceous plant communities are that:

1) annually, with dying parts, almost the same amount of nutrients that was used for growth is returned to the soil;

2) most of these substances return not to the soil surface, but directly into the soil with the roots;

3) among the chemical elements involved in the biological cycle, the first place belongs to silicon, followed by nitrogen, potassium and calcium.

The amount of plant mass of natural grass communities on chernozems is high: in the forest-steppe of the Russian Plain 30-40 c/ha of above-ground phytomass and 200 c/ha of roots. The annual increase in phytomass on chernozems is 1.5-2 times higher than the amount of biomass during the period of maximum development. The growth of roots accounts for 50-60% of their total mass. On average, the litterfall of herbaceous communities in the chernozem zone is 200 c / (ha per year) (A. A. Titlyanova, N. I. Bazilevich, 1978).

The role of the biological cycle in the formation of the properties of chernozems is determined not so much by the chemical composition of steppe plants, but by its high intensity (a large number of annually formed chemical elements), the entry of the bulk of litter into the soil, the active participation in the decomposition of bacteria, actinomycetes, and invertebrates, for which the chemical composition is favorable litter and general bioclimatic conditions.

Mesofauna plays a major role in the formation of chernozems, and the role of earthworms is especially important. Their number in the profile reaches 100 or more per 1 m2. With such numbers, earthworms annually throw up to 200 tons of soil per 1 hectare to the surface and, as a result of daily and seasonal migrations, make a large number of moves. Together with dead parts of plants, earthworms capture soil particles and, during the digestion process, form strong clay-humus complexes, which are released in the form of coprolites. According to G.N. Vysotsky, chernozems largely owe their granular structure to earthworms.

The virgin steppe was the habitat of a large number of vertebrates. The largest numbers and importance were the diggers (gophers, mole rats, voles and marmots), which mixed and threw large amounts of earth to the surface. By making burrows in the soil, they formed molehills - passages covered with a mass of the upper humus layer. Thanks to soil mixing, rodents gradually enriched humus horizons with carbonates, which slowed down the leaching processes, and deep horizons with humus, which led to a lowering of the humus horizon boundary. Thus, their activities contributed to the formation of the most characteristic properties of chernozems.

Currently, there are practically no virgin black soils left. Most of them are plowed. The biological factor of soil formation has changed significantly when chernozems are involved in agriculture. Agricultural vegetation covers the soil for no more than 4 months a year, with the exception of sowing perennial grasses. The biological cycle has become open. The amount of annually created phytomass in agrocenoses is less than in the virgin steppe; the difference in the amount of underground biomass produced is especially large. Less nitrogen and mineral elements are involved in the biological cycle.

On arable land, the number of microflora increases significantly, but at the same time the number and especially the biomass of invertebrates, especially earthworms, sharply decreases. Vertebrate shrews do not live in arable land.

The East European or Russian Plain is one of the largest in the world: from north to south it stretches for 2.5 thousand km; from west to east - 1 thousand km. In size, the Russian Plain is second only to the Amazon, located in Western America.

East European Plain - location

From the name it is clear that the plain is located in the East of Europe, and most of it extends into Russia. In the northwest, the Russian Plain runs through the Scandinavian mountains; in the southwest - along the Sudetes and other European mountain ranges; from the West the border is the river. Vistula; on the south-eastern side the border is the Caucasus; in the East - the Urals. In the North, the plain is washed by the White and Barents Seas; in the South - the waters of the Black, Azov and Caspian seas.

East European Plain - relief

The main type of relief is gently flat. Large cities and, accordingly, the bulk of the population of the Russian Federation are concentrated on the territory of the East European Plain. The Russian state was born on these lands. Minerals and other valuable natural resources are also found within the Russian Plain. The outlines of the Russian Plain practically repeat the outlines of the East European Platform. Thanks to such an advantageous location, there is no seismic hazard or likelihood of earthquakes. On the territory of the plain there are also hilly areas that appeared as a result of various tectonic processes. There are elevations up to 1000 m.

In ancient times, the Baltic shield platform was located in the center of glaciation. As a result, there is a glacial relief on the surface.

The terrain consists of lowlands and hills, because... The platform deposits are located almost horizontally.

In places where the folded foundation protruded, ridges (Timansky) and hills (Central Russian) formed.
The height of the plain above sea level is approximately 170 m. The lowest areas are located on the coast of the Caspian Sea.

East European Plain - glacier influence

Glaciation processes significantly influenced the relief of the Russian Plain, especially in its northern part. A glacier passed through this territory, as a result of which the famous lakes were formed: Chudskoye, Beloe, Pskovskoye.
Previously, glaciation affected the topography of the southeast of the plain, but its consequences disappeared due to erosion. Uplands were formed: Smolensk-Moscow, Borisoglebskaya, etc., as well as lowlands: Pechora and Caspian.

In the south there are highlands (Priazovskaya, Privolzhskaya, Central Russian) and lowlands (Ulyanovskaya, Meshcherskaya).
Further to the south are the Black Sea and Caspian lowlands.

The glacier contributed to the formation of valleys, the increase in tectonic depressions, the grinding of rocks, and the formation of ornate bays on the Kola Peninsula.

East European Plain - waterways

The rivers of the East European Plain belong to the basins of the Arctic and Atlantic oceans, the rest flow into the Caspian Sea and have no connection with the ocean.

The longest and deepest river in Europe, the Volga, flows through the Russian Plain.

East European Plain - natural areas, flora and fauna

Almost all natural zones of Russia are represented on the plain.

• Off the coast of the Barents Sea, in the subtropical zone, tundra is concentrated.
• In the temperate zone, to the south from Polesie and to the Urals, coniferous and mixed forests stretch, giving way to deciduous forests in the West.
• In the South, forest-steppe prevails with a gradual transition to steppe.
• In the region of the Caspian Lowland there is a strip of Deserts and Semi-Deserts.
• Arctic, forest and steppe animals live on the lands of the Russian Plain.

The most dangerous natural phenomena that occur on the territory of the Russian Plain include floods and tornadoes. The environmental problem is acute due to human activities.

The Russian Plain is an example of a territory with a pronounced latitudinal zonation of soils and vegetation. On its surface there is a complex zonal spectrum of vegetation and soils from arctic tundras to deserts on gray soils.

Climatic conditions on a significant part of the Russian Plain are favorable for forest growth. Three or four centuries ago they covered more than half of the entire area of ​​the Russian Plain. The extreme north of the plain, occupied by tundra, and its south-southeastern third, covered by steppes, are deprived of forests. The reasons for the lack of forests in the north and south of the plain are directly opposite. In the north they are not due to a lack of heat with excess moisture, in the south due to a lack of moisture with excess heat. Treeless tundra covers the coast of the Barents Sea from the state border with Norway to Pai Khoi and the Arctic islands. In the south, the tundra gradually turns into forest-tundra.

The tundra provides food for numerous herds of deer. The lichen tundras used as winter pastures are of exceptional value; moss and dwarf tundras serve primarily as summer pastures.

Forests occupy a large area on the Russian Plain. They are formed by coniferous, broad-leaved and small-leaved species. In the geographical distribution of forests, the following pattern can be noticed: coniferous - in the northern climatic region with a positive moisture balance, broad-leaved - in the transition zone from the northern climatic region; regions to the south, where the moisture balance is close to neutral, and small-leaved trees are equally common in both the north and south of the forest region of the Russian Plain. In general, looking at the map of forests, it is not difficult to notice their gravity towards the northern, fairly moist half of the Russian Plain.

The forested area of ​​the Russian Plain is a meeting place for western (European) and eastern (Siberian) species. Most conifers are of Siberian origin, and the western border of their distribution lies on the Russian Plain. These species include: Siberian spruce (Picea obovata), Sukachev larch (Larix Sukaczewii), Siberian fir (Abies sibirica), cedar (Pinus sibirica). Broad-leaved species - oak (Quercus robur), ash (Fraxinus excelsior), hornbeam (Carpinus betulus), maples (Acer platanoides, A. campestre, A. tataricum), linden (Tilia cordata), elm (Ulmus laevis, U. scabra) - on the contrary, are of western origin and, with the exception of linden, do not go east further than the Ural ridge.

In the transition zone between the tundra and the forest region, a narrow - from 50 to 100 km - strip of forest-tundra formed by low-growing open forest is developed. To the west of Timan, the forest-tundra is dominated by birch woodlands, to the east - spruce woodlands. Larch woodlands, characteristic of the Siberian forest-tundra, are rare on the Russian Plain.

Depending on the composition of the predominant species, the forest region of the Russian Plain is divided into two soil and plant zones: taiga and mixed forests.

The taiga of the Russian Plain is par excellence dark coniferous. Spruce, represented by two species: common spruce (Picea excelsa) and Siberian spruce (Picea obovata), the real queen of the Eastern European taiga. In the east, the dark coniferous character of the taiga is enhanced by the presence of fir. Although pine is widespread throughout the taiga, it is found only on sandy and swampy soils. Other conifers - Sukachev larch and cedar - occupy a subordinate place and are known only in the east of the taiga.

The predominance of spruce in the taiga of the Russian Plain is explained by its humid climate and satisfactory drainage. The widespread distribution of spruce in Western Siberia is hampered by swampiness, while in Eastern Siberia the climate is continental. An analogue of the Eastern European taiga appears on the Pacific coast - the Okhotsk taiga, formed by Ayan spruce and fir.

Dense shading interferes with the development of shrubs and grass in spruce forests. Oxalis (Oxalis acetosella), linnaea (Linnaea boreal is), mine (Majanthemum bifolium), club moss, (Lycopodium borealis), mountain bipetal (Circaea alpina), ramishiya (Ramischia secunda) - here are a few “faithful” plants of the spruce forest.

Depending on the location and floristic composition, the spruce forests of the Russian Plain are divided into five types:

Green spruce forests characterized by the presence of a continuous cover of shiny green mosses (Hylocomium, Dicranumetc.). This is the most valuable type of spruce forest, developed in well-drained areas. The green moss spruce forests include the associations of spruce-oxalis, spruce-blueberry, spruce-lingonberry, etc.

Long-growing spruce forests, occupying flatter and less drained areas than green moss grasses, they have a thick moss cover of cuckoo flax (Polytrichum commune). Excessive moisture, characteristic of long-growing spruce forests, adversely affects the growth of spruce.

Sphagnum spruce forests grow on marshy soils, their moss cover contains sphagnum. Spruce in this type of forest

strongly oppressed, it forms low-growing, sparse stands here.

Swamp-grass spruce forests located along the valleys of ravines and rivers with running water. They have thick and tall grass cover.

Complex (shrub) spruce forests, growing on fertile, drained soils, they contain an admixture of broad-leaved species. In most cases, the undergrowth and shrub layer are well developed.

Types of plantings similar to spruce forests are found in pine forests (green moss forest, long moss forest, complex shrub forest, sphagnum forest, white moss forest, or lichen forest).

Small-leaved forests of warty birch (Betula verrucosa) and aspen (Populus tremulA). Their largest tracts are concentrated in the south of the taiga, and, as a rule, they are located on the site of coniferous forests cut down by humans or damaged by fires.

In addition to forests, there are many in the taiga swamps high and lowland type. Among raised bogs, convex sphagnum peat bogs are widespread, in which the central part is raised above the outskirts to a height of 0.5-1.0 m to 5.0-8.0 m. In raised bogs, pine is common, forming special low-growing bog forms here. The shape is especially interesting pumila. The trunk of this pine is immersed in peat, and only a panicle of branches no more than 1.0 m high protrudes above the surface of the sphagnum carpet. It is hard to believe that this tree dwarf is an ordinary pine (Pinus silvestris), which took such an ugly form in the swamp. In the northern and middle parts of the taiga, the surface of convex sphagnum bogs is complicated by ridge-hollow complexes: low dry ridges covered with wild rosemary, andromeda, Cassandra and other marsh shrubs alternate with damp depressions covered with sedge and cotton grass (Eriophorum vaginatum) and Scheuchzeria (Scheuchzeria palustris).

Under the coniferous taiga, podzolic soils with a pronounced leaching horizon are formed. They contain free humus acid, but are poor in bases and humus. Typical podzolic soils are characteristic of the middle regions of the taiga. The manifestation of podzol formation in the north of the taiga is hampered by waterlogging processes, and in the south of the taiga by the turf process. The turf process takes place with the participation of coniferous and deciduous species and developed grass cover.

The main area of ​​forests remaining on the Russian Plain is occupied by the taiga zone. From here the wood goes to other, treeless zones and to the foreign market.

Mixed forest zone located mainly in the triangle: Leningrad, Kyiv, Gorky. Pure oak forests coexist with spruce forests and pine forests of the taiga type. Simultaneously with these two opposite plantings, there is a whole series of transitional, mixed associations: spruce forests with an admixture of broad-leaved species in the upper layer, spruce forests with an oak forest shrub layer, and finally spruce forests, in which a mixed character is manifested in the presence of oak forest elements only in the grass cover.

The composition of mixed forests changes from west to east: to the west of Minsk and Vilnius spruce-hornbeam-oak forests are developed, to the east of these cities there are hornbeam (Carpinus betulus) no, spruce-oak mixed forests predominate.

Zonal soils of mixed forests are soddy-podzolic. In the west, under oak groves on heavy structural clays, poddubicas are known, characterized by weak podzolization and the presence of a nutty structure. In the south of the zone, dark-colored soils similar to the dark gray soils of the forest-steppe are formed on loess-like loams. These are; for example, the soils of the Yuryevsky Opolye in the Vladimir region.

Mixed forests have suffered more from human activity than taiga forests. Instead of continuous massifs, the landscape of island forests, scattered among cultivated fields, dominates here.

The southern border of the forest region, passing in the south through Kyiv, Gorky, Kazan, coincides with the line of neutral moisture balance; to the south of it, the amount of evaporation begins to exceed the annual amount of precipitation. This climatic boundary is at the same time the most important soil and geobotanical boundary. Forests remain to the south of it, but their composition changes: spruce falls out; mixed forests are disappearing, giving way to broad-leaved forests; The continuous forest cover characteristic of the north is broken here by treeless areas - not swamps as in the north, but dry grassy steppes. The further you go south, the fewer forests, the more spacious the steppes become. The removal processes characteristic of podzolic soils of the north are weakened here, and in their place the humus-accumulative process intensifies, leading to the formation of gray forest-steppe soils and chernozems.

The combination of forests with grassy steppes on watersheds forms forest-steppe type of vegetation. Due to the temperate continental climate and dissected topography, the forest-steppe of the Russian Plain is strongly stretched from north to south. This is the main soil and vegetation zone of the south of the Russian Plain; it occupies a vast area, exceeding the area of ​​the steppe zone.

The forests of the forest-steppe of the Russian Plain are dominated by oak forests. The first tier in them consists of oak, ash, Norway maple and elm; the second - pear, apple, Tatarian and field maple; even lower - bushes grew densely: hazel, two types of euonymus - warty (Evonymus verrucosus) and European (E. europaeus), honeysuckle (Lonicera xylosteurn), buckthorn brittle (Rhammus frangula) and laxative (R. cathartica). The soil in the oak grove, unlike the soil under a coniferous forest, is devoid of a cover of green mosses, but is covered with broad-leaved grasses: lily of the valley (Convallaria majalis), hoof (Asarum europaeum), compatriot (Orobus vernus), fragrant violet (Viola mirabilis), whining (Aegopodium podagraria), hairy sedge (Carex pilosa) and Zelenchuk (Galeobdolon luteum).

In the oak forests of the forest-steppe on carbonate soils (loess-like loams), a humus-accumulative process actively occurs, leading to the formation of gray forest (forest-steppe) soils, and in the south of the forest-steppe under oak forests soils close to podzolized and leached chernozems are formed.

Currently, most of the oak forests of the forest-steppe have been cut down. The mixed-grass steppes, which once occupied at least half of the forest-steppe zone, suffered even more. Nowadays, the mixed-grass steppes of the Russian Plain are plowed and remain intact only in a few nature reserves. The most famous is the Central Black Earth Nature Reserve named after. V.V. Alekhina, located southeast of the city of Kursk. In the reserve, three areas of mixed-grass steppes are protected from plowing: Streletskaya, Kozatskaya and Yamskaya steppes.

The forb steppe is characterized by continuous turfing of the soil and exceptionally high species richness. In the Streletskaya steppe, up to 77 different plant species were found on an area of ​​one square meter. To estimate the magnitude of this saturation, it is enough to recall that only 1,450 plant species were found on the territory of all Central Chernozem regions.

In spring and early summer, the mixed-grass steppe changes its color many times. In early spring, for some time, it becomes golden yellow from the blooming adonis (Adonis vernalis), at other times it pleases the eye with a soft blue color - the forget-me-not is blooming (Myosotis suaveolens), later, during the flowering period of mountain clover (Trifolium montanum) and ground nuts (Filipendula hexapetah), the steppe turns white, as if covered with snow. Of the feather grasses in mixed-grass steppes, the feather grass of John (Stipa Ioannis).

Under the mixed-grass steppes, on loess and loess-like loams, the most fertile soils in the world are formed - typical thick and leached chernozems.

To the south of the forest-steppe, due to the increased continentality of the climate, the forb steppes turn into cereal steppes, already characteristic of the steppe zone.

IN cereal steppes turf grasses, especially tyrsa (Stipa capillata), Lessing's feather grass (St. Lessingiana), narrow-leaved feather grass (St. stenophylla), thin-legged (Koeleria gracilis), Ukrainian feather grass (St. ucrainica), fescue. (Festuca sulcata). The grass stand in the grass steppes gradually becomes sparse, the aspects are less colorful, and the species richness drops sharply. In the cereal steppes of Askania-Nova per 1 sq. m, an average of 17 plant species were found. Forests in the steppe zone are rare and, moreover, almost always in azonal conditions - along river floodplains, slopes of ravines, sandy terraces above the floodplain; as an exception, small groves of forests are known from the tops of hills.

The soils of cereal steppes are not as rich in humus as in forb steppes. The background is formed by medium-humus (ordinary) and low-humus (southern) chernozems and dark chestnut soils. Due to the dry continental climate, salinization processes begin to actively manifest themselves in soil formation; A common occurrence in the zone are patches of solonetz and solonetzic soils.

Cereal steppes in the southeast of the Russian Plain, in semi-deserts, turn into wormwood-grass steppes. The herbage of wormwood-grass steppes is sparse, complex, formed by steppe grasses and desert subshrubs. Typical cereals are: fescue, Lessing's feather grass, Sarepta feather grass (Stipa sareptana), desert wheatgrass (Agropyrum desertorum); among the desert subshrubs there is white wormwood (Artemisia Lercheana), black wormwood (Art. pauciflora), chamomile (Pyrethrum achilleifolium), prutnyak (Kochia prostrata).

In wormwood-grass steppes, the role of ephemerals and ephemeroids (grains, tulips, viviparous bluegrass) increases compared to cereal steppes.

Under conditions of sparse vegetation cover and insufficient moisture in semi-deserts, humus-poor and often solonetzic light chestnut soils are formed. Solonezes are the same “zonal” phenomenon for semi-deserts as swamps are for the northern taiga.

The south of the Caspian lowland belongs to the northern desert. On the brown desert-steppe soils and salt marshes in the desert, rare bushes of wormwood and saltwort are scattered - plants that tolerate a lack of moisture and excess salts in the soil. Large areas of deserts are covered with sand.