Zone of mixed and broad-leaved forests. Arctic deserts Zone of mixed and broad-leaved forests of water

The zone of deciduous forests is located on the territory of Manchuria, the Far East, within Europe, the eastern part of China, and North America. It also affects the southern part of South America and some parts of Central Asia.

Broad-leaved forests are most common where there is a moderately warm climate, and the ratio of moisture and heat is optimal. All this provides favorable conditions during the growing season. The leaf plates of the trees growing there are wide, hence the name of these forests. What other features does this natural area have? The broadleaf forests are home to numerous animals, reptiles, birds and insects.

Character traits

Features of broad-leaved forests are that two distinct tiers can be distinguished in them. One of them is higher, the other is lower. These forests are shrubby, the available grasses grow in three tiers, the ground cover is represented by lichens and mosses.

Another characteristic feature is the light mode. In such forests, two light maxima are distinguished. The first is observed in the spring, when the trees are not yet covered with leaves. The second - in the fall, when the foliage is thinning. In summer, light penetration is minimal. The above regime explains the peculiarity of the grass cover.

The soil of deciduous forests is rich in organo-mineral compounds. They appear as a result of the decomposition of plant litter. Broadleaf forest trees contain ash. Especially a lot of it in the leaves - about five percent. Ash, in turn, is rich in calcium (twenty percent of the total volume). It also contains potassium (about two percent) and silicon (up to three percent).

Broadleaf forest trees

Forests of this type are characterized by the richest variety of tree species. The latter can be counted here about ten. The broad-leaved forests of the taiga, for example, are not so rich in this regard. The reason is that the conditions of the harsh taiga climate are not so conducive to the growth and development of flora. Many tree species that are demanding on soil composition and climate simply will not survive in adverse conditions.

In the southern part of the Tula region there is a well-known forest. It gives a great idea of what broadleaf forests can be like. The soil of this area is favorable for the growth of such trees as small-leaved lindens, holly and field maples, ordinary ash-trees, elms, elms, wild apple-trees and pears. Oaks and ash trees are the tallest, followed by holly maples, elms and lindens. The lowest are field maples, wild pears and apple trees. As a rule, the dominant position is occupied by an oak, and the remaining trees act as satellites.

Let us consider in more detail the above representatives of the dendroflora.

Herbs

Plants of deciduous forests are characterized by large and wide leaf blades. For this reason, they are called broad-grass oak forests. Some herbs grow in single specimens, they never form impenetrable thickets. Others, on the contrary, form a kind of carpet covering large spaces. Such herbs are dominant. Among them, common goutweed, hairy sedge and yellow Zelenchuk are distinguished.

Most of the herbaceous plants found in broadleaf forests are perennials. They live up to several decades. As a rule, their existence is supported by vegetative propagation. They do not reproduce well by seed. A characteristic feature of these plants is long underground and above-ground shoots, rapidly growing in different directions and actively capturing new plots of land.

The above-ground parts of the majority of representatives of oak broad grasses die off in the autumn. Only roots and rhizomes located in the soil hibernate. They have special buds, from which new shoots are formed in the spring.

Exception to the rule

Rare representatives of broad grasses remain green both in winter and in summer. Such plants include the following: hoof, greenfinch, hairy sedge.

shrubs

As for these representatives of the flora, it is very difficult to meet them in deciduous forests. They are simply not characteristic of oak forests, which cannot be said about coniferous forests, where shrubs grow everywhere. Blueberries and lingonberries are the most widespread.

"Hurry" oak ephemeroids

These plants are of the greatest interest to specialists studying forest flora. Among them are spring chistyak, corydalis of various species and goose onions. These plants are usually small in size, but they develop very quickly. Ephemeroids rush to be born immediately after the snow cover melts. Some particularly frisky sprouts make their way even through the snow. After a week, a maximum of two, their buds are already blooming. After a few more weeks, the fruits and seeds ripen. After that, the plants lie down on the ground, turn yellow, after which that part of them that is above the ground dies off. Moreover, this process occurs at the very beginning of the summer period, when, as it may seem, the conditions for growth and development are as favorable as possible. The secret is simple. Ephemeroids have their own rhythm of life, which differs from the peculiar development schedule of other plants. They bloom luxuriantly only in spring, and summer for them is the time of wilting.

The period most conducive to their development is early spring. At this time of the year, the maximum amount of light is observed in the forest, since the shrubs and trees have not yet found their dense green cover. In addition, during this period, the soil is optimally saturated with moisture. As for the high summer temperature, the ephemeroids do not need it at all. All these plants are perennials. They do not die after their above-ground part dries up. Live underground roots are represented by tubers, bulbs or rhizomes. These organs act as repositories of nutrients, mainly starch. This is why stems, leaves and flowers appear so early and grow so rapidly.

Ephemeroids are widespread plants in broad-leaved oak forests. In total there are about ten species. Their flowers are painted in bright purple, blue, yellow colors. During flowering, ephemeroids form a thick beautiful carpet.

mosses

The broad-leaved forests of Russia are home to various types of mosses. In contrast to the taiga forests, in which these plants form a dense green soil cover, in oak forests, mosses do not cover the soil so widely. The role of mosses in deciduous forests is rather modest. The main reason is the fact that the leaf litter of the broad-leaved forest has a detrimental effect on these plants.

Fauna

Animals of the broad-leaved forests of Russia are ungulates, predators, insectivores, rodents and bats. The greatest diversity is observed in those territories that are not touched by man. So, in broad-leaved forests you can see roe deer, wild boars, fallow deer, spotted and red deer, elks. The squad of predators is represented by foxes, wolves, martens, ermines and weasels. The broad-leaved forests, with a rich and varied wildlife, are home to beavers, squirrels, muskrats and nutrias. In addition, these territories are inhabited by mice, rats, moles, hedgehogs, shrews, snakes, lizards and marsh turtles.

Birds of deciduous forests - larks, finches, warblers, tits, flycatchers, swallows, starlings. Crows, rooks, black grouse, woodpeckers, crossbills, jackdaws, hazel grouses also live there. Birds of prey are represented by hawks, owls, owls, owls and harriers. The swamps are home to waders, cranes, herons, gulls, ducks and geese.

In the past, broad-leaved forests were inhabited by bison. Now, unfortunately, there are only a few dozen left. These animals are protected by law. They live in Belovezhskaya Pushcha (in the Republic of Belarus), in the Prioksko-Terrasny Reserve (Russian Federation), in some states of Western Europe and in Poland. Several animals were transported to the Caucasus. There they coexist with bison.

The number of red deer has also changed. They have become much smaller due to the barbaric actions of man. Mass and plowing fields have become disastrous for these beautiful animals. Deer can reach two and a half meters in length and three hundred and forty kilograms of weight. They tend to live in small herds of up to ten animals. In most cases, the female is dominant. Her offspring lives with her.

In autumn sometimes males gather a kind of harem. Reminiscent of the sound of a trumpet, their roar spreads three to four kilometers around. The most successful deer, having won the fights of their rivals, can gather up to twenty females around them. This is how another type of reindeer herd is formed. At the beginning of the summer season, deer cubs are born. They are born weighing eight to eleven kilograms. Up to six months, they have intensive growth. One-year-old males acquire horns.

Deer feed on grass, leaves and shoots of trees, mushrooms, lichens, reeds, bitter wormwood. But the needles are not suitable for them to eat. In the wild, deer live for about fifteen years. In captivity, this figure doubles.

Beavers are another inhabitants of deciduous forests. The most favorable conditions for them are observed in Europe, North America, Asia. The maximum recorded weight of this animal is thirty kilograms, and the body length is one meter. Beavers are distinguished by a massive body and a flattened tail. The webbing between the toes of the hind legs helps to maintain an aquatic lifestyle. Fur color can vary from light brown to black. Lubricating their wool with a special secret, beavers are protected from getting wet. When immersed in water, the auricles of this animal fold and the nostrils close. The economical use of air helps him stay under water for up to fifteen minutes.

Beavers prefer to settle on the banks of lakes and oxbow lakes, as well as slow-flowing rivers. They are attracted by abundant coastal and aquatic vegetation. represents a hole or a kind of hut, the entrance to which is under the water surface. These animals build dams if the water level is unstable. Thanks to these structures, the flow is regulated, which allows it to enter the dwelling from the water. Gnawing branches and even large trees is easy for beavers. So, an aspen of five to seven centimeters in diameter lends itself to these animals in two minutes. Their favorite food is cane. In addition, they are not averse to eating iris, water lily, egg capsule. Beavers live in families. The young go in search of a mate in their third year of life.

Wild pigs are another typical inhabitants of deciduous forests. They have a huge head and a very strong long snout. The most powerful weapons of these animals are sharp trihedral fangs that are bent up and back. The vision of wild boars is not very good, but this is compensated by excellent hearing and a keen sense of smell. Large individuals reach a weight of three hundred kilograms. The body of this animal is protected by dark brown bristles. She is very durable.

Boars are excellent runners and swimmers. These animals are able to swim through a reservoir, the width of which is several kilometers. The basis of their diet is plants, but it can be said that wild boars are omnivores. Their favorite delicacy is acorns and beech nuts, they will not refuse frogs, mice, chicks, insects and snakes.

Representatives of reptiles

Broad-leaved forests are inhabited by snakes, vipers, copperheads, spindles, green and viviparous lizards. Only vipers are dangerous to humans. Many mistakenly believe that copperheads are also poisonous, but this is not so. The most numerous reptiles of deciduous forests are snakes.

Relief features

The zone of deciduous forests (and mixed) in the European part of Russia forms a kind of triangle, the base of which is located at the western borders of the country, and the top rests on the Ural Mountains. Since this territory was more than once covered with continental ice, its relief is mostly hilly. The most obvious traces of the presence of the Valdai glacier have been preserved in the northwest. There, the zone of broad-leaved and mixed forests is characterized by chaotic heaps of hills, steep ridges, closed lakes and hollows. The southern part of the described territory is represented by secondary moraine plains, which were formed as a result of a decrease in the sloping surface of hilly areas. The relief is characterized by the presence of sandy plains of different areas. Their origin is water-glacial. They have ripples, sometimes you can find pronounced sand dunes.

Russian plain

This zone is located in the temperate climate zone. The climate there is relatively mild and humid. The soil of these territories is soddy-podzolic. The close location of the Atlantic Ocean determined the features of the relief. The river network in coniferous-deciduous forests is well developed. Reservoirs are large.

The activity of the swamping process is determined by the proximity of groundwater and a humid climate. The plants that dominate the grass cover have broad leaf blades.

Conclusion

Broad-leaved forests located on the territory of Europe are classified as endangered ecosystems. But two or three centuries ago they were one of the most diverse on the planet and were located in most of Europe. So, in the sixteenth and eighteenth centuries, they occupied an area equal to several million hectares. Today there are no more than one hundred thousand hectares.

At the beginning of the twentieth century, only fragments of the former extensive broad-leaved belt remained unscathed. At the dawn of this century, attempts were made to grow oaks in the deserted territories. However, this turned out to be a rather complicated matter: the death of young oak groves was caused by constant droughts. At that time, studies were carried out, which were led by the famous Russian geographer Dokuchaev. As a result, it was found that failures in the cultivation of new trees are associated with large-scale deforestation, since this forever changed the hydrological regime and climate of the area.

Today, in areas previously occupied by broad-leaved forests, secondary forests grow, as well as artificial plantations. They are dominated by coniferous trees. Unfortunately, as experts note, the dynamics and structure of natural oak forests cannot be restored.

Arctic desert zone. Franz Josef Land, Novaya Zemlya, Severnaya Zemlya, and the New Siberian Islands lie in this zone. The zone is characterized by a huge amount of ice and snow in all seasons of the year. They are the main element of the landscape.

The arctic air prevails here all year round, the radiation balance for the year is less than 400 mJ/m 2 , the average temperature in July is 4-2°C. Relative humidity is very high - 85%. Precipitation is 400-200 mm, and almost all of it falls in solid form, which contributes to the formation of ice sheets and glaciers. However, in some places the supply of moisture in the air is small, and therefore, with an increase in temperature and a strong wind, a large lack of it is formed and strong evaporation of snow occurs.

The soil-forming process in the Arctic takes place in a thin active layer and is at the initial stage of development. In the valleys of rivers and streams and on sea terraces, two types of soils are formed - typical polar desert soils on drained polygonal plains and polar desert solonchak soils in saline coastal areas. They are characterized by a low content of humus (up to 1.5%), weakly expressed genetic horizons and very small thickness. In the Arctic deserts, there are almost no swamps, few lakes, and salt spots form on the surface of the soil in dry weather with strong winds.

The vegetation cover is extremely sparse and patchy, it is characterized by poor species composition and exceptionally low productivity. Low-organized plants dominate: lichens, mosses, algae. The annual growth of mosses and lichens does not exceed 1-2 mm. Plants are extremely selective in their distribution. More or less close groupings of plants exist only in places sheltered from cold winds, on fine earth, where the thickness of the active layer is greater.

The main background of the Arctic deserts is formed by scale lichens. Hypnum mosses are common, sphagnum mosses appear only in the south of the zone in very limited quantities. Of the higher plants, saxifrage, polar poppy, grains, chickweed, arctic pike, bluegrass and some others are characteristic. Cereals grow luxuriantly, forming hemispherical pillows up to 10 cm in diameter on a fertilized substrate near nesting gulls and lemming burrows. An ice ranunculus and a polar willow grow near the snow patches, reaching only 3-5 cm in height. The fauna, like the flora, is poor in species; there are lemmings, arctic foxes, reindeer, polar bears, and among the birds the white partridge and snowy owl are ubiquitous. On the rocky shores there are numerous bird colonies - mass nesting of sea birds (guillemots, little auks, white gulls, fulmars, eiders, etc.). The southern shores of Franz Josef Land, the western shores of Novaya Zemlya are a continuous bird colony.

Remember, within what natural zones Ukraine lies. What types of trees are common in the forests of Ukraine?

GEOGRAPHICAL POSITION. Forest northern and western parts of Ukraine and occupy 28% of the territory. The zone of mixed forests (coniferous-deciduous), which is called Polissya, stretches from west to east in a wide strip between the northern border of Ukraine and a conditional line passing through the cities of Vladimir-Volynsky - Lutsk - Rivne - Zhytomyr - Kyiv - Nizhyn - Glukhov. Polissya is an amazing land of forests and rivers, where there are no crushing droughts, where in some villages in the spring they move through the streets in boats, where the air smells of pine and hops, and it seems that you can drink it like birch sap.

This is how Poleshchuks poetically describe their land.

In the west of Ukraine, mixed forests are replaced in a southerly direction by broad-leaved ones, which extend to the Carpathian Upland and the border with Moldova.

RELIEF AND MINERALS. The zone of mixed forests occupies mainly the Polesskaya lowland (Fig. 138). Its surface is almost flat, with a slight slope towards the Dnieper and Pripyat. Its absolute heights rarely exceed 200 m, the highest section is the Slovechan-sko-Ovruch ridge (more than 300 m). The relief was affected by the influence of the glacier: it brought polished boulders from the north, left deposits in the form of sandy fields, moraine hills and ramparts (Volyn ridge). Wind-blown sands form dunes up to 5 km long and up to 18 m high.

Broad-leaved forests cover the uplands - Volynskaya, Rastochye, Podolskaya (western part), Khotynskaya. The uplands underwent tectonic uplift at the end of the Cenozoic era, which led to the incision of river valleys and the spread of water-erosive landforms.

As a result, the relief in many places has become hilly, the heights often exceed 400 m above sea level. At the same time, in the watershed areas of the Podolsk Upland, there are flat elevations - plateaus (Fig. 139). The Podolsk upland and the Prut-Dniester interfluve are the largest accumulation of karst landforms in Ukraine. There are concentrated more than 100 caves in gypsum deposits. Among them are the longest in the world - Optimistic (more than 240 km), Ozernaya, Cinderella, as well as Crystal, Mlynki, etc.

In places of shallow occurrence of crystalline rocks, deposits of copper (Volyn region), kaolins, granites, basalts, labradorites, gabbro and semi-precious stones - topaz, jasper, amber (Rivne, Zhytomyr regions), phosphorites (Sumsk, Khmelnytsky regions) were found. Everywhere in Polissya there are deposits of peat, and in Podolia - limestone. The Lviv-Volyn coal basin is located on the border with Poland.

CLIMATE AND INLAND WATER. The climate of the forest zones is temperate continental. The air temperature changes from west to east in January from -4 to -8 °С, in July - from + 17 to +19 °С. In forest areas, more precipitation falls compared to the flat areas of Ukraine (600-700 mm per year).

With low evaporation, moisture in the zone of mixed forests is excessive. Therefore, a characteristic feature of Polissya is swampiness. Among the swamps, low-lying ones lying along the rivers predominate. In the central-eastern part of the zone, the Dnieper crosses the zone, receiving the tributaries of the Pripyat, Desna, Teterev, and Irpin. A dense river network is formed by their river systems. Pripyat originates in the north-west of the Volyn region and is located only in the upper and lower reaches in Ukraine. Its numerous branches, straits and old channels are filled with water in the spring and form a continuous body of water. The major tributaries of the Pripyat are Turia, Stokhod, Styr, Uzh, Goryn (with the Sluch tributary). All rivers have wide valleys with low banks and slow flow. They are full-flowing, because they feed mainly on precipitation.

At the extreme

in the west, the Western Bug has similar characteristics. In the south, the zone of broad-leaved forests outlines the Dniester, its left tributaries, crossing the Podolsk Upland, form deep, often canyon-like valleys in the lower reaches.

There are many lakes in Polissya. Basically, these are small reservoirs with clean running water. In the northwestern part of the zone, the Shatsk Lakes (Svityaz, Pulemetskoe, Luka, Pesochnoye, etc.) are located, mainly of karst origin. Small oxbow lakes are common along the rivers. On the Podolsk Upland there are small karst lakes - "windows".

SOIL AND VEGETATION COVER AND LANDSCAPES. In the natural zoning of Ukraine, the zone of mixed forests is identified as the Polessky physical-geographical region (Ukrainian Polissya), and the zone of broad-leaved forests is identified as the Western Ukrainian region.

Soddy-podzolic soils predominate under mixed forests in the Polesie physiographic region. Their fertility is low due to high acidity and excessive moisture. Even less fertile are the soils formed in the river valleys and lower reaches - meadow, swamp, peat-bog and peat bogs. Compared to other landscapes of the flat part of Ukraine, the vegetation of Polissya (forest, meadow and marsh) is better preserved, but the name "Polesie" reflects its natural history rather than its current state. Once forests covered 90% of the territory, now they occupy only 25%. Another 10% of the area is meadows.

Swamps characteristic of Polissya occupy more than 4% of its territory. In total, more than 1,500 plant species are known in Polissya.

Of the forest communities, most of all are pine-oak forests. The undergrowth in them is formed by hazel, elderberry, willow, euonymus, and numerous herbaceous plants. Sparse pine forests (pine forests) grow on sandy massifs.

There are almost no shrubs and herbs in them, the lowered areas are completely covered with moss. Moist areas are occupied mainly by alder and birch forests. Meadows in Polissya are common not only in floodplains, but also in the place of cut down forests. The greatest variety of herbaceous plants is found in floodplain meadows. meet somewhere

sands covered with thyme or heather. Lowland swamps are famous for herbs (yellow killer whale, loosestrife, beaver, swamp belozor). Raised bogs overgrown with moss, cranberries, and sundew are rare. Among the sandy lowlands of Polissya there are large swamps covered with tussocks of grass.

In the Western Ukrainian region, gray forest soils have formed under broad-leaved forests. With advancement to the east, chernozems spread - typical, on which there was once rich meadow and steppe vegetation, and podzolized (formed in the process of natural overgrowth of steppe spaces with broad-leaved forests). Today, broad-leaved forests occupy less than 15% of the region's area. The predominant hardwoods are oak and beech (in the west), oak and hornbeam (in the east). Ash, maple, linden are also widespread, occasionally there are plantations of pine and spruce. The steppe vegetation has been preserved in small spots on the slopes of hills or in ravines.

Roe deer, raccoon dog, wild boar, wolf, fox, marten, hare, squirrel live in the forests. Occasionally there are brown bear and lynx. Beavers build their huts along the rivers. Many birds - black grouse, capercaillie, crane, stork.

So, the physical and geographical diversity of the forest zones of Ukraine forms such natural landscapes: mixed-forest coniferous-broad-leaved lowland (Polesye), broad-leaved-forest elevated, floodplain meadow and meadow-marsh. Nowadays, most of the territory of the zone is occupied by anthropogenic landscapes.

NATURE MANAGEMENT AND NATURE PROTECTION.

The zones of mixed and broad-leaved forests of Ukraine and the neighboring territories of Belarus and Poland are the ancestral home of the Slavs. From here they spread throughout Eastern Europe. For a long time, the forest zone was sparsely populated, natural forests remained almost untouched. Intensive destruction of forests due to human activities began in the 16th century. In the future, agricultural land development, industrial logging intensified, cities arose, roads were laid. Now agricultural landscapes cover more than 65% of the area of Polesie and about 80% of broad-leaved forests. Enormous changes have taken place in natural landscapes after the drainage of marshes and the straightening of river beds.

On the territory of the forest zone in 1986, an accident occurred at the Chernobyl nuclear power plant. People were evicted from the 30-kilometer zone around it, as a result of which natural processes take place there without their participation, but under the influence of severe radiation pollution. Their progress is monitored in the Drevlyansky Nature Reserve and the Chernobyl Radiation-Ecological Biosphere Reserve, established in 2016. To preserve the landscapes of Polissya, forest and marsh vegetation in mixed forests, a number of nature protection areas have been created. In particular, in the Cheremsky, Rovno and Polessky nature reserves, swampy-peat massifs, lakes, and pine forests are studied and protected. In the Shatsk National Natural Park, there are 22 protected lakes with valuable fish species (eel, catfish), and swamps located among pine forests and alder forests.

In broad-leaved forests in the natural reserve "Rostochye" and the national natural park "Yavorovsky" protect areas of forests made of beech and oak, and in the natural reserve "Medobory" and the national park "Podolsky Tovtry" - unique natural complexes Tovtr.

REMEMBER

Mixed forests (Polesie) occupy the northern part of the territory of Ukraine, and broad-leaved forests occupy the western part.

The zone of mixed forests is characterized by swampiness, glacial landforms, soddy-podzolic soils, pine-oak, pine and alder forests.

The zone of deciduous forests is characterized by elevated relief, gray forest soils and chernozems, oak-beech and oak-hornbeam forests.

QUESTIONS AND TASKS

1. Describe the geographical location of mixed and broad-leaved forest zones. Find out on the map which administrative regions of Ukraine are wholly or partially located in these zones.

2. What are the differences in the relief of mixed and broad-leaved forest zones?

3. Why are there many swamps in Polissya and why has a dense river network formed?

4. Name the plant communities and representatives of the animal world of mixed and deciduous forests.

5. How is the protection and preservation of the natural environment carried out in the forest zone?

This is textbook material.

In addition to coniferous forests in North America, there are zones of mixed and deciduous forests. Their formation and features are greatly influenced by the relief and properties of surface rocks.

Mixed forests of North America

The mixed forests of North America are located in the temperate climate zone between the taiga zone and broad-leaved forests. They are common in the northeastern United States, the eastern United States, and the border with Canada. The name of the forests speaks for itself: both coniferous trees and broad-leaved representatives of this species are concentrated here. Winter in this zone is cool (-5-14 degrees), and summer is quite warm (+20 degrees).

Mixed forests are characterized by gray forest and soddy-podzolic soils.

Coniferous species are dominated by white and red pine, Canadian hemlock, fir, and spruce. Of the deciduous, birch, sugar maple, American ash, elm, hornbeam, and linden are widespread.

Rice. 1. American ash.

The fauna of mixed forests is very similar to the fauna of the taiga. Here you can meet a black bear baribal, badgers, minks, wolves, otters, raccoons and skunks, virgin deer.

Rice. 2. Black bear baribal.

In mixed forests, in contrast to broad-leaved forests, grass cover is very well represented. in broad-leaved forests, large tree leaves prevent sunlight from reaching the ground, so the grass cover here is much poorer.

Broadleaf forests of North America

The broad-leaved forests of North America are located in the temperate climate zone in the eastern part of the mainland south of the mixed forests. This zone is characterized by long warm summers and mild winters. The climate here changes to a more humid and warmer one, so coniferous trees, characteristic of mixed forests, are practically not found. This area is characterized by gray forest soil rich in iron.

What have we learned?

Mixed and broad-leaved forests are located in the temperate climate zone. In deciduous forests, the climate is milder and warmer than in mixed ones. They have a diverse flora and fauna, and there are also endemics in this territory that are not found on other continents.

Topic quiz

Report Evaluation

Average rating: 4 . Total ratings received: 142.

The zone of mixed and broad-leaved forests is located in the western part of the plain between the taiga and the forest-steppe and extends from the western borders of Russia to the confluence of the Oka into 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 shows a combination of uplands (200 m or more) and lowlands. Stratum plains are overlain by moraine, lacustrine-alluvial, fluvioglacial and loess rocks. Soddy-podzolic and gray forest soils are formed within the zone under conditions of a moderately humid and moderately warm Atlantic-continental climate.

Here the large high-water rivers of the East European Plain begin - the Volga, the Dnieper, the Western Dvina, and others. Underground waters lie close to the surface. This contributes to the development of swamps and lakes with a dissected relief, clay-sand deposits and sufficient moisture.

The climate of the zone favors the growth of coniferous tree species together with broad-leaved trees. Depending on the relief conditions and the degree of moisture, meadows and swamps are also formed. European coniferous-broad-leaved forests are heterogeneous. Of the broad-leaved species in the zone, linden, ash, elm, and oak are common. As we move to the east, due to the increase in the continentality of the climate, the southern boundary of the zone is significantly shifted to the north, the role of spruce and fir increases, while the role of broad-leaved species decreases.

The widest distribution of 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 - oxalis, mainik - are combined with elements of oak forests, among which the role of goutweed, hoof, woodruff, etc. is significant.

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

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

In the zone of mixed and broad-leaved forests in historical times there were many wild animals and birds. At present, they are pushed back to the least populated places or completely exterminated and are only preserved and restored in reserves. Now 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 boundary of the range of the wild boar has moved to the northeast and southeast in some places up to 600 km or more. Coniferous-deciduous forests are characterized by species of animals characteristic of Eurasia, but mostly close in origin to species of western broad-leaved and mixed forests, for example, European roe deer, European red deer, European mink, marten, dormouse, European forest cat, muskrat. Maral, spotted deer, muskrat are acclimatized. Of the reptiles in mixed forests, the agile lizard and snake are common.

Rice. 7. Geological structure of the Valdai Upland

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 territory of the zone, the most convenient areas are plowed up or occupied by pastures; in the animal world, 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 partridges have become rare.

Great work has been 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 have been taken under protection. Reserves have been created in the zone that 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 an important role in the restoration of bison brought from Belovezhskaya Pushcha and the Caucasus in dense coniferous-deciduous forests.

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

The province is located on the western flank of the Moscow syneclise; therefore, the sequence of sedimentary rocks that make up the cover is monoclinal. The Valdai-Onega ledge is usually considered as a carboniferous glint (cuest ledge), which fixes 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, a well-preserved glacial-accumulative hilly-morainic relief with terminal moraine ridges (Torzhokskaya, Vyshnevolotskaya, Lesnaya, etc.) and numerous moraine lakes along the basins (Seliger, Volgo, Valdai, Velio, etc.). This strip of young picturesque landscapes is called Poozerye. The thickness of the moraine that covered the pre-glacial relief varies from 1–2 m to 100 m or more.

The carbonate rocks underlying the moraine determine the development of karst landforms where the thickness of the Quaternary deposits is small, within the limits of the Carboniferous scarp itself and in the valleys of the rivers cutting through it. Karst forms are represented by saucers, ponors, 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 hollows of the glacial melt waters, and their valleys are not yet fully formed. Short rivers connect numerous lakes, forming single water systems.

The climate of the province is humid with cool summers. The average July temperature 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°С. Often coming here cyclones cause thaws. The annual amount of precipitation is more than 800 mm, which is the maximum for the Russian Plain. The maximum is in the summer.

The province is characterized by an extraordinary variety of soil and vegetation cover, which is due to the frequent change of soil-forming rocks and landforms. Moraine hills and ridges are covered with broad-leaved spruce forests on soddy-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-broad-leaved forests grow with dominance of oak, with linden, ash and elm in the second tier.

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

A significant part of the area of the province has long been heavily modified by man, but in some places there are still slightly modified areas. Here, in 1931, the Central Forest Reserve was created, which now has the status of a biosphere reserve. Its territory is covered with spruce and spruce-broad-leaved forests, typical for this province.

The Meshchera province is located between the Klyazma and Oka rivers. In the north it is bounded by the slopes of the Smolensk-Moscow Upland, in the east by the Oka-Tsninsky swell. 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, moraine-erosion uplifts are common with average heights of 150-200 m.

This type of landscape is called woodland. Woodland landscapes were formed at the edge of the Pleistocene ice sheet, in depressions of the pre-glacial relief, through which the runoff of glacial melt waters occurred. Elevated remnants or "loess islands" - opolyas - have also been preserved here. On the East European Plain within Russia, the woodland type of landscape forms a whole belt consisting of the Bryansk-Zhizdrinsky, Meshchersky, Mokshinsky, Balakhna, Vetluzhsky, Kamsko-Vyatsky and other woodlands.

Meshchera is confined to the pre-glacial tectonic trough. At its base lie Carboniferous limestones overlain by Jurassic and Cretaceous sandy-argillaceous deposits. The Quaternary deposits consist of eroded moraine, preserved in the highest parts of the pre-glacial relief (the Yegoryevskoye Plateau, the Oksko-Tsninsky swell, etc.), and large strata of sands and loams of water-glacial and alluvial origin. In the central part of Meshchera, a lowland stretches with peat bogs and lakes (Holy, Great, 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 up to 150-160 days with a maximum snow cover height of 50-55 cm. Winter types of weather are unstable - with frosts and thaws. Due to the significant amount of snow, the high water on the Meshchera rivers is long. Summers are warm with maximum precipitation. The average July temperature is 18.5-19°C. The annual amount of precipitation (about 600 mm) exceeds evaporation, so the territory is excessively humidified.

The main area of Meshchera is covered with pine forests, places with an admixture of oak and swamps. Spruce and birch forests are less common. Soddy-podzolic and soddy-podzolic-gley soils were formed under the forests on sands and sandy-clay deposits. Light lichen forests are widespread on sandy shafts, hills and dunes; spruce-pine forests with an admixture of oak, maple and linden dominate in the interfluves along the slopes of the valleys; on moraine remnants, mixed forests of spruce, oak and linden grow, with an undergrowth of hazel and a dense grass cover of goutweed, hoof, lily of the valley; wet oak forests are found on the floodplains.

Bogs occupy about 35% of Meshchera's surface. The main types of bogs are low-lying and transitional, among which are sphagnum-sedge, hypnum-sedge, sedge and birch-sedge. Raised bogs are less common, but they form large massifs and contain thick peat beds (up to 8 m) of high quality. The Shatura thermal power plant operates on the Meshchersky peat.

A variety of 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. There, in 1935, the Oksky Reserve was created.