Broad-leaved forests: features, relief, plants and animals. Mixed and broad-leaved forests of Russia Zone of mixed and broad-leaved forests of water

A mixed forest is an area in which deciduous and coniferous trees. If the admixture of tree species is more than 5% of the total flora, we can already talk about a mixed type of forest.

The mixed forest forms a coniferous zone deciduous forests, and this is a whole natural zone, characteristic of forests in the temperate zone. There are also coniferous-small-leaved forests, which are formed in the taiga as a result of the restoration of previously cut down pines or spruces, which begin to displace different types birch and aspen.

Main characteristics

(Typical mixed forest)

Mixed forests almost always coexist with broad-leaved forests in the south. In the northern hemisphere they also border the taiga.

The following varieties are distinguished mixed forests in the temperate zone:

• coniferous-deciduous;
• secondary small-leaved with the addition of coniferous and broad-leaved species;
• mixed, which is a combination of deciduous and evergreen species.

Subtropical mixed foxes are distinguished by a combination of laurel leaves and conifers. Any mixed forest is distinguished by a pronounced layering, as well as the presence of areas without forest: the so-called opoles and woodlands.

Location of zones

Mixed forests as a combination of coniferous and broad-leaved species are found in Eastern European and West Siberian Plains, as well as in the Carpathians, the Caucasus and the Far East.

In general, both mixed and broad-leaved forests occupy not such a large proportion of the forest territory of the Russian Federation as coniferous taiga. The fact is that such ecosystems do not take root in Siberia. They are traditional only for the European and Far Eastern regions and at the same time grow broken lines. Pure mixed forests are found south of the taiga, as well as beyond the Urals to the Amur region.

Climate

Mixed-type forest plantations are characterized by cold, but not very long winters and hot summers. Climatic conditions such that precipitation falls no more than 700 mm per year. The moisture coefficient is increased, but can change throughout the summer. In our country, mixed forests stand on soddy-podzolic soil, and in the west - on brown forest soil. As a rule, winter temperatures do not fall below - 10˚C.

Broad-leaved forest plantations are characterized by moist and moderately humid climate, where precipitation is distributed evenly throughout the year. The temperatures are quite high, and even in January it never gets colder than -8˚C. High humidity and abundant heat stimulate the work of bacteria and fungal organisms, due to which the leaves quickly decompose and the soil maintains maximum fertility.

Features of the plant world

Features of biochemical and biological processes cause the consolidation of species diversity as they move towards broad-leaved species. European mixed forests are distinguished by the obligatory presence of pine, spruce, maple, oak, linden, ash, elm, and among the shrubs the leaders are viburnum, hazel, and honeysuckle. Ferns are very common as herbs. Caucasian mixed forests contain large quantities of beech and fir, while the Far Eastern forests contain birch, walnut, hornbeam, and larch. These same forests are distinguished by a variety of vines.

Representatives of fauna

IN mixed forests inhabited by those animals and birds that are generally considered typical for forest conditions. These are moose, foxes, wolves, bears, wild boars, hedgehogs, hares, badgers. If we talk about individual broad-leaved forests, the species diversity of birds, rodents and ungulates is especially striking here. Roe deer, fallow deer, deer, beavers, muskrats and nutria are found in such forests.

Economic activity

The temperate natural zone, including mixed forests, has long been developed local residents and densely populated. An impressive part of the forest plantations was cut down several centuries ago, which is why the composition of the forest has changed and the proportion of small-leaved species has increased. In place of many forests, agricultural areas and settlements appeared.

Broad-leaved forests can generally be considered rare forest ecosystems. After the 17th century, they were cut down on a large scale, largely because wood was needed for the sailing fleet. Also, broad-leaved forests were actively cut down for arable land and meadows. Oak plantations have suffered especially badly from such human activity, and it is unlikely that they will ever be restored.

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

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

Character traits

The peculiarity of broad-leaved forests is that they can be divided into two distinct tiers. One of them is higher, the other is lower. These forests are shrubby, the existing grasses grow in three tiers, and the ground cover is represented by lichens and mosses.

One more characteristic feature is the light mode. In such forests, two light maxima are distinguished. The first is observed in spring period when the trees are not yet covered with leaves. The second is in the fall, when the foliage thins. In summer, light penetration is minimal. The above-described 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. Trees in broadleaf forests contain ash. There is 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).

Trees of broadleaf forests

Forests of this type are characterized richest variety tree species. The latter can be counted here about ten. 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 unfavorable conditions.

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

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

Herbs

Plants of broad-leaved forests are characterized by large and wide leaf blades. For this reason they are called broad-grass oak forests. Some grasses 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 are common sedge, hairy sedge and yellow green grass.

Most of the herbaceous plants found in deciduous forests are perennial. They live up to several decades. As a rule, their existence is maintained thanks to vegetative propagation. They reproduce poorly by seeds. Characteristic specified plants- long underground and above-ground shoots, rapidly growing in different directions and actively capturing new areas of land.

The above-ground parts of most representatives of oak groves die off in the autumn. Only the roots and rhizomes in the soil overwinter. They contain special buds, from which new shoots form in the spring.

An exception

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

Shrubs

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

“Hasty” oak forest ephemeroids

These plants are of greatest interest to specialists studying forest flora. Among them are spring guillemot, various types of corydalis and goose onion. These plants are usually small in size, but they develop very quickly. Ephemeroids rush to be born immediately after disappearance snow cover. Some especially fast sprouts make their way even through the snow. After a week, maximum two, their buds are already blooming. After a few more weeks, the fruits and seeds ripen. After this, the plants lie down on the ground, turn yellow, after which the part of them that is above the ground dies. 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 lushly only in the spring, and summer for them is the time to wither.

The period most conducive to their development is early spring. At this time of year, the forest experiences maximum light as the bushes and trees have not yet acquired their thick green cover. In addition, during this period the soil is optimally saturated with moisture. As for high summer temperatures, ephemeroids do not need it at all. All these plants are perennial. They do not die after their aboveground part dries out. Living underground roots are represented by tubers, bulbs or rhizomes. These organs act as receptacles for 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. There are about ten species in total. Their flowers are painted in bright purple, blue, and yellow colors. During flowering, ephemeroids form a thick, beautiful carpet.

Mosses

Broad-leaved forests of Russia are home to various types of mosses. Unlike 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 leaf litter from broad-leaved forests 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 areas that are untouched by humans. Thus, in deciduous forests you can see roe deer, wild boars, fallow deer, sika and red deer, and elk. The order of predators is represented by foxes, wolves, martens, stoats and weasels. broadleaf forests, animal world which are rich and varied, are home to beavers, squirrels, muskrats and nutrias. In addition, these areas are inhabited by mice, rats, moles, hedgehogs, shrews, snakes, lizards and marsh turtles.

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

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

The number of red deer has also undergone a change. They have become much smaller due to the barbaric actions of man. Massive plowing of fields has 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 also live with her.

Sometimes in autumn, males gather a kind of harem. Resembling the sound of a trumpet, their roar spreads three to four kilometers around. The most successful deer, having defeated their rivals in fights, can gather up to twenty females around them. This is how another type of reindeer herd is formed. At first summer season deer give birth to babies. They are born weighing eight to eleven kilograms. Up to six months they experience intensive growth. One-year-old males acquire horns.

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

Beavers are another inhabitant 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 its body length is one meter. Beavers are distinguished by a massive body and a flattened tail. The membranes between the toes of the hind legs help to lead an aquatic lifestyle. Fur color can vary from light brown to black. By lubricating their fur with a special secretion, beavers protect themselves from getting wet. When immersed in water, the ears of this animal fold and the nostrils close. Economical consumption 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. It is a hole or a kind of hut, the entrance to which is located under the surface of the water. These animals build dams when the water level is unstable. Thanks to these structures, the flow is regulated, which allows water to enter the home. Gnawing branches and even large trees is easy for beavers. Thus, aspen trees of five to seven centimeters in diameter lend themselves to these animals in two minutes. Their favorite food is reed. In addition, they are not averse to eating iris, water lilies, and water lilies. Beavers live in families. The young go in search of a mate in the third year of life.

Wild pigs are another typical inhabitant of deciduous forests. They have a huge head and a very strong long snout. The most powerful weapon of these animals is sharp triangular fangs that are curved up and back. Boars' vision 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. It is very durable.

Boars are excellent runners and swimmers. These animals can swim across a body of water that is several kilometers wide. The basis of their diet is plants, but we can say 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, godwits, green and viviparous lizards. Only vipers pose a danger to humans. Many people mistakenly believe that copperheads are also poisonous, but this is not the case. The most numerous reptiles of deciduous forests are snakes.

Relief features

The zone of broad-leaved 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 abuts the Ural Mountains. Since the specified territory was covered more than once continental ice Its topography is mostly hilly. The most obvious traces of the presence of the Valdai Glacier are preserved in the north-west. There, the zone of broad-leaved and mixed forests is characterized by chaotic piles of hills, steep ridges, closed lakes and basins. South part The described territory is represented by secondary moraine plains, which were formed as a result of a decrease in the inclined surface of hilly areas. The relief is characterized by the presence of sandy plains of varying sizes. Their origin is water-glacial. They are undulating, and sometimes you can find pronounced sand dunes.

Russian Plain

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

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

Conclusion

Broad-leaved forests located in Europe are classified as endangered ecosystems. But just two or three centuries ago they were one of the most diverse on the planet and were located throughout most of Europe. Thus, in the sixteenth to 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 what was once a vast broadleaf belt remained intact. At the dawn of this century, attempts were made to grow oak trees in deserted territories. However, this turned out to be quite a difficult matter: the death of young oak groves was caused by constant droughts. At that time, research was carried out, led by the famous Russian geographer Dokuchaev. As a result, it was established that the failure to grow new trees was due to large-scale deforestation, since this forever changed the hydrology and climate of the area.

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

Coniferous-deciduous forests of the Russian Plain - natural area temperate zone, characterized by a relatively mild, humid climate, coniferous-broad-leaved forests growing along the watersheds on sod-podzolic soils. It is also called a zone of mixed forests, which is not entirely accurate, since taiga forests are often mixed in species composition. These two names can apparently be considered synonyms.

In the north, the zone borders on taiga, in the south – on forest-steppe, in the west, outside the USSR, it passes into the zone of broad-leaved forests of Western Europe. The leading role in the formation of the landscape is played by the location of the zone in the southwest of the forest belt of the USSR, in relative proximity to the Atlantic Ocean. Compared to the taiga, the climate of mixed forests is warmer and more humid, and in its extreme northwest (Kaliningrad region) it is transitional from maritime to continental.

During the year, about 50-55 cyclones pass through the Kaliningrad region; In winter here almost every second day there is a front passing through. The sum of temperatures for a period with a stable temperature above 10° in the north of the zone is about 1800°, in the south – 2400°. The average duration of the frost-free period increases from 120 days in the northeast of the zone to 165 days in the west Kaliningrad region and in the Kyiv region. There is more precipitation in the zone than in the taiga. Their annual amount varies between 600-700 mm, and on the western slopes of the hills it reaches 800 mm. The moisture balance is positive; in the south it approaches neutral: the amount of evaporation here is almost equal to the annual amount of precipitation. The Vysotsky-Ivanov humidification coefficient, as in the taiga, is greater than one, the Budyko dryness index increases slightly and ranges from 2/3 to 1. There is enough heat and moisture here for cultivation diverse cultures: gray bread, wheat, potatoes, flax, sugar beets (southwest), hemp (south zone), forage grasses.

Under conditions of a positive moisture balance, the surface runoff in coniferous-deciduous forests is large (350-150 mm), the river network is well developed, and the rivers themselves are characterized by high water content. The most significant rivers, the basin of which lies entirely within the zone, are the Western Dvina and the Neman. The Western Dvina, despite its small basin area (85,100 km 2), has an average long-term water flow at the mouth of 680 m 3 /sec. Due to the positive moisture balance, groundwater lies close to the surface (from 0 to 10 m) and is quite widely used for various economic needs. The waters of terminal moraine ridges are variable in their distribution and depth. As in the taiga, the mineralization of groundwater in the zone is weak, the salt concentration ranges from 100 to 500 mg/l.

The proximity of groundwater in a humid climate causes widespread development of waterlogging processes. High and lowland swamps cover most lowlands and basins, they are often found on high, but insufficiently drained watersheds. Among the swamps in the north of the zone, high-moor sphagnum peat bogs predominate, sometimes covered with low-growing pine. To the south of Moscow and Minsk, transitional and lowland swamps predominate, containing peat more Low quality compared to sphagnum peat of raised bogs. Peat from high-moor and transitional bogs in the zone of coniferous-deciduous forests is widely used for fuel and to fertilize fields. Large areas of swamps, after drainage, have been converted into fertile arable and hayfields. It seems most appropriate to drain transitional and lowland swamps, which are relatively rich in mineral salts. Agricultural development of raised bogs, poor in mineral salts, requires a lot of labor and material resources and does not always bring the desired economic effect. When producing peat in quarries, it is recommended to leave an agricultural protective layer (the lower layer of the peat deposit) 30 cm thick, which is then used as organic matter for the newly created soil.

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 - the Volga, Dnieper, Western Dvina, etc. - begin here. 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 we move east due to the increasing continentality of the climate southern border zones 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, oxalis - are combined with elements of oak forests, among which the role of sedum, hoofed 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 has increased significantly, river beaver and moose.

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. Common reptiles in mixed forests sand lizard and so on.

Rice. 7. 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; there has been a change in the animal kingdom species composition- European tarpans and aurochs that once lived in the forests have 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 from the Caucasus.

The Valdai province extends from upstream rivers Lovat and Western Dvina to the north-northeast to Lake Onega. It consists of the Valdai (341 m), Tikhvin (280 m) and Vepsovskaya (304 m) hills, 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 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, Velho, 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.

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. average temperature 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. On outwash plains, lakeside sands and sandy hills pine forests predominate. 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 the Bryansk-Zhizdra, Meshchersky, Mokshinsky, Balakhninsky, Vetluzhsky, Kama-Vyatka and other woodlands.

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 swell, etc.), and large layers 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 remains for up to 150-160 days at maximum height snow cover 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. The Oka Nature Reserve was created there in 1935.

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

GEOGRAPHICAL POSITION. Forests in the northern and western parts of Ukraine occupy 28% of the territory. The zone of mixed forests (coniferous-deciduous), which is called Polesie, 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 - Zhitomir - Kyiv - Nizhyn - Glukhov. Polesie is amazing land forests and rivers, where there are no crushing droughts, where in some villages in the spring they move along 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 the field pikes poetically describe their region.

In western Ukraine, mixed forests are replaced by south direction broad-leaved, which extend to the Cis-Carpathian Upland and the border with Moldova.

RELIEF AND MINERAL RESOURCES. The mixed forest zone occupies mainly the Polesie 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 Slovechansko-Ovruch Ridge (more than 300 m). The relief was affected by the influence of the glacier: it brought polished stones and boulders from the north, leaving sediments 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 hills - Volyn, Rastochye, Podolsk (western part), Khotyn. The hills underwent tectonic uplift at the end of the Cenozoic era, which resulted in the incision of river valleys and the spread of water-erosive landforms.

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

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

CLIMATE AND INTERNAL WATERS. The climate of forest zones is moderate continental. The air temperature varies from west to east in January from -4 to -8 °C, in July - from + 17 to +19 °C. In forest zones there is more precipitation compared to the flat areas of Ukraine (600-700 mm per year).

With low evaporation, moisture in the mixed forest zone is excessive. Therefore, a characteristic feature of Polesie is swampiness. Among the swamps, lowland ones prevail, lying along rivers. In the central-eastern part, the zone is crossed by the Dnieper, receiving the tributaries Pripyat, Desna, Teterev, Irpen. A dense river network forms them 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. Large tributaries of the Pripyat are Turia, Stokhod, Styr, Uzh, Goryn (with the tributary Sluch). All rivers have wide valleys with low banks, slow current. They are deep-water, as they feed mainly on precipitation.

At the extreme

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

There are many lakes in Polesie. These are mainly small bodies of water with clean running water. In the northwestern part of the zone there are Shatsk lakes (Svityaz, Pulemetskoe, Luka, Pesochnoe, etc.), mainly of karst origin. Small oxbow lakes are common along the rivers. On the Podolsk Upland there are small karst lakes - “windows”.

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

In the Polesie physical-geographical region, mixed forests are dominated by soddy-podzolic soils. Their fertility is low due to high acidity and excess moisture. Even less fertile are the soils formed in river valleys and lower reaches - meadows, swamps, peat bogs and peat bogs. Compared to other landscapes of the flat part of Ukraine, the vegetation of Polesie (forest, meadow and swamp) is better preserved, but the name “Polesie” itself rather reflects its natural history than current state. Forests once covered 90% of the territory, but now they occupy only 25%. Another 10% of the area is meadows.

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

Of the forest communities, the majority 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 areas.

There are almost no shrubs or grasses in them; low areas are completely covered with moss. Wet areas are occupied mainly by alder and birch forests. Meadows in Polesie are common not only in floodplains, but also in places where forests have been cut down. The greatest diversity of herbaceous plants is in floodplain meadows. They meet here and there

sands covered with thyme or heather. Lowland swamps are famous for their variety of grasses (yellow killer whale, loosestrife, beaver grass, and swamp beetle). Raised bogs overgrown with moss, cranberries, and sundews are rare. Among the sandy lowlands of Polesie there are large swamps covered with hummocks of grass.

In the Western Ukrainian region, gray forest soils have formed under broad-leaved forests. As we move east, chernozems spread - typical, on which there was once rich meadow and steppe vegetation, and podzolized (formed in the process of natural overgrowing of steppe spaces with broad-leaved forests). Today, broad-leaved forests occupy less than 15% of the region's area. The predominant deciduous species are oak and beech (in the west), oak and hornbeam (in the east). Ash, maple, and linden are also common, with occasional stands of pine and spruce. Steppe vegetation has been preserved in small patches on hillsides or in ravines.

The forests are inhabited by roe deer, raccoon dog, wild boar, wolf, fox, marten, hare, and squirrel. Occasionally found Brown bear and lynx. Beavers build their huts along the rivers. There are many birds - black grouse, wood grouse, crane, stork.

So, the physical and geographical diversity of forest zones of Ukraine forms the following natural landscapes: mixed-forest coniferous-deciduous lowland (Polessye), broad-leaved forest upland, floodplain meadow and meadow-swamp. Nowadays, most of the zone’s territory is occupied by anthropogenic landscapes.

NATURE MANAGEMENT AND NATURE CONSERVATION.

The zones of mixed and deciduous forests of Ukraine and the neighboring territories of Belarus and Poland are the ancestral home of the Slavs. From here they settled throughout Eastern Europe. For a long time the forest zone was sparsely populated, natural forests were preserved almost untouched. Intensive destruction of forests due to economic activity man began in the 16th century. Subsequently, agricultural development of land and industrial logging intensified, cities arose, and roads were laid. Currently, agricultural landscapes cover more than 65% of the Polesie area and about 80% of deciduous forests. Huge changes have occurred in natural landscapes after draining the swamps and straightening the river beds.

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

In the broad-leaved forests in the natural reserve "Raztochya" and the national natural park "Yavorovsky" forest areas of beech and oak are protected, and in the natural reserve "Medobory" and the national park "Podolskie Tovtry" - unique natural complexes of Tovtry.

REMEMBER

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

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

The broad-leaved forest zone is characterized by elevated terrain, gray forest soils and chernozems, oak-beech and oak-hornbeam forests.

QUESTIONS AND TASKS

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

2. What are the differences in the topography of mixed and deciduous forest zones?

3. Why are there many swamps in Polesie and 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 natural environment protected and preserved in the forest zone?

This is textbook material