Forest zone. Temperate forest zone

The content of the article

FOREST, compact array of trees and shrubs. More than a third of the land surface is covered with forests or suitable for their development. However, the area occupied by forests is unevenly distributed between the continents and even within each of them. For example, forest cover covers almost half of South America, about a third of Europe and the United States, and much of Africa and Asia; in Australia, on the contrary, there are few of them, and some large countries, for example Egypt, are generally treeless. Forests in Antarctica and Greenland are completely absent, but low trees grow in the extreme south of the latter.

Although the most characteristic feature of a forest is the presence of trees and shrubs, it is not just woody vegetation, but a complex community (or ecosystem) made up of closely related elements. Like all ecosystems, a forest is formed by a combination of living organisms (biota) and their nonliving (abiotic) habitat. In addition to trees and shrubs, forest biota includes other plants (grasses, mosses, fungi, algae and lichens), as well as vertebrates and invertebrates and bacteria. The abiotic component is represented by air, soil and water. All these components of living and inanimate nature are closely interconnected due to the passage of the flow of energy through the ecosystem and the circulation of oxygen and other substances in it. For example, the energy from sunlight is used by plants for photosynthesis, the process of making organic nutrients from water and carbon dioxide. Since this is only characteristic of green plants, all animals must eat either these plants or other animals, which in turn feed on plants. Thus, plants directly or indirectly provide food for all other organisms. As a by-product of photosynthesis, oxygen is released into the air, replenishing its reserves in the atmosphere. Bacteria and other organisms involved in the decomposition of organic matter play a vital role in forest ecosystems. They convert complex chemical compounds that make up metabolic waste and plant and animal residues into simple ones that can be reused by organisms.

In most forests, several layers are distinguished, formed by foliage of plants of different heights. The topmost one, consisting of the crowns of the tallest trees, is called the first tier or forest canopy. In some areas, especially in the tropics, individual giant trees rise significantly above the canopy. If there are other relatively closed tree layers under it, they are called the second, third, etc. Shrubs, tall grasses (in some forest types) and low-growing trees form the undergrowth. The herbaceous layer consists of shrubs and grasses. Mosses, lichens, and creeping plant species form the ground, or ground, layer.

Organic matter, consisting of fallen leaves, twigs, flowers, fruits, bark and other plant debris, as well as animal feces and carcasses, pupal and larval shells, etc., forms a forest floor on the soil surface. In most forests, litter is the most densely populated layer. It often contains several million living organisms per square meter - from protozoa and bacteria to mice and other small mammals.

The edge of the forest is a transitional strip between it and the adjacent type of vegetation. It is characteristic that within the forest edge the trees are covered with foliage almost to the very ground, and many shrubs and grasses common here are rare or not found at all in the forest and in neighboring open plant communities. Some species of birds, often considered forest birds, actually live mainly on forest edges, which are also an important habitat for mammals.

Forest classifications.

There are many types of forests and many ways to classify them. For example, they can be classified by geographic distribution (eastern, tropical, etc.) or by position in the relief (plain, floodplain, etc.). They can also be grouped according to their seasonal aspect. So, forests are considered evergreen if living foliage is preserved on trees all year round. In a deciduous forest, leaves fall off with the onset of the cold or dry season, and the trees remain bare for several weeks or months each year. Some forests, such as the oak groves of the US Southwest, are formed by trees shedding old leaves and forming new ones over the course of two to three weeks in the spring. Such communities can be called semi-deciduous or semi-evergreen.

Sometimes the basis for the classification of forests is the characteristic features of the tree species that form them, and forests are accordingly divided into coniferous, broad-leaved, mixed, etc. A combination of morphological and seasonal characteristics is also possible in the classification (for example, evergreen coniferous or deciduous deciduous forests). In another case, the names of forest-forming species are used (oak-brown or red-oak-white-oak-holokary forests, etc.).

For some purposes, especially commercial ones, it is useful to classify forests by the relative age of the trees. For example, stands of the same age consist of trees of approximately the same age, and different-age stands of trees of a wide age range.

There are also sparse (light) or closed forests. In the first case, tree crowns, as a rule, do not touch or overlap, and the canopy turns out to be discontinuous. In a closed forest, it is more or less continuous and is formed by intertwining or overlapping tree crowns.

Another descriptive classification is based on the degree of forest disturbance, mainly as a result of human activities. For example, in a virgin (indigenous) forest, mostly mature or old (overmature) trees grow, and the rest of the vegetation is not artificially altered. Secondary, or derivative, forests develop in clearings, conflagrations and abandoned fields.

FACTORS INFLUENCING FOREST GROWTH

It is believed that the distribution of forests is mainly determined by regional characteristics of the climate, i.e. mainly by temperatures and precipitation, and at a more local level - by the microclimate. Soils, fires, animals and non-woody vegetation play an important role in creating microclimatic conditions.

Climate and relief.

In general, forests are widespread in regions where the annual precipitation is at least 250–380 mm, and the duration of the frost-free period is at least 14–16 weeks. Moisture conditions depend on the temperature and the nature of the relief. For example, in the Tucson area (Arizona, USA) there is a desert, and on the watersheds there grow only sparsely scattered low trees and saguaro cacti (giant carnegia), and in the west of Colorado, in the national monument of the same name, the slopes of valleys and hilltops are covered with sparse forests from juniper and cedar pine. The differences in vegetation in these areas are explained by climatic conditions: despite the same amount of precipitation (about 280 mm per year), the relative humidity in Arizona is lower, because due to higher temperatures, more water is lost through evaporation and transpiration.

Low temperatures also make water inaccessible to plants (so-called physiological dryness). In such conditions, cold deserts are formed. The absence of trees in the polar regions and high in the mountains is explained by the short growing season and the inaccessibility of frozen water for plants.

The impact of local climatic conditions is most noticeable in latitudinal valleys or on the slopes of mountain ranges of the same orientation. In the Northern Hemisphere, the northern exposure slopes are not illuminated by direct sunlight. As a result, they are colder than southern ones, they have less evaporation and temperatures do not change so quickly and dramatically. Rock weathering is also weaker here, and these slopes are usually steeper. In semi-arid regions, forests can grow on them, while in adjacent southern regions, only shrub or herbaceous vegetation can grow. In humid areas, both slopes are usually covered with forest, but beech, maple, hemlock and other moisture-loving tree species grow in the north, and oak, hazel and other trees that can tolerate long periods of low soil moisture in the south.

Soils.

Moisture and chemical composition of soils are the main conditions that determine the distribution of trees. As mentioned above, humidity depends on the amount of precipitation and relief. In addition, it is influenced by the structure of the soil, i.e. the size of its constituent particles, the degree of their aggregation, or adhesion, and the amount of organic matter present. In general, the larger the particles, the less aggregated they are, the lower the organic matter content and the water-holding capacity of the soil.

On soils with a high content of certain chemicals, forests and even individual trees usually do not grow at all. A striking example is the soils formed on serpentinites - rocks consisting of magnesium silicate with an admixture of iron. Serpentine Wastes are small, prominent patches of grassy vegetation scattered among the forests of Pennsylvania, Maryland, California, several other states, and Canada. Salinization of the soil is much more widespread, which excludes the possibility of the growth of almost all tree species. It is observed along the shores of the seas and in deserts.

Some properties of soils, mainly their chemistry, affect the composition of the tree species that settle on them. This is especially noticeable in places where alkaline soils formed on limestones closely coexist with acidic soils formed on sandstones, gneisses and shales. For example, in the eastern United States, sugar maple, beech, and linden are common on limestone soils, while oak and hazel are often predominant on sour soils. In the southwestern United States, limestone soils are treeless, although forests grow nearby on soils formed on other rocks.

Fires.

Few trees are capable of surviving repeated fires annually or at intervals of several years, and most species do not tolerate fire at all. Thus, frequent fires usually prevent the forest from developing and lead to the spread of other types of vegetation, in particular grass. For example, much of the prairies in the United States and Canada were probably treeless for this reason. On almost every continent, territories devoid of trees due to frequent fires cover areas ranging from several hectares to thousands of square kilometers.

Within forest regions, fires can have a profound effect on the composition of forests. For example, in the western United States, twisted pine and Douglas (Menzies' false beetle) are usually found in large numbers, either after severe fires or in areas that are often burned out. In similar conditions, Banks pine grows in the northeastern United States, and swamp and closed pine in the southeast. In the absence of fires, these species are eventually replaced by other tree species. Forestry is now using the method of planned burns, which favors the growth of fire-resistant tree species with valuable wood.

Animals

have a significant impact on both the distribution and composition of forests. For example, rabbits in the UK and other countries not only leave vast areas treeless, but also deprive them of shrub cover. It is possible that the bison are partly responsible for the treelessness of the prairies of the North American Midwest. Even small mammals such as mice can hinder the reforestation of burned-out and abandoned farmland by eating seeds and nibbling tree seedlings. And yet, of all living things, the most powerful influence on forests is exerted by man, who cuts and burns them, poisoning them with pesticides until they are completely destroyed, and then plowing or building up the vacated lands. Grazing by domestic animals also impedes reforestation in clearings.

Other factors.

Few studies have focused on the role of shrubs, herbaceous plants, lichens and mosses in displacing forests or slowing down forest regeneration. However, in forested regions, areas covered with thickets of bushes sometimes remain treeless for more than 30 years. Even herbage from grasses or other plants, such as goldenrod or asters, can prevent many tree species from settling. Over the past few years, it has been experimentally shown that many of these plants secrete chemical compounds that inhibit the germination of tree seeds.

HISTORY OF FORESTS

The age of the Earth is 4.5–6.6 billion years. Primitive life forms probably arose very early in the history of our planet, as fossil remains of plant cells were found in rocks more than 3.1 billion years old. The oldest organisms we know are blue-green algae and bacteria, the fossil remains of which have been found in Africa. Treelike plants and, therefore, the first forests appeared relatively recently, and their history covers less than 10% of the time of existence of the Earth itself. Although trees seem to be evolutionarily more progressive than flowering grasses, fossil remains indicate that the latter descended from tall, tree-like ancestors, and not vice versa.

The oldest terrestrial plants are known from the Upper Silurian deposits of Australia with an age of approx. 395 million years. The vegetation, consisting of low shrub forms, spread widely on land in the early Devonian time, approx. 370 million years ago. The first trees were giant horsetails and lymphoids, reaching a height of more than 7.5 m. These trees in the Late Devonian formed low-growing forests with an underbrush of primitive ferns and other small plants.

During the Carboniferous period, which began about 345 million years ago, vast areas of land were covered by dense forests of giant horsetails, lyes and tree ferns up to 30 m and more in height. Apparently, they were confined to waterlogged lowlands, where dead leaves and fallen trunks did not decompose, but accumulated in the form of peat. Subsequently, the peat was covered with silty and sandy deposits. As they accumulated, peat under high pressure was gradually transformed into coal. Numerous fossil plant remains can often be discerned in it. An important evolutionary event in the Carboniferous period was the appearance of primitive gymnosperms - seed ferns and cordaites.

The Permian period began ca. 280 million years ago with drastic transformations. The climate became more and more arid, and the face of the planet was changing under the influence of the powerful glaciation of the Southern Hemisphere, mountain building and catastrophic redistribution of land and sea. During this period, giant horsetails, moons and tree ferns died out, they were supplanted by primitive cycads and conifers. The appearance of the Earth's forests began to change, and this process continued during the Mesozoic era, which began ca. 225 million years ago. In the Triassic and Jurassic periods, cycads and conifers were the main forest-forming species. Many ginkgoids appeared. One of the species - ginkgo biloba - is still found naturally in Eastern China and is planted as an ornamental tree in cities in Southern Europe, East Asia and North America. Sequoias also grew in abundance, the range of which is now limited to California and southern Oregon, and in the Triassic and Jurassic they were found in most of North America, Europe, Central Asia and even in Greenland. The most widespread were coniferous forests from species similar to modern araucaria. Fossilized coniferous trunks have survived in the Petrified Forest National Park (in translation - stone forest) in Arizona and in some other parts of the world.

The oldest known angiosperms, or flowering plants, are palms, the remains of which are found in Triassic deposits in Colorado. The next, Jurassic period was characterized by an increase in the diversity of flowering plants. The role of conifers and other gymnosperms declined, and gradually during the Cretaceous period (135–65 million years ago) flowering plants, mostly trees and shrubs, became dominant. They were represented by the ancestors of modern species such as ficus, magnolia, holly, oak, sassafras, willow and maple. During the Cretaceous and Paleogene, metasequoia, a "deciduous" coniferous tree that now grows only in the interior regions of China, also settled throughout the Northern Hemisphere. The widespread development of forests of this composition in North America, Greenland and most of the Arctic indicates that a mild climate prevailed on Earth.

The Paleocene period, which began ca. 65 million years ago, it was characterized by a warm, humid climate. In such conditions, the flora was distinguished by its species diversity and abounded in angiosperms. Almost everywhere in the Northern Hemisphere, forests were distributed, in composition similar to the modern forests of the tropics and the temperate zone. The most northerly of the main types of flora that existed at that time, the arctotretic, included deciduous trees and other plants very similar to those currently growing in eastern North America and Asia. The second type of flora - the Tertiary Neotropical - was confined to lower latitudes and was represented by evergreen broadleaf species, related to modern species growing in the tropics and subtropics.

In the Neogene, climatic conditions, apparently, became more diverse, and there was a shift in flora types towards the equator. Forest areas were shrinking, and herbaceous communities were spreading over more and more areas. The third type of flora - madrotretic - was formed, apparently, on the basis of the two above in connection with the progressive aridization of the climate in the west of North America. This flora is characterized by small-leaved trees and shrubs, similar to those growing now in the southwestern United States and Mexico.

The Arctic Tertiary flora spread circumpolarly in the northern regions of the globe. Forests throughout this area were marked by striking similarities. They were dominated by broad-leaved species (elm, chestnut, maple), as well as alder and metasequoia. In the Late Cenozoic period, many trees that are now characteristic of the eastern regions of the United States with a wet summer disappeared in western North America as a result of mountain building processes and climate changes that took place there. Conifers, which played an insignificant role in the Arctic Tertiary flora, became predominant in the western forests.

The final period of the Cenozoic era, called the Quaternary, began ca. 1.8 million years ago and continues to this day. It was characterized by an alternation of extensive continental glaciations and warm interglacial eras, similar to the modern one. Despite the short duration of the Quaternary period (only 0.5% of the history of our planet), the evolution of man, who has become the dominant species on Earth, is associated with it. In Europe, the composition of forests has simplified, as many tree species have become extinct, and the area of ​​the forests themselves has decreased significantly everywhere. Huge areas of land were repeatedly covered with powerful ice sheets, and then freed from ice. Even now, 10,000 years after the end of the last glaciation, the forests of the Northern Hemisphere are still adapting to the climatic changes that have occurred since then.

GLOBAL FORESTS

By the nature of the forest cover, three large latitudinal zones can be distinguished: boreal, or northern, coniferous forests (taiga); temperate forests; tropical and subtropical forests. There are several types of forests in each of these zones.

Boreal (taiga) forest zone

The boreal forest zone is the northernmost one. It extends from 72 ° 52ў N. in Asia (which is much north of the Arctic Circle) up to about 45 ° N. in the central part of this continent and in the west of North America. There is no similar zone in the Southern Hemisphere.

The taiga forests are characterized by evergreen conifers, mainly various types of spruce, fir and pine. Deciduous deciduous trees are also common, such as various types of birch, alder and poplar. In Siberia, larch dominates, dropping needles for the winter.

The zone of forests of temperate latitudes.

Such forests are common in North and South America, Asia, Africa, New Zealand and Australia. They are represented by summer-green (deciduous) broad-leaved, coniferous, evergreen, mixed (rain), hard-leaved (sclerophilous) and other less common types of forests.

Summer green forests are common in eastern North America, the British Isles, mainland Europe, East Asia and Japan, as well as in the extreme southwest of South America. Usually they consist of only one tree layer, although in some areas the second is also expressed. In some places shrub undergrowth is developed, which usually does not have a continuous distribution. There are few arboreal vines here, and from epiphytes, as a rule, only mosses, liverworts and lichens are represented. Herbaceous plants, which bloom in spring when the trees are bare, play a prominent role. Most trees also bloom in the spring, before the leaves open.

Coniferous forests of temperate latitudes are distributed mainly in the west and southeast of North America and in Eurasia. Various types of pines are most typical for them, but other conifers are common in the west of North America.

Evergreen mixed (rain) forests of temperate latitudes are found where there is a lot of precipitation, and temperatures rarely drop below 0 ° C. Such communities are represented in the southwestern North America, the southeastern United States, southern Japan, Korea, China, Australia, New Zealand and the extreme south of Africa. It is dominated by oaks, magnolia and notofagus, to which conifers are mixed. Of the epiphytes, lichens and mosses are most characteristic, densely covering the lower parts of tree trunks.

Stiff-leaved (sclerophilous) forests are common in areas with dry hot summers and cooler, wet winters, dominated by evergreen trees and shrubs with small leathery leaves. Trees are usually stunted with twisted trunks. Sparse forests of this type are typical for the Mediterranean and Black Sea regions, where evergreen oaks and pines predominate. Forests of the Mediterranean type, but with a different species composition, are also found in the extreme south of Africa, Australia, Mexico, central Chile and the southwestern United States.

Zone of tropical and subtropical forests.

This zone is the leader in species diversity of tree species. For example, at least 2,500 tree species grow in the Amazon basin alone. It is believed that there are about the same number of them on the Malacca Peninsula. As a rule, the trees in this zone are thin-bored with thick leathery leaves covered with a waxy coating. Usually the leaves fall off at the same time and are quickly replaced by new ones, so the plants are never naked. Although some species shed all the foliage at once, in different breeds this leaf fall occurs at different times and is not associated with any particular seasonal phenomenon. Caulifloria is extremely widespread in tropical rain forests, i.e. development of flowers and fruits directly on the trunk and branches of trees.

Savannah forests are common in tropical areas with a distinct dry season and less annual precipitation than in the zone of closed forests. It is characterized by trees from the legume family, usually with a flat umbrella-shaped crown, shedding foliage during the dry season. As a rule, they are far apart from each other, with the exception of places where groundwater is near the surface. The grass cover is almost continuous and is formed mainly by grasses. Typically, trees are less than 18 m tall, and often no more than 3-4.5 m, and therefore, during the wet season, grasses can rise above the tree layer. Savannah forests cover most of Cuba and other islands in the Caribbean, many parts of Brazil, northern Argentina, East and Central Africa, and parts of India, China and Australia.

In tropical regions where rainfall is even less and the dry season is longer, communities of xerophilous thorny trees and shrubs are widely developed. They are common in South America, the Caribbean, Mexico and Central America, northern Africa and Australia. The tree species here are deciduous or with leaves in the form of scales. Leafless shrubs with green stems are also characteristic. Many species are covered with thorns, and the stems or roots of plants are often swollen and composed of tissues that store water.

Typical savannahs are common in the tropics and subtropics. These are “park” communities in which individual deciduous or evergreen trees or groups of them are scattered among a thick carpet of tall grasses. Savannahs are found in hot climates with a fairly large amount of precipitation (more than 2000 mm per year), falling relatively evenly during the wet season lasting from 4 to 6.5 months. Large areas can be flooded during the rainy season. Acacias and other legume trees are most typical of savannahs, but palms are also common.

The roots of most tree species here usually reach the shallow water table, so the trees lack moisture only in extremely dry periods. Their trunks are generally low and often curved, and their crowns are located at a height of 3–6 m. Savanna grasses up to 4.5 m in height sometimes rise above the trees.

FOREST MANAGEMENT AND FOREST PROTECTION

The science that studies forests is called forestry. One of its main applied branches is forestry, which develops methods for the cultivation of forests from certain species, their use and restoration in clearings, burnt-out areas and otherwise disturbed forest areas. It also tackles the problem of reforestation in formerly treeless areas. Forestry requires knowledge of tree species and their genetics in order to breed hybrids or select natural lines with special traits, such as increased resistance to insect or disease damage and high growth rates. The direction called dendrology is associated with the classification of trees. Another area of ​​forestry is tree ecology.

Dendrometry, or forest inventory, is the establishment of quantitative parameters of forests: timber reserves, height and quality of trees and stands. Such data are needed to evaluate commercial forests, as well as to study their development and determine the effectiveness of various methods of their use and cultivation.

Forest management is a system of measures for cultivation and purposeful use of forests based on knowledge in the field of forestry, socio-economic information and business experience. The first attempts at rational forest management were aimed at improving hunting conditions and restoring game animals. In the 18th century, forest management work began in Germany with the aim of increasing wood production. Although in the USA already in 1817 protected plantations appeared to provide the navy with ship timber, but only at the end of the 19th century. showed interest in forest management. Initially, two goals were pursued: water protection and logging. Later, the concept of multipurpose use of forests was formed: for obtaining wood, reproducing wild fauna, protecting water and soil resources, recreation, scientific research, and meeting aesthetic and other needs. Usually one of these functions prevails, but multipurpose forests are also found.

Another important area of ​​modern forestry is forest protection. Forests suffer annually from insect infestations and diseases, fires and adverse weather events such as hurricanes, droughts and heavy snowfalls with gusty winds, leading to icing of trunks and branches. Humans can also cause great harm by unsustainable logging, grazing in unsuitable forest lands, destroying pest control predators, and direct deforestation.

Protection of the resources of the animal world.

Many species of game and game animals are part of forest ecosystems and are often found in forest lands and where forests alternate with open landscapes. In addition, many species of fish abound in dense, cool bodies of water in forested catchments. Beaver, mink, elk, bear, fox, deer, turkey, partridge and other large and small game animals inhabit mainly forests. Some species prefer old forests, others prefer young communities with dense undergrowth and undergrowth, and still others live where forests alternate with or border treeless areas. One of the tasks of the rational use of forests is to create the most favorable conditions for the habitation of a certain species of animals or to ensure the greatest species diversity of the fauna.

Protection of waters and soils.

Forests in general are very effective in regulating runoff and contributing to the conservation of water in the soil. Anyone who took shelter from the rain under the trees knows that their crowns intercept and delay part of the precipitation. Most of the rest of the water is absorbed by the soil, rather than flowing over its surface into rivers and lakes. Therefore, in forested areas, soil erosion is poorly developed. Although some of the absorbed moisture comes back to the surface from the springs, this does not happen immediately, but after a few days or weeks, and is not accompanied by sharp floods. Another part of the infiltrated moisture enters deeper aquifers and replenishes groundwater reserves.

Fighting forest fires and their prevention.

Fires damage or destroy valuable timber and adversely affect reforestation. By depriving the soil of the vegetation cover, they lead to a serious and long-term deterioration of the state of drainage basins, and reduce the recreational and scientific value of landscapes. At the same time, wild animals suffer or die, houses and other buildings are burned down, people die.

Of all the phenomena that cause economic damage to forests, forest fires are the most controllable, since most of them are caused by humans.

To prevent forest fires, mass propaganda (posters, thematic exhibitions, special environmental programs) and compliance with laws limiting the use of fire in forests are important. Reducing the risk of fire is equally important. For this, flammable bushes are removed along the roads. To reduce the risk of fire from lightning strikes, dead wood is cut down. Fire-prevention glades are laid inside the forest areas, dividing the forest into sections, within which the fire is easier to localize and extinguish.

When a forest fire starts, the first step is to accurately and quickly locate its focus. During periods of special fire hazard, for example, during a drought, air patrols additionally operate. When a fire is noticed, firefighters are notified of its location and extent. Dispatchers quickly form and dispatch fire brigades to the area, often assisted by volunteers. While the fire is being fought, observers on the towers and in the air broadcast information about the speed and direction of its propagation by radio, which helps to eliminate the fire as quickly as possible.

Insect and disease control.

The cost of wood loss due to insect and disease damage outweighs the damage to forests by all other factors, including fires.

Under normal conditions, the number of insect pests and disease-causing organisms (pathogens) in forests is relatively small. They facilitate thinning of dense young stands and destroy weak or damaged trees. Nevertheless, from time to time, the number of such insects or pathogens increases sharply, which leads to the death of trees in large areas. The complete extermination of all harmful species is economically unprofitable and biologically unreasonable. Therefore, the task of protecting forests is to prevent outbreaks in their numbers and reduce losses in cases where such outbreaks do occur.

Research is needed to develop methods to protect forests from damage. These include identifying the species of forest pests, studying their life cycle, food or host species, and natural enemies. These works make it possible to develop new lines or hybrids of tree species that combine resistance to diseases and pests with useful economic properties.

Aerial spraying of insecticides was widely used in the past to reduce populations of forest pests such as the gypsy moth, spruce budworm and moth. However, this destroys not only the pests against which it is used, but also beneficial insects. Insecticides are also deadly to birds, mammals and other animals, so such measures are usually only used when others are ineffective.

Herbicides are used to kill intermediate hosts of pathogens or infested trees to limit the spread of disease. Direct treatment of plants with pesticides is usually advisable only in nurseries and artificial plantations. Most pathogen control agents are applied to the soil or applied at the seedling stage prior to planting.

A number of preventive measures are taken to avoid or reduce damage to forests by pests or diseases. Especially susceptible to disease, weak or infected trees are removed by periodic sanitary felling. Intermediate hosts of pathogens are eliminated with herbicides. Measures are being taken to protect and increase the number of natural enemies of insect pests.

REDUCTION OF FORESTS

The destruction of forests on the ground is happening at an alarming rate. In the mid-1990s, according to the World Resources Institute, tropical forests alone were disappearing at a rate of 16-20 million hectares per year, i.e. 0.6 hectares per second, mainly to meet the needs of the growing population for agricultural land and timber. In the temperate zone of the Northern Hemisphere, forests are severely affected by industrial waste polluting the atmosphere, and the vast forests of Siberia (taiga) are under the threat of large-scale deforestation.

Deforestation is a serious global environmental problem. Forests in the process of photosynthesis absorb a huge amount of carbon dioxide, so their destruction can lead to an increase in its concentration in the atmosphere, which, as many scientists believe, in the 21st century. will contribute to global warming due to the so-called. greenhouse effect. Moreover, the widespread burning of tropical rainforests in developing countries now leads to an increase in the content of carbon dioxide in the atmosphere. Most species of animals, plants and microorganisms of the planet still live in tropical forests, the diversity of which is constantly decreasing. Some of them are used or will be used in the future in medicine and agriculture.

Literature:

The geography of the world's forest resources... M., 1960
Forests of the USSR, vols. 1-5. M., 1966-1970
Walter G. Vegetation of the globe, vols. 1-3. M., 1969-1975
Bukshtynov A.D., Groshev B.I., Krylov G.V. Forests... M., 1981



Reasons for the reduction of forests on the planet

test

in the discipline "Nature Protection"

Introduction

1. Forest classification

2. The value of the forest

3. Reasons for deforestation

4.1 Fighting forest fires

Conclusion

Bibliographic list

Introduction

Forest - many trees growing in a large area with closed crowns. This definition is given in the Ozhegov dictionary.

The forest is used in various sectors of the national economy, it serves as a source of chemicals obtained during the processing of wood, bark, pine needles. The timber supplies raw materials for obtaining over 20 thousand products and products. The forest is of great importance not only for humans, but also for animals and for the entire planet. Recently, however, there has been a decline in forests everywhere. And this brings at the present time and will bring big problems to the environment. The purpose of this work is to study the problems of deforestation on the planet and possible methods of saving them.

1. Forest classification

There are several classifications of the forest, depending on the place of distribution, the age of the trees, and their type.

Depending on latitude

Depending on the latitude in which the forest is located, there are:

• Tropical rainforests (selva, gilea, jungle) - equatorial evergreen forests: has a large species diversity of flora and fauna. The large tier allows only a very small amount of light to penetrate inside (to the lower tiers). More than half of all rainforests have already been destroyed. The Amazon forests, the Indian jungles and the Congo Basin are classic examples.
• Kaatinga is a dry, deciduous tropical forest that falls during dry periods.
• Eucalyptus groves of Australia are evergreen subtropical forests.
• Deciduous forests (deciduous and small-leaved): Found mainly in the Northern Hemisphere. Due to the penetration of light, life on the lower tiers is more active. Ancient forests of temperate latitudes are represented only by scattered remains.
• Taiga is a coniferous forest: the most extensive area. Includes forests over 50% of Siberia, Alaska, Scandinavia and Canada. There are also araucaria groves in South America. The flora is represented mainly by coniferous evergreen trees and plants.
• Mixed forests are forests in which both deciduous and coniferous trees grow. The range extends over almost all of Central and Western Europe.

2. The value of the forest

Forests have a significant impact on the weather, climate and processes occurring on the earth's surface and at some depth below it.

The forest interacts with the following environmental components:

• The forest participates in the oxygen cycle in nature in the most active way. Due to the huge mass of forests, the importance of the processes of photosynthesis and respiration of forests has a huge impact on the gas composition of the Earth's atmosphere. Solar energy is one of the main sources of the forest's livelihood. Thanks to solar energy, the forest can carry out the process of photosynthesis, which promotes the release of oxygen, which is necessary for the life of the subjects of the animal and plant world.

• Hydrosphere. The forest is directly involved in the water cycle in nature and thus interacts with the hydrosphere. The forest retains soil waters from their escape with rivers into large bodies of water. Predatory deforestation along the banks of rivers leads to their catastrophic shallowing, which leads to a deterioration in the water supply of settlements and a decrease in the fertility of agricultural land.
• In winter, snow masses that do not melt for a long time under the forest cover retain water and thereby weaken the intensity of the often destructive spring floods.

• Atmosphere. The influence of the forest on atmospheric processes is also great. The known practice of creating wind-shelter forest belts, also contributing to snow retention, as well as weakening the force of the wind, leading to the carry-over of the fertile soil layer, which is deprived of vegetation as a result of its cultivation for crops.

• Animal world. The forest serves as a habitat for many animals. Animals, in turn, often play a sanitary role in the forest.

• Human. The forest is of great importance for human health and life. Human activity, in turn, affects the forest.

• Lithosphere. The composition of the upper layers of the lithosphere is associated with the growth of forests in the corresponding areas.

2.1 The importance of forests for human life

In the old days in Russia they said: “To live near the forest - not to be hungry. The forest is richer than the king. The forest not only feeds the wolf, but also feeds the peasant to his fill.

The following main directions of forest use for economic purposes can be distinguished:

• Food source (mushrooms, berries, animals, birds, honey)
• Energy source (firewood)
• Construction material
• Raw materials for production (paper production)
• Regulator of natural processes (forest plantations to protect soil from weathering)

Unfortunately, today the volume of deforestation is often several times higher than the volume of its natural restoration.

In this regard, in civilized countries, attention is paid to the reproduction of the forest, both by restoring the number of trees planting trees, and by completely banning any economic activity in some forests. Thanks to this, natural forest reproduction is ensured in these areas, and in some countries there are few forest areas where human intervention in the life of the forest has never taken place. In Germany, these forests are called "urwald" - primeval or ancient forest. In them, even coniferous trees (spruce) live up to the age of 400 years.

2.2 The importance of forests for human health

The forest is of great sanitary and hygienic and medicinal value. In the air of natural forests, there are more than 300 names of various chemical compounds. Forests actively transform atmospheric pollution, especially gaseous ones. Conifers (pine, spruce, juniper), as well as some varieties of lindens and birches have the highest oxidizing ability. The forest actively absorbs industrial pollution, in particular dust, hydrocarbons.

Forest, especially coniferous, releases phytoncides - volatile substances with bactericidal properties. Phytoncides kill pathogenic microbes. In certain doses, they have a beneficial effect on the nervous system, enhance the motor and secretory functions of the gastrointestinal tract, improve metabolism and stimulate cardiac activity. Many of them are enemies of infectious agents. But only if there are few of them. Phytoncides of poplar buds, Antonov apples, eucalyptus have a detrimental effect on the influenza virus. Oak leaves kill the bacteria of typhoid and dysentery.

3. Reasons for deforestation

The state of the world's forests cannot be considered safe. Forests are intensively cut down and are not always restored. The annual felling volume is over 4.5 billion m3. The world community is especially concerned about the problem of forests in tropical and subtropical zones, where more than half of the world's annual logging area is cut down. Already 160 million hectares of tropical forests have been degraded, and only a tenth of the 11 million hectares cut down annually is being restored by plantations.

In the context of ever-increasing urbanization, the growth of the population of cities and industrial centers, the desire of people to relax in the bosom of nature - in forests and other natural recreation areas - is increasing. The health-improving effect of the forest is also great with a short-term stay in it: there is an improvement in the activity of the heart, deepening of breathing, a decrease in the excitability of the cerebral cortex, while the mood improves, the working capacity is restored.

Many forests, primarily suburban forests, have turned into places of mass recreation. However, the consequence of the desire for country air has become a great environmental damage that vacationers cause to nature. More and more forest territories fall into the sphere of reaction, recreational loads are growing, causing a deterioration in the quality of the forest, and in some cases, its complete degradation. The sanitary-hygienic, water-protective and soil-protective functions of natural forests decrease, their aesthetic value is lost. It is quite obvious that forests that are more or less actively used for recreation require certain modes of management, specific forms of organizing the territory and regular monitoring of their condition.

In the course of the evolution of society, the nature and extent of human impact on the forest, as well as on nature as a whole, changed. According to estimates, the occupied area of ​​forests for the historical period has decreased by 2 times. Some forests have been particularly affected: 40-50% of the original area of ​​mixed and deciduous forests has already been cleared, 85-90% monsoon, 70-80% Mediterranean dry.

Less than 5% of the forests remain on the great Chinese and Indo-Gangetic plains. The rate of forest felling is not slowing down: annually, their area is reduced by 200 thousand km². Of particular concern is the state of tropical forests, figuratively speaking, the "lungs" of our planet, which are being cut down at a speed of 15-20 hectares per minute (this issue will be discussed in more detail below).

The forests of Russia were also subjected to intensive destruction. In the European part alone, from the end of the 17th to the beginning of the 20th century, about 40 million hectares of forest were destroyed. As a result, the forest cover decreased from 50% to 33%, or one and a half times.

The area of ​​forests exposed to recreational stress in Russia and the CIS countries is 320-400 thousand km². In this territory, there is a significant violation of forest ecosystems, ecological ties. The forest cover of the territories is decreasing. The selectivity of felling affects the species composition of the forest. In our forests, this leads to a decrease in the proportion of conifers.

The worst enemy of the forest is fire. Fire is compared to soil erosion, and rightly so. Erosion is the scourge of agriculture, fire is the scourge of forests. In the 90s of the twentieth century, up to 30 thousand fires occurred annually on the territory of Russia, covering 2 and more million hectares.

Greater damage to forest resources is caused by waterlogging of the soil, flooding as a result of the construction of hydroelectric power plants (especially in flat areas), reservoirs, highways and railways, etc. The death of forests for these reasons can be observed in almost all regions of Russia. Industrial enterprises, emitting various chemical compounds into the atmosphere, water, soil, cause oppression and death of trees and shrubs.

Significant damage to forests, vegetation of meadows and pastures is caused by an increased content of lead in the air, especially near large highways with heavy traffic, leading to its accumulation in tissues and, as a result, causes depression, and often death.

The types of anthropogenic pollution of nature most negatively affecting forests are acid rain. Their intensity can be judged by the deposition of sulfur. The neighborhoods are characterized by the highest rates.

Dust from cement plants, limestone and siliceous rocks is harmful to forest vegetation. From their action, the stomata are clogged, chlorophyll is destroyed, and a crust forms on the surface.

The forests, which are often visited by tourists, are so thoroughly littered with cans, bottles, rags, paper, etc., and bear traces of large and small wounds that this negatively affects the natural reforestation. They carry and carry bouquets of flowers, branches of greenery, trees, bushes. The question is, what will happen if each of those who come to the forest picks only one branch, one flower? And it is no coincidence, after a number of years of poaching towards nature, in our, especially suburban, forests there were not many once in an abundance of growing plants, shrubs and trees. In the spring, tens of thousands of townspeople rush into the forests for bird cherry and lilac. Not satisfied with modest bouquets. Armfuls, brooms, often on the roofs of cars. How can you not envy the delicate taste of the Japanese, who believe that a bouquet is spoiled if it contains more than three flowers.

4. Protection and restoration of forests

The main task of forest protection is their rational use and restoration. It is important to increase the productivity of forests, to protect them from fires and pests.

With proper forestry, felling in some areas should be repeated after 80-100 years. In many central regions of European Russia, they are forced to return to re-felling much earlier. The excess of felling norms has led to the fact that in many regions forests have lost their climate-forming and water-regulating importance. The share of small-leaved forests has increased significantly.

Another important conservation measure is wood loss control. The greatest losses occur during timber harvesting. A lot of wood and pine needles remain at the felling sites, which can be used for making coniferous flour. This waste is promising for the production of essential oils.

Part of the wood is lost during felling. In some years, rivers carry so many logs into the northern seas that in the Scandinavian countries there are special vessels for catching them. Plants for the production of furniture from wood fiber boards are being built near the enterprises of the woodworking industry.

The most important condition for the conservation of forest resources is timely reforestation. Only a third of the forests cut down annually in Russia are restored naturally, the rest require special measures to restore them. An important role in the reproduction of forests is played by drainage reclamation: the planting of trees, shrubs and grasses that improve the soil. This contributes to the rapid growth of trees and an improvement in the quality of the wood.

In clearings where natural forest regeneration does not occur, after loosening the soil, sowing seeds or planting seedlings grown in pets is carried out.

In recent years, interest has revived in methods of sustainable forest management and sustainable forest management, that is, such use of forest resources in which the forest ecosystem is minimally damaged. In the clearings, the forest is gradually renewed, and after a few decades, it can be harvested again.

Let us consider how logging is carried out with sustainable forest management in tppic forests.

A professional arborist and his assistants walk through the small forest. They are one of several teams, which will spend about six months in the wilderness, taking inventory of the forest. The logging company has a long-term concession for the use of this forest. Therefore, workers have time to inspect the trees in order to preserve the forest for future use.

The arborist notes the registration number of each tree and identifies its species. He must be an expert in his field, because there are hundreds of varieties of tree species. At the next stage of work, you cannot do without modern technology.

In a portable device connected to satellites of the global positioning system, the arborist enters data about the tree, indicating its size, breed and registration number. Then he presses the enter key - and all this information is transferred from the wilderness to one of the computers in the distant noisy city.

The forest manager then uses his computer to print a map showing all the economically valuable trees in the forest area. He determines which of them can be cut in accordance with the current legislation. For many species, it is permissible to cut only 50 percent of trees larger than the concession diameter. The most mature and healthy trees are left standing to obtain seeds.

But how to cut wood without harming it? The stand map helps with this. It allows you to plan logging operations so that the forest is not seriously damaged. You can even plan in advance the direction in which you need to fell trees so that they damage neighboring ones as little as possible.

Loggers using this method think about how they will winch the trunks without having to bulldoze every felled tree. Before felling a tree, loggers chop off the vines that intertwine it with neighboring trees so that they are less damaged. They also develop the forest area allocated to them gradually, each year drawing up a plan and making felling so as not to fell trees in the same area for at least 20, and in some places for 30 years. "

“The health of the forest depends a lot on the animals. They play an important role in pollination as well as seed dispersal. Sustainable loggers do their best to ensure that forest dwellers are not disturbed. For example, they think carefully about where to lay access roads so that there are fewer of them and more distance between them. They make them as narrow as possible so that the crowns of the trees close up. Thanks to this, animals such as sloths and monkeys do not need to descend from the trees to cross the road. "

For example, protective forest belts left on both sides of each stream or river allow animals to move from one place to another through the untouched forest.

“They are trying to preserve not only vital forest areas along water streams, but also caves, exposed rock areas, old hollow or fruiting ones. After finishing cutting in one area, the loggers block the roads or patrol them so that no one will hunt in the forest and chop it down without permission.

Is sustainable forest management cost-effective? Aside from individual conservationists, loggers tend to be less than enthusiastic about wildlife conservation programs. They perceive any restrictions as obstacles on the way to making a profit.

However, studies in the eastern Amazon in the late 1990s showed that the costs of mapping, pruning vines and routine timber removal were more than offset by improved forest management. For example, mapping can reduce wood loss. And when there is no map, the timber transportation team often cannot find trees in the dense forest that were felled by lumberjacks.

In addition, timber products that are independently certified as resulting from sustainable forest management are in increasing demand.

Now in Eastern Europe there are almost no pristine places left. Even the majestic northern taiga, where, as is commonly believed, no man's foot has stepped, is the result of economic activity. The famous ship's pines have grown on the site of the former fires. The natural mixed character of flora and fauna, alas, has been lost. Any economic activity of man, even the restoration of forests, leads to a decrease in species diversity. People diligently plant the trees that they consider indigenous to these places - spruce, pine and oak, and many other species are included in the Red Book. Another reason for the depletion of species diversity is sanitary felling. Dead trees are unique ecological niches for many species of birds, insects, mushrooms and grasses. Spruce and fir grow only on sufficiently decomposed dead wood, which zealous foresters destroy with the best intentions.

To restore full-fledged, diversely populated forests, the authors of the study propose to plant as many different types of trees and grasses as possible, including rare and imported ones. Landings should be of different ages. To give the growing forests a semblance of a natural structure, it is necessary to arrange artificial "windows", cutting down trees on an area of ​​0.1-0.3 hectares. Previously, forests were interspersed with meadows - a haven for light-loving species. To preserve these species and maintain the meadows, either hay must be mowed there or cattle grazed. A more natural way is the reintroduction of bison. But for the stable existence of the bison population, a basin of a small river with tributaries - hundreds of square kilometers - is needed. It would be nice to settle beavers in this river, but first you need to determine whether there is enough food for them, and then carefully guard the valleys of all streams and rivers where beavers can swim. It is troublesome, expensive and time-consuming, but the forests themselves will take even longer to recover.

4.1 Fighting forest fires

Among the measures for the protection of forests, fire fighting is of great importance. The fire completely or partially destroys the forest biocenosis. Fires inflict large crowns, destroying plants, hunting and game animals, etc. The main cause of fires is the careless handling of a person with fire: fires not extinguished, burning matches, butts. Agricultural burns, fire cleaning of cutting areas, flames and sparks from the exhaust pipes of tractors and cars pose a great danger to the outbreak of fires.

Up to 97% of forest fires are caused by humans. Therefore, among fire fighting measures, an important place should be taken by fire-prevention propaganda among the population. In forest areas, there is a sentinel-sentry service to detect fire centers. When eliminating forest fires, aviation brigades are used, sometimes military units and the entire population are mobilized to fight the fires.

4.2 Protecting forests from pests and diseases

It is useful to attract insectivorous birds to control pests of forest plants. They can regulate the number of insects, preventing their mass reproduction. To attract birds, favorable conditions are created for them: they hang artificial nests, feed them.

Biological pest control methods are cheap, harmless, and most effective. They should be combined with other methods so that together they represent a single system of forest protection.

Conclusion

As my research has shown, the problem of deforestation on the planet is very urgent. But, unfortunately, very little action is taken to preserve and restore them. First, because a person is by nature selfish: for him, just to benefit for himself without thinking about others. Therefore, at the last climate summit, a country like the United States did not commit itself to reducing carbon dioxide emissions into the atmosphere, although it emits even more of it than developing countries. Second, the extraction of forests and their deforestation to make room for pasture is the only livelihood for many developing countries that cannot afford expensive technologies for conserving this resource. Thirdly, the population for the most part is indifferent to forests, using them for recreation, firewood and theft of trees.

It turns out that in order to solve this problem, cardinal measures are needed both within countries (from the introduction of strict laws to the introduction of forest conservation technologies and reducing emissions of harmful substances into the environment), and at the global level (where developed countries would help developing countries and, up to a compulsory level, to force everything countries to introduce new technologies). Otherwise, there will be no success from the attempts of individual countries to preserve our world heritage.

Bibliographic list

1. Ozhegov S.I. and Shvedova N.Yu. Explanatory dictionary of the Russian language: 80,000 words and expressions / Russian A.N .; Russian Cultural Foundation; 5th ed., Stereotyped - M .: AZ, 2004 - 928 p.
2. http://ru.wikipedia.org/wiki
3. Forest of Russia: Encyclopedia / [A.I. Akintieva and others] - M.: Big Ros. encyclopedia, 1998. - 446 p.
4. Sokolsky I. Healing red forest // Science and life: journal. - 2008. - No. 2. - P. 156-160.
5. N.M. Chernova, V.M. Galushin, V.M. Konstantinov, "Fundamentals of Ecology Grade 9", Moscow, ed. "Education", 1998.
6. "Can rainforests be saved?" Awake! Magazine dated May 8, 1998.
7. "Who will save the rainforests?" Awake! Magazine dated June 22, 2003.
8. Stepanovskikh A.S., Environmental Protection, Moscow: "Unity", - 2000, - p. 560.
9. Baranovsky, N.V. Integrated monitoring system for forest fires / N.V. Baranovsky, G.V. Kuznetsov // T. 3. -, 2007 .-- S. 102-104.
10. http://www.wood.ru/ru/loa398.html

1. Geographical location of the forest zone
2. Taiga
3. Mixed forest
4. Broadleaf forest
5. Fauna of the forest zone
6. Traditional occupations of the population
7. Environmental issues

1. Geographical location of the forest zone

The green ocean of forests is widespread on the map of our country. Our country is often called a great forest power. Indeed, the forest zone occupies more than half of the territory of Russia. This natural area is the largest. There are three parts in this natural zone: the largest part is taiga. It is painted over in dark green. There are also mixed forests - also green, but lighter. And one more part - deciduous forests, the green color is even lighter. But between the "Tundra" zone and the "Forests" zone there is an INTERMEDIATE ZONE - this is LESOTUNDRA. This is a smooth transition from one zone to another. The closer to the south, the softer the natural conditions.

Forests are located south of the tundra. They begin to grow gradually, as the warming of the earth increases. Therefore, after the tundra, there is, as it were, an interlayer, forest-tundra. The farther south, the higher the sun rises above the horizon and the more the earth heats up. Winter is still harsh here, but shorter. Summers are warmer than in the tundra. In more southerly areas, there is no longer permafrost. After winter, the snow melts and the earth warms up well. The soil layer is much thicker than in the tundra and more fertile. As you move southward, coniferous forests become thicker and gradually they occupy the entire space. Coniferous forests occupy most of Siberia, and the northern territories of the European part of Russia. These forests are called taiga. If we go further south, the weather conditions will change. Winters will become shorter and softer, summers longer and warmer. Therefore, to the south of the taiga there are mixed forests. Mixed forests grow in the southern regions of Siberia and in the central region of the European part of Russia. There are much fewer swamps here. Further south, forests of deciduous trees begin to occur. Such forests are called broadleaf forests. They grow in the south and west of Russia, as well as in the Far East.

2. Taiga

Taiga is a coniferous forest. it occupies most of the forest zone. Winters in the taiga are cold, and summers are warmer than in the tundra, so trees that are not very demanding on heat grow here - these are conifers. In conifers, the leaves are needles, and they are always green. They are tall trees with powerful roots. In the taiga grow: spruce, pine, fir, larch, cedar pine.

• Spruce is a familiar New Year tree. In the spruce, the needles are short, rough, arranged singly and densely cover the branches. The cones are oblong. Ate - long-livers. The spruce forest is dark and humid.

• Pine is a coniferous tree with a smooth yellow trunk. The pine needles are long, they sit in pairs. Pine cones are round in shape. Pine forests are light and dry.

• Fir - differs from spruce in that its needles are flat, and the cones stick up and even mature ones do not fall to the ground, but simply scales fall off them.

• Larch is the only coniferous tree that sheds needles for the winter.

• The cedar pine is popularly called the Siberian cedar. Its needles are collected in bunches of five, and the seeds are pine nuts.

The taiga is characterized by the absence or weak development of the undergrowth (since there is little light in the forest), as well as the monotony of the grass-shrub layer and moss cover (green mosses). The types of shrubs (juniper, honeysuckle, currant, willow, etc.), shrubs (blueberry, lingonberry, etc.) and herbs (oxalis, wintergreen) are few.

3. Mixed forest

To the south, the taiga is replaced by a mixed forest. Alder, birch, aspen grow in it along with coniferous trees. Winter in such a forest is milder. Deciduous trees have medium-sized leaves, which they shed for the winter.

• A birch can be recognized by its bark, it is white, no other tree propagating by seeds has such a bark.

• Aspen has rounded leaves, and they tremble with every breath of wind, the bark of the aspen is greenish, in the spring you can see long fluffy catkins.

• Alder has small dark bumps on the branches, the trunk is black or gray.

4. Broadleaf forest

Closer to the south, the zone becomes even warmer, and mixed forests are replaced by broad-leaved ones, in which large trees grow, shed their foliage for the winter, and multiply by seeds.

• The oak can be recognized by its mighty trunk and carved leaves; acorns are the fruits of the oak.

• The linden tree has heart-shaped leaves. In summer, linden blossoms with a wonderful scent. Linden fruits are dark nuts, sitting in several pieces under one wing.

• An elm tree can be recognized by its leaves and fruits: the leaves are "lopsided" at the base, one half is larger than the other, the fruits are winged nuts of a rounded shape.

• Maple is available as Holly, Tatar and American. The fruits of all types of maple are winged.

5. Fauna of the forest zone

The fauna of the forest zone is diverse: here you can find large and small animals, insects. In the taiga live: nutcracker, chipmunk, flying squirrel, sable. Also in the forest zone live: red deer, elk, bear, wolves, foxes, lynxes, hares, squirrels, wood grouses, chipmunks, voles. There are no boundaries for animals - they live throughout the entire zone. Some animals go into hibernation for the winter (hedgehogs, bears), others make supplies for the winter.

Nutcracker is a taiga bird that makes supplies of pine nuts for the winter.

The flying squirrel is a relative of the squirrel, but smaller than it. She can not only jump, but also fly: she has membranes between the front and hind legs.

The brown bear is an omnivorous animal, very mobile, can run quickly, jump, climb trees, swim.

Elk is a forest giant. Moose consume different amounts of food during different seasons of the year. In winter, they form groups.

Lynx is a predator, has a spotted color. Bucks are developed on the sides of the head, and tassels on the ears. The lynx, hiding, waits for the victim and quietly sneaks up on it.

The white hare changes color for the winter, becomes white, only the tips of the ears are black, the coat becomes thick. They are cautious animals.

The fauna of the taiga is richer and more diverse than the fauna of the tundra: here you can find large and small animals, insects. Numerous and widespread: lynx, mink, wolverine, chipmunk, marten, sable, squirrel, flying squirrel, etc. deer, elk, roe deer; rodents are numerous: shrews, mice. Common birds are: wood grouse, hazel grouse, nutcracker, crossbills, etc.

In the taiga forest, in comparison with the forest-tundra, the conditions for the life of animals are more favorable. There are more sedentary animals here. Nowhere in the world, except for the taiga, there are so many fur-bearing animals.

There are no boundaries for animals - they live throughout the entire zone. Some animals go into hibernation for the winter (hedgehogs, bears), others make supplies for the winter.

6. Traditional occupations of the population

The traditional occupations of the population are hunting for fur animals, collecting medicinal raw materials, wild fruits, nuts, berries and mushrooms, fishing, forestry, (building houses), cattle breeding.

7. Environmental issues

• reforestation work;
• creation of reserves, wildlife sanctuaries and other protected areas,
• rational use of wood

Many protected forest areas have been created in our country.

In the taiga, there are concentrated reserves of industrial wood, large deposits of minerals (coal, oil, gas, etc.) have been discovered and developed. also a lot of valuable wood

The volume of reforestation work has decreased as a result of the economic crisis.

The problem with the rational use of wood has not been resolved. In Russia, only 50-70% of the biomass of trees is used.

Home & nbsp> & nbsp Wiki-textbook & nbsp> & nbsp Geography & nbsp> & nbsp8 class & nbsp> & nbsp Forest zones of Russia: broad and small-leaved forests, taiga and forest-tundra

You may also be interested in the following topics:

Broadleaf forests

Deciduous forest zones are represented in the central regions of the European part of Russia: Samara, Ufa and partly the Oryol region.

There are also treeless zones here, but they were created artificially for the purpose of agricultural work.

In the strip that covers 55 ° and 50 ° N. NS. mainly oak and linden groves grow. Closer to the south are bird cherry, mountain ash and birch. Broad-leaved forests are also characteristic of the Far East, in particular in the valley of the Amur River.

Such forests appeared here due to the close proximity of two climatic directions at the same time: cold Siberia and warm China.

The main condition for the spread of deciduous forests is a temperate climate with warm, mild winters and high humidity in summer.

Small-leaved forests

Such arrays are represented by a set of trees, the leaf blade of which is rather narrow in comparison with the plates of oak and maple. The zone of small-leaved forests covers the East European Plains and some territories of the Far East.

A strip of small-leaved forests stretches from the Yenisei to the Urals.

Small-leaved trees include birch, aspen and gray alder.

Such trees are resistant to sudden changes in temperature conditions: neither heat nor frost will harm them.

Small-leaved forests are growing rapidly and recovering rapidly.

Taiga

The taiga forest zone is represented by coniferous trees, which form the basis of the biological system of the region. The taiga zone in Russia is divided into three main types: light coniferous (common pines), dark coniferous (spruce and fir) and mixed.

The undergrowth of the taiga forest zone is often represented by shrubs, tall grasses and mosses. Taiga forests include the Ural, Far Eastern, Altai, Kolyma, Trans-Baikal, Sakhalin forest mountain ranges.

Taiga occupies more than 80% of the forests of the Russian Federation.

Forest tundra

This zone is located in the subarctic belt, and covers the territory from the Kola Peninsula to the coast of the Indigirka River. Due to the low temperature and low amount of precipitation, which, despite this, do not have time to evaporate, the forest-tundra is very swampy.

The trees grow here thanks to the rivers that feed on the melted snow.

The forests here are located in small islands in desert areas. Spruce, fir, pine and a wide variety of shrubs are characteristic of this area.

Forest zones of Russia are unusually diverse and rich

However, the widespread deforestation for economic and economic purposes causes irreparable damage to the environment.

Therefore, the state, with the initiative of nature conservation societies, has created many reserves in which forest resources are protected from poaching.

Need help with your studies?

Previous topic: Natural zones of Russia: arctic, tundra, forest-tundra, taiga, deserts
Next topic: & nbsp & nbsp & nbspWoodless zones of southern Russia: steppe, semi-deserts, deserts, flora and fauna

Abstract on the topic:

Forest

Plan:

Introduction
• 1 Forest as a historical factor
• 2 Forest as a geographical factor
• 3 The importance of forests for human life
• 4 The importance of forests for human health
• 5Classification of forests
  • 5.1 Depending on latitude
• 6Forest parameters

Notes (edit)
Literature

Introduction

Forest- a part of the Earth's surface covered with woody plants.

Currently, forests occupy about a third of the land area. The total forest area on Earth is 38 million km². Half of this forest area belongs to tropical forests, a fourth is located in the northern hemisphere.

The forest area in Russia is 8 million km².

1. Forest as a historical factor

The presence or absence of a forest often had a direct impact on the course of historical processes and the fate of ethnic groups.

Among some economists, it was suggested that the life of primitive man in the forests, where the gathering of forest gifts, carried out mainly by women, and hunting and fishing, which were mainly done by men, became the basis for the division of labor, as one of the most important features of human society.

The further development of tools and means of production, associated with the development of cattle breeding and agriculture, which meant significant progress in social relations, is associated with the release of man from strong dependence on the forest.

The founding of settlements on the site of forests, uprooted and thereby gave a place for life and agricultural activity, is said, for example, by the toponyms of German geography: Friedrichroda, Gernrode, Osterode, Rodach, Walsrode, Wernigerode, Zeulenroda, etc.

Some of these settlements are roughly located on the territory of the extensive Hercynian forest, which roughly coincided with the place of residence of the Germanic tribes Germundurs, Hermions and Marcomans.

On the other hand, the forest, its proximity to housing, significantly influenced the historically evolving way of life of people, in particular, on national architecture.

So, log buildings were a typical type of housing for the Eastern Slavs. Even in the case when the first floor of the building was built of stone (brick), the second floor and higher floors were wooden.

This was facilitated by the belief that life in a wooden building is healthier than in a stone one.

For the first time, the historical role of the forest is documented in the notes of Julius Caesar (about 100-44 BC).

H.) about the Gallic War - De bello galliko, who between 58 and 51 came into contact with the Germanic tribes inhabiting the forested lands on the right bank of the Rhine. Caesar explained his refusal to expand expansion to these lands by the fact that these forests are inhabited by unicorns and other mythical animals, and therefore these lands can never be colonized, and it is more expedient to simply ignore them.

Most likely, the reason was Caesar's clear understanding of the uselessness of using the tactics of the Roman legions in a forest area, bringing a sure victory in open spaces.

And this fear was confirmed in 9 year, when the Cherusque Arminius in the Teutoburg forest utterly defeated the army of the Roman commander Publius Quintilius Varus. As a result, at the beginning of our era, the wooded area inhabited by the Germans even bore the name of "Free Germany" among the Romans ( Germania libera)

For the main part of humanity living in areas with a temperate climate, forests have long ceased to be a place of residence for sufficiently large communities, but their function as a refuge from the enemy, as well as from excessive regulation by society, has been preserved throughout human history.

The forest has always been associated with the habitat of marginal individuals, which is reflected in fiction (Robin Hood from Sherwood Forest) or in the national Russian epic - "Nightingale the Robber" from the Murom Forest.

During the Second World War, vast forests in Lithuania and Belarus were called the "Partisan Territory". Here, despite the occupation regime, the organs of Soviet power continued to exist.

After the war, these forests served as a refuge for nationalist groups called the "forest brothers".

In the forested areas of occupied Yugoslavia, the partisan community even had the character of a state formation with its own armed forces differentiated by type of service.

After World War II, vast forested areas of South America were also the site of operations for large partisan formations (Che Guevara).

2.

Forest as a geographical factor

Forests have a significant impact on the weather, climate and processes occurring on the earth's surface and at some depth below it.

The forest interacts with the following environmental components:

• The forest participates in the oxygen cycle in nature in the most active way.

  Due to the huge mass of forests, the importance of the processes of photosynthesis and respiration of forests has a huge impact on the gas composition of the Earth's atmosphere. Solar energy is one of the main sources of the forest's livelihood. Thanks to solar energy, the forest can carry out the process of photosynthesis, which promotes the release of oxygen, which is necessary for the life of the subjects of the animal and plant world.

• Hydrosphere.

  The forest is directly involved in the water cycle in nature and thus interacts with the hydrosphere. The forest retains soil waters from their escape with rivers into large bodies of water. Predatory deforestation along the banks of rivers leads to their catastrophic shallowing, which leads to a deterioration in the water supply of settlements and a decrease in the fertility of agricultural land.

• In winter, snow masses that do not melt for a long time under the forest cover retain water and thereby weaken the intensity of the often destructive spring floods.
• Atmosphere.

  The influence of the forest on atmospheric processes is also great.

  The known practice of creating wind-shelter forest belts, also contributing to snow retention, as well as weakening the force of the wind, leading to the carry-over of the fertile soil layer, which is deprived of vegetation as a result of its cultivation for crops.

• Animal world.

  The forest serves as a habitat for many animals. Animals, in turn, often play a sanitary role in the forest.

• Human. The forest is of great importance for human health and life.

  Human activity, in turn, affects the forest.

• Lithosphere. The composition of the upper layers of the lithosphere is associated with the growth of forests in the corresponding areas.

3. The value of the forest for human life

In the old days in Russia they said: “To live near the forest - not to be hungry.

The forest is richer than the king. The forest not only feeds the wolf, but also feeds the peasant to his fill.

The following main directions of forest use for economic purposes can be distinguished:

• Food source (mushrooms, berries, animals, birds, honey)
• Energy source (firewood)
• Construction material
• Raw materials for production (paper production)
• Regulator of natural processes (forest plantations to protect soil from weathering)

Unfortunately, today the volume of deforestation is often several times higher than the volume of its natural restoration.

In this regard, in civilized countries, much attention is paid to the reproduction of the forest, both by restoring the number of trees in forest plantations, and by completely banning any economic activity in some forests.

Thanks to this, natural forest reproduction is ensured in these areas, and in some countries there are few forest areas where human intervention in the life of the forest has never taken place. In Germany, these forests are called "urwald" - primeval or ancient forest. In them, even coniferous trees (spruce) live up to the age of 400 years.

4. The importance of forests for human health

The forest is of great sanitary and hygienic and medicinal value. In the air of natural forests, there are more than 300 names of various chemical compounds.

Forests actively transform atmospheric pollution, especially gaseous ones. Conifers (pine, spruce, juniper), as well as some varieties of lindens and birches have the highest oxidizing ability.

The forest actively absorbs industrial pollution, in particular dust, hydrocarbons.

Forests, especially coniferous ones, emit phytoncides - volatile substances with bactericidal properties.

Phytoncides kill pathogenic microbes. In certain doses, they have a beneficial effect on the nervous system, enhance the motor and secretory functions of the gastrointestinal tract, improve metabolism and stimulate cardiac activity. Many of them are enemies of pathogens of infectious diseases, but only if there are few of them.

Phytoncides of poplar buds, Antonov apples, eucalyptus have a detrimental effect on the influenza virus. Oak leaves kill the bacteria of typhoid and dysentery.

5. Forest classification

There are several classifications of the forest, depending on the place of distribution, the age of the trees, and their type.

5.1. Depending on latitude

Depending on the latitude in which the forest is located, there are:

• Tropical rainforest(selva, gilea, jungle) - equatorial evergreen forests: has a large species diversity of flora and fauna.

  The large tier allows only a very small amount of light to penetrate inside (to the lower tiers). More than half of all rainforests have already been destroyed.

  The Amazon forests, the Indian jungles and the Congo Basin are classic examples.

• Kaatinga- dry deciduous tropical forests, fall during dry periods.
• Eucalyptus groves Australia - evergreen subtropical forests.
• Deciduous forests(broadleaf and small-leaved): found mainly in the Northern Hemisphere.

  Due to the penetration of light, life on the lower tiers is more active. Ancient forests of temperate latitudes are represented only by scattered remains.

• Taiga- coniferous forest: the most extensive area. Includes forests over 50% of Siberia, Alaska, Scandinavia and Canada. There are also araucaria groves in South America.

  The flora is represented mainly by coniferous evergreen trees and plants.

• Mixed forests- forests in which both deciduous and coniferous trees grow. The range extends over almost all of Central and Western Europe.

6. Forest parameters

6.1. Grade

Notes (edit)

1. Engels Friedrich. The origin of the family, private property and the state. 1884 g.
2. 1 2 Baedecker.

   Deutschland. Verlag Karl Baedeker. 2002. ISBN 3-8297-1004-6

3. Weltatlas. Printed in Spain-2002. ISBN 3-85492-743-6
4. Feller, V.V. German Odyssey. Popular science edition. - Samara: Samar. House of the press. 2001 .-- 344 p. ISBN 5-7350-0325-9
5. Spegalsky Yu.P. Pskov.

   Artistic monuments. - Lenizdat, 1971.

6. Andreev V.F. The Northern Guard of Russia: Essays on the History of Medieval Novgorod. - 2nd ed., Add. and revised - L .: Lenizdat, 1989 .-- 175 p. ISBN 5-289-00256-1
7. Razgonov S. N. Northern etudes. M .: Molodaya gvardiya, 1972.192 pp., With ill.
8. Notes of Julius Caesar and his successors "On the Gallic War". - M., 1991
9. Dr.

   Fritz Winzer Weltgeschichte Daten Fakten Bilder. Georg Westermann Verlag. 1987. ISBN 3-07-509036-0

10. 1 2 ... Martin Kitchen. The Cambridge Illustrated History of Germany. Cambridge University Press, 1996. ISBN 0-521-45341-0
11. Reinhard Pözorny (Hg) Deutsches National-Lexikon. DSZ-Verlag, ISBN 3-925924-09-4

Literature

• Atlas of the forests of the USSR.
• Forests. - M., Mysl, 1981 .-- 316 p. - (The nature of the world).
• The Brazilian Amazon is cut down by 70% - zelenyshluz.narod.ru/articles/amazonia.htm
• Brazil banned deforestation in 36 regions of the Amazon - zelenyshluz.narod.ru/articles/amazon2.htm
• Sokolsky I. Healing red forest // Science and life: magazine.

  2008. - No. 2. - S. 156-160.

Broadleaved (beech) forest in Slovenia

Coniferous (pine) forest

Coniferous forest

San Juan Island, Washington

Valdive forests on the island of Chiloe

Winter forest. Pinega

Spring forest Slobozhanshchina

Mast forest (Lindulovskaya ship grove near St. Petersburg)

Urwald on the shores of Lake Arbersee

Flora secrets

Different trees require different amounts of heat, another one more. Conifers - spruce, Pine, larch, spruce, cedar pine(often called cedar) - less heat demanding. They grow well in the northern part of the forest.

These trees are composed of conifers - taiga. Taiga occupies most of the forest area.

conifers

Summer in tajga is much warmer than in tundra, but winter is very cold. There is also permafrost here.

True, in summer the surface of the earth sinks deeper than in the tundra. This is very important for trees with strong roots.

Flora of mixed and deciduous forests

To the south of the taiga, winters are rather mild.

There is no permafrost here. These conditions are more favorable for deciduous trees. This is why they are in the south of the Taj Mahal. mixed forests. Here, as if mixed with conifers and deciduous trees. More south stretched Broadband forests... They are formed by thermal trees with wide, large leaves.

These trees oak,maple, Linden, ashes, Brest.

These rocks are called wide shells, in contrast to the small leaves that include birch and aspen.

October trees

Fauna of forests

On this page we will talk about some of the animals living in the forest.

Questions and tasks

first

Natural regions of Russia:
a) tundra, arctic zone, forest zone
b) Arctic zone, forest zone, tundra
c) Arctic zone, tundra, forest zone.

second

In Thai they grow:
a) spruce, spruce, larch
b) oaks, pines, spruce
c) birch, lime and larch.

3. Lives in the forests ...
a) Arctic foxes, lemmings, wolves.
b) Sable, squirrels, squirrels.
c) seals, wet, whales.

4. Where are the mixed forests located?
a) south of the taiga
b) north of the taiga

5. Which tree is deciduous?
a) maple, larch, pine
b) spruce, spruce, larch
c) brest, ash, lime

to answer

first

Work is done
Elementary school teacher
School MCO. 4
Location Mineralnye Vody
Zhuravleva Natalia Nikolaevna

second

The forest zone is located south of the tundra zone, marked on the map in green
Colour.

The forest zone is located in the temperate zone, which means that they are different
all four seasons, cold winters and hot summers. More forest area
part is located on the eastern and western Siberian plains,
and also on the middle Siberian plateau.

This natural area is the largest.
There are three parts in this natural area: the largest part is taiga, colored
Dark green, they are still mixed forests - also green, but
lighter, and the other part is broadband forests, green is even lighter.

third

forests
taiga
Mixed forest
broadband
forests

fourth

fifth

Taiga is coniferous, she sits a lot
part of the forest area.

Winter in the taiga - frost and
in summer it is warmer than in the tundra, so they grow here,
trees that are not very demanding
warm, they are conifers.

In conifers
trees - leaves are needles and always
green. They are big trees with strong
roots.
In Thai they grow:

sixth

seventh

eighth

Macesen -
only
coniferous
which for the winter
reload the needles.

ninth

tenths

11

12

13th

fourteenth

In the south, the taez is a mixed forest.
It grows with conifers
birch, aspen, alder. Winter in such a forest
softer.

October trees are small
leaves that overflow for the winter.

fifteenth

We can recognize birch with bark, which is why it is white
There is no bark in any tree,
spreading seeds.

sixteenth

Aspen has rounded leaves and every moment hits
Windy, aspen aspen is greenish, but in spring it looks like a long fluffy
earrings.

seventeenth

Joji has small, dark hands on the branches
The trunk is black or gray.

In black alder leaves
they have a sharp tip.

eighteenth

Closer to the south, the area gets even warmer, and
mixed forests change
The broadband in which the oak grows
maple, autumn, brest, linden. This warm love
trees, so they have big
leaves, for winter discarded foliage,
multiply by seeds.

nineteenth

Oak can be recognized
powerful
trunk and carved
leaves
oak fruit
it's an acorn.

twentieth

Maple - holly (with large carved leaves), Tatar
(oval leaves with slight protrusions) and American
(each sheet contains three or five separate leaflets),
and the fruits of all types of maple are winged.

twenty first

twenty second

The board can be recognized from the list
and fruits: leaves at the bottom
cobos, half
more different, fruits -
winged rounded walnuts
the form.

twenty third

Lime has heart-shaped leaves.

In the summer, when it blooms, lime spreads
wonderful aroma. Linden fruits are dark nuts that sit on multiple pieces
under one wing.

The forest zone is located in the temperate zone

English Russian

Where does larch grow?

Larch, despite its name, is a coniferous plant of the pine family. Her only needles fall off for the winter, so you can't call her evergreen. Only larch seedlings retain needles throughout the year.

This suggests that the ability to shed needles was acquired by the plant as a result of adaptation to changing climate conditions.

In which natural area does larch grow?

The question of where and in what forests larch grows in nature can be generally answered as follows: it loves mixed forests located in Western and Northern Europe up to the Carpathians.

In general, there are many tree species, the range of which is slightly different.

Where does larch grow in Russia: most often it can be found in Siberia and the Far East. The plant is demanding on lighting. It does not grow in shaded areas.

Soils on which larch grows: the tree is completely undemanding to the soil. It can be found both in swamps and on dry soils and even in permafrost conditions.

However, the best soil for larch is sufficiently moist and well-drained.

Differences between larch and pine

First of all, larch sheds needles for the winter, while pine does not. Pine is an evergreen coniferous tree that changes the shade of needles at different times of the year.

Larch needles are soft and not long - up to 4.5 cm. It is located spirally on the shoots in bundles of 20-40 needles. At the same time, her needles do not prick at all. In pine, the needles reach 5 cm, located along the entire trunk in bunches of 2 pieces.

The trunk of a larch is more powerful, sometimes it reaches 1.8 m in diameter. And it lives twice as long as a pine. Her crown is more transparent, while that of a pine tree is thicker and more fluffy.

Cones on larch are very beautiful, round in shape.

In pine, they are conical.

By this name is meant a more or less significant area overgrown with trees, and all that vegetation that covers between the trees, consisting of shrubs, grasses, ferns, mushrooms, and so on. This vegetation can mainly live only under the shade of trees. In prehistoric times, after the period, forests occupied much more space than they do now. Although, according to some scientists, the period of afforestation in some places was preceded by the period of the steppe. Most of Western Europe, Russia and Siberia were once one continuous forest.

Together, the world's forests still cover about a quarter of the surface, although this estimate cannot be considered accurate. Decrease in forests went hand in hand with an increase in population and the development of civilization, giving rise to more and more diversified needs. In Russia, which has vast and vast saline, sandy and clayey steppes, there is also a decrease in forest natural resources.

The whole country lying between 66 ° and even 67 ° and 56 ° can be considered a real forest kingdom. This strip is dominated by coniferous forests, or redwood, that is, pine and spruce. Larch, Siberian fir and cedar are found in the east. Also here grow: birch, aspen, gray alder, mountain ash, bird cherry and some tall willows. This spruce or coniferous strip extends to almost 50 ° north latitude. Here, instead of one type of larch, we also find Daurian, and from deciduous, several poplars and black or stone birch, Siberian cedar, which in the mountains mainly takes the form of a creeping shrub (cedar elf).

Deciduous forest

Further south, to approximately 52 ° north latitude, there is a forest belt. But among this strip there are already sparsely wooded and even large treeless areas. These are the zones of the southern and eastern parts of the Oryol region, areas located near Tula, Ryazan, Tambov and Penza. Further to the east, treeless zones extend around Kazan, Samara, Ufa and Orenburg. This lack of trees, however, is mostly artificial.

In the forest belt, conifers are gradually replaced by black forests, although the pine goes to the most indigenous steppes, and the southern limit of spruce fluctuates between 55 ° and 50 ° northern latitude. The decisive predominance of oak begins around this same latitude. At the same time, there are still groves of linden, which once made up large forests and goes much further north than oak. This strip is called oak (or black-forest).

The composition of the forest zone is gradually becoming more diverse as one approaches the tropics. So, for example, in Northern Russia and Siberia, up to approximately 65 ° north latitude, the forest includes from 7 to 12 arboreal tall-stemmed ones. And in the tropics, they have to be counted in the thousands. In the north, solid pine or larch forests grow, to which separate birch, aspen, mountain ash and bird cherry are mixed. The further south the territories are located, the more noticeable this admixture is: blackwood groves begin to come across.

The forest zones of the surface of the globe are still very significant and, undoubtedly, are in connection with the distribution of climates and, mainly, with the distribution. The distribution of heat and soil has an effect on the composition of the forest, but their very presence is determined precisely by precipitation. In this respect, the still insufficiently explained absence of a forest zone in the so-called herbaceous or is still a mystery. But in general, we can say that where the amount of precipitation is low, there is no forest zone.

Mixed forest

On the other hand, the forest also affects the climate. It was found that this influence lies in the equation of distribution of heat and precipitation. Where forests are scattered and separated by significant treeless areas, they have only local influence. But where there are vast and closed forests, they determine the equation for the seasons. Forests weaken the continentality of the climate, lowering to a certain extent both the extremes of winter and the extremes of summer. In addition, forests moderate the dryness of the air, since direct experiments have shown that in forests it is more significant than in neighboring open places. By delaying the melting of snows, forests thereby also maintain soil dampness.

Mountain forests, in addition, restrain the impetuosity of snow and rain waters, hindering them, which often occur precisely from the bareness of the mountains. Undoubtedly, there is also the influence of the forest on the high flow of streams, small rivers, and other small water bodies. The influence of the forest also affects. Rapidly flowing snow and rainwater, not trapped by the forest, quickly rushes into the main river channels. Small bodies of water, not feeding on the waters gradually flowing from the forest, soon dry up and, finally, disappear without a trace. Examples of such drying up of streams, rivers, ponds and lakes are known from everyone. For example, in Central Russia, drying up is a common phenomenon that occurs in front of the eyes of local residents.

The influence of the forest on the fullness of the waters of large rivers, (for example, such as, or), has not yet been sufficiently clarified. The amount of water carried by them into the sea, apparently, does not decrease or decreases insignificantly, but the speed of their removal from the interior of the land is undoubtedly increasing. The consequence of deforestation is obviously the drying up of soils, affecting the culture. Therefore, it is necessary to take care, first of all, about the preservation or restoration of forests at the upper reaches of rivers, their tributaries and their coasts.

Several million years ago, forests covered approximately 80% of the Earth's land mass. Over the past 10 thousand years, our planet has lost 2/3 of the forest vegetation that covered it.

Currently, forests cover about a third of the land surface (not including the area of ​​Antarctica). The area occupied by forests continues to decline every year.

Geographic feature (meaning of forests)

A forest is a natural complex that consists of woody plants of one or many species growing close to each other and forming a canopy of partially or completely closed crowns, many organisms of other kingdoms in conjunction with soils, surface waters and the adjacent layer of the atmosphere. All components of the forest ecosystem affect each other and also interact with all other ecosystems of the planet, including the human ecosystem.

The forest is of general planning importance, since it has a significant impact on the Earth's climate, surface and groundwater runoff and soil formation. Russian scientists G.F. and V.N.Sukachev were the first to highlight the global role of the forest as an accumulator of living matter in the biosphere of the planet.

Through photosynthesis, the forest accumulates and transforms solar energy, producing oxygen. He is actively involved in the global carbon cycle. Climate change on the Earth and the problem of greenhouse gases are largely associated with the destruction of forest ecosystems.

Characteristics of forests

There are two world forest belts: North and South. The North includes Russia, Finland, Sweden, Canada and the United States, and the South includes Southeast Asia, the Amazon and the Congo Basin.

According to natural and territorial characteristics, it is customary to distinguish forests by continents and large regions:
- European,
- forests of Eastern Europe,
- Far Eastern,
- Siberian,
- forests of Southeast Asia,
- forests of North America
other.

Natural zones and types of forests

Within natural territorial zones, a description of the species composition of trees and climatic characteristics are used. The world's forests are subdivided into tropical forests and temperate forests.

Tropical humid forests (rainforests) have lower and mountainous zones. The plant grows during the rainy season. These equatorial evergreen forests are distinguished by a huge species diversity of flora and fauna. These include the forests of the Amazon, the Congo Basin and the jungles of India. The height of the trees here reaches tens of meters. Ficuses and palms grow in the upper tier, vines and tree ferns grow below. More than half of this type of forest has already been cleared.

Dry tropical deciduous and mountain forests fall during drought and vegetate during the rainy season. They are also known as "kaatinga", which means "white forest" in Tupi-Guarani language.

In the forests of temperate zones, broad-leaved, small-leaved, taiga and mixed types of forests are distinguished.

Temperate deciduous forests are located in Central Europe, in the east of North America, east of China, mountainous regions of the Crimea, the Caucasus and the Carpathians, the Far East of Russia, New Zealand, and Japan. The species composition of trees includes oak, elm, linden, chestnut, sycamore, hornbeam. From the ancient deciduous forests, now there are only small green islets in nature reserves and highly rugged areas.

Taiga forests with coniferous trees occupy the most extensive area. They include most of the forests of Siberia.

Deciduous and coniferous forests are usually replaced by small-leaved ones. This type of forest is characterized by various species of birch, alder, poplar, aspen, willow. Their wood is much softer than that of broad-leaved trees, which is why these forests are also called soft-leaved. They make up a significant part of the forests of Russia, and birch forests predominate.

Mixed forests include broadleaf, coniferous and small-leaved and coniferous trees and are found in Central and Western Europe.

Forest climate

The humid and hot equatorial climate, where the temperature does not drop less than 24 - 28 ° С all year round, is the growth conditions for humid tropical forests. Abundant rains are frequent here, the amount of precipitation is up to 10,000 mm per year. The dry season here alternates with tropical showers with an air humidity of 80%.

Dry tropical forests have to overcome drought and heat from 4 to 6 months a year. They get from 800 to 1300 mm of precipitation per year.

The taiga climate ranges from mild maritime in the west to sharply continental in the east, where in winter frosts can reach -60 ° C. The amount of precipitation ranges from 200 to 1000 mm. In permafrost conditions, moisture stagnates, which leads to the formation of swampy woodlands.

The temperate continental climate of mixed and deciduous forests is relatively mild and warm enough in summer, with long and cold winters. The average annual rainfall is about 700 mm. If moisture is excessive and evaporation is insufficient, waterlogging processes begin.

The largest forests in the world

Even authoritative sources claim that the largest forested areas are located in the Amazon basin. But actually it is not. The primacy belongs to the taiga. It occupied the boreal zone of Eurasia, Canada and Alaska, located in North America, in significant territories in Finland, Sweden and Norway, and stretched across the entire territory of Russia. Its area is 10.7 million sq. km.