Natural areas of the earth brief description. Natural areas

The warmth of the sun, clean air and water are the main criteria for life on Earth. Numerous climatic zones have led to the division of the territory of all continents and waters into certain natural zones. Some of them, even separated by huge distances, are very similar, others are unique.

Natural areas of the world: what are they?

This definition should be understood as very large natural complexes (in other words, parts geographical zone Earths) that have similar, homogeneous climatic conditions. The main characteristic of natural areas is the flora and fauna that inhabit the given territory. They are formed as a result of the uneven distribution of moisture and heat on the planet.

Table “Natural areas of the world”

Natural area	Climate zone	average temperature(winter/summer)
Antarctic and arctic deserts	Antarctic, Arctic	24-70°C /0-32°C
Tundra and forest-tundra	Subarctic and subantarctic	8-40°С/+8+16°С
	Moderate	8-48°С /+8+24°С
Mixed forests	Moderate	16-8°С /+16+24°С
Broadleaf forests	Moderate	8+8°С /+16+24°С
Steppes and forest-steppes	Subtropical and temperate	16+8 °С /+16+24°С
Temperate deserts and semi-deserts	Moderate	8-24 °С /+20+24 °С
Hardleaf forests	Subtropical	8+16 °С/ +20+24 °С
Tropical deserts and semi-deserts	Tropical	8+16 °С/ +20+32 °С
Savannas and woodlands		20+24°С and above
Variably humid forests	Subequatorial, tropical	20+24°С and above
Permanently wet forests	Equatorial	above +24°С

This characteristic of the natural zones of the world is only for informational purposes, because you can talk about each of them for a very long time, and all the information will not fit into the framework of one table.

Natural zones of the temperate climate zone

1. Taiga. It surpasses all other natural zones of the world in terms of land area (27% of the territory of all forests on the planet). It is characterized by very low winter temperatures. Deciduous trees cannot withstand them, so the taiga is dense coniferous forests (mainly pine, spruce, fir, larch). Very large areas Taigas in Canada and Russia are occupied by permafrost.

2. Mixed forests. Characteristic to a greater extent for the Northern Hemisphere of the Earth. It is a kind of border between the taiga and deciduous forest. They are more resistant to cold and long winters. Tree species: oak, maple, poplar, linden, as well as rowan, alder, birch, pine, spruce. As the table shows " Natural areas world", soils in the zone mixed forests gray, not very fertile, but still suitable for growing plants.

3. Broad-leaved forests. They are not adapted to harsh winters, are deciduous. They occupy most of Western Europe, the south of the Far East, northern China and Japan. Suitable for them is a maritime or temperate continental climate with hot summers and sufficient warm winter. As the table “Natural zones of the world” shows, the temperature in them does not fall below -8°C even in the cold season. The soil is fertile, rich in humus. The following types of trees are typical: ash, chestnut, oak, hornbeam, beech, maple, elm. The forests are very rich in mammals (ungulates, rodents, predators), birds, including game birds.

4. Temperate deserts and semi-deserts. Their main distinctive feature- almost complete absence of vegetation and meager animal world. There are quite a lot of natural areas of this nature; they are located mainly in the tropics. There are temperate deserts in Eurasia, and they are characterized by sharp changes in temperature across the seasons. Animals are represented mainly by reptiles.

Arctic deserts and semi-deserts

They are huge areas of land covered with snow and ice. A map of natural zones of the world clearly shows that they are located in the territory North America, Antarctica, Greenland and the northern tip of the Eurasian continent. In fact, these are lifeless places, and only along the coast are polar bears, walruses and seals, arctic foxes and lemmings, and penguins (in Antarctica). Where the ground is free of ice, lichens and mosses can be seen.

Equatorial rainforests

Their second name is rain forests. They are located mainly in South America, as well as in Africa, Australia and the Greater Sunda Islands. The main condition for their formation is constant and very high humidity (more than 2000 mm of precipitation per year) and hot climate(20°C and above). They are very rich in vegetation, the forest consists of several tiers and is an impenetrable, dense jungle, which has become home to more than 2/3 of all types of creatures now living on our planet. These rain forests are superior to all other natural areas in the world. The trees remain evergreen, changing foliage gradually and partially. Surprisingly, the soil rain forests contain little humus.

Natural zones of the equatorial and subtropical climate zone

1. Variably humid forests, they differ from rain forests in that precipitation falls there only during the rainy season, and during the period of drought that follows, the trees are forced to shed their leaves. The flora and fauna are also very diverse and rich in species.

2. Savannas and woodlands. They appear where moisture, as a rule, is no longer enough for growth variable-humid forests. Their development occurs in the interior of the continent, where tropical and equatorial climates predominate. air masses, and the rainy season lasts less than six months. They occupy a significant part of the territory of subequatorial Africa, the interior of South America, partly Hindustan and Australia. More detailed information about the location is reflected in the map of natural areas of the world (photo).

Hardleaf forests

This climate zone is considered the most suitable for human habitation. Hard-leaved and evergreen forests are located along sea and ocean coasts. Precipitation is not so abundant, but the leaves retain moisture due to their dense leathery shell (oaks, eucalyptus), which prevents them from falling. In some trees and plants they are modernized into spines.

Steppes and forest-steppes

They are characterized by an almost complete absence of woody vegetation, due to the poor level of precipitation. But the soils are the most fertile (chernozems), and therefore are actively used by humans for farming. The steppes occupy large areas in North America and Eurasia. The predominant number of inhabitants are reptiles, rodents and birds. Plants have adapted to the lack of moisture and most often manage to complete their life cycle during the short spring period, when the steppe is covered with a thick carpet of greenery.

Tundra and forest-tundra

In this zone the breath of the Arctic and Antarctic begins to be felt, the climate becomes more severe, and even coniferous trees cannot withstand it. There is an abundance of moisture, but there is no heat, which leads to swamping of very large areas. There are no trees at all in the tundra; the flora is mainly represented by mosses and lichens. It is considered to be the most unstable and fragile ecosystem. Due to the active development of gas and oil fields, it is on the verge of an environmental disaster.

All natural areas of the world are very interesting, be it the seemingly absolutely lifeless desert, the endless arctic ice or thousand-year-old rain forests with boiling life inside.

If a hundred artists living in different countries, offered to draw a portrait of the Earth, then we would get completely different portraits. On one we would see the harsh tundra, on the other - a lush jungle, on the third - a desert languishing in the heat... And if all the portraits were collected in one exhibition, we would be surprised: how many faces our planet has!

These different faces appeared on the Earth because the conditions for the life of organisms on it are very diverse and completely different natural zones have developed in different parts of the planet.

Among the natural zones of the Earth, several main ones can be distinguished, those that occupy most of its surface. Their distribution on the planet depends on climate, mainly on the distribution of heat and moisture.

In the northern regions of Eurasia and North America and on many adjacent islands it is located tundra. There is very little heat here, the soil is frozen by permafrost. The natural community of the tundra consists of lichens, mosses, dwarf trees, rodents lemmings, white partridge and snowy owl, reindeer, and arctic fox.

To the south of the tundra, where there are still very cold winters, there is taiga. The basis of the natural community of the taiga is coniferous trees that do not require heat. Larch, cedar pine, spruce, and fir form taiga forests that occupy vast spaces. The taiga is inhabited by capercaillie, nutcracker, flying squirrel, and sable.

To the south of the taiga, where there is more warmth and no permafrost at all, heat-loving deciduous trees grow - oak, maple, linden. Together with other trees, various shrubs, herbs, mushrooms and, of course, animals, they form mixed And broadleaf forests.

In areas where there is a lot of heat, but there is not enough moisture for the existence of forests, there are grassy plains- steppes and savannas. They are found on all continents except Antarctica. The steppes are especially extensive in Eurasia, and savannas in Africa. The basis of the community of grassy plains is, naturally, grasses, although separately growing trees are also found in savannas. A variety of insects and large animals feed on grasses: in the African savannah, for example, antelopes and zebras. These animals are hunted by predators. The most famous predator of the African savanna is the lion.

The driest areas of the Earth are occupied by desert. They are also found on all continents except Antarctica. Few organisms have adapted to life here, and yet the desert community is not so poor. In the deserts of Central Asia, for example, saxaul, sand sedge, camel thorn grow, and insects (darkling beetles, grasshoppers) live; reptiles (round-headed lizard, monitor lizard, sand boa, cobra); mammals (goitered gazelle, jerboas, gerbils).

On the map you see two lines encircling Earth, - Northern Tropic and Southern Tropic. Between them, on both sides of the equator, is located tropical rainforest. Here all year round It is very warm and there is heavy rainfall. These conditions are especially favorable for plants and animals. Therefore, the tropical rainforest is the richest in species natural community Earth.

Test your knowledge

List the main natural zones of the Earth.
What determines the distribution of natural zones on Earth?
Give brief description tundra
What trees form the basis of taiga, mixed and deciduous forests?
What do all the grassy plains on our planet have in common?
Give a brief description of the desert.
Why is the tropical rainforest the most species-rich natural community?

Think!

Using examples, prove that the distribution of natural zones on Earth depends on the distribution of heat and moisture.
The characteristic features of which natural areas are listed below?
1. Largest variety of species;
2. predominance of herbaceous plants;
3. an abundance of mosses, lichens and dwarf trees;
4. a bunch of coniferous plants few species.
Name these organisms. In what natural areas do they live?

The main natural zones of the Earth are tundra, taiga, mixed and deciduous forests, grassy plains, deserts, and tropical rainforests. Their distribution on Earth depends on climate.

In order to find out what natural zones are, let us remember that they are formed on the basis of geographical zones: equatorial, subequatorial, tropical, subtropical, temperate, subarctic and arctic. If you wonder how many of them there are, then in geography it is customary to count nine categories. Let's consider natural areas and their features.

Equatorial and tropical forests

Characterized by heat and large amounts of tropical rainfall. It has the highest humidity on Earth. The top layer of soil is very fertile, which makes it possible to grow fruit and vegetable crops all year round and harvest several times.

The largest tropical forest in the world is located in the Amazon River Valley. Many places in this impenetrable thicket have still not been explored by people. Equatorial forests are rich in different types flora and fauna. Here you can meet the smallest birds - hummingbirds, bloodthirsty alligators and apes.

Rice. 1. Equatorial forests

Equatorial deserts and semi-deserts

These areas are characterized by a very dry climate with scorching sunshine most of the year. The flora and fauna are very scarce; living organisms have to adapt to the harsh conditions of the desert. In soils there is practically no minerals, and the moisture is so far away that the roots of plants (cacti) have to go hundreds of meters deep.

The largest desert on Earth is the Sahara Desert in Africa.

Rice. 2. Desert

Savannas and woodlands

Already from the name it is obvious that this is an area of rare trees. The vegetation here is predominantly herbaceous, characterized by low shrubs and rare trees. There is very little rainfall per year and it is hot for most of the year.

Hard-leaved forests and shrubs

This zone is typical for Mediterranean countries. A variety of plants and many trees, mostly conifers, are found here. The characteristic fauna can now only be found in zoos. Urbanization and technological progress have led to the fact that forests have practically disappeared in Europe, and with them the ancient fragile natural world. The soils here are red-brown.

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Steppes and forest-steppes

The most fertile lands, chernozems, are formed in this zone. The climate is mild, with moderate winters and an arid climate. The forest-steppe has a rich flora and fauna; the steppes are inhabited mainly by rodents, predators, and large birds.

Broadleaf and mixed forests

Most of Russia is just a forest zone. Temperate climate, warm summers and Cold winter allow a large number of animals to survive here. Plant world represented by hundreds of species of bushes and trees.

Taiga

The Taiga zone is found in northern countries such as Canada, Sweden, Norway, Finland and Russia. Winter here is getting colder and there is less summer. The entire territory is covered with evergreen forests consisting of coniferous trees: spruce, pine, larch. Representatives of the fauna are mainly predators.

Tundra and forest-tundra

The climate zone in which it is located is subarctic. You can find it in two countries: Russia and Canada. In the forest-tundra there are still low-growing trees and shrubs, in the tundra there are only mosses and lichens. The soil is peaty and swamps predominate. Due to the fact that it is winter here most of the year, the earth does not warm up. Among the animals there are hares, arctic foxes, and reindeer.

Natural zones of the Earth

Complex Scientific research nature allowed V.V. Dokuchaev to formulate the law in 1898 geographical zonation, Whereby climate, water, soil, relief, vegetation and fauna on certain territory are closely interrelated and must be studied as a whole. He proposed dividing the Earth's surface into zones that are naturally repeated in the Northern and Southern Hemispheres.

Different geographical (natural) zones Earth characterized by a certain combination of heat and moisture, soils, flora and fauna and, as a consequence, characteristics economic activity their population. These are zones of forests, steppes, deserts, tundra, savanna, as well as transitional zones of forest-tundra, semi-deserts, forest-tundra. Natural areas are traditionally named according to the predominant type of vegetation, reflecting the most important features of the landscape.

A regular change in vegetation is an indicator of a general increase in heat. In the tundra the average temperature is warm month in the year - July - does not exceed + 10°С, in the taiga it fluctuates between + 10... + 18°С in the strip of deciduous and mixed forests + 18...+20°С, in the steppe and forest-steppe +22. ..+24°С, in semi-deserts and deserts - above +30°С.

Most animal organisms remain active at temperatures from 0 to +30°C. However, temperatures from + 10°C and above are considered the best for growth and development. Obviously, such a thermal regime is typical for the equatorial, subequatorial, tropical, subtropical, and temperate climatic zones of the Earth. The intensity of vegetation development in natural areas also depends on the amount of precipitation. Compare, for example, their number in the forest and desert zones (see atlas map).

So, natural areas- these are natural complexes that occupy large areas and are characterized by the dominance of one zonal type of landscape. They are formed mainly under the influence of climate - the distribution of heat and moisture, their ratio. Each natural zone has its own type of soil, vegetation and animal life.

The appearance of a natural area is determined by the type of vegetation cover. But the nature of vegetation depends on climatic conditions - thermal regime, moisture, light, soil, etc.

As a rule, natural zones are extended in the form of wide stripes from west to east. There are no clear boundaries between them; they gradually transform into one another. The latitudinal location of natural zones is disrupted by the unequal distribution of land and ocean, relief, distance from the ocean.

General characteristics of the main natural zones of the Earth

Let us characterize the main natural zones of the Earth, starting from the equator and moving towards the poles.

There are forests on all continents of the Earth, except Antarctica. Forest areas have common features, and special ones, characteristic only of taiga, mixed and broad-leaved forests or tropical forests.

The general features of the forest zone include: warm or hot summers, a fairly large amount of precipitation (from 600 to 1000 or more mm per year), large deep rivers, and the predominance of woody vegetation. The largest number equatorial forests, which occupy 6% of the land, receive heat and moisture. They rightfully belong to the first place among forest areas Earth by diversity of plants and animals. 4/5 of all plant species grow here and 1/2 of all land animal species live here.

Climate equatorial forests hot and humid. Average annual temperatures+24... + 28°С. The annual precipitation is more than 1000 mm. It is in the equatorial forest that you can find the largest number of ancient animal species, such as amphibians: frogs, newts, salamanders, toads or marsupials: possums in America, possums in Australia, tenrecs in Africa, lemurs in Madagascar, lorises in Asia; Ancient animals include such inhabitants of equatorial forests as armadillos, anteaters, and lizards.

IN equatorial forests The richest vegetation is located in several tiers. The treetops are home to many species of birds: hummingbirds, hornbills, birds of paradise, crowned pigeons, numerous species of parrots: cockatoos, macaws, Amazons, African Grays. These birds have tenacious legs and strong beaks: they not only fly, but also climb trees very well. Animals that live in treetops also have prehensile paws and tails: sloths, monkeys, howler monkeys, flying foxes, tree kangaroos. The largest animal that lives in the treetops is the gorilla. Such forests are home to many beautiful butterflies and other insects: termites, ants, etc. Various types of snakes. Anaconda - largest snake in the world, reaches a length of 10 m or more. The high-water rivers of the equatorial forests are rich in fish.

The largest areas of equatorial forests occupy in South America, in the Amazon River basin, and in Africa - in the Congo River basin. Amazon is the most deep river on the ground. Every second she endures Atlantic Ocean 220 thousand m3 of water. The Congo is the second most water-rich river in the world. Equatorial forests are also common on the islands of the Malaysian archipelago and Oceania, in the southeastern regions of Asia, and in northeastern Australia (see map in the atlas).

Valuable tree species: mahogany, black, yellow - the wealth of equatorial forests. Harvesting valuable timber threatens the conservation of the Earth's unique forests. Satellite images have shown that in a number of areas of the Amazon, destruction the forest is coming at a catastrophic pace, many times faster than their recovery. At the same time, many species of unique plants and animals are disappearing.

Variably wet monsoon forests

Variably humid monsoon forests can also be found on all continents of the Earth except Antarctica. If in the equatorial forests it is summer all the time, then three seasons are clearly defined here: dry cool (November-February) - winter monsoon; dry hot (March-May) - transitional season; humid hot (June-October) - summer monsoon. The hottest month is May, when the sun is almost at its zenith, rivers dry up, trees shed their leaves, and the grass turns yellow.

The summer monsoon arrives at the end of May with hurricane winds, thunderstorms, and torrential rains. Nature comes to life. Due to the alternation of dry and wet seasons, monsoon forests are called variable-wet.

India's monsoon forests are located in the tropical climatic zone. They grow here valuable breeds trees, characterized by the strength and durability of wood: teak, sal, sandalwood, satin and ironwood. Teak wood is not afraid of fire and water, it is widely used for the construction of ships. Sal also has a durable and strong wood. Sandalwood and satin trees are used in the manufacture of varnishes and paints.

The fauna of the Indian jungle is rich and diverse: elephants, bulls, rhinoceroses, monkeys. Lots of birds and reptiles.

Monsoon forests in tropical and subtropical regions are also characteristic of Southeast Asia, Central and South America, and the northern and northeastern regions of Australia (see map in the atlas).

Temperate monsoon forests

Temperate monsoon forests are found only in Eurasia. The Ussuri taiga is a special place in Far East. This is a real thicket: multi-tiered, dense forests, intertwined with vines and wild grapes. Cedar, walnut, linden, ash, and oak grow here. The lush vegetation is the result of abundant seasonal rainfall and a fairly mild climate. Here you can meet the Ussuri tiger - the most major representative of its own kind.
Rivers monsoon forests They are fed by rain and overflow during the summer monsoon rains. The largest of them are the Ganges, Indus, and Amur.

Monsoon forests have been heavily cut down. According to experts, in Eurasia only 5% of the former remains forest areas. Monsoon forests have suffered not only from forestry, but also from agriculture. It is known that the largest agricultural civilizations appeared on fertile soils in the valleys of the Ganges, Irrawaddy, Indus rivers and their tributaries. The development of agriculture required new territories - forests were cut down. Agriculture has adapted for centuries to alternating wet and dry seasons. The main agricultural season is the wet monsoon period. The most important crops are planted here - rice, jute, sugar cane. In the dry, cool season, barley, legumes, and potatoes are planted. During the dry hot season, farming is possible only with artificial irrigation. The monsoon is capricious, its delay leads to severe droughts and destruction of crops. Therefore, artificial irrigation is necessary.

temperate forests

Temperate forests occupy significant areas in Eurasia and North America (see map in the atlas).

IN northern regions- this is the taiga, to the south - mixed and deciduous forests. In the forest zone of the temperate zone, the seasons of the year are clearly defined. Average temperatures in January are negative throughout, in some places down to - 40°C, in July + 10... + 20°C; the amount of precipitation is 300-1000 mm per year. The vegetation of plants stops in winter, and there is snow cover for several months.

Spruce, fir, pine, and larch grow both in the taiga of North America and in the taiga of Eurasia. The animal world also has a lot in common. The bear is the master of the taiga. True, in the Siberian taiga it is called - Brown bear, and in the Canadian taiga - grizzly bears. Can be found bobcat, elk, wolf, as well as marten, ermine, wolverine, and sable. Flow through the taiga zone largest rivers Siberia - Ob, Irtysh, Yenisei, Lena, which in terms of flow are second only to the rivers of the equatorial forest zone.

To the south, the climate becomes milder: mixed and broad-leaved forests grow here, consisting of species such as birch, oak, maple, linden, among which there are also conifers. Characteristic of the forests of North America are: white oak, sugar maple, yellow birch. Red deer, elk, wild boar, hare; Among the predators, the wolf and the fox are representatives of the animal world of this zone known to us.

If the northern taiga is considered by geographers to be a zone slightly modified by humans, then mixed and broad-leaved forests have been cut down almost everywhere. Their place was taken by agricultural areas, for example, the “corn belt” in the United States; many cities and transport routes are concentrated in this zone. In Europe and North America, the natural landscapes of these forests have been preserved only in mountainous areas.

Savannah

Savannah - natural area low latitudes in the subequatorial, tropical and subtropical zones of the Northern and Southern Hemispheres. Occupies about 40% of the territory of Africa (sub-Saharan Africa), distributed in South and Central America, Southeast Asia, Australia (see map in the atlas). The savanna is dominated by herbaceous vegetation with separate standing trees or groups of trees (acacia, eucalyptus, baobab) and bushes.

The fauna of African savannas is surprisingly diverse. To adapt to the conditions of endless dry spaces, nature endowed animals with unique properties. For example, the giraffe is considered the tallest animal on Earth. Its height exceeds 5 m, it has a long tongue (about 50 cm). The giraffe needs all this in order to reach the high branches of the acacia trees. The crowns of acacias begin at a height of 5 m, and giraffes have practically no competitors, calmly eating tree branches. Typical savannah animals are zebras, elephants, and ostriches.

Steppes

Steppes are found on all continents of the Earth, except Antarctica (in temperate and subtropical zones Northern and Southern Hemispheres). They differ in abundance solar heat, low precipitation (up to 400 mm per year), as well as warm or hot summers. The main vegetation of the steppes is grass. Steppes are called differently. In South America, the tropical steppes are called pampa, which in the Indian language means “a large area without forest.” Animals characteristic of the pampa are the llama, the armadillo, and the viscacha, a rodent similar to a rabbit.

In North America, steppes are called prairies. They are located in both temperate and subtropical climate zones. The bison have long been the “kings” of the American prairies. By the end of the 19th century they were almost completely exterminated. Currently, through the efforts of the state and the public, the number of bison is being restored. Another resident of the prairies is the coyote - the steppe wolf. Along the banks of rivers in the bushes you can find a large spotted cat - a jaguar. Peccaries are a small boar-like animal also typical of the prairies.

The steppes of Eurasia are located in temperate zone. They are very different from the American prairies and African savannas. It's drier here, sharper continental climate. In winter it is very cold (average temperature - 20°C), and in summer it is very hot (average temperature + 25°C), with strong winds. In summer, the vegetation of the steppes is sparse, but in spring the steppe is transformed: it blooms with many varieties of lilies, poppies, and tulips.

The flowering time does not last long, about 10 days. Then drought sets in, the steppe dries out, the colors fade, and by autumn everything turns yellow-gray.

The steppes contain the most fertile soils on Earth, so they are almost completely plowed. The treeless spaces of the temperate steppes are characterized by strong winds. Wind soil erosion occurs here very intensively - frequent dust storms. To preserve soil fertility, forest belts are planted, organic fertilizers and light agricultural machinery are used.

Deserts

Deserts occupy vast areas - up to 10% of the Earth's land area. They are located on all continents and in different climatic zones: temperate, subtropical, tropical and even polar.

The desert climates of the tropical and temperate zones have common features. Firstly, an abundance of solar heat, secondly, a large amplitude of temperatures between winter and summer, day and night, and thirdly, a small amount of precipitation (up to 150 mm per year). However, the latter feature is also characteristic of polar deserts.

In the deserts of the tropical zone, the average summer temperature is +30°C, winter + 10°C. Greatest tropical desert The lands are located in Africa: Sahara, Kalahari, Namib.

Plants and animals of deserts adapt to dry and hot climates. For example, a giant cactus can store up to 3000 liters of water and “not drink” for up to two years; and the Welwitschia plant, found in the Namib Desert, is capable of absorbing water from the air. The camel is an indispensable helper for humans in the desert. It can be without food and water for a long time, storing it in its humps.

The largest desert in Asia, the Rub al-Khali, located on the Arabian Peninsula, is also in tropical zone. The desert regions of North and South America and Australia are located in the tropical and subtropical climate zones.

The temperate deserts of Eurasia are also characterized by low precipitation and a large temperature range, both annual and daily. However, they are characterized by lower winter temperatures and a pronounced flowering period in the spring. Such deserts are located in Central Asia east of the Caspian Sea. The fauna here is represented by various species of snakes, rodents, scorpions, turtles, and lizards. A typical plant is saxaul.

Polar deserts

Polar deserts are located in the polar regions of the Earth. The absolute minimum temperature recorded in Antarctica is 89.2 °C.

On average, winter temperatures are -30 °C, summer temperatures are 0 °C. Just like in the deserts of the tropical and temperate zones, the polar desert receives little precipitation, mainly in the form of snow. The polar night lasts almost half a year here, and the polar day lasts almost half a year. Antarctica is considered the highest continent on Earth, given the thickness of its ice shell at 4 km.

Indigenous inhabitants of the polar deserts of Antarctica - emperor penguins. They cannot fly, but they swim perfectly. They can dive to great depths and swim vast distances to escape their enemies - seals.

The northern polar region of the Earth - the Arctic - got its name from the ancient Greek arcticos - northern. The southern, as if opposite, polar region is Antarctica (anti - against). The Arctic occupies the island of Greenland, the islands of the Canadian Arctic Archipelago, as well as the islands and waters of the Arctic Ocean. This area is covered with snow and ice all year round. The polar bear is rightfully considered the owner of these places.

Tundra

Tundra is a treeless natural area with vegetation of mosses, lichens and creeping shrubs. Tundra is common in the subarctic climatic zone only in North America and Eurasia, characterized by harsh climatic conditions (little solar heat, low temperatures, short cold summers, low precipitation).

The moss lichen was called “reindeer moss” because it is the main food reindeer. Arctic foxes and lemmings - small rodents - also live in the tundra. Among the sparse vegetation there are berry bushes: blueberries, lingonberries, blueberries, as well as dwarf trees: birch, willow.

Permafrost in the soil is a phenomenon characteristic of the tundra, as well as the Siberian taiga. As soon as you start digging a hole, at a depth of about 1 m you will encounter a frozen layer of earth several tens of meters thick. This phenomenon must be taken into account during construction, industrial and agricultural development of the territory.

Everything grows very slowly in the tundra. This is precisely why the need for careful attention to its nature is connected. For example, pastures overrun by deer are restored only after 15-20 years.

Altitudinal zone

Unlike flat areas, climatic zones and natural zones in the mountains change according to the law of vertical zonation, i.e. from bottom to top. This is due to the fact that the air temperature decreases with altitude. Consider, as an example, the greatest mountain system in the world - the Himalayas. Almost all natural zones of the Earth are represented here: tropical forest grows at the foot, at an altitude of 1500 m it is replaced by broad-leaved forests, which in turn turn into mixed forests at an altitude of 2000 m. Further, as you rise into the mountains, they begin to predominate coniferous forests from Himalayan pine, fir and juniper. In winter, there is snow here for a long time and frosts persist.

Above 3500 m, shrubs and alpine meadows begin; they are called “alpine”. In summer, the meadows are covered with a carpet of brightly blooming herbs - poppies, primroses, gentians. Gradually the grasses become shorter. From approximately 4500 m altitude there is eternal snow and ice. Climatic conditions It's very harsh here. Rare species of animals live in the mountains: Mountain goat, chamois, argali, snow leopard.

Latitudinal zonation in the ocean

The world's oceans occupy more than 2/3 of the planet's surface. Physical properties And chemical composition Ocean waters are relatively constant and create an environment favorable for life. It is especially important for the life of plants and animals that oxygen and carbon dioxide coming from the air dissolve in water. Photosynthesis of algae occurs mainly in top layer water (up to 100 m).

Marine organisms live mainly in the surface layer of water illuminated by the Sun. These are the smallest plant and animal organisms - plankton (bacteria, algae, small animals), various fish and marine mammals(dolphins, whales, seals, etc.), squid, sea snakes and turtles.

There is life on the seabed too. These are bottom algae, corals, crustaceans, and mollusks. They are called benthos (from the Greek benthos - deep). The biomass of the World Ocean is 1000 times less than the biomass of the Earth's land.

Distribution of life in world ocean unevenly and depends on the amount of solar energy received on its surface. Polar waters are poor in plankton due to low temperatures and the long polar night. The largest amount of plankton develops in the waters of the temperate zone in summer. The abundance of plankton attracts fish here. The temperate zones of the Earth are the most fishy areas of the World Ocean. In the tropical zone, the amount of plankton decreases again due to the high salinity of the water and high temperatures.

Formation of natural areas

From today's topic, we learned how diverse the natural complexes of our planet are. The natural zones of the Earth are replete with evergreen forests, endless steppes, various mountain ranges, hot and icy deserts.

Each corner of our planet is distinguished by its uniqueness, varied climate, relief, flora and fauna, and therefore different natural zones are formed on the territories of each continent.

Let's try to figure out what natural areas are, how they were formed, and what was the impetus for their formation.

Natural zones include those complexes that have similar soils, vegetation, fauna and similarities temperature regime. Natural zones received their names based on the type of vegetation, and are called such as taiga zone or deciduous forests, etc.

Natural areas are diverse due to the uneven redistribution of solar energy on the Earth's surface. This is the main reason for the heterogeneity of the geographical envelope.

After all, if we consider one of the climatic zones, we will notice that those parts of the belt that are located closer to the ocean are more humidified than its continental parts. And this reason lies not so much in the amount of precipitation, but rather in the ratio of heat and moisture. Because of this, on some continents we experience a more humid climate, while on others we experience a drier climate.

And with the help of the redistribution of solar heat, we see how the same amount of moisture in some climate zones leads to excess moisture, and in others to a lack of moisture.

For example, in a hot tropical zone, a lack of moisture can cause drought and the formation of desert areas, while in the subtropics, excess moisture contributes to the formation of swamps.

So you learned that due to the difference in the amount of solar heat and moisture, different natural zones were formed.

Patterns of natural zones location

Natural zones of the Earth have clear patterns of their location, extending in the latitudinal direction and changing from north to south. Most often, a change in natural zones is observed in the direction from the coast making its way inland.

In mountainous areas there is an altitudinal zone, which changes from one zone to another, starting from the foot and moving towards the mountain peaks.

In the World Ocean, zones change from the equator to the poles. Here, changes in natural areas are reflected in the surface composition of waters, as well as differences in vegetation and fauna.

Features of the natural zones of the continents

Since planet Earth has a spherical surface, the Sun heats it unevenly. Those areas of the surface above which the Sun is high receive the most heat. And where Sun rays only glide over the Earth - a more severe climate prevails.

And although on different continents the vegetation and animals have similar features, they are influenced by climate, topography, geology and people. Therefore, historically it happened that due to changes in relief and climate in different continents There are also different species of plants and animals.

There are continents where endemics are found, where only a certain type of living beings and plants live, which are peculiar to these continents. For example, polar bears can only be found in nature in the Arctic, and kangaroos can only be found in Australia. But in African and South American shrouds there are similar species, although they have certain differences.

But human activity contributes to changes that occur in the geographical environment, and under such influence natural areas also change.

Questions and tasks to prepare for the exam

1. Create an interaction plan natural ingredients in the natural complex and explain it.
2. How do the concepts “ natural complex", "geographical envelope", "biosphere", "natural zone"? Show with a diagram.
3. Name the zonal type of soil for tundra, taiga, mixed and deciduous forest zones.
4. Where is the soil cover more difficult to restore: in the steppes of Southern Russia or in the tundra? Why?
5. What is the reason for the difference in the thickness of the fertile soil layer in different natural zones? What does soil fertility depend on?
6. What types of plants and animals are characteristic of the tundra and why?
7. What organisms live on the surface of the waters of the World Ocean?
8. Which of the following animals can be found in the African savanna: rhinoceros, lion, giraffe, tiger, tapir, baboon, llama, hedgehog, zebra, hyena?
9. In what forests is it impossible to determine its age from the cut of a cut tree?
10. What measures, in your opinion, will help preserve the human habitat?

Maksakovsky V.P., Petrova N.N., Physical and economic geography of the world. - M.: Iris-press, 2010. - 368 pp.: ill.

What is a natural area? Natural area- physical-geographical zone - is part of the geographical shell of the Earth and the geographical zone, has characteristic components of its natural components and processes. What types of natural areas are there?

Arctic (Antarctic) desert.
Forest-tundra and tundra.
Taiga, mixed, broad-leaved forests, tropical forests.
Forest-steppe and steppe.
Deserts and semi-deserts.
Savannah.

Arctic and Antarctic deserts - such deserts occupy about 5 million square kilometers ( greatest places Greenland, Antarctica, northern parts of Eurasia and North America) are mainly composed of small rocks or scree, as well as glaciers. Feature In the polar desert there is a lack of sunlight for a long period of time, approximately 10 months. Most of the soil is covered by permanent permafrost. The average temperature that occurs in these zones is up to -30 degrees Celsius, in winter -60 degrees, in warm seasons, the maximum temperature is +3 degrees. Such deserts are practically devoid of vegetation. Animals in the Arctic include polar bears, walruses, seals, arctic foxes, and seals. In Alaska, Canada and Russia, the Arctic deserts are already gradually turning into tundra.

Forest-tundra and tundra - The largest areas of tundra and forest-tundra are located in the north of North America and also Eurasia (mainly Russia and Canada), mainly, such areas are located in the subarctic climate zone. In the southern hemisphere of our planet, tundra and forest-tundra are practically absent. The vegetation is very low, the most common being mosses and lichens. The tundra has a large number of trees, such as Siberian larch, dwarf birch, and polar willow. Among the animals: deer, wolves, a large number of hares, arctic foxes. The average temperature in warm seasons is +5 +10 degrees, in winter the average temperature is -30 degrees. In the Tundra, winter can last up to 9 months. In the forest-tundra the average temperature is +10 +15 degrees. In winter from -10 to -45 degrees. In the tundra and forest-tundra there are a very large number of lakes, due to high humidity, as well as a large number of swamps.

Taiga, mixed, deciduous forests, tropical forests - These zones are characterized by a mild climate and fertile soils. Formed in temperate zones with average rainfall. Usually located in the temperate zone of Russia, Canada, and Scandinavia. Characterized by cold winters and fairly warm summers. Vegetation includes a large number of coniferous trees: pine, fir, larch, spruce. Taiga became famous through its dark coniferous boreal forests. There is also a large number deciduous trees: birch, poplar, aspen. The main seasons in the taiga and broad-leaved, tropical forests, is winter and summer. Autumn and spring are so short that you won't even notice they exist. In the taiga it is either very cold or very hot. It happens that the temperature exceeds +30 degrees Celsius, mostly warm and rainy. In winter there are frosts and up to -50 degrees. There are a very large number of wild animals: brown bear, wolf, fox, wolverine, ermine, sable; there are also deer, elk, and roe deer. But usually, they live in areas where there are a very large number of deciduous trees.

Forest-steppe and steppe - These are areas of the earth that do not have forests, occupy quite vast territories in Eurasia, North America and in the subtropical zones of South America. Very low rainfall. Forest-steppe zone passes in the north between the steppes and forests in the north, namely, from the steppes, a transition is formed to semi-deserts and then deserts begin. In forest-steppes it is just the opposite; there is a rather humid climate (up to 600 mm) than in the steppe, so an element such as meadow steppe is formed here. The temperature in the steppes, as well as in forest-steppes, ranges from -16 to +10 degrees in winter, +15 +30 degrees in summer. Vegetation usually changes from north to south, grasses are replaced by feather grass, and it is replaced by wormwood. Among the animals there are gophers, marmots, bustards, and steppe eagles. There are also hedgehogs, squirrels, foxes, hares, snakes, moose, storks, and beavers.

Deserts and semi-deserts - this is one of the most large areas, it occupies one fifth of earth's surface. It is clear that the most most of These zones are located in the tropics (deserts and semi-deserts): in Africa, Australia, the tropics of South America, as well as on the Arabian Peninsula in Eurasia. The driest desert is the Atacama, which is located in Chile; there is practically no rain there. In the largest desert on Earth - the Sahara, there is also very little precipitation; in summer the temperature can reach +50; for deserts this is a very common occurrence. There are frosts in winter. In deserts there is practically no flora, this is explained by low humidity and a very dry climate; there are very few plants that can survive in such a climate. There are plenty of animals: jerboas, gophers, snakes, lizards, scorpions, camels.

Savannah - such zones occur, for the most part, in subequatorial belt Earth. The climate here is varied, sometimes very dry, and sometimes quite rainy. The average temperature for the year ranges from +15 to +25 degrees. The largest number of shrouds are found in South America, Africa, Indochina, the Hindustan Peninsula, and the northern regions of Australia. Very diverse fauna, mainly herbaceous vegetation, various trees and shrubs. Among the animals that live in shrouds, the following can be distinguished: elephants, cheetahs, lions, rhinoceroses, leopards, zebras, giraffes, antelopes. A large number of birds and insects.

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