Natural zones of the Earth

A comprehensive scientific study of nature allowed V. V. Dokuchaev in 1898 to formulate the law of geographical zonality, according to which climate, water, soil, relief, flora and fauna in a certain area are closely interconnected and should be studied as a whole. He proposed dividing the Earth's surface into zones that naturally repeat themselves in the Northern and Southern hemispheres.

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

The regular change of vegetation is an indicator of a general increase in heat. In the tundra, the average temperature of the warmest month of 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 characteristic of 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 zone of forests and deserts (see map of the atlas).

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 features of the distribution of heat and moisture, their ratio. Each natural zone has its own type of soil, vegetation and wildlife.

The appearance of the natural zone is determined by the type of vegetation cover. But the nature of vegetation depends on climatic conditions - thermal conditions, moisture, illumination, soils, etc.

As a rule, natural zones are elongated in the form of wide strips from west to east. There are no clear boundaries between them, they gradually pass into one another. The latitudinal location of natural zones is disturbed by the uneven 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.

Forests are located on all continents of the Earth, except for Antarctica. Forest zones have both common features and special features that are characteristic only of the taiga, mixed and broad-leaved forests or tropical forests.

The common 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 full-flowing rivers, and the predominance of woody vegetation. The equatorial forests, which occupy 6% of the land, receive the greatest amount of heat and moisture. They rightfully hold the first place among the forest zones of the Earth in terms of the diversity of plants and animals. 4/5 of all plant species grow here and 1/2 of all land animal species live.

The climate of the equatorial forests is hot and humid. Average annual temperatures are +24... +28°С. The annual amount of 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: opossums in America, possums in Australia, tenrecs in Africa, lemurs in Madagascar, loris in Asia; ancient animals are also such inhabitants of the equatorial forests as armadillos, anteaters, pangolins.

In the equatorial forests, the richest vegetation is located in several tiers. Many species of birds live in the crowns of trees: hummingbirds, hornbills, birds of paradise, crowned pigeons, numerous species of parrots: cockatoos, macaws, Amazons, Jacos. These birds have tenacious paws and strong beaks: they not only fly, but also climb trees beautifully. Animals that live in the crowns of trees also have tenacious paws and a tail: sloths, monkeys, howler monkeys, flying foxes, tree kangaroos. The largest animal that lives in the crowns of trees is the gorilla. In such forests, many beautiful butterflies and other insects live: termites, ants, etc. Various types of snakes. Anaconda - the 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 equatorial forests occupy the largest areas in South America, in the Amazon River basin, and in Africa - in the Congo River basin. The Amazon is the deepest river in the world. Every second it carries 220 thousand m3 of water into the Atlantic Ocean. The Congo is the second largest river in the world. Equatorial forests are also common on the islands of the Malaysian archipelago and Oceania, in the southeastern regions of Asia, in northeastern Australia (see the map in the atlas).

Valuable tree species: mahogany, black, yellow - the wealth of equatorial forests. The harvesting of valuable wood species threatens the preservation of the Earth's unique forests. Space images have shown that in a number of areas of the Amazon, forest destruction is proceeding at a catastrophic pace, many times faster than their restoration. At the same time, many species of unique plants and animals are disappearing.

Variable wet monsoon forests

Variably humid monsoon forests can also be found on all continents of the Earth, except for Antarctica. If in the equatorial forests it is always summer, then three seasons are pronounced here: dry cool (November-February) - the 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, the rivers dry up, the trees shed their leaves, the grass turns yellow.

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

The monsoon forests of India are located in the tropical climate zone. Valuable species of trees grow here, distinguished 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 building ships. Sal also has a durable and strong wood. Sandalwood and satin wood are used in the manufacture of varnishes and paints.

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

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

Temperate monsoon forests

Temperate monsoon forests are found only in Eurasia. The Ussuri taiga is a special place in the Far East. This is a real thicket: the forests are multi-tiered, dense, intertwined with lianas and wild grapes. Cedar, walnut, linden, ash and oak grow here. Rough vegetation is the result of an abundance of seasonal rainfall and a rather mild climate. Here you can meet the Ussuri tiger - the largest representative of its kind.
The rivers of the monsoon forests are rain-fed and flood during the summer monsoon rains. The largest of them are the Ganges, Indus, Amur.

The monsoon forests are heavily cut down. According to experts, in Eurasia only 5% of the former forests remained. Monsoon forests suffered not so much 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 and their tributaries. The development of agriculture required new territories - forests were cut down. Farming has adapted over the centuries to alternating wet and dry seasons. The main agricultural season is the wet monsoon period. The most important crops - rice, jute, sugarcane - are dated for it. In the dry cool season, barley, legumes, and potatoes are planted. In the dry hot season, agriculture is possible only with artificial irrigation. The monsoon is capricious, its delay leads to severe droughts and the death 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 the northern regions - this is the taiga, to the south - mixed and broad-leaved forests. In the forest zone of the temperate zone, the seasons of the year are pronounced. Average temperatures in January are negative everywhere, in some places up to -40°С, in July + 10 ... + 20°С; the amount of precipitation is 300-1000 mm per year. Vegetation of plants in winter stops, for several months there is a snow cover.

Spruce, fir, pine, 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 a brown bear, and in the taiga of Canada it is called a grizzly bear. You can meet red lynx, elk, wolf, as well as marten, ermine, wolverine, sable. The largest rivers of Siberia - the Ob, Irtysh, Yenisei, Lena - flow through the taiga zone, which are second only to the rivers of the equatorial forest zone in terms of flow.

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

If the northern taiga is classified by scientists-geographers as a zone slightly modified by man, then mixed and broad-leaved forests have been cut down almost everywhere. Their place was taken by agricultural areas, such as the "corn belt" in the United States, in this zone many cities and highways are concentrated. In Europe and North America, the natural landscapes of these forests have been preserved only in mountainous regions.

Savannah

Savannah is a natural zone of low latitudes in the subequatorial, tropical and subtropical zones of the Northern and Southern Hemispheres. It occupies about 40% of the territory of Africa (south of the Sahara), distributed in South and Central America, Southeast Asia, Australia (see the map in the atlas). The savanna is dominated by herbaceous vegetation with isolated trees or groups of trees (acacia, eucalyptus, baobab) and shrubs.

The fauna of the 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). All this is necessary for a giraffe in order to reach the high branches of acacias. Crowns of acacias begin at a height of 5 m, and giraffes have practically no competitors, calmly eating tree branches. Typical animals of the savannas are zebras, elephants, ostriches.

Steppes

Steppes are found on all continents of the Earth, except for Antarctica (in the temperate and subtropical zones of the Northern and Southern Hemispheres). They are distinguished by an abundance of solar heat, low rainfall (up to 400 mm per year), as well as warm or hot summers. The main vegetation of the steppes is grasses. The steppes are called differently. In South America, the tropical steppes are called pampas, which in the language of the Indians means "a large expanse without a forest." Animals characteristic of the pampa are the llama, the armadillo, the viscacha, a rodent that looks like a rabbit.

In North America, the steppes are called prairies. They are located in both temperate and subtropical climatic zones. The "kings" of the American prairies have long been bison. 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 inhabitant of the prairies is the coyote - the steppe wolf. On the banks of the rivers in the bushes you can meet a large spotted cat - a jaguar. The peccary is a small boar-like animal also typical of the prairies.

The steppes of Eurasia are located in the temperate zone. They are very different from the American prairies and African savannas. It has a drier, sharply continental climate. It is very cold in winter (average temperature - 20°С), and very hot in summer (average temperature + 25°С), 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 and poppies, tulips.

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

The most fertile soils of the Earth are located in the steppes, so they are almost completely plowed up. The treeless expanses of the steppes of the temperate zone are distinguished by strong winds. Here, wind erosion of soils is very intensive - dust storms are frequent. To preserve soil fertility, forest belts are planted, organic fertilizers and light agricultural machinery are used.

desert

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

There are common features in the climate of the deserts of the tropical and temperate zones. Firstly, the abundance of solar heat, secondly, the large amplitude of temperatures in 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 the polar deserts.

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

Desert plants and animals adapt to dry and hot climates. So, 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 able to absorb water from the air. A camel is an indispensable helper of a person in the desert. He can be without food and water for a long time, storing them in his humps.

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

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

polar deserts

Polar deserts are located in the polar regions of the Earth. An absolute minimum temperature of 89.2°C has been recorded in Antarctica.

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

The indigenous inhabitants of the polar deserts of Antarctica are emperor penguins. They cannot fly, but they are excellent swimmers. They can dive to great depths and swim great distances, escaping from their enemies - seals.

The northern polar region of the Earth - the Arctic - got its name from the ancient Greek arcticos - northern. The southern, as it were, 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 throughout the year. The owner of these places is considered to be a polar bear.

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, which are characterized by harsh climatic conditions (little solar heat, low temperatures, short cold summers, low rainfall).

Moss lichen was called "reindeer moss" because it is the main food for reindeer. Arctic foxes also live in the tundra, lemmings are small rodents. 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. It is worth starting to dig a hole, as at a depth of about 1 m there will be a frozen layer of earth several tens of meters thick. This phenomenon must be taken into account in the construction, industrial and agricultural development of the territory.

In the tundra, everything grows very slowly. It is with this that the need for careful attention to its nature is connected. For example, pastures damaged by deer are restored only after 15-20 years.

Altitudinal zonality

Unlike flat territories, climatic zones and natural zones in the mountains change according to the law of vertical zonality, i.e., from bottom to top. This is because 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: a 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 ones at an altitude of 2000 m. fir and juniper. In winter, there is snow 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 flowering herbs - poppies, primroses, gentians. Gradually the grasses become lower. Approximately from a height of 4500 m, eternal snow and ice lie. The climatic conditions here are very harsh. Rare species of animals live in the mountains: mountain goat, chamois, argali, snow leopard.

Latitudinal zonality in the ocean

The world ocean occupies more than 2/3 of the planet's surface. The physical properties and chemical composition of ocean waters are relatively constant and create an environment conducive to 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 the upper layer of 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, smallest animals), various fish and marine mammals (dolphins, whales, seals, etc.), squids, sea snakes and turtles.

There is life on the sea floor too. These are bottom algae, corals, crustaceans, molluscs. They are called benthos (from the Greek benthos - deep). The biomass of the World Ocean is 1000 times smaller than the biomass of the land of the Earth.

The distribution of life in oceans uneven and depends on the amount of solar energy received on its surface. Polar waters are poor in plankton due to low temperatures and long polar nights. The greatest 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 oceans. In the tropical zone, the amount of plankton again decreases due to the high salinity of the water and high temperatures.

Formation of natural areas

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

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

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

Natural zones include such complexes that have similar soils, vegetation, wildlife and the similarity of the temperature regime. Natural zones got their names according to the type of vegetation, and they bear such names as the zone of taiga or broad-leaved 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 geographic envelope.

After all, if we consider one of the climatic zones, we can see that those parts of the belt that are closer to the ocean are more humid 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 observe a more humid climate, and on the other - arid.

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

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

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

Patterns of placement of natural zones

The natural zones of the Earth have clear patterns of their location, extending in a 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 deep into the mainland.

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

In the oceans, the change of zones occurs from the equator to the poles. Here, changes in natural zones are reflected in the surface composition of waters, as well as the difference in vegetation and wildlife.

Features of the natural zones of the continents

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

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

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

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

Questions and tasks for preparing for the exam

1. Make a diagram of the interaction of natural components in the natural complex and explain it.
2. How do the concepts of "natural complex", "geographical envelope", "biosphere", "natural zone" relate to each other? Show with a diagram.
3. Name the zonal soil type for the tundra, taiga, zones of mixed and broad-leaved forests.
4. Where is the soil cover more difficult to restore: in the steppes of the South of 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 oceans?
8. Which of the following animals can be found in the African savannah: rhinoceros, lion, giraffe, tiger, tapir, baboon, llama, hedgehog, zebra, hyena?
9. In what forests is it impossible to find out its age from a cut of a cut tree?
10. What measures, in your opinion, will help preserve the human habitat?

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

Physiographic zones - natural land zones, large subdivisions of the geographic (landscape) shell of the Earth, regularly and in a certain order replacing each other depending on climatic factors, mainly on the ratio of heat and moisture. In this regard, the change of zones and belts occurs from the equator to the poles and from the oceans to the interior of the continents. They are usually elongated in the sublatitudinal direction and do not have sharply defined boundaries. Each zone has typical features of its constituent natural components and processes (climatic, hydrological, geochemical, geomorphological, soil nature, vegetation cover and wildlife), its own type of interrelations that have historically developed between them and the dominant type of their combinations - zonal natural territorial complexes. Many physical-geographical zones are traditionally named according to the most striking indicator - the type of vegetation, which reflects the most important features of most natural components and processes (forest zones, steppe zones, savannah zones, etc.). The name of these zones is often assigned to individual components: tundra vegetation, tundra-gley soils, semi-desert and desert vegetation, desert soils, etc. Within the zones, which usually occupy vast strips, narrower divisions are distinguished - physiographic subzones. For example, the savannah zone as a whole is distinguished by the seasonal rhythm of the development of all natural components, due to the seasonal influx of precipitation. Depending on the number of the latter and the duration of the rainy period, subzones of moist tall grass, typical dry and desert savannas are distinguished within the zone; in the steppe zone - dry and typical steppes; in the zone of temperate forests - taiga subzones (often considered an independent zone), mixed and broad-leaved forests, etc.

Natural zones, if they are formed in more or less similar geological and geomorphological (azonal) conditions, are repeated in general terms on different continents with a similar geographical position (latitude, position in relation to the oceans, etc.). Therefore, there are types of zones that are typological units of the territorial classification of the geographical shell (for example, tropical western oceanic deserts). At the same time, the local features of a particular territory (relief, composition of rocks, paleogeographic development, etc.) give individual features to each zone, in connection with which specific natural zones are considered as regional units (for example, the Atacama Desert, the Himalaya highland, the desert Namib, West Siberian Plain). In the physical and geographical atlas of the world for 1964, the allocation of 13 geographical zones was adopted, based on the climatic classification of B.P. Alisov: the equatorial belt and two (for both hemispheres) subequatorial, tropical, subtropical, temperate, subpolar and polar (supporters of the thermal factor, as the main one in the formation of zoning, are limited to the allocation of only five or even three belts). Inside the belts, it is possible to distinguish sub-belts, or stripes.

Each belt and each of its major longitude segments - the sector (oceanic, continental and transitional between them) has its own zonal systems - its own set, a certain sequence and stretch of horizontal zones and subzones on the plains, its own set (spectrum) of altitudinal zones in the mountains. Thus, the forest-tundra zone is inherent only in the subpolar (subarctic) belt, the taiga subzone is in the temperate zone, the "Mediterranean" subzone is in the western oceanic sector of the subtropical belt, the monsoon mixed forest subzone is in its eastern oceanic sector, forest-steppe zones exist only in transitional sectors. . The forest-tundra spectrum of altitudinal zones is typical only for the temperate zone, and the hylainoparamos spectrum is characteristic only for the equatorial zone. Depending on the position in a particular sector or on a particular morphostructural basis within zones and subzones, smaller taxonomic units can be distinguished - typological: western oceanic dark coniferous taiga, continental light coniferous taiga, etc., or regional: Western - Siberian taiga, Central Yakut taiga, West Siberian forest-steppe, etc.

Since natural zones are determined mainly by the ratio of heat and moisture, this ratio can be expressed quantitatively (for the first time, the physical and quantitative basis of zoning was formulated in 1956 by A. A. Grigoriev and M. I. Budyko). For this purpose, various hydrothermal indicators are used (most often moisture indicators). The use of these indicators helps, first of all, the development of theoretical issues of zoning, the identification of general patterns, and the objective refinement of the characteristics of zones and their boundaries. For example, with values ​​of the Budyko radiation index of dryness less than 1 (excessive moisture), humid zones of forests, forest-tundra and tundra dominate, with values ​​​​more than 1 (insufficient moisture) - dry zones of steppes, semi-deserts and deserts, with values ​​close to 1 (optimal moisture ), - zones and subzones of forest-steppes, deciduous and light forests and humid savannahs. The definition and further refinement of quantitative indicators are also of great practical importance, for example, for the application of various agricultural activities in various sectors, zones, subzones. At the same time, it is very important to take into account not just the similarity of the final indicators, but also from which values ​​in these conditions they are made up. So, establishing the "periodic law of zoning", A. A. Grigoriev noted the periodic repetition of the same values ​​of the radiation index of dryness in zones of different belts (for example, in the tundra, subtropical hemihylae and equatorial forest swamps). However, while the index is common, both the annual radiation balance and the annual amount of precipitation in these zones are sharply different, just as all natural processes and complexes as a whole are different.

Along with zonal factors, the formation and structure of zonal systems are also strongly influenced by a number of azonal factors (in addition to the primary distribution of land and oceans, which largely determines circulation, currents, and moisture transfer). First of all, there is a polar asymmetry of the landscape envelope of the Earth, which is expressed not only in the greater oceanicity of the Southern Hemisphere, but also in the presence, for example, of the subtropical hemigil subzone peculiar only to it and, on the contrary, in the absence of many zones and subzones of the Northern Hemisphere (tundra, forest tundra, taiga, deciduous forests, etc.). In addition, the configuration and size of the land area in any latitudes play a significant role (for example, the wide distribution of tropical deserts in North Africa and Arabia or Australia and their limited territory in the tropical belts of North America or South Africa occupying a smaller area). The nature of the large features of the relief also greatly influences. The high meridional ridges of the Cordillera and the Andes enhance continentality and determine the presence of corresponding semi-desert and desert zones on the inner plateaus of the subtropical and tropical belts. The Himalayas contribute to the immediate proximity of the high-mountainous deserts of Tibet and the humid-forest zonal spectrum of the southern slopes, and the Patagonian Andes are even the primary reason for the presence of a semi-desert zone in the east of the temperate zone. But usually the influence of regional factors only strengthens or weakens the general zonal patterns.

Of course, the zonal systems have undergone significant changes in the process of paleogeographic development. Belt and sector differences have already been established for the end of the Paleozoic. Later, there were changes in the distribution of land and sea, macroforms of relief, climatic conditions, in connection with which, in the forming zonal systems, some zones disappeared and were replaced by others, the strike of zones varied. Modern zones are of different ages; due to the huge role that the Pleistocene glaciation played in their formation, the zones of high latitudes are the youngest. In addition, the increased temperature contrast between the poles and the equator in the Pleistocene increased the number of physiographic zones and significantly complicated their system. The impact of man also had a great influence, in particular on the boundaries of the zones.

The map in the appendix clearly shows the distribution of zones by belts and sectors and the differences in the manifestation of zoning in the high and middle latitudes of the Northern and Southern hemispheres. In the belts of high latitudes (polar, subpolar and the northern part of the northern temperate zone - the boreal subbelt, which is absent on land in the Southern Hemisphere), there are relatively small changes in the ratio of heat and moisture and almost universally excessive moisture. Natural differentiation is associated mainly with changes in thermal conditions, that is, with an increase in the radiation balance with decreasing latitude. Consequently, the zones of polar deserts, tundra, forest-tundra and taiga extend sublatitudinally, and sectoral differences are weakly expressed (ice deserts in the Atlantic sector of the Arctic are mainly due to regional features). At the same time, the polar asymmetry of the zonal spectra, caused by contrasts in the distribution of land and oceans in different hemispheres, is most pronounced. In the subboreal subbelts, with an even more increasing heat input, the role of moisture also increases. Its increase is determined by the predominance of westerly winds, and in the east by extratropical monsoons. Moisture indices vary significantly both in latitude and longitude, which is the reason for the diversity of zones and subzones and differences in their strike. The oceanic sectors are occupied by humid forests, the transitional sectors are occupied by forests, forest-steppes and steppes, and the continental sectors are predominantly semi-deserts and deserts. The most striking manifestation of these zonal features is observed in subtropical belts, within which there are still large latitudinal differences in radiation conditions, and moisture comes from both the west (only in winter) and from the east (mainly in summer). In the belts of low latitudes (tropical, subequatorial and equatorial), the asymmetry of the hemispheres is smoothed out, the radiation balance reaches its maximum, and its differences in latitude are weakly expressed. The leading role in changes in the ratio of heat and moisture passes to the latter. In tropical (trade wind) belts, moisture comes only from the east. This explains the presence of relatively humid zones (tropical forests, savannahs and light forests), extending submeridionally in the eastern sectors, semi-deserts and deserts that fill the continental and western sectors. Subequatorial belts receive moisture mainly from the equatorial monsoons, that is, its amount decreases rapidly from the equator to the tropics.

My small homeland is the Republic of Mari El. This is the land of lakes and pine forests. It is located at the junction of forest and forest-steppe natural zones. But, besides it, there are many other natural areas. Each corner of the earth is unique in its own way with its climate, relief, flora and fauna. And each continent has its own natural zones. I will talk about this in more detail. :)

What are natural areas

These are natural complexes with similar soils, flora and fauna, temperature regimes. The names of natural areas are determined by the type of vegetation, for example, subtropical forest. Usually, natural zones stretch in wide strips from west to east. They do not have clear boundaries and they smoothly pass one into another. The main natural areas are:

• arctic desert;
• taiga;
• tundra;
• mixed forest;
• steppe;
• deserts;
• subtropical forest;
• savannas and woodlands;
• tropical seasonally moist forest;
• tropical rainforest.

founder Russian geologist and soil scientist V. V. Dokuchaev is considered to be a natural zonality as a science. He defined zonality as a law of nature, equally manifested on land and on the sea, in the mountains and on the plains.

The reason for the formation of natural zones

The reason for the wide variety of zones is the energy of the Sun, which heats the earth unevenly. So, within one natural zone, it is clear that that part of it, which is closer to the ocean, is more humidified than its continental part. The reason lies in the ratio of solar heat and moisture. Thus, some continents have a humid climate, while others have an arid one. In the subtropics, excessive moisture leads to the formation of swamps, and a lack of moisture in the hot tropical zone causes the formation of deserts.

Features of the natural zones of the continents

We found out that the Earth, having the shape of a ball, is heated by the sun unequally. Those areas where the Sun stands high warm up more and more, and where the rays glide over the surface, it is cooler and even colder. And although the plants and animals of different continents are similar, the climate and topography leave their mark. There are continents with animal species inherent only to them ( endemic). In Australia, these are platypus, kangaroo, koala, wombats. And in the Arctic - a polar bear.

Polar poppy Moss pad Saxifraga Lichens Arctic desert plants. Moss pads growing among stones and rocks covered with a bizarre pattern and lichens, polar poppies and saxifrages look like real oases among the polar snows and glaciers.

Numerous bird markets are located on the Arctic coast, where guillemots, guillemots, and gulls nest. In addition to them, lemmings, arctic foxes and musk oxen are found in the polar deserts, but the polar bear is the true ruler of these places. It preys on seals that make their way to the shore or coastal ice. 1 - guillemot 2 - guillemot 3 - musk ox 4 - polar bear 5 - seal

Taiga plants. 1 - spruce 2 - fir 3 - larch 4 - juniper 5 - bilberry 6 - oxalis Due to the fact that little light penetrates under the canopy of coniferous trees, undergrowth is practically not developed in taiga forests. The most important tree species that form the taiga are pine, spruce, fir and larch, and among the shrubs juniper, honeysuckle, currant. Beneath them grow blueberries, lingonberries, and very few herbs such as oxalis and wintergreen.

Common pine. One of the most common conifers in the temperate zone of Eurasia is the pine. Its slender, soaring trunk is crowned with a spreading crown, which is formed by long and soft needles. The indescribable aroma and clean air of the pine forest have healing properties. Pine wood has been preserved for centuries. No wonder the famous wooden churches of Kizhi were built from it.

Larch. Among other coniferous trees, larch stands out in that it sheds its soft needles for the winter, resembling young leaves to the touch. Larch is the most numerous coniferous tree in the northern hemisphere. It occupies vast areas in Siberia and North America.

Tundra animals. 1 - elk 2 - musk deer 3 - brown bear 4 - lynx 5 - sable 6 - chipmunk 7 - capercaillie 8 - crossbill The fauna of the taiga is rich and diverse. Elk, deer, musk deer, brown bear, wolf, lynx, sable, chipmunk, squirrel are found here. Among the taiga birds, capercaillie, nutcracker, crossbill are common.

This large bird feeds in trees but nests on the ground. In spring, capercaillie males gather in special places - currents. Here they arrange competitions in singing, attracting females. During the mating, the capercaillie loses its hearing for a while, for which it got its name. In summer, capercaillie eat green parts of plants, in autumn - berries, and in winter - pine needles.

Brown bear. The largest brown bears live in the Far East and Alaska. Their growth can reach 2.5 meters. Bears are active from early spring to late autumn, and for the winter they lie in a den, fall into a shallow sleep. Unlike other predators, the brown bear is omnivorous. They are excellent swimmers and fish in river banks.

Squirrel. It spends most of its time in trees, although it often forages on the ground. They feed on berries, mushrooms, nuts and acorns, as well as seeds of conifers and buds, but do not pass by insects or bird eggs. Squirrels store part of their food for the winter. Making hiding places both in its nest and outside it.

Plants of the steppes 2 - fescue 3 - bluegrass 4 - sheep 5 - wormwood 6 - onion 7 - tulip Grasses predominate among the steppe plants - feather grass, fescue, bluegrass, oats, forming a dense grass cover. Other plants include wormwood, as well as onions and tulips. An unforgettable impression is made by the steppe blooming in spring, similar to a bright Persian carpet.

Most of the ungulates found in the steppes have sharp eyesight and are capable of fast and long running. These are, first of all, various antelopes - saigas and turfs. Rodents living in the steppes - ground squirrels and marmots - build complex burrows, sometimes resembling miniature cities. Typical birds of the steppes are the bustard and the steppe eagle. Steppe lark. There are also predatory animals in the steppes, such as the steppe fox - corsac and the steppe cat - manul. Animals of the steppe 1 - saiga 2 - ground squirrel 3 - marmot 4 - bustard 5 - steppe eagle 6 - steppe lark 7 - corsac 8 - manul

Dry hot summer months, spring and autumn are short, and winters are cold. t air = C (day), t air = -20°C (night), t sand = C. It rains in spring and autumn. Constant dry winds blow.

Savanna dry, hot winters, humid summers Savannahs are located between the tropical forests and deserts of Africa. They are huge grassy plains, occupied mainly by cereal vegetation, among which there are solitary trees.

Baobab. The tree, which is considered the "eighth wonder of the world." Being not very tall, baobabs amaze with the thickness of their trunk, the diameter of which can reach 9 meters. Their powerful roots go deep into the soil and cover a large area, providing the plant with the necessary moisture in the dry period.

Bottle tree In the savannahs of Central Australia, a close relative of cocoa grows - the bottle tree. It got its name due to the fact that its 15 - meter barrel is surprisingly similar to a bottle. In its lower part, cavities are formed in which water accumulates. In the dry season or during a drought, the plant uses these reserves without fear of drying up.

Savannah animals 1 - wildebeest 2 - zebra 3 - giraffe 4 - buffalo 5 - elephant 6 - lion 7 - cheetah 8 - spotted hyena In the African savannas there are a large number of large herbivores - antelopes, zebras, giraffes, buffaloes, elephants. They are hunted by various predators - lions, cheetahs, spotted hyenas.

Giraffe This is the tallest animal, whose growth reaches 6 meters. Spotted coloring well masks animals in thickets of bushes and among trees. Giraffes keep in small groups, sometimes forming common herds with antelopes and ostriches. They feed on shoots of umbrella-shaped acacias and other trees and shrubs.

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Ceiba. Ceiba grows in Central America. The height of the ceiba reaches 45 meters, and the diameter of the trunk is 4 meters. At the base of the ceiba trunk, numerous disc-shaped roots are formed - props, sometimes stretching along the soil surface for several meters. Ceiba fruits are lined on the inside with many silky hairs that are used instead of cotton wool.

Animals VEL 1 - bakers 2 - tapir 3 - howler monkey 4 - jaguar 5 - anaconda 6 - hummingbird 7 - heliconid butterfly 8 - morpho butterfly A huge number of various animals live in the equatorial forests. Under the canopy of the forest, various ungulates find food: wild pigs, rapiers, deer, capybaras, which are hunted by wild cats: leopard and jaguar, as well as snakes - anaconda and python. In the crowns of trees, many birds and monkeys echo. And bright butterflies fly between the trunks.

Natural zones of the Earth or natural-residential zones are large areas of land with the same characteristics: topography, soil, climate, and a special flora and fauna. The formation of a natural zone depends on the ratio of the level of heat and moisture, that is, the climate changes - the natural zone also changes.

Types of natural areas of the world

Geographers distinguish the following natural areas:

• arctic desert
• Tundra
• Taiga
• mixed forest
• broadleaf forest
• Steppe
• desert
• Subtropics
• Tropics

Rice. 1. Mixed forest

In addition to the main zones, there are also transitional ones:

• forest tundra
• forest-steppe
• Semi-desert.

They have features of two neighboring main zones. This is the complete official list of zones.

Some experts also distinguish such natural areas as:

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• Savannas;
• Monsoon forests;
• equatorial forests;
• Highlands or zones of altitudinal zonation.

Zones of high zonation have their own internal division.

Here are areas such as:

• broad-leaved forest;
• Mixed forest;
• Taiga;
• Subalpine belt;
• Alpine belt;
• Tundra;
• Snow and glacier zone.

Location of zones- strictly vertically, from the foot to the top: the higher, the more severe the climatic conditions, the lower the temperature, the lower the humidity, the higher the pressure.

The names of natural areas are not accidental. They reflect their main characteristics. For example, the term "tundra" means "plain without forest". Indeed, only single dwarf trees can be found in the tundra, for example, polar willow or dwarf birch.

Zone placement

What are the patterns of placement of natural and climatic zones? It's simple - there is a strict movement of the belts along the latitudes from the North (North Pole) to the South (South Pole). Their placement corresponds to the uneven redistribution of solar energy on the Earth's surface.

You can observe the change of natural zones from the coast deep into the mainland, that is, the relief and distance from the ocean also affect the location of natural zones and their width.

There is also a correspondence of natural zones to climatic zones. So, within what climatic zones are the above natural zones located:

• equatorial belt- moist equatorial forests with areas of humid evergreen forest and rainforest where short dry periods are observed;
• subequatorial belt- monsoon forests and savannas with areas of oceanic rain forests and monsoon deciduous forests;
• tropical belt- savannas, tropical forests, tropical deserts and semi-deserts;

Rice. 2. Savannas

• subtropical belt- zone of evergreen forest, steppe and desert;
• Temperate zone- deserts, semi-deserts, a zone of steppes, a zone of mixed, deciduous and coniferous forests;
• subtropical belt- forest-tundra and tundra;
• arctic belt- tundra and arctic desert.

Based on this ratio, in the same natural area, differences in climate, soil type and landscape can be observed.

Geographical position

Knowing where this or that natural zone is located, one can also indicate its geographical position. For example, the zone of the Arctic desert occupies the territories of Antarctica, Greenland and the entire northern tip of Eurasia. The tundra occupies large areas of countries such as Russia, Canada, Alaska. The desert zone is located on such continents as South America, Africa, Australia and Eurasia.

Characteristics of the main natural zones of the planet

All natural areas differ in:

• relief and composition of the soil;
• climate;
• animal and plant world.

Neighboring zones may have similar characteristics, especially where there is a gradual transition from one to the other. Thus, the answer to the question of how to define a natural area is very simple: note the climate features, as well as the features of flora and fauna.

The largest natural zones: the forest zone and the taiga (trees grow everywhere except Antarctica). These two zones have both similar characteristics and differences that are inherent only in the taiga, mixed forest, broadleaf forest, monsoon and equatorial forests.

Typical characteristic for the forest zone:

• warm and hot summer;
• a large amount of precipitation (up to 1000 mm per year);
• the presence of full-flowing rivers, lakes and swamps;
• the predominance of woody vegetation;
• diversity of the animal world.

The largest in area are equatorial forests; they occupy 6% of all land. The greatest diversity of flora and fauna is characteristic of these forests. 4/5 of all plant species grow here and 1/2 of all land animal species live, and many species are unique.

Rice. 3. Equatorial forests

The role of natural areas

Each natural zone plays its own special role in the life of the planet. If we consider natural areas in order, we can give the following examples:

• arctic desert, despite the fact that it is almost completely an icy desert, it is a kind of “pantry” where multi-ton fresh water reserves are stored, and also, being the polar region of the planet, it plays a key role in shaping the climate;
• climate tundra keeps the soils of the natural zone in a frozen state for most of the year and this plays an important role in the carbon cycle of the planet;
• taiga, as well as equatorial forests are a kind of "lungs" of the Earth; they produce the oxygen necessary for the life of all living things and absorb carbon dioxide.

What is the main role of all natural zones? They store a large amount of natural resources that are necessary for human life and activities.

The global geographic community has long come up with both color conventions for natural areas and emblems that define them. So the arctic deserts are indicated by blue waves, and just deserts and semi-deserts are indicated by red. The taiga zone has a symbol in the form of a coniferous tree, and the zone of mixed forests in the form of coniferous and deciduous trees.

What have we learned?

We learned what a natural area is, defined this term and identified the main features of the concept. We learned what the main zones of the Earth are called, and what are the intermediate zones. We also found out the reasons for such a zonality of the geographic envelope of the Earth. All this information will help prepare for a geography lesson in grade 5: write a report on the topic “Natural zones of the Earth”, prepare a message.

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