The geographical position of the deserts. The zone of deserts and semi-deserts of Russia: where is it located, map, climate, flora and fauna. Deserts and semi-deserts of Russia

Issues to consider:

1. Desert characteristic

2. desert vegetation

3. Animal world of deserts

4. Desertification

5. Semi-desert

6. Protection of deserts and semi-deserts

7. Occupations of the population of deserts and semi-deserts

1. Characteristics of the desert.

Desert - a geographical zone with a hot, arid climate and sparse sparse vegetation in the temperate subtropical and tropical zones of the Earth.

Desert area is estimated at 31.4 million km 2 (about 22% of land).

Deserts are found on all continents except Europe, and are located within the borders of about 60 countries. In the mountains, the desert forms a high-altitude belt (alpine desert), on the plains - a natural zone.Distributed in the temperate zone of the Northern Hemisphere, subtropical and tropical zones of the Northern and Southern Hemispheres.

Large deserts of the world:

Gobi - Central Asia, Mongolia and northern China

Takla-Makan borders the Pamirs and Tibet from the north. Central Asia

Sahara - North Africa

Libyan desert - north of the Sahara

Namib - Southwest coast of Africa

Kyzylkum - between the Syrdarya and Amudarya rivers, Uzbekistan, Kazakhstan

Karakum - Turkmenistan

Atacama - Northern Chile, South America

Northern Mexico

Great Victoria Desert

Great sandy desert

Climatic conditions:

One of the main features of the desert is the lack of moisture, which is explained by the negligible (50- 200 mm per year) the amount of precipitation that evaporates faster than seeps into the soil. Sometimes there is no rain for several years. Most of the territory is drainless, and only in some places there are transit rivers or lakes that periodically dry up and change their shape (Lob Nor, Chad, Air). Some deserts formed within the ancient river, delta and lake plains, others on platform land areas. Often deserts are surrounded by mountains or border on them.

Over the course of a long geological history, deserts have changed their boundaries. For example, the Sahara the greatest desert world - stretched for 400- 500 km south of the present position.

Precipitation 50-200 mm per year

Clear days 200-300 per year

Air temperature +45° in the shade. Surface temperature during the day + 50-60 ° (up to 80 ° and even 94 ° - Death Valley), at night + 2-5 ° (sudden changes)

Dry winds, storms. Winter in Russia frost with thin snow cover.

Contrary to the prevailing opinion that the desert is an endless monotonous sea of sand, the most common are rocky deserts, or hamads, often located on plateaus or mountain ranges with outliers of bizarre shapes. Pebble and gravelly deserts stand out among them, impressive with almost complete lifelessness. Parts of such deserts can be seen in the Sahara, the Kyzyl Kum, and on the Arabian Peninsula. In conditions of a huge daily temperature range, with periodic wetting and drying rocks a characteristic shiny dark crust forms on their surface, the so-called desert tan, which protects the rock from rapid weathering and destruction. Often, rocky deserts turn into sandy ones. IN Central Asia they are called kums, in Africa - ergs, in Arabia - nefuds. Sands are easily carried by the wind, forming eolian landforms: dunes, dunes, safes, etc. Single dunes and dunes not fixed by vegetation can move tens of meters per year. Sometimes sand blown by the wind makes a special sound. In such cases, they speak of singing dunes or dunes (in Dagestan, the singing dune is declared a natural monument). But the bulk of the sands are immobile, as they are held by the long roots of shrubs and grasses, which have adapted to the conditions of constant moisture deficiency. The largest sandy deserts of the world include: the Libyan Desert, Rub al-Khali, Nefud, the Great Sandy Desert, the Great Victoria Desert, the Karakum, the Kyzylkum.

Clay deserts develop on clay deposits various origins. The largest clay deserts: Ustyurt, Deshte-Lut , Deshte-Kevir Betpak-Dala and others. Their relief is characterized by takyrs and sors.

Saline deserts form on saline (saline) soils and are scattered in separate spots among other types of deserts.

TAKYR - flat clay surfaces, almost devoid of vegetation, in the deserts of sub tropical zone, area from several m2 up to tens of kilometers 2 . In the spring they are usually flooded with water.

SOLONCHAS - soil types of steppe, semi-desert and desert zones. They contain water-soluble salts, 0.5-10% humus. In the Russian Federation - in the Caspian region.

SORs (blinders), closed depressions in deserts Cf. Asia, covered with a crust of salts or a plump layer of salt dust. They are formed in sands due to evaporation and salinization of near-surface groundwater or on strata of salt-bearing bedrock under conditions of an effusion water regime with the formation of solonchaks.

SAHEL (Arabic - coast, outskirts) - the name of the transitional strip (width up to 400 km ) from the deserts of the Sahara to the savannas of West Africa. Semi-deserts and deserted savannas predominate. Precipitation 200- 600 mm in year; frequent droughts.

Desert types

According to their position, they distinguish between continental deserts (Gobi, Takla-Makan), located inside the continent, and coastal deserts (Atakama, Namib), stretching along the western coasts of the continents.

Deserts are sandy (Sahara, Karakum, Kyzylkum, Great Victoria Desert), clayey (South Kazakhstan, south of Central Asia), rocky (Egtpet, Israel) and saline (Caspian lowland).

2. Desert vegetation.

Desert vegetation does not form a dense cover and usually occupies less than 50% of the surface, being distinguished by a great originality of life forms and great sparseness.

Plant types:

1. Succulents - agave, aloe, cacti

2. The root system reaches groundwater

(roots 20-30 m ) - camel-thorn

3. Heat-resistant, able to tolerate dehydration - wormwood

4. Ephemeroids - develop over a short period, then rhizomes or bulbs remain in the soil. - tulip, sedge, bluegrass

Xerophytes (from the Greek xeros - dry and phyton - plant), plants adapted to life in arid habitats. Several types: succulents - heat-resistant, but do not tolerate dehydration (agave, aloe, cacti); hemixerophytes - do not tolerate prolonged dehydration, the root system reaches groundwater (sage, camel thorn); euxerophytes - heat-resistant, able to tolerate dehydration (wormwood, gray veronica, some mulleins); poikiloxerophytes - when dehydrated, they fall into suspended animation (some mosses).

EPHEMERAS, annuals herbaceous plants, all development of which usually occurs in a very short time (several weeks), more often in early spring. Characteristic for steppes, semi-deserts and deserts (for example, dimorphic quinoa).

EPHEMEROIDS, perennial herbaceous plants, the above-ground organs of which develop from autumn to spring and die off in summer, while the underground ones (bulbs, tubers) persist for several years. Characteristic for steppes, semi-deserts and deserts (species of tulip, sedge, bluegrass)

Plant adaptations:

root system deep into the soil;

modified leaves or spines, scales;

pubescence of leaves - contributes to less evaporation;

dropping leaves with the onset of heat;

flowering only in spring.

Sandy deserts of Asia (Karakum, Kyzylkum, mouth of the Volga river)

Herbs, trees, leafless shrubs and semi-shrubs:

white saxaul (5 m),

sand acacia,

silver chingil - shrub,

juzgun,

ephedra,

camel thorn (a genus of shrubs and perennial herbs of the legume family, eaten by camels, root length 20- 30 m.),

grate - cereal,

swollen sedge,

celine (aristida) - cereal

Clay deserts of Asia (Southern Kazakhstan, lower reaches of the Ural River, south of Central Asia)

wormwood,

saltwort,

black saxaul ( 12 m ), wood goes to fuel; green twigs are food for camels and sheep. Good sand binder

bulbous bluegrass,

desert beetroot,

spurges.

Asia. Saline deserts (Caspian lowland)

soleros

Sarsazan gnarled

Africa

Celine (Aristide)

Date palm trees in oases

America

Succulents (agave, aloe, cacti - cereus, prickly pear), yucca

3. Animal world of deserts

Attachments:

protective coloring of sand color,

fast run,

go long without water

fall into hibernation

nightlife,

holes in the sand

bird nests on the ground (on bushes and trees).

Insects and arachnids: scarab, lingering, scorpion, desert locust

Reptiles:foot-and-mouth disease, steppe agama, monitor lizard, round-headed, frilled lizard, land iguana, sand boa, arrow-snake, gyurza, efa, steppe viper, Central Asian tortoise, panther tortoise (Africa).

Birds:Sadzha (grouse), saxaul jay, desert warbler, field pipit, desert coinage, avdotka.

Rodents:jerboas, thin-toed ground squirrel, gerbils, giant mole rat.

Eared hedgehog.

Ungulates:goitered gazelle, antelopes, including gazelles, saiga, wild ass.

Carnivores:wolf, fennec fox, striped hyena, house (reed cat), dune cat, jackal, coyote, manul, caracal, South Russian dressing, honey badger, Cape South African fox.

4. Desertification

The encroachment of the desert on other parts of the earth is called desertification.

Causes:

Overgrazing.

Intensive perennial tillage.

Drought.

The Sahara, moving south, annually takes away 100 thousand hectares of arable land and pastures.

Atacama moving at speed 2.5 km per year.

Thar - 1 km per year.

5. Semi-deserts

semi-deserts - areas combining the nature of steppes and deserts, found in the temperate, subtropical and tropical zones of the Earth (except Antarctica) and forming a natural zone located between the steppe zone in the north and the desert zone in the south.

In the temperate zone of Asia:

from Caspian lowland to the eastern border of China.

In the subtropics:

Anatolian plateau, Armenian Highlands, Iranian highlands, Karoo , Flinders, foothills of the Andes, valleys of the Rocky Mountains, etc.

In the tropics of Africa:

south of the Sahara, in the Sahel zone (desert savannah)

Plants:

Russia:tulips, sedge, bluegrass, wormwood, mullein, saltwort.

America: cacti.

Africa and Australia: bushesand rare stunted trees (acacia, doum palm, baobab)

Animals:

hares

rodents (gophers, jerboas, gerbils, voles, hamsters), meerkats,

reptiles;

antelope,

bezoar goat,

mouflon,

kulan, Przewalski's horse

predators: jackal, striped hyena, caracal, serval, steppe cat, fennec fox, house

birds,

many insects and arachnids (karakurt, scorpions).

6. Protection of deserts and semi-deserts

Reserves and national parks

Desert:

Semi-desert:

Ustyurt Reserve,

tiger beam,

Aral-Paygambar.

Listed in the Red Book: Bandaging, mole rat, goitered gazelle, saiga, saja, caracal, serval

7. Occupations of the population of the desert and semi-desert

Desert:breeding of sheep, goats and camels, irrigated agriculture and gardening only in oases (cotton, wheat, barley, sugar cane, olive tree, date palm).

Semi-desert:pasture animal husbandry, oasis agriculture is developed on irrigated lands.

Camels live in deserts (one-humped dromedary in Africa, two-humped Bactrian in Asia).

The desert was and remains extreme natural environment for the life of people, although it was in the conditions of the desert that ancient civilizations originated and existed: Egypt, Mesopotamia, Khorezm, Assyria, etc. Life usually arose near a well, river or other water source. This is how oases appeared, the first "islands" of life created by human labor. Life in the oases and occupations of the population differed significantly from the conditions of the desert itself, where people are doomed to eternal wandering under the scorching sun and dust storms in search of water. Breeding sheep and camels has become a traditional occupation of nomads. Irrigated agriculture and horticulture developed only in oases, where such plants as cotton, wheat, barley, sugar cane, olive tree, date palm, etc. have long been cultivated. The rapid influx of population into large oases led to the formation of the first cities.

FAMOUS DESERT IN THE WORLD

GOBI (from Mong. beef - a waterless place), a strip of deserts and semi-deserts in Central Asia, in the south and southeast of Mongolia and in adjacent regions of China. Bounded in the north by mountainsMongolian Altai and Khangai, in the south - Nanshan and Altyntag. Subdivided intoTransaltai Gobi , Mongolian Gobi , Alashan Gobi , Gashunskaya Gobiand the Dzungarian Gobi. Area over 1000 thousand km2 .

Plains prevail at an altitude of 900- 1200 m , composed mainly of rockschalk, Paleogene And Neogene. They alternate with more ancient hillocks, ridges and island ranges (up to 1800 m ). The sloping piedmont plains are dissected by numerous dry channels flowing into closed depressions, which are occupied by drying lakes, solonchaks or hard clay surfaces; there are also small massifs of shifting sands.

The climate is sharply continental in the temperate zone (temperature fluctuations from -40 ° C in January to + 45°C in July). Precipitation per year falls from 68 mm in the northwest of the Alashan Gobi to 200 mm in the northeast of Mongolia; there is a summer maximum. There are almost no rivers with a constant flow, most of the channels are flooded only in summer. The soils are gray-brown and brown, often in combination with sandy desert soils, solonchaks and takyrs. Characteristic are carbonate, gypsum-bearing, and coarse gravelly soil varieties.

Desert vegetation is sparse and sparse. On the plateau and piedmont plains there is small-shrub gypsophilous vegetation (blackberry, double-leaved, teresken, reaumuria, several types of nitrate and saltwort). On the salt marshes, in addition to nitrates and saltworts, there are tamarisks, potash. On the sands - sandy wormwood, zaisan saxaul, kopek, perennial and annual grasses. In the northeast and east of Mongolia, semi-deserts are common, where, along with wormwood and saltwort, cereal groups are developed, and rare clumps of shrub caragana are found. Preserved wild camel, donkey-kulan, Przewalski's horse, several species of antelope, many rodents and reptiles. Many endemic species of flora and fauna. Big Gobi Nature Reserve (within Mongolia).

Animal husbandry (small cattle, camels, horses, to a lesser extent - cattle). Quite plentiful groundwater is of great importance for water supply. Agriculture is developed only along the river valleys.

KYZILKUM, desert in Wed. Asia, in the interfluve of the Amu Darya and Syr Darya, in Uzbekistan, Kazakhstan and partly in Turkmenistan. OK. 300 thousand km2 . Plain (height up to 300 m ) with a number of closed depressions and isolated mountain ranges (Sultanuizdag, Bukantau, etc.). Most of it is occupied by ridge sands; there are many takyrs in the northwest; there are oases. Used as pasture.

SAHARA, the desert in Africa, the largest in the world. St. 7 million km2 . On the territory of the Sahara are completely or partially the states of Morocco, Tunisia, Algeria, Libya, Egypt, Mauritania, Mali, Niger, Chad, Sudan. OK. 80% of the Sahara are plains 200- 500 m . In the north-east there are drainless depressions: Qattara (133 m), El-Fayoum, etc. In the central part - mountain ranges: Ahaggar, Tibesti (Mount Emi-Kusi, 3415 m , the highest point of the Sahara). Rocky and gravelly (hamady), pebble (reg) and sandy (including ergi) deserts predominate. The climate is tropical desert: rainfall in most parts of the territory is less 50 mm per year (on the outskirts of 100 - 200 mm ). Average January temperatures are not lower than 10 °С; absolute maximum 57.8 °C, absolute minimum -18 °C (Tibesti). Daily amplitudes of air temperature are more than 30 °C, soil - up to 70 °C. In addition to the transit river. Nile and parts of Niger, no permanent streams. Dry channels of ancient and modern watercourses (wadis or uedas) predominate. Groundwater feeds numerous oases. Vegetation cover is extremely sparse, sometimes absent. Agriculture (date palm, cereals, vegetables) in oases. Nomadic and semi-nomadic animal husbandry.

TAKLA-MAKAN, a desert in western China, one of the largest sandy deserts in the world. Length from west to east over 1000 km, width up to 400 km , the area of sands is over 300 thousand km2 .

It was formed under conditions of long-term accumulation of sediments within the Tarim Basin, which is composed mainly of alluvial deposits (of the Tarim River and its tributaries), partially blown over. The surface is flat, gradually decreasing to the north and east of 1200- 1300 m to 800- 900 m . In the west, single ridges rise above Takla Makan (the highest point is Mount Chongtag, 1664 m ) composed of sandstones.

Most of the territory is covered with sands up to 300 m . Dunes predominate in the southwest, and sandy ridges of complex configuration (including large ones, sometimes stretching for 10- 13 km , - the so-called whale backs), sand pyramids (height 150- 300 m ), etc. On the outskirts of Takla-Makan, large areas are occupied by solonchaks.

The climate is moderately warm, sharply continental, with negligible (less 50 mm per year) the amount of precipitation. The atmosphere is highly dusty. The rivers flowing from the Kunlun penetrate into the depths of the Takla-Makan for 100 200 km , gradually drying up in the sands. Only the Hotan River crosses the desert and in summer brings its waters to the Tarim River, which flows along the western and northern outskirts of the Taklamakan.

Depth of groundwater in relief depressions (within ancient deltas and old rivers) 3- 5 m , they are usually difficult to access for plants, so most of the territory is devoid of vegetation and only in places with a close occurrence of groundwater there are rare thickets of tamarisk, saltpeter, and reed. Along the outskirts of Takla-Makan and river valleys, poplar turanga, sucker, camel thorn, annual saltwort, saxaul are found. The animal world is poor (rare herds of antelopes, hares, gerbils, jerboas, voles); in the river valleys - wild boars.

Separate oases (mainly in the valleys of the Tarim and Yarkand rivers). There is no permanent population. Near the southern outskirts of Takla Makan, among the sands, are the ruins of ancient settlements confined to dry valleys.

ATACAMA (Atacama), a desert in northern Chile, in the South. America, along the coast of the Pacific Ocean, between 22-27 ° S. sh.; rainfall less 50 mm in year. River crosses. Loa. Large deposits copper ores(Chuquicamata, El Salvador), saltpeter (Taltal), table salt, storms.

ADDITIONAL MATERIAL

PRZHEWALSK'S HORSE (Equus caballus), not artiodactyl mammal kinds of horses. body length 2.3 m , height at withers about 1.3 m . This is quite a typical horse, densely built, with a heavy head, thick neck, strong legs and small ears. Its tail is shorter than that of a domestic horse, its mane is erect and short. The color is sandy-red or red-yellow. The mane and tail are black-brown, a black-brown belt runs in the middle of the back, the end of the muzzle is white. In summer the hair is short and tight, in winter it is longer and thicker.

This wild horse was discovered and described in Central Asia by N. M. Przhevalsky in 1878. Once it was widespread, but by the end of the 19th century it was preserved only in the south-west of Mongolia (in Dzungaria), where in 1967-1969 it was seen (in natural conditions) for the last time. Przewalski's horse herds consisted of 5-11 mares and foals led by a stallion. They were very mobile and constantly moved, which was determined both by poor winter pastures and uneven rainfall in their habitats. Constant migrations have led to the fact that these horses have become very hardy and strong. From fights with domestic stallions, they always came out victorious.

The main reason for the destruction of the population in natural conditions is fishing (hunting, poaching) and competition for watering places with livestock. Almost immediately after the discovery of the animals, the owner of the Askania-Nova park F. Falz-Fein and later the animal dealer K. Hagenbeck began to look for ways to get these rare animals. Various means were used in this struggle. Hagenbeck, having learned about Falz-Fein's suppliers in Biysk, bought 28 foals with the help of his agents. Despite the fact that by the beginning of the 20th century 52 thoroughbred Przewalski's horses were brought to Europe, only three pairs served as a source for breeding. The Przewalski's horse is kept in many zoos around the world; several dozen individuals live in semi-free keeping in the Askania-Nova reserve. An international plan has been developed for the reintroduction of the Przewalski's horse to its original habitats - to the mountain-steppe zone of Mongolia.

Jerboas (Jerboa, Dipodidae) - a family of mammals of the order of rodents; includes 11 genera and about 30 species, including three-toed pygmy jerboas, big jerboa, long-eared jerboa, furry-legged jerboa. jerboas are characterized by a large head with a blunt muzzle, long rounded ears, large round eyes and long vibrissae, a short, curvy body (body length 4- 26 cm ), small front legs, powerful jumping hind limbs. Large ears, eyes and long vibrissae indicate a high development of hearing, twilight vision and touch, which are necessary for jerboas when searching for food and protecting themselves from enemies at night. Small front legs serve to grasp and hold food, as well as to dig holes, in which jerboas achieve great skill. The hind limbs are jumping, and in connection with this function they are greatly modified: the foot is elongated and the three middle metatarsal bones grow together into one common bone, called the tarsus. The tail plays an important role in movement: it serves to maintain the balance of the body when jumping, especially when turning sharply at a fast gallop. A black and white tassel at the end of the tail in many species is called a banner and serves as a signaling tool for intraspecific communication. The incisors, in addition to gnawing food, serve to loosen the soil when digging holes, while the limbs are used mainly for raking loosened soil.

Jerboas are distributed from North and Northeast Africa, Southeast Europe, Asia Minor and Western Asia through the Caucasus, Central Asia, Kazakhstan, the extreme south of Siberia (Altai, Tuva, Transbaikalia) to Northeast China and Mongolia. They are mainly found in semi-desert and desert landscapes, only a few species inhabit the steppe zone, and some penetrate mountains to a height higher than 2 km above sea level. Different species have developed adaptations for living on loose or dense soils, and therefore jerboas can be found in sandy, clayey, and rubble semi-deserts and deserts.

Jerboas are typically nocturnal animals. Before dawn, they hide in burrows that they build themselves. The main burrow of the jerboa runs obliquely below the surface with one or more blind escape burrows coming close to the surface. The main passage for the day is clogged with an earthen plug, which is called a penny. On this penny, which has not yet dried out in the early morning, you can find a jerboa hole. If you start digging a habitable hole, then the animal knocks out the ceiling of one of the emergency passages and jumps out through it. In the far part of the main passage, the jerboa digs a hole with a rounded living chamber, which is lined with finely gnawed blades of grass. In winter, jerboas spend in deep hibernation in their burrows.

Jerboas feed on the seeds of various plants, lily bulbs, which they dig out of the ground. The diet also includes green parts and plant roots, and in some species a significant proportion of the diet is animal feed (small insects and their larvae). In spring and summer, reproduction of animals occurs, the female gives birth to 1-8 cubs (usually 2-5).

Jerboas play an important role in desert biocenoses. They have a significant impact on the soil and vegetation cover, serve as food for desert predators. In many areas, jerboas are background animals. Some species damage plants that strengthen the sands; they can be carriers of pathogens of a number of infectious diseases of animals and humans.

GINGERS (Gerbillinae), a subfamily of mammals of the order of rodents; includes about 100 species, united in 13 genera, including dwarf, small, large, short-eared, fat-tailed gerbils, taters (barefoot gerbils). Outwardly, gerbils resemble rats or mice. Their body length is up to 19 cm , reddish-yellow long tail with a tassel. The back is sandy yellow, the belly is white.

Gerbils are common in the desert steppes and deserts of Africa, Asia and Southeast Europe. They feed mainly on plant foods, but can also eat small invertebrates. They do not hibernate for the winter, but in cold weather they do not leave their holes for a long time, eating prepared supplies. Many breed all year round, with females bringing multiple litters of 2 to 12 cubs. Gerbils are carriers of plague pathogens, tick-borne typhus, they harm agricultural land. These animals are often kept at home.

Gazelle (Gazella subgutturosa), artiodactyl mammal of the genus of true gazelles (Gazella) of the subfamily of gazelles (Antilopinae); forms 2-4 weakly expressed subspecies. Body length 95- 125 cm , height at the withers 60- 75 cm, weight 18-33 kg . Males have black and lyre-shaped horns up to 40 cm . Females are usually hornless. The coloration of the upper body and sides is sandy. The underside of the body, the neck and the inside of the legs are white. The tail is two-colored: the main part is sandy, the end is black. When a frightened gazelle runs, it raises it to the top, and the tail stands out sharply against the background of a white mirror. For this feature, among the Kazakhs and Mongols, the gazelle was called the black tail (kara-kuiruk, hara-sulte). Young goitered gazelles have a pronounced facial pattern in the form of a dark brown spot on the bridge of the nose and two dark stripes stretching forward from the eyes.

Goitered gazelle is distributed in Western, Central and Central Asia, South Kazakhstan, and also in Eastern Transcaucasia. It lives on flat, hilly deserts and cereal-salt semi-deserts. As good runners, goitered gazelles prefer areas with dense soil, avoiding free-flowing sands. In summer, they graze in the morning and in the evening, and spend the hottest time on the hay, saving moisture. Beds are located on level ground near trees, often favorites, and bushes. The goitered gazelle moves after the shadow of the tree, hiding from the sun, first of all, its head. Raised from the prone, the goitered gazelle quickly jumps up and rushes at a speed of 55- 60 km/h about 200- 300 m , then inspected. In winter, it grazes almost all day.

Goitered gazelles feed on herbaceous or shrubby plants, choosing the most moisture-saturated grasses in summer: barnyard grass, onions, ferulas. Goitered gazelles usually go to watering places with open and flat banks without dense coastal thickets for 10- 15 km once every 3-7 days. They are able to quench their thirst not only with fresh, but also with brackish water (including from the Caspian Sea). The grass that goitered gazelles eat can also contain a significant amount of salt.

In spring and summer, animals are kept singly or in small groups of 2-5 heads. In autumn and winter, they gather in herds from several tens to hundreds of heads. Then the race happens. The beginning of the rut is preceded by the arrangement of rutting latrines by the males. In September, males dig small holes with the hooves of their front legs and leave their excrement there. Other males, finding such holes, may throw away old excrement and leave their own there. Obviously, such pits serve as marks of the occupied territory. Pregnancy of females lasts 5.5 months. In May, the female brings one, rarely two cubs. Newborns for the first days only lie on a bare piece of land. The sandy-brown coloring of the goitered gazelle so merges with the soil that you can easily step on the baby without noticing it. The cub begins to follow its mother and feed on its own in two weeks. Main natural enemy gazelle - wolf.

In captivity, the gazelle is well tamed and breeds, but does not live long. The goitered gazelle population is declining, although work is underway to restore the number of animals. A subspecies from the Arabian Peninsula (Gazella subgutturosa marica) is listed in the International Red Book.

Fenech (Fennecus zerda) is a species of predatory animal of the wolf family. It looks like a miniature fox. body length approx. 40 cm , tail to 30 cm ; weight 1.5 kg ; ears are large (up to 15 cm ) and wide. The coat is long, reddish-cream above, fawn or almost white; the tip of the fluffy tail is black. Fenech lives in the deserts of North Africa and Southwest Asia. It is active at night and spends the day in a deep burrow. Huge ears allow Fenech to catch the slightest rustle. In case of danger, he burrows into the sand. When hunting, the fennec fox can jump high and far. It feeds on small rodents, birds and their eggs, lizards, insects, carrion, and plants. Pregnancy in a female lasts 51 days. Cubs (2-5) will be born in March-April in a burrow with a nesting chamber lined with grass, feathers and wool.

JACKALS, a group of species of carnivorous mammals of the wolf family. The most common is the Asian jackal (Canis aureus), which appearance looks like a small wolf. His body length is 85 cm , tail about 20 cm ; weight 7–13 kg. The color of the coat in winter is fawn, dirty yellow, with a noticeable red and black tint, the tail is reddish-brown with a black end. It is found in the south of Eurasia, in North Africa; in Russia, mainly in the North Caucasus. The Asian jackal prefers to settle in thickets of bushes and reeds, on plains, near rivers, lakes and seas. It is less common in the foothills. As shelters, the jackal uses natural niches and depressions, crevices among stones, and sometimes abandoned burrows. The animal is active mainly in the dark, but often during the day. It migrates only in search of food.

The jackal is omnivorous, but feeds mainly on small animals: rodents, birds, fish, as well as insects, carrion and the remains of prey of large predators. Also eats fruits and berries, including grapes, watermelons, melons, plant bulbs. Living near the villages, he hunts for poultry. When going hunting, the jackal emits a loud howl, which is picked up by all its relatives located nearby. They often hunt alone or in pairs. The jackal forms pairs for life, the male takes an active part in creating a hole and raising offspring. The rut takes place from January to February. Pregnancy lasts about 2 months. Usually 4-6, less often 8 puppies are born. The Asian jackal is a carrier dangerous diseases(rabies and plague). It has no commercial value.

in Eastern and South Africa the scoop jackal (Canis mesomelas) and the striped jackal (Canis adustus) live. In their lifestyle and habits, they are similar to the Asian jackal. The Ethiopian jackal (Canis simensis) is found in Ethiopia. Outwardly, he looks like a dog with a fox head. A wide black stripe stretches along the middle of the back, sharply delimited from the red sides and limbs. The belly is white, the tail is long red, with a black end. Ethiopian jackal lives in the mountains at a height 3000 m , it feeds on rodents and hares. Its population is small and this animal is protected.

COYOT (meadow wolf, Canis latrans), a predatory mammal of the wolf family. body length approx. 90 cm , tail - 30 cm . Erect ears, a long fluffy tail, which, unlike a wolf on the run, keeps lowered down. The coat is thick, long, grayish or reddish-brown in color on the back and sides, very light on the belly. The end of the tail is black. The coyote is distinguished by a developed higher nervous activity, it is able to adapt to a changing environment.

Coyote lives in the prairies and steppes of North and Central America. Runs into the woods by accident. His lifestyle has a lot in common with the jackal. The lair suits in caves, hollows of fallen trees, deep holes. The loud howl of the coyote is an integral part of the color of the prairies. It feeds on rodents, hares, rabbits, birds and lizards, sometimes fish and fruits, and does not disdain carrion. Rarely attacks domestic animals (goats, sheep). Hunts alone or in packs. destroys a lot of harmful rodents. It is completely safe for humans. Pairs are formed for life, the rut takes place in January-February. Pregnancy lasts 60-65 days. In a brood 5-10, sometimes up to 20 cubs.

CARACAL (Felis caracal), a predatory mammal of the cat family, genus of cats. Body length 65- 82 cm , tail 20- 31 cm ; weight 11- 13 kg . In appearance and tassels on the ears, it resembles a lynx. But it has a thinner, slender body, on high thin legs; also has a uniform light red color. There are small black markings on the muzzle and ears, the ends of the ears are decorated with tassels.

It lives in the deserts of Africa and Asia, including in the south of Turkmenistan. It hunts mainly at night, and during the day it takes refuge in abandoned burrows. Caracal hides prey and overtakes it with large (up to 4.5 m ) jumps. It mainly feeds on rodents: gerbils, jerboas, ground squirrels, as well as tolai hares; less often birds, small antelopes, hedgehogs, porcupines. Can hunt livestock and poultry.

Cubs (from 1 to 4) are born in early April. In ancient times, caracals were trained to hunt antelopes, hares and birds. It has no commercial value. Few. Caracal is listed in the International Red Book. Protected in the Repetek Reserve.

Kulan (onager, Equus hemionus), equine mammal of the horse genus. Body length 2.0- 2.4 m , height at the withers 110- 137 cm , weight 120- 127 kg . In appearance, the kulan is slender and light. The head is relatively heavy, the ears are longer than those of a horse. The tail is short, with a black-brown brush at the end, like donkeys and zebras. Coloring sandy-yellow color of various shades. The belly and inner parts of the legs are white. From the withers to the croup and along the tail there is a narrow black-brown stripe. The mane is low.

The kulan is distributed in Western, Middle and Central Asia. However, the once large range has shrunk significantly. The number is restored only in reserves, including in the south of Turkmenistan (Badkhyz Reserve). The kulan was brought to the island of Barsakelmes and to the foothills of the Kopetdag. Habitats depend on territorial features. The animal can inhabit hilly plains or foothills, deserts and semi-deserts. With the exception of spring, when pastures are covered with young lush grass, kulans need a daily watering place and do not move further from water bodies than 10 15 km . When threatened, they can reach speeds of 60- 70 km/h without slowing down for several kilometers. There are no strictly defined periods of grazing and rest.

To most animals, except for sheep, the kulan is peaceful, often grazing with goitered gazelle and herds of horses. Mutual communication is developed among these animals, it is worth alerting goitered gazelles, or alarmingly shouting to birds, as a kulan takes off. An angry kulan is very ferocious.

Kulans have well-developed eyesight, hearing and smell. Approach the kulan unnoticed at a distance of 1- 1.5 km impossible. However, he can pass by a motionless person at a distance 1.5 m , and this is due to the peculiarities of his visual apparatus. The click of a camera can be heard from a distance. 60 m . They are silent animals. With a call, reminiscent of a donkey, but more deaf and hoarse, the male calls the herd.

The rut takes place from May to August. During the rut, the male begins to prance in front of the females, raising his head high. Often runs around the herd, jumps, screams, rides on his back, tears with his teeth and throws up tufts of grass.

Even before the start of the rut, adult males drive young kulans out of the herds. During this period, there are serious fights between males. Baring their mouths and flattening their ears, they rush at each other with bloodshot eyes, trying to grab the hock joint. If one succeeds, then he begins to twist the opponent around the axis and gnaw at his neck.

Pregnancy of females lasts 331-374 days, on average 345. Kulanyat will be born from April to August. The first hours they lie motionless, but already on the first day they begin to graze with their mother. The grown up kulanenok becomes very active. When he wants to eat, he walks around his mother, digs the ground near her belly with his foot, throws his legs around her neck. The male protects the cubs from possible attacks by young kulans. Animals breed in captivity. Kulans are protected everywhere, two subspecies - Syrian (Equus hemionus hemippus) and Indian kulan (Equus hemionus khur) are listed in the International Red Book.

CAMELS (Camelus), a genus of mammals of the camelid family of the corn-foot order; includes two species: dromedary (one-humped) and Bactrian (two-humped). Length up to 3.6 m . Camels are characterized by signs: they do not have hooves - their legs end in two fingers with blunt claws, and the lower surface of the foot is protected by an elastic callus cushion. They are common in the deserts of Central Asia (Bactrians), as well as in Africa, Arabia, Asia Minor, India (dromedary).

Camels feed on shrub and semi-shrub hodgepodges, tree leaves, and bulbs. The well-known ability of camels to go without water for a long time is due to the fact that they can tolerate a slight increase in body temperature without increased moisture loss. This feature allows you to spend less moisture on cooling. In addition, moderate dehydration in a camel is not accompanied by thickening of the blood and disruption of its circulation, as in mammals not adapted to desert conditions. Camels are able to drink quickly and a lot (in 10 minutes they drink about 130–135 liters of water).

The rut takes place in winter. Usually one, rarely two cubs are born. Only the Bactrian has survived in the wild. The dromedary is domesticated and used as pack and draft animals, as well as for milk, meat and wool.

Bactrian - domesticated Bactrian camel, differs little from the wild Bactrian camel. Many zoologists do not make a difference between the concepts of a Bactrian camel and a Bactrian. Domestic camels have larger humps, wider feet and well-developed calluses on the knees of their front legs. The proportions of the skull of domestic and wild have small but stable differences. The coat color of domestic camels is variable - from light, sandy-yellow to dark brown, while wild ones have a constant reddish-brown-sandy color. The Bactrian camel was domesticated more than a thousand years before our era. As an animal resistant to low temperatures and waterless conditions, it has become widespread in Mongolia, Northern China and Kazakhstan. There are several breeds of domestic Bactrian camels - Kalmyk, Kazakh, Mongolian.

DROMEDAR (dromedary, one-humped camel; Camelus dromedarius), a mammal of the camel genus of the callus-footed order. Length approx. 2.1 m , height at the withers 1.8- 2.1 m . Unlike the Bactrian, it has one hump, as well as a shorter and lighter coat. The one-humped camel was domesticated in ancient times, probably in Arabia or North Africa. Not found in the wild. It is widely distributed in Africa, Arabia, Asia Minor and Central Asia, India, introduced to Mexico and Australia. Several breeds are known: high-speed riding mahars (North Africa), riding Indian Rajputans, pack Turkmen dromedaries.

The way of life is similar to the Bactrian. It tolerates heat better, but worse - frost. Up to 10 days can do without water. Passes under the saddle in a day 80 km at speeds up to 23 km/h . However, in a caravan, a dromedary travels no more than 30 km , because he must graze for a long time. Herbivorous. The rut takes place in winter. When crossed with a Bactrian, it gives fertile offspring (the so-called bunks), which surpass their parents in endurance. But the offspring when crossing hybrids is weak.

Deserts and semi-deserts are found in:

Tropical belt- this is a large part of such territories - Africa, South America, the Arabian Peninsula of Eurasia.
Subtropical and temperate zone- in South and North America, Central Asia, where the low percentage of precipitation is complemented by the features of the relief.

Also distinguish a special type of desert - arctic and antarctic, which are associated with very low temperatures.

Climate features, desert classification

This natural zone occupies about 25% of the planet's land mass. In total there are 51 deserts, of which 2 are icy. Almost all deserts were formed on the most ancient geological platforms.

General signs

The natural zone called “desert” is characterized by:

flat surface;
critical volume of precipitation(annual norm - from 50 to 200 mm);
rare and specific flora;
peculiar fauna.

Deserts are often found in the temperate zone of the Northern Hemisphere of the Earth, as well as tropical and subtropical. The relief of such an area is very heterogeneous: it combines highlands, insular mountains, small hills and layered plains. Basically, these lands are drainless, but sometimes a river can flow through part of the territory (for example, the Nile, Syrdarya), and there are also drying lakes, the outlines of which are constantly changing.

Important! Almost all desert areas are surrounded by mountains or are located next to them.

Classification

Deserts are of different types:

Sandy. Such deserts are characterized by dunes and sandstorms often occur. The largest, the Sahara, is characterized by loose, light soil, which is easily blown by winds.
Clayey.They have a smooth clay surface. They are found in Kazakhstan, the western part of Betpak-Dala, on the Ustyurt plateau.
rocky. The surface is represented by stones and rubble, which forms placers. For example, Sonora in North America.
saline. The soil is dominated by salts, the surface often looks like a salt crust or a bog. Distributed on the coast of the Caspian Sea, in Central Asia.
arctic- located in the Arctic and. They are snowless or snowy.

Climatic conditions

The desert climate is warm and dry. The temperature depends on geographical location: maximum +58° It was registered in the Sahara on 09/13/1922 with summer. A distinctive feature of the desert area is a sharp temperature drop of 30-40° With day average temperature +45 ° С, at night - +2-5 ° C. In winter, in the deserts of Russia, there may be frost with little snow. In desert lands, the air is characterized by low humidity. Strong winds often occur here at a speed of 15-20 m/s or more.

Important! The driest desert is the Atacama. There has been no precipitation on its territory for more than 400 years.

Rice. 3. Semi-desert in Patagonia.

Flora

The desert flora is very sparse, mostly sparse shrubs that can extract moisture deep in the soil. In clay deserts, annual ephemera and perennial ephemeroids grow. In solonchaks - halophytes or saltworts. One of the most unusual plants that grow in such an area is saxaul.It often moves from place to place under the influence of the wind.

Fauna

The animal world is also not numerous - spiders, reptiles or small steppe animals (hare, gerbil) can live here. Of the representatives of the order of mammals, a camel, an antelope, a kulan, a steppe ram, a desert lynx live here. To survive in the desert, animals have a specific sandy coloration, they can run fast, dig holes and for a long time live without water, are preferably nocturnal. Of the birds, you can meet a crow, a saxaul jay, a desert chicken.

Important! IN sandy deserts sometimes there are oases - this is a place that is located above the accumulation of groundwater. There is always dense and abundant vegetation, ponds.

Characteristics of the climate, flora and fauna of the semi-desert

Semi-desert is a type of landscape that is an intermediate option between desert and steppe. Most of them are located in the temperate and tropical zones.

General signs

This zone is distinguished by the fact that there is absolutely no forest on it, the flora is rather peculiar, as is the composition of the soil (very mineralized).

Important! There are semi-deserts on all continents except Antarctica.

Climatic conditions

They are characterized by a hot and long summer period with a temperature of about 25° C. Evaporation here is five times higher than the level of precipitation. There are few rivers and they often dry up. In the temperate zone, they run in an unbroken line across Eurasia in an east-west direction. In the subtropical zone, they are often found on the slopes of plateaus, highlands and plateaus (Armenian Highlands, Karru). In the tropics, these are very large areas (Sahel zone).

Flora

The flora of this natural zone is uneven and sparse. It is represented by xerophytic grasses, sunflowers and wormwood, ephemerals grow. On the American continent, cacti and other succulents are most common, in Australia and Africa - xerophytic shrubs and stunted trees (baobab, acacia). Here vegetation is often used to feed livestock.

Fauna

The animal world is quite diverse. It is mostly represented by reptiles and rodents. The mouflon, antelope, caracal, jackal, fox and other predators and ungulates also live here. The semi-deserts are home to many birds, spiders, fish and insects.

Protection of natural areas

Part of the desert areas are protected by law and recognized as nature reserves and national parks. Their list is quite large. From the deserts man guards:

Etosha;
Joshua Tree (in Death Valley).

From the semi-deserts are subject to protection:

Ustyurt Reserve;
Tiger beam.

Important! The Red Book includes such desert inhabitants as serval, mole rat, caracal, saiga.

Economic activity

The climatic features of these zones are unfavorable for economic life, but throughout history, entire civilizations have developed in the desert zone, for example, Egypt. Special conditions made it necessary to look for a way to graze livestock, grow crops and develop industry. Taking advantage of the available vegetation, sheep are usually grazed in such areas. Bactrian camels are also bred in Russia. Farming here is possible only with additional irrigation.

The two largest deserts on planet Earth are Antarctica and the Sahara.
The height of the highest dunes reaches 180 meters.
The driest and hottest area in the world is Death Valley. But, nevertheless, more than 40 species of reptiles, animals and plants live in it.
Approximately 46,000 square miles of arable land turns into desert every year. This process is called desertification. According to the UN, the problem threatens the lives of more than 1 billion people.
Passing through the Sahara, people often see mirages. To protect travelers, a map of mirages was drawn up for caravaners.

Even more interesting facts and useful information about these climatic zones, see the video below.

The presence in Russia of all natural zones (with the exception of the tropics) is well known, but semi-deserts and deserts are very often and undeservedly forgotten. These natural areas of the country are so unique and atypical that they deserve close attention.

The reasons for the emergence of deserts and semi-deserts in scientific circles still remain a controversial issue. One side of theorists - geophysicists - believe that the low amount of precipitation in these natural zones is due to the fact that they are mainly located at the foot of mountain systems. The latter cover them from the ingress of moist air masses.

The deserts and semi-deserts of Russia, located in the temperate and arctic zones, do not fit into the framework of such explanations. Therefore, Russian scientists suggested that this process is formed as a result of the collision of continental air masses with sea ones.

As a result, dry continental ones displace moist sea air, which leads to extreme low level precipitation throughout the year. A striking example in this regard are the deserts and semi-deserts of Russia and Central Asia.

In addition, strongly heated equatorial masses rapidly rise to great heights, and with rapid cooling, moisture falls out in the form of tropical showers. In the future, already dehydrated air moves. The erosion factor also plays an important role. Dry gusts of wind lead to the weathering of the dried soil, its grinding and undulating movement.

Origin icy deserts due to a different reason, although quite similar in physical essence. Cold masses reach the coast and, with a sharp cooling, throw out the entire supply of snow here. When the ocean masses break through into the depths of the continent, snow falls over its entire area. Moreover, sometimes the level of precipitation reaches the annual norm.

Location of natural areas on the map of Russia

Deserts and semi-deserts of Russia are located in the southeastern part of the East - European plain along the Caspian Sea. This is the territory of Kalmykia, Astrakhan and Volgograd regions.

Small semi-deserts exist in the Volgograd and Rostov regions ( we are talking about the Archedinsky-Don and Tsimlyansky sands). In the south direction from Volgograd and the left bank of the Volga to Kazakhstan, and from the south to the Terek and the foothills of the Caucasus Range, the steppes turn into a desert.

Arctic deserts stretch from the Murmansk region to Anadyr to the north and east of the country. It includes the ocean coast from Murmansk to Taimyr and Chukotka, as well as all the northern Russian islands. The map shows that deserts occupy only a small part of the territory of the state.

Characteristics of the deserts of Russia

The desert zone is located on the Caspian lowland, which was the seabed several millennia ago. This factor imposes originality on this natural area.

An absolutely flat landscape with a zonal alternation of types of coverage is characteristic:

Arctic deserts are located above 75° north latitude. The relief is predominantly flat with a characteristic patterned pattern, which occurs as a result of numerous repetitions of the processes of melting and freezing. Most of the Arctic desert is in a frozen state, almost the entire calendar year. The permafrost never thaws.

The soil

The soils of the Russian desert are quite diverse:

chestnut;
sandy;
desert-steppe;
clay;
solonetzed;
serozems;
gray-brown.

There are a lot of takyrs (clay soils in the lowest parts of the plain). The soil characteristics of the Arctic deserts are poorer. The fertile horizon is thin with a small amount of nutrient fractions. Includes a lot of sand.

Takyrs can be found not only in the deserts, but also in the semi-deserts of Russia

In the warmest places, brown soils with the presence of fertile substances come across. Permafrost hinders drainage processes and in summer, as a result of thawing processes, numerous lakes are formed here. Placers of crushed stone and other rocks testify to the ancient movement of glaciers.

Climate

Deserts and semi-deserts of Russia are located in a sharply continental climatic zone. Deserts are the driest region of the country. Summer is long and very hot. At an average summer temperature of +25…+29°C, there are sharp rises to +50°C.

Winter is short with temperatures not falling below -4 - 8°C. Sometimes, against the backdrop of a breakthrough of arctic winds, the mercury column drops to -30°C. Characterized by sharp temperature fluctuations, both annual and daily. The daily difference, for example, can be up to 30°C.

Little snow. Precipitation in the form of rain and snow falls mostly in spring and summer. In total, the annual rainfall is 150 - 200 mm. Evaporation exceeds the rate of moisture loss by 10-15 times. Due to dryness, dust storms and dry winds are often accompanied by hurricane-force winds.

The climatic conditions of the polar deserts are distinguished by the presence of long and extremely frosty winters. The average daily thermometer readings fall to -50 C. The summer season is short and cold. The air temperature barely reaches + 10 C. The main part of the year the temperature is from -20 to 0 C.

Precipitation is rare, more active in the warm period, in the form of fine drizzle and snowballs. The average annual rainfall is about 240 mm. In the summer months, there is a polar day, lasting 60 days, when the solar disk does not hide behind the horizon all day long. The polar night comes along with winter.

Animal world

At first glance, it may seem that there are no inhabitants in the desert. In fact, the desert is quite densely populated. First of all, these are small mammals that are active only at night to protect themselves from the heat.

small mammals	jerboa; gecko; vole; hamster; gopher gerbil.
Large inhabitants of the Russian deserts	saiga; fenech; caracal; gazelle; wolf; desert sheep.
There are also many kinds of insects.	scorpion; tarantula; mosquito; locust.
snakes	4-stripe skid; Sarmatian snake; Caspian snake; muzzle; viper.

The arctic desert is also densely populated by inhabitants. About 120 species of fauna live in these harsh places. All of them are adapted to extreme climates. To survive, they have well-developed fatty layers and woolen integuments.

They are active in the arctic summer and go into hibernation or migrate with the onset of frost. The birds are moving south. Here are the main inhabitants of this harsh climatic zone.

Mammals:

arctic fox;
polar bear;
wolf;
squirrel;
hare;
arctic vole;
lemming;
reindeer;
seal;
walrus;

Birds: (most are migratory);

crow;
falcon;
loon;
sandpiper;
snipe;
gull.

Fish:

Insects:

grasshopper;
arctic bumblebee;
mosquito;
butterfly;
midge;
fly.

Plants

The life of desert plants is largely dependent on the nature and quality of desert soils. On sandy soils, the flora has a powerful root system, which is held in loose foundations and reaches the ground moisture.

The main mass in the northern part is made up of herbaceous plants:

They exist by adapting to conditions. Some retain bulbous bases in the ground, while others live the entire life cycle.

On salt marshes grow:

hodgepodge;
saline;
sarsazans.

In the south of the zone there are:

sand acacia;
Richter's hodgepodge;
white saxaul.

In the Arctic deserts, nature is less diverse. Vegetation covers exist on 5-10% of their territory. Only crops that have adapted to vegetation in the arctic climate grow.

lichens;
seaweed.

IN warm months a few shrubs bloom

Local residents, occupation

The deserts and semi-deserts of Russia are far from being the most habitable region. As a rule, there is no permanent population in the deserts. But since the desert expanses allow nomadic cattle breeding (sheep and horse breeding), separate ethnic groups are present in the desert.

The basis of the indigenous population is the most numerous peoples in these places - Tatars and Kazakhs.

Tatars are represented by several Turkic groups:

karagashi;
utari;
yurts.

All of them by origin stand next to the Nogais. The Nogais (or the historically established name "Nogai") are truly the indigenous population of the Caspian deserts. They belong to the Turkic group.

From the 16th century Kalmyks also live here, belonging to the Mongoloid group and being the distant descendants of the nomadic Oirat tribes. The Arctic deserts have a very low population density. It is based on indigenous minorities.

North:

Saami;
Nenets;
Yakuts;
Chukchi;
Koryaks;
Eskimos;
Aleuts.

All of them are engaged in reindeer breeding and folk crafts. Interesting and not too known fact. A particularly common occupation is walrus ivory cutting. However, walrus ivory is harvested here in a humane way. Indigenous people know well the places of walrus cemeteries (when dying, a walrus is thrown ashore in strictly certain place).

To get to such a cemetery is simply unthinkable for strangers: given the huge cost of raw materials and art objects made from walrus bone, over the past decades, many attempts have been made to gain access to sacred places. Local shamans claim that uninvited guests are taken away by spirits.

The protection of the deserts of Russia

Human activity causes major and irreparable damage to the nature of Russian deserts. Even ill-conceived cattle breeding begins to turn the desert into a wasteland. The destruction of scarce vegetation during grazing irreparably destroys its ability to reproduce.

In addition, many animals live in this area, both rare and already listed in the Red Book (for example, caracal). Poachers are putting many animal species on the brink of extinction.

Due to man-made factors in the Arctic, ice is melting, as a result, the zone of the Arctic desert is decreasing. With such a progress in its reduction, many species of animals will disappear. Mining, which is so rich in this unique area, violates the ecological balance.

In order to preserve protected areas and unique resources of deserts with a temperate climate, the government of the Russian Federation has taken a number of environmental measures.

For this purpose, nature protection zones have been created:

Polar bears breeding in Chukotka are in conditions leading to the extinction of the population. As a result of ice melting, their hunting grounds are reduced, and young bear cubs are doomed to starvation. In this regard, the polar reserve "Wrangel Island" was created. There are built dens for polar bears and conditions for proper nutrition and reproduction.

Characteristics of the semi-deserts of Russia

The deserts and semi-deserts of Russia are very similar in their natural conditions and pass one into another. Semi-deserts occupy a very small part of the lands of southern Russia. They are located in the southeast from the left bank of the Volga to the foothills of the Caucasus.

This is the westernmost region of the Caspian Sea, as well as the Ergeni Upland. The semi-desert starts from the banks of the Volga near Dubovka. To the west it stretches to the Don and the Great Manych Lakes, to the south to the lower reaches of the Sulak River. The subtropical semi-desert zone occupies a very small area. Dry subtropics are on Black Sea coast Caucasus near Novorossiysk.

Semi-deserts are an intermediate option between steppes and deserts, a smooth transition from one to another. Just as in the steppe, there are natural reservoirs (in this case, the largest are the Volga and Sarpinsky lakes).

And Europe's largest mineral lake Elton is located in the semi-desert near Volgograd. However, the vegetation here is already much poorer than in the steppe. Soil, water, both surface and underground are highly saline.

The soil

Since there are relic marine rocks at the base of the soils, the soils of semi-deserts are thoroughly saline. In their physical essence, semi-deserts are the same steppes, but dry. Accordingly, the fertile layer is much thinner and poorer.

The main ones here are chestnut soils. The name comes from the fact that the powerful roots of vegetation stretch deep to the groundwater, and there the layer of humus is thicker. But compared to black soil, it is much poorer and has a brown color.

The difference between the northern semi-desert soils also exists. In the north, the soils have a light chestnut color, and in the south - grayish-brown. Solonetzes and solonchaks are found everywhere.

Soils in dry subtropics are brown forest and brown. Water plays an important role in soil formation. Internal reserves of melt water are collected in small depressions and caverns. This is how a few small lakes with highly saline water are formed. Some of them contain a large amount of crystalline salt, which in some cases is mined by an open pit.

Due to salinity, local water is not suitable for use not only in domestic, but also in technical purposes. The main reserves of fresh water are rivers flowing in transit through semi-desert territories.

Only in the Caspian semi-deserts you can see an unusual natural phenomenon - salt domes. Rock salt, squeezed out by layers of dry soil, comes out in the form of a dome.

Climate

As already noted, the climatic regime of the Caspian lowland is very peculiar. This is also true for semi-deserts. Here the climate is dry, sharply continental. The average daily temperature in summer is +23 ... + 25C, in winter - -10 - -15C.

Moreover, sharp weather changes are characteristic: frosts can reach -40C, however, in an unpredictable way, they can be replaced by a thaw. Then, with subsequent cooling, an ice crust forms. This is the reason for the death of a large number of herbivores. The annual rainfall, as in the desert, is about 240 mm. The maximum level of precipitation occurs in May - June.

In the dry subtropical part, it is hot and dry in summer, the thermometer shows an average of +25 - +30C. Winter is not cold high level humidity. The thermometer readings are at the level of +4 - +10C. Frosts are rare. The precipitation rate is 600 - 700 mm per year. The maximum precipitation falls in winter.

Animal world

In Russia, the fauna of the semi-desert is very similar to steppe dwellers and desert dwellers at the same time.

Its main representatives are small mammals:

Of the major ones there are:

wolf;
saiga;
fox;
gazelle.

From insects:

scorpion;
tarantula;
mosquito;
locust.

Reptiles:

monitor lizard;
four-stripe snake;
Sarmatian snake;
Caspian snake;
muzzle;
viper.

Birds:

Plants

Unlike the steppes, the plant blanket does not completely cover the entire territory, but grows in sparse oases. The basis of herbaceous vegetation is feather grass and fescue.

Several types of shrubs also grow:

As well as a few herbaceous plants. In the dry subtropics, deciduous bushes grow - shiblyak. Evergreen maquis is also common.

locals

As noted above, the basis of the indigenous population of the Caspian region is:

Tatars;
Kazakhs;
Nogais;
Kalmyks.

It is characteristic that the indigenous people belong either to the Turkic ethnic group or to the Mongoloid one. At the same time, a significant Armenian diaspora lives in this area, which was formed back in the 17th century. The dry subtropics are rightly expanding the composition of the indigenous population.

Along with the already listed groups, a large share is occupied by:

Armenians;
Adyghe;
Abkhazians;
Avars.

A sufficient amount of solar radiation and a long growing season create all the conditions for growing on irrigated plots, excellent yields of melons and grapes.

The main occupations of the population here are:

animal husbandry;
vegetable growing;
melon growing;
viticulture.

Protection of the semi-deserts of Russia

The worst thing for Russian semi-deserts is their thoughtless devastation due to the barbaric use of territories. Are monuments historical development these unique areas. Therefore, along with measures for the protection of deserts, a number of measures have been taken that have affected the unique nature of the semi-desert.

Three main reserves have been established:

Ustyurt.
Tiger beam.
Aral-Paygambar.

In conclusion, it should be said that in Russia semi-deserts are represented by a very small area, and the deserts of the temperate zone and the harsh Arctic are truly unique. In no country in the world is it possible to simultaneously see such a variety of this natural complex.

Article formatting: Vladimir the Great

Video about the deserts and semi-deserts of Russia

Overview of the desert in Russia:

The desert only at first glance may seem like a lifeless territory. In fact, it is inhabited by unusual representatives of the animal and plant world, who managed to adapt to difficult climatic conditions. The natural zone The desert is very extensive and occupies 20% of the earth's land area.

Description of the natural zone of the Desert

The desert is a vast flat area with a monotonous landscape, poor soil, flora and fauna. Such landmasses are found on all continents except Europe. The main symptom of the desert is drought.

The features of the relief of the Desert natural complex include:

plains;
plateaus;
arteries of dry rivers and lakes.

This type of natural zone extends over most of Australia, a relatively small part of South America, is located in the subtropical and tropical zones of the Northern Hemisphere. On the territory of Russia, deserts are located in the south of the Astrakhan region in the eastern regions of Kalmykia.

The largest desert in the world is the Sahara, which is located on the territory of ten countries of the African continent. Life here is found only in rare oases, and on the territory of over 9,000 thousand square meters. km, only one river flows, communication with which is not available to everyone. Characteristically, the Sahara consists of several deserts, similar in their climatic conditions.

Rice. 1. The Sahara Desert is the largest in the world.

Desert types

Depending on the type of surface, the desert is divided into 4 classes: