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Animal world of the Sahara desert. Great Sahara Desert Who lives in the Sahara Desert

A truly endless sea of sand, stone and clay scorched by the sun, enlivened only by rare green spots of oases and a single river - this is what the Sahara is.

The gigantic scale of this largest desert in the world is simply amazing.

Its territory occupies almost eight million square kilometers - it is larger than Australia and only slightly smaller than Brazil. Its hot expanses stretch for five thousand kilometers from the Atlantic to the Red Sea.

Nowhere else on Earth is there such a huge waterless space. There are places in the interior of the Sahara where it doesn't rain for years.

So, in the oasis of In-Salah, in the heart of the desert, for eleven years, from 1903 to 1913, it rained only once - in 1910, and only eight millimeters of rain fell.

These days, the Sahara is not so difficult to access. From the city of Algiers on a good highway to the desert can be reached in one day.

Through the picturesque gorge of El Kantara - "Gateway to the Sahara" - the traveler finds himself in places that by their landscape do not at all resemble the "sandy sea" he expected with golden waves of dunes.

To the left and right of the road, which runs along a rocky and clay plain, small rocks rise, which the wind and sand have given the intricate outlines of fairy-tale castles and towers.

Sandy deserts - ergs - occupy less than a quarter of the entire territory of the Sahara, the rest falls on the share of rocky plains, as well as clayey areas cracked from the scorching heat and salt marshes white with salt, giving rise to deceptive mirages in the unsteady haze of heated air.

In general, the Sahara is a vast plateau, a table, the flat character of which is broken only by the depressions of the Nile and Niger valleys and Lake Chad.

On this plain, only in three places do truly high, albeit small in area, mountain ranges rise. These are the Ahaggar and Tibesti highlands and the Darfur plateau, rising more than three kilometers above sea level.

The mountainous, gorge-cut, absolutely dry landscapes of Ahaggar are often compared to lunar landscapes. But under the natural rocky canopies, archaeologists have discovered here a whole art gallery of the Stone Age.

The rock paintings of ancient people depicted elephants and hippos, crocodiles and giraffes, rivers with floating boats and people harvesting ...

All this suggests that before the climate of the Sahara was more humid, and savannahs were once located on most of the current desert.

Now they are found only on the slopes of the Tibesti highlands and the flat, elevated plains of Darfur, where for a month or two a year, while it rains, real rivers even flow through the gorges, and abundant springs feed the oases with water all year round.

In the rest of the Sahara, precipitation is less than two hundred and fifty millimeters per year. Geographers call such areas arid regions.

They are unsuitable for agriculture, and herds of sheep and camels can only be driven over them in search of scarce food.

Here are the hottest places on our planet. For example, in Libya there are areas where the heat reaches fifty-eight degrees! And in some areas of Ethiopia, even the average annual temperature does not fall below plus thirty-five.

The sun governs all life in the Sahara. Its radiation, taking into account rare cloudiness, low air humidity and lack of vegetation, reaches very high values.

The daily temperatures here are characterized by large jumps. The difference between day and night temperatures reaches thirty degrees! Sometimes frosts occur at night in February, and on Ahaggar or Tibesti the temperature can drop to minus eighteen degrees.

Of all the atmospheric phenomena, the traveler endures prolonged storms the hardest in the Sahara. The desert wind, hot and dry, causes hardship even when it is transparent, but it is even more difficult for travelers when it carries dust or fine grains of sand.

Dust storms are more common than sandstorms. The Sahara is perhaps the dustiest place on earth. These storms look from afar like fires quickly covering everything around, clouds of smoke from which rise high into the sky.

With furious force they rush through the plains and mountains, blowing dust from the destroyed rocks on their way.

Storms in the Sahara have extraordinary strength. The wind speed sometimes reaches fifty meters per second (remember that thirty meters per second is already a hurricane!).

Caravaneers say that sometimes heavy camel saddles are carried away by the wind for two hundred meters, and stones, the size of a chicken egg, roll along the ground like peas.

Quite often, tornadoes occur when the very heated air from the earth heated by the sun rapidly rises, capturing fine dust and carrying it high into the sky. Therefore, such whirlwinds are visible from afar, which, as a rule, allows the rider to save his life by avoiding a meeting with the "desert genie", as the Bedouins call the tornado.

A gray column rises into the air to the very clouds. Pilots met dust devils sometimes at a height of one and a half kilometers. It happens that the wind carries Saharan dust across the Mediterranean Sea to Southern Europe.

On the vast Saharan plains, the wind almost always blows. It is estimated that there are only six calm days in the desert for a hundred days. Especially notorious are the hot winds of the Northern Sahara, which can destroy the entire crop in the oasis in a few hours. These winds - sirocco - blow more often in early summer.

In Egypt, such a wind is called khamsin (literally - "fifty"), since it usually blows for fifty days after the vernal equinox.

During his almost two-month rampage, the window glass, not closed by the shutters, becomes dull - this is how grains of sand carried by the wind scratch it.

And when there is calm in the Sahara and the air is filled with dust, there is a "dry fog" known to all travelers. At the same time, visibility completely disappears, and the sun seems to be a dull spot and does not give a shadow. Even wild animals lose their bearings at such moments.

They say that there was a case when, during the "dry fog", usually very shy gazelles calmly walked in a caravan, walking between people and camels.

Sahara likes to be reminded of herself unexpectedly. It happens that the caravan sets off when nothing foretells bad weather. The air is still clean and calm, but some strange heaviness is already spreading in it. Gradually, the sky on the horizon begins to turn pink, then takes on a purple hue.

It is somewhere far away that the wind has picked up and drives the red sands of the desert towards the caravan. Soon, the cloudy sun barely breaks through the rapidly rushing sandy clouds. It becomes difficult to breathe, it seems that the sand has displaced the air and filled everything around.

Hurricane winds rush at speeds up to hundreds of kilometers per hour. Sand burns, chokes, knocks down. Such a storm sometimes lasts a week, and woe to those whom it caught on the way.

But if the weather is calm in the Sahara and the sky is not covered with wind-blown dust, it is difficult to find a more beautiful sight than a sunset in the desert. Perhaps only the aurora borealis makes a greater impression on the traveler.

The sky in the rays of the setting sun each time strikes with a new combination of shades - it is both blood-red and pink-pearl, imperceptibly merging with pale blue. All this is piled up on the horizon in several floors, it burns and sparkles, growing into some kind of bizarre, fabulous forms, and then gradually fades away.

Then, almost instantly, an absolutely black night sets in, the darkness of which even the bright southern stars cannot dispel.

Of course, the most desirable and most picturesque places in the Sahara are the oases.

The Algerian oasis of El Ouedd lies in the golden yellow sands of the Great East Erg. An asphalt highway connects it with the outside world, but it only appears as such on the map. In many places, the wide roadbed is thoroughly covered with sand.

A good two-thirds of the telegraph poles are buried in it, and teams of workers with shovels and whisks are constantly raking drifts, first in one area, then in another.

After all, the wind blows here all year round. And even a weak breeze, tearing off the tops of sandy dune hills, steadily moves sandy waves from place to place. With a strong wind, traffic on the roads of the desert sometimes stops completely, and not for one day.

Like all oases of the Sahara, El Ouedd is surrounded by a palm grove. Date palms are the basis of life for the locals. In other oases, in order to give them water to drink, irrigation systems are arranged, but in El Ouedd it is easier.

In the dry bed of the river flowing through the oasis, they dig deep funnel holes and plant palm trees in them. Water always flows under the rusdom at a depth of five or six meters, so that the roots of palm trees planted in this way easily reach the level of the underground stream, and they do not need irrigation.

In each funnel grows from fifty to one hundred palm trees. The sinkholes are arranged in rows along the channel, and they are all threatened by a common enemy - sand. To prevent the slopes from sliding, the edges of the funnels are strengthened with wattle from palm branches, but the sand still seeps down. You have to take it all year round on donkeys or carry it on yourself in baskets.

In the summer, in the heat, this hard work can only be done at night, by the light of torches or in the glow of the full moon. Water wells are also dug in these funnels. It is enough for drinking and for watering gardens. Camel droppings serve as fertilizer.

Dates and camel milk are the main food of fellah farmers. A valuable nutmeg variety of dates is sold and even exported to Europe.

The capital of the Algerian Sahara - the oasis of Ouargla - differs from other oases in that it has ... a real lake. This tiny town in the middle of the desert has a reservoir of four hundred hectares, huge by local standards.

It was formed from water discharged from palm plantations after irrigation. Water is always supplied to the fields and date groves in excess, otherwise evaporation will lead to the accumulation of salts in the soil.

Excess water, along with salts, is discharged into a depression next to the oasis. This is how artificial lakes appear in the Sahara.

True, most of them are not as large as in Ouargla, and do not withstand a deadly struggle with sand and sun. Most often, these are just swampy depressions, the surface of which is covered with a dense, transparent, like glass, layer of salt.

But oases in the Sahara are rare, and one has to get from one "island of life" to another along the endless roads of the desert, overcoming the heat of the sun, hot wind, dust and ... the temptation to turn off the road.

Such a temptation often arises among travelers both on ancient caravan trails and on modern paved highways in these inhospitable lands.

When the desired outlines of an oasis appear on the horizon in front of a traveler exhausted by a long journey, the Arab guide only shakes his head negatively.

He knows that there are still tens of kilometers to the oasis under the scorching sun, and what the traveler sees "with his own eyes" is just a mirage.

This optical illusion sometimes misleads even experienced people. Experienced travelers who have passed through the sands on more than one expeditionary route and have studied the desert for more than one year have also become victims of mirages.

When you see palm groves and a lake, white clay houses and a mosque with a high minaret at a short distance, it is hard to make yourself believe that in reality they are several hundred kilometers away. Experienced caravan guides sometimes fell under the power of a mirage.

One day, sixty people and ninety camels died in the desert, following a mirage that carried them sixty kilometers away from the well.

In ancient times, travelers, in order to make sure whether it was a mirage in front of them or reality, kindled a fire. If even a small breeze blew in the desert, then the smoke creeping along the ground quickly dispersed the mirage.

For many caravan routes, maps have been drawn up, which indicate places where mirages are often found. These maps even mark what exactly is seen in one place or another: wells, oases, palm groves, mountain ranges, and so on.

And yet, in our time, when two modern highways ran through the great desert from north to south, when multi-colored autocaravans of the Paris-Dakar rally rush through it every year, and artesian wells drilled along the roads allow, in case of anything, to walk to the nearest water source.

The Sahara gradually passes to be that disastrous place that European travelers feared more than the Arctic snows and the Amazonian jungle.

Increasingly, inquisitive tourists, fed up with beach idleness and contemplation of the ruins of Carthage and other picturesque ruins, go by car or on a camel into the depths of this unique region of the planet to inhale a sip of the night wind on the slopes of Ahaggar, to hear the rustle of palm crowns in the green coolness of the oasis to see a graceful run gazelles and admire the colors of the Sahara sunsets.

29Palms

Federal Agency for Education

Tomsk State University

Abstract on the discipline "Biogeography"

Flora and fauna of the Sahara

Introduction

The Greatest Desert in the World

Modern desert flora

Modern desert fauna

Conclusion

Bibliography

Introduction

The Sahara occupies a large part of the African continent. On the western, northern and eastern outskirts it is bounded by boundaries in the form of the Atlantic Ocean, the Mediterranean and Red Seas, in the south it merges with the tropics. Most of the greatest desert is located at an altitude of 200-500 meters above sea level, where there are almost no sources of water and well-developed vegetation.

Sahara means "desert" in Arabic. It stretches from west to east for five thousand and from north to south for one and a half thousand kilometers. Its area is about nine square kilometers.

The purpose of this essay is to consider the flora and fauna of the Sahara.

The purpose of the abstract is:

· Description of modern desert flora;

· Description of modern desert fauna;

Identification of the characteristics of organisms living in the Sahara.

This work is written on 17 pages, contains a table.

1. The Greatest Desert in the World

The area of the Sahara itself is about 9 million km 2, which is almost equal to the continental part of the United States. Although it is commonly believed that this desert is endless dunes, in fact, only one seventh of the desert is sandy, including ergs - sandy seas. The Great Sand Sea of Libya and Egypt, covering an area equal to that of France, is the largest in the world, with dunes 100 m or more high. Most of the Sahara, that which is not covered with sand, is a rocky desert (reg) with a gravel surface of polished black and purple stones, or a gamada covered with flat limestones.

Topographically, this desert is a region of plateaus and plains, intersected by highlands.

The Nile is the only river that flows through the Sahara; numerous dry riverbeds in other watersheds originate in mountain ranges within or along the edges of the desert and terminate in inland basins, some of them below sea level.

Since the Sahara is located in a subtropical high pressure zone, it generally receives less than 125 mm of precipitation per year. As in all deserts, these precipitations fall very unevenly. Daytime temperatures in summer usually exceed 40C, and often 50C.

In the northern third of the Sahara, precipitation falls mainly from autumn to spring. Bushes grow here and herds of sheep and goats graze, belonging to the Arabs, who two generations ago led a nomadic lifestyle, and now have become mostly sedentary. The central part of the Sahara is the driest zone, there is very little moisture here. Although these parts have the least vegetation, Muslim nomads graze herds of sheep and goats here. In the southern third of the Sahara, called the Sahel, prolonged droughts in recent years have led to a significant increase in the area of the desert.

In the Sahara, there are large mountains, and endless rocky plains, and incredible sand dunes that serve as a refuge for amazing animals. Here and there oases are scattered; in some places with clean and fresh water, in others with bitter or even poisonous. The scorching heat is replaced by night cold. Strong winds resulting from changes in temperature raise sand and dust, exhausting all living things. Sometimes, when the air is completely still and there is absolute silence, which is not disturbed by the singing of birds or the rustle of insects, sparkling stars are visible in the night sky. The bright sun can make a terrifying desert even beautiful, if you manage to forget that life in it is a constant fierce struggle for water.

The northern boundary of the Sahara is usually considered the Atlas mountain range. Its southern slopes are already attributed to the Sahara. The northern border of the Sahara is formed by several depressions, which are called the "Sahara fault". Some animals and plants never cross this ecological barrier. For example, a noisy viper that occurs south of the "rift" never appears north of it, not even a raven flies over it. The southern border is difficult to determine.

There are three main types of deserts in the Sahara: ergs, regs and hamads. Ergs are large sandy massifs, such as the Libyan Desert or the Great Western Erg. Regs are almost dead plains covered with a layer of coarse sand, rubble or pebbles. Hamads are huge flat spaces, the surface of which is formed by rocks.

The climate of the Sahara has been a desert climate for centuries. The few rivers of the Sahara, with the exception of the Nile, originate in the Atlas Mountains and flow until all their water disappears into the desert sands. There are oases in the Sahara - places where there are water sources or wells. In oases, water is strictly limited, and its use is usually controlled. The original plants of the oases are tamarisk, oleanders, and various shrubs. Groves of date palms, fruit trees, and wheat grow on fertile plots. The oases are distributed along four arcs: Saura, Gurara, Tuat and Tidikelt. This chain of oases, known as the "Palm Road", is 1200 km long. It stretches from the Moroccan border at Figig to In Salah in Tidikelt.

Like the Palm Road, the region of oases stretched along the northern border of the Sahara.

Among the largest oases of the Sahara, in addition to those mentioned, located from west to east, there are oases on the plateau of Mauritania, Dra and Tafilalet Djalo, Kufra (Libya), Kawar (Niger), Borku, Tibesti (Chad) and the oases of Egypt - Farafra, Dakhla, Kharga, Siwa.

The animals and plants of the Sahara are divided into those that exist only near water sources, and those that can live in a waterless desert. No part of the Sahara is completely devoid of life. Even where there is no rain for several years in a row and where we do not find vegetation, there are at least bacteria and fungi.

The uneven distribution of precipitation and different temperature regimes that characterize the northern and southern territories of the Sahara cause very significant differences in their floras. The Central Sahara is a border region between two large floristic kingdoms - the Paleotropical and the Holarctic. In the Northern Sahara, floristic elements of the Holarctic kingdom are found (first of all, plant species common in the Mediterranean region): representatives of the genera astragalus, mignonette, plantain, saltwort. The floristic elements of the Paleotropical kingdom, characteristic of the Southern Sahara, are the species of the genera indigo, hibiscus, cleome, acacia, field grass and syt, common here. In the Sahara, about 25% of endemic plant species. The flora of the Sahara is ten times poorer in species than the flora of Southern Europe. But still, 450 species of flowering and 75 species of other plants were found in the Central Sahara.

Plants in the desert struggle to obtain the necessary amount of moisture to continue their existence. Precipitation in the desert in the form of heavy rains is rare. Part of the water accumulates in the creeks and penetrates deep into the sand and silt. Quite tall perennial shrubs and trees can grow in such places. Along the dried up riverbeds, which are briefly filled with water after rains, thickets of tamarisk and oleander are visible. In places where there are constant sources of water, there are many large acacia trees; in the southern regions of the Sahara, you can also see the doom palm, although these are not typical desert plants. Perennial plants that create the green dress of the Sahara have to retain moisture in their tissues. Their main feature is a powerful root system, stretching for several meters. To reduce evaporation, desert plants have created various "devices", for example, their leaves are reduced to thorns, pubescent or covered with a kind of wax coating. Some species settle on the ground so that the winds do not dry them out, others collect water either in bulbs or in roots.

In the hamads of the Southern Atlas, an unusual plant grows - anabasia, which is sometimes called sugar cauliflower. It is a gray-green pads in the form of stars, similar to moss, but hard as a stone.

Countless gray-green stars act as leaves. Sand gets into the gaps between the leaves, and sometimes the plant absorbs it. These grains of sand make the plants hard and stable. "Pillows" of anabasia are scattered everywhere, as far as the eye can see.

The animals of the Sahara face the same problem as the plants: how to get water and how to save it. From this point of view, ergs are better for animals than regs and hamads, mainly because their soil is soft and animals can hide in the sand from the heat of the day. Animals such as the fox, the fox, or the jerboa usually live in ergs, where they can easily dig a hole.

Only a relatively small number of desert animals are able to do without water for a long time. The skink lizard lives in deserted and dry places. This nimble, sand-burrowing animal up to 20 cm long was known in Europe already in the Middle Ages. Its meat was considered medicinal. The inhabitants of the oases catch the skink, as they consider it a delicacy. The lizard is dried, crushed in a mortar, the resulting powder is mixed with date jam, leather bags are filled with this mass and sold to caravans.

Some animals cannot exist at all in waterless lands. This applies mainly to small animals that find it difficult to overcome waterless distances.

In the Sahara, you can find toads that spend only a small part of their lives in the water. When a puddle forms for a short time after a rainstorm, the water simply teems with toads. The growth period of tadpoles is shorter here than in other places, so their tail falls off, and they have time to become toads before the puddle dries up. The main task of these animals is to hold out until the next rain. To do this, toads burrow into the ground or cracks between stones and thus escape from the scorching sun. In their burrows they sleep, breathe slowly and lose a large amount of fluid, sometimes up to 60%. As soon as they fall into the water, they immediately come to life. Reptiles are best adapted to the harsh life in the desert: they have dry skin covered with horny scales, they retain fluid because they do not sweat. Reptiles feed not only on insects, but also on animals whose tissues contain a significant amount of water. The main enemies of reptiles are carnivores, primarily birds of prey.

Birds and some large mammals solve the problems that the desert confronts them with the help of fast movement. In the Sahara, two types of gazelles, the true inhabitants of the desert, can be found: the dorcas gazelle and the sand gazelle. In the southern regions of the Sahara, a lady gazelle is sometimes seen. Gazelles cannot live in a bare desert permanently. Although they can go without water for quite a long time, they need food, which most often grows around dry riverbeds, temporary puddles, or in places where there is enough underground moisture. The long legs and slender bodies of these animals allow them to quickly move through the desert in search of food and water.

Some birds, such as sandgrouse, found in all African deserts and semi-deserts, fly very far for water. When they drink, they stand in the water and wet their lower feathers. There are two types of larks that can live farthest from water sources in the desert: Saharan and desert larks. The Saharan lark (its length is 23 centimeters) on its high legs can run very quickly on the sand. It feeds mainly on beetle larvae, which it takes out of the sand with a long beak from a depth of up to 5 centimeters. It is inexplicable how he determines where a larva is hidden in the sand: his beak almost never dives into the sand to no avail. The desert lark is somewhat smaller than the Saharan, and the color of its plumage merges with the color of the land on which it lives. In larks living in the sand, it is sand-colored; those who live on dark rocks have a dark one. A bright lark never sits on dark ground, and vice versa. The desert lark is not afraid of people.

Large animals, due to their size, cannot dig a hole for themselves to hide from the sun. Such animals are forced to evaporate moisture, cooling themselves during the day, and at night, maintaining their temperature, lose energy. The most amazing of the animals living in the Sahara is the addax antelope. She lives in large sandy expanses, sometimes in the very heart of ergs. These antelopes, the size of a small donkey, with spiral horns, walk in small groups or singly, uniting in numerous herds only during the mating season. They drink very rarely, so they can live in absolutely dry places. Addaxes have disproportionately large hooves, well adapted for moving on loose sands.

There are no more wild camels in the Sahara, they are all tamed and serve people as a means of transportation or as a draft animal.

On the southern slopes of the Atlas and in the mountains of Tibesti, Ahaggar and Aira, a maned ram comes across. This shy mountain animal is very difficult to see. During the day, it hides from the scorching sun in caves or gorges, and goes out to graze at night.

2. Modern desert flora

The climate of the Saharan region is characterized by high air temperatures, often with sharp and large fluctuations, and a small amount of precipitation, which falls extremely unevenly. In the areas of genuine desert that are in the same region, rainfall, if any, is insufficient to support life. The combination of high temperatures and poor rainfall creates an environment of very low air humidity and high evapotranspiration, and in some areas these factors can also lead to an increase in the salt content of the topsoil. As a result of these contrasting external conditions, the vegetation becomes sparse and monotonous. In such an environment, ephemera xerophytes feel especially good, and the prevalence of halophytes is also noted.

The vegetation of the Sahara has 1200 species, including 104 families of angiosperms and 10 families of spore plants.

Table 1

Species diversity of Sahara plants

Family
			endemic species
Compositae

cruciferous


clove

An amazing feature of the flora is the appearance of a number of completely isolated monotypic genera with a wide and narrow distribution. The presence of such numerous monotypic genera is considered evidence of their origin in the distant Tertiary period with the probable disappearance of connecting forms.

3. Modern desert fauna

Since the outlines and boundaries of the Sahara are rather vague, the number of species of small mammals that live in this desert can only be estimated. If we talk about eight countries or localities, then 6 orders, 24 families and 83 species are registered in them. Judging by the number of species, rodents (40 species) master the Sahara especially successfully, and among rodents, the family Cricetidae (22 species) gives the largest number of species. All gerbils are characterized by brown or sandy hair on the back, a whitish color of the abdomen, long tails, usually with a brush at the end, large eyes and swollen auditory drums. Although representatives of the Muridae family, which are very numerous in pre-Saharan Africa, develop the desert, apparently less successfully, with the exception of only one of their species, the Egyptian jerboa, is widespread, and the rest are confined to separate areas of the Mediterranean coastal region. Other families of rodents are represented by a small number of species, often with small or broken ranges. Dormouse and mole rats are not truly desert rodents and exist as relict populations in a few outlying areas. Gundia or comb-toed rats and hyraxes are rock dwellers, forming isolated populations in mountains and other rocky habitats. The only other group of small herbivores in the Sahara are the hares, which form scattered populations in places where grasses grow in sufficient quantities.

An interesting and important group of small predators are insectivores and carnivores. Insectivores are represented by hedgehogs, shrews and long-eared jumpers. Hedgehogs are rarely seen, but they are quite widespread in areas teeming with insects; shrews are rarer and occur in rocky or wet habitats. Carnivores include three types of foxes, two types of mustelids, genet, mongoose, two types of cats. The populations of all these predators are small and dispersed, mainly due to the difficulty of obtaining food.

Monitor lizards are the most famous lizards. In the sandy areas of the northwest Sahara, there is a large desert monitor, which is 100-120 cm long. It is most often found in the reins and dunes, preferring hard areas where it can find shelter and prey. The desert monitor lizard feeds on lizards, sometimes feasts on snakes and birds. A hungry monitor digs holes and eats small rodents, in particular jerboas and gerbils.

In the extreme south of the Sahara, monitor lizard can be found on outcrops of granite rocks. During the day, these reptiles make long sorties at a distance of 4-5 km from their burrow. Going on such a long journey for them, they hope to find islands of vegetation in the desert, in the thickets of which you can hide from the heat and heat.

From enemies, including humans, monitor lizards defend themselves with the help of a tail and sharp claws, sometimes they can bite into the body of an animal with their teeth. The monitor lizards use their tail skillfully and masterfully. Waving them like cowboys with whips, they knock down even wild dogs. The bite of a monitor lizard is very dangerous: pathogenic microbes remaining on his teeth lead to suppuration of the wound, and the animal (like a person) can die from an infection.

On the territory of the central countries of Africa, the Nile monitor lizard lives - a well-known lover of crocodile eggs and small crocodiles. By extracting these delicacies, Nile monitor lizards show ingenuity and sharpness. They go hunting in pairs, one of them distracts the attention of the mother, the other at this time robs the egg laying. It is not easy to tame these lizards, they often run away from the cage, preferring freedom and tedious search for food. They eat quite a lot, they can swallow 10 eggs very quickly. Often Nile monitors raid chicken coops, devouring eggs and chickens.

Gray monitor lizards live in North Africa, most often they can be found in dry and rocky areas. Here, between rocky hills on sandy plains, he attacks small mammals. Upon an unexpected meeting with a person, representatives of this species of lizards instantly rush to the chest or face; attacking large mammals, they bite into their stomach. Gray monitor lizards are guests of many zoos in the world. They very quickly get used to life in captivity, are tamed and do not harm people.

Mamba is the most terrible and dangerous snake in Africa, distributed from the Sahara to the south of the continent. The locals are not afraid of cobras or vipers as much as these tree snakes. If ordinary snakes crawl at a speed of 1 km / h, then the mamba is able to reach speeds of up to 11.3 km / h, and it moves even faster along the branches of trees. In terms of speed of movement, mamba ranks second in the world.

Before biting, the snake raises its head, opens its mouth wide and hisses softly (and such a threat is usually short-lived), then swiftly attacks the victim and plunges its long poisonous teeth into it. The protective coloring allows it to remain invisible in the foliage; almost all mambas are painted green. But you can meet her not only in the thicket of the forest, but also in the fields, and sometimes these snakes even penetrate into houses.

Despite its impressive length (up to 4.5 m), mamba glides through trees and shrubs with fantastic dexterity and dexterity, seeping through dense vegetation without hindrance.

Mambas feed on birds and rodents. Not all mamba bites are fatal, and snake danger in the tropics is exaggerated.

Sahara Agama - These are reptiles that live in the Sahara. Some agamas live on rocky mountain cliffs, deftly and nimbly climb the rocks, others can be seen on wide and flat plateaus, but they all easily tolerate high temperatures and excess sunlight. Agamas feed on beetles, locusts, ants and termites, which are especially found in the desert after rains. Due to the protective coloration among cereal vegetation, it is very difficult to notice the agama.

The largest of all agamas is the Saharan, locals call it dabb. Males of this species are easily distinguished from females, their backs are decorated with a pattern of spots, lines and stripes. The color scheme of the picture depends on the habitat of the agama and combines yellow, green and red-orange tones. Females are most often painted dirty yellow or gray. Agamas try to stay away from settlements and villages, because people catch them and eat them. Both plants and insects serve as food for the Saharan agama. These reptiles spend most of the day hunting for locusts, sometimes attaching themselves to rock ledges and tracking insects.

The largest inhabitant of the Sahara is the camel. It belongs to the order of corns. Its characteristic features are a long neck with an elongated head, a split upper lip, a special structure of teeth, the absence of horns and posterior incisors, and calloused soles.

Two types of camels are known: the swift-footed two-humped Bactrian, living mainly in the Asian steppes, and the one-humped dromedary, common to the Sahara. The dromedary can also run fast, but prefers a measured caravan pace, which covers 4-4.5 km per hour. A pack camel can carry a load of up to 200 kg for weeks, being content with a small amount of water and food, and doing thirty to forty kilometers daily.

A camel can go without water for a long time. In its hump, it contains fat, from which water is formed as a result of transformations. In addition, with sweat, he releases a small amount of liquid. During the day, when the sun is burning, his body temperature rises to 40C, only after that he begins to sweat, which allows him to conserve a lot of water. At night, when the air temperature drops, the camel's body temperature drops significantly, sometimes even up to 34C.

Conclusion

It is difficult to count the number of species living in the Sahara. But according to approximate data, there are about 1,400 plant species and about 100 animal species in the desert now. In this abstract, examples of only some species are given, their descriptions are given. Also in this work, the features of organisms living in the Sahara are revealed.

Bibliography

1. Babaev A.G., Drozdov N.N., Zonn I.S. Deserts. - M.: Thought, 1986. - 318 p.

2. Wagner J. Africa: heaven and hell for animals. - M.: Thought, 1987. - 350 p.

3. Wagner F.Kh. Desert living world. - L.: Gidrometeoizdat, 1994. - 248 p.

4. Sahara / Ed. V.E. Sokolov. - M.: Progress, 1990. - 424 p.

5. Fukarek F., Hempel V., Huebel G. Plant world of the Earth./Ed. F. Fukareka. - M.: Mir, 1982. - T 2 - 184 p.

6. Höfling G. Hotter than hell / Per. with him. M.S. Osipova, Yu.M. Frolova. - M.: Thought, 1986. - 208 p.

7. Shapovalova O.A. Africa. - M.: TERRA - book club, 2003. - 384 p.

Sahara desert on the map of the world and Africa

The Sahara is the greatest desert in the world, not by its size, but by its influence on history and modern life. Mankind lived in the Sahara many millennia ago, as evidenced by more than 3 thousand rock paintings in various parts of the desert.

And now the Sahara has a huge impact on the political, economic and cultural life of North Africa.

Because of their huge The size of the Sahara is characterized by a rather diverse climate, soil type, living conditions and local inhabitants - from the Arabs in the north to the Negro peoples in the south of the desert.

What continent is it on?

The Sahara is located in the northern part African continent and extends from the coast in the north to the tropical savannas of the Sahel in the south at 16 ° N. sh., from the coast of the Atlantic Ocean in the west to the east of the continent.

Which country does it belong to?

The following African states are wholly or partially located on the territory of the Sahara:

Libya;
Tunisia;
Algeria;
West Sahara;
Mauritania;
Mali;
Niger;
Chad;
Sudan.

History of origin and name

Scientists believe that in 5th-4th millennium BC e. trees grew on the territory of the Sahara, the earth's surface was covered with grasses and shrubs, and water resources were represented by numerous lakes.

Presumably, complex desertification began at the same time due to a decrease in moisture and the predominance of evaporation of moisture over precipitation.

Cause This could be both natural factors (climate change) and an anthropogenic factor - the transition of local tribes to a pastoral type of animal husbandry, which led to desertification. On the other hand, such a transition could be caused by the transformation of the once flourishing savannahs into a desert.

Be that as it may, for about a thousand years The Sahara turned into a desert, and the process of desertification was completed by the middle of the 3rd millennium BC. e.

The name Sahara is believed to be derived from the Arabic word "ṣaḥārā" which means "desert". Another version of the origin of the name is from the Arabic "sahra", which means "red-brown". The name of the desert has been recorded since the 1st century AD. e. after the Arabic-speaking tribes reached the Sahara.

If acquaintance with the Sahara is accompanied by a vacation in Tunisia, then find out what the weather conditions are in the country for months.

Climatic conditions

The climate of the Sahara deserted(arid), a characteristic feature of which is the predominance of evaporation processes over moisturizing processes.

The southern part of the desert has dry tropical climate with hot summers and mild winters. The amount of precipitation per year is usually about 130 mm. In winter, at night, the air temperature can drop below zero, and in summer it often reaches +50°C.

The northern part of the desert has dry subtropical climate with hot summers and relatively cold winters. The average air temperature in summer reaches +37°C, and in winter in mountainous areas it can drop to -18°C. This part of the desert is characterized by high daily fluctuations in air temperature due to night cooling. The average annual rainfall does not exceed 75 mm.

Sandy sea - what is it?

Sahara - active desert, which annually increases its area, moving south by 10 km.

Characteristics of the Endless Sands

About a quarter of the sugar is made up of sand dunes, a quarter - from mountains of volcanic origin, and half from barren rocky plains and rocks. The area of the territory of sustainable vegetation does not exceed a few percent.

One of the reasons for the dryness of the Sahara is the presence of the Atlas Mountains in the north of the desert, which block the access of humid Mediterranean air to the Sahara.

The central part of the Sahara, where the least amount of annual precipitation is observed (no more than 20 mm per year) is one of the most lifeless places on earth. The average biomass in this part of the desert drops to 2 kg/ha or less.

Area the desert is almost 9 million km², which is equal to almost 30% of the territory of Africa. The desert stretches for 4.8 thousand km from west to east and for 1.2 thousand km from north to south.

Water sources in the Sahara are:

artesian groundwater, above the surface of which oases are located;
rainwater, which fills gelts (ponds or natural puddles) and wadis (drying channels of ancient rivers filled with rainwater);
major rivers on the outskirts of the desert (Nile, Niger).

Flora and fauna

A significant part of the desert has no vegetation at all and is a classic sand. Mostly dry climate-resistant plants grow in oases and high-altitude areas (grass, small shrubs and trees). Oases grow a variety of cultivated plants: dates, olives, figs, vegetables.

Fauna The Sahara is mainly represented by various species of rodents and reptiles, as well as birds, more than half of which are migratory. Large mammals include antelopes, rams, Nubian donkey. Predators - spotted hyena and cheetah. Most of the animals of the Sahara are active at night, when the heat is not so great.

For those wishing to visit the deeper places of the Sahara, it is recommended to get to Erga Shigaga- a conglomerate of sand dunes in the heart of the Moroccan Sahara. There is a campground here, where tourists can expect all the benefits of civilization available in the desert.

Picturesque Shigaga, which measures 30 by 15 km, exceeds any expectations: countless untouched dunes, almost devoid of vegetation, stretch to the end of the horizon.

Another popular route in the Moroccan Sahara is a trip to Ergu Shebbi through the village of Merzouga. Erg Chebbi is as colorful as Shigagu, but getting to him is a little more difficult.

Mauritania

Mauritania is located almost entirely within the Sahara, but trips here are rare due to the poverty of the local population, the lack of infrastructure and the rather high crime rate in the country.

For those who decide on a tour to this exotic country, it will be interesting to visit Adrar plateau, which houses the UNESCO World Heritage sites - the villages of Ouadan and Chinguetti. On the plateau itself, despite its lifelessness, there are more than 20 large oases, including the rather large city of Atar.

Algeria

Algeria is a country with greatest the territory of the Sahara in its composition, more than 80% of the country's area is occupied by the desert.

The most stunning desert landscapes are located in the southeastern part of Algiers at the foot of the Tassili mountains.

Tassil Plateau- one of the objects of the UNESCO list, the oldest petroglyphs were found in local caves, the age of which is from 2 to 9 thousand years.

Others man-made attractions Algerian Sahara are:

city of Ouargla;
Mzab valley with fortified cities.

These settlements are of great value from a historical and architectural point of view and were founded and built up in the 10th century. Ibadis- a branch of Muslims, different from Sunnis and Shiites.

Of the natural attractions of the Algerian part of the Sahara stands out Ahaggar highlands in the south of Algeria, consisting of volcanic remnants of bizarre shapes. The Ahaggar National Park is open on the territory, and the guides of tourists are local Tuareg residents, who will be interesting to get acquainted with the peculiar culture of any tourist.

The Sahara is the most famous desert. No wonder, because it is the largest desert in the world. It is located on the territory of 10 African states. The oldest text in which the Sahara appears as the "great" North African desert dates back to the 1st century AD. A truly endless sea of sand, stone and clay scorched by the sun, enlivened only by rare green spots of oases and a single river - this is what the Sahara is.

"Sahara" or "Sahra" is an Arabic word, it means a monotonous brown desert plain. Say this word aloud: do not you hear in it the wheezing of a man choking with thirst and sizzling heat? We Europeans pronounce the word "Sahara" softer than Africans, but it also conveys to us the formidable charm of the desert.

The word "Sahara" is associated with images of endless, hot sand dunes with very rare emerald green oases. But in reality, here, in the vast expanses of the Sahara, you can find almost any kind of desert landscape. In the Sahara, in addition to sand dunes, there are barren rocky plateaus strewn with stones; there are unusual fantastic geological formations; you can also see thickets of thorny bushes.

The Sahara stretches from the dry, thorny plains of northern Sudan and Mali to the shores of the Mediterranean Sea, where its sands cover the ruins of ancient Roman cities. In the east, it crosses the Nile and meets the waves of the Red Sea, and five thousand kilometers from there in the west it reaches the Atlantic Ocean. Thus, the Sahara occupies the entire north of Africa, stretching for 5149 km. from Egypt and Sudan to the western coasts of Mauritania and Western Sahara. The world's largest desert covers an area of 9,269,594 sq. km.

The Sahara is an arid desert, and not a single river intrudes into its borders. In many places, it receives less than 250 mm of precipitation per year, and in some parts of the Sahara it does not rain for years. The main desert area is located inland, and the prevailing winds have time to absorb moisture before it penetrates into the heart of the desert. The mountain ranges that separate the desert from the sea also force the clouds to pour rain, preventing them from passing further inland. Since clouds are rare here, the desert heat is relentless during the day. After sunset, hot air rises into the upper atmosphere, so that temperatures can drop below freezing at night. Kebili, where the temperature rises to 55 ° C, is one of the hottest places in the desert, not only because of the scorching sun, but also because it lies in the path of the sirocco, the wind that originates in the burning heart of the desert and drives north as hot as from the oven, air. The highest temperature on Earth in the shade + 58 ° was recorded here.

The sand dunes of the Sahara are extremely mobile in places and they move across the desert under the influence of wind at a speed of up to 11 m per year. Huge areas of rolling sand dunes, each occupying an area of up to 100 square kilometers, are known as ergi. The famous oasis of Fagja lives under the constant threat of impending dunes with all-suffocating sand. It is interesting that in other regions of the Sahara, dunes practically stand for millennia, and the depressions between them serve as permanent caravan routes.

The arid lands of the Sahara have never been cultivated, and only nomadic tribes roam here with small herds. From an economic point of view, most of the Sahara desert is not productive, and only in a few oases does diversified agriculture develop. Recently, serious concern has been caused by the onset of the desert in the territories adjacent to the Sahara. This phenomenon occurs when the wrong choice of agricultural methods is combined with natural factors such as drought and strong winds, and leads to the onset of the desert. The elimination of native vegetation weakens the soil, which is then dried out by the sun; the wind blows it away in the form of dust, and the desert reigns where shoots once rose.

The Tuareg, forever roaming the most remote and uninhabited regions of the Sahara, are called "blue ghosts". A blue veil that covers the face so that only a strip for the eyes remains, the young man receives at a family holiday when he turns eighteen years old. From that moment on, he becomes a man, and never again in his life, day or night, does he remove the veil from his face and will only move it a little away from his mouth while eating.

Although many areas of the Sahara are covered with sand, a much larger area is occupied by waterless plains strewn with large stones and pebbles polished by the wind. And in the very heart of the Sahara stretched ridges of sandstone cliffs that stick out vertically on the plateau of Tassilin-Adjer. Here they form an amazing labyrinth of dips, bizarre crooked columns and curved arches. Many resemble modern tower houses, and shallow caves are visible in their foundations. The lower columns often resemble skewed mushrooms. All these fantastic figures were sculpted by the wind, which picked up pebbles and sand, gouging and scratching the surface of the rocks, cutting horizontal furrows in the cliffs, deepening the cracks between the layers of sandstone. Exposed, sun-baked rock, not covered by vegetation or soil, gradually crumbles into sand, which other winds then carry away to other areas of the desert, to pile them up there.

In some places, under the ledges, on the walls of shallow caves, you can find animals painted in bright yellow and red ocher - gazelles, rhinos, hippos, horse antelopes, giraffes. There are also drawings of domestic animals - herds of motley cows and bulls with graceful horns, and some with a yoke around their necks. The artists also depicted themselves: they stand among their herds, sit near the huts, hunt, pulling their bows, dance in masks.

But who were these people? Perhaps the ancestors of the nomads who still follow the herds of semi-wild, long-horned, spotted cattle that roam among the thorny bushes beyond the southern border of the desert. The time when these drawings were applied to the rocks is not precisely established, but several styles are clearly distinguished in them, from which it clearly follows that this period was very long. According to most experts, the earliest drawings appeared about five thousand years ago, but none of the depicted animals currently lives on the hot barren sands and pebbles of the Sahara. And only in a narrow gorge with steep walls stands a bunch of old cypresses, the rings on the trunks of which indicate an age of at least two to three thousand years. They were young trees when the last drawings adorned the rocks in the neighborhood. Their thick, gnarled roots have carved their way through the sun-shattered slabs, widening cracks and overturning debris in their stubborn quest to find their way down to the underground moisture. Their dusty needles manage to turn green, resting the eye from the monotonous brown and rusty-yellow tones of the surrounding rocks. Their branches still bear cones with live seeds under the scales. But not a single seed is accepted. The ground is too dry.

And this , remember, we have already discussed it.

Climate change, which turned the Tassili plateau and the entire Sahara into a desert, lasted a very long time. They began about a million years ago, when the great glaciation that fettered the then world began to wane. The glaciers that had crept in from the Arctic, covering the entire North Sea with a hardened pack, and in Europe reached the south of England and the north of France, began to recede. As a result, the climate in this area of Africa became more humid, and Tassili dressed in greenery. But about five thousand years ago, the rains began to fall further south, and the Sahara became more and more dry. The shrubs and grass that covered it died from lack of moisture. Small lakes have evaporated. Animals and people living in it migrated in search of water and pastures further south. The soil was weathered and the former fertile plain, sparkling with wide lakes, eventually transformed into a realm of bare stones and loose sand ...

The sun governs all life in the Sahara. The desert is hot during the day and cold at night. Daily fluctuations in air temperature reach more than thirty degrees. But a person endures the heat of the day more easily than the cold of the night. Oddly enough, but in the Sahara people during the year suffer more from cold than from heat.
Long-lasting storms have the most severe effect on a person. Dust and sand storms are a majestic sight. They are like fires, quickly covering everything around. Puffs of smoke rise high into the sky. With furious force they rush through the plains and mountains, knocking out stone dust from the destroyed rocks in their path.
After hot days with storms, the air in the Sahara is highly electrified. If at this time in the dark you remove one blanket from the other, then the space between them is illuminated by sometimes crackling sparks. Not only from hair, clothes, but even from sharp iron objects, electric sparks can be extracted.

Storms in the Sahara are often of extraordinary strength. The wind speed reaches, according to some researchers, 50 m per second or more. There is a known case when, during a storm, camel saddles were thrown two hundred meters. It happens that the wind moves stones the size of a chicken egg without lifting them from the ground.

Knowing the wind regime is very important for traveling in the Sahara. One day in February in Erg Shegi a storm held a traveler under a rock for nine days. Connoisseurs of the Sahara have calculated that in the desert, on average, out of a hundred days, only six are calm. Unfortunately, little is known about the origin and laws of wind movement. in desert.
Destructive hot winds in the north of the Sahara. They come from the center of the desert and can destroy crops in a few hours. These winds most often blow in early summer and are called "sirocco", in Morocco they are called "shergi", in Algerian Sahara - "Shekhilli", in Libya - "Gebli", in Egypt - "Samum" or "Khamsin". They don't just move sand AND DUST, but also mountains of small pebbles pile up.

Sometimes there are tornadoes for a short time. These are rotating air currents that take the form of pipes. They arise in the daytime due to the heating of scorched earth and become visible due to the rising dust. Luckily, those "sand devils" that dance like ghosts in the mist only deal damage occasionally. Sometimes sand pipes break away from the ground, continuing their life in the high layers of the atmosphere. The pilots met dust devils at an altitude of 1500 m.

The Sahara has not always been a lifeless land.

As further studies confirmed, even during the Paleolithic period, that is, 10-12 thousand years ago (during the Ice Age), the climate here was much more humid. The Sahara was not a desert, but an African steppe-savannah. The population of the Sahara was engaged not only in cattle breeding and agriculture, but also in hunting and even fishing, as evidenced by rock paintings in different parts of the desert.

In many parts of the Sahara, ancient cities were buried under a layer of sand; this may be indicative of a comparatively recent desiccation of the climate.

Scientists at Boston University seem to have found another piece of evidence that the Sahara was not always a desert. According to the Center for Remote Sensing of Boston University, in the northwestern region of Sudan there used to be a huge lake, almost equal in area to Lake Baikal. Now a huge body of water, which because of its size was called Megalake, is hidden under the sands.

Boston University scientists in the northwestern region of Sudan, in the middle of the Sahara, Dr. Eman Ghoneim and Dr. Farouk El-Baz studied photographic and radar images of the Darfur region in order to accurately determine the location of the lake. According to their scientific data, the shoreline of the lake was once about 573 meters (plus or minus 3 meters) above sea level.

Researchers suggest that several rivers flowed into the lake at once. The maximum area that Megalake once occupied was 30,750 sq. km. In addition, the authors of the study calculated that at the best of times, the volume of water in the lake could reach 2,530 cubic meters. km.

Currently, scientists cannot accurately determine the age of the lake, but state another fact that the size of the Megalake indicates constant rains, due to which the volume of the reservoir was regularly replenished. The find once again confirms that before the territory of the Sahara was not always a desert. It lay within the temperate zone and was covered with plants.

Scientists led by El-Baz also suggest that most of the Megalake has seeped into the soil and now exists in the form of groundwater. This information is extremely important for local residents, as it can be used for purely practical purposes. The fact is that this particular region of Sudan is experiencing a severe shortage of fresh water, and the discovery of groundwater would be a gift for them.

Then, about 5-7 thousand years ago, a drought began, the heat increased, the surface of the Sahara lost moisture more and more, the grass dried up. Gradually, herbivores began to leave the Sahara, predators followed them. The animals had to retreat to the distant forests and savannahs of Central Africa, where all these representatives of the so-called Ethiopian fauna still live. Almost all people left the Sahara for animals, and only a few were able to survive where there was still some water left. They became nomads wandering in the desert. They are called Berbers or Tuareg, and the "father of history" Herodotus called this tribe the Garamantes - after the main city of Garama (modern Germa).

By this time, scientists also attribute the appearance of most of the famous frescoes of Tas-sili-Adzher, a plateau located in the center of the great desert. The name itself means "plateau of many rivers" and recalls the distant time when life flourished here. Fat herds and caravans carrying ivory are the central theme of the painting. There are also dancing people in masks and mysterious giant images of the so-called "Martian gods". Much has been written about the latter. The mystery of their origin still excites the minds: either they represent a scene of shamans' rituals, or aliens abducting people.

Sahara is, in fact, not the name of one particular desert, but the collective name of a number of deserts connected by a single space and climatic features. Its eastern part is occupied by the Libyan desert. On the right bank of the Nile, up to the Red Sea, the Arabian Desert extends, to the south of which, entering the territory of Sudan, the Nubian Desert is located. There are other, smaller deserts. Often they are separated by mountain ranges with fairly high peaks.

There are powerful mountains with peaks up to 2500 thousand meters in the Sahara, and the extinct crater of the Emi-Kusi volcano, whose diameter is 12 km, and plains covered with sand dunes, hollows with clay soil, salt lakes and salt marshes, blooming oases. All of them replace and complement each other. There are also giant cavities. One of them is located in Egypt in the northeastern part of the Libyan Desert. This is Qatar, the driest depression on our planet, its bottom is 150 m below sea level.

In general, the Sahara is a vast plateau, a table, the flat character of which is broken only by the depressions of the Nile and Niger valleys and Lake Chad. On this plain, only in three places do truly high, albeit small in area, mountain ranges rise. These are the highlands of Ahaggar (Algeria) and Tibesti (Chad) and the Darfur plateau, rising more than three kilometers above sea level.

The mountainous, gorge-cut, absolutely dry landscapes of Ahaggar are often compared to lunar landscapes.

To the north of them are closed saline depressions, the largest of which turn into shallow salt lakes during the winter rains (for example, Melgir in Algeria and Dzherid in Tunisia).

The surface of the Sahara is quite varied; vast expanses are covered with loose sand dunes, rocky surfaces carved into bedrock and covered with rubble (hamada) and gravel or pebbles (regi) are widespread.

In the northern part of the desert, deep wells or springs provide water to oases, thanks to which date palms, olive trees, grapes, wheat and barley are grown.

All the oases of the Sahara are surrounded by palm groves. Date palms are the basis of life for the locals. Dates and camel milk are the main food of fellah farmers.

It is assumed that the groundwater that feeds these oases comes from the slopes of the Atlas, located 300–500 km to the north. All life is concentrated mainly in the marginal parts of the Sahara. The largest human settlements are concentrated in the northern regions. Naturally, there are no roads connecting the oases. Only after the discovery and development of oil, several highways were built, but along with them, camel caravans continue to run.

In the east the desert is cut by the Nile valley; since ancient times, this river has provided residents with water for irrigation and created fertile soil, depositing silt during annual floods; the regime of the river changed after the construction of the Aswan Dam.

Few people dare to travel in the Sahara. During a difficult journey, mirages may occur. Moreover, they always come across in approximately the same place. Therefore, it was even possible to draw up maps of mirages, on which 160 thousand marks were made on the location of mirages. These maps even mark what exactly is seen in one place or another: wells, oases, palm groves, mountain ranges, and so on.

It is difficult to find a more beautiful sight than the sunset in the desert. Perhaps only the aurora borealis makes a greater impression on the traveler. The sky in the rays of the setting sun each time strikes with a new combination of shades - it is both blood-red and pink-pearl, imperceptibly merging with pale blue. All this is piled up on the horizon in several floors, it burns and sparkles, growing into some kind of bizarre, fabulous forms, and then gradually fades away. Then, almost instantly, an absolutely black night sets in, the darkness of which even the bright southern stars cannot dispel.

These days, the Sahara is not so difficult to access. From the city of Algiers on a good highway to the desert can be reached in one day. Through the picturesque gorge El Kantara - "Gateway to the Sahara" - the traveler finds himself in amazing places. To the left and right of the road, which runs along a rocky and clay plain, small rocks rise, which the wind and sand have given the intricate outlines of fairy-tale castles and towers.

In the Northern Sahara, the influence of the Mediterranean flora is significant, and in the south, species of the Paleotropical Sudanese flora widely penetrate into the desert. About 30 endemic genera of plants are known in the flora of the Sahara, belonging mainly to the families of cruciferous, haze and Compositae. In the most arid, extra-arid regions of the Central Sahara, the flora is especially poor.

So, in the south-west of Libya, only about nine species of native plants grow. And in the south of the Libyan desert, you can travel hundreds of kilometers without finding a single plant. However, there are regions in the Central Sahara that are distinguished by comparative floristic richness. These are the desert highlands of Tibesti and Ahaggar. In the Tibesti highlands, near water sources, willow-leaved ficus and even venus hair fern grow. On the Tassini-Adgenre plateau, northeast of Ahanar, there are relic plants: individual specimens of the Mediterranean cypress.

The Sahara is dominated by ephemera, appearing for a short time after rare rains. Perennial xerophytes are common. The most extensive in terms of area are grass-shrub desert plant formations (various types of Aristide grass). The tree-shrub layer is represented by free-standing acacias, low-growing xerophytic shrubs - cornulaca, randonia, etc.). In the northern belt of grass and shrub communities, jujube is often found.

In the extreme west of the desert, in the Atlantic Sahara, special plant groups are formed with the dominance of large succulents. Cactus euphorbia, acacia, dereza, sumac grow here. An Afghan tree grows near the ocean coast. At altitudes of more than 1700 m, here (highlands and plateaus of the Central Sahara) begin to dominate: cereals, feather grass, bonfire, ragwort, mallow, etc. The most characteristic plant of the Saharan oases is the date palm.

In the Sahara, there are about 70 species of mammals, about 80 species of nesting birds, about 80 species of ants, more than 300 species of dark beetles, and about 120 species of orthoptera. Species endemism in some groups of insects reaches 70%, in mammals it is about 40%, and in birds there are no endemics at all.

Of the mammals, rodents are the most numerous. Representatives of the family of hamsters, mice, jerboas, squirrels live here. Gerbils are diverse in the Sahara (red-tailed gerbil is common). Large ungulates in the Sahara are not numerous, and the reason for this is not only the harsh conditions of the desert, but also the long-term persecution of them by man. The largest antelope in the Sahara, the aryx, is slightly smaller than the addax antelope. Small antelopes, similar to our gazelles, are found in all regions of the Sahara. On the coasts and plateaus of Tibesti, Ahaggar, as well as in the mountains on the right bank of the Nile, a maned ram lives.

Let's digress a little from serious topics and take a walk ... through the Sahara Desert. Although in real life, many of us are unlikely to be able to do this. The hot sand will not allow you to walk on foot, as on some summer days the sand heats up to 80 degrees. And not everyone will be able to go to Africa to take a tour through the desert by bus.

But here we can take a virtual walk in the desert, and even learn interesting facts about this amazing desert. So, go!

Sahara Desert - geographical location

The Sahara Desert is the largest desert in the world. It is located in the north and occupies a third of the African continent, which is slightly larger than the territory of a state such as Brazil. It stretches over an area of about 8.6 million km². From west to east, the length of the desert is 4800 km, from north to south - 800-1200 km. On the western side, the desert borders the Atlas Mountains and is washed by the Mediterranean Sea, and from the east - the Red Sea, from the south is the Sahel - a transitional region to the Sudanese savannah.

There are 10 states in the desert: Algeria, Egypt, Western Sahara, Libya, Mauritania, Mali, Morocco, Sudan, Tunisia and Chad.

Life in the desert without water is impossible, but despite this, almost 2.5 million people live in the desert. They lead a settled way of life in oases in the valleys of the Nile and Niger rivers, where there is water and vegetation. The most numerous peoples of the desert are Tuareg and Berbers.

Features of the Sahara Desert

In our view, the desert is sands and dunes that move with the help of the wind. But the sands in the Sahara desert occupy only a fifth. The thickness of the sands is about 150 meters. The sands are swept into dunes, the height of some sometimes reaches the height of the Eiffel Tower in Paris. There is so much sand in the desert that if every person living on our planet had to scoop out sand with the help of 10-liter buckets, they would have to take out 3 million buckets.

70% of the territory of the desert is occupied by mountains - sandstones, and the remaining 10% - sand and pebble wastelands, on which you will not even see a trace of vegetation - this is barren rocky land and salt marshes.

Sahara Desert. Safari

On the territory of the Sahara there is the city of Tegazi, the walls of the houses in which are made of rock salt. But the inhabitants of this city are not afraid that their houses can be dissolved from the rains. This is the driest place on Earth.

Climate

Until recently, it was believed that the Sahara desert appeared about 5 million years ago. But at present, scientists believe that the lands of the modern Sahara became deserted only 2.7 thousand years ago.

The heat in the desert is still the same! In the sun, or rather in an open place, it is simply impossible to be. In summer, the air temperature rises to 58°C, and in winter - up to 15-28°C, which is typical for annual temperature fluctuations. We have such a temperature in summer, and in the desert - in winter! Such differences in annual temperatures are observed more often in the northern regions of the desert. But the differences during the day and at night are noted within 20-25 °.

The climate of the Sahara is determined by the northeast trade wind, very often there are sandstorms that even reach Europe. The climate in the north of the desert is dry subtropical, in the south - dry tropical.

Water

Life in the desert is concentrated only around water. The largest river in the Sahara Desert is the Nile. Its main tributaries - the Blue and White Nile - merge in the southeast of the Sahara, passing along the eastern side of the desert, flows into the Mediterranean Sea. In the sixties of the XX century, a large Nasser reservoir was created, which formed Lake Toshka when it flooded. The Niger River flows along the southwestern outskirts of the Sahara, near the inner delta of which there are lakes Fagibin, Garu, Niangai, and others.

River Nile near Luxor

Precipitation in the desert is rare. And what sometimes spills in the rain does not reach the ground, evaporating on the way from hot sand. The Sahara is one of the places where evaporation is several times higher than the amount of precipitation.

But the most interesting thing is that under the sands of the Sahara, there are huge "deposits" of groundwater, which are larger than our Baikal in area.

The subterranean waters of the Sahara are used for irrigation. The first mention of irrigation systems refers to the culture of Ancient Egypt. It can be said with certainty that the Egyptians developed a technique for irrigating the land. The Egyptians cut through many parallel small channels perpendicular to the movement of the Nile. Some of them converge into basins, from which water was distributed over irrigated lands, providing them with moisture.

Mirages

Mirages are another interesting fact in the Sahara Desert. How many people, traveling through the desert, have seen suddenly appeared oases with water and palm trees, thinking that it is about 2-3 km from them. In fact, sometimes you have to walk 500 or more kilometers to the nearest water.

A mirage is an optical phenomenon in the atmosphere - there is a refraction of a stream of light at the boundary between layers of air of different density and temperature.

More than 150 thousand mirages are observed in the Sahara. Even maps have been created of places where they can be seen and even what can be seen: an oasis, a river or a well. The difference from reality lies in the fact that along with the actually visible image of the object, its reflection in the atmosphere is visible.

Dear readers! You can read more about the amazing African country - Egypt and its ancient city of Luxor.

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Be healthy! Taisiya Filippova was with you.

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