12 May 2013

The presence of natural zones on the mainland and their location directly depend on the climatic zones. Based on the fact that Australia is considered the driest continent, it becomes clear that there simply cannot be a lot of diversity. But on the other hand, the natural zones of Australia have an extraordinary uniqueness of flora and fauna.

Many deserts and few forests

On the smallest continent, zoning is well traced. This is due to the prevailing flat relief. Natural areas of Australia are gradually replacing each other in the meridional direction following changes in temperature and precipitation.

The southern tropic crosses the mainland almost in the middle, and most of its territory is located in the hot tropical climatic zone, which makes the climate arid. Australia is in last place among all continents in terms of annual precipitation. Most of its territory receives only 250 mm of precipitation during the year. In many parts of the continent, not a drop of rain has fallen for several years.

Australia, whose natural zones divide the continent into three parts, in the east and west has several zones stretching along the coast, where the amount of precipitation is noticeably higher. The mainland is in first place in terms of the relative area of ​​desert regions and in last place in terms of forest area. In addition, only 2% of Australia's forested areas are of industrial importance.

Features of natural areas

Savannahs and woodlands are located in the subequatorial climatic zone. The vegetation is dominated by herbs, among which grow acacias, eucalyptus, bottle trees.

In the east of the mainland, in conditions of sufficient moisture, there are such natural areas of Australia as tropical rainforests. Among palms, ficuses and tree ferns, marsupial anteaters, wombats, and kangaroos live.

Natural areas of Australia differ from similar areas on other continents. For example, semi-deserts and tropical deserts occupy vast areas on the mainland - almost 44% of its territory. In the Australian deserts, you can find unusual thickets of dry thorny bushes called scrubs. Semi-desert areas, overgrown with tough grasses and shrubs, are used as pastures for sheep. There are also large sandy deserts, which differ from the deserts of other continents in that there are no oases in them.

In the southeastern part and in the southwest of the continent, there are subtropical forests, in which eucalyptus and evergreen beech grow.

The originality of the organic world

The flora of Australia, due to its long isolation from other continents, has a large number of endemic plants. Almost 75% of them can be seen only here and nowhere else. More than 600 species of eucalyptus trees, 490 species of acacia and 25 species of casaurines are found on the mainland.

The fauna is even more peculiar. Almost 90% of animals are endemic. Only in Australia can you find mammals that disappeared on other continents a long time ago, for example, the echidnu and the platypus, ancient primitive animals.

Source: fb.ru

Actual

Miscellaneous
Miscellaneous

Deserts and semi-deserts are waterless, dry areas of the planet, where no more than 25 cm of precipitation falls per year. The most important factor in their formation is wind. However, not all deserts experience hot weather; some of them, on the contrary, are considered the coldest regions of the Earth. Representatives of flora and fauna have adapted to the harsh conditions of these areas in different ways.

How do deserts and semi-deserts arise?

There are many reasons for the emergence of deserts. For example, there is little rainfall because it is located at the foot of the mountains, which, with their ridges, cover it from rain.

Ice deserts were formed for other reasons. In Antarctica and the Arctic, the bulk of the snow falls on the coast; snow clouds practically do not reach the interior regions. The level of precipitation generally varies greatly, for one snowfall, for example, an annual norm may fall. Such snow deposits form over hundreds of years.

Hot deserts are distinguished by the most varied relief. Only a few of them are completely covered with sand. The surface of most is dotted with pebbles, stones and other miscellaneous rocks. Deserts are almost completely open to weathering. Strong gusts of wind pick up fragments of small stones and hit them against the rocks.

In sandy deserts, the wind carries sand across the area, creating undulating sediments called dunes. The most common type of dunes are dunes. Sometimes their height can reach 30 meters. Ridge dunes can be up to 100 meters high and extend for 100 km.

Temperature regime

The climate of deserts and semi-deserts is quite varied. In some regions, daytime temperatures can reach 52 ° C. This phenomenon is due to the absence of clouds in the atmosphere, thus, nothing saves the surface from direct sunlight. At night, the temperature drops dramatically, again due to the absence of clouds that can trap the heat radiated from the surface.

In hot deserts, rains are rare, but sometimes heavy showers occur here. After the rain, the water is not absorbed into the soil, but rapidly flows from the surface, washing away soil particles and pebbles into dry channels, which are called wadis.

Location of deserts and semi-deserts

On the continents, which are located in northern latitudes, there are deserts and semi-deserts of the subtropical and sometimes tropical ones - in the Indo-Gangetic lowland, in Arabia, in Mexico, in the southwestern United States. In Eurasia, extratropical desert regions are located in the Central Asian and South Kazakh plains, in the basin of Central Asia and in the Near Asian highlands. The Central Asian desert formations are characterized by a sharply continental climate.

In the southern hemisphere, deserts and semi-deserts are less common. Here are located such desert and semi-desert formations as Namib, Atacama, desert formations on the coast of Peru and Venezuela, Victoria, Kalahari, Gibson Desert, Simpson, Gran Chaco, Patagonia, Great Sandy Desert and Karoo semi-desert in southwestern Africa.

Polar deserts are located on the continental islands of the periglacial regions of Eurasia, on the islands of the Canadian archipelago, in the north of Greenland.

Animals

Animals of deserts and semi-deserts for many years of existence in such areas have managed to adapt to the harsh climatic conditions. From cold and heat, they hide in underground burrows and feed mainly on underground parts of plants. Among the fauna, there are many species of carnivores: fennec fox, cougars, coyotes and even tigers. The climate of deserts and semi-deserts has contributed to the fact that many animals have a well-developed thermoregulation system. Some desert dwellers can withstand fluid loss of up to a third of their weight (for example, geckos, camel), and among invertebrates there are species that can lose water up to two-thirds of their weight.

In North America and Asia, there are a lot of reptiles, especially a lot of lizards. Snakes are also quite common: fphas, various poisonous snakes, boa constrictors. Of the large animals, there are saiga, kulans, camels, pronghorn; it has recently disappeared (it can still be found in captivity).

Desert and semi-desert animals of Russia are a wide variety of unique fauna representatives. The desert regions of the country are inhabited by sandstone hares, hedgehogs, kulan, jeyman, poisonous snakes. In the deserts that are located on the territory of Russia, you can also find 2 types of spiders - karakurt and tarantula.

Polar deserts are inhabited by polar bears, musk ox, arctic fox and some bird species.

Vegetation

If we talk about vegetation, then in deserts and semi-deserts there are various cactus, stiff-leaved grasses, psammophyte shrubs, ephedra, acacia, saxaul, soap palm, edible lichen and others.

Deserts and semi-deserts: soil

The soil, as a rule, is poorly developed; water-soluble salts prevail in its composition. Among them are dominated by ancient alluvial and loess-like deposits, which are recycled by winds. Gray-brown soil is inherent in elevated flat areas. Deserts are also characterized by salt marshes, that is, soils that contain about 1% of readily soluble salts. In addition to deserts, salt marshes are also found in steppes and semi-deserts. Groundwater, which contains salt, when it reaches the surface of the soil, is deposited in its upper layer, as a result of which salinization of the soil occurs.

Quite different are characteristic of such climatic zones as subtropical deserts and semi-deserts. The soil in these regions has a specific orange and brick-red color. Noble for its shades, it received the appropriate name - red soil and yellow soil. In the subtropical zone in northern Africa and in South and North America, there are deserts where gray soils have formed. In some tropical desert formations, red-yellow soils have formed.

Natural and semi-deserts are a huge variety of landscapes, climatic conditions, flora and fauna. Despite the harsh and cruel nature of the deserts, these regions have become home to many species of plants and animals.

Australia is often referred to as the continent of deserts because about 44% of its surface (3.8 million sq. km) is occupied by arid territories, of which 1.7 million sq. km. km - deserts.

Even the rest is seasonally dry.

This allows us to say that Australia is the driest continent on the globe.

Deserts of Australia is a complex of desert regions located in Australia.

The deserts of Australia are located in two climatic zones - tropical and subtropical, with most of them occupying the last belt.

Great Sandy Desert


The Great Sandy Desert or Western Desert is a sandy-saline desert in northwestern Australia (Western Australia).

The desert has an area of ​​360,000 km² and lies approximately within the boundaries of the Canning sedimentary basin. It stretches 900 km west to east from Eighty Mile Beach on the Indian Ocean deep into the Northern Territories to the Tanami Desert, and 600 km north to south from the Kimberley region to the Tropic of Capricorn, passing into the Gibson Desert.

It slopes gently to the north and west, the average height in the southern part is 400-500 m, in the north - 300 m.The predominant relief is sand dune ridges, the average height of which is 10-12 m, the maximum height is up to 30 m Ridges up to 50 km long are elongated in the latitudinal direction, which is determined by the direction of the prevailing trade winds. The region is home to numerous salt marsh lakes that occasionally fill with water: Disappointment in the south, McKie in the east, Gregory in the north, which is fed by the Sturt Creek River.

The Great Sandy Desert is the hottest region in Australia. In the summer period from December to February, the average temperature reaches 35 ° C, in winter - up to 20-15 ° C. Precipitation is rare and irregular, mainly brought in by the summer equatorial monsoons. In the northern part, about 450 mm of precipitation falls, in the southern - up to 200 mm, most of it evaporates and seeps into the sands.

The desert is covered with red sands; the dunes are dominated by thorny xerophytic grasses (spinifex, etc.). The dune ridges are separated by clay-saline plains, on which acacia bushes (in the south) and low-growing eucalyptus trees (in the north) grow.

There is almost no permanent population in the desert, with the exception of a few aboriginal groups, including the Karadjeri and Nygina tribes. It is assumed that the bowels of the desert may contain minerals. In the central part of the region is the Rudall River National Park, in the far south - the Uluru-Kata Tjuta National Park, included in the World Heritage List.

Europeans first crossed the desert (from east to west) and described it in 1873 under the leadership of Major P. Warburton. The 1,600 km Canning Stock Route from Wiluna across Disappointment Lake to Halls Creek runs through the desert in a northeastern direction. In the northeastern part of the desert is the Wolf Creek crater.

Great Victoria Desert


The Great Victoria Desert is a sandy saline desert in Australia (states of Western Australia and South Australia).

The name in honor of Queen Victoria was given by the British explorer of Australia Ernest Giles, who in 1875 was the first European to cross the desert.

The area is 424 400 km², while the length from east to west is more than 700 km. To the north of the desert is the Gibson Desert, to the south is the Nullarbor Plain. Due to the unfavorable climatic conditions (arid climate), there is no agricultural activity in the desert. It is a protected area in Western Australia.

In the state of South Australia, the Mamungari Protected Area is located in the desert, one of Australia's 12 biosphere reserves.

Average annual rainfall ranges from 200 to 250 mm of rain. Thunderstorms are frequent (15-20 per year). Daytime temperatures are 32-40 ° C in summer and 18-23 ° C in winter. The desert never snows.

The Great Victoria Desert is inhabited by several groups of Australian Aborigines, including the Kogara and Myrning tribes.

Gibson Desert


The Gibson Desert is a sandy desert in Australia (in the center of Western Australia), located south of the Tropic of Capricorn, between the Great Sandy Desert in the north and the Great Victoria Desert in the south.

The Gibson Desert has an area of ​​155 530 km² and is located within the plateau, which is composed of Precambrian rocks and covered with rubble, which arose as a result of the destruction of the ancient ferruginous shell. One of the first explorers of the region described it as "a huge hilly gravel desert." The average height of the desert is 411 m, in the eastern part there are remnant ridges up to 762 m high, composed of granites and sandstone. From the west, the desert is bounded by the Hamersley Ridge. In the western and eastern parts, it consists of long parallel sandy ridges, but in the central part the relief is leveled. In the western part there are several salt marsh lakes, including Lake Disappointment with an area of ​​330 km², which is located on the border with the Great Sandy Desert.

Precipitation falls extremely irregularly, their amount does not exceed 250 mm per year. The soils are sandy, rich in iron, and strongly weathered. In some places there are thickets of veinless acacia, quinoa and spinifex, which bloom with bright flowers after rare rains.

In 1977, a Gibson Desert Nature Reserve was established on the territory of the Gibson Desert, with an area of ​​1,859,286 hectares. The reserve is home to many desert animals such as large bilbies (endangered), red kangaroos, emu, Australian avdotka, striped herbal wrens moloch. Birds flock to Lake Disappointment and neighboring lakes, which appear after rare rains, in search of protection from an arid climate.

Inhabited mainly by Australian aborigines, the desert area is used for extensive pastoralism. The desert was discovered in 1873 (or 1874) by the English expedition of Ernest Giles, who crossed it in 1876. The desert was named after a member of the expedition, Alfred Gibson, who died in it while searching for water.

Small Sandy Desert


The Small Sandy Desert is a sandy desert in western Australia (Western Australia).

Located south of the Great Sandy Desert, in the east it passes into the Gibson Desert. The name of the desert is due to the fact that it is located next to the Great Sandy Desert, but has a much smaller size. According to the characteristics of the relief, fauna and flora, the Small Sandy Desert is similar to its big "sister".

The area of ​​the region is 101 thousand km². The average annual rainfall, which falls mainly in the summer, is 150-200 mm, the average annual evaporation is 3600-4000 mm. Average summer temperatures range from 22 to 38.3 ° C, in winter this figure is 5.4-21.3 ° C. Internal flow, the main watercourse - Saving Creek, flows into Lake Disappointment, located in the northern part of the region. There are also several small lakes in the south. The sources of the Rudall and Cotton rivers are at the northern borders of the region. Spinifex grows behind the soils of red sand.

Since 1997, several fires have been recorded in the region, the most significant was in 2000, when 18.5% of the region's area was affected. About 4.6% of the bioregion's territory has a conservation status.

There are no large settlements within the desert. Most of the land belongs to the aborigines, the largest settlement is Parnngurr. The 1,600 km Canning Cattle Range Trail runs north-east across the desert, the only desert route running from Wiloon across Disappointment Lake to Halls Creek.

Simpson desert


The Simpson Desert is a sandy desert in the center of Australia, mostly located in the southeastern corner of the Northern Territory, and a small part in the states of Queensland and South Australia.

It has an area of ​​143 thousand km², in the west it is bounded by the Finke River, in the north by the McDonnell Ridge and the Plenty River, in the east by the Mulligan and Diamantina Rivers, and in the south by the large salt lake Eyre.

The desert was discovered by Charles Sturt in 1845 and was named Arunta in a 1926 drawing by Griffith Taylor, together with the Sturt desert. After surveying the area from the air in 1929, geologist Cecil Medigen named the desert after Allen Simpson, president of the South Australia chapter of the Royal Geographical Society of Australasia. It is believed that the first Europeans to cross the desert in Medigen in 1939 (on camels), but in 1936 the expedition of Edmund Albert Coulson made it.

In the 1960s and 1980s, the Simpson Desert was unsuccessfully looking for oil. At the end of the 20th century, the desert became popular with tourists; excursions in four-wheel drive vehicles are of particular interest.

The soils are predominantly sandy with parallel ridges of dunes, sandy-pebble in the southeastern part, and clayey near the shores of Lake Eyre. Sand dunes with a height of 20-37 m stretch from north-west to south-east for distances up to 160 km. In the valleys between them (450 m wide), spinifex grows, fixing sandy soils. There are also xerophytic shrub acacias (veinless acacia) and eucalyptus trees.

The Simpson Desert is the final refuge for some of the rare Australian desert animals, including the crested-tailed marsupial. Large parts of the desert have received the status of protected areas:

Simpson Desert National Park, West Queensland, organized in 1967, covers 10 120 km²

Simpson Desert Conservation Park, South Australia, 1967, 6927 km²

Simpson Desert Regional Reserve, South Australia, 1988, 29,642 km²

Ouijira National Park, northern South Australia, 1985 7770 km²

In the northern part of the rainfall is less than 130 mm, dry channels of cries are lost in the sands.

The Todd, Plenty, Hale, Hay rivers flow through the Simpson Desert; in the southern part there are many dry salt lakes.

Small settlements that raise livestock draw water from the Great Artesian Basin.


Australian desert fauna precipitation

Tanami is a rocky sandy desert in northern Australia. Area - 292,194 km². The desert was the last border of the Northern Territory and was little explored by Europeans until the 20th century.

The Tanami Desert covers the central part of the Northern Territory of Australia and a small area of ​​the northeastern part of Western Australia. To the southeast of the desert is the settlement of Alice Springs, and to the west is the Great Sandy Desert.

The desert is a typical central Australian desert steppe with extensive sandy plains covered with Triodia grasses. The main landforms are dunes and sandy plains, as well as shallow water basins of the Lander River, in which there are water pits, dry bogs and salt lakes.

The climate in the desert is semi-desert. 75-80% of precipitation falls in the summer months (October-March). The average annual rainfall in the Tanami area is 429.7 mm, which is a large figure for a desert area. But due to the high temperatures, the rain that falls quickly evaporates, so the local climate is very arid. The average daily evaporation rate is 7.6 mm. The average daily temperature in the summer months (October - March) is around 36-38 ° C, at night - 20-22 ° C. The temperature of the winter months is much lower: daytime - about 25 ° C, night - below 10 ° C.

In April 2007, the Northern Tanami Aboriginal Protected Area was established in the desert, covering an area of ​​about 4 million hectares. It is home to a large number of vulnerable representatives of the local flora and fauna.

The first European to reach the desert was explorer Geoffrey Ryan, who did so in 1856. However, the first European to explore the Tanami was Allan Davidson. During his expedition in 1900, he discovered and mapped local gold deposits. The area is home to a small number of people due to unfavorable climatic conditions. The traditional inhabitants of the Tanami are Australian aborigines, namely the Walrpiri and Gurinji tribes, who are the landowners of most of the desert. The largest settlements are Tennant Creek and Vauchope.

Gold is mined in the desert. Tourism has been developing lately.

Strzelecki Desert

The Strzelecki Desert is located in the southeast of the mainland in the states of South Australia, New South Wales and Queensland. The area of ​​the desert is 1% of the area of ​​Australia. It was discovered by Europeans in 1845 and named after the Polish explorer Pavel Strzelecki. Also in Russian sources it is called as the Streletsky Desert.

Desert Stone Desert

The Stone Desert, which occupies 0.3% of Australia's territory, is located in the state of South Australia and is a cluster of sharp small stones. The local aborigines did not sharpen their arrows, but simply collected stone points here. The desert got its name in honor of Charles Sturt, who in 1844 tried to reach the center of Australia.

Tirari Desert

This desert, located in the state of South Australia and occupying 0.2% of the mainland, has some of the harshest climatic conditions in Australia, due to high temperatures and almost no rain. There are several salt lakes in the Tirari Desert, including Lake Eyre. The desert was discovered by Europeans in 1866.

Australia is often referred to as the continent of deserts. Desert and arid territories occupy about 44% of the continent's surface.
They are common in the Western Australian Highlands and in the plains of Central Australia.

In the driest areas of the center of the mainland, large areas are stony placers or mobile sands.
In the Western Australian Highlands, stony deserts form on thick ferruginous crusts (a legacy of the humid ages). Their bare surface has a characteristic bright orange color.
On the Nullarbor Plain, composed of fractured limestones, the desert extends to the southern coast of the mainland.

Great Victoria Desert

The largest desert on the Australian continent.
Its size is about 424,400 km2.
The desert was first crossed by European explorer Ernest Giles in 1875 and named after Queen Victoria.
Average annual rainfall ranges from 200 to 250 mm of rain. Thunderstorms often happen (15-20 per year).
Daytime temperatures are 32-40 ° C in summer and 18-23 ° C in winter.
It is believed that the desert is endless sand dunes or lifeless rocky plains. However, the Great Victoria Desert looks different. Huge variety of shrubs and small plants. Wildflowers and acacias contrasting on the red sand are an unforgettable sight after a rare rain.
And without rain, the caves, rocks and gorges of the desert are mesmerizing.

Great Sandy Desert

The second largest after Victoria. The desert is located in the north of Western Australia, in the Kimberley region, east of Pilbara. A small part of it lies in the Northern Territory.
The desert has an area of ​​360,000 km²
The Great Sandy Desert is the hottest region in Australia.
In the summer period from December to February, the average temperature reaches 35 ° C, in winter - up to 20 -15 ° C.
It is here that the famous Kata Tjuta National Park - Uluru (Ayers Rock) is located, which attracts travelers from all over the world.

Tanami

The stony-sandy desert is located northwest of the city of Alice Springs, in the Northern Territory of Australia.
The average annual rainfall in this area is over 400 mm, that is, there are enough rainy days for the desert. But the location of Tanami is such that high temperature prevails, and with this a high evaporation rate.
The average daily temperature in the summer months (October-March) is about 38 ° C, at night 22 ° C. Temperatures in winter: daytime - about 25 ° C, nighttime - below 10 ° C.
The main landforms are dunes and sandy plains, as well as shallow water basins of the Lander River, in which there are water pits, dry bogs and salt lakes.
Gold is mined in the desert. Tourism has been developing lately.

Gibson Desert

Sandy desert in the center of Western Australia. It borders the Great Sandy Desert to the north and the Great Victoria Desert to the south.
One of the first explorers of the region described it as "a huge hilly gravel desert."
The soils are sandy, rich in iron, and strongly weathered. In some places there are thickets of veinless acacia, quinoa and spinifex, which bloom with bright flowers after rare rains.
Annual rainfall in the Gibson Desert can range from 200 to 250 millimeters. The climate is typically hot; in the south, temperatures in summer can rise above 40 ° C, in winter the maximum is about 18 ° C, and the minimum is 6 ° C.

Simpson Desert

The Simpson Desert is the main part of Uluru-Kata-Tjuta National Park in Australia.
This desert is famous for the fact that its sands are bright red and like crimson waves continuously roll over the desert.
The landscapes of this place amaze the imagination: between the high dunes there are areas of smooth clay crust and rocky plains strewn with turned stones. Simpson is the driest desert
The average temperature in summer (January) is 28-30 ° C, in winter 12-15 ° C. In the northern part, precipitation is less than 130 mm.

Small Sandy Desert

The Small Sandy Desert is a piece of land in Western Australia located south of the Great Sandy Desert, and in the east it merges into the Gibson Desert.

There are several lakes in the Small Sandy Desert, the largest of which is Disapointment Lake, located in the north. The Seyviori is the main river that runs through this area. It flows into Lake Disapoinmet.

The area of ​​the region is 101 thousand km². The average annual rainfall, which falls mainly in the summer, is 150-200 mm
Average summer temperatures range from 22 to 38.3 ° C, in winter this figure is 5.4-21.3 ° C

Tirari Desert

It covers an area of ​​15 thousand square kilometers, and it is located in the eastern part of South Australia.

The desert contains salt lakes and large sand dunes. There are quite harsh conditions, high temperatures and very little precipitation, the average annual amount of which does not exceed 125 millimeters.

It is also part of Australia's rocky ecoregion.

The Pinnacles

A small desert in the southwest of Western Australia. The name of the desert is translated as "desert of pointed rocks". The desert got its name for the freestanding stones rising by 1-5 meters in the middle of a sandy plain. The nearest settlement is the town of Cervantes, which is a 20-minute drive from the desert. Stones are rocks or peaks.

Te Pinnacles is part of Nambung National Park.
The landscapes in this part are exceptional, you might think that you are on another planet.
If you are a visitor to Nambung National Park, do not miss the opportunity to see the beautiful nature of the Te Pinnacles Desert.

It does not have a single sea, even large stable lakes and rivers are absent. Areas of central and western Australia are especially deserted. Here, in a year, no more than 250 mm of water reaches the surface of the earth; nevertheless, the prevailing part of the deserts is covered with vegetation. The predominant plant species are triode and acacia cereals. Sometimes these areas are used for grazing. However, animals require very large areas, as the vegetation is sparse and not very nutritious.

The flora of the deserts of Australia is quite diverse, there are more than 2 thousand species of endemics alone. Eucalyptus trees are very diverse and frequent. In places with a large amount of food, you can meet animals. The largest is the kangaroo. In general, marsupials are characteristic of Australia. The desert is inhabited by marsupial shrews, moles, badgers, marten, etc. Many deserts are completely "dressed" with sand dunes, although they are fixed with sparse vegetation. Only stony deserts are practically lifeless. Moving sand dunes are very rare.

Rivers and lakes are filled with water sporadically - during rare rains. The largest lake - Eyre, is in the desert. It is replenished with water very rarely, even in the rainy season the water of the screams (temporary rivers) does not always reach it. Great desert Victoria quite a harsh place, but nevertheless it became native to some tribes (Kogara, Mirning). There is no economic activity in the desert. Maybe that's why they set up a biosphere reserve here. The Simpson Desert is quite arid, although it has a number of saline lakes. In addition, it is rich in artesian waters, but they do not contribute to the development of vegetation. The surface of the desert is represented by sandy ridges interspersed with stony-gravel plains.

Great Sandy Desert

With an area of ​​360 thousand sq. km is located in the northwestern part of the continent, and is stretched out in a wide strip (over 1300 km) from the coast of the Indian Ocean to the McDonnell Ridges. The surface of the desert is elevated above sea level to an altitude of 500-700 m. The typical relief form is latitudinal sand ridges. The amount of precipitation in the desert varies from 250 mm in the south to 400 mm in the north. There are no permanent streams, although there are many other dry streams along the periphery of the desert.

Great australian desert

The aborigines who moved to Australia 50 thousand years ago are directly responsible for the fact that most of the country's territory has turned into a desert. As reported CNN , recent studies conducted by scientists from the Green Continent and the United States have shown that the cause of the natural cataclysm that destroyed most of the flora in the country could be the fires made by the aborigines. "The methods used to start the fire of the ancient inhabitants of Australia could lead to consequences that changed the climate and landscape of the country," says Gifford MILLER of the US University of Colorado. Gifford Miller).

Geological studies have shown that 125,000 years ago, Australia's climate was much more humid than it is today. Fires caused by Aboriginal bonfires could drastically reduce the area of ​​forests, thus changing the concentration of water vapor in the atmosphere. It became insufficient for the formation of clouds, and the climate became more arid. Such assumptions are confirmed by computer modeling of variations in climatic conditions on the continent. Paleontologists also argue that the animals that inhabited most of Australia in antiquity were better suited to life in forests than in deserts and semi-deserts. Scientists believe that it is man who is to blame for the fact that by the time the Europeans arrived in Australia, 85 percent of the species of large animals, such as eight-meter lizards and car-sized turtles, had become extinct.

At the moment, deserts, some of which are generally devoid of any vegetation, cover more than half of Australia. A significant part of the Australian deserts, namely those that occupied the western part of the continent, are located at some elevation - on a huge plateau about 200 meters above sea level. Some deserts rise even higher, up to 600 meters. Australia has several large sandy-pebble deserts, there are deserts and pure sandy, but most are covered with rubble and pebbles. All deserts of Australia are in approximately equal weather conditions - very little precipitation falls here, on average 130-160 millimeters per year. The temperature is above zero all year round - in January about +30 Celsius, in July at least +10.

Great Victoria Desert

The climatic conditions of Australia are determined by its geographical position, orographic features, the vast Pacific Ocean and the proximity of the Asian continent. Of the three climatic zones of the southern hemisphere, the deserts of Australia are located in two: tropical and subtropical, and most of them are occupied by the last belt. In the tropical climate zone, which occupies an area between the 20th and 30th parallel in the desert zone, a tropical continental desert climate is formed.

The subtropical continental climate is common in the southern part of Australia, adjacent to the Great Australian Bight. These are the outskirts of the Great Victoria Desert. Therefore, in the summer period, from December to February, the average temperatures reach 30 ° С, and sometimes even higher, and in winter (July - August) they decrease on average to 15-18 ° С. In some years, the entire summer period, temperatures can reach 40 ° C, and winter at night in the vicinity of the tropics drops to 0 ° C and below. The amount and territorial distribution of precipitation is determined by the direction and nature of the winds. The main source of moisture is the "dry" southeast trade winds, since most of the moisture is trapped in the mountain ranges of Eastern Australia.

The central and western parts of the country, corresponding to about half of the area, receive an average of about 250-300 mm of precipitation per year. The Simpson Desert receives the smallest amount of precipitation, from 100 to 150 mm per year. The season of precipitation in the northern half of the continent, where the monsoon change of winds prevails, is confined to the summer period, and in its southern part during this period arid conditions prevail. It should be noted that the amount of winter precipitation in the southern half decreases as it moves inland, rarely reaching 28 ° S. In turn, summer precipitation in the northern half, having the same tendency, does not spread south of the tropic. Thus, in the zone between the tropic and 28 ° S lat. there is a belt of aridity.

Australia is characterized by excessive variability in average annual precipitation and uneven precipitation throughout the year. Long dry periods and high average annual temperatures prevailing over a large part of the continent cause high annual evaporation rates. In the central part of the continent, they are 2000-2200 mm, decreasing towards its marginal parts. The surface waters of the continent are extremely poor and extremely unevenly distributed over the territory. This is especially true for the desert western and central regions of Australia, which are practically drainless, but account for 50% of the continent's area. The hydrographic network of Australia is represented by temporary drying up streams (cries). The runoff of the rivers of the Australian deserts belongs in part to the Indian Ocean basin and the Lake Eyre basin.

The mainland's hydrographic network is complemented by lakes, of which there are about 800, and a significant part of them are located in deserts. The largest lakes - Eyre, Torrance, Carnegie and others - are salt marshes or dry basins covered with a thick layer of salt. The lack of surface water is compensated by the abundance of groundwater. A number of large artesian basins stand out here (the Desert Artesian Basin, the Northwest Basin, the northern Murray Basin and part of Australia's largest groundwater basin, the Great Artesian Basin).

The soil cover of deserts is very peculiar. In the northern and central regions, red, red-brown and brown soils are distinguished (characteristic features of these soils are an acid reaction, color with iron oxides). In southern parts of Australia, sierozem-like soils are widespread. In Western Australia, desert soils are found on the outskirts of drainless basins. The Great Sandy Desert and the Great Victoria Desert are characterized by red sandy desert soils. Salt marshes and solonetzes are widely developed in the internal drainage depressions in southwestern Australia and in the Lake Eyre basin.

In terms of landscape, Australian deserts are divided into many different types, among which most often Australian scientists distinguish mountain and foothill deserts, structural plains deserts, rocky deserts, sandy deserts, clay deserts, pline. The most widespread are sandy deserts, occupying about 32% of the continent's area. Along with sandy deserts, rocky deserts are also widespread (they occupy about 13% of the area of ​​arid territories.

The foothill plains are an alternation of large-stony deserts with dry beds of small rivers. This type of deserts is the source of most of the country's desert watercourses and has always served as aboriginal habitat. Deserts of structural plains are found in the form of plateaus with a height of no more than 600 m above sea level. After sandy deserts, they are the most developed, occupying 23% of the area of ​​arid territories, mainly confined to Western Australia.

Flora of the australian desert

All of Australia's deserts lie within the Central Australian Region of the Australian Floristic Kingdom. Although in terms of species richness and level of endemism, the desert flora of Australia is significantly inferior to the flora of the western and northeastern regions of this continent, however, in comparison with other desert regions of the globe, it stands out both in the number of species (more than 2 thousand) and the abundance of endemics.

Species endemism reaches 90% here: it has 85 endemic genera, of which 20 are in the family of Compositae or Asteraceae, 15 are haze and 12 are cruciferous. Among the endemic genera, there are also background desert grasses - Mitchell's herb and Triodia. Families of legumes, myrtle, Proteanaceae and Compositae are represented by a large number of species. The genera eucalyptus, acacia, and proteaceae — grevillea and hakea — demonstrate a significant species diversity.

In the very center of the mainland, in the gorge of the McDonnell Desert Mountains, narrow-range endemics have survived: the undersized Liviston palm and the Macrozamia cicadaceae. Even some types of orchids - ephemerals that germinate and bloom only in a short period after rains - live in the deserts. Sundews also penetrate here. The inter-ridge depressions and the lower part of the slopes of the ridges are overgrown with clumps of thorny grasses of Triodia.

The upper part of the slopes and the ridges of the dune ridges are almost completely devoid of vegetation, only individual curtiles of the prickly grasses of the zygochloi settle on loose sand. A sparse forest stand of casuarina, individual specimens of eucalyptus, and veinless acacia is formed in inter-barnian depressions and on flat sandy plains. The shrub layer is formed by proteaceae - these are hakea and several types of grevillea. On slightly saline places in depressions, saltwort, ragodia and euhilena appear.

After the rains, the inter-ridge depressions and the lower parts of the slopes are covered with colorful ephemera and ephemeroids. In the northern regions, on the sands of the Simpson and Bolshoy Peschanaya Desert, the species composition of the background grasses changes somewhat: other species of Triodia, plectrachne, and shuttlebeard dominate there; the diversity and species composition of acacias and other shrubs becomes. Gallery forests of several species of large eucalyptus form along the bed of temporary waters. The eastern outskirts of the Great Victoria Desert are occupied by sclerophilous scrub mama scrub thickets. In the south-west of the Great Victoria Desert, stunted species dominate.

Ayers Rock

Ayers Rock is the oldest and largest monolithic rock on earth (its age is about 500 million years), towering in the middle of a flat red desert. Tourists and photographers from all over the world flock here to admire the fantastic color change at sunrise and sunset, when the rock passes through all shades from brownish brown to intense glowing red, to gradually "cool down", turn into a black silhouette with sunset. Ayers Rock was and remains a sacred Aboriginal rock, and many cave paintings have survived at its base. It also offers excursions to the gems of the Northern Territory such as Mt. Olgas / Kata Tjuta and Kings Canyon.