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Deserts of Australia, Great Victoria Desert, Great Sandy Desert, Tanami Desert, Gibson Desert, Simpson Desert. Natural areas of Australia - many deserts and few forests Natural areas of Australia - deserts and semi-deserts

The most arid central regions of the continent occupy the largest areas of Australia. There are a variety of terrain types here, from shifting sands, salt marshes, gravelly rocky areas to thorny forests. However, two groups dominate: 1) acacia formation Mulga-scrub; 2) formation dominated by spinifex grass, or triodni. The latter dominates the most deserted central regions.

Acacia shrub and low-growing (3-5 m) tree-shrub deserts and semi-deserts are similar in nature to the dry thorny woodlands of Somalia or the Kalahari on African continent. The northern variants of these groups, with a short summer wet period and an abundance of tall termite mounds, can also be considered as an extreme arid variant of the savannah and woodland zone. The dominant plant almost everywhere is ours - veinless acacia - and other phyllodes species. The number of eucalyptus and casuarina trees is small; they are confined to dry river beds and extensive depressions with close groundwater. The grass cover is often almost absent or represented by very sparse groups of grasses, saltworts and other leafy succulents.

The sandy areas in the center and west of the continent are covered with thickets of extremely xeromorphic hard grasses of the genus Triodia. In Queensland and New South Wales, a prickly pear cactus has proliferated and become a nasty weed. Prickly pear was brought from South America in the 80s of the last century and settled over an area of about 24 million hectares.

Unlike the Sahara and Namib, the deserts of Australia do not have significant areas of “absolute” deserts, practically free from higher plants. In drainless basins and along the shores of salt lakes, halophytic formations formed special types widespread ancient genera (solyanka, quinoa, parfolia, prutnyak, saltpeter). Schober's saltpeter also grows in the semi-deserts of Eurasia. The Nullarbor Plain adjacent to the Great Australian Bight has semi-desert vegetation that already develops in a subtropical, close to temperate, climate. It is dominated by tall (up to 1.5 m) bushes of various halophytes - representatives of the goosefoot (hodgepodge, quinoa, etc.), which are considered a good forage plant for sheep. On the plain, due to the widespread occurrence of karst phenomena, there are almost no surface water bodies.

Some botanists believe that true deserts are almost never found in Australia, and semi-deserts predominate. Indeed, the density of vegetation cover in arid regions of the continent is usually relatively large, which is associated with regular short wet season. The annual amount of precipitation is never below 100 mm, but usually it is close to 200-300 mm. In addition, in many places there is a shallow aquifer, where moisture is retained for a long time and is available to plant roots.

Animal world. In the faunal aspect, the fauna of the arid inland regions of Australia as a whole is a depleted version of dry savannah and light forest groups. Most species are found in both deserts and savannas, although a number of groups of animals are especially numerous in desert and semi-desert habitats. Among mammals, such typical animals include the marsupial mole, marsupial jerboa, comb-tailed marsupial mice and comb-tailed marsupial rat. The entire central and western parts of the continent are inhabited by large red kangaroos. These animals are numerous in many places and are considered undesirable competitors for sheep. The same applies to smaller wallaby species. Of the smallest species of the kangaroo family (smaller than a rabbit), kangaroo rats are interesting for their ability to carry a “load” - an armful of grass, wrapping it with their long tail. Many species of kangaroo rats widely inhabited almost the entire continent, but are now severely exterminated by introduced dogs and foxes, and are also replaced by rabbits, which colonize and destroy their original habitats. Therefore, now they are better preserved in desert areas, where the influence of introduced animals is less felt. The most common dog here is the dingo. In some areas, feral dromedary camels, brought to the mainland in the last century as a means of transport on expeditions, have multiplied.

The most famous bird of the semi-desert regions of the mainland is the emu. This is the only species (sometimes two closely related species are distinguished) of a special family related to cassowaries. Weaverbirds and small parrots feeding on cereal seeds (including triodia) are common throughout arid regions. These are the already mentioned zebra finch, budgerigars, and nymph parakeets. All these species nest in hollows of dry trees. The night parrot is very typical for arid regions. This is truly a nocturnal bird. She spends most of her time on the ground; her diet is based on triodia seeds. Unlike most other parrots, the night parrot makes its nest not in hollows, but among thickets of thorny grasses.

Of the vertebrate animals, various reptiles are especially characteristic of deserts and semi-deserts, of which lizards of the agamidae, skink and monitor lizard families predominate. The Lepidopus family, characteristic of Australia, which includes snake-like lizards with reduced limbs, also has desert representatives. Among the agamidae in the tropical northern regions of dry woodlands and semi-deserts there are frilled lizards, which are also characteristic of the savannah. Species of this genus have the ability to run on two hind limbs. This method of movement was characteristic of some Mesozoic dinosaurs. Several species of bearded lizards, similar to our common dragons, live in deserts. The most original appearance of Moloch. This small, up to 20 cm, flat lizard is all covered with outgrowths and spines. Moloch's skin can absorb moisture. In its lifestyle and appearance it resembles the American desert toad-like lizards. Moloch's main source of nutrition is ants.

Skinks are mainly endemic to Australia (sometimes including New Zealand) genera, species of which live both in deserts and in other zones. There are especially many species of the endemic genus Ctenotus - small graceful lizards with smooth scales.

All Australian deserts lie within the Central Australian region of the Australian Floristic Kingdom. Although in terms of species richness and level of endemism desert flora Australia is significantly inferior to the flora of the western and northeastern regions of this continent, but compared to other desert regions globe it stands out both in the number of species (more than 2 thousand) and in the abundance of endemics. Species endemism here reaches 90%: there are 85 endemic genera, of which 20 are in the family Compositae, or Asteraceae, 15 - Chenopodiaceae and 12 - Cruciferae.

Among the endemic genera there are also background desert grasses - Mitchell's grass and triodia. Large numbers species are represented by the legume, myrtle, proteaceae and asteraceae families. Significant species diversity is demonstrated by the genera Eucalyptus, Acacia, Proteaceae - Grevillea and Hakea. In the very center of the continent, in the gorge of the deserted MacDonnell Mountains, narrow-area endemics have been preserved: the low-growing Liviston palm and Macrozamia from the cycads.

Even some types of orchids settle in deserts - ephemeral ones that germinate and bloom only in a short period after the rains. Sundews also penetrate here. The depressions between the ridges and the lower part of the slopes of the ridges are overgrown with clumps of the prickly grass triodia. The upper part of the slopes and the ridges of dune ridges are almost completely devoid of vegetation; only individual curls of the prickly grass Zygochloa settle on the loose sand. In interbarchan depressions and on flat sandy plains, a sparse tree stand of casuarina, individual specimens of eucalyptus, and veinless acacia is formed. The shrub layer is formed by Proteaceae - these are Hakea and several types of Grevillea.

In slightly saline areas in depressions, saltwort, ragodia and euhilena appear. After the rains, the interridge depressions and lower parts of the slopes are covered with colorful ephemerals and ephemeroids. In the northern regions on the sands of the Simpson and Great Sandy Deserts species composition the background grasses change somewhat: other species of triodia, plectrahne and shuttlebeard, dominate there; the diversity and species composition of acacias and other shrubs becomes greater. Along the channels of temporary waters, gallery forests of several species of large eucalyptus trees form. The eastern edges of the Great Victoria Desert are occupied by sclerophyllous mum scrub scrub. The southwestern Great Victoria Desert is dominated by low-growing eucalypts; The grass layer is formed by kangaroo grass, feather grass species and others.

The arid areas of Australia are very sparsely populated, but the vegetation is used for grazing.

Climate

In the tropical climate zone, which occupies the territory between the 20th and 30th parallel in the desert zone, a tropical continental desert climate is formed. A subtropical continental climate is common in southern Australia adjacent to the Great Australian Bight. These are the marginal parts of the Great Victoria Desert. Therefore, in the summer, from December to February, average temperatures reach 30 ° C, and sometimes higher, and in winter (July - August) they drop to an average of 15-18 ° C. In some years, the entire summer period temperatures can reach 40° C, and winter nights in the vicinity of the tropics drop 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” southeastern trade winds, since most of moisture is retained by the mountain ranges of Eastern Australia. The central and western parts of the country, corresponding to about half the area, receive an average of about 250-300 mm of precipitation per year. The Simpson Desert receives the least amount of precipitation, from 100 to 150 mm per year. Precipitation season in northern half The continent, where the monsoon change of winds dominates, is confined to the summer period, and, in its southern part, dry conditions prevail during this period. It should be noted that the amount of winter precipitation in the southern half decreases as one moves inland, rarely reaching 28° S. In turn, summer precipitation in the northern half, having the same trend, does not extend south of the tropic. Thus, in the zone between the tropics and 28° S. latitude. there is a belt of aridity.

Australia is characterized by excessive variability in average annual precipitation and uneven distribution throughout the year. The presence of long dry periods and high average annual temperatures prevailing over large parts of the continent cause high annual evaporation values. In the central part of the continent they are 2000-2200 mm, decreasing towards its marginal parts. Surface water continent are extremely poor and extremely unevenly distributed over the territory. This especially applies to the desert western and central regions of Australia, which are practically drainless, but make up 50% of the continent's area.

The exceptional originality and antiquity of the flora and fauna of Australia is explained by its long isolation. Most plant (75%) and animal (90%) species in Australia are endemic, i.e. they are not found anywhere else in the world. Among the animals there are few mammals, but species extinct on other continents have survived, including marsupials (about 160 species) (see Fig. 66 on p. 140). Characteristic representatives Australian flora are eucalyptus (600 species), acacia (490 species) and casuarina. The mainland has not given the world valuable cultivated plants.

Australia is located in four geographical zones- from subequatorial to moderate. The change in natural zones is due to changes in temperatures and precipitation patterns. The flat nature of the relief contributes to a well-defined latitudinal zonality, which is disrupted only in the east. The main part of the continent lies in tropical latitudes, so the greatest development has been achieved tropical desert and semi-deserts, occupying half the area of the continent.

Rice. 66. Endemic animals of Australia: 1 - kangaroo; 2 - frilled lizard; 3 - emu; 4 - koalas; 5 - platypus; 6 - echidna

Natural areas

In the subequatorial and tropical geographical zones, significant territories are occupied by savannah And woodlands . The zone arcs across the Carpentarian Plain and the Central Lowland. There are wet, typical and desert savannas, developing respectively on red, red-brown and red-brown soils. In subequatorial latitudes they replace each other from north to south, and in tropical latitudes - from east to west as moisture decreases. The Australian savannah is open spaces with a herbaceous cover of bearded vulture, alang-alang, with individual trees or groves of eucalyptus, acacia, casuarina and moisture-storing baobab Gregory (“bottle tree”). In the interior regions, thickets of low-growing thorny bushes with small leathery foliage appear - scrubs, consisting of drought-resistant species of acacias, eucalyptus and casuarinas (Fig. 67).

An integral part of the Australian savannas are marsupials - kangaroos (red, gray, hare, wallaby), wombats. Large ones are typical flightless birds- emu, cassowary, Australian bustard. Budgerigars breed their chicks in eucalyptus woodlands. Termite buildings - termite mounds - are ubiquitous.

There are a total of 60 species of kangaroos in Australia. In nature, they “replace” absent herbivorous ungulates. Kangaroo cubs are born tiny and immediately move into their mother's pouch - a fold of skin on her abdomen, where they spend the next 6-8 months, feeding on milk. The weight of an adult kangaroo can reach 90 kg with a height of up to 1.6 m. Kangaroos are record holders in jumping: the length of their jumps reaches 10-12 m, and they can reach speeds of up to 50 km/h. The kangaroo, along with the emu, are depicted as national symbols on the coat of arms of the Commonwealth of Australia.

Rice. 67. Acacia scrub Fig. 68. Spinifex desert brown soils

The central parts of the continent in two geographical zones (tropical and subtropical) occupy deserts and semi-deserts . Australia is rightly called the continent of deserts(Big sandy desert, Great Victoria Desert, Gibson Desert, etc.). On the Western Australian Plateau, in a tropical continental climate, tropical deserts and semi-deserts dominate. In rocky and sandy semi-deserts Light forests of casuarinas stretch along the river beds. In the depressions of clayey semi-deserts there are thickets of quinoa and salt-tolerant species of acacias and eucalyptus trees. Deserts are characterized by “cushions” of the spinifex bushy grass (Fig. 68). The soils of semi-deserts are gray soils; desert soils are primitive rocky, clayey or sandy.

In the south of the mainland in the subtropics, deserts and semi-deserts occupy the Nullarbor Plain (“treeless”) and the Murray-Darling Lowland. They are formed under subtropical continental climate conditions on brown semi-desert and gray-brown soils. Against the background of dry rare grasses there is wormwood and solyanka; there is no tree and shrub vegetation.

Animals of deserts and semi-deserts are adapted to life in conditions high temperatures and little moisture. Some burrow underground, like the marsupial mole, marsupial jerboa, and kangaroo rat. Others, like the kangaroo and the dingo, are able to travel long distances in search of food and water. Lizards (moloch, frilled lizard) and the most poisonous land snake, the taipan, hide from the heat in the crevices of the rocks.

On the windward moistened slopes of the Great Dividing Range in four geographical zones (subequatorial, tropical, subtropical, temperate) zones have formed variable-humid forests . The northeastern edge of the continent in conditions monsoon climate occupied by subequatorial variable-humid forests. Palm trees, pandanus, ficus, and tree ferns grow in them on red-yellow ferrallite soils.

South of 20°S w. they are replaced by rich evergreen tropical forests on red soils and yellow soils, formed in humid conditions tropical climate. In addition to evergreen trees intertwined with vines and epiphytes (ficus, palm trees, southern beeches, silver tree), conifers appear - Australian cedar and Australian araucaria.

In the southeast of the mainland and the north of the island. In Tasmania, they are replaced by subtropical variable-humid forests. On mountain brown forest soils, mixed forests of eucalyptus, southern beech, podocarpus, agathis and araucaria grow. On the dry leeward slopes of the Great Dividing Range they give way to eucalyptus open forests. Temperate forests occupy only the extreme south of the island. Tasmania.

Eucalyptus is one of the symbols of the Australian continent. Its leaves, with their edges towards sunlight, form a crown that does not provide shade. The powerful root system of the tree is capable of drawing water from a depth of 30 m, so eucalyptus trees are planted to drain waterlogged areas all over the world. The fast-growing eucalyptus is used not only in woodworking, but also in medicine thanks to its essential oils.

In the extreme southwest of the continent, in a Mediterranean climate, the zone is widespread dry hard-leaved forests and shrubs . Eucalyptus forests with xanthorea (“grass tree”) grow on yellow soils and red soils; towards the center of the continent they are replaced by scrubs.

The fauna of Australian forests is richer. This is the kingdom of marsupials: tree kangaroo, marsupial squirrel, marsupial bear(koala), marsupial marten(couscous). “Living fossils” found refuge in the forests - the platypus and the echidna. The world of forest birds is diverse: lyrebird, bird of paradise, cockatoos, weed chickens, kookaburras. Lots of snakes and lizards (methyst python, giant monitor lizard). Narrow-snouted crocodiles lie in wait for prey in rivers. In the 20th century The marsupial wolf was completely exterminated.

Ecological problems

During colonization in Australia, about 40% of all forests were cleared, with tropical rainforests suffering the most. Deforestation has resulted in depletion of vegetation cover, soil degradation and changes in animal habitats. Rabbits brought by the colonists also caused damage to the local fauna. As a result, more than 800 species of animals have become extinct over the past 500 years.

Global warming is having an increasing impact on the continent's nature. Due to decreased rainfall, droughts have become more frequent and Forest fires. Rivers with a constant flow have become shallow, and rivers that are drying up have ceased to fill even during the rainy season. This has led to the encroachment of deserts onto savannas - desertification, aggravated by overgrazing, which affects 90 million hectares of land. In the areas of the “wheat-sheep belt”, land use is difficult due to salinization and soil erosion.

The most acute problem in Australia is the scarcity of water resources. Previously, this problem was solved by pumping groundwater from numerous wells. But currently a decrease in water level has been recorded in artesian pools. The depletion of groundwater reserves, along with a decrease in river flows, has exacerbated water shortages in Australia, forcing the implementation of water conservation programs.

One of the ways to preserve nature is to create specially protected natural areas. They occupy 11% of the continent's area. One of the most visited national parks is Kosciuszko in the Australian Alps. In the north there is one of the world's largest parks - Kakadu, where not only wetlands that serve as habitat for many endemic birds are protected, but also caves with Aboriginal rock art. The Blue Mountains Park protects stunning mountain landscapes with a variety of eucalyptus forests. The nature of deserts (parks) is also taken under protection Great Victoria Desert, Simpson-Desert). The giant red sandstone monolith Ayers Rock, sacred to the Aboriginal people, is recognized as a UNESCO World Heritage Site in Uluru-Katayuta Park (Fig. 69). The fabulous world of corals is protected in an underwater park Great Barrier Reef.

In big barrier reef there is the greatest diversity of corals on the planet (up to 500 species). A threat, in addition to coastal water pollution and poaching, is posed by polyp-eating Starfish"crown of thorns" Temperature increase ocean waters Global warming is causing coral bleaching and death.

Bibliography

1. Geography 8th grade. Textbook for the 8th grade of general secondary education institutions with Russian as the language of instruction / Edited by Professor P. S. Lopukh - Minsk “People's Asveta” 2014

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

Even the rest is seasonally dry.

This suggests that Australia is the driest continent on the globe.

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

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

Great Sandy Desert

The Great Sandy Desert or Western Desert is a sandy-salt desert in the north-west of Australia (Western Australia).

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

It gradually decreases 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 ridges of sand dunes, the average height of which is 10-12 m, the maximum 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, Mackay in the east, Gregory in the north, which is fed by the Sturt Creek River.

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

The desert is covered with red sands; the dunes are predominantly inhabited by prickly xerophytic grasses (spinifex, etc.). The dune ridges are separated by clay-salt plains, on which acacia shrubs (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 several Aboriginal groups, including the Karadjeri and Nygina tribes. It is assumed that the interior of the desert may contain minerals. In the central part of the region there is national park Rudall River, in the far south is the World Heritage-listed Uluru-Kata Tjuta National Park.

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

Great Victoria Desert

The Great Victoria Desert is a sandy-salt desert in Australia (the 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 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 in the desert there is a protected area called Mamungari, one of 12 biosphere reserves Australia.

Average annual precipitation varies from 200 to 250 mm of rain. Thunderstorms occur frequently (15-20 per year). Daytime temperatures in summer are 32--40 °C, in winter 18--23 °C. Snow never falls in the desert.

The Great Victoria Desert is inhabited by several Aboriginal Australian groups, including the Kogarah and Mirning peoples.

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 a plateau that is composed of Precambrian rocks and covered with rubble resulting from the destruction of an ancient ferruginous shell. An early explorer of the region described it as “a vast, rolling 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. The desert is bordered on the west by the Hamersley Range. In Western and eastern parts consists of long parallel sandy ridges, but in the central part the relief levels out. In the western part lie several salt marsh lakes, including the 330 km² Disappointment Lake, which borders the Great Sandy Desert.

Precipitation is extremely irregular, its amount does not exceed 250 mm per year. The soils are sandy, rich in iron, and highly weathered. In some places there are thickets of veinless acacia, quinoa and spinifex grass, which bloom with bright colors after rare rains.

In 1977, a reserve (Gibson Desert Nature Reserve) was organized on the territory of the Gibson Desert, the area of which is 1,859,286 hectares. The reserve is home to many desert animals, such as great bilbies (threatened with extinction), red kangaroos, emus, Australian duckweed, striped grass wren and moloch. Birds flock to Disappointment Lake and neighboring lakes, which appear after rare rains, in search of protection from the dry climate.

Populated primarily by Australian Aborigines, the desert area is used for extensive grazing. The desert was discovered in 1873 (or 1874) by the English expedition of Ernest Giles, who crossed it in 1876. The desert received its name in honor of expedition member Alfred Gibson, who died in it while searching for water.

Small Sandy Desert

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

Located south of the Great Sandy Desert, in the east it becomes 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 large “sister”.

The area of the region is 101 thousand km². The average annual precipitation, which falls mainly in 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. The internal flow, the main watercourse is Savory Creek, flows into Disappointment Lake, located in the northern part of the region. There are also several small lakes in the south. The headwaters of the Rudall and Cotton rivers are located near the northern borders of the region. Spinifex grass grows in red sand soils.

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 damaged. About 4.6% of the bioregion's territory has conservation status.

There are no large settlements within the desert. Most of the land belongs to the Aborigines, their largest settlement is Parnngurr. Crossing the desert to the northeast is the 1,600 km long Canning Cattle Trail, the only route through the desert running from the town of Wiluna through Disappointment Lake to Halls Creek.

Simpson Desert

The Simpson Desert is a sandy desert in central Australia, mostly located in the south-eastern 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, bounded from the west by the Finke River, from the north by the MacDonnell Range and the Plenty River, from the east by the Mulligan and Diamantina rivers, and from the south by the large salt Lake Eyre.

The desert was discovered by Charles Sturt in 1845 and was named Arunta in Griffith Taylor's 1926 drawing. After surveying the area from the air in 1929, geologist Cecil Medigen named the desert after Allen Simpson, president of the South Australian Branch of the Royal Geographical Society Australasia. It is believed that the first European to cross the desert was Medigen in 1939 (on camels), but in 1936 it was done by the expedition of Edmund Albert Colson.

In the 1960s-80s, oil was searched unsuccessfully in the Simpson Desert. At the end of the 20th century, the desert became popular among 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 south-eastern part, and clayey near the shores of Lake Eyre. Sand dunes 20-37 m high stretch from northwest to southeast over distances of up to 160 km. In the valleys between them (450 m wide) the spinifex grass grows, fixing sandy soils. There are also xerophytic shrubby acacias (veinless acacia) and eucalyptus trees.

The Simpson Desert is the last refuge for some of Australia's rare desert animals, including the comb-tailed marsupial. Vast parts of the desert received the status of protected areas:

· Simpson Desert National Park, western Queensland, organized in 1967, occupies 10,120 km²

· Simpson Desert conservation park, South Australia, 1967, 6927 km²

· regional reserve Simpson Desert, South Australia, 1988, 29,642 km²

· Wijira National Park, northern South Australia, 1985 7770 km²

In the northern part, precipitation is less than 130 mm, dry creek beds are lost in the sand.

The Todd, Plenty, Hale, and Hay rivers flow through the Simpson Desert; in the southern part there are many drying up 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. There was a desert the last frontier Northern Territory and was little explored by Europeans until the 20th century.

The Tanami Desert occupies the central part of Australia's Northern Territory and a small area of north-eastern Western Australia. Located southeast of the desert locality Alice Springs, and to the west the Great Sandy Desert.

The desert is a typical central regions Australia is a desert steppe with vast sandy plains that are covered with grasses of the genus Triodia. The main landforms are dunes and sand plains, as well as shallow water basins of the Lander River, which contain water holes, dry marshes 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 region is 429.7 mm, which is high for a desert area. But due to high temperatures, the rain that falls quickly evaporates, so local climate is very dry. The average daily evaporation rate is 7.6 mm. The average daytime temperature in the summer months (October-March) is about 36--38 °C, night temperature is 20--22 °C. The temperature in the winter months is much lower: daytime is about 25 °C, nighttime is below 10 °C.

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

The first European to reach the desert was explorer Geoffrey Ryan 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 has a small population due to unfavorable climatic conditions. The traditional inhabitants of the Tanami are the Australian Aborigines, namely the Walrpiri and Gurindji tribes, who are the land owners of much of the desert. The largest settlements are Tennant Creek and Wauchope.

Gold mining is carried out in the desert. Tourism has been developing recently.

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 desert area makes up 1% of Australia. It was discovered by Europeans in 1845 and named after the Polish explorer Pawel Strzelecki. Also in Russian sources it is called the Streletsky Desert.

Stone Desert of Sturt

The rock desert, which occupies 0.3% of Australia's territory, is located in the state of South Australia and is a collection of sharp small stones. Local aborigines did not sharpen their arrows, but simply dialed stone tips 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's area, has some of the harshest climatic conditions in Australia, due to high temperatures and virtually no rain. The Tirari Desert is home to several salt lakes, including Lake Eyre. The desert was discovered by Europeans in 1866.

And semi-deserts are specific natural zones, the main distinguishing feature of which is drought, as well as poor flora and fauna. Such a zone can form in all climatic zones - the main factor is a critically low amount of precipitation. Deserts and semi-deserts are characterized by a climate with sharp daily temperature changes and low precipitation: no more than 150 mm per year (in spring). The climate is hot and dry, evaporates before it can be absorbed into the water. Temperature changes are characteristic not only of the change of day and night. The winter and summer temperature difference is also very large. General background weather conditions can be defined as extremely severe.

Deserts and semi-deserts are waterless, dry areas of the planet where no more than 15 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.

Sometimes the air in deserts in summer reaches 50 degrees in the shade, and in winter the thermometer drops to minus 30 degrees!

Such temperature changes cannot but affect the formation of the flora and fauna of the semi-deserts of Russia.

Deserts and semi-deserts are found in:

The tropical zone is most of these territories - Africa, South America, the Arabian Peninsula of Eurasia.
Subtropical and temperate zone- in South and North America, Central Asia, where the low percentage of precipitation is complemented by relief features.

There are also special types of deserts - Arctic and Antarctic, the formation of which is associated with very low temperatures.

There are many reasons why deserts arise. For example, the Atacama Desert receives little rainfall because it is located at the foot of the mountains, which cover it from rain with their ridges.

Ice deserts formed for other reasons. In Antarctica and the Arctic, the bulk of the snow falls on the coast; snow practically does not reach the interior regions. Precipitation levels generally vary greatly; one snowfall, for example, can result in a year's worth of precipitation. Such snow deposits form over hundreds of years.

Natural area desert

Climate features, desert classification

This natural area occupies about 25% of the planet's land area. There are 51 deserts in total, 2 of which are icy. Almost all deserts were formed on ancient geological platforms.

General signs

The natural zone called “desert” is characterized by:

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

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

Important! Almost all desert areas are surrounded by or near mountains.

Classification

There are different types of deserts:

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

Climatic conditions

The desert climate is warm and dry. The temperature depends on the geographical location: the maximum +58°C was recorded in the Sahara on September 13, 1922. Distinctive feature desert areas there is a sharp temperature drop of 30-40°C. During the day average temperature+45°C, at night - +2-5°C. In winter, the deserts in Russia can be frosty with light snow.

In desert lands it has low humidity. Strong winds with a speed of 15-20 m/s or more often occur here.

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

Semi-desert in Patagonia. Argentina

Flora

The desert flora is very sparse, consisting mainly of sparse shrubs that can extract moisture deep into the soil. These plants are specially adapted to live in hot and dry habitats. For example, a cactus has a thick waxy outer layer to keep water from evaporating. Sagebrush and desert grasses need very little water to survive. Desert and semi-desert plants have adapted to protect themselves from animals by growing sharp needles and thorns. Their leaves are replaced by scales and spines or covered with hairs that protect the plants from excessive evaporation. Almost all sand plants have long roots. In sandy deserts, in addition to herbaceous vegetation, there is also shrub vegetation: zhuzgun, sand acacia, teresken. Shrub plants are low and poorly leafy. Saxaul also grows in deserts: white on sandy soils, and black on saline soils.

Flora of desert and semi-desert

Most desert and semi-desert plants bloom in the spring, reproducing flowers until the hot summer begins. In the years wet winter and spring, semi-desert and desert plants can produce a surprising number of spring flowers. In desert canyons, on rocky mountains they get along pine trees, junipers and sage grow. They provide shelter from the scorching sun for many small animals.

The least known and underestimated species of desert and semi-desert plants are lichens and cryptogamous plants. Cryptogamous or secretogamous plants - spore fungi, algae, pteridophytes, bryophytes. Cryptogamous plants and lichens need very little water to survive and live in dry, hot climates. These plants are important because they help stop erosion, which is very important for all other plants and animals because it helps keep the soil fertile during high winds and hurricanes. They also add nitrogen to the soil. Nitrogen is an important nutrient for plants. Cryptogamous plants and lichens grow very slowly.

Annual ephemerals and perennial ephemeroids grow in clay deserts. In solonchaks there are halophytes or solyankas.

One of the most unusual plants that grow in such areas are saxaul. It often moves from place to place under the influence of the wind.

Fauna

The fauna is also sparse - reptiles, spiders, reptiles or small steppe animals (hare, gerbil) can live here. Among the representatives of the order of mammals, the camel, antelope, wild ass, steppe sheep, and desert lynx live here.

To survive in the desert, animals have a specific sandy coloration, can run fast, dig holes and for a long time live without water and are preferably nocturnal.

Among the birds you can find the raven, saxaul jay, and desert chicken.

Important! In sandy deserts there are sometimes oases - this is a place that is located above the accumulation of underground water. There is always dense and abundant vegetation and ponds here.

Leopard in the Sahara desert

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

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