Tropical deserts of Australia animals and plants. Australia: natural areas

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

Vegetable world The deserts of Australia are quite diverse, with more than 2 thousand endemic species found here. Eucalyptus trees are very diverse and common. In places with a lot of food, you can meet animals. The largest is the kangaroo. In general, marsupials are characteristic of Australia. The desert is home to marsupial shrews, moles, badgers, martens, etc. Many deserts are completely covered with sand dunes, although they are also supported by sparse vegetation. Only rocky deserts are practically lifeless. Moving sand dunes are very rare.

Rivers and lakes fill with water sporadically - during rare rains. The largest lake is Air, is located in the desert. It is replenished with water very rarely; even in the rainy season, the water of the creeks (temporary rivers) does not always reach it. Great Desert Victoria a rather harsh place, but still it became native to some tribes (Koghara, Mirning). There are no economic activities in the desert. Maybe that's why they arranged it here biosphere reserve. The Simpson Desert is quite arid, although it does have a number of salt marsh lakes. In addition, it is rich in artesian waters, but they do not contribute to the development of vegetation. The desert surface consists of sandy ridges interspersed with rocky and rubble plains.

Big sandy desert

With an area of 360 thousand square meters. km is located in the northwestern part of the continent, and stretches in a wide strip (over 1300 km) from the coast of the Indian Ocean to the MacDonnell Ranges. The desert surface is elevated above sea level to a height of 500-700 m. Typical shape The relief 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 watercourses, although there are many other dry riverbeds 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 turned into desert. According to CNN , recent studies conducted by scientists from the Green Continent and the United States have shown that the cause of the natural disaster that destroyed most of the flora in the country could have been fires lit by the aborigines. “The fire-making practices of Australia’s ancient inhabitants may have had consequences that changed the country’s climate and landscape,” says Gifford MILLER, a fellow at the University of Colorado in the US. Gifford Miller).

Geological studies have shown that 125 thousand years ago, Australia's climate was much wetter than it is today. Fires caused by Aboriginal fires could have dramatically reduced forest area, thereby changing the concentration of water vapor in the atmosphere. It became insufficient for cloud formation, and the climate became drier. Similar assumptions are confirmed by computer modeling of variations in climate conditions on the continent. Paleontologists also argue that the animals that inhabited most of Australia in ancient times were better suited to living in forests rather than in deserts and semi-deserts. Scientists believe that it is humans who are to blame for the fact that by the time Europeans arrived in Australia, 85 percent of the species of large animals, such as eight-meter lizards and car-sized turtles, had become extinct.

Currently, deserts, some of which are devoid of any vegetation at all, cover more than half of Australia. A significant part of the Australian deserts, namely those that occupy the western part of the continent, are located at some elevation - on a huge plateau approximately 200 meters above sea level. Some deserts rise even higher, up to 600 meters. Australia has several large sand and pebble deserts, some are purely sandy, but most are covered with rubble and pebbles. All deserts of Australia are in approximately equal weather conditions - there is very little precipitation 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

Australia's climatic conditions are determined by its geographical location, orographic features, the vast area of the 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, with most of them occupied by the latter zone. In the tropical climatic zone, occupying 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 can reach 40°C, while 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" southeast trade winds, since most of the 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. The precipitation season in the northern half of the continent, where monsoon winds prevail, is confined to the summer period, and in the 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, dominant over a large part 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. The surface waters of the continent are extremely poor and extremely unevenly distributed throughout 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. Australia's hydrographic network is represented by temporary drying watercourses (creeks). The drainage of Australia's desert rivers belongs partly to the Indian Ocean basin and the Lake Eyre basin.

The continent's hydrographic network is supplemented by lakes, of which there are about 800, with a significant part of them located in deserts. The largest lakes - Eyre, Torrens, Carnegie and others - are salt marshes or dry basins covered with a thick layer of salts. The lack of surface water is compensated by wealth groundwater. There are a number of large artesian basins here (the Desert Artesian Basin, the North-West Basin, the northern part of the Murray River basin and part of the large basin groundwater in Australia - the Great Artesian Basin).

The soil cover of deserts is very unique. In the northern and central regions there are red, red-brown and brown soils ( characteristic features These soils are acidic, colored by iron oxides). IN southern parts In Australia, sierozem-like soils are widespread. In Western Australia, desert soils are found along the edges of drainless basins. The Great Sandy Desert and Great Victoria Desert are characterized by red sandy desert soils. In the drainless inland depressions in southwestern Australia and in the Lake Eyre basin, salt marshes and solonetzes are widely developed.

The foothill plains are an alternation of coarse rocky deserts with dry riverbeds small rivers. This type of desert is the source of most of the country's desert streams and has always served as habitat for Aboriginal people. Structural plain deserts occur as plateaus no more than 600 m above sea level. After sandy deserts, they are the most developed, occupying 23% of the area of arid territories, confined mainly to Western Australia.

Flora of the Australian desert

All Australian deserts lie within the Central Australian region of the Australian Floristic Kingdom. Although the desert flora of Australia is significantly inferior in species richness and level of endemism 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 in the abundance of endemics.

Species endemism here reaches 90%: there are 85 endemic genera, of which 20 are in the Asteraceae family, 15 in the Chenopoaceae family, and 12 in the Cruciferae family. Among the endemic genera there are also background desert grasses - Mitchell's grass and triodia. A large number of species are represented by the families of legumes, myrtaceae, proteaceae and asteraceae. 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 - ephemeral ones that germinate and bloom only in a short period after the rains - settle in deserts. 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 areas of the sands in the Simpson and Great Sandy Deserts, the species composition of background grasses changes somewhat: other species of Triodia, Plectrachne 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. In the south-west of the Great Victoria Desert, low-growing trees dominate.

Ayers Rock

Ayers Rock is the oldest and largest monolithic rock on earth (about 500 million years old), rising in the middle of a flat red desert. Tourists and photographers from all over the world flock here to admire the fantastic change of colors at sunrise and sunset, when the rock passes through all shades ranging from brown-brown to intense glowing red, to gradually “cool down”, turning into a black silhouette with sunset. Ayers Rock was and remains a sacred Aboriginal rock and there are many rock carvings at its base. Excursions to such Northern Territory gems as Mt. Olgas/Kata Tjuta and Kings Canyon also depart from here.

Among the endemic genera there are also background desert grasses - Mitchell's grass and triodia. A large number of species are represented by the families of legumes, myrtaceae, proteaceae and asteraceae. 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 areas of the sands in the Simpson and Great Sandy Deserts, the species composition of background grasses changes somewhat: other species of Triodia, Plectrachne 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" southeast trade winds, since most of the 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. The precipitation season in the northern half of the continent, where monsoon winds prevail, is confined to the summer period, and in the 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. The surface waters of the continent are extremely poor and extremely unevenly distributed throughout 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.

MINISTRY OF EDUCATION OF THE MOSCOW REGION MOSCOW STATE REGIONAL UNIVERSITY

FACULTY OF GEOGRAPHY AND ECOLOGY

EXTRAMURAL

SPECIALTY "GEOECOLOGY"

Course work

by subject

"General Ecology"

"Deserts of Australia"

Completed:

IV year student group 42

Bubentsova O.A.

Moscow 2013

1.General physical and geographical description

The Commonwealth of Australia is the only state in the world that occupies the territory of an entire continent. The Australian continent is located entirely in the Southern Hemisphere, and its very name comes from the Latin Terra Australis Incognita (Unknown Southern Land) - this is what ancient geographers called the mysterious southern continent, the location of which was unknown to them, but whose existence they assumed. The Australian continent is washed on all sides by the Pacific, Indian and Southern oceans.

The Commonwealth of Australia includes, in addition to its own mainland, the island of Tasmania and small islands located off the coast of the continent. Australia administers the so-called external territories : islands and island groups in the Pacific and Indian Oceans.

The area of the Commonwealth of Australia is 7.7 million square meters. km. Its population is small - only 14 million people. At the same time, the vast majority of Australians live in cities, including almost half in the two largest: Sydney (over 3 million inhabitants) and Melbourne (about 3 million inhabitants). The capital of Australia is Canberra. Australia is one of the most urbanized countries in the world.

Australia's topography is dominated by plains. About 95% of the surface does not exceed 600 m above sea level. Most of Australia lies in the tropics, the North is in subequatorial latitudes, and the South is in subtropical latitudes. In Australia, the heights of the plains are low, which causes constantly high temperatures throughout the continent. Australia lies almost entirely within the summer isotherms of 20 °C - 28 °C, and the winter isotherms of 12 °C - 20 °C.

The position of most of Australia in the continental sector of the tropical zone causes a dry climate. Australia is the driest of the Earth's continents. 38% of Australia receives less than 250 mm of rainfall per year. About half of Australia's territory is occupied by deserts and semi-deserts.

Australia is rich in a variety of mineral resources. New discoveries of mineral ores made on the continent over the past 10-15 years have propelled the country to one of the first places in the world in reserves and production of minerals such as iron ore, bauxite, and lead-zinc ores. The main deposits of metallic minerals and deposits will be discussed in the next section of the work. Non-metallic minerals include clays, sands, limestones, asbestos, and mica, which vary in quality and industrial use.

The rivers flowing from the eastern slopes of the Great Dividing Range are short and flow in narrow gorges in the upper reaches. Here they may well be used, and in part they are already used for the construction of hydroelectric power stations. When entering the coastal plain, rivers slow down their flow and their depth increases. Many of them in estuarine areas are even accessible to large ocean-going vessels.

On the western slopes of the Great Dividing Range, rivers originate and make their way through the interior plains. The largest river in Australia, the Murray, begins in the area of Mount Kosciuszko. Food p. The Murray and its channels are mainly rain-fed and, to a lesser extent, snow-covered. Almost all rivers of the Murray system have dams and dams built, around which reservoirs are created, where flood waters are collected and used to irrigate fields, gardens and pastures.

The rivers of the northern and western coasts of Australia are shallow and relatively small. The longest of them, the Flinders, flows into the Gulf of Carpentaria. These rivers are fed by rain, and their water content varies greatly at different times of the year.

Rivers whose flow is directed to the interior of the continent, such as Coopers Creek (Barku), Diamant-ina, etc., lack not only a constant flow, but also a permanent, clearly defined channel. In Australia, such temporary rivers are called creeks. They are filled with water only during short rain showers.

Most lakes in Australia, like rivers, are fed by rainwater. They have neither a constant level nor a drain. In summer, the lakes dry up and become shallow saline depressions.

Since the Australian mainland long time, starting from the middle Cretaceous period, was isolated from other parts of the globe; its flora was very unique. Of the 12 thousand species of higher plants, more than 9 thousand are endemic, i.e. grow only on the Australian continent. Endemics include many species of eucalyptus and acacia, the most typical plant families of Australia. At the same time, there are also plants here that are native to South America (for example, southern beech), South Africa (representatives of the Proteaceae family) and the islands of the Malay Archipelago (ficus, pandanus, etc.). This indicates that many millions of years ago there were land connections between the continents.

Since the climate of most of Australia is characterized by extreme aridity, its flora is dominated by dry-loving plants: special cereals, eucalyptus trees, umbrella acacias, succulent trees (bottle tree, etc.). In the far north and north-west of the country, where it is hot and the warm north-west monsoons bring moisture, rainwater grows rainforests. Their tree composition is dominated by giant eucalyptus, ficus, palm trees, pandanus with narrow long leaves, etc. In some places on the coast itself there are thickets of bamboo. In places where the shores are flat and muddy, mangrove vegetation develops. Rain forests in the form of narrow galleries stretch for relatively short distances inland along river valleys.

The further south you go, the drier the climate becomes. Forest cover is gradually thinning. Eucalyptus and umbrella acacias are located in groups. This is a zone of wet savannas, stretching in the latitudinal direction south of the zone tropical forests. The central deserts of the mainland, where it is very hot and dry, are characterized by dense, almost impenetrable thickets of thorny low-growing shrubs, consisting mainly of eucalyptus and acacia trees.

The eastern and southeastern slopes of the Great Dividing Range, where precipitation is high, are covered with dense tropical and subtropical evergreen forests. Most of these forests, as elsewhere in Australia, are eucalyptus trees. Higher in the mountains there is a noticeable admixture of damarra pines and beech trees. The shrub and grass cover in these forests is varied and dense. In less humid variants of these forests, the second layer is formed by grass trees. On the island of Tasmania, in addition to eucalyptus trees, there are many evergreen beech trees related to South American species. In the southwest of the mainland, forests cover the western slopes of the Darling Range, facing the sea. These forests consist almost entirely of eucalyptus trees, reaching considerable heights. The number of endemic species here is especially high. In addition to eucalyptus, widespread bottle trees.

In general, Australia's forest resources are small. The total area of forests, including special plantations consisting mainly of softwood species (mainly radiata pine), amounted to only 5.6% of the country's territory at the end of the 1970s.

In Australia, all types of soils characteristic of tropical, subequatorial and subtropical natural zones are represented in a natural sequence.

In the area of tropical rainforests in the north, red soils are common, changing towards the south to red-brown and brown soils in wet savannas and gray-brown soils in dry savannas. Red-brown and brown soils containing humus, some phosphorus and potassium are valuable for agricultural use. The main wheat crops in Australia are located within the red-brown soil zone.

The Australian continent is located within three main warm climate zones of the southern hemisphere: subequatorial (in the north), tropical (in the central part), subtropical (in the south). Only a small part of. Tasmania lies within the temperate zone.

Most of the country is dominated by a dry and hot continental climate of the tropical zone. The northern part of Australia is located in the subequatorial climate zone - it is hot here all year round, the humidity is very high in summer and low in winter. The east coasts are hot and humid all year round. The subtropical zone, in which the southern part of Australia is located, is represented by a predominantly continental climate - hot and very dry summers and cool, wet winters. The southwest coast of Australia is dominated by a Mediterranean climate with hot, dry summers and mild, rainy winters. The south-eastern part of Australia and the northern part of the island of Tasmania are influenced by a monsoon climate with hot, rainy summers and mild, dry winters. The southernmost part of the island of Tasmania is located in a temperate zone with a mild, humid climate.

The hot climate and insignificant and uneven precipitation over most of the continent lead to the fact that almost 60% of its territory has no flow to the ocean and has only a sparse network of temporary watercourses.

.Deserts of Australia

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.

The Australian Deserts are 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 latter zone.

Great Sandy Desert

Great Sandy Desert or Western Desert- sandy-salt desert<#"justify">Great Victoria Desert

Great Victoria Desert - sandy-salt desert<#"justify">Gibson Desert

Gibson Desert - sandy desert<#"justify">Small Sandy Desert

Small Sandy Desert - sandy desert<#"justify">Simpson Desert

Simpson Desert - sandy desert<#"justify">The average temperature in January is 28-30 °C, in July - 12-15 °C.

In the northern part, precipitation is less than 130 mm, dry creek beds<#"justify">Tanami

Tanami - rocky sand desert<#"justify">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 continent'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<#"justify">3. Animal world

The long-term isolation of Australia from other continents has led to the exceptional uniqueness of the fauna of this continent, and in particular its desert region.

Species endemism is 90%, and the remaining species are subendemic, that is, their distribution extends beyond the deserts, but not beyond the continent as a whole. Among the endemic groups there are: marsupial moles, Australian wheatears, lizards.

In Australia there are no representatives of the orders of carnivores, ungulates, insectivores, and lagomorphs; the order of rodents is represented only by species of the mouse subfamily; Among the birds, the order of sandgrouse, the families of pheasants, bee-eaters, finches and a number of others are absent. The reptile fauna has also become impoverished: species of the families of lacertid lizards, colubrids, vipers and pit snakes have not penetrated here. Due to the absence of the mentioned and a number of other animals, local, endemic families and genera, as a result of widespread adaptive radiation, have mastered free ecological niches and developed a number of convergent forms in the process of evolution.

Among the aspid snakes, species arose that were morphologically and ecologically similar to vipers; lizards of the scinnidae family successfully replaced the lacertids that were absent here, but especially many convergent forms are observed in marsupial mammals. They ecologically replace insectivores (marsupial shrews), jerboas (marsupial jerboas), large rodents (wombats or marmots), small predators (marsupial martens) and even, to a large extent, ungulates (wallabies and kangaroos). Small mouse-like rodents widely inhabit all types of deserts (Australian mouse, jerboa mouse, and others). The role of large herbivores in the absence of ungulates is performed by marsupials from the kangaroo family: brush-tailed kangaroos live in the Gibson Desert; gigantic red kangaroo etc. Small predatory marsupials are similar in appearance and biology to shrews of the Old World (crest-tailed marsupial shrew, thick-tailed marsupial shrew). Marsupial moles lead an underground lifestyle and inhabit sandy plains.

Marsupial badgers live in the Simpson Desert. The largest native predator in the Australian deserts is marsupial marten. About 10 thousand years ago, man entered the Australian continent and settled it. Together with the man, the dog also came here - the constant companion of the primitive hunter. Subsequently, feral dogs spread widely in the deserts of the mainland, forming a stable form called the dingo dog. The appearance of such a large predator caused the first significant damage to the native fauna, especially various marsupials. However, the greatest damage to the local fauna was caused after Europeans arrived in Australia. Either intentionally or accidentally, they brought here a whole range of wild and domestic animals (the European rabbit - they multiplied quickly, settled in large colonies, and destroyed the already meager vegetation cover). Widely distributed throughout central Australia common fox and a house mouse. In the central and northern regions, small herds of feral donkeys or single dromedary camels are often found.

Many birds (parrots, zebra finches, emblem finches, pink cockatoos, diamond doves, emus) gather near temporary watering holes in the hottest hours of the day in the desert. Insectivorous birds do not need watering places and inhabit desert areas far from any sources of water (Australian wrens, Australian warblers). Since true larks did not penetrate the deserts of Australia, their ecological niche was occupied by representatives of the warbler family, which have adapted to a terrestrial lifestyle and are surprisingly similar in appearance to larks. Flat gravelly and rocky plains, salt marshes with sparse thickets of quinoa are inhabited by Australian wheatears. In the thickets of bushy eucalyptus trees, the large ocellated big-headed or weed chicken lives. Australian Carrion Crows can be seen in all desert habitats. Reptiles in the Australian deserts are extremely diverse (families skink, gecko, agamidae, and aspidae). Monitor lizards reach the greatest diversity in the deserts of Australia compared to other regions. Lots of snakes, insects (darkling beetles, bombardier beetles and others).

.Vegetable world

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

Climate

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. The surface waters of the continent are extremely poor and extremely unevenly distributed throughout 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.

Hydrography

Australian desert fauna precipitation

The flow characteristics of Australia and the islands close to it are well illustrated by the following figures: the flow volume of the rivers of Australia, Tasmania, New Guinea and New Zealand is 1600 km3, the runoff layer is 184 mm, i.e. slightly more than in Africa. The runoff volume of Australia alone is only 440 km3, and the thickness of the runoff layer is only 57 mm, i.e., several times less than on all other continents. This is due to the fact that most of the mainland, unlike the islands, receives little precipitation and there are no high mountains or glaciers within its borders.

The inland drainage area covers 60% of Australia's surface. Approximately 10% of the territory drains into the Pacific Ocean, the rest belongs to the Indian Ocean basin. The main watershed of the continent is the Great Watershed Range, from the slopes of which the largest and deepest rivers flow. These rivers are fed almost exclusively by rain.

Since the eastern slope of the ridge is short and steep, short, fast, winding rivers flow towards the Coral and Tasman Seas. Receiving more or less uniform nutrition, they are the most deep rivers Australia with a clearly defined summer maximum. Crossing ridges, some rivers form rapids and waterfalls. The length of the largest rivers (Fitzroy, Burdekin, Hunter) is several hundred kilometers. In their lower reaches, some of them are navigable for 100 km or more and are accessible to ocean-going ships at their mouths.

The rivers of Northern Australia flowing into the Arafura and Timor Seas are also deep. The most significant are those that flow from the northern part of the Great Dividing Range. But the rivers of northern Australia, due to the sharp difference in the amount of summer and winter precipitation, have a less uniform regime than the rivers of the east. They overflow with water and often overflow their banks during the summer. monsoon rains. In winter, these are weak, narrow watercourses that dry up in places in the upper reaches. Most large rivers in the north - Flinders, Victoria and Ord - in summer the lower reaches are navigable for several tens of kilometers.

There are also permanent watercourses in the southwest of the mainland. However, during the dry summer season, almost all of them turn into chains of shallow, polluted ponds.

In desert and semi-desert internal parts Australia has no permanent watercourses. But there is a network of dry channels there, which are the remnants of a previously developed water network, formed under the conditions of the pluvial era. These dry riverbeds fill with water after rains for a very short time. Such periodic watercourses are known in Australia as "creeks". They are especially numerous on the Central Plain and are directed towards the drainless, drying Lake Eyre. The Nullarbor Karst Plain is devoid of even periodic watercourses, but has an underground water network with flow towards the Great Australian Bight.

The soil. Landscape

The soil cover of deserts is unique. In the northern and central regions, red, red-brown and brown soils are distinguished (the characteristic features of these soils are an acidic reaction and coloration with iron oxides). In the southern parts of Australia, sierozem-like soils are widespread. In Western Australia, desert soils are found along the edges of drainless basins. The Great Sandy Desert and Great Victoria Desert are characterized by red sandy desert soils. In the drainless inland depressions in southwestern Australia and in the Lake Eyre basin, salt marshes and solonetzes are widely developed.

Australian deserts in landscape terms are divided into many different types, among which most often Australian scientists distinguish mountain and foothill deserts, deserts of structural plains, rocky deserts, sandy deserts, clayey deserts, and plains. Sandy deserts are the most common, 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. Foothill plains are an alternation of coarse rocky deserts with dry beds of small rivers. This type of desert is the source of most of the country's desert watercourses and always serves as a habitat for aborigines. Deserts Structural plains occur 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, confined mainly to Western Australia.

Population

Australia is the least populated continent on Earth. About 19 million people live on its territory. The total population of the islands of Oceania is about 10 million people.

The population of Australia and Oceania is divided into two unequal groups of different origins - indigenous and alien. There are few indigenous people on the mainland, but on the islands of Oceania, with the exception of New Zealand, Hawaii and Fiji, they make up the vast majority.

Start scientific research in the field of anthropology and ethnography of the peoples of Australia and Oceania laid in the second half of the 19th century. Russian scientist N. N. Miklouho-Maclay.

Like America, Australia could have been inhabited by humans not as a result of evolution, but only from the outside. In its ancient and modern fauna, not only primates are absent, but also all higher mammals in general.

No traces of the Early Paleolithic have yet been discovered within the continent. All known finds of human fossils have features of Homo sapiens and date back to the Upper Paleolithic.

Indigenous people Australia has such pronounced anthropological characteristics as: dark brown skin, wavy dark hair, significant beard growth, a wide nose with a low bridge. The faces of Australians are distinguished by prognathism, as well as a massive brow. These features bring Australians closer to the Veddas of Sri Lanka and some tribes of Southeast Asia. In addition, the following fact deserves attention: the oldest human fossils found in Australia bear a close resemblance to the bone remains discovered on the island of Java. They are roughly dated to a time coinciding with the last Ice Age.

Of great interest is the problem of the route along which humans settled Australia and the islands close to it. At the same time, the question of the time of development of the mainland is being resolved.

Undoubtedly, Australia could only be inhabited from the north, that is, from Southeast Asia.

This is confirmed both by the anthropological characteristics of modern Australians and by the paleoanthropological data discussed above. It is also obvious that modern humans penetrated into Australia, i.e. the settlement of the continent could not have occurred earlier than the second half of the last glacial period.

Australia has existed for a long time (obviously since the end of the Mesozoic) isolated from all other continents. However, during Quaternary period The landmass between Australia and Southeast Asia was for a time more extensive than it is at present. A continuous land “bridge” between the two continents obviously never existed, since if it had existed, the Asian fauna would have had to penetrate it into Australia. In all likelihood, in the late Quaternary, in place of the shallow basins separating Australia from New Guinea and the southern islands of the Sunda archipelago (their modern depths do not exceed 40 m), there were vast areas of land formed as a result of repeated fluctuations in sea level and land uplifts. The Torres Strait, which separates Australia from New Guinea, may have been formed quite recently. The Sunda Islands may also have been periodically connected by narrow strips of land or shoals. Most land animals were unable to overcome such an obstacle. People gradually, by land or overcoming shallow straits, penetrated through the Lesser Sunda Islands to New Guinea and to the Australian mainland. At the same time, the settlement of Australia could have occurred either directly from the Sunda Islands and the island of Timor, or through New Guinea. This process was very long, it probably lasted for millennia during the Late Paleolithic and Mesolithic. Currently, based on archaeological finds on the mainland, it is assumed that man first appeared there approximately 40 thousand years ago.

The process of spreading people across the mainland was also very slow. The settlement proceeded along the western and eastern coasts, and in the east there were two routes: one along the coast itself, the second to the west of the Great Dividing Range. These two branches converged in the central part of the mainland in the area of Lake Eyre. In general, Australians are distinguished by their anthropological unity, which indicates the formation of their main characteristics after their penetration into Australia.

The culture of Australians is very original and primitive. The originality of culture, the originality and proximity to each other of the languages of various tribes indicate the long isolation of Australians from other peoples and their autonomous historical development up to modern times.

By the beginning of European colonization, about 300 thousand Aborigines lived in Australia, divided into 500 tribes. They populated the entire continent quite evenly, especially eastern part. Currently, the number of indigenous Australians has decreased to 270 thousand people. They make up approximately 18% of Australia's rural population and less than 2% of its urban population. A significant proportion of Aboriginal people live on reserves in the northern, central and western regions or work in mines and cattle ranches. There are still tribes that continue to lead the same semi-nomadic lifestyle and speak languages that are part of the Australian language family. Interestingly, in some disadvantaged areas, Indigenous Australians make up the majority of the population.

The rest of Australia, that is, its most densely populated areas - the eastern third of the continent and its south-west, is inhabited by Anglo-Australians, who make up 80% of the population of the Commonwealth of Australia, and people from other countries of Europe and Asia, although people with white skin are poorly adapted for life in tropical latitudes. By the end of the 20th century. Australia ranks first in the world for skin cancer incidence. This is due to the fact that an “ozone hole” periodically forms over the continent, and the white skin of representatives of the Caucasian race is not as protected from ultraviolet radiation as the dark skin of the indigenous population of tropical countries.

In 2003, the population in Australia exceeded 20 million people. It is one of the most urbanized countries in the world - more than 90% are urban residents. Despite the lowest population density compared to other continents and the presence of vast, almost uninhabited and undeveloped territories, as well as the fact that the settlement of Australia by immigrants from Europe began only at the end of the 18th century and for a long time the basis of its economy was agriculture, human impact on nature in Australia has very large and not always positive consequences. This is due to the vulnerability of Australia’s nature itself: about half of the continent is occupied by deserts and semi-deserts, and the adjacent areas periodically suffer from droughts. It is known that arid landscapes are one of the most vulnerable types of natural environment, easily destroyed by outside interference. The cutting down of tree vegetation, fires, and overgrazing by livestock disturb the soil and vegetation cover, contribute to the drying out of water bodies and lead to complete degradation of landscapes. Ancient and primitive organic world Australia cannot compete with more highly organized and viable introduced forms. This organic world, especially fauna, cannot resist man - the hunter, fisherman, collector. The population of Australia, mainly living in cities, strives to relax among nature; tourism is increasingly developing, not only national, but also international.

.Agriculture

Agricultural map of Australia

Fishing

Cattle

Forestry

Gardening

pastures

Vegetable growing

Uncultivated land

Livestock

Aquaculture

Agriculture is one of the main sectors of the Australian economy<#"justify">1)Crop production

)Vegetable growing

)Winemaking

)Livestock

1) Beef

2) Lamb

3) Pork

)Dairy farming

)Fishing

)Wool

)Cotton

Australia produces large quantities of fruits, nuts and vegetables. More than 300 tons of products are oranges<#"justify">10.Assessment of the state of natural systems and characteristics of environmental protection measures in Australia

Based on all of the above, we can assess the state of natural systems and their capabilities to perform the following functions:

ensuring human living conditions;

providing a spatial basis for the development of productive forces;

provision of natural resources;

preservation of the gene pool of the biosphere.

Until recently, it was generally accepted that almost 1/3 of the continent’s territory was generally useless from the point of view of economic development. However, over the past three decades, huge deposits have been discovered in these desert places. iron ore, bauxite, coal, uranium and many other minerals, which has brought Australia to one of the first places in the world in terms of mineral wealth (in particular, it accounts for approximately 1/3 of the bauxite reserves of the capitalist world, 1/5 of iron and uranium).

For a century it has been said that Australia “rides on the back of a sheep” (wool production and export were the basis of its economic life). Now the country has largely “moved onto the ore wagon”, turning into one of the largest producers and exporters of mineral raw materials. The Commonwealth of Australia is rich in various mineral resources, which, with a few exceptions, almost entirely provide the development of the manufacturing industry with mineral raw materials.

The water resources of the continent itself are small; the most developed river network is on the island of Tasmania. The rivers there are fed with mixed rain and snow and are full of water throughout the year. They flow down from the mountains and are therefore stormy, rapids and have large reserves of hydroelectric power. The latter is widely used for the construction of hydroelectric power stations. The availability of cheap electricity contributes to the development of energy-intensive industries in Tasmania, such as the smelting of pure electrolyte metals, the production of cellulose, etc.

Australia's agricultural resources are also quite scarce, but this does not prevent the development of agriculture, albeit in limited areas.

Thus, all industry, manufacturing and most agriculture are concentrated in small areas - the southeast and (to a lesser extent) the southwest. Technogenic load on natural complexes here it is very high, which cannot but affect the environmental situation.

Based on the above, we can highlight the main directions of environmental protection measures in the territory of the Commonwealth of Australia:

Protection and rational use of those resources that the territory in question is poor in: water resources, forest and soil resources.

Protection and rational use of resources that are actively used - mineral resources, recreational resources.

Protection and rational use of resources specific to the Australian region: protection of biota, development of a network of specially protected natural areas networks of specially protected natural areas.

Protection of atmospheric air, especially in areas of high technogenic load.

It should be noted that environmental policy in the Commonwealth of Australia is managed by a separate government body - the Ministry of Environment, which gives reason to believe that very serious attention is paid to environmental problems here. The Ministry is developing economic and legal measures for environmental protection and rational use of natural resources in industry, energy, agriculture, pays attention to areas with high population concentrations and is developing a network of specially protected natural areas. The Ministry of Environment interacts with international organizations in the field of environmental protection, other states and other government bodies of the Commonwealth of Australia.

The Commonwealth of Australia has established limits for permissible exposure to components of the natural environment, standards for use natural resources, including water ones. Particular attention is paid to the protection of the continental shelf, water and forest resources. The special flora and fauna of the Commonwealth of Australia are protected by law, for which, among other things, nature reserves and other protected areas are created. Liability for violation of environmental legislation has been established.

The result of the activities of government bodies and public organizations for environmental protection and rationalization of environmental management is the fact that the Commonwealth of Australia is one of the most environmentally prosperous countries.

.Ecological problems Australia

Currently, over 65% of the country's territory has been developed. As a result of economic activity, Australia's nature has found itself under the threat of human alteration to a no lesser extent than in many densely populated countries on other continents. Forests are disappearing catastrophically quickly<#"justify">Bibliography

1.Physical geography of continents and oceans: a textbook for students. higher ped. textbook establishments / T.V. Vlasova, M.A. Arshinova, T.A. Kovaleva. - M.: Publishing center "Academy", 2007.

.Mikhailov N.I. Physiographic zoning. M.: Moscow State University Publishing House, 1985.

.Markov K.K. Introduction to physical geography M.: graduate School, 1978.

.“The whole world”, Encyclopedic reference book. - M., 2005

.Vazumovsky V.M. Physico-geographical and ecological-economic foundations of the territorial organization of society. - St. Petersburg, 1997.

.Working programm and methodological instructions for writing abstracts for the course “General Ecology and Environmental Management”. - St. Petersburg, 2001.

.Petrov M.P. Deserts of the globe L.: Nauka, 1973

Tutoring

Need help studying a topic?

Our specialists will advise or provide tutoring services on topics that interest you.
Submit your application indicating the topic right now to find out about the possibility of obtaining a consultation.

In addition to the largest deserts of Australia - Victoria and the Great Sandy Desert, on the territory of the Green Continent there are also other dry areas.

If you are interested in the deserts of Australia, then you worth knowing that the mainland has both tropical and subtropical desert areas. What are these dry zones like?

The Gibson Desert is located in the center.

Europeans first visited this desert, covered with rubble unsuitable for agriculture. in 1874.

Despite the harsh climatic and natural conditions, people live in this territory - Australian Aboriginal tribe Pintubi.

This tribe of the indigenous people of the mainland is one of the topics that preserved the traditional ancient way of life of the aborigines Green Continent.

Also, the Gibson Desert rich in wildlife. Typical representatives of Australia's animals live here - the red kangaroo, marsupial badger, moth lizard, grass wren and emu.

The marsupial badger also lives here, which previously inhabited 70% Australian territory, and today is on the verge of extinction. The main vegetation of the Gibson Desert is spinifex and acacia.

Simpson Desert

Simpson Desert, which is located in the heart of Australia is a protected area of the Green Continent, where the world famous is located.

This body of water temporarily filled with water, fed by Australia's underwater rivers and home to many of Australia's animals.

They live here ducks, eagles, seagulls, Australian pelicans, kingfishers, budgerigars, pink cockatoos, swallows and other representatives of the mainland avifauna.

Also found here marsupial jerboas, desert bandicoots, marsupial mice and moles, dingoes, wild camels and kangaroos.

The flora of the Simpson Desert consists of drought-resistant grasses and thorns. Today in the desert there are a number of protected areas. Tourists come here to take 4x4 rides through the dunes.

Interesting fact! In the 19th century, people wanted to graze cattle and build settlements here, but the climate did not allow this. The Simpson Desert has also been a disappointment to oil seekers who searched here in the 1970s and failed to find this natural resource.

Small Sandy Desert

The Small Sandy Desert is located in the west of the Green Continent. The flora and fauna, as well as the topography of this desert area, are similar to the characteristics of the Great Sandy Desert.

On the territory of the Small Sandy Desert there is its main watercourse - Savory Creek, which flows into Disappointment Lake located in the north of the desert.

Despite the rather harsh climate for which the deserts and semi-deserts of Australia are famous, tribes of the indigenous population of the mainland live here. The biggest one is Parnngurr tribe.

The only way through the desert, namely the Canning Cattle Route, runs in the northeast of the Little Sandy Desert.

Deserts of Australia - Tanami and Te Pinnacles

Another desert territory of Australia called Tanami, which is located in, has been explored more than other arid zones of the mainland. Europeans made expeditions here until 20th century.

The Tanami Desert is rocky sand dunes, the area of which 292,194 km².

Climate Tanami – semi-desert. The average annual rainfall here is much higher than in other Australian deserts.

In 2007 The Northern Tanami Aboriginal Protected Area was created here, which covers an area of approximately 4 million hectares. Today gold mining is carried out here. In recent years, various areas of tourism have been developing.

It is important to know! The North Tanami Protected Area is home to Australian fauna and flora that are on the verge of extinction.

The desert called The Pinnacles is a small area located in the southwest of the Green Continent.

The title translates as "desert of pointed rocks" and speaks for itself. The sandy desert area is “decorated” with towering stones from one to five meters.

Find out more about the drylands of Australia, it becomes clear why some species of unique Australian animals could not survive in such harsh climatic conditions.

The most arid central regions of the continent are occupied by the most large areas 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 the 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 of higher plants. In drainless basins and along the shores of salt lakes, halophytic formations are developed, formed by special species of 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 a 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.