Flora and fauna of the semi-desert deserts of Australia. Deserts of Australia, Great Victoria Desert, Great Sandy Desert, Tanami Desert, Gibson Desert, Simpson Desert. Location of deserts and semi-deserts

The presence of natural areas on the mainland and their location directly depend on climatic zones. Given that Australia is considered the driest continent, it becomes clear that there simply cannot be much diversity here. But the natural areas of Australia have an extremely unique flora and fauna.

Lots of deserts and few forests

On the smallest continent, zoning is clearly visible. This is due to the prevailing flat nature of the relief. Natural areas Australia gradually replace each other in the meridional direction following changes in temperature and precipitation.

The southern tropic crosses the continent almost in the middle, and most of its territory is in the hot tropical climate zone, which makes the climate arid. Australia ranks last among all continents in terms of annual precipitation. Most of its territory receives only 250 mm of precipitation throughout the year. In many areas of the continent, not a drop of rain falls for several years.

Australia, whose natural zones divide the continent into three parts, has several zones in the east and west, stretched along the coast, where the amount of precipitation is noticeably greater. The mainland is in first place in terms of the relative area of ​​desert areas and in last place in terms of forest area. Moreover, only 2% forest areas Australia is of industrial importance.

Features of natural areas

Savannas and open forests are located in the subequatorial climate zone. The vegetation is dominated by grasses, among which grow acacias, eucalyptus trees, and bottle trees.

In the east of the continent, in conditions of sufficient moisture, there are such natural zones of Australia as tropical rainforests. Among palm trees, ficus and tree ferns live marsupial anteaters, wombats, kangaroos.

Australia's natural areas differ from similar areas on other continents. For example, semi-deserts and tropical desert occupy huge areas on the mainland - almost 44% of its territory. In the Australian deserts you can find unusual thickets of dry thorny bushes called scrubs. Semi-desert areas overgrown with tough cereal plants and shrubs are used as pasture for sheep. There are also large sandy deserts, which differ from the deserts of other continents in that they do not have oases.

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

The originality of the organic world

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

Animal world even more peculiar. Among animals, endemics account for almost 90%. Only in Australia can you find mammals that disappeared on other continents a long time ago, for example, the echidna and the platypus - ancient primitive animals.

Current

Miscellaneous
Miscellaneous

Deserts and semi-deserts

Deserts and semi-deserts are a natural zone characterized by an almost complete absence of vegetation and very poor fauna. All this is due to the extremely harsh climatic conditions of the planet where they are located. Deserts, in principle, can form in almost any climate zone. Their education is primarily related to low quantity precipitation This is why deserts are primarily found in the tropics. Tropical deserts occupy the territory of most of tropical Africa and Australia, the western coast of the tropical zone of South America, as well as the territory of the Arabian Peninsula in Eurasia. Here their formation is associated with the year-round dominance of tropical air mass, the influence of which is enhanced by the terrain and cold currents off the coast. Also a large number of Deserts are located in the subtropical and temperate zones of the Earth. This is the territory of Patagonia in South America, where their formation is due to the isolation of the southern tip of the continent from penetration humid air cold currents, as well as in the interior of North America and Central Asia. Here, the formation of deserts is already associated with a strong continental climate due to the great distance from the coast, as well as mountain systems preventing the penetration of moisture from the ocean. The formation of deserts may also be associated with extreme low temperatures on the planet, this type of desert, called Arctic and Antarctic deserts, is considered by us separately.
The natural conditions of deserts are extremely harsh. The amount of precipitation here does not exceed 250 mm per year, and in large areas it is less than 100 mm. The driest desert in the world is the Atacama Desert in South America, where there has been no precipitation for 400 years. The largest desert in the world is the Sahara, located in North Africa (pictured by Rosa Cabecinhas and Alcino Cunha). Its name is translated from Arabic as “desert”. The highest air temperature on the planet was recorded here: +58°C. Under the scorching rays of the sun in summer months When it reaches its zenith at noon, the sand under your feet heats up to enormous temperatures, and sometimes you can even fry eggs on the stones. However, as the sun sets, the temperature in the desert drops sharply, changes reaching tens of degrees during the day, and on a winter night frosts even occur here. This is due to the constantly clear sky due to the downward flows of dry air from the equator, because of this, almost no clouds form here. The vast open spaces of deserts do not at all prevent the movement of air along the surface of the Earth, which leads to the emergence of strong winds. Dusty sandstorms come unexpectedly, bringing clouds of sand and streams of hot air. In spring and summer the Sahara rises strong wind- samum, which can be literally translated as “poisonous wind.” It can last only 10-15 minutes, but the hot dusty air is very dangerous for humans, it burns the skin, the sand does not allow you to breathe freely, many travelers and caravans died in the deserts under this deadly wind. Also, at the end of winter - beginning of spring in North Africa, a seasonal wind begins to blow from the desert almost every year - khamsin, which in Arabic means “fifty”, since on average it blows for fifty days.
Deserts of temperate latitudes, unlike tropical deserts, are also characterized by strong temperature changes throughout the year. Hot summer gives way to cold, harsh winter. Air temperature fluctuations over the year can be about 100°C. Winter frosts in the deserts of the temperate zone of Eurasia drop to -50°C, the climate is sharply continental.
The flora of deserts in particularly difficult climatic conditions may be completely absent; where moisture remains sufficient, some plants grow, but the flora is still not diverse. Desert plants usually have very long roots - more than 10 meters - in order to extract moisture from groundwater. In the deserts Central Asia A small shrub grows - saxaul. In America, a significant part of the flora is made up of cacti, in Africa - milkweed. The fauna of deserts is also not rich. Reptiles predominate here - snakes, monitor lizards, scorpions also live here, and there are few mammals. One of the few that was able to adapt to these difficult conditions was the camel, which was not accidentally called the “ship of the desert.” By storing water in the form of fat in their humps, camels are able to travel long distances. For the indigenous nomadic peoples of the deserts, camels are the basis of their economy. Desert soils are not rich in humus, however, they often contain many minerals and are suitable for agriculture. The main problem for plants remains water shortage.

About 3.8 million sq. km of Australia's surface (44%) are occupied by arid territories, of which 1.7 million square meters. km - desert. This suggests that Australia is the driest continent on the globe.

The deserts of Australia are confined to ancient structural elevated plains. The climatic conditions of Australia 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 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 period, 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 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. 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 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 most large lakes– Eyre, Torrens, Carnegie and others are salt marshes or dried-up basins covered with a thick layer of salts. The lack of surface water is compensated by the abundance of groundwater. There are a number of large artesian basins here (the Desert Artesian Basin, the North West Basin, the northern Murray River Basin and part of Australia's largest groundwater basin, the Great Artesian Basin).

The soil cover of deserts is very 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 drainless internal depressions In the south-west of Australia and in the Lake Eyre basin, salt marshes and solonetzes are widely developed.

Australian deserts are landscape-wise divided into many Various types, among which Australian scientists most often 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.

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, meaning 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). Typical representatives of the 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 terrain, disturbed only in the east. The main part of the continent lies in tropical latitudes, That's why greatest development received tropical deserts and semi-deserts, occupying half the area of ​​the continent.

The central parts of the continent in two geographical zones (tropical and subtropical) are occupied by deserts and semi-deserts. Australia is rightly called a continent of deserts (Great Sandy, Great Desert Victoria, Gibson Desert, etc.). On the Western Australian plateau in tropical conditions continental climate Tropical deserts and semi-deserts dominate. In rocky and sandy river beds, light forests of casuarinas stretch. 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 bushy grass spinifex. 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.

The most acute problem in Australia is the shortage. Previously, it was solved by pumping groundwater from numerous wells. But currently a decrease in water level in artesian basins has been recorded. 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 is Kosciuszko Park in Australia. 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 is also under protection (Great Victoria Desert and Simpson Desert parks). Object World Heritage UNESCO in Uluru-Katayuta Park recognizes the giant red sandstone monolith Ayers Rock as sacred to the Aboriginal people. Fairytale world corals are protected in the Great Barrier Reef Underwater Park.

The Great Barrier Reef has 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.

The main feature of the animal and flora Australia - predominance of endemics. Australia is the most deserted continent. Global, exhaustion water resources, depletion of flora and fauna pose a threat to the nature of the continent. Specially protected natural areas occupy 11% of the continent's area.

Australia is located in the Southern and Eastern hemispheres of the planet. The world's smallest continent occupies only 5% of the Earth's landmass. The area of ​​the continent with islands is 7,692,024 km². The length from north to south is 3.7 thousand km, and from west to east - about 4 thousand km.

The coastline extends for 35,877 km and is slightly indented. The waters of the Gulf of Carpentaria jut into the northern coast of the continent, and the Cape York Peninsula protrudes prominently against the background of the main coastline. The main bays are located in the southeast of Australia.

The most extreme points continent include:

• in the north - Cape York, washed by the waters of the Coral and Arafura seas;
• in the south - Cape South Point, washed by the waters of the Tasman Sea;
• in the west - Cape Steep Point, washed by the waters of the Indian Ocean;
• in the east is Cape Byron, washed by the waters of the Tasman Sea.

The largest island belonging to Australia is Tasmania. Its total area is 68,401 km². Off the northern coast are the islands of Groot Island, Melville and Bathurst, as well as the large islands of Derk Hartog in the west and Fraser in the east. Within the mainland shallows are Kangaroo, King and Flinders Islands.

Big Barrier Reef is an invaluable natural monument located along the northeastern line of the continent. It includes clusters of small underwater and surface islands, as well as Coral reefs. Its length is more than 2000 km.

In the north, west and south, Australia is washed by Indian Ocean, and in the east - Pacific Ocean. In addition, the continent is washed by the waters of four seas: Timor or Orange, Arafura, Tasman and Coral, which all year round attract tourists from all over the world.

Relief

Blue Mountains, Australia

The relief of Australia is dominated by flat areas. Mount Kosciuszko, 2228 m above sea level, is highest point continent. Average height on the continent is 215 m. The Australian plate, which was once part of the ancient continent of Gondwana, represents the basis of the continent today. The basement area is covered by strata of marine and continental sedimentary rocks.

Modern relief includes the Western Australian Tablelands, the Central Lowlands and the East Australian Mountains. As a result of rising and falling earth's crust, a trough filled with sedimentary rocks formed in the east of the Australian Platform. Big watershed ridge located in the eastern part of the mainland. The mountains formed in the area collapsed over time. Only the Australian Alps exceed the two thousand mark. This is the only place on the continent where snow lies in places in the shaded gorges.

There are no active volcanoes or earthquakes on the mainland. It is located in the center of the Australian Plate, which spares it from seismically active faults at tectonic plate boundaries.

Deserts

Great Sandy Desert in Australia

Australia is the driest continent on Earth. Desert zones make up 44% of the entire region. They are mainly located in the northwest of the continent. The largest deserts in Australia are listed below:

Great Victoria Desert

The largest region, which occupies 4% of the total area of ​​the continent. Named after the British Queen. Part of the territory belongs to the aborigines. Agricultural activities are impossible due to lack of water.

Great Sandy Desert

Occupies an area equal to Japan. Due to the climate, sand forms high dunes. There is no permanent population. Precipitation does not occur every year, and there are no bodies of water.

Tanami Desert

A little-studied area in the north of the continent. There are small ones water pools, precipitation falls periodically. But because high temperatures moisture evaporates very quickly. Gold mining is carried out in the desert.

Simpson Desert

The scarlet-colored sands that roll across the area are famous among tourists. The region is named after the English geographer. In the 20th century they searched for oil here to no avail. Today the desert is popular among off-road enthusiasts.

Gibson Desert

Located between the Great Sandy Desert and the Victoria Desert. There are several saline lakes on the territory. The state has created a reserve here for animals adapted to harsh climatic conditions.

Small Sandy Desert

There are several lakes in the area. The biggest, Disappointment. The water in it is unsuitable for drinking and household needs, although this did not prevent the aborigines from settling in the desert.

Strzelecki Desert

Named after the Polish explorer. There are several villages around the desert whose population is engaged in agriculture. On the territory itself is located national park, which offers entertainment for fans of extreme tourism.

Inland waters

The main river system on the continent is the Murray River and its tributaries: the Darling, Murrumbidgee and Goulburn. The total area is more than 1 million km². Due to low rainfall, most rivers dry up. Springs originating in the mountains have constant water outflow Eastern Australia and rivers of Tasmania.

The largest lakes: Eyre, Gairdner, Frome and Torrens are located in the south. Most of the time they are pits covered with salt-bearing clays. On the southeastern coast there are numerous lagoons, separated from the sea by shallows. Freshwater lakes are located on the island of Tasmania. Great Lake is exploited for hydraulic purposes.

Australia has large reserves of artesian water. The total reserves of freshwater underground sources are about 3240 thousand km². However, they are deep, warm and often salty. The water is suitable for watering livestock, but is unsuitable for use on the farm due to its high mineral content. The Great Artesian Basin occupies 1751.5 thousand km². The development of agriculture on the mainland depends on it.

Climate

The continent is located in three climatic zones:

Tasmania has a temperate climate. Since Australia is located south of the line, winter begins in June and summer begins in December. Sudden temperature changes or extreme weather conditions not visible. From May to October it is always sunny, air humidity is 30%. average temperature V winter period usually not lower than 13º C. A cold winter is considered when the thermometer drops to zero. Summer is a period of cyclones and thunderstorms, the air warms up to 29º C. On the southeast coast the climate resembles. The coldest region of Australia is the island of Tasmania. In winter there are frosts. In the central regions of the continent, minor temperature changes are observed.

Flora and fauna:

Vegetable world

The flora is quite unique and endemic, since Australia is located at a considerable distance from the rest of the continents. The climate is characterized by severe aridity, because of this, only resilient plants dominate in nature. Trees have a powerful root system, which is adapted to suck water from a depth of up to 30 meters. Some plant species have hard, leathery leaves that are turned away from the sun to avoid excessive evaporation. Eucalyptus, bottle tree, palms and ficus trees dominate.

Represented by acacia and turf grasses. In places where there is a lot of rainfall, the same eucalyptus trees grow, but accompanied by horsetails and ferns, as well as other plants characteristic of the Mediterranean climate. continents are small. The total area of ​​green areas is 5% of Australia's territory, including artificial plantations of pine and other soft tree species. The colonists brought European species trees, grasses and shrubs. Grapes and cotton have taken root well, as have fruit trees and vegetables. Corn, rye, oats, wheat and barley grow well on Australian soil.

Animal world

Because Australia was discovered later than other continents and developed separately, it is home to animals that are unique and not found anywhere else in the world. There are practically no ruminants, ungulates or monkeys on the mainland. But there are a lot of representatives of marsupials: kangaroos; marsupial squirrel; ant-eater; Tasmanian devil; marsupial mouse. There are about 250 species in total. There are many fancy animals: echidna, koala, platypus, frilled lizards. To the number unusual birds include lyrebirds and emus. In terms of the number of dangerous representatives of the fauna, Australia can be given the palm. Better stay away from wild dog Dingo, cassowary, reptiles and spiders. The most dangerous animal, oddly enough, is considered to be a mosquito from the genus Kusaki. He is a carrier of dangerous diseases. Marine animals are also dangerous. Species of sharks, jellyfish and octopuses can pose a serious threat to people vacationing on the coast.

Minerals

The main wealth of the continent is considered to be, the potential of which is 20% higher than in the rest of the world. Australia has a lot of bauxite. From the second half of the 20th century. development has begun iron ore. In the west there are deposits of polymetals. Gold is mined in the southwest of the mainland. Scientists have found that there are deposits in the depths natural gas and oil. On this moment Research is underway.

Ecological situation

The country's economy is maintained in high positions due to the extraction of mineral resources. Mining development depletes the subsoil and destroys upper layer soil. Because of this, areas under Agriculture. Chronic water shortages forced the government to create a series of bans. At certain times of the year, people should not water their lawns, wash their cars, or fill their swimming pools.
During times cold war were held on the territory of the country nuclear tests. This had a negative impact on the radiation situation. Maraling, the area where the tests were carried out, is still considered contaminated.

Modern uranium springs are located close to Spencer Gulf and national park Cockatoo. This worries the public: a precedent has already been created when dirty water was poured into the reserve. The life of the aborigines depends on natural factors. As a result of desertification of the continent, they have to leave their settled settlements forever. State and world famous public organizations make every effort to preserve the uniqueness of Australia and its . New reserves and national parks are being created.

Population

The first generation of colonists arrived on the mainland in 1788. At that time, Australia was a place of exile for lawbreakers. The number of the first settlers was just over a thousand people. As a result of forced immigration, the number of people increased significantly. Australia ceased to be a place of exile for convicts in 1868. The influx of voluntary colonizers was associated with the development of cattle breeding and the opening of mines.

Modern society does not remind us of anything difficult years development and formation of the country. The population is 24.5 million people. In terms of population, the country ranks fiftieth in the world. The number of Aboriginal people is 2.7%. Migrants most often have British, German, New Zealand, Italian and Filipino roots. There are a large number of faiths in the country. Official language considered Australian English. It is used by 80% of the population.

Population density differs in different regions. On average per square kilometer no more than three people live. The southeastern coast of the mainland is most densely populated. Australia has a high life expectancy, with an average of about eighty years. The process of rapid aging due to low birth rates, as in Europe, is not observed. Australians are still considered a young nation.