Asia Vegetation

ASIAN LANDS: 

Vegetation & The Global Ecological Zones

Vegetation 

the plan plantt lif life e or the plan plantt ground cover of a reg cove egion, ion, not not the par partticular taxa, life lif e forms, st struc ructtur ure e, spat spatial exte ten nt, or any othe therr spe specific bot botani-cal or ge geo ograp raph hic ch cha racte rac risttics. teris

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e stan Primeval re Prime redwood fore forests, coast coastal mang mangrov rove ds, sph sphagnum bog bogs, de desert soil crust crusts, roadside roadside w eed ee hes, elds, cult ted ens and d pat patche s, whe whea at fi fie cultiva ivate d gard arde ed by term egeta lawns; all are are encompass ncompasse by the te rm veget ati on

Climate

and Vegetation

THE CONNECTION

  Asian

plants, which include ferns, gymnosperms, and flowering vascular plants, make up 40 percent of the earth's plant species . The endemic plant species come from more than forty plant families and fifteen hundred genera.  Asia is divided into five major vegetation regions based on the richness and types of each region's flora: tropical rain forests in Southeast Asia, Asia , temperate mixed forests in East Asia, Asia , tropical rain dry forests in South Asia, Asia , desert and steppe in Central and West Asia, and taiga and tundra in North Asia.

Global

Ecological Zone

Surface area Km2

% of total land area Region

% of GEZ worldtotal

Tropical rain forest

3 009 375

11.1

20.6

Tropical moist deciduous forest

1 379 477

5.1

12.5

Tropical dry forest

1 426 603

5.2

19.1

Tropical shrubland

1 167 107

4.3

14.0

Tropical desert

2 704 536

9.9

23.4

834 931

3.1

18.5

2 047 862

7.5

43.7

129 040

0.5

8.1

Subtropical steppe

1 180 330

4.3

2.4

Subtropical desert

1 446 347

5.3

21.7

Subtropical mountain systems

3 459 622

12.7

71.2

0

0

0

Temperate continental forest

1 253 135

4.6

18.0

Temperate steppe

1 115 606

4.1

18.9

Temperate desert

2 181 946

8.0

40.4

Temperate mountain systems

3 604 836

13.2

49.9

Boreal coniferous forest

157 450

0.6

1.9

Boreal tundra woodland

0

0

0

109 168

0.4

1.7

27 207 371

99.9

Tropical mountain systems Subtropical humid forest Subtropical dry forest

Temperate oceanic forest

Boreal mountain systems Total land area

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The Asian regions regions richest richest in flora, tropic tropical al rain forests, forests, are found in the island nations of Southeast of Southeast Asia, Asia, which exten extend d from Kinabalu in the north to Java in the south and from New Guinea in the east to Sumatra in the west. west. In this vast archipelago, archipel ago, the longest island chain between Asia and Australia, are thirty-five thousand to forty thousand vascular plant species. species. Tropical rain forests grow there year-round because of the region's warm temperatures and plentiful rainfall. rainf all. The forests contain great varieties of tall trees, some towering 148 feet (45 meters) high. Within any 1-square-mile area, one can see as many as one hundred tree species with no single species dominant. The rain forests have mostly broad leafed ever greens, with some palm trees and tree ferns. The uppermost branches of the trees form canopies that cover and protect the earth below. Because little sunlight penetrates the dense canopies, few shrubs or  or herbs herbs grow in the rain forests. Instead, many vines, lianas, epiphytes, andparasites are twined on tree branches and trunks. Mangroves fringe the tropical rain forests along the coasts.

The prevailing vegetation vegetation type is dense moist evergreen evergreen forest. Floristic variations exist, exist, depending on the location. The most striking st riking difference is the occurrence of Dipterocarpaceae, an important  Asian endemic family, family, to the west of the Wallace¶s line, whereas whereas they are totally absent to the east of  this line. As these forests grow in lowlands, they are under greatest pressure for timber exploitation and conversion to agricultural land. The Sundarbans mangrove forests of the Ganges Delta and those of western New Guinea are by far the most extensive in the world. In the drier parts of t he area, mainly in eastern Indonesia and the Himalayas foothill, semi-deciduous or moist deciduous forests occur; especially in the Brahmaputra valley, valley, they are valuable Sal forests (Shorea robusta).

Some more remarkable plants are blooms, carnivoro carni vorous us pitcher pitcher plants, plants, and Rafflesia Rafflesia flow flowers ers the world's largest flowers, which are endemic to  Asia.

Tropical rain forest (T (Tar) ar) the world's largest flowers, which are endemic to Asia Pitcher plant from Sabah Malaysia Raflessia

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Second in floral richness, richness, East Asia's temperate mixed forests contain thirty thousand to thirtyfive thousand plant species. species. This region ranges from Japan in the east to the Himalayan nations (Bhutan, Sikkim, and Nepal) in the west, and from Russi a's Amur River Valley in the north to China's Hainan Island in the south. south. East Asia's temperate weather is similar to the climate of eastern eastern North America, with with hot summers and cool winters. From south to north and from the east coasts to lower elevations in mountainous areas in the west, the vegetation changes from evergreen to deciduous broad-leafed forests, with dense shrubs, bamboo, and herbs in different layers beneath the forest canopy. The major tree specie s are of the magnolia, oak, tea, laurel, spurge, azalea, and maple families. Herbs include members of the primrose, gentian, gentian, pea, carrot, foxglove, composite, composite, buttercup, buttercup, and rose families.

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The Himalayan range is the point where the regions of South Asia, East Asia, and Central and West Asia join. From the Qinghai-Tibet Plateau in southwest China to the lower areas of  the Himalayas, elevation usually is between about 5,000 and 13 ,000 feet (1,500 and 4,000 meters). Mountains with deep valleys showcase complex, multiple vegetation types from mixed forests and dense shrubs to alpine meadows in mountain plains. Many primary seed plants (gym (gymnosperms nosperms and flowerin flowering g plants) plants),, grow grow there.

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Untouched native vegetation in East Asia is usual ly found only in mountainous or remote areas. On mountains at high elevations, the points where the temperatures are so cold that trees cannot grow form what is called the tree line. Nea r the tree line, only plants related to coniferous and alpine species grow. Above about 13,000 feet (4,000 meters) in high mountain areas, no vegetation grows. Instead, snowcaps or icebergs exist year round.

Due to the dry season, the natural vegetation vege tation is nearly everywhere a deciduous deciduo us or  semi-deciduous forest. This forest type is in Asia commonly known as monsoon forest. Its flora varies according to the region and the actual leafless period varies between species. On average, moist deciduous forests are leafless l eafless for at least 8 weeks in February and March. Many dominant trees belong to the Leguminosae, Combretaceae, Meliaceae Meliac eae or Verbenac Verbenaceae. eae. Dipterocar Dipterocarps ps are also present, present, but less conspicuous conspicuous as in the rain forest. The forest is 20 to 25 m tall tal l and a sparse grass cover is i s usually present.

Tropical moist deciduous forest (TAwa) (TAwa)

 An Asian valuable medicinal plant

 Asian Ginseng

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The third-richest region, tropical rain/dry forests, is found f ound in South Asia, Asia, which reaches from the Philippines in the east to Pakistan in the west, and from the Himalayas in the north to Thailand in the south. south. Twenty five thousand to thirty thousand species of plants grow there. This region has both tropical rain forests and tropical seasonal dry forests. forests . The tropical rain forest is mainly found in the region's lowlands and the seasonal se asonal dry forests in the highlands hi ghlands or  mountainous areas. More often, these two types of forests are combined.

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The tropical seasonal dry forests usually grow in a climate with wet and dry seasons or under a somewhat cooler climate c limate than the tropical rainforests. rainforests . The canopy, formed from primarily deciduous broad leafed species, speci es, is much thinner than the canopy in the tropical rain forest, so more sunlight reaches plants below. below. Many Many different plant species live live together, together, forming forming tropical tropical  jungles. Tall, thick-trunked trees, colorful orchids, ferns, dense mosses, and twined vines and lianas dominate this vast region. The major components of  these kinds of forests are members of the dipterocarpas, sweetsop, laurel, piper, fig, dissotis, akee, gardenia, periwinkle, milkweed, Afric an violet, palm, and aroid families. In central and southern south ern India and in some areas of  Pakistan there are tropical grasslands, called the savanna. Because B ecause of the savanna's hot, dry weather, mainly coarse grasses grow there.

 A complex of vegetation types are found in this Ecological Zone. Dry evergreen forest occurs on the dry eastern Coromandel Coast of India and in north Sri Lanka. This very peculiar and vestigial plant community is unknown elsewhere in Asia and is limited to a small area. Today Today,, most of these forests f orests have been cleared cleared for agriculture agriculture and locally replaced by Casuarina Casuarina equisetifolia and Eucalyptus plantations. The ecologically decisive factors include the rainfall regime with well-marked maxima in October,, November or December October December and a summer of 5 ± 7 dry months. This rainfall pattern pattern is uncommon in the tropics. The natural vegetation is a stunted woody formation with a peculiar floristic composition compo sition,, including including Manilkara Manilkara hexa hexandra ndra,, Chlo Chloroxy roxylon lon swie swietenia tenia,, Albizia amar amara a and Capparis Capparis zeylanica. The total flora is poor.

Tropical Dry forest (TA (TAwb) wb)

Fruit with long wings developed from persista persistant nt caly calyx x

Shorea obtuse

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The desert and steppe region in Central and West Asia has twenty to twentyfive thousand species of plants. plants. This region stretches from north and northwest China and Mongolia in the east to Turkey in the west and from Kazakhstan in the north to the Arabian Peninsula in the south. south. This region's vegetation changes from semi desert or desert to the temperate grassland called the steppe.

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Central and West W est Asia contains the largest desert steppe landscape landsc ape in the Northern Hemisphere. Few plant species grow in the steppe and nearly none in the desert. The herbs and few woody plants that grow in these dry areas are members of the grass, pink, pink , mustard, pea, saxifrage, stonecrops, lignum vitae, forget-m forget-me-not, e-not, and and lily families. families.

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Because the desert desert environm environment ent is so dry, plant species species must be able to survive in the arid weather for long periods of time. Central and West Asia with its steppe between the desert in the south and coniferous conif erous forests in the north forms one of the world's largest foraging f oraging areas, providing food resources for  both wild and domestic animals, such as camels, sheep, goats, cows, and horses.

Periploca

Tropical desert (TBWh)

In some places, between the dunes, a pseudo-steppic vegetation may occur. Sandy or  rocky deserts are extensive. The boundary of the Tropical desert in the Arabian Peninsula is based on the presence of tropical plants (south of this line) belonging to the Sudanian Region. The sparse vegetation consists of perennial shrubs, bushes, succulents and grasses.  Acacia flora is the indicator of the region with plants like Balanites,  Abutilon, Haloxylon, Retametalia, Eremopogon, Trichodesma, Cucumis, Cenchrus, Cyperus, Tribulus, Maerua, Boscia, Tephrosia, Rynchosia, Periploca, Pergularia. Thorny thickets of   Acacia  Acaci a tortilis tortilis and Maerua Maerua crassifolia crassi folia chara characteriz cterize e the foothills. footh ills. Panicum turgi turgidum, dum, Lasiurus Lasiu rus hirsu hirsutus tus are found in sandy plains, Yemen and the Hadramut.

Tropical Tro pical shrubland shrubland (TBSh)

Good

honey plant

Capparis

In these very dry conditions, only a low open forest can grow, often giving way to woodland, savanna woodland or thickets. Moreover, in densely populated India most of  this area is devoted to cultivation and grazing. Stretches of poor  degraded savanna or pseudosteppe intermingle with the crops. The thickets are composed of  thorny bushes of Acacia, Capparis, Capp aris, Maytenus Maytenus and Ziziphus. Ziziphus. In semi-arid Rajasthan, in the northwest of India, SudanoDeccanian Decca nian flori floristic stic eleme elements nts prevail. Some thorny thickets and low forest types dominated by  Anoge  An ogeissu issus s pen pendul dula a can be considered as a virtual climax. In these formations, several Acacia species (A. jacquemontii, A. leucophloea), Prosopis, Salvadora and Cappar Capparis is are common common shrubs. In southeastern Viet Nam and Indonesia, the low deciduous forest often gives way to a sclerophy scler ophyllous llous thicke thicket. t.

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The poorest region in floral richness, with only onl y about five thousand vascular plant species,, is North Asia. species Asia. This region is primarily Siberia, the eastern part of Russia Russia,, reaching from the Ural Mountains in the west to the Bering Strait in the east and from the Arctic Circle in the north to Mongolia and Kazakhstan in the south. The region's weather is temperate, with short, mild mil d summers and long, cold winters. The predominant vegetation in North Asia is coniferous (boreal) forest. This region, called the taiga, contains mainly pine, spruce, fir, larch, la rch, and some species in the birch, aspen, and willow families. Because the trees there are straight and tall, the taiga provides timber for Russia's forestry industry. Small, perennial herbs and a few types of  shrubs grow in the taiga's taiga's swamps swamps or marshes. marshes.

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Farther north is the cooler Arctic area called call ed the tundra. Plants that grow in tundra are resistant to the cold climate. During the summer they co mplete their life cycle quickly, before winter comes. Tundra plant species are members me mbers of such common families famili es as composites, peas, grasses, and reeds. Far beyond the tundra is Arctic ice.

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 Asia's native plant species provide shelter and food for animals. For example, arrow bamboo and umbrella bamboo, found in the forests of central to southwest China, Chi na, are the main food of the giant panda. Many plants in Asia also provide food, food , ornaments, or  medicine for humans.