Article Outline
Asia incorporates many different biomes, which are landscapes having similar combinations of climate, vegetation, and animal life.
The northernmost areas of Asia, which experience a subpolar climate, have tundra vegetation consisting of grasses, mosses, and other small plants. Farther inland from the Arctic coast, the tundra gives way to the taiga, a region of vast coniferous forests composed of trees such as spruce, larch, and fir. Farther south, the taiga merges with forests of broadleaf trees, or mixed forests of broadleaf and needleleaf trees.
In Asia’s north central interior the forests merge into vast grasslands, much of which is short, steppe grasses. Large portions of Southwest Asia and the continent’s interior have semiarid or desert vegetation. Short grasses and other vegetation that require minimal precipitation surround many of the most barren areas in the deserts.
Although tropical rain forest predominates along the southern coastal strip and on the island of Sri Lanka, the eastern side of South Asia is characterized by semiarid tropical vegetation. The Deccan Plateau has mainly tropical dry forest vegetation.
Mainland and island Southeast Asia once supported extensive areas of tropical rain forest, which thrived in the warm, moist climate. Significant tracts of forest remain in most countries, but legal and illegal harvesting are too rapid to support sustainable regrowth.
Inland from the coastal strips of mainland Southeast Asia and stretching into southern China, tropical seasonal forests predominate. These merge into temperate forests farther north. Around the rim of the Bo Hai gulf the vegetation is chaparral, woody shrubs that grow to 4 m (13 ft) in height.
Asia has three main crop production systems. Across a broad band encompassing the Middle East, Central Asia, much of Russian Asia, and the inner regions of China, subsistence livestock production is the mainstay. Around coastal China, and most of South and Southeast Asia, the major form of agricultural activity is subsistence crop production. Scattered throughout the region?especially in Japan, Southeast Asia, the western parts of Russia, and some fertile patches of the Middle East?are pockets of commercial crop production.
Economically important activities throughout Central Asia and Russia include the production of wheat and other grains, cotton, and vegetables. Southeast Asia and the southern parts of China and India are major rice-growing areas, although grain production and consumption is more common in the northern regions of China and India. Rubber trees and oil palm plantations are significant in Malaysia and Indonesia. Tea plantations are significant in India, Sri Lanka, and Indonesia.
Asia’s soils are related mainly to climate and vegetation. In some areas the origins of soils, perhaps from volcanic action or from materials carried by streams, may be more important. Such volcanic or alluvial soils are especially fertile.
The tundra soils of the northernmost part of the continent are acidic and infertile. Many of these areas are underlain by permanently frozen subsoils that never thaw during the brief summers. Subsoils of this type, known as
permafrost
, cover a very large area in the northern part of Siberia.
South of the tundra, the soils of the taiga are also acidic and relatively infertile. Somewhat less acidic and more fertile soils are found in the mixed forests and the broadleaf forests farther south.
Prairie and black chernozem soils are south of the forests. Because these soils developed where there is limited precipitation, their desirable minerals have not been absorbed or washed away, a process known as leaching. These soils are among the most fertile in the world. The best farmland of Russian Asia occurs largely on black soils and on the more inferior soils of the mixed and broadleaf forests.
The unleached soils of the semiarid and arid areas of the continent are often fertile, except where they are too saturated with salts or alkaline minerals. The availability of water for irrigation largely determines their use. Continued irrigation, however, may increase the concentration of salts or alkaline minerals and make the growing of crops impossible.
The soils of the rainy tropics are generally infertile. High precipitation and high temperatures cause most of the valuable minerals to be leached from the soil. Less leaching occurs in the rainy-and-dry tropics and the humid subtropics.
Many of the red and yellow soils of the humid subtropical area of China have been improved by thousands of years of care, which has included the use of compost, or rotted plant refuse. In some semiarid regions of China, however, natural vegetation with deep roots?which kept the soils in place?was cleared for food crops that lacked sufficient root systems and caused the topsoil to become terribly eroded.
The great variety of wildlife in Asia includes many species that are unique to the continent.
Orangutans
, the second tallest of the ape family after gorillas, are found on Borneo and Sumatra.
Giant pandas
make their home in southwestern China, and snow leopards roam the plateaus and mountains of Central Asia. A rare freshwater seal lives in Lake Baikal. China’s Yangtze River is home to a freshwater dolphin threatened by water pollution and increased numbers of motorized river vessels. The Komodo dragon, the world’s largest lizard and among the oldest surviving lizards, inhabits a small island in eastern Indonesia.
Asia’s wildlife generally can be classified by the particular vegetation zones they inhabit.
Reindeer
live in the southern tundra region of northern Siberia. Small fur-bearing animals, such as sables and foxes, are plentiful in the taiga forest of Russian Asia. The grasslands are home to antelope and many rodents, including
marmots
. In the mountainous areas of Central Asia live tiny
musk deer
. Tigers, one species of which inhabits northern Siberia, are found throughout the tropical rain forests of South and Southeast Asia. This area is also home to rhinoceroses, monkeys, and several subspecies of elephants.
In the hilly regions of Southwest Asia live
gazelles
. A rare species of antelope known as the
oryx
is found on the fringes of the desert areas of the Arabian Peninsula. Other animals commonly found in Southwest Asia include wolves and
hyenas
.
The remote mountainous region of Vietnam adjacent to the border with Laos has yielded some remarkable discoveries of animals previously unknown by scientists. A new species of cattle-like animal, the
sao la
(vu quang), was discovered in 1993, only the fourth discovery of this kind in the 20th century. Scientists have discovered other creatures since 1992, including two deerlike animals, the giant muntjac and the quang khem.
Asia’s domesticated animals include water buffalo, which are harnessed to plows and carts. Cattle are also used for hauling, especially in India, which has the world’s largest cattle population. Most people in India do not eat beef because they belong to the Hindu religion, which considers cows sacred. Pigs are a major source of protein in China, although they are considered unclean in the Islamic countries, which include Pakistan, Afghanistan, and most countries of the Middle East. Sheep are kept across vast areas of semiarid Russian Asia, and reindeer are farmed in the north. People throughout the dry areas of the Middle East use camels.
The bird life of Asia is varied and includes several rare species. In the mountains of northern India lives the lammergeier, a huge bird similar to the vulture, that can obtain a wingspread of almost 3 m (10 ft).
Peacocks
and birds of paradise are found in the rain forests of Southeast Asia.
The continent of Asia is also home to many of the world’s poisonous snakes.
Cobras
, which are especially common in India, and
kraits
and
vipers
, which are found throughout the continent, are the leading poisonous snakes. Numerous other reptiles, such as
crocodiles
, live in the rivers of Southeast Asia.
The tropical climates of large portions of Asia are particularly favorable to the development of insects and of parasites with long, complex life cycles. Tropical
walkingsticks
can exceed 30 cm (12 in) in length. Malarial organisms and the mosquitoes that carry them are favored by the absence of cold winters and, in rainy tropical areas, by the abundance of precipitation. The deadliest of the malarial organisms,
Plasmodium falciparum,
can survive year round in tropical areas.
Filariae
, small parasitic roundworms, are common in India and much of Southeast Asia; the parasite can cause
elephantiasis
, a disease that produces grotesque swellings. Great swarms of
locusts
are a periodic menace to farming in various areas of the Asian continent, particularly in Southwest Asia.
Asia is rich in known mineral resources, and additional resources are suspected in some areas, such as Tibet, which are still unexplored geologically. Asia is particularly endowed with energy resources. Petroleum and natural gas are well distributed, but the greatest concentrations of mapped energy fuels are at the head of the Persian Gulf; in parts of Indonesia, especially Sumatra and Borneo; in northern and interior China; on the shores of the Caspian Sea; and in the West Siberian Plain. Large offshore reserves are believed to exist along the coasts of China, Indonesia, Malaysia, and western India.
Since Vietnam’s economy began opening to foreign investment in the late 1980s, offshore oil and gas reserves have been tapped for commercial production. China, Taiwan, Vietnam, Brunei, Malaysia, and the Philippines each claim all or part of the
Spratly Islands
in the South China Sea, an area thought to contain rich energy and mineral reserves.
Coal exists in great abundance in Siberia, northeastern India, and especially in Shaanxi province in northern China, which contains 30 percent of China’s proven reserves. Despite enormous reserves, China is a coal importer because it does not have the capacity to transport sufficient coal from the northern to the southern parts of the country.
With the exception of Turkey, which is a major chromium producer, metallic minerals are relatively scarce in Southwest Asia. China and Siberia are particularly well endowed with mineral resources. Malaysia is rich in tin and India in iron and manganese ores. Indonesia has bauxite, which is used in aluminum production. Gemstones such as diamonds are found in Siberia, and sapphires and rubies occur in South and Southeast Asia. Other important mineral resources include gold, silver, uranium, copper, lead, and zinc. The major manufacturing centers of Asia, such as Japan, Singapore, and Hong Kong, have few or no significant mineral resources.