Sumatra island

The great island of Sumatra the third largest in the archipelago and fifth largest in the world (roughly the size of California or Sweden), is Indonesia’s most important territory. In just about every way, strategically, economically and politically, Sumatra has always formed a pivotal "backbone" for the nation. Second among the major islands in population numbers but first in exports (principally oil, natural gas, rubber, tin and palm oil, but also tobacco, tea, coffee and timber), it stands at the crossroads of Asia.

Like Java, Sumatra is formed by a longitudinal range of mountains, a double fold in the earth’s crust with a central trough through which towering volcanoes have thrust upwards. This so-called Bukit Barisan Range extends for about 1,600 kms (1000 miles) in a northwest-southeasterly direction rising at several points above 300 meters (1000 feet). There are about 90 volcanoes in this range, 15 of which are active, but unlike those in Java and Bali they frequently deposit material of an acidic nature which does not improve the fertility of the surrounding soils.

The majority of Sumatrans live in the long range of undulating foothills, plateaus, river basins and highland lakes along the island’s spine, where they make a living as subsistence cultivators. Two major ethnic groups the Minangkabau and the Bataks, and a number of minor ones (the Gayo, Alas, Kubu, Kerinci, Rejang, Lampung and others) can be identified. The Minangkabau are settled people who are related to the Malay of the east Sumatran coast and are thought to be descended from an inland. The other great highland people of Sumatra, the Bataks, inhabit a fertile volcanic plateau, roughly oval in shape, that covers much of the northern central Sumatra.

The island of Sumatra was once covered in dense rainforest and inhabited by many exotic Asian animals (elephants, tigers, rhinos, gibbons, orangutans, mousedeer, tapir, flying foxes), unfortunately the flora and fauna of Sumatra has decreased in recent years as land has been altered from tropical rainforest to agricultural land.

http://www.asia-planet.net/indonesia/sumatra.htm