Sumatra : 473 606 km2, 30 million inhabitants, approximately 38 languages.
Since 1965, the transmigration of Javanese to the east and south of Sumatra has entailed a major population increase (3,3%) ; each year, 60% of Java's transmigrants settle in this territory, i.e. about 570 000 families between 1969 and 1980. This human element, added to a forest policy entirely based towards the export of wood (Indonesia is the first world producer of plywood), has entailed excessive deforestation.
It covers half the island, but all accessible forests are about to be exploited. Other than wood, the forest also provides secondary resources for the world market, but in such vast quantities that the natural vegetation is in danger because there is no longer enough time for complete or even partial regeneration. 60% of the national production of rattan comes from Sumatra.
The forest covers the mountainous ridge and the south-western coast :
- below 300 m : forests of Dipterocarpaceae
- above 300 m : mixed forests, not as thick as the former
- above 1000 m : forests with Fagaceae et Burseraceae
The rhinoceros of Sumatra, Dicerorhinus sumatrensis (approximately 400 left) ; three national parks for their protection (+/- 25 000 km2) : Gunung Leuser, Kerinci-Seblat, Barisan Selatan (Species ndeg.17 : 47-48).
Tigers : there is a lot of illegal trading in tiger bones, used in Chinese and Corean medicinal traditions, and this has led to heavy poaching (by poisoning carcasses of animals ) (Species ndeg.17 : 52).
The orang utan in Sumatra (Gunung Leuser Reserve) and Borneo (in the following reserves : Gotawaringin Sampit, Kutai, Bukit Raya, Gunung Mulu, Mount Kinabalu, Danum Valley) (RIJKSEN, 1978).
Agroforestry : centuries ago the cultivators of Sumatra adopted a system of cultivation using both arboriculture and horticulture. The result is a useful forest which has been remodelled and appears natural though it is actually man-made through a process of careful selection of different tree species.
This "agroforest is by essence a complex system where one can find together in one area some plants that are planted and tended, harvested in a systematic way, and others that were chosen from natural seedbeds, also protected and encouraged, and yet other species that are tolerated or occasionally fought against. The agroforest is the result of the cultivated area being superimposed on a forest area defined by gathering activities and altered by them ; its management is a movement to and fro between gathering and cultivating" (MICHON, 1985 : 35)
Swidden agriculture : Researchers have pointed out that the ladang of Kalimantan and Sumatra are highly sophisticated systems and they provide strong evidence to show that such a system does not destroy the jungle but simply uses its limited resources ; and, as opposed to modern mechanized agriculture, swidden agriculture has few negative effects on the environment (VAYDA, 1979).