The Greening of Koh Chang with Dipterocarpus turbinatus Trees
As an indigenous tree species of Thailand, Dipterocarpus turbinatus is gregarious in the protected rainforests of Koh Chang. It is a common Mountain View sight when one is occupying a hotel room facing the eastern portion of the island. This kind of tree is not endemic to the place for records show that it is native to western India and mainland Southeast Asia such as Cambodia, Laos, Myanmar, Philippines, Thailand and Vietnam. It is also can be found in China particularly in southeast Xizang, southern and western Yunnan.
Dipterocarpus turbinarus is a lofty tree species that grows ranging at 30-45 meters tall. It has a shallowly longitudinal fissured and flaky gray or dark brown bark. Its branchlets are glabrescent. The buds and twigs are densely gray puberulous and the leaf buds are falcate. Dipterocarpus turbinarus stipules are densed, have dark grayish or dark yellow puberulous and they are measured between 2-6 centimeters while its petiole are between 2-3 centimeters in size and also densely glabrescent. Its leaf blade are ovate-oblong which are measured 20-30 x 8-13 centimeters, are leathery, glabrous or sparsely stellate pubescent. This tree species flowers in March to April and fruits occur in June and July as normally observed. Its natural habitat is mixed deciduous, evergreen and semi-evergreen forests.
It thrives abundantly in wet dense forest, sometimes on sandy, clay soils and even in red soils. In Koh Chang, this tree species is under protection and cutting is strictly prohibited as most number of this tree is located in the protected rainforests of the island. This tree is considered an important source of wood known as keruing and in some countries it is used in the plywood industry, sawing, woodwork and tea cabinet. In India, for example, the resin of the tree is known internationally as East Indian copaiba balsam where it is the source of kanyin oil and gurjun oil. It has medicinal value that treats gonorrhea, leprosy, psoriasis and other skin diseases. In China, it is cultivated both as medicinal and as a perfume plant.