Indonesia is one of the countries with the highest biodiversity in the world, and its land area is 5 times as big as Japan. It has, then, diversified vegetations. I will introduce them from vegetational studies of myself and Indonesian colleagues mainly on Kalimantan, Java and Sumatra.

Lowland of Kalimantan can be separated into wet and dry lands. The latter has higher diversity (300 tree species with DBH>4.8cm/ha) though both are dominated by Dipterocarpaceae. The wet land has three kinds, mangrove, peat swamp, and kerangas. In Java, Dipterocarpaceae is much less than in Kalimantan. But it is difficult to analysis the lowland natural vegetations in Java because few areas are remained in natural condition. The mountain vegetations in Java and Kalimantan are dominated Fagaceae, Lauraceae, Theaceae, Hamamelidaceae etc, and the diversity is lower than lowland (50-100 tree species/ha). Most forest areas in Indonesia have been disturbed by logging, fire etc. Then secondary forests dominated by pioneer trees of Euphorbiaceae, Asteraceae etc are common vegetations. The diversities secondary forests are lower than the primary forests, but some are still higher than primary forests in Japan.