a1 Laboratory of Ecology, Chiba University, Chiba 260, Japan.
a2 Forest Biology Program, BIOTROP, Bogor, Indonesia.
a3 Forestry and Forest Products Research Institute, Tsukuba Norin-Kenkyu-Danchi, Ibaraki 305, Japan
a4 Forest Kesearch Institute, Bogor, Indonesia.
The altitudinal zonation of forests on Mount Kerinci, Sumatra (3800 m) is described and compared with that in the temperate region of east Asia. Nine plots were selected between 1750 m in altitude and the upper limit of vegetation at 3250 m, at intervals of about 200 m in altitude. The plots are distinguished according to their main dominants, and the population structure of the dominant species is examined. The lower forests have species showing the whole range of size classes as well as solitary giants as dominants, but the upper forests lack these giants and are floristically poorer. Between 1750 m (the start of well preserved natural vegetation) and 2950 m (the forest limit) three forest zones are distinguished, and between 2950 and 3250 m a scrub zone. Upper forest zones tend to be dominated by species of the same genus or family which form important understory components of the zone below. Based on floristic comparisons with mountains of higher latitudes (i.e. Himalayas and Japan), the two lower forest zones (up to 2400 m) represent a subtropical zone, and the upper forest zone a warm-temperate zone. Climatic conditions at the forest limit on Mount Kerinci are similar to those at the latitudinal limit of warm-temperate evergreen trees; in the Himalayas the forest limit represents the latitudinal limit of the cool-temperate, and in Japan of the subarctic Altitudinal zonation patterns change with latitude, reaching their most complex on subtropical mountains where the two floristic realms, the Boreal and Palaeotropical, meet. A scheme for the pattern of vegetation zonation in east Asia is proposed.
(Accepted June 04 1985)