An Altitudinal Zonation of Tropical Rain Forests Using Byrophytes

Recent studies on the cover, phytomass and turnover of bryophytes in tropical rain forests along altitudinal transects in the high mountains of Columbia, Peru, Borneo and Papua New Guinea reveal the existence of similar altitudinal zonations in different parts of the humid Tropics. As bryophytes are excellent climate indicators, are rather few in terms of species number, have very wide geographical ranges, and are a characteristic component of the structure of the tropical rain forest, they may be useful tools for the construction of a general scheme of the altitudinal zonation of tropical rain forests. Five altitudinal belts are distinguished: the lowland forest, the submontane forest, the upper lower montane forest, the montane forest, and the subalpine forest. A comparison is made with other zonation terminologies and the elevational variations of the belts, due to local climate, latitude, and other factors, are discussed briefly.