Highest Treeline in the Northern Hemisphere Found in Southern Tibet

Determining the upper treeline is certainly one of the most interesting research challenges in comparative high mountain research. Careful compilations (Hermes 1955; von Wissmann 1961; Schickhoff 2005) have documented that the highest treelines in the northern hemisphere are found on the eastern declivity of the Tibetan Highlands. However, regional and global synopses of upper treeline altitudes can only be useful sources when information on growth form and habitat structure as well as data on human impact are provided. Therefore, all available compilations admittedly compare data of differing reliability. Inconsistencies result from different definitions of what constitutes a tree, or from failure to take account of human interference (Troll 1948; Figure 1).