Alpine zone 0 Morare forest 144 2 2 Picea purpurea treeline ecotone (4100 – 4300 m a.s.l.) in Huang-Long, Sichuan Ch Koerner, J Paulsen 2004 Tree height < 2 or 3 m Tree height > 2 or 3 m Kyi Chu, North of Lhasa 29°42‘ N, 96°45 ‘ E Miehe et al. 2007. Mountain Res. & Develop. 27, 169-173 Factors affecting trees at the alpine treelines Holtmeier & Broll, 2009. Polarforschung 79, 139-153