Abstract:The forest of Picea likiangensis var. linzhiensis Cheng et L. K. Fu, widely distributed in southeast Xizang (Tibet), China, is one of the major Tibetan plateau subalpine dark coniferous forest types. Twelve sample plots in southeast Tibet were selected from the distribution center of this forest type to investigate its community characteristics, including the species composition, floristic characteristics, community physiognomy, and vertical and horizontal structure. The results showed that there were 144 vascular plants, belonging to 53 families and 116 genera, and 81.03% of the genera contain only one species. The floristic components, life-form spectrum, and leaf characters of the communities showed a typical temperate character. In vertical structure, the communities could be clearly divided into arbor layer, shrub layer, herb layer, and some interlayer plants. The canopy density of arbor layer ranged from 0.4 to 0.8, and which was dominated by individuals of Picea likiangensis var. linzhiensis. The horizontal structure was not symmetrical in the communities. The age structure of dominant population showed that the communities were steady state. The species diversity of the community is relatively low with richness index of 32.6364, Shannon-Wiener index of 3.0926, Simpson index of 0.9366, and evenness index of 0.8942. The diversity pattern was in order as herb layer > shrub layer > arbor layer.
