林芝云杉群落特征的研究

Studies on the Characteristics of Picea likiangensis var. linzhiensis Communities in Xizang (Tibet), China

摘要:

析了林芝云杉( Picea likiangensis var. linzhiensis )群落的种类组成、区系特征、群落外貌、垂直结构和水平结构等特性。结果表明：调查样地共有维管植物144种，隶属于53科116属，其中只含1种的属占81.03%。林芝云杉群落的区系组成、植物生活型谱、叶片性质等特征反映了群落的温带性质。群落垂直结构明显，可分为乔木层、灌木层、草本层及层间植物，乔木层郁闭度为0.4~0.8，林芝云杉大多为乔木层的单一优势种，有时与急尖长苞冷杉(Abies georgei var. smithii)、华山松(Pinus armandii)等混生，而群落植物的水平分布不均匀。优势种种群的年龄结构分析表明，该种群处于稳定状态；群落的物种丰富度为32.6364，其Shannon-Wiener指数为3.0926，Simpson指数为0.9366，均匀度指数为0.8942，且均为草本层>灌木层>乔木层。

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.