色季拉山植物群落物种多样性研究

通过对西藏东南部地区色季拉山样地的调查，从不同类型群落的物种多样性与海拔、坡向的关系等方面对其植被进行分析,结果表明：在该特定的地带性地区，植物群落层次结构受海拔、坡向的影响，群落物种多样性程度为阴坡低于阳坡；森林群落内不同生长型的物种多样性指数在阴坡大小顺序为灌木层〉草本层〉乔木层，在阳坡则表现为草本层〉灌木层〉乔木层；随海拔的升高，阴、阳坡的物种组成差异缩小，植被群落类型和植物组成也相似，丰富度指数、多样性指数和均匀度指数表现出基本一致的变化趋势．

Species Diversity of Sejila Mountain Forest Plant Community

The relations of species diversity of different types of plant communities with elevation,slope orientation and other geographic factors on Sejila Mountain which is situated in southeastern part of Tibet were studied based on plot investigation.The results showed that the layering structure of plant communities in this specific zone was influenced by elevation and slope orientation.The species diversity index of the plant communities on the shady slopes was generally lower than that of on the sunny slopes.The species diversity index of the different growth types of plants inside the forest communities on the shady slopes was in the order: shrub layer > herbaceous layer > arbor tree layer.While the species diversity index of the different growth types of plants inside the forest communities on the sunny slopes was in the order: herbaceous layer > shrub layer > arbor tree layer.The differences in plant species composition and types of plant communities between the shady and sunny slopes decreased along with the increment of altitude,The similar change tendency took place with species richness index,diversity index and evenness index of the plant communities.