西藏濒危植物桃儿七群落结构及其环境因子

通过样地调查和数据统计,分析了三个桃儿七生长的典型群落的物种组成、物种重要值和群落多样性指数,应用主成分分析法分析了环境因子对群落的影响.结果表明:三个群落中桃儿七重要值均较高,在草本层具有一定优势;物种丰富度指数和多样性指数均为群落C的最大,均匀度指数为群落A的最大;主成分分析表明环境因子中土壤肥沃和光照强度对桃儿七是有利的,而人为干扰为不利因素.林缘、林窗和灌木林均为桃儿七群落的适生环境,但需要肥沃的土壤和一定的光照条件,避免人为干扰.在林缘的半阳坡地带或较为平缓的林间空地,散射光丰富,空气湿度和土壤肥力较高,人为干扰少的区域是野生桃儿七的适生区,可通过建立保护区进行保护;人工种植时,应充分考虑土壤、光照和温度等环境因子,提高人工种植的成功率.

Environment factors and characteristics of endangered Sinopodophyllum hexandrum communities in Tibet

A field investigation was conducted on the species composition,species importance value and diversity index of three natural S.hexandrum communities in Tibet;the effect of environment factors on S.hexandrum communities were analyzed through the principal component analysis.The importance value of S.hexandrum was maximal in the three communities and it was an important species in the herb layers.The richness indices, Simpson’s diversity indices and Shannon-wiener’s diversity indices were maximal in community C,but Pielou’s diversity indices and Alatalo’s diversity indices were maximal in community A.The principal component analysis showed that the organic matter content of soil and light were beneficial to S.hexandrum,but the intensity of human disturbance and water content of soil were adverse effects.These indicated that the forest edge,forest gap and the space under the shrub were suitable to the survival of S.hexandrum community.The semi-sunny slope region near the edge of forest and the gently opening space among trees were conducive to the life of S. hexandrum,due to the abundant scattering of light,moist air,fertile soil and little human disturbance.Therefore, building reserves is an efficient way to protect the wild S.hexandrum resource.The environmental factors,such as soil,light and air temperature,etc,must be considered during artificial planting,because they are necessary for the cultivation and protection S.hexandrum resource.