摘要
文章采用双向指示种分析(TWINSPAN)和典范对应分析(CCA)法,对拉鲁湿地植被群落组成、分布格局与环境因素之间的关系进行研究。结果表明,拉鲁湿地29种主要植物种隶属17科25属,其中最常见的种类有苔草、嵩草、芦苇、委陵菜和水蓼。TWINSPAN表明,28个样方分为四个主要样方组,分别代表不同的生境类型并与CCA排序结果基本一致。CCA分析反映了拉鲁湿地植物群落组成和分布格局随环境因子变化的趋势,并且由CCA渐进选择分析确定了影响拉鲁湿地植物群落组成和分布的主要环境因子,包括放牧、水位和践踏干扰等。
The relationship between vegetation composition,their distribution and environmental factors of the unique marshland-Lhalu Dhamra in Lhasa was studied using TWINSPAN and CCA.The results showed that the major 29 plant species in the marshland belong to 25 genera,17 families and the commonest plant species in the marshland include Carex spp.,Kobresia spp.,Phragmites communis,Potentilla anserine and Polygonum spp.TWINSPAN classification shows four ecological species groups and four plot groups that represent four different habitats and are consistent with CCA ordination result.CCA direct gradient analysis effectively summarized the relationship between the vegetation composition and environmental variables in the marshland.The CCA forward selection allowed detecting the most important factors namely grazing,water level and trampling for affecting vegetation composition and distribution in the marshland.