草海流域植物群落结构数量分类与排序

Numerical classification and ordination of forest communities in Caohai basin

采用典型样地法对草海流域森林植被进行取样,利用22块样地资料对群落进行双向指示种分析法(TWINSPAN)分类、除趋势对应分析(DCA)排序和典范对应分析(CCA)排序,研究了草海流域植被的群落结构。结果表明:(1)利用TWINSPAN对流域内物种进行了分类,按照不同的指示种将其划分为7个群丛类型,同时在DCA二维排序图上得到了很好的印证。(2)CCA排序结果显示,对排序贡献由大到小依次为海拔、坡向、坡度、坡位。第1排序轴与海拔有关,反映了研究区温度条件的差异;第2排序轴与坡向和坡度显著的相关关系,反映了研究区水热和光照条件的差异。综合认为,草海流域植物群落分布主要受海拔和坡向两个环境因子的影响,具有明显的垂直地带性分布。

In this research,a typical sampling method was adopted to sample in forests of Caohai basin.And based on the data from 22 sample plots,forest communities in Caohai basin were investigated using TWINSPAN and DCA and CCA in order to analyze the structure of the communities.（1）The results of TWINSPAN classification indicated that these quadrate were classified into 7 types based on the species of Caohai basin,and they were further verified in the DCA two-dimensional ranking diagram.（2）CCA ordination results showed that the contribution in descending order was elevation,aspect,slope,and slope position.The first axis expressed the gradient of altitude among the communities,indicating the function of temperature.On the other hand,the second axis showed significant correlation with slop and aspect,which suggested that humidity,illumination and other things played key roles in community assembly.The results also indicated that the distribution of the vegetation communities was mainly impacted by two environment factors including elevation and aspect.At the same time,the vertical distribution character was obvious.