摘要
应用数量分类(TWINSPAN)和排序(DCA)方法分析了安西砾石戈壁荒漠植被,并应用逐步回归分析方法确定了群落和环境因素的关系方程。结果表明,该区砾石戈壁荒漠植被可分为6个主要群落类型。这些群落类型与土壤总含盐量、氯化物含量、硫酸盐含量及年降水量有密切的关系。群落按低盐到高盐和干旱到极旱的环境梯度分布。60个样地在DCA排序第一轴的位置(X_1)与土壤含盐量(S)、氯化物含量(Cl)、硫酸盐含量(SO)显著相关,而第二轴的位置(X_2)与年降水量(R)有密切的关系,其关系式为:1/X_1=2.1992+0.0225/S-0.0188/Cl-0.0567/SO(R=0.797,P<0.01);X_2=-82.8561+117.9219logR(R=0.817,P<0.01)。
Quantitative classification (TWINSPAN) and ordination (DCA) methods were used to study the gobi deserta in Anxi, and the stepwise vegression method was used to decide the interrela-tive equations among the communities and the environmental factors. The results indicated that the gobi deserta could be divided into 6 types of plant communities in this region. These types were a closely related to the soil contents of total salt ( S) , Cl- and SO42+ and the annual precipitation. They were distributed according to the environmental gradients from low to high salt content and from arid to extreme arid. The position of 60 sample plots in DCA ordinational first axis ( X1) significantly correlated with the environmental factors, viz. the soil contents of salt, Cl- and SO42-. And that in the second axis of the DCA ordination (X2) correlated well with the annual precipitation. Their relationships are expressed in the following equations: 1/X1= 2.199 2+0.022 5/S-0.0188/Cl -0.0567/SO (R=0.797,P<0.01);X2=-82.8561+117.9219logR(R=0.817, P<0.01).
关键词
植物生态学
荒漠
植被
多元分析
Deserta, Multivariate analysis, Stepwise regression
