山西高原植被与气候的关系分析及植被数量区划的研究

本义利用去势典范对应分析和数量区划的方法，研究了山西高原植被与气候之间的关系，并进行了数量区划。排序的结果表明：ＤＣＣＡ的第一轴代表山西高原植被和气候梯度的纬向性，热量梯度是决定植被分布最主要的气候因子，水分梯度中的年降水量也对第一轴有较大的影响，由于山西高原南北跨度大，植被与气候因子表现出明显的纬向性；ＤＣＣＡ第二轴代表山西高原植被和气候梯度的经向性，与ＤＣＣＡ第二轴相关性较大的是水分因子中的年降水量、年蒸发量，由于山西高原东西跨度不大，而且大部分地区处在吕梁山脉和太行山脉之间，东西向的气候变化幅度不大，所以植被与气候梯度的经向性不明显。植被数量区划的结果表明：山西高原可划分为１７个植被区，用图示的方法确定山西高原大致有三个极点和一个中心。

ANALYSIS OF RELATIONSHIPS BETWEEN VEGETATIONAND CLIMATE IN SHANXI PLATEAU

Relationships between vegetation and climate,numerical regfonalization of vegetation in Shanxi Plateau were studied using the detrended canonical correspondence analysis (DCCA ) and two-way indicator species analysis (TWINSPAN ). It is shown that the first DCCA are expresses the variation of vegetation and climate along latitude in Shanxi plateau. The vegetation types and their distribution along latitude were mainly correlated with the thermal and water-condition gradients. The second DCCA are expresses the variation of vegetation and climate along longitude in Shanxi Plateau. The vegetation types and their distribution in this direction were mainly related with the annual precipitation and the evapotranspiration. In the plateau the changes in vegetation and climate along altitude are much greater than those along longitude because it extends longer from south to north than from east to west. Shanxi Plateau was divided into 17 vegetation districts using TWINSPAN and DCCA. Three poles and a canter were recognized in the figure of DCCA ordination plot.