中国东北西部地区沙质荒漠化过程与植被动态关系的生态学研究:植被的排序

Ecological studies on relationship between the process of des ertification and vegetation dynamics in the west of northeast China:Vegetation o rdination

根据东北沙质荒漠化地区呼伦贝尔沙地、科尔沁沙地的 72个沙地植物群落样地、2 76种植物的调查数据进行DCA排序 ,排序结果充分反映了沙地植被与地理因子、气候因子、地形因子、水文因子、干扰因子的关系 .DCA排序的第 1轴反映沙地植被分布的水分梯度 ;第 2轴反映土壤梯度 ;第 4轴主要反映热量梯度 ;DCA的1、4轴排序图和 1、2、4轴排序图 ,反映沙地植被与沙质荒漠化的生态规律 .采用定性因子评价赋值与定量因子相结合的方法 ,经双重筛选逐步回归分析 ,建立了沙地植被DCA排序坐标与地理、气候、地形、水文、干扰等诸多生态因子的线性回归模型 .

Based on the data obtained from 72 plots of plant community and 276 plant species in Hulunbeier Sandy Land and Kerqin Sandy Land in the northeast deserti fication region of China, TWINSPAN analysis and DCA (Detrended Correspondence An alysis) were carried out. The result of DCA ordination reflected sufficiently th e relationship between vegetation in sandy land and geographical, climatic, topo graphical, hydrological, disturbance factors. The axis 1, axis 2, axis 4 of DCA ordination reflected water, soil and heats gradients of vegetation distribution in sandy land respectively. The figure of DCA ordination of axis 1 & axis 2, and axis 1, axis 2 & axis 4 reflected the ecological regulations between vegetation and sandy desertification. Combined with qualitative and quantitative factors, the linear regression model was established between DCA ordination axis and geog raphy, climate, topography, hydrology and disturbances by using dual selection stepwise regression analysis.