内蒙古呼伦贝尔草甸草原的草地退化等级数量分析

采用样方取样方法实地调查内蒙古呼伦贝尔草甸草原的植物群落特征,利用植被和土壤数据,应用系统聚类分析方法对其草地退化等级进行定量划分.结果表明:(1)植被指标聚类可将草地划分为3个等级,即轻度退化、中度退化和重度退化草地,而利用土壤指标聚类则划分为2个等级,其中轻度退化和中度退化草地的土壤状况相似合为一个等级,重度退化草地为另一个等级;(2)随着放牧梯度的变化,植被和土壤都发生了变化,中度退化草地植被变化大,而土壤变化不大;(3)内蒙古呼伦贝尔草甸草原为同一草地利用单元,所划分的草地退化等级系列是由放牧引起的.

Quantitative Analysis of Degeneration Stage of Meadow Steppe in Hulunbeier,Inner Mongolia

The plant community characteristics were measured with quadrat samples in Hulunbeier meadow steppe.The vegetation and soil data were used to divide the quantitative stage of degradation with systematic cluster analysis.The results showed as follows:(1) The degradation of meadow steppe can be divided into three stages:light degradation,moderate degradation and heavy degradation according to vegetation,and two stages:a little of light degradation and heavy degradation according to soil data;(2) Plant community and soil changed as the grazing pressure increased,but the vegetation change is quicker than that of the soil;(3) All the degradation stages are located in one range site.Therefore,the degradation is mainly caused by the grazing disturbance.