北疆地区伊犁绢蒿荒漠草地退化与土壤理化性状相关分析

研究了不同退化阶段的伊犁绢蒿草地主要经济性状的特征与变化，结果表明，伊犁绢蒿荒漠草地在原生阶段，重度退化阶段和极度退化阶段，草地的各项经济性状均发生了一定变化，草地中植物种数逐渐减少。伊犁绢蒿由原生的建群种退至偶见种乃至消失；植物高度、盖度下降显著。由于牧压的加强，致使退化草地土壤的物理性状变差，退化草地的表层土壤容重和比重较原生草地增大了1．3倍和1．1倍，孔隙度过大或过小，不利植物生长，并引起土壤肥力下降；退化草地土壤表层有机质含量较原生草地下降了2倍，使土壤肥力不能满足植物所需。退化愈严重的草地其土壤水溶性盐含量愈高。因此，研究土壤的变化状况与草地退化的关系，可改善土壤肥力，使草地向健康的方向发展。

Correltion analysis on sward degradation and soil fertility of Yili spunsilksage grassland

The main characteristics and economic properties in different degradation stages of Yili spunsilksage(Seriphidium transiliense)grassland were studied in this article.The results indicate that a series of changes happened in economic properties of Yili spunsilksage pasture from the primary stage through to the last i.e the serious or extremely degradated stage.The plants quantities reduced gradually,Yili spunsilksage became incidental species even disappeared from the constructive species originally.The height and coverage of Yili spunsilksage plants dropped down remarkably.Because of the enhance of grazing stress,soil physical properties of the degradated pasture were lead to become worse.The volume weight and specific weight of the surface soil in the degradated pasture increased to 1.3 and 1.1 times than those of the primary stage,too big or too small for the soil porosity being unfavorable to plant growth and causing the soil fertility dropped down.Organic matter in the surface soil dropped down about two times of that in the primary status.These made the soil fertility unsatisfied to the needs of pasture plants.,and more salts accumulated in the soil.