人工柠条灌木林营造对退化沙地改良效果的评价

在干旱风沙区．以营造林的方式开展防沙治沙是目前进行生态建设和防治土地退化的主要技术措施。为此选用显示土地退化与否的标志性指标——土壤结构、水分、养分、植被等作为评价指标．研究在干旱风沙区退化沙地营造人工柠条林后上述指标的变化．结果表明：在宁夏盐池干旱风沙区，营造适宜密度的人工柠条林（1665丛／hm^2、2490丛／hm^2），可增大植被盖度，全面改善退化沙地的土壤理化性质、土壤水分状况及植被群落的稳定性。

Evaluations on Construction of Artificial Caragana intermedia toImproved Effects of Degenerated Sand Land

At present,in the arid wind-desert region,by the means of constructing forestation,developing to defend and control the sands is the main technical measures by which we can carry on the ecological construction and the preventing and controlling land degeneration.Therefore,through selecting the symbol target of soil structure,the moisture content,the nutrient,the vegetation as the appraisal targets,which showed land degenerated or not,we studied these indexes changes after constructing the artificial Caragana intermedia in the degeneration sand of arid wind-desert region.The results showed: in the arid wind-desert region of Yanchi,Ningxia,constructing suitable density artificial Caragana intermedia(1 665 clump /hectare,2 490 clump /hectare) could increase the vegetation fraction,comprehensively improve the soil physical and chemical property,the soil moisture condition as well as the stability of the vegetation community in the degenerated sand.