中文摘要：

研究原生梭梭根区土壤水分动态变化对深入理解古尔班通古特沙漠水文过程与植被的相互作用具有重要意义.2007年8月至2008年7月,利用TDR土壤水分测定系统测定古尔班通古特沙漠南缘梭梭林地的土壤体积含水量,分析梭梭根区土壤水分时空分布及其变化规律.结果表明：梭梭根区土壤存在＂湿岛＂效应,根区60 cm土层水分储量是裸地的1.49倍,这种差异夏季比春季、降雨后比降雨前明显.春季积雪融化后,古尔班通古特沙漠土壤水分最丰富,而冬季的土壤水分含量最低.土壤水分年内变化可分为春季（3—5月）土壤水分迅速补充-消耗期、夏秋（6—9月）土壤水分缓慢消耗期和秋冬（10月至次年2月）土壤水分稳定期.经小波计算,根区和裸地土壤水分含量分别出现43 d、40 d的小周期和110 d、103 d的大周期.树冠的遮荫和自集水效应,以及根区土壤良好的渗透性是梭梭根区土壤水分相对丰富的主要原因.

英文摘要：

To understand the dynamic variations of soil moisture in the root zone of original Haloxylon ammodendron land is of significance for further understanding the interactions between hydrological processes and vegetations in the Gurbantunggut Desert.By using TDR probes system,this paper measured the volumetric soil moisture content in H.ammodendron land in the southern edge of Gurbantunggut Desert,and analyzed the spatiotemporal distribution of soil moisture in the root zone of H.ammodendron in August 2007-July 2008.There existed ＇wet island＇ effect in H.ammodendron root zone.The 0-60 cm soil water storage in the root zone was 1.49 times of that in bare land.Such a difference was greater in summer than in spring and after rainfall than before rainfall.The soil moisture content in the Desert was the richest in spring after snow melting and the lowest in winter,and its annual variation could be divided into three periods,i.e.,quick supplement-consumption period in spring（from March to May）,slow consumption period in summer and autumn（from June to September）,and stable period in winter（form October to next February）.Based on wavelet analysis, the soil moisture variation in H.ammodendron root zone and bare land had a short cycle of 43 and 40 days and a long cycle of 110 and 103 days,respectively.The relatively rich soil moisture content in H.ammodendron root zone could be mainly due to the stem flow water collection,tree canopy shading,and the better water percolating capacity in root zone.