中文摘要：

为了探讨柠条群落及环境因子与土壤水分动态响应关系,选择半干旱黄土区流域尺度不同地形条件下成熟柠条林作为观测样地,于2009-2011年生长季节（5月上旬至10月下旬）,每15 d1次,对0~220 cm剖面土壤水分进行了连续测定,2010年8月测定了0~600 cm土壤水分,2011年9月调查了柠条林群落结构特征。采用SPSS17.0软件的Duncan进行多重比较、EXCEL软件进行分析作图,对各样地剖面土壤水分差异、不同年度生长季节变异、干燥化程度以及其影响因子进行了综合分析。结果表明：浅层土壤水分含量为北坡〉东坡〉南坡,下坡位高于上坡位,坡度越大土壤含水量越低。由表层至深层,地形因子影响土壤水分作用逐渐减弱,植被因子影响土壤水分作用逐渐增强。在一定区域,柠条群落盖度和高度与深层土壤水分含量呈明显的负相关。人工柠条林加重了入渗层以下的土壤干燥化程度,而且连续干旱会造成入渗层范围的临时性土壤干层,而永久性干层是柠条发育至成熟阶段的过程中,逐渐形成并一直存在的一种现象。研究结论将对进一步从多尺度（年际和季节的时间尺度、水平和垂直的空间尺度）、多因子（气候、土壤、植被、微地形等）综合研究半干旱黄土区人工植被群落及其土壤水分环境动态提供重要参考。

英文摘要：

In order to discuss the relationship of dynamic response between community of Caragana korshinskii, environmental factors and soil moisture, the sampling sites were selected on mature forest of Caragana korshinskii under different terrain conditions at scale of watershed in semiarid loess area. Soil moisture in the 0-220 cm soil lay- ers was measured biweekly in each sampling site from the beginning of May to the end of October during 2009-2011, and the soil moisture in the 0-600 cm soil layers was measured in August of 2010. The investigation on community structure characteristics of Caragana korshinskii was conducted in September 2011. The multiple com- parison and the analyzing-plotting were carried out using SPSS 17.0＇ s Duncan and Excel 2007, the soil moisture differences in different soil layers, variance on season of growth in different years, the degree of desiccation and envi- ronmental impact factors have been done a comprehensive analysis. The results showed that： for the shallow layers, the results are as follows ： soil moisture content of north slope 〉 one of east slope 〉 one of south slope, and one of be- low slope position 〉 one of upper slope position, and there is a negative relationship between the slope gradient and soil water content. The sequences of PCSWDI are as follows：for 0-220 cm layers, upper slope position of south slope 〉 middle slope position of south slope 〉 upper slope position of north slope 〉 lower slope position of south slope 〉 lower slope position of east slope 〉 upper slope position of south slope 〉 lower slope position of north slope 〉 middle slope position of east slope; for 220-600 cm layers, middle slope position of east slope 〉 lower slope position of south slope 〉 lower slope position of north slope 〉 middle slope position of north slope 〉 upper slope position of north slope 〉 lower slope position of north slope 〉 upper slope position of east slope 〉 middle slope position of south slope 〉 upper slope position of south slope. F