干旱区不同荒漠植被土壤水分的时空变化特征分析

土壤水分是连接气候变化和植被覆盖动态的关键因子。以额济纳地区为研究对象，通过在6～10月间，于四种荒漠植被类型：胡杨林地，人工梭梭林，苜蓿地及戈壁观测点，布置管式时域反射仪（TDR）水分测定仪进行定点、定位观测，研究了上游放水前后，同一观测点不同深度及不同土地利用条件下土壤水分的时空分布和动态变化状况。分析表明：潜水蒸发对土壤水的补给作用越强，剖面水分条件越好；受土壤特性影响，垂直剖面含水量自下而上并不是严格递减的，对外界环境条件变化所做出的反应也不同，其中戈壁及人工梭梭林地土壤水分在垂直剖面上分布较均匀；胡杨林地和苜蓿地各剖面土壤水分差异较大。

Study on the Characteristics of Space-Time Change on Soil Moisture in Arid Region

Soil moisture is the key factor, which connects climate with vegetation change. Four typical desert vegetations in Ejina natural oasis were taken as examples. Soil moisture were observed by the time domain reflectometry probes at those sampling sites since June to October,which in order to investigate the space--time distribution and dynamic change of soil moisture around the water coming from upper reaches. The expand of dive evaporation will strengthen the supply of soil. moisture,and hydrology conditions of section. By the influence of soil characteristics,soil moisture is not degressive strictly from bottom to top at the vertical section. It is comparatively steady at the vertical section of Gobi and Haloxylon ammodendron forest;but have great difference comparatively in Populus euphrtaicr forest region and clover land.