中文摘要：

为揭示咸水滴灌下塔克拉玛干沙漠腹地人工防护林的土壤水盐动态规律,研究了4-7月份各灌水周期内土壤水盐的时间变化特征和二维空间分布格局。结果表明：（1）咸水滴灌下的防护林土壤水盐动态具有显著的周期性规律;一个周期内（1~15 d）,水分先后经历了快速下降（1~4d）、缓慢变化（4~10 d）和基本稳定（10~15 d）三个时期,整体呈幂函数递减规律（y=8.746t-0.270,t=1,2,3…）;盐分则先后经历了脱盐（1~7 d）和积盐（7~15 d）两个阶段,整体变化规律符合抛物线函数（y=0.009t2-0.138t＋2.269,t=1,2,3…）。（2）水平0~60 cm空间上的土壤水分呈一元线性递减分布,而盐分呈一元线性递增分布;垂直0~120 cm空间上的土壤水分表现为较明显的单峰曲线,其峰值位于20 cm土层处,而盐分分布满足逆函数模型,并在表土层距滴头45~60 cm处有显著积盐现象,含盐量高达10~20 g kg-1。由于受灌溉、蒸发、气温、降雨、植被等环境因素及土壤自身空间变异性等的影响,具体不同时空尺度上的绿地土壤水盐动态既具有一致性规律又表现出差异性特征。本文可对区域土壤水盐动态预测、盐渍化评估以及灌水制度进一步优化等提供科学支撑。

英文摘要：

Soil water,as the major component of water in desert ecosystems,is the most important environmental factor which limits the growth and productivity of the vegetation. Specifically,soil water plays a significant role in the development,evolution and productivity of sand soils,as well as in maintaining the structure stability and function of desert ecosystems. Besides,it can make a great difference on the windbreak and sand-fixation,etc. The Tarim Desert Highway,crossing the Taklimakan desert,is protected by the artificial plantation shelterbelts along the highway. Due to high evaporation demand and extremely low rainfall in this region,it is very difficult to maintain the water balance of the sandy soil along the plantation shelter,thus leading to failure in meeting the normal water demand of plants without irrigation. Consequently,how to meet the water demand of plants is the key problem to sustain the plantation shelterbelt. Currently,pumped saline groundwater has been utilized to supplement the soil water loss in the shelterbelt. However,the soil salinization,caused by the long-term saline water（especially the saline water of high salinity）irrigation,inevitably hampers the construction and maintenance of the plantation shelterbelt. Solution for this problem is highly dependent on the understanding of the soil water and salt dynamics. Based on these,it is very necessary to carry out the dynamics of the soil water and salt in this region,and so on. In order to reveal the laws of spatial and temporal dynamics of the soil water and salt in the soil under artificial shelterbelt dripirrigated with saline water in the center of the Taklimakan Desert,a field study was carried out to monitor temporal variation and two-dimensional spatial distribution of soil water and salt in the soil between April and July during which four irrigation events occurred at the interval of 15 days. Results show that（1）in the soil under artificial shelterbelt drip-irrigated with saline water,dynamics of the soil water and salt displ