黄土高原北部草地土壤水分空间变异研究  

Spatial Variability of Soil Moisture in Northern Grassland of the Loess Plateau

作　　者：冯博 贾小旭[2,3] 于冬雪 赵春雷 贾玉华 FENG Bo;JIA Xiao-xu;YU Dong-xue;ZHAO Chun-lei;JIA Yu-hua(College of Water Conservancy,Shenyang Agricultural University,Key Laboratory of Soil Erosion Control and Ecological Restoration in Liaoning Province,Shenyang 110866,China;Key laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]沈阳农业大学水利学院,辽宁省水土流失防控与生态修复重点实验室,辽宁沈阳110866 [2]中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室,北京100101 [3]中国科学院大学资源与环境学院,北京100190

出　　处：《土壤通报》2019年第5期1123-1130,共8页Chinese Journal of Soil Science

基　　金：国家自然科学基金项目（41877016）资助

摘　　要：土壤水是维系黄土高原恢复生态系统稳定性和可持续性的关键因子。为深入理解黄土高原不同类型草地恢复生态系统土壤水的分布特征,采用经典统计学与地统计学方法,分析了陕北神木六道沟小流域样地尺度长芒草和苜蓿草地0~500 cm剖面土壤水分的空间变异特征。结果表明:两种草地土壤水分随土层深度增加均呈先增大、后减小,而后趋于稳定的变化趋势,具有中等程度变异性。垂直方向上两种草地土壤含水量及空间变异系数均具有显著差异(P<0.001),苜蓿和长芒草地0~500 cm剖面土壤水分变异系数平均值分别为0.19和0.33。总体上,苜蓿导致深层土壤水过度消耗,70cm以下土层土壤含水量明显低于长芒草地,其高耗水特性削弱了垂直方向140 cm以下土层土壤水的空间变异强度。因此,苜蓿植被强化了土壤水在垂直方向上的循环,并导致深层土壤水负平衡,进而使样地尺度土壤水在水平方向的分布趋于均质化。Soil moisture is a key factor in maintaining the stability and sustainability of the ecosystem in the Loess Plateau. In order to understand the distribution characteristics of soil moisture in different types of grassland restoration ecosystems, we analyzed the spatial variability of soil moisture at the 0-500 cm depth in the Medicago sativa L. and the Stipa bungeana Trin. grasslands in the Liudaogou small watershed of Shenmu, northern Shaanxi Province by using the classical statistics and geostatistics methods. The results showed that the soil moisture contents in the two grasslands increased first and then decreased with soil depth, then tended to be stable and had moderate variation characteristics. The soil moisture content and its spatial variability were significantly different(P < 0.001)between the two grassland species. The average variability coefficients of soil moisture at the 0-500 cm depths in the Medicago sativa L. and Stipa bungeana Trin. grasslands were 0.19 and 0.33, respectively. In general, due to the excessive consumption of deep soil moisture, its content below 70 cm depth was significantly lower in the Medicago sativa L.than in the Stipa bungeana Trin. grasslands. The high moisture consumption characteristics weakened the spatial variability of soil moisture below 140 cm depth. Therefore, Medicago sativa L. strengthened the circulation of soil moisture in the vertical direction, and led to the negative balance of deep soil moisture, which in turn made the distribution of soil moisture in the horizontal direction at the plot scale homogenized.

关 键 词：黄土高原 苜蓿 长芒草 土壤水分 空间变异 

分 类 号：S152.7[农业科学—土壤学]