延河流域人工与自然植被土壤水分空间差异性研究

目的]研究延河流域自然植被与人工植被土壤含水量及其空间变化,为黄土高原土壤水分的利用和人工植被建设提供理论依据。方法]针对延河流域人工植被建造存在植被退化问题,根据降雨温度变化,将延河流域划分为17个环境梯度单元,对自然植被与人工植被进行了野外调查,研究了降雨梯度、坡位及坡向对植被0~500 cm土层土壤含水量的影响。结果]流域内土壤水分具有很强的空间变异性。自然植被0~500 cm土壤含水量为8.15%,变异系数为33.12%;人工植被土壤含水量较低,仅6.74%。地形因子能够显著影响自然植被与人工植被的土壤含水量,自然植被不同坡位和坡向的0~500 cm土壤含水量大于人工植被。结论]综合考虑土壤水分生态环境的可持续性,阴坡下与平地相对适合人工植被的营造,在植被配置时,需要考虑植被类型及耗水特点。

Spatial Difference of Soil Water Contents between Artificial and Natural Vegetations in Yanhe Basin

Objective] To study soil water content of artificial and natural vegetations in Yanhe Basin and their spatial variation ,and to provide theoretical foundation for the soil water use and artificial vegetation construction in Loess Plateau . Method] According to the problem of artificial vegetation degradation in Yanhe Basin,we divided the Yanhe Basin into 17 environmental gradient units based on the rainfall and temperature changes,Field investigation was carried out on the artificial and natural vegetations.Effects of the rainfall gradient,slope position and slope on 0-500 cm soil layer water content were researched.Result] Soil moisture had a strong spatial variability in Yanhe Basin.The 0-500 cm soil water content of natural vegetation was 8.15% and coefficient of variation was 33.12%.The soil water content of artificial vegetation was lower than natural vegetation.Volatile terrain factors could significantly affect soil moisture in the natural and artificial vegetation.The 0-500 cm soil content of natural vegetation was higher than that of artificial vegetation in different position and aspect of slope.Conclusion] Considering the sustainability of soil moisture ecological environment ,it is concluded that shady slope of mountain and flat land is more suitable for planting artifi-cial vegetation.But during vegetation allocation,we should consider the vegetation type and water consumption characteristics .