论文部分内容阅读
[目的]研究毛乌素沙地不同地貌下沙柳(Salixpsammophila)根系分布特征,揭示干旱地区不同地貌下植物适应机理。[方法]利用中子水分仪观测沙丘上和丘间洼地沙柳样地的土壤水分动态,采用挖掘法分别对沙丘和丘间洼地上的沙柳样地进行根系分布的调查研究。[结果]在水平方向上,沙丘上沙柳根量呈指数函数减少;丘间洼地的沙柳根量呈乘幂函数减少。在垂直方向上,沙丘上的沙柳根系主要分布在0 ~30和80 ~120 cm的土层范围内,根量占总根量的72%;丘间洼地上的沙柳根系主要分布在0 ~40 cm的土层范围内,根量占总根量的54%。[结论]沙丘上沙柳根系不仅利用表层土壤水,而且还利用中层地下水。丘间洼地沙柳根系则以利用表层土壤水为主。
[Objective] The research aimed to study the distribution characteristics of Salix psammophila roots in different landforms in Mu Us sandy land, and to reveal the adaptation mechanism of plants under different landforms in arid land. [Method] The dynamic changes of soil water in sand and willow plot on sand dune and mound were observed by neutron moisture meter. The root distribution of sand and willow in sand dune and mound depression were investigated by digging method. [Result] In the horizontal direction, the root volume of Salix psammophila decreased exponentially, while the Salix root volume decreased in a power function. In the vertical direction, the root of Salix psammophila distributes mainly in the soil layer of 0-30 and 80-120 cm, and the root volume accounts for 72% of the total. The root of Salix psammophila distributes mainly in 0 ~ 40 cm soil layer, the total amount of roots accounted for 54%. [Conclusion] The Salix root system on the sand dune utilized not only surface soil water but also middle groundwater. Salix depression Shaliu root system to the use of surface soil water-based.