北方农牧交错带封育草地土壤含水量变化研究——以宁夏盐池县为例

Study on the Variation of Soil Water Content in the Fenced Meadows of Farming-pastoral Zone in North China

[目的]掌握封育草地的土壤含水量变化规律。[方法]以当地自然状态下的流动沙地为对照,通过野外调查、测定对照和样地的土壤含水量,研究了封育草地土壤水分的变化动态。[结果]5月初土壤含水量总体呈上升趋势,7、8月土壤含水量呈现明显的层次性特征且60～100cm深处的土壤含水量变化最显著;在相同的气候和立地条件下,不同样地的土壤含水量高低依次为自然恢复封育1年>人工封育(人工补播+自然恢复封育)1年>自然恢复封育3年>人工封育3年>自然恢复封育5年>人工封育5年。在封育年限相同的情况下,自然恢复封育草地的土壤含水量高于人工封育草地;生长期不同植被类型的土壤含水量高低为流动沙地>草本类样地>沙蒿等半灌木林地>沙打旺、棕条混杂的灌木林地。[结论]该试验为盐池县草地的生态恢复与建设提供了方法支持。

[Objective]The aim was to master the variation law of soil water content in fenced meadows.[Method]With local naturally mobile sand land as CK,the dynamic changes of soil water in fenced meadows were studied through field investigation and determining the soil water contents in CK and sample plots.[Result]The soil water content showed increasing trend totally in early May.In Jul.and Aug.,it showed obvious hierarchical features and changed most significantly in the depth range of 60-100 cm.In the same location with same climate,the soil water contents in different sample plots were as follows：fencing for natural restoration for 1 year artificial fencing（fencing with artificial reseeding for natural restoration） for 1 year fencing for natural restoration for 3 years artificial fencing for 3 years fencing for natural restoration for 5 years artificial fencing for 5 years.When the fencing periods were same,the soil water content in the fenced meadows for natural restoration was higher than that in the artificially fenced meadows.The soil water contents of different vegetation types in growth period were as follows：mobile sand land grass sample plot woodland of subshrub such as sand sagebrush shrub woodland mixed of Astragalus adsurgens Pall and palm sticks.[Conclusion]This experiment supplied methodological support for the ecological restoration and construction of meadows in Yanchi County.