【摘要】 开展晋西北黄土丘陵区土壤干燥化效应研究对该区域植被恢复重建具有重要的现实意义。以晋西北五寨县张家坪林场3种不同林龄的人工柠条林为研究对象,对照撂荒地,分别对其2013年生长季(4—10月)0—600cm深层土壤水分进行了测定分析。结果表明:研究区内的不同林龄柠条林及撂荒地均发生了不同程度的土壤水分亏缺及土壤干燥化现象。(1)不同林龄柠条林及撂荒地由于降雨的入渗补充,除部分土层剖面土壤储水量有少量亏缺外,其余均呈不同程度的盈余状态,土壤储水量总体变化情况为:20a柠条>10a柠条>35a柠条>撂荒地;(2)不同林龄柠条林0—600cm土层的土壤干燥化强度达轻度至中度干燥化强度,平均土壤干层厚度达447cm,并且随着林龄的增长,土壤干燥化的强度逐渐加强,各强度土壤干燥层厚度、总干层厚度及干化深度均呈增加趋势。而对照撂荒地的土壤干燥化指数SDI值为78%,并以轻度和中度干燥层居多;(3)综合考虑各降水年型,不同林龄柠条林及撂荒地剖面土壤干层水分恢复所需年限随着林龄的增加而逐渐增加,土壤湿度恢复难度呈增加趋势。更多还原

【Abstract】 It was of great significance to carry out a study on the evaluation of soil desiccation intensity for vegetation restoration in water-limited hilly areas of the Loess Plateau.In this paper,soil moisture dynamics in profile with depth of 600 cm was measured under three different ages of Caraganashrub sites and the uncultivated land at Zhangjiaping forestry station of Wuzhai County in the growing season(from April to October)in 2013.By analyzing,there were different levels of soil water deficits and soil desiccation in each sample plot,and the main findings were as follows:(1)As for the rainfall infiltration function,most of the soil layers showed the surplus state except for few soil layers,and the overall water storage in different ages of Caraganashrubs decreased in the order:20-year Caragana>10-year Caragana>35-year Caragana>the uncultivated land.(2)In general,soil desiccation level reached to the mild or moderate desiccation intensity at each sampling site,and the average thickness of desiccated soil layer was approximately 447 cm.Both of the dried soil density,total thickness of the desiccated soil layer and the initial formation depth of soil dry layers gradually increased with the growth age of forest.(3)With respect to all kinds of precipitation years,the time needed for water restoration in desiccated soil layers increased with the increase of forest ages.Meanwhile,the difficulty coefficient for soil moisture restoration gradually experienced the increasing trend as well.更多还原