不同固沙植被下沙丘土壤水分动态比较

以毛乌素沙地覆盖度>90%的油蒿、50%～60%的沙柳、35%～40%的樟子松固定沙丘为研究对象,流动沙丘为对照,采用自动监测系统实时监测降雨、0～200 cm土壤含水量及200 cm以下渗漏量,分析5—11月不同固沙植被下沙丘土壤水分动态差异,以期为固沙植被稳定性评价提供参考。结果表明:较低覆盖度樟子松与高盖度油蒿、沙柳相比更具固沙优势。3种固沙植被表层0～30 cm土壤水分受降雨影响大,对>20 mm降雨均产生响应;60～200 cm土壤水分时间变化特征存在差异,樟子松与对照变化趋势一致,油蒿和沙柳仅对40 mm降雨产生响应;0～200 cm土壤水分垂直变化没有相同规律,变异性较大,樟子松变幅最大,为(5.03±3.09)%;深层渗漏特征基本一致,均有极少量水分渗漏到200 cm以下。

Comparative Study on Soil Moisture Dynamics of Dunes in Different Sand-binding Vegetations

Taking the dune soil under the main sand-fixing vegetation Artemisia ordosica (coverage 90%) 9Salix psammophila (coverage 50% — 60%) , Pinus sylvestris var. mongolica (coverage 35% —40%) in Mu Us Sand Land as test object. The auto-monitoring system used to quantitative monitor precipitation,soil water for 0一200 cm depth,200 cm following leakage water. Analysis for dunes soil moisture dynamic characteristics in different sand-binding vegetation and provides reference for vegetation suitability, stability and sustainability, in order to provide a reference for the stability evaluation of sand-fixing vegetation. The results showed that greater than 20 mm rainfall was large effect 0—30 cm soil moisture. Differences for 60一200 cm soil moisture dynamic characteristics, the P.sylvestris and control the same trend,greater than 40 mm rainfall can be influence 60一200 cm soil moisture for the A. ordosica and S? psammophila? The 0 — 200 cm vertical variation of soil moisture variability was large and among P. sylvestris has maximum amplitude for (5? 03±3? 09)%. The three sand-fixing vegetations had water leaking into the following 200 cm depth and consistent with deep percolation characteristics? Overall,low coverage P. sylvestris had good sand-fixing advantage?