毛乌素沙地3种主要植物群落的阻沙效益

目的]对毛乌素沙地天然沙蒿、沙柳和锦鸡儿这3种主要植物群落的阻沙效益进行分析,为毛乌素沙地沙漠化防治及生态建设提供理论依据。方法]通过测定标杆风蚀沙埋程度,分析各植物群落的风蚀量与阻沙量,从而对其阻沙效益进行比较分析。结果](1)植被盖度越大,各植物群落的防风阻沙效果越明显;(2)地形条件相似,风速相同的情况下,3种植物群落在风蚀季节的临界防风蚀盖度不同。沙蒿群落的临界防风蚀盖度最小,约为60%,沙柳群落与锦鸡儿群落的临界防风蚀盖度相对较大,均大于60%,但锦鸡儿群落相对沙柳群落的临界防风蚀盖度小;(3)相同盖度下,3种植物群落的风蚀量与阻沙量之和大小顺序为:沙柳锦鸡儿沙蒿。结论]在毛乌素沙地固定、半固定沙地上,沙蒿群落的防风阻沙效益突出,可作为主要固沙植物进行推广。

Efficiency of Sand Resistance of Three Main Plant Communities in Mu Us Sandland

Objective] The state of wind erosion and sand resistance of three main natural plant communities, Artemisia ordosica, Salix psammophllia and Caragana microphylla, in Mu Us Sandland, were demonstrated and the efficiency of sand resistance of them was analyzed in order to provide references for desertification control and environment preservation. Methods] Erosion rods were set upright and the buried scales were observed to calculate the indices of wind erosion and sand resistance by the three communities. Results] The large vegetation coverage was the high efficiency of sand resistance of these communities had. Under similar terrain condition and the same wind speed, their threshold vegetation coverage were different in erosive season. The critical vegetation coverage for controlling wind erosion of Artemisia ordosica, was about 60%, smaller than those of Salix psammophllia and Caragana microphylla. The threshold vegetation coverage of Salix psammophllia and Caragana microphylla were larger than 60%, but the former was bigger than the one of the latter. Under same coverage, the amount of wind erosion and sand resistance ranked as Salix psammophllia > Caragana microphylla > Artemisia ordosica. Conclusion] Artemisia ordosica had the most significant efficiency of sand resistance and be promoted to act as the main sand-fixation plant in Mu Us Sandland.