华西雨屏区退耕地不同植被经营模式坡面径流和产沙特征分析

Runoff and Erosion Analysis on Different Patterns of Vegetation Restoration and Management on Slope Land in High Precipitation Area of Western China

利用建立坡面径流观测场,对洪雅县低山区退耕还林中几种植被恢复模式进行定点观测。结果表明:(1)该区域产生坡面地表径流和土壤侵蚀最更本的原因是土地的耕作与否,3年未被直接扰动土壤的退耕地土壤侵蚀量仅是耕地的13.3%～37.9%;(2)林+草、竹+草种植模式的地表径流和土壤侵蚀特征既不同于农耕地,又与未被扰动的生态林植被相差较大。表现为随植被经营利用而出现阶段性的变化,牛鞭草的刈割对退耕地地表径流和土壤侵蚀影响较大。进一步研究、完善林+草、竹+草生态经营技术体系,提高该类退耕种植植被恢复模式的调蓄降雨能力,对指导退耕还林及植被经营有重要的意义。

Observation was conducted on the fixed sites of several vegetation restoration patterns by establishing runoff plots in the area of converting slope farmland to forest (CSFF) in Liujiang town, Hongya county. The results were as following: (1)Tilling or not was the key reason of runoff and sediment yield in this area. The sediment yield in yang stand of CSFF for 3 years was only 13.3%～37.9% of the farmland;(2)The ground runoff and erosion features in the patterns of tree + grass, bamboo + grass vegetation restoration were different from farmland, and also far different from undisturbed yang forest. The periodic change of runoff and erosion occurred after the tilling operation and the cutting of grass. Further studies about the ecological management techniques of tree + grass, bamboo + grass are needed to up-grading the capacity of rainfall regularity, and it could be a guideline to engineering of converting farmland to forest in the area.