众所周知．每一条自 然的河流两岸，在一定的 范围内都生长着一定数量 的柳树丛、次生杨、小叶 乔榛本等无经济价值但水保价值极高的矮、次生林，这其中又以柳丛为主要堤岸屏障临水而生。柳树特有的根须盘根错节，伸延数米甚至数十米远，常常直接伸入水下抓牢泥沙，像卫士一样 We all know. Each of the two sides of a natural river grows a certain amount of low and secondary forests with a certain amount of willow trees, secondary poplars and leaflets of Jojoba, which have no economic value but high water and soil conservation values. As the main bank barrier water born. Willow roots and roots unique root defects, extending a few meters or even tens of meters away, often directly into the water and grab sand, like guards