研究表明 ,5～ 7年生沙棘林冠层可截留降水 8 5%～ 4 9 0 % ,并降低雨滴动能 ;枯枝落叶层重5 4 6t·hm- 2 ,其最大持水量可达 15 31t·hm- 2 ,有 1cm厚枯枝落叶层覆盖地表 ,即可基本控制水土流失 ;根系可以提高土壤的抗冲性和抗蚀性 ,与无根系土壤相比 ,可减少土壤冲刷量 55%～ 88% .据1988～ 1994年雨季径流小区测定 ,沙棘林在栽植后 4～ 5年可充分发挥水土保持作用 ,与农地相比 ,可减少地表径流量 87 1% ,减少土壤流失量 99 0 % .此外 ,它还可以每 4～ 5年提供薪材 10～ 30t·hm- 2 ,提高土壤中有机质和氮素含量 115%和 90 % ,生产沙棘果实 50 0kg·hm- 2 .所有这些表明了沙棘在治理黄土高原水土流失和改善人民生活条件 ,在实现由“恶性循环”向“良性循环”转变等方面 ,具有十分重要的作用 .目前 ,黄土地区已建立起若干利用沙棘固坡、防洪、解决燃料短缺和综合治理小流域的成功典型 The results showed that the canopy of 5-7-year-old seabuckthorn forest intercepted 8.5% -490% of precipitation and decreased the kinetic energy of raindrops. The litter layer weighs 546t · hm-2 and the maximum water holding capacity can reach 15 31t · hm - 2, a 1cm thick litter layer covering the surface, you can basically control soil erosion; root system can improve the soil impact resistance and corrosion resistance, compared with non-rooted soil, soil erosion can reduce 55% to 88% According to the determination of runoff plots in the rainy season from 1988 to 1994, the seabuckthorn forest can fully exert water and soil conservation 4 to 5 years after planting, reducing 87 1% of the surface runoff and 99 0% of the soil loss compared with the farmland. In addition, it can also provide fuelwood of 10-30 t · hm-2 every 4 to 5 years, increase soil organic matter and nitrogen content by 115% and 90%, and produce seabuckthorn fruits at 50 kg · hm-2. All of these show that sea buckthorn It plays a very important role in controlling soil and water loss and improving people’s living conditions in the Loess Plateau and in realizing the transformation from a “vicious cycle” to a “virtuous cycle.” At present, Shortage of fuel and comprehensive management of small watershed success typical