黄土丘陵区主要人工林水保及其土壤水分生态效益研究

通过研究表明，不同类型植被减少径流和泥沙的功效不同，东坡不同类型植被小区径流深由大到小的顺序为：荒坡＞沙棘（平茬）＞沙棘＋小叶杨＞农地；北坡为：油松＞油松＋沙棘＞沙棘林；东坡产沙量由大到小的顺序为：农地＞荒坡＞沙棘（平茬）＞沙棘＋小叶杨，北坡为：油松＞油松＋沙棘＞沙棘。不同类型植被在生长季的土壤水分平均值均很低，其中对土壤水分利用强度由大到小分别为柠条＞沙棘＞刺槐，100cm以下土层，不同类型林地土壤均存在利用性干层。

Soil and Water Conservation as Well as Soil Water Ecology Benefits of Main Vegetation Types in Semi arid Loess Hilly Region

The research results have showed that the efficacy of vegetation decreasing runoff and sediment was different with vegetation types. The depth of runoff in differ-ent vegetation types plots on eastern slope was barren slope > seabuckthorn stand (seabuckthorn is cut)> seabuckthorn +leaflet poplar stand > farmland. Sediment dis-charge on eastern slope was farmland >barren slope >seabukthorn stand (seabuck-thorn is cut) >seabukthorn +leaflet poplar stand, and on northern slope pine planta-tion > pine + seabuckthorn stands> seabuckthorn. Mean values of soil moisture in dif-ferent vegetation types plots during the growing season were very low, ranging from 6. 33% to 9. 60%. There was dry layer formed by the plants absorbing water in seabuck-thorn plantation.