黄土高原森林带人工油松林水土保持作用

Soil and Water Conservation Function of Pinus tabulaeformis Plantation in the Forest Zone of Loess Plateau

采用长期定位观测方法,建立标准人工径流小区,观测了3种处理人工油松林地及对照农地的径流量和产沙量。结果表明:(1)农地14 a平均土壤侵蚀量分别为自然油松林、采伐上层乔木林地、去枯落物地的908、97、58倍;(2)农地14 a平均含沙量分别为自然油松林地、去枯落物地和采伐上层乔木林地的81、35和46倍;(3)自然油松林和采伐上层乔木林地年产流量分别为农地的13.7%和12.2%;(4)综合分析对于不同类型、农地的径流与降雨量、含沙量与降雨强度均存在显著的相关关系。土壤侵蚀量与各降雨因子的相关性与含沙量的相似。

Soil and water conservation functions of Pinus tabulaeformis plantation in the forest zone of Loess Plateau were investigated by long term observation,establishment of standard artificial runoff and sediment modulus.The results showed that（1） soil erosion amount on farmland was 908,97,and 58 times more than those of natural P.tabulaeformis forest land,land of cutting trees and keeping bushes and grasses,land of clearing ground litter cover and keeping trees and bush during 14 years,respectively.（2） The sediment concentration of farmland was 81,35,and 46 times more than those in the three kinds of lands mentioned above,respectively during 14 years.（3）The mean annual runoffs in the land of undisturbed P.tabulaeformis stand and the land of cutting trees and keeping bush and grass were 0.137 and 0.122 times more than that of the farmland,respectively.（4） Comparison between runoff and rainfall,sediment concentration and rainfall intensity showed significant correlation on different types of land.