Effects of different ages biological soil crust on infiltration in revegetated grassland in the Hilly Loess Plateau region, China
Biological soil crust (biocrust) covers up to 60-70％ of the soil surface in grasslands rehabilitated during the “Grain for Green project implemented in the hilly Loess Plateau region in 1999, which exerted a profound influence on water infiltration as well as soil and water conservation. The study reported here aimed to explore the temporal variation of soil permeability with development of biocrust in revegetated grasslands and to determine the impact of biological crust on water infiltration in the semi-arid hilly Loess region. The research was conducted on the typical semi-arid hilly Loess Plateau in Ansai county, Shaanxi province, China. Five grasslands in different rehabilitated ages (1, 4, 7, 10 and 13years) were selected as experimental plots. In each site, component and thickness of biocrusts in each plot were also investigated. Then, soil permeability was measured by using the disc permeameter. All treatments were repeated four times. Soil hydraulic conductivity, infiltration rates (q15, q30 and q) and sorptivity were tested. The results showed that biocrust had a significant influence on soil permeability. Soil infiltration rates (q15, q30 and q) with biocrust were reduced to half of that biocrust scalped. Soil sorptivity was decreased significantly for the developing of biocrusts; sorptivity of soil without biocrust was twice of that with biocrust. But no significant difference was found in Ks between soil with and without biocrust. However, in the study region, the difference between influences of biocrusts in successional stages on soil hydraulic properties was not significant in their first ten developing years. Soil infiltration rates (q30 and q) and Ks increased significantly of soil with 13 years old biocrusts. The results demonstrated that compared with the soil that without biocrust, biocrust may increase soil surface runoff and but control soil erosion. However, with the development of biological crust, the negative of biocrusts on infiltration in revegetated grasslands would be relieved.
biological soil crust water infiltration hydraulic parameters rehabilitated grassland hilly Loess Plateau
Yunge Zhao Mingxiang Xu
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation,Northwest A&F University, Yangling, Shaanxi, 712100, China
国际会议
西安
英文
902-906
2010-10-11（万方平台首次上网日期，不代表论文的发表时间）