[Effects of forest vegetation on runoff and sediment production on sloping lands of Loess area].
Based on the 1985 - 2003 fixed-position data in 9 runoff plots of Caijiachuan watershed in the Jixian county of Shanxi Province in loess area, this paper discussed the relationships between vegetation and runoff and sediment production on sloping lands of loess area. The results showed that natural-secondary forest had better function in soil and water conservation than artifical Robinia pseudoacacia forest, with runoff and sediment produced 65% - 82% and 23% - 92%, respectively. Multiple regression analysis indicated that runoff and sediment production had a significant correlation with rainfall and its intensity, but this relationship was decreased gradually with increasing canopy density. Different land-use type had different runoff and sediment production, e. g., Ostryopsis davidiana and natural-secondary forests had the least runoff and sediment production, artificial Robinia pseudoacacia and Pinus tabulaeformis forests had 5 folds of it as much as Ostryopsis davidiana forest, mixed apple trees and crops had 17.14 and 3.96 folds of it than Ostryopsis davidiana forest, respectively, while high-standard soil preparation could decrease the production obviously. Gray correlation analysis suggested that the stand canopy density and the biomass of herb and litter were the most important factors affecting the runoff and sediment production on sloping land, whose gray correlation degrees all exceeded 0.6. Mixed forest with multi-layer stand structure and shrub forest should be developed in vegetation re-construction of loess area, which could help to increase the coverage and litter thickness to dramatically decrease the runoff and sediment production on sloping land.
Zhang
Xiaoming
X
Key Laboratory of Soil and Water Conservation and Combating Desertification of Education Ministry, College of Soil and Water Conservation, Beijing Forestry University, Beijing, China. zxm55@163.com
Yu
Xinxiao
X
Wu
Sihong
S
Wei
Tianxing
T
Zhang
Xuepei
X
D029401:Betulaceae / Q000254:growth & development; D003247:Conservation of Natural Resources; D017753:Ecosystem; D019015:Geologic Sediments / Q000032:analysis*; D028223:Pinus / Q000254:growth & development; D031301:Robinia / Q000254:growth & development; D012987:Soil / Q000032:analysis*; D014197:Trees / Q000254:growth & development*
D012987:Soil