Saturated hydraulic conductivity of soils of typical forests of the south coast of guanting reservoir in Yongding River Watershed

In order to explore the characteristics of saturated hydraulic conductivity(Kfs) of the soils of the south coast of Guanting Reservoir in Yongding River watershed and to assess the function of water resource protection forests scientifically, this study used typical water resource protection forest stands as study objects, which were compared with local mature forests and non-forest land. Variance analysis, correlation analysis, and factor analysis methods were applied to investigate the influence of edaphic physical and chemical properties on saturated hydraulic conductivity, and the forest stands with the best soil permeability were screened according to the score ranking of influencing factors. The results showed that:（1） Saturated hydraulic conductivity decreased as the soil depth increased. The saturated hydraulic conductivity of mixed forests of water resource protection forests was greater than that of pure forests but similar to that of mature forests, among which Platycladus orientalis and Armeniaca sibirica mixed forest had the highest Kfs value;（2） Factor analysis indicated that the primary factors affecting Kfs were saturated moisture, soil bulk density, and soil organic matter content, while the secondary influencing factors were the contents of sand, silt, and clay in soil. Soil capillary porosity and non-capillary porosity had little effects on the Kfs value;（3） According to the score ranking of the comprehensive factors, soil permeability in the P. orientalis and A. sibirica mixed forest was the best, followed by that in the mixed forest of Pinus tabuliformis and A. sibirica. The present study demonstrated that ecological water conservation forests have the superiority in improving soil permeability, and that the afforestation project has shown remarkable achievements.