1.College of Soil and Water Conservation,Beijing Forestry University, 100083, Beijing, China;
2.Forest Resources Authority in Simian Mountain of Jiangjin District of Chongqing City, 402296, Chongqing, China
Abstract：This paper focused on the forestland with three different vegetation types, i. e. , conifer + broadleaf forestland, Phyllostachys pubescens forestland and grassland in purple sandstone regions of the Simianshan Mountain in the Three Gorges Reservoir Area of Chongqing, using the methods of brilliant blue dye, image analysis and the SPSS software to present the soil preferential flow features and the influencing factors of the three vegetation types. The research results showed that: 1) The soil preferential flow zones were different for the three vegetation types, the soil preferential flow occurred in 0 -20 cm of soil surface layer of the Phyllostachys pubescens forestland and grassland, while it always occurred in the 10 -40 cm of soil layer in the conifer + broadleaf forestland. 2) The conifer + broadleaf forestland had more soil preferential flow paths than in the Phyllostachys pubescens forestland andgrassland, the development degree of the soil preferential flow was in the order of conifer + broadleaf forestland > Phyllostachys pubescens forest land > grassland. 3) The root system impacted the occurrence of soil preferential flow: the root diameter between 3 and 5 mm had a noticeable impact on the soil preferential flow of conifer + broadleaf forestland; however, the soil preferential flow of the Phyllostachys pubescens forestland and grassland were affected mainly by the root diameter between 1 and 3 mm. 4) The mass fraction of the sand in the three different vegetation types affected the occurrence of the soil preferential flow, in the meantime, the soil preferential flow had an impact on the saturated soil hydraulic conductivity: it contributed to raise the saturated soil hydraulic conductivity.
2014, Vol. 12 
