紫色砂岩区不同植被类型土壤优先流特征及其影响因素

以三峡库区内的重庆市四面山针阔混交林、竹林和草地3种不同植被类型土地为研究对象,应用亮蓝染色示踪法和图像分析法,同时结合SPSS软件对比研究紫色砂岩区针阔混交林、竹林和草地3种不同植被类型下的土壤优先流特征及其影响因素。结果表明：1）3种植被类型下土壤优先流的主要发生区域不同,竹林和草地的土壤优先流主要发生在0~20 cm土壤表层,而针阔混交林的土壤优先流主要发生在10~40 cm土层;2）针阔混交林的土壤优先路径数量较竹林和草地多,优先路径发育程度表现为针阔混交林〉竹林〉草地;3）根系直径d影响土壤中优先流的发生,

Characteristics and influencing factors of preferential flow in different vegetation types of purple sandstone regions

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 in0- 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.