林分不同径级根系对土壤饱和导水率的影响  

Effects of root system with different diameters on soil saturated hydraulic conductivity in stands

作　　者：师雪淇 付晓 朱美菲 史德威 程金花[1] SHI Xueqi;FU Xiao;ZHU Meifei;SHI Dewei;CHENG Jinhua(School of Soil and Water Conservation,Beijing Forestry University,100083,Beijing,China;Department of Urban Science,College of Applied Arts and Sciences,Beijing Union University,100191,Beijing,China)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]北京联合大学应用文理学院城市科学系,北京100191

出　　处：《中国水土保持科学》2023年第3期86-93,共8页Science of Soil and Water Conservation

基　　金：国家自然科学基金“融合时空大数据的城乡地域系统空间韧性研 究”(42271112)。

摘　　要：为研究重庆四面山根系分布对土壤饱和导水率的影响,选取四面山典型人工林,采用恒定水头法测定土壤饱和导水率,通过origin方差分析、相关系数分析探究不同林分类型、土壤深度、径级根系对饱和导水率的影响,旨为延缓地表径流和植物种植提供数据支撑及科学指导。结果表明:1)不同林分间径级根系所占比例存在差异,总体上根系所占比例呈现随垂直深度向下减少趋势,针叶纯林≤5 mm的根系比例最高,为71.00%~98.67%;针叶混交林中,不同径级根系分布均匀;针阔混交林根系径级分布呈现随土层垂直深度增加径级根系增大的规律;2)各林分随着土层深度的增加,其土壤饱和导水率呈现递减趋势,且在0~20 cm显著高于其他土层;相同土层深度的不同林分条件,土壤饱和导水率具有显著差异;另外,同一深度不同林分平均土壤饱和导水率从大到小依次是:针阔混交林>阔叶混交林>针叶混交林>杉木纯林>马尾松纯林;3)5种林分中,根系直径为>1~3 mm与土壤饱和导水率有极强相关性,根系直径≤1 mm及>3 mm与土壤饱和导水率的相关性较低。[Background]There are many species of forest stands and a well-developed root system in the Simian Mountains,Chongqing;however,this has led to the creation of a large amount of preferential root flow,generating more erosion and detrimental to the growth and development of the local vegetation.Therefore,this work is aimed to study the influence of root distribution on the saturated hydraulic conductivity of soil in Simian Mountain and to provide data support and scientific guidance for surface runoff mitigation and planting.[Methods]Five kinds of typical stand types in there plantation forest were selected,and one in situ soil column containing root characteristics was taken every 20 cm in the 0-60 cm soil layer(three replicate groups were set up in each layer,45 in situ soil columns in total)and brought back to the laboratory for root characteristics collection and constant head method to determine the saturated hydraulic conductivity of soil,and to investigate the influence of different stand types,soil depth and diameter class root system on the saturated hydraulic conductivity.The data were processed by origin ANOVA and correlation coefficient analysis.[Results]1)There were differences in root proportion among different stands,and the root proportion decreased with vertical depth.The percentage of roots in pure coniferous forest≤5 mm was the highest,reaching 71.00%-98.67%.In coniferous mixed forest,roots with different diameters were evenly distributed.The root diameter distribution of coniferous and broad-leaved mixed forest showed the law that the root diameter increased with the vertical depth of soil layer.2)With the increase of soil depth,the soil saturated hydraulic conductivity of each stand showed a decreasing trend,and it was significantly higher in 0-20 cm than other soil layers.The saturated hydraulic conductivity of soil was significantly different under different stand conditions with the same soil depth.In addition,the average K s of different stands at the same depth was as follows:Theropenced

关 键 词：土壤饱和导水率 恒定水头 不同径级根系 四面山 

分 类 号：S157.1[农业科学—土壤学]