杨树与小麦间作系统林冠层降雨再分配对地表径流和淋溶的影响  

Effects of Canopy Rainfall Redistribution on Surface Runoff and Leaching in Poplar-Wheat Intercropping System

作　　者：褚军[1] 金梅娟[2] 佟思纯 吴永波 薛建辉[4] Chu Jun;Jin Meijuan;Tong Sichun;Wu Yongbo;Xue Jianhui(Yangzhou Polytechnic College,Engineering Research Center for Agricultural Security and Environmental Protection of Jiangsu Province,Yangzhou,Jiangsu 225009,China;Suzhou Academy of Agricultural Sciences/Institute of Agricultural Sciences in Taihu Lake District,Suzhou,Jiangsu 215155,China;College of Biology and the Environment,Nanjing Forestry University,Jiangsu Key Laboratory of Forestry Ecological Engineering,Nanjing,Jiangsu 210037,China;Institute of Botany Jiangsu Province,and Chinese Academy of Sciences,Nanjing,Jiangsu 210014,China)

机构地区：[1]扬州市职业大学江苏省农业安全生产与环境保护工程技术研究中心,江苏扬州225009 [2]苏州市农业科学院江苏太湖地区农业科学研究所,江苏苏州215155 [3]南京林业大学生物与环境学院,江苏省林业生态工程重点实验室,江苏南京210037 [4]江苏省中国科学院植物研究所,江苏南京210014

出　　处：《水土保持通报》2020年第2期69-76,共8页Bulletin of Soil and Water Conservation

基　　金：国家林业公益性行业科研专项“生境胁迫立地植被恢复与重建技术研究”(201104002);江苏省高校自然科学研究重大项目(12KJA180003);扬州市“绿杨金凤”人才引进项目;扬州市职业大学校级科研课题(2017ZR27)。

摘　　要：[目的]探讨杨树林冠层降雨再分配对地表径流量、侵蚀量和淋溶量的影响,为农林间作系统削减水土流失提供理论依据。[方法]以太湖流域杨树与小麦作系统为研究对象,通过对2013年全年101场降雨的降雨量、林内穿透雨量、树干径流量的野外观测及对地表径流量、侵蚀量和淋溶量的样品收集进行测定分析。[结果]①总降雨量为943.5 mm,林内总穿透雨量、树干径流量及截留量分别为796.2,7.3和140.0 mm,分别占总降雨量的84.4%,0.8%和14.8%。其中,降雨量<10 mm的中、小降雨发生最频繁,占总降雨场次的80.2%;②穿透雨量(R^2=0.993)和树干径流量(R^2=0.748 4)与林外降雨量呈线性正相关关系;当降雨量大于5.5 mm时,树干开始产生径流;林冠截留率与降雨量呈负幂函数相关关系(R^2=0.414 7);除了降雨量外,林冠截留率还与林冠叶面积指数有关;③间作系统林分密度越大,冠层叶面积指数越大,林冠层对径流量和侵蚀量的削减作用就越强。④单株杨树距离树干1.5 m处平均穿透雨量较0.5 m,7.5 m处分别减少了3.2%,9.3%,淋溶水量分别减少了3.5%,10.8%;就单株林木而言,除降雨量外,林冠结构特征对淋溶流失起着重要作用。[结论]①间作系统中杨树林冠层对降雨的再分配作用主要取决于降雨量,降雨量越大林冠层截留效果越不显著;②杨树密度的增大能显著减少系统内地表径流量和侵蚀量;③单株杨树在距离树干1.5 m处的冠层对降雨的削减作用最大,淋溶水量亦最少。[Objective]The effects of canopy rainfall redistribution on surface runoff,erosion and leaching in poplar forests were discussed,in order to provide a theoretical basis for reducing soil erosion in agroforestry systems.[Methods]Taking the poplar-wheat intercropping system in Taihu Lake basin as the research object,the surface runoff,erosion and leaching were measured and analyzed,based on the field observation of rainfall,throughfall and stem flow of 101 rainfall events in 2013.[Results]①The total rainfall was 943.5 mm.The throughfall,stem flow and interception were 796.2 mm,7.3 mm and 140.0 mm,respectively,accounting for 84.4%,0.8%and 14.8%of the total precipitation.The small and medium-sized rainfall which was less than 10 mm occurred most frequently,accounting for 80.2%of the total rainfall events.②Throughfall and stem flow were correlated with rainfall outside the forest(R^2=0.993,R^2=0.7484).The stem flow started when the rainfall was greater than 5.5 mm.A negative function correlation existed between the rate of canopy interception and rainfall(R^2=0.4147).In addition to rainfall,the rate of canopy interception was also related to canopy leaf area index.③The higher the intercropping system stand density,the greater the canopy leaf area index,and the stronger the effects of canopy layer on surface runoff and erosion.④The average throughfall at 1.5 m from the trunk of a single poplar was reduced by 3.2%and 9.3%respectively compared with that at 0.5 m and 7.5 m,and the leached water decreased by 3.5%and 10.8%respectively.Besides,canopy structure played an important role in leaching loss.[Conclusion]①The redistribution effect of poplar canopy on rainfall in intercropping system mainly depended on rainfall.The greater the rainfall is,the less significant the interception effect is.②The increase of poplar intercropping can significantly reduce the surface runoff and erosion in the system.③The canopy of a single poplar tree at 1.5 m from the stem has the greatest effect on rainfall reduction and the

关 键 词：农林间作系统 降雨再分配 地表径流 淋溶 

分 类 号：S715.2[农业科学—林学]