太湖湖泊缓冲带不同类型草林复合系统中氮、磷的溶出与沉降特征

环境污染与防治第37卷第2期2015年2月太湖湖泊缓冲带不同类型草林复合系统中氮、磷的溶出与沉降特征*李春江叶春。李春华。许士洪(1．东华大学环境科学与工程学院，上海201620；2．中国环境科学研究院环境基准与风险评估国家重点实验室，中国环境科学研究院湖泊工程技术中心，北京100012)摘要以太湖竺山湾缓冲带中湿地岸带、支浜岸带、人工防护林3种主要类型的草林复合系统为研究对象，分别对其自身氮、磷溶出及沉降特征进行了研究，从而揭示缓冲带本身对地表径流和地下渗流的影响。结果表明，3种样地中总氮的溶出率在0．3～2．5，平均溶出率表现为人工防护林>支浜岸带>湿地岸带；总磷的溶出率在o．8～4．0％，平均溶出率表现为支浜岸带>湿地岸带>人工防护林。氮、磷在向下沉降的过程中表现出不同的规律。各样地不同深度土壤渗透液中总氮浓度的变化趋势不一，基本表现为随深度增加而增加，总氮浓度为湿地岸带>人工防护林>支浜岸带；总磷浓度的变化趋势也不尽相同，与总氮相比，总磷的沉降效果不显著。综合来看，3种草林复合系统对污染物的沉降效果为湿地岸带>人工防护林>支浜岸带。关键词缓冲带溶出率沉降DOI：10．15985／j．cnki．1OO1-3865．2015．02．008CharacteristicsofN，Pdissolutionanddepositionindifferenttypesofgrass-treecomplexsysteminTaihuLakebufferzonesLIChunjiang，YEChun。，LIChunhua。，XUShihong．(1．CollegeofEnvironmentScienceandEngineer—ing，DonghuaUniversity，Shanghai201620；2．StateKeyLaboratoryofEnvironmentalCriteriaandRiskAssess—ment，CentreofLakeEngineeringandTechnology，ChineseResearchAcademyofEnvironmentalSciences，Beijing100012)Abstract：Takingthreetypicalgrass—treecomplexsystemsinTaihuLakebufferzonesasresearchsubjects，thecharacteristicsofN，Pdissolutionanddepositionindifferenttypesofgrass—treecomplexsystemwerestudiedbythestaticdesorptionexperimentandtestplots，whichrevealedtheeffectofeachtypeonsurfacerunoffandundergroundseepage．ResultsshowedthatthedissolutionrateofTNinsoilfollowingtheorderofpoplarplantationbufferzone>ruraltributariesbufferzone>wetlandbufferzone，thedissolutionrateofTPinsoilfollowingtheorderofruraltribu—tariesbufferzone>wetlandbufferzone>poplarplantationbufferzone．ThedissolutionratesofTNandTPwereO．3一2．5，O．8一4．0．Nitrogenandphosphorusshoweddifferentpatternsintheprocessofdeposition．ThechangetrendofTNindifferentdepthsoilinfiltrationfluidwasdifferent，whichincreasedwithdepth．TheconcentrationofTNfollowedtheorderofwetlandbufferzone>poplarplantationbufferzone>ruraltributariesbufferzone．ThechangetrendofTPconcentrationwasalsonotthesame．AndcomparedwithTN，theTPsedimentationeffectwasnotsignificant．Onthewhole，theeffectsontheabsorptionofpollutantsfollowedtheorderofwetlandbufferzone>poplarplantat