太湖草源性“湖泛”水域沉积物营养盐释放估算

J．LakeSci．(湖泊科学)，2014，26(2)：177—184http：／／www．jlakes．org．E—mail：jlakes@niglas．ac．cn⑥2014byJournalofSciences太湖草源性“湖泛水域沉积物营养盐释放估算中秋实，周麒麟，邵世光，刘成，张雷，范成新(1：巾国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室，南京210008)(2：巾国科学院大学，北京100049)(3：河海大学水文水资源学院，南京210098)摘要：于太湖草源性“湖泛”暴发期，采集柱状沉积物并应用peeper被动采样装置获得“湖泛”区原位沉积物间隙水．泥水样品分析表明：“湖泛”发生水域表层(0～7cm)沉积物的含水率、孑L隙度和有机质含量均明显高于对照区，其中有机质含量更是对照区样品的4倍左右，沉水植物残体促使表层沉积物物化性质改变的作用明显；“湖泛”发生水域表层沉积物间隙水中铵态氮(NH4+一N)、溶解性反应磷(SRP)及“含量远高于未发生Ⅸ，植物残体降解对沉积物厌氧环境的营造显著．运用分子扩散模型对沉积物释放通量估算：“湖泛”发生区沉积物NH4+一N、SRP和Fe的释放速率分别是对照区的49．8、15．3和123．1倍．研究认为，草源性“湖泛”水体氮、磷等营养物含世升高的主要原因是沉积物的释放，而“湖泛”所营造的厌氧环境是氮、磷释放急剧增加的主要驱动因素．关键词：湖泛；氮；磷；沉积物释放；peeper；太湖Estimationof／n-situsedimentnutrientsreleaseatthesubmergedplantinducedblackbloomareainLakeTaihuSHENQiushi，ZHOUQilin。一，SHAOShiguang，LIUCheng。一，ZHANGLet‘&FANChengxin‘(1：StateKeyLaboratoryofScienceandEnvironment，NanjingInstituteofGeographyandLimnology，ChineseAcademyofSciences，Nanjing210008，P．R．China)(2：UniversityofChineseAcademyofSciences，BeOing100049，P．R．China)(3：CollegeofHydrologyandWaterResource，HohaiUniversity，Nanjing210098，P．R．China)Abstract：DuringthesubmergedplantinducedblackbloomperiodinLakeTaihu，sedimentcoreswerecollectedandporewaterswereaequiredusingpeeperin—situpassiveporewatersamplersattheblackbloomandthecontrolareas．Thesedimentsanalysisre—suitsshowedthatthewatercontent，porosityandorganicmatter(LOI)wereobviouslyhigherinthesurfacesediment(0—7cm)intheblackbloomareathanthoseinthecontrolarea，amongwhichtheLOIcontentswereabout4timeshighcr．Thephysicalandehemicalcharacteristicsofsurfacesedimentswereinfluencedbythesubmergedplantresiduesgreatly．Ammonium(NH4+一N)，sol-ublereactivephosphorus(SRP)andFecontentsinsurfaceporewatersattheblackbloomareaweresignificantlyhigherthanthoseatthecontrolarea．ThesedimentreleasefluxesofNH4+-N，SRP，andFewerealsoestimatedbyusingtheporewaterdif-filsionmodelapproach．Comparedtothecontrolarea，thereleasefluxesofNH4+一N，SRP，andFeintheblaekbloomareawere49．8，15．3，and123．1timeshigher，respectively．Theresearchimpliedthattheincreaseofnutrientse