• 关键词：浅水湖泊  沉积物  磷  生物地球化学  连续提取法  富营养化  水生生态系统

• 基金项目：中国科学院知识创新工程重大项目(KZCX1-SW-12);国家自然科学基金项目(40071019);中国博士后科学基金(2002031226)联合资助

• 朱广伟
• 中国科学院南京地理与湖泊研究所,南京 210008

• 秦伯强
• 中国科学院南京地理与湖泊研究所,南京 210008

• 高光
• 中国科学院南京地理与湖泊研究所,南京 210008

• 张路
• 中国科学院南京地理与湖泊研究所,南京 210008

• 范成新
• 中国科学院南京地理与湖泊研究所,南京 210008

• 摘要：研究了长江中下游22个不同生态类型的浅水湖泊表层沉积物中磷的地球化学形态及水相磷含量等水质特征.对沉积物中磷形态的连续提取分析发现,自然粒度下,绝大部分湖泊的沉积物中90%以上的磷是以生物较难利用的形态存在的,活性磷所占比例很小.而在严重污染的城市湖泊中,活性磷含量则可以占到总磷的35%以上.沉积物中活性磷含量的高低与总磷含量并不一致.水草的存在对水相磷含量及沉积物中磷的活性都有显著的影响.水相磷的含量与沉积物中交换态磷的含量、沉积物铁磷比有显著的相关关系.研究表明,沉积物地球化学性质、水体营养盐含量及浅水湖泊生态类型之间存在复杂而密切的联系.

• Abstract：Geochemical forms of phosphorus in sediments sampled from 22 shallow lakes, and the water chemistry in the middle and lower reaches of Changjiang River, China were investigated. Sediments were sequentially extracted by the modified Ruttenberg's method, in which exchangeable form （Ex-P） was extracted with 1mol·L^-1 MgCl₂, Al combined form （Al-P） was extracted with 1mol·L^-1 NH₄F, Fe combined form （Fe-P） was extracted with 0.1mol·L^-1 NaOH and 0.05 mol·L^-1 Na₂CO₃, and the sum of Ex-P, Al-P and Fe-P was defined as bioavailable phosphorus. Ex-P content varied in the range of less than 0.01mg·kg^-1～15.35mg·kg^-1, and bioavailable phosphorus content varied in the range of 2.24mg·kg^-1～1080.33mg·kg^-1. Bioavailable phosphorus only takes less than 10% of the total extracted phosphorus in all but two heavily polluted lake sediments. Macrophyte significantly affects the contents of phosphorus in lake water and the mobility of phosphorus in lake sediment. Contents of total phosphorus （TP） and dissolved total phosphorus （DTP） in water from macrophyte-dominated lakes are significantly lower than those from seldom-macrophyte lakes. Contents of TP and DTP in lake water were also closely correlated to the content of Ex-P and the ratio of iron to phosphorus in the sediment.

• Key words：shallow lake  sediment  phosphorus  biogeochemistry  sequential extraction  eutrophication  aquatic ecosystem

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