| 河蚬(bicula fluminea)扰动对湖泊沉积物性质及磷迁移的影响 |
| 摘要点击 3321 全文点击 3940 投稿时间：2010-02-05 修订日期：2010-03-30 |
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| 中文关键词 生物扰动 溶解活性磷 磷形态 二价铁 太湖 |
| 英文关键词 bioturbation soluble reactive phosphorus phosphorus fraction ferrous iron Taihu Lake |
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| 中文摘要 |
| 为探讨河蚬(Corbicula fluminea)扰动对湖泊沉积物性质及磷在沉积物-水界面迁移转化过程，以太湖西岸富营养化湖区大浦口为对象，开展室内培养实验，利用Rhizon间隙水采集器获取实时间隙水，测定溶解活性磷(soluble reactive phosphorus，SRP)在沉积物-水界面通量、分析沉积物基本性质. 结果表明，河蚬扰动破坏了沉积物表层原有结构、混合了沉积物原有分层，增加氧气在沉积物中的渗透深度、沉积物含水率与总微生物活性. 上覆水伴随河蚬活动下渗，氧化了表层间隙水中Fe2+，减小了间隙水中Fe2+浓度. 氧化生成的水合铁氧化物吸附间隙水中SRP，减小表层沉积物中间隙水SRP浓度. 水合铁氧化物吸附的磷沉积到沉积物中，增大了沉积物铁结合态磷含量. 河蚬同时促进了沉积物中SRP向上覆水的释放，且释放通量随河蚬密度的增加而增大，河蚬自身代谢可能对促进SRP向上覆水释放具有主导作用. |
| 英文摘要 |
| To examine the impact of Corbicula flumineaon sediment properties and phosphorus dynamics across sediment-water interface in lake, the microcosm experiment was carried out with sediment and lake water from the estuary of Dapu River, a eutrophic area in Taihu Lake. Rhizon samplers were used to acquire pore water, and soluble reactive phosphorus (SRP) flux across sediment-water interface and sediment properties were determined. The activity of C. fluminea destroyed the initial sediment structure, mixed sediment in different depths, increased oxygen penetration depth, sediment water content, and total microbial activity in sediment. The downward movement of overlying water was enhanced by the activity of C. fluminea, which decreased Fe2+ in pore water by oxidation. The production of ferric iron oxyhydroxide adsorbed SRP from pore water and decreased SRP concentration in pore water, and this increased iron bound phosphorus in corresponding sediment. The emergence of C. fluminea accelerated SRP release from sediment to overlying water, and enhanced SRP flux increased with the rise of introduced C. fluminea density. Metabolization of C. fluminea might play an important role in accelerating SRP release. |
