中文摘要：

为阐明水华过程藻群动态对水-泥界面磷素变化的影响,采集太湖梅梁湾水样和泥样,以莱茵衣藻（Chlamydomonas reinhardtii）为对象,通过室内模拟实验（76 d）,研究藻体增殖、悬浮与沉降过程水-泥界面不同形态磷素含量及碱性磷酸酶活性（APA）的变化。结果表明：衣藻快速增殖与悬浮导致水体p H与DO含量明显升高,总磷和无机磷浓度迅速降低,但底泥有机磷含量平均高出无藻处理1.5倍。此外,衣藻沉降期底泥水溶性磷含量明显降低,这是由于部分沉降在底泥表面的藻体继续存活并吸收利用了水溶性磷。上覆水APA在藻体大量沉降后平均高于增殖和悬浮期1-3倍。相比较而言,底泥APA在藻体快速增殖与悬浮期达到最高,此后,APA降低,但仍高于无藻处理2倍以上。因此,衣藻水华过程加速了水-泥界面磷素的释放,部分沉降至底泥表面的存活藻体吸收利用磷素进而增殖和再悬浮,这可能是富营养化水体水华反复和多次暴发的重要原因之一。

英文摘要：

Water and sediment samples,which were taken from Meiliang Bay,Taihu Lake,were used to mimic a sediment-water system with Chlamydomonas reinhardtii. A variety of phosphorous（ P） contents and alkaline phosphatase activities（ APA） were measured during C. reinhardtii proliferating,blooming and decaying（ 76 d）,to estimate the contribution of alga to P contents and availabilities at the surface between water column and sediments. The rapid proliferation and blooms for C. reinhardtii resulted in noticeable increases in p H and DO contents with substantial decreases in total P and inorganic P in water column. However,the organic P contents in sediments with alga addition treatment（ AT） were averagely 1. 5 times higher than those without alga addition treatment（ WAT）. In addition,water-dissolved P（ WP）contents in sediments with AT were observed a clear decrease during the decaying stage,possibly implying that parts of algae survived in the surface of sediments could continue to use WP to a large extent. Moreover,APA in water column was found a 1- 3 times higher in average during the decaying stage than those in proliferating and blooming stages,while APA in sediments arrived at the highest level during the proliferating and blooming stages. After then,although APA in sediments for AT decreased over time,it was 2 times above higher than those in WAT. Therefore,C. reinhardtii＇s blooms accelerated the release of P in a water-sediment system. Parts of algae survived in sediments can proliferate and re-suspend by using the released P. This potentially contributes to the blooms repeatedly occurring during short periods in eutrophic waters.