马来眼子菜群丛对太湖不同湖区沉积物磷形态的影响

The influence of Potamogeton malaianus community on sedimentary phosphorus fraction in different sites of Lake Taihu

采用磷分级提取的方法对太湖贡湖湾、南部湖区马来眼子菜（Potamogeton malaianus）群落内外的沉积物样品进行了采集和分析,调查了沉积物中的不同形态磷的垂直分布状况,研究马来眼子菜群落对沉积物磷迁移转化的影响.结果表明：植物群丛对沉积物铁铝磷（Fe/Al-P）的影响在贡湖湾和南太湖表现不同.贡湖湾马来眼子菜群丛内部沉积物Fe/Al-P高于群落外部的27.6%,差异性显著（P〈0.05）；南太湖马来眼子菜群丛内部沉积物中Fe/Al-P均值低于群丛外部的47.4%,差异性显著（P〈0.05）.植物群丛对沉积物有机磷（OP）的影响在贡湖湾和南太湖表现相似,两湖区植物群丛外部沉积物中OP含量均值高于群落内部.马来眼子菜群丛对贡湖湾和南太湖沉积物中Ca-P有较明显的影响,植物的影响主要体现在表层0-15cm范围内,贡湖湾湖区沉积物Fe/Al-P和OP含量较高,在植物的影响下转化为Ca-P,因此Ca-P在表层沉积物中呈上升趋势；南太湖沉积物中Ca-P含量较高,在植物影响下Ca-P有一定量的释放,因此Ca-P在表层沉积物中呈下降趋势.

To understand the effect of the submerged macrophytePotamogeton malaianus on the sedimentary phosphorus （P） fraction in Lake Taihu, China, various forms of P inP. malaianus vegetated and non-vegetated areas were quantified with the standard measurement and test （SMT） approach in surface sediments （0-40cm） from the northeast （Gonghu bay） and the south lake regions. Results showed that in Gonghu bay, Fe/Al-P inP. malaianusvegetated areas were significantly higher （P〈0.05） in comparison with the non-vegetated areas. However in the south lake, Fe/Al-P in the vegetated areas were significantly lower （P〈0.05） in comparison with the non-vegetated areas. OP in the vegetated areas were greatly decreased in comparison with the non-vegetated area in the south lake （P〈0.05）. The effect ofP. malaianus on the sedimentary Ca-P in Gonghu bay and the south lake was within 0-15cm. It is concluded that the submerged macrophyteP. malaianus has an clear effect on the retention of P nutrients.