马来眼子菜群丛对太湖不同湖区沉积物磷形态的影响

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.

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

To understand the effect of the submerged macrophyte Potamogeton malaianus on the sedimentary phosphorus (P) fraction in Lake Taihu, China, various forms of P in P. 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 in P. malaianus vegetated 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 of P. malaianus on the sedimentary Ca-P in Gonghu bay and the south lake was within 0~15cm. It is concluded that the submerged macrophyte P. malaianus has an clear effect on the retention of P nutrients.