中文摘要：

在沉水植物的生活史中,沉积物提供植物固着基质和所需的大量营养元素,对沉水植物的兴衰有长期且深远的影响。通过模拟试验,研究了北里湖沉积物经过3种处理（覆盖砂、锁磷剂、粘土）后对苦草（Vallisneria natans）生长的影响,初步获得该湖生态恢复中适宜沉水植物生长的沉积物的最佳改良措施。结果表明：3种沉积物处理对沉积物的化学性状改变相对不大,而对物理性状改变效果较明显;生长于砂、锁磷剂和粘土处理的沉积物上的苦草株高、生物量和根冠比表现出明显的差异性（P〈0.001）;生长在砂处理上的苦草的生物量和株高最高,根系指标（表面积、体积、根尖数及长度）也证明砂处理对苦草生长起到了促进作用;锁磷剂和粘土处理对苦草生长效果不明显,甚至抑制其生长。因此,北里湖沉积物的改良采用砂处理方法较为适宜。

英文摘要：

In the life history of submerged macrophytes,sediment supplies them growth medium and large amount of nutrients,and exerts long-term and far-reaching effects on their growth and development.In this paper,sediment samples collected from Beili Lake of China were amended（covering with sandstone,Phoslock,or clay）,and planted with submerged macrophyte Vallisneria rtalans,aimed to study the effects of sediment amendment on the growth of the macrophyte.All the three amendment measures had little effects on the chemical properties of the sediments,but obvious effects on their physical properties.The mean biomass,mean shoot height,and root/shoot ratio of V.natans growing on the sediments covered with sandstone,Phoslock,and clay differed significantly（P0.001）,with the highest biomass and shoot height on the sediment covered with sandstone.The root indices（surface area,volume,tip number,and length） also showed the promotion effect of sandstone cover on the growth of V.natans.Covering sediments with Phoslock and clay had little effects,and even,inhibited the growth of V.natans.It was suggested that using sandstone to amend the sediment of Beili Lake could be more appropriate.