Aquatic macrophytes in East Lake Taihu and its interaction with water environment

2006-2007年对东太湖网围养殖区及航道水生植物种群结构和水环境状况进行了调查.结果表明:采样区内共有水生植物10种,其中沉水植物6种﹑浮叶植物3种﹑漂浮植物1种;养殖区植物种类较单一,耐污染、再生能力强以及水质净化能力好的金鱼藻﹑狐尾藻和伊乐藻在养殖区呈优势种分布;航道和敞水区优势种类为苦草和马来眼子菜.从水生植物生物量变化来看,9月生物量最高,平均为2882.4±748.8g/m2;养殖区水生植物生物量高于航道和敞水区,两个网区平均可达1251.2±1012.7g/m2、993.9±968.6g/m2.水生植物与水环境相互关系来看,温度、透明度和pH等水体物理环境因子对水生植物季节生长和光合作用具有重要影响;水生植物具有吸收水体氮磷营养盐和抑制藻类生长的作用,从而改善了东太湖水质,同时植物季节性生长以及空间分布差异也影响水质时空差异.;The aquatic macrophytes and water environments in the enclosure aquaculture area and waterway of East Lake Taihu were investigated during 2006 and 2007. The results showed that there were ten species of aquatic macrophytes in the investigated area, among six submerged macrophytes, three emergent plants and one floating plant. The plant species were dominant by Ceratophyllum demersum, Myriophyllum spicatum and Elodea nuttalli in the enclosure aquaculture area, which are pollutant-resistant, regeneration-strong and purification-good macrophytes, while Potamogeton malaianus and Vallisneria spiralis were the dominant species both in the waterway and open water region. Aquatic macrophytes grew vigorously between summer and autumn and the maximum macrophyte biomass was in September when it could reach to 2882.4 ± 748.8g/m2. The biomasses of macrophyte in two enclosure aquaculture areas were 1251.2±1012.7g/m2 and 993.9±968.6g/m2, respectively, which were higher biomass than other water area. The physical factors in water, such as temperature, transparency and pH, had important influences on photosynthesis and seasonal growth of aquatic macrophytes. Through absorption of nitrogen and phosphorus nutrients and inhibition of algae growth by aquatic macrophyte in the water body, the water quality of East Lake Taihu had been improved. The patterns of aquatic macrophyte in the lake could also affect the temporal-spatial difference of water quality.