太湖康山湾示范区水生植物对水体氮、磷控制的适用性分析

Applicability analysis of aquatic macrophytes on controlling nitrogen and phosphorus from water in the Kangshan Bay demonstration area of Lake Taihu

为重建湖泊水生植被,改善太湖局部水域水质,在太湖康山湾示范区两个大型围隔进行了两种类型水生植物重建.通过2010年8月-2011年8月的现场采样及分析测定发现,人工控制条件下,浮叶植物荇菜和菱以及沉水植物马来眼子菜的重建效果较好,在其生长季节具有较高的覆盖度;研究表明,控制风浪及提高透明度是恢复水生植被的前提;植被重建区沉水植物氮、磷含量与浮叶植物差别不大,但浮叶植物重建区水体氮、磷浓度的控制比沉水植物重建区好;从经济及水环境效益角度来看,太湖敞水区的沿岸带由于风浪的控制比较困难,恢复水生植被时,应选择浮叶植物荇菜、菱、沉水植物马来眼子菜等抗风浪能力强的物种.本研究为太湖敞水区沿岸带的生态恢复方案制定提供了理论依据.

In order to restore the aquatic vegetation and improve local water quality, reconstruction of two ecological types of aquat- ic plants were carried out in two large enclosures in the Kangshan Bay demonstration area of Lake Taihu. By annual investigation, results showed that floating-leaved aquatic plants such as Limrtanthemun nymphoides and Trapa bicorni, and submerged plant such as Potamogeton macckianus grew better than other plants under controlled conditions. Their coverage was quite high during the growing season. Results also showed that, controlling wind-driven wave disturbance and improving water transparency were the pre- requisite for aquatic vegetation restoration ; there was no difference about N and P contents between submerged macrophyte and floating-leaved aquatic plants, but floating-leaved aquatic plants performed better than submerged macrophyte in removing water N and P content. Concerning the economic and environmental benefit, aquatic plants including L. nymphoides , T. bicorni and P. macckianus with powerful anti-wave ability could be selected as the pioneering species to rebuild the aquatic vegetation in the open area of Lake Taihu. This research provided theoretical basis for ecological restoration in the open littoral area of Lake Taihu.