东太湖茭草植被改造实验研究

Experimental studies on reconstructing aquatic vegetation

东太湖的茭草和浮叶植物有显著的加速湖泊淤积和二次污染效应。１９９３年开展了面积５ｈａ的植被改造实验，当年剔除原有植物，培育成为沉水植被，平均生物量达３ｋｇ／ｍ２。由茭草残体形成的腐殖层对沉水植物生长发育有不利影响，在实验区大部分面积上表层沉积物中ＴＯＣ含量低于３０％，沉水植物能正常生长；ＴＯＣ含量超过３０％时沉水植物生长较为缓慢。对东太湖４６．６ｋｍ２湖面上由茭草和浮叶植物组成的植被进行全面改造，可获得显著的环境生态效益，起到延缓湖泊衰亡和改善水质的作用。

It's remarkable that Zizania latifolia and some floating leaved plants in Lake East Taihu have strong effects on speeding up silting up of the lake basin and enhancing secondary pollution of the lake water. Experiment was carried out successfully in a plot of 5ha to remove Zizania latifolia and replace it with submerged plant. The surface layer of sediment made very loose by fibers of decayed plants affects plant growth. Submerged plant could grow normally with TOC content of the surface layer sediment less then 30%, however, higher TOC content could stunt plant growth intensely. If all the Zizania latifolia and floating leaved plants in 46.6km 2 are replaced by submerged plant, it will yield out standing results on delaying silting up of the lake and improving water quality.