农村污染河道生态修复中浮游植物的群落特征

Characteristics of Phytoplankton Community in Country Contaminated Ditches During Ecological Restoration

以沸石和生态浮床构建丁型潜坝,结合曝气及边坡湿地等措施在直湖港支流朱家浜(太湖北部)实施生态修复工程。从浮游植物群落的角度,考察生态修复工程对农村污染河道的修复效果。结果显示:(1)生态修复改变了浮游植物的群落结构及演替方向,硅藻门、绿藻门、甲藻门的部分种类取代了蓝藻门、隐藻门的优势地位;(2)生态工程显著抑制了浮游植物群落的现存量,修复期间浮游植物总生物量均小于6 mg·L-1;(3)生态修复过程中浮游植物的生物多样性维持在相对较高的水平(Shannon-Wiener指数平均值为2.32)。结合生态修复工程对水质的净化效率及浮游植物现存量与水体营养盐水平之间的相关性分析可知,生态修复工程对水体营养盐的有效去除是浮游植物群落特征发生变化的主要因素之一。

An ecological restoration project of a delta submerged dam constructed by zeolite and floating bed, combined with aeration and wetlands, was conducted in Zhujia ditch, a tributary of the Zhihu river located to the north of Lake Taihu. Water quality and phytoplankton community were investigated during the ecological restoration. The ecological restoration changed the community structure and succession direction of phytoplankton. The dominant Cyanophyta and Cryptophyta were replaced by species belonged to Bacillariophyta, Chlorophyta and Pyrrophyta. The standing crop of phytoplankton was inhibited significantly by ecological restoration, and the total phytoplankton biomass was less than 6 mg·L-1of during the restoration. However, the biodiversity of phytoplankton maintained at a relatively high level, with the mean Shannon-Wiener index of 2.32 during the ecological restoration. The removal of nutrients by the ecological restoration was a major factor influencing the phytoplankton community changes.