Qu Ning, Deng Jian-Ming, Zhang Zhen, Cai Yong-Jiu, Gong Zhi-Jun, Li Ming
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China.
Huan Jing Ke Xue. 2022 Jun 8;43(6):3097-3105. doi: 10.13227/j.hjkx.202109022.
Lake Hongze is an essential storage lake for the "Eastern Route of the South-North Water Diversion Project" and plays an important role in climate adjustment and flood prevention and control. To study the structural evolution of phytoplankton communities in Lake Hongze and their relationship with environmental factors and to understand the status of the ecosystem of Lake Hongze before the "ten-year fishing ban," monthly monitoring was carried out from 2015 to 2020. During the study period, total nitrogen showed a significant downward trend starting in 2017, the total phosphorus and chemical oxygen demand declined slightly, the water temperature had no obvious change trend, and the water depth and transparency increased from 2015 to 2018 and then declined significantly. A total of 102 genera of phytoplankton in eight phyla were identified, with a total of 310 species. The dominant phytoplankton phyla mainly included Chlorophyta and Bacillariophyta, followed by Cyanophyta and Pyrrophyta. The dominant genera were , , , , and . The results of non-metric multidimensional scaling (NMDS) showed that the structural composition of the phytoplankton community differed significantly among years, seasons, and sampling areas, mainly due to the redistribution among dominant genera. NMDS analysis also indicated that variation in the phytoplankton community in Lake Hongze was mainly related to water temperature, total nitrogen, total phosphorus, water depth, and transparency. Total nitrogen, water depth, and phytoplankton community structure were significantly correlated with interannual succession, whereas water temperature, total nitrogen, and phytoplankton seasonal succession were also significantly correlated. Combined with the measures taken by the management department in recent years, the changes in the structure of the phytoplankton community may be related to the removal of the fence and other management and restoration measures in Lake Hongze.
洪泽湖是“南水北调东线工程”的重要调蓄湖泊，在气候调节和防洪减灾中发挥着重要作用。为研究洪泽湖浮游植物群落的结构演变及其与环境因子的关系，了解“十年禁渔”前洪泽湖生态系统状况，于2015年至2020年进行了逐月监测。研究期间，总氮自2017年起呈显著下降趋势，总磷和化学需氧量略有下降，水温无明显变化趋势，水深和透明度在2015年至2018年上升后显著下降。共鉴定出浮游植物8门102属，共310种。浮游植物优势门类主要包括绿藻门和硅藻门，其次是蓝藻门和甲藻门。优势属为 ， ， ， ，和 。非度量多维尺度分析（NMDS）结果表明，浮游植物群落的结构组成在年份、季节和采样区域间存在显著差异，主要是由于优势属的重新分布。NMDS分析还表明，洪泽湖浮游植物群落的变化主要与水温、总氮、总磷、水深和透明度有关。总氮、水深与浮游植物群落结构的年际演替显著相关，水温、总氮与浮游植物的季节演替也显著相关。结合管理部门近年来采取的措施，浮游植物群落结构的变化可能与洪泽湖围栏拆除等管理与修复措施有关。
