浮游植物群落动态变化及其与环境因子的关系是了解湖库水环境变动及开展水环境质量评价的重要依据。于2021—2022年对千岛湖浮游植物与水环境因子进行逐月调查,分析了浮游植物群落结构特征、时空分布格局及其主要环境驱动因子,旨在为了解千岛湖最新水环境变化和生态系统的演变提供重要的基础资料。结果显示：调查期间共鉴定出藻类8门240种,物种组成以绿藻门（51.67%）、硅藻门（21.67%）和蓝藻门（17.84%）为主,优势种以蓝藻和硅藻为主。2021—2022年均生物密度为（404.21±116.59）×10⁴ cells/L,年均生物量为（0.84±0.22） mg/L,密度和生物量均存在显著的时空差异,浮游植物各门类密度和生物量占比最高的是蓝藻门。Shannon多样性指数存在显著的季节差异,空间上差异不显著,其余指数无显著时空差异。Spearman相关性分析显示,浮游植物密度和生物量与水温、氨氮及高锰酸盐指数呈显著正相关,与透明度呈显著负相关。RDA分析显示,水温、氨氮和亚硝酸盐氮是影响千岛湖浮游植物优势种群群落分布的主要环境因子。

The dynamic changes of phytoplankton community and its relationship with major environmental factors are important for understanding the changes of lake and reservoir water environment and carrying out water environmental quality assessment. In this study, a monthly survey of phytoplankton and water environmental factors in Qiandao Lake was conducted from 2021 to 2022, and the characteristics of phytoplankton community structure, spatial and temporal distribution pattern and main environmental driving factors were analyzed, in order to provide important basic data for understanding the latest water environment changes and ecosystem evolution in Qiandao Lake. The results showed that a total of 240 species belonging to 8 phyla were identified, with Chlorophyta (51.67%), Bacillariophyta (21.67%) and Cyanophyta (17.84%) as the main species, and Cyanophyta and Bacillariophyta as the main dominant species. The average annual biological density from 2021 to 2022 was (404.21±116.59)×10⁴ cells/L, and the average annual biomass was (0.84±0.22) mg/L, showing significant spatio-temporal differences in both biological density and biomass. Cyanophyta had the highest biological density and biomass of phytoplankton. Shannon diversity index showed significant seasonal differences, but no significant spatial differences, and there was no spatio-temporal difference in other indices. Spearman correlation analysis showed that phytoplankton density and biomass were significantly positively correlated with water temperature, ammonia nitrogen and permanganate index, and negatively correlated with transparency. RDA analysis showed that water temperature, ammonia nitrogen and nitrite were the main environmental factors affecting the distribution of phytoplankton dominant species in Qiandao Lake.

Q142;S932.7;X131.3

国家重点研发计划(2023YFD2400900)