Abstract:

We studied the phytoplankton community structure and the environmental factors in different hydrological periods during the wet season in 2020 and the wet and dry season in 2021 of Dongzhang Reservoir including the inlet, the center and the outlet, which locates in Fuqing City of Fujian Province. The results showed that the average total phytoplankton density varied from 2.3×10⁷ to 5.2 ×10⁷ cell/L at the outlet of Dongzhang Reservoir during the wet season in 2021, which was more than three times that of the average phytoplankton density varied from 5.6×10⁶ to 2.3×10⁷cell/L during the dry season. The Bacillariophyta, Cyanophyta and Chlorophyta were the dominated and the average proportions were 47.5%, 31.6% and 14.0%, respectively, in the dry season. The Cyanophyta occupied an absolute advantage with an average proportion of 77.7% in the wet season. The content of the soluble reactive phosphorus (SRP) was low in the water during wet and dry season, but the content of total phosphorus (TP), total dissloved phosphorus (TDP) and dissolved organic phosphorus (DOP) were relatively high. Pearson correlation analysis showed that Cyanophyta, Chlorophyta and total algae density were extremely significantly negatively associated with SRP, and Chlorophyta and Bacillariophyta were significantly positively associated with DOP and TDP. The RDA analysis of environmental factors and phytoplankton density revealed that the Cyanophyta was strongly and positively correlated with the air temperature, and the Bacillariophyta positively correlated with the water level. This study provided a reference for the prevention and control of Cyanobacteria bloom and the protection of drinking water sources in Dongzhang Reservoir.

Key words: Cyanobacteriaa, phosphorus, temperature, water level, Dongzhang Reservoir, drinking water source reservoir

摘要：

本研究以饮用水水源地福建省福清市东张水库为研究对象,于2020年丰水期与2021丰、枯水期对东张水库进口、库心和出口3个站位的浮游植物群落结构以及环境因子进行采样监测。结果表明:东张水库出口站位2021年丰水期浮游植物总密度(2.3×10⁷~5.2×10⁷ cells/L)平均值是枯水期浮游植物总密度(5.6×10⁶~2.3×10⁷ cells/L)平均值的3倍多,枯水期以硅藻门、蓝藻门和绿藻门为主,平均占比分别为47.5%、31.6%和14.0%,而丰水期蓝藻门占据绝对优势,平均占比为77.7%。丰水期和枯水期水体中溶解性活性磷(SRP)的含量较低,但总磷(TP)、总溶解性磷(TDP)和溶解性有机磷(DOP)的含量均较高。Pearson相关性分析结果显示蓝藻门、绿藻门、甲藻门和总藻密度与SRP呈极显著负相关,绿藻门和硅藻门与DOP、TDP呈极显著正相关。将环境因子与浮游植物密度进行RDA分析可知,蓝藻门与气温呈极显著正相关,硅藻门与水位呈显著正相关。本研究结果可为东张水库蓝藻水华防控和饮用水水源地保护提供参考。

关键词: 蓝藻, 磷, 气温, 水位, 东张水库, 饮用水水源地