优势种的演替总是发生在蓝藻水华期间,因为不同蓝藻形成的蓝藻水华存在一定的条件;这导致蓝藻水华的更不确定和复杂的影响。然而,在蓝藻水华期间,优势种的演替模式和后果及其驱动因素没有得到足够的重视。在这项研究中,南鹏水库浮游植物群落特征及水环境因子,重庆的饮用水源,在2018年4月至9月期间进行了监测和分析。结果表明:①在南鹏水库共鉴定出浮游植物108种,隶属于59属8门。其中,4门13种被确定为优势种,其中raciborskii的优势度指数最高,其次是假的。②5月和7月最主要的蓝藻是假单胞菌和圆柱孢子虫,分别,其中蓝细菌密度达到峰值,而Shannon-Weiner多样性和Pielou均匀度明显低于其他月份。③NMDS结果表明,柱皮和假单胞菌与环境浮游植物群落的相关性分别为0.58和0.48。此外,VPA结果表明,47.51%的群落变异可以由环境因素解释,只有12.04%和12.74%的群落组成变异可以解释为Cylindrospermopsis和Pseudoanabaena,分别。④WT显著正向影响圆周状胚芽的丰度,pH值,和RUEN,并受到SD和RUEP的负面影响。然而,假单胞菌的丰度受高锰酸盐指数的显着正影响,而受EC和DO的负面影响。这些结果表明,两种主要的蓝藻对周围的浮游植物群落都有显着影响。相对于假的,然而,圆柱毛对水生生态系统的影响更为明显。此外,N限制和水柱变暖的协同作用可能导致Pseudoanabaena被圆柱精子替代,形成了优势种群。
The succession of dominant species always occurs during cyanobacterial blooms because there are certain conditions for cyanobacterial blooms formed by different cyanobacteria; this results in more uncertain and complex effects in cyanobacterial blooms. However, the succession pattern and consequences of dominant species and its driving factors have not received enough attention during cyanobacteria blooms. In this study, the phytoplankton community characteristics and water environment factors of Nanpeng Reservoir, a drinking water source in Chongqing, were monitored and analyzed from April to September 2018. The results showed that:① a total of 108 species of phytoplankton belonging to 59 genera and 8 phyla were identified in Nanpeng Reservoir. Of this, 13 species of 4 phyla were identified as dominant species, among which the dominance index of
Cylindrospermopsis raciborskii was the highest, followed by that of Pseudoanabaena sp. ② The most dominant cyanobacteria were Pseudoanabaena and Cylindrospermopsis in May and July, respectively, in which cyanobacteria density peaked, whereas the Shannon-Weiner diversity and Pielou evenness were significantly lower than those in the other months. ③ NMDS results showed that the correlation between
Cylindrospermopsis or Pseudoanabaena and the ambient phytoplankton community was 0.58 and 0.48, respectively. Moreover, the VPA results showed that 47.51% of the community variation could be explained by environmental factors, and only 12.04% and 12.74% of variation in community composition could be explained by Cylindrospermopsis and Pseudoanabaena, respectively. ④ The abundance of
Cylindrospermopsis was significantly positively affected by WT, pH, and RUEN and negatively affected by SD and RUEP. However, the abundance of Pseudoanabaena was significantly positively affected by permanganate index and negatively affected by EC and DO. These results suggested that both dominating cyanobacteria had significant effects on the surrounding phytoplankton community. Relative to that of Pseudoanabaena, however,
Cylindrospermopsis had a more obvious impact on the aquatic ecosystem. Moreover, the synergistic effect of N limitation and warming of the water column may have caused the replacement of Pseudoanabaena with
Cylindrospermopsis to form a dominant population.