Aquatic Eco-Health Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Aquatic Eco-Health Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; College of Life Sciences, Huaibei Normal University, Huaibei 235000, China.
Sci Total Environ. 2023 Feb 1;858(Pt 2):159866. doi: 10.1016/j.scitotenv.2022.159866. Epub 2022 Nov 1.
It is well-established that environmental variability and cyanobacterial blooms have major effects on the assembly and functioning of bacterial communities in both marine and freshwater habitats. It remains unclear, however, how the ciliate community responds to such changes over the long-term, particularly in subtropical lake and reservoir ecosystems. We analysed 9-year planktonic ciliate data series from the surface water of two subtropical reservoirs to elucidate the role of cyanobacterial bloom and environmental variabilities on the ciliate temporal dynamics. We identified five distinct periods of cyanobacterial succession in both reservoirs. Using multiple time-scale analyses, we found that the interannual variability of ciliate communities was more strongly related to cyanobacterial blooms than to other environmental variables or to seasonality. Moreover, the percentage of species turnover across cyanobacterial bloom and non-bloom periods increased significantly with time over the 9-year period. Phylogenetic analyses further indicated that 84 %-86 % of ciliate community turnover was governed by stochastic dispersal limitation or undominated processes, suggesting that the ciliate communities in subtropical reservoirs were mainly controlled by neutral processes. However, short-term blooms increased the selection pressure and drove 30 %-53 % of the ciliate community turnover. We found that the ciliate community composition was influenced by environmental conditions with nutrients, cyanobacterial biomass and microzooplankton having direct and/or indirect significant effects on the ciliate taxonomic or functional community dynamics. Our results provide new insights into the long-term temporal dynamics of planktonic ciliate communities under cyanobacterial bloom disturbance.
已有大量研究证实，环境变异性和蓝藻水华对海洋和淡水生境中的细菌群落的组装和功能有重大影响。然而，对于纤毛虫群落如何长期应对这些变化，人们仍不清楚，尤其是在亚热带湖泊和水库生态系统中。我们分析了两个亚热带水库的浮游纤毛虫 9 年的数据集，以阐明蓝藻水华和环境变异性对纤毛虫时间动态的作用。我们在两个水库中都确定了五个不同的蓝藻演替期。使用多时间尺度分析，我们发现纤毛虫群落的年际变异性与蓝藻水华比其他环境变量或季节性更为密切相关。此外，跨蓝藻水华和非水华期的物种周转率在 9 年期间随着时间的推移显著增加。系统发育分析进一步表明，纤毛虫群落 84%-86%的周转率受随机扩散限制或非主导过程控制，这表明亚热带水库中的纤毛虫群落主要受中性过程控制。然而，短期水华增加了选择压力，驱动了 30%-53%的纤毛虫群落周转率。我们发现，纤毛虫群落组成受到环境条件的影响，营养物质、蓝藻生物量和微型浮游动物对纤毛虫分类或功能群落动态具有直接和/或间接的显著影响。我们的研究结果为蓝藻水华干扰下浮游纤毛虫群落的长期时间动态提供了新的见解。
