Abstract：
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.
摘要：
众所周知，环境变异性和蓝藻水华对海洋和淡水生境中细菌群落的组装和功能都有重大影响。目前还不清楚,然而,从长远来看，纤毛虫社区如何应对这种变化，特别是在亚热带湖泊和水库生态系统中。我们分析了来自两个亚热带水库地表水的9年浮游纤毛虫数据系列，以阐明蓝藻水华和环境变化对纤毛虫时间动态的作用。我们确定了两个水库中蓝藻演替的五个不同时期。使用多个时间尺度分析，我们发现纤毛虫群落的年际变化与蓝藻水华的相关性比与其他环境变量或季节性的相关性更强。此外，在9年期间，蓝藻水华和非水华期间的物种周转百分比随时间显着增加。系统发育分析进一步表明，84%-86%的纤毛虫群落周转受随机扩散限制或不占主导地位的过程控制。表明亚热带水库纤毛虫群落主要受中性过程控制。然而,短期开花增加了选择压力，带动30%-53%的纤毛虫社区营业额。我们发现纤毛虫群落组成受营养环境条件的影响，蓝细菌生物量和微浮游动物对纤毛虫分类或功能群落动态具有直接和/或间接的显着影响。我们的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。
