Department of Ecology and Institute of Hydrobiology, Jinan University, Guangzhou, China.
State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, China; Sino-Danish Centre for Education and Research, University of Chinese Academy of Sciences, Beijing, China.
Water Res. 2021 Sep 1;202:117460. doi: 10.1016/j.watres.2021.117460. Epub 2021 Jul 26.
Understanding microbial metacommunity assembly and the underlying methanisms are fundamental objectives of aquatic ecology. However, little is known about how eutrophication, the primary water quality issue of aquatic ecosystems, regulates bacterioplankton metacommunity assembly at a regional scale in reservoirs. In this study, we applied a metacommunity framework to study bacterioplankton communities in 210 samples collected from 42 tropical coastal reservoirs in the wet summer season. We found that the spatial pattern of bacterioplankton community compositions (BCCs) at a regional scale was shaped mainly by species sorting. The reservoir trophic state index (TSI) was the key determinant of bacterioplankton metacommunity assembly. BCC turnover increased significantly with the TSI differences between sites (∆TSI) when ∆TSI was < 20, but remained at a level of about 80% when ∆TSI was > 20. Compared to oligo-mesotrophic and mesotrophic reservoirs, increased heterogeneity of co-occurrence bacterioplankton networks and bacterioplankton β-diversity were observed across eutrophic reservoirs. We propose that larger variation in phytoplankton community assembly may play directly or indirectly deterministic processes in controlling the bacterioplankton metacommunity assembly and became the potential mechanisms behind the observed higher BCC heterogeneity across the eutrophic reservoirs. Our research contributes to a broader understanding of the ecological effects of eutrophication on reservoir ecosystems and provides clues to the management of the tropical coastal reservoirs.
理解微生物宏群落组装及其潜在机制是水生生态学的基本目标。然而，对于富营养化（水生生态系统的主要水质问题）如何在区域尺度上调节水库中细菌浮游生物宏群落组装，我们知之甚少。在这项研究中，我们应用宏群落框架研究了在湿夏季节从 42 个热带沿海水库中采集的 210 个样本中的细菌浮游生物群落。我们发现，细菌浮游生物群落组成（BCC）的区域尺度空间格局主要由物种分选塑造。水库营养状态指数（TSI）是细菌浮游生物宏群落组装的关键决定因素。当 ∆TSI < 20 时，BCC 周转率随站点之间的 TSI 差异（∆TSI）显著增加，但当 ∆TSI > 20 时，BCC 周转率保持在约 80%的水平。与寡营养和中营养水库相比，在富营养水库中观察到共现细菌浮游生物网络和细菌浮游生物 β 多样性的异质性增加。我们提出，浮游植物群落组装的更大变异性可能直接或间接地在控制细菌浮游生物宏群落组装中发挥决定性作用，并成为观察到富营养水库中更高 BCC 异质性的潜在机制。我们的研究有助于更全面地了解富营养化对水库生态系统的生态影响，并为热带沿海水库的管理提供线索。
