Cai Lanlan, Feng Chao, Xie Le, Xu Bu, Wei Wei, Jiao Nianzhi, Zhang Rui
Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China.
State Key Laboratory of Marine Environmental Science, Fujian Key Laboratory of Marine Carbon Sequestration, College of Ocean and Earth Sciences, Xiamen University, Fujian, China.
Water Res. 2022 Nov 1;226:119237. doi: 10.1016/j.watres.2022.119237. Epub 2022 Oct 10.
Estuaries are important ecosystems providing irreplaceable services for humankind and, in turn, are extensively influenced by human activities and climate changes. Microbial processes, which are largely controlled by viruses, are always responsible for the ecological function and environmental problems in estuaries. However, we know little about the ecology and importance of viruses in estuarine systems. Here, we investigated viral ecological dynamics in estuarine systems on local (four largest estuaries in China in different seasons) and global scales. Viral production varied by almost 20-fold in Chinese estuaries with significant seasonality, being responsible for the removal of 1.41%-21.45% of the bacterioplankton standing stock each day, and contributed directly to the organic carbon pool by releasing an average of 3.57 µg of cellular carbon per liter per day. By compiling data from 21 estuaries across the world, we found for the first time that viral population size peaked at mid-latitude and viral production increased towards the equator in estuarine ecosystems. The results indicated the higher viral impact on microbial mortality and dissolved organic matter cycling in tropical estuaries. Our field investigation and global synthesized analysis provide compelling evidence of spatiotemporal variations in estuarine viral dynamics. The global view of viral impacts on estuarine microbial mortality offers important insight for incorporating viruses into ecological models and understanding the environmental implications of the tropicalization of temperate aquatic ecosystems under a scenario of climate warming.
河口是重要的生态系统，为人类提供不可替代的服务，反过来，又受到人类活动和气候变化的广泛影响。微生物过程在很大程度上受病毒控制，始终是河口生态功能和环境问题的根源。然而，我们对河口系统中病毒的生态学及重要性知之甚少。在此，我们在局部（中国四个最大河口不同季节）和全球尺度上研究了河口系统中的病毒生态动态。中国河口的病毒产量变化近20倍，具有显著的季节性，每天负责去除1.41%-21.45%的浮游细菌存量，并通过每天每升平均释放3.57微克细胞碳直接促进有机碳库的形成。通过汇总来自全球21个河口的数据，我们首次发现河口生态系统中病毒种群数量在中纬度地区达到峰值，病毒产量向赤道方向增加。结果表明热带河口的病毒对微生物死亡率和溶解有机物循环的影响更大。我们的实地调查和全球综合分析提供了令人信服的证据，证明河口病毒动态存在时空变化。病毒对河口微生物死亡率影响的全球视角为将病毒纳入生态模型以及理解气候变暖情景下温带水生生态系统热带化的环境影响提供了重要见解。
