Ren Ze, Qu Xiaodong, Zhang Min, Yu Yang, Peng Wenqi
State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing, China.
Division of Biological Sciences, University of Montana, Missoula, MT, United States.
Front Microbiol. 2019 May 21;10:1167. doi: 10.3389/fmicb.2019.01167. eCollection 2019.
Water level fluctuations (WLFs) are an inherent feature of lake ecosystems and have been regarded as a pervasive pressure on lacustrine ecosystems globally due to anthropogenic activities and climate change. However, the impacts of WLFs on lake microbial communities is one of our knowledge gaps. Here, we used the high-throughput 16S rRNA gene sequencing approach to investigate the taxonomic and functional dynamics of bacterial communities in wet-season and dry-season of Poyang Lake (PYL) in China. The results showed that dry-season was enriched in total nitrogen (TN), nitrate (NO ), ammonia (NH ), and soluble reactive phosphorus (SRP), while wet-season was enriched in dissolved organic carbon (DOC) and total phosphorus (TP). Bacterial communities were distinct taxonomically and functionally in dry-season and wet-season and the nutrients especially P variation had a significant contribution to the seasonal variation of bacterial communities. Moreover, bacterial communities responded differently to nutrient dynamics in different seasons. DOC, NO , and SRP had strong influences on bacterial communities in dry-season while only TP in wet-season. Alpha-diversity, functional redundancy, taxonomic dissimilarities, and taxa niche width were higher in dry-season, while functional dissimilarities were higher in wet-season, suggesting that the bacterial communities were more taxonomically sensitive in dry-season while more functionally sensitive in wet-season. Bacterial communities were more efficient in nutrients utilization in wet-season and might have different nitrogen removal mechanisms in different seasons. Bacterial communities in wet-season had significantly higher relative abundance of denitrification genes but lower anammox genes than in dry-season. This study enriched our knowledge of the impacts of WLFs and seasonal dynamics of lake ecosystems. Given the increasingly pervasive pressure of WLFs on lake ecosystems worldwide, our findings have important implications for conservation and management of lake ecosystems.
水位波动（WLFs）是湖泊生态系统的一个固有特征，由于人为活动和气候变化，已被视为全球湖泊生态系统普遍存在的压力。然而，水位波动对湖泊微生物群落的影响是我们知识上的空白之一。在此，我们采用高通量16S rRNA基因测序方法，研究了中国鄱阳湖（PYL）湿季和干季细菌群落的分类和功能动态。结果表明，干季总氮（TN）、硝酸盐（NO）、氨（NH）和可溶性活性磷（SRP）含量较高，而湿季溶解有机碳（DOC）和总磷（TP）含量较高。干季和湿季的细菌群落在分类和功能上存在差异，营养物质尤其是磷的变化对细菌群落的季节变化有显著贡献。此外，不同季节细菌群落对营养动态的反应不同。DOC、NO和SRP对干季细菌群落有强烈影响，而湿季仅TP有影响。干季的α多样性、功能冗余、分类差异和分类单元生态位宽度较高，而湿季的功能差异较高，这表明细菌群落在干季对分类更敏感，而在湿季对功能更敏感。湿季细菌群落在营养物质利用方面更有效，并且在不同季节可能有不同的脱氮机制。与干季相比，湿季细菌群落中反硝化基因的相对丰度显著更高，但厌氧氨氧化基因更低。本研究丰富了我们对水位波动影响和湖泊生态系统季节动态的认识。鉴于水位波动对全球湖泊生态系统的压力日益普遍，我们的研究结果对湖泊生态系统的保护和管理具有重要意义。
