The National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China; College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China.
College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China.
Environ Res. 2023 Dec 1;238(Pt 1):117153. doi: 10.1016/j.envres.2023.117153. Epub 2023 Sep 17.
Estuaries are known for their high ecological diversity and biological productivity. Sediment microorganisms, as crucial components of estuarine ecosystems, play a pivotal role in reflecting the intricate and dynamic ecological niches. However, our research on microbial community characteristics in estuarine ecosystems under different sedimentary types remains limited. In this study, we collected a total of 27 samples from three sampling sites at Hangbu estuary in Chaohu Lake, and three sedimentary areas were classified based on the overlying water flow conditions and sediment particle properties to elucidate their microbial community structure, environmental drivers, assembly processes, and co-occurrence network characteristics. Our results showed significant differences in microbial community composition and diversity among three sedimentary areas. Redundancy analysis indicated that the differences in microbial community composition at the OTU level among the three sedimentary areas were mainly determined by nitrate-nitrogen, temperature, and water content. Phylogenetic bin-based null model analysis revealed that temperature was a key factor influencing deterministic processes among the three sedimentary areas, while stochastic processes predominantly governed the assembly of microbial communities. In addition, co-occurrence network analysis demonstrated that the network in the hydraulically driven sedimentary area of the lake, consisting mainly of medium and fine silt, had the highest complexity, stability, and cohesion, but was missing potential keystone taxa. The remaining two sedimentary areas had 5 and 8 potential keystone taxa, respectively. Overall, our study proposes the delineation of sedimentary types and comprehensively elucidates the microbial community characteristics under different sedimentary areas, providing a new perspective for studying sediment microbial community structure and helping future scholars systematically study ecological dynamics in estuaries.
河口以其高生态多样性和生物生产力而闻名。作为河口生态系统的关键组成部分，沉积物微生物在反映复杂和动态生态位方面起着至关重要的作用。然而，我们对不同沉积类型的河口生态系统中微生物群落特征的研究仍然有限。在这项研究中，我们从巢湖杭埠河口的三个采样点共采集了 27 个样本，并根据上覆水流条件和沉积物颗粒特性将三个沉积区进行分类，以阐明它们的微生物群落结构、环境驱动因素、组装过程和共生网络特征。我们的结果表明，三个沉积区的微生物群落组成和多样性存在显著差异。冗余分析表明，三个沉积区在 OTU 水平上的微生物群落组成差异主要由硝酸盐氮、温度和含水量决定。基于系统发育-bin 的零模型分析表明，温度是影响三个沉积区确定性过程的关键因素，而随机过程主要控制微生物群落的组装。此外，共生网络分析表明，在水力驱动的沉积区（主要由中细砂组成）中，网络具有最高的复杂性、稳定性和内聚性，但缺少潜在的关键类群。其余两个沉积区分别有 5 个和 8 个潜在的关键类群。总体而言，我们的研究提出了沉积类型的划分，并全面阐明了不同沉积区的微生物群落特征，为研究沉积微生物群落结构提供了新的视角，并有助于未来学者系统地研究河口的生态动态。
