State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an 710048, Shaanxi Province, China.
State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an 710048, Shaanxi Province, China.
Sci Total Environ. 2024 Nov 1;949:175271. doi: 10.1016/j.scitotenv.2024.175271. Epub 2024 Aug 3.
Plateau lakes (e.g., freshwater and saltwater lakes) are formed through intricate processes and harbor diverse microorganisms that mediate aquatic ecosystem functions. The adaptive mechanisms of lake microbiota to environmental changes and the ecological impacts of such changes on microbial community assembly are still poorly understood in plateau regions. This study investigated the structure and assembly of planktonic bacterial communities in 24 lakes across the Qinghai-Tibetan and Inner Mongolia Plateaus, with particular focus on habitat generalists, opportunists, and specialists. High-throughput sequencing of the 16S ribosomal RNA genes revealed that bacterial generalists had a lower species number (2196) but higher alpha diversity than the specialist and opportunist counterparts. Taxonomic dissimilarity and phylogenetic diversity analyses unraveled less pronounced difference in the community composition of bacterial generalists compared to the specialist and opportunist counterparts. Geographical scale (14.4 %) and water quality (12.6 %) emerged as major ecological variables structuring bacterial communities. Selection by water temperature and related variables, including mean annual temperature, elevation, longitude, and latitude, mainly shaped the assembly of bacterial generalists. Ecological drift coupled with selection by salt ions and related variables, including total phosphorus, chlorophyll a, and salinity, predominantly drove the assembly of bacterial specialists and opportunists. This study uncovers distinct bacterial responses to interacting ecological variables in diverse plateau lakes and the ecological processes structuring bacterial communities across various lake habitats under anthropogenic disturbance or climate change.
高原湖泊（如淡水和咸水湖泊）是通过复杂的过程形成的，它们蕴藏着多种多样的微生物，这些微生物调节着水生生态系统的功能。然而，在高原地区，湖泊微生物组对环境变化的适应机制以及这种变化对微生物群落组装的生态影响仍知之甚少。本研究调查了青藏高原和内蒙古高原 24 个湖泊浮游细菌群落的结构和组装，特别关注了栖息地广适种、机会种和专性种。通过高通量测序 16S 核糖体 RNA 基因揭示，细菌广适种的物种数量（2196）较低，但比专性种和机会种具有更高的α多样性。分类差异和系统发育多样性分析表明，与专性种和机会种相比，细菌广适种的群落组成差异不太明显。地理尺度（14.4%）和水质（12.6%）是塑造细菌群落的主要生态变量。水温及其相关变量（包括年均温、海拔、经度和纬度）的选择主要影响了细菌广适种的组装。生态漂移加上盐离子及其相关变量（包括总磷、叶绿素 a 和盐度）的选择，主要驱动了细菌专性种和机会种的组装。本研究揭示了不同高原湖泊中细菌对相互作用的生态变量的不同响应，以及在人为干扰或气候变化下，各种湖泊生境中细菌群落的生态过程。
