Peoples Logan M, Giersch J Joseph, Tappenbeck Tyler H, Vanderwall Joseph W, Ranieri John M, Vick-Majors Trista J, Elser James J, Church Matthew J
Flathead Lake Biological Station, University of Montana, Polson, MT 59860, USA.
Department of Biological Sciences, Michigan Technological University, Houghton, MI 49931, USA.
FEMS Microbiol Ecol. 2025 Jun 24;101(7). doi: 10.1093/femsec/fiaf060.
Glaciers are retreating, altering alpine ecosystems and creating new proglacial lakes. Compared to lakes fed by snowpack, glacial lakes are often enriched in nutrients and suspended solids that decrease light penetration. However, the microorganisms and biogeochemical conditions within these newly formed lakes are not well characterized. We describe the microbial communities in 14 glacial lakes in Glacier National Park, MT, USA using 16S rRNA gene amplicon sequencing and measurements of nutrient concentrations, water clarity, and other environmental properties. Microbial communities were distinct between lakes, including those connected to the same glacier, indicating the importance of site-specific biogeochemical and physical dynamics on these systems. Microbial community composition correlated with lake age (formation before or after the Little Ice Age) and conductivity but not with whether a lake was connected to a contemporaneous glacier > 0.1 km2. Heterotrophic lineages found in other glacial systems were abundant and widespread, while cyanobacteria only reached appreciable abundances in shallow lakes where light reached the benthos. Relative abundances of ammonia and nitrite oxidizers correlated with concentrations of nitrate and nitrite, suggesting nitrification may help control nitrogen forms and concentrations in glacial lakes. We show that as glaciers recede, unique glacial lake microbial communities will be formed and lost with them.
冰川正在消退，改变着高山生态系统并形成新的冰前湖。与由积雪补给的湖泊相比，冰川湖通常富含营养物质和悬浮固体，这会降低光的穿透率。然而，这些新形成湖泊中的微生物和生物地球化学条件尚未得到充分描述。我们利用16S rRNA基因扩增子测序以及对营养物浓度、水体透明度和其他环境特性的测量，描述了美国蒙大拿州冰川国家公园14个冰川湖中的微生物群落。不同湖泊之间的微生物群落存在差异，包括那些与同一冰川相连的湖泊，这表明特定地点的生物地球化学和物理动态对这些系统的重要性。微生物群落组成与湖泊年龄（小冰期之前或之后形成）和电导率相关，但与湖泊是否与面积大于0.1平方公里的同期冰川相连无关。在其他冰川系统中发现的异养谱系丰富且广泛分布，而蓝细菌仅在光照能到达底栖生物的浅湖中达到可观的丰度。氨氧化菌和亚硝酸氧化菌的相对丰度与硝酸盐和亚硝酸盐的浓度相关，这表明硝化作用可能有助于控制冰川湖中的氮形态和浓度。我们表明，随着冰川消退，独特的冰川湖微生物群落将随之形成和消失。
