The retreat of glaciers in response to climate change has major impacts on the hydrology and ecosystems of glacier forefield catchments. Microbes are key players in ecosystem functionality, supporting the supply of ecosystem services that glacier systems provide. The interaction between surface and groundwaters in glacier forefields has only recently gained much attention, and how these interactions influence the microbiology is still unclear. Here, we identify the microbial communities in groundwater from shallow (<15 m deep) boreholes in a glacial forefield floodplain (‘sandur’) aquifer at different distances from the rapidly retreating Virkisjökull glacier, Iceland, and with varying hydraulic connectivity with the glacial meltwater river that flows over the sandur. Groundwater communities are shown to differ from those in nearby glacial and non-glacial surface water communities. Groundwater–meltwater interactions and groundwater flow dynamics affect the microbial community structure, leading to different microbial communities at different sampling points in the glacier forefield. Groundwater communities differ from those in nearby glacial and non-glacial surface waters. Functional potential for microbial nitrogen and methane cycling was detected, although the functional gene copy numbers of specific groups were low.

中文翻译：

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Following the flow——冰岛快速消退冰川的冰川前场地表水和地下水中的微生物生态学

冰川因气候变化而退缩对冰川前域集水区的水文和生态系统产生重大影响。微生物是生态系统功能的关键参与者，支持冰川系统提供的生态系统服务的供应。冰川前域地表水和地下水之间的相互作用直到最近才引起人们的广泛关注，而这些相互作用如何影响微生物学仍不清楚。在这里，我们从冰川前场泛滥平原 ('sandur') 含水层的浅层（<15 m 深）钻孔中识别地下水中的微生物群落，该含水层距离冰岛快速消退的 Virkisjökull 冰川不同距离，并且与冰川融水的水力连通性不同流过桑杜尔的河流。地下水群落与附近的冰川和非冰川地表水群落不同。地下水-融水相互作用和地下水流动动力学影响微生物群落结构，导致冰川前缘不同采样点的微生物群落不同。地下水群落与附近冰川和非冰川地表水中的群落不同。检测到微生物氮和甲烷循环的功能潜力，尽管特定组的功能基因拷贝数较低。地下水群落与附近冰川和非冰川地表水中的群落不同。检测到微生物氮和甲烷循环的功能潜力，尽管特定组的功能基因拷贝数较低。地下水群落与附近冰川和非冰川地表水中的群落不同。检测到微生物氮和甲烷循环的功能潜力，尽管特定组的功能基因拷贝数较低。