Effects of aufeis on the structure and function of Arctic river-floodplain ecosystems, Alaska, 2016-2017

The goal of this study is to assess the potential effects of aufeis (i.e., river icings) on the structure and function of arctic river-floodplain ecosystems in a warming climate. Aufeis are massive accumulations of ice that are features of many arctic rivers. They form during freeze-up when thickening surface ice causes local overflows. Successive cycles of overflow result in accumulations of enormous volumes of ice, with aufeis on some Alaskan rivers attaining thicknesses of 3-5 meters, covering more than 20 square kilometers, and storing as much as 30% of the annual river discharge. Although aufeis have been studied by hydrologists and are known to be required for winter and spawning habitat for some fish, understanding of their ecology is poor. We propose that aufeis be viewed as winter oases due to their wet bases that supply water and heat to otherwise frozen habitats. Aufeis function as summer oases by providing a stable supply of water to hyporheic and downstream habitats. These data come from intensive study of the Kuparuk River aufeis field. We collected subsurface invertebrate community and water chemistry data during 12-17 August 2017 from 45 ~0.7-meter (m) deep ground-water wells that were installed in the aufeis field. These data are were collected coincidentally with those provided in: doi: 10.18739/A20P0WR15.

本研究旨在评估气候变暖背景下，冰群（aufeis，即河道冰积层）对北极河流-泛滥平原生态系统结构与功能的潜在影响。冰群是众多北极河流特有的巨型冰堆积体，在河道封冻期因表层冰层增厚引发局部溢流而形成。经多次溢流循环后，会形成体积庞大的冰堆积体：部分阿拉斯加河流的冰群厚度可达3-5米，覆盖面积超20平方公里，储水量可达年径流量的30%。尽管水文学家已对冰群开展过相关研究，且已知其可为部分鱼类提供冬季栖息及产卵生境，但当前学界对其生态功能的认知仍较为匮乏。我们提出，冰群可被视为冬季绿洲——其湿润的基底可为原本封冻的生境提供水源与热量；同时，冰群还能为潜流生境与下游区域提供稳定水源，发挥夏季绿洲的功能。本数据集源自对库帕鲁克河（Kuparuk River）冰群区域的深入调研：2017年8月12日至17日，研究人员在该冰群区域布设的45口深度约0.7米的地下水井中，采集了地下无脊椎动物群落与水化学数据。本数据集与DOI: 10.18739/A20P0WR15中收录的数据同期采集完成。