Alpine streams are particularly valuable for downstream water resources and of high ecological relevance; however, a detailed understanding of water storage and release in such heterogeneous environments is often still lacking. Observations of naturally occurring tracers, such as stable isotopes of water or electrical conductivity, are frequently used to track and explain hydrologic patterns and processes. Importantly, some of these hydrologic processes also create microhabitat variations in Alpine aquatic systems, each inhabited by characteristic organismal communities. The inclusion of such ecological diversity in a hydrologic assessment of an Alpine system may improve our understanding of hydrologic flows while also delivering biological information. Recently, the application of environmental DNA (eDNA) to assess biological diversity in water and connected habitats has gained popularity in the field of aquatic ecology. A few of these studies have started to link aquatic diversity with hydrologic processes but hitherto never in an Alpine system. Here, we collected water from an Alpine catchment in Switzerland and compared the genetic information of eukaryotic organisms conveyed by eDNA with the hydrologic information conveyed by naturally occurring hydrologic tracers. Between March and September 2017, we sampled water at multiple time points at 10 sites distributed over the 13.4? km 2 Vallon de Nant catchment (Switzerland). The sites corresponded to three different water types and habitats, namely low-flow or ephemeral tributaries, groundwater-fed springs, and the main channel receiving water from both previous mentioned water types. Accompanying observations of typical physicochemical hydrologic characteristics with eDNA revealed that in the main channel and in the tributaries, the biological richness increases according to the change in streamflow, d q / d t , whereas, in contrast, the richness in springs increased in correlation with electrical conductivity. At the catchment scale, our results suggest that transport of additional, and probably terrestrial, DNA into water storage or flow compartments occurs with increasing streamflow. Such processes include overbank flow, stream network expansion, and hyporheic exchange. In general, our results highlight the importance of considering the at-site sampling habitat in combination with upstream connected habitats to understand how streams integrate eDNA over a catchment and to interpret spatially distributed eDNA samples, both for hydrologic and biodiversity assessments. At the intersection of two disciplines, our study provides complementary knowledge gains and identifies the next steps to be addressed for using eDNA to achieve complementary insights into Alpine water sources. Finally, we provide recommendations for future observation of eDNA in Alpine stream ecosystems.
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机译：高山溪流对下游水资源和高生态相关性特别有价值;然而，在这种异构环境中对储水和释放的详细了解通常仍然缺乏。天然存在的示踪剂的观察，例如水或导电性的稳定同位素，经常用于跟踪和解释水文图案和方法。重要的是，这些水文过程中的一些还产生了高山水生系统的微藻变化，每个系统受到特征的有机体社区的居住。将这种生态多样性列入了高山系统的水文评估中，可以改善我们对水文流动的理解，同时还提供生物信息。最近，环境DNA（EDNA）的应用评估水中的生物多样性和关联栖息地在水生生态领域的普及度受到普及。这些研究中的一些人开始将水生多样性与水文过程联系起来，但迄今为止从未在高山系统中。在这里，我们从瑞士中的高山集水区收集了水，并比较了EDNA传达的真核生物的遗传信息与天然存在的水文示踪剂传达的水文信息。 2017年3月和9月在2017年9月之间，我们在10个网站分布在13.4的地点的多个时间点中的水进行了采样？ KM 2 Vallon De Nant Catchment（瑞士）。该网站对应于三种不同的水类型和栖息地，即低流量或短暂的支流，地下水供给弹簧和来自先前提到的水类型的主要通道。伴随着典型物理化学特性与edna的观察结果显示，在主通道和支流中，生物丰富度根据流流量，dq / dt的变化而增加，而相比之下，弹簧中的丰富性与电导率相关的相关性。在集水区，我们的结果表明，随着流出流出的增加，将额外的额外和陆地DNA运输到储水或流量隔间。此类过程包括超银行流，流网络扩展和低于交换。一般而言，我们的结果突出了考虑现场采样栖息地与上游相关栖息地的重要性，了解流源如何在集水区集成，并解释用于水文和生物多样性评估的空间分布的EDNA样本。在两条学科的交叉点，我们的研究提供了互补知识收益，并确定使用EDNA对高山水源实现互补见解进行互补的下一个步骤。最后，我们为未来观察EDNA在高山流生态系统中提供建议。
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