Isotopes of dissolved oxygen as dynamic tracers for aerobic turnover in surface and shallow groundwaters (IsoDO)

溶解氧（DO）的陡峭梯度表明，在河岸和水下环境中存在有氧活动的临界区。这些重要的区域需要新的工具来量化溶解氧的来源和汇，作为水生生物地球化学活动的关键参数。结合浓度测量，我们计划研究溶解氧的稳定同位素比率以及溶解碳和颗粒碳的稳定同位素比率，以追踪其生物成分。该方法可以量化大气和光合作用源的DO。此外，DO池中系统的18o富集将量化有氧呼吸速率。调查将集中在哈茨山脉的塞尔克河野外实验室，进行河岸、涟漪和溪流内及以下采样。本研究旨在探讨生物控制大陆水域氧和相关碳动态的假设。该方法将能够区分和量化氧气消耗和输入的速率，这也将通过反应传输模型进行验证。应用和测试的方法也将用于调查其他水生系统，包括湖泊、河流和地下水。

Steep gradients of dissolved oxygen (DO) indicate that critical zones of aerobic activity exist in riparian and hyporheic subsurface environments. These important zones need new tools to quantify sources and sinks of dissolved oxygen as a key parameter for aquatic biogeochemical activity. Together with concentration measurements, we plan to investigate stable isotope ratios of DO together with those of dissolved and particulate carbon in order to trace their biological components. The approach enables quantification of atmospheric and photosynthetic sources of DO. In addition, systematic 18O-enrichment in the DO pool will quantify aerobic respiration rates. The survey will focus on the Selke River field laboratory in the Harz Mountains with riparian, ripple and in- as well as below stream sampling. The work aims to investigate the hypothesis of biological controls on oxygen and related carbon dynamics in continental waters. The approach will enable to differentiate and quantify rates of oxygen consumption and input that will also be verified with reactive transport models. Applied and tested methods will also be available to investigations of other aquatic systems including lakes, rivers and groundwaters.