Bioturbation occurs in streambeds by the action of a range of faunal species, but little is known about how it could modify the hyporheic exchange in streams. Previous experimental work investigating the effects of sediment‐biota interaction on exchange across the sediment‐water interface has been largely conducted in small mesocosms or infiltration columns that do not represent the lotic environment adequately. Therefore, the experimental findings from these studies may not be transferable to flowing water environments (e.g., streams). In this work, we first present a conceptual model demonstrating the causal pathways through which the sediment reworking and burrow ventilation processes (together referred to as bioturbation) could potentially modify the hyporheic flow regime. Next, to study the role of activities of faunal organisms in lotic environments and test some of the arguments presented in the model, laboratory experiments are conducted in re‐circulating flumes. The experiments involved investigating the modification of dune‐induced hyporheic flow due to the activities of a model bioturbating organism, Lumbriculus variegatus, following a control (without organisms) and treatment (with organisms) based experimental design. The sediment reworking activities such as surficial deposition of fecal pellets and burrowing by L. variegatus caused significantly higher hyporheic flux, longer mean residence times, and deeper solute penetration in the treatment flumes relative to the control flumes. We advocate that more intensive laboratory experiments and field investigations must be conducted to test the propositions put forward in the conceptual model and advance our understanding of the role of bioturbation process in fluvial ecosystems.

中文翻译：

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生物扰动对河水交换的影响：概念模型和实验室实验的见解。

生物扰动是通过一系列动物物种的作用而在河床中发生的，但人们对其如何改变河水交换性的了解很少。以前的研究工作是调查沉积物与生物群间的相互作用对通过沉积物-水界面的交换的影响，这主要是在不能充分代表抽水环境的小型中尺度或渗透柱中进行的。因此，这些研究的实验结果可能无法转移到流动的水环境（例如溪流）中。在这项工作中，我们首先提出一个概念模型，说明沉积物再加工和洞穴通风过程（统称为生物扰动）可潜在地改变低渗流状态的因果路径。下一个，为了研究动物有机体在抽水环境中的作用，并检验模型中提出的一些论点，在再循环水槽中进行了实验室实验。实验涉及调查由于模型生物扰动生物的活动而引起的沙丘诱导的流变流动的变化，按照对照（无生物体）和治疗（有生物体）的实验设计方法设计了百日草。相对于对照水槽，沉积物的再加工活动（例如粪便颗粒的表面沉积和变乳杆菌的穴入）导致明显更高的水流通量，更长的平均停留时间和更深的溶质渗透。我们主张必须进行更深入的实验室实验和现场调查，以检验概念模型中提出的主张，并加深我们对生物扰动过程在河流生态系统中的作用的理解。