Aquino Tomás, Roche Kevin R, Aubeneau Antoine, Packman Aaron I, Bolster Diogo
Spanish National Research Council (IDAEA - CSIC), 08034, Barcelona, Spain.
Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, 46556, Indiana, USA.
Sci Rep. 2017 Oct 27;7(1):14287. doi: 10.1038/s41598-017-14705-1.
Bioturbation refers to the transport processes carried out by living organisms and their physical effects on soils and sediments. It is widely recognized as an important mixing mechanism, particularly at the sediment-water interface in many natural systems. In order to quantify its impact on mixing, we propose a process-based model based on simple assumptions about organism burrowing behavior. Specifically, we consider burrowing events to be stochastic but memoryless, leading to exponential inter-burrow waiting times and depths. We then explore the impact of two different transport mechanisms on the vertical concentration distributions predicted by the model for a conservative (inert) tracer. We compare the results of our model to experimental data from a recent laboratory study of bioturbation by the freshwater oligochaete worm Lumbriculus variegatus, and find good quantitative agreement.
生物扰动是指生物体进行的输运过程及其对土壤和沉积物的物理影响。它被广泛认为是一种重要的混合机制，特别是在许多自然系统的沉积物 - 水界面处。为了量化其对混合的影响，我们基于关于生物体挖掘行为的简单假设提出了一个基于过程的模型。具体而言，我们认为挖掘事件是随机且无记忆的，导致挖掘间隔等待时间和深度呈指数分布。然后，我们探讨了两种不同输运机制对模型预测的保守（惰性）示踪剂垂直浓度分布的影响。我们将模型结果与最近关于淡水寡毛类蠕虫颤蚓属生物扰动的实验室研究的实验数据进行比较，发现了良好的定量一致性。
