Mass Exchange between Flexible Submerged Canopies and Adjacent Open Water

海草草甸在沿海地区具有重要的生态和经济影响。它们提供的养分循环每年价值3.8万亿美元。此外，海草床为许多经济上重要的海洋物种提供栖息地，并影响沿海地区沉积物和碳的命运。海草草甸内重要的生物地球化学过程，以及海草对周围环境的影响，都是由草甸与周围开放水域之间的动量和质量交换来调节的。以前的一些研究已经描述了与刚性冠层相关的质量和动量输运。然而，我们对柔性冠层中的运输只有有限的了解。本项目将在现有刚性冠层理论的基础上，发展单向流和波浪条件下柔性冠层的质量输运模型。智力优势：该项目将开发在单向流和波浪条件下柔性水下冠层湍流交换的新模型。这项工作将有助于我们对生物流相互作用的基本理解。此外，该工作还有助于研究多孔层附近的流动和运输这一广泛主题，涉及气象学（陆地冠层）、多孔介质（潜流交换）和生物海洋学（海带森林、海草、珊瑚生态学）等学科。通过提供柔性水下植被内部和周围通量的物理模型，该项目将有助于为研究和测量这些冠层内发生的吸收、沉降和吸收过程提供更好的框架。此外，通量模型将能够更定量地考虑草甸几何形状（长度、高度、茎密度）对草甸的影响。这将有助于更好地预测生态系统对养分负荷变化或海草分布变化的响应。此外，该项目每年将为一名研究生和至少一名本科生提供培训。该项目也将成为一个新的本科生实验室活动的基础，并将纳入首席研究员？it’现在是大三的课程。最后，研究者将利用这项工作作为一个平台，继续与麻省理工学院西格兰鳗鱼草恢复项目进行互动。

Seagrass meadows have a significant ecologic and economic impact in coastal regions. The nutrient cycling they provide is valued at 3.8 trillion dollars per year. In addition seagrass beds provide habitat for many economically important marine species and influence the fate of sediment and carbon in the coastal-zone. The important biogeochemical processes within a seagrass meadow, as well as the impact of seagrass on the surrounding environment, are regulated by the exchanges of momentum and mass between the meadow and surrounding open water. Several previous studies have described the mass and momentum transport associated with rigid canopies. However, we have only a limited understanding of transport in flexible canopies. This project will build on existing theories for rigid canopies to develop mass transport models for flexible canopies under both unidirectional flow and wave conditions. Intellectual Merit: The project will develop new models for turbulent exchange in flexible submerged canopies under both unidirectional flow and wave conditions. This work will contribute to our basic understanding of bio-flow interaction. In addition, the work contributes to the broad topic of flow and transport near porous layers that touches disciplines in meteorology (terrestrial canopies), porous media (hyporheic exchange), and biological oceanography (kelp forest, seagrass, coral ecology)Broader Impacts and Potential Benefits to Society: By providing physical models for flux in and around flexible, submerged vegetation, this project will contribute to a better framework for studying and measuring the uptake, settling, and recruitment processes that occur within these canopies. In addition, the flux models will enable a more quantitative consideration of how meadow geometry (length, height, stem density) influences a meadow?s impact on the surrounding ecosystem, which in turn will lead to better predictions of ecosystem response to changes in nutrient load or changes in seagrass distribution. In addition, the project will provide training for one graduate and at least one undergraduate student per year. The project will also form the basis for a new undergraduate laboratory activity, to be incorporated into the Principal Investigator?s current Junior year course. Finally, the investigator will use this work as a platform for continued interaction with the MIT Seagrant Eelgrass Restoration Project.