OCE-PRF Effects of below-ground complexity on seagrass sediment structure and function

OCE-PRF 地下复杂性对海草沉积物结构和功能的影响

• 批准号: 2126708
• 负责人: Kara Gadeken
• 金额: $ 21.09万
• 依托单位: SUNY at Stony Brook
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-12-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2126708&HistoricalAwards=false
• 关键词: OCE; PRF; Effects; below; ground

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Marine sediments control the fate of carbon in the ocean by either metabolizing (“breaking down”) organic matter or burying it away. However, sediments are somewhat of a “black box”. Chemistry and ecology are closely connected in sediments, making it difficult to identify which processes control metabolism. This problem is even more pronounced in seagrass beds which are important coastal ecosystems and sites of very high carbon burial. Seagrass roots create complex structures that exchange nutrients and oxygen with the surrounding sediment, and burrowing animals can increase sediment metabolism by mixing and flushing water through sediments. This results in variability in seagrass sediment metabolism that is currently not well explained. The proposed research will link differences in seagrass root structure and animal communities to variation in sediment metabolism rates. The results of this research will inform strategies to manage and protect seagrass beds and anticipate changes in their valuable ecosystem services. Undergraduates from underrepresented groups will be involved in the research and mentored in their own research projects. The findings of the project will be adapted into a middle/high school level lesson plan on “Hidden Complexity” to teach students about the relationships between physical structure, chemistry and ecology in nature. The overarching goal of the proposed research is to integrate the complex physical structure and geochemical activity of seagrass roots and rhizomes into a model of the seagrass below-ground environment to assess which features of that environment affect sediment metabolism. Dense, complex root mats may oxygenate sediments more and drive higher sediment metabolism rates, and the 3D structure of the roots may control what fauna can live there and by extension the metabolism-enhancing activities the fauna perform. Specific goals of the project are to; (1) determine how the physical-chemical environment created by seagrass roots and rhizomes influences macrofaunal functional diversity, (2) assess how variation in the sediment physical-chemical environment at different locations in an expanding seagrass bed corresponds to variation in sediment metabolism, and (3) assess how differences in the sediment physical-chemical environment between seagrass taxa corresponds to variation in sediment metabolism. Physical structure will be characterized using CT imaging and geochemical patterns will be measured using planar optode imaging and targeted microprofiling. The structural and geochemical data will be integrated together using multiphysics modeling techniques to simulate geochemical permeance into the sediment around seagrass roots. These model results will then be compared to measurements of sediment metabolism from in situ benthic chambers to draw conclusions about the influence of roots on total sediment oxygenation and faunal behavior. The combination of non-destructive CT and planar optode imaging into a unified model will provide valuable information on the 3D structuring of seagrass sediments previously only described to a limited extent. The developed methodologies will also be of use to other researchers studying complexity in “opaque” systems, such as marshes, mangroves, and soils. By describing variation in below-ground structure, this work will provide a mechanistic understanding of its processes that can then be connected to larger-scale patterns in seagrass ecosystems, generating valuable knowledge for seagrass conservation, restoration, and management, and informing on seagrass susceptibility to climate change.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该奖项是根据2021年《美国救援计划法》（公法117-2）全部或部分资助的。海军沉积物通过代谢（“分解”）有机物或掩埋它来控制海洋中碳的命运。但是，沉积物是“黑匣子”的某些东西。化学和生态学在沉积物中密切相关，因此难以确定哪些过程控制代谢。在海草床中，这个问题更加明显，这是重要的沿海生态系统和非常高的碳埋葬地点。海草根创建了复杂的结构，可将营养和氧气与周围的沉积物交换，而挖洞的动物可以通过将水混合和冲水通过沉积物来增加沉积物代谢。这会导致海草沉积物代谢的变化，目前尚未得到很好的解释。拟议的研究将将海草根结构和动物群落的差异与沉积物代谢率的变化联系起来。这项研究的结果将为管理和保护海草床的策略提供信息，并预测其宝贵的生态系统服务的变化。来自代表性不足的小组的本科生将参与研究，并在自己的研究项目中进行指导。该项目的发现将适应“隐藏复杂性”的中学/高中课程计划，以向学生传授自然界物理结构，化学和生态学之间的关系。拟议研究的总体目标是将海草根和根茎的复杂物理结构和地球化学活动整合到地下环境下的海草模型中，以评估该环境的哪些特征会影响沉积物代谢。稠密，复杂的根垫可能会更多地氧合沉积物并促进较高的沉积物代谢率，并且根的3D结构可能控制动物区系可以居住的东西，并通过扩展为动物动物的增强作用。该项目的具体目标是（1）确定海草根和根茎创造的物理化学环境如何影响大小的功能多样性，（2）评估在膨胀的海草床的不同位置的沉积物物理化学环境中的变化如何对应于沉积物代谢的变化，以及（3）评估对沉积物之间的替代环境的差异，（3）对环境的差异差异。将使用CT成像来表征物理结构，并将使用平面光极成像和靶向微填面来测量地球化学模式。结构和地球化学数据将使用多物理建模技术集成在一起，以模拟地球化学的渗透性在海草根周围的沉积物中。然后，将将这些模型结果与从原位底栖室的沉积物代谢的测量进行比较，以得出有关根对总沉积物氧合和动物性行为的影响的结论。非破坏性CT和Planar Optode成像与统一模型的组合将提供有关以前仅在有限范围内描述的海草沉积物的3D结构的有价值信息。开发的方法还将用于其他研究人员，研究“不透明”系统（例如沼泽，红树林和土壤）中的复杂性。通过描述地下结构的变化，这项工作将提供对其过程的机械理解，然后可以与海草生态系统中的较大尺度模式相关联，为海草保护，恢复和管理产生有价值的知识，并告知海格质对海格的易感性，以表现出NSF的智力和范围的依据，这反映了NSF的构建范围，这是跨国公司的启发性的，这取决于NSF的范围。审查标准。