Keeping above the waves? The response of coastal freshwater peatlands to sea-level rise.

保持在波浪之上？

• 批准号: 2400204
• 金额: --
• 依托单位: UNIVERSITY OF EXETER
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2400204
• 关键词: Keeping; above; waves; response; coastal

Project Background There is considerable interest in how coastal saltwater ecosystems might adjust to sea-level rise and whether they will accrete rapidly enough to maintain their relative position in the tidal prism. This interest has arisen because of the importance of salt marshes and mangroves as natural coastal defences and as regionally- and globally-important (blue) carbon stores. Significantly less attention has been given to coastal freshwater wetlands, in particular peatlands such as floodplain fens. Sea-level rise caused by climate change is a potential major threat to these coastal freshwater wetlands. The ingress of saline water or higher groundwater could destroy their existing plant communities and their carbon sink function. In addition, inland areas currently protected by these wetlands may become more prone to flooding. There is some evidence that such wetlands have in the past increased their rates of peat accumulation in response to rising sea levels. However, the mechanisms involved are poorly understood, and without that understanding we cannot predict their likely response to future, rapid, increases in sea level. Understanding freshwater wetland response to sea level rise is a priority for policymakers and land managers as they adapt for a warmer world. The work has international relevance, with a large number of at-risk low-lying wetlands around the world. It will help indicate where to prioritise management efforts and may also show where new peatlands might form as shorelines move inland.Project Aims and Methods To address this critical research gap, this project will use a past-present-future approach, combining palaeoecological, process-based, and modelling work to understand the response of coastal freshwater peatlands to sea-level rise. The study will focus on two contrasting UK sites: Cors Fochno (an estuarine ombrotrophic bog in mid-Wales) and Wheatfen (a floodplain fen in Norfolk). Specifically, the project will involve: i) analysis of peat cores taken from both sites to understand their response to periods of past sea-level rise; ii) data collection to understand how current process and carbon accumulation rates adjust to hydrological and salinity changes; iii) modelling work using Met Office sea level projections in areas of freshwater peatlands, and the DigiBog peatland model to simulate past and future responses of the peatlands to changes in both climate and sea level. Wheatfen has been set up as an 'ecohydrological observatory' by members of the project team, and recently-collected datasets on fen water levels and saline surges are available.

项目背景 人们对沿海咸水生态系统如何适应海平面上升以及它们是否会快速增长以维持其在潮汐棱镜中的相对位置非常感兴趣。人们之所以产生这种兴趣，是因为盐沼和红树林作为天然海岸防御和区域和全球重要（蓝色）碳储存的重要性。对沿海淡水湿地，特别是洪泛平原沼泽等泥炭地的关注要少得多。气候变化引起的海平面上升是这些沿海淡水湿地的潜在主要威胁。咸水或较高地下水的进入可能会破坏其现有的植物群落及其碳汇功能。此外，目前受这些湿地保护的内陆地区可能更容易发生洪水。有证据表明，这些湿地过去因海平面上升而增加了泥炭积累率。然而，人们对其中所涉及的机制知之甚少，如果没有这种了解，我们就无法预测它们对未来海平面快速上升的可能反应。了解淡水湿地对海平面上升的反应是政策制定者和土地管理者适应变暖世界的首要任务。这项工作具有国际意义，世界各地有大量处于危险中的低洼湿地。它将有助于指出管理工作的优先顺序，还可能显示随着海岸线向内陆移动，新的泥炭地可能在哪里形成。项目目标和方法为了解决这一关键的研究空白，该项目将使用过去现在未来的方法，结合古生态学、过程基于模型的工作，以了解沿海淡水泥炭地对海平面上升的响应。该研究将重点关注两个截然不同的英国地点：Cors Fochno（威尔士中部的河口营养沼泽）和 Wheatfen（诺福克的洪泛区沼泽）。具体来说，该项目将涉及： i) 对从两个地点采集的泥炭岩心进行分析，以了解它们对过去海平面上升时期的反应； ii) 收集数据以了解当前过程和碳积累速率如何适应水文和盐度变化； iii) 使用气象局对淡水泥炭地区域的海平面预测和 DigiBog 泥炭地模型进行建模工作，以模拟泥炭地过去和未来对气候和海平面变化的响应。项目团队成员将惠特芬建立为“生态水文观测站”，最近收集的沼泽水位和盐水涌动数据集可供使用。