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

项目背景关于沿海咸水生态系统如何适应海平面上升，以及它们是否会足够快地生长以维持它们在潮汐棱柱中的相对位置，人们对此很感兴趣。之所以产生这种兴趣，是因为盐沼和红树林作为天然的海岸防御工事以及作为地区和全球重要的(蓝色)碳库的重要性。对沿海淡水湿地，特别是诸如泛滥平原沼泽等泥炭地的关注明显较少。气候变化导致的海平面上升是这些沿海淡水湿地的潜在主要威胁。咸水或更高的地下水进入可能会破坏它们现有的植物群落和它们的碳汇功能。此外，目前受这些湿地保护的内陆地区可能会变得更容易发生洪水。有一些证据表明，这些湿地在过去增加了泥炭堆积的速度，以应对海平面上升。然而，人们对所涉及的机制知之甚少，如果不了解这些机制，我们就无法预测它们对未来海平面快速上升的可能反应。在政策制定者和土地管理者适应全球变暖之际，了解淡水湿地对海平面上升的反应是他们的优先事项。这项工作具有国际意义，世界各地有大量处于危险之中的低洼湿地。这将有助于指出管理工作的优先顺序，并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。该项目的目标和方法为解决这一关键的研究差距，该项目将使用过去-现在-未来的方法，结合古生态学、基于过程的和模型工作，以了解沿海淡水泥炭地对海平面上升的反应。这项研究将聚焦于两个截然不同的英国遗址：科尔斯福奇诺(威尔士中部的河口营养沼泽)和惠特芬(诺福克的泛滥平原沼泽)。具体来说，该项目将涉及：i)分析从两个地点采集的泥炭岩芯，以了解它们对过去海平面上升时期的反应；ii)数据收集，以了解当前的过程和碳累积速度如何适应水文和盐度变化；iii)利用气象局对淡水泥炭地地区的海平面预测和DigiBog泥炭地模型来模拟泥炭地过去和未来对气候和海平面变化的反应。Wheatfen已经被项目团队的成员建立为一个生态水文观测站，最近收集的关于Fen水位和盐潮的数据集已经可用。

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.