Resilience of Estuarine Ecosystems with Environmental Change

河口生态系统对环境变化的恢复力

• 批准号: RGPIN-2018-06501
• 负责人: Chmura, Gail
• 金额: $ 4.37万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=754775
• 关键词: Resilience; Estuarine; Ecosystems; Environmental; Change

Estuaries are presently subject to stresses from climate warming, increased rates of sea level rise with climate warming, nutrient loading from urban development and agriculture, introduction of invasive species, and changes in sediment supplies due to land use change in their watersheds. This proposal focusses on the resilience of a major ecosystem of cold climate estuaries salt marshes. These are grassy meadows flooded daily by tides. To survive with rising sea level marsh soil must accumulate volume and increase in elevation. It is thought that production of organic matter by marsh plants is a major driver of this process, critical to the ecosystem's resilience. Indeed, salt marshes store so much organic matter in their soil that they are one of the world's most efficient carbon sinks, providing a benefit (ecosystem service) to society and its carbon is referred to as “blue carbon”.Two major stresses on the Eastern Canada coastline are nutrient loading and invasion by an exotic strain of common reed (Phragmites australis) on the St. Lawrence Estuary coast. Both are assumed to affect the C storage in salt marsh soils. Phragmites is exceptionally productive, but there have been no measurements comparing rates of C stored in its soil to that of the native plants communities it is invading. Increased availability of nutrients has been shown to both enhance root production by marsh vegetation and decrease root production, so it is not clear whether soil C storage would increase or decrease, thus what the affect is on marsh resilience to accelerated sea level rise. The research proposed here is intended to answer these questions in the context of salt marshes of Eastern Canada and advance the science of marsh dynamics. A greater understanding of these processes has not just scientific value, but informs coastal management.Extensive area of salt marsh has been lost in globally, as well as in Canada, and efforts are underway to restore them. Blue carbon is so valued that the carbon stored through restoration of salt marshes can be sold on voluntary C markets if the C is stored by the salt marsh ecosystem. Exceptional amounts of C has been measured in a restored marsh on the Bay of Fundy, but the source (internal or external?) of the C is not clear. The research proposed here will determine the source of C and controls on its storage. This will answer important questions needed for applying C credits to fund restoration, but also increase our knowledge of wetland biogeochemistry.

河口目前受到来自气候变暖的压力，随着气候变暖，海平面上升速度加快，城市发展和农业的营养负荷，入侵物种的引入，以及由于流域土地利用变化而导致的沉积物供应变化。该提案侧重于寒冷气候河口盐沼的主要生态系统的恢复能力。这些是每天被潮水淹没的草地。为了在海平面上升的情况下生存，沼泽土壤必须积累体积并增加海拔。据认为，沼泽植物产生的有机物质是这一过程的主要驱动力，对生态系统的恢复力至关重要。事实上，盐沼在土壤中储存了如此多的有机物质，它们是世界上最有效的碳汇之一，为社会提供了一种效益（生态系统服务），其碳被称为“蓝碳”。加拿大东部海岸线的两个主要压力是营养负荷和入侵圣劳伦斯河口海岸的外来芦苇（芦苇）。两者都被认为会影响盐沼土壤中的C储存。芦苇是非常多产的，但一直没有测量比较率的C存储在其土壤中的本地植物群落，它是入侵。增加养分的可用性已被证明既能提高沼泽植被的根系生产，又能降低根系生产，因此尚不清楚土壤碳储量是否会增加或减少，从而对沼泽对海平面加速上升的恢复力有何影响。这里提出的研究是为了回答这些问题的背景下，加拿大东部的盐沼和推进沼泽动力学的科学。更好地了解这些过程不仅具有科学价值，而且可以为沿海管理提供信息。全球以及加拿大的大面积盐沼已经消失，正在努力恢复它们。蓝碳的价值是如此之高，以至于通过恢复盐沼而储存的碳可以在自愿的碳市场上出售，如果碳被盐沼生态系统储存的话。在芬迪湾恢复的沼泽中测量到了异常数量的C，但是来源（内部还是外部？）C不清楚。本文提出的研究将确定C的来源及其储存控制。这将回答应用碳信用额资助恢复所需的重要问题，同时也增加了我们对湿地生态地球化学的了解。