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: $ 2.19万
• 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: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=683610
• 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.

河口目前受到气候变暖、气候变暖导致海平面上升速度加快、城市发展和农业带来的营养负荷、入侵物种的引入以及由于流域土地利用变化导致的沉积物供应变化的压力。本方案的重点是寒冷气候河口盐沼主要生态系统的恢复力。这些草地每天都被潮水淹没。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是这一过程的主要驱动力，对生态系统的恢复能力至关重要。事实上，盐沼在土壤中储存了如此多的有机物质，是世界上最有效的碳汇之一，为社会提供了利益（生态系统服务），其碳被称为“蓝碳”。***加拿大东部海岸线上的两个主要压力是营养负荷和圣劳伦斯河口海岸普通芦苇（芦苇）外来菌株的入侵。假设两者都影响盐沼土壤的碳储量。芦苇的产量非常高，但没有测量方法可以将其土壤中的碳储量与其入侵的本地植物群落的碳储量进行比较。营养物质有效性的增加已被证明既能增加沼泽植被的根系产量，又能减少根系产量，因此尚不清楚土壤C储量是增加还是减少，因此对沼泽对海平面加速上升的恢复能力有什么影响。本文提出的研究旨在回答加拿大东部盐沼背景下的这些问题，并推进沼泽动力学科学。对这些过程的更深入了解不仅具有科学价值，而且有助于海岸管理。***包括加拿大在内，全球范围内大面积的盐沼已经消失，目前正在努力恢复它们。蓝碳是如此珍贵，通过恢复盐沼储存的碳可以在自愿C市场上出售，如果C是由盐沼生态系统储存的。在芬迪湾（Bay of Fundy）的一片恢复后的沼泽中，测量到了异常数量的碳，但碳的来源（内部还是外部？）尚不清楚。这里提出的研究将确定C的来源和控制其储存。这将回答申请C学分以资助恢复所需的重要问题，同时也增加了我们对湿地生物地球化学的了解。