Resilience of Estuarine Ecosystems with Environmental Change

河口目前受到气候变暖、海平面上升速度随气候变暖而加快、城市发展和农业带来的营养负荷、外来入侵物种的引入以及流域土地利用变化造成的泥沙供应变化的压力。这项建议侧重于寒冷气候河口盐沼的主要生态系统的复原力。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提高海拔。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，对生态系统的弹性至关重要。事实上，盐沼在其土壤中储存了如此多的有机物质，以至于它们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”。*加拿大东部海岸线的两个主要压力是养分负载和圣劳伦斯河口海岸外来芦苇的入侵。两者都被认为会影响盐沼土壤的碳贮量。芦荟的产量非常高，但还没有测量到将土壤中储存的碳的速率与它入侵的本地植物群落的碳含量进行比较。养分有效性的增加既增加了沼泽植被的根产量，又减少了根产量，因此尚不清楚土壤C储量是增加还是减少，从而对沼泽对海平面加速上升的适应能力有什么影响。这项研究的目的是在加拿大东部盐沼的背景下回答这些问题，并促进沼泽动力学的科学研究。更好地了解这些过程不仅具有科学价值，而且为沿海管理提供了信息。*全球和加拿大的大片盐沼已经消失，正在努力恢复它们。蓝碳的价值如此之高，以至于通过盐沼恢复储存的碳可以在自愿的C市场上出售，如果C是由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多的碳，但来源(内部或外部？)C的位置尚不清楚。这里提出的研究将确定碳的来源和对其储存的控制。这将回答应用碳信用为恢复提供资金所需的重要问题，同时也增加了我们对湿地生物地球化学的了解。

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.