Marshes more resilient to sea level rise than previously thought

More settled science.

The media release and study abstract are below.


Marsh resilience to sea-level rise

Carbon dioxide fertilization effects may increase rates of coastal marsh soil accretion and marsh resilience to sea-level rise, according to a study. Sea-level rise endangers coastal marshes, but the rate of marsh drowning depends on rates of inorganic sediment deposition and organic soil formation, and changes to these processes under elevated carbon dioxide and climate change scenarios are poorly understood. Marco Marani and colleagues constructed a model of marsh vegetation and morphology that incorporated published observations of marsh vegetation response to elevated atmospheric carbon dioxide. The authors found that by increasing plant productivity, carbon dioxide fertilization may increase marsh resilience to an accelerating sea-level rise by increasing both above-ground soil accretion and below-ground organic soil generation. Increased below-ground productivity accelerates organic soil generation, according to the authors, and increased above-ground productivity boosts trapping of suspended inorganic sediment. In some cases, modeled increases in marsh productivity increased the threshold sea level-rise rate that could initiate marsh drowning by up to 60%. Further, the authors found that carbon dioxide fertilization effects on marshes displayed high spatial variation, suggesting that studies of point responses may be useful in elucidating some marsh processes but may fail to capture full-scale marsh responses to climate change. The results suggest that marsh ecosystems may be more resilient to sea-level rise than previously thought.

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2 thoughts on “Marshes more resilient to sea level rise than previously thought”

  1. i live on an island of sorts, Nova Scotia Canada. On the border with New Brunswick there is/was a salt water marsh which was harnessed by creating berms on the marsh which kept out the tidal advances. Now I am not a scientist, however these berms have been in place for centuries, and predate the Industrial Revolution. These man made berms have failed occasionally over the centuries, but mostly due to lack of maintenance. The point being that in hundreds of years the land link between Nova Scotia and New Brunswick has never been flooded out. Nova Scotia has not been an island in some time. Where is the evidence of ocean rise when berms which were constructed hundreds of years ago and have been allowed to collapse and shrink from lack of maintenance, have never been breached by the rising ocean?

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