Abstract
Tidal marshes have been recognized globally for their ability to sequester “blue carbon” but there is still a need for studies investigating the marsh response to restoration, particularly in the Pacific Northwest United States. Here we report carbon stocks and accumulation rates for restored and natural tidal marshes in the Stillaguamish River estuary in Puget Sound, Washington, where a 60-hectare marsh was reintroduced to the tidal regime from its previous use as diked and drained farmland. We found that the restoration not only maximized carbon accumulation but also enhanced resilience to rising sea levels. Four years after restoration, mean sediment carbon stocks in the upper 30 cm within the restored marsh (4.43 kg C m-2) were slightly lower than those measured in the adjacent natural marshes (5.95 kg C m-2). Mean carbon accumulation rates, however, were nearly twice as high in the restored marsh (230.49 g C m-2 yr-1) compared to the natural marshes (123.00 g C m-2 yr-1) due to high rates of accretion in the restored marsh (1.57 cm yr-1). Mean elevation change rates were nearly twice that of corresponding 210Pb accretion rates, but all were greater than the current rate of sea level rise.
Highlights
Coastal wetlands are among the most valuable ecosystems in terms of the ecosystem services they provide [1] (Costanza et al 2014) and they have been recognized for their role in blue carbon sequestration and climate change mitigation [2]
Aboveground biomass ranged from 0 g dw m-2 to 978.64 g dw m-2 (HM5) (Fig 2)
Organic matter content, organic carbon content, and carbon density values were highest at natural marsh sites, intermediate at restored sites, and lowest at the tidal flat site
Summary
Coastal wetlands are among the most valuable ecosystems in terms of the ecosystem services they provide [1] (Costanza et al 2014) and they have been recognized for their role in blue carbon sequestration and climate change mitigation [2]. “Blue carbon” refers to the fraction of atmospheric carbon captured by the world’s oceans, typically stored in the sediments of saline coastal wetlands such as mangroves, salt marshes, and seagrasses [3]. Draining and converting coastal wetlands to other land uses often results in the release of that stored carbon back into the atmosphere [4, 5]. Restoring these same wetlands can potentially reverse that loss. Restoration efforts have increased in recent decades, often with the primary goal of regaining fish and wildlife habitat, but other ecosystem benefits such as carbon sequestration have more recently been added to the list of reasons.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
