Plant biomass and rates of carbon dioxide uptake are enhanced by successful restoration of tidal connectivity in salt marshes.

Autor: Wang F; Xiaoliang Research Station of Tropical Coastal Ecosystems and CAS Engineering Laboratory for Ecological Restoration of Island and Coastal Ecosystems, South China Botanical Garden, and Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, PR China; The Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA 02543, USA; State Key Laboratory of Estuarine and Coastal Research and Institute of Eco-Chongming, East China Normal University, Shanghai 201100, PR China., Eagle M; U.S. Geological Survey, Woods Hole Coastal & Marine Science Center, Woods Hole, MA 02543, USA., Kroeger KD; U.S. Geological Survey, Woods Hole Coastal & Marine Science Center, Woods Hole, MA 02543, USA., Spivak AC; Department of Marine Sciences, University of Georgia, Athens, GA 30606, USA., Tang J; The Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA 02543, USA; State Key Laboratory of Estuarine and Coastal Research and Institute of Eco-Chongming, East China Normal University, Shanghai 201100, PR China. Electronic address: jtang@mbl.edu.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2021 Jan 01; Vol. 750, pp. 141566. Date of Electronic Publication: 2020 Aug 10.
DOI: 10.1016/j.scitotenv.2020.141566
Abstrakt: Salt marshes, due to their capability to bury soil carbon (C), are potentially important regional C sinks. Efforts to restore tidal flow to former salt marshes have increased in recent decades in New England (USA), as well as in some other parts of the world. In this study, we investigated plant biomass and carbon dioxide (CO 2 ) fluxes at four sites where restoration of tidal flow occurred five to ten years prior to the study. Site elevation, aboveground biomass, CO 2 flux, and porewater chemistry were measured in 2015 and 2016 in both restored marshes and adjacent marshes where tidal flow had never been restricted. We found that the elevation in restored marsh sites was 2-16 cm lower than their natural references. Restored marshes where porewater chemistry was similar to the natural reference had greater plant aboveground biomass, gross ecosystem production, ecosystem respiration, as well as net ecosystem CO 2 exchange (NEE) than the natural reference, even though they had the same plant species. We also compared respiration rates in aboveground biomass (AR) and soil (BR) during July 2016, and found that restored marshes had higher AR and BR fluxes than natural references. Our findings indicated that well-restored salt marshes can result in greater plant biomass and NEP, which has the potential to enhance rates of C sequestration at 10-yrs post restoration. Those differences were likely due to lower elevation and greater flooding frequency in the recently restored marshes than the natural marsh. The inverse relationship between elevation and productivity further suggests that, where sea-level rise rate does not surpass the threshold of plant survival, the restoration of these salt marshes may lead to enhanced organic and mineral sedimentation, extending marsh survival under increased sea level, and recouping carbon stocks that were lost during decades of tidal restriction.
Competing Interests: Declaration of competing interest The authors declared no conflicting interests.
(Copyright © 2020. Published by Elsevier B.V.)
Databáze: MEDLINE
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