Document Type

Journal Article

Publication Title

Science of The Total Environment

Volume

787

Publisher

Elsevier

School

School of Science / Centre for Marine Ecosystems Research

Funders

Edith Cowan University - Open Access Support Scheme 2021

Edith Cowan University

Australian Research Council

Funding details : https://doi.org/10.1016/j.scitotenv.2021.147482

Grant Number

ARC Number : LE170100219, 170101524

Comments

Gorham, C., Lavery, P. S., Kelleway, J. J., Masque, P., & Serrano, O. (2021). Heterogeneous tidal marsh soil organic carbon accumulation among and within temperate estuaries in Australia. Science of The Total Environment, 787, article 147482. https://doi.org/10.1016/j.scitotenv.2021.147482

Abstract

The scarcity of data on tidal marsh soil accumulation rates (SAR) and soil organic carbon accumulation rates (CAR) globally precludes a comprehensive assessment of the role of tidal marshes in climate change mitigation and adaptation. Particularly few data exist from the southern hemisphere and for Australia in particular, which contains ~24% of globally recognised tidal marsh extent. Here we estimate SAR and CAR over the last 70 years using 210Pb-based geochronologies in temperate estuarine tidal marsh ecosystems in southern Western Australia (WA). Specifically, we assessed tidal marsh ecosystems situated in two geomorphic settings (marine vs. fluvial deltas) within 10 wave-dominated, barrier estuaries. Overall, average SAR (1.1 ± 0.3 mm yr−1) and CAR (32 ± 9 g m−2 yr−1) estimates were 5-fold lower than global mean estimates. Furthermore, we showed that hotspots of soil organic carbon stocks are not indicative of current hotspots for CAR. The lack of significant differences (P > 0.05) in SAR, CAR, and excess 210Pb inventories between marine and fluvial settings can be explained by the high heterogeneity among and within estuaries throughout the region. The relative stability of recent and Holocene relative sea-levels in WA likely explains the limited CAR potential in tidal marshes under relatively stable sea-level conditions. However, further research exploring interactions among biotic and abiotic factors within estuaries is required to shed more light on the small spatial-scale variability in SAR and CAR across tidal marsh ecosystems in WA and elsewhere. This study provides baseline estimates for the inclusion of tidal marshes in national carbon inventories, identifies hotspots for the development of blue carbon projects, and supports the use of site-specific assessments opposed to regional means for estimating blue carbon resources.

DOI

10.1016/j.scitotenv.2021.147482

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

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