Geomorphic Gradients in Shallow Seagrass Carbon Stocks

Authors

Jahson Berhane Alemu
Siti Maryam Yaakub
Erik S. Yando, Old Dominion UniversityFollow
Rachel Yu San Lau
Cheng Chang Lim
Jun Yu Puah
Daniel A. Friess

Document Type

Article

Publication Date

2022

DOI

10.1016/j.ecss.2021.107681

Publication Title

Estuarine Coastal and Shelf Science

Volume

265

Pages

107681 (1-8)

Abstract

Seagrass meadows are important sinks of organic carbon (C_org), in particular the near-surface C_org pool (≤ 15 cm) compared to deeper sediments. Near-surface carbon is highly susceptible to disturbance and loss to the atmosphere, however, inadequate accounting for variability in this pool of carbon limits their uptake into carbon accounting frameworks. We therefore investigated the spatial variability in seagrass near-surface C_org and biomass C_org across different geomorphic (estuary, lagoonal and reef-associated) and community typologies (pioneer and persistent). Near-surface C_org stock in vegetated areas (25.78 Mg C_org ha⁻¹ ± 26.64) was twice that from unvegetated areas (14.27 Mg C_org ha⁻¹ ± 15.86), reinforcing the paradigm that the presence of seagrass enhances carbon stocks. Lagoonal and reef-associated meadows showed similar C_org stocks (p > 0.05), which were substantially higher (p < 0.05) than estuary meadows. Likewise, persistent seagrass communities (Cymodocea dominance) stored higher (p < 0.05) stocks of C_org than pioneer communities (Halophila and Halodule dominance). Linear regression models showed significant but weak relationships between seagrass cover, shoot density and standing biomass with near-surface C_org stocks, whereas significant and strong relationships were observed for organic matter, dry bulk density and median grain size. The results highlight the need for higher resolution carbon assessments to better understand local and regional variability, in order to better inform carbon accounting and conservation policy.

Rights

© 2021 The Authors.

Published under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0).

Original Publication Citation

Alemu I, J. B., Yaakub, S. M., Yando, E. S., Lau, R. Y. S., Lim, C. C., Puah, J. Y., & Friess, D. A. (2022). Geomorphic gradients in shallow seagrass carbon stocks. Estuarine, Coastal and Shelf Science, 265, 1-8, Article 107681. https://doi.org/10.1016/j.ecss.2021.107681

Repository Citation

Berhane Alemu, Jahson; Maryam Yaakub, Siti; Yando, Erik S.; Yu San Lau, Rachel; Lim, Cheng Chang; Puah, Jun Yu; and Friess, Daniel A., "Geomorphic Gradients in Shallow Seagrass Carbon Stocks" (2022). Biological Sciences Faculty Publications. 476.
https://digitalcommons.odu.edu/biology_fac_pubs/476

ORCID

0000-0002-8786-6178 (Yando)