Soil carbon in the world’s tidal marshes
A 30 m global map of tidal‑marsh soil carbon shows 1.44 Pg stored to 1 m depth, with one‑third in the U.S. Using data from 3710 sites, the study estimates high SOC densities in both shallow and deep layers, offering valuable insight for conservation and carbon‑storage assessments.
Subject Tags
- Estuary
- Soils
- Wetlands
Abstract
Tidal marshes are threatened coastal ecosystems known for their capacity to store large amounts of carbon in their water-logged soils. Accurate quantification and mapping of global tidal marshes soil organic carbon (SOC) stocks is of considerable value to conservation efforts. Here, we used training data from 3710 unique locations, landscape-level environmental drivers and a global tidal marsh extent map to produce a global, spatially explicit map of SOC storage in tidal marshes at 30 m resolution. Here we show the total global SOC stock to 1 m to be 1.44 Pg C, with a third of this value stored in the United States of America. On average, SOC in tidal marshes’ 0–30 and 30–100 cm soil layers are estimated at 83.1 Mg C ha−1 (average predicted error 44.8 Mg C ha−1) and 185.3 Mg C ha−1 (average predicted error 105.7 Mg C ha−1), respectively.
Citation
Maxwell, T.L., Spalding, M.D., Friess, D.A., Murray, N.J., Rogers, K., Rovai, A.S., Smart, L.S., Weilguny, L., Adame, M.F., Adams, J.B. and Austin, W.E., 2024. Soil carbon in the world’s tidal marshes. Nature Communications, 15(1), p.10265. doi:10.1038/s41467-024-54572-9
TNC Authors
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Mark D. Spalding
Senior Marine Scientist
The Nature Conservancy
Phone: Phone
Email: mspalding@tnc.org -
Emily Landis
Global Climate Adaptation and Resilience Director
The Nature Conservancy
Phone: Phone
Email: elandis@tnc.org