Soil carbon in the world’s tidal marshes
Tania L. Maxwell, Mark Spalding, Daniel A. Friess, Nicholas Murray, Kerrylee Rogers, André Rovai, Lindsey S. Smart, Lukas Weilguny, María Fernanda Adame, Janine B. Adams, William E. N. Austin, Margareth Copertino, Grace M. Cott, Micheli Duarte de Paula Costa, James R. Holmquist, Cai Ladd, Catherine E. Lovelock, Marvin Ludwig, Monica M. Moritsch, Alejandro Navarro, Jacqueline L. Raw, Ana Carolina Ruíz-Fernández, Óscar Serrano, Craig Smeaton, Marijn Van de Broek, Lisamarie Windham‐Myers, Emily Landis, Thomas A. Worthington
Abstract
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.