Refining the Global Estimate of Mangrove Carbon Burial Rates Using Sedimentary and Geomorphic Settings

Abstract

AbstractThis study provides updated analysis of multi‐decadal mangrove organic carbon (OC) burial rates. The available data indicate mangroves bury 138.6 (120.3–158.8, 95% C.I.) g OC m−2 yr−1 locally, or 20.18 (17.52–23.12) Tg yr−1 globally. We contend that this common approach of upscaling from a single local‐scale rate obscures critical environmental differences in burial rates. By implementing a recently formalized, spatially explicit global mangrove typology, we find carbonate setting mangroves have lower burial rates than terrigenous settings, and that upscaling based on representative rates for sedimentary setting alone or a combination of sedimentary and geomorphic settings, increased the global scale annual burial to 22.10 (18.26–26.05) and 24.17 (19.77–25.50) Tg yr−1, respectively. We propose that future work should focus less on consolidating a single confidence interval for mangrove OC burial rates, and should instead explore drivers of spatial variability based on sedimentary and geomorphic settings.