title: Coastal landforms and accumulation of mangrove peat increase carbon sequestration and storage.
abstract: Given their relatively small area, mangroves and their organic sediments are of disproportionate importance to global carbon sequestration and carbon storage. Peat deposition and preservation allows some mangroves to accrete vertically and keep pace with sea-level rise by growing on their own root remains. In this study we show that mangroves in desert inlets in the coasts of the Baja California have been accumulating root peat for nearly 2,000 y and harbor a belowground carbon content of 900-34,00 Mg C/ha, with an average value of 1,130 (± 128) Mg C/ha, and a belowground carbon accumulation similar to that found under some of the tallest tropical mangroves in the Mexican Pacific coast. The depth-age curve for the mangrove sediments of Baja California indicates that sea level in the peninsula has been rising at a mean rate of 0.70 mm/y (± 0.07) during the last 17 centuries, a value similar to the rates of sea-level rise estimated for the Caribbean during a comparable period. By accreting on their own accumulated peat, these desert mangroves store large amounts of carbon in their sediments. We estimate that mangroves and halophyte scrubs in Mexico's arid northwest, with less than 1% of the terrestrial area, store in their belowground sediments around 28% of the total belowground carbon pool of the whole region.
authors.affiliation: Marine Biology Research Division, Scripps Institution of Oceanography, La Jolla, CA 92093; pezcurra@ucsd.edu.
authors.forename: Paula
authors.identifier: http://orcid.org/0000-0002-6545-9133
authors.initials: P
authors.lastname: Ezcurra
authors.affiliation: Department of Botany and Plant Sciences, University of California, Riverside, CA 92521;
authors.forename: Exequiel
authors.identifier: http://orcid.org/0000-0002-3505-5859
authors.initials: E
authors.lastname: Ezcurra
authors.affiliation: Centro de Investigaciones Biológicas del Noroeste, Playa Palo de Santa Rita Sur, La Paz, Baja California Sur 23096, Mexico.
authors.forename: Pedro P
authors.initials: PP
authors.lastname: Garcillán
authors.affiliation: Marine Biology Research Division, Scripps Institution of Oceanography, La Jolla, CA 92093;
authors.forename: Matthew T
authors.identifier: http://orcid.org/0000-0002-2323-9343
authors.initials: MT
authors.lastname: Costa
authors.affiliation: Marine Biology Research Division, Scripps Institution of Oceanography, La Jolla, CA 92093;
authors.forename: Octavio
authors.identifier: http://orcid.org/0000-0002-8173-1432
authors.initials: O
authors.lastname: Aburto-Oropeza
mesh_terms: D002244:Carbon / Q000378:metabolism*; D008800:Mexico; D053833:Wetlands
chemical_list: D002244:Carbon
keywords: Baja California; blue carbon; carbon sequestration; mangroves; peat