Long term (>100 years) Carbon Sequestration in California Coastal Salt Marshes

Abstract:

Coastal salt marsh ecosystems rank as one of the ecosystems which sequester the most carbon (C) in the world (Chmura, 2003; Mcleod et al., 2011). California hosts multiple small marsh ecosystems outside of the San Francisco Bay that are limited in geographic extent but still contribute significantly to global soil C. This study evaluates 11 marsh sites along the California coast for annual soil C sequestration rates using ¹⁴C, ¹³⁷Cs, and ²¹⁰Pb chronologies. Estimates of carbon sequestration for California over the past 100 years from this study average at 49 g C m^-2 yr^-1. Long term estimates of soil C generally are lower because of natural decomposition of organic C, but this study indicates a persistence of high C storage capacity for coastal marsh systems. These estimates provide valuable insight into the long term capacity for coastal salt marshes to mitigate climate change through sequestration of C.