Fig. 2: Exchange of carbon at the marsh-bay interface increases with sea level rise (SLR) rate, and recycled carbon remains important in all SLR scenarios.

A Fluxes (kg yr⁻¹ per meter of marsh edge) of carbon eroded from the marsh edge into the bay (blue line) and of allochthonous carbon (C) deposited on the marsh platform from the bay (red line). The carbon flux from the marsh to the bay represents the mass flux of carbon eroded from the marsh edge, averaged over the last 50 years of the model experiment. The carbon flux from the bay to the marsh represents the mass flux of allochthonous carbon deposited on the marsh surface (surface deposition), averaged over the last 50 years of the model experiment. B The material eroded from the marsh edge makes up ~15% of the total carbon deposited on the marsh surface. This contribution decreases until an intermediate rate of SLR, and then increases as SLR increases. Colored envelopes show the variation (minimum and maximum) in results with suspended sediment concentration (SSC) = 20–60 mg L⁻¹.