Accretionary marsh levees act as emerging barriers to interior elevation gain

Many small coastal plain watersheds have experienced extensive land clearing and increased sediment loading as coastal populations expand, yet microtidal marsh platforms are failing to keep pace with sea-level rise while adjacent subtidal areas are infilling. Here, we developed sub-decadal records of sedimentation from the shoreline into the salt marsh in watersheds with distinct land-use histories to determine how emerging microtopography may promote this disconnect. We find a divergence in mar