Rising Sea-Level Effects on Plant-Nutrient Interactions at the Boundary of Migrating Tidal Marsh and Farmland.

Rising sea levels are pushing tidal wetlands into uplands. On the lower eastern shore of the Chesapeake Bay, low-lying agricultural lands with histories of heavy fertilizer application sit just upslope of migrating tidal marsh. We are examining the rate of marsh migration into coastal farmland and forest, comparing nutrient releases across these ecotones, and investigating downstream effects on marsh plant species diversity. We examine nutrient and species dynamics in five sites across Somerset and Dorchester Counties, MD. Within each site, we identify six distinct sublocations: (1) coastal forest, (2) forest that has recently become marsh, (3) marsh adjacent to forest, (4) coastal farmland, (5) farmland recently become marsh, and (6) marsh adjacent to farmland. We present data on the effects of upland migration of salt marshes on both nutrient dynamics and wetland plant diversity. We will discuss how our findings can be used to inform salt marsh conservation practices, including the management of problem species Phragmites australis, prioritize protected land acquisition, and probe the capacity of migrating wetlands and transitioning forest to buffer water quality, which could provide the basis for a best management practice for coastal farms.