Effective use of thin layer sediment application in Spartina alterniflora marshes is guided by elevation-biomass relationship

Thin layer application (TLA) of dredged sediments has emerged as an adaptive management option for marshes that are not increasing in elevation fast enough to keep pace with local relative sea level rise. While there have been multiple previous demonstrations TLA, is limited pre-and post-application monitoring data available from past projects develop guidance concerning optimal siting, design and implementation projects. To address this gap, we conducted a controlled TLA experiment Spartina alterniflora marsh adjacent the Atlantic Intracoastal Waterway central North Carolina. The project was informed by results long-term research program which had identified area particularly vulnerable experimental included triplicate meso-scale (24m2) treatment control cells quarterly (during first year) annual efforts document trends surface vegetative biomass. In addition, sampling characterize porewater chemistry sediment characteristics. resulted average gain 6 cm plots. Monitoring indicate gains achieved maintained over five growing seasons. response biomass added well-predicted elevation-biomass relationship surrounding platform. Treatment exhibited continued increases after placement, while cell remained constant. These illustrate potential tool resilience low-lying rise value elevation-marsh providing its use S. alterniflora-dominated marshes.