Understanding the Trajectory of Mississippi Coastal Salt Marsh Structure, Function, and Processes in the face of Sea Level Rise: A Synthesis

Project Summary:

The proposed research will integrate and synthesize existing historical aerial photography and satellite imagery with fragmentation analysis, as well as existing biophysical and CO₂ flux data with biophysical process models to better understand the trajectory and implications of sea-level rise (SLR) on coastal marshes in the northern Gulf of Mexico. The goal of the proposed research are to analyze and synthesize the long-term health and productivity trends of coastal wetlands by developing a better mechanistic understanding of the current and historical extent, condition, productivity, and function of these saltmarshes. The specific objectives are to combine existing data from archives of aerial photography and satellite imagery with geospatial mapping and fragmentation analysis, to use existing in-situ vegetation monitoring data to refine and develop biophysical process models and hierarchical Bayesian modeling at multiple spatial scales that will help to improve future predictions for this vulnerable habitat. The proposed research addresses key components of the Gulf Research Program by developing innovative ideas on the use and analysis of existing data collected in the Gulf of Mexico and associated coastal wetland communities to advance the understanding of environmental conditions, ecosystem services, and community health important for developing improved restoration outcomes in the face of future climate change and sea level rise. The anticipated products will be a time-series of historical maps showing change in marsh extent, composition, and fragmentation, overlayed with biophysical process rates (productivity, canopy traits, plant biomass) for selected dominant plant species. The result of this historical mapping data analysis and modeling synthesis will be an efficient and non-destructive protocol for wetland structural and biophysical characteristics, which can be used for assessing the success of future restoration projects, identifying areas of degradation from oil and energy related activities in the coastal zone, and in evaluating the productivity of marshes that are impacted by anthropogenic development activity and sea level rise. The various biophysical modeling products will be integrated and spatially scaled using an hierarchical Bayesian model to develop better future forecasts for sea level rise and marsh vulnerability. The resultant products will be broadly applicable to inform plans for marsh preservation, restoration, and the future viability of the numerous ecosystem services provided by coastal marshes to human communities. This project will address goals 2 and 3 of the Gulf Research Program by improving understanding of key connections in long-term salt marsh resilience that will help to support healthy future Gulf communities, and by advancing understanding of the multiple linkages between climate, sea level rise and marsh habitat dynamics over decadal time scales to better inform the protection and restoration of this key ecosystem.