Rural Coastal Ecosystem Responses to Widespread Salt Water Intrusion and Sea Level Rise

Heightened climate variability, water extraction and anthropogenically enhanced drainage density are all allowing marine salts to regularly penetrate well inland from the coastal margin. The primarily rural landscapes of the interior coastal plain are at considerable risk from salinization, a biogeochemical regime shift that threatens both iconic ecosystems and agricultural livelihoods. Coastal rural communities are highly vulnerable as a result of both their landscape position and their limited socioeconomic power to prevent or mitigate the damage caused by episodic or permanent salinization. Even before ecosystems undergo permanent transitions (e.g. land to open water or forested wetland to salt marsh), salinization leads to significant shifts in vegetation structure, composition and productivity in both managed and unmanaged lands. This talk will report our first estimates of the total extent of coastal forested wetland loss across the North American Coastal Plain (NACP) and will describe the drivers of the variation we see in both the extent and the timing of loss. This analysis is a first step in our efforts to synthesize current knowledge on salinization risks for rural coastal landscapes and to explore how the risks of exposure, the degree of hydrologic exchange, and the intrinsic soil properties that resist salinization together determine the distribution of environmental harm and economic risk across the NACP. While ultimately salinization leads to declines in aboveground biomass and crop yields, and substantial losses of total ecosystem carbon stocks, the pace of forest and agricultural yield losses varies considerably both within and across basins.