Climate Change Driving Widespread Loss of Coastal Forested Wetlands Throughout the North American Coastal Plain

Coastal forested wetlands support many endemic species, sequester substantial carbon stocks, and have been reduced in extent due to historic drainage and agricultural expansion. Many of these unique coastal ecosystems have been drained, while those that remain are now threatened by saltwater intrusion and sea level rise in hydrologically modified coastal landscapes. Several recent studies have documented rapid and accelerating losses of coastal forested wetlands in small areas of the Atlantic and Gulf coasts of North America, but the full extent of loss across North America's Coastal Plain (NACP) has not been quantified. We used classified satellite imagery to document a net loss of similar to 13,682 km(2) (8%) of forested coastal wetlands across the NACP between 1996 and 2016. Most forests transitioned to scrub-shrub (53%) and marsh habitats (24%). Even within protected areas, we measured substantial rates of wetland deforestation and significant fragmentation of forested wetland habitats. Variation in the rate of sea level rise, the number of tropical storm landings, and the average elevation of coastal watersheds explained about 78% of the variation in coastal wetland deforestation extent along the SouthAtlantic and Gulf Coasts. The rate of coastal forest loss within the NACP (684 km(2)/y) exceeds the recent estimate of global losses of coastal mangroves (210 km(2)/y). At the current rate of deforestation, in the absence of widespread protection or restoration efforts, coastal forested wetlands may not persist into the next century.

Automated summary

Coastal forested wetlands in North America have been diminishing in extent due to historic drainage and agricultural expansion. Satellite imagery analysis shows that between 1996 and 2016, there was a net loss of approximately 13,682 km² of forested coastal wetlands across the North America's Coastal Plain. Factors such as sea level rise, tropical storm landings, and watershed elevation explain most of the variation in coastal wetland deforestation extent.