For most of us, the word wetland conjures a marshy expanse of shallow ponds, stiff grasses, and soft boggy earth. But a dramatically different ecosystem once lined many waterways and low-lying areas of the Gulf Coast of the United States. In old-growth coastal forested wetlands (CFWs), towering trees rise from broad buttresses, which disappear into placid water. Mosses and orchids adorn the trees, fish nurseries hide among the roots, and a fabulous diversity of birdlife flits among the branches overhead. Most of us don’t have this picture of wetlands simply because there are few such forests left.
As an ecosystem, CFWs offer extraordinary benefits. They store tremendous quantities of carbon, mitigate both riverine and coastal flooding, facilitate recharge of fresh groundwater, and provide critical habitat for many terrestrial and aquatic species. Yet those few CFWs that remain are in rapid retreat: Over two decades, from 1996 to 2016, nearly 14,000 square kilometers of CFWs were lost from the North American Coastal Plain. This staggeringly swift disappearance is due in part to conversion in land-use, and in part to climate change, which drives sea level rise, resulting in salt-water intrusion that transforms ecologically rich stands of trees into what are known as ghost forests—graveyards of leafless, blanched trunks. Often, forests cannot migrate inland or upland fast enough to stay ahead of rising salinity.
For the global community, these forest losses mean a surge of greenhouse gases and the loss of a singular and magnificent ecosystem. For local populations, there are additional consequences. Rural and indigenous communities that relied on CFWs for hunting and fishing have lost a vital source of food as well as spiritual sustenance. Less obviously, urban communities that lie downstream from deforested riverbanks face heightened flooding risk, because storm waters that would have been absorbed by intact forest are instead released directly to rising rivers and expanding floodplains. Many of these downstream urban communities are socio-economically underserved and consequently vulnerable.
Collaborative Earth’s Coastal Forested Wetlands Lab has brought people across disciplinary and cultural boundaries to design and create a forested wetland system that serves vulnerable communities most impacted by flooding. Under the leadership of Elliott White Jr.—an environmental scientist at Stanford University, one of the world’s leading experts on CFW ecology, and also a native of coastal Louisiana—the CFW Lab brought together expertise in wetland ecology, processing and analysis of satellite imagery, and machine learning. This team built a predictive machine learning model that identifies areas of potential habitat for CFW. Critically, the model incorporates projections of future climate variables, such as temperature and precipitation, as well as sea-level rise, so it is capable of identifying not just locations that are presently suitable for CFW, but those areas that are likely to be suitable under probable climate-change scenarios.
The team then overlayed their newly constructed habitat suitability map with additional maps of waterways, socio-economic vulnerability, community resilience, flooding risks, and agricultural lands. This layering enabled the team to identify areas of potential CFW habitat that would be most likely to provide flood mitigation to downstream communities that are especially socio-economically vulnerable. In short, the team has identified locations for CFW reforestation that are not only ecologically viable, but also socially impactful. The intersection of those two categories yields our highest-priority set of targets for socio-ecological regeneration through CFW reforestation.
Much of the agricultural land in our highest-priority targets is at high and growing risk of flooding. Consequently, while the value of this land for ecosystem benefits is high and rising, it is also becoming more difficult to farm. In view of the social, economic, and cultural importance of local food systems, our plan aims to support simultaneous adaptation of local agricultural practices and introduction of opportunities for revenue-generating restoration of ecosystem services.We are now in the process of engaging with land stewards and community organizations in these highest-priority locations. Our engagement has multiple interrelated stages and goals, including:
1. communicate to land stewards the extraordinary potential of their land to provide ecosystem benefits at scales ranging from their own property to downstream high-density areas to the global atmosphere;
2. coordinate neighbors to organize larger continuous areas for reforestation efforts;
3. educate land stewards in potential streams of financial support for restoration efforts that provide ecosystem benefits, including flood mitigation and carbon sequestration;
4. educate land stewards in potential adaptations of agricultural practices to be implemented in concert with restoration of ecosystem benefits, including re-arrangement of land use, crop and rotation choices, and management of local hydrology;
5. connect land stewards with potential key partners, including trustworthy carbon project developers, regenerative agriculture practitioners, and buyers for new, post-adaptation products;
6. maintain ongoing communication with and advocacy for land stewards, guarding against the informational and financial asymmetry that has, in some rural communities, resulted in inequitable outcomes of carbon development projects.
We are tremendously excited to be moving from the ‘Research’ phase into the ‘Act’ phase of the Coastal Forested Wetlands Lab. By combining the leading-edge research and technology of the Lab, culturally appropriate and locally adapted organizing efforts, and finally, strong connections in the realms of ecosystem service development, regenerative agriculture, and innovative project financing, we will advance ecological as well as social regeneration in the Southeastern United States.