A new study published May 6 in Science by a team of Dutch, American and German scientists shows that it’s not too late to reverse the losses.
The key to success, the paper’s authors say, is using innovative restoration practices — identified in the new paper — that replicate natural landscape-building processes and enhance the restored wetlands’ carbon-storing potential.
In the case of raised peat bogs, the process works a little differently, Silliman noted. Layers of living peat moss on the surface act as sponges, holding enormous amounts of rainwater that sustain its own growth and keeps a much thicker layer of dead peat moss below it permanently under water. This prevents the lower layer of peat, which can measure up to 10 meters thick, from drying out, decomposing, and releasing its stored carbon back into the atmosphere. As the living mosses gradually build up, the amount of carbon stored below ground continually grows.
Successful restorations must replicate these processes, he said.
“More than half of all wetland restorations fail because the landscape-forming properties of the plants are insufficiently taken into account,” said study coauthor Tjisse van der Heide of the Royal Institute for Sea Research and the University of Groningen in the Netherlands. Planting seedlings and plugs in orderly rows equidistant from each other may seem logical, but it’s counter-productive, he said.
Silliman and van der Heide conducted the new study with scientists from the Netherlands’ Royal Institute for Sea Research, Utrecht University, Radboud University, the University of Groningen, the University of Florida, Duke University, and Greifswald University.
By synthesizing data on carbon capture from recent scientific studies, they found that oceans and forests hold the most CO2 globally, followed by wetlands.
Funding for the new study came from the Dutch Research Council, the Oak Foundation, Duke RESTORE, the Lenfest Ocean Program, the National Science Foundation, and Natuurmonumenten.
In addition to his faculty appointment at Duke’s Nicholas School, Silliman is director of Duke RESTORE.