Acre for acre, a salt marsh like this one within the Netherlands’ Western Scheldt estuary, shops 5 instances extra carbon than a forest. Credit: Edwin Paree
Wetlands are Earth’s most effective pure storage system for climate-warming carbon dioxide.
Human actions akin to marsh draining for agriculture and logging are more and more consuming away at saltwater and freshwater wetlands. These important areas cowl only one% of Earth’s floor however retailer greater than 20% of all of the climate-warming carbon dioxide absorbed by ecosystems worldwide.
A brand new research revealed on May 6, 2022, within the journal Science by a workforce of Dutch, American, and German scientists exhibits that it’s not too late to reverse the losses.
The key to success, in keeping with the paper’s authors, is utilizing modern restoration practices — recognized within the new analysis paper — that replicate pure landscape-building processes and improve the restored wetlands’ carbon-storing potential.
And doing it on an enormous scale.
“About 1 percent of the world’s wetlands are being lost each year to pollution or marsh draining for agriculture, development, and other human activities,” stated Brian R. Silliman, Rachel Carson Distinguished Professor of Marine Conservation Biology at Duke University, who co-authored the research.
“Once disturbed, these wetlands release enormous amounts of CO2 from their soils, accounting for about 5 percent of global CO2 emissions annually,” Silliman stated. “Hundreds, even thousands of years of stored carbon are exposed to air and start to rapidly decompose and release greenhouse gases. The result is an invisible reverse waterfall of CO2 draining into the atmosphere. The wetlands switch from being carbon sinks to sources.”
“The good news is, we now know how to restore these wetlands at a scale that was never before possible and in a way that both stops this release of carbon and re-establishes the wetland’s carbon-storing capacity,” he stated.
What makes most wetlands so efficient at carbon storage is that they’re fashioned and held collectively by crops that develop shut to one another, Silliman defined. Their dense above- and below-ground mats of stems and roots lure nutrient-rich particles and defend the soil in opposition to erosion or drying out — all of which helps the crops to develop higher and the soil layer to construct up, locking in much more CO2 within the course of.
In the case of raised peat bogs, the method works a little bit in a different way, Silliman famous. Layers of residing peat moss on the floor act as sponges, holding huge quantities of rainwater that maintain its personal progress and retains a a lot thicker layer of lifeless peat moss under it completely below water. This prevents the decrease layer of peat, which may measure as much as 10 meters thick, from drying out, decomposing, and releasing its saved carbon again into the ambiance. As the residing mosses regularly construct up, the quantity of carbon saved belowground frequently grows.
Successful restorations should replicate these processes, he stated.
“More than half of all wetland restorations fail because the landscape-forming properties of the plants are insufficiently taken into account,” stated research coauthor Tjisse van der Heide of the Royal Institute for Sea Research and the University of Groningen within the Netherlands. Planting seedlings and plugs in orderly rows equidistant from one another could appear logical, nevertheless it’s counter-productive, he stated.
“Restoration is much more successful when the plants are placed in large dense clumps, when their landscape-forming properties are mimicked, or simply when very large areas are restored in one go,” van der Heide stated.
“Following this guidance will allow us to restore lost wetlands at a much larger scale and increase the odds that they will thrive and continue to store carbon and perform other vital ecosystem services for years to come,” Silliman stated. “The plants win, the planet wins, we all win.”
Silliman and van der Heide performed the brand new research 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.
“But when we looked at the amount of CO2 stored per square meter, it turned out that wetlands store about five times more CO2 than forests and as much as 500 times more than oceans,” says Ralph Temmink, a researcher at Utrecht University, who was first author on the study.
Reference: “Recovering wetland biogeomorphic feedbacks to restore the world’s biotic carbon hotspots” by Ralph J. M. Temmink, Leon P. M. Lamers, Christine Angelini, Tjeerd J. Bouma, Christian Fritz, Johan van de Koppel, Robin Lexmond, Max Rietkerk, Brian R. Silliman, Hans Joosten and Tjisse van der Heide, 6 May 2022, Science.
DOI: 10.1126/science.abn1479
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.
