The West’s wetlands are struggling. Some have been overlooked altogether.
On a warm day in August, Anthony Stewart hiked through a forest on Washington’s Olympic Peninsula, making his way through a tangle of ferns and grasses. Wispy, lichen-coated branches hung overhead, providing shade as he set down his backpack and shovel, and he and his team prepared to dig.
This was one of Stewart’s favorite study sites, he said. It’s relatively dry on the surface, but just underneath it, a layer of reddish soil, full of organic matter, gives way to gray-blue, claylike soil. These layers, formed over time as water flooded the area, are signs of a wetland. But like many forested wetlands in the Pacific Northwest, this area doesn’t appear on any state maps. One of Anthony Stewart’s study sites in the Hoh Rainforest. The layers, formed over time as water flooded the area, are tell-tale signs of a wetland. Credit: Courtesy Anthony Stewart
In a recent study published in Nature Communications, Stewart and his team reported the surprising abundance of unmapped, carbon-rich wetlands in the Pacific Northwest’s forests. The scientists studied the Hoh River watershed, which snakes westward across the Olympic Peninsula, documenting wetlands that were invisible to satellite imaging, the standard technique for measuring wetlands, owing to the thick forest canopy. Including them in estimates of the watershed’s carbon-storage capacity increased them by fivefold.
