The Hall of Mosses, a looped hiking trail in Washington State’s Hoh Rain Forest, is known for a kind of otherworldly lusciousness. Vibrant ferns line misty paths. The roots of centuries-old trees tangle around each other, forming miniature mazes. Most spectacularly, soft moss coats the towering Sitka spruce trees, drooping in fringed curtains from the branches. It’s awe-inspiring, but there’s more wonder in store. “When you look up, you see that beautiful green drapery,” says Korena Mafune, a soil ecologist based at the University of Washington in Seattle, “but the…
