On a cool September morning, a caravan of international scientists rumbles past the iconic formations of Canyonlands National Park in Utah. Over the eons, wind and water have carved this landscape into a maze of stunning red sandstone arches and spires. The researchers marvel at the formations, so different from their own backyards — places as distant as China, Niger, Australia and Spain. But when they pull into the parking lot for a short hike to Pothole Point, their attention goes straight toward their feet.
A thick, bumpy film covers large patches of the giant sandstone slabs. The patches resemble burnt soil, as if a fire left behind only these charred remains. Up close, the spots mimic the Canyonlands’ topography on a tiny scale: Centimeter-tall towers rise above a network of valleys. These dark, crusty soils span the arid Colorado Plateau in the Four Corners region.
Here, the ground is alive.
Biological soil crusts, or biocrusts, are crammed with communities of tiny photosynthetic organisms and other life-forms. Biocrusts in some parts of the world are mostly cyanobacteria, one of the oldest microorganisms on Earth. Other biocrust communities, like these on the Colorado Plateau, include mosses, lichens and fungi. The first scientists to study them called these living crusts “cryptogamic” — Greek for “hidden marriage” — because their inner workings were still mysterious. And while they might seem secretive, biocrusts are critical to healthy drylands around the world. But now, ecologists are worried that a changing climate will put them in jeopardy.
