Earth Notes: Restoring Biocrust

Mar 4, 2020

Biocrust is a vital, but fragile material that covers a good portion of the soil surface on the Colorado Plateau. This “living skin” is a complex concoction of cyanobacteria, algae, fungi, moss and lichen.

Biocrust is the "living skin" that covers much of the soil surface of the Colorado Plateau.
Credit nau.edu

Though it looks unassuming, biocrust performs essential services in dryland areas—protecting soil from erosion, helping retain water and cycling nutrients.

But it’s easily damaged by vehicles, development and climate change, as well as livestock and human footprints. When the protective layer is broken, soil blows away. And it can take decades or even centuries for the crust to recover.

Scientists have been experimenting with ways to restore biocrust. At Northern Arizona University, researchers have tried cultivating crust in labs and greenhouses, then putting it back into disturbed dryland areas. Farms and nurseries around Canyonlands National Park near Moab, Utah have started growing it outdoors.

According to ecologists Matt Bowker at NAU and Sasha Reed with the U.S. Geological Survey’s Southwest Biological Science Center, outdoor cultivation may hold the most promise for biocrust restoration. When exposed to the sun and varying temperature and moisture conditions—farmed biocrust has a chance to thrive in conditions more like the real world it must endure when replanted on the landscape.

The crust material is ground up and sprinkled onto the soil, hydroseeded or rolled up in mats like sod where it can take root. More mature biocrust that’s developed moss and lichen seems to have the best chance of reestablishing—and providing necessary services to arid ecosystems.