Summary
Arid and semi-arid lands cover a large fraction of Earth’s surface and support the livelihoods of hundreds of millions of people. Many of these landscapes are changing. A critical, but often overlooked, component of healthy drylands is biological soil crusts (“biocrusts”), thin, living soils formed by communities of microorganisms. Biocrusts stabilize soil, support nutrient cycling, and regulate dust emissions, thereby protecting soil fertility and human health. Biocrusts are sensitive to environmental stress, particularly exposure to strong daily and seasonal temperature variations that chara
