Biological soil crust: The living skin of the desert

The Gurbantunggut Desert, the second largest in China, is located in the center of the Junggar Basin in northwest China's Xinjiang Uygur Autonomous Region. At first glance, it appears to be an endless sea of sand. But look closer, you might notice something unexpected – a thin, dark crust on the sand. This is a biological soil crust, a living layer formed by lichens, mosses, cyanobacteria, and other organisms.

It helps stabilize shifting sand, fight desertification, and support biodiversity. That's why it's often called the "engineer of desert ecosystems." Under natural conditions, it takes 10 to 20 years for this crust to form. But once it does, it signals a turning point – the slow healing of the land and the recovery of fragile desert ecosystems. Today, scientists are working to understand, protect, and even recreate these hidden heroes of dryland ecosystems. Because sometimes, the smallest things make the biggest difference.