Biological Soil Crust
Don’t Bust the Crust! It’s Alive!
The plant communities of Arches National Park are dependent upon microbial communities called biological soil crusts or cryptobiotic crusts. These communities – made up of cyanobacteria, green algae, fungi, lichens, mosses, and other tiny organisms – create a matted crust atop the sand that retains moisture, creates nutrients, and provides grasses and shrubs a foothold in the sand.
Once damaged, crusts may take many years to grow back. Areas that have been stripped of crusts are vulnerable to erosion, flooding, dust storms, loss of organic materials, and invasion by non-native weeds that thrive on disturbed soil.
Take a Closer Look
Looking through an electron microscope, one can see the sheaths and filaments that make up the crust. Additional scientific analysis reveals how crusts function.