Trampling breaks up the sheaths and filaments holding the soil together and reduces the capability of the soil organisms to function, particularly in nitrogen fixation and soil holding capability. Sagebrush, saltbush, and winterfat may have allelopathic effects on the nitrogen fixing capabilities of crusts. Crusts can be buried by eroding soils. They can tolerate shallow burial by extending sheaths to the surface to begin photosynthesis again. Deeper burial can kill them.
Fire is a common component of many regions where crusts grow.
Fire can cause severe damage to crusts, but recovery is possible. Intensity of fire can make a difference. Low intensity fires do not remove all the structure of crusts allowing for regrowth without significant soil loss. Management Implications Recreation Recreational activities have impacts similar to large animals. The major difference is that people are harder to control.