In the absence of fire, shrubs became more abundant. In the early 1900's cheatgrass, an annual grass native to central Asia, became well established in much of the big sagebrush vegetation type of Nevada. Because cheatgrass is very flammable, today's fires are more frequent, occur earlier in the year, and when shrubs are involved, more intense than the presettlement fires. Fire readily kills some plants, rejuvenates others, and some may even require fire to exist. The manner in which plants are affected by fire is largely determined by their biological characteristics and fire behavior.
Some plants have the ability to sprout when the above ground portion has been burned.
Depending upon the plant species, sprouting can occur from roots, rhizomes, base of the trunk, branches, below ground root crown, and grass crowns. For some plants, the stage of growth determines the degree of damage from fire. Most perennial grasses, for example, are more susceptible to fire damage when actively growing than when dormant. Small grasses with many stems, for example, may burn at lower temperatures than larger leafier grasses and therefore may be more likely to survive a fire. Also, temperatures during a wildfire are usually less at ground surface that is conducive to the survival of small plants.