Cheatgrass, wildfire and stand renewal process

Authors: Clements, Darin - Charlie; Harmon, Daniel - Dan

Submitted to: The Progressive Rancher
Publication Type: Popular Publication
Publication Acceptance Date: 1/21/2023
Publication Date: 2/6/2023
Citation: Clements, D.D., Harmon, D.N. 2023. Cheatgrass, wildfire and stand renewal process. The Progressive Rancher. 23(2):22-24.

Interpretive Summary:

Technical Abstract: Cheatgrass is native to the cold deserts of central Asia, which are very similar to the big sagebrush/bunchgrass and salt desert shrub ranges of the Intermountain Area of North America. Cheatgrass was first collected in Pennsylvania in 1861 and believed to be accidentally introduced in contaminated wheat and then dispersed from farm to farm and across railways through equipment and stock. By 1902, cheatgrass was identified in Nevada and reported to occur along railways, roadsides and croplands. By 1935, cheatgrass was abundant throughout the Wyoming big sagebrush/bunchgrass communities throughout the Great Basin. The central issue in any discussion of the ecological ramifications of cheatgrass invasion and dominance on Great Basin rangelands is the role cheatgrass plays in the stand renewal process. The stand renewal process is based on the premise that the species composition and dominance of a given community are highly influenced by how the tenure of the previous assemblage of plants on the site was terminated. It is easy to fall into the trap of believing that all of the ecological problems associated with cheatgrass in the Great Basin would be solved if wildfires were eliminated. Cheatgrass invades a community, not because of wildfire per se, but because of the relative lack of competition from degraded populations of perennial grasses. Cheatgrass also invades high ecological condition native plant communities because there is a niche available for a competitive annual grass that native plant species do not fill. Excessive, improperly timed, and annually repeated grazing enlarges the adaptive niche available to cheatgrass. Cheatgrass dominates because of this degradation and destruction of sagebrush by wildfires. Stands that become old, decadent and dense suppress perennial grasses that are needed to suppress the exotic and invasive annual, cheatgrass. Passive management of shrub communities ensures an increase in fuel loads, increased wildfire risks and the transformation of shrub communities to cheatgrass dominance. Active management of habitats to improve perennial grass densities decreases wildfire frequencies and allows for the return of critical browse species. Fire as a stand renewal process is an inherent part of the Great Basin ecology, especially in the big sagebrush/bunchgrass zone.