Fire and Grazing Influence Site Resistance to Cheatgrass Invasion

Release Date:

Shrubs, bunchgrasses, and biological soil crusts (biocrusts) are believed to contribute to site resistance to plant invasions. 

USGS scientists Lea Condon and David Pyke tested the idea that biotic communities mediate the effects of disturbances such as fire and grazing on site resistance by using structural equation modeling to test relationships between disturbance events, the biotic community, and resistance to cheatgrass invasion. Increased site resistance following fire was associated with higher bunchgrass cover and recovery of bunchgrasses and mosses with time since fire. Fire reduced near-term site resistance to cheatgrass on actively grazed rangelands, and evidence of grazing was more pronounced on burned sites and was positively correlated with cheatgrass cover. Independent of fire, grazing impacts resulted in reduced site resistance to cheatgrass, suggesting that grazing management that enhances plant and biocrust communities will also enhance site resistance.

Condon, L.A., Pyke, D.A., 2018, Fire and grazing influence site resistance to Bromus tectorum through their effects on shrub, bunchgrass and biocrust communities in the Great Basin (USA): Ecosystems, https://doi.org/10.1007/s10021-018-0230-8.

Related Content

Filter Total Items: 1
Date published: November 28, 2017
Status: Active

Restoration and Ecology of Arid Lands Team (FRESC)

The focus of our research is on the restoration and monitoring of the plants and soils of the Intermountain West. Our lab is part of the Snake River Field Station, but is located in Corvallis, Oregon. Research topics include fire rehabilitation effects and effectiveness, indicators of rangeland health, invasive species ecology, and restoration of shrub steppe ecosystems.

Contacts: David A Pyke
Filter Total Items: 1
Date published: January 1, 2018

Disturbance characteristics, vegetation and biocrust cover from the northern Great Basin (USA) 2012-2013

Fifteen fires from the Chronosequence dataset (see Knutson et al. 2014) were visited in 2012 and 2013 and surveyed for cover of lichens and mosses. Fires were selected to cover the range of average precipitation for each of three water years following fire, fire severity, time since fire, season of ignition, total acres burned and grazing intensity. Cattle grazing was characterized by distance...

Filter Total Items: 2
Date published: November 2, 2018

Effects of Disturbance on Vascular Plants and Biocrusts in Sagebrush Steppe

Semi-arid sagebrush ecosystems experience chronic disturbances through grazing, invasive grasses, and acute disturbance of fire. Biocrusts, a community of cyanobacteria, mosses, and lichens, develop on soil surfaces and contribute to the land’s resistance to invasive plants. 

Date published: October 14, 2016

Experiments to Help Restore Mosses in Arid Lands

Biological soil crusts are beneficial to arid ecosystems and occupy bare ground, deterring establishment of invasive annual grasses.