Evaluating the efficacy of targeted cattle grazing for fuel break creation and maintenance

Authors: Clark, Pat; Porter, Benjamin; PELLANT, MIKE - Retired Non ARS Employee; DYER, KATHRYN - Bureau Of Land Management; NORTON, TYLER - Us Geological Survey (USGS)

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/17/2023
Publication Date: 3/21/2023
Citation: Clark, P., Porter, B.A., Pellant, M., Dyer, K., Norton, T. 2023. Evaluating the efficacy of targeted cattle grazing for fuel break creation and maintenance. Rangeland Ecology and Management. 89:69-86. https://doi.org/10.1016/j.rama.2023.02.005.
DOI: https://doi.org/10.1016/j.rama.2023.02.005

Interpretive Summary: Targeted livestock grazing might serve as an effective fuels management tool that could be wielded at a scale commensurate with the annual grass-wildfire problem of the western U.S., however, this practice lacks a rigorous scientific foundation to support management and policy decision making. In a broad-scale experiment distributed across the northern Great Basin of Idaho, Nevada, and Oregon during 2017-2021, we evaluated the efficacy of targeted beef cattle grazing, applied during the spring, for reducing herbaceous fuel heights, loads, and continuity while maintaining ecosystem health in fuel breaks strategically positioned between invaded, fire-prone landscapes and wildland-urban interface, greater sage-grouse (Centrocercus urophasianus) habitat, and other critical resources threatened by wildfire damage. We found this targeted grazing treatment reduced total herbaceous and cheatgrass fuel heights and in some cases, total 1-hour and cheatgrass fuels loads and fuel continuity while producing no consistent adverse effects or trends in ecosystem health within the fuel break treatments relative to nominally-grazed controls. Although additional research is required, these findings suggest targeted grazing provides an effective means of reducing fine fuels, while avoiding adverse ecosystem impacts, which in turn, can improve wildland firefighting safety and efficacy, reduce wildfire size, protect human lives, property, and critical natural and cultural resources using a tool (cattle grazing) widely available to ranchers, private landowners, rural fire districts, and natural resource management agencies at the scope of the annual grass-wildfire problem.

Technical Abstract: Invasion of introduced and highly flammable annual grasses continues to alter wildfire regimes across rangelands of the western United States, contributing to the increasing prevalence of megafires in recent decades. It is clearly evident that existing rangeland fuel management strategies are challenged to keep pace with this growing threat. Targeted livestock grazing might serve as an effective fuels management tool that could be wielded at a scale commensurate with the annual grass-wildfire problem, however, this practice lacks a rigorous scientific foundation to support management and policy decision making. We evaluated the efficacy of targeted beef cattle grazing, applied during the spring, for reducing herbaceous fuel heights, loads, and continuity while maintaining ecosystem health in fuel breaks strategically positioned between invaded, fire-prone landscapes and wildland-urban interface, greater sage-grouse (Centrocercus urophasianus) habitat, and other critical resources threatened by wildfire damage. Our broad-scale experiment was conducted during 2017-2021 as three replicate research projects distributed across the northern Great Basin of Idaho, Nevada, and Oregon. We found targeted grazing in spring reduced total herbaceous and cheatgrass fuel heights and in some cases, total 1-hour and cheatgrass fuels loads and fuel continuity, while producing no consistent adverse effects or trends in ecosystem health within the fuel break treatments relative to nominally-grazing controls. Although additional research is required, these findings suggest targeted grazing provides an effective means of reducing fine fuels, while avoiding adverse ecosystem impacts, which in turn, can improve wildland firefighting safety and efficacy, reduce wildfire size, protect human lives, property, and critical natural and cultural resources using a tool (cattle grazing) widely available to ranchers, private landowners, rural fire districts, and natural resource management agencies at the scope of annual grass-wildfire problem.