Fire regimes in sagebrush (Artemisia spp.) ecosystems have been greatly altered across the western United States. Broad-scale invasion of non-native annual grasses, climate change, and human activities have accelerated wildfire cycles, increased fire size and severity, and lengthened fire seasons in many sagebrush ecosystems to the point that current wildfire-management practices and postfire restoration efforts cannot keep pace to ameliorate the ecological consequences of sagebrush ecosystem loss. The greatest impact of uncharacteristically frequent fire is the transition from native sagebrush-perennial grass communities to invasive, non-native, annual grasslands that are highly flammable. These community transitions are often permanent, owing to the low probability of reestablishing native perennial plants in non-native annual grass–dominated communities. Moreover, these grasses can form extensive and continuous fine fuel loads that promote more frequent fire and the continued expansion of invasive, non-native annuals. More frequent, larger, and severe wildfires necessitate greater resources for fire-prevention, fire-suppression, and postfire restoration activities, while decreasing critical ecosystem services, economic and recreational opportunities, and cultural traditions. Increased flexibility and better prioritization of management activities based on ecological needs, including commitment to long-term prefire and postfire management, are needed to achieve notable reductions in uncharacteristic wildfire activity and associated negative impacts. Collaboration and partnerships across jurisdictional boundaries, agencies, and disciplines can improve consistency in sagebrush-management approaches and thereby contribute to this effort. Here, we provide a synthesis on sagebrush wildfire trends and the impacts of uncharacteristic fire regimes on sagebrush plant communities, dependent wildlife species, fire-suppression costs, and ecosystem services. We also provide an overview of wildland fire coordination efforts among federal, state, and tribal entities.

Wildfires are a growing management concern in western US rangelands, where invasive annual grasses have altered fire regimes and contributed to an increased incidence of catastrophic large wildfires. Fire activity in arid, nonforested ecosystems is thought to be largely controlled by interannual variation in fuel amount, which in turn is controlled by antecedent weather. Thus, long-range forecasting of fire activity in rangelands should be feasible given annual estimates of fuel quantity. Using a 32-yr time series of spatial data, we employed machine learning algorithms to predict the relative probability of large (> 405 ha) wildfire in the Great Basin based on fine-scale annual and 16-d estimates of cover and production of vegetation functional groups, weather, and multitemporal scale drought indices. We evaluated the predictive utility of these models with a leave-1-yr-out cross-validation, building spatial hindcasts of fire probability for each year that we compared against actual footprints of large wildfires. Herbaceous aboveground biomass production, bare ground cover, and long-term drought indices were the most important predictors of burning. Across 32 fire seasons, 88% of the area burned in large wildfires coincided with the upper 3 deciles of predicted fire probabilities. At the scale of the Great Basin, several metrics of fire activity were moderately to strongly correlated with average fire probability, including total area burned in large wildfires, number of large wildfires, and maximum fire size. Our findings show that recent years of exceptional fire activity in the Great Basin were predictable based on antecedent weather-driven growth of fine fuels and reveal a significant increasing trend in fire probability over the past 3 decades driven by widespread changes in fine fuel characteristics.

Spatial and temporal dynamics of rangeland fuels is a primary factor driving large wildfires. Yet detailed information capturing variation in fine fuels has largely been missing from rangeland fire planning and fuels management. New fuels-based maps of Great Basin rangeland fire probability help bridge this gap by coupling dynamic vegetation cover and production data from the Rangeland Analysis Platform with weather and climate data to provide annual forecasts of the relative probability of large wildfire. In this paper, we review these new fuels-based maps and discuss implications for prefire planning, preparedness, and strategic fuels management. Examining patterns of fire probability through time reveals high spatial and temporal variation in risk of large wildfires across the Great Basin. Certain areas are chronically impacted with high fire probability most years, while others have more sporadic or low probability of large fire annually. Maps confirm previous research that the recent increase in large fire risk in the region is highly associated with invasive annual grasses, but total aboveground herbaceous production (including perennials) continues to be a primary predictor of fire probability. Fuels-based fire probability maps can be used alongside existing data sources and prioritization frameworks by fire and fuels managers to inform questions of 1) what kind of fire year might this be, 2) where large fires are most likely to occur given an ignition, and 3) where resources should be focused. We provide examples of how maps can be used to improve prefire preparedness and planning to enhance suppression, facilitate annual targeting of fine fuels reductions, and support land use planning for implementation of landscape-scale fuels management. Proactively incorporating this new information into rangeland fire and fuels management can help address altered fire regimes threatening the region's wildlife and working lands.

Limiting fire in Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis [Beetle & A. Young] S.L. Welsh) steppe is often a management priority as fires threatens its ecological integrity and rural economies that depend on it. However, the Wyoming big sagebrush steppe is vast and occurs in different community states from intact (sagebrush-bunchgrass dominated) to exotic annual grass dominated. Grazing has been suggested as the only tool that is likely feasible to apply across such large landscapes to manage fine fuels, but there is concern that over time grazing may induce undesirable shifts in plant community composition (e.g., increases in exotic annuals) that increase fire risk. Therefore, we evaluated the longer-term (+10 yr) effects of contemporary, moderate grazing by cattle compared with grazing exclusion on fuel characteristics in three community states: intact, degraded, and exotic annual grass states. We accomplished this by measuring fuel characteristics in five grazed and ungrazed areas in each community state in 2020 and 2021. Grazing generally decreased fine fuel continuity and biomass and increased the live-to-dead ratio. These fuel alterations are consistent with decreasing the probability of fire ignition and, if ignited, producing a slower spreading fire with shorter flame lengths. The response of several fine fuel characteristics to grazing varied by community state. Fine fuel characteristics also commonly varied among community states and between years. These results suggest that fuel management plans need to recognize that grazing effects will vary by community state and be flexible because fuel characteristics vary spatially and temporally. Overall, our results suggest that contemporary grazing in the Wyoming big sagebrush steppe reduces the probability of wildfire and likely increases the effectiveness and safety of fire suppression. Consequently, grazing exclusion in these communities increases the probability of frequent, large wildfires that are difficult and dangerous to suppress.

Wildfire activity is accelerating on many rangelands worldwide, yet the potential for grazing to be used as a fire management tool remains largely unknown. Particularly, little is known about the influence of grazing on ignition and initial spread of fire, as well as how these vary by differences in grazing management. We investigated effects of grazing intensity (light, moderate, high) on fuel characteristics, fire ignition, and initial spread during the wildfire season in a native-dominated shrub steppe in eastern Oregon. We found that differences in grazing intensity have differential effects on fuel profiles (cover, height, moisture, biomass) with resulting impacts on fire behavior, but these relationships varied across study years. In particular, grazing had a stronger effect on ignition probability in drier years. Fire behavior in lightly grazed plots were similar to ungrazed plots, while moderate grazing was similar to high-intensity grazing. Results of this study highlight that grazing can be useful as a tool for wildfire management, and grazing at moderate and high intensities can reduce the probability of fire propagation in native-dominated sagebrush ecosystems. Further, the effects of grazing are context dependent and therefore may depend on specific objectives and environmental conditions.

Management of areas invaded by cheatgrass (Bromus tectorum) continues to be one of the greatest challenges for US Great Basin ecosystems. Targeted cattle grazing in the fall and winter has shown positive results as a management tool to reduce dormant fine fuel biomass within cheatgrass-invaded areas, but management of targeted grazing within large pastures can be challenging. We evaluated the use of strategically placed liquid protein supplement stations over a 4-wk period in the fall to focus cattle grazing along a linear transect stretching away from water to reduce residual cheatgrass biomass on a production-scale, working ranch from 2014 to 2017. Liquid protein supplement stations were moved approximately 1 km farther from water during each week of the study, eventually reaching 4 km from a single water source. Global Positioning System–tracked cattle visited supplement stations 52% ± 4% of the days during the study period and were within 100 m of the supplement station transect line 17.7% ± 2.6% of the time: more than 3 × greater (P= 0.07) than random locations (5.1% ± 2.6%). Week of the study and the subsequent supplement distance from water did not influence the number of visits cattle made to supplement. The duration that cattle remained at supplement was greater in wk 4, when supplement was placed 4 km from water, compared with wk 1 and 2, when the supplement was 1 and 2 km from water, respectively. At the conclusion of grazing, utilization along the supplement station transect averaged 66.0% ± 5.7% and did not differ between supplement stations at 1 km, 3 km, or 4 km from water. Strategic supplementation provides a valuable tool to target cattle grazing at specific locations within cheatgrass-invaded systems to reduce fine fuel buildup during the dormant season.

Invasive and highly flammable annual grasses continue to alter wildfire regimes across rangelands of the western United States. These hazardous fuels have contributed to the increasing prevalence of western megafires in recent decades. It is clear that existing rangeland fuel management strategies are challenged to keep pace with this growing threat. Targeted livestock grazing, however, might serve as a novel and effective fuels management tool that could be wielded at a scale commensurate with the annual grass–wildfire problem. Unfortunately, this practice has lacked a rigorous scientific foundation to support broad-scale application and 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-h 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. One targeted grazed fuel break in this research successfully intercepted three wildfires in 4 yr conserving sage-grouse habitat downwind. Although additional research is required, these findings suggest targeted grazing provides an effective means of reducing fine fuels while avoiding adverse ecosystem impacts. Some expected outcomes from the use of this tool would be improved wildland firefighting safety and efficacy, reduced wildfire size, and enhanced protection of human lives, property, and critical natural and cultural resources within the broad scope of annual grass-wildfire problem.

Wildfires are increasingly impacting ecosystem processes and ecological services provided by sagebrush rangelands in the western United States. Mitigating this problem involves actions taken before, during, and after fire. In recent years, there has been increased emphasis on prefire fuel management, including fuel breaks. Cattle grazing can be used as a tool to manage fine fuel loading within fuel breaks; however, spatially focusing grazing impacts inside a linear fuel break is challenging. We evaluated using virtual fencing (VF) technology for concentrating grazing impacts inside a 200-m wide, 3-km long fuel break within a 410-ha pasture in sagebrush steppe. The fuel break was bounded by four 35-m wide virtual fences, each consisting of boundaries for auditory (10-m wide) and electrical cues (25-m wide), and a traditional 5-strand barbed wire perimeter fence delineated the pasture perimeter. In June 2021 we introduced 16 dry cows and 23 cow/calf pairs into the fuel break following a 5-d VF training period; cattle were removed after 30 d. Cows were fitted with VF collars (calves not collared) that use Global Positioning System positioning to contain cattle inside fuel break boundaries and record animal locations at 5-min intervals. End-of-trial forage utilization was 48.5% ± 3.7% and 5.5% ± 0.7% for areas inside and outside of the fuel break, respectively. Daily percentage of cattle locations inside the fuel break was initially > 94% but declined to approximately 75% by the end of the trial. Percentage daily locations of dry cows and cow/calf pairs inside the fuel break was 98.5% ± 0.5% and 80.6% ± 1.1%, respectively (P < 0.001). Our data suggest virtual fencing can be a highly effective method of concentrating grazing to reduce herbaceous fuel biomass within linear fuel breaks. Efficacy of this method could be substantially impacted by use of dry versus cow/calf pairs.

Rangeland wildfire is a wicked problem that cuts across a mosaic of public and private rangelands in the western United States and countless countries worldwide. Fine fuel accumulation in these ecosystems contributes to large-scale wildfires and undermines plant communities' resistance to invasive annual grasses and resilience to disturbances such as fire. Yet it can be difficult to implement fuels management practices, such as grazing, in socially and politically complex contexts such as federally managed rangelands in the United States. In this Research-Partnership Highlight, we argue that private-public partners in such settings must be strategic in their selection of tasks to generate “small wins” in order to build the trust, competency, and legitimacy needed to advance an approach for landscape-scale fine fuels management. We highlight a fine fuels reduction partnership consisting of public and private entities in southeastern Oregon that established a research and education project and applied dormant-season grazing on three pastures within the Vale District Bureau of Land Management. We describe the impetus for the partnership, antecedents, strategic tactics, and ongoing learning and reflection used to revise processes. In this example, implementing dormant-season grazing as a research and education project allowed the partners to assess the efficaciousness of the treatment, as well as the operational logistics and administrative competencies necessary to apply the treatment to manage fine fuels at broader scales. Because dormant-season grazing may, in some instances, conflict with established practices and norms, small-scale projects such as this allow partners to refine understandings of the social and administrative conditions that make implementation possible. Generating small wins through projects such as this is a critical precursor for partnerships seeking to take on larger, more complex endeavors that involve increasing ecological, economic, and social uncertainty.

Research continually adds to our understanding of the ecological factors and biophysical processes driving frequent, large-scale fires on Great Basin rangelands in the western United States. Yet even with advances in forecasting rangeland fire probabilities and likely ecological outcomes of fire, it remains difficult for individuals, communities, or organizations to coordinate their actions across jurisdictions and at an ecologically relevant scale to address collective wildfire risk. In this forum, we discuss current institutional arrangements that perpetuate scale mismatches in this system; that is, institutional objectives, authorities, and capacities that limit coordinated actions to mitigate collective wildfire risk. We make a case for fireshed-scale coordination via rangeland Fireshed Councils, proposed rangeland and fire planning and management units that have both biophysical and social relevance to individuals and organizations engaged in fire risk mitigation. A rangeland Fireshed Council offers a venue for diverse group members to mix and match their respective rules and tools to navigate institutional barriers and capacity challenges in new ways. Operating in a collective arrangement at this scale aims to ensure that an individual's or entity's activities transcend traditional modes of planning (i.e., parcel-scale), complement concurrent management activities, and translate to fire-resilient landscapes and human communities. Rangeland Fireshed Councils will require resources and support from high governance levels for sustainability and legitimacy and relative autonomy to determine how best to support local needs.

Sagebrush ecosystems in the United States have been declining since EuroAmerican settlement, largely due to agricultural and urban development, invasive species, and altered fire regimes, resulting in loss of biodiversity and wildlife habitat. To combat continued conversion to undesirable ecological states and loss of habitat to invasive species fueled by frequent fire, a variety of fuel treatments, including networks of fuel breaks, are being implemented or proposed in sagebrush ecosystems, particularly in and around the Great Basin. In this forum paper we briefly review current knowledge of common fuel treatment approaches, their intended benefits, potential risks, and limitations. We additionally discuss challenges for fuel treatment strategies in the context of changes in climate, invasive species, wildlife habitat, and human population, and we explore how advances in geospatial technologies, monitoring, and fire behavior modeling, as well as accounting for social context, can improve the efficacy of fuels management in sagebrush ecosystems. Finally, given continued potential for ecosystem transformation, we describe approaches to future fuels management, by considering the applicability of the Resist-Accept-Direct framework. The intent of this paper is to provide scientists and land managers with key information and a forward-thinking framework for fuels science and adaptive management that can respond to both expected and unexpected changes in sagebrush rangelands.