Newly expanded visual tool on the SGI Web App allows managers to better predict and mitigate negative impacts of fire and cheatgrass across sagebrush range.
Photo: The updated rangewide Resilience & Resistance map helps facilitate rapid risk assessments and prioritize resources in fighting the twin threats of wildfires and weeds.
In sagebrush country, invasive weeds like cheatgrass present one of the biggest threats to rangeland health and wildlife habitat. The spread of this invasive annual grass is linked to more frequent wildfires because it’s more flammable than native plants. These fires create a vicious loop — once the sagebrush sea’s diverse, native plants (like sagebrush, wildflowers, and perennial bunchgrasses) burn, it sets them back and opens the door for cheatgrass. Too often, the burned landscape is replaced with more weeds that further accelerate the fire cycle. That’s bad news for sage grouse and livestock, which both depend on native range plants as a reliable source of food and cover.
Three years ago, the NRCS-led Sage Grouse Initiative joined forces with interagency partners to begin working on ways to better address the twin threats of invasive cheatgrass and wildfire. A team of experts from across the range developed a strategic framework for prioritizing management actions by capitalizing on the variability in the sagebrush ecosystem’s resilience to wildfire and resistance cheatgrass invasion. “Resistance” means the landscapes ability to keep weeds at bay. “Resilience” means the landscapes ability to recover the ecosystem’s structure, function, and processes after a disturbance like fire (as opposed to slipping toward a different ecosystem dominated by invasive species).
Picture a valley framed by mountains, a common landscape in sagebrush country. In the valley, the soils are typically warmer and drier — a fragile environment with prime conditions for cheatgrass to dominate once it takes hold. But as you go up in elevation, the climate gets wetter and cooler, leaving native perennials better equipped to outcompete weeds. These higher elevation areas tend to be more resilient to fire and resistant to cheatgrass, but expanding conifers pose a threat to healthy sagebrush habitats by outcompeting native understory plants.
Although managers on the ground understood this risk variability, they lacked the ability to visualize it across large landscapes. Based on widely available NRCS soil survey data, a team of experts created an “R&R” index which uses soil temperature and moisture regimes as the key predictors of resilience and resistance. Using existing science and expert input, the team rated each soil type based on its relative R&R (high, moderate, or low) to help facilitate rapid risk assessments and prioritize resources in fighting both wildfires and weeds.
Initially, this team focused on creating an R&R risk map and decision support information for the western portion of sage grouse range, since the Great Basin experiences the biggest impacts from fire and invasive grasses. Now, a brand new publication applies the same concepts across the eastern portion of the range, too, showing relative risk levels in Montana, Wyoming, and Colorado—including Gunnison sage-grouse country. The new comprehensive map, available here on the SGI Interactive Web App, now provides a complete rangewide perspective. The R&R map is most useful for landscape-level planning and is meant to be combined with local knowledge of site conditions to design specific treatments.
R&R concepts and tools have already proven useful for communicating risks and helping reduce the costly impacts of wildfire and invasive grasses over time. For example, this risk-based framework was a key component underpinning the Department of Interior’s new Integrated Rangeland Fire Management Strategy. The Bureau of Land Management, U.S. Forest Service, NRCS, and other SGI partners are now beginning to apply these tools to help target practices and resources where they’re needed most for wildfire prevention, suppression, and rehabilitation, including pre-positioning of firefighting resources, strategic placement of fuel breaks, removal of conifers, cheatgrass treatments, and native plant seeding.
Not only does the R&R index depict the threat of cheatgrass across the West, it also helps us work together to keep the sagebrush sea and its grazing lands thriving. SGI staff and our partners have authored several papers explaining the R&R approach, including recent research in peer-reviewed literature that further strengthens the science foundation.
> Read our Science to Solutions study on reducing threats from weeds and fire
> Use SGI’s Interactive Web App to map ecosystem resistance to cheatgrass near you
> Learn more about how to manage for healthy, diverse plants