A Strategic and Science-Based Framework for Management of Invasive Annual Grasses in the Sagebrush Biome

Abstract

In the last 20 years, the North American sagebrush biome has lost over 500 000 ha of intact and largely intact sagebrush plant communities on an annual basis. Much of this loss has been associated with expansion and infilling of invasive annual grasses (IAGs). These species are highly competitive against native perennial grasses in disturbed environments, and create fuel conditions that increase both the likelihood of fire ignition and the ease of wildfire spread across large landscapes. Given the current rate of IAG expansion in both burned and unburned rangelands, we propose a range-wide paradigm shift from opportunistic and reactive management, to a framework that spatially prioritizes maintenance of largely intact, uninvaded areas and improvement of invaded habitats in strategic locations. We created a framework accompanied by biome-wide priority maps using geospatial overlays that target areas to MAINTAIN large, uninvaded areas as natural resource anchors through activities to prevent IAGs, IMPROVE areas where management success in restoring large, intact landscapes is most likely, and CONTAIN IAG infestations where necessary. We then offer three case studies to illustrate the use of these concepts and map products at multiple scales. Our map products operate at the biome scale using regional data sources and additional data sources will be needed to inform local conservation planning. However, the basic strategic management principles of (1) maintaining the intact and uninvaded areas that we can least afford to lose to IAGs, (2) improving areas where we have a reasonable likelihood of restoration success, and (3) containing problems where we must, are timely, relevant, and scalable from the biome to local levels.