Defend the core: Maintaining intact rangelands by reducing vulnerability to invasive annual grasses

Science in Practice

From the Great Plains to the Great Basin, an onslaught of invasive plants, including unwanted grasses like cheatgrass or woody species like eastern redcedar, are degrading rangeland health and agricultural productivity. A new paradigm in rangeland conservation and management is emerging to tackle this threat. Succinctly captured in the phrase “Defend the Core,” this approach leverages spatial data to focus rangeland management on proactive and preventative efforts that address large-scale threats within otherwise intact landscapes, or “cores.” By applying a common vulnerability-based model to threat reduction, the authors describe how land managers can reduce the risk of annual grass invasion by implementing guiding actions at the scales needed to perpetuate healthy and resilient sagebrush rangelands. Satellite-based technology is key to providing critical landscape context missing from past local management, allowing rangeland managers to visualize rangeland vegetation cover at a variety of scales, from pastures to entire biomes. This allows managers to identify large and intact rangeland cores where invasion is minimal and proactive and preventative measures can still be taken to reduce risks. Understanding this landscape context allows managers to focus the right actions in the right place at the right time. For example, eliminating small infestations within a large, intact core landscape can help managers more effectively and efficiently prevent those infestations from expanding into the surrounding landscape. Conversely, attempting to save isolated islands of uninvaded lands in a landscape dominated by annual grasses is unlikely to have long-term success and requires different crisis mitigation strategies.