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.
Resources & Links
Read an associated paper detailing how the Defend the Core strategy is being implemented to address invasive annual grasses in Oregon here.
Read more about the Defend the Core strategy here.
Jeremy D. Maestas, Mark Porter, Matt Cahill, Dirac Twidwell, Defend the core: Maintaining intact rangelands by reducing vulnerability to invasive annual grasses, Rangelands, Volume 44, Issue 3, 2022, Pages 181-186, ISSN 0190-0528.
New geographic strategies provide the landscape context needed for effective management of invasive annual grasses in sagebrush country.
Identifying and proactively defending intact rangeland cores from annual grass invasion is a top priority for management.
Minimizing vulnerability of rangeland cores to annual grass conversion includes reducing exposure to annual grass seed sources, improving resilience and resistance by promoting perennial plants, and building capacity of communities and partnerships to adapt to changing conditions and respond to the problem with appropriate actions in a timely manner.