Assessing Restoration and Management Needs for Ecosystems Invaded by Exotic Annual Bromus Species

Invasive annual grass research and management in arid and semiarid ecosystems of the Western United States (USA) have historically focused on reducing weed abundance as opposed to ecosystem restoration, which addresses the underlying processes responsible for their persistence. Given the current impact of invasive annual grasses and their continued spread in this region, we identified common characteristics responsible for persistence of the most problematic exotic annual Bromus. For heavily invaded areas, these include transient, yet typically large seed banks, altered soil resource availability and litter production, displacement of native species, and frequent disturbance from fire. To better address these common characteristics for future management, we illustrate how an adaptive management framework can reduce existing uncertainty associated with the restoration of arid and semiarid ecosystems. We also assess how research and management influence these characteristics with a case study of treatment outcomes for Bromus tectorum L. (cheatgrass or downy brome) control and a case study of current approaches used by the US Department of Interior’s Bureau of Land Management to restore landscapes impacted by B. tectorum and improve greater sage-grouse (Centrocercus urophasianus) habitat in the Great Basin region of the Western USA. We conclude that adapting for the future will require continued integration between research and management, greater inclusion of ecological processes, and long-term experiments to inform adaptive management decisions.