Description:
<jats:title>Abstract</jats:title><jats:sec><jats:title>Question</jats:title><jats:p>How does type of disturbance alter plant community composition when an invasive species with high intrinsic population growth rate is present? The sagebrush steppe is a cold semi‐arid steppe dominated by the native shrub <jats:italic>Artemisia tridentata</jats:italic> Nutt., native bunchgrasses, and has been invaded by the non‐native winter annual <jats:italic>Bromus tectorum</jats:italic> L.</jats:p></jats:sec><jats:sec><jats:title>Location</jats:title><jats:p>Sagebrush steppe, Montana, USA.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>We assessed the effect of fire and soil disturbance, due to bulldozing to create a firebreak, on the resilience of plant communities and their resistance to invasion by <jats:italic>B. tectorum</jats:italic>. Plant species richness and species composition were monitored for 3 years at two sites post‐fire and firebreak construction.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Burned plant communities were resilient and had similar native grass cover and native species richness compared with the unburned sites after 3 years. Soil disturbance from firebreak construction resulted in species composition that was distinct and had lower native grass cover. Type of disturbance also affected the community's resistance to <jats:italic>B. tectorum</jats:italic>. <jats:italic>Bromus tectorum</jats:italic> cover was similar in burned and unburned areas, but increased up to three times and remained high where soil disturbance occurred, suggesting a shift to an alternative state.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>In this northern portion of the sagebrush steppe, communities with native plant cover were resilient to fire but not soil disturbance, which facilitated <jats:italic>B. tectorum</jats:italic> increase and a transition to an alternative state. In areas of high native plant cover, management tactics should avoid soil disturbance.</jats:p></jats:sec>