Long-term effects of restoration treatments in invaded Wyoming big sagebrush
Western US sagebrush ecosystems are threatened due to multiple interacting factors: encroachment by conifer woodlands, exotic annual grass invasion, severe wildfire, climate change, and anthropogenic development. Restoration of these communities is primarily focused on reducing conifer species such as western juniper, with the goal of increasing native herbaceous perennials and sagebrush and decreasing exotic annual grass invasion. Assessing the long-term success of restoration treatments is critical for informing future management and treatment strategies since short-term patterns do not generally predict long-term trends. Using a designed experiment from a Wyoming big sagebrush community that was established in 2008, we examined the long-term vegetation response to juniper removal and seeding (cultivar and local) in disturbed and undisturbed areas (slash pile, skid trails, no disturbance). We also examined the landscape scale plant response to juniper removal using repeatedly measured randomly located transects across two restoration units. We found that seeded species persisted in the long term and also mitigated exotic grass increases.