A systematic review and meta-analysis of Old-World bluestem control in the United States

• In the United States, “Old-World” bluestems – non-native grasses from the genera Bothriochloa and Dichanthium – have become destructive invasive species in rangeland systems due to their aggressive spread, severe negative impacts on local biodiversity, and relatively poor forage value to livestock and native grazers. • Controlling Old-World bluestems is an important ecological and economic priority, but no attempts have been made to quantitatively synthesize the effectiveness of contemporary management practices. • Our objective was to conduct a systematic review and meta-analysis of Old-World bluestem management in the United States, with the goal of identifying practices providing effective control. • Our systematic review included 16 research articles satisfying our search criteria that resulted in 89 observations for meta-analysis. Selected studies were conducted in Texas, Oklahoma, and Kansas. • Burn, herbicide + burn, rain shelter + burn, and competition (e.g., overseeding) treatments significantly improved control of invasive bluestems. Counterintuitively, removal treatments resulted in a significant increase of invasive bluestems. Herbicides used singularly were not effective. • Old-World bluestems pose substantial threats to working ecosystems. Some practices afford effective control, but in general, the practical management of these invasive species is understudied.