Comparing common Buffelgrass ( Pennisetum ciliare ) removal techniques: cost efficacy and response of native plant community

Invasive species are one of the greatest threats to natural systems. Invasive buffelgrass ( Pennisetum ciliare ) displaces native plant communities, increases wildfire risk and extent, and disrupts ecological systems and processes. Cost-effective removal efforts that protect native plant communities are urgently needed. We conducted an experiment from 2018 to 2022 in 25 m 2 plots to compare efficacy, cost, and impact to native vegetation of P. ciliare removal techniques (combinations of manual removal, cutting, and herbicide applied at different frequencies each year) in the Sonoran Desert, Arizona, United States. None of the treatments were 100% effective at eradicating P. ciliare in the plots over the five years of the experiment, but herbicide applied 3+ times per year was the most effective. Manual removal was the least effective with the highest labor and supply costs; 9–12 times more expensive than herbicide once a year or 3+ times a year. When considering total costs, which include preparation and travel time, herbicide once a year and manual removal were most cost-effective for smaller areas, but herbicide 3+ times a year was cheapest for areas larger than 0.70 ha. Native plant cover and richness in the invaded treatment plots recovered to similar levels as uninvaded control plots after P. ciliare removals. Managers can use these results to select removal treatments based on a balance of convenience, resources, and scale of the infestation.