Can Buffelgrass Invasions Be Controlled in the American Southwest? Using Invasion Ecology Theory to Understand Buffelgrass Success and Develop Comprehensive Restoration and Management

Abstract

Since being introduced for rangeland improvements in the early to mid-20th century, several non-native grass species have spread beyond their initial planting sites in the American Southwest. Many of these species, especially those that have infiltrated desert ecosystems, can alter fire regimes, which in turn threatens native plant species. In Arizona desert ecosystems, buffelgrass (Pennisetum ciliare) increases fire frequency and intensity, which may create a positive feedback loop, resulting in a shift from native fire-sensitive plant communities to non-native grasslands. Although control efforts are currently underway, a more comprehensive ecosystem approach will be required to treat buffelgrass invasions in southeastern Arizona's deserts. Here, we evaluate the species and environmental factors that may contribute to plant invasion success. We highlight empirical buffelgrass literature as it pertains to invasion, integrate basic invasion ecology theory and restoration ecology to examine potential practical approaches for controlling buffelgrass invasions in southeastern Arizona, and use this information to provide the basis for comprehensive restoration and management. We also briefly discuss public policy related to buffelgrass control in the southwestern United States.