干旱区生态环境知识资源中心

We examined relationships between land disturbance and the extent and abundance of exotic buffelgrass (Pennisetum ciliare) at the interface of cultivated pastures and native desert lands in Sonora, Mexico. Plot and transect surveys of lands inside and outside pasture fences and general linear mixed models revealed complex relationships among buffelgrass, native vegetation, distance from pasture fences, and three categories of land disturbance (undisturbed, moderate, and severe). Results illustrate that buffelgrass invasion is extensive in lands surrounding pastures, and that buffelgrass abundance declines steeply with distance from pasture fences. The role of disturbance is weak but significant in its interaction with distance from the fence. Buffelgrass is more successful at colonizing severely disturbed lands than native vegetation, and its decline in abundance on severely. disturbed lands is relatively more gradual than on other disturbance regimes, so landscapes where severely disturbed lands are interspersed with buffelgrass pastures could become centers of extensive buffelgrass invasion. In light of its potential to transform the Sonoran Desert, bnffelgrass outside pastures warrants attention in a region-wide control scheme, as well as in future research, which ideally would involve remote sensing.