Crossing the fence? Buffelgrass (Cenchrus ciliaris L.) spreading along the coastal scrub of Baja California, Mexico.

摘要

Buffelgrass (Cenchrus ciliaris L.) is one of the most invasive species of plants in arid lands of North America, especially in the Sonoran Desert. The climatic niche described by previous studies for this species suggests that the climatic conditions of its adjacent Mediterranean region are a constraint on the establishment of buffelgrass. However, collections registered in recent years in herbaria and repeated observations of its presence along roadsides in the coastal scrub of Mediterranean Baja California would suggest the opposite. To analyze this apparent contradiction, we surveyed the principal paved roads of the northern half of Baja California peninsula, established its current distribution along roadsides, and contrasted the climatic conditions of the observed distribution with the climatic niche established in the literature. We found buffelgrass to be scant with scattered distribution in the Sonoran Desert and, contrastingly, widespread in the Mediterranean Region. About half of the observed distribution of buffelgrass in the Mediterranean Region (42%) has climatic conditions to persist and even spread.