Annual grass invasion in sagebrush steppe: the relative importance of climate, soil properties and biotic interactions

The invasion by winter-annual grasses (AGs) such as Bromus tectorum into sagebrush steppe throughout the western USA is a classic example of a biological invasion with multiple, interacting climate, soil and biotic factors driving the invasion, although few studies have examined all components together. Across a 6000-km(2) area of the northern Great Basin, we conducted a field assessment of 100 climate, soil, and biotic (functional group...