Shrub–steppe

While arid, shrub-steppes have sufficient moisture to support a cover of perennial grasses or shrubs, a feature which distinguishes them from deserts.

Shrub-steppe plant species have developed particular adaptations to low annual precipitation and summer drought conditions.

Other important plants are bunchgrasses such as Pseudoroegneria spicata, which have historically provided forage for livestock as well as wildlife, but are quickly being replaced by nonnative annual species like cheatgrass (Bromus tectorum), tumble mustard (Sisymbrium altissimum), and Russian thistle (Salsola kali).

There is also a suite of animals that call the shrub-steppe home, including sage grouse, pygmy rabbit, Western rattlesnake, and pronghorn.

Historically, much of the shrub-steppe in Washington state was referred to as scabland because of the deep channels cut into pure basalt rock by cataclysmic floods more than 10,000 years ago.