Mesic to dry grassland in the steppe to subalpine zones (Douglas et al., 2001). Open pine and poplar forests; exposed bench lands in meadows (Pahl and Smreciu, 1999).
Deep, fertile, silt and clay soils (Pahl and Smreciu, 1999); Shallow and or strongly drained soils on stony and rocky sites; characteristic of Mor humus forms (Klinka et al., 1989).
Nitrogen-poor soils (Klinka et al., 1989).
Moist to dry.
Shade-tolerant (Klinka et al., 1989).
Late successional to climax. Less common in open forests.
Major component of three sub-communities: oak -Idaho fescue; oak-Idaho fescue-Cerastium arvense; and oak-Idaho fescue-Trifolium microcephalum.