A relatively dense woodland, locally dominated by Pinus quadrifolia (72310) rather than Pinus monophylla, or with Juniperus californica (72320) conspicuous or even dominating xeric sites to the exclusion of any Pinus. Typical stands have scattered or clumped individuals emergent through relatively dense chaparral.
SITE FACTORS:
The Pinyon type is similar to but more mesic than Mojavean Pinyon Woodland (72220), with which it intergrades near its lower eastern (desert) margins; intergrades with Upper Sonoran Mixed, Chamise, or Red Shank chaparrals (37100-37300) along its lower western margin; also intergrades with Montane Coniferous Forests (84000) near its upper margin. The Juniper type is found on Alluvial fans and desert slopes, slightly lower and more xeric than the Pinyon type. Fuel loads usually are insufficient to carry a fire. The woodland species do not tolerate fire: burning this type usually leads to Semi-Desert Chaparral (37400).
DISTRIBUTION:
A conspicuous component of west-facing drainages in the desert transition from the San Jacinto Mountains south into northern Baja California.
Source: Adapted from Holland, 1986