A fire-maintained, variable forest dominated by Pinus attenuata that may reach 25-30m, though usually closer to 15m tall. Stands usually are even-aged except on relatively "fire-proof", rocky sites. Understories usually are sparse scatters of chaparral shrubs whose composition varies greatly over the type's range.
SITE FACTORS:
Shallow, dry, stoney sites, often on serpentine or other magnesium-rich ultramafics that limit effective conifer competition. Adapted to frequent fires by means of very early and abundant production of seeds, which are retained in the closed cones until released by the heat of a fire. Similar to Bishop Pine Forest (83120), but in more interior, hotter and drier localities, where growth is probably more limited by drought in summer. Often associated with Serpentine Chaparral (37600), Chamise Chaparral (37200) or Californian Mixed Chaparral (37110). On better-developed or nonserpentine soils, may intergrade with Broadleaved Upland Forest (81000), North Coast Coniferous Forest (82000) or Lower Montane Coniferous Forest (84000).
DISTRIBUTION:
Abundant in the Siskiyou, Klamath and North Coast Ranges away from the immediate coast, from southwestern Oregon to southern Sonoma and Napa counties. On Mt. Diablo, Contra Costa Co. Abundant in the Santa Cruz Mtns. in Santa Cruz and Santa Clara counties. In the Santa Lucia Mtns. of Monterey Co. and near San Luis Obispo. Eastward from the Klamath Mtns. across the southern Cascade Range to Modoc Co. On the west slope of the Sierra Nevada from Sierra to El Dorado counties and Mariposa Co. Also in the San Bernardino Mtns. and Santa Ana Mtns. in southern California, and near Ensenada, Baja California. Elevation usually between 1,000-5,000 feet (300-1500m), occasionally to 6,000 feet (1800m).
UPDATE: 10/86
Source: Holland, 1986
Digital Text: NatureBase