Zaca Uplands
Map SatelliteOn the north slope of a ridge to the east of Zaca Peak, on a serpentine-derived soil, stands the southernmost population of the Sargent cypress, Cupressus sargentii. This population is separated by 100 kilometers (60 miles) from the nearest population to the north which is on Cuesta Ridge in San Luis Obispo County (see Cuesta Ridge). The rare Caulanthus amplexicaulis var. barbarae occurs in this area.
Several plant communities are found here, including a woodland that contains digger pine, Pinus sabiniana, and ponderosa pine, Pinus ponderosa, as well as the cypress. Other communities include chaparral and grassland. The diversity of substrates and exposures has engendered a number of habitats within a small area. On the south slope, grass and shrub species run up the ridge with some stands of Pinus sabiniana. On the north slope are remnants of north coastal forest, with montane conifers near the top. On Zaca Peak the big-cone Douglas fir, Pseudotsuga macrocarpa, is at the western limit of its range.
Much of the area is exposed Franciscan formation, predominantly intrusive serpentine and greenstone. There are also some sharply folded rocks of the Monterey formation, dating to the Miocene.
Integrity: There are Forest Service roads in the area and the vegetation is grazed, sometimes overly so.
Use: Research, educational, observational, light recreation.
March 1977
Inventory of California Natural Areas
Revision © 2009 Steven Louis Hartman