Endemic to California, USA where altered fire regimes and ubanisation are the main threats
USA distributed in the Coast Ranges of central and northwestern California: Mendocino, Sonoma and Monterey Counties. Found in the following localities: 1) SW slope of Huckleberry Hill, Monterey Peninsula; 2) Cypress Point Pine Barrens, near a large water reservoir close to Seventeen Mile Drive; 3) A seaward hill slope near Gibson Creek, well above Point Lobos State Park road; 4) Canyon of Gibson Creek ca. 2 miles east of Point Lobos; and 5) Pacific Grove, Monterey peninsula; 6) the "white plains" or "pine barrens" of Mendocino County (sometimes referred to as subsp. pigmaea).
This nominate variety is known from less than 2000 mature individuals scattered between about 10 subpopulations in 5 localities. It is unlikely that any of these subpopulations contains more than 250 mature individuals. The dwarf form can produce seed cones when only a few decimeters tall, but in very low quantities. Strictly speaking these are also mature individuals and if counted as such could increase these numbers.
Habitat and Ecology
This variety grows in chaparral, in “pine barrens” [large stands of pines (Pinus spp.)], on sandstone outcrops, on white or yellow sandy slopes and on leached, sometimes sterile sandy “hardpan” which causes the dwarfed individuals (“pigmaea”). In some areas it is a component of closed-cone pine-cypress woodlands.
Used in southern Europe as an ornamental tree in gardens and parks.
This variety meets the B criterion for Endangered due to its limited area of occupancy (AOO) even when calculated with an enlarged grid width of 4km due to missing map points in the northernmost subpopulation (formerly recognized as subsp. pigmaea). A continuing decline is suspected due to fire exclusion and indirect threats associated with urban developments.
There are threats from development (urbanization, making and maintenance of golf courses, road building), erosion, invasive non-native species and agriculture. Altered fire regimes through fire suppression can favour Pinus spp. and could reduce the fecundity of mature cypress trees, which rely on fire for opening the cones and subsequent release of seeds.
This variety occurs in S.F.B. Morse Botanical Reserve and Point Lobos Reserve (Monterey Co.) and outside reserves along the coast in Mendocino and NW Sonoma Counties. The S.F.B. Morse Botanical Reserve is located within the Gowen Cypress Planning Area in two parcels to the south and east of Congress Road. The S.F.B. Morse Botanical Reserve was established in 1972 to protect the endangered Gowen Cypress (sensu stricto), as well as other species or associations of species found only on the acidic clay-pan soils found in this area. This reserve is adjoined by the 372 acres of the Huckleberry Hill Natural Habitat Area.
This variety is listed under the U.S. Endangered Species Act: and has also been listed as Critically Imperilled on NatureServe database (NatureServe 2012).