Californian Closed-Cone Pines and Cypress Forests

These forests form a unique series of plant communities scattered the length of California’s coast, mountains and islands. Many of the characteristic species are relict endemics such as Cupressus abramsiana, C. bakeri, C. forbesii, C. goveniana, C. macnabiana, C. macrocarpa, C. nevadensis, C. pigmaea, C. sagentii, C. stephensonii (Cupressaceae), Pinus muricata, P. radiata and P. torreyana (Pinaceae). In fact of California’s ten native cypress species eight are endemic.  Most of these are highly adapted to fire and their cones remain sealed after maturity, usually accumulating on the tree and only opening when heated by fire. Cypress species tend to occur in groves often within other communities such as chaparral, although no native species occur in the Central Valley or on the offshore islands. These groves support a variety of endemics some of which are confined to just one or a few groves. For example, Arctostaphylos otayensis (Ericaceae), Ceanothus otayensis (Rhamnaceae) and Lepechinia ganderi (Lamiaceae) are confined to the Otay Mountain grove; Nolina parryi (Ruscaceae) is confined to the Sierra Peak grove; Arctostaphylos hookeri (Ericaceae), and Haplopappus eastwoodae (Asteraceae) are confined to the Monterey Peninsula; Arctostaphylos silvicola (Ericaceae) is confined to the sandy soils of the Santa Cruz Mountains and Arctostaphylos pungens var. montana (Ericaceae) is largely confined to groves on serpentine soils. In other cypress groves endemics include Arctostaphylos nummularia (Ericaceae), Baccharis pilularis (Asteraceae), Chamaebatia australis (Rosaceae), Cneoridium dumosum (Rutaceae), Dudleya farinose (Crassulaceae), Eriodictyon californicum (Boraginaceae), Lathyrus splendens (Fabaceae), Lepechinia cardiophylla (Lamiaceae), Lithocarpus densiflorus (Fagaceae), Myrica gale (Myricaceae), Pseudotsuga macrocarpa (Pinaceae), Rosa californica (Rosaceae) and Xerophyllum tenax (Melanthiaceae).

The most widespread of the pine species is Pinus attenuata occurring nearly the whole length of California, but other species like Pinus radiata are more restricted. When first discovered in 1602 this species was confined to just three small areas near Monterey. All of these closed-cone pines are believed to be relicts of a more widespread Tertiary forest. Some of the endemic species found in these forests include Achillea borealis subsp. californica (Asteraceae), Ceanothus papillosus (Rhamnaceae), Galium angustifolium (Rubiaceae) and the conifer Libocedrus decurrens (Cupressaceae).  On the ultrabasic soils Pinus jeffreyi, P. monticola, P. lambertiana and other conifers occur in varying degrees of dominance, and in some of the more open of these stands, especially in the dryer areas, the associated grasslands include species such as Sitanion jubatum, Stipa lemmoni and the endemic Danthonia californica (Poaceae).

References

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