Santa Cruz Cypress

Cupressus abramsiana

Description

Santa Cruz cypress, Cupressus abramsiana, is a densely branched evergreen tree, reaching a mature height of about 34 ft (10 m) and developing a compact, symmetrical pyramid shape. Mature trees have light green, scale-like foliage and fibrous, gray bark. Trees produce numerous, tiny female cones, no larger than a walnut, near the tips of growing branches. These cones, which are firmly attached to the branch, remain closed and retain their seeds until the tree or supporting branch dies, generally as a result of fire. The late-opening (serotinous) cones enable cypresses to drop abundant quantities of seed to the ground after a fire.

The species grows vigorously under favorable conditions for several decades; an 18-year old tree was estimated at 20 ft (6.1 m) in height, although many trees may grow much more slowly due to competition or poor soil conditions. The champion tree, cut down by vandals in 1983, was estimated to be 98 years old when killed. The tree is considered intermediate in size and other characteristics between Gowen (C. goveniana ) and Sargent cypress (C. sargentii ).

Habitat

Santa Cruz cypress has historically been located in patches within coastal chaparral and mixed evergreen forests on sandy or gravelly, well-drained soils. The habitat consists of thickets of low shrubs, called chaparral, within a larger context of redwood and mixed evergreens. Cypress groves are found in soils derived from Eocene or Lower Miocene sandstone. The Mediterranean climate consists of cool, wet winters; hot, dry summers; and little coastal fog. Habitat elevations range from 1,020 to 2,550 ft (300 to 750 m).

Periodically, wild fires burn across the habitat, a historic cycle that has shaped the reproductive strategy of Santa Cruz cypress. Because individual trees fail to sprout again from fire-charred trunks, the species depends upon seed stored in its cones for regeneration. If a grove burns too frequently trees fail to reach seed-bearing age; conversely, the prolonged absence of fire (200 years or more) allows other tree species to replace Santa Cruz cypress as stands die off from old-age.

Distribution

The Santa Cruz Cypress was first collected in 1881 on top of Ben Lomond Mountain within the Santa Cruz Mountains (Santa Cruz County), California. The species is endemic to Santa Cruz and San Mateo counties, California. The Santa Cruz cypress is restricted to five populations totaling approximately 5,100 individuals in Santa Cruz and San Mateo counties, California, including four small groves in Santa Cruz County and a single grove on Butano Ridge in San Mateo County. The Santa Cruz County groves are located mostly on private land near Bonny Doon, Eagle Rock, Braken Brae Creek, and between Majors and Laguna creeks. A significant portion of the Butano Ridge stand falls within Pescadero Creek County Park, which is under the jurisdiction of the San Mateo County Department of Parks and Recreation.

Threats

Groves of Santa Cruz cypress have been affected by past construction (Bracken Brae and Majors Creek), logging (Butano Ridge and Eagle Rock), vandalism, fire, and a proposed vineyard development (Bonny Doon). The largest tree at the Bonny Doon site was cut down in 1986.

Proposed oil and gas exploration threatens the northernmost Butano Ridge grove. Since the grove is on federal land managed by the Bureau of Land Management any drilling activities will be closely monitored to protect the trees.

Introduced exotic cypresses, such as Monterey (C. macrocarpa ) and Arizona smooth cypress (C. glabra ) have been cultivated on tree farms on Ben Lomond Mountain and could easily hybridize with the native strands of C. abramsiana, threatening the genetic integrity of the species.

Conservation and Recovery

Limited protection of Santa Cruz cypress is provided by the state of California, which requires landowners, after being alerted that a state-listed plant grows on their property, to notify the state in advance of land-use changes to allow for salvaging the plant. The state also provides funding for research and land acquisition.

In 1997, a draft recovery plan was announced to provide a framework for the recovery of the Santa Cruz cypress so that protection by the Endangered Species Act is no longer necessary. To accomplish this objective, needed tasks include: protection from incompatible land uses (i.e., timber harvest, agriculture, developments, recreation), implementation of resource management plans that would manage for long-term viability of the populations (i.e., mimic natural fire regime, address genetic introgression, and control insect infestations), and further research into the biology of the species and the threats facing it.

Contact

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N.E. 11th Ave.
Portland, Oregon 97232-4181
(503) 231-6121
http://pacific.fws.gov/

References

Bartel, J. A., and M. D. Knudsen. 1982. "Status Review of the Santa Cruz Cypress." U.S. Fish and Wildlife Service, Sacramento.

Libby, J. 1979. "Cupressus abramsiana Goes to Court"Fremontia 7(3):15.

Young, P. G. 1977. "Rare Plant Status Report, Cupressus abramsiana." C. B. Wolf. California Native Plant Society.