Gowen Cypress

Cupressus goveniana ssp. goveniana

Description

Cupressus goveniana ssp. goveniana (Gowen cypress) is a small coniferous tree or shrub in the cypress (Cupressaceae) family. Most of the ten taxa in the genus Cupressus found in California currently have relatively small ranges. Of the three coastal cypresses, native stands of C. macrocarpa (Monterey cypress) and C. goveniana ssp. goveniana are both restricted to the Monterey Peninsula and Point Lobos in Monterey County. C. goveniana ssp. goveniana generally reaches a height between 17-23 ft (5-7 m) though Griffin noted one individual that was 33 ft (10 m) high at Huckleberry Hill. The sparsely branched tree forms a short, broad crown with a spread of 7-13 ft (2-4 m). The bark is smooth brown to gray, then becomes rough and fibrous on old trees. The scale-like foliage is a light rich green, with leaves 0.04-0.08 in (1-2 mm). The female cones are subglobose (nearly spherical), 0.4-0.5 in (1-1.3 cm) long, and produce 90-110 seeds. The cones, which typically mature in two years, remain closed for many years while attached to the tree. Seeds can be released upon mechanical removal from the tree or, more typically, upon death of the tree or supporting branch. C. goveniana ssp. goveniana is distinguished from its close relative C. goveniana ssp. pigmaea by its much taller stature, the lack of a long, whip-like terminal shoot, and light to yellow-green rather than dark dull green foliage. Gowen cypress is a closed-cone cypress, a member of a fire-adapted family that possesses cones which, after seed has matured, remain sealed and attached to the trees, typically until heat from fires breaks the cones' resinous seal and allows the once-hidden seeds to escape.

C. goveniana ssp. goveniana was first collected by Karl Hartweg from Huckleberry Hill on the Monterey Peninsula in 1846. The plant was described as C. goveniana by British horticulturalist George Gordon in 1849, who named it after fellow horticulturalist James R. Gowen. Sargent described the tree in 1896 as being widely distributed "from the plains of Mendocino County to the mountains of San Diego County," including taxa now recognized as distinct in his definition of C. goveniana. John G. Lemmon published the name C. goveniana var. pigmaea in 1895 to refer to the stands found on the "White Plains" of Mendocino County, also referred to as pygmy cypress or Mendocino cypress. As a result of this segregation, the material from the Monterey area would be treated as C. goveniana var. goveniana. The taxon is currently treated as C. goveniana ssp. goveniana.

Habitat

Gowen cypress is associated with Monterey Pine (Pinus radiata ), Pinus muricata, and several taxa in the heath family (Ericaceae )—Vaccinium, Gaultheria, Arctostaphylos —on poorly drained and acidic soils. This taxon also needs adequate sunlight and bare mineral soils for seedling establishment; in areas with herbaceous cover seedling mortality is higher due to fungal infections.

Distribution

Only two natural stands of Gowen cypress are known to exist, although individuals can be found locally in cultivation. The largest stand, referred to here as the Del Monte Forest stand, is near Huck-leberry Hill on the western side of the Monterey Peninsula. This stand covers approximately 100 acres (40 hectares), with individuals scattered within 0.6 mi (1 km) of the main stand. It was reported in 1948 that patches of crowded, poorly developed individuals, referred to as "canes," were cut for posts, making it difficult to determine the original extent of the grove. At least three fires have burned portions of the Del Monte Forest stand in the last 100 years. A large fire burned most of the stand in 1901. The northern portion of the stand apparently burned in 1959. The most recent fire burned the south central portion of the population in 1987. In each case, regeneration of Gowen cypress has occurred. The Del Monte Forest stand is on lands owned by the Pebble Beach Company and the Del Monte Forest Foundation (DMFF). Originally established as the Del Monte Foundation in 1961 by the Pebble Beach Company, its purpose is to acquire, accept, maintain, and manage lands in the Del Monte Forest which are dedicated to open space and greenbelt. A large portion of the Del Monte Forest stand is within a 84-acre (34-hectare) area designated as the Samuel F. B. Morse Botanical Reserve in the 1960s and donated to DMFF in 1976. Development of the Poppy Hills Golf Course in the early 1980s removed 840 trees of Gowen cypress outside of the reserve and surrounded other small patches with fairways. The majority of the remaining portion of this stand is on lands owned by Pebble Beach Company that are designated as "forested open space" in the Huck-leberry Hill Open Space area, through a conservation easement held by the DMFF. Scattered groups of trees that radiate out from this stand are located on Pebble Beach Company lands within their most recently proposed residential developmens. A second smaller stand of Gowen cypress 40-80 acres (16-32 hectares) in size occurs 6 mi (10 km) to the south at Point Lobos State Reserve near Gibson Creek on a 150-acre (60-hectare) parcel acquired by the California Department of Parks and Recreation (CDPR) in 1962. The very western edge of the stand is on lands recently purchased by the Big Sur Land Trust from a private owner. This parcel was to be transferred to the CDPR in 1997.

In this stand, Gowen cypress is associated with Pinus radiata and chaparral species. Due to the physical inaccessibility of the Point Lobos stand and the Reserve's mandate to protect sensitive plant taxa, the Point Lobos stand exhibits fewer signs of human disturbance than the Del Monte Forest stand.

Threats

Gowen cypress is considered threatened rather than endangered because one of two populations, the Gibson Creek stand managed by the California Department of Parks and Recreation, has not been significantly affected by human activities. This long-lived taxon also appears able to withstand several decades without fire as long as sufficient habitat is maintained. This species is threatened by habitat alteration due to the influence of continued urban development in Pebble Beach and to the disruption of natural fire cycles that are likely to result from fire suppression activities. In addition, stands of C. goveniana var. goveniana at both locations have been invaded by aggressive alien species, including Cortaderia jubata (pampasgrass), Genista monspessulana(French broom), and Erechtites spp. (fireweeds). Invasion of alien plants alters the composition of the plant community and may adversely affect Gowen cypress. Despite measures taken to protect the Cupressus goveniana ssp. goveniana stand at the Del Monte Forest, the opportunities for maintaining a viable long-term population of this taxon may be compromised by the site's proximity to urbanization. Gowen cypress is adapted to regenerate after fires. While some regeneration following mechanical clearing has occurred along a fire road, periodic fire is the most effective and efficient method of promoting forest regeneration. Fire opens cones that otherwise remain sealed on the trees, and it creates conditions appropriate for seedling establishment. The lands on which most of the cypress grows are included in the Morse Botanical Reserve and will not therefore be developed. Unfortunately, the periodic fires that create conditions necessary for regeneration of the grove, are less likely to occur as residential development encroaches on the Reserve and the Huckleberry Hill Open Space area. This residential development that is occurring on all sides of the stand impede the continuation of vital ecosystem processes, especially the periodic fires so essential for stand regeneration.

Prescribed burning has not been tried at the Pt. Lobos Ranch occurrence, in part due to the risks to surrounding privately owned lands.

Gowen cypress is restricted to only two sites in western Monterey County. The occurrence on the Monterey Peninsula is located in the Morse Botanical Reserve and the Huckleberry Hill Open Space area. As development has surrounded this location, the edges and outlying stands of this occur-rence have been eliminated or diminished. For example, portions of this occurrence were lost during construction of the Poppy Hills golf course in the 1980s. Trees planted as mitigation for that loss and a small stand of naturally occurring C. goveniana ssp. goveniana and Pinus muricata were left in a 19.5-acre (8-hectare) habitat patch of Monterey pine forest and chaparral, bounded by golf green. As proposed for the most recent subdivision and development, this site would be converted to a 21-lot residential area, eliminating most of the naturally occurring cypress and leaving the remaining cypress in a portion of 7 acres (3 hectares) of Forested Open Space bounded by roads, a golf green and houses. At least three of the subdivisions proposed for development by the Pebble Beach Company are within 984 ft (300 m) of the Gowen cypress stands in the Morse Reserve, and one proposed residential development abuts the Reserve's southwest corner. The proximity of these residential areas substantially diminishes the opportunity to use prescribed fire as a management tool within the reserve. In addition, due to concern about potential wildfire, 12-ft (4-m) wide fire roads have been maintained throughout the Reserve and Huckleberry Hill Open Space, removing individual Cupressus trees and causing erosion in some places. These fire roads provide a suitable path for alien plants to enter and spread through the stands. An extensive stand of Genista monspessu-lana has been mapped adjacent to the grove of Gowen cypress at Pt. Lobos Reserve, where it may interferes with stand regeneration in the future. The Pebble Beach Company has an on-going eradication program for Cortaderia jubata and G. monspessulana in the Huckleberry Hill area adjacent to stands of this taxon. However, numerous fire roads provide open habitat for these invasive taxa and it is unlikely that they will ever be completely eradicated from the area. There is some concern among biologists that the establishment of Pinus radiata seedlings after the 1987 fire has been so vigorous that this taxon may be expanding its range at the expense of C. goveniana ssp. goveniana. This view is by no means universally accepted. Other scientsists feel that this pine's preference for richer soils than those that support Gowen cypress would prevent long-term establishment of pines in Gowen cypress habitat.

Conservation and Recovery

One of the two natural habitats of the Gowen cypress, the Gibson Creek stand managed by the CDPR, has not been significantly affected by human activities and is being maintained in a natural condition. The Del Monte Forest stand is on lands owned by the private Pebble Beach Company and the DMFF, and is being managed as the Samuel F.B. Morse Botanical Reserve. However, trees outside of the designated reserve are threatened by development activities. In addition, the conserved habitat must be managed properly, particularly with regards to the fire regime and actions to control invasive non-native plants. The Gowen cypress is also grown in cultivation, although this does not diminish the importance of preserving the rare plant in its wild habitat. The populations of the Gowen cypress should be monitored, and research undertaken into its biology and habitat needs, with the aim of developing management practices appropriate to maintaining or enhancing its habitat.

Contacts

U.S. Fish and Wildlife Service
Ventura Fish and Wildlife Office
2493 Portola Road, Suite B
Ventura, California 93003-7726
Telephone: (805) 644-1766

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

Reference

U.S. Fish and Wildlife Service. 12 August 1998. "Endangered and Threatened Wildlife and Plants; Final Rule Listing Five Plants From Monterey County, CA, as Endangered or Threatened." Federal Register 63(155): 43100-43116.