Taxonomy [top]

Kingdom Phylum Class Order Family
Plantae Tracheophyta Pinopsida Pinales Cupressaceae

Scientific Name: Cupressus guadalupensis
Species Authority: S.Watson
Infra-specific Taxa Assessed:
Common Name(s):
English Guadalupe Cypress, Tecate Cypress, Forbes Cypress
Spanish Ciprés
Hesperocyparis guadalupensis (S.Watson) Bartel
Taxonomic Source(s): Farjon, A. 2010. A Handbook of the World's Conifers. Koninklijke Brill, Leiden.

Assessment Information [top]

Red List Category & Criteria: Endangered B2ab(ii,iii,iv,v) ver 3.1
Year Published: 2013
Date Assessed: 2011-05-04
Assessor(s): Farjon, A.
Reviewer(s): Thomas, P.
Due to the far greater population size and area of occupancy of the mainland population (var. forbesii) the category of threat for the entire species (including var. guadalupensis on Guadalupe Island) is driven by this mainland population; it is considered to be Endangered. The combined area of occupancy for both varieties is about 42 km², the population is severely fragmented and there are significant continuing declines and fluctuations in mature individuals due to the increasing frequency of fires.
Previously published Red List assessments:
2000 Vulnerable (VU)

Geographic Range [top]

Range Description: This species is found in Mexico (Baja California Norte, Guadalupe Island, also along the border with California) and the USA (SW California, a few localities in Orange Co. and San Diego Co.).
Countries occurrence:
Mexico (Baja California, Guadalupe I.); United States (California)
Estimated area of occupancy (AOO) - km2: 42
Continuing decline in area of occupancy (AOO): Yes
Estimated extent of occurrence (EOO) - km2:
Number of Locations: 7
Continuing decline in number of locations: Yes
Lower elevation limit (metres): 210
Upper elevation limit (metres): 1400
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: On the mainland, the population consists of >10,000 mature trees, but on Guadalupe Island fewer than 200 remain. The population on the mainland continues to decline, while on the island an increase has recently begun, after the eradication of feral goats in 2005.
Current Population Trend: Decreasing
Additional data:
Continuing decline of mature individuals: Yes
Extreme fluctuations: Yes Population severely fragmented: Yes
Continuing decline in subpopulations: Yes

Habitat and Ecology [top]

Habitat and Ecology: This cypress is found in chaparral on slopes with Adenostoma spp., Arctostaphylos sp., in ravines in the Upper Sonoran Life Zone associated with Acer sp., Rhus laurina, Quercus spp., and Arctostaphylos sp., also locally associated with Pinus radiata var. binata; often along intermittent streams on loamy, sandy, gravelly or rocky soils (or 'adobe soil') over sandstone or granite in full sun. The altitudinal range of var. guadalupensis is from 800 m to 1,280 m and of var. forbesii from 210 m to 1,400 m a.s.l. The climate is of the Mediterranean type with dry, hot summers and winter rain; with frequent fog on Guadalupe Island.
Systems: Terrestrial
Continuing decline in area, extent and/or quality of habitat: Yes
Generation Length (years): 30

Use and Trade [top]

Use and Trade: No uses are known of this species and its varieties. Only a few botanical collections in California (e.g. Rancho Santa Ana Botanical Garden) have grown this species successfully. It should be taken into cultivation more widely especially for reasons of ex situ conservation of the variety native to Guadalupe Island.

Threats [top]

Major Threat(s): Urbanization in southern California and adjacent parts of Baja California has brought an increased risk of wildfires and the prevention as well as the attempts to put these down or restrict them will be concentrated around urban properties, not in the first place around populations of rare trees. Like its congeners in California, this cypress will regenerate after fire but there is a definite risk to survival if frequency or intensity of fires are increasing due to human impact factors. This increase is definitely happening on the mainland. On Guadalupe Island the feral goat threat has been removed, but chances of fire may increase as the island is more often visited by tourists than in the past.

Conservation Actions [top]

Conservation Actions: The main management issue for the conservation of this species is to reduce the current frequency and/or intensity of wildfires. The species is fire dependent for successful regeneration and establishment, but at a fire frequency that is closely balanced with other factors influencing the vegetation, and neither too frequent nor too infrequent. This may differ from sub-population to sub-population. Management on the uninhabited island of Guadalupe has its own difficulties. The feral goats there have now finally been eradicated.

Citation: Farjon, A. 2013. Cupressus guadalupensis. The IUCN Red List of Threatened Species 2013: e.T42220A2962608. . Downloaded on 09 October 2015.
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