Taxonomy [top]

Kingdom Phylum Class Order Family
Plantae Tracheophyta Pinopsida Pinales Taxaceae

Scientific Name: Taxus brevifolia
Species Authority: Nutt.
Common Name(s):
English Pacific Yew, Canadian Yew
Taxonomic Source(s): Farjon, A. 2010. A Handbook of the World's Conifers. Koninklijke Brill, Leiden.

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2013
Date Assessed: 2012-03-15
Assessor(s): Thomas, P.
Reviewer(s): Stritch, L. & Farjon, A.
Taxus brevifolia has undergone a population decline within the last three generations that is estimated to be less than 30%. A significant part of that decline related to its overexploitation for the production of anti-cancer medicines. This exploitation has largely ceased following the development of alternative methods for Taxol production and the focus on exploiting Asian Yew species. The majority of the Asian species are now listed as threatened in the IUCN Red List and are also listed on Appendix II of CITES.
A second cause for the decline in T. brevifolia relates to habitat destruction from logging activities. This is continuing but at a lower rate. On this basis an assessment of Near Threatened under the A2acd criterion is appropriate until the next assessment.
Previously published Red List assessments:
1998 Lower Risk/near threatened (LR/nt)
1998 Rare (R)

Geographic Range [top]

Range Description:Widely distributed in the Pacific northwest of the United States and Canada from northern California to southern Alaska. The extent of occurrence is well in excess of 20,000 km2 and there are more than 10 locations. The area of occupancy is unknown but estimated to be more than 2,000 km2.
Countries occurrence:
Canada (Alberta, British Columbia); United States (Alaska, Idaho, Montana, Nevada, Oregon, Washington)
Lower elevation limit (metres):1
Upper elevation limit (metres):2440
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:Taxus brevifolia is not uncommon within the main range of its distribution. Patterns of distribution vary from scattered to dense patches throughout its wide range. There has been an estimated population reduction of 10-30% within the last three generations as a result of logging and bark harvesting for Taxol production. One generation is estimated to be at least 30 years due to its slow growth rates.
Current Population Trend:Decreasing
Additional data:
Continuing decline of mature individuals:Yes
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:In coastal areas this very fire susceptible and slow growing species is usually found as a small tree; in montane and some inland areas it may be a decumbent shrub. It is most abundant in the shaded understorey of late seral or old growth coniferous forests (Busing et al. 1995). Common associates in more mesic situations (where most of the trees are found) include Abies grandis, Tsuga heterophylla, Thuja plicata, Berberis nervosa, Polystichum munitum and Acer circinatum. In inland areas and in the drier parts of its range it is restricted to moist areas such as streamsides. Its generation length is likely to be in excess of 30 years. It is recorded from sea  level up to 2,440 m.
Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):30

Use and Trade [top]

Use and Trade: The strong, dense timber from this species is highly prized by west coast Native Americans for bows, tools and carving. In the 1980s and 1990s it was heavily exploited for its bark which was used for the production of anti-cancer drugs. Following the discovery of alternative sources and methods for Taxol production by the mid-1990s, the pressure on T. brevifolia populations has eased.

Threats [top]

Major Threat(s): Taxus brevifolia was heavily exploited for its bark over a considerable part of its range in the recent past. Populations have also been reduced as a consequence of logging and fires. These latter threats are ongoing. The overall reduction is estimated to be less than 30%.

Conservation Actions [top]

Conservation Actions: This species is recorded from numerous protected areas throughout its range. Guidelines for the management and harvesting of T. brevifolia were produced in response to its heavy exploitation.

Classifications [top]

1. Forest -> 1.4. Forest - Temperate
suitability: Suitable  major importance:Yes
1. Land/water protection -> 1.2. Resource & habitat protection
3. Species management -> 3.1. Species management -> 3.1.1. Harvest management

In-Place Research, Monitoring and Planning
  Action Recovery plan:No
  Systematic monitoring scheme:Yes
In-Place Land/Water Protection and Management
  Occur in at least one PA:Yes
  Area based regional management plan:Yes
  Invasive species control or prevention:Yes
In-Place Species Management
  Harvest management plan:Yes
  Successfully reintroduced or introduced beningly:No
  Subject to ex-situ conservation:No
In-Place Education
  Subject to recent education and awareness programmes:Yes
  Included in international legislation:No
  Subject to any international management/trade controls:No
2. Agriculture & aquaculture -> 2.2. Wood & pulp plantations -> 2.2.2. Agro-industry plantations
♦ timing: Ongoing ♦ scope: Minority (<50%) ♦ severity: Slow, Significant Declines ⇒ Impact score: Low Impact: 5 
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

5. Biological resource use -> 5.2. Gathering terrestrial plants -> 5.2.1. Intentional use (species is the target)
♦ timing: Past, Unlikely to Return ♦ scope: Majority (50-90%) ♦ severity: Rapid Declines ⇒ Impact score: Past Impact 
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

5. Biological resource use -> 5.3. Logging & wood harvesting -> 5.3.4. Unintentional effects: (large scale)
♦ timing: Ongoing ♦ scope: Minority (<50%) ♦ severity: Slow, Significant Declines ⇒ Impact score: Low Impact: 5 
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

2. Conservation Planning -> 2.3. Harvest & Trade Management Plan
3. Monitoring -> 3.1. Population trends
3. Monitoring -> 3.4. Habitat trends

♦  Medicine - human & veterinary
 National : ✓ 

♦  Handicrafts, jewellery, etc.
 Local : ✓ 

Bibliography [top]

Busing, R.T., Halpern, C.B. and Spies, T.A. 1995. Ecology of Pacific Yew (Taxus brevifolia) in Western Oregon and Washington. Conservation Biology 9(5): 1199-1207.

Farjon, A. 2010. A Handbook of the World's Conifers. Koninklijke Brill, Leiden.

Frisvold, G. and Day-Rubenstein, K. 2008. Bioprospecting and biodiversity conservation: what happens when discoveries are made. Arizona Law Review 50: 545-576.

IUCN. 2013. IUCN Red List of Threatened Species (ver. 2013.1). Available at: (Accessed: 12 June 2013).

NatureServe. 2011. Taxus brevifolia in NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. Arlington, Virginia Available at: (Accessed: March 20).

Vance, N.C., Borsting, M., Pilz, D. and Freed. J. 2001. Special forest products: Species information guide for the Pacific Northwest. General Technical Report PNW-GTR-513. UDSA Forest Service, Pacific Northwest Research Station, Portland, Oregon.

Citation: Thomas, P. 2013. Taxus brevifolia. In: The IUCN Red List of Threatened Species 2013: e.T34041A2841142. . Downloaded on 09 October 2015.
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