The IUCN Red List of Threatened Species™
ISSN 2307-8235 (online)
IUCN 2008: T34023A2840676
Sequoiadendron giganteum, Giant Sequoia
Assessment by: Schmid, R. & Farjon, A.
View on www.iucnredlist.org
Citation: Schmid, R. & Farjon, A. 2013. Sequoiadendron giganteum. The IUCN Red List of Threatened
Species 2013: e.T34023A2840676. http://dx.doi.org/10.2305/IUCN.UK.20131.RLTS.T34023A2840676.en
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THE IUCN RED LIST OF THREATENED SPECIES™
Taxonomy
Kingdom
Phylum
Class
Order
Family
Plantae
Tracheophyta
Pinopsida
Pinales
Cupressaceae
Taxon Name: Sequoiadendron giganteum (Lindl.) J.T.Buchholz
Synonym(s):
• Wellingtonia gigantea Lindl.
Common Name(s):
• English:
Giant Sequoia, Bigtree, Sequoia, Sierra Redwood
Taxonomic Source(s):
Farjon, A. 2010. A Handbook of the World's Conifers. Koninklijke Brill, Leiden.
Taxonomic Notes:
This species was formerly included under the family Taxodiaceae. That family is now merged with
Cupressaceae (see Farjon 2005).
Assessment Information
Red List Category & Criteria:
Endangered B2ab(ii,iii,v) ver 3.1
Year Published:
2013
Date Assessed:
April 18, 2011
Justification:
Despite the fact that almost all existing ‘groves’ of Sequoiadendron giganteum are in protected areas
and some have been protected for more than a century, the population is in continuous decline. The
actual area of occupancy, estimated to be 142 km2, falls well below the threshold for Endangered (500
km²) and with a continuing decline due to inadequate regeneration and natural death of (over)mature
trees, which are being replaced by other, competing conifers, the B2 criterion applies and the species
meets the criteria for listing as Endangered.
Previously Published Red List Assessments
1998 – Vulnerable (VU)
1998 – Vulnerable (V)
Geographic Range
Range Description:
Endemic to the USA: California, Sierra Nevada (Calaveras, Fresno, Madera, Mariposa, Placer, Tulare &
Tuolumne Counties). It is known to occur in ca. 67 groves which stretch over a length of ca. 400 km
along the western slopes of the Sierra Nevada in a belt at most 25 km wide (severely fragmented),
© The IUCN Red List of Threatened Species: Sequoiadendron giganteum – published in 2013.
http://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T34023A2840676.en
1
covering a total area of occupancy of ca. 14,200 ha. Most of the groves (59) are in the two southernmost
counties: Fresno and Tulare.
Country Occurrence:
Native: United States (California)
© The IUCN Red List of Threatened Species: Sequoiadendron giganteum – published in 2013.
http://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T34023A2840676.en
2
Population
The present trend in recruitment of Sequoiadendron giganteum is downwards, due to competition in
the absence of periodic fires in many of the protected groves. This leads over time to a downward trend
in the number of mature individuals in the population. There is at present insufficient regeneration to
maintain Sequoia populations in these groves (Stephenson in Aune1992, Stephenson 1996).
Current Population Trend: Decreasing
Habitat and Ecology (see Appendix for additional information)
This species is forming 'groves' of a few to over 20,000 individuals in the Mixed Conifer Forest belt on
the western slopes of the Sierra Nevada. It is mixed with other conifers: Abies concolor, A. magnifica,
Calocedrus decurrens, Pinus lambertiana, P. ponderosa, P. jeffreyi, Pseudotsuga menziesii, Taxus
brevifolia, and with fewer broad-leaved trees: Quercus kelloggii, Q. chrysolepis, Cornus nuttallii, Alnus
rhombifolia, Salix scoulerana, Acer macrophyllum, and shrubs: Castanopsis sempervirens, Ceanothus
cordulatus, C. parvifolius, C. integerrimus, Arctostaphylos patula, etc. The relatively narrow altitudinal
belt, (830-)1,400-2,150(-2,700) m a.s.l., and the scattered concentration of groves, which tend to
become smaller and further apart going north, indicate rather narrow climatic and soil conditions that
are optimal in its natural habitat. Most groves are on granite-based residual and alluvial soils, some on
glacial outwash, and mildly acidic; best growth is on deep, well-drained sandy loams with available
ground water, the latter appears to be an important limiting factor. The climate is humid, with mostly
autumn rain and winter snow, and dry summers, with mean annual precipitation between 900-1,400
mm, but with high year-to-year variation. Temperature in winter is mild, with light frosts but occasional
extremes, and warm, occasionally hot, in summer. Sequoiadendron giganteum is well adapted to lowintensity forest fires (extremely thick bark) and resists windfall exceptionally well; its wood is also rotresistant. As a result its longevity ranges from 2,000-3,000(-3,200) years.
Systems: Terrestrial
Use and Trade (see Appendix for additional information)
Since its discovery by Europeans in the mid-19th century, exploitation during the latter half of that
century and into the next was considerable. The trees, though of high lumber quality and rot-resistant,
often shattered on impact of the giant boles. What wood could be used was put into mainly building
applications, and many larger houses in San Francisco and the Bay Area were built of its timber. No
commercial exploitation of wild groves occurs at present, and most of these were protected for their
scenic and scientific values many years ago. The giant trees are a major international tourist attraction in
California. The Giant Sequoia is also highly regarded as an ornamental tree in parks and gardens of large
homes and, being easily propagated from seed, is sold by many tree nurseries. Several cultivars have
been named and are in the trade. The species also has potential as a managed-forest tree for timber
production, but has found few applications in commercial forestry thus far.
Threats (see Appendix for additional information)
Although nearly all groves (or 92% of the area of occupancy) are on public land, enjoying various levels
of protection, the species was previously listed as Vulnerable primarily because of historic rates of
decline caused by exploitation. Present problems include fire risks, largely due to (past) management
© The IUCN Red List of Threatened Species: Sequoiadendron giganteum – published in 2013.
http://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T34023A2840676.en
3
practices which tended to benefit its coniferous competitors (especially Abies) rather than the target
species, and which have greatly accumulated the fuel load for future fires to burn more devastatingly
(Elliott-Fisk et al.1997). Crown fires could easily spread from adjacent stands of other conifers. Genetic
integrity of the small northernmost (and isolated) grove in Placer County is jeopardized by nearby
plantings of S. giganteum from other sources (Elliott-Fisk et al. 1997).
Conservation Actions (see Appendix for additional information)
Nearly all know ‘groves’ of this species are in protected areas; many are within famous national parks or
within wilderness reserves of National Forests. There is a considerable literature on the conservation
aspects of this species; for compilations see Aune (1994) and Stephenson (1996). The main conservation
issue is the long absence of naturally occurring fires in the protected areas where many of the groves of
Giant Sequoia occur. Different approaches to solve this problem, from controlled burning to selective
logging, have been applied on different lands (burning in national parks, logging in national forests), but
so far on too limited a scale to reverse the downward trend in recruitment necessary to maintain the
population in the long term. More drastic measures seem to be needed, but are difficult to safely apply
and/or are controversial (Elliott-Fisk et al. 1997).
Credits
Assessor(s):
Schmid, R. & Farjon, A.
Reviewer(s):
Thomas, P. & Stritch, L.
© The IUCN Red List of Threatened Species: Sequoiadendron giganteum – published in 2013.
http://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T34023A2840676.en
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Bibliography
Aune, P.S. 1994. Proceedings of the symposium on Giant Sequoias: their place in the ecosystem and
society, June 23-25, 1992. Gen. Tech. Report PSW-GTR-151. USDA Forest Service , Visalia, California.
Burns, R.M. and Honkala, B.H. 1990. Silvics of North America. USDA, Forest Service, Washington, DC.
Elliott-Fisk, D.L., Stephens, S.L., Aubert, J.E., Murphy, D. and Schaber, J. 1997. Mediated Settlement
Agreement for Sequoia National Forest, Section B. Giant Sequoia Groves: an evaluation. Pp. 277-328 in
SNEP Science Team and special consultants, Sierra Nevada Ecosystem Project: Final report to Congress:
status of the Sierra Nevada. Wildland Resources Center report, no. 40. Centers for Water and Wildland
Resources, University of California, Davis.
Farjon, A. 2005. A Monograph of Cupressaceae and Sciadopitys. The Royal Botanic Gardens, Kew.
Farjon, A. 2010. Conifer Database (June 2008) In Species 2000 & ITIS Catalogue of Life: 2010 Annual
Checklist (Bisby F.A., Roskov Y.R., Orrell T.M., Nicolson D., Paglinawan L.E., Bailly N., Kirk P.M., Bourgoin
T., Baillargeon G., eds). Reading, UK. Available at: http://www.catalogueoflife.org/.
Farjon, A. 2010. A Handbook of the World's Conifers. Koninklijke Brill, Leiden.
Hartesveldt, R.J., Harvey, H.T., Shellhammer, H.S. and Stecker, R.E. 1975. The Giant Sequoia of the Sierra
Nevada. U.S. Dept. of the Interior, National Park Service, Washington, D.C.
IUCN. 2013. IUCN Red List of Threatened Species (ver. 2013.1). Available at: http://www.iucnredlist.org.
(Accessed: 12 June 2013).
Stephenson, N.L. 1996. Giant sequoia management issues: protection, restoration, and conservation.
SNEP Science Team and special consultants, Sierra Nevada Ecosystem Project: Final report to Congress:
Status of the Sierra Nevada. Vol. 2. Assessments and scientific basis for management options. Centers for
Water and Wildland Resources, University of California, Davis (series: Wildland Resources Center report,
no. 37, pp. 1431-1467. Centers for Water and Wildland Resources, University of California, Davis (series:
Wildland Resources Center report.
Willard, D. 2000. A guide to the sequoia groves of California. Yosemite Association, Yosemite National
Park.
Citation
Schmid, R. & Farjon, A. 2013. Sequoiadendron giganteum. The IUCN Red List of Threatened Species
2013: e.T34023A2840676. http://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T34023A2840676.en
Disclaimer
To make use of this information, please check the Terms of Use.
External Resources
For Images and External Links to Additional Information, please see the Red List website.
© The IUCN Red List of Threatened Species: Sequoiadendron giganteum – published in 2013.
http://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T34023A2840676.en
5
Appendix
Habitats
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Habitat
Season
Suitability
Major
Importance?
1. Forest -> 1.4. Forest - Temperate
-
Suitable
Yes
Use and Trade
(http://www.iucnredlist.org/technical-documents/classification-schemes)
End Use
Local
National
International
Construction or structural materials
Yes
No
No
Pets/display animals, horticulture
No
Yes
Yes
Establishing ex-situ production *
No
No
No
Threats
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Threat
Timing
Scope
Severity
Impact Score
7. Natural system modifications -> 7.1. Fire & fire
suppression -> 7.1.1. Increase in fire
frequency/intensity
Ongoing
-
-
-
Stresses:
1. Ecosystem stresses -> 1.2. Ecosystem degradation
2. Species Stresses -> 2.1. Species mortality
2. Species Stresses -> 2.2. Species disturbance
2. Species Stresses -> 2.3. Indirect species effects ->
2.3.2. Competition
Ongoing
-
Stresses:
2. Species Stresses -> 2.3. Indirect species effects ->
2.3.1. Hybridisation
2. Species Stresses -> 2.3. Indirect species effects ->
2.3.5. Inbreeding
8. Invasive & other problematic species & genes ->
8.3. Introduced genetic material
-
-
Conservation Actions in Place
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Conservation Actions in Place
In-Place Research, Monitoring and Planning
Action Recovery plan: Yes
Systematic monitoring scheme: Yes
© The IUCN Red List of Threatened Species: Sequoiadendron giganteum – published in 2013.
http://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T34023A2840676.en
6
Conservation Actions in Place
In-Place Land/Water Protection and Management
Occur in at least one PA: Yes
Percentage of population protected by PAs (0-100): 91-100
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
Conservation Actions Needed
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Conservation Actions Needed
2. Land/water management -> 2.1. Site/area management
Research Needed
(http://www.iucnredlist.org/technical-documents/classification-schemes)
Research Needed
3. Monitoring -> 3.4. Habitat trends
Additional Data Fields
Distribution
Estimated area of occupancy (AOO) (km²): 142
Continuing decline in area of occupancy (AOO): Yes
Estimated extent of occurrence (EOO) (km²): 13000
Number of Locations: 20
Lower elevation limit (m): 830
© The IUCN Red List of Threatened Species: Sequoiadendron giganteum – published in 2013.
http://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T34023A2840676.en
7
Distribution
Upper elevation limit (m): 2700
Population
Continuing decline of mature individuals: Yes
Population severely fragmented: Yes
Habitats and Ecology
Continuing decline in area, extent and/or quality of habitat: Yes
Generation Length (years): 100
© The IUCN Red List of Threatened Species: Sequoiadendron giganteum – published in 2013.
http://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T34023A2840676.en
8
The IUCN Red List Partnership
The IUCN Red List of Threatened Species™ is produced and managed by the IUCN Global Species
Programme, the IUCN Species Survival Commission (SSC) and The IUCN Red List Partnership. The IUCN
Red List Partners are: BirdLife International; Botanic Gardens Conservation International; Conservation
International; Microsoft; NatureServe; Royal Botanic Gardens, Kew; Sapienza University of Rome; Texas
A&M University; Wildscreen; and Zoological Society of London.
THE IUCN RED LIST OF THREATENED SPECIES™