View source for Thuja plicata

{{Short description|Species of conifer}}
{{Use dmy dates|date=June 2023}}
{{Speciesbox
| image = Thuja plicata Vancouver.jpg
| image_caption = An old tree in [[Vancouver]]
| status = LC
| status_system = IUCN3.1
| status_ref = <ref name="iucn status 19 November 2021">{{cite iucn |author=Farjon, A. |date=2013 |title=''Thuja plicata'' |volume=2013 |article-number=e.T42263A2968155 |doi=10.2305/IUCN.UK.2013-1.RLTS.T42263A2968155.en}}</ref>
| genus = Thuja
| species = plicata
| authority = [[James Donn|Donn]] ''ex'' [[David Don|D.Don]]
| range_map = Thuja plicata range.png
| range_map_caption = Range of ''T.&nbsp;plicata'' in the [[Pacific Northwest]]
}}

'''''Thuja plicata''''' is a large [[evergreen]] [[conifer]]ous [[tree]] in the family [[Cupressaceae]], native to the [[Pacific Northwest]] of North America. Its common name is '''western redcedar'''.<ref name="PLANTS">{{PLANTS |id=THPL |taxon=Thuja plicata |access-date=10 December 2015}}</ref> It is also less commonly called '''western red cedar''',<ref>{{cite web |title=''Thuja plicata'' |url=https://www.rhs.org.uk/plants/18154/thuja-plicata/details |url-status=live |archive-url=https://web.archive.org/web/20210802151825/https://www.rhs.org.uk/Plants/18154/Thuja-plicata/Details |archive-date=2 August 2021 |access-date=7 September 2021 |publisher=[[Royal Horticultural Society]] (RHS)}}</ref> '''pacific red cedar''', '''giant arborvitae''', '''western arborvitae''', just '''cedar''', '''giant cedar''', or '''shinglewood'''.<ref name=GRIN>{{GRIN | access-date = 11 December 2017}}</ref> It is not a true cedar of the genus ''[[Cedrus]]''. ''T. plicata'' is the largest species in the genus ''[[Thuja]]'', growing up to {{convert|70|m|ft}} tall and {{convert|7|m|ft|abbr=on}} in diameter. It mostly grows in areas that experience a mild climate with plentiful rainfall, although it is sometimes present in drier areas on sites where water is available year-round, such as wet valley bottoms and mountain streamsides. The species is [[shade-tolerant]] and able to establish in forest understories and is thus considered a [[climax species]]. It is a very long-lived tree, with some specimens reaching ages of well over 1,000 years.

[[Indigenous peoples of the Pacific Northwest]] use the wood of this species for many purposes, such as building canoes, [[totem pole]]s, and tools. The bark is harvested by indigenous peoples and processed into a fiber, which they use to make items such as rope, baskets, clothing, and rain hats. Because of its wide range of uses, the species is of great cultural importance to these people. Western redcedar wood is aromatic and rot-resistant and is used for applications such as the construction of shingles and siding. It has been introduced to cool temperate areas in other parts of the world, such as [[Northern Europe]] and [[New Zealand]].

== Description ==
''Thuja plicata'' is a large to very large tree, ranging up to {{convert|45|to|70|m|abbr=off|-1}} tall and {{cvt|2.4|to|7|m|ft|0}} in trunk diameter,<ref name="Arno">{{Cite book |last1=Arno |first1=Stephen F. |url=https://books.google.com/books?id=qDD4DwAAQBAJ |title=Northwest Trees: Identifying & Understanding the Region's Native Trees |last2=Hammerly |first2=Ramona P. |publisher=[[Mountaineers Books]] |year=2020 |isbn=978-1-68051-329-5 |edition=field guide |location=Seattle |pages=155–162 |language=en |oclc=1141235469 |orig-date=1977 |access-date=13 March 2022 |archive-date=19 September 2023 |archive-url=https://web.archive.org/web/20230919000929/https://books.google.com/books?id=qDD4DwAAQBAJ |url-status=live }}</ref><ref name="Gymnosperm">{{Gymnosperm Database|family=Cupressaceae|genus=Thuja|species=plicata}}</ref>{{sfn|Farjon|2005}} larger than any other species in its genus.<ref>{{Gymnosperm Database|family=Cupressaceae|genus=Thuja}}</ref> The trunk swells at the base and has shallow roots.<ref name="Arno" /> The [[Bark (botany)|bark]] is thin, gray-brown, and fissured into vertical bands.<ref name="Arno" /> Trees growing in the open may have a crown that reaches the ground, whereas trees densely spaced together will exhibit a crown only at the top, where light can reach the leaves.{{sfn|Stewart|1984|p=24}} As the tree ages, the top is damaged by wind and replaced by inferior branches.<ref name="Arno" /> The species is long-lived; some trees can live well over a thousand years, with the oldest verified aged 1,460.<ref name="Gymnosperm" />{{sfn|Farjon|2005}}

The foliage forms flat sprays with scale-like leaves in opposite pairs, with successive pairs at 90 degrees to each other. The foliage sprays are green throughout but marked with whitish [[Stoma|stomatal]] bands below; they emit a strong aroma reminiscent of [[pineapple]] when crushed. The individual leaves are {{convert|1|to|4|mm|frac=32}} long and {{cvt|1|to|2|mm|frac=32}} broad on most foliage sprays but up to {{cvt|12|mm|frac=8}} long on strong-growing lead shoots.<ref name="Gymnosperm" />{{sfn|Farjon|2005}} The foliage of individual branchlets turns orange-brown before falling off in autumn.<ref name="Arno" /> Branches growing in full sunlight produce denser foliage with more overlap, while shaded branches grow more horizontally, with less overlap.<ref>{{cite journal |last1 = Edelstein |first1 = Zoe R. |last2 = Ford |first2 = E. David |date = 2 June 2003 |title = Branch and foliage morphological plasticity in old-growth ''Thuja plicata'' |journal = Tree Physiology |publisher = Heron Publishing |publication-place = Victoria, BC |volume = 23 |issue = 10 |pages = 649{{ndash}}662 |doi = 10.1093/treephys/23.10.649 |pmid = 12777238 |doi-access=free}}</ref>

The [[conifer cone|cones]] are slender, {{cvt|10|to|18|mm|frac=16}} long, and {{cvt|4|to|5|mm|frac=32}} broad, with 8 to 12 (rarely 14) thin, overlapping scales. They are green to yellow-green, ripening brown in fall about six months after pollination, and open at maturity to shed the seeds. The seeds are {{cvt|4|to|5|mm|frac=32}} long and {{cvt|1|mm|frac=32}} broad, with a narrow papery wing down each side. The [[pollen]] cones are {{cvt|3|to|4|mm|frac=32}} long, red or purple initially, and shed yellow pollen in spring.<ref name="Gymnosperm" />{{sfn|Farjon|2005}}

<gallery>
File:Thuja bark Łazienki.JPG|[[Bark (botany)|Bark]]|alt=The bark is fibrous and longitudinally fissured.
File:Thuja plicata kz3.JPG|[[Leaves]]|alt=The leaves have white markings on the undersides of the flat foliage sprays.
File:Thuja plicata 21 4 2017 Kaisaniemi 0016 (cropped).jpg|[[Shoot (botany)|Shoot]] with [[pollen cone]]s
File:Thuja plicata 43569.JPG|Shoot with mature [[seed cone]]s
File:Western red cedars, looking up.jpg|[[Keats Island (British Columbia)|Keats Island]]
File:Radial section of a WRC wood specimen (Thuja plicata).jpg|[[Wood]] specimen
</gallery>

=== Chemistry ===
The [[heartwood]] of western redcedar contains numerous chemical substances, such as [[plicatic acid]], [[thujaplicatin methyl ether]], [[hinokitiol]] and other [[thujaplicin]]s, {{nowrap|β-[[thujaplicinol]]}}, [[thujic acid]], [[methyl thujate]], [[1,4-cineole]], and {{nowrap|[[γ-eudesmol]]}}.<ref>{{cite journal |last1=Daniels |first1=C. R. |last2=Russell |first2=J. H. |date=1 May 2007 |title=Analysis of Western Redcedar (''Thuja plicata'' Donn) Heartwood Components by HPLC as a Possible Screening Tool for Trees with Enhanced Natural Durability |journal=[[Journal of Chromatographic Science]]|volume=45 |issue=5 |pages=281–285 |doi=10.1093/chromsci/45.5.281 |pmid=17555638 |doi-access=free}}</ref> Plicatic acid is believed to be the main irritant and [[contact allergen]] responsible for provoking [[allergic reaction]]s and [[asthma]] exacerbation. This leads to [[occupational asthma]] in [[woodworker]]s that are exposed to western redcedar [[wood dust]].<ref>{{cite journal |last1=Chan-Yeung |first1=Moira |date=January 1994 |title=Mechanism of occupational asthma due to western redcedar (''Thuja plicata'') |journal=[[American Journal of Industrial Medicine]]|volume=25 |issue=1 |pages=13–18 |doi=10.1002/ajim.4700250106 |pmid=8116639}}</ref> Thujaplicins serve as natural [[fungicide]]s{{sfn|Gardner|1963|p=21}}{{sfn|Chedgy|Lim|Breuil|2009}} which prevent the wood from [[Wood-decay fungus|rotting]]. This effect lasts around a century even after the tree is felled. However, thujaplicins are only found in older trees. Saplings do not produce the chemical, causing them to often develop rot at an early stage, causing some trees to grow with a somewhat hollow trunk, as the tree moves to heal itself as it grows.{{sfn|Stewart|1984|p=22}} Due to their fungicidal and anti-[[Food browning|browning]] properties, thujaplicins are used in agriculture for fungal diseases and to prevent [[Post-harvest losses (vegetables)|post-harvest decay]].<ref>{{cite journal |last1=Morita |first1=Yasuhiro |last2=Matsumura |first2=Eiko |last3=Okabe |first3=Toshihiro |last4=Fukui |first4=Toru |last5=Shibata |first5=Mitsunobu |last6=Sugiura |first6=Masaaki |last7=Ohe |first7=Tatsuhiko |last8=Tsujibo |first8=Hiroshi |last9=Ishida |first9=Nakao |last10=Inamori |first10=Yoshihiko |date=2004 |title=Biological Activity of α-Thujaplicin, the Isomer of Hinokitiol |journal=[[Biological & Pharmaceutical Bulletin]]|volume=27 |issue=6 |pages=899–902 |doi=10.1248/bpb.27.899 |pmid=15187442 |doi-access=free}}</ref><ref>{{cite journal |last1=Vanitha |first1=Thiraviam |last2=Thammawong |first2=Manasikan |last3=Umehara |first3=Hitomi |last4=Nakamura |first4=Nobutaka |last5=Shiina |first5=Takeo |date=December 2019 |title=Effect of hinokitiol impregnated sheets on shelf life and quality of "KEK-1" tomatoes during storage |journal=[[Packaging Technology and Science]]|volume=32 |issue=12 |pages=641–648 |doi=10.1002/pts.2479 |s2cid=202995336}}</ref> Thujaplicins, like other tropolones, are potent chelating agents and bind divalent metal ions.<ref>{{cite journal |last1=Pietra |first1=Francesco |date=August 1973 |title=Seven-membered conjugated carbo- and heterocyclic compounds and their homoconjugated analogs and metal complexes. Synthesis, biosynthesis, structure, and reactivity |journal=[[Chemical Reviews]]|volume=73 |issue=4 |pages=293–364 |doi=10.1021/cr60284a002}}</ref> [[Basic research|Basic]] and [[animal studies]] have shown that thujaplicins may have other biological properties, including antibacterial, antiviral, and antioxidant activities,<ref>{{cite journal |last1=Saniewski |first1=Marian |last2=Horbowicz |first2=Marcin |last3=Kanlayanarat |first3=Sirichai |date=10 September 2014 |title=The Biological Activities of Troponoids and Their Use in Agriculture A Review |journal=[[Journal of Horticultural Research]]|volume=22 |issue=1 |pages=5–19 |doi=10.2478/johr-2014-0001 |doi-access=free |s2cid=33834249}}</ref> however reliable evidence on their effectiveness is still lacking.{{Cn|date=May 2025}}

== Taxonomy ==
''Thuja plicata'' is one of two ''Thuja'' species native to North America, the other being [[Thuja occidentalis|''T.&nbsp;occidentalis'']]. [[Nuclear genome]] analysis indicates that it is likely more closely related to [[Thuja koraiensis|''T.&nbsp;koraiensis'']], which is native to the Korean Peninsula. The two species are hypothesized to have diverged in the [[Miocene]].<ref>{{cite journal |last1 = Peng |first1 = Dan |last2 = Wang |first2 = Xiao-Quan |date = June 2008 |title = Reticulate evolution in ''Thuja'' inferred from multiple gene sequences: Implications for the study of biogeographical disjunction between eastern Asia and North America |journal=[[Molecular Phylogenetics and Evolution]]|volume = 47 |issue = 3 |publisher =[[Elsevier]]|pages = 1190{{ndash}}1202 |doi = 10.1016/j.ympev.2008.02.001|pmid = 18346917 |bibcode = 2008MolPE..47.1190P }}</ref>

A 2008 study found that western redcedar populations in coastal areas of [[Washington (state)|Washington]] and [[Oregon]] are more genetically variable than populations in the [[Rocky Mountains]] and coastal [[British Columbia]], indicating that the species most likely spread throughout its current range from a single [[Refugium (population biology)|refugium]] in the southern portion of its range after the [[Last Glacial Maximum]].<ref>{{cite journal |last1 = O'Connell |first1 = Lisa M. |last2 = Ritland |first2 = Kermit |last3 = Thompson |first3 = Stacey Lee |date = 1 February 2008 |title = Patterns of post-glacial colonization by western redcedar (Thuja plicata, Cupressaceae) as revealed by microsatellite markers |journal =[[Botany (journal)|Botany]]|publisher=[[Canadian Science Publishing]]|volume = 86 |issue = 2 |pages = 194{{ndash}}203 |doi = 10.1139/B07-124|bibcode = 2008Botan..86..194O }}</ref> Some studies have suggested the existence of an inland refugium during the Last Glacial Maximum, likely in central [[Idaho]].<ref name="Ruffley">{{cite journal |last1 = Ruffley |first1 = Megan |last2 = Smith |first2 = Megan L. |last3 = Espíndola |first3 = Anahí |last4 = Turck |first4 = Daniel F. |last5 = Mitchell |first5 = Niels |last6 = Carstens |first6 = Brian |last7 = Sullivan |first7 = Jack |last8 = Tank |first8 = David C. |date = 24 March 2022 |editor-last = Sork |editor-first = Victoria |title = Genomic evidence of an ancient inland temperate rainforest in the Pacific Northwest of North America |journal =[[Molecular Ecology (journal)|Molecular Ecology]]|publisher =[[Wiley-Blackwell]]|volume = 31 |issue = 10 |pages = 2985{{ndash}}3001 |doi = 10.1111/mec.16431 |pmid = 35322900 |pmc = 9322681 |doi-access = free|bibcode = 2022MolEc..31.2985R }}</ref><ref>{{cite journal |last1 = Fernandez |first1 = Matias |last2 = Hu |first2 = Feng Sheng |last3 = Gavin |first3 = Daniel G. |last4 = de Lafontaine |first4 = Guillaume |last5 = Heath |first5 = Katy D. |date = 4 July 2021 |title = A tale of two conifers: Migration across a dispersal barrier outpaced regional expansion from refugia |journal =[[Journal of Biogeography]]|publisher =[[Wiley-Blackwell]]|volume = 48 |issue = 9 |pages = 2133{{ndash}}2143 |doi = 10.1111/jbi.14209 |doi-access = free|bibcode = 2021JBiog..48.2133F }}</ref> However, more recent genomic approaches corroborate the existence of only a single glacial refugium near the south of the current distribution, with subsequent expansion northward and inland since the last glacial maximum.<ref name="Shalev">{{cite journal |last1 = Shalev |first1 = Tal J. |last2 = Gamal El-Dien |first2 = Omnia |last3 = Yuen |first3 = Macaire M. S. |last4 = Shengqiang |first4 = Shu |last5 = Jackman |first5 = Shaun D. |last6 = Warren |first6 = Rene L. |last7 = Coombe |first7 = Lauren |last8 = van der Merwe |first8 = Lise |last9 = Stewart |first9 = Ada |last10 = Boston |first10 = Lori B. |last11 = Plott |first11 = Christopher |last12 = Jenkins |first12 = Jerry |last13 = He |first13 = Guifen |last14 = Yan |first14 = Juying |last15 = Yan |first15 = Mi |last16 = Guo |first16 = Jie |last17 = Breinholt |first17 = Jesse W. |last18 = Neves |first18 = Leandro G. |last19 = Grimwood |first19 = Jane |last20 = Rieseberg |first20 = Loren H. |last21 = Schmutz |first21 = Jeremy |last22 = Birol |first22 = Inanc |last23 = Kirst |first23 = Matias |last24 = Yanchuk |first24 = Alvin D. |last25 = Ritland |first25 = Carol |last26 = Russell |first26 = John H. |last27 = Bohlmann |first27 = Joerg |date = 15 September 2022 |title = The western redcedar genome reveals low genetic diversity in a self-compatible conifer |journal =[[Genome Research]]|publisher =[[Cold Spring Harbor Laboratory Press]]|volume = 32 |issue = 10 |pages = 1952{{ndash}}1964 |doi = 10.1101/gr.276358.121 |pmid = 36109148 |pmc = 9712635 |doi-access = free}}</ref> Refugial populations may have undergone repeated [[population bottlenecks]] during the glacial maxima of the [[Pleistocene]].<ref name="Ruffley"/><ref name="Shalev"/> [[Pollen core]]s indicate that ''T.&nbsp;plicata'' only became common in southern coastal British Columbia starting at approximately 6,000 [[before present|YBP]]. This coincides with a transition from the warmer, drier climate of the early [[Holocene]] to a cooler, wetter climate. The species arrived later in the [[Canadian Rockies]], as recently as 4,000–5,000 YBP.<ref>{{cite journal |last = Hebda |first = Richard J. |date = 1995 |title = British Columbia Vegetation and Climate History with Focus on 6 ka BP |journal = Géographie physique et Quaternaire |publisher = [[Presses de l'Université de Montréal]] |volume = 49 |issue = 1 |pages = 55{{ndash}}79 |doi = 10.7202/033030ar|doi-access = free }}</ref> Pollen assemblages at [[Seeley Lake Provincial Park|Seeley Lake]], on the eastern slope of the [[Coast Mountains]] east of [[Haida Gwaii]], indicate that western redcedar became common there at approximately 2,200 YBP.<ref>{{cite journal |last1 = Gottesfield |first1 = Alan S. |last2 = Mathewes |first2 = Rolf W. |last3 = Johnson Gottesfield |first3 = Leslie M. |date = October 1991 |title = Holocene debris flows and environmental history, Hazelton area, British Columbia |journal = [[Canadian Journal of Earth Sciences]] |publisher = [[Canadian Science Publishing]] |volume = 28 |issue = 10 |pages = 1583{{ndash}}1593 |doi = 10.1139/e91-142|bibcode = 1991CaJES..28.1583G }}</ref>

=== Etymology ===
The species name ''plicata'' derives from the Latin word {{wikt-lang|la|plico|plicāre}} and means 'folded in plaits' or 'braided,' a reference to the pattern of its small leaves.{{sfn|Stewart|1984|p=24}}

Most authorities, both in Canada<ref>British Columbia Forests & Range Tree Book: [http://www.for.gov.bc.ca/hfd/library/documents/treebook/westernredcedar.htm ''Thuja plicata''] {{Webarchive|url=https://web.archive.org/web/20100626073844/http://www.for.gov.bc.ca/hfd/library/documents/treebook/westernredcedar.htm|date=26 June 2010}}</ref><ref>British Columbia Tree Species Compendium [http://www.for.gov.bc.ca/hfp/silviculture/Compendium/WesternRedcedar.htm Western redcedar] {{Webarchive|url=https://web.archive.org/web/20100618151538/http://www.for.gov.bc.ca/hfp/silviculture/Compendium/WesternRedcedar.htm|date=18 June 2010}}</ref> and the United States<ref name="Silvics" /><ref name="PLANTS" /><ref name="Tesky">{{FEIS|type=tree|genus=Thuja|species=plicata|last=Tesky|first=Julie L.|date=1992}} {{webarchive|url=https://web.archive.org/web/20230813155144/https://www.fs.usda.gov/database/feis/plants/tree/thupli/all.html|date=13 August 2023}} {{source-attribution}}</ref> transliterate the English name in two words as 'western redcedar', or occasionally hyphenated as 'western red-cedar',{{sfn|Farjon|2005}} to indicate that it is not a true cedar (''[[Cedrus]]''), but it also appears as 'western red cedar' in some popular works. In the American [[horticultural]] trade, it is also known as the giant [[arborvitae]], by comparison with arborvitae for its close relative ''T.&nbsp;occidentalis''. Other names include giant red cedar, Pacific red cedar, shinglewood, [[British Columbia]] cedar (being the province's [[List of Canadian provincial and territorial symbols|official tree]]),<ref name="Arno" /> canoe cedar, and red cedar.<ref name="Gymnosperm" />{{sfn|Stewart|1984|p=22}} ''Arborvitae'' comes from the [[Latin]] for 'tree of life'; coincidentally, Native Americans of the West Coast also address the species as "long life maker".{{sfn|Stewart|1984|p=22}}

One [[Endonym and exonym|endonymous]] name for the tree is the [[Halkomelem]] word '''xepá:y''',<ref>Dictionary of Upriver Halkomelem, Volume II pp. 1605. Galloway, Brent Douglas</ref> from the roots {{lang|hur|xíp}}, meaning 'scratch' or 'line', and {{lang|hur|á:y}}, 'bark';<ref>Dictionary of Upriver Halkomelem, Volume I pp. 996. Galloway, Brent Douglas</ref> the former root may be in reference to both the lined or "folded/braided" appearance of the bark and the tree's ubiquity in carving and other forms of woodwork. It is called '''x̱ápay̓ay''' in the [[Squamish language]].<ref>{{cite web |last1=Duncan |first1=Rebecca |title=Indigenous Plant Guide: Sḵwx̱wú7mesh sníchim |url=https://museumofvancouver.ca/indigenous-plant-guide-in-squamish-language |url-status=live |archive-url=https://web.archive.org/web/20230319030718/https://museumofvancouver.ca/indigenous-plant-guide-in-squamish-language |archive-date=19 March 2023 |access-date=19 March 2023 |website=Museum of Vancouver |publisher=Sḵwx̱wú7mesh Úxwumixw}}</ref> Further south, in the [[Lushootseed|Lushootseed language]], the root for red cedar is '''x̌payʔ''' and '''x̌payʔac''' refers to a red cedar tree.<ref>{{Cite book |last1=Bates |first1=Dawn |title=Lushootseed Dictionary |last2=Hess |first2=Thom |last3=Hilbert |first3=Vi |publisher=University of Washington Press |year=1995 |location=Seattle |page=600}}</ref>

==Distribution and habitat==
[[File:Western redcedar grove, Moose Creek, Selway-Bitteroot Wilderness, Idaho, USA.jpg|thumb|alt=A dense forest of western redcedar growing on flat terrain, with a lush understory|''Thuja plicata'' often grows in moist valley bottoms.]]

''Thuja plicata'' is among the most widespread trees in the [[Pacific Northwest]]. It is associated with Douglas-fir (''[[Pseudotsuga menziesii]]'') and western hemlock (''[[Tsuga heterophylla]]'') in most places where it grows. It grows best on moist sites in areas with a wet, maritime climate,<ref name="Tesky"/> and only occurs where precipitation exceeds {{Convert|71|cm}} annually.<ref name="Silvics"/> It grows from the [[Cascade Range]] and [[Coast Mountains]] westward to the [[Pacific Ocean]], from central [[Southeast Alaska|South East]] Alaska (near the village of Kake) to [[northern California]] (growing closer to the coast at the northern and southern extremes). A [[disjunct population]] occurs inland from central-southeast British Columbia through the [[Idaho Panhandle]].<ref name="Arno" /> The easternmost extent of its distribution occurs in [[Glacier National Park (U.S.)|Glacier National Park]] in Montana, where it is a major component of forests surrounding [[Lake McDonald]].<ref>{{cite journal |last = Aller |first = Alvin R. |date = January 1960 |title = The Composition of the Lake McDonald Forest, Glacier National Park |journal =[[Ecology (journal)|Ecology]]|volume = 41 |issue = 1 |publisher = Ecological Society of America |via =[[John Wiley & Sons, Ltd]] |pages = 29{{ndash}}33 |doi = 10.2307/1931936|jstor = 1931936 |bibcode = 1960Ecol...41...29A }}</ref> It is present east of the [[Continental Divide of the Americas|continental divide]] in the park, growing in a handful of small, isolated stands.<ref name="McKenzie_Tinker">{{cite journal |last1 = Mackenzie |first1 = David A. |last2 = Tinker |first2 = Daniel B. |date = 7 February 2013 |title = A tree-community-level analysis of successional status and gap-phase and postfire regeneration of range-margin ''Thuja plicata'' (western redcedar) |journal =[[Canadian Journal of Forest Research]]|volume = 43 |issue = 2 |publisher =[[Canadian Science Publishing]]|pages = 119{{ndash}}128 |doi = 10.1139/cjfr-2012-0333|bibcode = 2013CaJFR..43..119M }}</ref> It is usually found from [[sea level]] to elevations of {{Convert|1100|m|abbr=on}},<ref name="Arno" /> but grows at altitudes of up to {{Convert|2290|m|abbr=on}} at [[Crater Lake]] in Oregon<ref name="Silvics">{{Silvics |last=Minore |first=Don |volume=1 |genus=Thuja |species=plicata}} {{source-attribution}}</ref> and {{Convert|1500|m|abbr=on}} in Idaho.<ref name="Arno" />

Western redcedar grows on many types of soils.<ref name="Silvics" /> It is present on all landforms and soil classes on Vancouver Island,<ref name="Silvics"/> but is restricted to wet, low-lying areas and streamsides in the drier eastern portions of its range.<ref name="Tesky"/> Unlike its associates western hemlock and Douglas-fir, western redcedar can grow well in environments with stagnant groundwater present less than {{convert|5|cm|in|frac=4}} below the soil surface in the winter. It does not grow as well in areas with flowing groundwater, unlike another common associate, Sitka spruce (''[[Picea sitchensis]]'').<ref>{{cite report |last1 = Minore |first1 = Don |last2 = Smith |first2 = Clark E. |date = August 1971 |title = Occurrence and growth of four northwestern tree species over shallow water tables |work = Forest Research Notes |volume = 160 |publisher = [[United States Forest Service]] (USFS), [[United States Department of Agriculture]] (USDA) |location = [[Portland, Oregon]] |via = Pacific Northwest Research Station |doi = 10.5962/bhl.title.70617|hdl = 2027/umn.31951d02995494q |hdl-access = free }}</ref> Western redcedars growing in the Rocky Mountains and along the eastern slope of the Washington Cascades are subject to higher mortality rates when growing on [[glacial till]] and sedimentary rocks than on other substrates. Western white pine (''[[Pinus monticola]]'') and Douglas-fir growing in these areas exhibit the opposite pattern, exhibiting low mortality rates on these substrates but high mortality rates on nutrient-poor [[metasedimentary rock]]s, a substrate on which western redcedar does not exhibit elevated mortality rates.<ref>{{cite journal |last1 = Moore |first1 = James A. |last2 = Hamilton |first2 = David A. |last3 = Xiao |first3 = Yu |last4 = Byrne |first4 = John |date = January 2004 |title = Bedrock type significantly affects individual tree mortality for various conifers in the inland Northwest, U.S.A. |journal = [[Canadian Journal of Forest Research]] |volume = 34 |issue = 1 |publisher = [[Canadian Science Publishing]] |pages = 31{{ndash}}42 |doi = 10.1139/x03-196|bibcode = 2004CaJFR..34...31M }}</ref>

Western redcedar is less cold-tolerant than many conifer species that it shares its range with and is vulnerable to frost damage in late spring and early fall. Its northern range limit in Southeast Alaska and its upper elevational limits on Vancouver Island are controlled by temperature. In Southeast Alaska, it is absent from areas with mean summer temperatures less than {{convert|11|C|F}}. It does not grow in areas of coastal British Columbia with minimum temperatures of less than {{convert|-30|C|F}}, although some interior populations experience colder temperatures.<ref name="Silvics"/>

It has been introduced to other temperate zones, including further north in Alaska, western Europe, [[Australia]] (at least as far north as [[Sydney]]), [[New Zealand]],{{sfn|Flora of North America|p=411}}{{sfn|Hill|1985|p=103}} and higher elevations of [[Hawaii]].<ref name=skolmen>{{cite web|first=Roger G.|last=Skolmen|url=https://books.google.com/books?id=MUPVCrgCEMAC&pg=PA2|title=Natural Durability of Some Woods Used in Hawaii|work=Pacific Southwest Forest and Range Experiment Station|year=1974|publisher=[[U.S. Forest Service]]|access-date=21 July 2013|archive-date=19 September 2023|archive-url=https://web.archive.org/web/20230919000930/https://books.google.com/books?id=MUPVCrgCEMAC&pg=PA2|url-status=live}}</ref> The species was described as [[invasive species|invasive]] in Great Britain by a 2004 survey,<ref name="InvasiveConifers">{{cite journal |last1 = Richardson |first1 = David M. |last2 = Rejmánek |first2 = Marcel |date = 6 September 2004 |title = Conifers as invasive aliens: a global survey and predictive framework |journal = Diversity and Distributions |volume = 10 |issue = 5{{ndash}}6 |publisher =[[Wiley-Blackwell]]|pages = 321{{ndash}}331 |doi = 10.1111/j.1366-9516.2004.00096.x |doi-access = free|bibcode = 2004DivDi..10..321R }}</ref> although it is not listed as such by the United Kingdom [[Department for Environment, Food and Rural Affairs]] under the [[Wildlife and Countryside Act 1981]] as of September 2022.<ref>{{cite web |url = https://www.gov.uk/guidance/invasive-non-native-alien-plant-species-rules-in-england-and-wales |title = Invasive non-native (alien) plant species: rules in England and Wales |website = gov.uk |date = 20 September 2022 |orig-date = 26 August 2020 |access-date = 31 January 2023 |archive-date = 13 February 2023 |archive-url = https://web.archive.org/web/20230213054152/https://www.gov.uk/guidance/invasive-non-native-alien-plant-species-rules-in-england-and-wales |url-status = live }}</ref> Its presence has also been recorded in Poland,<ref name="InvasiveConifers"/> where it has been identified as a potentially problematic exotic species in the [[Białowieża Forest]].<ref>{{cite report |date = February 2014 |title = IUCN Evaluation of Bialowieza Forest: Request for Supplementary Information |url = https://whc.unesco.org/uploads/nominations/33ter.pdf#page=235 |page = 39 |access-date = 1 February 2023 |archive-date = 1 February 2023 |archive-url = https://web.archive.org/web/20230201062212/https://whc.unesco.org/uploads/nominations/33ter.pdf#page=235 |url-status = live }}</ref>

==Ecology==
=== Use by wildlife ===
Western redcedar provides cover for bears, raccoons, skunks, and other animals which nest inside trunk cavities. It is used as a nest tree by cavity-nesting bird species such as [[yellow-bellied sapsucker]]s, [[hairy woodpecker]]s, [[tree swallow]]s, [[chestnut-backed chickadee]]s, and [[Vaux's swift]]s.<ref name="Tesky"/> [[Pileated woodpecker]]s on the [[Olympic Peninsula]] prefer very large western redcedars with [[heart rot]] when selecting [[roosting]] sites, but do not use them for nesting, instead relying on Pacific silver fir (''[[Abies amabilis]]'') for that purpose.<ref>{{cite journal |last1 = Aubry |first1 = Keith B. |last2 = Raley |first2 = Catherine M. |date = April 2022 |title = Selection of Nest and Roost Trees by Pileated Woodpeckers in Coastal Forests of Washington |journal = [[Journal of Wildlife Management]] |volume = 66 |issue = 2 |pages = 396{{hyphen}}402 |publisher = [[The Wildlife Society]] |via = [[Wiley (publisher)|Wiley]] |doi = 10.2307/3803172|jstor = 3803172 }}</ref> Old-growth valley bottom forests of western redcedar and western hemlock are the preferred habitat for [[white-tailed deer]] in the [[Priest River]] drainage of northern Idaho. The dense canopies of these forests prevent deep snow accumulation, which makes movement difficult for the deer.<ref>{{cite journal |last1 = Pauley |first1 = George R. |last2 = Peek |first2 = James M. |last3 = Zager |first3 = Peter |date = October 1993 |title = Predicting White-Tailed Deer Habitat Use in Northern Idaho |journal = [[Journal of Wildlife Management]] |volume = 57 |issue = 4 |pages = 904{{ndash}}913 |publisher = [[The Wildlife Society]] |via = [[Wiley (publisher)|Wiley]] |doi = 10.2307/3809096|jstor = 3809096 }}</ref>

The foliage, especially that of saplings, is an important food source year-round for [[browsing (herbivory)|browsing]] [[ungulate]]s such as [[Roosevelt elk]] and [[black-tailed deer]], especially during the winter months when little else is available.<ref name="Tesky"/> Western redcedar foliage is more palatable for browsing herbivores than the commonly associated Sitka spruce and western hemlock. Browsing by introduced [[Sitka black-tailed deer]] is a major source of mortality for seedlings and saplings in old-growth forests on Haida Gwaii, where the deer lack natural predators. The presence of deer there has been linked to a decline in western redcedar [[recruitment (biology)|recruitment]].<ref>{{cite journal |last1 = Stroh |first1 = Noémie |last2 = Baltzinger |first2 = Christophe |last3 = Martin |first3 = Jean-Louis |date = 2008 |title = Deer prevent western redcedar (Thuya plicata) regeneration in old-growth forests of Haida Gwaii: Is there a potential for recovery? |journal = [[Forest Ecology and Management]] |volume = 255 |issue = 12 |pages = 3973{{ndash}}3979 |publisher = [[Elsevier]] |doi = 10.1016/j.foreco.2008.03.039|bibcode = 2008ForEM.255.3973S }}</ref> The seeds may be eaten by birds and rodents such as [[deer mice]], but are apparently not the preferred food source for most species, possibly due to their small size or unpleasant odor.<ref>{{cite journal |last1 = Gashwiler |first1 = Jay S. |date = May 1967 |title = Conifer Seed Survival in a Western Oregon Clearcut |journal = [[Ecology (journal)|Ecology]] |volume = 48 |issue = 3 |publisher = Ecological Society of North America |pages = 431{{ndash}}438 |doi = 10.2307/1932678|jstor = 1932678 |bibcode = 1967Ecol...48..431G }}</ref><ref>{{cite journal |last1 = Gashwiler |first1 = Jay S. |date = September 1970 |title = Further Study of Conifer Seed Survival in a Western Oregon Clearcut |journal = [[Ecology (journal)|Ecology]] |volume = 51 |issue = 5 |publisher = Ecological Society of North America |pages = 849{{ndash}}854 |doi = 10.2307/1932678|jstor = 1932678 |bibcode = 1967Ecol...48..431G }}</ref> A 1937 study conducted in western [[Cowlitz County, Washington]] demonstrated a strong preference among deer mice for Douglas-fir and western hemlock seeds over western redcedar seeds.<ref>{{cite report |last1 = Moore |first1 = A. W. |date = June 1940 |title =  Wild Animal Damage to Seed and Seedlings on Cut-over Douglas Fir Lands of Oregon and Washington |work = United States Department of Agriculture Technical Bulletins |volume = 709 |page = 8 |doi = 10.22004/ag.econ.168487 |doi-access = free}}</ref> However, [[pine siskin]]s apparently favor western redcedar seeds over those of Douglas-fir and western hemlock.<ref>{{cite journal |last1 = Gashwiler |first1 = Jay S. |last2 = Ward |first2 = A. Lorin |date = 1966 |title = Western Redcedar Seed, a Food of Pine Siskins |journal = The Murrelet |volume = 47 |issue = 3 |pages = 73{{ndash}}75 |publisher = Society for Northwestern Vertebrate Biology |doi = 10.2307/3533673|jstor = 3533673 }}</ref>

=== Forest succession ===
Western redcedar appears in all stages of forest succession, but as one of the most shade-tolerant species in the Rocky Mountains and Pacific Northwest it is considered to be a [[climax species]] along with western hemlock.<ref name="Tesky"/> It will readily establish and grow in the shade of other, less shade-tolerant species such as red alder (''[[Alnus rubra]]''), black cottonwood (''[[Populus trichocarpa]]''), or Douglas-fir, and prevent seedlings of those species from establishing themselves in its shade. However, western hemlock and Pacific silver fir are more tolerant of shade.<ref name="Arno" />

A 2010 study found that ''Thuja plicata'' growing in old-growth forests {{convert|300|to|700|m|ft}} above sea level in the [[North Shore Mountains]] of British Columbia have higher growth rates than associated western hemlock and Pacific silver fir when growing underneath a closed canopy. The study also found that western redcedars do not increase their growth rates in response to canopy gap formation that occurs after the death of a mature [[overstory]] tree as much as the two other species. This result indicates that western redcedar may be less reliant on canopy gaps for recruitment than western hemlock and Pacific silver fir.<ref>{{cite journal |last1 = Stan |first1 = Amanda B. |last2 = Daniels |first2 = Lori D. |date = February 2010 |title = Growth releases of three shade-tolerant species following canopy gap formation in old-growth forests |journal = [[Journal of Vegetation Science]] |publisher = [[Wiley-Blackwell]] |volume = 21 |issue = 1 |pages = 74{{ndash}}87 |doi = 10.1111/j.1654-1103.2009.01120.x|bibcode = 2010JVegS..21...74S }}</ref> Western redcedar can also reproduce vegetatively via [[layering (horticulture)|layering]], as well as branch development from fallen branches or entire trees.<ref name="Arno" /><ref name="Silvics"/>

On northeastern Vancouver Island, western redcedar grows along with western hemlock in relatively open-canopied forests with an understory dominated by salal (''[[Gaultheria shallon]]''). Another type of forest characterized by dense stands of western hemlock and Pacific silver fir with sparse understory vegetation also occurs in the area. The two forest types occur in areas with very similar environmental conditions and are separated by sharp boundaries, often less than {{convert|10|m|ft}} wide. Western redcedar [[recruitment (biology)|recruitment]] is nearly absent in the western hemlock-Pacific silver fir forest type, and there is no evidence of a transitional stage between the two types. It has been hypothesized that, once established, these forest types are self-sustaining and are unlikely to change unless a major [[disturbance (ecology)|disturbance]] occurs.<ref>{{cite journal |last1 = Weber |first1 = Adrian |last2 = Kimmins |first2 = J. P. |last3 = Gilbert |first3 = Benjamin |last4 = Lo |first4 = Yueh-Hsin |last5 = Blanco |first5 = Juan A. |date = October 2014 |title = Multiple-pathway succession in coastal ''Tsuga heterophylla'', ''Thuja plicata'', and ''Abies amabilis'' forests on northeastern Vancouver Island, British Columbia |journal = [[Canadian Journal of Forest Research]] |publisher = [[Canadian Science Publishing]] |volume = 44 |issue = 10 |pages = 1145{{ndash}}1155 |doi = 10.1139/cjfr-2014-0060|bibcode = 2014CaJFR..44.1145W |hdl = 2454/19816 |hdl-access = free }}</ref>

=== Fire ecology ===
It is considered to have low to moderate fire resistance, as its thin bark, shallow roots, low dense branching [[habit (biology)|habit]] and flammable foliage offer little protection. Smaller trees are commonly killed by fire, but larger specimens often survive due to their size if they are not completely [[girdling|girdled]]. The intervals between fires within western redcedar stands tend to be very long, from 50 up to 350 years or more.<ref name="Tesky"/>

=== Pathology ===
Western redcedar shows susceptibility of varying degrees to the following soil pathogens: ''[[Armillaria ostoyae]], [[Fomitopsis pinicola]], [[Heterobasidion annosum]], [[Phaeolus schweinitzii]], [[Phellinus weirii]], [[Rhizina undulata|Rhizinia undulata]],'' and ''[[Postia sericeomollis]].''<ref>{{Cite book|last1 = Allen |first1 = Eric Andrew |last2 = Morrison |first2 = D. J. |last3 = Wallis |first3 = G. W.|title=Common tree diseases of British Columbia|date=1996|publisher=Pacific Forestry Centre|isbn=0-662-24870-8|location=Victoria, B.C.|oclc=35976392}}</ref>

''P. sericeomollis'' is responsible for brown cubical butt and pocket rot of cedar. It is the second-most common cause of decay in Western redcedar following ''P.&nbsp;weirii''. Rather than forming a single column of decay in the heartwood, ''P.&nbsp;sericeomollis'' tends to cause rings or pockets of decay in the lower bole.<ref>{{Cite journal|last=Buckland|first=D. C.|date=1946-10-01|title=Investigations of decay in western red cedar in british columbia|url=https://www.nrcresearchpress.com/doi/10.1139/cjr46c-018|journal=Canadian Journal of Research|volume=24c|issue=5|pages=158–181|doi=10.1139/cjr46c-018|issn=1923-4287|access-date=13 June 2020|archive-date=19 September 2023|archive-url=https://web.archive.org/web/20230919000927/https://cdnsciencepub.com/doi/10.1139/cjr46c-018|url-status=live|url-access=subscription}}</ref>

While Western redcedar is a host to ''P. weirii,'' the fungus which causes the disease laminated root rot, it is rated as resistant while other conifers are rated as highly susceptible or susceptible.<ref name="Thies1995">{{cite journal |last1 = Thies |first1 = Walter G. |last2 = Sturrock |first2 = Rona N. |date = April 1995 |title = Laminated root rot in western North America |url = https://www.fs.usda.gov/pnw/pubs/pnw_gtr349.pdf |journal = Gen. Tech. Rep. PNW-GTR-349 |publisher = [[United States Forest Service]] (USFS), [[United States Department of Agriculture]] (USDA). In collaboration with [[Natural Resources Canada]], [[Canadian Forest Service]], Pacific Forestry Centre |via = Pacific Northwest Research Station |publication-place = Portland, OR |doi = 10.2737/PNW-GTR-349 |doi-access = free |hdl = 2027/umn.31951d02889118b |access-date = 8 April 2023 |archive-date = 8 April 2023 |archive-url = https://web.archive.org/web/20230408022639/https://www.fs.usda.gov/pnw/pubs/pnw_gtr349.pdf |url-status = live }}</ref> ''P.&nbsp;weirii'' in Western redcedar expresses as a butt rot.<ref name="Thies1995"/>

In addition to ''P. weirii,'' western redcedar is also less susceptible to ''H.&nbsp;annosum'' and ''A.&nbsp;ostoyae'' than other conifer species.<ref>{{Cite book|last=Wood, David L.|title=Pests of the Native California Conifers.|date=2003|publisher=University of California Press|others=Koerber, Thomas W., Scharpf, Robert F., Storer, Andrew J.|isbn=978-0-520-93637-9|location=Berkeley|oclc=773564950}}</ref> Studies have found that western redcedar produces a phytochemical called [[thujaplicin]] which has been credited with granting the species its natural resistance to fungal attacks.{{sfn|Chedgy|Lim|Breuil|2009}} Additional research has shown that western redcedar responds to ''A.&nbsp;ostoye'' infection by producing [[wikt:necrophylactic|necrophylactic]] [[periderm]]s and [[resin duct]]s near infection sites.<ref>{{cite journal|last1 = Cleary |first1 = Michelle R. |last2 = Holmes |first2 = Terry |date = 2011 |title = Formation of traumatic resin ducts in the phloem of western redcedar (''Thuja plicata'') roots following abiotic injury and pathogenic invasion by ''Armillaria ostoyae'' |journal = [[IAWA Journal]] |publisher = [[Brill Publishers]] |volume = 32 |issue = 3 |pages = 351{{ndash}}359 |doi = 10.1163/22941932-90000063|doi-access = free }}</ref> Because of these natural defenses, it has been suggested that western redcedar may serve as a suitable alternative to other conifers when regenerating a site affected by these pathogens.<ref name="Silvics"/>

==== Cedar leaf blight ====
Western redcedar foliage can become infected by the [[ascomycete]] fungus ''[[Didymascella thujina]]'', which causes cedar leaf blight. The fungus causes leaves to turn brown and does not spread between adjacent leaves through [[hyphae]]. It is present throughout the native range of western redcedar, but reproduces best when western redcedar foliage is wet for long periods of time, with minimal wind exposure.<ref name="Kope">{{cite journal |last = Kope |first = Hary H. |date = 2000 |title = ''Didymascella thujina'' |journal = [[Canadian Journal of Plant Pathology]] |publisher = [[Taylor & Francis]] |volume = 22 |issue = 4 |pages = 407{{ndash}}409 |doi = 10.1080/07060660009500460|bibcode = 2000CaJPP..22..407K |s2cid = 218589256 }}</ref> Significant variation in resistance to cedar leaf blight exists between populations of ''Thuja plicata''; trees sourced from coastal populations exhibit higher resistance than trees from interior populations. Additional variation also occurs within populations.<ref>{{cite journal |last1 = Russell |first1 = John H. |last2 = Kope |first2 = Harry H. |last3 = Ades |first3 = Peter |last4 = Collinson |first4 = Heidi |date = 24 October 2007 |title = Variation in cedar leaf blight (''Didymascella thujina'') resistance of western redcedar (''Thuja plicata'') |journal = [[Canadian Journal of Forest Research]] |publisher = [[Canadian Science Publishing]] |volume = 37 |issue = 10 |pages = 1978{{ndash}}1986 |doi = 10.1139/X07-034|bibcode = 2007CaJFR..37.1978R }}</ref> A study published in 2013 projected a decrease in the incidence of cedar leaf blight among western redcedars in coastal British Columbia by late 21st century as a result of warmer, drier summers due to [[climate change]]. The authors of the study conceded that they were unable to incorporate the impacts of warmer winter temperatures into their model because research on the topic was lacking at the time of their study. They hypothesized that warmer winter temperatures could result in increased incidence of cedar leaf blight and cautioned that management decisions should take this uncertainty into account.<ref>{{cite journal |last1 = Gray |first1 = Lara K. |last2 = Russell |first2 = John H. |last3 = Yanchuk |first3 = Alvin D. |last4 = Hawkins |first4 = Barbara J. |date = 15 October 2013 |title = Predicting the risk of cedar leaf blight (Didymascella thujina) in British Columbia under future climate change |url = https://sites.ualberta.ca/~lkgray/uploads/7/3/6/2/7362679/gray_et_al-2013-afm-main.pdf |journal = [[Agricultural and Forest Meteorology]] |publisher = [[Elsevier]] |volume = 180 |pages = 152{{ndash}}163 |doi = 10.1016/j.agrformet.2013.04.023 |bibcode = 2013AgFM..180..152G |access-date = 17 March 2023 |archive-date = 20 January 2022 |archive-url = https://web.archive.org/web/20220120163139/https://sites.ualberta.ca/~lkgray/uploads/7/3/6/2/7362679/gray_et_al-2013-afm-main.pdf |url-status = live }}</ref>

==== Insect pathogens ====
''Thuja plicata'' is a host to several destructive insect species such as the [[Trachykele blondeli|western cedar borer]], [[Phloeosinus punctatus|cedar bark beetle]], [[redcedar cone midge]], and [[Steremnius carinatus|conifer seedling weevils]].<ref name="USDA">{{cite book |last1=Patterson |first1=Patricia A. |url=https://www.fs.fed.us/rm/pubs_int/int_gtr180.pdf |title=Field Guide to the Forest Plants of Northern Idaho |date=1985 |publisher=[[United States Forest Service]] |page=25 |access-date=3 February 2020 |archive-date=12 April 2022 |archive-url=https://web.archive.org/web/20220412204653/https://www.fs.fed.us/rm/pubs_int/int_gtr180.pdf |url-status=live }}</ref><ref name="Tesky"/> Redcedar cone midge (''Mayetiola thujae'') larvae hatch from eggs laid between the scales of immature cones, then feed on the cone scales and seeds.<ref>{{cite journal |last = Hedlin |first = A. F. |date = November 1959 |title = Description and Habits of a New Species of ''Phytophaga'' (Diptera: Cecidomyiidae) from Western Red Cedar Cones |journal = [[The Canadian Entomologist]] |publisher = [[Entomological Society of Canada]] |volume = 91 |issue = 11 |pages = 719{{ndash}}723 |doi = 10.4039/Ent91719-11|s2cid = 84794683 }}</ref> The application of [[insecticide]]s has been used as a control measure.<ref>{{cite web |title = Cone and Seed Insect Pest Leaflet no. 1: Redcedar Cone Midge (''Mayetiola thujae'') |date = February 2014 |orig-date = August 2010 |website = forestgeneticsbc.ca |publisher = Forest Genetics Council of British Columbia |via = [[British Columbia Ministry of Forests]] |url = https://forestgeneticsbc.ca/wp-content/uploads/2020/07/1-Redcedar-Cone-Midge-Mayetiola-thujae.pdf |access-date = 24 March 2023 |archive-date = 24 March 2023 |archive-url = https://web.archive.org/web/20230324023501/https://forestgeneticsbc.ca/wp-content/uploads/2020/07/1-Redcedar-Cone-Midge-Mayetiola-thujae.pdf |url-status = live }}</ref>

===Cedar dieback attributed to climate change===

"Uncommonly hot, dry weather" in coastal Washington State, beginning in 2015, has been attributed as the underlying cause of a large dieback of this species that could not otherwise be attributed to any "killer pest or known pathogen."<ref>{{cite news |last1=Turner |first1=Nicholas |title=Has this iconic Northwest tree reached a tipping point? |url=https://www.seattletimes.com/seattle-news/environment/has-this-iconic-northwest-tree-reached-a-tipping-point/ |publisher=Seattle Times |date=30 October 2022 |access-date=6 September 2023 |archive-date=6 September 2023 |archive-url=https://web.archive.org/web/20230906225755/https://www.seattletimes.com/seattle-news/environment/has-this-iconic-northwest-tree-reached-a-tipping-point/ |url-status=live }}</ref>

== Cultivation ==
Like its relative ''[[Thuja occidentalis]]'' and many other conifer species, ''T. plicata'' is grown as an [[ornamental tree]], and for screens and [[Hedge (gardening)|hedge]]s, throughout the world in [[garden]]s and parks. A wide variety of forms, sizes, and colors are available.{{sfn|Bitner|2007|p=424}}

;Cultivars
The following [[cultivar]]s have gained the [[Royal Horticultural Society]]'s [[Award of Garden Merit]]:
* 'Atrovirens'<ref>{{cite web |title=RHS Plant Selector – ''Thuja plicata'' 'Atrovirens' |url=https://www.rhs.org.uk/Plants/90085/Thuja-plicata-Atrovirens/Details |access-date=5 March 2021 |publisher=RHS |archive-date=29 January 2022 |archive-url=https://web.archive.org/web/20220129013016/https://www.rhs.org.uk/plants/90085/thuja-plicata-atrovirens/details |url-status=live }}</ref>
* 'Aurea'<ref>{{cite web |title=RHS Plant Selector – ''Thuja plicata'' 'Aurea' |url=https://www.rhs.org.uk/Plants/96463/Thuja-plicata-Aurea/Details |access-date=5 March 2021 |publisher=RHS |archive-date=29 January 2022 |archive-url=https://web.archive.org/web/20220129005040/https://www.rhs.org.uk/plants/96463/thuja-plicata-aurea/details |url-status=live }}</ref>
* 'Stoneham Gold'<ref>{{cite web |title=RHS Plant Selector – ''Thuja plicata'' 'Stoneham Gold' |url=https://www.rhs.org.uk/Plants/44836/Thuja-plicata-Stoneham-Gold/Details |access-date=5 March 2021 |publisher=RHS |archive-date=29 January 2022 |archive-url=https://web.archive.org/web/20220129003653/https://www.rhs.org.uk/plants/44836/thuja-plicata-stoneham-gold/details |url-status=live }}</ref>
* 'Whipcord'<ref>{{cite web |title=RHS Plantfinder – ''Thuja plicata'' 'Whipcord' |url=https://www.rhs.org.uk/Plants/220111/Thuja-plicata-Whipcord/Details |access-date=23 December 2018 |archive-date=19 September 2023 |archive-url=https://web.archive.org/web/20230919000933/https://www.rhs.org.uk/plants/220111/thuja-plicata-whipcord/details |url-status=live }}</ref>
* 'Zebrina'<ref>{{cite web |title=''Thuja plicata'' 'Zebrina' |url=https://www.rhs.org.uk/Plants/89917/Thuja-plicata-Zebrina-(v)/Details |access-date=5 March 2021 |publisher=RHS |archive-date=29 January 2022 |archive-url=https://web.archive.org/web/20220129005846/https://www.rhs.org.uk/plants/89917/thuja-plicata-zebrina-(v)/details |url-status=live }}</ref>

==Uses==

=== In indigenous societies ===
[[File:Klallam people near canoe.jpg|thumb|upright=1.3|[[Klallam]] people and canoe, ca. 1914]]

Western redcedar is considered the Tree of Life by many of the First Nations of the Pacific Northwest, as the tree gave them everything that they needed for life: food, water (in the form of water tight woven cedar bark baskets), clothing, medicine, transportation (their canoes made from the wood), shelter (boards of wood used to build their long houses), and spirituality (the boughs being used in many ceremonies).{{sfn|Stewart|1984}}{{page needed|date=January 2023}} Some northwest coast tribes refer to themselves as "people of the Red Cedar" because of their extensive dependence on the tree for basic materials. The wood has been used for constructing housing and [[totem pole]]s, and crafted into many objects, including masks, utensils, boxes, boards, instruments, canoes, vessels, houses, and ceremonial objects. Western redcedar is also associated with a long tradition of curing and cooking fish over the open fire. Roots and bark are used for baskets, bowls, ropes, clothing, blankets, and rings.{{sfn|Stewart|1984|pp=17–19}}{{sfn|Van Pelt|2001|p=30}}

A huge number of archaeological finds point to the continuous use of redcedar wood in native societies. Woodworking tools dating between 8,000 and 5,000 years ago, such as carved antlers, were discovered in [[shell midden]]s at the Glenrose site, near [[Vancouver]], British Columbia.{{sfn|Stewart|1984|p=27}} In [[Yuquot]], on the west coast of Vancouver Island, tools dating 4,000 to 3,000 years old have been found.{{sfn|Stewart|1984|p=27}} The Musqueam site, also near Vancouver, yielded bark baskets woven in five different styles, along with ropes and ships dated to 3,000 years ago. At [[Pitt River]], [[adze]]s and baskets were dated around 2,900 years ago. Wooden artefacts 1000 years old were unearthed on the east coast of Vancouver Island.{{sfn|Stewart|1984|p=26}}

Western redcedar was used extensively wherever it was found along the northwest coast (British Columbia, [[Washington state]], parts of Alaska). Evidence of this use is found in [[culturally modified trees]] (CMTs) that are found throughout the coast. When First Nations people removed the bark from cedars, it left a scar{{Snd}}which is considered a CMT. Other types of harvest (for planks, tinder, and other uses) leave different types of evidence of cultural modification.

A legend amongst the [[Coast Salish peoples]] describes the origins of the western redcedar. In this legend, there was a generous man who gave the people whatever they needed. When the [[Great Spirit]] saw this, he declared that when the generous man died, a great Red Cedar tree will grow where he is buried, and that the cedar will be useful to all the people, providing its roots for baskets, bark for clothing, and wood for shelter.{{sfn|Stewart|1984|p=27}}

==== Tools ====
The wood was worked primarily with the [[adze]], which was preferred over all other tools, even ones introduced by Europeans. Alexander Walker, an ensign on the fur trade ship ''Captain Cook'', reported that the indigenous peoples used an elbow adze, which they valued over tools brought by the Europeans, such as the [[saw]] or the [[axe]], going so far as to modify traded tools back into an adze. Tools were generally made from stone, bone, [[obsidian]], or a harder wood such as [[Tsuga|hemlock]]. A variety of hand [[Post maul|maul]]s, wedges, chisels, and knives are also used.

Excavations done at [[Ozette, Washington]], turned up iron tools nearly 800 years old, far before European contact. When [[James Cook]] passed the area, he observed that almost all tools were made of iron.{{sfn|Stewart|1984|p=36}} There has been speculation on the origin of these iron tools. Some theories include shipwrecks from [[East Asia]] or possible contact with iron-using cultures from [[Siberia]], as hinted in the more advanced woodworking found in northern tribes such as the [[Tlingit people|Tlingit]].{{sfn|Stewart|1984|p=36}}{{sfn|Pritzker|1998|p=292}}{{sfn|Miller|2008|p=67}}<ref>DeCapua, pp. 16–20</ref>

==== Wood ====
[[File:Moa-4.jpg|thumb|left|A [[totem pole]] outside a six-post house at the [[University of British Columbia]]]]

Harvesting western redcedar required some ceremony and included propitiation of the tree's spirits as well as those of the surrounding trees. In particular, many people specifically requested the tree and its brethren not to fall or drop heavy branches on the harvester,{{sfn|Stewart|1984|p=39}} a situation which is mentioned in a number of different stories of people who were not sufficiently careful. Some professional loggers of Native American descent have mentioned that they offer quiet or silent propitiations to trees which they fell, following in this tradition.

Felling of large trees such as western redcedar before the introduction of steel tools was a complex and time-consuming art. Typically the bark was removed around the base of the tree above the buttresses. Then some amount of cutting and splitting with stone adzes and mauls would be done, creating a wide triangular cut. The area above and below the cut would be covered with a mixture of wet moss and clay as a firebreak. Then the cut would be packed with tinder and small kindling and slowly burned. The process of cutting and burning would alternate until the tree was mostly penetrated through, and then careful tending of the fire would fell the tree in the best direction for handling. This process could take many days. A constant rotation of workers was involved to keep the fires burning through night and day, often in a remote and forbidding location.{{sfn|Stewart|1984|pp=37–38}}

Once the tree was felled, the work had only just begun, as it then had to be stripped and dragged down to the shore. If the tree was to become canoes, then it would often be divided into sections and worked into rough canoe shapes before transport. If it were to be used for a totem pole or building materials, it would be towed in the round to the village.{{sfn|Stewart|1984|p=40}} Many trees are still felled in this traditional manner for use as totem poles and canoes, particularly by artists who feel that using modern tools is detrimental to the traditional spirit of the art. Non-traditionalists simply buy redcedar logs or lumber at mills or lumber yards, a practice that is commonly followed by most working in smaller sizes such as for masks and staves.

Because felling required such an extraordinary amount of work, if only planks for housing were needed, these would be split from the living tree. The bark was stripped and saved, and two cuts were made at the ends of the planking. Then wedges would be pounded in along the sides and the planks slowly split off the side of the tree.{{sfn|Stewart|1984|p=42}} Trees which have been so harvested are still visible in some places in the rainforest, with obvious chunks taken off of their sides. Such trees usually continue to grow perfectly well, since redcedar wood is resistant to decay. Planks are straightened by a variety of methods, including weighing them down with stones, lashing them together with rope, or forcing them between a line of stakes.{{sfn|Stewart|1984|p=43}}

Redcedar wood is used to make huge [[monoxyla]] [[canoe]]s in which the men went out to high sea to harpoon [[whale]]s and conduct trade.{{sfn|McNeese|2002|p=43}} One of those canoes, a {{convert|38|ft|m|adj=on|order=flip}} craft dug out about a century ago, was bought in 1901 by Captain [[John Voss (sailor)|John Voss]], an adventurer. He gave her the name of [[Tilikum (boat)|Tilikum]] ('Relative' in Chinook jargon), rigged her, and led her in a hectic three-year voyage from British Columbia to [[London]].{{sfn|Dill|2006|pp=127–128}}

Redcedar branches are very flexible and have good tensile strength. They were stripped and used as strong cords for [[fishing]] line, nets,<ref name="Arno" /> rope cores, twine, and other purposes where bark cord was not strong enough or might fray. Both the branches and bark rope have been replaced by modern fiber and nylon cordage among the aboriginal northwest coast peoples, though the bark is still in use for the other purposes mentioned above.{{Cn|date=May 2025}}

==== Bark ====
[[File:Thuja plicata bark.png|thumb|upright|Illustration of women pulling bark from a tree, from ''Indian Legends of Vancouver Island'' by Alfred Carmichael]]

At the right time of year, the bark is easily removed from live trees in long strips. It is harvested for use in making mats, [[rope]] and cordage, [[basket]]ry, rain hats, [[clothing]], and other soft goods. The harvesting of bark must be done with care, as stripping too much bark will kill the tree. To prevent this, the harvester usually only harvests from trees that have not been stripped before.{{sfn|Stewart|1984|p=116}} After harvesting, the tree is not used for bark again, although it may later be felled for wood. Stripping bark is usually started with a series of cuts at the base of the tree above any buttresses, after which the bark is peeled upwards. To remove bark high up, a pair of platforms strung on rope around the tree are used and the harvester climbs by alternating between them for support. Since western redcedars lose their lower branches as all tall trees do in the rainforest, the harvester may climb {{cvt|10|m|ft}} or more into the tree by this method. The harvested bark is folded and carried in backpacks.{{sfn|Stewart|1984|p=115}} It can be stored for quite some time as mold does not grow on it and is moistened before unfolding and working. It is then split lengthwise into the required width and woven or twisted into shape. Bark harvesting was mostly done by women, despite the danger of climbing ten meters in the air, because they were the primary makers of bark goods.{{sfn|Stewart|1984|p=113}}

Today bark rope making is a lost art in many communities, although it is still practiced for decoration or art in a few places. Other uses of bark are still common for artistic or practical purposes. In recent years there has been a revival of cedar weaving in some communities, and along with it, new forms of cedar bark products. For example, in some recent weddings cedar roses are used to decorate the tables.

===Timber===
[[File:SeneddFunnel.jpg|thumb|left|upright=1.3|Canadian western redcedar cowl in the [[Senedd building|National Assembly for Wales]]]]

The soft red-brown timber has a tight, straight grain and few knots. It is valued for its distinct appearance, aroma, and its high natural resistance to decay, being extensively used for outdoor construction in the form of posts, decking, [[Shake (shingle)|shingles]], and siding.<ref name="forestsor08">{{cite web | url=http://www.oregon.gov/odf/pubs/docs/forests_for_oregon/ffo_fall_08.pdf | title=Western Redcedar, "Tree of Life" | publisher=Oregon Department of Forestry | work=Forests for Oregon | date=Fall 2008 | access-date=18 September 2014 | author=Chase, Jeri | pages=18–19 | archive-date=24 November 2014 | archive-url=https://web.archive.org/web/20141124090603/http://www.oregon.gov/odf/pubs/docs/forests_for_oregon/ffo_fall_08.pdf | url-status=live }}</ref> It is commonly used for the framing and longwood in lightweight sail boats and kayaks. In larger boats it is often used in sandwich construction between two layers of epoxy resin and/or fiberglass or similar products. Due to its light weight{{Snd}}{{cvt|390|to|400|kg/m3|lb/cuft}} dried{{Snd}}it is about 30% lighter than common boat building woods, such as mahogany. For its weight it is quite strong but can be brittle. It glues well with epoxy resin or [[resorcinol]] adhesive.

Its light weight, strength, and dark, warm sound make it a popular choice for [[guitar]] [[sound board (music)|soundboards]], particularly among European guitar builders such as Lowden and Furch.

Western redcedar wood is [[Export Administration Regulations|export-restricted in the United States]].<ref>{{Cite web |date=2016-06-06 |title=5 Things You Would Never Expect Need an Export License |url=https://www.visualcompliance.com/blog/?p=185 |access-date=2022-03-12 |website=The Export Compliance Journal |language=en-US |archive-date=28 June 2022 |archive-url=https://web.archive.org/web/20220628215948/https://www.visualcompliance.com/blog/?p=185 |url-status=live }}</ref> The tree is highly allergenic and woodworkers or [[loggers]] who work with it may have adverse reactions, including the development of [[occupational asthma]], exacerbation of existing [[asthma]], reduction of [[lung function]], and eye irritation. Approximately 5% of workers are allergic to western redcedar. The US [[Occupational Safety and Health Administration]] has set a [[permissible exposure limit]] for western redcedar dust of 2.5&nbsp;mg/m<sup>3</sup> as a time-weighted average over eight hours.<ref>{{Cite web|url = https://www.cdc.gov/niosh/pel88/WOODDUST.html|title = Wood Dust|date = 28 September 2011|publisher = OSHA/NIOSH|access-date = 16 September 2017|archive-date = 6 April 2021|archive-url = https://web.archive.org/web/20210406003839/https://www.cdc.gov/niosh/pel88/wooddust.html|url-status = live}}</ref>

{{clear}}

=== Essential oil ===
The [[essential oil]] of western redcedar leaves contains natural compounds, such as α-[[thujone]], β-[[thujone]], [[fenchone]], [[sabinene]], [[terpinen-4-ol]] and beyerene,<ref>{{cite journal |last1=Lis |first1=Anna |last2=Swaczyna |first2=Agata |last3=Krajewska |first3=Agnieszka |last4=Mellor |first4=Karolina |date=July 2019 |title=Chemical Composition of the Essential Oils From Twigs, Leaves, and Cones of Thuja plicata and Its Cultivar Varieties "Fastigiata", "Kornik," and "Zebrina" |journal=Natural Product Communications |volume=14 |issue=7 |pages=1934578X1986290 |doi=10.1177/1934578X19862904 |doi-access=free |s2cid=202164043}}</ref> which have also been isolated from different other essential oils. Some of these substances are [[Aromatic compound|aroma compounds]] and are used in [[perfume]]ry.<ref>{{cite journal |last1=Fahlbusch |first1=Karl-Georg |last2=Hammerschmidt |first2=Franz-Josef |last3=Panten |first3=Johannes |last4=Pickenhagen |first4=Wilhelm |last5=Schatkowski |first5=Dietmar |last6=Bauer |first6=Kurt |last7=Garbe |first7=Dorothea |last8=Surburg |first8=Horst |date=15 January 2003 |title=Flavors and Fragrances |journal=Ullmann's Encyclopedia of Industrial Chemistry |pages=a11_141 |doi=10.1002/14356007.a11_141 |isbn=3-527-30673-0}}</ref> Thujones are [[GABAA receptor|GABA<sub>A</sub> receptor]] [[GABA receptor antagonist|competitive antagonists]], but do not have any pharmacological use due to their high toxicity and [[convulsive]] activity.<ref>{{cite journal |last1=Olsen |first1=R. W. |date=25 April 2000 |title=Absinthe and gamma -aminobutyric acid receptors |journal=Proceedings of the National Academy of Sciences |volume=97 |issue=9 |pages=4417–4418 |bibcode=2000PNAS...97.4417O |doi=10.1073/pnas.97.9.4417 |pmc=34311 |pmid=10781032 |doi-access=free}}</ref>
[[File:Wester-redcedar-guitar-top.jpg|thumb|Western redcedar used as a guitar top for a steel stringed guitar]]

=== Other uses ===
It is also widely used throughout Europe and America for making [[beehive]] components.{{Cn|date=May 2024}}

Its bark has been studied for applications in [[polyurethane]].<ref>{{Cite web|last=Chen|first=Heyu|title=The Utilization of Bark and Bark Components from Western Red Cedar (Thuja plicata) for Polyurethane Applications|url=https://tspace.library.utoronto.ca/bitstream/1807/101061/1/Chen_Heyu_%20_202006_PhD_thesis.pdf|url-status=live|access-date=26 April 2021|archive-date=26 April 2021|archive-url=https://web.archive.org/web/20210426192249/https://tspace.library.utoronto.ca/bitstream/1807/101061/1/Chen_Heyu_%20_202006_PhD_thesis.pdf}}</ref>

Used in the construction of windows and doors (joinery grade timber).{{Cn|date=May 2024}}

Western red cedar is still highly valued as "tonewood" for stringed instruments' sound boards.{{Cn|date=May 2024}}

==Notable specimens==
[[File:QuinaultLakeCedar 7274c.jpg|thumb|upright=.96|The Quinault Lake Redcedar was the world's largest western redcedar.]]

The largest living specimen is the [[Cheewhat Giant]], in [[Pacific Rim National Park Reserve]] on [[Vancouver Island]], at {{convert|15870|cuft|m3|-1|order=flip}}, with a diameter of 5.8 m (19 ft).{{sfn|Van Pelt|2001|p=34}}<ref name=":0" /> The tallest well-documented individual is called Whisky Creek Cedar II in [[Qualicum Beach]], on Vancouver Island. It stands {{convert|206|ft|m|abbr=on|order=flip}} in height,<ref>{{Cite web |title=Western Redcedar 'Whisky Creek Cedar II' along Whisky Creek, Qualicum Beach, British Columbia, Canada |url=https://www.monumentaltrees.com/en/can/britishcolumbia/qualicumbeach/32914_whiskycreek/60462/ |access-date=2023-09-23 |website=www.monumentaltrees.com}}</ref><ref name=":0">{{Cite web |title=Conifers {{!}} BC BigTree |url=https://bigtrees.forestry.ubc.ca/bc-bigtree-registry/conifers/ |access-date=2023-09-23 |website=BC BigTree Website |language=en-US}}</ref> although even taller ones are known to exist.<ref name=":0" /><ref>{{Cite web |title=Western Redcedars (Thuja plicata) worldwide |url=https://www.monumentaltrees.com/en/world-westernredcedar/hd1 |access-date=2023-09-23 |website=www.monumentaltrees.com}}</ref> The 'Quinault Lake Redcedar' was the largest known western redcedar in the world, with a wood volume of {{convert|17650|cuft|m3|abbr=on|order=flip}}. Located near the northwest shore of [[Lake Quinault]] north of [[Aberdeen, Washington]], about {{convert|34|km}} from the Pacific Ocean, it was one-third the volume of the largest known tree, a [[giant sequoia]] named '[[General Sherman Tree|General Sherman]]'. The Quinault Lake Redcedar was {{convert|174|ft|m|abbr=on|order=flip}} tall with a diameter of {{convert|19.5|ft|m|abbr=on|order=flip}} at breast height. The Quinault Lake Redcedar was destroyed by a series of storms in 2014 and 2016 and is now only a stump.<ref name="Gymnosperm" />{{sfn|Van Pelt|2001|p=32}} The fifth-largest known was the Kalaloch Cedar in [[Olympic National Park]], at {{convert|12370|cuft|m3|abbr=on|order=flip}},{{sfn|Van Pelt|2001|p=37}} until it was destroyed by a storm in March 2014.<ref>Exotic Hikes, [http://exotichikes.com/olympic-national-parks-kalaloch-cedar-destroyed-by-storm/ "Olympic National Park's Kalaloch Cedar Destroyed by Storm"] {{Webarchive|url=https://web.archive.org/web/20141024022919/http://exotichikes.com/olympic-national-parks-kalaloch-cedar-destroyed-by-storm/ |date=24 October 2014 }}</ref>

A redcedar over {{cvt|71|m|ft}} tall, {{cvt|4.5|m|ft}} in diameter, and over 700 years old stood in [[Cathedral Grove]] on Vancouver Island before it was set on fire and destroyed by vandals in 1972. That tree now lies in "Giant's Grave", a self-dug 'grave' created by the force of its own impact.<ref name="Cathedral Grove Site">{{Cite web |url=http://www.cathedralgrove.eu/text/01-Cathedral-Grove-4.htm |title=Picture of the Cathedral Grove stump. |access-date=30 March 2010 |archive-date=7 April 2010 |archive-url=https://web.archive.org/web/20100407084559/http://www.cathedralgrove.eu/text/01-Cathedral-Grove-4.htm |url-status=live }}</ref> A specimen measuring {{cvt|18|ft|m|order=flip}} diameter and {{cvt|177|ft|m|order=flip}} tall on the Giant Red Cedar National Recreation Trail in the [[Idaho Panhandle National Forests]] is designated the "Champion Tree of Idaho".<ref>{{Cite web |title=Idaho Giant Red Cedar – NRT Database |url=https://www.nrtdatabase.org/trailDetail.php?recordID=3333 |access-date=20 November 2021 |archive-date=20 November 2021 |archive-url=https://web.archive.org/web/20211120190130/https://www.nrtdatabase.org/trailDetail.php?recordID=3333 |url-status=live }}</ref>

The [[Giant Cedar Stump]] is an ancient redcedar turned [[roadside attraction]] in [[Snohomish County, Washington|Snohomish County]], [[Washington (state)|Washington]].<ref name="EarlyDriveThroughAttraction">{{cite news |last=Dorpat |first=Paul |date=27 October 2016 |title=This tunneled tree stump in Snohomish County was an early drive-through attraction |url=https://www.seattletimes.com/pacific-nw-magazine/this-tunneled-tree-stump-in-snohomish-county-was-an-early-drive-through-attraction/ |newspaper=The Seattle Times |access-date=31 May 2022 |archive-date=31 May 2022 |archive-url=https://web.archive.org/web/20220531091916/https://www.seattletimes.com/pacific-nw-magazine/this-tunneled-tree-stump-in-snohomish-county-was-an-early-drive-through-attraction/ |url-status=live }}</ref>

==See also==
* [[List of plants known as cedar]]
* [[List of superlative trees]]

==References==
{{Reflist}}

==Works cited==
{{Refbegin|32em}}
* {{cite book|last=Bitner|first=Richard L.|title=Conifers for Gardens: an Illustrated Encyclopedia|year=2007|publisher=Timber Press|location=United Kingdom|isbn=978-0-88192-830-3|url=https://archive.org/details/conifersforgarde0000bitn}}
* {{eFloras|1 |volume=2 |first=Kenton L. |last=Chambers |ref={{harvid|Flora of North America}}}}
* {{cite journal |last1=Chedgy |first1=Russell J. |first2=Young Woon |last2=Lim |first3=Colette |last3=Breuil |name-list-style=amp |year=2009 |title=Effects of leaching on fungal growth and decay of western redcedar (''Thuja plicata'') |journal=[[Canadian Journal of Microbiology]] |volume=55 |issue=5 |pages=578–586 |pmid=19483786 |doi=10.1139/W08-161 }}
* {{cite book|last=DeCapua|first=Sarah|title=The Tlingit|series=First Americans|location=Tarrytown, New York|publisher=Marshall Cavendish Benchmark|year=2010|isbn=978-0-7614-4135-9}}
* {{cite book|last=Dill|first=J. Gregory|title=Myth, Fact, And Navigators' Secrets: Incredible Tales of the Sea And Sailors|url=https://archive.org/details/mythfactnavigato0000dill|url-access=registration|year=2006|location=Guilford, Connecticut|publisher=The Lyons Press|isbn=1-59228-879-0}}
* {{cite book |last=Farjon |first=A. |year=2005 |title=Monograph of Cupressaceae and ''Sciadopitys'' |publisher=[[Royal Botanic Gardens, Kew]] |isbn=1-84246-068-4 }}
* {{cite book|last=Gardner|first=J. A. F.|title=The Chemistry and Utilization of Western Red Cedar|year=1963|location=Ottawa, Ontario|publisher=Department of Forestry|oclc=65814710}}
* {{cite book|last=Hill|first=Anthony|title=Antique Furniture in Australia|location=Victoria, British Columbia|publisher=Viking Press|year=1985|isbn=0-670-80319-7}}
* {{cite book|last=McNeese|first=Tim|title=Early North America|location=St. Louis, Missouri|year=2002|publisher=Milliken Publishing|isbn=0-7877-0527-6}}
* {{cite book|last=Miller|first=Mike|title=Alaska's Southeast: Touring the Inside Passage|edition=11th|year=2008|publisher=Globe Pequot Press|location=Guilford, Connecticut|issn=1545-1941|isbn=978-0-7627-4535-7}}
* {{cite book|last=Pritzker|first=Barry M.|title=Native Americans: An Encyclopedia of History, Culture, and Peoples|year=1998|publisher=ABC-CLIO|location=Santa Barbara, California|volume=1|isbn=0-87436-836-7|url=https://archive.org/details/nativeamericanse00barr}}
* {{cite book|last=Stewart|first=Hilary|year=1984|title=Cedar: Tree of Life to the Northwest Coast Indians|url=https://archive.org/details/cedartreeoflifet0000stew|url-access=registration|location=Vancouver, British Columbia|publisher=Douglas & McIntyre|isbn=0-88894-437-3}}
* {{cite book|last=Van Pelt|first=Robert|year=2001|title=Forest Giants of the Pacific Coast|publisher=Global Forest Society and University of Washington Press|isbn=0-295-98140-7|url=https://archive.org/details/forestgiantsofpa0000vanp}}
* {{cite book|title=Conifers Around the World|year=2012|publisher=DendroPress|isbn=978-963-219-061-7|page=1089|url=http://conifersaroundtheworld.com/|author1=Zsolt Debreczy|author2=Istvan Racz|edition=1st|editor=Kathy Musial|access-date=24 September 2013|archive-date=8 December 2015|archive-url=https://web.archive.org/web/20151208103230/http://conifersaroundtheworld.com/|url-status=live}}
{{Refend}}

==External links==
* {{Commons-inline|Thuja plicata|''Thuja plicata''}}
* {{PFAF|Thuja plicata}}
* {{Calflora}}
* {{CalPhotos|Thuja|plicata}}

{{Cupressaceae}}
{{Taxonbar|from=Q147417}}
{{Authority control}}

[[Category:Thuja|plicata]]
[[Category:Flora of the Cascade Range]]
[[Category:Flora of the Klamath Mountains]]
[[Category:Flora of the Rocky Mountains]]
[[Category:Flora of California]]
[[Category:Trees of mild maritime climate]]
[[Category:Trees of temperate climates]]
[[Category:Trees of Northern America]]
[[Category:Plants described in 1824]]
[[Category:Building materials]]
[[Category:Provincial symbols of British Columbia]]
[[Category:Least concern plants]]
[[Category:Least concern flora of North America]]
[[Category:Least concern flora of the United States]]