Editing Thuja plicata (section)

==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>