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Course:CONS200/2026WT2/Climate change impacts on Western redcedar

2026-04-13T05:09:47Z

AdrianTan:

== Introduction ==
Western redcedars (''Thuja plicata'') are one of the most significant tree species to the ecosystems of the Pacific Northwest (PNW) along with being very culturally, and economically significant.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref> The Coast Salish people refer to this tree as the "tree of life"; it has sustained Indigenous communities for centuries, providing materials for all sorts of utilities; shelter, tools, clothing, canoes, ceremonial and many more uses.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref> The Western redcedar is a keystone species to the coastal and wet interior forests of the ecosystems across British Columbia and the PNW.
[[File:Thuja plicata Vancouver.jpg|thumb|''Thuja plicata'', Vancouver, BC, Canada.]]
Currently, the largest species of the cypress cedar family is being driven to extinction by the rapidly accelerating climate change, prolonged and harsh summer conditions, droughts, and rapidly rising temperatures, killing off the Western redcedar populations en masse.<ref>{{Cite web | last=Canada | date=2023 | title=Information archivée dans le Web | Information Archived on the Web | url=https://publications.gc.ca/site/eng/9.915415/publication.html | url-status=live | website=Publications.gc.ca}}</ref> Since such a large amount Western redcedars are turning into snags and the rapid changes of climate that the species are adapted to is destabilizing, it has alarmed ecologists, foresters, and Indigenous communities pushing them to act to save the trees from mass extinction. The decline is not uniform and unpredictable due to the ever changing weather patterns: low elevation, south-facing, and low moisture sites are experiencing the most severe casualties, even so the coastal and interior populations have some variance in both their vulnerability and resilience due to the differing adaptations overtime they have attained.<ref>{{Cite web | last=Brend | first=Y. | date=2019-05-14 | title=Western red cedars die off as extended dry spells continue, say experts | url=https://www.cbc.ca/news/canada/british-columbia/western-red-cedars-death-dry-climate-change-1.5134262 | url-status=live | website=CBC News}}</ref><ref>{{Cite web | author=College of the Environment & Northwest Climate Adaptation Science Center | date=2020 | title=Decline of Western redcedar: Using tree rings to understand mortality patterns and identify drought-resilient populations under climate change | url=https://nwcasc.uw.edu/science/project/decline-of-western-red-cedar-using-tree-rings-to-understand-mortality-patterns-and-identify-drought-resilient-populations-under-climate-change/ | url-status=live | website=Northwest Climate Adaptation Science Center}}</ref> To understand the forces behind the dire population decline and the strategies being developed to counter it, it is essential to preserve and use the ecosystem services of the tree it provides to our advantage, the micro climates it induces and cultural heritage and knowledge that the Western redcedar represents. This article examines the cultural and economic importance of the species, the climate-driven stressors accelerating its decline, observed impacts across the Pacific Northwest, emerging management strategies of the future, and the regional differences shaping how this crisis unfolds through climate models and future projections.

== Economic and Cultural Importance ==

=== Economic Importance ===
The Western redcedar holds significant economic value through its contributions to forest productivity and the timber industry. When planted alongside other species, Western redcedars produce calcium in its foliage, acting like a nutrient supply for surrounding trees. Other species tend to benefit, as the Western redcedar helps suppress the spread of diseases within a site.<ref>{{Cite web | last=Omari | first=K. | last2=Kranabetter | first2=J. M. | last3=de Montigny | first3=L. | date=2021 | title=Productivity of coastal Douglas-fir and western redcedar in response to species mixture, planting density, and soil carbon:nitrogen ratio | url=https://doi.org/10.1139/cjfr-2020-0223 | url-status=live | website=Canadian Journal of Forest Research}}</ref> Beyond its ecological contributions, the Western redcedar’s long lifespan and low mortality rate make it exceptionally resilient under harsh conditions, allowing it to form a symbiotic relationship with the species surrounding it.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref> Economically, the species accounts for approximately 18% of British Columbia’s coastal timber harvest. and around 3% of the interior harvest, making it a crucial resource for forestry business across the province.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref> The western redcedar is one of the most important sources in British Columbia showing the importance of this tree. Timber harvests create job opportunities for many people and have over one million dollars from Western redcedar products.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref> The Western redcedar also has resistance to many pests making the tree a desirable species to do reforestation on a site.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref> This is good for restoring places that are deforested and improving economic value.

=== Cultural Importance ===
[[File:Coast Salish style canoe.jpg|left|thumb|Coast Salish style canoe]]
The Western redcedar provides cultural importance. The First Peoples would use the Western redcedar to make shelters, drying racks, spear shafts, dipnet frames, paddles, canoe frames, and many other items.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref> This shows that the Western redcedar tree was not just a tree, but something that is a part of their culture through all the items they make through the tree. The First Peoples also used the Western redcedar for building material, clothing, fuel, and medicine. The Western redcedar was also used for survival giving importance to this tree species. The Coast Salish people refer this tree to the tree of life.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref> The people would pray of respect and gratitude to the tree before harvesting the tree.<ref>{{Cite web | last=Joseph | first=B. | date=2025-04-04 | title=Indigenous sacred plants: Red cedar | url=https://www.ictinc.ca/blog/indigenous-sacred-plants-cedar | url-status=live | website=Indigenous Corporate Training Inc.}}</ref> This shows the significance it has in their culture. The reason why the Western redcedar has value is because of how it provided for the First Peoples that were here for a long time.

== Climate Change Drivers ==
Climate change has intensified drought and heat stress across the Pacific Northwest, creating conditions that directly contribute to widespread Western redcedar (''Thuja plicata'') decline. Extended dry periods have become more frequent and severe, reducing soil moisture during critical growing months. Field observations in British Columbia show that redcedar dieback often follows consecutive years of unusually hot, dry summers, with mortality concentrated in low‑elevation and exposed sites where moisture deficits accumulate most rapidly.<ref>{{Cite web | last=Brend | first=Y. | date=2019-05-14 | title=Western red cedars die off as extended dry spells continue, say experts | url=https://www.cbc.ca/news/canada/british-columbia/western-red-cedars-death-dry-climate-change-1.5134262 | url-status=live | website=CBC News}}</ref>

Long‑term climate assessments from Natural Resources Canada indicate that warming trends are accelerating across coastal and interior regions, increasing both evapotranspiration and the frequency of extreme heat events.<ref>{{Cite web | last=Canada | date=2023 | title=Information archivée dans le Web | Information Archived on the Web | url=https://publications.gc.ca/site/eng/9.915415/publication.html | url-status=live | website=Publications.gc.ca}}</ref> These conditions place redcedar at heightened risk of hydraulic failure, as the species relies on consistent soil moisture to maintain xylem function. When drought and heat coincide, trees experience reduced growth, canopy dieback, and eventual mortality.

Tree‑ring research further supports the link between climate stress and redcedar decline. Studies examining growth patterns across the Pacific Northwest reveal that mortality events align closely with years of high vapor pressure deficit and prolonged summer drought.<ref>{{Cite web | author=College of the Environment & Northwest Climate Adaptation Science Center | date=2020 | title=Decline of Western redcedar: Using tree rings to understand mortality patterns and identify drought-resilient populations under climate change | url=https://nwcasc.uw.edu/science/project/decline-of-western-red-cedar-using-tree-rings-to-understand-mortality-patterns-and-identify-drought-resilient-populations-under-climate-change/ | url-status=live | website=Northwest Climate Adaptation Science Center}}</ref> These findings highlight that redcedar is particularly sensitive to warm, dry conditions, and that climate‑driven moisture stress is a primary driver of recent dieback patterns.

Historical analyses also show early evidence of climate‑related decline. Seebacher (2007) documented redcedar dieback on Vancouver Island associated with warming temperatures and altered hydrological regimes, suggesting that climate‑linked stressors have been building for decades.<ref>{{Cite web | last=Seebacher | first=T. M. | date=2007 | title=Western redcedar dieback: possible links to climate change and implications for forest management on Vancouver Island, B.C. | url=https://open.library.ubc.ca/soa/cIRcle/collections/ubctheses/831/items/1.0074955 | url-status=live | website=Open.library.ubc.ca}}</ref> Together, these studies demonstrate that drought and heat, amplified by ongoing climate change. are the dominant environmental drivers of Western redcedar decline. As regional temperatures continue to rise, moisture stress is expected to intensify, placing additional pressure on vulnerable populations across the species’ range.

== Observed Impacts ==
Climate shifts, particularly the increase in frequency and intensity of droughts, have played a crucial role in these changes. Western red cedar naturally grows in moist coastal environments and depends on consistent soil moisture to maintain growth and health.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref><ref>{{Cite web | last=Hamann | first=J. T. | date=2023 | title=The impact of climate change on selected PNW watersheds through the lens of western red cedar habitat (Order No. 30524108) | url=https://www.proquest.com/dissertations-theses/impact-climate-change-on-selected-pnw-watersheds/docview/2842790237/se-2 | url-status=live | website=ProQuest Dissertations & Theses Global}}</ref> When dry summers occur more frequently, the trees experience water stress. Extended drought conditions reduce soil moisture levels, making it harder for the trees to carry out essential processes such as photosynthesis and nutrient transport.<ref>{{Cite web | last=Canada | date=2023 | title=Information archivée dans le Web | Information Archived on the Web | url=https://publications.gc.ca/site/eng/9.915415/publication.html | url-status=live | website=Publications.gc.ca}}</ref><ref>{{Cite web | last=Lam | first=D. | last2=Garden | first2=A. | last3=Hang | first3=V. | date=2022 | title=Preparing for the Future: Climate Change and Western Redcedars at the | url=https://mufl.sites.olt.ubc.ca/files/2022/12/0817_Ginny_UFOR531_Report-Final_nonum-min.pdf | url-status=live | website=UBC Faculty of Forestry}}</ref> Reports summarized by Brend (2019) highlight a concerning trend, with researchers across British Columbia documenting significant cedar mortality following unusually dry summers.<ref>{{Cite web | last=Brend | first=Y. | date=2019-05-14 | title=Western red cedars die off as extended dry spells continue, say experts | url=https://www.cbc.ca/news/canada/british-columbia/western-red-cedars-death-dry-climate-change-1.5134262 | url-status=live | website=CBC News}}</ref> As drought conditions continue, trees become weakened and more vulnerable to other stressors.

== Management Strategies ==
The management that has changed towards the Western redcedar focuses on the increasingly rapid decline in its population due to droughts, climate change, and pathogens. Recently redcedar snags are tied to prolonged summer droughts, increased temperatures and reduced soil moisture due to climate change. This happens particularly in the lower elevation ranges which are south‑facing aspects having the most intense heat and solar exposure.<ref>{{Cite web | last=Brend | first=Y. | date=2019-05-14 | title=Western red cedars die off as extended dry spells continue, say experts | url=https://www.cbc.ca/news/canada/british-columbia/western-red-cedars-death-dry-climate-change-1.5134262 | url-status=live | website=CBC News}}</ref><ref>{{Cite web | author=College of the Environment & Northwest Climate Adaptation Science Center | date=2020 | title=Decline of Western redcedar: Using tree rings to understand mortality patterns and identify drought-resilient populations under climate change | url=https://nwcasc.uw.edu/science/project/decline-of-western-red-cedar-using-tree-rings-to-understand-mortality-patterns-and-identify-drought-resilient-populations-under-climate-change/ | url-status=live | website=Northwest Climate Adaptation Science Center}}</ref> As a result, management strategies prioritize using strategic site selection and species diversification to reduce these vulnerabilities.

A common practice is planting red cedar only on high moisture‑retentive sites with higher water tables, with north‑facing aspects, or deep soils. Provincial guidance suggests avoiding the inverse; shallow, rocky, or rapidly draining sites where drought‑related dieback has been the most severe.<ref>{{Cite web | last=Canada | date=2023 | title=Information archivée dans le Web | Information Archived on the Web | url=https://publications.gc.ca/site/eng/9.915415/publication.html | url-status=live | website=Publications.gc.ca}}</ref> In biodiverse zones, redcedar often performs better due to neighbouring root systems and microclimates. The experimental trials show that mixtures with douglas firs can improve ecosystem services and protect red cedars against environmental stressors, particularly where the soil compositions of carbon and nitrogen are proper.<ref>{{Cite web | last=Omari | first=K. | last2=Kranabetter | first2=J. M. | last3=de Montigny | first3=L. | date=2021 | title=Productivity of coastal Douglas-fir and western redcedar in response to species mixture, planting density, and soil carbon:nitrogen ratio | url=https://doi.org/10.1139/cjfr-2020-0223 | url-status=live | website=Canadian Journal of Forest Research}}</ref>

Another strategy is identifying drought‑resilient genotypes and helping them thrive. The tree‑ring data across the Pacific Northwest reveal that some red cedar populations can maintain growth during severe droughts, which tells us that a potential gene for climate adapted seed can be selected and used for species survival.<ref>{{Cite web | author=College of the Environment & Northwest Climate Adaptation Science Center | date=2020 | title=Decline of Western redcedar: Using tree rings to understand mortality patterns and identify drought-resilient populations under climate change | url=https://nwcasc.uw.edu/science/project/decline-of-western-red-cedar-using-tree-rings-to-understand-mortality-patterns-and-identify-drought-resilient-populations-under-climate-change/ | url-status=live | website=Northwest Climate Adaptation Science Center}}</ref>

The people involved in the management of the forest are also adapting silviculture to reduce the stress during initial seedling stages. Which includes, wider spacing to reduce competition for water among saplings, planting in areas of partial canopy cover to moderate temperature extremes and specific solar aspects and elevations, along with mulching vegetation to conserve the soil moisture.<ref>{{Cite web | last=Lam | first=D. | last2=Garden | first2=A. | last3=Hang | first3=V. | date=2022 | title=Preparing for the Future: Climate Change and Western Redcedars at the | url=https://mufl.sites.olt.ubc.ca/files/2022/12/0817_Ginny_UFOR531_Report-Final_nonum-min.pdf | url-status=live | website=UBC Faculty of Forestry}}</ref>

Finally, monitoring and keeping track of pathogens like ''Didymascella thujina'', which causes Cedar needle blight. Although the climate‑driven drought is the main driver of the decline, management must still consider abiotic and biotic stressors and adapt with these too.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref>

== Regional Variations: Coastal and Interior ==
Across its range, Western red cedar is strongly associated with coastal environments characterized by mild temperatures and high moisture availability.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref><ref>{{Cite web | author=Sierra Club BC | date=2025-07-09 | title=Western Red-Cedar | url=https://sierraclub.bc.ca/ecomap/western-red-cedar/ | url-status=live | website=Sierra Club BC}}</ref> In these regions, the species typically thrives on humid, temperate sites, often forming a prominent component of old-growth forests alongside Sitka spruce, Douglas-fir, and Western hemlock.<ref>{{Cite web | last=Minore | first=D. | date=1990-12-01 | title=Western Redcedar | Silvics of North America | url=https://research.fs.usda.gov/silvics/western-redcedar | url-status=live | website=USDA Forest Service}}</ref> The cool, wet conditions of the Pacific Coast are the ideal growing conditions, allowing Western redcedars to reach exceptional sizes and ages in these environments, with some individuals often reaching ages of 800 to 1,000 years.<ref>{{Cite web | last=Minore | first=D. | date=1990-12-01 | title=Western Redcedar | Silvics of North America | url=https://research.fs.usda.gov/silvics/western-redcedar | url-status=live | website=USDA Forest Service}}</ref>

However, increasing drought stress has led to noticeable patterns of decline.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref><ref>{{Cite web | last=Brend | first=Y. | date=2019-05-14 | title=Western red cedars die off as extended dry spells continue, say experts | url=https://www.cbc.ca/news/canada/british-columbia/western-red-cedars-death-dry-climate-change-1.5134262 | url-status=live | website=CBC News}}</ref><ref>{{Cite web | last=Seebacher | first=T. M. | date=2007 | title=Western redcedar dieback: possible links to climate change and implications for forest management on Vancouver Island, B.C. | url=https://open.library.ubc.ca/soa/cIRcle/collections/ubctheses/831/items/1.0074955 | url-status=live | website=Open.library.ubc.ca}}</ref> Coastal areas with the lowest moisture availability have seen the most documented cases of dieback, as dry conditions continue to worsen.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref><ref>{{Cite web | last=Seebacher | first=T. M. | date=2007 | title=Western redcedar dieback: possible links to climate change and implications for forest management on Vancouver Island, B.C. | url=https://open.library.ubc.ca/soa/cIRcle/collections/ubctheses/831/items/1.0074955 | url-status=live | website=Open.library.ubc.ca}}</ref> Warmer summers and reduced snowpack, both associated with current climate change effects, are contributing to longer and more intense summer drought periods that cause considerable physiological strain on the species.<ref>{{Cite web | last=Hamann | first=J. T. | date=2023 | title=The impact of climate change on selected PNW watersheds through the lens of western red cedar habitat (Order No. 30524108) | url=https://www.proquest.com/dissertations-theses/impact-climate-change-on-selected-pnw-watersheds/docview/2842790237/se-2 | url-status=live | website=ProQuest Dissertations & Theses Global}}</ref> Even within coastal zones, impacts are not uniform: wetter and more productive sites tend to experience less severe effects, with decline occurring in a more patchy pattern, often affecting individual trees or small groups than entire stands.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref> This suggests factors such as local topography, soil moisture retention, and availability to water sources all play an important role in mediating tree-level vulnerability.
[[File:Western Redcedar milling 07082008-DSC 6857.jpg|thumb|Western redcedar utilized as lumber]]
Western red cedar is also economically important in coastal forests, contributing significantly to the timber industry.<ref>{{Cite web | last=Canada | date=2023 | title=Information archivée dans le Web | Information Archived on the Web | url=https://publications.gc.ca/site/eng/9.915415/publication.html | url-status=live | website=Publications.gc.ca}}</ref> Its wood is widely valued for its natural decay resistance and workability, and is used principally for shingles, exterior siding, ship and boat building, and lumber.<ref>{{Cite web | last=Minore | first=D. | date=1990-12-01 | title=Western Redcedar | Silvics of North America | url=https://research.fs.usda.gov/silvics/western-redcedar | url-status=live | website=USDA Forest Service}}</ref> Due to this, declines in coastal populations have both ecological and economic consequences.<ref>{{Cite web | last=Canada | date=2023 | title=Information archivée dans le Web | Information Archived on the Web | url=https://publications.gc.ca/site/eng/9.915415/publication.html | url-status=live | website=Publications.gc.ca}}</ref> Climate projections suggest that suitable habitat in coastal regions may shift or contract as drought stress increases, with marginal growing areas expected to expand substantially under future climate scenarios.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref> These habitat shifts may also affect the many species of wildlife that rely on Western red cedars, because the species is home to a range of birds and small mammals.

In contrast, interior populations of Western red cedar occupy environments that are generally drier and more climatically variable than their coastal counterparts. In these regions, the species tends to be restricted by valley bottoms, stream corridors, and other moist sites where soil moisture is more consistently available.<ref>{{Cite web | last=Minore | first=D. | date=1990-12-01 | title=Western Redcedar | Silvics of North America | url=https://research.fs.usda.gov/silvics/western-redcedar | url-status=live | website=USDA Forest Service}}</ref> Moisture availability during the growing season is a key limiting factor, defining much of the species’ inland distribution.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref>

Western red cedar is also particularly vulnerable to forest fires due to traits such as thin bark, shallow roots, low dense branching, and flammable foliage.<ref>{{Cite web | last=Hood | first=S. | last2=Abrahamson | first2=I. | last3=Cansler | first3=C. | date=2010 | title=Fire Resistance and Regeneration Characteristics of Northern Rockies Tree Species | url=https://www.fs.usda.gov/database/feis/pdfs/other/FireResistRegen.pdf | url-status=live | website=USDA Forest Service}}</ref> Unlike fire-adapted species such as Ponderosa pine or Western larch, Western redcedars have few mechanisms to survive or regenerate their years of growing, with younger trees having almost no chance in surviving.<ref>{{Cite web | last=Hood | first=S. | last2=Abrahamson | first2=I. | last3=Cansler | first3=C. | date=2010 | title=Fire Resistance and Regeneration Characteristics of Northern Rockies Tree Species | url=https://www.fs.usda.gov/database/feis/pdfs/other/FireResistRegen.pdf | url-status=live | website=USDA Forest Service}}</ref>

Despite these harsher conditions, interior populations often exhibit greater drought tolerance compared to coastal populations. Physiological adaptations, including lower osmotic potential at the turgor loss point and reduced cuticular water loss, indicate that trees from drier inland environments are better equipped to withstand water stress.<ref>{{Cite web | last=Lam | first=D. | last2=Garden | first2=A. | last3=Hang | first3=V. | date=2022 | title=Preparing for the Future: Climate Change and Western Redcedars at the | url=https://mufl.sites.olt.ubc.ca/files/2022/12/0817_Ginny_UFOR531_Report-Final_nonum-min.pdf | url-status=live | website=UBC Faculty of Forestry}}</ref> Research comparing radial growth responses to drought has similarly found that interior populations demonstrate greater resistance and resilience than coastal populations, a pattern consistent with long-term adaptation to moisture-limiting conditions.<ref>{{Cite web | last=Grossnickle | first=S. C. | last2=Russell | first2=J. H. | date=2010 | title=Physiological variation among western redcedar (Thuja plicata Donn ex D. Don) populations in response to short-term drought | url=https://doi.org/10.1051/forest/2010008 | url-status=live | website=Annals of Forest Science}}</ref> This variation matters for conservation, as drought-tolerant interior populations may be used for assisted migration into drier areas.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref>

However, ongoing climate change is expected to intensify these challenges, potentially leading to a significant reduction in suitable habitats and increased mortality rates among Western red cedar populations. Increasing temperatures and reduced moisture availability in interior regions are projected to place growing pressure on Western red cedar populations, potentially exceeding the adaptive capacity of even drought-tolerant trees.<ref>{{Cite web | last=Aldana | first=J. A. | last2=Kope | first2=H. H. | last3=Hawkins | first3=B. J. | date=2023 | title=Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight | url=https://doi.org/10.1080/07060661.2023.2198489 | url-status=live | website=Canadian Journal of Plant Pathology}}</ref><ref>{{Cite web | last=Hamann | first=J. T. | date=2023 | title=The impact of climate change on selected PNW watersheds through the lens of western red cedar habitat (Order No. 30524108) | url=https://www.proquest.com/dissertations-theses/impact-climate-change-on-selected-pnw-watersheds/docview/2842790237/se-2 | url-status=live | website=ProQuest Dissertations & Theses Global}}</ref>

== Future Projections ==

=== Current Future Projection ===
Future projections indicate that the health of the Western redcedar will deteriorate further as climate change continues to worsen. Climate models for the Pacific Northwest project continued warming and reduced summer soil moisture, which means that zones of high mortality risk will expand.<ref>{{Cite web | author=Natural Resources Canada | date=2018 | title=Tree mortality - Natural Resources Canada | url=https://natural-resources.canada.ca/climate-change/climate-change-impacts-forests/tree-mortality | url-status=live | website=Canada.ca}}</ref> As a result, areas currently considered marginal, especially places with low elevation, are expected to experience a larger increase in mortality rate and reduced successful regeneration. In contrast, more suitable habitats climate-wise are projected to move towards higher elevations, where cooler and wetter conditions will be more present. With this all in mind, the rate of climate change may exceed the Western redcedar’s natural migration capacity. This would limit the species from being able to fully populate the emerging habitats. Additionally, increased frequency of droughts is likely to reduce long term stand productivity. These projections suggest that without adaptive management and assisted migration strategies, Western redcedar populations will be faced with continued decline across significant portions of their current range.

The future projection of the Western redcedar tree relies on many factors. Some redcedars are struggling to drought after periods of drought which could make this tree possibly vanish in the future.<ref>{{Cite web | last=Brend | first=Y. | date=2019-05-14 | title=Western red cedars die off as extended dry spells continue, say experts | url=https://www.cbc.ca/news/canada/british-columbia/western-red-cedars-death-dry-climate-change-1.5134262 | url-status=live | website=CBC News}}</ref> This could set the projection of the Western redcedar to decline due to the factors that are making the Western redcedar struggle such as drought. It has been observed that in the driest areas on the coast of British Colombia, periods of drought over the summer in 2007 which resulted in stressed Western redcedars appearing in large numbers throughout the southern interior of BC.<ref>{{Cite web | last=Woods | first=A. J. | last2=Heppner | first2=D. | last3=Kope | first3=H. H. | last4=Burleigh | first4=J. | last5=Maclauchlan | first5=L. | date=2010 | title=Forest Health and Climate Change: A British Columbia perspective | url=https://doi.org/10.5558/tfc86412-4 | url-status=live | website=The Forestry Chronicle}}</ref> This shows that Western redcedars declining in British Columbia are going in a downward projection for the population of Western redcedars as the health of the trees are affected from the drought. The Western redcedar could possibly lose economic value in dry places.

=== Possible Future Projections ===
The only thing that could protect the future of the Western is to change the projection by acting on the problem. This study suggests planting Western redcedars along an elevational gradient or higher elevations in the interior of British Columbia.<ref>{{Cite web | author=Government of Canada | date=2025 | title=Tree mortality | url=https://natural-resources.canada.ca/climate-change/climate-change-impacts-forests/tree-mortality | url-status=live | website=Natural Resources Canada}}</ref> The reason why is because Western redcedars increase growth and productivity at higher elevations is because of warmer winters, longer growing season, and there will be more carbon dioxide with climate change.<ref>{{Cite web | last=Seebacher | first=T. M. | date=2007 | title=Western redcedar dieback: possible links to climate change and implications for forest management on Vancouver Island, B.C. | url=https://open.library.ubc.ca/soa/cIRcle/collections/ubctheses/831/items/1.0074955 | url-status=live | website=Open.library.ubc.ca}}</ref> This solution could possibly change the projection of the Western redcedar because of the effects it has on the Western redcedar in higher elevation.

==Conclusion==
The Western redcedar is facing a rapid and alarming decline across the Pacific Northwest, and the evidence throughout this article shows that the climate change induced stress is the main driving force behind it. Prolonged droughts, hotter summers, and reduced soil moisture are the main forces pushing the species beyond the conditions it has adapted to over millennia, leading to the destruction and mortality of the Western redcedar and the ecosystems it is supporting. The Western redcedar’s decline in population is usually followed by years of hot, dry summers, which are becoming patterns due to climate change increasing the frequency of these droughts.<ref>{{Cite web | last=Brend | first=Y. | date=2019-05-14 | title=Western red cedars die off as extended dry spells continue, say experts | url=https://www.cbc.ca/news/canada/british-columbia/western-red-cedars-death-dry-climate-change-1.5134262 | url-status=live | website=CBC News}}</ref><ref>{{Cite web | last=Canada | date=2023 | title=Information archivée dans le Web | Information Archived on the Web | url=https://publications.gc.ca/site/eng/9.915415/publication.html | url-status=live | website=Publications.gc.ca}}</ref> This decline is especially concerning because the Western redcedar is not just a regular and common tree; it is a keystone species, a major economic resource, and a central part of the Indigenous peoples of the PNW’s cultural identity.

Management strategies have been focusing on planting red cedar in sites that have better moisture retention, selecting drought‑resilient genotypes, and adjusting silvicultural practices to reduce early‑stage stress.<ref>{{Cite web | last=Canada | date=2023 | title=Information archivée dans le Web | Information Archived on the Web | url=https://publications.gc.ca/site/eng/9.915415/publication.html | url-status=live | website=Publications.gc.ca}}</ref> The good news is that some redcedar populations can maintain growth during severe droughts, which suggests that assisted migration and climate‑adapted seed selection could play a major role in the survival of the species for the future like many other endangered species affected by climate change.<ref>{{Cite web | author=College of the Environment & Northwest Climate Adaptation Science Center | date=2020 | title=Decline of Western redcedar: Using tree rings to understand mortality patterns and identify drought-resilient populations under climate change | url=https://nwcasc.uw.edu/science/project/decline-of-western-red-cedar-using-tree-rings-to-understand-mortality-patterns-and-identify-drought-resilient-populations-under-climate-change/ | url-status=live | website=Northwest Climate Adaptation Science Center}}</ref>

Overall, the future of the Western redcedar depends on how quickly and effectively we can respond to this crisis. Without human intervention along with fast action, climate projections show the continued decline of the Western redcedar’s population across the PNW. With the efforts to target management resources, proper site selection, and the integration of Indigenous knowledge combined with modern ecological research, there is still light at the end of the tunnel. Through the restoration projects of the Western redcedar and other species in similar cases we can use all the combined knowledge and resources learned to help further progress the fight against climate change and its main drivers. Protecting the Pacific Northwestern redcedar or Thuja plicata means protecting its ecosystems, cultures, and communities that have relied on it and have taken care of it for generations. The choices we make now can and will determine whether the Western redcedar, ''Thuja plicata'' can survive in the rapidly changing anthropic climate.

==References==
<references/>

{{Projectbox CONS200
|names=
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[[Category:Conservation]]

Course:CONS200/2026WT2/Climate change impacts on Western redcedar

2026-04-13T02:30:05Z

AdrianTan: /* References */

== Introduction ==
Western redcedars (''Thuja plicata'') are one of the most significant tree species to the ecosystems of the Pacific Northwest (PNW) along with being very culturally, and economically significant (Aldana et al., 2023). The Coast Salish people refer to this tree as the "tree of life"; it has sustained Indigenous communities for centuries, providing materials for all sorts of utilities; shelter, tools, clothing, canoes, ceremonial and many more uses (Aldana et al., 2023). The Western redcedar is a keystone species to the coastal and wet interior forests of the ecosystems across British Columbia and the PNW. Currently, the largest species of the cypress cedar family is being driven to extinction by the rapidly accelerating climate change, prolonged and harsh summer conditions, droughts, and rapidly rising temperatures, killing off the Western redcedar populations en masse (Canada, 2023). Since such a large amount Western redcedars are turning into snags and the rapid changes of climate that the species are adapted to is destabilizing, it has alarmed ecologists, foresters, and Indigenous communities pushing them to act to save the trees from mass extinction. The decline is not uniform and unpredictable due to the ever changing weather patterns: low elevation, south-facing, and low moisture sites are experiencing the most severe casualties, even so the coastal and interior populations have some variance in both their vulnerability and resilience due to the differing adaptations overtime they have attained (Brend, 2019; College of the Environment & NW CASC, 2020). To understand the forces behind the dire population decline and the strategies being developed to counter it, it is essential to preserve and use the ecosystem services of the tree it provides to our advantage, the micro climates it induces and cultural heritage and knowledge that the Western redcedar represents. This article examines the cultural and economic importance of the species, the climate-driven stressors accelerating its decline, observed impacts across the Pacific Northwest, emerging management strategies of the future, and the regional differences shaping how this crisis unfolds through climate models and future projections.

== Economic and Cultural Importance ==

=== Economic Importance ===
The Western redcedar holds significant economic value through its contributions to forest productivity and the timber industry. When planted alongside other species, Western redcedars produce calcium in its foliage, acting like a nutrient supply for surrounding trees. Other species tend to benefit, as the Western redcedar helps suppress the spread of diseases within a site (Omari et al., 2021). Beyond its ecological contributions, the Western redcedar’s long lifespan and low mortality rate make it exceptionally resilient under harsh conditions, allowing it to form a symbiotic relationship with the species surrounding it (Aldana et al., 2023). Economically, the species accounts for approximately 18% of British Columbia’s coastal timber harvest. and around 3% of the interior harvest, making it a crucial resource for forestry business across the province (Aldana et al., 2023). The western redcedar is one of the most important sources in British Columbia showing the importance of this tree. Timber harvests create job opportunities for many people and have over one million dollars from Western redcedar products (Aldana et al., 2023). The Western redcedar also has resistance to many pests making the tree a desirable species to do reforestation on a site (Aldana et al., 2023). This is good for restoring places that are deforested and improving economic value.

=== Cultural Importance ===
The Western redcedar provides cultural importance. The First Peoples would use the Western redcedar to make shelters, drying racks, spear shafts, dipnet frames, paddles, canoe frames, and many other items (Aldana et al., 2023). This shows that the Western redcedar tree was not just a tree, but something that is a part of their culture through all the items they make through the tree. The First Peoples also used the Western redcedar for building material, clothing, fuel, and medicine. The Western redcedar was also used for survival giving importance to this tree species. The Coast Salish people refer this tree to the tree of life (Aldana et al., 2023). The people would pray of respect and gratitude to the tree before harvesting the tree (Joseph). This shows the significance it has in their culture. The reason why the Western redcedar has value is because of how it provided for the First Peoples that were here for a long time.

== Climate Change Drivers ==
Climate change has intensified drought and heat stress across the Pacific Northwest, creating conditions that directly contribute to widespread Western redcedar (''Thuja plicata'') decline. Extended dry periods have become more frequent and severe, reducing soil moisture during critical growing months. Field observations in British Columbia show that redcedar dieback often follows consecutive years of unusually hot, dry summers, with mortality concentrated in low‑elevation and exposed sites where moisture deficits accumulate most rapidly (Brend, 2019).

Long‑term climate assessments from Natural Resources Canada indicate that warming trends are accelerating across coastal and interior regions, increasing both evapotranspiration and the frequency of extreme heat events (Canada, 2023). These conditions place redcedar at heightened risk of hydraulic failure, as the species relies on consistent soil moisture to maintain xylem function. When drought and heat coincide, trees experience reduced growth, canopy dieback, and eventual mortality.

Tree‑ring research further supports the link between climate stress and redcedar decline. Studies examining growth patterns across the Pacific Northwest reveal that mortality events align closely with years of high vapor pressure deficit and prolonged summer drought (College of the Environment & Northwest Climate Adaptation Science Center, 2020). These findings highlight that redcedar is particularly sensitive to warm, dry conditions, and that climate‑driven moisture stress is a primary driver of recent dieback patterns.

Historical analyses also show early evidence of climate‑related decline. Seebacher (2007) documented redcedar dieback on Vancouver Island associated with warming temperatures and altered hydrological regimes, suggesting that climate‑linked stressors have been building for decades.

Together, these studies demonstrate that drought and heat, amplified by ongoing climate change. are the dominant environmental drivers of Western redcedar decline. As regional temperatures continue to rise, moisture stress is expected to intensify, placing additional pressure on vulnerable populations across the species’ range.

== Observed Impacts ==
Climate shifts, particularly the increase in frequency and intensity of droughts, have played a crucial role in these changes. Western red cedar naturally grows in moist coastal environments and depends on consistent soil moisture to maintain growth and health (Aldana et al., 2023; Hamann, 2023). When dry summers occur more frequently, the trees experience water stress. Extended drought conditions reduce soil moisture levels, making it harder for the trees to carry out essential processes such as photosynthesis and nutrient transport (Canada, 2023; Lam et al., 2022). Reports summarized by Brend (2019) highlight a concerning trend, with researchers across British Columbia documenting significant cedar mortality following unusually dry summers. As drought conditions continue, trees become weakened and more vulnerable to other stressors.

== Management Strategies ==
The management that has changed towards the Western redcedar focuses on the increasingly rapid decline in its population due to droughts, climate change, and pathogens. Recently redcedar snags are tied to prolonged summer droughts, increased temperatures and reduced soil moisture due to climate change. This happens particularly in the lower elevation ranges which are south‑facing aspects having the most intense heat and solar exposure (Brend, 2019; College of the Environment & NW CASC, 2020). As a result, management strategies prioritize using strategic site selection and species diversification to reduce these vulnerabilities.

A common practice is planting red cedar only on high moisture‑retentive sites with higher water tables, with north‑facing aspects, or deep soils. Provincial guidance suggests avoiding the inverse; shallow, rocky, or rapidly draining sites where drought‑related dieback has been the most severe (Canada, 2023). In biodiverse zones, redcedar often performs better due to neighbouring root systems and microclimates. The experimental trials show that mixtures with douglas firs can improve ecosystem services and protect red cedars against environmental stressors, particularly where the soil compositions of carbon and nitrogen are proper (Omari et al., 2021).

Another strategy is identifying drought‑resilient genotypes and helping them thrive. The tree‑ring data across the Pacific Northwest reveal that some red cedar populations can maintain growth during severe droughts, which tells us that a potential gene for climate adapted seed can be selected and used for species survival (College of the Environment & NW CASC, 2020).

The people involved in the management of the forest are also adapting silviculture to reduce the stress during initial seedling stages. Which includes, wider spacing to reduce competition for water among saplings, planting in areas of partial canopy cover to moderate temperature extremes and specific solar aspects and elevations, along with mulching vegetation to conserve the soil moisture (Lam et al., 2022).

Finally, monitoring and keeping track of pathogens like ''Didymascella thujina'', which causes Cedar needle blight. Although the climate‑driven drought is the main driver of the decline, management must still consider abiotic and biotic stressors and adapt with these too (Aldana et al., 2023).

== Regional Variations: Coastal and Interior ==
Across its range, Western red cedar is strongly associated with coastal environments characterized by mild temperatures and high moisture availability (Aldana et al., 2023; Sierra Club BC, 2025). In these regions, the species typically thrives on humid, temperate sites, often forming a prominent component of old-growth forests alongside Sitka spruce, Douglas-fir, and Western hemlock (Minore, 1990). The cool, wet conditions of the Pacific Coast are the ideal growing conditions, allowing Western redcedars to reach exceptional sizes and ages in these environments, with some individuals often reaching ages of 800 to 1,000 years (Minore, 1990).

However, increasing drought stress has led to noticeable patterns of decline (Seebacher, 2007; Aldana et al., 2023; Brend, 2019). Coastal areas with the lowest moisture availability have seen the most documented cases of dieback, as dry conditions continue to worsen (Seebacher, 2007; Aldana et al., 2023). Warmer summers and reduced snowpack, both associated with current climate change effects, are contributing to longer and more intense summer drought periods that cause considerable physiological strain on the species (Hamann, 2023). Even within coastal zones, impacts are not uniform: wetter and more productive sites tend to experience less severe effects, with decline occurring in a more patchy pattern, often affecting individual trees or small groups than entire stands (Aldana et al., 2023). This suggests factors such as local topography, soil moisture retention, and availability to water sources all play an important role in mediating tree-level vulnerability.

Western red cedar is also economically important in coastal forests, contributing significantly to the timber industry (Canada, 2023). Its wood is widely valued for its natural decay resistance and workability, and is used principally for shingles, exterior siding, ship and boat building, and lumber (USDA Forest Products Laboratory, n.d.). Due to this, declines in coastal populations have both ecological and economic consequences (Canada, 2023). Climate projections suggest that suitable habitat in coastal regions may shift or contract as drought stress increases, with marginal growing areas expected to expand substantially under future climate scenarios (Aldana et al., 2023). These habitat shifts may also affect the many species of wildlife that rely on Western red cedars, because the species is home to a range of birds and small mammals.

In contrast, interior populations of Western red cedar occupy environments that are generally drier and more climatically variable than their coastal counterparts. In these regions, the species tends to be restricted by valley bottoms, stream corridors, and other moist sites where soil moisture is more consistently available (Minore, 1990). Moisture availability during the growing season is a key limiting factor, defining much of the species’ inland distribution (Aldana et al., 2023).

Western red cedar is also particularly vulnerable to forest fires due to traits such as thin bark, shallow roots, low dense branching, and flammable foliage (Hood et al., 2010). Unlike fire-adapted species such as Ponderosa pine or Western larch, Western redcedars have few mechanisms to survive or regenerate their years of growing, with younger trees having almost no chance in surviving (Hood et al., 2010).

Despite these harsher conditions, interior populations often exhibit greater drought tolerance compared to coastal populations. Physiological adaptations, including lower osmotic potential at the turgor loss point and reduced cuticular water loss, indicate that trees from drier inland environments are better equipped to withstand water stress (Lam et al., 2022). Research comparing radial growth responses to drought has similarly found that interior populations demonstrate greater resistance and resilience than coastal populations, a pattern consistent with long-term adaptation to moisture-limiting conditions (Grossnickle & Russell, 2010). This variation matters for conservation, as drought-tolerant interior populations may be used for assisted migration into drier areas (Aldana et al., 2023).

However, ongoing climate change is expected to intensify these challenges, potentially leading to a significant reduction in suitable habitats and increased mortality rates among Western red cedar populations. Increasing temperatures and reduced moisture availability in interior regions are projected to place growing pressure on Western red cedar populations, potentially exceeding the adaptive capacity of even drought-tolerant trees (Aldana et al., 2023; Hamann, 2023).

== Future Projections ==

=== Current Future Projection ===
Future projections indicate that the health of the Western redcedar will deteriorate further as climate change continues to worsen. Climate models for the Pacific Northwest project continued warming and reduced summer soil moisture, which means that zones of high mortality risk will expand (Natural Resources Canada, 2023). As a result, areas currently considered marginal, especially places with low elevation, are expected to experience a larger increase in mortality rate and reduced successful regeneration. In contrast, more suitable habitats climate-wise are projected to move towards higher elevations, where cooler and wetter conditions will be more present. With this all in mind, the rate of climate change may exceed the Western redcedar’s natural migration capacity. This would limit the species from being able to fully populate the emerging habitats. Additionally, increased frequency of droughts is likely to reduce long term stand productivity. These projections suggest that without adaptive management and assisted migration strategies, Western redcedar populations will be faced with continued decline across significant portions of their current range.

The future projection of the Western redcedar tree relies on many factors. Some redcedars are struggling to drought after periods of drought which could make this tree possibly vanish in the future (Brend). This could set the projection of the Western redcedar to decline due to the factors that are making the Western redcedar struggle such as drought. It has been observed that in the driest areas on the coast of British Colombia, periods of drought over the summer in 2007 which resulted in stressed Western redcedars appearing in large numbers throughout the southern interior of BC (Wood et al.,). This shows that Western redcedars declining in British Columbia are going in a downward projection for the population of Western redcedars as the health of the trees are affected from the drought. The Western redcedar could possibly lose economic value in dry places.

=== Possible Future Projections ===
The only thing that could protect the future of the Western is to change the projection by acting on the problem. This study suggests planting Western redcedars along an elevational gradient or higher elevations in the interior of British Columbia (Seebeacher). The reason why is because Western redcedars increase growth and productivity at higher elevations is because of warmer winters, longer growing season, and there will be more carbon dioxide with climate change (Seebeacher). This solution could possibly change the projection of the Western redcedar because of the effects it has on the Western redcedar in higher elevation.

==Conclusion==
The Western redcedar is facing a rapid and alarming decline across the Pacific Northwest, and the evidence throughout this article shows that the climate change induced stress is the main driving force behind it. Prolonged droughts, hotter summers, and reduced soil moisture are the main forces pushing the species beyond the conditions it has adapted to over millennia, leading to the destruction and mortality of the Western redcedar and the ecosystems it is supporting. The Western redcedar’s decline in population is usually followed by years of hot, dry summers, which are becoming patterns due to climate change increasing the frequency of these droughts (Brend, 2019; Canada, 2023). This decline is especially concerning because the Western redcedar is not just a regular and common tree; it is a keystone species, a major economic resource, and a central part of the Indigenous peoples of the PNW’s cultural identity.

Management strategies have been focusing on planting red cedar in sites that have better moisture retention, selecting drought‑resilient genotypes, and adjusting silvicultural practices to reduce early‑stage stress (Canada, 2023). The good news is that some redcedar populations can maintain growth during severe droughts, which suggests that assisted migration and climate‑adapted seed selection could play a major role in the survival of the species for the future like many other endangered species affected by climate change (College of the Environment & NW CASC, 2020).

Overall, the future of the Western redcedar depends on how quickly and effectively we can respond to this crisis. Without human intervention along with fast action, climate projections show the continued decline of the Western redcedar’s population across the PNW. With the efforts to target management resources, proper site selection, and the integration of Indigenous knowledge combined with modern ecological research, there is still light at the end of the tunnel. Through the restoration projects of the Western redcedar and other species in similar cases we can use all the combined knowledge and resources learned to help further progress the fight against climate change and its main drivers. Protecting the Pacific Northwestern redcedar or Thuja plicata means protecting its ecosystems, cultures, and communities that have relied on it and have taken care of it for generations. The choices we make now can and will determine whether the Western redcedar, ''Thuja plicata'' can survive in the rapidly changing anthropic climate.
==References==
<div style="column-count: 2;">
1. Aldana, J. A., Kope, H. H., & Hawkins, B. J. (2023). Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight. ''Canadian Journal of Plant Pathology'', ''45''(4), 377–390. <nowiki>https://doi.org/10.1080/07060661.2023.2198489</nowiki>

2. Brend, Y. (2019, May 14). Western red cedars die off as extended dry spells continue, say experts | CBC News. ''CBC''. <nowiki>https://www.cbc.ca/news/canada/british-columbia/western-red-cedars-death-dry-climate-change-1.5134262</nowiki>

3. Canada,. (2023). ''Information archivée dans le Web | Information Archived on the Web''. Publications.gc.ca. <nowiki>https://publications.gc.ca/site/eng/9.915415/publication.html</nowiki>

4. Canada, N. R. (2018). ''Tree mortality - Natural Resources Canada''. Canada.ca. <nowiki>https://natural-resources.canada.ca/climate-change/climate-change-impacts-forests/tree-mortality</nowiki>

5. College of the Environment & Northwest Climate Adaptation Science Center. (2020). ''Decline of Western redcedar: Using tree rings to understand mortality patterns and identify drought-resilient populations under climate change''. <nowiki>https://nwcasc.uw.edu/science/project/decline-of-western-red-cedar-using-tree-rings-to-understand-mortality-patterns-and-identify-drought-resilient-populations-under-climate-change/</nowiki>

6. Government of Canada. (2025). ''Tree mortality''. Natural Resources Canada. <nowiki>https://natural-resources.canada.ca/climate-change/climate-change-impacts-forests/tree-</nowiki> mortality

7. Grossnickle, S. C., & Russell, J. H. (2010). Physiological variation among western redcedar (Thuja plicata Donn ex D. Don) populations in response to short-term drought. Annals of Forest Science, 67(5), 506 506. <nowiki>https://doi.org/10.1051/forest/2010008</nowiki>

8. Hall, S., Stotts, S., & Haaf, L. (2022). Influence of climate and coastal flooding on eastern red cedar growth along a marsh-forest ecotone. ''Forests'', ''13''(6), 862. <nowiki>https://doi.org/10.3390/f13060862</nowiki>

9. Hamann, J. T. (2023). ''The impact of climate change on selected PNW watersheds through the lens of western red cedar habitat'' (Order No. 30524108). Available from ProQuest Dissertations & Theses Global. (2842790237). Retrieved from <nowiki>https://www.proquest.com/dissertations-theses/impact-climate-change-on-selected-pnw-watersheds/docview/2842790237/se-2</nowiki>

10. Joseph, B. (2025, April 4). ''Indigenous sacred plants: Red cedar''. Indigenous Corporate Training Inc. <nowiki>https://www.ictinc.ca/blog/indigenous-sacred-plants-cedar</nowiki>

11. Lam, D., Garden, A., & Hang, V. (2022). ''Preparing for the Future: Climate Change and Western Redcedars at the''. <nowiki>https://mufl.sites.olt.ubc.ca/files/2022/12/0817_Ginny_UFOR531_Report-Final_nonum-min.pdf</nowiki>

12. Minore, D. (1990, December 1). ''Western Redcedar | Silvics of North America''. Usda.gov. <nowiki>https://research.fs.usda.gov/silvics/western-redcedar</nowiki>

13. Omari, K., Kranabetter, J. M., & de Montigny, L. (2021). Productivity of coastal Douglas-fir and western redcedar in response to species mixture, planting density, and soil carbon:nitrogen ratio. ''Canadian Journal of Forest Research'', ''51''(5), 668–674. <nowiki>https://doi.org/10.1139/cjfr-2020-0223</nowiki>

14. Seebacher, T. M. (2007). ''Western redcedar dieback : possible links to climate change and implications for forest management on Vancouver Island, B.C.'' Open.library.ubc.ca. <nowiki>https://open.library.ubc.ca/soa/cIRcle/collections/ubctheses/831/items/1.0074955</nowiki>

15. Sierra Club BC. (2025, July 9). ''Western Red-Cedar''. Sierra Club BC. <nowiki>https://sierraclub.bc.ca/ecomap/western-red-cedar/</nowiki>

16. Woods, A. J., Heppner, D., Kope, H. H., Burleigh, J., & Maclauchlan, L. (2010). Forest Health and Climate Change: A british columbia perspective. ''The Forestry Chronicle'', ''86''(4), 412–422. <nowiki>https://doi.org/10.5558/tfc86412-4</nowiki>
<references />
</div>{{Projectbox CONS200
|names=
|share=no
}}

[[Category:Conservation]]

Course:CONS200/2026WT2/Climate change impacts on Western redcedar

2026-04-13T02:27:59Z

AdrianTan:

== Introduction ==
Western redcedars (''Thuja plicata'') are one of the most significant tree species to the ecosystems of the Pacific Northwest (PNW) along with being very culturally, and economically significant (Aldana et al., 2023). The Coast Salish people refer to this tree as the "tree of life"; it has sustained Indigenous communities for centuries, providing materials for all sorts of utilities; shelter, tools, clothing, canoes, ceremonial and many more uses (Aldana et al., 2023). The Western redcedar is a keystone species to the coastal and wet interior forests of the ecosystems across British Columbia and the PNW. Currently, the largest species of the cypress cedar family is being driven to extinction by the rapidly accelerating climate change, prolonged and harsh summer conditions, droughts, and rapidly rising temperatures, killing off the Western redcedar populations en masse (Canada, 2023). Since such a large amount Western redcedars are turning into snags and the rapid changes of climate that the species are adapted to is destabilizing, it has alarmed ecologists, foresters, and Indigenous communities pushing them to act to save the trees from mass extinction. The decline is not uniform and unpredictable due to the ever changing weather patterns: low elevation, south-facing, and low moisture sites are experiencing the most severe casualties, even so the coastal and interior populations have some variance in both their vulnerability and resilience due to the differing adaptations overtime they have attained (Brend, 2019; College of the Environment & NW CASC, 2020). To understand the forces behind the dire population decline and the strategies being developed to counter it, it is essential to preserve and use the ecosystem services of the tree it provides to our advantage, the micro climates it induces and cultural heritage and knowledge that the Western redcedar represents. This article examines the cultural and economic importance of the species, the climate-driven stressors accelerating its decline, observed impacts across the Pacific Northwest, emerging management strategies of the future, and the regional differences shaping how this crisis unfolds through climate models and future projections.

== Economic and Cultural Importance ==

=== Economic Importance ===
The Western redcedar holds significant economic value through its contributions to forest productivity and the timber industry. When planted alongside other species, Western redcedars produce calcium in its foliage, acting like a nutrient supply for surrounding trees. Other species tend to benefit, as the Western redcedar helps suppress the spread of diseases within a site (Omari et al., 2021). Beyond its ecological contributions, the Western redcedar’s long lifespan and low mortality rate make it exceptionally resilient under harsh conditions, allowing it to form a symbiotic relationship with the species surrounding it (Aldana et al., 2023). Economically, the species accounts for approximately 18% of British Columbia’s coastal timber harvest. and around 3% of the interior harvest, making it a crucial resource for forestry business across the province (Aldana et al., 2023). The western redcedar is one of the most important sources in British Columbia showing the importance of this tree. Timber harvests create job opportunities for many people and have over one million dollars from Western redcedar products (Aldana et al., 2023). The Western redcedar also has resistance to many pests making the tree a desirable species to do reforestation on a site (Aldana et al., 2023). This is good for restoring places that are deforested and improving economic value.

=== Cultural Importance ===
The Western redcedar provides cultural importance. The First Peoples would use the Western redcedar to make shelters, drying racks, spear shafts, dipnet frames, paddles, canoe frames, and many other items (Aldana et al., 2023). This shows that the Western redcedar tree was not just a tree, but something that is a part of their culture through all the items they make through the tree. The First Peoples also used the Western redcedar for building material, clothing, fuel, and medicine. The Western redcedar was also used for survival giving importance to this tree species. The Coast Salish people refer this tree to the tree of life (Aldana et al., 2023). The people would pray of respect and gratitude to the tree before harvesting the tree (Joseph). This shows the significance it has in their culture. The reason why the Western redcedar has value is because of how it provided for the First Peoples that were here for a long time.

== Climate Change Drivers ==
Climate change has intensified drought and heat stress across the Pacific Northwest, creating conditions that directly contribute to widespread Western redcedar (''Thuja plicata'') decline. Extended dry periods have become more frequent and severe, reducing soil moisture during critical growing months. Field observations in British Columbia show that redcedar dieback often follows consecutive years of unusually hot, dry summers, with mortality concentrated in low‑elevation and exposed sites where moisture deficits accumulate most rapidly (Brend, 2019).

Long‑term climate assessments from Natural Resources Canada indicate that warming trends are accelerating across coastal and interior regions, increasing both evapotranspiration and the frequency of extreme heat events (Canada, 2023). These conditions place redcedar at heightened risk of hydraulic failure, as the species relies on consistent soil moisture to maintain xylem function. When drought and heat coincide, trees experience reduced growth, canopy dieback, and eventual mortality.

Tree‑ring research further supports the link between climate stress and redcedar decline. Studies examining growth patterns across the Pacific Northwest reveal that mortality events align closely with years of high vapor pressure deficit and prolonged summer drought (College of the Environment & Northwest Climate Adaptation Science Center, 2020). These findings highlight that redcedar is particularly sensitive to warm, dry conditions, and that climate‑driven moisture stress is a primary driver of recent dieback patterns.

Historical analyses also show early evidence of climate‑related decline. Seebacher (2007) documented redcedar dieback on Vancouver Island associated with warming temperatures and altered hydrological regimes, suggesting that climate‑linked stressors have been building for decades.

Together, these studies demonstrate that drought and heat, amplified by ongoing climate change. are the dominant environmental drivers of Western redcedar decline. As regional temperatures continue to rise, moisture stress is expected to intensify, placing additional pressure on vulnerable populations across the species’ range.

== Observed Impacts ==
Climate shifts, particularly the increase in frequency and intensity of droughts, have played a crucial role in these changes. Western red cedar naturally grows in moist coastal environments and depends on consistent soil moisture to maintain growth and health (Aldana et al., 2023; Hamann, 2023). When dry summers occur more frequently, the trees experience water stress. Extended drought conditions reduce soil moisture levels, making it harder for the trees to carry out essential processes such as photosynthesis and nutrient transport (Canada, 2023; Lam et al., 2022). Reports summarized by Brend (2019) highlight a concerning trend, with researchers across British Columbia documenting significant cedar mortality following unusually dry summers. As drought conditions continue, trees become weakened and more vulnerable to other stressors.

== Management Strategies ==
The management that has changed towards the Western redcedar focuses on the increasingly rapid decline in its population due to droughts, climate change, and pathogens. Recently redcedar snags are tied to prolonged summer droughts, increased temperatures and reduced soil moisture due to climate change. This happens particularly in the lower elevation ranges which are south‑facing aspects having the most intense heat and solar exposure (Brend, 2019; College of the Environment & NW CASC, 2020). As a result, management strategies prioritize using strategic site selection and species diversification to reduce these vulnerabilities.

A common practice is planting red cedar only on high moisture‑retentive sites with higher water tables, with north‑facing aspects, or deep soils. Provincial guidance suggests avoiding the inverse; shallow, rocky, or rapidly draining sites where drought‑related dieback has been the most severe (Canada, 2023). In biodiverse zones, redcedar often performs better due to neighbouring root systems and microclimates. The experimental trials show that mixtures with douglas firs can improve ecosystem services and protect red cedars against environmental stressors, particularly where the soil compositions of carbon and nitrogen are proper (Omari et al., 2021).

Another strategy is identifying drought‑resilient genotypes and helping them thrive. The tree‑ring data across the Pacific Northwest reveal that some red cedar populations can maintain growth during severe droughts, which tells us that a potential gene for climate adapted seed can be selected and used for species survival (College of the Environment & NW CASC, 2020).

The people involved in the management of the forest are also adapting silviculture to reduce the stress during initial seedling stages. Which includes, wider spacing to reduce competition for water among saplings, planting in areas of partial canopy cover to moderate temperature extremes and specific solar aspects and elevations, along with mulching vegetation to conserve the soil moisture (Lam et al., 2022).

Finally, monitoring and keeping track of pathogens like ''Didymascella thujina'', which causes Cedar needle blight. Although the climate‑driven drought is the main driver of the decline, management must still consider abiotic and biotic stressors and adapt with these too (Aldana et al., 2023).

== Regional Variations: Coastal and Interior ==
Across its range, Western red cedar is strongly associated with coastal environments characterized by mild temperatures and high moisture availability (Aldana et al., 2023; Sierra Club BC, 2025). In these regions, the species typically thrives on humid, temperate sites, often forming a prominent component of old-growth forests alongside Sitka spruce, Douglas-fir, and Western hemlock (Minore, 1990). The cool, wet conditions of the Pacific Coast are the ideal growing conditions, allowing Western redcedars to reach exceptional sizes and ages in these environments, with some individuals often reaching ages of 800 to 1,000 years (Minore, 1990).

However, increasing drought stress has led to noticeable patterns of decline (Seebacher, 2007; Aldana et al., 2023; Brend, 2019). Coastal areas with the lowest moisture availability have seen the most documented cases of dieback, as dry conditions continue to worsen (Seebacher, 2007; Aldana et al., 2023). Warmer summers and reduced snowpack, both associated with current climate change effects, are contributing to longer and more intense summer drought periods that cause considerable physiological strain on the species (Hamann, 2023). Even within coastal zones, impacts are not uniform: wetter and more productive sites tend to experience less severe effects, with decline occurring in a more patchy pattern, often affecting individual trees or small groups than entire stands (Aldana et al., 2023). This suggests factors such as local topography, soil moisture retention, and availability to water sources all play an important role in mediating tree-level vulnerability.

Western red cedar is also economically important in coastal forests, contributing significantly to the timber industry (Canada, 2023). Its wood is widely valued for its natural decay resistance and workability, and is used principally for shingles, exterior siding, ship and boat building, and lumber (USDA Forest Products Laboratory, n.d.). Due to this, declines in coastal populations have both ecological and economic consequences (Canada, 2023). Climate projections suggest that suitable habitat in coastal regions may shift or contract as drought stress increases, with marginal growing areas expected to expand substantially under future climate scenarios (Aldana et al., 2023). These habitat shifts may also affect the many species of wildlife that rely on Western red cedars, because the species is home to a range of birds and small mammals.

In contrast, interior populations of Western red cedar occupy environments that are generally drier and more climatically variable than their coastal counterparts. In these regions, the species tends to be restricted by valley bottoms, stream corridors, and other moist sites where soil moisture is more consistently available (Minore, 1990). Moisture availability during the growing season is a key limiting factor, defining much of the species’ inland distribution (Aldana et al., 2023).

Western red cedar is also particularly vulnerable to forest fires due to traits such as thin bark, shallow roots, low dense branching, and flammable foliage (Hood et al., 2010). Unlike fire-adapted species such as Ponderosa pine or Western larch, Western redcedars have few mechanisms to survive or regenerate their years of growing, with younger trees having almost no chance in surviving (Hood et al., 2010).

Despite these harsher conditions, interior populations often exhibit greater drought tolerance compared to coastal populations. Physiological adaptations, including lower osmotic potential at the turgor loss point and reduced cuticular water loss, indicate that trees from drier inland environments are better equipped to withstand water stress (Lam et al., 2022). Research comparing radial growth responses to drought has similarly found that interior populations demonstrate greater resistance and resilience than coastal populations, a pattern consistent with long-term adaptation to moisture-limiting conditions (Grossnickle & Russell, 2010). This variation matters for conservation, as drought-tolerant interior populations may be used for assisted migration into drier areas (Aldana et al., 2023).

However, ongoing climate change is expected to intensify these challenges, potentially leading to a significant reduction in suitable habitats and increased mortality rates among Western red cedar populations. Increasing temperatures and reduced moisture availability in interior regions are projected to place growing pressure on Western red cedar populations, potentially exceeding the adaptive capacity of even drought-tolerant trees (Aldana et al., 2023; Hamann, 2023).

== Future Projections ==

=== Current Future Projection ===
Future projections indicate that the health of the Western redcedar will deteriorate further as climate change continues to worsen. Climate models for the Pacific Northwest project continued warming and reduced summer soil moisture, which means that zones of high mortality risk will expand (Natural Resources Canada, 2023). As a result, areas currently considered marginal, especially places with low elevation, are expected to experience a larger increase in mortality rate and reduced successful regeneration. In contrast, more suitable habitats climate-wise are projected to move towards higher elevations, where cooler and wetter conditions will be more present. With this all in mind, the rate of climate change may exceed the Western redcedar’s natural migration capacity. This would limit the species from being able to fully populate the emerging habitats. Additionally, increased frequency of droughts is likely to reduce long term stand productivity. These projections suggest that without adaptive management and assisted migration strategies, Western redcedar populations will be faced with continued decline across significant portions of their current range.

The future projection of the Western redcedar tree relies on many factors. Some redcedars are struggling to drought after periods of drought which could make this tree possibly vanish in the future (Brend). This could set the projection of the Western redcedar to decline due to the factors that are making the Western redcedar struggle such as drought. It has been observed that in the driest areas on the coast of British Colombia, periods of drought over the summer in 2007 which resulted in stressed Western redcedars appearing in large numbers throughout the southern interior of BC (Wood et al.,). This shows that Western redcedars declining in British Columbia are going in a downward projection for the population of Western redcedars as the health of the trees are affected from the drought. The Western redcedar could possibly lose economic value in dry places.

=== Possible Future Projections ===
The only thing that could protect the future of the Western is to change the projection by acting on the problem. This study suggests planting Western redcedars along an elevational gradient or higher elevations in the interior of British Columbia (Seebeacher). The reason why is because Western redcedars increase growth and productivity at higher elevations is because of warmer winters, longer growing season, and there will be more carbon dioxide with climate change (Seebeacher). This solution could possibly change the projection of the Western redcedar because of the effects it has on the Western redcedar in higher elevation.

==Conclusion==
The Western redcedar is facing a rapid and alarming decline across the Pacific Northwest, and the evidence throughout this article shows that the climate change induced stress is the main driving force behind it. Prolonged droughts, hotter summers, and reduced soil moisture are the main forces pushing the species beyond the conditions it has adapted to over millennia, leading to the destruction and mortality of the Western redcedar and the ecosystems it is supporting. The Western redcedar’s decline in population is usually followed by years of hot, dry summers, which are becoming patterns due to climate change increasing the frequency of these droughts (Brend, 2019; Canada, 2023). This decline is especially concerning because the Western redcedar is not just a regular and common tree; it is a keystone species, a major economic resource, and a central part of the Indigenous peoples of the PNW’s cultural identity.

Management strategies have been focusing on planting red cedar in sites that have better moisture retention, selecting drought‑resilient genotypes, and adjusting silvicultural practices to reduce early‑stage stress (Canada, 2023). The good news is that some redcedar populations can maintain growth during severe droughts, which suggests that assisted migration and climate‑adapted seed selection could play a major role in the survival of the species for the future like many other endangered species affected by climate change (College of the Environment & NW CASC, 2020).

Overall, the future of the Western redcedar depends on how quickly and effectively we can respond to this crisis. Without human intervention along with fast action, climate projections show the continued decline of the Western redcedar’s population across the PNW. With the efforts to target management resources, proper site selection, and the integration of Indigenous knowledge combined with modern ecological research, there is still light at the end of the tunnel. Through the restoration projects of the Western redcedar and other species in similar cases we can use all the combined knowledge and resources learned to help further progress the fight against climate change and its main drivers. Protecting the Pacific Northwestern redcedar or Thuja plicata means protecting its ecosystems, cultures, and communities that have relied on it and have taken care of it for generations. The choices we make now can and will determine whether the Western redcedar, ''Thuja plicata'' can survive in the rapidly changing anthropic climate.
==References==
<div style="column-count: 2;">
*1. Aldana, J. A., Kope, H. H., & Hawkins, B. J. (2023). Western redcedar — natural history and pathosystems, with emphasis on Cedar Leaf Blight. ''Canadian Journal of Plant Pathology'', ''45''(4), 377–390. <nowiki>https://doi.org/10.1080/07060661.2023.2198489</nowiki>
* 2. Brend, Y. (2019, May 14). Western red cedars die off as extended dry spells continue, say experts | CBC News. ''CBC''. <nowiki>https://www.cbc.ca/news/canada/british-columbia/western-red-cedars-death-dry-climate-change-1.5134262</nowiki>
* 3. Canada,. (2023). ''Information archivée dans le Web | Information Archived on the Web''. Publications.gc.ca. <nowiki>https://publications.gc.ca/site/eng/9.915415/publication.html</nowiki>
* 4. Canada, N. R. (2018). ''Tree mortality - Natural Resources Canada''. Canada.ca. <nowiki>https://natural-resources.canada.ca/climate-change/climate-change-impacts-forests/tree-mortality</nowiki>
* 5. College of the Environment & Northwest Climate Adaptation Science Center. (2020). ''Decline of Western redcedar: Using tree rings to understand mortality patterns and identify drought-resilient populations under climate change''. <nowiki>https://nwcasc.uw.edu/science/project/decline-of-western-red-cedar-using-tree-rings-to-understand-mortality-patterns-and-identify-drought-resilient-populations-under-climate-change/</nowiki>
* 6. Government of Canada. (2025). ''Tree mortality''. Natural Resources Canada. <nowiki>https://natural-resources.canada.ca/climate-change/climate-change-impacts-forests/tree-</nowiki> mortality
* 7. Grossnickle, S. C., & Russell, J. H. (2010). Physiological variation among western redcedar (Thuja plicata Donn ex D. Don) populations in response to short-term drought. Annals of Forest Science, 67(5), 506 506. <nowiki>https://doi.org/10.1051/forest/2010008</nowiki>
* 8. Hall, S., Stotts, S., & Haaf, L. (2022). Influence of climate and coastal flooding on eastern red cedar growth along a marsh-forest ecotone. ''Forests'', ''13''(6), 862. <nowiki>https://doi.org/10.3390/f13060862</nowiki>
* 9. Hamann, J. T. (2023). ''The impact of climate change on selected PNW watersheds through the lens of western red cedar habitat'' (Order No. 30524108). Available from ProQuest Dissertations & Theses Global. (2842790237). Retrieved from <nowiki>https://www.proquest.com/dissertations-theses/impact-climate-change-on-selected-pnw-watersheds/docview/2842790237/se-2</nowiki>
* 10. Joseph, B. (2025, April 4). ''Indigenous sacred plants: Red cedar''. Indigenous Corporate Training Inc. <nowiki>https://www.ictinc.ca/blog/indigenous-sacred-plants-cedar</nowiki>
* 11. Lam, D., Garden, A., & Hang, V. (2022). ''Preparing for the Future: Climate Change and Western Redcedars at the''. <nowiki>https://mufl.sites.olt.ubc.ca/files/2022/12/0817_Ginny_UFOR531_Report-Final_nonum-min.pdf</nowiki>
* 12. Minore, D. (1990, December 1). ''Western Redcedar | Silvics of North America''. Usda.gov. <nowiki>https://research.fs.usda.gov/silvics/western-redcedar</nowiki>
* 13. Omari, K., Kranabetter, J. M., & de Montigny, L. (2021). Productivity of coastal Douglas-fir and western redcedar in response to species mixture, planting density, and soil carbon:nitrogen ratio. ''Canadian Journal of Forest Research'', ''51''(5), 668–674. <nowiki>https://doi.org/10.1139/cjfr-2020-0223</nowiki>
* 14. Seebacher, T. M. (2007). ''Western redcedar dieback : possible links to climate change and implications for forest management on Vancouver Island, B.C.'' Open.library.ubc.ca. <nowiki>https://open.library.ubc.ca/soa/cIRcle/collections/ubctheses/831/items/1.0074955</nowiki>
* 15. Sierra Club BC. (2025, July 9). ''Western Red-Cedar''. Sierra Club BC. <nowiki>https://sierraclub.bc.ca/ecomap/western-red-cedar/</nowiki>
* 16. Woods, A. J., Heppner, D., Kope, H. H., Burleigh, J., & Maclauchlan, L. (2010). Forest Health and Climate Change: A british columbia perspective. ''The Forestry Chronicle'', ''86''(4), 412–422. <nowiki>https://doi.org/10.5558/tfc86412-4</nowiki>
<references />
</div>{{Projectbox CONS200
|names=
|share=no
}}

[[Category:Conservation]]