Thuja plicata

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Thuja plicata
Thuja plicata Vancouver.jpg
An old tree in Vancouver
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Division: Pinophyta
Class: Pinopsida
Order: Pinales
Family: Cupressaceae
Genus: Thuja
Species:
T. plicata
Binomial name
Thuja plicata
Donn ex D.Don
Thuja plicata range.png
Range of T. plicata in the Pacific Northwest

Thuja plicata, commonly called western red cedar [2] or Pacific red cedar, [3] giant arborvitae or western arborvitae, or just cedar, [3] giant cedar, [3] or shinglewood, [3] is a species of Thuja , an evergreen coniferous tree in the cypress family Cupressaceae native to western North America. It is not a true cedar of the genus Cedrus .

Contents

Distribution

Thuja plicata is among the most widespread trees in the Pacific Northwest. It is associated with Douglas-fir and western hemlock in most places where it grows. It is found at the elevation range of sea level to a maximum of 2,290 m (7,510 ft) above sea level at Crater Lake in Oregon. [4] In addition to growing in lush forests and mountainsides, western redcedar is also a riparian tree, growing in many forested swamps and streambanks in its range. [5] The tree is shade-tolerant and able to reproduce under dense shade. [6]

It has been introduced to other temperate zones, including western Europe, Australia (at least as far north as Sydney), New Zealand, [7] [8] the eastern United States (at least as far north as Central New York),[ citation needed ] and higher elevations of Hawaii. [9]

The species is naturalized in Britain. [10]

Description

Thuja plicata is a large to very large tree, ranging up to 65 to 70 m (210 to 230 ft) tall and 3 to 7 m (10 to 23 ft) in trunk diameter. [11] [12] Trees growing in the open may have a crown that reaches the ground, whereas trees densely spaced together will exhibit a crown only at the top, where light can reach the leaves. [13] It is long-lived; some individuals can live well over a thousand years, with the oldest verified being 1460 years. [11] [12]

The foliage forms flat sprays with scale-like leaves in opposite pairs, with successive pairs at 90 degrees to each other. The foliage sprays are green above and green marked with whitish stomatal bands below; they are strongly aromatic, with a scent reminiscent of pineapple when crushed. The individual leaves are 1 to 4 mm (0.04 to 0.16 in) long and 1 to 2 mm (0.04 to 0.08 in) broad on most foliage sprays, but up to 12 mm (0.5 in) long on strong-growing lead shoots. [11] [12]

The cones are slender, 10 to 18 mm (0.4 to 0.7 in) long, and 4 to 5 mm (0.16 to 0.20 in) broad, with 8 to 12 (rarely 14) thin, overlapping scales. They are green to yellow-green, ripening brown in fall about six months after pollination, and open at maturity to shed the seeds. The seeds are 4 to 5 mm (0.16 to 0.20 in) long and 1 mm (0.04 in) broad, with a narrow papery wing down each side. The pollen cones are 3 to 4 mm (0.12 to 0.16 in) long, red or purple at first, and shed yellow pollen in spring. [11] [12]

Taxonomy and name

Western red-cedars on Keats Island, British Columbia, in May 2017 Western red cedars, looking up.jpg
Western red-cedars on Keats Island, British Columbia, in May 2017

Thuja plicata is one of two Thuja species native to North America, the other being Thuja occidentalis . The species name plicata derives from the Latin word plicāre and means "folded in plaits" or "braided," a reference to the pattern of its small leaves. [13]

Most authorities, both in Canada [14] [15] and the United States [4] [2] [16] [17] cite the English name in two words as western redcedar, or occasionally hyphenated as western red-cedar, [12] to indicate it is not a true cedar ( Cedrus ), but it is also cited as western red cedar in some popular works. In the American horticultural trade, it is also known as the giant arborvitae, by comparison with arborvitae for its close relative Thuja occidentalis . Other names include giant redcedar, Pacific redcedar, shinglewood, British Columbia cedar, canoe cedar, and red cedar. [11] [18] Arborvitae comes from the Latin for "tree of life"; coincidentally, Native Americans of the West coast also address the species as "long life maker". [18]

One endonymous name for the tree is the Halkomelem word xepá:y, [19] from the roots xíp, meaning "scratch" or "line", and á:y, "bark"; [20] the former root may be in reference to both the lined or "folded/braided" appearance of the bark and the tree's ubiquity in carving and other forms of woodwork.

Pathology

Western redcedar shows susceptibility of varying degrees to the following soil pathogens: Armillaria ostoyae, Fomitopsis pinicola, Heterobasidion annosum, Phaeolus schweinitzii, Phellinus weirii, Rhizinia undulata, and Postia sericeomollis. [21]

While western redcedar is a host to P. weirii, the fungus which causes the disease laminated root rot, redcedar is rated as resistant while other conifers are rated as highly susceptible or susceptible. [22] Instead of laminated root rot, P. weirri in western redcedar expresses as a butt rot that can extend 2–3 m up the boles of living trees with the most extreme cases reaching 10 m. While the heart rot caused by the redcedar form of P. weirii does not kill the tree outright, it does severely weaken the lower portion of the bole which makes the tree highly susceptible to stem breakage.

P. sericeomollis is responsible for brown cubical butt and pocket rot of cedar. It is the second-most common cause of decay in western redcedar following P. weirii. Rather than forming a single column of decay in the heartwood, though, P. sericeomollis tends to cause rings or pockets of decay in the lower bole. [23]

In addition to P. weirii, western redcedar is also less susceptible to H. annosum and A. ostoyae than other conifer species. [24] Studies have found that western redcedar produces a phytochemical called thujaplicin which has been credited with granting the species its natural resistance to fungal attacks. [25] Because of these natural defenses, it has been suggested that western redcedar may serve as a suitable alternative to other conifers when regenerating a site affected by these pathogens. [26]

Insects

It attracts the western cedar borer and cedar bark beetle. [27]

Notable specimens

The "Quinault Lake Redcedar" was the largest western redcedar in the world. QuinaultLakeCedar 7274c.jpg
The "Quinault Lake Redcedar" was the largest western redcedar in the world.

The largest living specimen is the Cheewhat Giant, in Pacific Rim National Park Reserve on Vancouver Island, at 15,870 cubic feet (450 m3). [28] The tallest known individual is the Willaby Creek Tree south of Lake Quinault, 195 feet (59 m) in height. [29] The "Quinault Lake Redcedar" was the largest known western redcedar in the world, with a wood volume of 17,650 cubic feet (500 m3). Located near the northwest shore of Lake Quinault north of Aberdeen, Washington, about 34 km (21 mi) from the Pacific Ocean, it was one-third the volume of the largest known tree, a giant sequoia named "General Sherman". The Quinault Lake Redcedar was 174 feet (53 m) tall with a diameter of 19.5 feet (5.9 m) at breast height. The "Quinault Lake Red Cedar" was destroyed by a series of storms in 2014 and 2016 and is now only a glorified stump. [11] [30] The fifth known largest was the Kalaloch Cedar in the Olympic National Park, at 12,370 cubic feet (350 m3), [31] until it was destroyed by storm in March 2014. [32]

A redcedar over 71 m (233 ft) tall, 4.5 m (15 ft) in diameter, and over 700 years old stood in Cathedral Grove on Vancouver Island, British Columbia, before it was set on fire and destroyed by vandals in 1972. That tree now lies in "Giant's Grave", a self-dug 'grave' created by the force of its own impact. [33]

Uses

Timber

Canadian western redcedar cowl in the National Assembly for Wales SeneddFunnel.jpg
Canadian western redcedar cowl in the National Assembly for Wales

The soft red-brown timber has a tight, straight grain and few knots. It is valued for its distinct appearance, aroma, and its high natural resistance to decay, being extensively used for outdoor construction in the form of posts, decking, shingles, and siding. [34] It is commonly used for the framing and longwood in lightweight sail boats and kayaks. In larger boats it is often used in sandwich construction between two layers of epoxy resin and/or fibreglass or similar products. Due to its light weight – 390 to 400 kg/m3 (24 to 25 lb/cu ft) dried – it is about 30% lighter than common boat building woods, such as mahogany. For its weight it is quite strong but can be brittle. It glues well with epoxy resin or resorcinol adhesive.

The wood typically used as an insect-repelling closet lining and to make cedar chests is a different species, Juniperus virginiana (also known as red cedar).

Its light weight, strength, and dark, warm sound make it a popular choice for guitar soundboards.

Cultivation

Like its relative Thuja occidentalis and many other conifer species, Thuja plicata is grown as an ornamental tree, and for screens and hedges, throughout the world in gardens and parks. A wide variety of forms, sizes, and colours is available. [35]

Cultivars

The following cultivars have gained the Royal Horticultural Society's Award of Garden Merit:

Other uses

It is also widely used throughout Europe and America for making beehive components.

Chemistry

The heartwood of western red cedar contains different chemical substances, such as plicatic acid, thujaplicatin methyl ether, hinokitiol and other thujaplicins, β-thujaplicinol, thujic acid, methyl thujate, 1,4-cineole and γ-eudesmol. [40] Plicatic acid is believed to be the main irritant and contact allergen responsible for provoking allergic reactions and asthma exaggeration and leading to occupational asthma in woodworkers that are exposed to western red cedar wood dust. [41] Thujaplicins serve as natural fungicides, [42] [25] and thereby prevent the wood from rotting. This effect lasts around a century even after the tree is felled. However, thujaplicins are only found in older trees. Saplings do not produce the chemical, causing them to often develop rot at an early stage, causing some trees to grow with a somewhat hollow trunk, as the tree moves to heal itself as it grows. [18] Due to their fungicidal and anti-browning properties, thujaplicins are used in agriculture for fungal diseases and to prevent post-harvest decay. [43] [44] Thujaplicins, as other tropolones, are potent chelating agents and bind divalent metal ions. [45] Basic and animal studies have shown that thujaplicins may have other biological properties, including antibacterial, antiviral and antioxidant activities, [46] however reliable evidence on their effectiveness is still lacking.

Essential oil

The essential oil of western red cedar leaves contains natural compounds, such as α-thujone, β-thujone, fenchone, sabinene, terpinen-4-ol and beyerene, [47] which have also been isolated from different other essential oils. Some of these substances are aroma compounds and are used in perfumery. [48] Thujones are GABAA receptor competitive antagonists however because of their high toxicity and convulsive activity they do not have any pharmacological use. [49]

Role in indigenous societies

Klallam people and canoe, ca. 1914 Klallam people near canoe.jpg
Klallam people and canoe, ca. 1914

Western red cedar has an extensive history of use by Native Americans of coastal Oregon to southeast Alaska. Some northwest coast tribes refer to themselves as "people of the redcedar" because of their extensive dependence on the tree for basic materials. The wood has been used for constructing housing and totem poles, and crafted into many objects, including masks, utensils, boxes, boards, instruments, canoes, vessels, houses, and ceremonial objects. Western Red Cedar is also associated with a long tradition of curing and cooking fish over the open fire. Roots and bark are used for baskets, bowls, ropes, clothing, blankets, and rings. [50] [51]

History

A huge number of archaeological finds point to the continuous use of redcedar wood in native societies. Woodworking tools dating between 8000 and 5000 years ago, such as carved antlers, were discovered in shell middens at the Glenrose site, near Vancouver, British Columbia. [52] In Yuquot, on the west coast of Vancouver Island, tools dating 4000 to 3000 years old have been found. [52] The Musqueam site, also near Vancouver, yielded bark baskets woven in five different styles, along with ropes and ships dated to 3000 years ago. At Pitt River, adzes and baskets were dated around 2900 years aol. Wooden artifacts 1000 years old were unearthed on the east coast of Vancouver Island. [53]

Red cedar was used extensively wherever it was found along the northwest coast (British Columbia, Washington state, Parts of Alaska). Evidence of this use is found in CMTs (Culturally Modified Trees) that are found throughout the coast. When First Nations people removed the bark from cedars, it left a scar - which is considered a CMT. Other types of harvest (for planks, tinder, and other uses) leave different types of evidence of cultural modification.

A legend amongst the Coast Salish peoples describes the origins of the western redcedar. In this legend, there was a generous man who gave the people whatever they needed. When the Great Spirit saw this, he declared that when the generous man died, a great redcedar tree will grow where he is buried, and that the cedar will be useful to all the people, providing its roots for baskets, bark for clothing, and wood for shelter. [52]

Tools

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

Excavations done at Ozette, Washington turned up iron tools nearly 800 years old, far before European contact. When James Cook passed the area, he observed that almost all tools were made of iron. [54] There has been speculation on the origin of these iron tools. Some theories include shipwrecks from East Asia or possible contact with iron-using cultures from Siberia, as hinted in the more advanced woodworking found in northern tribes such as the Tlingit. [54] [55] [56] [57]

Wood

A totem pole outside a six-post house at the University of British Columbia Moa-4.jpg
A totem pole outside a six-post house at the University of British Columbia

Harvesting redcedars required some ceremony and included propitiation of the tree's spirits as well as those of the surrounding trees. In particular, many people specifically requested the tree and its brethren not to fall or drop heavy branches on the harvester, [58] a situation which is mentioned in a number of different stories of people who were not sufficiently careful. Some professional loggers of Native American descent have mentioned that they offer quiet or silent propitiations to trees which they fell, following in this tradition.

Felling of large trees such as redcedar before the introduction of steel tools was a complex and time-consuming art. Typically the bark was removed around the base of the tree above the buttresses. Then some amount of cutting and splitting with stone adzes and mauls would be done, creating a wide triangular cut. The area above and below the cut would be covered with a mixture of wet moss and clay as a firebreak. Then the cut would be packed with tinder and small kindling and slowly burned. The process of cutting and burning would alternate until the tree was mostly penetrated through, and then careful tending of the fire would fell the tree in the best direction for handling. This process could take many days. Constant rotation of workers was involved to keep the fires burning through night and day, often in a remote and forbidding location. [59]

Once the tree was felled, the work had only just begun, as it then had to be stripped and dragged down to shore. If the tree was to become canoes, then it would often be divided into sections and worked into rough canoe shapes before transport. If it were to be used for a totem pole or building materials, it would be towed in the round to the village. [60] Many trees are still felled in this traditional manner for use as totem poles and canoes, particularly by artists who feel that using modern tools is detrimental to the traditional spirit of the art. Non-traditionalists simply buy redcedar logs or lumber at mills or lumber yards, a practice that is commonly followed by most working in smaller sizes such as for masks and staves.

Because felling required such an extraordinary amount of work, if only planks for housing were needed, these would be split from the living tree. The bark was stripped and saved, and two cuts were made at the ends of the planking. Then wedges would be pounded in along the sides and the planks slowly split off the side of the tree. [61] Trees which have been so harvested are still visible in some places in the rainforest, with obvious chunks taken off of their sides. Such trees usually continue to grow perfectly well, since redcedar wood is resistant to decay. Planks are straightened by a variety of methods, including weighing them down with stones, lashing them together with rope, or forcing them between a line of stakes. [62]

Illustration of women pulling bark from a tree, from Indian Legends of Vancouver Island by Alfred Carmichael Thuja plicata bark.png
Illustration of women pulling bark from a tree, from Indian Legends of Vancouver Island by Alfred Carmichael

Redcedar wood is used to make huge monoxyla canoes in which the men went out to high sea to harpoon whales and conduct trade. [63] One of those canoes, a 38-foot (12 m) craft dug out about a century ago, was bought in 1901 by Captain John Voss, an adventurer. He gave her the name of Tilikum ("Relative" in Chinook jargon), rigged her, and led her in a hectic three-year voyage from British Columbia to London. [64]

Redcedar branches are very flexible and have good tensile strength. They were stripped and used as strong cords for fishing line, rope cores, twine, and other purposes where bark cord was not strong enough or might fray. Both the branches and bark rope have been replaced by modern fiber and nylon cordage among the aboriginal northwest coast peoples, though the bark is still in use for the other purposes mentioned above.

Bark

At the right time of year, the bark is easily removed from live trees in long strips. It is harvested for use in making mats, rope and cordage, basketry, rain hats, clothing, and other soft goods. The harvesting of bark must be done with care, as stripping too much bark will kill the tree. To prevent this, the harvester usually only harvests from trees which have not been stripped before. [65] After harvesting, the tree is not used for bark again, although it may later be felled for wood. Stripping bark is usually started with a series of cuts at the base of the tree above any buttresses, after which the bark is peeled upwards. To remove bark high up, a pair of platforms strung on rope around the tree are used and the harvester climbs by alternating between them for support. Since redcedars lose their lower branches as all tall trees do in the rainforest, the harvester may climb 10 m (33 ft) or more into the tree by this method. The harvested bark is folded and carried in backpacks. [66] It can be stored for quite some time as mold does not grow on it, and is moistened before unfolding and working. It is then split lengthwise into the required width and woven or twisted into shape. Bark harvesting was mostly done by women, despite the danger of climbing 10 meters in the air, because they were the primary makers of bark goods. [67]

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

Western red cedar is export-restricted in the United States under the Export Administration Regulations.

Health and safety

Western red cedar is highly allergenic and woodworkers or loggers who work with it may have adverse reactions, including the development of occupational asthma, exacerbation of existing asthma, reduction of lung function, and eye irritation. Approximately 5% of workers are allergic to western red cedar. The US Occupational Safety and Health Administration has set a permissible exposure limit for red cedar dust of 2.5 mg/m3 as a time-weighted average over 8 hours. [68]

See also

Related Research Articles

<i>Cedrus</i> Genus of plants (coniferous trees)

Cedrus, common English name cedar, is a genus of coniferous trees in the plant family Pinaceae. They are native to the mountains of the western Himalayas and the Mediterranean region, occurring at altitudes of 1,500–3,200 m in the Himalayas and 1,000–2,200 m in the Mediterranean.

<i>Thuja</i>

Thuja is a genus of coniferous trees in the Cupressaceae. There are five species in the genus, two native to North America and three native to eastern Asia. The genus is monophyletic and sister to Thujopsis. Members are commonly known as arborvitaes, thujas or cedars.

<i>Cupressus nootkatensis</i>

Cupressus nootkatensis is a species of trees in the cypress family native to the coastal regions of northwestern North America. This species goes by many common names including: Nootka cypress, yellow cypress, Alaska cypress, Nootka cedar, yellow cedar, Alaska cedar, and Alaska yellow cedar. The specific epithet "nootkatensis" is derived from its discovery by Europeans on the lands of a First Nation of Canada, those lands of the Nuu-chah-nulth people of Vancouver Island, British Columbia, who were formerly referred to as the Nootka.

<i>Alnus rubra</i>

Alnus rubra, the red alder, is a deciduous broadleaf tree native to western North America.

<i>Thuja occidentalis</i> Species of evergreen coniferous tree

Thuja occidentalis, also known as northern white cedar, eastern white cedar, or arborvitae, is an evergreen coniferous tree, in the cypress family Cupressaceae, which is native to eastern Canada and much of the northcentral and northeastern United States. It is widely cultivated as an ornamental plant.

<i>Thujopsis</i>

Thujopsis is a genus of conifers in the cypress family (Cupressaceae), the sole member of which is Thujopsis dolabrata. It is endemic to Japan, where it is named asunaro (あすなろ). It is similar to the closely related genus Thuja (arborvitae), differing in the broader, thicker leaves and thick cones. It is also called hiba, false arborvitae, or hiba arborvitae.

Cedar bark textile Wood-based textile of the indigenous peoples of the Pacific Northwest

Cedar bark textile was used by indigenous people in the Pacific Northwest region of modern-day Canada and the United States. Historically, most items of clothing were made of shredded and woven cedar bark.

Plicatic acid

Plicatic acid is a carboxylic acid from the resin acid group. It is naturally found in Thuja and cypress resin. It is the main irritant and contact allergen present in thuja wood.

Northern Pacific coastal forests

The Northern Pacific coastal forests are temperate coniferous forest ecoregion of the Pacific coast of North America. It occupies a narrow coastal zone of Alaska, between the Pacific Ocean and the northernmost Pacific Coast Ranges, covering an area of 23,300 square miles, extending from the Alexander Archipelago in southeast Alaska along the Gulf of Alaska to the western Kenai Peninsula and eastern Kodiak Island. The Pacific Coastal Mountain icefields and tundra ecoregion lies inland, at higher elevations in the Coast Mountains. The ecoregion receives high rainfall, which varies considerably based on exposure and elevation. It contains a quarter of the world's remaining temperate rain forest.

Management of Pacific Northwest riparian forests is necessary because many of these forests have been dramatically changed from their original makeup. The primary interest in riparian forest and aquatic ecosystems under the Northwest Forest Plan (NWFP) is the need to restore stream habitat for fish populations, particularly Anadromous salmonids. Some of these forests have been grazed by cattle or other livestock. The heavy hooves of these animals compact the soil. This compaction does not allow the water to be absorbed into the ground, so the water runs off into the stream carrying topsoil along the way.

Wood-decay fungus

A wood-decay or xylophagous fungus is any species of fungus that digests moist wood, causing it to rot. Some species of wood-decay fungi attack dead wood, such as brown rot, and some, such as Armillaria, are parasitic and colonize living trees. Excessive moisture above the fibre saturation point in wood is required for fungal colonization and proliferation. Fungi that not only grow on wood but permeate its fibrous structure and actually cause decay, are called lignicolous fungi. In nature, this process causes the breakdown of complex molecules and leads to the return of nutrients to the soil. Various lignicolous fungi consume wood in various ways; for example, some attack the carbohydrates in wood and some others decay lignin. The rate of decay of wooden materials in various climates can be estimated by empirical models.

<i>Stereum sanguinolentum</i>

Stereum sanguinolentum is a species of fungus in the Stereaceae family. A plant pathogen, it causes red heart rot, a red discoloration on conifers, particularly spruces or Douglas-firs. Fruit bodies are produced on dead wood, or sometimes on dead branches of living trees. They are a thin leathery crust of the wood surface. Fresh fruit bodies will bleed a red-colored juice if injured, reflected in the common names bleeding Stereum or the bleeding conifer parchment. It can be the host of the parasitic jelly fungus Tremella encephala.

<i>Didymascella thujina</i>

Didymascella thujina is an ascomycete fungus in the family Helotiaceae. D. thujina causes cedar leaf blight, a leaf disease, on western red cedar and white cedar (T. occidentalis).

<i>Laminated root rot</i>

Laminated root rot also known as yellow ring rot is caused by the fungal pathogen Phellinus weirii. Laminated root rot is one of the most damaging root disease amongst conifers in northwestern America and true firs, Douglas-fir, Mountain hemlock, and Western hemlock are highly susceptible to infection with P. weirii. A few species of plants such as Western white pine and Lodgepole pine are tolerant to the pathogen while Ponderosa pine is resistant to it. Only hardwoods are known to be immune to the pathogen.

Thujaplicin

Thujaplicins are a series of tropolone-related chemical substances that have been isolated from the hardwoods of the trees of Cupressaceae family. These compounds are known for their antibacterial, antifungal and antioxidant properties. They were the first natural tropolones to be made synthetically.

Hinokitiol

Hinokitiol (β-thujaplicin) is a natural monoterpenoid found in the wood of trees in the family Cupressaceae. It is a tropolone derivative and one of the thujaplicins. Hinokitiol is used in oral and skin care products, and is a food additive used in Japan.

<i>Pseudotsuga menziesii <span style="font-style:normal;">var.</span> menziesii</i>

Pseudotsuga menziesii var. menziesii, also known as Coast Douglas-fir, Pacific Douglas-fir, Oregon pine, or Douglas spruce, is an evergreen conifer native to western North America from west-central British Columbia, Canada southward to central California, United States. In Oregon and Washington its range is continuous from the Cascades crest west to the Pacific Coast Ranges and Pacific Ocean. In California, it is found in the Klamath and California Coast Ranges as far south as the Santa Lucia Mountains with a small stand as far south as the Purisima Hills, Santa Barbara County. In the Sierra Nevada it ranges as far south as the Yosemite region. It occurs from near sea level along the coast to 1,800 metres (5,900 ft) in the California Mountains. Further inland, coast Douglas-fir is replaced by Rocky Mountain or interior Douglas-fir. Interior Douglas-fir intergrades with coast Douglas-fir in the Cascades of northern Washington and southern British Columbia.

Yellow-cedar decline

Yellow-cedar decline is the accelerated decline and mortality of yellow cedar occurring in the Pacific Northwest Temperate Rainforest of Southeast Alaska and British Columbia in North America. This phenomenon has been observed on over 200,000 hectares of forest and is believed to be due to reduced winter snowpacks and increased soil freezing.

Cheewhat Giant, also known as the Cheewhat Lake Cedar, is a large western red cedar tree located within Pacific Rim National Park Reserve on Vancouver Island in British Columbia, Canada. It is the largest living Western redcedar, the largest known tree in Canada and one of the largest in the world.

Duncan Cedar

The Duncan Cedar, also known as the Duncan Memorial Cedar and the Nolan Creek Tree, is a large specimen of Western redcedar. The tree is located on the Olympic Peninsula in the U.S. state of Washington. It is currently the second largest known Western redcedar in the world, after the Cheewhat Giant on Canada's Vancouver Island.

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