The Douglas fir (''Pseudotsuga menziesii'') is an

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, whic ...

conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All ext ...

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

in the pine family, Pinaceae. It is

native Native may refer to: People * Jus soli, citizenship by right of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Native Americans (disambiguation) In arts and entert ...

to western

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

and is also known as Douglas-fir, Douglas spruce, Oregon pine, and Columbian pine. There are three varieties: coast Douglas-fir (''P. menziesii'' var. ''menziesii''), Rocky Mountain Douglas-fir (''P. menziesii'' var. ''glauca'') and

Mexican Douglas-fir ''Pseudotsuga menziesii var. lindleyana'', commonly known as the Mexican Douglas-fir, is a conifer in the genus '' Pseudotsuga'' that is endemic to Mexico. DNA sequence and morphological evidence suggests it is most closely related to Rocky Mou ...

(''P. menziesii'' var. ''lindleyana''). Despite its

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...

s, it is not a true fir (

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

Abies Firs (''Abies'') are a genus of 48–56 species of evergreen coniferous trees in the family Pinaceae. They are found on mountains throughout much of North and Central America, Europe, Asia, and North Africa. The genus is most closely re ...

''),

spruce A spruce is a tree of the genus ''Picea'' (), a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfam ...

(genus '' Picea''), or

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family (biology), family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanic ...

(genus '' Pinus''). It is also not a hemlock; the genus name ''Pseudotsuga'' means "false hemlock".

Description

Douglas-firs are medium-size to extremely large

trees, tall (although only ''Pseudotsuga menziesii var. menziesii'', common name coast Douglas-firs, reach heights near 100 m) and commonly reach in diameter, although trees with diameters of almost exist. The largest coast Douglas-firs regularly live over 500 years, with the oldest specimens living for over 1,300 years. Rocky Mountain Douglas-firs, found further to the east, are less long-lived, usually not exceeding 400 years in age. There are records of former coast Douglas-firs exceeding in height, which if alive today would make it the tallest tree species on Earth. Some particular specimens that exceeded 400 feet tall were the Lynn Valley Tree and the Nooksack Giant. The leaves are flat, soft, linear needles long, generally resembling those of the firs, occurring singly rather than in

fascicle Fascicle or ''fasciculus'' may refer to: Anatomy and histology * Muscle fascicle, a bundle of skeletal muscle fibers * Nerve fascicle, a bundle of axons (nerve fibers) ** Superior longitudinal fasciculus *** Arcuate fasciculus ** Gracile fasc ...

s; they completely encircle the branches, which can be useful in recognizing the species. As the trees grow taller in denser forest, they lose their lower branches, such that the foliage may start as high as off the ground. Douglas-firs in environments with more light may have branches much closer to the ground. The

bark Bark may refer to: * Bark (botany), an outer layer of a woody plant such as a tree or stick * Bark (sound), a vocalization of some animals (which is commonly the dog) Places * Bark, Germany * Bark, Warmian-Masurian Voivodeship, Poland Arts, e ...

on young trees is thin, smooth, grey, and contains numerous

resin In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses on nat ...

blisters. On mature trees, usually exceeding 80 years, it is very thick and corky, growing up to thick with distinctive, deep vertical fissures caused by growth. Layers of darker brown bark are interspersed with layers of lighter colored, corky material. This thickness makes the Douglas-fir perhaps the most fire-resistant tree native to the Pacific Northwest. The female cones are pendulous, with persistent scales, unlike those of true firs. They have distinctive long,

trifid Trifid is Latin for "split into three parts" or "threefold" and may refer to: * ''Trifid'' (journal), a Czech-language periodical * Trifid Nebula in the constellation Sagittarius * Trifid cipher, a fractionated cipher * Trifid (software), suite of ...

(three-pointed)

bract In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or o ...

s which protrude prominently above each scale and are said to resemble the back half of a mouse, with two feet and a tail. The cones are tan when mature, measuring long for coastal Douglas-firs and a couple of centimetres shorter inland. The massive mega-

genome In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ...

of Douglas fir was sequenced in 2017 by the large PineRefSeq consortium, revealing a specialized photosynthetic apparatus in the light-harvesting complex genes.

Taxonomy

The common name honors David Douglas, a Scottish botanist and collector who first reported the extraordinary nature and potential of the species. The common name is misleading since it is not a true fir, i.e., not a member of the genus ''

''. For this reason, the name is often written as Douglas-fir (a name also used for the genus ''

Pseudotsuga ''Pseudotsuga'' is a genus of evergreen coniferous trees in the family Pinaceae (subfamily Laricoideae). Common names for species in the genus include Douglas fir, Douglas-fir, Douglas tree, Oregon pine and Bigcone spruce. ''Pseudotsuga menzie ...

'' as a whole). The specific epithet ''menziesii'' is after Archibald Menzies, a Scottish physician and rival naturalist to David Douglas. Menzies first documented the tree on

Vancouver Island Vancouver Island is an island in the northeastern Pacific Ocean and part of the Canadian province of British Columbia. The island is in length, in width at its widest point, and in total area, while are of land. The island is the largest by ...

in 1791. Colloquially, the species is also known simply as Doug fir or Douglas pine (although the latter common name may also refer to ''

Pinus douglasiana ''Pinus douglasiana'' is a species of evergreen conifer in the family Pinaceae. It is found only in Mexico. A common name is Douglas pine, but that name is often applied to the more widespread species ''Pseudotsuga menziesii'' which is also kno ...

''). Other names for this tree have included Oregon pine, British Columbian pine, Puget Sound pine, Douglas spruce, false hemlock, red fir, or red pine (although again red pine may refer to a different tree species, '' Pinus resinosa'', and red fir may refer to '' Abies magnifica''). One Coast Salish name for the tree, used in the Halkomelem language, is . In the Lushootseed language, the tree is called .

Distribution

''Pseudotsuga menziesii'' var. ''menziesii'', the coast Douglas-fir, grows in the coastal regions from west-central

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, for ...

southward to central

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

. In

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

and

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

, its range is continuous from the eastern edge of the Cascades west to the Pacific Coast Ranges and Pacific Ocean. In California, it is found in the Klamath and

California Coast Ranges The Coast Ranges of California span from Del Norte or Humboldt County, California, south to Santa Barbara County. The other three coastal California mountain ranges are the Transverse Ranges, Peninsular Ranges and the Klamath Mountains. ...

as far south as the Santa Lucia Range, with a small stand as far south as the

Purisima Hills The Purisima Hills are a northwest-to-southeast trending low mountain range of the Outer Southern California Coast Ranges, located in Santa Barbara County, California. They divide the Santa Ynez Valley The Santa Ynez Valley is located in San ...

in Santa Barbara County. One of the last remaining old growth stands of conifers is in the Mattole Watershed, and is under threat of logging. In the

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primar ...

, it ranges as far south as the Yosemite region. It occurs from sea level along the coast to elevations of or higher, and inland in some cases up to . Another variety exists further inland, ''Pseudotsuga menziesii'' var. ''glauca'', the Rocky Mountain Douglas-fir or interior Douglas-fir. Interior Douglas-fir intergrades with coast Douglas-fir in the Cascades of northern Washington and southern British Columbia, and from there ranges northward to central British Columbia and southeastward to the Mexican border, becoming increasingly disjunct as latitude decreases and altitude increases.

(''P. lindleyana''), which ranges as far south as

Oaxaca Oaxaca ( , also , , from nci, Huāxyacac ), officially the Free and Sovereign State of Oaxaca ( es, Estado Libre y Soberano de Oaxaca), is one of the 32 states that compose the Federative Entities of Mexico. It is divided into 570 municipaliti ...

, is often considered a variety of ''P. menziesii''. Fossils (wood, pollen) of ''Pseudotsuga'' are recorded from the

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

and

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Siebengebirge,

Gleiwitz Gliwice (; german: Gleiwitz) is a city in Upper Silesia, in southern Poland. The city is located in the Silesian Highlands, on the Kłodnica river (a tributary of the Oder). It lies approximately 25 km west from Katowice, the regional capi ...

, Austria). It is also

naturalised Naturalization (or naturalisation) is the legal act or process by which a non-citizen of a country may acquire citizenship or nationality of that country. It may be done automatically by a statute, i.e., without any effort on the part of the in ...

throughout Europe, Argentina and Chile (called ''Pino Oregón''). In New Zealand it is considered to be an invasive species, called a wilding conifer, and is subject to control measures. But is also one of the most common lumber trees used in forestry alongside Radiata pine with large plantations throughout the country. The species was introduced in the 1900s for its wood.

Ecology

Preferred sites

Douglas-fir prefers acidic or neutral soils. However, it exhibits considerable morphological plasticity, and on drier sites ''P. menziesii'' var. ''menziesii'' will generate deeper taproots. ''Pseudotsuga menziesii'' var. ''glauca'' exhibits even greater plasticity, occurring in stands of interior temperate rainforest in British Columbia, as well as at the edge of semi-arid sagebrush steppe throughout much of its range, where it generates even deeper taproots still. The coast Douglas-fir variety is the dominant tree west of the Cascade Mountains in the

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Thou ...

. It occurs in nearly all forest types and competes well on most parent materials, aspects, and slopes. Adapted to a more moist, mild climate than the interior subspecies, it grows larger and faster than Rocky Mountain Douglas-fir. Associated trees include western hemlock,

Sitka spruce ''Picea sitchensis'', the Sitka spruce, is a large, coniferous, evergreen tree growing to almost tall, with a trunk diameter at breast height that can exceed 5 m (16 ft). It is by far the largest species of spruce and the fifth-lar ...

, sugar pine,

western white pine Western white pine (''Pinus monticola''), also called silver pine and California mountain pine, is a species of pine in the family Pinaceae. It occurs in mountain ranges of northwestern North America. It is the state tree of Idaho. Description ...

, ponderosa pine, grand fir, coast redwood, western redcedar, California incense-cedar,

Lawson's cypress ''Chamaecyparis lawsoniana'', known as Port Orford cedar or Lawson cypress, is a species of conifer in the genus '' Chamaecyparis'', family Cupressaceae. It is native to Oregon and northwestern California, and grows from sea level up to in the ...

, tanoak, bigleaf maple and several others. Pure stands are also common, particularly north of the Umpqua River in Oregon. It is most dominant in areas with a more frequent fire regime that suppresses less fire-resistant conifers.

Use by animals

Douglas-fir seeds are an extremely important food source for small mammals such as

moles Moles can refer to: * Moles de Xert, a mountain range in the Baix Maestrat comarca, Valencian Community, Spain *The Moles (Australian band) *The Moles, alter ego of Scottish band Simon Dupree and the Big Sound People * Abraham Moles, French engin ...

shrew Shrews (family Soricidae) are small mole-like mammals classified in the order Eulipotyphla. True shrews are not to be confused with treeshrews, otter shrews, elephant shrews, West Indies shrews, or marsupial shrews, which belong to differ ...

s, and chipmunks, which consume an estimated 65% of each annual seed crop. The Douglas squirrel harvests and hoards great quantities of Douglas-fir cones, and also consumes mature pollen cones, the inner bark, terminal shoots, and developing young needles. Mature or "old-growth" Douglas-fir forest is the primary habitat of the red tree vole (''Arborimus longicaudus'') and the spotted owl (''Strix occidentalis''). Home range requirements for breeding pairs of spotted owls are at least 400 ha () of old growth. Red tree voles may also be found in immature forests if Douglas-fir is a significant component. The red vole nests almost exclusively in the foliage of the trees, typically above the ground, and its diet consists chiefly of Douglas-fir needles. Douglas-fir needles are generally poor

browse Browsing is a kind of orienting strategy. It is supposed to identify something of relevance for the browsing organism. When used about human beings it is a metaphor taken from the animal kingdom. It is used, for example, about people browsing o ...

for

ungulate Ungulates ( ) are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. These include odd-toed ungulates such as horses, rhinoceroses, and tapirs; and even-toed ungulates such as cattle, pigs, giraffes, ...

s, although in the winter when other food sources are lacking it can become important, and black-tailed deer browse new seedlings and saplings in spring and summer. The spring diet of the blue grouse features Douglas-fir needles prominently. The leaves are also used by the woolly conifer aphid '' Adelges cooleyi''; this 0.5 mm-long sap-sucking

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pa ...

is conspicuous on the undersides of the leaves by the small white "fluff spots" of protective wax that it produces. It is often present in large numbers, and can cause the foliage to turn yellowish from the damage it causes. Exceptionally, trees may be partially defoliated by it, but the damage is rarely this severe. Among

Lepidoptera Lepidoptera ( ) is an order of insects that includes butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 families and 46 superfamilies, 10 percent of the total described speci ...

, apart from some that feed on ''Pseudotsuga'' in general, the gelechiid moths ''Chionodes abella'' and ''C. periculella'' as well as the cone scale-eating tortrix moth ''

Cydia illutana __NOTOC__ ''Cydia illutana'' is a small moth of the family Tortricidae. It is found from western and central Europe (Great Britain, the Netherlands, Austria, Germany and France), north to Scandinavia (Denmark, Norway, Sweden and Finland) and e ...

'' have been recorded specifically on ''P. menziesii''. The inner bark is the primary winter food for the North American porcupine. Poriol is a flavanone, a type of flavonoid, produced by ''P. menziesii'' in reaction to infection by ''

Poria weirii ''Phellinus weirii'' is a plant pathogen causing laminated root rot in certain conifers, typically Douglas-fir and western redcedar. It is widespread in the Douglas-fir growing regions of British Columbia, Washington and Oregon Oregon ...

''.

Value to other plants

parasitic plant A parasitic plant is a plant that derives some or all of its nutritional requirements from another living plant. They make up about 1% of angiosperms and are found in almost every biome. All parasitic plants develop a specialized organ called th ...

which uses ''P. menziesii'' is the Douglas-fir dwarf mistletoe (''Arceuthobium douglasii''). Epiphytes such as

crustose lichen Crustose lichens are lichens that form a crust which strongly adheres to the substrate (soil, rock, tree bark, etc.), making separation from the substrate impossible without destruction. The basic structure of crustose lichens consists of a co ...

s and mosses are common sights on Douglas-firs. As it is only moderately shade tolerant, undisturbed Douglas-fir stands in humid areas will eventually give way to later successional, more shade-tolerant associates such as the western redcedar and western hemlock—though this process may take a thousand years or more. It is more shade tolerant than some associated fire-dependent species, such as western larch and ponderosa pine, and often replaces these species further inland.

Diseases and insects

Fungal diseases such as laminated root rot and shoestring root-rot can cause significant damage, and in plantation settings dominated by Douglas-fir monocultures may cause extreme damage to vast swathes of trees. Interplanting with resistant or nonhost species such as western redcedar and beaked hazelnut can reduce this risk. Other threats to Douglas-fir include red ring rot and the Douglas-fir beetle.

Uses

Many different Native American groups used the bark, resin, and pine needles to make herbal treatments for various diseases. British Columbia's Bella Coola tribe mixed the resin with dogfish oil for many medicinal applications. Some tribes used the foliage as a hygienic freshener in sweat baths, and the leaves were used as a

coffee substitute Coffee substitutes are non- coffee products, usually without caffeine, that are used to imitate coffee. Coffee substitutes can be used for medical, economic and religious reasons, or simply because coffee is not readily available. Roasted grain ...

. Native Hawaiians built ''waʻa kaulua'' ( double-hulled canoes) from coast Douglas-fir logs that had drifted ashore. The wood has historically been favored as firewood, especially from the coastal variety. In addition early settlers used Douglas fir for all forms of building construction, including floors, beams, and fine carving. Even today much of the Northwest chain saw art is completed on Douglas fir logs. The structures built from fir have lasted 150 years and more. The species is extensively used in

forestry Forestry is the science and craft of creating, managing, planting, using, conserving and repairing forests, woodlands, and associated resources for human and environmental benefits. Forestry is practiced in plantations and natural stands. ...

management as a

plantation A plantation is an agricultural estate, generally centered on a plantation house, meant for farming that specializes in cash crops, usually mainly planted with a single crop, with perhaps ancillary areas for vegetables for eating and so on. Th ...

tree for softwood

timber Lumber is wood that has been processed into dimensional lumber, including beams and planks or boards, a stage in the process of wood production. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, w ...

. Douglas-fir is one of the world's best timber-producing species and yields more timber than any other species in North America, making the forestlands of western Oregon, Washington, and British Columbia the most productive on the continent. In 2011, Douglas-fir represented 34.2% of US lumber exports, to a total of 1.053 billion board-feet. Douglas fir timber is used for timber frame construction and timber trusses using traditional joinery, veneer, and

flooring Flooring is the general term for a permanent covering of a floor, or for the work of installing such a floor covering. Floor covering is a term to generically describe any finish material applied over a floor structure to provide a walking surface ...

due to its strength, hardness and durability. As of 2012, the only wooden ships still currently in use by the U.S. Navy are Avenger-class minesweepers, made of Douglas-fir. Douglas fir sees wide use in heavy timber structures, as its wood is strong, available in a number of specifications including kiln dried and grade stamped, and can be supplied in very long lengths to 60 feet. West coast mills are sophisticated in their processing of timbers, making lead times predictable and availability reliable. Paints adhere well to Douglas fir. Stains perform well on Douglas fir timbers with the mild caution that the natural color of this species varies and care must be taken to ensure uniformity of color. Pitch pockets that may ooze resin can be present in timbers that have not been kiln dried. Because of the timber sizes available, stamped timber grading, and relatively short lead times, Douglas fir sees wide use in both public and residential projects. The species has ornamental value in large parks and gardens. It has been commonly used as a

Christmas tree A Christmas tree is a decorated tree, usually an evergreen conifer, such as a spruce, pine or fir, or an artificial tree of similar appearance, associated with the celebration of Christmas. The custom was further developed in early modern ...

since the 1920s, and the trees are typically grown on plantations. Douglas Fir is also becoming a popular species to use in the art of bonsai. The buds have been used to flavor eau de vie, a clear, colorless fruit brandy. Douglas-fir pine leaves can be used to make pine needle tea. They possess a tangy citrus flavor and may serve in some recipes as a wild substitute for

rosemary ''Salvia rosmarinus'' (), commonly known as rosemary, is a shrub with fragrant, evergreen, needle-like leaves and white, pink, purple, or blue flowers, native plant, native to the Mediterranean Region, Mediterranean region. Until 2017, it was kn ...

References

External links

Conifers.org: ''Pseudotsuga menziesii''

Humboldt State University — Photo Tour: Douglas-fir, ''Pseudotsuga menziesii''
— Institute for Redwood Ecology.
''Pseudotsuga menziesii''
- information, genetic conservation units and related resources. European Forest Genetic Resources Programme (EUFORGEN). {{Authority control Pseudotsuga Pacific temperate rainforests Trees of British Columbia Trees of the Northwestern United States Trees of the Southwestern United States Trees of the South-Central United States Trees of mild maritime climate Least concern flora of the United States Trees of Mexico Trees of Alberta