Description and Taxonomy
– Douglas-firs are medium-size to extremely large evergreen trees, reaching heights of 20–100 meters (70–330 feet) and diameters of up to 2.4 meters (8 feet).
– The largest coast Douglas-firs can live over 500 years, with some specimens reaching over 1,300 years.
– Rocky Mountain Douglas-firs are less long-lived, usually not exceeding 400 years.
– Former coast Douglas-firs have been recorded exceeding 120 meters (390 feet) in height, making them potentially the tallest tree species on Earth.
– The leaves are flat, soft, linear needles 2–4 centimeters (3/4–1 1/2 inches) long, occurring singly rather than in fascicles.
– The common name ‘Douglas-fir’ honors David Douglas, a Scottish botanist who first reported on the species.
– Despite the common name, Douglas-fir is not a true fir (genus Abies), but belongs to the genus Pseudotsuga.
– There are three varieties: coast Douglas-fir, Rocky Mountain Douglas-fir, and Mexican Douglas-fir.
– Coast Douglas-fir is found in coastal regions from British Columbia to California.
– Rocky Mountain Douglas-fir ranges from northern Washington to central British Columbia and southeastward to the Mexican border.
Ecology
– Douglas-fir prefers acidic or neutral soils.
– It exhibits morphological plasticity, with coast Douglas-fir generating deeper taproots on drier sites.
– Rocky Mountain Douglas-fir shows even greater plasticity, occurring in interior temperate rainforests and semi-arid sagebrush steppe environments.
– Coast Douglas-fir dominates forests west of the Cascade Mountains in the Pacific Northwest, growing larger and faster than Rocky Mountain Douglas-fir.
– It competes well on various parent materials, aspects, and slopes, and is associated with a diverse range of tree species.
– Douglas-fir seeds are an important food source for small mammals like moles, shrews, and chipmunks.
– The Douglas squirrel harvests and hoards large quantities of Douglas-fir cones, as well as consumes other parts of the tree.
– Snags created by Douglas-fir provide nest cavities for birds.
– The species supports a diverse range of wildlife, including birds, mammals, and insects.
– Douglas-fir forests contribute to overall ecosystem biodiversity and provide habitat for various species.
Conservation
– The conservation status of Douglas-fir is classified as ‘Least Concern’ by the IUCN.
– The species is widely distributed and not currently facing significant threats.
– However, specific varieties or populations may face localized threats due to habitat loss or degradation.
– Conservation efforts may focus on protecting old-growth forests and managing invasive species.
– Monitoring and research are important for understanding the long-term conservation needs of Douglas-fir.
Uses
– Native American groups used various parts of Douglas-fir for herbal treatments and medicinal applications.
– Native Hawaiians used coast Douglas-fir logs to build waʻa kaulua (double-hulled canoes).
– Douglas-fir has been historically favored as firewood, especially the coastal variety.
– The wood of Douglas-fir is extensively used in forestry management for softwood timber production.
– Douglas-fir timber is used for construction, flooring, veneer, and carving due to its strength and durability.
– Douglas-fir has ornamental value and is commonly used in large parks and gardens.
– It has been widely used as a Christmas tree since the 1920s.
– The buds of Douglas-fir have been used to flavor eau de vie, a fruit brandy.
– Douglas-fir pine leaves can be used to make pine needle tea and can serve as a substitute for rosemary in recipes.
– The species has cultural significance and has been used in traditional crafts and art, such as chain saw art and wooden shipbuilding.
Interactions and Threats
– Douglas-fir forests are the primary habitat for the red tree vole and the spotted owl.
– Breeding pairs of spotted owls require at least 400 hectares of old-growth forest.
– Red tree voles can also be found in immature forests with Douglas-fir.
– Red tree voles nest in the foliage of trees, typically 2-50 meters above the ground.
– The diet of red tree voles consists mainly of Douglas-fir needles.
– Douglas-fir needles are poor browse for ungulates, but can become important in winter when other food sources are lacking.
– Black-tailed deer browse on new seedlings and saplings of Douglas-fir in spring and summer.
– The spring diet of blue grouse prominently features Douglas-fir needles.
– The woolly conifer aphid uses Douglas-fir needles for feeding and produces protective wax spots on the undersides of the leaves.
– Several species of moths and tortrix moths have been recorded feeding specifically on Douglas-fir.
– Fungal diseases like laminated root rot and shoestring root-rot can cause significant damage to Douglas-fir.
– Interplanting with resistant or nonhost species can help reduce the risk of fungal diseases.
– Red ring rot and the Douglas-fir beetle are also threats to Douglas-fir.
– Monocultures of Douglas-fir in plantation settings are particularly vulnerable to disease outbreaks.
– Douglas Fir forests are threatened by logging and habitat loss.
– Climate change poses a risk to the species’ distribution and health.
– Invasive species can negatively impact Douglas Fir ecosystems.
– Conservation efforts aim to protect old-growth forests and promote sustainable forestry practices.
– The IUCN Red List classifies Douglas Fir as a species of least concern. Source: https://en.wikipedia.org/wiki/Douglas_fir
The Douglas fir (Pseudotsuga menziesii) is an evergreen conifer species in the pine family, Pinaceae. It is native to western North America 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 (P. menziesii var. lindleyana).
| Douglas fir | |
|---|---|
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Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Gymnospermae |
| Division: | Pinophyta |
| Class: | Pinopsida |
| Order: | Pinales |
| Family: | Pinaceae |
| Genus: | Pseudotsuga |
| Species: | P. menziesii |
| Binomial name | |
| Pseudotsuga menziesii | |
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Green: Coast Douglas-fir (Pseudotsuga menziesii var. menziesii) Blue: Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca) | |
| Synonyms | |
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Despite its common names, it is not a true fir (genus Abies), spruce (genus Picea), or pine (genus Pinus). It is also not a hemlock; the genus name Pseudotsuga means "false hemlock".
