Pseudotsuga menziesii var. menziesii, commonly known as coast Douglas-fir, Pacific Douglas-fir, Oregon pine, or Douglas spruce, is a very tall evergreen conifer, being a variety of P. menziesii (Douglas-fir).
It is native to western North America and is used as timber.
Pseudotsuga menziesii var. glauca, or Rocky Mountain Douglas-fir, is an evergreen conifer native to the interior mountainous regions of western North America, from central British Columbia and southwest Alberta in Canada southward through the United States to the far north of Mexico. The range is continuous in the northern Rocky Mountains south to eastern Washington, eastern Oregon, Idaho, western and south-central Montana and western Wyoming, but becomes discontinuous further south, confined to "sky islands" on the higher mountains in Utah, Colorado, Arizona and New Mexico, with only very isolated small populations in eastern Nevada, westernmost Texas, and northern Mexico. It occurs from 600 m altitude in the north of the range, up to 3,000 m, rarely 3,200 m, in the south. Further west towards the Pacific coast, it is replaced by the related coast Douglas-fir (Pseudotsuga menziesii var. menziesii), and to the south, it is replaced by Mexican Douglas-fir in high mountains as far south as Oaxaca. Some botanists have grouped Mexican Douglas-fir with P. menziesii var. glauca, but genetic and morphological evidence suggest that Mexican populations should be considered a different variety (Pseudotsuga menziesii var. lindleyana).
Rocky Mountain Douglas-fir is most commonly treated as a variety (Pseudotsuga menziesii var. glauca), but has also been called a subspecies (Pseudotsuga menziesii subsp. glauca) or more rarely (mainly in the past) a distinct species (Pseudotsuga glauca). The strong ecological and genetic differentiation with intergradation limited primarily to postglacial contact zones in British Columbia supports infraspecific groupings. Some botanists have further split Rocky Mountain Douglas-fir into two varieties, but these are not widely acknowledged and have only limited support from genetic testing.
The Douglas fir (Pseudotsuga menziesii) is an evergreen conifer species in the pine family, Pinaceae. It is the tallest tree in the Pinaceae family. 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).
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 (genus Tsuga); the genus name Pseudotsuga means "false hemlock".
A tree plantation, forest plantation, plantation forest, timber plantation, or tree farm is a forest planted for high volume production of wood, usually by planting one type of tree as a monoculture forest. The term tree farm also is used to refer to tree nurseries and Christmas tree farms. Plantation forestry can produce a high volume of wood in a short period of time. Plantations are grown by state forestry authorities (for example, the Forestry Commission in Britain) and/or the paper and wood industries and other private landowners (such as Weyerhaeuser, Rayonier, and Sierra Pacific Industries in the United States or Asia Pulp & Paper in Indonesia). Christmas trees are often grown on plantations, and in southern and southeastern Asia, teak plantations have replaced the natural forest.
Industrial plantations are actively managed for the commercial production of forest products. Industrial plantations are usually large-scale. Individual blocks are usually even-aged and often consist of just one or two species. These species can be exotic or indigenous. The plants used for the plantation are often genetically altered for desired traits such as growth and resistance to pests and diseases in general and specific traits, for example in the case of timber species, volumic wood production and stem straightness. Forest genetic resources are the basis for genetic alteration. Selected individuals grown in seed orchards are a good source for seeds to develop adequate planting material.
David Douglas (25 June 1799 – 12 July 1834) was a Scottish botanist, best known as the namesake of the Douglas fir. He worked as a gardener, and explored the Scottish Highlands, North America and Hawaii, where he died. The standard author abbreviation Douglas is used to indicate this person as the author when citing a botanical name.