Pinus contorta, with the common names lodgepole pine, shore pine, twisted pine, and contorta pine, The murrayana subspecies is the tallest. The crown is rounded and the top of the tree is flattened. In dense forests, the tree has a slim, conical crown. The formation of twin trees is common in some populations in British Columbia. The elastic branches stand upright or overhang and are difficult to break. The branches are covered with short shoots that are easy to remove.

The species name is contorta because of the twisted, bent pines (shore pine) Pinus contorta is occasionally known under several English names: black pine, scrub pine, and coast pine. The variation in their serotiny has been correlated with wildfires and mountain pine beetle attacks. The cones of the coastal Pacific subspecies, P. contorta subsp. contorta, are typically non-serotinous, and those of the inland Pacific subspecies, P. contorta subsp. murrayana, are completely non-serotinous. Sometimes cones will become buried by the continued growth of a branch. If the seeds are collected, they have germinated as much as 150 years after confinement.

Distribution

Pinus contorta occurs from upper, dry montane forests to the subalpine region of western North America.

The natural fire regime for this species is primarily driven by climate. The fires occur most often after years of drought . Forests in the upper montane to subalpine region experience much moisture in the winter via snow. The density of tree stands with the species inhibit the establishment of an understory (allowing ladder fuel to form), and surface fire is rare regardless. Thus, infrequent but severe fires dominate this species.

An example of the climate that plays a huge role in the fire regime of the species is quite complex. There are three different oscillations that play a major role in droughts. These are the Pacific decadal oscillation (PDO), Atlantic multidecadal oscillation (AMO) and El Niño (ENSO). A combination of these oscillations being in effect (+) or not in effect (−) have a global effect on the water available to these forests. The combination of AMO +, ENSO − and PDO − means there is going to be a drought and likely a severe subalpine fire.

thumb|right|upright=1.04|A cluster of pollen-bearing male cones at [[Mount San Antonio]]

Suillus tomentosus, a fungus, produces specialized structures called tuberculate ectomycorrhizae with the roots of lodgepole pine (Pinus contorta var. latifolia). These structures have been shown to be the location of concentrations of nitrogen-fixing bacteria which contribute a significant amount of nitrogen to tree growth and allow the pines to colonize nutrient-poor sites.

Porcupines consume the inner bark of lodgepole pine.

As an invasive species

Pinus contorta is considered a serious invasive species of wilding conifer in New Zealand, along with several other western North American pine species. It is listed on the National Pest Plant Accord and is prohibited from sale, commercial propagation, and distribution.

Subspecies

There are four subspecies of Pinus contorta, and one of them is sometimes considered to have two varieties. The subspecies are sometimes treated at the rank of variety.

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! Cone !!Image !! Subspecies !! Common name!! Distribution

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|120px||120px|| Pinus contorta subsp. bolanderi ||Bolander's beach pine, Bolander pine, Also treated as Pinus contorta subsp. contorta var. bolanderi, in which case what is treated here as Pinus contorta subsp. contorta is the variety Pinus contorta subsp. contorta var. contorta. || endemic to Mendocino County on the northwestern California coast; near threatened by fires and development

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|120px||120px||Pinus contorta subsp. contorta || shore pine || Pacific Coast, southern Alaska to northwest California.

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|120px|| 120px||Pinus contorta subsp. murrayana ||tamarack pine, or Sierra lodgepole pine ||Cascade Range from Oregon into northern California; the Sierra Nevada, the Transverse Ranges of southern California (including the San Bernardino Mountains, the Peninsular Ranges into northern Baja California, and the Spring Mountains of southern Nevada).

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|120px||120px|| Pinus contorta subsp. latifolia ||lodgepole pine || Rocky Mountains, Colorado to Yukon and Saskatchewan; aspen parkland and boreal forests.

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Uses

Construction

The common name "lodgepole pine" comes from the custom of Native Americans using the tall, straight trees to construct lodges (tepees) in the Rocky Mountain area. Ireland and the UK for forestry, such as timber uses. In Iceland it is used for reforestation and afforestation purposes. It is also commonly used for pressure-treated lumber throughout North America.

Food

Native Americans consumed the inner bark of lodgepole pine to prevent starvation for themselves and their horses.

Medicinal

The indigenous peoples of the Pacific Northwest and of California used different parts of the plant internally and externally as a traditional medicine for various ailments. The gum of shore pine was used medicinally as well as for chewing.

Emblem

Lodgepole pine is the provincial tree of Alberta, Canada.

References

  • University of Wisconsin: Lodgepole forest webpage
  • Virginia Tech dendrology website: Pinus contorta
  • Guardian (U.K.) article: "Plague of beetles raises climate change fears for American beauty"
  • Picea sitchensis – information, genetic conservation units and related resources. European Forest Genetic Resources Programme (EUFORGEN)