Pinus contorta

lodgepole pine

Pinaceae

The Basics

USFS Silvics Manual

Lodgepole pine (Pinus contorta) is a two-needled pine of the subgenus Pinus. The species has been divided geographically into four varieties: P. contorta var. contorta, the coastal form known as shore pine, coast pine, or beach pine; P. contorta var. bolanderi, a Mendocino County White Plains form in California called Bolander pine; P. contorta var. murrayana in the Sierra Nevada, called Sierra lodgepole pine or tamarack pine; and P. contorta var. latifolia, the inland form often referred to as Rocky Mountain lodgepole pine or black pine. Although the coastal form grows mainly between sea level and 610 m, the inland form is found from 490 to 3660 m.

Lodgepole pine grows both in extensive, pure stands, and in association with many western conifers... Lodgepole pine's successional role depends upon environmental conditions and extent of competition from associated species. Lodgepole pine is a minor seral species in warm, moist habitats and a dominant seral species in cool dry habitats. It is often persistent even on cool and dry sites and can attain edaphic climax at relatively high elevations on poor sites. Fire regimes have played a role in this successional continuum, especially where repeated fires have eliminated a seed source for other species. Lodgepole pine may even overwhelm a site with seed stored in serotinous cones.

Identification

Lodgepole pine or beach pine is a small pine that grows quickly to 20 ft. and may reach 30 ft. at maturity. It has a crooked, windswept, dense habit and dark-green needles. Mature bark is red-brown and scaly. Cones are small, numerous and slow to open. Widely distributed pine that may grow tall with narrow, dense, conical crown, or remain small with broad, rounded crown; 3 geographic varieties.

Threats

Drought is a common cause of mortality among first-year seedlings; losses vary with soil type and seedbed condition. Greatest losses occur on soils with low water-holding capacity, and duff and litter...Lodgepole pine is very intolerant of shade and competition from other plant species. Occasionally seedlings become established under a forest canopy, but these individuals rarely do well.

The mountain pine beetle (Dendroctonus ponderosae) is the most severe insect pest of lodgepole pine. The epidemics that periodically occur in many lodgepole pine stands seriously affect the sustained yield and regulation of managed stands... Another aggressive bark beetle that attacks lodgepole pine is the pine engraver (Ips pini). Ips commonly develops in logging slash, especially slash that is shaded and does not dry quickly. Prompt slash disposal is an effective control measure. Ips also can build up in windthrows.

Dwarf mistletoe (particularly Arceuthobium americanum) is the most widespread and serious parasite affecting lodgepole pine. A. americanum seeds are forcibly ejected from the fruit for distances as great as 9 m. The sticky seeds adhere to the foliage of potential host trees. The proportion of trees visibly infected can double each 5 years between the ages of 10 and 25, with nearly a third of the trees infected at age 25.

One of the most serious diseases in lodgepole pine is a stem canker caused by Atropellis piniphila. Cankered stems are usually useless for lumber or posts and poles. Stem cankers of rust fungi cause extensive mortality, growth loss, and cull in lodgepole pine. Of these comandra blister rust (Cronartium comandrae) isthe most serious. The western gall rust (Peridermium harknessii) isespecially damaging; trunk cankers can cause cull in logs and can kill seedlings and saplings.

Because of its relatively thin bark, lodgepole pine is more susceptible to fire than Douglas-fir and many other associates. It is less susceptible than Engelmann spruce or subalpine fir. Mortality from beetle epidemics often creates large amounts of jackstrawed fuel, which ignites easily from lightning and other sources and hampers fire control efforts.

Reproduction

Flowering and Fruiting - Male and female strobili generally are home separately on the same tree in this monoecious species, with female flowers most often at the apical end of main branches in the upper crown, and male flowers on older lateral branches of the lower crown. The reddish purple female flowers grow in whorls of two to five and are 10 to 12 mm long. The pale yellow to yellowish orange male flowers are crowded clusters of catkins at the base of new shoots and are 8 to 14 mm long.

Seed Production and Dissemination - Lodgepole pine produces viable seed at an early age, commonly 5 to 10 years; germination percentage is as high as that of seed borne by mature trees... The serotinous cone habit varies over wide geographic areas as well as locally. Serotinous cones are not common in eastern Oregon, rare in coastal populations, and absent in the Sierra Nevada and southern California and Baja California populations. Although common in the Rocky Mountains, this cone habit varies considerably. Many stands in the Rockies have less than 50 percent serotinous-cone trees.

Seedling Development - Germination under field conditions is good if climate and seedbed are favorable. Best germination occurs in full sunlight and on bare mineral soil or disturbed duff, free of competing vegetation... Both shading and competition inhibit germination and survival. Newly germinated seedlings are relatively insensitive to temperature extremes.

Vegetative Reproduction - Lodgepole pine can be grafted successfully, but results vary depending upon the clone. Natural sprouting has been observed on the Bitterroot National Forest in Montana. Branches not severed often become leaders on stumps left in thinning operations.

Species Distribution

Citation

USDA Plant Database
http://plants.usda.gov/characteristics.html
USDA, NRCS. 2016. The PLANTS Database (http://plants.usda.gov, 4 February 2016). National Plant Data Team, Greensboro, NC 27401-4901 USA.

Flora of North America
http://www.efloras.org/flora_page.aspx?flora_id=1
Flora of North America Editorial Committee, eds.  1993+.  Flora of North America North of Mexico.  19+ vols.  New York and Oxford.

Silvics of North America
http://www.srs.fs.usda.gov/pubs/misc/ag_654/volume_1/pinus/contorta.htm
Burns, R.M., and B.H. Honkala. 1990. Silvics of North America (Volume 1: Conifers). USDA Forest Service Agricultural Handbook 654.

Intermountain Herbarium
http://intermountainbiota.org/portal/collections/harvestparams.php
Consortium of Intermountain Herbaria. 2016. http//:intermountainbiota.org/portal/index.php. Accessed on February 04.

Burke Museum Plant Image Collection
The plant image collection at the Burke Museum, University of Washington.

Jepson Manual
http://ucjeps.berkeley.edu/eflora/
The Jepson Manual: Vascular Plants of California. B.G. Baldwin, D.H. Goldman, D.J. Keil, R. Patterson, T.J. Rosatti, and D.H. Wilken [editors]. 2012. 2nd edition, thoroughly revised and expanded. University of California Press, Berkeley, CA. $131.95, hardcover; 1600 pages. ISBN-13: 978-0520253124.

USGS Plant Species Range Maps
http://esp.cr.usgs.gov/data/little/
Critchfield, W.B., and Little, E.L., Jr., 1966, Geographic distribution of the pines of the world: U.S. Department of Agriculture Miscellaneous Publication 991, p. 1-97.
Little, E.L., Jr., 1971-1978, Atlas of United States trees, volume 1,3,13,17, conifers and important hardwoods: U.S. Department of Agriculture Miscellaneous Publications.