Lodgepole Pine

Pinus contorta – Lodgepole pine, an evergreen conifer tree, is the provincial tree of Alberta. The leaves are needle-like, paired and often twisted, and 3-7 cm long. In the late spring, small male cones at the branch tips release pollen. Bears sometimes eat the nutritious inner bark of lodgepole pine which makes their fur matted and sticky with resin. Sometimes you can see trees where bears have been scratching for the inner bark.

Other Names

  • in LatinPinus contorta Doug. ex Loud. (var. latifolia Engelm.)
  • in English: Rocky Mountain lodgepole pine, black pine, scrub pine
  • in French: pin tordu

Taxonomy

Pine Family (Pinaceae)

Description

A straight coniferous tree, up to 30 m high, 60 cm in diameter, and 200 years old. The bark is thin (less than 2 cm thick), orange-brown to gray, and has fine scales. Branches generally curve upward, and usually only grow on the top third of the tree when trees are growing under crowded conditions.

Male or pollen cones (watch these!) are small (8 mm to 10 mm long), and reddish-green. They grow in clusters and are produced in the spring at branch tips.

The seed cones (4-6 cm long cylinders) have prickles on the scales, and often point backwards toward the tree trunk.

  • Leaves: Evergreen needles in bundles of 2, each needle 3 cm to 7 cm long, and sharp-pointed.
  • Buds: Buds grow up to 15 mm long, are reddish-brown, resinous, and have blunt points.
  • Cones: Male and female cones are found on the same tree. The reddish green, male pollen cones occur in dense clusters at the base of the new shoots.
    Female (seed) cones are egg-shaped, 3 cm to 6 cm long, green when young, purplish-brown when mature, stalkless, at right angles to the branch or pointing back towards the tree trunk, and grow in small clusters at the branch nodes.Note the short prickles on the scales of the female seed cones.

Distribution

Occurs in central and western Alberta.

Habitat

Occurs on a wide range of soils and sites, including wet hollows. Usually grows in dense stands, but can grow in open stands. Very common at lower elevations of the supalpine zone of the Rocky Mountains, and in Cypress Hills.

How to Observe

1. Tag a tree for observation.

2. Record these dates:

  • First bloom: When the first pollen is being shed from the male cones in at least three places on the observed tree.
  • Mid bloom: When half (50%) of the male cones are abundantly shedding pollen.

When does this tree bloom?

Bloom time is May to July, depending on the elevation.

Life Cycle

The scales on lodgepole pine cones are usually held closed by a resin bond, and are opened when exposed to the heat from a wildfire or from direct sunlight. Seed production begins at 5 to 10 years, and a good crop will appear every 1 to 3 years. Cones can remain on the tree for 10 to 20 years.

Older trees are less resistant to disease and insect infestation, end extensive outbreaks in mature stands can kill the trees, providing fuel for a forest fire, which begins the cycle again.

Pollen is wind born in this species. A typical pollen grain has two tiny air sacs to aid in dispersal.

Ecology

Lodegpole pine is able to colonize recently burned areas mainly because of an abundant seed supply in the closed cones. Most stands are created as a result of fire, as the heat melts the resin bonds on the cones, allowing for seed dispersal. Large, pure stands are common, and their density sometimes restricts normal growth. Some stands have over 100, 000 trees per hectare, and are sometimes called ‘dog-hair’ stands. Lodgepole pine sometimes hybridizes with jack pine.

Lodgepole pine trees provide excellent habitat for birds, small mammals, insects, and other animals. Birds not only build nests in these trees but woodpeckers also hollow out nesting cavities in dead trees. Nuthatches, woodpeckers, and other birds use lodgepole pines as a source of food, probing underneath the bark to discover juicy insects. Bears sometimes eat the inner bark, which makes their fur matted and sticky. Sometimes you can see trees where bears have been scratching for the inner bark. Lodgepole stands also provide important, spacious habitat for larger mammals such as deer, moose, elk, and bears.

Various bark beetles are serious pests, such as the mountain pine beetle. For more information on the beetle in Alberta see http://esrd.alberta.ca/lands-forests/forest-health/forest-pests/default.aspx

As well, comandra blister rust forms cankers on the stems that may kill the tree. The alternate host is Geocaulon lividum, “bastard toadflax” which develops striking green and white variegated leaves when attached by the rust.

With a bad reputation for causing serious damage to pines, the pine white butterfly (Neophasia menapia menapia) is another insect pest that could mean bad news for lodgepole stands. The pine white is a small white butterfly with brown wing tips that lays 5-20 light green eggs on needles near the treetop. When the young hatch, groups encircle the needle to feed. Older caterpillars feed alone, and may be seen as they descend from long, silk threads to pupate on the ground. The dark green caterpillars have white stripes and a light green head.

In Idaho, outbreaks of pine whites have caused death to almost one quarter of the pines, probably because bark beetles then attacked the weakened trees. The outbreaks usually decrease within three years as the butterfly’s natural enemies begin to increase. Spraying efforts have not been successful and only interfere with the natural cycles.

Another butterfly that feeds on the lodgepole pine is the western pine elfin (Incisalia eryphon eryphon), a small brown gossamer wing butterfly with checkered wing margins and jagged lines on its ventral wing. The velvety green caterpillars have white markings and are covered with brown hairs.

Phenology

Pollen is release in May, and into June or July at higher elevations.

In late spring, greenish-yellow clouds of pollen can fill the air, often landing on water. Here it can form yellow lines on shore rocks, marking the water level height.

Human Uses

First Nations Peoples found a use for almost every part of the tree, from trunk to roots. As the name implies, these trees were used as poles to support lodges and teepees. The wood was considered a good fuel sources as it is very resinous and burns even when it is green. Large branches were fashioned into drills and arrow shafts while the hard knots were made into fishhooks. Lodgepole pine resin was used to waterproof canoes, baskets and moccasins, and also as a natural glue. Coil baskets were fashioned from the roots.

Medicinally, the fragrant lodgepole pine tea, an excellent source of Vitamin C, became important in curing or preventing scurvy. Some tribes also used the tea as a contraceptive. Dried blueberries or raspberries were sometimes added to flavour pine tea. Though there is no indication that tea is harmful, it should be used in moderation and avoided by pregnant women.

Native people and settlers at the inner bark in the spring, chewed it like gum, cooked it like spaghetti, or dried it for future consumption. The nourishing seeds were also eaten. The resin was sometimes used to help stop infection, soothe sore throats, and cure toothaches. The inner bark was softened in water, used as a dressing for scalds, burns and skin infections. Poultices of dried, powdered pine needles were also used to sooth frostbite.

Today, lodgepole pine is important for timber, which is used in general construction and for wood pulp. After treatment with preservatives the timber is made into railway ties, poles, and mine timbers. Pine oil is extracted from the boughs, resin, and bark for commercial cleaners.

Lodgepole pine is Alberta’s provincial tree.

References

Farrar, J. L. 1995. Trees in Canada. Fitzhenry & Whiteside Ltd., Markham, Ontario, and the Canadian Forest        Service, Natural Resources Canada, Ottawa, Ontario.

Johnson, D. et. al. 1995. Plants of the Western Boreal Forest and Aspen Parkland. Lone Pine Publishing.             Edmonton, Alberta.

Kershaw, L. A. MacKinnon, and J. Pojar. 1998. Plants of the Rocky Mountains. Lone Pine Publishing.Edmonton, Alberta.

Kershaw, L. 2000. Edible and medicinal plants of the Rockies. Lone Pine Publishing. Edmonton, Alberta.

Kindscher, K. 1992. Medicinal Wild Plants of the Prairie: An Ethnobotanical Guide. University Press of Kansas. Lawrence, Kansas.

MacKinnon, A. J. Pojar, and R. Coupe. 1992. Plants of northern British Columbia. B.C. Ministry of Forests and Lone Pine Publishing.

Marie-Victorian, F. 1964. Flore Laurentienne. Les Presses de l’Université de Montreal. Montreal, Quebec.

Marles, Robin J. et al. 2000. Aboriginal plant use in Canada’s Northwest Boreal Forest. Natural Resources Canada. UBC Press. Vancouver, British Columbia.

Moss, E. H. 1983. Flora of Alberta. 2nd edition. University of Toronto Press. Toronto, Ontario.

Proctor, M., P. Yeo, and L. Lack. 1996. The Natural History of Pollination. Timber Press. Portland, Oregon.

Turner, N. J. 1997. Food plants of Interior First Peoples. UBC Press. Vancouver, British Columbia.

Wilkinson, Kathleen. 1990. Trees and shrubs of Alberta. Lone Pine Publishing. Edmonton, Alberta.


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