Norway pine ( Pinus resinosa ) is the state tree of Minnesota.
Fire weather
Moisture content of fuels
(% oven-dried weight)
Rate of spread
(feet/minute)
Wind speed near ground
(mph)
Relative humidity
(%)
Effects of a spring and summer wildfire
on the structure of a pure red pine and mixed stand at 3 topographic
locations [227]
SL1 (spring 1977 fire)
Grant's Pit (summer 1979 fire)
Prefire live stems/ha and postfire seedlings/ha of red
pine high-severity and low-severity burn sites at Quetico
Provincial Park [177]
Pine regeneration and soil bared following burning of
11 sites [285]
Seed germination and seedling growth of
red pine in sand, unheated organic matter, and heated organic matter
[180]
Length (mm)
This description provides characteristics that may be relevant to fire ecology, and is not meant for
identification. Keys for identification are available (e.g., [52,80,89,96,267]).
Aboveground description:
Red pine is a long-lived (200-400 years), coniferous tree [22,57,89,231,252].
It grows in pure, even-aged stands and uneven-aged mixed stands primarily with
eastern white pine, jack pine, and/or quaking aspen [252,258]. Red pine has
an average height of 75 feet (23 m), but under ideal conditions may grow as tall
as 200 feet (50 m) [96,107,252,266,267]. It has a straight trunk with little
taper, few branches occurring below the canopy [231,252], and an average DBH of
10 to 20 inches (30-60 cm) [96,231,252,267], with a maximum reported DBH of 59.8
inches (152 cm) [266]. The bark is furrowed and cross-checked into irregular
rectangular, scaly plates up to 2 inches (6 cm) thick [96,266]. Details on the thermophysical
properties of red pine bark are available in Reifsnyder and others [225].
Red pine has 2 straight to slightly twisted, flexible, slender, sharp-pointed
needles/fascicle, measuring 4 to 6.7 inches (9-17 cm) long
[80,89,96,107,252,267]. The majority of red pine needles live for 3 years, but
some may persist for as long as 6 years [80,87,107,252,266]. Red pine cones are
produced near the tips of twigs [80] and are approximately 1.4 to 3 inches
(3.5-7 cm) long [80,89,96]. The middle third of the crown produces the greatest
number and heaviest cones [71,231]. The cones contain ovoid seeds 3 to 5 mm
across [96,107]. On Black Island in Lake Winnipeg, Manitoba, red pine cones
averaged 1.91 ÃÂ 1.08 inches (48.61 ÃÂ 27.47 mm) long, with a mean fresh mass of about
0.49 ounce (13.88 g). The mean number of seeds/cone was 53 [270].
Crown structure:
Red pine has a dense and symmetrical, generally
ovoid-shaped crown and upcurved branches with stout twigs up to 0.4 inch (1 cm)
thick [89,96,252]. One whorl of branches is produced
annually from lateral buds formed at the leading shoot. Occasionally a second
flush produces shoots in late summer, likely due to substantial rainfall after
a dry period. Foliage weight increases from the top downwards for the first few
whorls, remains constant for several more, and then diminishes towards the crown
base, with the mean weight at or slightly below the midpoint. Crowns are
enlarged by the annual extension of the main stem and branches. As red pine
ages, branch extension and height growth diminish [266].
Belowground description:
Red pine produces lateral roots with vertical sinker roots
that are moderately deep and wide-spreading [89,252,266].
It may also produce a taproot extending 0.39 to 10 feet (0.12-3 m) below ground [89,252,252,266].
Lateral roots radiate from the tree in a spoke-like fashion and remain
relatively close to the soil surface (4-18 inches (10-45 cm)) [266]. In a review, the
lateral roots of red pine were described as being as long as 36 feet (11 m) at a
site in Ontario. There were approximately a dozen main lateral roots/tree, and they reached their greatest length in 15 to
20 years [266]. Vertical sinker roots develop from lateral roots to depths of 8.9 to 20 feet (2.7-5.0 m) [47,252,266].
Prescribed fire:
Prescribed fire can be used to prepare a bare mineral seedbed
for red pine and to reduce competing vegetation [11,15,79].
To prepare a seedbed, remove aboveground portions of competing vegetation,
and keep from crown scorching mature red pines, McRae and others [187] caution
that flame length should not exceed 3 feet (1 m) and recommend a frontal fire intensity ranging from 400 to 600 kW/m.
Understory prescribed burning is best in spring [187]. Two
successive burns may be required to remove understory species, particularly
beaked hazelnut, and to prepare a mineral seedbed [79]. A review of the positive
and negative effects of prescribed burning in red
pine stands by Dickmann [72] is available. Guidelines for prescribed fire in red
pine stands are available in these sources: [187,293]. Prescribed fire can be
used in seed-producing red pine stands to control red pine cone beetle. Spring
burning these stands may kill up to 100% of beetles, while fall burns may result in 95% insect mortality [15].
Avian populations:
Many bird species preferred burned over logged
mixed conifer-deciduous forests in northeastern
Minnesota. Schulte and Niemi [242]
conducted bird censuses in early-successional burned (7%
red pine cover) and logged forests (1% red
pine cover) during breeding seasons, 2 and 3 years
after fire. Time of logging was not provided; logged sites were
selected to match the burned site. Overall bird species richness and density
(territorial males/ha) were significantly higher in burned than logged forests (P<0.05) [242].
Van Wagner [286] measured the moisture content of new (current year's growth)
and old (previous year's growth) red pine foliage from 1962 to 1965 in eastern
Canada. The trees, growing on dry, sandy loam or dry sand, ranged from 20 to 40
years old and from 4 to 9 inches (10-20 cm) in diameter.
The moisture content of new foliage reached a maximum of 270% in the middle of
June and steadily declined to a low of 130% in October. Old foliage had a much
lower moisture content, reaching a maximum of 110% in mid-March, declining to a
low of 90% in early June, then increasing to approximately 107% by the end of
October [286].
Mature red pine (beginning at age 20 to 40) can survive low- to
moderate-severity surface fires [4,15,27,46,56,57,72,94,134] due to thick, fire-resistant bark
[4,46,51,94,95,125,126,141,147,288] that protects the tree's cambium [230].
High-severity fires raise the risk of tree mortality via crown fires,
crown scorch, cambial injury, and root mortality [4,15,29,72,94,134]. Red pine can,
however, survive following "substantial" crown scorch [72,134,187,189,285],
cambial injury [44,230,288], charring [227], and needle kill [269]. Trees have a
better chance of survival following crown scorch if scorch occurs before bud
flush [187]. Van Wagner's [288] prescribed fire studies red pine stands in eastern
Canada showed that surface fires of less than 200 BTU/sec-ft rarely scorch the
crown of red pine, a surface fire of 500 BTU/sec-ft is "on the edge of dangerous"
for the largest red pines, and a surface fire of 1,000 BTU/sec-ft or more
results in complete red pine mortality.
Red pine seedlings and saplings are more susceptible than mature trees to fire mortality [3,129,130]
and heat damage (see Heat tolerance). Crown fires
are much more likely in younger red pine stands, where crowns are closer to the
ground [3]. Red pine stands may support crown fires at 15 to
20 years of age [129,130]. However, Methven [189] found that
red pine seedlings can survive following a high degree of needle scorch.
There was little information (as of 2008) on the immediate effect of fire on the
seeds and/or cones of red pine, though several researchers state that cones and
seeds are "very susceptible" to fire mortality [4,129,130,230].
While red pine is an important tree species for wildlife, but there is
little in the literature describing its importance. The seeds are listed as a
valuable food for wildlife [80], and Naylor [197] states
that approximately 80% of the wildlife found in central Ontario use forests
containing red pine and/or eastern white pine. In 2 reviews, however, red pine stands are described
as poor habitat for game birds and animals [231,252].
Birds:
Red pine stands can support a large variety of bird species. The Kirtland's warbler and the pine
warbler are found exclusively in eastern white pine-jack pine-red pine
stands, highly preferring jack pine stands over 80 acres (30 ha) in size [48,221].
Red pine and mixed stands with red pine provide habitat for numerous bird
species in north-central and northeastern US forests [199,276,277]. Bald eagles
and osprey nest in and colonies of great blue heron use
red pines along waterways in central Ontario. Many other species of birds nest in
red pines in central Ontario. See Naylor [197] for an extensive list of birds
using red pine habitats.
Ungulates:
Red pine is a low-preference food for
white-tailed deer in Minnesota [91] and Massachusetts [138]. In northeastern Minnesota,
white-tailed deer browse red pine minimally in the
winter. Most red pine browsed is blowndown trees and limbs [310]. Red pine in northeastern
Minnesota is a very minor moose dietary
component, with the highest use occurring in the winter [213]. During the dormant
season in the Lake Superior region, moose show a
"moderate" preference for red pine browse [12].
Small mammals:
Red pine is a major food of snowshoe hares of Canada [120]. Eastern white pine and red pine
are the 2 most preferred conifer species for snowshoe hares. During the winters of 1958 to 1961, snowshoe
hares on Manitoulin Island, Ontario, heavily browsed red pine bark and browsed
red pine needles with medium to high intensity [69]. Snowshoe hares also browse
red pine seedlings in the winter and can damage seedlings. In Quebec, snowshoe
hare damage to 3-year-old red pine seedlings was primarily incomplete stem
girdling or complete browsing of terminal shoots,
while some seedlings incurred severe browsing of the trunk or complete girdling
of the stem below the lowest whorl of lateral branches [24].
In a mixed forest in northern Wisconsin, red squirrels abundantly consume red pine seeds.
Red squirrels cache red pine cones in tunnels
beneath middens not exceeding 3 feet (1 m) in diameter and 5.9 inches (15 cm)
deep. Eastern gray squirrels also feed on red pine seeds in the area, but not with
the abundance that red squirrels do [226]. White-footed mice and meadow
voles of the Northeast have a high preference for red pine seeds [1].
Palatability/nutritional value:
At the time of this review (2008), there was only one article pertaining to the
nutritional value of red pine foliage and no articles discussing the
palatability of red pine. For foliar nutrient concentrations of mature red
pines on the Cloquet Forestry Center, Minnesota, see Comerford and White [59].
Cover value:
Red pine is an important cover species for a variety of bird species and other wildlife
[22,231,252]. It is a prime nesting tree for bald eagles. On the Chippewa
National Forest, Minnesota, 78% of bald eagle nests occur in red pines or eastern
white pines. Bald eagles almost always nest in live trees. They position
their nest below the crown at a main branch. Ospreys also nest in red pine and
eastern white pines at Chippewa, but with less frequency (18%).
Ospreys build their nests at the top of the tree [182]. Bald eagles also nest in red pine
on the Superior National Forest, Minnesota, but prefer eastern white
pine [183]. Bird species listed
in the literature as using red pine for cover include prairie sharp-tailed grouse
in the pine barrens of Wisconsin [117] and in northeast and
north-central Minnesota [119], barred owls in north-central
Minnesota [143], and ruffed grouse in Minnesota [179].
Downed red pine and red pine cavities are used as cover for a
large variety of mammals in central Ontario [197]. Red and eastern gray squirrels
use red pine stands for cover in mixed forests of
northern Wisconsin [226]. Red pine, black spruce, jack pine, and
eastern white pine are favored
nesting trees for red squirrels in the Boundary Waters Canoe Area [128].
Snowshoe hares are prevalent in red pine communities in north-central
Minnesota [215]. Gray wolves travel through and live within red pine and mixed forest stands
on the Superior National Forest [188]. Bats in
Manistee National Forest, Michigan, use red pine as cover to hunt for flies,
moths, and caddis flies [280].
Red pine is generally the dominant overstory species where it occurs. It may
occur as an understory species with eastern white pine
(P. strobus) and/or jack pine(P. banksiana). Red pine is found in
pure, mixed-conifer, mixed-conifer/hardwood, and hardwood stands.
Throughout most of its habitats, red pine can be both an early- and late-seral
species and most commonly occurs with eastern white pine. In outlying West Virginia
populations, red pine is most often a late-seral
species on xeric rocky sites with pitch pine (P. rigida),
Virginia pine (P. virginiana), and Table Mountain pine (P. pungens) [64,231].
For a list of common red pine associates by soil type,
see Associated species by soil type.
For lists of associated species of red pine, see the following sources:
[23,50,64,79,114,231].
Red pine is described as a dominant species in the following vegetation
classifications and locations.
Red pine communities on sand dunes at the southern end of Lake Michigan [65]
Red pine communities on the Vanderbilt moraines in the lower part of the state
Red pine communities on sand dunes on the west coast of Lake Michigan
Eastern white pine-red pine communities on steep end-moraine ridges of Williamsburg
Eastern white pine-red pine forests on Presque Isle at the extreme northern end of the lower part of the state
Red pine communities in upland forests near Cheboygan
Eastern white pine-red pine forests at the Grand Marais Sandy End moraine and outwash area of Lake Superior
Eastern white pine-red pine forests on the Spread Eagle-Dunbar Barrens
Eastern white pine-red pine-northern red oak (Quercus rubra) forests on the Michigamme Highland
Eastern white pine-red pine forests on the Lac Veaux Desert outwash plain
Eastern white pine-red pine forests in the Gogebic-Penokee Iron Range
Eastern white pine-red pine-northern red oak on bedrock ridges with thin soil at Calumet [10]
Eastern white pine-red pine-quaking aspen (Populus tremuloides) forest at Isle Royale National Park [278]
Red pine communities on upland sites of the Boundary Waters Canoe Area [112]
Red pine communities near the shores of the Boundary Waters Canoe Area [202]
Eastern white pine-red pine forests on the Mille Lac uplands along Mille Lac Lake
Eastern white pine-red pine forests on Itasca, Alexandria, and St Croix moraines
Eastern white pine-red pine forests on the Black Duck till plains
Eastern white pine-red pine forests on the St Louis moraines
Eastern white pine-red pine forests on the North Shore Highlands of Lake Superior
Eastern white pine-red pine forests along the Border Lakes
Eastern white pine-red pine forests on the Littlefork-Vermilion uplands [10]
Red pine-eastern white pine/twinflower (Linnaea borealis)
habitat type on dry hilltops and upper slopes of Voyageurs National Park [159]
Red pine-jack pine upland forests on sand or loamy sand soils in Itasca State Park [142]
Red pine-eastern white pine-paper birch-maple (Betula papyrifera-Acer spp.) subclimax association at low elevations
on shallow sandy soil of the White Mountain National Forest
Northern red oak-eastern white pine-red pine-red maple (A. rubrum) subclimax association on long, steep southerly-facing
slopes at low to middle elevation in the White Mountain National Forest
Red pine-eastern white pine-red maple forest association on deep sandy or cobble
outwash soils in the White Mountain National Forest [93]
Eastern white pine-red pine-jack pine ecosystem on smooth to irregular plains and tablelands [106]
Red pine-eastern white pine on sand bars of the lee shores of the Apostle Islands [20]
Red pine-eastern white pine-jack pine communities on outwash soils of southern Washburn County [81]
Eastern white pine-red pine communities on the Spread Eagle-Dunbar Barrens
Eastern white pine-red pine forests on the Lac Veaux Desert outwash plain
Eastern white pine-red pine forests in the Gogebic-Penokee Iron Range
Eastern white pine-red pine forests on the Mille Lac uplands along Mille Lac Lake [10]
Red pine monotypic communities on sand barrens of the Ottawa Valley [49]
Red pine monotypic or mixed red pine-eastern white pine-jack pine
communities, typically on level or rolling sand plains [23]
Red pine upland forests in Algonquin Park [218]
Red pine monotypic or mixed red pine-eastern white pine-jack pine
communities, typically on level or rolling sand plains in the Lake States [23]
Eastern white pine-red pine-jack pine ecosystem on smooth to irregular plains
and tablelands of the northern Lake States and parts of New England [106,233,283]
Red pine-eastern white pine forests in mesic areas and grading into the
ice-contact hills of the northern Great Lakes [232]
Red pine communities in the Great Lakes Canadian forests [50]
Bark:
Information on the chemical constituents of red pine bark is available in Harum and Labosky [123].
Browsing:
White-tailed deer browsing can decrease red pine cover. White-tailed deer exclusion
from a 230-year-old red pine forest promoted establishment and growth of red pine saplings in
Itasca State Park. In 1937, white-tailed deer were excluded from a
severely overbrowsed red pine site. At the time, white-tailed deer numbers were at or above starvation levels, and
virtually no red pine saplings (or saplings of any other tree species) were
present. By 1948, 84 red pine saplings ranging from 0.49 to 6.9 feet (0.15-2.1 m) high
occurred in the 2-acre (1-ha) plot, while 0 saplings existed outside the enclosure.
Beginning in the late 1940s, white-tailed deer were virtually eliminated from
the Park due to hunting, so red pine saplings recovered outside of the
exclosure. By 1957, there were 99 saplings inside and 309 outside the
exclosure ranging from 0.49 to 6.9 feet (0.15-2.1 m) tall [229].
Disease:
Red pine is relatively free of disease problems. Diseases that most commonly infect
red pine are Fomes root rot [252], Scleroderris canker [252], and shoestring root rot [252].
Herbicides:
There are several articles on the effects of herbicides
on red pine. Sasaki and Kozlowski [237] studied the effects of 8
common herbicides on red pine seed germination and early seedling
development. The effects of 11 different herbicides on red pine seed
germination is reviewed by Baskin and Baskin [19]. Noste and Phipps [201] and McCormack [185]
provide information on the effects herbicides meant to control weeds have on red pine.
Host species:
Red pine is rarely a host to eastern dwarf mistletoe (Arceuthobium pusillum) [206].
Insects:
Red pine is exploited by over 200 insect
species. Insect diversity is less than 50 species for most pine species [68]. The most serious insect damage to red pine is
to seed production during the second year of cone development [252]. Insects that most commonly attack and damage red pine
are the pine root collar weevil [76], pine shoot beetle [154],
European pine shoot moth [252], jack pine budworm [252], red pine cone beetle [193,252], and white pine weevil [252].
Studies in Michigan indicate that bark beetles produced little red pine
damage to unburned trees and did not select
slower-growing trees. In Itasca State Park, infested red pines showed no
evidence of declining growth when compared uninfested trees in the years
preceding infestations. In Lower Michigan, the pine shoot beetle causes minimal damage to red pine
shoots. Damage caused by the pine shoot beetle at 2
sites (northern Lower Michigan and southwestern Lower Michigan) from 1997 to 1999 ranged from 0.82 to 1.18
red pine shoots/mò in the north to 0.21 to 0.70 red pine shoots/mò in the southwest, where
the pine shoot beetle is less established [249].
Needle droop:
Red pine, particularly planted stock, is susceptible to needle droop. This occurs if sudden and excessive rapid
transpiration occurs when there is limited soil moisture. Succulent
tissues in the needle base collapse, which causes the needles to droop. Needle
droop can cause mortality or deformation to large numbers of red pine seedlings [136].
Pest management:
A pest management (insects, disease, and abiotic factors) analysis in red pine forests of
Wisconsin is available from Schmoldt [240].
Red pine plantations:
There is a plethora of information pertaining to
red pine plantations. Topics include growth and development [35,211,219,300,311,312], stocking rates [211,219],
fertilization [8,108], thinning and harvesting [21,63,88], establishing a plantation [204],
site quality [304], growth with other species [312], and insect/fungal infestations [84,153].
Salt tolerance:
Red pine seedlings have limited tolerance to sodium chloride spray [282].
Red pine is used as an ornamental [80].
Wood products:
Red pine is a very important source of wood products [14,80,88,89]. It is used for lumber,
pilings, poles, cabin logs, railway ties, posts, mine timbers, box boards,
pulpwood, and fuel [22,89,231,252].
For more information on red pine and its importance in the wood industry, see
the following articles: [22,85,88,89,99,205,231,252,253]
Fire-killed red pine:
Basham [18] examines the deterioration of red pine by
fungi following fire mortality in the Mississagi-Chapleau area of Ontario.
Studies have also found that fire-killed, merchantable red pine is susceptible to beetle attacks [210].
A flush of new red pine needles begins in early April to
mid-May, and needles complete growth by late summer [187,231,266]. Red pine cone
production begins during May and June [80,156,266], pollination
occurs from late May to mid-July [252], and second-year cones ripen from
August to October [156,243,266]. Growth of cone primordia occurs
throughout fall and winter [166].
Seed dispersal generally occurs a few days after ripening (mid-August to
October) and continues throughout fall and into the next spring. Most seeds are
dispersed within a month of ripening, with a few seeds remaining on the
tree for 2 to 3 years [252,266]. Red pine cones open and disperse seeds best on
warm autumn days [4,231,266].
At Stephentown, New York, the growing period for a 5-year-old seedling ranged from 45 to 63 days
over 5 years, beginning near the end of April and ending about the
end of June [60]. At the same location, Cook [61] observed the growth
period for a 7-foot-tall (2 m) red pine during 1940. Growth began on 7 May and
ended 7 July, for a total of 61 days. During the growing period, the red pine
tree increased in height by 17.5 inches (44.4 cm) [61].
Many authors describe red pine as fire-dependent [28,94,127,128,129,130].
It regenerates following fire by seed from crown-stored cones or seeds
dispersed from off-site sources [4,22,80,89,96,166,187,230,231,266]. However,
red pine seeds are generally dispersed within a radius equal to the height of the seed
tree [4,252,266]; with a maximum dispersal range of 900 to 1,000 feet (275-300
m) [252], and a likely dispersal distance of about 40 feet (12 m) [231]. Thus,
regeneration is probably most likely to occur from crown-stored cones not
damaged by fire. Successful red pine
germination and seedling establishment requires little vegetative "competition",
adequate light, and a mineral soil base [4,27,94,214,231,252,288].
Seeds generally germinate several years after fire when ash minerals have been
reduced by leaching [4]. Peaks in red pine regeneration generally
occur in the years following fire [4,15,27,28,89,288]. Given that red pines
only produce "good" seed crops
every 3 to 7 years [4,27,89,166,187,231,252] and "bumper" crops every 10 to 12 years
[4,22,231,252], red pine regeneration
may be delayed following fire depending on the seed crop size.
Fire not only promotes red pine seedling establishment, but can promote
root/shoot growth in surviving trees [180] and an increase in resin flow [171,236].
Increased resin flow helps stop bark beetles and wood-decaying fungi from entering fire scars
[11,236,294].
Red pine regenerates via seeds [4,22,80,89,96,166,187,230,231,266].
Pollination:
Red pine is wind- and self-pollinated [46,98]. Self-pollination is restricted by several factors, most
important of which is the position of male and female cones in the tree crown.
Female cones are generally found in the upper crown and male cones in the
lower crown [98]. In closed red pine stands self-pollination probably does not exceed
10%, but the percent of trees that self-pollinate in small isolated stands or in
single isolated trees is likely greater (review by [98]), [266]. Butson and others [46] state
that red pine has a high degree of self-fertility, which assures viable seed
production even when trees are isolated.
Red pine seedling establishment by distance from seed
trees [88]
Leachate from red pine and sheep-laurel litter significantly reduced growth
of red pine seedlings in sand compared to seedlings growing in burned-over mineral soil
[180]. Red pine seedlings were grown for 8 months in sand,
sand watered with either red pine or
sheep-laurel leachate, and burned-over mineral soil. The leachate experiments might have mimicked red pine
seedling growth in red pine or sheep-laurel litter. After 8 months, red
pine seedlings grew significantly better in the burned-over soil than in the other
3 treatments. There were no significant differences in growth between seedlings exposed
to sheep-laurel leachate and those exposed to red pine leachate, though
seedlings in the sand without leachate grew significantly better than seedlings exposed
to leachate [180].
Red pine seedling characteristics on sites with
and without other vegetation [302]
Growth characteristics for red pine seedlings grown in
4 levels of lights for 4 to 6 years [170]
Despite its need for sunlight, red pine apparently does not require an open
stand structure. Red pine sapling height was positively correlated with density
on the Chippewa National Forest (r=0.609)
[247]. On plots where red pine saplings were spaced approximately 20 Ã 20 feet (6 Ã 6 m) apart, average height was 5.5
feet (1.7 m), while saplings spaced as close as 5 Ã 5 feet (2 Ã 2 m) apart,
average height was 14 feet (4.3 m). Further analysis showed that trees of the
same height grew more rapidly during the following 10 years if they were
located within 5 feet (2 m) of another tree than trees spaced more than 5 feet
(2 m) apart [247].
Length (mm)
Red pine succession in the absence of fire by
region
Red pine has been successfully used to rehabilitate disturbed sites
[13,121,139,169,194,223,241,295,316] and is useful for windbreaks, snowbreaks,
and watershed protection [89].
Seed storage:
Red pine seeds can be stored for up to 30 years if kept in a dry, sealed container at
temperatures of 30 to 40 ðF (1-3 ðC) [305].
Pinus resinosa, known as red pine[2][3] (also Norway pine in Minnesota),[4] is a pine native to North America.
Red pine is a coniferous evergreen tree characterized by tall, straight growth.[5] It usually ranges from 20–35 metres (66–115 feet) in height and 1 m (3 ft 3 in) in trunk diameter, exceptionally reaching 43.77 m (143+1⁄2 ft) tall.[6] The crown is conical, becoming a narrow rounded dome with age. The bark is thick and gray-brown at the base of the tree, but thin, flaky and bright orange-red in the upper crown; the tree's name derives from this distinctive character. Some red color may be seen in the fissures of the bark. The species is self pruning; there tend not to be dead branches on the trees, and older trees may have very long lengths of branchless trunk below the canopy.
The leaves are needle-like, dark yellow-green, in fascicles of two,[5] 12–18 centimetres (4+3⁄4–7 inches) long, and brittle. The leaves snap cleanly when bent; this character, stated as diagnostic for red pine in some texts, is however shared by several other pine species. The cones are symmetrical ovoid, 4–6 cm (1+1⁄2–2+1⁄4 in) long by 2.5 cm (1 in) broad, and purple before maturity, ripening to nut-blue and opening to 4–5 cm (1+1⁄2–2 in) broad, the scales without a prickle and almost stalkless.[2]
Red pine is notable for its very constant morphology and low genetic variation throughout its range, suggesting it has been through a near extinction in its recent evolutionary history.[7][8] A genetic study of nuclear microsatellite polymorphisms among populations distributed throughout its natural range found that red pine populations from Newfoundland are genetically distinct from most mainland populations, consistent with dispersal from different glacial refugia in this highly self-pollinating species.[9]
An old tree in Itasca State Park, Minnesota
Pollen cones in spring
Cone (scale in cm)
Red pine boughs, showing yellowing and abscission of older foliage in the autumn.
It occurs from Newfoundland west to Manitoba, and south to Pennsylvania, with several smaller, disjunct populations occurring in the Appalachian Mountains in Virginia and West Virginia, as well as a few small pockets in extreme northern New Jersey and northern Illinois.[1][10]
It can be found in a variety of habitats.
It is intolerant of shade, but does well in windy sites; it grows best in well-drained soil. It is a long-lived tree, reaching a maximum age of about 500 years.[11]
The wood is commercially valuable in forestry for timber and paper pulp, and the tree is also used for landscaping.
The red pine is Minnesota's state tree.[12] In Minnesota the use of the name "Norway"[4] may stem from early Scandinavian immigrants who likened the American red pines to the Scots pines back home.[13]
{{cite journal}}: CS1 maint: uses authors parameter (link) Pinus resinosa, known as red pine (also Norway pine in Minnesota), is a pine native to North America.
