Name: |
- Betula, from the Latin for birch
- papyrifera, from the Greek, papurus
(papyrus), "paper" and the Latin, fero, "to bear, carry,
bring"; "paper bearing"
- Paper Birch, from the paper-like bark
- Other common names include Canoe Birch, Silver Birch, White Birch,
Bouleau blanc, Bouleau à papier (Qué),
Papier-Birken (Ger)
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Taxonomy: |
- Kingdom Plantae, the Plants
- Division Magnoliophyta, the Angiosperms (flowering plants)
- Class Magnoliopsida, the Dicotyledons
- Subclass Hamamelididae
- Order Fagales
- Family Betulaceae, the Birches
- Genus Betula, the Birches
- Taxonomic Serial Number: 19489
- Also known as Betula alaskana, Betula cordifolia, Betula neoalaskana
- Betula is a genetically plastic genus, often with variation
continuous between species. Hybridization is common. Paper Birch naturally
hybridizes with almost every native birch species.
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Description: |
- Medium sized, single or multiple stemmed, deciduous tree. In forests
a slender trunk with a narrow crown, but in openings a wider crown spreading
out from near the base. Multiple-stemmed trees are relatively common
as a result of browsing by moose and snowhoe hares.
- Height at maturity 70'-80' and 10"-12" in diameter,
sometimes to 30".
- Short-lived. Height growth ceases at about 60-70
years of age; few live more than 140 years.
- Shallow-rooted: few roots deeper than 24" below the
soil surface.
- Bark reddish-brown on saplings; on mature trees thin,
white, and smooth, often separating into papery strips, and easily peeled
off in sheets.
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Identification: |
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Distribution: |
- Alaska to Newfoundland,
- Transcontinental distribution across northern North America.
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Habitat: |
- Grows in climates ranging from boreal to humid and tolerates wide
variations in the amount and pattern of precipitation. It grows at the
northern limit of tree growth in arctic Canada and Alaska, in boreal
spruce woodlands and forests, in montane and subalpine forests of the
West, in wooded draws of the northern Great Plains, and in coniferous,
deciduous, and, mixed forests of the Northeast and Lake States.
- Shade-intolerant; abundant on burned or cut lands,
often in pure stands. Restricted to openings in older forests.
- Most abundant on rolling upland terrain and alluvial sites but grows
on almost any soil and topographic situation, including mountain slopes,
open slopes, rock slides, muskegs, and borders of bogs and swamps.
- Soils: Grows best on deep, well-drained to moderately
well-drained, sandy or silty soils common on glacial deposits. It grows
on a wide range of soil textures from gravels to silts, and grows on
organic bog and peat soils.
- Birch shade is unfavorable for germination of birch seed, but spruce
seedlings are common. By 120-150 years after fire, black or white spruce
dominate. In boreal mixed woods, paper birch begin dying by 75 years
after fire; Jack Pine (Pinus banksiana),
Black Spruce (Picea mariana), and
White Spruce (Picea glauca)
begin to dominate or codominate. By 125 years most paper birch are dead.
In Minnesota, often replaced by communities dominated by shrubs, particularly
Beaked Hazel (Corylus cornuta).
In boreal spruce ecosystems, paper birch forms nearly pure, pioneer
communities on disturbed sites.
- Rare in late successional or climax forests and generally restricted
to openings. A principal component of boreal mixed woods in Canada because
its pioneering habit is favored by the relatively frequent 50-125 year
fire return interval. Codominants in mixed woods include Balsam Fir
(Abies balsamifera), White Spruce
(Picea glauca), Black Spruce
(Picea mariana), Jack Pine (Pinus
banksiana), and Quaking Aspen (Populus
tremuloides)
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Fire: |
- Rapidly colonizes open disturbed sites created by wildfire or windthrow,
but lasts only one generation before being replaced by shade-tolerant
conifers or northern hardwoods. Re-seeds aggressively after wildfire,
often forming large, essentially pure stands.
- Depending on the recovery of other species following fire, may also
occur in mixed postfire stands with spruces, aspen, and other hardwoods.
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Associates: |
- Trees: Balsam Fir (Abies
balsamea),Red Maple (Acer
rubrum), Sugar Maple (Acer saccharum), Yellow Birch
(Betula alleghaniensis), White Spruce, (Picea
glauca), Black Spruce, (Picea mariana),
Jack Pine (Pinus banksiana),
Bigtooth Aspen (Populus grandidentata),
Quaking Aspen (Populus tremuloides)
- Shrubs: Green Alder (Alnus
crispa), Bearberry (Arctostaphylos
uva-ursi), Beaked Hazel (Corylus
cornuta), Bush Honeysuckle (Diervilla
lonicera), Labrador Tea (Ledum
groenlandicum), Pin Cherry (Prunus
pensylvanica), Gooseberry (Ribes
oxyacanthoides), Raspberries and Blackberries (Rubus spp.),
Bebb Willow (Salix bebbiana),
Scouler Willow (Salix scouleriana), Red Elderberry (Sambucus
racemosa ssp. pubens), Blueberries (Vaccinium
angustifolium, and myrtilloides),
Highbush Cranberry (Viburnum
edule)
- Herbs: Wild Sarsaparilla (Aralia
nudicaulis), Large Leaf Aster (Aster
macrophyllus), Blue Bead Lily (Clintonia
borealis), Jewelweed (Impatiens biflora), Horsetails
(Equisetum spp.), Canada Mayflower (Maianthemum
canadense), Interrupted Fern (Osmunda
claytonia), Bracken Fern (Pteridium
aquilinum), Shinleaf (Pyrola spp.), Rose Twisted Stalk
(Streptopus rosea),
Starflower (Trientalis borealis),
Violets (Viola spp.)
- Ground Covers: Bristly Club Moss (Lycopodium
annotinum), Running Club Moss (Lycopodium
clavatum), Ground Pine Clubmoss (Lycopodiumobscurum),
Schreber's Feathermoss (Pleurozium
schreberi)
- Mammals
- Moose: Important browse throughout most of range.
Nutritional quality is poor in winter, but is important to wintering
moose because of its sheer abundance in young stands.
- White-tailed Deer: though considered a "secondary-choice
food", it is an important dietary component. In Minnesota, white-tailed
deer eat considerable amounts of paper birch leaves in the fall.
- Snowshoe hare browse paper birch seedlings and
saplings.
- Porcupines feed on the inner bark
- Beaver also eat it though generally prefer aspen,
while willow and paper birch are second choice foods.
- Voles and shrews eat the seeds.
- Numerous birds and small mammals eat paper birch buds, catkins
and seeds.
- Young paper birch stands provide prime deer and moose cover.
- Birds:
- Numerous cavity-nesting birds nest in paper birch, including woodpeckers,
chickadees, nuthatches, and swallows.
- A favorite feeding tree of yellow-bellied sapsuckers, which peck
holes in the bark to feed on the sap. Hummingbirds and red squirrels
also feed at sapwells in paper birch created by sapsuckers.
- Ruffed grouse eat the catkins and buds.
- Redpolls, siskins, and chickadees obtain a considerable portion
of their annual diet from birch seeds.
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History: |
- During the last Ice Age, a part of the vast White Spruce forest which
covered the Great Plains and eastern US, just south of the windswept
tundra bordering the great ice sheets. One of the earliest species,
along with spruce, to follow the retreating ice northward reaching the
Canadian border soon after the ice had passed.
- Native Americans used bark to make baskets, storage containers, mats,
baby carriers, moose and bird calls, torches, household utensils, and,
of course, canoes.
- The strong and flexible wood was made into spears, bows, arrows, snowshoes,
sleds, and other items
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Uses: |
- Commercially for veneer, plywood, and pulpwood. It is easily worked
and takes finishes and stains readily. Furniture, cabinets, and numerous
specialty items are made from birch lumber.
- Tree chips used for pulp and paper manufacture, reconstituted uses,
and fuel.
- Commonly used as fireplace and wood stove fuel
- Graceful form and attractive bark make it a popular landscape plant.
- The sap is made into syrup, wine, beer, and medicinal tonics.
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Reproduction: |
- Reproduces by seed and vegetatively by root sprouts
- Flowers, male and female, occur in separate, pendulous
catkins on the same tree. Male catkins are partially formed in the fall,
remain dormant in the winter, and expand to about 4" before flowering
in the spring. Female catkins appear in the spring before the leaves
are fully expanded.
- Fruits winged nutlets, 0.06" long, 0.03" wide.
- Seed production begins at about age 15, with optimum
production at 40 to 70 years. Trees produce good seed crops about every
other year.
- Dispersal: The small, double-winged seeds are dispersed
primarily by wind. Most seeds fall 100'-200' from the parent tree. Nearly
all the seed is shed from September through November. A small percentage
of the seeds can remain viable on the forest floor for several years.
- Germination normally takes place in the spring following
dispersal and is generally best on disturbed mineral or mixed mineral/organic
soil. The small seeds are sensitive to soil moisture and temperature.
Thus shade usually favors germination and initial establishment by preventing
seedbeds from drying out and reaching excessively high temperatures.
South or southwest exposures, excessively drained soils, insufficient
rainfall, competing vegetation, and unshaded and undisturbed seedbeds
deter establishment. Seedlings will not grow on soils with a pH less
than 5.0. Although germination and early survival are often best on
mineral soils, seedling growth is best on humus seedbeds in moderate
or full sunlight. First year seedlings are about 2"-5".
- Vegetative reproduction: Sprouts following cutting
or fire from the stump base or root collar. Prolific sprouting common
in young trees, with some individuals producing up to 100 sprouts. Sprout
growth is rapid, sometimes up to 24" the first growing season, decreasing
with age.
- Phenology for NE Minnesota:
- bud burst April
- leafing out late April - early May
- flowering begins April
- pollen shed late April - May
- seedfall begins August
- leaf color change September
- leaf fall late September - October
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Propagation: |
- Best results are obtained by planting 2-year-old or older bare-root
or containerized stock. Occasionally transplanted from the wild.
- Also by grafting, air layering, rooting of cuttings, or tissue-culture.
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Cultivation: |
- Hardy to USDA Zone 3 (average minimum annual temperature -40ºF)
- Cultivars and species available by mail order from specialty suppliers
or at local nurseries
- Shade-intolerant
- Leaf litter inhibits Jack Pine (Pinus
banksiana), Red Pine (Pinus resinosa),
and White Pine (Pinus strobus)
seed germination.
- Insects: Bronze Birch Borer the most serious insect
pest. It attacks and can kill injured, overmature, or decadent trees.
There are numerous defoliators of Paper Birch, but they rarely kill
healthy trees.
- Diseases: Bacteria or decay fungi enter through wounds
and branch stubs, and roots which come in contact with the roots of
other trees infected with root-rotting fungi.
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Links: |
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Comments: |
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Last updated on
4 March, 2006
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