Betula papyrifera (Paper Birch, also known as American White Birch and Canoe Birch) is a species of birch native to northern North America.
Description
It is a medium-sized deciduous tree reaching 20 m tall (exceptionally to 35 m) with a trunk up to 80 cm diameter. The bark is white, commonly brightly so, flaking in fine horizontal strips, and often with small black marks and scars. In individuals younger than five years the bark appears brown with white lenticels, making the tree much harder to distinguish from other trees. The leaves are alternate, ovate, 5-12 cm long and 4-9 cm broad, with a doubly serrate margin. The leaf buds are conical and small, they are green colored with brown edges. The flowers are wind-pollinated catkins 3-8 cm long growing from the tips of twigs, the fruit matures in the fall. The mature fruit is composed of numerous tiny winged seeds packed between the catkin bracts. They drop between September and spring.
Distribution
Betula papyrifera has a wide range. It is found in interior (var. humilus) and southcentral (var. kenaica) Alaska and in all provinces and territories of Canada, except Nunavut, as well as the northern continental United States, south to Pennsylvania and Washington, with small isolated populations further south in mountains to North Carolina and Colorado.
Ecology
Betula papyrifera is a pioneer species. It needs high nutrients and a lot of sun. The bark is highly weather-resistant. Often, the wood of a downed paper birch will rot away leaving the hollow bark intact.[1] Birch bark is a winter staple food for moose. The nutritional quality is poor, but is important to wintering moose because of its sheer abundance. Although white-tailed deer consider Birch 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 hares browse paper birch seedlings, porcupines feed on the inner bark and mice eat the seeds. The leaves of the Paper Birch serve as food for various Lepidoptera. See List of Lepidoptera that feed on birches.
Conservation
It is considered vulnerable in Indiana, imperiled in Illinois, Virginia, West Virginia and Wyoming, and critically imperiled in Colorado and Tennessee.
Uses
Betula papyrifera has a soft, yet moderately heavy, white wood. It makes horrible firewood, but the bark is a great fire starter, as it burns at high temperatures. It is acceptable for furniture parts, floors, and Oriented Strand Board. It does not have a very high economic value. The sap can be used to produce birch syrup. The bark is also flammable even when wet which makes it very useful when on the trail. Its name reflects the use of the tree's bark, primarily by Native Americans, for a writing material and also that the waterproof bark was used for the outer covering of canoes. In the construction of sod-roofed houses, the bark is used to create a durable waterproof layer.[2]
Culture
Betula papyrifera is the Provincial tree of Saskatchewan and the State tree of New Hampshire.
References
- ^ Ewing, Susan. The Great Alaska Nature Factbook. Portland: Alaska Northwest Books, 1996.
- ^ Ewing, Susan. The Great Alaska Nature Factbook. Portland: Alaska Northwest Books, 1996.
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