Tuesday, October 16, 2012

Birch bark canoes in tree form

Species name: Betula papyrifera

Common name: paper birch, white birch

Location: Ontario

This tree species is incredibly common in Canada, from the northern edge of the Carolinian forest north to the tree line. Despite being a deciduous tree, it is most common in coniferous forests like the Boreal forest. It is not shade tolerant, so is one of the first species to colonize an area that has been burned or deforested. It is also a popular ornamental tree for the attractive bark: white, peeling bark on the trunk, and reddish-brown bark on the twigs.

There are a few notable uses of the white birch. The first is in the lumber and construction industry. While the lumber generated from a white birch is not ideal for building anything other than ornamental pieces (chairs, tables, etc.), chipping the trunks and pressing them into boards gives OSB or oriented strand board, which is incredibly important in the housing industry. It is used most commonly as sub-flooring in homes (and as wall panels on which to attach other decorative surfaces), but also sometimes as sub-roofing (but is not very water resistant and so requires a membrane before the roof can be shingled). By far, the most substantial use of white birch today is in the manufacture of (drumroll) popsicle sticks.

There are unusual pockets of boreal forest that exist in the middle of the United States that are likely remnants from the last major ice age. Because it is now (more than likely) too warm for the white birch to happily exist in those locations, it is listed as threatened or vulnerable (or some variation thereof) in seven states: Tennessee, Colorado, Wyoming, West Virginia, Virginia, Illinois and Indiana. It is the provincial tree of Saskatchewan and the state tree of New Hampshire.

Historically, it was very important to Native North Americans as a canoe tree. There were two different kinds of canoes built from this tree, depending on the intended use. The first is to cut down a large tree and hollow out the inside to make a thin shell. These types of canoes weren't very common since finding trees large enough to do this is rare. Using bark pieces to form a waterproof barrier and shaping around a frame made of thin branches was much more common, and is still done in some areas today (although more of an ornamental canoe as opposed to one used for fishing and transport).