In a broad band around the world’s Northern hemisphere, from Ireland to Kamchatka and from Alaska to Newfoundland, you will find the ubiquitous birch. In Europe and Asia the silver birch, with its slender trunk, pale ruptured bark, delicate leaves and catkins is a hardy pioneer, its tiny windborne seeds finding a foothold on any bare or cleared ground. It grows quickly to a height of perhaps 80 feet (25 metres) but is no long-lived forest giant, living to not much more than 100 years. Its North American cousin, the paper birch, may grow taller, to 130 feet (40 metres) and is often found in the company of aspens and maples. It thrives on periodic forest fires, after which its seeds quickly colonise the freshly scorched earth.
In the end, both species give way to the great forest canopy trees; but their winter hardiness ensures that they have few competitors in their most northerly ranges. Like maples, birch trees are adapted to extreme winters, their roots able to reprime any vessels left with air pockets after deep frosts. The positive pressure from the roots drives sugars and water back up the tree – with the welcome by-product of a sweet sap that can be tapped to make a refreshing drink. The thin, horizontal scars that appear on the trunk are lenticels, pores through which the tree exchanges gases with the atmosphere.
Birches are not just pioneers, but are trees of pioneers. They provide cover for mammals, birds and insects, lichens and fungi, allowing other, fruiting species to establish. Woodpeckers commonly nest in old birch trees. The resinous outer bark, which peels easily without harm to the tree, provides a very handy firelighter even when damp. In North America native communities valued paper birch bark above all for its use in making boxes and baskets and because, when removed in large sheets, it was the perfect material for roofing shelters and constructing lightweight, portable, waterproof and tough hulled canoes. Early European traders and fur trappers quickly adopted the these canoes as their means of accessing the great lakes and rivers of the North. The wood and charcoal of both species is used as fuel; in making plywoods, especially for high quality drums, and as pulp for paper mills.