White Birch

Betula papyrifera (paper birch,[3] also known as white birch[3] and canoe birch[3]) is a species of birch native to northernNorth America. It is the provincial tree of Saskatchewan and the state tree of New Hampshire.[4][5]

It is a medium-sized deciduous tree reaching 60 feet tall (18m), and exceptionally to 130 feet (40m) with a trunk up to 32 inches diameter (0.8m). They live to about 140 years. 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, 1-5 in. long and 2-4 in. 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 1.5 in. 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.

Paper birch handles heat and humidity poorly and may only live 30 years in zones six and up, while trees in colder-climate regions can exceed 50 years and grow to much larger sizes. When stressed, it can succumb to bronze birch borer beetles.

Betula papyrifera has a wide range. It is found in interior (var. humilus) and south-central (var. kenaica) Alaska and in allprovinces and territories of Canada, except Nunavut, as well as the northern continental United States, south toPennsylvania and Washington, with small isolated populations further south in mountains to North Carolina, New Mexico, and Colorado. The most southerly stand in the Western United States is located in Lost Gulch in the City of Boulder Mountain Parks, an isolated Pleistocene relict that most likely reflects the southern reach of boreal vegetation into the area during the last Ice Age.[6]

Betula papyrifera is a pioneer species; for example, it is frequently an early invader after fire in Black Spruce Boreal forests.[7] B. papyrifera requires high nutrients and sun exposure. The bark is highly weather-resistant. Often, the wood of a downed paper birch will rot away leaving the hollow bark intact.[8] 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.