The Jack Pine (Pinus banksiana) is a North American pine with its native range in Canada east of the Rocky Mountains from Northwest Territories to Nova Scotia, and the northeast of the United States from Minnesota to Maine, with the southernmost part of the range just into northwest Indiana. In the far west of its range, it hybridizes readily with the closely related Lodgepole Pine (P. contorta).
It is not a large tree, ranging from 9-22 m (30–72 ft) in height. Some Jack Pines are shrub-sized. Jack Pine does not usually grow perfectly straight but when mature has a irregular shape similar to the Pitch Pine. This pine often forms pure stands on sandy or rocky soil. It is fire-adapted to stand-replacing fires, with the cones remaining closed for many years, until a natural forest fire kills the mature trees and opens the cones. These then reseed the burnt ground.
The leaves are in fascicles of two, needle-like, twisted, slightly yellowish-green, and 2-4 cm (0.8–1.6 in) long. The cones are 3-5 cm (1.2–2.0 in) long, the scales with a small, fragile prickle that usually wears off before maturity, leaving the cones smooth. Unusually for a pine, the cones normally point forward along the branch, sometimes curling around it.That is a easy to tell it apart from the similar lodgepole pine in more western areas of north America. Unopened cones are smooth and serotinous - the scales opening in fire or intense heat.
Kirtland's Warbler (Dendroica kirtlandii), an endangered bird, depends on pure stands of young Jack Pine in a very limited area in the north of the Lower Peninsula of Michigan for breeding. Mature Jack Pine forests are usually open and the fall of their needles creates acidic soil, so blueberries are often abundant in the understory.
The Jack Pine has a long list of minor alternative names, including Eastern Jack Pine, Gray Pine, Black Pine and Scrub Pine; the last more commonly refers to Virginia Pine (P. virginiana), and Gray Pine to P. sabineana. The Canadian French name is Pin gris or (incorrectly) Cyprès.
References
|
