Balsam poplar (Acb) - Populus balsamifera
Balsam poplar is a medium-sized (exceptionally over 30 m tall), deciduous broad-leaved tree, at maturity with a narrow, open crown of thick ascending branches and gray and deeply furrowed bark. Many kinds of wildlife use the twigs for food. The light, soft wood is used for pulp and construction.
|Geographic Range||Geographic element:
North American transcontinental-incomplete
Distribution in Western North America:
north in the Pacific region; north and central in the Cordilleran region
subarctic - subalpine boreal - montane boreal - cool temperate
submontane - montane - subalpine
Occurrence in biogeoclimatic zones:
(lower SWB), BWBS, (SBS), (IDF), (ICH)
Range of soil moisture regimes:
slightly dry - fresh - moist - very moist - (wet)
Range of soil nutrient regimes:
(poor) - medium - rich - very rich
Balsam poplar does not tolerate acid Mor humus forms because it requires a good supply of nitrate nitrogen, calcium, and magnesium. Therefore, it benefits from soils in which these nutrients are replenished by flooding in spring or before summer. As with black cottonwood, balsam poplar does not tolerate brackish water.
|Root System Characteristics||On floodplains, the root system of balsam poplar is multi-layered, owing to the deposition of new soil by periodic flooding. Although early root development is downward, subsequent development progresses upward as root growth occurs on the buried stem. Lateral root spread can be >14 m. Roots are associated with ecto- and endo-mycorrhizae.|
|Associated tree species and successional role||In British Columbia, balsam poplar grows predominantly in even-aged, pure stands, and, in the later stages of primary succession on floodplains, with shade-tolerant conifers. The most commonly associated tree species are subalpine fir and white spruce (& its hybrids). Balsam poplar is a pioneer species (primary succession) on floodplains, and is present in early and intermediate stages of secondary succession on floodplains and upland sites.|
|Genetics||Two varieties have been identified: var. balsamifera and var. subcordata. Balsam poplar and black cottonwood hybridize and produce mixed populations fairly frequently where both taxa are sympatric, or even when they are separated by rather large distances, because it is wind-pollinated and its pollen grains may be easily transported a long distance. Interbreeding may be seen as intraspecific, providing we consider, as it is often done, that both taxa belong to the same species; the scientific name in this case is Populus balsamifera L. s.l.|
|Notes||Balsam poplar produces in a short time high yields of wood suitable for mechanical pulping. Considering its productivity, vegetative reproduction, and low risk of being affected by damaging agents, it is a suitable species for intensive management on flooded sites. More detailed silvics information is given by:
Peterson, E.B. and N.M. Peterson. 1992. Ecology, management, and use of aspen and balsam poplar in the prairie provinces. Special Report 1, For. Can., Northern Forestry Centre, Edmonton, Alberta. 252 pp.
Zasada, J.S. and H.N. Phipps. 1990. Populus balsamifera. Pp. 518-529 in R.M. Burns and B.H. Honkala (technical coordinators) Silvics of North America, Vol. 2. Agri. Handbook 654, USDA For. Serv., Washington, D.C.