Canadian Forest Service Publications

Creating boreal mixedwoods by planting spruce under aspen: successful establishment in uncertain future climates. 2016. Kabzems, R.; Comeau, P.G.; Filipescu, C.N.; Rogers, B.; Linnell Nemec, A. F. Can. J. For. Res. 46: 1217–1223.

Year: 2016

Available from: Pacific Forestry Centre

Catalog ID: 37316

Language: English

CFS Availability: PDF (request by e-mail)

Available from the Journal's Web site.
DOI: 10.1139/cjfr-2015-0440

† This site may require a fee.


Planting white spruce (Picea glauca (Moench) Voss) under established aspen (Populus tremuloides Michx.) stands has substantial potential for regenerating mixedwood ecosystems in the western Canadian boreal forest. The presence of an aspen overstory serves to ameliorate frost and winter injury problems and suppresses understory vegetation that may compete with white spruce. Under future climatic regimes with more frequent and severe drought episodes, underplanting may be a costeffective strategy for lowering the risk of mortality in mixedwood regeneration. We examine the growth of white spruce during the first 18 years after being planted beneath a 39-year-old stand of trembling aspen. Treatments included thinning from over 6000 stems·ha−1 to 3000, 2000, and 1000 stems·ha−1 and fertilization. Initial stimulation of understory vegetation by fertilization had no measureable effect on spruce heights or diameters at year 18. Aspen thinning treatments did not have a significant effect on spruce height growth rates after spruce crowns had emerged above the understory shrub layer due to rapid aspen basal area increases after thinning. Small, but significant, increases for spruce height and diameter were present in the 1000 and 2000 stem·ha−1 aspen thinnings. A much wider range of aspen stand conditions may be suitable for planting spruce to create mixedwood ecosystems than has been previously considered.

Date modified: