Canadian Forest Service Publications

Growth response of white spruce to release from trembling aspen. 1989. Yang, R.C. Forestry Canada, Northern Forestry Centre, Edmonton, Alberta. Information Report NOR-X-302.

Year: 1989

Available from: Northern Forestry Centre

Catalog ID: 12164

Language: English

Series: Information Report (NoFC - Edmonton)

CFS Availability: Order paper copy (free), PDF (download)

Abstract

Complete release of young to intermediate-age white spruce (Picea glauca [Moench] Voss) from trembling aspen (Populus tremuloides Michx.) competition in mixed stands in Manitoba and Saskatchewan increased diameter at breast height, height, basal area, total stand volume, and merchantable stand volume growth. Stand diameter at breast height growth was improved up to 177% in 30 years after treatment, the best growth occurred when the spruce was released at 15–40 years of age. Small trees (2–6 m) had greater height response than large trees. Spruce periodic annual total volume increment increased 93%, from 2.50 m3 ha-1 yr-1 for the control stands to 4.83 m3 ha-1 yr-1 for the released stands. Residual densities of 690–840 spruce per hectare released at 20–40 years of age are adequate for normal yield development. Mortality of small spruce was higher in the control stands, but mortality of large spruce was higher in the released stands due to windthrow.

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