Canadian Forest Service Publications
Guide-terrain pour l'identification des stades de débourrement et de formation du bourgeon apical chez l'épinette blanche / Field Guide for Identifying Apical Bud Break and Bud Formation Stages in White Spruce. 2010. Dhont, C.; Sylvestre, P.; Gros-Louis, M.-C.; Isabel, N. Ressources naturelles Canada, Centre de foresterie des Laurentides. 18 p.
Issued by: Laurentian Forestry Centre
Catalog ID: 32086
Language: French / English
Availability: PDF (download)
The purpose of this guide is to detail phenological stages in white spruce that can be observed with the naked eye, specifically the apical bud break stages occurring in the spring and apical bud formation stages occurring at the end of the growing season. Although six phenological stages were previously identified in a characterization of apical bud break in white spruce, the morphological changes that occur in the buds were not detailed. By contrast, in black spruce, seven bud break stages were described in detail for the lateral buds. The bud break stages described in this guide for the apical buds of white spruce are largely based on the bud break stages previously described for black spruce. The apical bud formation stages in white spruce were defined by using the four phenological stages previously described for black spruce and adding two significant intermediate stages.