|Sponsor:||Alberta-Pacific Forest Industries Inc.|
Object & Deliverables
The principle objective of this project was to test the repeated success of induction of flowering in white spruce through girdling and injection of Gibberellin. The rationale for the research project was to be able to induce flowering in phenotypically “superior” and “site-adapted” white spruce parent trees in the mixedwood boreal forest by girdling and Gibberellin A4/7 (GA4/7) hormone injection so as to produce an appreciable and significant increase in flowering (conebud production) and subsequent seedcone production. A further component of the research project was to make the conebud induction process time and cost effective.
Over the summer field seasons of 2002, 2003, and 2004 the effects of injecting Gibberellin A4/7 was tested on mature white spruce in a “semi-operational” mode at several locations in areas near Fort McMurray and Calling Lake of northeastern Alberta.
Using hormone injection to induce flowering in residual white spruce trees of mixedwood boreal forests can mimic one of the natural events that occur after a fire. Combining this abundant seed production with proper seedbed preparation should allow re-establishment of the mixedwood forest after logging, without the use of fire.
The induction of flowering, expressed by assessment of conebud numbers using a class ranking, were highly successful during the trials. The treatment of girdling and injection of Gibberellin hormone can be utilized to provide sufficient numbers of seed/seedlings for regeneration of the white spruce component in boreal mixedwood forests. Girdling, especially the overlapping, non-destructive girdle, seemed to amplify the response and was as such deemed necessary. Treatment one to several years prior to harvest allows seed to be sourced from local sites.
Project results are contained in a twenty-four page technical report entitled “Induction of Flowering in White Spruce Using a Simultaneous “Early” Girdling and Injection of Gibberellin A4/7 Mixture” prepared by Richard P. Pharis and Gitte Grover December 2005.