Canadian Forest Service Publications
Effect of precommercial thinning on the production of young fir stands on the Upper North Shore. 1996. Zarnovican, R.; Laberge, C. Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Sainte-Foy, Quebec. Information Report LAU-X-118E. 26 p.
Available from: Laurentian Forestry Centre
Catalog ID: 16701
Analysis of balsam fir morphological and growth data from 16 plots in the Les Escoumins management unit on the Upper North Shore was made to assess the effects of precommercial thinning on sawlog quality, radial growth and volume production. The results indicate that precommercial thinning significantly stimulates radial growth of residual stems. However, this increase in radial growth was more significant on the stump than on the dbh. The effect of precommercial thinning on radial growth was maximal 4 years after the treatment and ceased after 7 years. Precommercial thinning had a significant impact on the qualitative parameters of the logs. In thinned stands stem taper was greater than in control stands, principally due to the distribution of the wood between dbh and the stump. Finally, precommercial thinning increased the number of live whorls as well as the knottiness on the first 8-foot section. Comparison of the yield indicates that heavy precommercial thinning, in addition to affecting the quality of the logs, can also affect the production level of fir stands. Finally, the report proposes a density model for fir stands based on dominant height and the spacing factor.