Canadian Forest Service Publications
Stand dynamics and tree quality response to precommercial thinning in a northern hardwood forest of the Acadian forest region: 23 years of intermediate results. 2017. Swift, D.E., Knight, W., Béland, M., Boureima, I., Bouque, C.P.-A., and Meng, F.-R.Scandinavian Journal of Forest Research 32(1): 45–59.
Year: 2017
Issued by: Atlantic Forestry Centre
Catalog ID: 39572
Language: English
Availability: PDF (download)
Available from the Journal's Web site. †
DOI: 10.1080/02827581.2016.1186219
† This site may require a fee
Abstract
In the late 1980s, large forest companies began precommercial thinning (PCT) operations in young northern hardwood cutovers in New Brunswick, Canada. To provide supporting growth and yield information, an industrial experiment was established at residual stand densities of 1300, 1600, 1900, and 2200 stems ha−1. Stand responses were examined for measurements recorded at 0 (1987), 5 (1992), 10 (1997), 16 (2003), and 23 (2010) years after establishment. Average diameter at breast height, quadratic mean diameter, stand basal area, and stand total volume growth increased as stem density decreased from PCT. There were significant linear differences for many of these variables between treatments and time periods (year). No significant differences were detected in tree height between treatments. In 2010, the four PCT thinning treatments did not exhibit any differences in potential sawlogs at 2.4 m (8 ft) and 3.6 m (12 ft) lengths. Significant differences were observed for 4.9 m (16 ft) sawlogs that were produced at the least dense spacing (1300 stems ha−1). Results from this study and recommendations from the European literature suggest that value-added timber products may be produced from more intense PCT treatments than are currently being practiced on sites dominated by yellow birch (Betula alleghaniensis Britt.).
Plain Language Summary
Precommercial thinning (PCT) is the removal of smaller and lesser quality trees around selected crop trees to achieve the desired uniform spacing, leaving the cut trees on site. Stand dynamics and stem quality intermediate responses were examined from a long-term experiment in New Brunswick. The four uniform density treatments were 2200, 1900, 1600, and 1300 stems ha-1. Average stem diameter, basal area, and total volume growth increased as stem density decreased. No significant differences were detected in tree height growth. Significant differences were observed for 4.9 m sawlogs that were produced at the least dense spacing. Results from this study and recommendations from the European literature suggest that value-added timber products may be produced from more intense PCT treatments than are currently being practiced on sites dominated by yellow birch. Such information will assist managers to produce more value-added timber products required for the hardwood industry.