Knot properties of sawn boards from unthinned lodgepole pine stands planted in different initial spacings: a case study from northern Sweden

Abstract

The aim of this study was to investigate the effects of different initial spacings on the quality of boards sawn from logs from unthinned lodgepole pine stands in northern Sweden. The study was conducted in the 44 years-old experiment that had been storm damaged in January 2014. Logs from six unthinned plots planted in four initial spacings (1.1 x 1.1 m, 2.0 x 2.0 m, 2.85 x 2.85 m and 4.0 x 4.0 m) were extracted and sawn into boards. Knot position and size on each board were measured and classified into pre-defined knot types. Mean knot size increased with wider spacing, and the difference between the two spacing extremes was 0.65 cm. Mean knot size also increased with height, showing the highest values around a height of 3.0 m. The number of knots did not depend on the initial spacing. There was an average of 40 knots per board regardless of spacing. This study gives an indication about the knot properties of lodgepole pine timber and identifies a possibility for decreasing the number of seedlings used in regeneration without compromising wood-quality.

Keywords

Initial density; initial spacing; knot area ratio; knot type; knots; lodgepole pine; sawn-timber

Published in

Scandinavian Journal of Forest Research
2019, volume: 34, number: 8, pages: 732-738
Publisher: TAYLOR & FRANCIS AS

SLU Authors

• Lula, Mikolaj

  • Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Wood Science
Forest Science

Publication identifier

• DOI: https://doi.org/10.1080/02827581.2019.1664625

Permanent link to this page (URI)

https://res.slu.se/id/publ/102049