Luostarinen, K. and Heikkonen, S. 2010. Effects of Provenance, Radial Location of Wood and Drying Schedule on Colour of Dried Siberian Larch (Larix sibirica) Timber.  Baltic Forestry 16 (2): 255 – 263.

Siberian larch (Larix sibirica Ledeb.) timber is a good raw material, particularly for the mechanical wood industry, but drying it without any decrease in value is d ifficult and slow. The purpose of this research was to determine if radial location or drying schedule affect the colour of conventionally dried larch wood coming from two different provenances (Finland and Siberia). The basic density, final moisture content and width of annual rings differed between provenances and were taken into account as covariates. A total of five drying tests with three different schedules were performed, with reflectance spectra being measured from the inner parts of dried timber. The effect of drying schedule on the colour was minor. However, radial location affected the colour more clearly. The middle and inner heartwood were darker and redder than the wood located near the pith, particularly in the Siberian timber, while the wood located around the pith was reddest in the Finnish timber. In addition, the colour correlated with density regarding the Siberian, but not the Finnish timber, with the colour of the timbers of different provenances visibly differing. Thus provenances should be separated when drying larch wood to attain uniform colour.

Key words: annual ring width, basic density, conventional drying, L*C*h -colour coordinates, moisture content.