Fibre length and wood colour radial and circumferential variation in three radiata pine stem cross-sections with mild, moderate and severe compression wood

摘要

Growth-layer level radial and circumferential variation in fibre length and wood colour (L~* darkness-brightness coordinate) were determined for three discs of very different compression wood content (mild, moderate and severe). Property measurements were made on a number of radial bark-to-pith strips from each disc. Both replicate strips (located adjacent one to another in a disc before cutting) and nominal east, west, north and south radial strips were assessed. The fibre length and wood colour (L~*) radial and circumferential variation for each disc show clear relationships which appear to be attributable to compression wood. Fibre length decreases with decreasing L~* values (increasing darkness), particularly for the discs with moderate and severe compression wood for which length and L~* residual correlations are moderate to strong. Measurement precision for the wood colour and fibre length methods are more than adequate to quantify growth-layer-level radial and circumferential variation within a disc. Furthermore, the measurement procedures will allow growth-layer level SilviScan fibre property values to be compared against corresponding growth-layer level fibre length as well as a colour based measure of compression wood.