Rapid measurement of variation in tracheid transverse dimensions in a radiata pine tree

TLDR: In this article, the tracheid cross-section dimensions of a 19 year old radiata pine tree were mapped for properties important to the pulp and paper industry: wood density, wall thickness, coarseness and wall thickness.

Abstract: Variation in tracheid cross-section dimensions has been mapped in a 19 year old radiata pine tree. An instrument recently developed for the rapid estimation of transverse tracheid dimensions was used for the analysis. Sixty radii (four directions at each of fifteen heights) were processed. Variation was mapped for properties important to the pulp and paper industry: wood density, tracheid perimeter, coarseness and wall thickness. In this tree, coarseness, wall thickness and density trends were approximately linear from pith to bark, and the rate of rise was similar at all sampling heights. As a result, variation of these properties in the three was approximately cylincrically symmetric. Average coarseness, density and wall thickness fell by 25% from the 0.8 metre level to the 20 metre level in the tree. Average tracheid perimeter was almost independent of sampling height. At breast height, coarseness rose by 86% from pith to bark (350 to 650 μg m -1 ), density rose by 45% (380 to 550 kg m -3 ) and wall thickness by 57% (2.1 to 3.3 μm). Unweighted breast height core properties for this tree were similar to volume-weighted whole tree properties above breast height. Correlations between properties such as coarseness and wall thickness were strong when ring averages or trends were considered, but poor within individual tree rings. Understanding of the mechanisms of short term regulation of tracheid properties should allow increased selectivity in the silvicultural and genetic control of individual properties