Inter-tree and intra-tree variation in the physical properties of wood of laurel (Laurus nobilis)

Abstract

The laurel (Laurus nobilis L.) is a common species in southern Europe, but the properties of its wood are not well described in the literature and from that perspective any novel information is valuable. Because of that, a group of laurels was felled for the analysis of wood properties on small defect-free specimens (17 trees and 1250 valid specimens). The sampled wood was moderately heavy and unstable. The following mean values were obtained (density at 12% moisture content 699 kg m⁻³; basic density 566 kg m⁻³; total volumetric shrinkage 18.0%; volumetric shrinkage coefficient 0.59%). Highly significant inter-tree and intra-tree variation was observed for most of the properties considered. The inter-tree variation was attributed to tree dimensions, being remarkable that volumetric, radial and tangential shrinkage coefficients were significantly related to breast height diameter and slenderness. The trends of these variables suggest that in trees older than those used in the study (24–41 years old) the dimensional stability would increase. As regards the inter-tree variation, a low but highly significant decrease was found for density at highest positions in the tree. Volumetric and linear shrinkage diminish very significantly along the stem. Due to the uniformity of density and the increment of wood dimensional stability along the trunk, the harvesting of the full stem is advisable.