Models to predict the radial variation of stiffness, strength, and density in planted noble fir, Norway spruce, western hemlock, and western red cedar in Great Britain

Gil-Moreno, David; MClean, J. Paul; Ridley-Ellis, Dan

Abstract

Key message: This study compares the measured radial variation in wood stiffness, strength, and density of noble fir, Norway spruce, western hemlock, and western red cedar by developing mixed-effects models for each property using age as the explanatory variable. These models could be used to simulate the effect of rotation length and species choice on sawn wood properties.

Context: Timber production in Great Britain relies primarily on Sitka spruce. The use of multiple species is desirable to mitigate against biotic and abiotic risks posed to a single species. When considering alternative species, quantifying and modeling radial variation in wood properties is important to determine the potential for sawn timber production at a given rotation length.

Aims: To build empirical models for the radial variation in wood properties that can account for species.

Methods: Clear-wood samples were produced along radial transects in trees from four conifer species: Abies procera Rehder, Picea abies (L.) Karst, Tsuga heterophylla (Raf.) Sarg., Thuja plicata Donn. ex D.Don. Modulus of Elasticity, Modulus of Rupture, and density were measured on each species according to established standards. Mixed-effects models were built using ring numbers from the pith and species as explanatory variables.

Results: The same model forms could be used across the four species. Nonlinear models were developed for the Modulus of Elasticity and density. For the Modulus of Rupture, a linear model was most appropriate. The effect of species in the models was significant.

Conclusion: At similar rotation lengths, noble fir, Norway spruce, and western hemlock can produce timber with comparable properties to Sitka spruce. Overall, western red cedar would have worse properties for structural use.

Citation

Gil-Moreno, D., MClean, J. P., & Ridley-Ellis, D. (2023). Models to predict the radial variation of stiffness, strength, and density in planted noble fir, Norway spruce, western hemlock, and western red cedar in Great Britain. Annals of Forest Science, 80, Article 48. https://doi.org/10.1186/s13595-023-01214-7

• Journal Article Type: Article
• Acceptance Date: Nov 15, 2023
• Online Publication Date: Dec 14, 2023
• Publication Date: 2023
• Deposit Date: Dec 14, 2023
• Publicly Available Date: Dec 15, 2023
• Print ISSN: 1286-4560
• Publisher: Springer
• Peer Reviewed: Peer Reviewed
• Volume: 80
• Article Number: 48
• DOI: https://doi.org/10.1186/s13595-023-01214-7
• Keywords: MOE; MOR; Radial variation; Tree growth; Alternative species
• Public URL: http://researchrepository.napier.ac.uk/Output/3423078