Longitudinal shrinkage variations within trees of sugi (Cryptomeria japonica) cultivars

Yamashita, Kana; Hirakawa, Yasuhiko; Nakatani, Hiroshi; Ikeda, Motoyoshi

doi:10.1007/s10086-008-0987-z

Cited by 19 publications

(17 citation statements)

References 11 publications

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“…Either way, selection at very early ages for MFA would result in producing 'prime' material in the center of the stem (Lima et al, 2004). A reduction of corewood MFA would also reduce the MFA gradient, improving wood dimensional stability and stiffness (Walker and Butterfield, 1995;Yamashita et al, 2009). …”

Section: A Pathway To Very Early Selectionmentioning

confidence: 99%

Sélection très précoce pour les propriétés du bois massif : détection précoce des individus les plus performants

Apiolaza

2009

Ann. For. Sci.

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Abstract• This article reviews the theoretical basis for indirect selection -where early selection is an example -and how correlated response is calculated.• The review is followed by a description of issues as to the choice of selection criteria that could explain the lack of substantial progress on breeding for wood quality. These include: the autoregressive nature of selection criteria, overemphasizing the importance of basic density as selection criterion, ignoring age-related trends of wood properties, using rotation age rather than technical thresholds as objective traits and ignoring that not all grades have identical marginal economic value.• Three data sets are either analyzed for the first time or reanalyzed under different assumptions, to explore the importance of these criticisms.• Finally, the use of critical value thresholds as very early selection criteria is suggested and discussed in the context of improving intrinsic corewood quality. Mots-clés :rigidité / sélection précoce / caractère seuil / Pinus radiata Résumé -Sélection très précoce pour les propriétés du bois massif : détection précoce des individus les plus performants.• Cet article passe en revue les bases théoriques des méthodes de sélection indirecte -parmi lesquelles figure la sélection précoce -et la manière dont le gain corrélé est calculé.• Cette revue est suivie d'une description des problèmes liés au choix des critères de sélection et qui pourraient expliquer le manque de progrès substantiel suite à l'amélioration pour les propriétés du bois. Ceux-ci incluent l'auto-corrélation des critères de sélection, l'exagération de l'importance de la densité comme critère de sélection, l'oubli de l'évolution des propriétés du bois avec l'âge cambial, l'utilisation de l'âge de révolution comme caractère-cible plutôt que des seuils techniques et l'oubli que toutes les classes de produits n'ont pas la même valeur économique marginale.• Trois jeux de données ont été soit analysés pour la première fois soit ré-analysés sous différentes hypothèses pour explorer l'importance de ces critiques.• Enfin, l'utilisation de seuils critiques comme critères de sélection très précoce est suggérée et discutée dans le cadre de l'amélioration intrinsèque de la qualité du bois juvénile.

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Section: A Pathway To Very Early Selectionmentioning

confidence: 99%

Sélection très précoce pour les propriétés du bois massif : détection précoce des individus les plus performants

Apiolaza

2009

Ann. For. Sci.

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“…The sample trees were used in our previous studies on shrinkage [6,7] and bow [8]. The trees of each cultivar were taken from the same stands (boka-sugi: Takaoka, Toyama; aya-sugi and yabukururi: Kahoku, Kumamoto; ryuunohige and kumotooshi: Kikuchi, Kumamoto).…”

Section: Methodsmentioning

confidence: 99%

“…The moisture content of heartwood varies largely among cultivars and along the stem [4,5]. The shrinkage, which is affected by microfibril angle (MFA), density, and tree ring parameters, also exhibits variation among cultivars and within the stem especially at the core of stem [6,7].…”

Section: Introductionmentioning

confidence: 99%

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Surface-check variation in boxed-heart square timber of sugi (Cryptomeria japonica) cultivars dried by the conventional kiln drying

et al. 2012

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To investigate the factors affecting the surfacecheck variation in boxed-heart square timber of sugi (Cryptomeria japonica), surface checks formed by the conventional kiln drying were compared for two stem heights of five cultivars with different wood properties. The total length and average length of the surface checks were greater at the upper part of the stems for all the cultivars. This might be caused by more sapwood at the upper part of the stem, and large drying stresses between the outer sapwood and the inner heartwood. The cultivars, in which tangential shrinkage was large owing to small microfibril angle, formed longer surface checks and smaller bow. There was a positive relationship between surface-check length and tangential shrinkage. The heartwood percentage and tangential shrinkage were thought to be important factors affecting the surface-check variation in sugi boxedheart square timber.

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“…Johansson and Kliger (2002), Ekevad (2005), Ormarsson and Cown (2005), Astrup (2009) and Gereke et al (2010). It is also well documented that wood is an inhomogeneous material concerning such parameters as the modulus of elasticity (MOE) [Dahlblom et al (1999a)] and shrinkage coefficients in the fibre direction [Yamashita et al (2009), and Dahlblom et al (1999b)]. For normally grown trees, the MOE often increases quite linearly (up to factor of two) from pith to bark whereas the shrinkage coefficient usually decreases [Wormuth (1993), and Dahlblom et al (1999b)].…”

Section: Introductionmentioning

confidence: 99%

Finite element modelling of moisture related and visco-elastic deformations in inhomogeneous timber beams

Ormarsson¹,

Dahlblom²

2013

Engineering Structures

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Wood is a hygro-mechanical, non-isotropic and inhomogeneous material concerning both modulus of elasticity (MOE) and shrinkage properties. In stress calculations associated with ordinary timber design, these matters are often not dealt with properly. The main reason for this is that stress distributions in inhomogeneous glued laminated members (glulams) and in composite beams exposed to combined mechanical action and variable climate conditions are extremely difficult to predict by hand. Several experimental studies of Norway spruce have shown that the longitudinal modulus of elasticity and the longitudinal shrinkage coefficient vary considerably from pith to bark. The question is how much these variations affect the stress distribution in wooden structures exposed to variable moisture climate. The paper presents a finite element implementation of a beam element with the aim of studying how wooden composites behave during both mechanical and environmental load action. The beam element is exposed to both axial and lateral deformation. The material model employed concerns the elastic, shrinkage, mechano-sorption and visco-elastic behaviour of the wood material. It is used here to simulate the behaviour of several simplysupported and continuous composite beams subjected to both mechanical and environmental loading to illustrate the advantages this can provide. The results indicate clearly both the inhomogeneity of the material and the variable moisture action occurring to have had a significant effect on the stress distribution within the cross-section of the products that were studied.

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Longitudinal shrinkage variations within trees of sugi (Cryptomeria japonica) cultivars

Cited by 19 publications

References 11 publications

Sélection très précoce pour les propriétés du bois massif : détection précoce des individus les plus performants

Sélection très précoce pour les propriétés du bois massif : détection précoce des individus les plus performants

Surface-check variation in boxed-heart square timber of sugi (Cryptomeria japonica) cultivars dried by the conventional kiln drying

Finite element modelling of moisture related and visco-elastic deformations in inhomogeneous timber beams

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