Interlocked grain and density patterns in Bagassa guianensis: changes with ontogeny and mechanical consequences for trees
Interlocked grain and basic density increase from pith to bark in Bagassa guianensis and greatly improve trunk torsional stiffness and wood tenacity in the radial plane.
Trees modulate their building material, wood, throughout their lifetime to meet changing mechanical needs. Basic density, a widely studied wood property, has been proved to be negatively correlated to growth rate and is then considered to reflect the diversity of species growth strategies. An alternative way for trees to modulate growth strategy at constant construction cost is changing the organisation of their fibre network. Interlocked grain, the result of a periodic change in the orientation of the fibres in the tangential plane, is found in numerous tropical tree species. In this study, we first describe the variations in basic density and interlocked grain occurring during ontogeny of Bagassa guianensis, a fast-growing Amazonian species, and analyse their influence on the local mechanical properties of wood at the tissue level. The observed radial patterns and properties are then incorporated in a finite element model to investigate their effect on mechanical properties of the trunk. We report extreme and highly reproducible concomitant radial variations in basic density and interlocked grain in all the sampled trees, with grain angle variations ranging from − 31° to 23°. Such changes in wood during ontogeny allows trees to tailor their growth rate while greatly improving resistance to torsion and reducing the risk of splitting.
KeywordsInterlocked grain Basic density Wood radial patterns Tree architecture Growth strategy Biomechanics
The authors thank Eric Nicolini (CIRAD—AMAP) and Onoefé NGwete (CIRAD—ECOFOG) for their help in tree identification and field work and Yves Caraglio (CIRAD—AMAP) to share his knowledge on Bagassa guianensis architecture. This research project was financially supported by the Labex CEBA (ANR-10-LABX-25-01), CNRS-INSIS and European Social Fund awards.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Arets EJMM, Van der Hout P, Zagt RJ (2003) Responses of tree populations and forest composition to selective logging in Guyana. In: Steege H (ed) Long-term changes in tropical tree diversity. Studies from the Guiana Shield, Africa, Borneo and Melanesia, Tropenbos Series 22. Tropenbos International Wageningen, Wageningen, pp 95–115Google Scholar
- Arostegui A (1982) Recopilacion y analisis de studios tecnologicos de maderas peruanas. FAO, LimaGoogle Scholar
- Bossu J, Beauchêne J, Estevez Y, Duplais C, Clair B (2016) New Insights on wood dimensional stability influenced by secondary metabolites: the case of a fast-growing tropical species Bagassa guianensis Aubl. PLoS One 11:e0150777. https://doi.org/10.1371/journal.pone.0150777 CrossRefPubMedPubMedCentralGoogle Scholar
- Cabrolier P (2009) Is interlocked grain an adaptive trait for tropical tree species in rainforest. In: 6th Plant Biomechanics Conference, CayenneGoogle Scholar
- Détienne P (1979) Contrefil à rythme annuel dans les faro Daniellia sp. Bois&Forêts des Tropiques 183:67–71Google Scholar
- Fimbel R, Sjaastad E (1994) Wood specific gravity variability in Ceiba pentandra. Wood Fiber Sci 26(1):91–96Google Scholar
- Guitard D (1987) Mécanique du matériau bois et composites. Cépaduès (ed) 238p. ISBN 2 8548 152 7Google Scholar
- Hernandez RE, Almeida G (2003) Effects of wood density and interlocked grain on the shear strength of three Amazonian tropical hardwoods. Wood Fiber Sci 35(2):89–96Google Scholar
- Hernandez RE, Restrepo G (1995) Natural variation in wood properties of Alnus acuminata H.B.K. grown in Colombia. Wood and Fiber Sci 27:41–48Google Scholar
- Kollmann FFP, Côté WA (1968) Principles of wood science and technology. In: Solid wood. Springer, Berlin, 592 pGoogle Scholar
- Kribs DA (1950) Commercial foreign woods on the American market, a manual to their structure, identification, uses and distribution. Dissertation, Tropical Wood Laboratory, State College, 241 ppGoogle Scholar
- Lachenbruch B, Moore JR, Evans R (2011) Radial variation in wood structure and function in woody plants, and hypotheses for its occurrence. In: Meinzer F, Lachenbruch B, Dawson T (eds) Size- and age-related changes in tree structure and function. Tree physiology, 4th edn. Springer, DordrechtGoogle Scholar
- Lehnebach R, Morel H, Bossu J, Le Moguédec G, Amusant N, Beauchêne J, Nicolini E (2017) Heartwood/sapwood profile and the tradeoff between trunk and crown increment in a natural forest: the case study of a tropical tree (Dicorynia guianensis Amsh., Fabaceae). Trees Struct Funct 33(1):199–214. https://doi.org/10.1007/s00468-016-1473-7 CrossRefGoogle Scholar
- Marsoem SN, Kikata Y (1987) The effect of interlocked grain on the mechanical properties of white meranti. Bull Nagoya Univ 9:51–77Google Scholar
- Morel H, Nicolini É, Bossu J, Blanc L, Beauchêne J (2017) Qualité et usages du bois de cinq espèces forestières adaptées à la plantation à vocation de bois d’oeuvre et testées en Guyane française. Bois&Forêts des Tropiques 334:61–74. https://doi.org/10.19182/bft2017.334.a31492 CrossRefGoogle Scholar
- Muller-Landau HC (2004) Interspecific and inter-site variation in wood specific gravity of tropical trees. Biotropica 36(1):20–32Google Scholar
- Omolodun OO, Cutter BE, Krause GF, McGinnes EA (1991) Wood quality in Hildegardia barteri (Mast.) Kossern—an African tropical pioneer species. Wood Fiber Sci 23(3):419–435Google Scholar
- Parolin P (2002) Radial gradients in wood specific gravity in trees of central Amazonian floodplains. IAWA J 23(4):449–457Google Scholar
- Webb CD (1969) Variation of interlocked grain in sweetgum (Liquidambar styracifula). For Prod J 19(8):45–48Google Scholar
- Weddell E (1961) Influence of interlocked grain on the bending strength of timber, with particular reference to utile and greenheart. J Inst Wood Sci 7:56–72Google Scholar
- Whitmore JL (1973) Wood density variation in Costa Rican balsa. Wood Sci 5(3):223–229Google Scholar
- Wiemann MC, Williamson GB (1988) Extreme radial changes in wood specific gravity in some tropical pioneers. Wood Fiber Sci 20(3):344–349Google Scholar
- Wiemann MC, Williamson GB (1989) Radial gradients in the specific gravity of wood in some tropical and temperate trees. For Sci 35(1):197–210Google Scholar