Skip to main content

Official Journal of the Japan Wood Research Society

Mechanical characterization of juvenile European aspen (Populus tremula) and hybrid aspen (Populus tremula × Populus tremuloides) using full-field strain measurements


Functional analysis of genes and proteins involved in wood formation and fiber properties often involves phenotyping saplings of transgenic trees. The objective of the present study was to develop a tensile test method for small green samples from saplings, and to compare mechanical properties of juvenile European aspen (Populus tremula) and hybrid aspen (Populus tremula × tremuloides). Small microtomed sections were manufactured and successfully tested in tension parallel to fiber orientation. Strain was determined by digital speckle photography. Results showed significantly lower values for juvenile hybrid aspen in both Young’s modulus and tensile strength parallel to the grain. Average Young’s moduli spanned the ranges of 5.9–6.6 and 4.8–6.0 GPa for European aspen and hybrid aspen, respectively. Tensile strength was in the range of 45–49 MPa for European aspen and 32–45 MPa for hybrid aspen. The average density (oven-dry) was 284 kg/m3 for European aspen and 221 kg/m3 for hybrid aspen. Differences in mechanical properties correlated with differences in density.


  1. Boerjan W (2005) Biotechnology and the domestication of forest trees. Curr Opin Biotechnol 16:159–166

    Article  CAS  PubMed  Google Scholar 

  2. Mellerowicz EJ, Baucher M, Sundberg B, Boerjan W (2001) Unraveling cell wall formation in the woody dicot stem. Plant Mol Biol 47:239–274

    Article  CAS  PubMed  Google Scholar 

  3. Tuskan GA, DiFazio S, Jansson S, Bohlmann J, Grigoriev I, Hellsten U, Putnam N, Ralph S, Rombauts S, Salamov A, Schein J, Sterck L, Aerts A, Bhalerao RR, Bhalerao RP, Blaudez, Boerjan W, Brun A, Brunner A, Busov V, Campbell M, Carlson J, Chalot M, Chapman J, Chen GL, Cooper D, Coutinho PM, Couturier J, Covert S, Cronk Q, Cunningham R, Davis J, Degroeve S, Déjardin A, dePamphilis C, Detter J, Dirks B, Dubchak I, Duplessis S, Ehlting J, Ellis B, Gendler K, Goodstein D, Gribskov M, Grimwood J, Groover A, Gunter L, Hamberger B, Heinze B, Helariutta Y, Henrissat B, Holligan D, Holt R, Huang W, Islam-Faridi N, Jones S, Jones-Rhoades M, Jorgensen R, Joshi C, Kangasjärvi J, Karlsson J, Kelleher C, Kirkpatrick R, Kirst M, Kohler A, Kalluri U, Larimer F, Leebens-Mack J, Leplé JC, Locascio P, Lou Y, Lucas S, Martin F, Montanini B, Napoli C, Nelson DR, Nelson C, Nieminen K, Nilsson O, Pereda V, Peter G, Philippe R, Pilate G, Poliakov A, Razumovskaya J, Richardson P, Rinaldi C, Ritland K, Rouzé P, Ryaboy D, Schmutz J, Schrader J, Segerman B, Shin H, Siddiqui A, Sterky F, Terry A, Tsai CJ, Uberbacher E, Unneberg P, Vahala J, Wall K, Wessler S, Yang G, Yin T, Douglas C, Marra M, Sandberg G, Van de Peer Y, Rokhsar D (2006) The genome of black cottonwood Populus trichocarpa (Torr. & Gray). Science 313:1596–1604

    Article  CAS  PubMed  Google Scholar 

  4. Sterky F, Bhalerao RR, Unneberg P, Segerman B, Nilsson P, Brunner AM, Charbonnel-Campaa L, Jonsson Lindvall J, Tandre K, Strauss SH, Sundberg B, Gustafsson P, Uhlén M, Bhalerao RP, Nilsson O, Sandberg G, Karlsson J, Lundeberg J, Jansson S (2004) A Populus EST resource for plant functional genomics. Proc Natl Acad Sci USA 101:13951–13956

    Article  PubMed  PubMed Central  Google Scholar 

  5. Taylor G (2002) Populus: Arabidopsis for forestry. Do we need a model tree? Ann Bot 90:681–689

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  6. Kasal B, Pezlen I, Peralta P, Li L (2007) Preliminary tests to evaluate the mechanical properties of young trees with small diameter. Holzforschung 61:390–393

    Article  CAS  Google Scholar 

  7. Coutand C, Jeronimidis G, Chanson B, Loup C (2004) Comparison of mechanical properties of tension and opposite wood in Populus. Wood Sci Technol 38:11–24

    Article  CAS  Google Scholar 

  8. De Boever L, Vansteenkiste D, Van Acker J, Ceulemans R, Scarascia-Mugnozza G, Calfapietra C (2005) Effects of free-air carbon dioxide enrichment (FACE) on intra-ring microdensity variations and micromechanical properties of juvenile poplar trees (Populus nigra L.). In: Randle T (ed) Forest and timber quality in Europe: modelling and forecasting yield and quality in Europe (MEFYQUE). Final report, Project QLK5-CT-2001-00345, Faculty of Bioscience Engineering, Laboratory of Wood Technology, Ghent University, Belgium

    Google Scholar 

  9. Schwab E, Krause HA, Fladung M (2003) Selected wood properties of transgenic aspen trees. Mitteilungen der Bundesforschunganstalt für Forst-und Holzwirtschaft (BFH), Germany

    Google Scholar 

  10. Schniewind AP (1959) Transverse anisotropy of wood: a function of gross anatomic structure. Forest Prod J 9:350–359

    CAS  Google Scholar 

  11. Danvind J (2005) Analysis of drying wood based on nondestructive measurements and numerical tools. PhD Thesis, Division of Wood Technology, Luleå University of Technology, Luleå

    Google Scholar 

  12. Jernkvist LO, Thuvander F (2001) Experimental determination of stiffness variation across growth rings in Picea abies. Holzforschung 55:309–317

    Article  CAS  Google Scholar 

  13. Ljungdahl J, Berglund LA, Burman M (2006) Transverse anisotropy of compressive failure in European oak — a digital speckle photography study. Holzforschung 60:190–195

    Article  CAS  Google Scholar 

  14. Gibson LJ, Ashby MF (1997) Cellular solids — structure and properties, 2nd edn. Cambridge University Press, Cambridge, UK, pp 390–391, 419

    Book  Google Scholar 

  15. Kollmann FFP, Côté WA (1968) Principles of wood science and technology I: solid wood. Springer, Berlin Heidelberg New York, p 165

    Book  Google Scholar 

  16. Bodig J, Jayne BA (1982) Mechanics of wood and wood composites. Van Nostrand Reinhold, New York, pp 42, 296-303, 476-477, 684-686

    Google Scholar 

  17. Torelli N, Gorisek Z (1995) Mexican tropical hardwoods: mechanical properties in green condition. Holz Roh Werkst 53: 421–423

    Article  CAS  Google Scholar 

  18. Anonymous (1999) Wood handbook: wood as an engineering material. General technical report 113. US Department of Agriculture, Forest Service, Forest Products Laboratory, Madison, WI, pp 4-2–4-8

  19. Kufner M (1978) Elastizitätsmodul und Zugfestigkeit von Holz verschedener Rohdichte in Abhängigleit von Feuchtigkeitsgehalt. Holz Roh Werkst 36:435–439

    Article  Google Scholar 

  20. Heräjärvi H (2007) Shear and tensile strength of conventionally dried, press dried and heat treated aspen. In: Hill CAS, Jones D, Militz H, Ormondryd GA (eds) Proceedings of the 3rd European Conference on Wood Modifi cation, Cardiff, UK, pp 173–176

  21. Heräjärvi H, Junkkonen R (2006) Wood density and growth rate of European and hybrid aspen in southern Finland. Baltic Forest 12:2–8

    Google Scholar 

  22. Säll H, Källsner B, Olsson A (2007) Bending strength and stiffness of aspen sawn timber. In: Grzeskiewicz M (ed) Proceedings of the 1st COST Action E53 Conference — Quality Control for Wood and Wood Products, Warsaw, Poland, pp 121–126

  23. Tsoumis G (1991) Science and technology of wood — structure, properties, utilisation. Van Nostrand Reinhold, New York, USA, pp 70–72, 112, 114-120, 172-176

    Google Scholar 

  24. Lang EM, Bejo L, Divos F, Kovacs Z, Anderson RB (2003) Orthotropic strength and elasticity of hardwoods in relation to composite manufacture. Part III: orthotropic elasticity of structural veneers. Wood Fiber Sci 35:308–320

    CAS  Google Scholar 

  25. Nagoda L (1981) Mekaniska egenskaper hos osp (Populus tremula L.). Scientific Reports of the Agricultural University of Norway 60:8

    Google Scholar 

  26. Junkkonen R, Heräjärvi H (2006) Physical properties of European and hybrid aspen wood after three different drying treatments. In: Kurjatko S, Kudela J, Lagana R (eds) Proceedings of the 5th International Symposium of Wood Structure and Properties, Zvolen, Slovakia, pp 257–263

  27. Bhat KM, Priya PB, Rugmini P (2001) Characterisation of juvenile wood in teak. Wood Sci Technol 34:517–532

    Article  CAS  Google Scholar 

  28. Cown DJ, Parker ML (1978) Comparison of annual ring density profiles in hardwoods and softwoods by X-ray densitometry. Can J Forest Res 8:442–449

    Article  Google Scholar 

  29. Koch P (1985) Utilization of hardwoods growing on southern pine sites. USDA Forest Service agriculture handbook no 605, vol 1, Washington DC, pp 506–514, 733–734

    Google Scholar 

Download references

Author information

Authors and Affiliations


Additional information

Part of this article was presented at the 3rd International Symposium on Wood Machining, May 21–23, 2007, Lausanne, Switzerland

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Bjurhager, I., Berglund, L.A., Bardage, S.L. et al. Mechanical characterization of juvenile European aspen (Populus tremula) and hybrid aspen (Populus tremula × Populus tremuloides) using full-field strain measurements. J Wood Sci 54, 349–355 (2008).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

Key words

  • Hybrid aspen
  • Juvenile
  • Populus tremula × tremuloides
  • Tensile strength
  • Young’s modulus