Department of Biosphere Resources Science

Division of Biological Material Sciences


Prof. SASAKI, Yasutoshi D. Agr. gasteig@
Assoc. Prof. YAMASAKI, Mariko D. Agr. D. Eng. marikoy@
Asst. Prof. ANDO, Kosei D. Agr. musica@
On-site measurement of stress wave velocity for non-destructive inspection of mechanical property of wood members and structural safety of historical timber construction (Main building “Kondo” of Kongoji temple in Osaka, a nationally important cultural asset)

The research target of the laboratory is to establish the effective utilization of timber using physical and engineering methods. The research is developed mainly in the fields of “Timber Engineering” which covers the following three research areas;

(1) Time dependent mechanical behavior of wood and wood-based materials:
The mechanical behavior of wood and wood-based materials in pure and combined stresses are investigated. This research focuses on the influence of the loading states on the strength and deformation in the evaluation of the mechanical characteristics of wood under static and dynamic loading, for example, Poisson’s ratio, fatigue life, and fatigue limit. The mechanical durability is discussed by energetic and reaction kinetics approaches.
(2) Wood utilization in urban design:
Large-scale inputs of forest resources into urban areas will need to be taken into consideration for the foreseeable future. Urban areas that enjoy the multiple services provided by forests have an obligation to actively promote wood utilization in their design. To help fulfil this obligation, we have launched a research group called “Wood Urban Design Project”. Its purpose is to engage in cross-sectional collaboration toward a fundamental solution to the problems faced by the forestry and timber industries. We discuss the project’s ambit and the problems that may be faced in the effort to revitalize forest and forestry.
(3) Nondestructive inspection for structural safety of historical timber construction:
A method of estimating Young’s modulus of wood-member by measuring only stress wave velocity is newly developed (Japanese patent: 2007-232698). When the method is used, density measurements are not needed. Historical timber construction is inspected with special concern with their structural safety.

Recent Publications:

  1. Watanabe, A.; Sasaki, Y.; Yamasaki, M.: Bending Fatigue of Wood: Strain energy-based failure criterion and fatigue life prediction, Wood and Fiber Science, 46(2), 216-227, 2014
  2. Nakaya, T.; Yamasaki, M.; Sasaki, Y.: Influence of wall composition on thermal environment of wooden houses, Journal of Wood Science, 60(2), 117-126, 2014
  3. Sasaki, Y.; Oya, A.; Yamasaki, M.: Energetic Investigation of the Fatigue of Wood, Holzforschung, 68(7), 843-848, 2014
  4. Yamasaki, M.; Uchida, M.; Torichigai, T.; Sasaki, Y.: Strain Measurement and Stress Estimation of Axial Members in the Traditional Wooden Buildings, Journal of Wood Science, 60(6), 403-413, 2014
  5. Fukuta, S.; Nomura, M.; Nishizawa, M.; Yamasaki, M.; Sasaki, Y.: Evaluation and fireproofing treatment of wooden heat insulating/acoustic absorbing materials, European Journal of Wood and Wood Products, 72(6), 713-720, 2014
  6. Mizutani, M.; Ando, K.: Influence of a wide range of moisture contents on the Poisson's ratio of wood, Journal of Wood Science, 61(1), 81-85, 2015
  7. Kawahara, K.; Ando, K.; Taniguchi, Y.: Time dependence of Poisson's effect in wood IV. influence of grain angle, Journal of Wood Science, 61(4), 372-383, 2015
  8. Ogawa, K.; Sasaki, Y.; Yamasaki, M.; Fukuta, S.: Theoretical Estimation of Mechanical Properties of Plywood-Sheathed Shear Wall with Combined Use of Adhesive Tape and Wood Dowels, Wood and Fiber Science, 47(4), 421-430, 2015
  9. Ogawa, K.; Sasaki, Y.; Yamasaki, M.: Theoretical Modeling and Experimental Study of Japanese "Watari-ago" Joints, Journal of Wood Science, 61(5), 481-491, 2015


  FAX: +81-52-789-4150
Prof. YAMAMOTO, Hiroyuki D. Agr., D. Eng. hiro@
Assoc. Prof. YOSHIDA, Masato D. Agr. yoshida@
Lecturer MATSUO, Miyuki D. Agr. miyuki@
Field measurement of the growth stress in 16-year-old Eucalyptus plantation in Southern Brazil.
Experiment in our laboratory – Approaches by Molecular biology and SEM observation.

The major research objective of BMP is to understand the material properties of wood as well as to clarify the processes of tree growth and cell wall formation, from the physical point of view. Methodology extends over the physical, mechanical, chemical, anatomical and computing methods. Recent our research covers the following topics.

(1): Biomechanics of the living tree: Generation of growth stress and its biological meanings are investigated by means of the field measurement, laboratory analysis, and computing mechanics.

(2) Generation mechanism of the physical properties of wood cell wall: Material testing, electron-microscopic observation, UV-micro-spectrophotometry, X-ray diffraction analysis, molecular biology, as well as theoretical modeling, are employed to make clear the diversity in the physical properties of wood cell wall.

(3) Growth properties and wood qualities of tropical fast-growing species: Wood qualities and maturation properties of tropical fast-growing species are investigated in relation to their rapid lateral growth rate. Our research fields extend over many countries, e.g., Indonesia, Malaysia, Philippine, Brazil, French Guyana, Australia, Argentina, and so forth.

Recent Publications:

  1. Kojima, M.; Yamamoto, H.; Yoshida, M.; Ojio,Y.; Okumura, K.: Maturation property of fast-growing hardwood plantation species: A view of fiber length, Forest Ecology and Management, in press (DOI: 10.1016/j.foreco.2008.08.012)
  2. Yamashita, S.; Yoshida, M.; Yamamoto, H.; Okuyama, T.: Screening genes that change expression during compression wood formation in Chamaecyparis obtusa, Tree Physiology, 21, 1331-1340, 2008
  3. Clair, B.; Gril, J.; Di Renzo, F.; Yamamoto, H.; Quignard, F.: Characterization of a gel in the cell wall to elucidate the paradoxical shrinkage of tension wood, Biomacromolecules, 9, 494-498, 2008
  4. Ruelle, J.: Yamamoto, H.: Thibaut, B. : Growth stresses and cellulose structural parameter in tension and normal wood from three tropical rainforest angiosperm species, Bioresources, 2, 235-251, 2007
  5. Yamashita, S.; Yoshida, M.; Takayama,S.; Okuyama, T.: Stem-righting mechanism in gymnosperm trees deduced from limitations in compression wood development, Annals of Botany, 99, 487-493, 2007
  6. Ruelle, J.: Yoshida, M.; Clair, B.; Thibaut, B.: Peculiar tension wood structure in Laetia procera (Poepp.) Eichl. (Flacourtiaceae), Trees, 21, 345-355, 2007
  7. Abe, K.; Yamamoto, H.: The influence of boiling and drying treatments on the behaviors of tension wood with gelatinous layers in Zelkova serrata, Journal of Wood Science, 53,5-10, 2007
  8. Nakai, T.; Yamamoto, H.: Properties of the piezoelectric voltage considering the microscopic structure of wood cell walls, Holzforschung, 61, 95-100, 2007


Prof. TSUCHIKAWA, Satoru D. Agr. St3842@
Assoc. Prof. YOKOCHI, Hideyuki D. Agr. yokochi@
Lecturer INAGAKI, Tetsuya D. Agr. inatetsu@


Prof. FUKUSHIMA, Kazuhiko D. Agr. kazu@
Assoc. Prof. MATSUSHITA, Yasuyuki D. Agr. ysmatsu@
Lecturer AOKI, Dan D. Agr. daoki@

The major research interests of this laboratory are to understand the biosynthesis and chemical properties of lignin, cellulose, hemicellulose and extractives. The current research projects are:

  1. Analysis of the components of cell wall by ToF-SIMS
  2. Elucidation of biosynthesis of lignin
  3. Investigation of bio-conversion from lignocellulosic materials
  4. Functionalization of lignin
  5. Basic studies for pulp and paper industry