Environmentally Induced Physical Changes in Ancient Kauri (<i>Agathis Australis</i>) Wood
Keywords:
<i>Agathis australis</i>, ancient wood, buried wood, carbohydrates, lignin, scanning electron microscopy (SEM), strengthAbstract
The physical properties of 30,000-year-old and modern kauri (Agathis australis) were explored. The acidic burial environment had modified the ancient wood cell-wall structure, affecting strength properties. Degradation of labile cell-wall polysaccharides resulted in strength differences in the ancient kauri both below and above the proportional limit (PL) of the wood. Significantly lower modulus of elasticity (MOE) and work to proportional limit (WPL) values, as compared with modern kauri, indicated that the ancient material was more readily deformed. Above the PL, the modulus of rupture (MOR) of the ancient wood was significantly lower and the work to maximum load (WML) significantly higher than the corresponding values for recently felled kauri, suggesting that the ancient material did not resist stress; rather, the structure gradually "gave way" under imposed stress. Scanning electron micrographs (SEM) of the fractured ancient kauri surfaces reveal degradation of the woody cell wall.References
American Society For Testing and Materials. 1986. Standard test method for specific gravity of wood and wood-based materials. ASTM D2395-83, Philadelphia, PA.nAmerican Society For Testing and Materials. 1986. Standard methods of testing small clear specimens of timber. ASTM D143-83, Philadelphia, PA.nBlanchette, R. A., T. Nilsson, G. Daniel, and A. Abad. 1990. Biological degradration of wood. Pages 141-174 in R. M. Rowell and R. J. Barbour, eds. Archaeological wood: Properties, chemistry and preservation. Advances in Chemisty Series 225. American Chemical Society, Washington, D.C.nButterfield, B. G., and B. A. Meylan. 1980. Three-dimensional structure of wood. Chapman and Hall, London, UK.nEffland, M. J. 1977. Modified procedure to determine acid insoluble lignin in wood and pulp. TAPPI 60:143-144.nFreedland, C., R. M. Rowell, and R. A. Young. In press. Environmentally induced chemical changes in ancient kauri (Agathis australis) wood. Holzforschung.nGarratt, G. A. 1924. Some New Zealand woods. New Zealand State Forest Service. Professional Paper 1.nGortner, W. A. 1938. Analyses of glacial and preglacial woods. J. Am. Chem. Soc. 60:2509-2511.nHedges, J. I., G. L. Cowie, J. R. Ertel, R. J. Barbour, and P. G. Hatcher. 1985. Degradation of carbohydrates and lignins in buried woods. Geochimica et Cos-mochimica Acta 49:701-711.nJagels, R., B. Siefert, J. E. Shottafer, J. L. Wolfhagen, and J. D. Carlisle. 1988. Analysis of wet-site archeological wood samples. Forest Prod. J. 38(5):33-38.nKohara, J. 1953. Studies of the durability of wood—I. Mechanical properties of old timbers. Scientific Reports of Saikyo University, Kyoto 2-4:116-131.nKohara, J. 1954. Studies of the durability of wood—The change in mechanical properties of old timbers. Scientific Reports of Saikyo University, Kyoto 6164-174.nKohara, J. 1956. Studies of Japanese old timbers, XX: Chemical analysis of unearthed wood. Japan Wood Res. J. 2:195-203.nMeylan, B. A., and B.G. Butterfield. 1978. The structure of New Zealand woods. DSIR, Wellington, New Zealand.nMitchell, R. L., and G. J. Ritter. 1934. Composition of three fossil woods mined from the miocene auriferous gravels of California. J. Am. Chem. Soc. 56:1603-1605.nPettersen, R. C., and V. H. Schwandt. 1991. Wood sugar analysis by anion chromatography. J. Wood Chem. Technol. 11:495-501.nSchniewind, A. P. 1964. The mechanical behavior of wood in the light of its anatomical structure. In A. P. Schniewind, ed. The mechanical behavior of wood. Berkeley, CA.nSchniewind, A. P. 1990. Physical and mechanical properties of archaeological wood. Pages 87-109 in R. M. Rowell and R. J. Barbour, eds. Archaeological wood: Properties, chemistry, and preservation. Advances in Chemistry Series 225. American Chemical Society, Washington, D.C.nSchniewind, A. P., and R. Jagels. 1985. Conservation of the Ronson ship's bow. Pages 269-297 in Waterlogged wood: Study and conservation. CETBGE, Grenoble, France.nUSDA Forest Service, Forest Products Laboratory. 1987. Wood handbook. USDA Agric. Handbook 72 (rev.). Madison, WI.nVarossieau, W. W., and I. A. Breger. 1952. Chemical studies on ancient buried wood and the origin of humus. Pages 637-646 in Compte Rendu 3rd congress on stratigraphy and geology of the Carboniferous. Heerlen.nWaksman, S. A., and K. R. Stevens. 1929. Processes involved in the decomposition of wood with reference to the chemical composition of fossilized wood. J. Am. Chem. Soc. 51:1187-1196.nWayman, M., M. R. Azhar, and Z. Koran. 1971. Morphology and chemistry of two ancient woods. Wood Fiber 3(3):153-165.nWinandy, J. E. 1984. Evaluation of live oak submerged underwater for 50 years and proposed for use in rebuilding the U.S.S. Constitution. Forest Prod. J. 34(5): 61-63.nWinandy, J. E., and R. M. Rowell. 1984. The chemistry of wood strength. Pages 211-255 in R. M. Rowell, ed. The chemistry of solid wood. Advances in Chemistry Series 207. American Chemical Society, Washington, D.C.nWood, B. F., A. H. Conner, and C. G. Hill. 1986. The effect of precipitation on the molecular weight distribution of cellulose tricarbanilate. J. Appl. Polymer Sci. 32:3703-3712.n
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