Relationship Between Incipient Decay, Strength, and Chemical Composition of Douglas-Fir Heartwood
Keywords:
Decay, mechanical properties, wood chemistry, brown rotAbstract
A new laboratory technique to simulate the initiation of wood decay and to assess the effects of incipient decay on material properties is described. Douglas-fir heartwood specimens were exposed to brown-rot (Postia placenta and Gloeophyllum trabeum) fungi for various periods. Bending properties were determined by nondestructive and destructive tests, and chemical composition of specimens was analyzed. Weight losses of 1 to 18% were linearly related to strength losses of 5 to 70%. Wood strength loss by brown-rot fungi was also closely related to degradation of hemicellulose components. Hemi-cellulose sidechains, such as arabinose and galactose, were degraded in the earliest stages of decay; main-chain hemicellulose carbohydrates, such as mannose and xylose, were degraded in the later stages. Changes in glucose content, a measure of residual cellulose, were minimal. Our technique was effective for establishing and assessing brown-rot decay.References
Bendtsen, B. A., P. L., Platinga, and T. A. Snellgrove. 1988. The influence of juvenile wood on the mechanical properties of 2 x 4's cut from Douglas-fir plantations, in R. F. Itani, ed. Proc. 1st International Timber Engineering Conference, Seattle, WA. Forest Products Research Society, Madison. WI.nCowling, E. B. 1961. Comparative biochemistry of the decay of sweetgum sapwood by white-rot and brown-rot fungi. Tech. Bull. 1258. U.S. Department of Agriculture, Washington, DC. 79 pp.nEffland, M. J. 1977. Modified procedure to determine acid-insoluble lignin in wood and pulp. Tappi 60(10): 143-144.nGreen III. F., M. J. Larsen. J. E. Winandy. and T. L. Highley. 1991. Role of oxalic acid in incipient brown-rot decay. Mater. Org. 26(3):193-213.nHenningsson, B. 1967. Changes in impact bending strength, weight, and alkali solubility following fungal attack on birch wood. Studia Forestalia Suecica, No. 41. Stockholm. Sweden.nHighley, T. L. 1987. Changes in chemical components of hardwood and softwood by brown-rot fungi. Mater. Org. 22(1):39-45.nKeilich, G., P. Bailey, and W. Liese. 1970. Enzymatic degradation of cellulose, cellulose derivatives, and hemicelluloses in relation to the fungal decay of wood. Wood Sci. Technol. 4:273-283.nKennedy, R. W., and G. Ifju. 1962. Applications of microtensile testing in thin wood sections. Tappi 45(9): 725-733.nKirk, T. K., and T. L. Highley. 1973. Quantitative changes in structural components of conifer woods during decay by white- and brown-rot fungi. Phytopathology 63:1338-1342.nKutscha, N. P., and I. B. Sachs. 1962. Color tests for differentiating heartwood and sapwood in certain softwood tree species. Res. Rep. No. 2246. USDA, Forest Service, Forest Products Laboratory, Madison, WI.nLeVan, S. L., R. J. Ross, and J. E. Winandy. 1990. Effects of fire retardant chemicals on the bending properties of wood at elevated temperatures. Res. Pap. FPL 498. USDA, Forest Service, Forest Products Laboratory, Madison, WI.nMitchell., R. L., R. M. Seborg, and M. A. Millett. 1953. Effect of heat and chemical composition of Douglas-fir wood and its major components. J. Forest Prod. Res. Soc. 3(4):38-42, 72-73.nPettersen, R. C. 1984. Chapter 2: The chemical composition of wood, in R. M. Rowell, ed. The chemistry of solid wood. ACS Advancements in Chemistry Series No. 207. Amer. Chem. Soc., Washington, DC.nPettersen, R. C., and V. H. Schwandt. 1991. Wood sugar analysis by anion chromatography. J. Wood Chem. Technol. 11(4):495-501.nRoss, R. J., and R. F. Pellerin. 1991. Nondestructive testing for assessing wood members in structures: A review. Gen. Tech. Rep. FPL-GTR-70. USDA, Forest Service, Forest Products Laboratory, Madison. WI.nSAS Institute, Inc. 1988. SAS/STAT user's guide, release 6.03 edition. Cary, NC. 1,028 pp.nScheffer, T. C. 1936. Progressive effects of Polyporus versicolor on the physical and chemical properties of red gum sapwood. Tech. Bull. No. 527. U.S. Department of Agriculture, Washington, DC.nScheffer, T. C., and E. B. Cowling. 1966. Natural resistance of wood to microbial deterioration. Ann. Rev. Phytopathol. 4:147-170.nSjostrom, E. 1981. Wood chemistry: Fundamentals and applications. Academic Press. NY. 223 pp.nSmith, S. M., J. J. Morrell, and C. Sexton. 1992. Residual strength of Douglas-fir sapwood and heartwood as affected by fungus colony size and number of colony forming units. Forest Prod. J. 42(4):19-24.nTAPPI. 1988. One percent sodium hydroxide solubility of wood and pulp. Standard T-212 om-83, in Annual book of TAPPI standards, Technical Association of the Pulp and Paper Industry, Atlanta, GA.nU.S. Department of Agriculture. 1987. Wood handbook—Wood as an engineering material. Agricultural Handbook 72. Washington, DC.nWilcox, W. W. 1978. Review of literature on the effects of early stages of decay on wood strength. Wood Fiber 9(4):252-257.nZabel, R. A., F. F. Lombard, and A. M. Kenderes. 1980. Fungi associated with decay in treated Douglas-fir transmission poles in the Northeastern United States. Forest Prod. J. 30(4):51-56.nZabel, R. A., F. F. Lombard, and A. M. Kenderes. 1985. Fungi associated with decay in treated southern pine utility poles in the Eastern United States. Wood Fiber Sci. 17(1):75-91.n
Downloads
Published
Issue
Section
License
The copyright of an article published in Wood and Fiber Science is transferred to the Society of Wood Science and Technology (for U. S. Government employees: to the extent transferable), effective if and when the article is accepted for publication. This transfer grants the Society of Wood Science and Technology permission to republish all or any part of the article in any form, e.g., reprints for sale, microfiche, proceedings, etc. However, the authors reserve the following as set forth in the Copyright Law:
1. All proprietary rights other than copyright, such as patent rights.
2. The right to grant or refuse permission to third parties to republish all or part of the article or translations thereof. In the case of whole articles, such third parties must obtain Society of Wood Science and Technology written permission as well. However, the Society may grant rights with respect to Journal issues as a whole.
3. The right to use all or part of this article in future works of their own, such as lectures, press releases, reviews, text books, or reprint books.
