Characterization of Wetwood From Four Balsam Fir Trees


  • M. H. Schneider
  • Lei Zhou


Abies balsamifera, air permeability, anatomy, balsam fir, extractive content, moisture content, ultrastructure, wetwood


Balsam fir wetwood had lower longitudinal permeability to both water and air than sapwood, but higher than heartwood. Based upon the average initial flow rate of water in sapwood, wetwood, and heartwood, a ratio of 45:6:2 was calculated. The ratio of average air permeability of sapwood to wetwood to heartwood was 50:9:1 calculated at an average mean pressure of 0.5 atmosphere (38 cm Hg). The low permeability of wetwood and heartwood results from pit aspiration and incrustation of bordered-pit membranes. Scanning electron microscopy suggested that deposits on wetwood-bordered pit membranes facilitated greater flow through wetwood than heartwood. Sapwood and wetwood moisture contents were comparable and were higher than heartwood. Extractive content values of green wetwood were between those for sapwood and heartwood.


Arganbright, D. G., and W. W. Wilcox. 1969. Comparison of parameters for predicting permeability of white fir. Proc. Am. Wood-Preserv. Assoc. 65:57-62.nBailey, P. J., and R. D. Preston. 1970. Some aspects of softwood permeability. II. Flow of polar and non-polar liquids through sapwood and heartwood of Douglas fir. Holzforschung 24(2):37-45.nComstock, G. L. 1967. Longitudinal permeability of wood to gasses and non-swelling liquids. For. Prod. J. 17(10):41-46.nDokken, M., and R. Lefebvre. 1973. Drying veneer peeled from seven New Brunswick balsam fir logs. Can. Dep. Environ. Inf. Rep. OP-X-60. 20 pp. Ottawa.nKnutson, D. M. 1973. Bacteria in trembling aspen (Populus tremuloides (Michx.). Ph.D. dissertation, University of Minnesota, St. Paul. 152 pp.nLagerberg, T. 1935. Barrtgradens Vattved. (Wetwood in conifers.) Sven. Skogsvardsforeningens Tidskr. 33(3):177-264.nLin, R. T., E. P. Lancaster, and R. L. Krahmer. 1973. Longitudinal water permeability of western hemlock. Wood Fiber 4(4):278-289.nSachs, I. B., J. C. Ward, and R. E. Kinney. 1974. Scanning electron microscopy of bacterial wetwood and normal heartwood in poplar trees. Pages 453-459 in Proc. Workshop Scanning Electron Microsc. Plant Sci., I.I.T. Res. Inst., Chicago.nSchlink, C. G. R. 1967. Pit structure in sapwood and heartwood of white fir [Abies concolor, (Gord. and Glend.) Lindl.]. M.Sc. thesis, University of California, Berkeley. 54 pp.nSchroeder, H. A., and C. J. Kozlik. 1972. The characterization of wetwood in western hemlock. Wood Sci. Technol. 6:85-94.nSiau, J. F. 1984. Transport processes in wood. Springer-Verlag, Berlin. 245 pp.nWard, J. C. 1986. The effect of wetwood on lumber drying times and rates: an explorative evaluation with longitudinal gas permeability. Wood Fiber Sci. 18(2):288-307.nWilcox, W. W., and C. G. R. Schlink. 1971. Absorptivity and pit structure as related to wetwood in white fur. Wood Fiber 2(4):373-379.n






Research Contributions