Permeability of Douglas-Fir Heartwood from Western Washington

Essentially constant rate of longitudinal flow of water was obtained with fresh unseasoned samples of heartwood, or on fresh samples that had been frozen. With the few samples of heartwood tried, decreasing flow rather than a constant rate was attained, but the sampling was too limited to conclude that all seasoned heartwood will not permit constant rate of flow. Based on average rates of flow for 47 trees, the tangential, radial, and longitudinal permeabilities of unseasoned Douglas-fir heartwood to water at 80 psi for two thicknesses were in the ratio of 1, 14, and 63, respectively. Longitudinal permeability of the trees from the high-elevation area, west of the Cascade ridge, was generally less than that from trees from several other areas. There was evidence that the higher percentages of summerwood in a section were associated with a higher rate of flow.

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