Crawford, Ralph H.; Carpenter, Steven E.; Harmon, Mark E. 1990. Communities of filamentous fungi and yeast in decomposing logs of Pseudotsuga menziesii. Mycologia. 82(6): 759-765.
Concentrations of extractable total phenols and tannins have been analyzed in the outer bark, inner bark, sapwood,and heart wood from logs of four conifer species, after 1 year on the ground. To estimate decay rates, initial tissuedensities were compared with those after 1 and 2 years of decomposition. The four species studied, Pacific silver fir(Abies amabilis Dougl. ex Forbs), western hemlock ( Tsuga heterophylla (Raf.) Sarg.), Douglas-fir (Pseudotsuga menziesii(Mirb.) Franco), and western red cedar ( Thuja plicata D. Don) represent a gradient of decay resistance. Within a species,outer bark contained the greatest quantities of extractable total phenols followed by inner bark, heart wood, and sap-wood. Outer barks also had the highest extractable tannin concentrations. Woody tissues contained very low concen-trations of tannin compared with the barks. Total phenol concentrations were highest in the heart wood of red cedar,the most resistant, and lowest in the heart wood of silver fir, the least resistant. There was no obvious relationshipbetween tannins, in any tissues, and the resistance gradient. Density measurements indicated minimal decay in all tissuesafter 1 year. At 2 years, the inner barks of Douglas-fir, western hemlock, and silver fir had decreased significantly.In general, tissues with the highest extractable phenols appear to be decomposing most slow ly.