Birch decay classes

bepe1l Decay class one boles usually have no decay, fine twigs remaining, and complete bark coverage. The sapwood and heartwood are clear or slightly blue stained. Moss is absent. bepe1c


bepe2l Decay class two boles are slightly decayed with all of the bark present but no fine twigs. The sapwood and heartwood show some signs of decay. bepe2c


bepe3l Decay class three boles are moderately decayed with almost all of the bark present but only stubs of branches remaining. Where the bark is gone, the decomposition of wood is less apparent. The sapwood and heartwood show strong signs of decay. The bole still can support itself due to presence of outer bark, but breaks easily with the applied force. bepe3c


bepe4l Decay class four boles can no longer support themselves. Frequently, all the bark is still present. The sapwood and heartwood are impossible to distinguish. bepe4c


bepe5l Decay class five boles are detected only by their moss or grass outline on the forest floor. The cross section of the bole is no longer round but elliptical, and the most of the bark is still present. The wood resembles soil alike compound with little discernible structure or sign of rings penetrated by roots. bepe5c


Decay class descriptions after Graham and Cromack, 1982.

Questions? Email Dr. Mark Harmon at
mark.harmon@oregonstate.edu or Dr. Olga Krankina at olga.krankina@orst.edu

Back to the Main Page.

Return to the top of this page.