A photo guide to the patterns of discoloration and decay in living northern hardwood trees

Abstract

This guide has been prepared to help you estimate the extent and severity of discoloration and decay in northern hardwood trees. Though this certainly is not the last word on the subject, our research in this has progressed to the point where our findings, combined with the findings of others, can be put to practical use. By dissecting living trees and studying the organisms that infect them, we now know that discoloration and decay develop in certain definite patterns. And the patterns of discoloration and decay within the tree can be predicted from external signs. Discoloration and decay are the most serious defects of northern hardwood trees. In speaking of defect, we must distinguish between injury and damage. Injury harms the tree: damage lowers the quality of the wood.

Citation

Shigo, Alex L.; Larson, Edwin vH. 1969. A photo guide to the patterns of discoloration and decay in living northern hardwood trees. Res. Pap. NE-127. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 100 p.