Arborists are encouraged to recognize the wood-decay process as an important factor in tree health and public safety. Technical experts who develop training materials to recognize wood-decay processes in living trees are frequently forest pathologists. Much of the history of forest pathology was to support production of sound, high-quality timber. That heritage is passed on in terms used by arborists today that are derived from timber production, such as "defect" and "degrade." These terms are used for genuinely adverse conditions such as cracks and seams. Unfortunately, the terms are also sometimes applied to positive features that contribute to tree recovery and stability, such as response growth and woundwood formation. Mushrooms and other fungal fruiting bodies are signs of infection. However, such infections are not necessarily the enemy of healthy and safe landscapes.
Smith, Kevin T.; Glaeser, Jessie A. 2017. Wood decay and the cleanup crew. Tree Care Industry. 28 (6): 54-59.