Basidiomycete Wood Decay Life Cycle
Host Infection
Spore germination and
infection of wounds.
Fruiting and
Spore Release
Spores are produced on a
structure known as a basidium.**
Spores are aerially dispersed.
Root Contact
Initial Wood
Invasion
Spread can also occur by root contact
rhizomorphs (Armillaria only).*
or by certain decay fungi or *Photo by the
USDA Forest Service
Host Reaction to Invasion
The arrow shows a
fungal hyphae within a
cell. Fungi use enzymes
to digest wood.**
Decay Progression
Over time decay progression
continues vertically and
radially. Internal and
external cavities may form.
**Photos courtesy of Dr. Bob
Blanchette, University of
Minnesota, with permission
Discoloration and decay of wood – host reaction to decay
spread by compartmentalization of decay (CODIT). The arrow
shows CODIT wall 4, the strongest and most important wall.
Information and photographs provided based on Visual Identification Series, Wood Fungi Decay Common To Urban Living Trees In The Northeast and
Central United States, Copyright © 2005 by Christopher J. Luley, Ph.D., Urban Forestry LLC • www.urbanforestryllc.com