Disturbance patterns in the sub-boreal spruce forests of central British Columbia (Canada) have long been thought to result from frequent stand-initiating fires. However, recent evidence suggests that fires in the wetter areas of this region are infrequent (intervals of >500 yr) and the uneven-aged stand structures have been shown to be self-maintaining in the absence of fire. The importance of decay fungi as agents of gap-formation and facilitators of uneven-aged stand structure was investigated. Three plots in each of 2 recently clear felled sites were established. Each stump in the plots was stem mapped and the species and diameter recorded. Decay at the stump top was recorded as white or brown rot, and the area occupied by decay was measured. Spruce (Picea glauca x Picea engelmannii) stumps dominated the larger diameter classes but had less butt rot than subalpine fir (Abies lasiocarpa) stumps. Decay fungi contribute to stem breakage in living trees with heart rot, and as sap rots of dead trees. Therefore, the results suggest that decay fungi play an important role in removing subalpine fir trees from the canopy of these wetter sub-boreal ecosystems, and in enabling spruce recruitment. The type of decay observed in subalpine fir suggests that breakage is predominantly due to white rot fungi causing heart rot, such as Echinodontium tinctorium and Stereum sanguinolentum. In spruce, brown rot fungi, which are predominantly sap rot or wound-entry decay fungi, became more common in larger spruce, and may result from wounding as subalpine firs fall from the canopy. Spatial analysis indicated the stumps with stem decay were clumped. However, this is more likely to be due to strong clumping of the host, rather than to spreading of butt rot pathogens through the roots.