Pathogenicity
The disease is of particular interest to forest managers, as the species is highly pathogenic to a number of commercial softwoods, notably Douglas-fir (Pseudotsuga menziesii), true firs (Abies spp.) and Western Hemlock (Tsuga heterophylla). A commonly prescribed treatment is the clear cutting of an infected stand followed by planting with more resistant species such as Western redcedar (Thuja plicata) or deciduous seedlings.
Pathogenicity is seen to differ among trees of varying age and location. Younger conifer trees at age 10 and below are more susceptible to infection leading to mortality, with an increased chance of survival against the fungus where mortality can become rare by age 20. While mortality among older conifers is less likely to occur, this does happen, however, in forests with dryer climates.
The pathogenicity of Armillaria solidipes appears to be more common in interior stands, but its virulence is seen to be greater in coastal conifers. Although conifers along the coastal regions show a lower rate of mortality against the root disease, infections can be much worse. While the differences for how infections occur between these two regions, pathogenicity is attributed to rhizomorph production.
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