Forest Pathogens
Last updated on January 30, 2025Forest pathogens include diseases caused by fungi attacking tree foliage or roots. Pathogens are also parasitic seed plants such as dwarf mistletoe that can only survive on a live host tree. Pathogens can result in damaged tree health, reduced growth and tree mortality.
Signs of pathogens
- Unusual swellings on stems
- Spores and fruiting bodies (mushrooms)
- Cankers
- Dead tops
- Yellowing or discoloured foliage
- Yellowing or discoloured foliage
- Crown thinning
- Distress cone crops
- Decay
- Dead or dying leaders or branch tips
Foliar Pathogens
Foliar pathogens can defoliate trees reducing photosynthetic capacity causing growth loss. In some cases they can also damage trees by causing branch and stem deformation.
Root Diseases
Tree root diseases caused by fungal pathogens occur in all forest ecosystems in B.C. Root disease is more economically damaging to forests than losses caused by insects and fire combined.
Dwarf Mistletoe
Dwarf mistletoes are parasitic seed plants that only survive on live hosts. Dwarf mistletoes affect several coniferous tree species in forested ecosystems across North America.