- Declines
- Characteristics
- large area affected
- affects the mature trees
- often only ONE spp. (sometimes several)
- slow to develop (10+ yrs)
- "generic symptoms", hard to diagnose
- reduced growth
- dieback of crown (& roots)
- scattered mortality ... over time
- Stages
- predisposing ("prolonged")
- long term stress (drought, pollution)
- reduces energy stores
- reduced resilience
- inciting ("event")
- short term sig. stress factor
- e.g. defoliation, frost
- not able to recover, insufficient reserves
- contributing ("last straw")
- often a minor pathogen
- little no defences left
- often gets "credit"
- White Pine
- Yellow Cedar
- Sugar Maple
- Lotsa others
