Neil Sugihara
Regional Fire Ecologist
US Forest Service
Pacific Southwest Region
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Mountain Pine Beetle
White pine blister rust
Fire exclusion
Climate change
Is fire and important ecological
process in Whitebark pine
ecosystems?
Is fire and important ecological
process in Whitebark pine
ecosystems?
 Mature stands on relatively productive sites can be
gradually replaced by subalpine fire and other shade
tolerant trees if fire is excluded.
 Absence of fire has resulted in conversion of some stands
from whitebark pine to other subalpine forest types
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Life History
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Seed dispersal (Clark’s Nutcrackers) is
effective
Trees produce seed only after several decades
of age (36+)
Individual trees are very long lived – several
centuries
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1) A fire dependent, early seral or minor climax
associate in drier forest habitats.
2) A persistent seral or minor climax associate
in drier forest habitats
3) a major climax species or the only tree under
still drier or more wind exposed conditions
4) a major component or sole dominant of
krummholz communities above tree line
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Surface fires –
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Mixed severity fire –
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non-lethal
sparse fuel load
60-300 year Fire Return Interval
Intensity and severity vary with changing conditions
Stand replacement fire
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250+ year Fire Return Interval
Stand replacing
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Seasonality – short summer season
Fire Return Interval – very long (200+ years)
Fire size – small, fuel discontinuous
Spatial complexity – low, simple mosaic
Fire intensity - uniformly low, little heat
produced
Fire severity – low, mixed, or high
Fire type surface or mixed