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Silvicultural Use of Prescribed Fire. FOR 406. Harvest. Regenerate. The Silvicultural Cycle. Tend. Prescribed burning is. Fire. Applied in a skillful manner At a definite location & time Under pre-defined weather conditions To achieve specific management objectives.
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Silvicultural Use of Prescribed Fire FOR 406
Harvest Regenerate The Silvicultural Cycle Tend
Prescribed burning is... Fire • Applied in a skillful manner • At a definite location & time • Under pre-defined weather conditions • To achieve specific management objectives Anything else is a Wildfire
Pines Western larch Douglas-fir Giant sequoia
Oaks Eucalyptus
“Fire and life, in brief, form a necessary kind of symbiosis.” Stephen Pyne
Frontal Fire Intensity I (kW m-1) = 2.598 L2.174 I (kW m-1) = 300 L2
WIND Average flame length
~1.0 m I = 300 kW m-1 ~0.5 m I = 58 kW m-1 Low Intensity
~0.5 m I = 75 kW m-1 Low Intensity
~91 m I = 2,484,300 kW m-1 High Intensity High Intensity High Intensity High Intensity
Why use prescribed fire? • Reduces hazardous fuels
Why use prescribed fire? • Controls woody understory
Why use prescribed fire? • Controls woody understory
Why use prescribed fire? • Stimulates natural regeneration & increases diversity of ground flora
Why use prescribed fire? • Improves wildlife habitat & livestock forage
Why use prescribed fire? • Controls certain insects & diseases
Why use prescribed fire? • Recycles nutrient cations (Ca, Mg, P, K) & stimulates N fixation
Why use prescribed fire? • Restores a natural (pre-European settle-ment) ecological process
Why use prescribed fire? • Enhances aesthetics & improves access
Why use prescribed fire? • Watch it burn!
Weather • Fuel moisture • Fire behavior
Weather Good forecastsare essential!
Weather for prescribed fire • Wind • Speed & direction steady • 5 mph or less in the stand • Direction more important than speed • Interacts with topography
Weather for prescribed fire • Wind • Speed & direction steady • 5 mph or less in the stand • Direction more important than speed • Interacts with topography
Weather for prescribed fire • Relative humidity • 25 to 40% RH M N M
Weather for prescribed fire • Temperature • <90o F (35o C) • Lethal temperature for plant tissue ~145o F • High temperature dry fuels quickly