fire & the forest
TRANSCRIPT
FIRE & THE FOREST
TERMSWildfire-the uncontrolled burning of
fire
Incendiary-the unlawful & intentional setting of fire
Debris burning-burning of trashPrevention-any action associated
with stopping a wildfire before it is started
Justification: Wildfires in Montana and Idaho …Justification: Wildfires in Montana and Idaho …
Justification: Wildfires in Florida and Georgia …Justification: Wildfires in Florida and Georgia …
Justification: Wildfires in California …Justification: Wildfires in California …
Justification: Wildfires in Arizona …Justification: Wildfires in Arizona …
Justification: Wildfires in Arizona …Justification: Wildfires in Arizona …
Low severity wildfires …Low severity wildfires …
… … versus high severity wildfires.versus high severity wildfires.
Pre-suppression-any action associated with being ready in case a wildfire occurs
Suppression-any action associated with stopping a wildfire
Prescribed burning-the controlled use of fire.
Origin-where a fire starts
Perimeter-the outmost area of the blaze including the head, flank & rear
Relative humidity-the amount of moisture in the air
Alidade-an instrument used in locating fires
Wind velocity—the speed of the wind measured in miles per hour
Psychrometer—an instrument that measures temperature & relative humidity
Heavy fuels—contains a high percentage of thick material such as logs, large limb & tree tops
Medium fuels—contains light materials such as limbs & tree tops less than 4” in diameter
Light fuels—grass, leaves, small limbs & twigs
Duff—forest litter & other organic debris in various stages of decomposition on top of the mineral soil
Ignite—to burn or burst into flames
Mortality—death or destruction of forests due to fires
Fire Season—the period of the year which fires are likely to occur
Mixing height—height the smoke mixes with the wind, should be at least 1500 feet
Transport wind speed—speed of the wind at mixing height, should be at least 9 mph
Effects of Wildfires1. Destroy or reduce value of standing
timber
2. Destroy young seedlings
3. Reduce the growth rate
4. Reduce the water holding capacity of watershed & cause erosion
5. Pollute local streams & ponds
6. Kill or injure wildlife as well as the habitat
7. Encourage insects & disease in the stand
8. Can effect local & state economy
Causes of Wildfires65% of fires caused by:
40% escaped debris burning fires25% woods arson
Average size wildfire in the Southeast is 19 acres per fire
Ga. Average wildfire is 4.7 acres
Requirements for a Fire1. Fuel-wood or other plant material
2. Oxygen-air is the main supply
3. Heat Source-sparks, lightning, cigarettes
A fire is like a 3-legged stool, remove one leg & the fire goes out
Types of Forest FiresGround Fire-fires that burn the organic
materials beneath the surface litter of the forest floor
Surface Fire-fires that burn surface litter of loose debris on the forest floor & small vegetation
Crown Fires-fires that burn from top to top of trees or shrubs
Fire BehaviorFire is affected by a wide range of
conditions1. Air movement-both horizontal &
vertical movement of air as well as wind speed
2. Fire season-for Georgia is fall & spring of the year
3. Topography-slope of an area affects the rate of a fire, generally the steeper the slope the faster the fire
Weather conditions that reduce the rate of spread1. Rain on the fire
2. Wind reversal
3. Increases in relative humidity
Types of fuelsThe two basic fuel types are:
Ground fuels-fuels found on the surface of the soil
Aerial fuels-fuels include all burnable materials located in the canopies above 6 feet from the ground
Fire ControlDivided into 2 main headings1. Prevention-things done to
prevent a fire from happening
2. Suppression-things done to stop a fire once it has begun
PreventionThe most effective & least expensive
method of controlPrevention Measures include:Clear all fuel back several feet from
trash, camp or warming firesNever leave fires unattendedHave suppression tools & methods
availableKeep fires small
Avoid burning during dry spells, windy days or when RH is low
Maintain fire equipment in safe running condition
Extinguish all matches & smokes before discarding
Use prescribed fires to reduce or eliminate fuel
Methods1. Be familiar with the property &
the best way to get equipment to each area under all conditions
2. Locate firebreaks & keep them maintained
Pre-suppression: Preparations made before a fire starts to more effectively control it.
3. Know your neighbors & ask them to report you on any unusual smoke in your area
4. Keep your fire fighting equipment in a handy, known location
5. Know how to contact the County Forest Ranger;
478-934-3124
Suppression: action necessary to extinguish a fire after it has started.
Basic jobs of fire suppression:1. Rob the fire of fuel
2. Reduce the fire’s temperature
3. Cut off the oxygen from the fire.
Major parts of a FireHead: the portion of the fire toward
which the air is moving; the fastest moving part of a fire
Rear: the portion of the fire which air is moving away; slowest part of a fire
Flank: the sides of the fire
Methods of attack in suppressing a fireDirect: fighting the fire at the head
of the flames. Used when the flames are not too intense & moving slowly.
Indirect: Used where heat & rate of spread will not permit a direct attack
Additional control methodsMop-up: making sure that all fire &
smoking material is out or safe inside the fire breaks.
Patrol: Periodic inspections made over the area until the fire is “dead out”
Beneficial Uses of Fire1. Hazard Reduction-Reducing the
forest litter & undergrowth
2. Hardwood Control-Hardwoods under 2” dbh can be controlled with fire. Summer burns give the best results
3. Site Preparation-the most economical tool to provide conditions for re-establishment of forests. Reduces competition & provides suitable seedbed.
4. Wildlife Habitat-Reduces predator cover, exposes hidden seeds & produces fresh low browse for wildlife.
5. Disease control-Only practical method of controlling Brown Spot Needle Blight. Burns away infected needles without killing the well protected bud. Litter reduction seems to reduce the incidence of Annosus Root Rot. No know control for this disease once established.
6. Improved Accessibility-Improves accessibility & visibility for marking & cruising timber. Also helps for harvesting operations. Can improve recreational & aesthetic values.