fire & the forest

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.