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  1. FIRE & THE FOREST Forestry Revision Team May 2007

  2. The Fire Triangle • To produce fire, three things must be present at the same time- FUEL HEAT OXYGEN

  3. The Fire Triangle The fire triangle is like a three-legged stool. If you remove one leg, the fire goes out. heat fuel oxygen

  4. How is the triangle broken? • Some of the ways used to break the fire triangle are: • fire rake • fire flap or pine top • backpack water pump • tractor with a fire plow • backfire torch • airplane water bomb • prescribed burning

  5. What is fire behavior? When we talk about fire behavior, we are thinking in terms of the intensity of the fire itself, and the rate of spread or speed of the fire.

  6. What determines fire behavior? • Fire behavior is affected by a wide range of conditions. • Three important factors: • Time of occurrence of the fire season • air movements • topography (slope of the land, presence of roads, fields, streams, etc.)

  7. TERMS Wildfire the uncontrolled burning of fire Incendiary the unlawful & intentional setting of fire Debris burning burning of trash Prevention any action associated with stopping a wildfire before it is started

  8. 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.

  9. 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

  10. Buildup index a rating of the cumulative effect of drying since a rain of 1/10” or more; indicative of the intensity with which a fire can burn. Scale 1-100 Spread index a relative rating of the forward movement of a fire; rated on a scale of 1-100

  11. 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

  12. 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

  13. 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

  14. 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

  15. Effects of Wildfires • Destroy or reduce value of standing timber • Destroy young seedlings 3. Reduce the growth rate 4. Reduce the water holding capacity of watershed & cause erosion

  16. Pollute local streams & ponds • Kill or injure wildlife as well as the habitat • Encourage insects & disease in the stand • Can effect local & state economy

  17. Causes of Wildfires 65% of fires caused by: 40% escaped debris burning fires 25% woods arson Average size wildfire in the Southeast is 19 acres per fire Ga. Average wildfire is 4.7 acres

  18. Requirements for a Fire • Fuel-wood or other plant material • Oxygen-air is the main supply • Heat Source-sparks, lightning, cigarettes A fire is like a 3-legged stool, remove one leg & the fire goes out

  19. Types of Forest Fires Ground 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

  20. Georgia Forestry Fire Laws Criminal Damage to property in the first degree • Knowingly & without authority interferes with any property in a manner so as to endanger human life • Punishment of not less than 1 or more than 10 years

  21. Criminal Damage to property in the second degree • Intentionally damages any property of another person without his consent & the damage exceeds $100 • Punishment of imprisonment of not less than 1 or more than 5 years

  22. Criminal Trespass • Intentionally damaging property of another without his consent & damage is less than $100 • Punishment is a misdemeanor

  23. Use of fires & ignited objects It shall be unlawful: • Start or cause a fire on any woodland not one’s own or leased without owner’s permission • Burn without taking necessary precautions to prevent the escape of the fire • Cause a fire by discarding any burning object • Destroy or damage any material or device used in detection or suppression of wildfires

  24. Notice of intention to burn Law • County forestry unit must be notified of time & location before setting fire to any combustible materials • Violation is a misdemeanor • Must obtain a permit before burning

  25. Fire Behavior Fire is affected by a wide range of conditions • Air movement-both horizontal & vertical movement of air as well as wind speed • Fire season-for Georgia is fall & spring of the year • Topography-slope of an area affects the rate of a fire, generally the steeper the slope the faster the fire

  26. Weather conditions that reduce the rate of spread • Rain on the fire • Wind reversal • Increases in relative humidity

  27. Types of fuels The 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

  28. Fire Control Divided into 3 main headings • Prevention things done to prevent a fire from happening • Presuppression things done to be prepared when a fire does occur • Suppression things done to stop a fire once it has begun

  29. Prevention The most effective & least expensive method of control Prevention Measures include: Clear all fuel back several feet from trash, camp or warming fires Never leave fires unattended Have suppression tools & methods available Keep fires small

  30. 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

  31. Pre-suppression: Preparations made before a fire starts to more effectively control it. Methods • Be familiar with the property & the best way to get equipment to each area under all conditions • Locate firebreaks & keep them maintained

  32. 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;

  33. Suppression: action necessary to extinguish a fire after it has started. Basic jobs of fire suppression: • Rob the fire of fuel • Reduce the fire’s temperature • Cut off the oxygen from the fire.

  34. Major parts of a Fire Head: 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

  35. Methods of attack in suppressing a fire Direct: 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

  36. Additional control methods Mop-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”

  37. Beneficial Uses of Fire • Hazard Reduction-Reducing the forest litter & undergrowth • Hardwood Control-Hardwoods under 2” dbh can be controlled with fire. Summer burns give the best results

  38. Site Preparation-the most economical tool to provide conditions for re-establishment of forests. Reduces competition & provides suitable seedbed. • Wildlife Habitat-Reduces predator cover, exposes hidden seeds & produces fresh low browse for wildlife.

  39. 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.

  40. Improved Accessibility-Improves accessibility & visibility for marking & cruising timber. Also helps for harvesting operations. Can improve recreational & aesthetic values.

  41. Prescribed (Prescription) Burning The controlled use of fire in the forest to accomplish specific purposes • Most economical tool used for cleaning operations in young pine stands

  42. Can be used for less than $3 per acre. • Should only be done by persons trained in its use.

  43. Conditions to consider prior to prescribed burning • Relative humidity • Temperature • Wind, velocity & direction • Fuel moisture

  44. Fuel Conditions Refer to the amount & arrangement of the fuel, along with the desired intensity of the fire. A continuous litter of needles or grass is usually needed

  45. On well-stocked pine sites, fuels reach critical levels in about 5 years. Low growing shrubs with pine straw can cause a level of aerial fuels which can create a great level of heat & should be considered when burning

  46. Weather Factors Temperature—20 to 60 degrees is the ideal range for winter burning; Hardwood control or site prep is often best accomplished in the summer with temperatures of 80 degrees or above.

  47. Wind—Steady at 2-10 mph northerly is best. Steady wind direction & speed are vital for good burning. Relative Humidity—30to 50% is the best range. A 20 degree rise in temperature can reduce the RH by half.

  48. Rainfall—one half to one inch, one week before burning is recommended. For most prescribed burns the upper litter layer should be dry to the touch.

  49. Season of the Year Winter burns—offer the advantage of less stand damage, more predictable weather & steady winds Summer burns—offer hotter fires to burn more of the rough for seed bed & site preparation

  50. Time of Day Day time fires offer better weather conditions. Burns should start about 10 a.m. & stopped so to burn out by night. Night fires have problems with light winds & higher humidity