1. Prescribed Burning What is prescribed burning?
Why do we used prescribed burning?
What are the effects of prescribed burning?
What influences fire behavior?
What are the different firing techniques?
How do we contain a prescribed burn?
What is a burn plan?
How is a burn permit obtained?

2. Prescribed Burning What is Prescribed (Controlled) Burning?
Controlled application of fire
Vegetative fuels
Specified environmental conditions
Following precautionary measures
Appropriate intensity & rate of spread
Meet habitat management objectives
Credit: forestryimages.org

3. Prescribed Burning History of Prescribed Burning Wildfires
High lightning
Southeast: natural peak in June-July
Large areas
Used by Native Americans & Early settlers
Mimic natural fires & manage land
A custom is established

4. Prescribed Burning History of Prescribed Burning
Credit: Flickr.com
History of Prescribed Burning
Fire suppression movement began in the late 1890s
Fire destroys!
Gifford Pinchot - USFS
Industrial logging & fires
Fire control the principal duty of US Forest Service
USFS experiments with light burning in 1910
It was destructive
Smokey the Bear introduced mid-1940s
Fires are bad

5. Prescribed Burning History of Prescribed Burning
Prescribed burning banned for 50 years
Changes in forest structure & composition
Longleaf ecosystems of the SE
Prescribed burning reintroduced in the 1970s
Credit: prairiefriends.org

6. Prescribed Burning History of Prescribed Burning
Most state & federal agencies & private
3.2 million ha (8 million ac) of land burned annually in the South
Fuel reduction
Wildlife & range management
Ecosystem restoration
Challenges

7. Prescribed Burning Why Use Prescribed Burning? Wildlife managers
Set back succession – mimic natural processes
Favor understory & ground cover
Early successional species
Mast & herbage production
SE: many game and T&E wildlife species
(Encyclopedia Britannica 2008)

8. Prescribed Burning Why Use Prescribed Burning? Reduce hazardous fuels
Reduce heavy roughs (>5-6 yrs fire suppression)
Prepare site for seeding & planting
Manage competing vegetation
Hardwood (e.g., oaks) & shrub (e.g., saw palmetto) control
Exotics
Credit: forestryimages.org
Credit: forestryimages.org
Credit: forestryimages.org

9. Prescribed Burning Why Use Prescribed Burning?
Control insects & disease
White pine cone beetle (burn cones on ground)
Improve forage quality & quantity
Calcium, phosphorous, & protein
Wiregrass
Enhance appearance & improve access
Perpetuate fire-dependent species (e.g., orchids)
Credit: landscapeonline.com
Credit: dnr.state.oh.us

10. Prescribed Burning Effects of Prescribed Burning Vegetation
Dependent on
Plant physiology
Fire intensity
Topography
Season of burning
Frequency of burning

11. Prescribed Burning Effects of Prescribed Burning Vegetation
High temperatures
Directly damage via combustion
Indirectly disrupt physiological processes via radiant heating
Mortality dependent on exposure to lethal temps
Short exposure to high temps
Long exposure to lower temps

12. Prescribed Burning Effects of Prescribed Burning Vegetation
Mortality influenced by
Growth stage- meristem tissue & cambium killed
Pre-fire conditions/stressors- drought, flood
Post-fire stressors- herbivores, pests, & disease
Credit: about.com

13. Prescribed Burning Effects of Prescribed Burning Vegetation
Fire-adapted traits
Growing points, cambium, & propagules protected or removed from exposure
Ponderosa & longleaf pines (thick bark/protection)
Death but fire activated seed banks
Credit: cdu.edu.au

14. Prescribed Burning
(FWS 2008)

15. Prescribed Burning Effects of Prescribed Burning Vegetation
After fire plant community includes
Plants that survived fire intact
Sprouts or suckers from top-killed plants
Plants that established from seed
Credit: inhs.uiuc.edu

16. Prescribed Burning Effects of Prescribed Burning
Vegetation – sometimes difficult to predict
Change plant community composition
Set back succession
Alter plant community structure
Consuming dead & living plants, litter, CWD, etc.
Openings & bare ground
Change vegetation patterns
Often more diverse

17. Prescribed Burning Effects of Prescribed Burning Wildlife
Direct mortality – typically little
Limited mobility
Nests, nestlings, & juveniles
Flee
Seek refuge
Credit: arkive.org

18. Prescribed Burning Effects of Prescribed Burning Wildlife
Immediate response determined by
Season
Intensity
Rate of spread
Uniformity
Size

19. Prescribed Burning Effects of Prescribed Burning Wildlife
Long-term effects on habitat > than on animals
Food & cover
Survival & reproduction
Movements
Temporary
Attraction to burns

20. Prescribed Burning Effects of Prescribed Burning Water
Potential for increased runoff & erosion
Soil particles
Nutrients

21. Prescribed Burning Effects of Prescribed Burning Air
Smoke (depends on type of fire & atmospheric conditions)
Particulates (ash particles, partly consumed fuel, liquid droplets)
Visibility issues
Effects on human health & welfare
Credit: forestryimages.org
Credit: forestryimages.org

22. Prescribed Burning Fire (Combustion) Triangle
How we burn: requirements for fire

23. Prescribed Burning We need to understand: Fire Behavior
How hot
How fast (residence time)
How continuous or patchy
How high (scorch height)
Completeness of combustion
Other characteristics
Affects habitat & wildlife
Credit: fws.gov

24. Prescribed Burning Fire Behavior affected by
Fuel load
Weather
- Temperature Relative Humidity
- Precipitation Wind
- Atmospheric dispersion
Chemical factors
Topography

25. Prescribed Burning Fire Behavior Fuel load
Total dry weight of fuel/unit of surface area
Potential (total) v. Available (actually consumed)
Out of reach, high moisture content, etc.
Difficult to separate
Credit: pwrc.usgs.gov

26. Prescribed Burning Fire Behavior Fuel load affects
Fire spread & intensity influenced by
Species of fuel
Size
Arrangement
Moisture content

27. Prescribed Burning Fire Behavior Fuel load Determines
Likelihood of ignition – is there enough fuel
Maximum energy available to fire (intensity)
Fire continuity (spread)
Low fuel load needs
Higher temp and wind
Lower humidity
How long since last fire
Productivity of site
(Whelan 1995)

28. Prescribed Burning Fire Behavior Weather – we need to know
Key to successful burning
Control
Smoke management
Forecast for day of burn & following night
Sources of weather information
National Weather Service
State Forestry Agencies
Local Observations
Private Weather Forecasting Services

29. Prescribed Burning Fire Behavior Weather- temperature
>20 C (>68 F)
Higher temps- generally drier fuel = greater intensity
Higher/total fuel consumption
Need greater control
<30-32 C (<85-90 F)

30. Prescribed Burning Fire Behavior Weather- relative humidity
Moisture & temperature effects
20 F increase = ½ reduction in rel. humidity (and other way)
Often in morning (and afternoon)
After cold front its cooler & drier (optimum burning)
Preferably 30-55%
<30%
Very high intensity
Increased risk of spotting
>55%
Patchy burn

31. Prescribed Burning Fire Behavior Weather- precipitation Soil Moisture*
Damp soils protect roots & microorganisms
Retain some organic material
Cease burning during drought
Several days of good burning
cm (¼-½ in) rain
Brisk wind
Sunny skies
Low humidity

32. Prescribed Burning Fire Behavior Weather- precipitation
Fine fuel moisture- upper litter
10-20% ideal
<6-7% damage
>30% poor burn
20-25% with heavy fuel build up
Rough estimate with needle bending

33. Prescribed Burning Fire Behavior Weather- precipitation
Fine fuel moisture- lower litter
Must be damp – typically greater than upper layer
Dew & light precipitation problems
Ignition of organic soil
More smoke with moist fuels
Credit: blogspot.com

34. Prescribed Burning Fire Behavior Weather- wind
Generally increases through early afternoon
Fire-weather forecasts are max. not mean
Eye-level: kph (1-4 mph)
6.1 m (20 ft): kph (6-20 mph)
Higher wind speeds steadier in direction
Potentially risky to burn on calm days
Fires more predictable with steady wind speed & direction
(Often in winter; following for a few days after cold front; then winds often turn easterly which is undesirable)

35. Prescribed Burning Fire Behavior Weather- wind
High winds dissipate heat of backing fires
Less crown scorch
Heading fires need low-medium winds
Preheating
Eye level: kph (1-2 mph)
6.1 m (20 ft): kph (6-14 mph)

36. Prescribed Burning Fire Behavior Weather- atmospheric dispersion
Determined by height of mixing layer
Stability- slightly unstable or neutral
Greater instability lowers mixing height
Mixing height- >518 m (>1700 ft)
Transport wind speed kph (9-20 mph)
Credit: forestry images.org
Credit: forestry images.org

37. Prescribed Burning Fire Behavior Chemical factors Oils & resins
Increase burn intensity
Mineral elements (e.g., P, S)
Decrease burn intensity

38. Prescribed Burning Fire Behavior Topography- slope Downhill- slow
Uphill- fast
(Whelan 1995)

39. Prescribed Burning Firing Techniques
Ignition & movement (not method of ignition)
Technique chosen appropriate
Burning objectives
Fuels
Topography
Weather conditions
Credit: firecenter.umt.edu

40. Prescribed Burning Firing Techniques Backing fire Heading fire
Flanking fire (right angles)
Spot fire
Credit: fl-dof.com

41. Prescribed Burning Firing Techniques Backing fire Against the wind
Baseline/anchor point
Often safest
Beginners
Fire hazards

42. Prescribed Burning Firing Techniques Backing fire
Produces minimal crown scorch
Used in heavy fuels & young stands
Wind speed little effect on rate of spread
Moves at m/hr; used on smaller areas
Often used to establish base control line
Credit: fs.fed.us

43. Prescribed Burning Firing Techniques Heading fire With the wind
(Whelan 1995)

44. Prescribed Burning Firing Techniques Heading fire
Used in most fuel types (not heavy)
Light & discontinuous
Low wind speed required (Eye-level: 1-2 mph)
Burns with high humidity & fuel moisture
Care needed
Quick spread
Taller flame/scorch
Pre-heating

45. Prescribed Burning Firing Techniques Flanking fire
Line of fire set into the wind

46. Prescribed Burning Firing Techniques Flanking fire
Used to burn small areas
Alternative to head fire
Light to medium fuels needed
Requires constant wind direction
Intermediate to back & head fires

47. Prescribed Burning Firing Techniques Spot fire
Series of fires set at predetermined spacing
Optimal spacing

48. Prescribed Burning Firing Techniques Spot fire
Used with uniform light to medium fuels
Variable winds acceptable
Burns with low temp & high fuel moisture

49. Prescribed Burning Firing Techniques Perimeter fire Chevron fire
Care needed: intense fires & spotting
Chevron fire
In hilly areas; lines along ridges
(Payne 1992)

50. Prescribed Burning Fire Containment Firebreaks
Fire roads, fire lines, fuel breaks
Keep fire contained to designated area
Gap in Vegetation
Barrier to progress of fire

51. Prescribed Burning Fire Containment Types of firebreak Natural*
River
Lake
Canyon
Nonflammable vegetation (e.g., oak hammock)
Man-made
Roads
Trails
Cultivated soils
Soil strips
Credit: about.com

52. Prescribed Burning Fire Containment Width of firebreaks Fuel dependent
Two parallel strips m apart
Low fuel load: 2-3 m wide strips
High fuel load: >5 m wide strips
>1 month before fire
Florida: single strip 2-5 m wide
Credit: totalearthworks.co.au

53. Prescribed Burning Personnel & Equipment Number of people required
Size of area to be burned
Fuel, weather, & topography
Experience level of burn crew
Usually 6-12 people
Credit: audubon.org

54. Prescribed Burning Personnel & Equipment Two-way radios
Ignition devices & fuel
Fire suppression equipment
Weather kit
Fence cutters
Credit: daylife.com

55. Prescribed Burning Ignition Devices Drip torch
Flame thrower (terra torch)
Helitorch
Flare pistols
Pyroshot Hand Launcher
Electrical ignition (e.g., primacord)
Fuses
Delayed Aerial Ignition Devices
Balls of potassium permanganate & ethylene glycol
Credit: pc.gc.ca
Credit: mdconsult.com

56. Prescribed Burning Ignition Devices Fuel mixture (e.g., drip torch)
3 to 1 - diesel to gas
More gas to increase volatility
More diesel to increase adhesion, burn time, & heat
FWC: 2:1
Credit: pc.gc.ca

57. Prescribed Burning Burn Plan Geographic location
Sources of emergency assistance
Description of the prescribed burn unit area
Vegetation, fuel, etc.
Goals & objectives
Fuel & weather prescription
Desired fire behavior to meet objectives

58. Prescribed Burning Burn Plan Smoke management Crew Equipment
Day of burn operations
Contingency plan
Safety & medical information
Post-burn activities
Credit: daylife.com

59. Prescribed Burning Burn Permit In FL must be obtained before burning
FL Forest Service (Division of Forestry)
For uncertified & certified burns
Adequate firebreaks around burn area
Sufficient staff & firefighting equipment
Burn remains within authorized area
Have someone present until fire extinguished
No spreading flame

60. Prescribed Burning Burn Permit For certified burn
A written burn plan to FLFS
Certified burner on site with plan
Liability

61. Prescribed Burning Prescribed Burning Effects
Influences on fire behavior
Firing techniques
Fire containment
Burn plans
Burn permits