61
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?

Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Embed Size (px)

Citation preview

Page 1: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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?

Page 2: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 3: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 4: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• 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

Credit: Flickr.com

Page 5: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 6: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 7: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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)

Page 8: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 9: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 10: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Effects of Prescribed Burning– Vegetation

• Dependent on– Plant physiology– Fire intensity– Topography– Season of burning– Frequency of burning

Page 11: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 12: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 13: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 14: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

(FWS 2008)

Page 15: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 16: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 17: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Effects of Prescribed Burning– Wildlife

• Direct mortality – typically little– Limited mobility

» Nests, nestlings, & juveniles

– Flee– Seek refuge

Credit: arkive.org

Page 18: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Effects of Prescribed Burning– Wildlife

• Immediate response determined by– Season– Intensity– Rate of spread – Uniformity– Size

Page 19: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Effects of Prescribed Burning– Wildlife

• Long-term effects on habitat > than on animals– Food & cover– Survival & reproduction– Movements

» Temporary» Attraction to burns

Page 20: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Effects of Prescribed Burning– Water

• Potential for increased runoff & erosion– Soil particles– Nutrients

Page 21: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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.orgCredit: forestryimages.org

Page 22: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Fire (Combustion) Triangle– How we burn: requirements for fire

Page 23: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 24: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Fire Behavior affected by– Fuel load– Weather

- Temperature - Relative Humidity

- Precipitation - Wind

- Atmospheric dispersion

– Chemical factors– Topography

Page 25: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 26: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Fire Behavior– Fuel load affects

• Fire spread & intensity influenced by – Species of fuel– Size– Arrangement– Moisture content

Page 27: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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)

Page 28: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 29: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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)

Page 30: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 31: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

» 0.6-1.3 cm (¼-½ in) rain» Brisk wind» Sunny skies» Low humidity

Page 32: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 33: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 34: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning• Fire Behavior

– Weather- wind• Generally increases through early afternoon

• Fire-weather forecasts are max. not mean

• Eye-level: 1.6-6.4 kph (1-4 mph)

• 6.1 m (20 ft): 9.7-32.2 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)

Page 35: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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: 1.6-3.2 kph (1-2 mph)– 6.1 m (20 ft): 9.7-22.5 kph (6-14 mph)

Page 36: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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- 14.5-32.2 kph (9-20 mph)

Credit: forestry images.orgCredit: forestry images.org

Page 37: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Fire Behavior– Chemical factors

• Oils & resins– Increase burn intensity

• Mineral elements (e.g., P, S)– Decrease burn intensity

Page 38: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Fire Behavior– Topography- slope

• Downhill- slow• Uphill- fast

(Whelan 1995)

Page 39: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Firing Techniques– Ignition & movement (not method of ignition)

– Technique chosen appropriate• Burning objectives• Fuels• Topography• Weather conditions

Credit: firecenter.umt.edu

Page 40: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Firing Techniques– Backing fire– Heading fire– Flanking fire (right angles)– Spot fire

Credit: fl-dof.com

Page 41: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Firing Techniques– Backing fire

• Against the wind• Baseline/anchor point

• Often safest– Beginners– Fire hazards

Page 42: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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 20-60 m/hr; used on smaller areas• Often used to establish base control line

Credit: fs.fed.us

Page 43: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Firing Techniques– Heading fire

• With the wind

(Whelan 1995)

Page 44: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 45: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Firing Techniques– Flanking fire

• Line of fire set into the wind

Page 46: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 47: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Firing Techniques– Spot fire

• Series of fires set at predetermined spacing– Optimal spacing

Page 48: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Firing Techniques– Spot fire

• Used with uniform light to medium fuels• Variable winds acceptable• Burns with low temp & high fuel moisture

Page 49: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Firing Techniques– Perimeter fire

• Care needed: intense fires & spotting

– Chevron fire• In hilly areas; lines along ridges

(Payne 1992)

Page 50: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 51: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 52: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Fire Containment – Width of firebreaks

• Fuel dependent– Two parallel strips 30-90 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

Page 53: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 54: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Personnel & Equipment– Two-way radios– Ignition devices & fuel– Fire suppression equipment– Weather kit– Fence cutters

Credit: daylife.com

Page 55: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 56: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 57: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 58: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Burn Plan– Smoke management – Crew– Equipment – Day of burn operations– Contingency plan– Safety & medical information – Post-burn activities

Credit: daylife.com

Page 59: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

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

Page 60: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Burn Permit– For certified burn

• A written burn plan to FLFS• Certified burner on site with plan

• Liability

Page 61: Prescribed Burning What is prescribed burning? Why do we used prescribed burning? What are the effects of prescribed burning? What influences fire behavior?

Prescribed Burning

• Prescribed Burning– Effects– Influences on fire behavior– Firing techniques– Fire containment– Burn plans– Burn permits