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 (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

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

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

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

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

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)

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

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

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

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

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

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

Prescribed Burning (FWS 2008)

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

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

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

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

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

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

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

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

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

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

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

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

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)

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

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)

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

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

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

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

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)

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)

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.org Credit: forestry images.org

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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