Fuel treatments. Do Fuel Treatments Work? Crown Fire Spread Depends on. Canopy bulk density & rate of spread. Transition to a Crown Fire Depends on:

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1 Do Fuel Treatments Work? Fuel treatments Physical alteration of the e fuelbed to reduce fire hazard and therefore the potential fire intensity Improving firefighting effectiveness Increasing safety for fire fighters and other people and buildings Reducing fire severity Modeling and case studies In 2007, wildfires burned through many fuel treatments Transition to a Crown Fire Depends on: Crown base height Crown moisture content Surface fire intensity (fuel models) Flame lengths, crown moisture, crown base heights ength (ft) Flame Le Canopy Base Height (ft) Crown Fire Spread Depends on Canopy bulk density (weight per unit volume, e.g. pounds per cubic foot) Wind Slope In general, as crown bulk density increases, lower rates of spread are required to sustain the crown fire Canopy bulk density & rate of spread active crown fire (ft/min) Minimum spread rate for Canopy bulk density (lb/cu.ft) 1

2 Key Elements Fuel treatments from site to landscape Canopy base height Surface fuels Crown fuels Fuel moisture Total Canopy height height Uncompacted crown ratio Canopy base height Values & Areas of Interest 70 plus structures Forest Service work camp Campgrounds Lodges Youth camps South Fork Salmon River Warm Lake Hazardous Fuel Reduction Warm Lake South Mechanical HF (2000) Past wildfire Reeves Cr. Underburn (1998) Paradise Valley Structure Protection Project (2005) Church Camp HF Chipmunk Cr. HF Reduction Project (2004) Underburn (1997) Warm Lake Hwy. Mulch Project (2004) Kline Mtn. HF Underburn (2006) Warm Lake North Warm Lake Cr. HF HF Project Warm Lake East Underburn (1996) Mechanical HF (2005) Past wildfire Equally spaced trees North Fork and Monumental Wildfires Fire Progression, August 2009 Fuel Treatment/ Suppression Interactions Mechanical Burn-out August 12 August 12 August 13 Orange is the fire progression for day August 17 2

3 Fuel Treatments, Suppression/ Wildfire Interactions Kenny Point Mechanical Burn-out August 12 Wildfire August 13 Spot fire suppression Wildfire Short-term Success Provided suppression opportunities Crown fire changed to a surface fire No houses burned No one was hurt Needed suppression and other infrastructure in addition to fuel treatments Fuel Treatments Alone Did Not Stop the Fire Treatments Burnout Long-term Effects Will treated areas function like a forest? Limited wildlife elements No woody debris Trees were equally spaced Surface vegetation was homogeneous Unpublished data Hudak et al acres burned near Lake Tahoe, CA in 2007 Angora Fire Angora Fire Area fuel treatments Changed crown fire to surface fire Increased suppression effectiveness Urban lot treatments Increased fire fighter effectiveness Many houses burned from firebrands from other houses Some treated areas burned intensely Steep slopes Adjacent to untreated 3

4 Fuel treatments burned in Rodeo-Chediski fire Figures from Strom and Fulé 2007 IJWF Are fuel treatments effective? Over a 20-yr period, only 2.0 to 4.2% of fuel treatments in 11 western US states are likely to encounter fires that would otherwise be high or highmoderate severity without treatment (Rhodes and Baker 2008) Map is from Schoennagel et al PNAS Schoennagel et al. (2004) 44,000 fuels treatments implemented across the western US ( ) Federal policies stipulate that significant resources should be invested in the WUI Only 3% of the area treated was within the WUI (plus 8% within 2.5- km of WUI) Only 17% of area within 2.5 km of WUI is in federal ownership Yes. Fuel treatments can work. Fuel treatments mitigate fire effects Treatments are more effective when both surface and aerial fuels were reduced (Van Wagner 1968, Weatherspoon and Skinner 1995, Martinson et al. 2003, Skinner et al. 2004, Raymond and Peterson 2005, Cram et al. 2006, Omi et al. 2007) Time since treatment t t matters. Skinner et al. (2004) treatments conducted 2-4 years prior to wildfires showed the least tree mortality; Finney et al. (2005) found treatments four years old or less reduced severity more significantly than those completed nine years prior to wildfires. Type of treatment matters Omi et al. (2007) found that treatments that removed slash and significantly reduced surface fuel loading were effective within ten years, while thinning-only treatments were only found to be effective if they were one year old or less. Short-term Create defensible space Can increase safety for firefighters Can alter fire behavior and burn severity Expensive 4

5 Long-term Effects Affect habitat for plants and animals Clean air, water, & healthy soils Carbon and nutrient cycling Economic health of communities Unanswered questions When and where are fuel treatments effective? We expect them to be less effective in some locations than others, e.g. we think they are more effective in dry forests and near houses How long do they last? We think they will be less effective with time, and more so in productive sites. Strong scientific basis (models, case studies) for fuel treatment effectiveness in dry forests Fuel treatments t t in dry forests don t stop fires can aid fire suppression, and can alter fire behavior and ecological effects Retreatment will be necessary Key points Most fuel treatments are outside the WUI Many fuel treatments never burn Fuel treatments may be less successful in other forest types and in extreme weather conditions Be prepared for scientific challenges to fuel treatments Short-term and long-term Case studies from 2007 fires Murphy et al An Assessment of Fuel Treatment Effects on Fire Behavior, Suppression Effectiveness, and Structure Ignition on the Angora Fire. United States Department of Agriculture R5-TP p. Available online Accessed 23 July 2009 Fites, et al Fire Behavior and Effects Relating to Suppression, Fuel Treatments, and Protected Areas on the Antelope Complex Wheeler Fire. Available online Accessed 23 July Rogers et al Fuel Treatment Effects on Fire Behavior, Suppression Effectiveness, and Structure Ignition, Grass Valley Fire, San Bernadino National Forest. United States Department of Agriculture, Forest Service. R5-TP-026a. 31 p. and appendices. Available online: Harbert, Steve, Andrew Hudak, Laura Mayer, Tim Rich, and Sarah Robertson An Assessment of Fuel Treatments on Three Large 2007 Pacific Northwest Fires. USDA Forest Service Pacific Northwest Region and Oregon State Office USDI Bureau of Land Management. Available online Accessed 24 July Useful references Graham, R.T., A.E. Harvey, T.B. Jain, J.R. Tonn The effects of thinning and similar stand treatments on fire behavior in Western forests. Gen. Tech. Rep. PNW- GTR p. Graham, R. T., McCaffrey, S. And T. B. Jain (technical editors) Science basis for changing forest structure to modify wildfire behavior and severity. USDA Forest Service General Technical Report RMRS-GTR-120. Johnson, Morris C.; Peterson, David L.; Raymond, Crystal L Guide to fuel treatments in dry forests of the Western United States: assessing forest structure and fire hazard. Gen. Tech. Rep. PNW-GTR-686. Portland, OR: U.S. Department t of Agriculture, Forest Service, Pacific Northwest Research Station. 322 p. Online at Rhodes, J.J. and W.L. Baker Fire probability, fuel treatment effectiveness and ecological tradeoffs in western U.S. public forests The Open Forest Science Journal 1: 1-7. Schoennagel, T., C.R. Nelson, D.M. Theobald, G.C. Carnwath, and T.B. Chapman Implementation of National Fire Plan treatments near the wildland urban interface in the western United States. Proc. Nat. Acad. Sci. 106(26): Schoennagel, T., T.T. Veblen, and W.H. Romme The Interaction of Fire,, and Climate across Rocky Mountain Forests. BioScience 54(7): Topography Science of Fuel Treatments Fire (forest structure and moisture) Weather 5