What Drives Fire Frequency, Intensity, and Spread (focused on the Rocky Mountains) Aka: Fuels vs. Climate Bottom up or Top down Local vs Regional

The Facts Both area and intensity of fires appears to be increasing

The Political Rhetoric “Healthy Forests Restoration Act of 2003… reduces the threat of destructive wildfires while upholding environmental standards and encouraging early public input during review and planning processes. The legislation is based on sound science and helps further the President.s Healthy Forests Initiative pledge…..” “The Need for Common-Sense Forest Legislation” Source:

The Enviro Response: Debunking the "Healthy Forests Initiative" The initiative is based on the false assumption that landscape-wide logging will decrease forest fires This premise is contradicted by the general scientific consensus, which has found that logging can increase fire risk. This disconnect between what the administration says and what science says about logging and fire reveals the administration’s true goal which is to use the forest fire issue to cut the public out of the public lands management decision making process and to give logging companies virtually free access to our National Forests. Source:

Where Do We Go From Here? Stephens 1998 Stephens 1998 Modeling of effect of fuels treatment on fire behavior Modeling of effect of fuels treatment on fire behavior Schoennagel et al Schoennagel et al Synthesis of geographical patterns in historical fire regimes and 20 th century changes in these Synthesis of geographical patterns in historical fire regimes and 20 th century changes in these Stephens and Ruth 2005 Stephens and Ruth 2005 Review of federal forest-fire policy Review of federal forest-fire policy

Questions to Address (Schoennagel et al. 2004) Where, and in what ecosystem forest types have fuels increased? Where, and in what ecosystem forest types have fuels increased? How will fire respond to fuel reduction in different forest types? How will fire respond to fuel reduction in different forest types? Where and when will climate override fuels in determining fire behavior? Where and when will climate override fuels in determining fire behavior?

Methods Low severity fires Low elevation ponderosa pine Mixed severity fires Mid elevation Mixed conifers High severity fires High elevation, subalpine forests (spruce-fir to lodgepole to limber and bristlecone)

Typical sub-alpine forest Spruce-fir abundant live ladder fuels Lodgepole stand, sparse understory fuels high tree densities

High Intensity fires Climate governs fire behavior Climate governs fire behavior regional synchronicity regional synchronicity fire interval>suppression interval fire interval>suppression interval No consis. relation: time since fire and fuel abund. No consis. relation: time since fire and fuel abund. Fires are infrequent and historically intense. Fires are infrequent and historically intense. Fire suppression has had little effect on fire frequency, intensity, or size. Fire suppression has had little effect on fire frequency, intensity, or size.

High Intensity Fires continued Fuels treatments ineffective. Fuels treatments ineffective. Abundant ladder fuels and dense trees are natural Abundant ladder fuels and dense trees are natural Mechanical fuel reduction not restoration, but departure from natural range of stand structure. Mechanical fuel reduction not restoration, but departure from natural range of stand structure.

Dry ponderosa pine stand from Jemez Mtns, NM

Recruitment rate over time in the same forest (this and preceding slide from Allen et al. 1988) Year

Low Severity Fires Fine fuels govern fire behavior Fine fuels govern fire behavior But climate plays a role too (El Nino/Nina) But climate plays a role too (El Nino/Nina) Fires were historically frequent and low- intensity. Fires were historically frequent and low- intensity. Fire suppression has significantly increased tree density and ladder fuels thereby increasing fire severity. Fire suppression has significantly increased tree density and ladder fuels thereby increasing fire severity. Fuels reduction treatments can mitigate extreme fire behavior Fuels reduction treatments can mitigate extreme fire behavior

Proportion pre-fire fuels treatments burned in Rodeo-Chediski fire

Mixed Severity Fires Historical fire regime is complex. Historical fire regime is complex. Fuels and climate are both major influences on frequency, size, intensity. Fuels and climate are both major influences on frequency, size, intensity. Suppression has had variable effects. Suppression has had variable effects. Occurrence of high-severity fires is not outside historical range but size/frequency may be increasing. Occurrence of high-severity fires is not outside historical range but size/frequency may be increasing. Supression has probably significantly affected only sites at lower elev., drier aspects, and adj. to grasslands. Supression has probably significantly affected only sites at lower elev., drier aspects, and adj. to grasslands.

Mixed Severity Fires continued Extreme climate and weather can override stand structure and fuels. Extreme climate and weather can override stand structure and fuels. Fuel treatments may reduce severity under moderate conditions but may not under extreme weather conditions. Fuel treatments may reduce severity under moderate conditions but may not under extreme weather conditions. Stephens 1998 Stephens 1998 Fuel treatments may not restore historical stand complexity or structure. Fuel treatments may not restore historical stand complexity or structure.

Summary High intensity fires systems climate driven High intensity fires systems climate driven Low intensity fire systems fuels driven Low intensity fire systems fuels driven Mixed intensity fires systems are a bit of both. Mixed intensity fires systems are a bit of both.

Policy implications? One-size fits all approach won’t work One-size fits all approach won’t work Is that what is happening with the HFI? Is that what is happening with the HFI? WHO KNOWS?? WHO KNOWS?? Bushies say NO (local imput) Bushies say NO (local imput) Enviros say YES (excuse for logging) Enviros say YES (excuse for logging) Scientists say ?? Scientists say ??

How can either side know? (Stephens and Ruth 2005) Federal policy has focused on fuels reduction, not fire behavior and effects. Federal policy has focused on fuels reduction, not fire behavior and effects. Assumption that forests that have missed more fire intervals will have higher hazards. Assumption that forests that have missed more fire intervals will have higher hazards. Policies attempt to maximize acres treated. Policies attempt to maximize acres treated. Most fuel treatments do not measure before and after fuel loads! Most fuel treatments do not measure before and after fuel loads!

Where do we go from here? Who’s telling the truth? Who’s telling the truth? bushy or the enviros bushy or the enviros What are our goals/priorities? What are our goals/priorities? Restoration (and to what state)? Restoration (and to what state)? Community protection? Community protection? Protect all structures? Protect all structures?

More Research is Needed! Into the complexities of of mixed-severity fires and forests. Into the complexities of of mixed-severity fires and forests. Ground-truth evaluation of fuels treatments. Ground-truth evaluation of fuels treatments. Study and address the urban-wildland interface issue. Study and address the urban-wildland interface issue.

More Research is Needed! Stand, NF, and regional mapping of forest types and likely fire types to help prioritize fuels treatments Stand, NF, and regional mapping of forest types and likely fire types to help prioritize fuels treatments Extend fire/fuels models to other community types and regions. Extend fire/fuels models to other community types and regions. Effects of Climate change? Effects of Climate change?