Wildfire Damages to Homes and Resources: Understanding Causes and Reducing Losses
Wildfire Damages to Homes and Resources:
Understanding Causes and Reducing Losses
June 2, 2008
Ross W. Gorte
Specialist in Natural Resources Policy
Resources, Science, and Industry Division
Wildfire Damages to Homes and Resources:
Understanding Causes and Reducing Losses
Wildfires are getting more severe, with more acres and houses burned and more
people at risk. This results from excess biomass in the forests, due to past logging
and grazing and a century of fire suppression, combined with an expanding wildland-
urban interface — more people and houses in and near the forests — along with
climate change, exacerbating drought and insect and disease problems. Some assert
that current efforts to reduce biomass (fuel treatments, such as thinning) and to
protect houses are inadequate, and that public objections to activities on federal lands
raise costs and delay action. Others counter that proposals for federal lands allow
timber harvesting, with substantial environmental damage and little fire protection.
Congress is addressing these issues through various legislative proposals and through
funding for protection programs.
Wildfires are inevitable — biomass, dry conditions, and lightning create fires.
Some are surface fires, burning needles, grasses, and other fine fuels and leaving
most trees alive. Others are crown fires, burning biomass at all levels from the
ground through the tree tops, and typically driven by high winds. Many wildfires
contain areas of both surface and crown fires. Surface fires are relatively easy to
control, but crown fires are difficult, if not impossible, to stop; often, crown fires
burn until they run out of fuel or the weather changes.
Homes can be ignited by direct contact with the fire, by radiative heating, and
by firebrands (burning materials lifted by the wind or the fire’s own convection
column). Protection of homes must address all three. Research has identified the
keys to protecting structures: having a non-flammable roof; clearing burnable
materials that abut the house (e.g., plants, flammable mulch, woodpiles, wooden
decks); and landscaping to create a defensible space around the structure.
Wildland and resource damages from fire vary widely, depending on the nature
of the ecosystem as well as on site-specific conditions. Surface-fire ecosystems,
which burned on 5- to 35-year cycles, can be damaged by crown fires, due to
unnatural fuel accumulations and fuel ladders; fuel treatments probably prevent some
crown fires in such ecosystems. Stand-replacement-fire ecosystems are where crown
fires are natural and the species are adapted to periodic crown fires; fuel treatments
are unlikely to alter the historic fire regime of such ecosystems. In mixed-intensity-
fire ecosystems, where a mix of surface and crown fires is historically normal, it is
unclear whether fuel treatments would alter wildfire patterns.
Prescribed burning (intentional fires) and mechanical treatments (cutting and
removing some trees) can reduce resource damages caused by wildfires in some
ecosystems. However, prescribed fires are risky, mechanical treatments can cause
other ecological damages, and both are expensive. Proponents of more treatment
advocate expedited processes for environmental and public review of projects to
hasten action and cut costs, but others caution that inadequate review can allow
unintended damages with few fire protection benefits.
Background: Fires Happen...........................................2
Protecting Structures from Wildfires...................................3
Responsibility for Protecting Structures........................5
Protecting Wildlands and Natural Resources.............................6
Wildland Ecosystems and Wildfire................................7
Protecting Wildlands and Resources..............................10
Benefits and Limitations...............................13
Area Needing Treatment...................................15
Delays and Changes in Federal Decision-Making....................16
NEPA Environmental Analysis and Public Involvement..........19
Categorical Exclusions (CEs)...........................20
Forest Service Appeals Reform Act...........................21
Expedited ESA Consultations...........................22
Expedited NEPA Reviews (other than through CEs).........22
Healthy Forests Restoration Act.........................23
Considerations in Expediting Decisions...................24
Appendix A: Excerpts from Forest Service Handbook on NEPA Categorical
Exclusions Related to Structural or Resource Protection From Wildfires.26
Wildfire Damages to Homes and Resources:
Understanding Causes and
Wildfires have been getting more severe in recent fire seasons; the last four
seasons are the most severe since 1960.1 National attention was focused on the
growing wildfire problem by an escaped prescribed fire that burned 239 houses in
Los Alamos, NM, in May 2000. The fire in Los Alamos highlighted the wildland-
urban interface problem. Also, at that time, 2000 was the second most severe fire
season since 1960, eclipsed only by the 1988 Yellowstone fires.2 President Clinton
responded with a new National Fire Plan to increase funding for wildfire protection.
It has been widely proclaimed that the increasing severity of wildfires is a result
of excessive biomass accumulations. In at least some ecosystems, logging, livestock
grazing, and a century of fire suppression efforts have allowed biomass fuels to
accumulate to unnatural levels. Climate change, and its impacts on drought, fire, and
insects and diseases, could exacerbate these problems. Many interests have proposed
fuel reduction treatments as a means to lower the fuel levels and thus reduce the
wildfire threat to homes and to wildlands. The severe 2002 fire season led President
Bush to propose a Healthy Forests Initiative to expedite efforts to reduce biomass
fuels on federal lands, and in 2003, Congress enacted the Healthy Forests Restoration
Act to expedite federal fuel reduction and other forest protection programs.
Some interests are concerned that current efforts to reduce fuel levels on federal
lands are inadequate, and that “environmentalist objections” to some of those efforts
are unnecessarily raising costs and delaying action. Others counter that some efforts
are so broad that they permit substantial timber sales without significantly reducing
wildfire risks for communities. Congress continues to address these issues as it
considers funding and legislative proposals.
This report focuses on options for protecting structures and for protecting
wildlands and natural resources from wildfires. It begins with a brief overview of the
nature of wildfires, followed by a discussion of protecting structures. Then, it
discusses wildfire damages to wildlands and natural resources, fuel treatment options
and their benefits and limitations, and public involvement in federal decisions.
1 National Interagency Fire Center, “Fire Information — Wildland Fire Statistics,” at
[http://www.nifc.gov/fire_info/fires_stats.htm]. Fire season severity is commonly assessed
by acres burned, but larger fires may not be “worse” if they burn less intensely, because
their damages may be lower. However, fire intensity and damages are not measured for
each wildfire, and thus cannot be used to gauge the severity of fire seasons. It is unclear
whether acreage burned might be a reasonable approximation of severity.
2 The past four fire seasons have surpassed the 2000 season, while the 1988 data have been
Background: Fires Happen
In temperate ecosystems, wildfires are inevitable. The combination of biomass
plus dry conditions — in the short term (e.g., the annual dry season) or in the long
term (e.g., drought or climate change) — equals fuel to burn. Add an ignition source,
such as lightning, and wildfire happens. Fire is a self-sustaining chemical reaction
that perpetuates itself as long as all three elements of the fire triangle — fuel, heat,
and oxygen — remain available. Fire control focuses on removing one of those
There are two principal kinds of wildfire, although an individual wildfire may3
contain areas of both kinds. One is a surface fire, which burns the needles or leaves,
grass, and other small biomass within a foot or so of the ground and quickly moves
on. Such fires are relatively easy to control by removing fuel with a fireline,
essentially a dirt path wide enough to eliminate the continuous fuels needed to
sustain the fire, or by cooling or smothering the flames with water or dirt.
The other principal kind of wildfire is a crown fire, also called a conflagration.
Crown fires burn biomass at all levels — from the surface through the tops of the
crowns of the trees — although they do not consume all the biomass; logs and large
limbs may need to burn for hours before being completely reduced to ashes. Rather,
a crown fire quickly burns the needles or leaves and small twigs and limbs on the
surface and throughout the crown of the trees. Because the needles and leaves in the
crown are green, they require more energy to burn than dry fuels on the surface.
Furthermore, because of the green fuels and the often discontinuous biomass of the
canopy, wind is usually needed to sustain a crown fire. Once burning vigorously, a
crown fire can create its own wind (the strong upward convection of the heated air
can draw in cooler air from surrounding areas, thus creating a wind that feeds the
fire). The strong upward convection can also lift burning biomass (firebrands) and
send it soaring ahead of the fire, creating spot fires and accelerating the spread of the
Not surprisingly, crown fires are difficult, if not impossible, to control. Unless
quite wide, firelines may be ineffective, especially if winds are causing spot fires.
Water or fire retardant (slurry) dropped from helicopters or airplanes can sometimes
knock a crown fire down (back to a surface fire) if the area burning and the winds are
not too great. Oftentimes, however, crown fires burn until they run out of fuel or the
weather changes (the wind dies or it rains or snows).
Crown fires also typically include areas of surface fire and unburned areas
within their perimeters. Nearly all fires are “patchy,” with a mix of areas of varying
fire severities, depending on site-specific fuel, moisture, and wind conditions. This
patchiness makes understanding and controlling wildfires difficult, at best.
3 See Stephen F. Arno and Steven Allison-Bunnell, Flames in Our Forest: Disaster or
Renewal? (Washington, DC: Island Press, 2002), pp. 45-46.
Protecting Structures from Wildfires
Wildfires occasionally burn houses, in a zone commonly called the wildland-4
urban interface. In recent years, it seems one or more fires annually have burned
down several to few hundred homes and outbuildings (sheds, garages, etc.). These
structures generally have ignited in one of three ways: through direct contact with
fire, through radiation (heating from exposure to flames), and through firebrands.5
The likelihood of a structure burning from one of these ignition methods is called
Home Ignitability. Research has identified three essential elements to
protecting structures: the roof; adjacent burnable materials; and the landscaping.
Treating these three elements address all three ways by which structures are ignited
— direct contact, radiation, and firebrands.
The roof is critical to protecting structures from wildfires.7 Firebrands that land
on a flammable roof can ignite the roof. Untreated red cedar shakes and shingles are
particularly problematic: “A major cause of home loss in wildland areas is flammable
woodshake roofs.”8 Fire retardant treatments offer sufficient for wood shakes, but
the effectiveness of such treatments degrades over time.9 Alternatives include tile,
slate, metals (e.g., copper or aluminum), and other non-flammable materials. Walls,
doors and windows, and vents can also contribute to the protection, or destruction,
of a structure, depending on materials, location, and other variables.10
Adjacent burnable materials are items which can burn that abut the house. This
can include plants (live or dead) and flammable mulch (e.g., wood chips or bark)
under an overhang or eave or next to the structure, gutters clogged with leaves or
needles, decks and porches, sheds and garages, and especially woodpiles. These
factors were particularly important for the 239 homes burned by the Cerro Grande
fire in Las Alamos, NM, in May 2000: “... the high ignitability of Los Alamos was
principally due to the abundance and ubiquity of pine needles, dead leaves, cured
vegetation, flammable shrubs, and wood piles that were adjacent to, touching, or
4 For information on the interface, see CRS Report RS21880, Wildfire Protection in the
Wildland-Urban Interface, by Ross W. Gorte.
5 National Wildland/Urban Interface, Fire Protection Program, Wildland/Urban Interface
Fire Hazard Assessment Methodology, p. 5, at [http://www.firewise.org/resources/files/
6 Jack D. Cohen, “Preventing Disaster: Home Ignitability in the Wildland-Urban Interface,”
Journal of Forestry (March 2000): p. 17.
7 FireSmart: Protecting Your Community From Wildfire (Edmonton, Alberta: Partners in
Protection, May 1999), p. 2-5.
8 Wildland/Urban Interface Fire Hazard Assessment Methodology, p. 7.
9 Is Your Home Protected From Wildfire Disaster? A Homeowner’s Guide to Wildfire
Retrofit (Tampa, FL: Institute for Business and Home Safety, n.d.), p. 9, at [http://www.
10 Wildland/Urban Interface Fire Hazard Assessment Methodology, p. 7.
covering parts of homes.”11 One source recommended that “when assessing the
ignition potential of a structure, attachments [such as decks, porches, and fences] are
considered part of the structure.”12
Finally, landscaping — the characteristics of the vegetation surrounding the
house — is critical to preventing both direct burning and ignition by radiation.
Recommended defensible space around structures is at least 30 feet or 10 meters,
with greater distances for steeper slopes (because of up-slope convection heating) and
for larger vegetation (least for grass, more for shrubs, most for mature forest).13
Others recommend greater distances, such as 100 feet.14 One researcher calculated
the ignition time for an untreated wood wall was more than 10 minutes at a distance
of 40 meters (about 130 feet).15 With burning durations for crown fires “on the order
of 1 minute at a specific location,” the “safe distance” for an untreated wood wall
was calculated to be 27 meters (less than 90 feet), which is consistent with field tests
documenting wall ignition times for experimental crown fires in Canada.16 The same
source notes older fire case studies documenting structure survival — 95% survival
for 10-18 meter (about 32-60 feet) clearance in the 1961 Belair-Brentwood (CA) Fire
and 86% survival for 10+ meter clearance in the 1990 Painted Cave (CA) Fire.17
Thus, clearing to 40 meters would likely be considered ideal, to 30 meters desirable,
and to at least 10 meters essential to achieving about 90% probability of survival.
Note also that “clearing a defensible space” does not require an expanse of concrete
or gravel; relatively non-flammable vegetation, such as a lawn or succulent,
herbaceous plants and flowers, can provide comparable protection.18
The importance of landscapes in protecting structures can also be deduced from
evidence from the 2002 Hayman Fire, the largest wildfire in Colorado history. A
total of 132 homes were burned in the Hayman Fire. Of these, 70 (53%) “were
destroyed in association with the occurrence of torching or crown fire in the home
ignition zone. Sixty-two [47%] were destroyed by surface fire or firebrands.”19
11 Jack Cohen, “The Cerro Grande Fire: Why Houses Burned,” Forest Trust Quarterly
Report, No. 23 (Dec. 2000): p. 7.
12 Wildland/Urban Interface Fire Hazard Assessment Methodology, p. 7.
13 FireSmart, p. 2-11, and Robert Bardon and Robin Carter, Minimizing Wildfire Risk — A
Forest Landowner’s Guide, 03/03 — 30M — DSB/SSS AG-616 (North Carolina
Cooperative Extension Service, n.d.), p. 6.
14 Wildland/Urban Interface Fire Hazard Assessment Methodology, p. 7.
15 Jack D. Cohen, “Reducing the Wildland Fire Threat to Homes: Where and How Much?”
Proceedings of the Symposium on Fire Economics, Planning, and Policy: Bottom Lines,
Gen. Tech. Rept. PSW-GTR-173 (Berkeley, CA: USDA Forest Service, Pacific Southwest
Research Station, Dec. 1999): pp. 189-195.
16 Cohen, “Reducing the Wildland Fire Threat to Homes,” p. 191.
17 Cohen, “Reducing the Wildland Fire Threat to Homes,” pp. 191-192.
18 FireSmart, p. 2-16.
19 Jack Cohen and Rick Stratton, “Home Destruction Within the Hayman Fire Perimeter,”
Hayman Fire Case Study, Gen. Tech. Rept. RMRS-GTR-114 (Ft. Collins, CO: USDA Forest
Conversely, 662 homes — 83% of the homes within the fire perimeter — survived
the Hayman Fire relatively unscathed.20 Since 35% of the Hayman Fire was a high-
severity burn, and another 16% was a moderate-severity burn,21 it seems likely that
at least some of these homes (the number and portion are not documented) survived
despite crown fire around them. Thus, it seems reasonable to conclude that the
nature of the structure — rather the nature of the fire — primarily determines whether
a structure survives a wildfire.
Responsibility for Protecting Structures. Owners are responsible for
their structures. Insurance companies and the relevant state agencies that regulate
insurance can contribute to structural protection by requiring certain materials and
actions to obtain a policy for compensation following wildfire losses or by adjusting
premiums based on homeowner actions. Local governmental agencies also play a
role, since the building and zoning codes that could implement some of the safe-22
structure requirements are generally developed and enforced locally. Alternatively,
states can play a role; as of January 1, 2008, the California Building Standards23
Commission is enforcing wildland-urban interface building standards in very high
The structure owners are also primarily responsible for the defensible space
surrounding their structures. A 10-meter-wide clearing around a 3,000 square-foot
structure encompasses less than a third of an acre — almost certainly private land
owned in conjunction with the structure. Even a 40-meter clearing encompasses less
than 2 acres, and thus is commonly part of the structure owner’s property in the
When a structural fire starts, the local fire department is responsible for
controlling the blaze. State agencies may provide support for local fire departments,
especially in the wildland-urban interface where a structural fire could cause a
wildland fire. Occasionally, because of the location of fire-fighting resources, the
federal agencies may be the first responders on a structural fire in the interface, but
federal fire-fighters are generally not trained for safety in structural fire-fighting. The
federal government has no responsibility for structural fire control in the wildland-
Service, Rocky Mountain Research Station, Sept. 2003): p. 264.
20 Cohen and Stratton, “Home Destruction Within the Hayman Fire,” p. 263.
21 Peter Robichaud, Lee MacDonald, Jeff Freeouf, Dan Neary, Deborah Martin, and Louise
Ashman, “Postfire Rehabilitation of the Hayman Fire,” Hayman Fire Case Study, Gen.
Tech. Rept. RMRS-GTR-114 (Ft. Collins, CO: USDA Forest Service, Rocky Mountain
Research Station, Sept. 2003): p. 294.
22 Model building codes for local governments exist. For example, in January 2006, the
International Code Council (ICC) published its International Wildland-Urban Interface Code
[http://www.iccsafe.org/news/about/#cd], with a separate chapter on ignition-resistant
construction specifications. In June 2007, the National Fire Protection Association (NFPA)
approved an updated standard, Standard for Reducing Structure Ignition Hazards from
Wildland Fire, [http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=1144].
23 See [http://www.bsc.ca.gov/default.htm].
urban interface. However, the Forest Service (FS) does have programs to provide
technical and financial assistance to states and to volunteer fire departments.24
Given the nature of efforts needed to protect structures and that developing,
adopting, and enforcing building codes are local and state responsibilities, there is no
clear federal responsibility in protecting structures from wildfires. However, the
federal government often provides disaster assistance in the wake of a catastrophic
wildfire, generally at the request of a governor. Federal disaster assistance is
expensive and could be avoided if action to protect homes were taken in advance.
Several federal agencies currently support FIREWISE, a program aimed at educating
homeowners about how to make their structures safe from wildfire.25 Assistance to
homeowners — such as technical assistance, low-cost loans, and cost-sharing on
projects — might be a cost-saving federal investment. Federal assistance to prepare
local firefighters is another means for addressing home protection from wildfires.26
Research on wildland-urban interface fire protection can also reduce losses.27
Another possibility might be federal wildfire insurance, comparable to the National
Flood Insurance Program.28 Those living in an identified wildfire-prone zone would
be required to purchase federal wildfire insurance (probably with an annual premium)
to receive compensation for wildfire damages. The premiums could vary by eco-
region, depending on the likelihood and risk of wildfires, and by aspects of the
structure and landscaping (which might require periodic inspections).
Protecting Wildlands and Natural Resources
Wildlands and natural resources can also be damaged by wildfires. Wildfire
damages vary widely, depending on the nature of the ecosystems burned as well as
site-specific conditions. Activities to modify wildland biomass fuels can reduce
damages, although the cost and effectiveness also vary. Finally, for fuel reduction
activities on federal lands, delays and modifications — related to endangered species
concerns and public involvement in decision-making — can affect the cost of fuel
24 For a description of these programs, see CRS Report RL31065, Forestry Assistance
Programs, by Ross W. Gorte.
25 FIREWISE is part of the National Wildland/Urban Interface Fire Program, directed and
sponsored by the Wildland/Urban Interface Working Team, which includes the USDA
Forest Service, several DOI agencies (the Bureau of Land Management, Bureau of Indian
Affairs, Fish and Wildlife Service, and National Park Service), and two agencies of the
Department of Homeland Security (the Federal Emergency Management Agency and U.S.
Fire Administration). It also includes the International Association of Fire Chiefs, National
Association of State Fire Marshals, National Association of State Foresters, National
Emergency Management Association, and National Fire Protection Association.
26 See the program announced by the U.S. Fire Administration and the National Wildfire
Coordinating Group, at [https://www.usfa.dhs.gov/media/press/2008releases/012308.shtm].
27 See the National Institute of Standards and Technology website, at [http://www2.bfrl.
nist.gov/proj ects/2008Progr amCont ainer.asp?BFRLProgram= FWUI].
28 For information on this program, see CRS Report RS22394, National Flood Insurance
Program: Treasury Borrowing in the Aftermath of Hurricane Katrina, by Rawle O. King.
Wildland Ecosystems and Wildfire
Ecosystem fire regimes can be classified in several ways; one common approach
is to distinguish among surface fire ecosystems, stand-replacement fire ecosystems,
and mixed fire ecosystems.29 Damages to lands and resources depend on the nature
of those ecosystems.
Surface-Fire Ecosystems. Surface-fire ecosystems are ecosystems where
fires burned relatively frequently (typically 5- to 35-year intervals), with the fires
consuming leaves or needles, grasses, twigs and small branches, and sometimes small
trees, but generally leaving moderate and large trees unharmed by the fire. The
classic surface-fire ecosystem is the western Ponderosa pine, where seedlings
occasionally survive the surface fire to become the scattered, stately pines in fields
of grass or low brush. The other archetypical surface fire ecosystem is the southern
yellow pines — shortleaf, slash, loblolly, and especially longleaf pine. Surface-fire30
ecosystems account for about 34% of all U.S. wildlands.
Over the past century, surface-fire ecosystems in the West have been affected
by grazing, logging, and fire protection. Heavy grazing reduced grass cover, which
commonly carried the surface fires. Logging in many areas emphasized the large
pines, often leaving the true firs and Douglas-fir (which are more susceptible to
drought, insect damage, and crown fires) to replace the pines, at least in the northern
Rockies and Pacific Northwest. Fire protection has similarly led to more firs and
Douglas-firs, and small Ponderosa pines, than would typically have survived. With
fire return intervals of 5-35 years (i.e., fires typically burning once in that period),
many surface-fire ecosystems have missed two or more burning cycles. Thus, many
forests now have an unnaturally large accumulation of small burnable materials and
of trees susceptible to crown fires.
Many are concerned that the unnatural fuel accumulations and the fuel ladders
(continuous fuels from the ground to the tree crowns) from many small and medium-
sized pines, firs, and Douglas-firs are causing crown fires in ecosystems where such
fires were rare. This could cause significant ecological damage to plants and animals
ill-adapted to crown fires. It is unclear whether a new surface-fire ecosystem will
develop in the wake of an intense crown fire.
Research on fuel reduction treatments (discussed below) have documented the31
effectiveness of such treatments on Ponderosa pine (a surface-fire ecosystem), and
activities that reduce fuel accumulations have been shown to reduce wildfire severity
29 Arno and Allison-Bunnell, Flames in Our Forest, pp. 44-45.
30 Fire Modeling Institute, Historical Fire Regimes by Current Condition Classes: Data
Summary Tables (Missoula, MT: USDA Forest Service, Rocky Mountain Research Station,
Feb. 22, 2001), at [http://www.fs.fed.us/fire/fuelman/data_summary_tables.pdf].
31 Russell T. Graham, Alan E. Harvey, Theresa B. Jain, and Jonalea R. Tonn, The Effects of
Thinning and Similar Stand Treatments on Fire Behavior in Western Forests, Gen. Tech.
Rept. PNW-GTR-463 (Portland, OR: USDA Forest Service, Pacific Northwest Research
Station, 1999), 27 pp.
in surface-fire ecosystems.32 Presumably, less severe wildfires cause less damage to
timber, to watersheds, and to wildlife and wildlife habitats.
Stand-Replacement-Fire/Crown-Fire Ecosystems. Stand-replacement-
fire ecosystems are ecosystems where crown fires are normal, natural, periodic events
to which the ecosystem has adapted. The interval for the stand-replacement fires
varies widely — from a few years (prairie grasses) to more than 1,000 years (coastal
Douglas-fir) — depending on the ecosystem. Some ecosystems require periodic
crown fires to regenerate the ecosystem. For example, lodgepole pine in much of the
West and jack pine in the Lake States have serotinous cones, which only open and
release their seeds after exposure to temperatures exceeding 250° Fahrenheit.
Similarly, chaparral in southern California and the desert Southwest, most perennial
grasses, and aspen everywhere regenerate from rootstocks; burning the surface
vegetation allows new plants to sprout from the underground stems, rhizomes, and
root crowns. Stand-replacement-fire ecosystems account for about 42% of all U.S.
It seems unlikely that stand-replacement-fire ecosystems could suffer significant
ecological damage from severe wildfires. In contrast to surface-fire ecosystems,
where crown fires could alter the ecosystem, in stand-replacement-fire ecosystems,
the exclusion of crown fires (if it were possible) would likely alter the ecosystems.
This ecological change is implied by evidence from grass ecosystems (prairies and
meadows), where fire suppression is feasible and which are being encroached upon
by trees that would normally have been eliminated by the frequent fires.
Activities that reduce fuel levels in stand-replacement-fire ecosystems have no
documented effect on wildfire severity. Anecdotal reports have asserted that crown
fires were halted (became surface fires) when they arrived at treated areas, but
research has not documented where and when such occurrences have happened. To
date, no research has shown that fuel treatments consistently reduce the extent or
severity of wildfires in stand-replacement-fire ecosystems. The ineffectiveness of
fuel reduction was particularly noted for southern California chaparral: “large fires
were not dependent on old age classes of fuels, and it is thus unlikely that age class
manipulation of fuels can prevent large fires.”34
Mixed-Fire-Intensity Ecosystems. Many wildlands have ecosystems that
burn in crown fires of relatively limited scale, substantially mixed with surface fires.
These ecosystems are called mixed-fire-intensity ecosystems. A classic example is
whitebark pine, a species generally limited to high elevation sites, near timberline.
Whitebark pine is a slow-growing species that invades harsh sites and moderates the
micro-climatic conditions to allow true firs and spruces to germinate and grow. The
sporadic mixed-intensity fires kill most of the competing trees and some of the
32 Philip N. Omi and Erik J. Martinson, Final Report: Effect of Fuels Treatment on Wildfire
Severity, submitted to the Joint Fire Science Program Governing Board (Ft. Collins, CO:
Colorado State Univ., Western Forest Fire Research Center, Mar. 25, 2002).
33 Historical Fire Regimes by Current Condition Classes.
34 Jon E. Keeley, C.J. Fotheringham, and Marco Marais, “Reexamining Fire Suppression
Impacts on Brushland Fire Regimes,” Science, v. 284 (June 11, 1999): p. 1829.
whitebark pines, but some pines survive. Also, burned sites are preferred “cache”
sites for Clark’s nutcrackers, which is the primary means of whitebark pine tree
regeneration.35 Other species that are commonly surface-fire or stand-replacement-
fire species, such as Ponderosa pine and lodgepole pine, can be mixed-fire-intensity
types under certain conditions, typically near the transition to another area with a
different dominant tree species. Ponderosa pine, for example, may be a mixed-fire-
intensity type on relatively moist sites, especially where it mixes naturally with
Douglas-fir, such as on north-facing slopes in the northern Rockies. Lodgepole pine
may be a mixed-fire-intensity type on relatively dry sites, where the trees naturally
grow farther apart, such as on the eastern slopes of the Sierra Nevada Mountains.
Less is known about wildfire in mixed-fire-intensity ecosystems, even though
they occupy about 24% of U.S. wildlands.36 It is unclear whether fuel loads have
accumulated to unnatural levels, whether crown fires could cause significant
ecological damage, or whether fuel reduction activities would alter wildfire extent
or severity in these ecosystems.
Wildfire Effects. The effects of wildfires on natural resources are difficult to
assess and are commonly overstated for two reasons. First, burned areas look bad —
blackened trees and ground cover — even following surface fires. However, many
plants recover from being burned. Conifers generally survive even with as much as
60% of their crowns scorched.37 Other plants, especially grasses, aspen, and some
brush species, resprout vigorously after being burned. Furthermore, animals
(regardless of their size and mobility) are only rarely killed by wildfire.38
The other reason that wildfire effects are commonly overstated is that reported
burned area includes all the acres within the fire perimeter. However, even severe
crown fires are patchy, leaving some areas lightly burned or unburned. For example,
in the Yellowstone fires that were on the nightly news for weeks in the summer of
had only surface fire. In the 2002 Hayman Fire, the worst wildfire in Colorado
history, 35% of the area had a high severity burn and 16% had a moderate severity40
burn; 34% had a low severity burn and 15% was unburned. Thus, severely burned
acreage is substantially less than the burned area that is reported.
35 Diana F. Tomback, “Clark’s Nutcracker; Agent of Regeneration,” Whitebark Pine
Ecology and Restoration, Diana F. Tomback, Stephen F. Arno, and Robert E. Keane, eds.
(Washington, DC, Island Press, 2001), pp. 90-100.
36 Historical Fire Regimes by Current Condition Classes.
37 See Ross W. Gorte, Fire Effects Appraisal: The Wisconsin DNR Example, Ph.D.
dissertation (East Lansing, MI: Michigan State Univ., June 1981).
38 L. Jack Lyon, Mark H. Huff, Robert G. Hooper, Edmund S. Telfer, David Scott Schreiner,
and Jane Kapler Smith, Wildland Fire in Ecosystems: Effects of Fire on Fauna, Gen. Tech.
Rept. RMRS-GTR-42-vol. 1 (Ogden, UT: USDA Forest Service, Rocky Mountain Research
Station, Jan. 2000).
39 Lyon, et al., Effects of Fire on Fauna, p. 44.
40 Robichaud et al., “Postfire Rehabilitation of the Hayman Fire,” p. 294.
Severe wildfires can cause long-lasting resource damages. Crown fires kill
many plants within the burned area, increasing the potential for erosion until the
vegetation recovers. Some observers have reported “soil glassification,” where the
silica in the soils has been melted and fused, forming an impermeable layer in the
soil, although research has yet to document the extent, frequency, and duration of the
condition and the soils and conditions under which it occurs. Landslides can also
occur in areas with unstable soils where the vegetation has burned, such as in coastal
southern California. Timber can also be damaged, although burned trees can often
be salvaged for lumber and other wood products. However, harvesting and
processing costs are typically higher in burned areas, and many object to post-fire
salvage harvesting because of its possible additional impacts on soils and other
resource values. Wildfires, especially crown fires, can also have significant local
economic effects — directly on tourism, and indirectly through effects on timber
supply, water quality, and aesthetics. On the other hand, federal wildfire suppression
efforts include substantial expenditures, many of which are made locally, and fire-
fighting jobs are considered financially desirable in many areas.41
Protecting Wildlands and Resources
The federal government is generally responsible for protecting federal lands and
their natural resources from wildfire.42 Wildfire protection of other wildlands and
natural resources — state, local government, and private lands — is the responsibility
of the states, although the individual landowners are responsible for excessive fuel
accumulations and other hazardous conditions on their own lands. As noted above,
the FS has a technical and financial assistance program for state fire agencies.
The principal goal for land and resource protection is to reduce the damages
caused by wildfires. This can best be achieved by reducing burnable biomass (live
and dead) to reduce wildfire intensity and duration, and especially by eliminating the
fuel ladders (relatively continuous biomass from the surface to tree crowns) that
facilitate wildfire transition from a surface fire to a crown fire.43 Fuel treatments can
also reduce the crown bulk density (the biomass, especially fine fuels, in the tree
crowns), making it more difficult for a crown fire to sustain itself, thus making a
wildfire more controllable.44 Reducing burnable biomass, however, does not
eliminate wildfires, because fuel reduction does not directly alter the dryness of the
biomass or the probability of an ignition.
41 Nelson, A Burning Issue, pp. 37-38.
42 The federal government also protects some state and private lands where the landowner
has a cooperative agreement with a federal agency, while some federal lands similarly are
protected by state or private organizations under cooperative agreements.
43 Russell T. Graham, Alan E. Harvey, Theresa B. Jain, and Jonalea R. Tonn, The Effects of
Thinning and Similar Stand Treatments on Fire Behavior in Western Forests, Gen. Tech.
Rept. PNW-GTR-463 (Portland, OR: USDA Forest Service, Pacific Northwest Research
44 Graham et al., The Effects of Thinning on Fire Behavior.
The two principal mechanisms for reducing fuels are prescribed burning and
mechanical treatments, although the two tools can also be combined. Each tool has
benefits, costs, and risks or limitations to its use.
Prescribed Burning. Prescribed burning is intentionally setting fires in
specified areas when fuel and weather conditions are within prescribed limits (e.g.,
fuel moisture content, relative humidity, wind speed). Some observers include, in
their definition of prescribed burning, naturally occurring fires that are allowed to
burn because they are within acceptable areas and conditions, as identified in fire
management plans. The agencies term such fires wildland fire use, and do not
identify them as prescribed fires, but do include the acres burned in wildland-fire-use
fires as acres treated for fuel reduction.
Prescribed burning is used for reducing biomass fuels because it is the only
means available for eliminating fine fuels (grasses, needles, leaves, forbs, and twigs
and shrubs less than a quarter-inch in diameter [pencil-sized]). Burning converts the
vegetation to smoke (carbon dioxide, water vapor, fine particulates, and other
pollutants) and ashes (mineralized forms of the organic matter, readily available for
absorption by new plant growth). Reducing fine fuels is critical in wildfire protection
and control, because fine fuels are necessary to carry wildfires; without fine fuels,
wildfires cannot spread.
Prescribed burning has various limitations, as well. Smoke can be a problem,
contributing to human health problems, especially in areas where inversions are
common or with relatively stagnant airsheds. Also, prescribed burning is risky. It
is not controlled burning; there is no such thing as controlled burning, because there
is no switch to turn the fire off. Prescribed fire is also an indiscriminate tool for
reducing tree density, crown density, and fuel ladders, burning what is available,
depending on a host of site-specific and micro-climatic conditions.
Finally, prescribed burning is expensive. Actually starting the prescribed fire
is cheap — matches don’t cost a lot. However, minimizing the risk to surrounding
areas (especially private lands and housing developments) requires planning and
preparation as well as having sufficient trained personnel and supervisors to react if
(when) unexpected fire behavior occurs or weather conditions change. A prescribed
fire that becomes a wildfire, such as the Cerro Grande Fire in Los Alamos, NM (that
burned 237 houses in town) raises questions about the practice and about the fire
managers who use it. Thus, fire managers tend to err on the side of excessive
personnel (and cost) for a prescribed fire, rather than risk it becoming a costly,
damaging wildfire with far higher costs.
Mechanical Treatment. Mechanical fuel treatment includes a wide array of
activities designed to reduce biomass on a site. Foresters have a variety of terms for
the various activities, including:45
45 For more information, see David M. Smith, Bruce C. Larson, Matthew J. Kelty, and P.
Mark S. Ashton, The Practice of Silviculture: Applied Forest Ecology, 9th ed. (New York,
NY: John Wiley & Sons, 1997).
!pruning — removing lower tree branches, which eliminates fuel
ladders and can reduce crown density;
!release — removing several to many trees from a young stand
(saplings or smaller) to concentrate wood growth on desirable trees,
which reduces crown density;
!thinning — removing a portion of the standing trees; the portion can
vary widely from very light (relatively few trees) to very heavy
(more than half the trees in the stand). Thinning can be commercial
(if the trees are large enough for products) or precommercial. It can
be used to eliminate fuel ladders and reduce crown density,
depending on the approach and portion of trees removed. Thinning
— low thinning, or thinning from below, to remove the smallest
and poorest specimens, which eliminates fuel ladders and can
reduce crown density;
— crown thinning, or thinning from above, to open the canopy
to stimulate growth on the remaining trees, which substantially
reduces crown density;
— selection thinning, to remove the least desirable trees for the
future stand, which reduces crown density and can eliminate fuel
— mechanical thinning, to provide appropriate spacing for the
remaining trees, which reduces crown density and can eliminate
!salvage harvesting — removing a portion to all of the standing trees,
many of which have been killed or are in imminent danger; includes
presalvage harvesting (removing highly vulnerable trees before they
are killed) and sanitation harvesting (removing trees to control the
spread of insects or diseases). It reduces (or eliminates) crown bulk
density, and might reduce fuel ladders.
Treatment Choices. Mechanical fuel treatment clearly involves choices —
about the amount of biomass to be removed, and about the nature of the biomass to
be removed (small and weak trees, lower limbs, vulnerable trees or species, etc.).
The choice can also be over the method used for the treatment: a commercial sale,
if the treatment yields commercially usable wood; a stewardship contract, if
commercially usable wood can be exchanged for other activities; a service contract,
for specified actions; an end-results contract, to specify what is left after treatment;
or even treatment by agency personnel. All of these choices affect the public
acceptance of the proposed treatment.
Benefits and Limitations. The primary benefit of mechanical fuel treatment
is the high degree of control over the results. One report stated:46
Mechanical thinning has the ability to more precisely create targeted stand
structure than does prescribed fire ... Used alone, mechanical thinning,
especially emphasizing the smaller trees and shrubs, can be effective in reducing
the vertical fuel continuity that fosters initiation of crown fires. In addition,
thinning of small material and pruning branches are more precise methods than
prescribed fire for targeting ladder fuels and specific fuel components ...
The authors also observed some of the limitations of mechanical fuel treatment:47
However, by itself mechanical thinning does little to beneficially affect surface
fuels with the exception of possibly compacting, crushing, or masticating it
during the thinning process. Depending on how it is accomplished, mechanical
thinning may add to surface fuels (and increase surface fire intensity) unless the
fine fuels that result from the thinning are removed from the stand or otherwise
Thinning and prescribed fires can modify understory microclimate that was
previously buffered by overstory vegetation ... Thinned stands (open tree
canopies) allow solar radiation to penetrate to the forest floor, which then
increases surface temperatures, decreases fire fuel moisture, and decreases
relative humidity compared to unthinned stands — conditions that can increase
surface fire intensity ... An increase in surface fire intensity may increase the
likelihood that overstory tree crowns ignite ...
Other sources have similarly reported the limitations of thinning:48
Depending on the forest type and its structure, thinning has both positive and
negative impacts on crown fire potential. Crown bulk density, surface fuel , and
crown base height [fuel ladders] are primary stand characteristics that determine
crown fire potential. Thinning from below, free thinning, and reserve tree
shelterwoods have the greatest opportunity for reducing the risk of crown fire
behavior. Selection thinning and crown thinning that maintain multiple crown
layers ... will not reduce the risk of crown fires except in the driest ponderosa
pine ... forests. Moreover, unless the surface fuels created by using these
treatments are themselves treated, intense surface wildfire may result, likely
negating positive effects of reducing crown fire potential. No single thinning
approach can be applied to reduce the risk of wildfires in the multiple forest
types of the West.
Thus, thinning and pruning have the potential to reduce the risk of crown fire,
but may increase wildfire risk until the slash (non-commercial biomass) degrades
(rots or burns, typically in a few years to decades, depending on the ecosystem), or
46 Russell T. Graham, Sarah McCaffery, and Theresa N. Jain, tech. eds., Science Basis for
Changing Forest Structure to Modify Wildfire Behavior and Severity, Gen. Tech. Rept.
RMRS-GTR-120 (Ft. Collins, CO: USDA Forest Service, Rocky Mountain Research
Station, Apr. 2004), p. 25.
47 Graham, et al., Science Basis for Changing Forest Structure, pp. 25, 27.
48 Graham, et al., The Effects of Thinning on Fire Behavior, abstract.
is removed. In addition, thinning is an expensive proposition, with treatment costs
ranging “from $35 to over $1000 per acre depending on the type of operation, terrain,
and number of trees to be treated.”49
Commercial operations — commercial thinning, stewardship contracting, and
salvage logging — have been suggested as a means to moderate the high cost of
mechanical fuel treatment. However, commercial timber sales on federal lands
commonly cost more to prepare and administer than they return to the Treasury.50
The results of commercial operations for fuel reduction are also questionable:51
The proposal that commercial logging can reduce the incidence of canopy fires
was untested in the scientific literature. Commercial logging focuses on large
diameter trees and does not address crown base height — the branches, seedlings
and saplings which contribute so significantly to the “ladder effect” in wildfire
behavior. (Emphasis in original)
Others have also noted the likely net cost of thinning to reduce the risk of crown
Although large trees can be removed for valuable products, the market value for
the smaller logs may be less than the harvest and hauling charges, resulting in a
net cost for thinning operations. However, the failure to remove these small logs
results in the retention of ladder fuels that support crown fires with destructive
impacts to the forest landscape. A cost/benefit analysis broadened to include
market and nonmarket considerations indicates that the negative impacts of
crown fires are underestimated and that the benefits of government investments
in fuel reductions are substantial.
Combined Operations. The ability to control the resulting stand structure
with mechanical treatments and the ability to remove fine fuels with prescribed
burning make combining the two treatments seem a logical choice. However,
empirical evidence to document the effectiveness of such combined operations is
A more limited number of studies addressed the effectiveness of a combination
of thinning and burning in moderating wildfire behavior. The impacts varied,
49 A Strategic Assessment of Forest Biomass and Fuel Reduction Treatment in Western
States, Gen. Tech. Rept. RMRS-GTR-149 (Ft. Collins, CO: USDA Forest Service, Rocky
Mountain Research Station, 2005).
50 CRS Report RL32485, Below-Cost Timber Sales: An Overview, by Ross W. Gorte.
51 Henry Carey and Martha Schumann, Modifying WildFire Behavior — The Effectiveness
of Fuel Treatments: The Status of Our Knowledge, Southwest Region Working Paper 2
(Santa Fe, NM: National Community Forestry Center, April 2003), pp. I-ii.
52 C. Larry Mason, Bruce R. Lippke, Kevin W. Zobrist, Thomas D. Bloxton, Jr., Kevin R.
Cedar, Jeffrey M. Comnick, James B. McCarter, and Heather K. Rogers, “Investments in
Fuel Removal to Avoid Forest Fires Result in Substantial Benefits,” Journal of Forestry,
v. 104 (Jan./Feb. 2006): p. 27.
53 Carey and Schumann, Modifying WildFire Behavior, pp. I-ii.
depending on the treatment of the thinning slash prior to burning.... (Emphasis
In addition, the cost of combined operations is substantially greater than the cost
of either alone.
Area Needing Treatment. The areas that might benefit from prescribed
burning and/or mechanical treatment is not entirely clear. Table 1, below, shows the
acreage of national forest land, Department of the Interior land, and all other land by
(a) historical fire regime (comparable to the ecosystem types described above); and
(b) condition class — low risk (Class 1), moderate risk (Class 2), and high risk (Class
Based on the discussion (above) of the effectiveness of various treatments, it
seems reasonable to conclude that treating lands in class 3 (high risk), low severity
(surface fire) regime could reduce the likelihood of crown fires in these ecosystems
where such fires are unnatural (or at least very rare). Table 1 shows this to include
28.8 million acres of national forest land, 6.5 million acres of Interior land, and 42.2
million acres of other federal, state, and private land.
Table 1. Lands At Risk of Ecological Damage from Wildfire,
by Landowner Group and Historical Fire Regime
(in millions of acres)
Landowner/TotalClass 1Class 2Class 3
Historical Fire Regime(low risk)(mod. risk)(high risk)
USDA Forest Service
Low severity (surface fire)83.6719.8734.9628.83
Forest Service, total196.5264.9580.4551.12
Dept. of the Interior
Low severity (surface fire)49.0018.7023.836.46
Interior Dept., total227.72128.4275.8323.47
Other federal, state, and private lands
Low severity (surface fire)296.02136.46117.3742.20
Other lands, total825.01404.60313.24107.18
Source: Kirsten M. Schmidt, James P. Menakis, Colin C. Hardy, Wendel J. Hann, and David L.
Bunnell, Development of Coarse-Scale Spatial Data for Wildland Fire and Fuel Management, Gen.
Tech. Rept. RMRS-87 (Ft. Collins, CO: USDA Forest Service, Rocky Mountain Research Station,
Apr. 2002), pp. 13-15.
The cost to treat these lands varies widely. One study, cited above, reported
mechanical treatment costs of $35 to $1,000 per acre, depending on terrain, type of
operation, and number of trees to be cut.54 Others have similarly reported highly
variable costs for commercial mechanical treatment above and below the “base case”
cost of $150 per acre, depending on tree size, stand density, terrain, and whether the
treatment was conducted in the wildland-urban interface.55 The same source reported
similar variability in costs for prescribed burning, above and below the “base case”
cost of $105 per acre. Federal appropriations for fuel treatment averaged about $170
per acre for FY2001 — FY2006 — $165 per acre for the Forest Service and $174 per
acre for the BLM.56 The General Accounting Office (GAO, now the Government
Accountability Office) used a Forest Service estimate of $300 per acre in its 1999
estimate of needed funding for fuel treatment, because of the higher cost per acre to
treat additional western lands.57 At $300 per acre, Forest Service costs to treat the
Class 3 — surface fire regime lands would be $8.6 billion, and Department of the
Interior costs would be $1.9 billion. Other surface (low severity) fire regime lands
might also warrant treatment, although the lower risk of ecological damage suggests
a lower priority for treatment.
It is unclear whether any lands other than the surface fire regime lands warrant
fuel treatment. The existing research evidence on fuel treatment for stand
replacement fire regimes raises questions about the effectiveness of both mechanical
treatment and prescribed fire for reducing the likelihood of damages from a crown
fire. One might even question whether ecological damage can be ascribed to a crown
fire in a stand-replacement fire ecosystem, since these ecosystems have evolved
adaptations to reestablish themselves following crown fires. Evidence is also lacking
on the effectiveness of mechanical treatments and prescribed burning on mixed-
intensity fire ecosystems. Thus, it is not certain whether fuel treatment on these
mixed-intensity fire regime lands and stand-replacement fire regime lands would
provide any significant wildfire protection.
Delays and Changes in Federal Decision-Making
Some advocates of fuel treatment are concerned that the delays and changes to
the implementation of fuel treatments might lead to catastrophic crown fires that
could have been prevented by more expeditious fuel treatment. Concerns are
generally linked to consultations under the Endangered Species Act (ESA, P.L. 93-
54 A Strategic Assessment of Forest Biomass.
55 Roger D. Fight and R. James Barbour, Financial Analysis of Fuel Treatments, Gen. Tech.
Rept. PNW-GTR-662 (Portland, OR: USDA Forest Service, Pacific Northwest Research
Station, Dec. 2005).
56 Data from annual agency budget justifications, presented in CRS Report RL33990,
Wildfire Funding, by Ross W. Gorte, at pages CRS-6 and CRS-12.
57 GAO, Western National Forests: A Cohesive Strategy is Needed to Address Catastrophic
Wildfire Threats, GAO/RCED-99-65 (Washington, DC: April 1999). The Forest Service
has done more fuel treatment in the South, where the generally gentler terrains, denser and
more uniform timber stands, and historic fire patterns have kept treatment costs per acre
lower than in the West.
205; 16 U.S.C. §§ 1531-1544), and to public involvement under the National
Environmental Policy Act of 1969 (NEPA; P.L. 91-190, 42 U.S.C. §§ 4321-4347)
and the Forest Service Appeals Reform Act (ARA; §322 of P.L. 102-381 [the
FY1993 Interior appropriations act], 16 U.S.C. § 1612 note).58
Involving the public and consulting over possible impacts on endangered or
threatened species take time, and concerns and objections can delay, modify, or even
prevent some proposed actions. However, others caution that expedited review or
limits on ESA consultation and on public oversight of proposed fuel treatments may
allow treatments to include commercial timber harvests or other actions that provide
little wildfire protection and exacerbate fuel accumulations in the short run, while
causing other environmental damages.
This raises the question of the effect of delays on wildfire threats. Clearly,
structures in the wildland-urban interface are threatened by wildfire, but as shown
above, fuel treatment provides little, if any, fire protection for structures, and thus
delaying fuel treatments has little consequence for structure protection. Resources
in surface-fire ecosystems with unnatural fuel accumulations are at risk from severe
wildfires. The odds of having treated the “right” acres to prevent a crown fire with
significant resource damages are, however, quite low. Over the past four years,
during which more area burned annually than in any other year since 1960, wildfires
have burned an average of 9.0 million acres annually. Total wildlands in the United
States are 1.47 billion acres — 653.3 million acres of federal land,59 and 812.1
million acres of private forest and rangeland.60 Thus, the likelihood of any particular
acre burning in any given year, on average, is less than 0.66% (i.e., burning once
every 150 years). Obviously, the risk for certain areas in particular years can be
much higher — 5.4% of Idaho’s wildlands burned in 2007, for example — but this
is offset by much lower risks for those areas in other years and for other areas in the
same year — 0.2% of Idaho’s wildlands burned in 2002, while 0.04% of Colorado
wildlands burned in 2007, in contrast to 1.8% in 2002, when the Hayman Fire
burned.61 Wildfire risk is probably somewhat higher in western states than the
national average, because the ecosystems in the Lake States, Mid-Atlantic region, and
New England experience less fire; however, even if the risk were 50% greater than
the national average (which seems unlikely because the larger area in the West
already contributes to a higher national average), the risk would still be less than 1%
In addition to the low probability of a particular acre burning is the modest
likelihood of an area being treated. The Forest Service and BLM have treated 2.7
58 See CRS Report RL32436, Public Participation in the Management of Forest Service and
Bureau of Land Management Lands: Overview and Recent Changes, by Pamela Baldwin.
59 U.S. General Services Administration, Office of Governmentwide Policy, Federal Real Property
Profile, as of September 30, 2004, pp. 18-19.
60 USDA Natural Resources Conservation Service and the Iowa State University Statistical
Laboratory, Summary Report, 1997 Natural Resources Inventory (revised December 2000).
61 See CRS Memoranda, Wildfire and Wildland Data, by Ross W. Gorte, June 20, 2003, and
March 3, 2008; available from the author.
million acres of their lands annually over the past five years.62 This is less than 8%
of their Class 3 — surface fire ecosystem lands, and less than 3% of Class 3 plus
Class 2 surface fire ecosystem lands. If the same acreage of treatments are spread
more broadly — to Class 1 — surface fire ecosystem lands or to lands in other fire
regimes — the probability of treating a particular acre to prevent a crown fire
Nonetheless, lengthy delays can exacerbate the risks. Annual probabilities of
a wildfire burning an area and of an area being treated are both cumulative. Over a
10-year period, the likelihood of an area burning is more than 6%, while the
likelihood of a moderate- or high-risk surface-fire ecosystem being treated rises to
15% (if half of all treatments are concentrated on these lands). Thus, relatively brief
delays may have relatively little impact of the likelihood of an area being burned in
an unnatural crown fire, but longer delays (a decade or more) could have a significant
ESA Consultations.63 The ESA established a process for federal agencies
to consult with the Fish and Wildlife Service (FWS), or with the National Marine
Fisheries Service (NMFS) for some species, on any actions that might jeopardize a
listed endangered or threatened species or adversely modify its critical habitat. This
is not a problem for fire-fighting, as immediate, informal consultations can occur
during an emergency, with formal consultation to follow after the emergency has
passed. However, some fuel treatments might jeopardize a species or adversely
modify its habitat, which would require ESA consultation. Consultation means the
FWS (or NMFS) would review the proposed action and, if jeopardy or adverse
habitat impacts are likely, propose a “reasonable and prudent alternative” to achieve
the same purpose without jeopardy or adverse habitat modification. The vast
majority of agency activities have a finding of no jeopardy, and most with jeopardy
have a reasonable and prudent alternative; actions with jeopardy and no alternative
findings are exceedingly rare.
Fuel treatments that reduce the likelihood of crown fires in ecosystems where
such fires were historically rare are generally unlikely to jeopardize or adversely
modify the critical habitat of endangered species. Many species in North America
are adapted to survive and even thrive with natural wildfires. One study reported that
more than 90% of rare, threatened, and endangered plants in the 48 coterminous64
states either benefit from fire or are found in fire-adapted ecosystems. Also, as
noted above, animal mortality in wildfires is rare. Thus, treatments that only restore
forests to conditions that allow an historically natural ecological role for wildfire are
more likely to benefit endangered and threatened species than to harm them.
62 See CRS Report RL33990, Wildfire Funding, Table 7 (page CRS-12), by Ross W. Gorte.
63 For information on ESA generally, see CRS Report RL31654, The Endangered Species
Act: A Primer, by M. Lynne Corn, Eugene H. Buck, and Kristina Alexander.
64 Amy Hessl and Susan Spackman, Effects of Fire on Threatened and Endangered Plants:
An Annotated Bibliography, Information and Technical Report 2 (Ft. Collins, CO: U.S.
Dept. of the Interior, National Biological Service, n.d.).
Nonetheless, ESA consultations take time, and can delay fuel treatments. This
is more likely to be the case when restoration treatments (e.g., prescribed burning or
thinning from below) are combined with other activities (e.g., commercial timber
harvesting), such as in a stewardship contract. Thus, the method used to undertake
the treatment, as well as the nature of the treatment itself, determines the length of
delays and possible project modifications from ESA consultations.
NEPA Environmental Analysis and Public Involvement.65 NEPA
requires federal agencies to review the environmental effects of “major Federal
actions significantly affecting the quality of the human environment.” Agencies must
consider every significant aspect of the environmental impacts of a proposed action
before making an irreversible commitment of resources to the project. NEPA also
requires that agencies inform the public that they have considered those impacts in
their decision-making process. In his Executive Order on NEPA implementation,
President Richard Nixon directed the agencies to go beyond just informing the
public, to actively involve the public early in the decision-making process.66 Fuel
reduction treatments to protect resources from wildfires are generally considered to
be major federal actions subject to NEPA.
Environmental Analysis. The action agency must analyze the possible
environmental consequences of its actions. The first step is to determine if the action
will have significant environmental impacts. There are three possible outcomes. If
significant impacts are likely, then the agency prepares an environmental impact
statement (EIS). If the impacts are normally insignificant — individually and
cumulatively — the activity can be categorically excluded from further NEPA
environmental analysis and public involvement. (See below.) If the significance of
the impacts is uncertain, the agency prepares an environmental assessment (EA) to
determine the significance of the impacts. The EA leads either to a finding of no
significant impact (FONSI) or to an EIS.
Advocates of expedited fuel treatment are concerned about the time needed to
prepare an EIS or even an EA. Information collection and analysis may take from
several days to a few months, depending on the magnitude and complexity of the
proposed action. An EIS involves additional steps to assess the likely and the
possible environmental impacts and to inform and involve the public. These steps
include scoping (public discussions about the nature, location, and possible
consequences of the proposal); a draft EIS, examining a range of alternatives and
generally identifying a preferred alternative; public comments on the draft and the
preferred alternative; and then a final EIS and Record of Decision (ROD).67 Only
after completing this process — which can take a year or more for large, complex
65 For more information on NEPA generally, see CRS Report RL33152, The National
Environmental Policy Act: Background and Implementation, by Linda Luther, and CRS
Report RS20621, Overview of National Environmental Policy Act (NEPA) Requirements,
by Kristina Alexander.
66 Executive Order 11514, “Protection and Enhancement of Environmental Quality,” 35 Fed.
Reg. 4247 (March 5, 1970).
67 A simplified flowchart of this process can be found in Figure 1 (page CRS-22) of CRS
projects — can the agency undertake the action. Thus, proponents of expeditious
fuel reduction projects often advocate various approaches to accelerate the process,
Categorical Exclusions (CEs). As noted above, certain projects can be
categorically excluded from the requirement to prepare an EA or an EIS. Such a CE68
action is defined as:
... a category of actions which do not individually or cumulatively have a signifi-
cant effect on the human environment ... and for which, therefore, neither an
environmental assessment nor an environmental impact statement is required....
Any procedures under this section shall provide for extraordinary circumstances
in which a normally excluded action may have a significant environmental effect.
CEs are typically used for relatively minor, routine actions that the agency does
frequently and has found to have at most insignificant environmental impacts. For
projects approved under CEs, the Forest Service is not required to provide notice and
opportunity for public comment as otherwise required for agency activities under the
ARA. (See below.)
In certain situations — such as controversial issues (e.g., wetlands and roadless
areas) or specifically protected resources (e.g., endangered species and archaeological
sites) — known as extraordinary circumstances, CEs cannot be used. In 2002, the
Forest Service modified its application of extraordinary circumstances, allowing the
responsible official to determine whether the extraordinary circumstances warranted
an EA or an EIS rather than automatically precluding use of a CE in the presence of69
The Forest Service has identified numerous categories of actions for which a CE
may be used; two relate directly to wildfire protection (for details on Forest Service
CEs and extraordinary circumstances, see Appendix A):70
[including] thinning or brush control to improve growth or reduce fire hazard ...,
prescribed burning to control understory hardwoods in stands of southern pine,
and prescribed burning to reduce natural fuel build-up ....
10. Hazardous fuel reduction activities using prescribed fire, not to exceed
cutting, chipping, mulching, and mowing, not to exceed 1,000 acres ... limited to
... the wildland-urban interface; or Condition Classes 2 or 3 [moderate or high
risk of ecological damage] in Fire Regimes I, II, or III [surface fire, stand-
replacement fire with a return interval of 35 years or less, and mixed-intensity
fire] ... (Emphasis in original)
68 40 C.F.R. § 1508.4.
69 67 Fed. Reg. 54622 (Aug. 23, 2002).
70 Forest Service Handbook, National Headquarters (WO), Washington, DC, FSH 1909.15 -
Environmental Policy and Procedures Handbook. Chapter 30 - Categorical Exclusion from
Documentation, Amendment No. 1909.15-2007-1 (Feb. 15, 2007).
Forest Service use of the latter CE was halted after a court found it was arbitrary
and capricious.71 Other CEs have also been challenged, raising questions about the
availability of CEs for fuel reduction projects.72
Forest Service Appeals Reform Act. In addition to public involvement
under NEPA, the Forest Service must also inform the public of its decisions and
provide an opportunity for the public to request an administrative review of its
decisions under the Forest Service Decisionmaking and Appeals Reform Act73
(ARA). Subsections (a) and (b) require the Forest Service to provide notice and an
opportunity for public comment on proposed actions; this is the only provision
requiring notice and comment on Forest Service proposals other than under NEPA.
Subsections (c) and (d) specify an administrative appeals process — review by a
higher-ranking official — for those who had commented on the proposal and object
to the decision.
GAO was asked to examine administrative appeals of fuel reduction projects.74
For FY2001 and FY2002, prior to promulgation of the hazardous fuel reduction CE,
59% of fuel reduction projects used CEs and could not be appealed. Of those that
could be appealed, 58% were appealed (i.e., 24% of all fuel reduction projects during
that period). Of those, 73% were implemented without change, 8% were modified,
and 19% (less than 5% of all projects) were withdrawn or reversed. Furthermore,
supported by a study of all Forest Service administrative appeals. This study found
that 8% of appeals were granted (i.e., decision reversed) and that 9% of appealed
decisions were withdrawn.
A different study examined factors that increased the likelihood of a fuel
reduction project being appealed.76 They reported that appeals were more likely for
fuel reduction projects that (1) affected more area; (2) included more activities for the
site; (3) included commercial timber harvest; (4) included as a purpose reducing fuels
generated by the project; and (5) had at least one threatened or endangered mammal
near the site. These factors are indirectly confirmed in the GAO study, since 92% of
71 Sierra Club v. Bosworth, 510 F. 3d 1016 (9th Cir. 2007).
72 For information on the status of relevant judicial decisions, see CRS Report RL33792,
Federal Lands Managed by the Bureau of Land Management (BLM) and the Forest Serviceth
(FS): Issues for the 110 Congress, “FS NEPA Application and Categorical Exclusions,”
by Ross W. Gorte and Kristina Alexander.
73 Section 322 of the Department of the Interior and Related Agencies Appropriations Act,
74 GAO, Forest Service: Information on Appeals and Litigation Involving Fuels Reduction
Activities, GAO-04-52 (Washington, DC: Oct. 2003).
75 Gretchen M.R. Teich, Jacqueline Vaughn, and Hanna J. Cortner, “National Trends in the
Use of Forest Service Administrative Appeals,” Journal of Forestry, v. 102 (March 2004):
76 David N. LaBand, Armando González-Cabán, and Anwar Hussain, “Factors That
Influence Administrative Appeals of Proposed USDA Forest Service Fuels Reduction
Actions,” Forest Science, v. 52, no. 2 (2006): pp. 477-488.
projects with EISs (larger projects with likely environmental impacts) were appealed,
compared to 52% of projects with EAs (projects with uncertain environmental
impacts).77 Conversely, projects were significantly less likely to be appealed if the
project was: (1) implemented by Forest Service personnel or a service contract; and
(2) in the wildland-urban interface.
These data suggest that administrative appeals are less of a problem than the
advocates of fuel treatment suggests. Only about a quarter of proposed projects are
appealed, with less than 5% prevented from being implemented, and delays of less
than 90 days for most projects. However, for prescribed burning, a 90-day delay can
be significant, since the period within the prescribed conditions can be brief.
Expedited Procedures. Proponents of aggressive fuel treatment continue
to be concerned about delays from the ESA, NEPA, and ARA review processes, and
have pressed for various means for accelerating the reviews. Some procedures are
currently feasible under existing regulations, others have been enacted by Congress
in various contexts, and more have been proposed.
Expedited ESA Consultations. As noted above, during emergencies, the
agencies can consult informally for rapid action, with formal consultations to follow
when the situation has stabilized. This clearly applied during wildfire suppression
activities, but fuel reduction treatments are not emergency actions that require an
immediate response to prevent damages. As discussed above, lengthy (multi-year)
delays in fuel reduction activities can increase the likelihood of resource damages
from wildfires, but brief delays have minor impacts.
The agencies have developed an alternative approach to ESA consultations that
is intended to accelerate the ESA review process: counterpart regulations.78 These
regulations allow the Forest Service, BLM, and others to assess whether the proposed
fuel reduction action is likely to jeopardize a listed threatened or endangered species
or to adversely modify critical habitat, rather than to consult with the Fish and
Wildfire Service on the likelihood of jeopardy or adverse habitat modification.
While some ESA counterpart regulations have been challenged successfully, the
counterpart regulations related to wildfire management remain in place.79
Expedited NEPA Reviews (other than through CEs). In addition to the
option of CEs, the NEPA regulations of the Council on Environmental Quality
(CEQ) allow for alternative arrangements in the event of an emergency.80 These
alternative arrangements do not waive NEPA requirements, but establish an
alternative means of fulfilling those requirements for actions necessary to control the
immediate impacts of an emergency, typically with conditions on short-term and
77 GAO, Information on Appeals of Fuel Reduction Activities.
78 68 Fed. Reg. 68254 (Dec. 8, 2003).
79 See CRS Report RL33779, The Endangered Species Act (ESA) in the 110th Congress:
Conflicting Values and Difficult Choices, by Eugene H. Buck, M. Lynne Corn, Pervaze A.
Sheikh, Robert Meltz, and Kristina Alexander, at p. CRS-18.
80 40 C.F.R. § 1506.11.
long-term actions.81 For example, in 1998, the Forest Service requested alternative
arrangements for rapid restoration actions following a windstorm that damaged
103,000 acres of national forest land in Texas that contained critical habitat for the
endangered red-cockaded woodpecker; CEQ concurred that the situation was an
emergency and agreed to alternative arrangements that included subsequent
preparation of an EA, limits on tree removal, long-term public involvement,
emergency consultation under ESA, and more.
For fuel treatment, NEPA alternative arrangements will rarely provide a means
of accelerated action. First, alternative arrangements are not used very often — 41
requests were made from 1978 through 2006.82 Second, alternative arrangements are
to be used for emergencies. Fuel conditions in a delineated area might occasionally
be an emergency, such as in the wake of a ice storm or a tornado, but fuel levels
generally do not constitute an emergency requiring immediate action.
Healthy Forests Restoration Act. The Healthy Forests Restoration Act of
2003 (HFRA; P.L. 108-148, 16 U.S.C. §§ 6501-6591) expedited review processes
in several ways. In Title I, it modifies the NEPA environmental analysis and public
involvement processes for authorized Forest Service and BLM fuel reduction projects
(based on priorities, exclusions, and other standards in the act). The EA or EIS for
each project may be limited to the proposed action, the no-action alternative, and
possibly an additional alternative (in contrast to the range of alternatives normally
required). The agencies “shall facilitate collaboration” with tribes and state and local
governments and “participation” of interested persons; however, it does not explain
the distinction between collaboration with certain interests and participation by other
Title I includes two other changes to accelerate fuel reduction projects. First,
for the Forest Service, it replaces ARA administrative appeals with a “predecisional
administrative review process.” This process is only available to persons who
submitted “specific written comments that relate to the proposed action” during
scoping or the public comment period on the draft NEPA document. The process is
also limited to the period between completing the EA or EIS and issuing the Record
of Decision, with no requirements for how long that period must be. Then, the act
restricts judicial review, generally limiting plaintiffs to those who have exhausted
administrative review processes and specifying the venue for review, while
encouraging expeditious judicial review and requiring the courts to balance the short-
and long-term effects of action and inaction in deciding on injunctions.
In Title IV, HFRA allows the use of CEs for “applied silvicultural assessments”
— timber harvesting and other vegetative treatments “for information gathering and
research purposes.” Each treatment is limited to 1,000 acres, with exclusions for
certain areas and limitations on the adjacency of treatments, and with public notice
and comment and “peer reviewed by scientific experts selected by the Secretary [of
Agriculture or of the Interior], which shall include non-Federal experts.” Total
81 See CRS Report RL33104, NEPA and Hurricane Response, Recovery, and Rebuilding
Efforts, by Linda Luther.
82 Email communication from Ted Bolling, CEQ, to Linda Luther, CRS, Jan. 22, 2008.
acreage of all applied silvicultural assessments using this CE is limited to 250,000
Other Possibilities. Congress can create other means of accelerating the
decision-making process for fuel reduction treatments. Congress has exempted
certain federal activities (such as construction of the Trans-Alaska Pipeline to deliver83
oil from the North Slope) from NEPA compliance. Congress has also directed in
law that no EIS or EA be prepared in certain instances, through direct statutory
language or by deeming that the authorized activities are not major federal actions
that significantly affect the human environment. Congress has also pronounced
certain analyses or substitute processes to be sufficient or adequate under NEPA.
Congress has also established alternative review processes. Typically this is in
addition to NEPA public involvement, to accelerate the review by obtaining broader,
organized review early in the decision-making process, vetting the decision before
public review. Examples include resource advisory committees (RACs) under § 403
of the Federal Land Policy and Management Act of 1976 (FLPMA; P.L. 94-579, 43
U.S.C. § 1753) and under Title II of the Secure Rural Schools and Community Self-
Determination Act of 2000 (P.L. 106-393; 16 U.S.C. § 500 note). Other advisory or
collaborative groups have been established or acknowledged statutorily, commonly
to provide supplemental public involvement.
Considerations in Expediting Decisions. Public acceptance of options
to accelerate fuel treatments depends on a variety of factors. In general, earlier
discourse among interests about the risks and needed treatments lead to greater
comfort with the resulting decisions. One study found that survey respondents were
willing to accept limitations on the rights to appeal and litigate agency decisions, but
wanted to be more informed and involved in those decisions.84 Greater specificity
in approved treatments also is likely to result in greater acceptance. For example, a
treatment prescription that specifies “thinning from below to approximately 20-foot
spacing of remaining trees and emphasizing retention of Ponderosa pine” is likely to
be more acceptable than “mechanical treatment to reduce stand density.” Finally,
authors have identified the need for collective action to minimize conflict over
decisions, and three broad social factors to achieve collective action: developing
collaborative capacity, framing problems in mutually-understood terms, and creating
mutual trust among groups.85 These are factors that take time, and cannot be
legislated directly, although Congress can foster (or negate) their development by the
ways in which it authorizes agency action to promote wildfire protection.
83 See CRS Report 98-417 A, Statutory Modifications of the Application of NEPA, by
84 David M. Ostergren, Kimberly A. Lowe, Jesse B. Abrams, and Elizabeth J. Ruther,
“Public Perceptions of Forest Management in North Central Arizona: The Paradox of
Demanding More Involvement but Allowing Limits to Legal Action,” Journal of Forestry,
v. 104 (Oct./Nov. 2006): pp. 375-382.
85 Jeffrey J. Brooks, Alexander N. Bujak, Joseph G. Champ, and Daniel R. Williams,
Collaborative Capacity, Problem Framing, and Mutual Trust in Addressing the Wildland
Fire Social Problem: An Annotated Reading List, Gen. Tech. Rept. RMRS-GTR-182 (Ft.
Collins, CO: USDA Forest Service, Rocky Mountain Research Station, Nov. 2006).
As more acres and more homes have burned in the past few years, and more
people at risk from wildfires, Congress has faced increasing pressures to protect
structures and resources. Congress decides what programs to authorize and fund, and
many options exist.
To protect homes, Congress could create new programs and expand existing
ones for installing non-flammable roofing, removing burnable materials adjacent to
structures, and creating a defensible space of at least 30 feet around the building.
Programs could inform homeowners, or assist or require landowner action; the
programs could be federal or implemented through state or local governments.
Protecting resources poses different challenges for Congress, because ecological
damages vary widely, depending on the ecosystem and on site-specific conditions.
Fuel reduction can probably moderate crown fire damages in surface-fire ecosystems,
and possibly in mixed-intensity-fire ecosystems. Existing programs for federal lands
authorize prescribed burning (intentional fires under prescribed conditions) and
mechanical treatments (cutting and removing some trees), the principal means of
reducing fuel levels. However, prescribed fires are risky and mechanical treatments
can cause other ecological damages, and both are expensive. Proponents of more
fuel treatment advocate accelerated processes for environmental analysis and public
review to reduce costs and expedite action. Others caution that inadequate analysis
and review can allow projects with unintended damages and few fire protection
benefits. Congress can alter the existing environmental and public review processes,
recognizing the trade-offs between expeditious action and insufficient review.
However, the fact is that crown fires occur; they cannot be halted and the damages
they cause cannot be totally prevented.
Excerpts from Forest Service Handbook on
NEPA Categorical Exclusions Related to
Structural or Resource Protection From Wildfires
The following material are excerpts from the Forest Service handbook on NEPA
categorical exclusions — FSH 1909.15 - Environmental Policy and Procedures
Handbook. Chapter 30 - Categorical Exclusion from Documentation, Amendment
No. 1909.15-2007-1 (Feb. 15, 2007). Emphases (underscoring and boldface font) are
in the original.
30.3 - Policy
2. Resource conditions that should be considered in determining whether
extraordinary circumstances related to the proposed action warrant further analysis
and documentation in an EA or EIS are:
a. Federally listed threatened or endangered species or designated critical
habitat, species proposed for Federal listing or proposed critical habitat, or
Forest Service sensitive species.
b. Flood plains, wetlands, or municipal watersheds.
c. Congressionally designated areas, such as wilderness, wilderness study
areas, or national recreation areas.
d. Inventoried roadless areas.
e. Research natural areas.
f. American Indians or Alaska Native religious or cultural sites.
g. Archaeological sites, or historic properties or areas.
31.2 - Categories of Actions for Which a Project or Case File and Decision
Memo Are Required
6. Timber stand and/or wildlife habitat improvement activities which do not
include the use of herbicides or do not require more than one mile of low standard
road construction .... Examples include but are not limited to:
b. Thinning or brush control to improve growth or to reduce fire hazard
including the opening of an existing road to a dense timber stand.
c. Prescribed burning to control understory hardwoods in stands of
d. Prescribed burning to reduce natural fuel build-up and improve plant
10. Hazardous fuels reduction activities using prescribed fire, not to exceed
chipping, mulching, and mowing, not to exceed 1,000 acres. Such activities:
a. Shall be limited to areas:
(1) In the wildland-urban interface; or
(2) Condition Classes 2 or 3 [moderate or high risk of ecological
damage] in Fire Regimes I, II, or III [surface fire, stand-replacement
fire at 35 years or less, and mixed-intensity fire], outside the
b. Shall be identified through a collaborative framework as described in “A
Collaborative Approach for Reducing Wildland Fire Risks to Communities and
Environment 10-Year Comprehensive Strategy Implementation Plan”;
c. Shall be conducted consistent with agency and Departmental procedures and
applicable land and resource management plans;
d. Shall not be conducted in wilderness areas or impair the suitability of
wilderness study areas for preservation as wilderness; and
e. Shall not include the use of herbicides or pesticides or the construction of
new permanent roads or other new permanent infrastructure; and may include
the sale of vegetative material if the primary purpose of the activity is hazardous
12. Harvest of live trees not to exceed 70 acres, requiring no more than ½ mile
of temporary road construction. Do not use this category for even-aged regeneration
harvest or vegetation type conversion. The proposed action may include incidental
removal of trees for landings, skid trails, and road clearing. Examples include but
are not limited to:
a. Removal of individual trees for sawlogs, specialty products, or
b. Commercial thinning of overstocked stands to achieve the desired stocking
level to increase health and vigor.
13. Salvage of dead and/or dying trees not to exceed 250 acres, requiring no
more than ½ mile of temporary road construction. The proposed action may include
incidental removal of live or dead trees for landings, skid trails, and road clearing.
Examples include but are not limited to:
a. Harvest of a portion of a stand damaged by a wind or ice event and
construction of a short temporary road to access the damaged trees.
b. Harvest of fire-damaged trees.
14. Commercial and non-commercial sanitation harvest of trees to control
insects or disease not to exceed 250 acres, requiring no more than ½ mile of
temporary road construction, including removal of infested/infected trees and
adjacent live uninfested/uninfected trees as determined necessary to control the
spread of insects or disease. The proposed action may include incidental removal
of live or dead trees for landings, skid trails, and road clearing. Examples include but
are not limited to:
a. Felling and harvest of trees infested with southern pine beetles and
immediately adjacent uninfested trees to control expanding spot infestations.
b. Removal and/or destruction of infested trees affected by a new exotic insect
or disease, such as emerald ash borer, Asian long horned beetle, and sudden oak