Fire Ecology
Pete Fulé
Northern Arizona University
Overview
1) Fire regimes
2) Fire history methods
a) Fire scars
b) Comparison to records
3) Fire and climate
4) Effects of forest restoration on
fire behavior
5) Future fires: drought & beetles
Fire Regimes
Frequency
Intensity
High frequency
High intensity
(e.g., FL Everglades)
Low frequency
High intensity
(e.g., boreal,
subalpine, lodgepole)
High frequency
Low intensity
(e.g., ponderosa pine)
Low frequency
Low intensity
(some deserts?)
Fire History Methods
Fire scars — common technique in surface-fire ecosystems.
Advantages: exact dates (even seasons of fires),
locations of scarred trees.
Disadvantages: can’t map fire perimeter, absence of
scars ≠ absence of fire.
Stand age — common technique in stand-replacing
ecosystems.
Advantages: map perimeter/area of fire.
Disadvantages: imprecise fire date, newer fires
obliterate evidence of older ones.
How good are fire scar methods? Critiqued by Baker & Ehle
(2001, Can. J. Forest Research 31:1205-1226)
Comparison to Fire Records
• Across western North America, we usually find
sites with good records but no fires (USA), or
many fires but limited records (Mexico).
Comparison to Fire Records
• Across western North America, we usually find
sites with good records but no fires (USA), or
many fires but limited records (Mexico).
• Grand Canyon has both: earliest recorded fire is
the 1924 “Powell” fire.
Comparison to Fire Records
• Across western North America, we usually find
sites with good records but no fires (USA), or
many fires but limited records (Mexico).
• Grand Canyon has both: earliest recorded fire is
the 1924 “Powell” fire.
• Independent fire scar analysis found each of the
13 recorded fires > 20 acres since 1924 on the
Powell, Rainbow, & Fire Pt. study sites (total of
1700 acres).
Fulé, P.Z., T.A. Heinlein, W.W. Covington, and M.M. Moore. 2003. Assessing fire regimes on Grand Canyon landscapes
with fire scar and fire record data. International Journal of Wildland Fire 12(2):129-145.
Emerald Prescribed
Natural Fire
August 10-24, 1993
Final size: 138 ha
Stars indicate six samples that
recorded the fire
Six additional samples did not
record the fire
Fire History 1700 to 1997
All Fires
Fires scarring 25%or more of the samples
Fulé, P.Z., T.A. Heinlein, W.W. Covington, and M.M. Moore. 2000. Continuing fire regimes in remote forests of Grand
Canyon National Park. USDA Forest Service Proceedings RMRS-P-15-VOL-5: 242-248.
Powell Plateau, Grand Canyon National Park
Mixed Conifer
Mid elevation site
(2500 m):
Swamp Ridge
Northwest III
Fire frequency:
6-9 years
Swamp Ridge, Grand Canyon N.P.
Last fire 1879
Forest: mixed
conifer, formerly
ponderosa pine
High elevation sites
(2550-2800 m):
Little Park
Fire frequency:
complex patterns,
MFI25%= 31 yr
MFIPoint= 32 yr
Wt avg of fire-initiated
stands = 22 yrs
Last fire 1879
Forest: aspen, mixed
conifer, spruce-fir
Forest Simulation and Fire Behavior Modeling
Current
Forest
Structure
(circa 2000)
Dendro
Tested
procedures
Site data
1880 Forest
Structure
Intersecting evidence:
• Lang & Stewart survey (1910)
• Historical photos & data
• Rasmussen (1941)
Smoke
Wildlife
FVS
Add regen
Compared to
measured
data in 2000,
+/- 20%
Simulate
1880-2040
Fire Plan
Forest Plan
Landscape Maps
1880-2040
Compared to
observed fire
behavior
(NWIII fire
& Outlet fire)
Biomass
equations
Crowning
Index
Crown
Biomass
Nexus
Fire weather
Crown biomass changes in Grand Canyon forests, 1880-2040
Percent Mesic Species
Crown Biomass Changes 1880-2040
Crown Biomass (kg/ha)
18000
1880:
FP
RP
30% @ 2500 m
65% @ 2650 m
86% @ 2700 m
PP
12000
SR
BS
LP
6000
2040:
0
1880
1900
1920
1940
1960
Decade
1980
2000
2020
2040
60% @ 2500 m
86% @ 2650 m
96% @ 2700 m
Fulé, P.Z., J.E. Crouse, A.E. Cocke, M.M. Moore, and W.W. Covington. 2003. Changes in canopy fuels and potential fire
behavior 1880-2040: Grand Canyon, Arizona. Final Report to the Joint Fire Science Program, CA-1200-99-009-NAU 04
(Part 2).
Kaibab Plateau, Arizona
Site
Kaibab
National
Forest
2
1
5
3
6
7
4
Grand Canyon
National Park
Elev.
Veg.
MFI*
1) Powell
Plateau
2296
Pine
4.5
2) Fire Point
2338
Pine
4.9
3) Rainbow
Plateau
2320
Pine
5.3
4) Galahad
Point
2350
Pine
4.0
5) Swamp
Ridge
2482
Mix Con
7.1
6) Big Spring
2650
Aspen,
Spruce
31
7) Little Park
2724
Aspen,
Spruce
31
* Mean Fire Interval (10%-scarred < 2,500 m)
Fulé, P.Z., T.A. Heinlein, W.W. Covington, and M.M. Moore. 2003.
Assessing fire regimes on Grand Canyon landscapes with fire scar and
fire record data. International Journal of Wildland Fire 12(2).
Fulé, P.Z., J.E. Crouse, T.A. Heinlein, M.M. Moore, W.W. Covington,
and G. Verkamp. 2003. Mixed-Severity Fire Regime in a HighElevation Forest: Grand Canyon, Arizona. Landscape Ecology 18:465486.
Fire and Climate
• Climate is the major factor influencing distribution of
ecosystems and occurrence of “fire weather”.
• Southwest has frequent fires because climate is dry,
hot, and windy nearly every summer.
• Climate causes synchrony in burning across landscapes,
mountain ranges, states.
• Drought affects likelihood of fire.
• El Niño/Southern Oscillation affects likelihood of fire.
Synchrony of Major Fire Years in the Southwest
Swetnam, T.W., and C.H. Baisan. 2003. Tree-ring reconstructions of fire and climate history in the Sierra Nevada
and southwestern United States. In: T.T. Veblen, W.L. Baker, G. Montenegro, and T.W. Swetnam (Editors), Fire
and Climatic Change in Temperate Ecosystems of the Western Americas, Springer, New York, pp. 158-195.
Fire-ENSO Relationship Across the Southwest
Swetnam, T.W., and C.H. Baisan. 2003. Tree-ring reconstructions of fire and climate history in the Sierra Nevada
and southwestern United States. In: T.T. Veblen, W.L. Baker, G. Montenegro, and T.W. Swetnam (Editors), Fire
and Climatic Change in Temperate Ecosystems of the Western Americas, Springer, New York, pp. 158-195.
Horseshoe Fire (1996)
8,650 acres
(/
Wallace Fire (1979)
327 acres
Slate Fire (1996)
379 acres
Curley Fire (1980)
2,708 acres
Wild Bill Fire (1973)
7,814 acres
Kendrick Fire (1980)
185 acres
(/
Kelly Fire (1971)
2,732 acres
Kelly Fire (1954)
4,582 acres
Kendrick Fire (1956)
292 acres
Hostetter Fire
(1950) 1,077 acres
(1968) 225 acres
Burnt Fire (1973)
7,316 acres
Pumpkin Fire (2000)
15,779 acres
Hochderffer Fire (1996)
Bear Jaw Fire (1995)
16,400 acres
780 acres
Trick Fire (1993)
344 acres
White Horse Fire (1967)
865 acres
Ft. Valley Fire (1948)
2,068 acres
Leroux Fire (2001)
1,113 acres
Radio Fire (1977)
4,600 acres
Pipe Fire (2000)
664 acres
Belle Fire (1951)
,.1,128 acres
Side Fire (1996)
320 acres
Power Fire (2000)
1,527 acres
,.-
A-1 Fire (1950)
1,002 acres
,.-
Joe(/ Crouse, Andy Meador, Coconino NF data
Arizona 2002
Scar of the RodeoChediski fire
468,638 acres
NASA Visible Earth
Credit:Jacques Descloitres, MODIS
Land Rapid Response Team,
NASA/GSFC
Satellite:Terra
Sensor:MODIS
Data Start Date:06-30-2002
Does forest structure make a difference?
This is the Trick Fire, 1993, burning near the San Francisco
Peaks, AZ
Effects of forest restoration on fire behavior:
Grand Canyon, Arizona
Restoration Techniques
• Overstory trees: thinning, species composition,
spatial pattern, old-growth.
• Understory herbs and shrubs: natural
regeneration, seeding, planting.
• Fuels:
accumulated fuels, canopy fuels, dead biomass
as nutrient sources and habitat.
• Fire: re-introducing fire, unique initial burn
conditions, smoke.
• Monitoring and adapting:
making changes.
evaluating results and
Covington, W.W., P.Z. Fulé, M.M. Moore, S.C. Hart, T.E. Kolb, J.N. Mast, S.S. Sackett, and M.R. Wagner. 1997.
Restoration of ecosystem health in southwestern ponderosa pine forests. Journal of Forestry 95(4):23-29.
Project Progress
• Goal is to reduce uncharacteristically severe
wildfire hazard, restore forest structure and
dynamics.
• Three experimental blocks measured 1997 (in
the snow!)
• Grand Canyon NP: draft EA 1998, protests of
“logging in canyon,” no action taken.
• New environmental process completed in 2002
with 5” diameter cap. Thinning completed by
Northern Arizona Conservation Corps.
Northern Arizona Conservation
Corps members thinning and piling
slash with hand tools on Grand
Canyon’s North Rim, October, 2002
Experimental Design
• Kaibab National Forest: EA part of “Scott,”
thinned 1999, burned fall 1999, remeasured 2000.
• Control: continued fire exclusion.
• Three restoration alternatives.
• Full restoration: thinning (1.5/3 Rx), fuel
treatment, rx fire.
• Minimal thinning: thinning around old-growth trees,
fuels, rx fire.
• Burn-only: no fuel treatment, rx fire -- represents
current management practice.
Burned October 1999
Full Restoration
Minimal Thinning
Burn Only
Fulé, P.Z., W.W. Covington, H.B. Smith, J.D. Springer,
T.A. Heinlein, K.D. Huisinga, and M.M. Moore. 2002.
Testing ecological restoration alternatives: Grand
Canyon, Arizona. Forest Ecology and Management
170:19-41.
Forest structure
influences fire behavior
Crown bulk density
Fuel model 2 or 9
Canopy base height
Fuel model 9 or 10
45
PRE-Treatment:
torching at 21 mph,
crowning at 33-40
mph.
POST-Treatment
(FULL): torching at
35 mph, crowning at
75 mph.
PRE-Treatment Torching and Crowning
Indices
Torching Index
Crowning Index
40
Windspeed (mph)
35
30
25
20
15
10
5
0
Full
Min
Comparison to
reference (1887)
fire behavior:
torching 42 mph,
crowning 55-80 mph
Burn
POST-Treatment Torching and Crowning
Indices
90
Torching Index
Crowning Index
80
Windspeed (mph)
Control
70
60
50
40
30
20
10
0
Control
Full
Min
Burn
Do model results hold up in real fires?
Untreated stand, high
density/high fuel
Treated stand,
low density/low
fuel
Rodeo-Chediski fire 2002: White Mountain Apache lands
No treatment, killed by fire
Tree thinning and prescribed burning,
survived fire
Rodeo-Chediski Fire, 2002
Effects of Treatments
70
Treatments 19912001, forest above
6,560’, ≤ 45% slope
Low
Percent of Fire Area
60
50
Moderate
High
76% of untreated
area burned
moderate or high
severity
40
30
Only 4% (~1000
acres) of cut + burn
had high severity
20
10
0
Cut and Burned
Burn Only
No Treatment
Future Fires
• Increasing in size,
intensity, and severity.
• Increasing fire
suppression costs and loss
of life.
• Firefighting priorities
require focus on urban
interface (lives & property)
 sacrificing wildlands.
• Interaction with climate
change: drought & beetles.
Great Basin Incident Mgt Team (above)
Fuel hazards associated
with bark beetle-caused
tree mortality in the
Southwest.
forestfire.nau.edu/beetles.htm
University of Arizona
Arizona Public Service
“The most destructive fire …
was fed by more than a million
mature pine trees killed over
the past year by a bark beetle
infestation and drought. The
fire front in the national
forest was nearly 40 miles
long … “
John M. Broder, NY Times, October
27, 2003
“Even before the winds came,
the risk of fire in Southern
California was considered
extremely high because
several years of drought had
left trees vulnerable to the
bark beetle and other pests
and diseases. Hundreds of
thousands of trees are
estimated to have died,
making them easy to burn.”
Andrew Pollack, NY Times, October
27, 2003
Pine Bark Beetle Attack
Forest
Acres
Ponderosa
Acres
Beetle
Attack
Percent
Affected
ApacheSitgreaves
729,306
129,895
18%
Coconino
714,864
60,425
8%
Coronado
6,916
10,255 *
100% +
Kaibab
432,023
6,010
1%
Prescott
50,650
75,580 *
100% +
Tonto
140,128
66,585
48%
* Much of the “piñon/juniper type” forest includes some
ponderosa pine. Figures for 2003 from FS Forest
Health Protection program.