Fuels Planning: Science Synthesis &
Integration Forest Structure & Fire Hazard
David L. Peterson and Morris Johnson
Forest Service – PNW Research Station
Pacific Wildland Fire Sciences Lab
Objectives
• Synthesize & publish scientific knowledge &
principles about how modifications of forest
structure affect fire hazard & fire behavior.
• Develop quantitative guidelines for how
silvicultural prescriptions affect fire hazard & fire
behavior – guide for representative forest types
of the western U.S.
Application: Assist the NEPA process, planning, and
decision making primarily at the scale of forest
stands.
Linkage: Provide input for economic and
ecological analyses.
PRODUCT 1:
Fact Sheets
Six fact sheets on forest structure and fire
hazard
•
•
•
•
•
•
Project overview: stand structure and fire
Fire hazard concepts
Visualizing fuels and stand structure
Role of silviculture in fuel treatments
Large-scale fuel treatments
Principles of fuel management in complex
ecosystems
PRODUCT 2:
PNW General Technical Report PNW-GTR-628
Forest Structure and Fire Hazard in Dry Forests of
the Western United States
DL Peterson, MC Johnson, JK Agee, TB Jain, D
McKenzie, ED Reinhardt
• Subjected to anonymous peer review through
editor of Natural Resources Journal
• Synthesis of existing literature and concepts on
forest structure, fuels, and fire hazard
• Qualitative and quantitative guidelines for fuel
treatments
• Intended to provide scientific support for NEPA
analysis of fuel treatments
PRODUCT 3:
Guide to Fuel Treatments in Dry Forests of the
Western United States: Assessing Forest
Structure and Fire Hazard
MC Johnson, DL Peterson, CL Raymond
• Analyzes a range of potential fuel and vegetation
treatments for dry forest in the western United States
• Direct linkage to My Fuel Treatment Planner
• Extensive review by fire managers and silviculturists
• Quantitative
-- Stand attributes, fuel loadings, potential fire
behavior
• Qualitative
-- Pre and post treatment EnVision images
Purpose
• Testing the scientific basic of silvicultural and
surface fuel treatments on modifying fire
behavior in dry interior forests through
designing and implementing thinning and
surface fuel treatments based on the four
principles of fire resistance forests: (1) treat
surface fuels, (2) raise the height to live
crown, (3) decrease crown density, and (4)
leave the big trees.
Approach
Stand exam data
from National
Forests in FVS ready
format
98th and 75th
percentile historical
fire weather data
from Desert
Research Institute
Build FFE-FVS
portfolio for each
National Forest
Design silvicultural
and surface fuel
treatments and
Regeneration
Matrix
Determine
candidate stands
for treatment from
each forest
Implement and
analyze effects of
treatments
Summarization of
Treatment Effects
Develop Fuel
Treatment
Guidebook
Study Areas
Fuel Treatment Guidebook
• Selected Forest Types
– Ponderosa Pine
– Mixed Conifer
– Pinyon-Juniper
• Stand Exams
• FIA FVS Ready
FVS variants
Stand Exam Data Sources
• Natural Resources Information System
(NRIS) Field Sampled Vegetation (FSVeg)
Module is an Oracle database
– store data from stand examinations,
grid-based strategic inventories,
permanent re-measured inventory plots
• FVS DataBase Extension List Builder
• 37,000 stands in FVS ready file format
Historical Fire Weather Data
Remote Automated Weather Stations (RAWS)
• 75th (moderate) and
98th (severe)
percentile historical
fire weather data
from (RAWS)
– Temperature,
– Wind speeds*
– 1,10,100*, 1000* hr fuel
moistures
– FFE-FVS variant default
live and duff fuel
moistures
Approach
Stand exam data
from National
Forests in FVS ready
format
98th and 75th
percentile historical
fire weather data
from Desert
Research Institute
Build FFE-FVS
portfolio for each
National Forest
Design silvicultural
and surface fuel
treatments and
regeneration matrix
Determine
candidate stands
for treatment from
each forest
Implement and
analyze effects of
treatments
Model
Shortcomings and
Recommendations
Develop Fuel
Treatment
Guidebook
Principles of fire resistance for dry forests
Principle
Effect
Advantage
Concerns
Reduce surface
fuels
Reduces
potential flame
length
Control easier;
less torching
Surface
disturbance less
with fire than
other techniques
Increase height
to live crown
Requires longer
flame length to
begin torching
Less torching
Opens
understory; may
allow surface
wind to increase
Decrease crown
density
Makes tree-totree crown fire
less probable
Reduces crown
fire potential
Surface wind
may increase
and surface fuels
may be drier
Keep big trees of
resistant species
Less mortality for
same fire
intensity
Generally
restores historic
structure
Less economical;
may keep tree at
risk of insect
attack
Adopted Agee 2002
No action Prescribed Thin from
fire only
below to 50
tpa, 18 inch
dbh limit
No action
Thin from
below to 100
tpa, 18 inch
dbh limit
Thin from
below to 200
tpa, 18 inch
dbh limit
Pile & burn
Thin from
below to 300
tpa, 18 inch
dbh limit
Prescribed fire
Regeneration Matrix
• Partial Establishment Model
• (Region 3, 5, & 6 National Forests)
– planting or stump sprouting; user must provide
estimates of natural regeneration
– residual trees per acre and surface fuel
treatment
• Full Establishment Model
• (Region 1 & 4 National Forests)
– calibrated for western Montana, central and
northern Idaho, and coastal Alaska
Regeneration Matrix
Residual Density
Surface fuel
treatment
Region No Action
6
Pile & burn
Prescribed fire
Region No action
5
Pile & burn
Prescribed fire
Region No action
3
Pile & burn
Prescribed fire
50 tpa
100 tpa
200 tpa
300 tpa
100
50
25
25
150
75
38
38
300
150
75
74
50
25
13
13
75
38
20
20
150
75
40
40
15
8
4
4
23
12
6
6
45
25
12
12
Approach
Stand exam data
from National
Forests in FVS ready
format
98th and 75th
percentile historical
fire weather data
from Desert
Research Institute
Build FFE-FVS
portfolio for each
National Forest
Design silvicultural
and surface fuel
treatments and
regeneration matrix
Determine
candidate stands
for treatment from
each forest
Implement and
analyze effects of
treatments
Model
Shortcomings and
Recommendations
Develop Fuel
Treatment
Guidebook
Select Candidate Stands
• high stem densities
and heavy ladder
fuels, common
due to fire
exclusion
Select Candidate Stands
Modeled in EnVision
Analyze Results
• Evaluate immediate consequences of
thinning treatments and determine which
treatments were most effective at reducing
fire hazard
– Examine change crown fire hazard
•Torching and crowning index
– Examine change in fire behavior
•fire type, flame length, mortality
• Project candidate stands 50 years to
evaluate silvicultural and surface fuel
treatments influence on forest structure and
fire behavior over time
Analyze Results
• Determine which treatments were
effective at modifying fire hazard and
why?
• Evaluate the effects of prescribed fire
only and determine if this treatment
was effective as a stand alone
management strategy for reducing
fire hazard
• Discuss limitations and shortcomings of
modeling approach
Preliminary Results
50 TPA
200 TPA
100 TPA
300 TPA
Preliminary Results
Fire behavior
Fire Hazard
Treatment
Fire type
Mortality %
TI
CI
Moderate
Severe
CBH
CBD
Moderate
Severe
No action
0
31
s
p
2
0.08
21
75
Prescribed
fire only
19
43
s
s
10
0.04
7
11
50 TPA
63
53
s
s
31
0.06
11
25
100 TPA
22
40
s
s
11
0.07
16
26
200 TPA
26
34
s
s
11
0.07
19
23
300 TPA
34
31
s
s
14
0.05
16
30
Fire
Weather
conditions
% moisture
Wind
Temp
1-hr
10-hr
100-hr
1000-hr
mph
(F)
0-0.25”
0.25-1”
1-3”
3”
Duff
Live
Severe
14
81
3
5
8
11
50
100
Moderate
8
61
6
8
11
14
125
150
Acknowledgements
• Fire and Environmental Applications Team
• Pacific Northwest Research Station
• Fire and Aviation Management Staff WO
•
Acknowledgements
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Brian Ferguson
Stephanie A Rebain
Chad Keyser
Pat Jackson
Kama Kennedy
Renee Lundberg
Bill MacArthur
Charles Maxwell
Georgi Porter
Eric Twombly
Leo Yanez