modeling bark beetle effects in a fireshed assessment an application of the westwide pine beetle...
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Modeling bark beetle effects in a fireshed assessment
An application of the Westwide Pine Beetle Model & the FFE in the
Deschutes National Forest
Andrew McMahan1
Alan Ager2, Helen Maffei3, Eric L Smith4
1 Systems Analyst, ITX, Inc., Ft. Collins2 Operations Research Analyst, PNW Research Station3 Forest Pathologist, Deschutes National Forest, Bend4 Program Manager, Quantitative Analysis, FHTET, Ft Collins
Primary Objective
• Simulate effects of bark beetles on stands in context of landscape-scale fuel mgmt and wildlife habitat mgmt projects– How might beetle dynamics respond to fuel
treatments?– How might beetle dynamics affect fuel
dynamics (spatially and temporally)?
Secondary Objectives
• Simulate beetle “sanitation” concurrent with simulated thinning treatments
• Consider dwarf mistletoe effects on beetle dynamics (partially done)
• Consider fire effects on bark beetle dynamics (not done)– simulate effects of live, fire-scorched trees on
stand attractiveness to beetles
Scenario design• With & without thinning treatment• With & without beetles
NoTRT-bNoTRT+BTRT-bTRT+B
• Treatments include WWPBM “sanitation”– Sanitation removes dead, beetle-infested
trees and their beetles
• Treatments are SDI-based thins from below (thinning by point)
Simulation Details
• SDIMAX for pines set to 429 (Cochran)
• If BSDI > 236 (55% of 429),
and year=2003, then...
• SetPThin to target SDI=150 (from below)
• Favor retention of pines and DF
• Run PPE for 7 3-yr cycles (2000-2021)
WWPB Model details
• Beetles (BKP) initialized into stands containing “significant” amounts of host in an amount = 1% of host BA
• “Severe” bark beetle outbreak initiated in simulation year=2005 for 5 years
Oregon
Deschutes National Forest
Five Buttes Analysis Area
Davis Fire (2003)
Mixed Conifer PAGs
0
20
40
60
80
100
120
140
160
2000 2005 2010 2015 2020
NoTRT-b All NoTRT+B All
TRT-b All TRT+B All
Average stand Basal Area (sq ft / acre)
Green=No Beetles
Red=with beetles
Dashed=treated
0
2
4
6
8
2000 2005 2010 2015 2020B
AK
/ac
re
TRT other
TRT MC
NOTRT other
NOTRT MC
Basal area beetle-killed (BAK; sq ft / acre) in Mixed Conifer (MC) PAG and “Other” PAGs
0
2
4
6
8
2000 2005 2010 2015 2020B
AK
/ac
re
NOTRT other NOTRT MC
Basal area beetle-killed (BAK) No Treatment (NoTRT) scenario
Mixed Conifer (MC) and “other” PAGs
0
2
4
6
8
2000 2005 2010 2015 2020B
AK
/ac
re
TRT other TRT MC
Basal area beetle-killed (BAK) Thinned (TRT) scenario
Mixed Conifer (MC) and “other” PAGs
0
2
4
6
8
2000 2005 2010 2015 2020B
AK
/ac
re
TRT MC NOTRT MC
Basal area beetle-killed (BAK) Mixed Conifer (MC) PAG
Both TRT & NoTRT scenarios
0
2
4
6
8
2000 2005 2010 2015 2020B
AK
/ac
re
TRT other NOTRT other
Basal area beetle-killed (BAK) “Other” PAGs
Both TRT & NoTRT scenarios
Orange: experience greater simulated beetle mortalityafter TRTGreens & blue: “protected”
0
100
200
300
400
500
600
2000 2005 2010 2015 2020
NoTrt+B NoTrt-b
TRT+B TRT-b
Potential Volume Mortality (Severe Fire)
(Millions of Cu Ft)
0
10
20
30
40
50
2000 2005 2010 2015 2020
Th
ou
sa
nd
s o
f A
cre
s
NoTrt-b NoTrt+B
Trt-b Trt+B
Acres Active Crown Fire Potential
Polygons with Active Crown Fire Potential in 2020Landscapes Without Treatments Without Beetles (ORANGE) on top ofWith Beetles (RED)
Red: stands classed as“Active” Crown Fireif beetle outbreak
Polygons with Active Crown Fire Potential in 2020Landscapes With Treatments Without Beetles (ORANGE) on top ofWith Beetles (RED)
Red: stands classed as“Active” Crown Fireif beetle outbreak
Surface Fuels2020Thinned landscapeNo Beetles
Surface Fuels2020Thinned landscapeWith Beetles
Orange Blue:Increase in surface fuelsdue to beetles
Treated Landscape 2018
Orange Blue:Increase in surface fuelsdue to beetles
Untreated Landscape 2018
Orange Blue:Decrease in standing fuelsdue to beetles
Untreated Landscape 2018
Orange Blue:Decrease in standing fuelsdue to beetles
Treated Landscape 2018
Mixed Conifer Forest types
0
10000
20000
30000
40000
50000
60000N
OT
RT
-b
NO
TR
T+
B
TR
T-b
TR
T+
B
NO
TR
T-b
NO
TR
T+
B
TR
T-b
TR
T+
B
NO
TR
T-b
NO
TR
T+
B
TR
T-b
TR
T+
B
NO
TR
T-b
NO
TR
T+
B
TR
T-b
TR
T+
B
NO
TR
T-b
NO
TR
T+
B
TR
T-b
TR
T+
B
NO
TR
T-b
NO
TR
T+
B
TR
T-b
TR
T+
B
NO
TR
T-b
NO
TR
T+
B
TR
T-b
TR
T+
B
Acr
es
OM
OS
YM
UR
SE
SI
Treatment Effect Beetle Effects
"Other" forest types
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
NO
TR
T-b
NO
TR
T+
B
TR
T-b
TR
T+
B
NO
TR
T-b
NO
TR
T+
B
TR
T-b
TR
T+
B
NO
TR
T-b
NO
TR
T+
B
TR
T-b
TR
T+
B
NO
TR
T-b
NO
TR
T+
B
TR
T-b
TR
T+
B
NO
TR
T-b
NO
TR
T+
B
TR
T-b
TR
T+
B
NO
TR
T-b
NO
TR
T+
B
TR
T-b
TR
T+
B
NO
TR
T-b
NO
TR
T+
B
TR
T-b
TR
T+
B
ac
res
OM
OS
YM
UR
SE
SI
Growth Effects Beetle Effects
Discussion: BKP migration
• Simulated beetles efficiently find remaining host
• How realistically does the WWPBM simulate beetle migration?– Should in-flight beetle mortality algorithms be
adjusted to account for distance traveled?
Orange: experience greater simulated beetle mortalityafter TRTGreens & blue: “protected”
Discussion: SDIMAX
• Although FVS users may explicitly enter site-specific SDIMAX values, they can be overwritten by FVS when input treelists “disagree”
• Should FVS handle SDIMAX readjustments differently? How?
Summary• WWPB Model can be used in landscape
analyses to simulate effects of beetles on landscape fuel dynamics
• WWPB Model is sensitive to changes in host availability
• ArcFuels—w/ FVS-DB—streamlines landscape-scale FVS simulation-building
• ArcFuels—w/ FVS-DB—simplifies mapping FVS output data
Acknowledgements
Western Wildland Threat Assessment CenterPrineville
Jim StoneDana Simon
Lance David, ITX, Inc (FHTET)
Gary Dixon, FMSC
Frank Krist, FHTET
Vern Thomas, ITX, Inc. (FHTET)
END
0
5
10
15
20
25
2005 2007 2009 2011 2013 2015
BK
PNOTRT
TRT(wSAN)
SAN_Only(NoTRT)
TRT (withoutSAN)
In all cases BAHost must be > 50 AND BA total > 100 sq ft
Case 1: all stands that are MIXED CONIFER ("MC"), and meet above criteriaCase 2: For those that are NOT classed as mixed conifer,they must either:a) have > 100 tpa LPP > 9"dbh, ORb) have > 50% host AND >50% of the host must be PP