EFFECTS OF FUEL REDUCTION TREATMENTS ON WILDFIRE AND CARBON MASS BALANCES IN THE SIERRA NEVADA, CALIFORNIA

Abstract

We quantified the effects and efficacy of fuel reduction treatments in the Sierra Nevada as
measured by expected fire behavior and carbon life cycle pathways. The analysis integrated forecasted forest growth and GHG sequestration, expected changes in wildfire behavior following fuel reduction treatments (efficacy), expected changes in wildfire emissions following fuel reduction treatments, and a life cycle analysis (LCA) of the fate of GHGs in wood removals over a forty year period post‐treatment. The LCA tracked the fate of carbon from wood removals stored in durable wood products, woody material used for bioenergy and biofuels, forest harvest residues and waste, operational emissions. There was a net GHG liability (carbon loss) incurred by the one‐time treatment of the landscape between 2003 and 2008, under a 1% annual probability of fire occurrence. The treatments only remained effective at reducing fire size through 2025 (17‐22 years after treatment) after which simulated fires were actually larger on the project landscape. Benefits that were slowly accumulating from avoided direct stock loss and improved growth rates on the treated landscape (by 2045) were erased by this outcome.

Performing two maintenance prescribed fires on the treated landscape resulted in additional carbon deficit of in‐forest C stock, but kept fire sizes smaller. Although under a 1% annual probability of fire a benefit was not realized by 2050, the liability was decreasing from 2025 onward, suggesting that a benefit was forthcoming. With a higher assumed probability of fire (2% annual), a benefit was realized by 2045. A sensitivity analysis of growth rates used in modeling suggests that if rates in the untreated stands are overestimated then recovery of carbon in the treated landscape may occur more rapidly compared to the baseline, which would result in a much quicker achievement of greenhouse gas emissions benefits.

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MARCH2016
CEC‐600‐10‐006
AlternativeandRenewableFuelandVehicle
TechnologyProgram
FINALPROJECTREPORT
EFFECTSOFFUELREDUCTION
TREATMENTSONWILDFIREAND
CARBONMASSBALANCESINTHE
SIERRANEVADA,CALIFORNIA,USA
Preparedfor:CaliforniaEnergyCommission
Preparedby:SpatialInformaticsGroup,LLC

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DISCLAIMER
This report was prepared as the result of work sponsored by the California Energy Commission. It
does not necessarily represent the views of the Energy Commission, its employees or the State of
California. The Energy Commission, the State of California, its employees, contractors and
subcontractors make no warrant, express or implied, and assume no legal liability for the information
in this report; nor does any party represent that the uses of this information will not infringe upon
privately owned rights. This report has not been approved or disapproved by the California Energy
Commission nor has the California Energy Commission passed upon the accuracy or adequacy of
the information in this report.
Prepared by:
Primary Author(s):
Tadashi J. Moody1, Saah, David, Ph.D. 1,Travis Freed1, Roller, Gary1, John
Gunn, Ph.D.2, Paul Lilly, Ph.D.1, and Jason J. Moghaddas1
1Spatial Informatics Group, LLC and Spatial Informatics Group, Natural Assets
Laboratory2
3248 Northampton Ct., Pleasanton, CA 94588
Agreement Number: 600-10-006
Prepared for:
California Energy Commission
William Kinney
Agreement Manager
John P. Butler
Office Manager
Emerging Fuels and Technology Office
John Kato
Deputy Director
Robert P. Oglesby
Executive Director

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ACKNOWLEDGEMENTS
TheauthorswouldliketoacknowledgeJonathanLongoftheUSDAForestServicePacific
SouthwestResearchStationforallofhiseffortsmanagingthiscomplexproject.Wewouldalso
liketoacknowledgeDr.ScottStephensoftheUniversityofCaliforniaandDr.BrandonCollins
fortheirinputandexpertise.
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PREFACE
ThisreportissubmittedinfulfillmentofworkcontractedbytheUSForestService,Pacific
SouthwestResearchStationandCaliforniaEnergyCommissionunderthe“Assessingthe
SustainabilityofForestBiomassUtilizationinCalifornia”studyasTask11“Quantifythe
EfficacyofFuelReductionTreatments.”
AssemblyBill118(Núñez,Chapter750,Statutesof2007),createdtheAlternativeand
RenewableFuelandVehicleTechnologyProgram(ARFVTProgram).Thestatute,subsequently
amendedbyAB109(Núñez)Chapter313,Statutesof2008),authorizestheCaliforniaEnergy
Commissiontodevelopanddeployalternativeandrenewablefuelsandadvanced
transportationtechnologiestohelpattainthestate’sclimatechangepolicies.TheEnergy
Commissionhasanannualprogrambudgetofabout$100millionandprovidesfinancial
supportforprojectsthat:
 Developandimprovealternativeandrenewablelow‐carbonfuels.
 Enhancealternativeandrenewablefuelsforexistinganddevelopingengine
technologies.
 Producealternativeandrenewablelow‐carbonfuelsinCalifornia.
 Decrease,onafull‐fuel‐cyclebasis,theoverallimpactandcarbonfootprintof
alternativeandrenewablefuelsandincreasesustainability.
 Expandfuelinfrastructure,fuelingstations,andequipment.
 Improvelight‐,medium‐,andheavy‐dutyvehicletechnologies.
 Retrofitmedium‐andheavy‐dutyon‐roadandnonroadvehiclefleets.
 Expandinfrastructureconnectedwithexistingfleets,publictransit,and
transportationcorridors.
 Establishworkforcetrainingprograms,conductpubliceducationandpromotion,
andcreatetechnologycenters.
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ThisreportissubmittedinfulfillmentofworkcontractedbytheUSForestServiceand
CaliforniaEnergyCommissionunderthe“AssessingtheSustainabilityofForestBiomass
UtilizationinCalifornia”studyasTask11underAgreementNumber600‐10‐006withthe
SpatialInformaticsGroup,LLC.
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ABSTRACT
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WequantifiedtheeffectsandefficacyoffuelreductiontreatmentsintheSierraNevadaas
measuredbyexpectedfirebehaviorandcarbonlifecyclepathways.Theanalysisintegrated
forecastedforestgrowthandGHGsequestration,expectedchangesinwildfirebehavior
followingfuelreductiontreatments(efficacy),expectedchangesinwildfireemissionsfollowing
fuelreductiontreatments,andalifecycleanalysis(LCA)ofthefateofGHGsinwoodremovals
overafortyyearperiodpost‐treatment.TheLCAtrackedthefateofcarbonfromwood
removalsstoredindurablewoodproducts,woodymaterialusedforbioenergyandbiofuels,
forestharvestresiduesandwaste,operationalemissions.TherewasanetGHGliability(carbon
loss)incurredbytheone‐timetreatmentofthelandscapebetween2003and2008,undera1%
annualprobabilityoffireoccurrence.Thetreatmentsonlyremainedeffectiveatreducingfire
sizethrough2025(17‐22yearsaftertreatment)afterwhichsimulatedfireswereactuallylarger
ontheprojectlandscape.Benefitsthatwereslowlyaccumulatingfromavoideddirectstockloss
andimprovedgrowthratesonthetreatedlandscape(by2045)wereerasedbythisoutcome.
Performingtwomaintenanceprescribedfiresonthetreatedlandscaperesultedinadditional
carbondeficitofin‐forestCstock,butkeptfiresizessmaller.Althoughundera1%annual
probabilityoffireabenefitwasnotrealizedby2050,theliabilitywasdecreasingfrom2025
onward,suggestingthatabenefitwasforthcoming.Withahigherassumedprobabilityoffire
(2%annual),abenefitwasrealizedby2045.Asensitivityanalysisofgrowthratesusedin
modelingsuggeststhatifratesintheuntreatedstandsareoverestimatedthenrecoveryof
carboninthetreatedlandscapemayoccurmorerapidlycomparedtothebaseline,whichwould
resultinamuchquickerachievementofgreenhousegasemissionsbenefits.
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Keywords:Wildfire,forestcarbon,wildfireemissions,SierraNevada,Plumas,MeadowValley
fire,lifecycleanalysis
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
Pleaseusethefollowingcitationforthisreport:
Moody,Tadashi,Saah,David,Ph.D.TravisFreed,Roller,Gary,JohnGunn,Ph.D.,PaulLilly,
Ph.D.,Schmidt,David,andJasonJ.Moghaddas.2016.EffectsofFuelReductionTreatmentson
WildfireandCarbonMassBalancesintheSierraNevada,California,USA.Preparedforthe
CaliforniaEnergyCommissionundercontract#600‐10‐006.


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TABLE OF CONTENTS
ACKNOWLEDGEMENTS....................................................................................................................iii
PREFACE..................................................................................................................................................iv
ABSTRACT................................................................................................................................................v
TABLEOFCONTENTS.........................................................................................................................vi
EXECUTIVESUMMARY........................................................................................................................1
CHAPTER1:Introduction.......................................................................................................................5
1.1BackgroundandPurpose................................................................................................................5
1.2GoalsandObjectives1.2.................................................................................................................7
1.2.1ResearchQuestions...................................................................................................................7
CHAPTER2:Methods..............................................................................................................................8
2.1FireandCarbonAnalysisFramework..........................................................................................8
2.2StudyArea......................................................................................................................................11
2.2.1FireshedDelineation...............................................................................................................12
2.2.2FuelTreatments.......................................................................................................................13
2.3DataCollectionandDevelopment...............................................................................................14
2.4ForestGrowth,TreatmentSimulationandModelCalibration...............................................15
2.5FireBehaviorandEffectsSimulation..........................................................................................18
2.5.1FuelCharacteristics.................................................................................................................19
2.5.2FireSpread...............................................................................................................................21
2.6FireProbabilityEstimation...........................................................................................................25
2.7ForestCarbonStockandFluxEstimation..................................................................................26
2.7.1In‐ForestCarbonStock...........................................................................................................27
2.7.2RemovedCarbonLifeCycleAnalysis.................................................................................27
2.7.3AvoidedStockLossfromFire...............................................................................................28
2.8ForestCarbonAccounting............................................................................................................35
CHAPTER3:Results..............................................................................................................................37
3.1ForestGrowthandTreatment......................................................................................................37

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3.2Fuels,FireBehaviorandFireSpread..........................................................................................39
3.3FireProbability...............................................................................................................................47
3.4ForestCarbonEstimationandAccounting................................................................................48
3.5SensitivityAnalysis........................................................................................................................60
3.5.1EffectofTreatmentMaintenance..........................................................................................60
3.5.2EffectofFireProbability.........................................................................................................61
3.5.3EffectofGrowthRates............................................................................................................62
CHAPTER4:DiscussionandRecommendations............................................................................63
4.1QuestionsForFurtherStudyResultingfromCompletionofthisProject..........................65
REFERENCES..........................................................................................................................................67
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EXECUTIVE SUMMARY
WequantifiedtheeffectsandefficacyoffuelreductiontreatmentsintheSierraNevadaas
measuredbyexpectedfirebehaviorandcarbonlifecyclepathways.Theanalysisintegrated
forecastedforestgrowthandGHGsequestration,expectedchangesinwildfirebehavior
followingfuelreductiontreatments(efficacy),expectedchangesinwildfireemissionsfollowing
fuelreductiontreatments,andalifecycleanalysis(LCA)ofthefateofGHGsinwoodremovals
overafortyyearperiodpost‐treatment.TheLCAtrackedthefateofcarbonfromwood
removalsstoredindurablewoodproducts,woodymaterialusedforbioenergyandbiofuels,
forestharvestresiduesandwaste,operationalemissions.
Theconditionthatfueltreatmentsareintendedtoaddressisessentiallyoneofinstability.
Whetherconsideringthemarketvalueofwoodproducts,sequestrationofcarbon,orthe
provisionofservicessuchascleanwater,recreation,orwildlifehabitat,forestedecosystems
storeresourcesandprovideservicesthatarevaluedbyhumans,andputatriskbydisturbances
suchasfire,drought,insectsanddisease.Andwhiletheseagentsareknowntobenaturaland
cyclical,thereisageneralconsensusthatthecurrentconditions,bothwithinandexertedupon
westernfire‐adaptedforestsarenowlargelyoutofarangeofvariabilitywhichwouldallow
themtowithstandperiodicdisturbancewithoutlong‐termchange.Buildupofhazardousfuel
conditions,stressfromoverstocking,andchangingclimateplacethematgreaterriskofloss.
Fueltreatmentsareintendednotonlytoprotectresourcesdirectly,butalsotorestoreoverall
healthandresiliencetotheforest,andtherebyenhanceorimprovestabilityoftheresourcesit
provides.Giventheinevitablenatureoffireinthesesystems,thisistheprimarybenefitoffuel
treatmentsintermsofcarbonstorageandgreenhousegassequestration.
Fueltreatmentsbydefinitionremovecarbonfromthesystem,butevaluatingtheirbenefit
requiresnotonlyquantifyingstoredcarbonandreducedemissions,butalsoimprovedsystem
stabilityandresiliencetolossfromdisturbance.Furthermore,treatingtheselandscapesplaces
themonadifferentecologicaltrajectory,andthereforeevaluationoftreatmentsmustconsider
theireffectsoverappropriatelylongtimescales.Theframeworkappliedinthiscasestudytries
tocapturethreeprimaryeffectsoffueltreatmentswithinthestandsthemselves:
1. Changestoin‐forestcarbonaccumulationovertime,inducedbytreatment
2. Changestostandandlandscapeabilitytowithstandseverefire
3. Modificationofexpectedfirespreadacrossthelandscape.
Additionally,wetrytocapturethetruelossofcarbon,whichismitigatedbyplacing
merchantableremovalsintolong‐livedwoodproducts,andbyutilizingwoodybiomassfor
energyproduction.
Overall,theprimaryanalysisinthisstudyindicatedthattherewasanetGHGliability(carbon
loss)incurredbytheone‐timetreatmentofthelandscapebetween2003and2008,undera1%
annualprobabilityoffireoccurrence.However,itisimportanttoconsidertheindividual
elementsofthisanalysis,asidentifiedabove.First,thedeficitofin‐forestforestcarboncreated
bytreatmentgrows(withoutfire)between2010and2045,butappearstobegindecreasingby


2
2050duetoaslightincreaseinaccumulationrateintheprojectscenarioandhigherproportion
ofcarboninlivepools.Ifthedeficitcontinuestodecrease,thenpresumablythein‐forestcarbon
onthetreatedlandscapewouldeventuallyovercometheBaselinestocklevels.Asensitivity
analysisofgrowthratesindicatesthatifFVSisindeedoverestimatinggrowthratesinthe
untreatedstands,thiseffectmightactuallybeenhanced,andrecoveryofcarbonoverBaseline
stocksmayoccurmorerapidly.
Intermsofdirectstockloss(theeffectivenessoftreatmentsatreducingseverity),thetreatments
remainedeffectiveforfiressimulatedthrough2050,i.e.asaproportionofstock,lesscarbonwas
lostperacreintheProjectscenariothantheBaselineunderthesamefireconditions.The
benefitsresultingfromthiseffectivenessaregreaterthefartheroutoneevaluates,through2050.
Thisisduenotonlytohigherlikelihoodoffireinalongertimewindow,butalsotolarger
proportionsofdeadbiomassdecayingovertime.
However,thetreatmentsonlyremainedeffectiveatreducingfiresizethrough2025(17‐22years
aftertreatment)afterwhichsimulatedfireswereactuallylargerontheprojectlandscape.
Benefitsthatwereslowlyaccumulatingfromavoideddirectstocklossandimprovedgrowth
ratesonthetreatedlandscape(by2045)wereerasedbythisoutcome.Performingtwo
maintenanceprescribedfiresonthetreatedlandscaperesultedinadditionalcarbondeficitofin‐
forestCstock,butkeptfiresizessmaller.Althoughundera1%annualprobabilityoffirea
benefitwasnotrealizedby2050,theliabilitywasdecreasingfrom2025onward,suggestingthat
abenefitwasforthcoming.Withahigherassumedprobabilityoffire(2%annual),abenefitwas
realizedby2045.
Althoughthefirescenariomodeledherewassevere(~98thpercentile),itstillresultedinless
carbonlossonthetreatedlandscape.Treatmentsmayhavebeenmoreeffectiveatreducing
severityandspreadunderlessthanextremeconditions(e.g.90thor95thpercentile),scenarios
whichshouldbeinvestigatedfurther.Furthermore,theprobabilityoffireinthisanalysiswas
characterizedbyanalyzingallfiresinsimilarforesttypes.Theprobabilityoffireoccurring
underanyweatherconditionisnecessarilyhigherthanunderextremeconditions.Although
thisisindirectlycapturedinthearea‐basedmetricoffire‐rotation,thesensitivityoftheanalysis
tovaryingprobabilitiesofweatherconditionsthatsupportdifferingseveritiesandextentsof
firesisalsoworthfurtherconsideration.
Puttingremovedcarbonintolong‐livedwoodproductsandenergyproductionoffset
approximatelyhalfofthepotentiallossofcarbonfromharvestremovals(deterioratingonly
about11%overthestudyperiod).However,inthistreatmentregime,overhalfofthecarbon
removedintreatmentwasduetoprescribedfires,animmediateemissionorloss.Puttingmore
carboninwoodproductsratherthantreatingwithprescribedfiremayhavereducedthisloss,
butthiswouldhavetobebalancedwiththeconcomitantdeficitofin‐forestcarboncreatedby
harvest,andchangesinpotentialfireseverityandspreadwouldalsoneedtobeaccountedfor.
Theseresultssupportseveralconclusionsfromthisstudy:
1. TreatmentssuchasthoseperformedinMeadowValleymayenhancetheoverall
sequestrationrateofcarbonacrossthelandscape,thoughrecoveryofCoverbaseline


3
levelsmaynotoccuruntilwellbeyonda40yearwindow.Ifthisenhancementisbeing
underestimatedbythemodel,recoverymayactuallyoccurmorerapidly.
2. Treatmentsthatreducepotentialfireseverityareofgreaterbenefitwhenanalyzed
fartheroutfromtimeoftreatment,sincehigherproportionsofdeadcarboninthe
untreatedlandscapedecayovertime,whilehigherproportionsoflivecarboninthe
treatedlandscapecontinuetoaccruecarbon.
3. One‐timetreatmentsmayreduceexpectedfireextent,butmayalsocausechangesin
fuelsthatresultinunwantedeffectsaftersomeperiodoftime.Theseeffectsmay
swampbenefitsfrom(1)and(2)above.
4. Maintenanceoftreatmentsmayincreasethein‐forestcarbondeficitincurred,butcan
alsokeepfiresizessmallerandseveritieslower.Itappearsthismayresultincarbon
benefits,butoverlongertimeperiodsthanthe40yearsanalyzedhere.
5. Thoughtreatmentsareoftenconsideredtohavealimited“lifespan”orperiodof
effectivefirebehaviormodification,thelandscapedoesnotnecessarilyreturntoapre‐
treatmentstate.Treatmentsputthelandscapeontoadifferenttrajectory,whichmayor
maynotshowacarbonbenefitwithintheirlifespan.Longerevaluationperiods(80or
100years)maybenecessarytotrulyevaluatethebenefitsofatreatmentortreatment
regime.
6. Theprobabilityoffireoccurrenceonthelandscapeisamajorfactorindeterminingthe
netbenefitgainedorliabilityincurredduetreatment,atleastintermsofavoidedcarbon
stockloss.Alandscapeunderanassumed2%probabilityoffire(50‐yearrotation)will
resultinanetbenefitsoonerthana1%probability(100‐yearrotation),potentiallywithin
a40‐yearwindowasanalyzedhere.Assuch,sound,defensiblecharacterizationofthe
probabilityoffireimpactingthelandscapeiscrucialtoquantifyingGHGbenefitsfrom
fueltreatment.Site‐specific,spatiallyexplicitcharacterizationoftheprobabilityoffires
ofvaryingseveritymayaidinmoreaccuratecharacterizationofcarbonoutcomes.
Theseresultsrelyheavilyonmultiplemodels,datasources,andassumptions.Specificallyfuel
characteristicssensitivetogrowthmodelparameterssuchasSDI,regeneration,fuelmodel
selection,mayrequireadditionalfieldbaseddataforvalidationofaccuracyinmodeling.Fire
spreadinparticularsensitivetohowFVSmodelssurfacefuels.Fireintensityandseverityover
timeareafunctionofmultiplefuelcharacteristics,whichareinturnafunctionofmultiple
standcharacteristicsinthemodel.RegenerationinFVSisnon‐spatialwithinstands,andhigh
spatialvariabilityinregenerationisdifficulttocaptureinFVS.Homogeneityoflandscapeover
timeresultingfromourregenerationparametersmayhavehadaneffectonfuturestand
density,andresultingmodeledbehavior.Thereremainoutstandingquestionstothebroader
FVSmodelofthedecayratesusedfordeadwood,andwhetherornottheyarereflectiveof
localizedconditions.
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5
CHAPTER 1: Introduction
1.1 Background and Purpose
ThewesternU.S.hasmillionsofacresofoverstockedforestlandsatriskoflarge,
uncharacteristicallysevereorcatastrophicwildfireowingtoavarietyoffactors,including
anthropogenicchangesfromnearlyacenturyoftimberharvest,grazing,andparticularlyfire
suppression(Milleretal.2009).Modificationoffuelstructuresandreductionofunnaturally
highfuelloadsinordertoalterfirepatternsandbehaviorareaprimarycomponentofplanning
effortssuchastheNationalCohesiveWildlandFireManagementStrategy(WildlandFire
LeadershipCouncil2011)andtheSierraNevadaForestPlanAmendment(USDAForestService
2001),andarelikelytocontinueorincreaseintothefutureinresponsetoclimatechangeand
theresultingchangesinfireandfuels.Variousmethodsforfuelmodification,collectively
termed“fueltreatments,”includemasticationorremovalofsub‐merchantabletimberand
understorybiomass,pre‐commercialandcommercialtimberharvest,andprescribedfire.Cost
perunitareaforfueltreatmentsvariesbytreatmentmethodandvegetationtype(Hartsoughet
al.2008),butcompletetreatmentofvastareasofat‐riskwildlandsisneitherfinanciallyfeasible
norlogisticallyrealistic,orevendesirableundercertainlandmanagementobjectives.
Mechanismsforcostrecoveryoffueltreatmentsarenotwellestablished,andreturnon
investmentcomesprimarilyintheformofavoidedwildfire,thoughtheabsoluteprobabilityof
wildfireimpactingfueltreatmentsornearbyareaswithintheireffectivelifespancanbe
relativelylowandvariableacrossthelandscape(Hurteauetal.2009,Ageretal.2010,Syphard
etal.2011).
Variousstrategiesareemergingtodealwithfueltreatmentcost.Givenlimitedresourcesand
theinabilitytotreateveryat‐riskacre,treatmentscanbestrategicallyarrangedonthelandscape
inordertoincreasetheireffectivenessinprotectingcommunitieswithinthewildlandurban
interface(WUI)andnaturalresources,changingexpectedfireeffects,andaidingfire
suppressionefforts,whichcanreduceoverallfiresizes(Ageretal..2007a,Ageretal..2007b,
Moghaddasetal..2010).Additionally,forestwoodybiomassremovedinfueltreatmentscan
beusedforhighervaluepurposesandproducts,suchaselectricityandheat,transportation
fuels(e.g.,advancedbiofuels),chemicals,andphysicalproductsuseddirectlyinmanyactivities
andindustries(e.g.bioplastics,ash,glassaggregates).ThefederalinteragencyBiomass
ResearchandDevelopmentTechnicalAdvisoryCommittee,createdtosupporttheBiomass
R&Dactof2000,hassetgoalsofincreasingthemarketshareofbiopowerto7.0%(3.8
quadrillionBtu)by2030(BiomassResearchDevelopmentTechnicalAdvisoryCommittee2006).
However,whilethemarketforwoodybiomassmaybeexpanding,itstillfacessignificant
hurdles,suchaslimitedaccesstofunding,distancebetweenforesttreatmentandbiomass
utilizationfacilities,publicperceptionoftheeffectsofbiomassremoval,andscientific
documentationtosupportthesustainabilityoftheseactivities(Evans2008).
Asmarket‐basedapproachestoglobalclimatechangearebeingconsideredandimplemented,
oneimportantemergingstrategyforchangingtheeconomicsoffuelstreatmentsistosell
carbonemissionoffsets,tradablecertificatesorpermitsrepresentingtherighttoemita
designatedamountofcarbondioxideorothergreenhousegasses(GHGs).Theseoffsetsare

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6
generatedwhenprojectsoractionsreduceGHGemissionsbeyondwhatisrequiredbypermits
andrules,andcanbetraded,leased,bankedforfutureuse,orsoldtootherentitiesthatneedto
provideemissionoffsets(SedjoandMarland2003).Inthecaseoffueltreatments,carbon
emissionoffsetscantheoreticallybegeneratedbyprojectsthatreducepotentialemissionsfrom
wildfire,asbymodifyingtheprobabilityofextremefirebehaviorandresultantemissionsfora
givenportionofland.Carboncreditscanbegeneratedforeithervoluntaryorregulatory
(compliance)markets,andcarbonoffsetprojectsmustmeetthestandardsandprotocolssetby
oneofseveralregistryorganizations,suchastheAmericanCarbonRegistry.Thisis
accomplishedbyusingoneregistry‐approvedaccountingmethodologiesfordifferenttypesof
carbonprojects.Forforestryprojects,approvedmethodologiesexistforImprovedForest
Management(IFM)projects,Afforestation‐Reforestation(AR)projects,andReducedEmissions
fromDeforestationandDegradation(REDD)projects.
Currently,nomethodologiesexistthataccountforavoidedwildfireemissions,andfuel
treatmentactivity(primarilymechanicalthinningandprescribedfire)isconsideredasnet
emissions.Demonstratinganetcarbonbenefitfromfueltreatmentthereforerequiresan
integratedapproachthataccountsfornetforestcarbonsequestrationovertime,woodremovals
fromtheforest,thefateofwoodfiber(lifecycleanalysis)inwoodproducts,bioenergy,
transportationfuels,andwaste,andthereductioninGHGemissionsexpectedfromtreatment.
Additionally,becausetheremovalsareinanticipationofafutureevent(wildfire)thistypeof
analysismustaccountforanexpectedprobabilityoffireoccurring,similartoavoided
conversionmethodologies.
Westernforestshavethepotentialtosequesterlargeamountsofcarbonintheformofwoody
biomass,butincreasedforestdensitiesandunderstorygrowthcanalsoincreasefirehazard
(Stephensetal.2009a).Fueltreatmentsintendedtoreducetheriskofseverewildfireand
associatedemissions,bydefinition,removeliveanddeadwoodybiomassavailableforburning,
therebyreducingstoredcarbon.Fueltreatmentoperationsthemselvescanalsoresultindirect
anddelayedatmosphericcarbonemissions,aswithbiomasstransportationandprescribed
broadcastorpileburning(e.g.Jonesetal.2010).Increasedfireresistancecanbeachievedwith
relativelysmallreductionsincurrentcarbonstockswhilegrowingandretaininglargertreescan
reducecarbonlossfromwildfire(Stephensetal.2012b).Inwildfire‐proneforests,tree‐based
carbonstocksarebestprotectedbyfueltreatmentsthatproducealow‐densitystandstructure
dominatedbylarge,fire‐resistantpines(HurteauandNorth2009).Ifforestsweremanagedfor
maximumcarbonsequestrationtotalcarbonstockscoulddoubleintheCoastRangeandSierra
Nevada,giventheabsenceofstandreplacingdisturbance.Thepotentialtostoreadditional
carbonintheseforestsishighastheyarelonglivedandmaintainrelativelyhighproductivity
andbiomass(Hudibergetal.2009).Severalrecentstudieshaveinvestigatedtheseemingly
competingvaluesofcarbonsequestrationandfueltreatment,examiningwhetherandtowhat
extentreducedcarbonsequestrationfromtreatmentismitigatedbyavoidedemissions
(HurteauandNorth2009,Northetal..2009,Stephensetal..2009b,Ageretal..2010,Reinhardt
andHolsinger2010,Campbelletal..2011).Improvingtheaccuracyandusefulnessof
assessmentsoffueltreatmentwildfiretrade‐offsforCstorage,requiresunderstandingthelong‐

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7
termeffectsofmultiplemanagementanddisturbancescenarios,includingpostwildfire
treatments(salvage,reforestation)overtime(Loehmanetal.2014;RestainoandPeterson2013).
1.2 Goals and Objectives 1.2
Thegoalofthistaskistoquantifytheeffectsandefficacyoffuelreductiontreatmentsinthe
SierraNevadaasmeasuredbyexpectedfirebehaviorandcarbonlifecyclepathways.Takinga
long‐termapproach(40yearsposttreatment),theanalysisintegratesforecastedforestgrowth
andGHGsequestration,expectedchangesinwildfirebehaviorfromtreatment(efficacy),
expectedchangesinwildfireemissionsfromtreatment,andalifecycleanalysis(LCA)ofthe
fateofGHGsinwoodremovals.TheLCAincludes,butisnotlimitedto,ananalysisofwood
removalsstoredindurablewoodproducts,woodfibergoingtobioenergyandbiofuels,forest
residuesandwaste,operationalemissions,andmillefficiencies.
1.2.1 Research Questions
 Whataretheeffectsovertimeofcomprehensivefueltreatmentplansonexpectedfire
behavior,GHGbalances,andbiomassutilization?
 Howeffectivearethefueltreatmentplansatreducingadversefirebehaviorandeffects
overtime?
 HoweffectiveisthefueltreatmentplanatreducingGHGemissionsovertime?
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CHAPTER 2: Methods
ThisprojectleveragespreviousworkdonebySpatialInformaticsGroup(SIG),UCBerkeley
(UCB),andtheUSDAForestServicePacificSouthwestResearchStation(PSW),inorderto
examineastudysitethathashadafullimplementationoffueltreatmentsapplied.Priorwork
atthisnorthernSierraNevadasite(“MeadowValley”)generatedanextensivefielddatasetused
tocharacterizeforeststandcharacteristics,structure,andfirebehavior.Weusethisfielddatain
anintegratedframeworkofacceptedmodelsforforestgrowth,firebehavior,firerisk,and
wildfireemissions,alongwithlocalinformationaboutGHGlifecyclepathwaystoevaluatethe
effectsandeffectivenessoffueltreatments.

2.1 Fire and Carbon Analysis Framework
Theframeworkusedtoevaluateprojecteffectsongreenhousegasesismodifiedfromearlier
workperformedbySIGonsimilarforesttypesinnearbyPlacerCounty,CA(Saahetal.2012,
Figure1).Thisandpriorversionsoftheframeworkareintendedtocaptureandquantifythe
effectofhazardousfuelreductionorotherforesthealthtreatments(hereafterreferredto
collectivelyas“fueltreatments”)ongreenhousegas(GHG)storageandsequestration.GHG’s
arequantifiedintermsofcarbon(C),whichisconvertedtometrictonsofcarbondioxide
equivalent(MTCO2e).
Themodifiedframeworktakesacarbonstockapproach,quantifyingCstoredinforestsor
displaced(asinwithalternativeenergyproduction)overtime,withnetpositivechangesin
carbonstockconsideredassequestration,andnetnegativechangesinstockconsideredaslosses
oremissions.Thisdiffersfrompriorversionsoftheframeworkwhichalsotriedtocapturethe
massofCemittedduringfires.Itconsiderssixprimaryelements,describedinfurtherdetail
belowandinfigure1.Figure1isaconceptualdiagramoftheanalysisframework.The
frameworkincludesthefollowingsteps,describedindetailbelow:
1. Firesheddelineation,selection,andcharacterization:Thefireshedisthebasicunitof
measureusedinthisanalysisframework.Itisanareaoflandlargeenoughtoallowthe
ecologicallyrelevantintegrationofwildfirerisk,wildfirehazard,andforestcarbon
accounting.Afireshedisdelineated,vegetationwithinisquantifiedandclassified,and
theresultsfromeachoftheotherframeworkelementsaregeo‐summarizedatthe
fireshedscaleintocommonunits.FireshedsforMeadowValleyhadbeendefined
previously,andanextensivefielddatasethasbeendevelopedandintegratedintoan
analysis‐readydatabase.
2. ManagementScenarioDevelopmentandFuelTreatmentDesign:Ecological,
operational,andothergoalsandobjectivesunderdifferentmanagementscenariosfora
fireshedorlandscapehelpdeterminethetype,intensity,andgeographicallayoutoffuel
treatments.Comparingdifferentmanagementscenariosoralternativeswithdifferent
treatmentschemesagainstabaselinescenario(e.g.“no‐treatment”)withinthe
frameworkallowsforcomparisonofeffectsanddifferences.Asfueltreatmentsforthe

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9
MeadowValleystudyareahadalreadybeendesignedandimplemented,thisproject
wasintendedtoevaluatetheGHGimplicationsofanalreadycompletedmanagement
scenario,ratherthananalyzingalterativetreatmentschemes.
3. In‐ForestCarbon(ForestGrowthandSequestration):Forestgrowthandnetcarbon
balancesunderBaseline(e.g.untreated)andProject(e.g.treated)scenariosaremodeled
usingtheUSForestServicemodelForestVegetationSimulator(FVS).FVSisinitialized
withthefield‐deriveddatabaseforpre‐treatmentforestconditionstoprojectforest
growthanddevelopmentunderBaselineandProjectscenariosoutatleast40years,
quantifiedin5‐yeartimesteps.Weexaminethenetdifferencesincarbonstored
betweentheBaselineandProjectlandscapes,wherewoodisremovedfromthestand.
FVSsimulatesindividualtreegrowthanddevelopment,regeneration,backgroundand
density‐inducedmortality,andchangesinstandcharacteristicssuchasfirefuels.
4. ForestRemovalsLifeCycleAnalysis(Bioenergy,WoodProducts):Understandingthe
fateofbiomassremovedfromthefireshed,andultimatelyhowmuchwindsupas
carbonsourcesvs.sinksisanimportantcomponentofthisframework.Merchantable
andnon‐merchantablewoodremovalsareconsideredinseparateLCAs.Theduration
ofCstoredinwoodproducts,quantitiesofslashandwastefromharvestoperations,
biomassutilizationandefficiency,millefficiencyandwaste,andtransportation
emissionsareconsidered.
5. PotentialCarbonStockLossfromWildfire:Inadditiontoimprovingthehealthand
vigorofpreviouslyoverstockedstands,fueltreatmentsintheirvariousformsare
intendedtomodifypotentialwildfirebehaviorintwoways.Firsttheycanreducefire
severity,ortheamountofvegetationkilledbyfire,byreducingfireintensityand
potentialforfiretoenterintoforestcanopy.Secondtheycanslow,stoporotherwise
modifythelateralspreadoffire,providingbetteropportunitiesforsuppressionand
ultimatelyresultinginsmallerfires.Treatmentsthushavea“shadoweffect”,changing
theoutcomesoffireonthelandscapebeyondjusttheirboundaries.Thisframework
termsthesetwoprimaryeffectsasDirectStockLossandExtentStockLoss,and
quantifiesthemasdescribedbelow.
a. DirectStockLoss:Directstocklossisdefinedasthelossinstoredcarbon
observedorexpectedforeachunitofareaonthelandscape,ifthatunitburned
instantaneouslyandindependently.Reductions(benefits)indirectemissions
fromtreatmentareadirectresultoffuelloadreductionandre‐arrangements
(andless‐intenseresultantfirebehavior)withinthosetreatmentareas.Potential
directstocklossisestimatedusingtheFireandFuelsExtensiontoFVS,and
summarizedatthefireshedscale(perunit‐area).Itisindependentofanyeffect
oftreatmentonlateralwildfirespread.DirectstocklossexpectedunderBaseline
andProjectscenariosarecompared.Changesinefficacyoffueltreatmentsover
timeiscapturedbyestimatingpotentialdirectstocklossunderchangingforest
conditionsateach5‐yeartimestep.Additionally,onlyaportionofthestockloss
isincurredinthefireitselfincombustion.Fire‐killedvegetationcontinuesto
emitcarbonasitdecaysforyearsafterfire.Thisframeworkattemptstocapture

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10
andquantifythesedelayedemissionsbysimulatingfireatvarioustimespriorto
anevaluationpoint.
b. ExtentStockLoss:Extentstocklossisdefinedastheobservedorexpectedlossof
carbononthelandscaperelativetotheexpectedsizeofwildfire.Inthis
framework,thepotentialsizeoffiresburningforagivendurationundera
specifiedweatherscenarioisestimatedfortheBaselineandProjectscenarios,
andcompared.Weuseinformationfromforestgrowthanddevelopment
simulations(FVS)tocharacterizesurfaceandcanopyfuelsforeachstandonthe
landscape,andsimulatefirespreadintheFlamMapprogram.Changesinfuel
treatmentefficacyovertimearecapturedbysimulatingfireunderchangingfuel
conditionsateach5‐yeartimestep.
6. FireProbability:Weanalyzetheprobabilityoffireactuallyimpactinganygivenacre
onthefireshedbyexaminingpre‐historicfirefrequency(e.g.fromtreeringstudies)for
thestudyareaandsimilarvegetationtypes,historicandcontemporaryrecordsoffire,
andfuturefiremanagementexpectations.Weadjustourexpecteddirectandextent
stocklossfromfirerelativetotheprobabilityoffireactuallyoccurring.
7. EmissionsAccounting:AllGHGlossesorsavingsaresummarizedfortheentire
fireshedonaper‐unit‐areabasis.Foreachtreatmentscenario(vs.baseline)ateachtime
step,weexaminenetGHGstoragelossfromtreatment,offsetbyGHGbenefitsrealized
frommerchantableandnon‐merchantablewoodremovallifecycles.Weexaminethe
benefitsexpectedfrombothavoided‐directandavoided‐extentstocklossfromfire,and
modifythesebenefitsbytheprobabilityoffireactuallyoccurringonthelandscape.We
sumtheselossesandsavingstodeterminetheeffectoffueltreatmentonthecarbon
balanceateachtimestep.


11

Figure1:Conceptualframeworkforcarbonaccountingusedinthisproject.

2.2 Study Area
ThestudyareausedinthistaskislocatednearthecommunityofMeadowValley,California,
andincludesthesurroundinglandwhichislargelymanagedbythePlumasNationalForest
(Figure2)(Collinsetal.2013).Thestudyarea(hereafterreferredtoasMeadowValley)has
beenthefocusofalargefueltreatmenteffort,aspartoftheHerger‐FeinsteinQuincyLibrary
GroupAct(USDA2004,HFQLG1998).Anetworkoffueltreatmentswasimplementedin
MeadowValley,mostlybetween2003and2008.
Thestudyareaincludesthefireshed(describedbelow)aswellasa2kilometerbuffer.
Elevationswithinthestudyarearangefrom850to2100m(Collinsetal.2013).Vegetationon
thislandscapeisprimarilySierranmixedconiferforest(Schoenherr,1992),includingprimarily
whitefir(Abiesconcolor),Douglas‐fir(Pseudotsugamenzesii),sugarpine(Pinuslambertiana),
ponderosapine(Pinusponderosa),Jeffreypine(Pinusjeffreyi),incensecedar(Calocedrus
decurrens),andCaliforniablackoak(Quercuskellogii),withredfir(Abiesmagnifica)occurringat
higherelevations.Additional,lesscommonhardwoodandsoftwoodspecies,aswellas
montanechaparralandsomemeadowsareinterspersedinthelandscape.Treedensityvariesas


12
aresultofrecentfireandtimbermanagementhistory,elevation,slope,aspect,andedaphic
conditions.Historicalfireoccurrence,inferredfromfirescarsrecordedintreerings,suggestsa
historicalfireregimewithpredominantlyfrequent,low‐tomoderate‐severityfiresoccurringat
intervalsrangingfrom7to19years(Moodyetal.2006).


Figure2:MeadowValleyStudyArea(fromCollinsetal.2013)

2.2.1 Fireshed Delineation
Thefireshed,delineatedforapriorstudy,wasdefinedgenerallyasfourHUC12watersheds,
withafurthermodificationtoincludeareatothesouth.Thisistheareauponwhichvaluesin
thisstudyaregeo‐summarized,andwasconsideredappropriateforanalysisinthepresent
study.Thesefourwatershedscombinetocreateabasinencompassingthecommunityof
MeadowValley,andformalogicalforestmanagementandplanningunit.Firehaslargelybeen


13
excludedfromthisbasininthecontemporaryera,andrecentnearbylargefiressuchasthe2007
Moonlightfirehighlighttheneedforalargeareaforfiremanagementplanning.Mostofthe
fueltreatmentsimplementedintheMeadowValleyareaareincludedinthefireshed.Thefull
studyareaincludes2kmbufferofthefireshed.Totalfireshedareais47,533acres(19,236
hectares).Thefullstudyarea(bufferedfireshed)is84,842acres(34,334hectares).Thetotalarea
treatedcomprised19.2%ofthefireshed(FigureXX).

2.2.2 Fuel Treatments
Treatmentswereimplementedbetween2003and2008,creatinganetworkofDefensibleFuel
ProfileZones(DFPZ’s),withthebulkofthetreatmentsoccurringin2007and2008.Treatments
canbeclassifiedintofivegroups(Collinsetal..2013)asfollows:(1)Handthinandpileburn:
treesupto12”werecutandburnedinpiles;(2)Mastication:primarilyshrubsandsmalltrees
wereshreddedandchippedinplace,withmaterialleftonsite;(3)Prescribedfireonly:stand
burnedundermoderaterelativehumidityandfuelmoistureconditions;(4)Mechanicalthinand
prescribedburn:Treesupto20”or30”DBH(dependingonwhetherornotstandswere
consideredinthewildland‐urbaninterface)werethinnedfrombelow,usingawhole‐tree
harvestsystem,toaresidualcanopycoverofapproximately40%,andthenunderburned;and
(5)Groupselectionharvest:removalofallconifersupto30inchesDBH,followedbyslash
removal,theneithernaturalregenerationorreplantingtoadensityofapproximately100trees
peracrewithamixofsugarpine,ponderosapine,andDouglas‐fir.Treatmenttypesandthe
areacoveredareshowninFigure3andTable1.

Table1:AreaandproportionoffireshedbytreatmenttypeimplementedinMeadowValley.
TreatmentType Area(ac) ProportionofFireshed
DFPZharvestfollowedbyprescribedfire 3,915.04 8.24%
Prescribedfireonly 2,661.23 5.60%
Handthinfollowedbypileandburn 1,191.85 2.51%
Understorymastication 765.98 1.61%
Groupselectionfollowedbyslashremoval 591.23 1.24%
Subtotal 9,125.34 19.20%

NoTreatment 38,407.17 80.80%
GrandTotal 47,532.50 100.00%



14

Figure3:Studyarea,includingfireshed,modelingbuffer,andtreatments.

2.3 Data Collection and Development
Datatocharacterizeforestandfuelcharacteristicswascollectedinfieldplotspriortotreatment,
aswellaspost‐treatment.Plot‐leveldatawasassignedtoeachstandintheforeststandmap,
(roughlyequivalenttoFSexistingvegetationpolygons).Standdatawasusedtocreatepre‐
treatmentandpost‐treatmentFVSinputdatabases.Pre‐andPost‐treatmentdatabaseswere
providedforthisprojectbyBrandonCollins(USFS)andJasonMoghaddas(SIG).
Thepre‐treatmentdatabaseformedthefoundationofthedataforthisproject.Treatmentswere
simulatedinFVS,andcalibratedtomatchthepost‐treatmentdatabaseascloselyaspossible.In
thisway,themodelingofforestgrowthanddevelopmentrepresentstheimplementationofa
fulltreatmentprograminarealisticmanner.Treatmentsweresimulatedoverthecourseof8
years.VariabilityinthefinaloutcomesofplannedtreatmentswererepresentedinFVSthrough
thecalibrationprocess,describedinmoredetailbelow.


15

2.4 Forest Growth, Treatment Simulation and Model Calibration
Thepre‐andpost‐treatmentdatabasesofstandsandtreeswereusedforforestgrowthand
developmentmodelingintheForestVegetationSimulator(FVS)program.FVSisamodelfor
predictingforestgrowthandstanddynamicsdevelopedandmaintainedbytheUSForest
Service.AtitscoreFVSinanintegratedsetofmodelsforestimatingindividualtree‐growth
andmortality,standdevelopment,wildfirepotentialandotherstandcharacteristics.Specific
variantsofFVSareusedfordifferentgeographicregionsoftheUnitedStates,andFVS
capabilitiesareextendedbyuseofmodulesforfireandfuels,economics,climate,water,and
more.FVSusesasystemof“keywords”tosendcommandstotheprogram.Additional
informationcanbefoundinthedocument“EssentialFVS:AUser’sGuidetotheForest
VegetationSimulator”(Dixon2015).
ForestgrowthsimulationwasperformedfortheBaseline(notreatment)andProject(treatment)
scenariosintheWesternSierravariantofFVS(KeyserandDixon2013)fromthestand
inventoryyear(e.g.pre‐treatmentmeasurementdate)through2050.Siteindexforallstands
wasadjustedtomatchtheaverageofFIAsiteindexforthearea,asrecordedinthe2003
vegetationdataforthePlumasNF(PonderosaPineSI50=65).Densityinducedmortalitywas
settobeginat70%oftheoreticalmaximumSDI,insteadofthedefault55%,inordertoslow
whatappearedoveralltobetoo‐rapidoverstorymortalityandunusualcanopyfuel
development.Thischangeresultedinonlyslightincreases(0.0‐0.2%)intotalnon‐soilforest
carbonateachtimestep,andveryslightdifferencesincarbonaccumulationrates(0.00‐0.01%).
TreatmentsweresimulatedinFVSaccordingtotheirparticularprescriptionandyearof
implementation.Itwasassumedthatforaparticularstand,theyearrecordedinthepost‐
treatmentdatabasewasone‐yearposttreatment,andthatthepre‐treatmentdatawasmeasured
one‐yearpriortotreatment.Treatmentparameterswerecalibratedsuchthatthesimulatedpost‐
treatmentlandscape(Projectscenario)matchedtheactualpost‐treatmentlandscapeascloselyas
possiblefortheyear2010.Becausetreatmentsareimperfectintheiractualexecution,this
methodologywasintendedtosimulateareal‐worldoutcomeascloselyaspossible,ratherthan
atheoreticalbest‐casescenario.
ExampletreatmentsimulationsforaDFPZtreatmentandaprescribedfireonlytreatmentare
showninFigure4.








16
Stand3712–DFPZharvestfollowedby
underburn

Stand3717–Prescribedfireonly

(a) Stand3712–Atinventory (d)Stand3717‐Atinventory

(b) Stand3712‐Duringharvest (e)Stand3717‐Duringfire

(c) Stand3712‐Post‐treatment(2010) (f) Stand3717‐Post‐treatment(2010)
Figure4:ExampletreatmentsimulationsinaDFPZtreatmentandaprescribedfireonlytreatment



17
SimulatedharvesttreatmentswerecalibratedbythinningthroughouteachofseveralDBH
ranges(>1in)toachievesimilarresidualstandstructureasreal‐worldstands,asmeasuredby
treesperacre(TPA),basalareaperacre(BA),quadraticmeandiameter(QMD),andStand
DensityIndex(SDI)aggregatedoverallstandsforaparticulartreatmenttype.Handlingof
slash,sub‐merchantable,andmasticatedmaterialsinsimulationswashandledinasimilar
fashiontothegeneralmethodemployedontheground.Simulatedprescribedfireswere
performedundermoderateconditions,withmodificationstoflamelengthmadetoachievea
posttreatmentstandstructureassimilartorealworldstandconditionsaspossible.Keywords
andparametersusedcanbefoundinthereportappendix.Treeslessthan1”DBHwerenot
calibrated,duetodifferencesinmeasurementmethodologybetweenthepre‐andpost‐
treatmentdatabase.Calibrationmetricsfortrees>1”DBHforsimulationyear2010areshown
inFigure5.


(a)TPA (b)BA

(c)QMD (d)SDI

Figure5:Calibrationmetricsfortrees>1”DBHforsimulationyear2010.“BASE”istheuntreated
stands,“FVS”isthetreatmentssimulatedinFVS,and“POST”isthereal‐world‐posttreatment
landscape(grownto2010).
Inoursimulationdatabase,thenumberoftrees<1”DBHineachstandattimeofinventorywas
highlyvariableandrangedfrom0togreaterthan2000treesperacre.Insimulatingingrowth
fromnaturalregeneration,wewerenotabletoreplicatethishighspatialvariability,butrather


18
followedtheseedlingdensitiessuggestedas“moderate”byCollinsetal.(2013).Seedlings
wereestablishedafterdisturbance(treatment),andthenevery5yearsfrom2010‐2050.Exact
numberofseedlingswasrandomizedwithinasomewhatnarrowrange,withseedlingdensities
from2010onwardaveragingapproximately70TPA.
Oncetreatmentswerecalibrated,twoscenariosweremodelledinFVS:
1. Baselinescenario–Allstandsweregrownfrominventoryyearto2050,withcommon
cycleboundaries(outputs)at2010andeach5yearsafter.Notreatmentswereapplied.
2. Projectscenario–Allstandsweregrownfrominventoryyearto2050,withcommon
cycleboundaries(outputs)at2010andeach5yearsafter.Calibratedtreatmentswere
applied1yearafterinventory.

2.5 Fire Behavior and Effects Simulation
FirebehaviorandeffectsweresimulatedusingacombinationofFVSandFlamMap.FVSwas
usedtoestimatesurfaceandcanopyfuelcharacteristicsacrossthelandscapeandtheir
developmentthroughtimeat5‐yeartimesteps(2010‐2050),aswellaspotentialwithin‐stand
firebehaviorcharacteristicsandvegetationmortality.Additionally,expectedfirebehavior(rate
ofspread,flamelength,firelineintensity)wasestimatedinFVSforeachstandateachtime
step.Dataforeachstandateachtimestepundereachscenariowereusedtogeneratethe
following18spatialfuellandscapes,basedonthestudyareastandmap.

Table2:Inputlandscapes(fuelsandtopography)generatedforuseinfirespreadsimulations.
BaselineScenario ProjectScenario
Baseline2010 Project2010
Baseline2015 Project2015
Baseline2020 Project2020
Baseline2025 Project2025
Baseline2030 Project2030
Baseline2035 Project2035
Baseline2040 Project2040
Baseline2045 Project2045
Baseline2050 Project2050




19
2.5.1 Fuel Characteristics
SurfaceandcanopyfuelcharacteristicsforeachstandateachtimestepwereestimatedinFVS.
Surfacefuels(dead/downwoodymaterial)areestimatedinFVSasmassperunitareain
differentsizeclasses,thenmatchedtotheclosestofthe53stylizedfuelmodelscommonlyused
infirebehaviorsimulation(Anderson’s13orScottandBurgan’s40).BecauseFVShasbeen
notedtomisclassifysurfacefuelmodelsandpossiblyover‐estimatefirebehaviorwithinthe
WesternSierravariant,weadoptedamethodology,examinedelsewhereintheCECprojectby
Sharmaandothers(inprep),inwhichwelimitthepooloffuelmodelsfromwhichFVScanpick
initsmatchingroutine.
Fornotreatment,DFPZ,handthinorfire‐onlytreatments,thepick‐listwasasfollows(Table3:Listof
possiblesurfacefuelmodelsforgroups1(notreatmentstands,andstandstreatedwithDFPZ,hand
thin,orfireonlytreatmentprescriptions)and2(groupselectionprescriptions)treatments.
).Forstandsclassifiedasshrub‐type,thepicklistwaslimitedtoGS1,GS2,SH1andSH2.For
standsclassifiedasgrass‐type,possiblefuelmodelswerelimitedtoGR1,GR2,GR4,GS1,and
GS2.

Table3:Listofpossiblesurfacefuelmodelsforgroups1(notreatmentstands,andstandstreated
withDFPZ,handthin,orfireonlytreatmentprescriptions)and2(groupselectionprescriptions)
treatments.
Fuel
Model
Code
FuelModel
Number
FuelModelType TreatmentGroup
GR1 101 Short,sparsedryclimategrass 1
GR2 102 Lowload,dryclimategrass 1
GS1 121 Lowload,dryclimategrass‐shrub 1,2
GS2 122 Moderateload,dryclimategrass‐shrub 1,2
SH1 141 Lowload,dryclimateshrub 1,2
SH2 142 Moderateload,dryclimateshrub 1,2
TU1 161 Lowload,dryclimatetimber‐grass‐shrub 1,2
TU5 165 Veryhighload,dryclimatetimber‐shrub 2
TL1 181 Lowload,compactconiferlitter 1
TL2 182 Lowload,broadleaflitter 1,2
TL3 183 Moderateload,coniferlitter 1,2
TL4 184 Smalldownedlogs 1,2
TL5 185 Highload,coniferlitter 1
TL6 186 Moderateload,broadleaflitter 1,2
TL7 187 Largedownedlogs 1
TL8 188 Long‐Needlelitter 1
TL9 189 Veryhighload,broadleaflitter 1,2
SB1 201 Lowload,activityfuel 1,2


20
SB2 202 Moderateload,activityfuelorlowload,blowdown 1,2

Forgroupselectiontreatments,thepicklistwasasfollows(Table4).

Table4:Listofpossiblesurfacefuelmodelsforstandstreatedwithgroupselectionprescriptions.
FM
Code
FMNumber FMType
GS1 121 Lowload,dryclimategrass‐shrub
GS2 122 Moderateload,dryclimategrass‐shrub
SH1 141 Lowload,dryclimateshrub
SH2 142 Moderateload,dryclimateshrub
TU1 161 Lowload,dryclimatetimber‐grass‐shrub
TU2 162 Moderateload,humidclimatetimber‐shrub
TL1 181 Lowload,compactconiferlitter
TL2 182 Lowload,broadleaflitter
TL3 183 Moderateload,coniferlitter
TL5 185 Highload,coniferlitter
TL8 188 Long‐Needlelitter
TL9 189 Veryhighload,broadleaflitter
SB1 201 Lowload,activityfuel

FVShasthecapabilityofchoosingmultiplefuelmodelsincombinationtorepresentastand
(“dynamic”fuels)whichisintendedtoallowformoreaccuraterepresentationoffuel
successionovertimewithinastand,withlessabruptchanges.However,thiscomplicates
translationofaspatialdatafromFVSintospatiallyexplicitdatathatcanbereadbyfirebehavior
simulationprogramssuchasFlamMap,sincemultiplefuelmodelswouldneedtobeassigned
torastercellsintheproperproportionswithinastand.Weturnedthisfeatureoffusingthe
STATFUELkeyword,choosingonlythesinglebest‐fitfuelmodelfromthepick‐listforastand
inagivenyear.
IthasalsobeennotedthatinFVSsimulations,canopybaseheightcanrisemorerapidlythan
couldbeexpectedrealisticallyovertime.Inoursimulations,wemodulatedcanopybaseheight
estimationusingFVSkeywordswhichcontroltherateatwhichcrownratiochangeson
individualtreesovertime,andthebreakpointintree‐heightswhichdeterminesthetreesare
usedforCBHcalculations.
Wealsomodulatedcanopybulkdensitybyadjustingdensitydependentmortalityparameters.
Thetheoreticalandactualmaximumsofstanddensityindexwereleftatdefaultforallspecies,
butthedensityatwhichmortalitybeginswasraisedfrom55%to70%oftheoreticalmaxSDI.
Asnotedinsection2.4,thishadverylittleeffectonoverallcarbonvaluesorratesof
accumulation.

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21
PotentialfirebehaviorwasestimatedinFFE‐FVSbasedonthesefuelsandaseverefireweather
scenario,listedinTable5.ThisscenariowaschosentocloselymatchconditionsusedinCollins
etal.(2013),whichwasderivedfromhistoricalanalysisoflocalRAWSweatherstationdata.It
isalsoconsistentwithsevereweatherscenarioderivedandusedformodelinginSharmaetal.
(inprep).

Table5:WeatherparametersusedinFVSfiresimulationmodeling.
Parameter Value
20FootWindSpeed 20mph
Temperature 90deg
Season Fall
1hr.FuelMoisture 2%
10hr.FuelMoisture 3%
100hr.FuelMoisture 5%
1000hr.FuelMoisture 8%
DuffFuelMoisture 25%
LiveHerbacousFuelMoisture 35%
LiveWoodyFuelMoisture 70%
ProportionofStandBurned 95%


2.5.2 Fire Spread
Fuelcharacteristicsundereachscenario(BaselineandProject)werecalculatedforeachstandat
eachtimestep(2010‐2050)byFFE‐FVSandwrittentoanoutputdatabase.Thisdatabasewas
usedwiththestandmaptogeneratethespatiallyexplicitlandscapedatafiles(.LCP’s)required
asinputstotheFlamMapfiresimulationprogram(Finney,2006).Fuelcharacteristicsforeach
scenario‐yearsimulatedinFVS(canopycover,fuelmodel,canopyheight,canopybulkdensity,
canopybaseheight,elevation,slopeandaspect)wereusedtocreatethe18fuellandscapesupon
whichfirewouldbesimulated.WeusedArcFuels,anextensionfortheArcGISsoftware,to
createthe18landscapefiles(Table2)(Vaillantetal.2013).
FirespreadsimulationswereperformedinFlamMap5x64,usingtheMinimumTravelTime
(MTT)algorithm(Finney2016).5000randomlylocatedignitionpointsweredistributedacross
thelandscapewithinthefireshed.Foreachscenario‐yearlandscape,firewasignitedateachof
the5000pointsandallowedtospreadfor240minutesundersevereweatherconditions,
identicaltothoseusedinFVS,butaddingspatialcomponentsandrequiredparameters(Table
6).




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22
Table6:WeatherparametersusedinFlamMapfirespreadmodeling.
Parameter Value
Domain20FootWindSpeed 20mph
DomainWindAzimuth 225
Windmodification WindNinja(Gridded)
FuelMoistureType Fixed(noconditioning)
1hr.FuelMoisture 2%
10hr.FuelMoisture 3%
100hr.FuelMoisture 5%
LiveHerbacousFuelMoisture 35%
LiveWoodyFuelMoisture 70%
FoliarMoistureContent 100%
CrownFireEstimationMethod ScottandReinhardt(2001)
SimulatedIgnitions 5000randomlylocated
Simulationtime 240minutes
CalculationResolution 60m
MinTravelPathsInterval 500m
SpotFires(Probability/Delay) 0.02/0
SearchDepth(Lat/Vert) 6/4


Thesame5000ignitionpointswereusedforeverysimulation(Figure6).Outputsfromfire
simulationsincludedindividualfireperimeters(e.g.Figure7,Figure8)andfiresizelist,aswell
asconditionalrasteroutputsforburnprobability,rateofspread,flamelengthandcrownfire
activity.Aftereachscenario‐yearsimulationcompleted,eachofthe5000fireperimeterswere
dissolvedsothateachfireconsistedofonlyonedatabaserecord.Thesizeofeachfirewas
calculatedinArcGISandoutputtoexaminechangesinfiresize.Meanfiresizewascalculated
foreachscenario‐year.


23

Figure6:Ignitionlocationsfor5000firespreadsimulations.



24

Figure7:Examplefirespreadsimulation‐Ignitionpoint98,burningontheBaseline(blueperimeter)
andProject(redperimeter)landscapes.



25

Figure8:Examplefirespreadsimulation–outcomesfor5000randomignitionsatyear2015forthe
Baselinescenario


2.6 Fire Probability Estimation
Weestimatedtheprobabilityoffireoccurringbyexamininghistoricalratesofburningin
relevantforesttypeswithintheprojectareabioregion.Wefirstidentifiedalltheconiferous
foresttypeswithintheSierranSteppe‐MixedForest‐ConiferousForest‐AlpineMeadow
vegetationprovince,andcalculatedtheirarea(Table7).Wethenidentifiedallfiresthathad
burnedwithinthisareabetween1960and2014usingCalFire’s2014fireperimeterdatabase.
Wecalculatedtheareaofeachofthesefires.Thesetwoareainputsallowedustocalculatethe
firerotationforthosetypes.Firerotationisanarea‐basedmeasureoffirefrequency,which
givesthetimeitwouldtakefortheentireareatoburnatanobservedrate(Agee1992).Wethen
calculatedthe10‐yearrunningfirerotationforeachyearbetween1960and2014.

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
Table7:Areaofexistingforestvegetationtypesconsideredforfirerotationcalculations.
ExistingVegetationType AreainEco‐Province(acres)
DouglasFir 2,555,536
EastsidePine 1,191,236
JeffreyPine 366,017
KlamathMixedConifer 1,333,587
MontaneHardwood‐Conifer 1,448,534
PonderosaPine 1,132,303
RedFir 1,167,948
SierranMixedConifer 4,353,630
WhiteFir 975,664
GrandTotal 14,524,456

Annualprobabilityoffirewascalculatedastheinverseoffirerotation,e.g.a100yearfire
rotationresultsina1/100annualprobabilityoffire,or1%.Theannualprobabilityoffirewas
modifiedtorepresentamulti‐yearprobabilityoffire(e.g.5years)basedonthefollowing
formulafortheprobabilityofaneventhappeningatleastonceinagivenperiodoftime.
q=1‐(1‐p)^nwhere:
qistheprobabilityofaneventhappeningatleastonceinnunitsoftime
pistheprobabilityoftheeventhappeninginoneunitoftime


2.7 Forest Carbon Stock and Flux Estimation
Carbonstoredbothwithinandremovedfromthebaselineandprojectscenariostandswas
estimatedinFVSforeach5‐yearmodelcycleusingtheCarbonsub‐modeloftheFireandFuels
Extension(Rebain2015).CarbonwasestimatedbyFVSinmetrictonsperacre(MTC/ac)and
summarizedforrelevantpools(Table8).Wherepossible,estimatesweremadeusingFVS‐FFE
equationsandmethodology,asrecommendedbyHooverandRebain(2010),sincethese
methodsaretheoreticallymoreregionspecificthanthenationalscaleequationsofJenkinsetal.
(2003).Carbonmassvalueswereconvertedpost‐hoctometrictonsofCO2equivalentperacre
(MTCO2e/ac)forreportinginthepresentdocumentusingthefollowingconversionfactor,to
accountforthemolecularweightofCvs.CO2:
MTCO2e=MTC*(44/12)


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27
Table8:Carbonpoolsconsideredforthisstudy.
CarbonPool Description Method
1. AbovegroundTotal
Live
Livetrees,includingstems,branches,andfoliage,
butnotincludingroots
FFE‐FVSEquations
2. BelowgroundLive Rootsoflivetrees Jenkinsetal.2003
3. StandingDead Deadtrees,includingstemsandanybranches
andfoliagestillpresent,butnotincludingroots
FFE‐FVSEquations
4. BelowgroundDead Rootsofdeadandcuttrees Jenkinsetal.2003
5. DeadandDown
Wood
Allwoodysurfacefuel,regardlessofsize FFE‐FVSEquations
6. ForestFloor LitterandDuff FFE‐FVSEquations
7. HerbsandShrubs Liveherbaceousandshrubvegetation FFE‐FVSEquations
8. RemovedCarbon Carboninremovedlivetrees,deadtrees,and
woodydebris
FFE‐FVSEquations,
Merchantabilitylimits.

2.7.1 In-Forest Carbon Stock
Carbonstoredwithineachforeststand(Table8,Pools1‐7,summed)wasestimatedusingFFE‐
FVSfortheBaselineandProjectScenarios.Per‐acrestandvaluesfromFFEwereweightedby
standsizeandaveragedacrossthefireshedtogetmeanin‐forestcarbonstockfortheBaseline
scenario(BFCS)andtheProjectscenario(PFCS)ateachtimestepe.
Thenetin‐forestcarbonstock(NFCSe)foragivenevaluationyeareiscalculatedasthe
differencebetweentheProjectstock(PFCSe)andtheBaselinestock(BFCSe).Thisrepresentsthe
neteffectofthefueltreatmentsoncarbonstockacrossthefireshed
𝑁𝐹𝐶𝑆𝑃𝐹𝐶𝑆
𝐵𝐹𝐶𝑆

Immediatelyaftertreatment,PFCSwillbesmallerthanBFCSduetoremovalsandtreatment
emissions,thusthenetin‐forestcarbonstockwillberepresentedasanegativevalue(stock
deficit).

2.7.2 Removed Carbon Life Cycle Analysis
Estimatesoftheproportionofcarboninsawlogs(merchantablewoodbothstoredand
removed)weremadebasedonboardfootspecificationsusedinFVSforUSForestService
Region5(KeyserandDixon2013)asfollows:

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28
DBH: 10.0inches
TopDiameter: 4.5inches
StumpHeight: 1.0feet

Toaccountforthedispositionofcarbonremovedfromstandsasaresultoftreatment,wemade
thefollowingassumptions.
67%ofmerchantablecarbonremovedwasassumedtogointodurablewoodproducts(DWP–
e.g.paperandstructuralwood).ValuesateachtimestepforcarbonremaininginDWP,and
DWPthathavegonetoandremaininwaste(landfill)weremadeinFVS,followingthedecay‐
faterelationshipsdescribedinSmithetal.(2006).Foragiventimestep,carbonfromthis
lineagenotstoredinwoodproductsorlandfillisassumedtohavebeenemittedthroughdecay
orcombustion.
Oftheremaining33%ofmerchantablecarbonthatdoesn’twindupasDWP,weassumed75%
isdivertedforbiomassenergyproduction.Thisenergyproductionwasassumedtoresultina
25%additionalityoverequivalentfossilfuelproduction.
Allsub‐merchantableharvestedmaterialsremovedfromthefireshedareassumedtogoto
biomassenergyproduction.95%ofthesematerialsareassumedtomakeittotheenergy
productionfacility,andenergyproductionisassumedtoresultina25%additionalityover
equivalentfossilfuelproduction.
Wasteremainingafterbiomassutilizationwasassumedtobeimmediatelyemitted.Carbon
emittedintransportationofmaterialsfromthefireshedtowoodproductorbiomassenergy
facilitieswasnotexplicitlyaccountedforbeyondtheadditionalitycoefficientsusedabove.
Foragivenevaluationyeare,wecalculatetotalremovedcarbonthatcontinuestobestored,or<