a
U
-
Crown Fuel Characteristics,StandStrucfure,andFire Hazardin
RiparianForestsof the Blue Mountains,Oregon
by
NathanMichaelWilliamson
A thesissubmittedin partialfulfillment of the
requirementsfor the degreeof
Masterof Science
University of Washington
v
r999
ProgramAuthorizedto Offer Degree:Collegeof ForestResources
urmllt tF,s0.
fficulqp.Urut
tilt ,.. 13!' - -
\-
U
Universityof Washington
GraduateSchool
This is to certify that I haveexaminedthis copyof a master'sthesisby
NATHAN MICHAEL WILLIAMSON
and havefound tfrat it is completeand satisfactoryin all respects,
andthat any and all revisionsrequiredby the final
examiningcommitteehavebeenmade:
J
Approvedby:
CHAIRPERSONOF SUPERVISORYCOMMTTEE
Date:
.l.e..{Hh llLI'iiili
' - . . . - n r t | , r' , . ' l . ;' t1 - l ::'
}'i
J
{.bii".':'i
...-.***---'-'"-*"'iii'i
,
-,i.*,<{r,*d.*l9irl
rl-.
-
-
Master's Thesis
for a Master'sdegreeat
In presentingthis thesisin partialfulfillment of the requirements
make
its copies freely
Library
shall
that
the
I
agree
the Universlty of Washington,
availablefor inspection.I furtheragreethat extensivecopyingof this thesisis allowable
only for scholarly purposes,consistentwith "fair use" as prescribedin the U.S.
CopyrightLaw. Any otherreproductionfor any purposesor by any meansshall not be
allowedwithout my written permission.
Signature
Date
I
v
TABLE OF CONTENTS
v
Methods
Laboratory
................31
5: Rrsulrs
CHepreR
.....................40
Ten-hour
FuelMoisture
BakerCii Watershed
............40
FoliarMoisture.....
BakerCity Watershed
......................50
FoliarHeatContent.................
....................50
RiparianandUplandStandStructure................
Pinusponderosa
/ Pseudotsuga
menziesii
forestseries..........
.............52
.......................54
Abiesgrandisforestseries
.........
...........55
Abieslasiocarpaforestseries.........
......57
CrownFireIgnition(Torching)Potential.....
Potential
CrownFireSpread
.......................61
Little FrenchCreekStandReconstruction
lnternetSurvey........
.....................62
..................63
Aerial PhotoInterpretation
CHarren6: DrscussroN..............
FuelMoisture................
FoliarHeatContent.................
RiparianandUplandStandStructure................
CrownFirelgnitionandSpread
LittleFrenchCreekStandReconstruction
InternetSurvey........
AeriafPhotoInterpretation......
RSSNARCHNEEDS
CHAPTERT:
8: MeNeceMENT
Iupr.rcerroNs
................
CHAPTER
CIrEo
LITERATURE
A: SYTT,TSOLS
USEDINTEXT......
APPENDIX
......................66
............66
....................6;
.............71
..................71
.....................72
..................73
....................74
.......75
..........76
......79
........93
B: ScrpNtrprc
ANDCoMMoNNAMES
oF Specrcs
UsponqTExr................................94
AppENDrx
C: SrRucruRALDATAFoRRTpARTAN[Jplauo
SraNoCotiap,qRrsoxs
......................95
AppENDrx
FORRIPARIAN/UPInWOSTAND
APPENDIXD: SAVPIING PLOTCHARACTERISTICS
coMpARrsoNS.................
..........97
LIST oF FIGURES
Number
page
FigureI . Studyareas...........
..........27
Figure2. Ten-hourfuel moisturelevelsandrelativehumiditieson 22 July 1998,
Pseudotsuga
menziesiiforestseries,BakerCity watershed.......................................41
Figure3. Ten-hourfuel moisturelevelsandrelativehumiditieson22 July 1998,Abies
grandisforestseries,
BakerCity watershed...........................j..... ............42
Figure4. Ten-hourfuel moisturelevelsandrelativehumiditieson22 July 1998,Abies
Iasiocarpaforestseries,BakerCity watershed.............
.......43
Figure5. Ten-hourfuel moisturelevelsandrelativehumiditieson 14August 1998,
Pseudotsuga
menziesiiforestseries,BakerCity watershed.............
.......44
Figure6. Ten-hourfuel moisturelevelsandrelativehumiditieson 14August 1998,Abies
grandisforestseries,BakerCity watershed.............
............45
a
Figure7. Ten-hourfuel moisturelevelsandrelativehumiditieson 14August 1998,Abies
Iasiocarpaforesf
series,BakerCity watershed.............
.......46
Figure8. Ten-hourfuel moisturelevelsandrelativehumiditieson l5 September
1998,
Pseudotsuga
menziesii
forestseries,BakerCity watershed...............
........................47
Figure9. Ten-hourfuel moisturelevelsandrelativehumiditieson 15September
1998,Abies
grandisforestseries,
BakerCity watershed............;
............49
Figure10. Ten-hourfuel moisturelevelsandrelativehumiditieson 15September
1998,
Abieslasiocarpaforestseries,BakerCity watershed..
...........
................49
g
ill
LIST OFTABLES
Page
Number
Tablel. Fuelmoistureinputsusedin BEHAVEfire simulations............
.................33
Table2. Wind inputsusedin BEHAVEfire simulations.............
..........33
Table3. Estimatedfuel moistureconditionson 16August,1994at time of fire at Little
......:............
FrenchCreek.........
.......38
Table4. Estimatedwind conditionson 16August,1994at time of fire at Little French
...................38
Creek.........
'FRENCHCR"representingestimatedfuel
Table5. Parameterlist for customfuel model
conditionsat time of fire at Little FrenchCreek.
.................38
..........50
Table6. Lateseasonfoliar moistureconten!BakerCity watershed...............
Table7. Samplemeansandgrandmeansof foliar ashcontentsfor Pinusponderosa,
..'.......51
menziesii,andAbiesgrandis/concolor.
Pseudotsuga
Table8. Samplemeansandgrandmeansof low foliar heatcontentswith ash for Pinus
menziesii,andAbiesgrandis/concolor..
ponderosa,Pseudotsuga
.........51
Table9. Samplemeansandgrandmeansof low foliar heatcontentswithout ashfor Pinus
ponderosa,Pseudotsuga
menziesii,andAbiesgrandis/concolor..
.......-.52
by forestseriesandstreamorder............53
Table10. Averageripariananduplandtreediameters
TableI l. Averageripariananduplandtreeheightsby forestseriesandstreamorder................53
Table12. Averageripariananduplandbasalareaby forestseriesandstreamorder...................53
Table13. Averageripariananduplandtreedensityby forestseriesandstreamorder................53
Table 14. Averageripariananduplandpercentcanopycoverby forestseriesandstream
...............-...54
order..........
Table 15. Averageripariananduplandoverstoryfoliageweightsby forestseriesand stream
...................54
order..........
potentialof
firstorderstreams.................
Table16. Torching
potential
orderstreams.................
of second
Table17. Torching
\'
lv
...............58
...........59
v
of thirdorderstreams.................
Table18. Torchingpotential
..............60
to heightto live crownsurvey........................63
Table19. Employeror affiliationof respondents
for eachphotograph.
Table20. Rangeof heightto live crownestimates
..................63
of heightsto live crownfor eachphotograph
Table21. Meansof estimates
............64
Table22. Observedandexpectedfrequenciesof crown scorchlevelson the Twin Lakesfire
asdetermined
from aerialphotographs.
............65
Table23. Observedandexpectedfrequenciesof crown scorchlevelson the Ironsidefire as
determined
fromaerialphotographs.................
....................65
Table 24. Percentashcontentsreportedin previousstudiesfor Pinw ponderosa and
Pseudotsuga
menziesii
foliage........
...................:.....................................69
Table 25. Low heatcontentswith ashreportedin previousstudiesfor Pinusponderosa,
Pseudotsuga
menziesii,Abiesconcolor,andAbiesgrandisfoliage.
......70
Table 26. I-ow heatcontentswithout ashreportedin previousstudiesfor Pinusponderosa,
Pseudotsuga
menziesii,andAbiesconcolorfoliage........
Table27. Structuraldatafor ripariar/uplandstandcomparisons.
................
........................71
.............95
J
Table28. Samplingplot characteristics
for riparian/upland
standcomparisons.................
.........97
g
ACKNOWLEDGMENTS
Many folks havehelpedme throughoutthis project in numerousways, whetherproviding advice
and guidance,financial and logistical support,or evenjust an encouragingword. Specialthanks
to Jim Agee, my advisor and mentor, for bringing me on board and providing me the opportunity
to work on this project. It has truly been a privilege. Thanks also to Dave Petersonand Ernesto
Alvarado for serving on my supervisory commiffee. Their insight and perspectiveadded greatly
to this project. I would also like to take this opportunity to thank the faculty and my fellow
graduate studentshere at the College of Forest Resourcesfor continually challenging me to think
about forest ecology from a variety of angles. Thanks to my officemate Diana Olson, not only
for putting up with me, but also for never hesitating to lend a hand or a smile when I needed
either one. A number of Forest Service personnelassistedme in site selection and provided
necessaryequipment in the field. In particular, I would like to thank John Szymoniak on the
Wallowa-Whitman NationalForest and Lance Delgado and Greg Whipple on the Malheur
National Forest. Emily Heyerdahl gave me my first tour of the Blue Mountains that didn,t
require wearing Nomex or carrying a pulaski. Janet Erickson put together the height to live
crown survey.
Thanksto my family and family-in-law for their unwaveringsupportand constantfaith in me,
evenwhen I doubtedmyself. And finally, thanksto my wonderfulwife, Jackie,whose love,
humor, patience,and understandingthroughout this entire processhas meant the world to me.
This project was supportedby USDA Forest ServiceCooperativeAgreementsPNW-97-5082-ICA, PNW-93-0479, and PNW-93-0401 between the Pacific Northwest ResearchStation and the
University of Washington.
vl
INTRODUCTION
Disturbances are inherent components of all forest ecosystems (White and Pickett 1985, Sprugel
1991). They play an extremely important role in the shaping of populations and communities
through the alteration of landscape pattern and subsequent impacts on future ecological processes
(White 1979, Oliver 1981, Pickett and White 1985, Rogers 1996, Camp et al. 1997, Agee 1998).
The type, timing, extent, and intensity of disturbances can dramatically affect species
distributions, successional pathways, and community composition and .structure in forest
ecosystems (Baker 1992, Agee 1993, Attiwilll994, Veblen et al. 1994, Huff 1995, Whelan
1995). For example, a relatively frequent patchy or discontinuous disturbance may generate
substantial spatial and temporal heterogeneity within a landscape and potentially increase species
diversity by creating a variety of different habitats. On the other hand, a less recurrent, more
widespread disturbance of greater severity may have the opposite effect, creating a more
homogeneous environment (Gregory et al. 1991). Disturbances can both create, and be
constrained by, landscape pattern (Swanson et al. 1988, Agee 1993, Hadley 1994, Turner and
Romme 1994, Bessie and Johnson 1995, Castello et al. 1995). Any alteration in disturbance
regime can, and likely will, result in an alteration in community composition and structure.
Successful management of forested communities requires an understanding of disturbance
processes. Increasingly there is an interest (and need) within land management to better
incorporate natural disturbances into management planning.
Of the many disturbance types found in natural systems (e.g. wind, floods, insects, and disease),
perhaps the most widespread is that of fire. Fire has played a significant role in the shaping of
many of the Inland Northwest's diverse plant communities. The current structure, species
composition, and dynamics of many ecosystems are often the direct result of past fires or in other
cases, the resu It of other processes that have themselves been affected by fire (Agee 1993). In
turn, other processes may have effects on the occurrence of fire across a landscape. An example
of the complex relationships between disturbances is that of fire and insect outbreaks. It is
hypothesized that fire exclusion has led to more widespread and more severe western spruce
2
budworm (Choristoneura occidentalis) outbreaks within this century (McCune 1983, Anderson
et al. 1987, Swetnam and Lynch 1989, Wickman 1992, Swetnam and Lynch 1993, Hadley 1994,
Powell 1994, Wickman et al. 1994, Swetnam et al. 1995). However, fire-induced stress can also
predispose stands to insect attacks (Fischer 1980, Gara et al. 1985).
There is a great concern among land managers that the hazard of high-severity wildfires has
increased throughout western North America in this century as a result of fire exclusion and
various land use practices. High-severity fires are difficult to control and can often result in
extensive damage to aquatic systems. This damage can occur directly, as when riparian forests
burn, or indirectly as when upslope fires result in large inputs of sediment and debris to aquatic
systems (Brown 1989, Minshall et al. 1989, Beschta 1990, Wissmar et al. 1994, Young 1994,
Rieman and Clayton 1997).
There is a growing interest in the use of prescribed fire and silvicultural treatments to reduce the
hazards of stand-replacement fire. Although much is known about the historic role of fire in
upland forests, very little attention has been paid to the role of fire in riparian forests. The
success of efforts to protect these sensitive areas requires a thorough understanding of the
disturbance processes that created and maintained these forests and how these processes have
changed over the last century. This study examines a number of factors that influence fire
behavior and in particular influence the occurrence of crown fire behavior. This study also
compares crown fire hazard between riparian and upslope stands in the Blue Mountains of
northeast Oregon. It is hoped that the results of this study will increase our understanding of the
fire hazards faced by land managers in the Inland Northwest and perhaps contribute to a means
of accurately assessing those hazards.
Throughout this paper the term "forest series" is used to describe the forested areas found within
the study area. A forest series is a broad vegetation classification based on the potential climax
overstory tree species (Daubenmire 1966). The forest series are named for the later successional
tree species that would dominate a site in the absence of disturbance. By describing the tree
species that dominate a site in the absence of disturbance, the forest series classification
necessarily takes into account site environmental characteristics such as slope, aspect, elevation,
,.\
3
Y
climate,and moistureregime. It is importantto notethatthe overstoryspeciesthat would
the currentdominanttree species.
dominatea site in the absenceof disturbanceis not necessarily
pine(Pinusponderosa)mayin fact
For example,a standwith a dominantoverstoryof ponderosa
be classifiedasa grandfir (Abiesgrandis)forestseriesif grandfir is presentin the understory.
of a disturbancesuchas fire, the
The site is capableof supportinggrandfir andin the absence
standwill graduallybe convertedto a grandfir dominatedforest and is thereforeclassifiedas a
grandfir forestseries.
v
v
CHAPTERI: LITERaTUREREVIEw
Fire Regimes
The conceptof the fire regimehas beendevelopedto aid in the descriptionof the general
characteristicsof fire in particular ecosystems. Attributes of a fire regime include frequency,
predictability, intensity, seasonality,extent and synergismwith other disturbances(White and
Pickett 1985,Agee 1993,Whelan 1995). Severaldifferent fire regimeclassificationschemes
have been developed(e.g.Heinselman1973,Davis et al. 1980). The classificationsystemused
in this paper is that of Agee (1990, 1993)which is basedon forest qeriesand historicalfire
severity. Within this systemare three broad categories(high-, moderate-,and low-severity fire
regimes) which tend to follow different combinations of temperatureand moisture.
In areascharacterizedby low-severity fire regimes, fires kill less than 20Yoof standbasal area.
Fires occur at frequent intervals, usually on the order of every l-25 years. Fires tend to be of
low-intensity and have little impact on establishedoverstory trees, which are often fire resistant.
These light surface fires kill smaller understory trees and thereby reduce the effects of
competition for limited resources.Foresttypes of this regime include oak woodlands,ponderosa
pine, and mixed-coniferforests(Agee 1990, 1993).
Moderate-severity fire regimesencompassa broad range of environments and tend to experience
fires at intervalsof 25-100years. Fires in this regime are quite complex, including mixtures of
both high-severity fire and low-severity fire. The result is a heterogeneouslandscapecomposed
of patchesof treesof different standagesand multi-agedstands. Foreststypicalof this regime
include dry Douglas-fir(Pseudotsugamenziesii),mixed-evergreen,and red fir (Abiesmagnifica)
forests(Agee 1990,1993).
Fires kill over 70Yoof standbasalareaand usually occur at intervalsexceeding100years in
v
areaswith high-severityfire regimes. As the name implies, fires in this regime are of stand-
5
replacementseverityandmay includecrown fire behavior.Treemortality is high in all size
classes.Foresttypescharacterized
by high-severityfire regimesincludeportionsof the western
hemlock(Tsugaheterophylla),Pacificsilver fir (Abiesamabilis),andsubalpineforestseries
(Agee1990,1993).
Ignition
The majority of fires on federallandsin the PacificNorthwestarecausedby lightning(Morris
1934,Pickfordet al. 1980,Pyneet al. 1996).It is estimated
thatup to ?0o/o
of fires in western
North Americaarecausedby lightning(Taylor 1973).Anthropogenicsourcesaccountfor most
of the remainingignitions. The merepresenceof a sourceof ignitionhowever,is not sufficient
to starta fire. Only a very smallpercentage
(<l%) of cloud-to-ground
lightningstrikesresultin
wildfires (Fuquay1962).Ignition requiresthat the heatsuppliedby the ignition sourceequalsor
that necessary
exceeds
to bringavailablefuelsto thepointof ignition. Oncethis occurs,the
processshifu from an endothermicreactionto a self-sustaining
exothermicreaction. Successful
v
ignition of a wildfire is highly dependenton the firelsencountered
by the ignition sourceandthe
moisturelevelsandalrangementof thosefuels(SchroederandBuck 1970,Agee 1993,Whelan
1995,Pyneet al. 1996).Thesefactorsalsohavea considerable
influenceon determining
subsequent
fire behavioroncecombustionhasbeenachieved.
Fire Behavior
Three fundamental elementscontrol fire behavior. These factors are topography, weather, and
fuels. The interactions of thesethree elementsof fire behavior determine the characteristicsof a
fire, and knowledge of these factors allows a certain degree of predictive ability in the behavior
of a fire.
Topography
Topographyis the leasttemporally variable elementof fire behaviorand perhapsthe most
spatially variablecomponent. Topographycan be characterizedby slope,aspect,and elevation.
v
6
An increasein slopecanhavea substantial
impacton fire behavior.Slopewill tendto tilt flames
closerto the unburnedfuel aheadof a fire, bringingthe fuel to ignitiontemperature
fasterthana
to theground(Rothermel1983,Martin 1990,Agee1993).As a result,the
flameperpendicular
spreadrateandintensityof a fire cangreatlyincrease.Aspectaffectsfire behaviorprimarilyby
controllingthe amountof solarradiationa sitereceives.South-andwest-facingslopesreceive
moresunthando east-or north-facingslopesandasa resulttendto havelower fuel moistures
andarethusmoreconduciveto fire spread(Agee1993,Pyneet al. 1996).Amountof solar
radiationinterceptedcanalsoaffectspeciescompositionon a site,furtherinfluencingfire
behavior(Martin 1990).Elevationaffectsthe climateandspeciescompositionof a site,thereby
exertingsomemeasureof controloverfire behavior(Martin 1990,Agee 1993). Topographycan
affectthe probabilityof ignitionby lightningwith the upperonethird of slopesexperiencingthe
mostignitions(Agee 1993).This resultsfrom the interactionof fuel moistureandpotentialfor
with elevation(FowlerandAsleson1984).
lightningstrikes,bothof whichtendto increase
Landformcanalsoaffectfire spreadby channelingwinds. In steep,narow canyonsa "chimney
effect" cansubstantiallyincreasefire spreadand intensity(Agee 1988).
Weather
ln contrastto the relativelyfixed natureof topography,weatheris the mosthighly variable
elementof fire behavior.At timesthe impactof weathercancompletelyoverwhelmthe
of bothtopography
andfuels(Rothermel1991,BessieandJohnson1995).Weather
influences
canchangeon time scalesrangingfrom diurnalchangesin temperature
andhumidityto
changesin globalclimate. Wind, temperature,
centuries-long
humidity,and precipitationcanall
havesignificanteffectson fire behavior.Wind, the resultof the differentialheatingof the
earth'ssurface,will increasefire spreadin muchthe sameway as slopeby bendingflames
towardstheunburnedfuel aheadof a fire. Bothgeneralwind patternsandlocalwind patterns
influences
canaffectfire behavior(Schroeder
resultingfromtopographical
andBuck 1970,
Brown andDavis 1973). Foehnwindsoccurin the PacificNorthwestasan inlandhigh-pressure
systemforcesair westward.As theair descends
the leewardsideof mountains
andloses
altitude,it driesandwarmsastheresultof beingcompressed.
WithinthePacificNorthwest
tlresewindsareknownasEastwindsandareespeciallyimportantin termsof theireffectson fire
\,
I
v
behavior(SchroederandBuck 1970,Agee 1993,Pyneet al. 1996).Temperatureinfluencesfire
behaviorby affectingfuel moisturecontentsandthe heatinputrequiredto sustaincombustion.
Humidity andprecipitationareimportantfactorsin fire behaviorthroughtheir effectson fuel
moisture. Droughtconditionswill greatlyincreasefire potentialandfire intensity(Schroeder
andBuck 1970,BrownandDavis 1973).
Fuel
Fuel,the third componentof fire behaviorandthe focusof muchof this project,alsofluctuates
throughtime. Fine deadfuelsrespondalmostimmediatelyto changesin temperatureandrelative
humidity. Seasonalchangesin fuelsoccurasplantscompletedifferentstagesof their life cycles.
fuel accumulationand
to disturbance,
Fuelschangeover longerperiodsin response
changesthat altervegetativecommunities.
and successional
decomposition,
Not all fuels will be consumedin anygivenfire. The amountof fuel consumedin a fire will
dependto a largeextenton the propertiesof thosefuelsandthe weatherconditionsexperienced
v
duringa fire. Importantpropertiesof fuels includechemicalcomposition,moisturecontent,size,
and arrangement.
An inherentpropertyof fuel is its chemicalconstituency.The chemicalcompositionof a fuel
componentdeterminesits heatof combustion,the heatreleaseduponcompleteoxidation(Hough
1969,PhilpotandMutch l97l). Inorganicmaterialspresentin fuels canhavean active
process(Countryman1982,Agee1993,Pyneet al. 1996).
effecton the combustion
dampening
the rateof volatilizationandflaming
The presenceof mineralconstituentsin fuelsdecreases
the productionof charandtar (Philpot1968,Philpot 1970,Pyneet al.
andincreases
combustion
predictionmodelsassumea relatively
fuel modelsusedin fire-behavior
1996).Standard
for alt forest
of 18.61MJ kg I anda mineralashcontentof 5.55%o
constantheatof combustion
fuels(Albini 1976,Rothermel1983,BurganandRothermel1984).The FARSITEfire-growth
simulationmodelusesa constantheatof combustionof 18.0MJ kg-t for both surfaceandcrownfuels(Finney1998).However,severalstudieshaveshownthatthe heatcontentsof forestfuels
do varybetweenspeciesandevenwithin speciesthroughoutthe courseof the growingseason
\,,
8
andmay be under-predicted
by the standardfuel models(e.g.Hough 1969,PhilpotandMutch
1971,Susottetal.1975,Kelseyetal.1979,Susott1982,Chrosciewicz
1986,vanWagtendonk
et
al. 1998).Mineralashcontents
of differentfuelshavealsobeenshownto vary considerably
(e.g.Philpot1968,Philpot1970,Susott1982,van
betweenspeciesandfuel component
Wagtendonk
et al. 1998).
Fuelmoisturedirectlyaffectsflammability. The moremoisturecontainedin a fuel particle,the
moreenergyis requiredto heatandvaporizethat waterbeforethe fuel canbe heatedto thepoint
of ignition. Without sufficientenergyto vaporizethe moisture,combustiondoesnot occur. Fuel
aseitherlive or deadfuel moistureon a dry weight basisandalsovaries
moistureis expressed
bothseasonallyandby location.
Fuelmoisturein deadfuels(expressed
asa percentof dry weight)is a functionof atmospheric
t
conditionsandfuel particlesize. Weatherinfluencesthe amountof availablemoistureandfuel
particlesizeaffectsthe rateat which moistureis eitherlost to or gainedfrom the environment.
In determiningdeadfuel moisturesfuel particlesareclassifiedby sizecategoriesaccordingto the,
timelagrequiredto reach63%o
towardsits equilibriummoisturecontent(Lancaster1970,
Deeminget al. 1977).Equilibriummoisturecontentis the moisturecontenta fuel particlewould
reachunderconstantenvironmental
conditions(Agee1993,Pyneet al. 1996).One-hourtimelag
fuelsconsistof deadplantmateriallessthan0.6 cm in diameterandthe upper0.6 cm of litter on
the forestfloor. Ten-hourtimelagfuelsconsistof deadbranchwoodbetween0.6 cm and2.5 cm
in diameterandthe portionof the litter layerbetween0.6 cm and 1.9cm in depth. Dead
branchwood
between2.5 cmand7.6cm in diameterandlitter andduff between1.9cm and 10.2
cm in depthconstitute
the 100-hour
timelagfuels. Deadbranchwood
largerthan7.6cm in
diameterandduff below10.2cm in depthmakeup the 1000-hour
timelagfuels(Deeminget al.
t977).
Typically,foliageis theonly live fuel involvedin fires. Largerlive fuelscontaintoo much
moistureandhavetoo smalla surfacearea./volume
ratioto contributesignificantlyto the
process.Live fuel moistureis affectedof season,
combustion
species,
andweather.Fuel
!
moisture
(e.g.Philpot1965,PhilpotandMutch lgTl) with moisture
of foliagevariesseasonally
9
Y
contentsoftenexceeding300% immediatelyfollowing budbreakandgraduallydecreasing
throughoutthe seasonto the level of olderfoliage,usuallyaround100%in the PacificNorthwest
(Huffet al. 1989). At live fuel moisturesbelow l00yo,standsareat high risk of crown fire
(Woodardet al. 1983).
of fuelsare importantaspectsof fire behavior.Smallerfuelstendto
The sizeandarrangement
ignitefasterandburn morerapidly than largerfuelsandto a largeextentdeterminethe rateof
spreadof a fire. In contrast,largerfuelsmayreleasemoreenergyover a longerperiodof time
of fuelsaffectsfire behaviorin
andresult in higherfire severity(Agee 1993).The arrangement
the amountof orygen availableto
of the fuelbeddetermines
two ways. First,the compactness
the combustionprocess,which candirectlyaffectthe rateof spreadof the fire (Agee 1993).
Second,the horizontalandverticalcontinuityof fuelsaffectsfire spreadlaterallyand into the
crowns,respectively(Whelan1995,Agee 1996,Pyneet al. 1996).
Fire BehaviorModeling
v
ln orderto adequatelyexpressthe behaviorof a fire, a numberof mathematicalrelationships
havebeendevelopedto quantifuvariousfire behaviorattributes.The useofthese behavioral
to be madebetweendifferentfires andamongdifferentobservers.
attributesallowscomparisons
usedto describefire behaviorarerateof spread,
Amongthe commonlyacceptedcharacteristics
fireline intensity,andflame length. Rateof spreadis simplythe distancea fire advancesper unit
time. Rateof spreadcanbe calculatedfor any portionof a fire's perimeter,howeverfire spread
is fastestat the headof the fire andthis valuetendsto be of mostinterestto investigators.Rate
ofspreadin this paperrefersto the rateofspreadat the headofthe fire and is expressedas m
min-r. Firelineintensityis a measureof the energyreleasedper unit fireline and is expressedas
kW m-r. Flamelengthis a functionof fireline intensityand is expressed
as meters.
relationshipsunderlyingthe fire-behaviorcharacteristics
The mathematical
describedin the
previousparagraph
form the foundationof the BEF{AVEfire-behavior
predictionmodel. The
predictionmodelis a suiteof programsusedto estimatethe
BEHAVEfire-behavior
of fire behaviorundervariousfuel andenvironmentat
conditions.BEHAVE was
characteristics
\-
l0
I
developedfor useby landmanagers
to assess
fire behavioron wildfires,estimateof equipment
andpersonnelrequiredfor fire containment,
defineacceptable
burningconditionsfor prescribed
fire, and providefire behavioreducationandtraining(Rothermel1983). BEI-IAVEcontainstwo
FUEL,thefuel modelingsubsystem,
subsystems:
andBURN,thefire behaviorprediction
system.
FUEL Subsystem
Predictingfire behavioraccuratelyrequirescarefulselectionor creationof an appropriatefuel
model(BurganandRothermel1984).Informationregardingthe fuelspresenton a site can
consistof oneof 13generalfuel modelsdevelopedto representcommonlyencountered
fuel
typesacrossthe United States(Anderson1982).For fire behaviorpredictionpurposes,fuelsare
dividedinto threesizecategories:
lessthan0.6cm in diameter,0.6:2.5 cm in diameter,and2.5
-7.6 cm in diameter.Fuelslargerthan7.6cm in diameterarenot consideredbecausethey are
assumed
to havea negligibleeffecton fire behaviorat the advancingfront of the fire with the
I
exceptionof partiallydecayedfuelsunderextremefire weatherconditions(Rothermel1983). A
fuel modelincorporates
dataconcerningfuel loading(kg har) fuel depth(m), surfaceareato
volumeratio (m2m'3),heatcontent(MJ kg-r),andmoistureof extinction(%) for eachof the three
sizecategoriesfor deadfuelsandfor live fuelsin the smallestsizeclass(< 0.6 cm diameter)
(Albini 1976). Live fi.relsgreaterthan0.6 cm in diameterarealsoassumed
to havelittle eftecton
fire behaviorat the headof the fire dueto their high moisturecontent(Rothermel1983). Eachof
the thirteengeneralfuel modelsdiffers in fuel loadingandthe ratio of fuelsin eachsizeclass
(Anderson1982).
BURN Subsystem
The BURN subsystem
within BEHAVE producesfire behaviorpredictionsbasedon the fuel
modelandenvironmental
datainputby theuser.TheFIREI andFIRE2programs
within BURN
producea varietyof outputsincludingtheestimated
intensityandsizeof a fire, a fire's rateof
spread,andthe attackforcesrequiredto containa fire (Andrews1986,AndrewsandChase
1989).For the purposes
of this projectthepredictedfirelineintensity(kW m-'),flamelength
(m), andrateof spread(m min-t)areof primaryinterest.
;
ll
v
The environmental parametersrequired for the calculation of fireline intensity are amount of
fuel, fuel Wpe(s),fuel moisture,wind, and slope(Rothermel1972). The amount and type(s) of
fuel presentare containedin the fuel model chosenor createdfor a particular site. Flame length
is derived directly from fireline intensity.
Assumptions and Limitations of the Model
Any model of naturalphenomenacontainscertain limitationsand BEHAVE is no exception.
BEHAVE assumesthat a fire has stabilized to a steady-statecondition, advancing at a constant
rate through uniform fuels (exceptwhere the two-fuel model conceptis used)within 1.8 m of the
ground. Fire behavior is predicted at the head of the fire and is does not take into account the
effects of fire behavior in other parts of the fire (Rothermel 1983). Variability in fire behavior
cannot be predicted; predictions representmean values for given fu.el and environmental
conditions (Rothermel 1972).
v
Crown Fire
A fire may spreadas a ground fire, surface fire, a crown fire, or some combination of these fire
types (Van Wagner 1977, Alexander1988,Agee 1996). A crown fire developsusually as the
result of a surface fire that has attained sufficient intensity to involve the fuels contained in the
forest canopy,primarily foliage and to a certain extent,fine branches(Van Wagner 1977,Pyne et
al. 1996). Conditionsconduciveto the onsetof crown fire include high temperatures,low
humidity and correspondinglow fuel moistures,large amountsof surface-fuels,continuous
canopies,multi-layered canopy structure, steep slopes,an unstable atmosphere,and strong winds
(Beighley and Bishop 1990). Although relatively rare,crown fires can be highly destructive,
dangerous,and difficult to control. In a study of crowning activity in the northern Rocky
Mountains,Rothermel(1991) estimatedthat on averagecrown fires spreadover three times
fasterthan surfacefires in standscharacterizedby fuel model l0 (a timber dominatedfuel model
with heavyground-fuelsand a live understorycomponent)(Anderson 1982).
v
l2
Someforestseries,particularlythosefoundat higherelevations,
historicallytendedto burnwith
high-severityfire, which can includecrownfire. Of greaterconcernhowever,is the potentialfor
an increasingoccurrenceof crownfire andotherextremefire behaviorin forestseriesthat
typically burnedwith lower severityfire. Thesechangesin fire behavioraredue in largepartto
foreststructuralandcompositionalchangesasa resultof effectivefire suppression
andvarious
landusepracticesoverthe lastcentury(Bamett1988,CovingtonandMoore 1994,Agee1997,
Campetal.1997,Everettetal.1997,Agee1998).
Van Wagner(1977)describesthreeclassesof crownfire behavior:passive,active,and
independent.In a passivecrownfire, fire intensityis greatenoughthat'flamesfrom the surface
fire reachinto the canopyandinvolvecrownfuelsin combustion,but the passivecrownfire is
entirelydependenton heatfrom the surfacefire for propagation.The active.crownfire, although
dependenton the surfacefire for a portionof its ignitionenergy,actsin concertwith the surface
fire andthe two fires spreadsimultaneously
with a continuouswall of flame extendingfrom the
groundsurfaceto well abovethe crown. The third typeof crownfire, the independent
crown
fire, suppliesall of its own requiredignition energyandspreadsseparatelyfrom the surfacefire.
Althoughthe occurrenceof independent
crownfires hasbeendocumented(e.g.Huff 1988),this
type of crown fire is likely rareandrequiresexceptionallylow foliar moisturecontents,steep
slopes,andextremelyhighwinds(Albini andStocks1986,Van Wagner1993).
Determiningthe conditionsnecessary
for the onsetof crowningactivity and for crown fire spread
is of greatinterestto landmanagers.Economically,crownfires canresultin extensiveoverstory
mortalityandsignificantresourceloss. Froma safetystandpoint,crown fires arevery hazardous
andcannotbe foughtusingdirectsuppression
tactics(BrownandDavis 1973,Alexander1988,
Pyneet al.1996). Fromtheperspective
ofpreservingbiodiversity,threatened
andendangered
plantandanimalspeciesmaybe in jeopardywhencriticalhabitatand/orneighboringstandsare
at risk to crownfire (Everettet al. 1997, RiemanandClaytonI 997,WilsonandBaker1998).
TheBEHAVE mathematicalfire
spreadmodelpredictsonly the behaviorof surfacefires. The
abilityto predictcrownfire behavior
tlrerefore
is ratherlimited.Fahnestock
(1970)developed
;
thefirstkeyto detennining
crownfire hazard.Thiswasa dichotomous
keythatrateda stand's
13
Y
crown ftehazard on a scaleof oneto ten. Althoughhe recognizedthe importanceof weather
on theabilityof a standto sustaincrowningactivity,Fahnestock's
conditionsandsurface-fuels
of the crown in determininghazardratings.
key takesinto considerationonly the characteristics
Basedon studiesof crownfire behaviorin borealforests,Van Wagner(1977)developed
the first
relationships
linkingstandconditionsto theignitionandspreadof crownfire. Due
mathematical
to limited empiricalinformationregardingstandconditionsandcrown fire hazard,these
equationsarecommonlyusedin determiningcrownfire hazardin forestsoutsidethe boreal
region(Alexander1988,Agee1996,Keyes1996,Finney1998,WilsonandBaker1998)
FromVan Wagner's(1977)equationto determinethe fireline intensityiequiredto initiate
crowningactivity,
Is= {0.01x cBH x [460+ (26 xFMC)]]32
where
(Equationl)
Io = critical surfacefire intensityrequiredfor crown
fire ignition(kW m-t)
v
CBH = live crownbaseheight(m)
FMC = foliar moisturecontent(percentdry weight)
it canbe seenthat crownfire ignition dependson the heightto live crown baseandthe foliar
moisturecontentof the crownfoliage. Oncefireline intensityexceedsIi, crown fire behaviorcan
be expected.It is importantto note,however,that fireline intensitiesbelowthat requiredfor
of crown
crown fire initiation maystill resultin extensiveoverstorymortalityas a consequence
heatingof cambialtissue(Agee1993,Ageeet al. in press).
scorchandexcessive
to initiatecrownfire behavior(Is) is reached,
Oncethe critical fireline intensitynecessary
anotherrelationshipbecomesimportantin determiningwhetheror not a crown fire will spread.
This relationshipdescribesthe net horizontalheatflux into the unburnedfuel aheadof the fire
(Van Wagner1977):
v
t4
E=RxCBDxh
where
(Equation2)
E = net horizontal heat flux (kW m-2)
R: rateofspread1m sec-l)
CBD : bulk density of crown (kg m-')
h : heatof ignition (kJ kg r)
The net horizontalheatflux (E) is the energythat is suppliedto the crown-fuelsat givenspread
rates(R), crownbulk densities(CBD), andheatsof ignition(h). Therearecritical levelsof both
the spreadrateandbulk densitybelowwhich a crownfire will not propagate.By rearranging
equation2,Yan Wagner(1977)definedthe massflow rateof fuel into the crown spaceas:
S=RxCBD:E/h
where
(Equation3)
S : massflow rate(kg m'2sec-l)
Van Wagner (1977) suggestedvisualizing a crown fire as a stationary fire front into which fuel
flows horizontally. A minimum massof fuel must passthrough the fire front in order to sustain
crown fire behavior. Below certain thresholds of spreadrate and./orbulk density, this minimum
mass of fuel is not supplied to the fire front and active crown fire spreadceasesalthough torching
(passivecrowning) may still occur (Van Wagner 1977). Van Wagner (1977) determineda
minimum massflow rate (Ss)of 0.05 kgrn-'sec-l belo* which a crown fire will not spread.
Rearrangingequation 3, substituting 0.05 kg rn-t sec-tfor S, and multiplying by 60 to produce
spreadrate in units of m min-r,Alexander(1988) arrived at the following equationfor the critical
minimum rate of spreadrequiredfor sustainedcrown fire behavior(&):
Ro=3.0/CBD
where
Rs: criticalrateof spreadrequiredto sustaincrowning
activity(m sec-')
(Equation4)
t5
Y
Oncea crown fire is fully developed,it may be furtherclassifiedaseithera wind-drivenor
crownfire (Rothermell99l). A winddriven crownfire spreadsas strong
plume-dominated
winds pushthe flamesfrom burningcrownsinto the crownsof neighboringtrees. In a plumedominatedcrownfire a strongconvectioncolumndevelopsoverthe fire, creatingturbulent
crown
surfacewindswhich in turn increasefire intensityandfire spread.A plume-dominated
fire hasthe potentialto createhigherwind speedsat the surfacethanwinds at higheraltitudes,
fire behavior. Plumegreatlyacceleratingfire spreadandcreatinghighly unpredictable
with welldominatedcrownfires may alsoresultin "downbursts",severedowndraftsassociated
developedconvectioncells. Downburstsoccurasprecipitationcoolssurroundingair causingit
I
to descendrapidlyto the ground. Surfacewinds in a downbursttypically exceed100km h and
candramaticallyincreasefire spread(Haines1988).
FederalFire Policy
The increasedhazardof large,highly destructivefires with the potentialof exhibitingcrown fire
behavioris a dramaticsymptomof the "foresthealth"crisiscurrentlyfacing landmanagers
v
is largelythe resultof well-intentioned
throughoutthe InlandNorthwest. This increasedhazard
but often inappropriatefire policiesoverthe lastcentury. Beginning
andextremelysuccessful,
Act of 1897(the OrganicAdministrationAct) which requiredthat
with the ForestManagement
uponthe public
"...provisionsfor the protectionagainstdestructionby fire anddepredations
hasbeena top priority in the
forestsandnationalforests..."be made,fire suppression
of federallands(Robinson1975,BarneyandAldrich 1980,Pyne 1997).
management
tendedto be fairly selectiveup until the
andfundingconstraints,fire suppression
Due to stafFrng
was focusedwherethe resourcesat stakewereconsideredof valueand
1930's. Fire suppression
wereessentiallyallowedto burn (Loveridge1944,
areasof little perceivedworth or usefulness
numberof firesbeginning
BrownandDavis1973,Chandleret al. 1983).Howeveran increasing
afterabout19 I 9 andcontinuingover the nexttwo decadesforcedagenciesto rethinktheir
to fire control. Because
of thecostsandnearimpossibilityof controllinglarge
approach
firesandthedifficulty in predictingwhich fireshavethe potentialto become
destructive
\-
t6
conflagrations,
supportbeganto grow for a policy of completefire suppression.[t wasthought
thatif all fireswerequicklysuppressed
while small,bothcostsanddamages
wouldbe reduced
(ShowandKotok 1930,Loveridge1944,Gisborne1950).Followingthe continuedheavylosses
in regionsadheringto a selectivefire suppression
policy,theForestServiceadoptedthe l0 a.m.
policy in 1935(Loveridge1944).The goalof the l0 a.m.policy wasto attackeveryfire with
sufficientresources
to gain controlwithin the first work period(i.e. before l0 a.m.the day
following initial fire detection).The Civilian Conservation
Corps(CCC), createdtwo years
earlierin 1933,suppliedtheworkforcenecessary
to implement
thenew pollcy on all landswithin
thenationalforestsystem(Pyne1997).
DuringWorld War II, fire controlbecamean issueof nationalsecurity. This urgencydid not
diminishfollowing the endof thewar andin fact largeamountsof military surplusequipment
wereconvertedfor usein fire suppression.The resultwasa highly mechanizedandmuchmore
efficientfire controlorganization(Sanderson1974).Aggressivesuppression
greatlyreducedthe
numbersof acresburnedannuallyin theyearsfollowingthe war (pyne 1997).
Graduallyhowever,the ecologicalimportanceof fire in forestedareasbeganto be realizedasa
driving force behindmanyecosystem
prooesses
andspeciesassemblages
(e.g.HabeckandMutch
1973,Wright andHeinselman1973).In fact,the heavy-handed
control effiortsof the pastoften
causedgreaterenvironmental
damage
thanthefiresthemselves
(Chandleret al. 1983,pyneet al.
1996).Despitethe hugesumsof moneyspenton fire control,burnedareabeganto increase.In
the summerof 1970,largefires in WashingtonandCaliforniaburnedmoreareaon the national
foreststhanin anyyear sincel9l0 (Pyneet al. 1996).Somemanagerssuspected
that fire control
hadreached
a pointof diminishingreturns(Moorelg74).
In response
to the increasedawareness
of the role of fire in manyecosystems
andthe occurrence
of largefiressuchas in Yellowstone
NationalParkin 1988,a numberof reevaluations
of fire
policyledto an abandonment
of thecompletesuppression
policy. Insteadthe focuswouldbeon
fire management
which includedtheuseof prescribed
fire (DeBruin1974).Despitetheshift
awayfroma completesuppression
policyandtlrerecognition
of the beneficialeffectsfire, the
\-
l7
mostrecentpolicy review in 1995concludedthat not enoughprescribedburningwas being
carriedout by any federalagency(USDA andUSDI 1995).
Although thereis a greatinterestin the useof fire as a management
tool, a multitudeof barriers
existto the increaseduseof fire in our forestsincludingrisk-averselandmanagers,
budgeting
procedures,air quality concerns,organizationalinertia,lack of understanding
on the part of the
public, and mixed landownership(Czech1996). Perhapsthe mostsignificantbarrieris what
Arno and Brown (1991)referto as"the paradoxin managingwildland fire". Successfulefforts
at protectingforestsfrom fire this century,howeverwell-intentioned,havealteredvegetationand
fuels,shifting low-severityfire regimesto moderate-andhigh-severityfireregimes.Attemptsto
havecreateda fuel problem(Babbitt 1997).
eliminatethe problemof wildfire on the landscape
of crownfire andotherextremefire behavior'inforestseriesthat in the
The increasedhazard
pasttypically burnedwith lowerseverityfire is due in largepartto changesresultingfrom nearly
(Barrett1988,Covingtonet al.1994,CovingtonandMoore 1994,
a centuryof fire suppression
Campet al.1997).
Agee1997,Arno et a1.1997,
ForestHealth in the Blue Mountains
The almostcompleteexclusionof fire combinedwith otherpastmanagement
practiceshave
alteredhistoricdisturbanceregimesandshiftedstandstowardsdominanceby latersuccessional
treespecies(Gastet al. 1991,Wickman1992,Covingtonet al. 1994).In additionto the
increasedthreatof high-severityfire, conditionsin thesealteredforestsarealsoincreasingly
conduciveto the occurrenceof epidemicinsectoutbreaks.Perhapsnowherein the Westhave
thesechangesbeenmoredramaticthanin the Blue Mountainsof southeastWashingtonand
northeastOregon(Gastet al. 1991,USDA l99Z,Everettet al. 1994). A varietyof forestinsects
in the Blue Mountainshavereachedlevelsmuchhigherin this centurythanwerethoughtto have
occurredhistorically. Theseinsectsincludethe fir engraver(scolytusventralis),Douglas-fir
pseudotsugae),
barkbeetle(Dendroctonus
mountainpine beetle(Dendroctonus
ponderosae),and
Engelmannsprucebark beetle(Dendroctonus
rufipennis),but by far the mostwidespreadand
damagingspeciesis the westernsprucebudworm(Tanakaet al. 1995).
l8
Two budwormoutbreaksoccurredin the Blue Mountainsthis century,eachlasting
andcomparison
of treering
l3 years(ScottandSchmitt1996).Examination
approximately
thatat leasteightregional
suggest
of bothhostandnon-hostspecies
width chronologies
budwormoutbreakshaveoccurredin the Blue MountainssinceaboutA.D. 1700. Datasuggest
that the durationof outbreakswerefairly consistentthroughoutthe last300 yearsrangingfrom
13to 17 yearsin length. However,temporalchangesin the frequencyof outbreaksmayhave
budwormoutbreaks.
occurred.Priorto 1910,about45 to 53 yearsappearto haveseparated
After 1910,the lengthof time betweenoutbreakshasbeenreducedto 2l to 36 years.
Additionally,it is thoughtthat the high levelsof mortalitywitnessedduringthe mostrecent
budwormoutbreak(over 80 percentmortalityof overstoryhosttrees)could not havebeen
sustainedoverthe manypreviousoutbreaksrecordedin the treering record. The increased
in budwormoutbreakdynamicshas
frequencyandintensityof outbreakssuggestthat a c.hange
occurredin the Blue Mountainsin the twentiethcentury(Swetnamet al. 1995).
I
In an additionalstudyof historicinsectinfestationpatterns,Wickmanet al. (1994)examined
forestinventoryrecords,andjournal entriesfrom earlyexplorers,
tree-ringchronologies,
trappers,andsettlerstravelingthroughthe Blue Mountains.Again,the tree-ringrecordsshow
defoliatoractivityin the Blue Mountainshasincreasedin the 20thcenturyabovelevelsthoughtto
overthe longterm. A dramaticshift in forestcompositiontowardsdominanceby
be sustainable
treespecies,as supportedin thejournal entriesandearly inventoryrecords
budwormsusceptible
is thoughtto bethe causeof the increasein insectdefoliationandmortality.
in bothfrequencyandintensityof budworm
Onepossiblecontributingfactorcausingincreases
outbreaksin theBlue Mountainsandelsewherein the rangeof this insectis the effectof climate
variation. Of moreimmediateconcernarethe widespreadforestchangesthat haveoccurredasa
practices.In particular,aggressive
and
fire suppression
directresultof pastmanagement
compositionand
selectiveharvestmethodshaveresultedin dramaticchangesin termsof species
(Covingtonet al. 1994,Agee1996).
of bothliving anddeadvegetation
thespatialorientation
thedense,multi-storiedstandsof shade-tolerant
Theseactivitieshaveallowedthedevelopment
\,
greatlyfavoredby thebudworm.
species
l9
v
Fire in the BlueMountains
The importanceof fire in the Blue Mountainscannotbe understated.Prior to European
settlement,fire wasthe mostubiquitousdisturbance
type in the drier forestsof northeastern
Oregon(Hall 1980,Gastet al. 1991,Agee 1993,Mutchet al. 1993,Maruoka1994,Arno et al.
l99T,Heyerdahl1997). FrequentlightningandNativeAmericanignitionsoftenresultedin
extremelyshortfire returnintervalsinthe Pinusponderosa,andPseudotsuga
menziesiiforest
seriesanddrier portionsof thelDres grandistype(Agee1993). For example,Maruoka(1994)
menziesiianddry
{o,undhistoricmeanfire retum intervalsof l0 to 49 yearsin Pseudotsuga
Abiesgrandisforestsin the Blue Mountains.Heyerdahl(1997)foundhistoricmeanfire retum
intervalsof approximatelyl}years in the southernBlue Mountainsbetween1687and 1900.
Becausevery little fuel could accumulateduringthe brief periodsbetweenfires, fires in the drier
forestseriesof this regionwerefuel-limitedandtendedto be low-severityin nature.These
treesof their lower branches,
frequen! light fires consumedsurfacefuelsandprunedestablished
thusmaintainingthe low-severityfire regime(Agee 1993).Firesthinnedthe understoryand
v
preventedor limited the establishment
of latersuccessional
shade-tolerant
treespeciessuchas
grandfir andDouglas-firfavoredby the budworm(Weaver1943,Harvey 1994).Theseforests
by the openstandsoffire-resistantnon-hostspeciessuchasponderosa
wereoften characterized
pineandwesternlarch(Larix occidentalis),oftendescribedin the accountsof earlypioneersin
theBlueMountains(seeEvans1990).
Logging,gazingof livestoclgandfire suppression
following Europeansettlementhaveall had
substantialimpactson a multitudeof forestprocesses
affectingplant communitiesin this region
(Mutchet al: 1993,Agee1994,Johnsonetal.1994,Sampsonetal.1994,Wissmaretal.1994).
Intensegrazinglocally removedgrassesandforbsthat suppliedthe fine, flashyfuelsnecessary
for frequent,low-intensityfire (Hobbs1996,BelskyandBlumenthal1997).High-gradelogging
removedthe largest,mostfire resistanttreeswhile leavingsmaller,and often lessfire resistant
treesbehind(Graham1994,Oliveret al. 1994).Resultsof a 1936forestinventoryshowed80%
landin theBlueMountainswasdominatedby ponderosa
of commercialtimber
pine(Cowlinet
al. 1942).Remainingcommercialponderosa
pine is presentlyestimatedat20-25Vo
of thetotal
v
20
forestedarea(Wickmanet al. 1994).Fire exclusionhasexacerbated
this situation,allowingtree
densitiesto reachlevelsfar higherthanhadbeenexperienced
in the past(Carlsonet al. 1985,
Gastet al.1991,USDA l992,Everettet al. 1994,Pyneetal.1996,Everettetal.1997). Species
haveshiftedfrompark-likestandsof largeindividualsof fire tolerantspeciesto
compositions
(Weaver1959,Baker1992,Graham
densethicketsof smallindividualsof fire sensitivespecies
et al.1994,Arno 1996).
1994,Sampson
Hydrologiccycleshavealsobeenalteredin thesesystemsdueto fire exclusionandresulting
increasedtreedensities.The greatersurfaceareaofthe currentcanopyinterceptsmore
precipitationthandid the moreopencanopyof the past(Sampsonet al: 1994,Wissmaret al.
1994). As a result,moremoistureis lost dueto evaporationandlessmoisturereachesthe soil.
This reducedsoil moistureavailability,combinedwith a greaterdemandfor waterandnutrients
from a largenumberof trees,createsa very stressfulgrowingenvironment.
5
In contrastto the considerable
changesthat haveoccurredin the dry, low elevationforestseries
of the InlandNorthwest,forestsat higherelevationsin colder,wetterenvironmentshavefared
considerablybetter. Theseareashavenot facedthe samehigh levelsof resourceextractionand
exploitationashavethe forestsat lower elevations.Howeverwith their thin bark,shallowroots,
andlow branchinghabits,treespeciesfoundat high elevationssuchas subalpinefir arenot
adaptedto fire andtherefore,whenthey do occur,fires tendto be high-severityin nature(Starker
1934).Higherelevationforestsin this regiontypically experiencefires of stand-replacement
severityat intervalsexceeding100yearsandconsequently
the effectsoffire exclusionhavehad
little impact(FryerandJohnson1988,Barrettet al. 1991,Agee1993).
RiparianForests
The potentialfor an increasedoccurrenceof high-severitywildfires hasincreasedawareness
of theroleof fire in maintaining
amonglandmanagers
desiredstandstructureandspecies
compositionin thesedry forestseries.This increasedawareness
has led to a greaterinterestin
theuseof fire asa manag€ment
tool andthe possibilityof manipulatingforestfuelsin order
reducethehazardof stand-replacement
fires. A considerable
bodyof literatureexistsconcerning
2l
v
the historic role of fire in the uplandforestsof this regionandthe impactsvariousmanagement
practiceshavehadon resultingforests. However,very little is knownaboutthe role of fire in the
riparianzonesof this region.
Riparianzonesform the interfacebetweenterrestrialandaquaticenvironmentsandas a resultare
subjectto the influencesof both systems.Theseareasarequitedynamic,owing to high ratesof
associated
with streams,fire
disturbancesuchasthe erosionalanddepositionalprocesses
with uplandvegetation,andwind, which maybe accelerated
in narrowvalley bottoms.
associated
The structureandcompositionof the vegetationpresentin a riparianQfest reflectsits
disturbancehistory. This complexdisturbancehistorycanleadto greaterspeciesdiversityand
thanis found in adjacentupslopeforests(Swansonet al. 1988,Gregoryet al.
heterogeneity
1991).
Althoughriparianforestsmakeup only a smallportionof the forestedareain the Inland
Northwest,theyplay extremelyimportantrolesin this arid region. Riparianzonesare often
highly productiveareasthat providehabitatfor diversegroupsof plantsand animals(Bilby 1988,
on theseforestsfor
Franklin1992,Naimanet al. 1993).Many speciesof wildlife aredependent
a varietyof functionssuchasthermalandhiding cover,andnestingandfeedinghabitat
(Kauffman1988,Arno 1996,Harrington1996,Sedellet al. 1997).It is estimated
that 60%of
vertebratespecieswithin the stateof Washingtonmakeuseof riparianzonesat somepoint in
their life cycles(Raedeke1988).Properlyfunctioningriparianzonesarevitally importantin the
andregulatelight regimes
of fish habitat. Thesezonesmoderatewatertemperature
maintenance
by shadingthestream,providea sourcefor the inputof organicmaterialuponwhichaquatic
organismscanfeed,andaddstructuralcomplexityto the streamby contributingcoarsewoody
et al. 1986,Bissonet al. 1987,Bilby 1988,Franklin1992,
debristo thestreamchannel(Harmon
Naimanet al. 1993,MinoreandWeatherly1994,RiemanandClayton1997,Sedellet al. 1997).
v
22
Riparianforestsareessentialin the maintenance
of waterquality by actingas naturalfilters,
andpollutionin run-offfrom adjacent(oftenhighlyaltered)uplandforests
trappingsediments
(Bilby 1988).Largeamountsof excessnutrientsfrom surfacerun-offcanbe storedwithin plant
tissueof riparianvegetationandmayreducethe deleteriouseffectsof non-pointsourcesof
pollution on aquaticsystems(PeterjohnandCorrell 1984).Riparianvegetationactsto anchor
and limit erosion(MitschandGosselink1993).A riparianzonecanminimizethe
streambanks
effectsof floodingby actingasa natural"sponge",absorbingandmoderatingthe effectsof peak
groundwater
(Bilby 1988).
supplies
flowsandrecharging
Riparianvegetationis oftenassumed
to burn lessfrequentlythanuplandvegetationin
evaluationsof fire ha"ardandin manycasesmayform a barrierto fire spread(Heinselman1973,
RommeandKnight 1981,Agee1994,Whelan1995).This is dueto the increased
availabilityof
moisturein riparianforestswhich reducestheir likelihoodof carryinglow-severitysurfacefire.
However,the complexmulti-layeredstructureandhigh proportionof fire-sensitivespecies
I
within riparianareasmaketheseareasparticularlysusceptible
to high-severityfire undercertain
weatherconditions.As a resultof thesestructuralandcompositionaldifferences,riparian
vegetationmayburnwith muchgreaterintensitythanadjacentuplandvegetation(Seguraand
Snook1992,Agee1994,Agee1998).Consequently,
crownfire hazardin riparianzones,under
unusualconditions,may be higherthanin associated
uplandareas.
\-_
v
z)
v
CHAPTER
2: Srupy OerEcrrves
The overall objective of this project is to evaluate crown fire hazard and potential fire behavior
in riparian forests of the Blue Mountains in northeastOregon. This study consists of four subprojects. It is hoped that the information in each of these sub-projectscombined can shed some
light on the subject of crown fire in Inland Northwest forests and contribute to a better system for
identiffing hazard.
Refining the definition of h
The first sub-project deals with refining the definition of the critical fireline intensity required for
crown fire initiation (Io). The critical fireline intensity required for crown fire initiation depends
on the height to the crown baseand the heat of ignition of the crown foliage. Heat of ignition is
thought to dependprimarily on foliar moisture content. Late seasonfoliar moisture content
differences between riparian and upland vegetation data from several forest serieswere
compared and their resulting effects on predicted fire behavior evaluated. Seasonalchangesin
lO-hour fuel moisture contents in riparian and upland settings were also investigated. The
incorporation of this information will hopefully allow for more accuratepredictions of fire
behaviorwithin riparian zones.
The heat contents of forest fuels are assumedto be constant for the purpose of fire behavior
modeling regardlessof fuel type, speciesor location. However, this may be a faulty assumption.
The low heat content value used in the BEHAVE fire behavior prediction program for all fuels is
18.61MJ kg'' lalbini 1976,Rothermel1983,Burganand Rothermel1984). The specific
objectiveof this portion of the project was to documentthe differencesin foliar heat content
betweendominanttree speciesand within speciesat different locationsand to comparethese
heatcontentvaluesto the assumedconstant.
J
24
of foreststructurebetweenripariananduplandforests
Comparisons
investigates
thestructuraldifferences
This secondsub-project
betweenriparianandupland
forestsacrossseveralforestseriesthat experiencea rangeof fire severity. Thereweretwo
objectiveswithin this sub-project.The first wasto documentthe differencesin standstructure
betweenriparianforestsanduplandforestsacrossseveralforestseriesthat experiencea rangeof
fire severityfrom low to high. This sectionof the studyconsistedof comparisonsof densityand
verticalandhorizontalcontinuityoftrees in ripariananduplandforestedstands.
The secondobjectiveof this projectwasto comparethe hazardof stand-replacement
severityfire
betweenripariananduplandforests.This wasaccomplished
throughcomparisonsof the fireline
intensitiesproducedby the BEHAVE fire behaviorpredictionprogram(Andrews 1986,Andrews
criticalfirelineintensities
requiredfor initiationof crown
andChase1989)andthecalculated
fire.
Evaluationof heightto live crownestimates
Heightto live crownestimationscanbe quite difficult in multi-layeredstands.The objectiveof
the third sub-projectwasto attemptto find someagreement
on wherethe live crown startsin
structurallycomplexstands.This wasdoneusinga surveyin whichfire professionals
were
askedto visuallyestimatetheheightsto live crownin photographs
of differentforestedstands.
Evaluation of actual fire behavior
The fourth sub-project consistsof evaluationsof fire severity in forested areasthat burned in the
Blue Mountains in 1994. Post-fire aerial photographswere examined to contrast fire severity
experiencedin riparian foreststo that of upland forests. The objective of this portion of the
study was to determineif fire behaviordiffered betweenriparianand upland forest stands.
25
CuerrnR3:SruoyAnnas
Different studyareaswereutilized for portionsof eachof the four sub-projects(Figure l).
Seasonalchangesin l0-hour timelagfuel moisturecontentsandlateseasonriparianandupland
foliar moisturecontentswerecollectedfrom threeforestserieswithin a singlewatershedin
the
Blue Mountains. Datawerecollectedfrom thePseudotsuga
menziesii,Abiesgrandis, andAbies
lasi.ocarpaforestseriesalongMarbleCreekon the BakerRangerDistrict of the WallowaWhitmanNationalForestjust westof BakerCity, Oregon. This areaw4schosenafter
consultationwith U.S. ForestServicepersonnel.The watershedis accessibleby road,hasbeen
minimally impactedby harvestoperations,andspansan elevationalrangesufficientto
encompass
the threeforestseriesof interest.
For the foliar heatcontentportionof this study,sampleswerecollectedfrom fou, conif",
species:Douglas-fir,ponderosapine,andgrandfirlwhite fir. Sampleswere collectedat five
locationsthroughoutthe Northwest the easternslopeof the WashingtonCascades
(nearCle
Y
Elum),northeastWashington(nearColville),northeastOregon(nearBakerCity), the eastern
slopeof the OregonCascades
(nearSisters),andsouthwestOregon(nearMedford). Foliage
sampleswerecollectedfrom areaswhereall threetreespeciescoexisted.Samplesfrom all sites
exceptsouthwestOregonwerecollectedwithin theAbiesgrandisforestseries.Foliagesamples
from southwestoregon werecollectedfrom theAbiesconcolorforestseries.
Datafor the structuralcomparisonsbetweenripariananduplandforestswerecollectedfrom the
PrairieCity RangerDistrict of the MalheurNationalForestlocatedin the southernBlue
Mountainsof northeastOregon. This areawasselectedbecauseit containsa varietyof different
forestseriesacrossa broadelevationalgradient(approximately1300to 2250m) andbecausea
portionof the areaoverlapswith a concurrentriparianfire historystudy.
Becausethe truePinusponderosaforestseriesmakesup sucha smallportion of the forestedarea
in tlreBlueMountains,it wasgroupedtogetherwith thePseudotsuga
menziesiiforestseriesfor
v
26
l
comparisonportionof this study. ThePinusponderosa
the purposesof the riparian/upland
forestseriesis foundat lowerelevationsandoftenmarksthetransitionfrom shrub-steppe
environmentsto forestedenvironments.ThePinusponderosaforestseriesoftengradesinto the
menziesiiforestseries. ThePseudotsuga
Pseudotsuga
menziesiiforestseriesis typically
boundedby theAbiesgrandisforestseriesat higherelevationswhich. TheAbieslasiocarpa
forestseriesoccursabovetheAbiesgrandisforestseries.The combinedPinusponderosa/
menziesiiforestseriesspannedthe narrowestrangeof elevationin the study,
Pseudotsuga
rangingfrom 1384m to 1628m abovesealevel. TheAbiesgrandisforestseriesshowedthe
greatestelevationalrangein this study,extendingfrom 1295m to 1829m abovesealevel. Plot
elevationswithin theAbieslasiocarpaforestseriesrangedfrom I 920 m to 2256m.
The burnedareasexaminedin the aerialphotographinterpretationportionof the studyconsisted
of the Ironsidefire andthe Twin Lakesfire, both of which burnedin the Blue Mountainsin
northeastOregonin 1994. The lronsidefire occurredon theUnity RangerDistrict of the
Wallowa-WhitmanNationalForestandspannedan elevationalrangeof 5200-6200m. The Twiri
Lakesfire burnedon the PineRangerDistrict of the Wallowa-WhitmanNationalForestandon ":;
the Hells CanyonNationalR.ecreation
Areabetween4800-7200m in elevation.Thesetwo fires
wereselectedbasedon the availabilityof post-fireaerialphotographiccoverage.
TheBlue Mountainsregionis characteriz.edby
a continental
climatewith warmdry summers
and
cool winterswith the majorityof precipitationfalling assnowduringthe winter months.The
lowestforestedelevationsin this regionfall within the rain shadowof the CascadeRange.These
pineandwesternjuniper (Juniperusoccidentalis).At higher
areasaredominatedby ponderosa
. elevationsa moremesicforestpredominates
dueto increasedmoistureasa resultof
precipitation.Grandfir andDouglas-firtendto dominatethesesiteswith
orographically-induced
ponderosapine,lodgepolepine(Pinuscontorta),Engelmannspruce(Piceaengelmannii),
westernlarch,andsubalpine
fir alsopresentto varyingdegrees
depending
on localsite
conditions.Heavysnowpackanda shortgrowingseason
characterize
the highestforested
in thestudyarea.Subalpine
elevations
fir is thedominanttreespeciesin thesecold
with lodgepolepine,Engelmann
environments
spruce,whitebarkpine(Pinusalbicaulis),and
rnountainhemlock(Tsugantertensiana)
alsopresent(BryceandOmernik1997).
\,
27
Y
0
150
?5
Kilometers
{
4l
I
N
v
Figure I. Studyareas.
28
CHAPTER4: METHODS
Field Methods
Ten-hourtimelag fuel moisturecontentswere collectedthreetimes throughoutthe 1998 fire
season(22luly,14 August, and 15 September).Prior to sampling,a 100 m transectwas
establishedon each side of and perpendicularto Marble Creek in each of the Pseudotsuga
menziesii,Abies grandis, andAbies lasiocarpa forest series. Along each transect standardfuel
moisture sticks were placed immediately adjacentto the streamand at distancesof 5, 15, 30, 50,
75, and 100 m away from the stream along both sidesof Marble Crpek. Fuel moisture sticks
were placed on wire racks approximately 25 cm above a bed of coniferous needlesas outlined by
Fischerand Hardy (1976). Percentslope,aspect,elevation,percentcanopy cover, and basalarea
were recorded at each fuel moisture sampling point. All points along each transect were sampled
as quickly as possible so as to minimize the effects that changesin temperature and relative
humidity might have on fuel moisturelevels. During sampling,lO-hourtimelag fuel moisture
was measuredby weighing fuel moisture sticks with a handheld scale. In addition, time of day
was recorded and relative humidity was determinedusing a sling psychrometer at each sampling
point.
Late seasonfoliar moisture measurementswere collected from both riparian and upland
vegetation in each of the Pseudotsugamenziesii,Abies grandis, andAbies lasiocarpa forest
series. On l6 September,1998foliage was collectedin the immediatevicinity of the fuel
moisture transects. Riparian foliage was collected immediately adjacent to Marble Creek (within
5 m). Upland vegetationwas collectedapproximately50 m from and on the north side of Marble
Creek(southfacing aspect). Four sampleseachof overstoryfoliage, shrub foliage, and
herbaceousvegetationwere collected at eachriparian and upland location. Sampleweights were
between30 and 60 g. Sampleswere storedin airtight nalgenecontainersand transportedback to
the lab for processing.
29
Y
Five individualtreesof threedifferentspecies(ponderosa
pine,Douglas-fir,andgrandfir or
white fir) were sampledat eachof five locationsthroughouttheNorthwestchosenfor the heat
contentdeterminationportionof the study. Samplelocationswerechosensubjectivelyto
a broadgeographicrange. Locationssampledwere:the easternslopeof the Cascades
encompass
in Washington,northeastWashington,southwestOregon,the easternslopeof the Cascades
in
Oregon,andthe Blue Mountainsin northeastOregon.Foliagewas sampledfrom dominantand
codominanttreeschosenrandomlyat eachsite from standscontainingall threespeciesof
interest. Severallive brancheswereremovedfrom the lower onethird of the south-facingsideof
eachcrown sampled.New foliagewasremovedin the field. The brancheswith the remaining
l+ year old foliageweretrimmedto fit in paperbagsandtransportedtd the lab. Samplingdates
wereas follows: easternWashingtonCascades
sampled19June1997,southwestOregon
sampled26 June1997,northeast
Washington
sampled3 July 1997,'BlueMountainssampledl8
September1997, andeasternOregonCascades
sampled2l Septemb
er 1997.
Foreststructuraldatawerecollectedfrom 38 paired30 x l5 m (450 m2)riparian/uplandplots
acrossseveralforestseriesandstreamorders. Sampleplots within eachforestserieswere
v
establishedsubjectivelyafterconsultationwith ForestServicepersonnelandfield
The absenceof any signsof pasttreeharvestwas a primaryconsiderationfor
reconnaissance.
site selection.Becausethe forestseriesclassificationis a reflectionof slope,aspectand
elevation,siteswere chosenonly on the basisof forestseriesand not with respectto anyother
topographicfeature. Standstructuraldatacollectedweretreediameterat breastheight
(approximately1.5m), total treeheighgandheightto live crown for all treestaller than 1.5m
within a plot. Canopycoverwas alsorecordedfor eachplot. In addition,the slope,
encountered
aspect,elevation,latitudeand longitudeof eachplot wasrecorded.
Thereis no universallyaccepteddefinitionfor riparianforests. For the purposesof this study,
therefore,I havedefineda riparianforestasthe forestedareawithin one site potentialtree length
of first andsecondorderstreamsandwithin two site potentialtree lengthsof third orderand
higherstreams.The sitepotentialtreelengthsusedwerethoseof Sedelletal. (1997). Site
potentialtree lengthswere 45.7m in the Pinusponderosa/Pseudotsuga
menziesiiandAbies
grandisforestseriesand27.4m in theAbieslasiocarpaforestseries.This loosedefinitionof
v
30
riparian forest roughly coincideswith the "riparian zoneof influence" as definedby Oregon's
riparian task force (Carlesonand Wilson 1985,Raedeke1988). This zone is a transitionalarea
betweenthe riparian and uplandenvironmentsand includestreesthat could affect the stream
environmentthrough shadingand the contributionof both fine and coarsewoody debris
(Carlesonand Wilson 1985). This riparian forest definition is also generallyconsistentwith the
definitions provided by the interim Pacific Anadromous Fish Strategy (PACFISH) and
alternatives2,3,4,6, and 7 of the Interior Columbia Basin EcosystemManagementProject
(ICBEMP) (USDA and USDI 1994,Sedellet al. 1997). Thesewidths are thoughtto be adequate
in maintaining the majority of important riparian functions for several decadesto a century
(Sedell etal.1997).
Data from at least four paired riparian/upland plots were recorded for each of three forest series
and three stream categories. Forest seriesencompassedin the study follow a gradient of
increasing fire severity and elevation and include: Douglas-fir or ponderosapine, grand fir, and
subalpine fir. Streamcategoriesconsist of: first order, or headwater,stTeams,secondorder
streamswhich occur below the confluence of two or more headwater streamsand large streams
(third to fifth order streams). Large streamsdo not occur within the subalpine fir forest series in
the study area and therefore were not considered. Forest structure data were also estimatedand
recorded from a riparian area and associatedupland areathat recently experiencedcrown fire on
the PavetteNational Forest in western Idaho.
Physicalsite characteristicsand fuel conditionswere recordedon the samepairedriparian/upland
forested plots used in the forest structure investigation mentioned above. The physical site
characteristicsrecordedfor eachplot were slope,aspect,and elevation. Fuel condition
estimationswere madeby assigningone of thirteen generalfuel modelsto eachplot sampled
using Anderson's(1982) guide to determiningfuel modelsfor fire behaviorestimation.
b
3l
LaboratoryMethods
Foliar moisturesampleswereweighedin the laboratoryprior to placementin a drying oven.
weredriedatT0 Celsiusfor 72 hours.Samplebottleswereimmediatelycappedupon
Samples
removalfrom the dryingovenandsampleswereallowedto cool. Sampleswerethenweighed
andmoisturecontentsdetermined.Box plots showedfoliar moisturecontentdatato be normally
distributed.Comparisons
of foliar moisturecontentbetweenripariananduplandplots were
madewithin eachforestseriesusingsinglefactoranalysisof variancetestswith a 0.05 level of
significance(Zar 1996).
In the laboratory,foliagesamplescollectedto determineheatcontentwerecleanedof foreign
materialsandallowedto dry at roomtemperature.Foliagewas left on the branchto facilitateair
movementandpreventthe growthof mold. Whensamplesweresufficientlydry, needleswere
removedfrom the branchesandgroundin a smallWiley Mill to passthrougha 20-meshscreen.
Five pelletsof approximately0.6 g eachweremadefrom eachsampleusinga Parrpellet press.
Pelletswerethendriedfor 24 hoursat75" Celsius.
v
Thethermalcoefficientof the model l24l Pan calorimeterwasdeterminedfollowing the
procedureusingbenzoicacid. Dried pelletswerequickly weighedandthe gross
standardization
higherheatof combustiondeterminedfor eachsampleas perthe manufacturer'sinstructions
(Anonymous1978).At leastthreepelletsfrom eachsamplewereprocessed.
Corrections
were
madefor the heatof combustionof the ignitionwire, but not for the heatreleasedfrom the
formationof free acidsduringthe combustionprocesslThe energyproducedin the formationof
free acidsis minor when comparedto the differencesin heatcontentvaluesthat occurbetween
replicatetests(L.C. Bliss personalcommunication,
Gorbatova1964).
Because
thecalorimeteris a completelyclosedsystem,theheatcontentvaluesobtainedare
termed"high" heatsof combustion
that includetheheatof condensation
of watervaporproduced
in thecombustion
process.In contrastto combustion
occurringin a calorimeterbombwhich is a
completelyclosedsystem,the moisturereleased
in free-burning
fuelsis assumed
to remainin the
v
32
gaseousstate.To accountfor this discrepancy1.26MJ kgr wassubtractedfrom the grosshigher
heatsof combustionto obtainlow heatcontentvalues(Byram1959,Alexander1982).
The grosshigherheatof combustionis basedon the ovendryweightof the samplewhich
includesinorganicmaterial(Hough 1969).Ash-freeheatcontentvalueswerealsodeterminedby
correctingfor inorganicresidueproducedin the combustionprocess.The mineralashcontentof
eachsamplewasdeterminedusinga portionof eachfoliagesampleandrecordingthe weights
beforeandafterbeingplacedin a muffle furnaceat 600oCelsiusfor 24 hours. Box plots showed
heatcontentdata(with andwithout ash)andashcontentdatato be normallydistributed.Data
wereanalyzedusingtwo-factoranalysisof variancetests. Significantdifferencesbetween
samplelocationsweredeterminedusingNewman-Keulsmultiplerangetests. All testsuseda
significancelevelof 0.05(Znr 1996).
As mentionedpreviously,standstructurecangreatlyinfluenceboth standignition potentialand
the severityof fire experienced.An evaluationof standstructureis thereforeimportantin any
investigationof fire haz.ard.Structuralcomparisons
betweenripariananduplandplotswere
wereaveragediameterat breastheight
madeusingseveraldifferentmeasures.Thesemeasures
for eachstand,treeheight,basalarea,treedensity,percentcanopycover,andstandfoliage
weight. Becauseof the largenumbersof smalltreespresentin the understory,valuesfor average
treeheightwould be ratherlow andof little use. As a consequence,
the "average"treeheight
reportedhereis the averageheightof thetallestzs% of treesin eachstand.
Box plotsshowedstructuraldatawerenot normallydistributed.Logarithmictransformations
werecarriedout on averagetreediameter,treeheight,basalarea,standdensity,andfoliage
weightdata. Percentcanopycoverdataweretransformedusingarcsine-square
root
transformations.Dataweretransformedsothat parametricanalysescould be carriedout.
of structuralcharacteristics
Comparisons
betweenripariananduplandplotsweremadewithin
eachstreamorderusingtwo-factoranalysisof variancetestswith a 0.05levelof significance
(Zar 1996).
!
JJ
ln additionto physicalsite characteristics
andthe amountsandtypesof fuel present,weather
data(fuel moistureandwind data)arealsorequiredto determineexpectedfire behavior.Using
localhistoricweatherdata,90thand97thpercentile
summerfire weatherconditionswereusedin
all predictionsof expectedfire behavior(TablesI and2). The 90thpercentileweatherinputsare
wannerand drier andthereforemoreconduciveto fire spreadthan90%o
of the daysexperienced
in the studyareaduringthe fire season.Similarly,97thpercentileweatherexceedsconditions
locally experiencedon97%oof the daysduringthe fire season.The sameweatherdataareused
for all fire behaviorpredictionswith the exceptionof midflamewindspeed(an input requiredfor
BEHAVE fire behaviorpredictions).Albini andBaughman(1979)reportedwind reduction
factorsof 0.113to 0.248for standard6.1 meteropenwindspeedsin t5fical matureforested
stairds.A reductionfactorof 0.2 wasusedto lower 6.1 meteropenwindspeedsto midflamelevel
in determiningcrownfire ignition potentialfor all stands.To determinecritical crown fire rates
of spread,midflamewindspeeds
werecalculatedby reducing6.1meteropenwindspeedsby
Rothermel's(1983)correctionfactorof 0.4. This wind reductionfactor hasproducedresults
consistentwith actualcrown fire observations
(Rothermel1991).
v
Table I. Fuel moistureinputs usedin BEHAVEfiTesimulations.
l-hour
9TthPercentile
4
Moisture (7o)
l0-hour
100-hour Herbaceous
6
7
Woodv
37
Table2. Wind inputs usedin BEHAVEfiTesimulations.
In Van Wagner's(1977) equationfor determiningthe onsetof crown fire activity (equation l),
the critical fireline intensityrequiredfor crown fire ignition(Io) is a functionof the baseto live
V
34
crown and foliar moisture content. However, equation I can be rearrangedto produce a new
equation in which the baseto live crown is the dependentvariablecontingenton fireline
intensity:
cBlto =12t3
/{0.0t ' [(460+ (26 x FMC)]]
where
(Equation5)
CBHg: minimumlive crownbaseheightabovewhich
torchingis not possible(m)
I = firelineintensity(kW m-r)
FMC = foliar moisturecontent(percentdry weight)
In order for torching to occur, the crown baseheight of a stand must fall below the critical crown
baseheight (CBI{o) required for crown fire ignition. Using predicted fireline intensities from the
BEHAVE fire behavior model and estimatesof foliar moisture content, critical crown base
height thresholds can be determinedfor each stand below which crown fire ignition can be
expected. For the purposesof this study, a foliar moisture content of 100% was used for all
speciesin all stands. This value is consistentwith Rothermel's(1983) estimationof live fuel
moisture for maturefoliage as well as empirically derived mid-August foliar moisturecontents
(Agee et al. unpublisheddata,Philpot and Mutch l97l). The critical crown baseheights
calculatedusing equation5 can then be comparedto the actual crown baseheightsfor each
stand.
Stand conditions conducive to the onset of crowning activity do not by themselvesguaranteethat
a surfacefire will developinto an active crown fire. The fire's massflow rate must be
sufficiently high enoughto maintaincrown fire activity. The spreadrate requiredto maintain
active crown fire activity dependson the bulk densityof the crown (the densityof the fuel,
primarily foliage, within the crown) and variesbetweenstands. The rate of spreadof a crown
fire must exceeda certainthresholdspreadrate(Ra),which is dependenton crown bulk density
to carry the fire through the canopy. When favorableconditionsexist for a surfacefire to enter
the crown, but the surfacefire rate of spreadremainsbelow Ro,the thresholdrequiredfor active
crown fire spread,a passivecrown fire will result. Although a passivecrown fire may burn with
35
Y
greatintensityandcauseextensivetreemortalityandadvancefasterthana surfacefire, it is
wholly dependenton the surfacefire for enerry inputandspreadsat a muchslowerratethan an
activecrown fire. Conversely,the fire will remaina surfacefire if it spreadsat a rateexceeding
& andthe crown is capableof carryingan activecrownfire, but standstructurepreventsthe fire
from enteringthe crown.
It is importantto notethat oncean activecrown fire hasinitiated,its spreadratemay greatly
exceedthat of the surfacefire from which it originated.Crownfire activity reinforcesand
the surfacefire rateof spread(Alexander1988).Basedon observationsof crown fire
accelerates
activity from a numberof differentfires,Rothermel(1991)foundthat ciown fire ratesof spread
wereon average3.34timesfasterthansurfacefire ratesof spreadpredictedfor fuel model 10.
Anothermeansof approximatingcrownfire ratesof spreadsuggested
by Alexander(1988)is to
fully or partiallyadjustthe midflamewindspeedto the standard6.1 meteropenwindspeed.In
this study,critical ratesof spreadrequiredto maintaincrownfire activity (fu) werecalculated
usingRothermel's(1991)crown fire spreadmodelwhich requiresuseof fuel model l0 input for
-
all standsregardlessof actualsurface-fuelconditions.Fuelmodel l0 spreadratesproducedby
BEHAVE weremultipliedby a factorof 3.34to determinecritical crown fire spreadrates.
Critical ratesof spreadweredeterminedfor both 90hand97rhpercentileweatherconditions.
Crownbulk densityestimateswerecalculatedfor eachstandin 3-meterincrementsusingfoliage
weightestimatesfrom the COVERextensionof the FVS growthmodel(Wykoffet al.1982,
to producea new equationin which the critical
Moeur 1985). Equation4 wasthenrearranged
crown bulk densityrequiredto sustaincrown fire behavior(CBDo)becomesa functionof Ro:
CBDg:3.0 / Ro
where
(Equation6)
CBDg= critical crown bulk densityrequiredto sustain
crowningactivity (kg m'')
Criticalcrown bulk densitieswere calculatedfor eachstandusing the critical ratesof spreadfor
both weatherscenarios.Thesecritical crown bulk densitieswere then comparedto the actual
crown bulk densitv estimatesfor each3-metercrown sectionin each stand. Where the estimated
J
36
crown bulk densityexceedsCBDo,activecrownfire behaviorcanbe expectedunderthe given
weatherconditions.Wherethe estimatedcrownbulk densityfalls belowCBD9,activecrowning
underthe givenweatherconditionsandthe fire will remaina surfacefire or
cannotbe sustained
CBDgat heights
passivecrownfire. In somecasesestimatedcrownbulk densitiesexceeded
at risk to activecrowning
aboveany expectedsurfacefire activity. Althoughthe crownsegments
not capableof
from the surfacefire by crownsegments
behaviorin thesestandsareseparated
carryingan activecrownfire, thesestandsmay still be capableof sustainingcrownfire activity if
torching(passivecrowning)occursandflamesenterthe "at risk" crownsegments.
Determiningtheheightto live crownin multi-storiedstandscanbe very difFrcultandrather
no standardmeansof estimationexists(Van Wagner1993). Merely
subjectivebecause
calculatingthe averageheightto live crownfor all treesacrossan entirestandtendsto
the heightto live crownfor predictingfire behavior.Assigningthe lowestheightto
overestimate
asthe crownbaseheightfor the entirestandmayunderestimate
height
live crownmeasurement
to live crown. For the purposesof this study,the heightto live crownfor eachstandwas
\,
of the lowest25s .
determinedby assigningthe actuallive crownbaseheightmeasurement
compromise
percentiletreewithin eachstand.This is purelyarbitrary,but seemeda reasonable
in establishinga practicalmeansfor determiningheightto live crown in multi-layeredstands.It
shouldalsobe notedthat the potentialeffectsofdead branchesstill attachedto the bole below
the live crownandlichenhangingbelowthe live crownwerenot takeninto considerationin this
study. Thesecouldaffectcrownfire ignition potentialby facilitatingthe spreadof a surfacefire
into the crown(Fahnestock1970,Agee 1996).
Firelineintensitiesusingextremefire weatherweredeterminedfor eachof the studyplots using
theBEHAVEfire behaviormodelingprogram(Andrews1986,AndrewsandChase1989).
Predictedfireline intensitieswerecomparedto Ie,the critical fireline intensityrequiredfor the
on the
initiationof crownfire (VanWagner1977).Crownfire ignitionis entirelydependent
heightto crownbaseandtheheatof ignitionof thecrownfoliage. Heightto live crown
for eachplot weremadeusingthe individualheightto live crownmeasurements.
estimates
\-
37
Crown bulk densityestimatesarerequiredto predictthe spreadof crown fire. Theseestimates
werecalculatedusingthe COVERextensionof the FVS growthmodel(Wykoffet al. 1982,
Moeur 1985). Potentialfire behaviorbetweenripariananduplandsitesand betweenforestseries
wascompared.
Pre-fire standstructureconditionswerereconstructedfor a riparian areathat experienceda fire
of stand-replacement
severityalongLittle FrenchCreekon the PayetteNationalForestin 1994.
Standstructuredatawerealsorecordedfrom the adjacentupslopeforestthat hadnot burnedin
1994. The riparianstandconsistedprimarilyof subalpinefir andEngelmannsprucewhile the
upslopestandsweredominatedby lodgepolepine. Priorto the fire in I994,this areahad
previouslyexperiencedan intenseEngelmannsprucehark beetleoutbreakand consequentlydead
fuel loadswerehigh in the riparianzone. Althougha fire of high severityspreadthroughthe
riparianareacausingneartotal overstorymortality,theupslopestandson eithersideof Little
FrenchCreekdid not burn. Evidenceof spottingfrom the adjacentcrownfire wasapparentin
the upslopestands,howeversurface-fuelloadswerenot sufficientto maintainfire spreadand
the manyspotfires quickly burnedout.
consequently
J
Fire behaviorpredictionswerecomputedby the BEIIAVE programusingthe estimatedweather
andwind conditionsfor 16August l994,the dayof the burn(Tables3 and4). Although
historicalaverageweatherconditionswerenot availablefor this particularare4 the conditions
experienced
on the day of the burnwereconsideredexfreme(D. Havalinapersonal
communication).Due to the substantialEngelmannsprucemortalitywithin the riparianzane,a
customfuel modelnamed'FRENCHCR"wascreatedby adjustingfuel loadingvaluesfor
standardfuel model l0 (Table5). This fuel modelwasusedin determiningexpectedsurfacefire
behaviorwithin the riparianzone. The uplandstandadjacentto Little FrenchCreekwas
assignedstandardfuel model8 (a timber-dominated
fuel modelwith light ground-fuelsand little
understoryvegetation)(AndersonI 982).
g
38
Table3. Estimatedfuelmoistureconditionson 16August,1994at time of"fireat Little French
Creek.
DeadFuelMoisture(70)
Live FuelMoisture(%)
l-hour
l0-hour 100-hour
Woody
368
Table4. Estimatedwindconditionson 16August,1994at time of.fire at Little FrenchCreek
6.1 m openwindspeed
(kmhr'r)
l6.l
crownfire ignitionmidflamewindspeed
(kmhr't)
3.2
crownfire spreadmidflamewindspeed(kmhr't)
6.4
Table5. Parameterlistfor customfuelmodel"FRENCHCR"representingestimatedfuel
conditionsat time ofrtre at Little French Creek
I
l-hour
DeadFuels
l0-hour
Live Fuels
100-hour Herbaceous Woodv
Althoughrelationshipshavebeendeterminedto predictthe heightto live crown in standswith a
singlecanopylayer(e.g.McAlpine andHobbs 1994),crownbaseheightis oftendifficult to
determinein structurallycomplexforeststands.To help dealwith this problem,photographs
weretakenin severalforestseriesthroughoutOregonandWashingtonwith a wide rangeof
structuralcharacteristics.The forestsrepresented
in the photographs
werethe Pinusponderosa,
menziesii,Abiesgrandis,andAbieslasiocarpaforestseries.An Internet-based
Pseudotsuga
surveywascreatedusinga total of 33 photographs.Individualsin the fire management
communitywere invitedto participatein the surveyto evaluateconsensus
on visualclassification
of baseto live crownestimates.Althoughthe surveywasopento anyonewho wishedto
from individualsspecificallyinvolvedin fire management
only responses
respond,
wereusedfor
of heightto live crownestimations.Respondents
evaluation
w€reaskedto estimatethe heightto
39
Y
live crown of the standin eachphotographto thenearestmeter. Estimatesof 9 m andhigher
weregroupedtogetherin a singlecategory.Box plotsshowedmeansof estimatesandvariances
of eachphotographto be normallydistributed.Meansof estimatesandvariancesbetweenforest
serieswerecomparedusingsingle-factoranalysisof variancetestswith a 0.05 level of
significance(7ar 1996).
Boundariesof the lronsideandTwin Lakesfiresweredrawnon USGS7.5 minutetopographic
mapsafter examinationof post-fireaerialphotographs.All streamswithin the fire boundaries
werelocatedon the mapsand identifiedasbelongingto eithera first orderor secondorder+ (all
streamslargerthanfirst order)classification.A pointalongeachstreariiwas chosenat random
anda circular areawhosediameterwasno greaterthanthe width of the riparianareawas
examinedfor evidenceof crown scorch.An areaof the samesizein the adjacentuplandforest
wasalsoexaminedfor evidenceof crownscorch.Uplandforestsampleareaswereestablished
outsidethe "riparianzoneof influence"describedearlier. Which sideof the streamthe upland
sampleareaoccured on was chosenrandomly.Thedegreeof crown scorchwithin eachsample
v
areawasclassifiedasunburned/low,moderate,or high. Within the unburned/lowcategoryless
than30Yoof the sampleareashowedevidenceof crownscorch. Sampleareaswith 3O-10%
crownscorchwereplacedin the moderatecategory.The remainingsampleareasexperienced
percentcrown scorchandwereplacedin the high crown scorchcategory.
greaterthan70%o
Fifty-five first orderstreamsand l3 secondorderandhigherstreamswere locatedand sampled
within the boundaryof the Twin Lakesfire. Twenty-onefirst order streamsand 6 secondorder
andhigherstreamsweresampledwithin thelronsidefire.
The frequenciesof eachof the threescorchlevels(unburned/low,moderate,andhigh) were
tabulatedfor eachofthree standlocations:first orderriparian,secondorderandhigherriparian,
andupland. Crownscorchdatafor eachfire werearrangedby standlocationin 3 x 3
contingencytables. Datawere analyzedusinga chi-squaretestof independence
to determinethe
relationshipbetweenstandlocationandcrownscorchseverity. The significancelevelwas setat
0.05(Zar 1996).
v
40
Cgaprpn5:Rrsulrs
BakerCity WatershedTen-hourFuel Moisture
Although l0-hour fuel moisturelevelstendedto be slightlyhigherthe closereachsamplingpoint
wasto the streamin eachforestseries,the resultswerehighly variable(Figures2-10). The
highestrecordedvaluesfor l0-hour fuel moisturealongeachtransectoften did not occurat the
samplingpoint closestto the stream.Within eachforestseries,fuel moisturelevelsweresimilar
on 22 July and 14Augustwhile valueswerehigheron 15 September.This lateseasonincrease
in fuel moisturewasmostlikely causedby rainfall that occurredduringthe weekprior to
sampling.On severaloccasionsthroughoutthe summer,fuel moisturesticksweredisturbedand
founddirectly on the groundat the time of sampling.This led to the recordingof artificially high
fuel moisturevaluesat thesesamplingpoints. Ten-hourfuel moisturelevelsrecordedfrom fuel
moisturesticksfoundon the groundarenotedwith an asteriskin figures2-10.
\.
-
41
v
e
.F
s)
V2
qN
v)
.9
N
tr
()
E
GI
bo
=
v)
o
E
c)
(t)
o
o
$
o\
o
o
s
E
o
o
o
c\
N
s
a
.!
v,
o
o
N
N
G
"s
p
v,
s
N
s
;3
E
tr,
o
J
P
E
o
\
a.
G
E
\l
U,
*
.go
P
=
il
I
€
or
o)
t
b
:r
E
s)
q)
N
N
s
-:3
3
s
qqe
tl)oto
(o@to
P
.E
:Sscqqqsqeo
3$g33RR3e;;
s
q)
.3
o
N
a)
.9
o
E
c)
o
f
ol
Fl
trl
€,x
\ -rX
q
5$
.ss
tt
:
iq
".i
qrY
\b
.st
l\e
J
42
h
*H
na;
U)
E
o
o
'S
$i\
'sE
?i
d\
k;s
rR
ES
qJ'
Q)
€s
g6
bo>.
ot'
oo
EP
<t
st
r&
R*
..r E
o
o
o
\ql
ss
tA
6
o
o
$F
.:\
s€,
ta
E
.Ss
tr
$e
G
b
t4
o
t$
\F
a
{
s\-
\t aa
a.F
a
t"S
@
ss
o)
(D
h, \r
i
tS
R'S
ol
N
$N
Sb
*as
$s
PS
z
E
o
o
e
o
o
Sp
s
o
s
.9 =
o p
E
E
6
o
E
b
tr
()
.:
o
o
x.
R.E
\x
T\\
E'i
"t
sd
NE
!F*.
trs$
43
v
@
E
b
o
o
qi
.F
q
fi
lu
q,
(g
C)
an
s
Q
q)
p
od
a\
0\
o
q,
>.
o
o
o
o
o
{
\
s
o
c\
s
'G
e.
a
fJ
"s
o
a)
v,
t!
v
ss)
ao
o
\
R
(]
a
q
G
I
CD
o
ot
"s
.go
q)
b
>.
s
ol
N
q)
5
s)
s)
e
l.a
q)
q)
$
E;fi;EgEgfiFEEs:
.3
s
s
o
q)
.E.t
.9
o
E
6
e.S
-6{l as
o
o
s
5
o o
t
B
-v
*s
\f
;:
q,Y
\*
N"-U
\l
:3
v
44
:?
:v
a,
(t)
ll)
N
0)
E
G!
bo
(A
'oo
cl
V)
oo'
o\
o\
a
.E
3
q,
o
o
o
o
\
u,
o
I
N
N
s;s
$
\t
s
o
c
o
E
,s
G
q)
S
.4
s
o,
P
o
!
\
E
B
o
ao
a.
a
"s
.go
p
s
\
\'
I
@
o)
o)
S
a
R
q)
C'I
P
q)
g
&p
\f
sp
s
qqqqqqaooooooo
uri oc| ird) !i fdt (dod( rc) jGdt dc \; l;
(aoo( o
'x \i
!q)
o
s
o .=
E .E
6
.q
E
o
o
o
b
tr
g
o
E
B
Nf
th:
.:3 <
5s!s
A>.
< ii'
J\)
t- ': s. t
.u
r^'Q
P";
N".P
;i" s
\%
45
Y
s)
"s
$E
HFo
$r
H+
Fo$
.E€
€\
$q
s{
EE
$r
\s
o
.g
o
o
rE
sN
o
o
o
i{
NS
s\
u,
E
G
*$
.iF
o,
a4
E\-
o
a
v
ES
xS
a3
a
o
o)
G s qJ
(D
"S
.!9 -s
s's
o
$E
o,
S(l
{
8s
cs
*S
$s
z
E
$F
o
o
c
o
o
o
5
.a
s
=
E s
6 E
=
5
o
o
o
-g
q)
t
FS
t\
€t
r'3
$$s
NSR
XR
lsR'3
rit'
$$$
v
46
?is
.sE
s\
%s
EF
es
(€ "\
Bs
's.
,=
(,h
cl
)t
j€*s
tE
$e
s€
o
EE
o
o
\€
sr
.g
r3
sF
o
o
o
ie
NS
o
a.
N \ q)
a
o
o
o
:s
tb
.iF
G
ii \-
u,
o
a
NT
xS
c3
ss
.99
a
€
or
"s
o)
SE
o
h\
t*
ss
c',
sN
cs
t
*l
$s
z
E
$E
o
o
?
qoqrqo e
t rq
l oqr q
o oqrqo q
o tqr q
l oer o
odc;
(o(ororo$rt(.,(oc!N
us
Fi
s
o
x\
a)
d,N
@
o
E
6
E
o
o
;
g
o
u
\d
$$ $
stF
*i{B
Pib.
tr$.$
47
Y
3
\
U)
A
E
o
o
(D
C)
N
o
b0
v)
o
c)
a)
od
o\
o\
o
.g
o
o
o
o
o
L
q)
'a
s
q)
o_
r.a
s
o
a
o
3
N
s
o
E
s
s
*s
a
o,
o
o
v
q)
sp
!
o
\
vl
a.
R
s
i
.s
a
@
o)
o)
.90
p
=
o
et
t
h
E
q)
o
o.
o
v,
ro
s)
q)
e
&a)
z
E
q)
P
S
o
o
q
ro
(o
.kr
ad
Nf,
??eqeqqqeqeoo
333Sg33RRP3;J
:ir:
.9
o
E
o
.x .s
p
E
o
o
o
E
5S
\s
R
x
-: s'
5;\
eb
rad
g
o
E,
"d€
L%
Fo-L. 9
e
q)
i:
v
48
$t
ut
ES
&$
€'$
Es
b0x
ot'
gN
<t
$i
:'x
s€
SE
s$
r.t
o
.g
o
o
o
o
o
aN
ati
$€.
ss
s\
u,
!
c
G
*$
.iF
U,
U'
o
a
q
E\-
FS
ES
EE
I
@
o)
ol
6
s
-S\J
.PP"s
s'E
o
.o
E
h\
o
o.
o
(n
:*
sts
8s
cs
{.s
rO
F
9s,
ss
z
E
$F
o
o
q
ro
(o
o
s
6
.=
p
6
E
E
a,
o
s
(l)
t
tr tr
F}
-d\
C,N
Ft
+S$.
siF
ai i-i
Pit'
d
s$$
U
v
\/
49
\
R
(/)
E
o
Eb.
o
o
&,"$
F.E
(ll\
HE
tr
jiS
1e
H*
;$
.at
s.E
o
o
$s
o
o
,-, I
\$\
o
o
o
ss
8t,
a
i$$
a
a
(,
o
!
EF
;t \'5; ,59
ES
v,
G
TE
v,
o
rsE
a
Es
a
G1
@
Ep
iR
(D
ot
o
&t
IE
E
FS
o
ct
o
s$
13U
o
tO
$R
pt
z
E
o
o
SrS
.3
{$
qqqqqqgeqqeeqq
lo
lo
ro
o
o
(o(olotr)${(oG)(\tN
o
ll)
o
lo
o
to
o
ro
o
o
o
E
o
p
E
:
E
o
o
E
o
sq)
x.
tr $
siF
o.8
.$
H bb
RH
X
\) ^\
ilF*
rigE
v
s0
BakerCity WatershedFoliar Moisture
menziesiiforestseriestherewasno significantdifferencebetween
Within thePseudotsuga
ripariananduplandaverageoverstoryfoliar moisturecontent(Table6). However,both riparian
shrubsandherbsweresignificantlywetterthantheir uplandcounterparts
within thePseudotsuga
menziesiiforestseries.
Table6. Late seasonfoliar moisturecontent(percentdry weight + SD),Baker City watershed.
Riparian
ForestSeries
143.1* 18.3
Pseudotsugamenziesii
Upland
134.7*9.5
Abiesgrandis
146.3+10.8 153.2*ll.9
Abieslaslogqpa
120,]+!16
137.8+7.1
Riparian
Upland
198.2+13.2 122.1+16.4 289.0+59.5
233.6r17.9 124.8+15.8
Upland
71.0+8.3
197.2*.78.0 t04.9+12.7
131.0*2.7 136.0+29.1 106.6*6.1
1 2 4 . 5 *1 6 . l
\,
Therewas alsono significantdifferencein averagepercentmoisturebetweeneitherriparianand
uplandoverstoryfoliageor ripariananduplandherbsin theAbiesgrandisforestseries.Riparian
shrubsweresignificantlywetterthanuplandshrubswithin theAbiesgrandis forestseries.
Averagepercentmoisturelevelsweresignificantlyhigherfor uplandoverstoryfoliagethan
riparianoverstoryfoliagewithin theAbieslasiocarpaforestseries.Averagefoliar moisture
.contentswerenot significantlydifferentbetweenripariananduplandshrubsor uplandand
riparianherbsalthoughuplandvalueswerehigherthanriparianvaluesfor both shrubsandherbs.
Foliar Heat Content
Significant differences between specieswere found for mean foliar percent ash content and mean
low foliar heatcontentwithout ash (Tables7 and9). Differencesbetweenspeciesfor low foliar
heatcontentwith ash were not found to be significant(Table 8). Grand/white fir had both the
highestmeanpercentash contentand highestmean low heatcontentwithout ash acrossall
pine had the lowestmean
locations(5.44%ashand 21.65 MJ kg-rrespectively).Ponderosa
\-
5l
percentash contentand lowest mean heatcontentwithout ashof the speciessampledacrossall
locations(3.49%ash and 21.33 MJ kg-r respectively).In contrast,although no significant
differencesin low foliar heatcontentwith ashwere found betweenspecies,ponderosapine had
the highest mean low heatcontentwith ashacrossall locationswith a value of 20.59 MJ kg-'.
Grand/white fir foliage had the lowest mean low heat content with ash across all locations with a
value of 20.47 MJ kgr. Values for percentash content,heatcontentwith ash and heat content
without ash for Douglas-fir were intermediatebetweenthose of grand/white fir and ponderosa
pine.
Table 7. Sample meansand grand means (+ SD) offoliar ash contents-(Y")fo, Pinus ponderosa,
Pseudotsugamenziesii, and Abies grandis/concolor.
Pinusponderosa
NortheastWA
2.99+ 0.42
EastCascades
WA
3.10+ 0.25
BIueMtns.OR
3.62+.075
EastCascades
OR
3 . 7 1* 0 . 1 9
SouthwestOR
4.03+ 0.32
Ovcrallmean
3.49* 0.54
SouthwestOR
5 . 1 4+ 0 . 4 1
Overallmean
4.96* 0.47
NonheastWA
5.90+ 0.66
Overallmean
5.44* 0.59
Pseudotsugamenziesii
NortheastWA
4.7710.46
EastCascades
OR
4.93+0.52
EastCascades
WA
Blue Mtns.OR
4.93+ 0.77
5.03* 0.42
AbiesgrandidAbiesconcolor
EastCascadesWA
4.84+ 0.59
EastCascadesOR
5.09+ 0.09
Blue Mtts. OR
5.47* 0.26
Southwest
OR
5.87+ 0.48
-'
Table8. Samplemeansandgrand means(* SD)of lowfoliar heatcontentswith ash (W kS )
menziesii,and Abiesgrandis/concolor.Meansconnectedby
/or Pinusponderos4Pseudotsuga
are
not
different.
significantly
an underline
Pinusponderosa
SouthwestOR
20.29+
EastCascades
WA
20.41+0.12
EastCascades
OR
20.64+ 0.19
NortheastWA
20.66+ 0.15
Overallmean
20.59+ 0.30
Pseudotsuga
menziesii
WA
EastCascades
20.02*0.09
Southwest
OR
20.28*0.22
NortheastWA
20.60+0.18
Blue Mtns.OR
20.78+0.r8
EastCascades
OR
2l .05+ 0.24
Overallmean
20.55+ 0.41
BlueMtns.OR
2 0 . 8 7 + 0l l.
Overall mean
2 0 . 4 7+ 0 . 3 6
A hies grandis/A bies co nc olor
OR
Southwest
20.t4+ 0.35
WA
EastCascades
20.22+0.35
NortheastWA
20.54 + 0.25
EastCascadesOR
20.56 * 0.22
v
52
Table9. Samplemeansand grand means(+ SD)of lowfoliar heatcontentswithout ash (MI kg
-')
menziesii,and Abiesgrandis/concolor.
Meansconnected
fo, Pinusponderos4Pseudotsuga
by an underlineare not signirtcantlydiferent.
Piausponderosa
EastCascadcsWA
2 1 . 0 7+ 0 . 1 3
SouthwcstOR
2 1 . t 5+ 0 . 3 3
NorthcastWA
2 1 . 3 0+ 0 . 1 5
EastCascadesOR
2 t . 4 4+ 0 . 1 9
Blue Mtns.OR
21.72x0.24
Overallmean
2 t . 3 3a 0 3 1
EastCascades
OR
22.t4+.026
Ovcrallmean
2t.62+0.43
Blue Mtrs. OR
22.08+0.11
Ovcrattmean
2t.64*0.40
Pseudotsugamengiesii
WA
EastCascades
21.06+ 0.09
SouthwestOR
21.38* 0.23
NortheastWA
2 1 . 6 3* 0 . t 9
Blue Mtns.OR
2 1 . 8 8+ 0 . 1 9
A b iesg randMA bies concolor
WA
EastCascades
2t.25+0.36
SouthwestOR
2t.40+0.37
EastCascades
OR
2t.67+0.23
NortheastWA
2t.83*0.26
Meanlow foliar heatcontentswith ashandmeanlow foliar heatcontentswithout ashdiffered
significantlyby location. Meanfoliar ashcontentswerenot significantlydifferentbetween
samplelocations.Multiple comparisontestingof meanlow foliar heatcontentswith ashand
meanlow foliar heatcontentswithout ashby locationfor eachspeciesshowedconsiderable
v
overlapwithin eachspecies(Tables8 and9). Foliagesamplesfrom southwestOregonhadthe
highestor secondhighestmeanfoliar ashcontentsfor all speciessampled.Amongall species,
foliagesamplesfrom southwestOregonandthe easternslopeof the Cascades
in Washingtonhad
the lowestmeanheatcontentsboth with andwithout ash. Foliagesamplesfrom the Blue
Mountainsin northeastOregonconsistentlyhadthe highestor secondhighestmeanheatcontents
"withandwithout ashof all speciessampled.
RiparianandUplandStandStructure
Tablesl0-15 describethe structuralattributesrecordedin the riparian/upland
standstructure
comparisonportionof this project. Datais presented
for all forestseriesandstreamorder
combinations.
\.
53
Table 10. Average riparian and upland tree diameters (+ SD) byforest series and stream order
(values in cm).
ABGR
PIPO/PSME
ForestSeries
I
2
3
|
|
2
3
2
StreamOrder
Plot Wpe
1 3 . 5 * 5 . 1 2 2 . 3 + 1 0 . 01 8 . 5 + 2 . 4 2 0 . 0 * 6 . 1 1 5 . 6 + 4 . 6 1 2 . l + 3 . 5 9 . 6 * 3 . 3 l 0 . l + 3 . 8
Upland
R i p a r i a n 1 4 . 6 + 6 . 0 1 4 . 2 + 1 . 62 l . l + l l . 3 l 7 . l + 8 . 0 l l . 5 + 4 . 4 1 2 . 6 + 4 . 1 1 0 . 6 + 5 . 6 l l . 0 * 3 . 3
PPO/PSME= Pinusporulerosa/Pseulotsuga
memiesdi, ABGR= Abiesgrandis, ABLA= Abieslasiocarpd
Table I I. Averageriparian and uplandtree heights(+ SD)byforest seriesand streamorder
(valuesin m).
ForestScries
StreamOrder
PIPO/PSME
t2312312
ABCR
ABLA
Plotwpe
Riparian 20.6*5.5 20.6*.3.925.4*6.7 23.2+8.0 19.3+4.5 21.2+5.2 16.2*.7.018.7+25
PIPO/PSME= Pinusponderosa/Pseudotsuga
merciesii , ABGR = lbr'es grandis , ABLA= ,qbieslasiocarpa
Table 12. Averageriparian and uplandbasalarea (*SD) byforest seriesand streamorder
(valuesin m2ha't1.
ABLA
ABGR
PPO/PSME
ForcstSeries
2
2
3
|
2
I
|
3
Streamorder
Plot type
U p l a n d 3 4 . 1 +1 4 . 5 3 8 . 4 * 9 . 0 4 2 . 5 + 1 2 . 35 5 . 6 + 2 6 . 5 3 7 . 3 * 4 . 2 5 0 + 8 . 9 3 9 . 3 +1 8 . 53 2 . 1 +1 8 . 9
1 2 2 . 5 + 5 6 . 0 5 6 . 4 + 1 85.52. 1 + 1 5 . 18 9 . 7 * 2 5 . 87 2 . 1 + 4 2 . 07 6 . 3 + 3 9 . 8
Riparian 39.8*8.6 55.4+23.4
=
porulerosa/Psewlotsuga
menziesri, ABGR= Abtesgrandb, ABLA= Abieslasiocarpd
PIPO/PSME Pinus
Table 13. Average riparian and upland tree density (* SD) byforest series and stream order
(values in tees ha't).
ForcstScrics
StreamOrder
Plot
Riparian
PIPO/PSME
ABGR
2
t 7 4 . t + 8 6 . 3 1 0 5 . 6 + 6 3 . 9 t 0 2 . 7 * 1 9 . 7 t 8 2 . 8 + i l 6 . 3 1 5 4 . 2 + 5 5 . 4 2 7 8 . 3 + 8 9 . 4 389.7* 190.2 242.2+84.1
2 1 7 . 8 + 1 8 7 . 2 2 2 0 . 4 + 6 5 . 5 2 7 9 . 0 + 1 5 1 . ? 2 2 0 . 7 + 1 2 5 . 9 3 1 3 . 8 + 8 9 . 5 4 4 0 . 0 + 1 3 9 . 2 608.3+ 276.0 608.3a 2t6.2
PIPO/PSME =Prrus pondemsa/Pseudotsuga menziuii ABCIR =Abies grandis, ABLA =Abies lasiocnrpo
!
54
Table I 4. Averageriparian and uplandpercentcanopycover (+ SD)byforest seriesand stream
order.
ABGR
ForestScries
PPO/PSME
|
I
2
2
3
3
StreamOrder
Plottype
60.9*13.5 53.8+21.7 68.6*ll.2
Upland
75.7*11.9 67.4+9.5 70.1+8.5
74.5+3.0
Riparian
65.8+7.4 E0.7+6.6 80.9+10.? 73.8+6.1 74.3*8.1
=Prauspondercsa/Pseudoaugo
PIPO/PSME
mentisii, ABGR-Abiesgrandis,ABLA-Abieslasiourpa
|
2
51.7+33.1 63.7*9.0
75.1+ l4.l 82.2t5.2
Table 15. Averageriparian and upland overstoryfoliageweights(+ SD)byforest seriesand
streamorder (valuesin kg ha-t).
ForcstScrics
StrcsmOrdcr
Plot
PIPO/PSME
ABGR
2
*1680 10314+47E3 EEEz+2050 t3403*5EEZ t7425*1527 10824r
75E5+2380 8887+2824 l715l*6312 11280+5911 l5n5*6032 21410+31?4 28406*11444 29245r14785
PIPO/PSME*hus pondetosalheudotuga menzi4iABGR 4bies grandig ABLA +lbir-s lasiocarpa
Riparian
menziesiiforestseries
Pinusponderosa/ Pseudotsuga
v
Therewereno significantdifferencesin averagetreediameteror averagetree heightbetween
ripariananduplandplotsor betweenstreamordersinthe Pinusponderosa/ Pseudotsuga
menziesiiforestseries(Tablesl0 and 1l). Averagetreediametersweresimilar for riparianand
uplandplotsalongfirst andsecondorderstreamswith the exceptionof the secondorderupland
plots. Averagetreeheightsfor all plotsalongfirst andsecondorderstreamswere similar.
Basalareatendedto increasewith increasingstreamorderin thePinusponderosa/ Pseudotsuga
menziesiiforestseries(Table l2). Significantdifferencesin basalareaoccurredbetween
ripariananduplandplotsandalsobetweenstreamorders.The greateramountof moisture
availableto riparianforestsappearsto supporta greateramountof basalareawithin thesestands
to associated
ascompared
uplandstands.In additionto increased
availability,moisturesupplyis
likely moreconsistentalonglargerstreamsthroughoutthe growingseasonand alsotendsto
supporta greateramountof basalareathanalongsmallerstreams.
v
55
Differencesin treedensiryweresignificantlydifferentbetweenriparianand uplandplots in the
menziesiiforestseries(Table l3). As streamorderincreased,so
Pinusponderosa/ Pseudotsuga
did thedifferencesbetweenripariananduplandplot treedensities.Densitieswerenot
significantlydifferentbetweenstreamorders,however.Riparianplots supportedhighertree
moistureavailability.
densitiesthan uplandplotsaswould be expectedwith increased
Differencesin percentcanopycoverweresignificantbetweenripariananduplandplots and
menziesiiforestseries(Table 14).
betweenstreamordersinthe PinusponderosaI Pseudotsuga
The highestpercentcanopycovervaluesfor bothripariananduplandplots occurredalongthird
orderstreams.This is not surprisingconsideringthird orderplots(both riparianandupland)
supportedthe greatestamountsof basalarea. No trendswere readily apparentfor percentcanopy
coverfor first andsecondorderstreamswith the lowestmeanvaluesfor riparianandupland
plotsrecordedalongsecondorderstreams.
Averagefoliageweightdifferencesweresignificantbetweenripariananduplandplots and
menziesiiforestseries(Table 15).
betweenstreamordersin thePinusponderosaI Pseudotsuga
Averagefoliageweightswerelowestalongfirst orderstreamsfor both ripariananduplandplots.
The interactionbetweenslopepositionandstreamorderwasalsosignificant. Riparianplots
alongthird orderstreamssupportedroughlytwice the foliageweight of any otherslope
ordercombination.
position/stream
Abiesgrandisforestseries
Averagetreediametersinthe Abiesgrandisforestseriesweresignificantlydifferentbetween
streamorders,but not betweenslopepositions(Table l0). Averagetree diameterswere highest
alongfirst orderstreams.Along secondandthird orderstreams,averagetreediameterswere
similarwith averagediametersrangingfrom I 1.5cm to 15.6crn. The lower meantreediameters
alongsecondandthird orderstreamsis likely dueto higherdensitiesof understoryregeneration
moistureavailability.
resultingfrom increased
!
56
Y
Averagetreeheightswerenot significantlydifferentbetweenripariananduplandplotsor
betweenstreamordersinthe Abiesgrandisforestseries(TabteI l). The highestvaluesfor
averagetreeheightfor bothripariananduplandplotsoccurredalongfirst orderstreams.
Averagetreeheightvaluesfor ripariananduplandplotsweresimilarfor secondandthird order
streams.Althoughnot significant,the higheraveragetreeheightvaluesalongfirst orderstreams
treediametersfoundalongfirst orderstreamsin thelDies
may corespondto the higherav.erage
grandisforestseries.
::Meanbasalareavaluesweresignificantlydifferentbetweenripariananduplandplots and
-betweenstreamord6rsinthe Abiesgrandisforestseries(Tablel2). The differencebetween
with increasingstreamorder. The
meanbasalareavaluesfor ripariananduplandplots increased
increasingdifferencesin basalareabetweenripariananduplandplotsarelikely the resultof
increasingmoisturegradientsbetweenripariananduplandstandsasstreamsizeincreases.
with increasing
Wateravailabilitywill tendto increaseandvariabilitywill tendto decrease
streamsize. Onereasonuplandmeanbasalareawashighestfor first orderplotswasthe
v
samplingof two sites(HuckleberryCreekand SouthFork Elk Creek)which both contained
pine in the uplandplots.
numbersof largeponderosa
considerable
Meantreedensitiesweresignificantlydifferentbetweenripariananduplandplots andbetween
streamordersinthe Abiesgrandisforestseries(Table l3). As with basalarea,the generaltrend
seemedto be oneof increasingtreedensitydifferencesbetweenripariananduplandplotswith
:increasing
streamorder. The increasingtreedensityalongincreasinglylargerstreamsis also
probablydueto greatermoistureavailability. The relativelyhigh meantreedensityfor first
orderuplandplots(182.8trees/ha)is due in largepartto an exceptionallyhigh uplandtree
densityrecordedat Horseshoe
Creek.This sitewasparticularlyflat (riparianplot slope= l9Yo,
uplandplot slope: ll%o)andalthoughI haveno measure
of sitemoisture,wasby far the wettest
of the first ordersitesin theAbiesgrandisforestseries.Althoughtree densitieswere
significantlydifferent,valuesfor percentcanopycoverwerenot significantlydifferentbetween
ripariananduplandplotsor betweenstreamorderin theAbiesgrandisforestseries(Tablel4).
v
57
Averagefoliageweightswere significantlydifferentbetweenripariananduplandplots and
betweenstreamordersin theAbiesgrandisforestseries(Table l5). Foliageweight differences
betweenriparianand uplandplotstendedto increasewith increasingstreamorderasthe moisture
gradientincreasedbetweenripariananduplandplots. The increasein averagefoliageweight
to an increasein treedensityfor all plots.
with increasingstreamsizecorresponded
Abieslasiocarpaforestseries
Therewereno significantdifGrencesin averagetreediameteror averagetreeheightfound
betweenripariananduplandplots or betweenstreamordersinthe Abieslasiocarpaforestseries
(Tablesl0 and 11). Diametersincreasedonly slightlywith increasingstreamorder. Similarly,
treeheightsincreasedonly slightly with increasingstreamorderwith the tallesttreestypically
foundin riparianplots.
Both basalareaandtreedensitydifferedsignificantlybetweenripariananduplandplots standsin
theAbieslasiocarpaforestseries(Tables12and l3). Riparianmeanbasalareawas roughly
twice the uplandmeanbasalareafor bothfirst andsecondorderstreams.The higherriparian
meanbasalareavaluesareduepredominantlyto a singlebasalareaplot measurement
that
greatlyexceeded
the otherplots in the samplefor boththe first orderand secondorderpairings.
No significantdifferenceswerefoundin basalareaor treedensitybetweenstreamorders.
Percentcanopycoverand averagestandfoliageweightdifferenceswere significantbetween
ripariananduplandstandsinthe Abieslasiocarpaforestseries(Tables14and l5). Differences
in percentcanopycoverwere not significantbetweenstreamordersalthoughvalueswere
somewhathigheralongsecondorderstreams.Riparianmeanfoliage weight increasedslightly
with increasedstreamorder,while uplandmeanfoliageweight decreased
with increasingstream
with the lower meantreedensity
order. This drop in uplandplot foliageweightcorresponds
recordedfor secondorderuplandplotscompared
to first orderuplandplots. Foliageweight
differenceswerenot significantbetweenstreamorders.
I
v
58
CrownFire lgnition(Torching)Potential
crownbaseheightsrangedfrom 0 m to 10.0m with 55oZof standshavingcrown
Individualstand
baseheightsof 0 m andonly six standshavingcrownbaseheightshigherthan2 m (Tablesl6l8). To determine
crownfire ignitionor torchingpotential,thecrownbaseheightof eachstand
wascomparedto the critical crownbaseheightrequiredfor crownfire ignition (CBFIo).The
valuesfor CBHowerecomputedfrom equation5 usingpredictedfireline intensityoutputfrom
theBEHAVE fire behaviorpredictionmodel(Andrews1986,AndrewsandChase1989).
Table16. Torchingpotentialoffirst orderstreams.
Sitenamc
BamettSpring
Bamet Spring
Cold Spring
Cold Spring
CraneCreeklst
CraneCreeklst
DugoutCreek
DugoutCreek
Horscshoe
Creek
Horseshoc
Creek
HoneshoeSpring
HoneshocSpring
HuckleberryCreek
HuckleberryCreek
IndianSpring
IndianSpring
LakeCreeklst
LakeCreeklst
ReynoldsCreeklst
RcynoldsCreeklst
RockSpring
RockSpring
RootSpring
RootSpring
SouthForkElk Creek
SouthForkElk Crcek
StrawberryLake lst
StrawberryLake lst
Sitetype
riparian
upland
riparian
upland
riparian
upland
riparian
upland
npanan
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
Forestseries
PIPO/PSME
PIPO/PSME
ABGR
ABGR
PIPO/PSME
PIPO/PSME
PIPO/PSME
PIPO/PSME
ABGR
ABGR
PIPO/PSME
PIPO/PSME
ABGR
ABGR
ABLA
ABLA
ABLA
ABLA
ABCR
ABGR
ABLA
ABLA
PIPO/PSME
PIPO/PSME
ABGR
ABGR
ABLA
ABLA
CBH (m)
0.0
0.5
0.5
2.0
1.0
0.0
0.0
0.0
10.0
8.0
0.5
0.5
0.0
0.0
0.0
0.0
0.0
0.0
1.0
0.0
0.0
0.0
2.3
2.1
0.0
0.0
0.0
1.0
CBHo(m)
2.8
t.7
2.3
2.0
2.3
2.3
2.0
2.8
0.2
0.2
3.8
2.3
2.0
0.2
0.2
.,4
1.8
2.8
2.3
3.1
0.2
0.2
2.7
0.2
2.0
1.8
3.1
2.7
Torch
Ycs
Yes
Yes
Yes
Yes
Ycs
Yes
Yes
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Ycs
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
977owcather
CBFL (m)
Torch
ycs
3.6
2.3
Yes
2.9
Ycs
2.9
Yes
2.9
Yes
3.2
Yes
2.7
Yes
3.6
Yes
0.2
No
0.2
No
4.6
Yes
Yes
3.2
2.7
Yes
Yes
0.3
Yes
0.2
2.9
Yes
2.4
Yes
Yes
3.6
Yes
2.9
5.t
Yes
Yes
0.3
Yes
0.2
J.J
Yes
No
0.3
Yes
2.7
Yes
2.4
Yes
3.'l
J.i
Ycs
v
CBH = crownbaseheight
CBH,,= 11,".;nt.um crownbaschcightabovewhichtorchingis not possibleunderthegivenweatherconditions
= Pinuspondercsa/PseudoEuga
PIPO/PSME
menziuii , ABGR = Abiu grandis , ABLA = Abiesluiocnrpa
v
59
Table 17. Torchingpotential of secondorder streams.
Site name
BearCreek
BearCreek
Cleu Creck
ClearCrcek
CrancCreek 2nd
CrancCrcek 2nd
FopianCreek
FopianCreek
Halfway Crcek
Halfiray Creek
HuntcrCreck
HunterCrcek
Lake Creck 2nd
LakcCrcek2nd
MeadowFork Big Ctcck
MeadowFork Big Crcek
North Fork Elk Crcek
North Fork Elk Crcck
ReynoldsCreek 2nd
RcynoldsCreek2nd
SpringCreek
SpringCrcek
StationCrcck
StationCreek
StinkCreck
StinkCreek
StrawbcrryLake 2nd
Strawberry Lake 2nd
Sitetype
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
Forestseries
ABLA
ABLA
ABGR
ABCR
PIPO/PSME
PIPO/PSME
ABGR
ABGR
PIPO/PSME
PIPO/PSME
PIPO/PSME
PIPO/PSME
ABLA
ABLA
ABIA
ABLA
ABGR
ABGR
ABGR
ABGR
ABGR
ABGR
PIPO/PSME
PIPO/PSME
CBH (m)
0.0
ABCR
ABL-A
0.5
0.0
0.0
0.0
t.0
0.0
0.0
0.5
t.0
0.0
0.5
t.0
0.0
0.0
0.0
0.0
0.0
0.0
t.5
0.0
0.5
0.5
1.0
0.0
1.0
0.5
ABL,A
0.0
ABGR
90%weather
Torch
CBIL (m)
2.0
Yes
1.8
Yes
Yes
3.1
2.3
Yes
2.7
3.2
2.0
2.3
2.7
2.3
1.8
3.2
1.7
0.2
t.8
1.8
1.7
2.7
3.t
5.1
2.3
0.2
2.8
2.0
2.0
2.3
2.0
0.3
97%oweather
CBIL (m)
Torch
2.7
Yes
Yes
Yes
No
Ycs
Yes
Yes
Yes
Yes
2.4
3.7
2.9
3.3
4.1
2.7
3.2
3.3
3.2
2.4
4.1
23
0.2
2.4
2.4
2.3
3.3
3.7
5.9
2.9
0.3
3.6
2.9
2.7
3.2
2.7
Ycs
Yes
Yes
Ycs
Yes
Ycs
Yes
Yes
Ycs
Yes
Ycs
Ycs
Ycs
Yes
Ycs
Yes
Ycs
Ycs
Ycs
Ycs
No
Ycs
Yes
Ycs
Yes
Yes
Yes
0.3
Yes
Yes
Yes
Yes
Yes
Yes
Ycs
Yes
Yes
. .Yes
Ycs
Yes
Yes
Yes
Yes
Yes
CBH - crownbaschcight
CBH. - thc minimumcmwnbaschcightabovcwhichtorchingis notpossibleunderthc givcnweathcrconditions
menziesri , ABGR - Abies gmndis , ABLA - Abieslasioearpa
PIPO/PSME= PinusponderosalPseudotsuga
60
Table 18. Torchingpotentialof third orderstreams.
sitename
CraneCreek3rd
Elk Creek
Elk Crcek
Little CraneCreek
Little CraneCreek
Little Malheur@ facing)
Littlc Malhcur(E facing)
Little Malheur(W facing)
Little Malheur(W facing)
"North Fork Malhcur @ facing)
North Fork Malheur @ facing)
North Fork Malhcur (W facing)
North Fo* Malheur(W facing)
North RcynoldsCreek
NorthReynoldsCrcek
ReynoldsCrcck3rd
ReynoldsCrcck3rd
SquawCreek
SquawCreck
Sitetype
907oweather
Forest
series cBH (m) cBrL (m) Torch
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
riparian
upland
PIPO/PSME
ABCR
ABGR
ABCR
ABGR
ABGR
ABGR
PIPO/PSME
PIPO/PSME
PIPO/PSME
PIPO/PSME
PIPO/PSME
PIPO/PSME
ABGR
ABGR
ABGR
ABCR
PIPO/PSME
PIPO/PSME
t.0
0.0
0.0
0.5
0.5
0.0
1.0
0.0
0.0
2.0
3.6
0.0
1.9
0.0
4.0
0.0
0.0
1.0
0.0
0.3
t.8
0.3
t.8
0.2
3.1
2.7
0.2
3.8
2.7
3.1
3.1
2.0
0.3
0.3
2.0
0.3
2.8
3.2
No
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Ycs
Yes
No
Yes
Yes
Yes
Yes
gt%wemtcBHo(m) Torch
0.4
2.4
0.3
2.4
0.3
3.7
3.3
0.3
4.6
3.3
3.7
3.7
2.7
0.4
0.3
2.7
0.4
3.6
4.1
No
Yes
Yes
Yes
No
Yes
Ycs
Yes
Ycs
Ycs
Yes
Yes
Yes
Ycs
No
Yes
Yes
Yes
Ycs
CBH - crown bascheight
CBH' = 6s lninitum crown baschcight abovewhich torching is not possibleundcrthc given weathermnditions
PIPOPSME - Pinuspondercsa/PseudoEuga
mcnziesii , ABGR - Abiesgrandis , ABLA = Abies lasiocarpa
Becauseof the low averagebaseto live crown heights found at almost all locations, the vast
majority of standsin the study area were at risk to fire entering the crowns as a result of a surface
fire. Sixty-eight of the seventy-six stands(90%) sampled in the riparian/upland plot comparison
portion of the study were at risk to crown fire ignition under 90thpercentile weather conditions.
Using 97thpercentile weather resulted in one additional stand being placed at risk to crown fire
ignition. Sevenstands(9%) were found to be at no risk to crown ignition under either the 90tr'or
97thpercentile weather scenarios.
Along first order streams25 of 28 stands(89%) sampled were at risk to crown ignition under
both 90tl'and97tl'percentileweatherconditions. One of the three standsnot at risk to crown
ignition along first order streamswas an upland stand in the Pinus ponderosa / Pseudotsuga
menziesiiforest series(Root Spring). The remainingtwo standsnot at risk to crown ignition
were a riparianand upland plot pairing in theAbies grandis forest series(HorseshoeCreek). It
should be notedthat thesetwo standscontaineda substantialcomponentof lodgepolepine and
v
6l
hadthe highestaverageheightsto live crownof all plotssampled(riparianheightto live crown=
10.0m, uplandheightto live crown= 8.0m).
of 28 stands(96%)adjacentto secondorderstreamswere foundto be at risk to
Twenty-seven
crownfire ignitionregardlessof weatherinput,forestseries,or plot type (riparianor upland).
The onestandnot at risk to crown fire ignitionamongthe secondorderstandswas an upland
standin theAbiesgrandis forestseries(SpringCreek). Along third orderstreams,16 of 20
stands(50%) werefoundto be at risk to crownfire ignitionunder90thpercentileweather
conditions.Of the four third orderstandsnot at risk to crownfire ignition under90trpercentile
conditions,two wereuplandstandsinthe Abiesgrandisforestseries(North ReynoldsCreekand
Little CraneCreek)andtwo werea riparian/upland
pairinginthe PinusponderosaI Pseudotsuga
menziesiiforestseries(CraneCreek3'dorder). However,underthe gTtLpercentileweather
scenario,the CraneCreek3d orderriparianstandwasat risk to crown fire ignition.
CrownFire SpreadPotential
Seventy-fourof the 76 standssampledin the riparian/upland
comparisonportionof the study
werenot at risk to crown fire spreadunderthe 90rr'percentile
weatherconditions.In all of these
stands,the crownbulk densitywasbelowthe critical crownbulk densitynec€ssary
for active
crowningto occur(CBDo)throughoutthe entirecrown. The 2 standsfoundto be at risk to active
crownfire behaviorunderthe 90il'percentileweatherconditionswere uplandstandsadjacentto
secondorderstreamsin thelDres lasiocarpaforestseries(LakeCreek2ndorder,Strawberry
Lake2"dorder).
(97i1'percentile),
Undereventhemostextremeweatherscenario
of the 76 standssampled,
the
overwhelmingmajority of stands(6 I ), werenot at risk to crown fire spread.Amongthe 15
standsfoundto be at risk to crownfire spreadunder97thpercentileweatherconditions(which
includethe2 standsat risk to activecrowningunderthe90tr'percentileweatherscenario),l0
occurredin theAbieslasiocarpaforestseries,4 in theAbiesgrandis forestseries,and I in the
I Pseudotsuga
Pinusponderosa
menziesii
forestseries.Overhalf(8 stands)occurredadjacentto
4 alongsecondorderstreams,
first orderstreams,
and3 alorrgthird orderstreams.The stands
62
v
found to be at risk to active crown fire behavior were fairly evenly divided between riparian and
upland positions(8 standsand 7 standsrespectively).
Little FrenchCreekStandReconstruction
Accordingto ForestServicerecords,a fire hadbeendocumented
in theupslopeforestabove
Little FrenchCreekin I 933. An examinationof severaltreecoresin the field suggested
that the
rpslope lodgepolepine forestwaseven-aged
andhadprobablyestablished
after a stand
fire ca. 1900. Examinationof treecoresfrom fire-killed F.ngelmann
:replacement
sprucedirectly
adjacentto the creekindicatedthatthe riparianforestconsistedof a multi-agedstandwith tree
agesin excessof 150years.
The estimated height to the baseof the live crown for the riparian stand along Liffle French
Creekwas 1.7 m. This approximationmay be somewhathigh howeveras individual estimates
were recordedas the height of the lowest branchremainingafter the fire. In all likelihood
v
branchlets,foliage, and lichen hung lower than the height of the lowest remaining branch. The
estimatedheight to live crown for the upland standwas considerablyhigher at 2.4 m. The
critical heights to live crown for crown fire ignition were calculated for the riparian and upland
standsusing equation5. A critical height to live crown of 1.9 m was calculatedfor the riparian
stand,placing it at risk to initiation of crowning activity. The critical height to live crown for the
upland standwas 0.2 m, well below the estimatedactualcrown height.
Under the weatherconditionsapproximatedto have occurredon the day of the fire, the
calculatedcrown bulk densitiesfor both the riparian and upland standsdid not exceedthe critical
crown bulk densitiesneededto maintainactivecrowning activity along Little French Creek. As
a result,neitherthe riparian or upland standwas found to be at risk to active crowning behavior.
However,becausethe estimatedheight to live crown fell below the critical height necessaryfor
torching to occur, passivecrown fire activity would have occurredwithin the riparian stand.
v
63
lnternet SurveY
height to live crown survey. The
A total of 32 individualsrespondedto the Internet-based
majority of respondents(65.6%) were employedby federalgovernmentagencies(Table l9).
There was little consensui among respondentsas to where the height to live crown started in any
of the 33 photographs(Table 20). In only one photographwas the rangeof estimatesof height to
live crown as small as 3 m. In over half of the photographs( I 8) height to live crown estimates
spanneda range of at least 7 m. Comparisonsof mean heights to live crown and variancesof
estimatesof height to live crown were not found to be significant between forest types (Table
21). Although differences were not significant for mean heights to live crown or for variances of
estimates,Abies grandis standshad both the highest averageestimatedheights to live crown
(3.53 m) and the most variation in height to live crown estimates(averagestandarddeviation of
1.77 m). Abies lasiocarpa standshad the lowest estimatedaverageheights to live crown (2.37
m) and Ponderosapine standshad the lowest variation in height to live crown estimates(average
standarddeviation of l.13 m).
to heightto live crownsurvey.
Table 19. Employeror ffiliation of respondents
Table 20. Range of height to live crown estimatesfor eachphotograph.
Range of estimates
3 meters
I
4 meters
5 meters
6 meters
2
7 meters
5
8meters 9*meters
64
Table 21. Meansof estimatesof heightsto live crown (+ SD)for eachphotograph (valuesin m).
Abieslasiocatpa
8
9
Abies lasiocarpa
Abies lasiocarpa
Abies lasiocarpa
Abies lasiocarpa
Abies grandis
Abies grandis
Abies grandis
Abies grandis
19
20
I
2
4
6
Abiesgrandis
Abiesgrandis
ll
l4
Abies grandis
Psandotsuga menziesii
Pseudotsuga menziesii
Pseudotsugamenziesii
Psandotsuga menziesii
Pseudotsuga menziesii
Psandotsuga menziesii
Pseudotsuga menziesii
Pseudotsuga menziesii
Pinus ponderosa
Pinus ponderosa
Pinus ponderosa
Pinus ponderosa
Pinus ponderosa
Pinus ponderosa
Pinus ponderosa
Pinus ponderosa
Pinus ponderosa
Pinus ponderosa
Pinus ponderosa
Pinus ponderosa
Pinus ponderosa
17
3
7
l0
l6
t2
l3
l8
2l
27
)
l5
22
23
24
25
26
28
29
30
3l
32
JJ
2.38
1.78
3.72
1.84
2.13
3.41
4.09
3 .l 3
2.50
3.81
4.97
2.81
4.t6
2.66
4.34
3.25
3.56
L78
3.00
3.53
2.03
1.44
4.22
5 .l 9
5.16
3.53
4.44
l.8l
3.s9
3.09
2.13
3.3r
3.41
+ 1.36
+ 0.94
+2.84
*0.77
+ t.2l
+ 2.58
*2.39
+ 0.71
* 1.98
+ 1.84
+ 1.80
+ 1.09
+2.54
+ l.4l
+2.44
+ 1.32
+ 1.37
+ 1.70
+ 0.89
+ 1.37
+ 0.93
*.0.67
+ 1.62
+2.09
+ 1.78
+ t.44
+ 0.95
+ 0.78
+ l.l0
+ 0.89
+ 0.71
+ 0.82
* 0.95
Aerial PhotoInterpretation
Examinationof crown scorchfrom post-fireaerialphotographsrevealedthat sampleplotswere
moderate
morelikelyto haveexperienced
to high-severity
fire thanlow-severityfire duringthe
of sampleplotsburnedwith high-severity
Twin Lakesfire (50%o
fire, 37.5ohof plotsburnedwith
fire, 12.5%o
moderate-severity
of plotsdid not burnor burnedwith low-severityfire). Crown
v
65
O
scorchlevelsweremoreevenlydistributedon the lronsidefire with 30% of sampleplots
of plotseachexperiencingmoderateand low-severity
experiencinghigh-severityfire and35%o
of stand
fire. However,analysisshowedthat for bothfires,burnseveritywas independent
position. Relativefrequenciesof eachcrownscorchclassification(unburned/low,moderate,and
high) did not differ significantlybetweenfirst orderstreamriparianstands,secondorderand
higherriparianstands,and uplandstands(Tables22 and23).
of crown scorch levelson the Twin Lakes/ire as
Table22. Observedand expectedfrequencies
determinedlrom aerial photograpls.
Low (< 307o)
Twin Lakesfrre
Moderate(30-70m
High (> 707o)
9
6.9
22
20.6
24
Sccondordcr + riparian
0
1.6
3
4.9
l0
6.5
Upland
8
8.5
26
25.5
34
34.0
of crown scorch levelson the lronsidefire as
Table23. Observedand expectedfrequencies
photograPls.
aerial
determinedfrom
Firstorderriparian
I
Low (< 307o)
Observed
il
lronsidefire
Moderate(30-70Yo)
Observed
High (> 7@/o)
Secondordcr+ riparian
2
2.1
4
2.1
1.8
Upland
6
9.5
l0
9.5
8.0
66
CunprBR
6: DtscusstoN
FuelMoisture
1O-hour
fuel moisturewasevidentwith increasing
Althougha slighttrendof increasing
proximity to the stream,the resultswerehighly variable. Theseresultssuggestthat while
- proximity to the streamdoeshavean effecton fuel moisture,micrositedifferencesarealsovery
':importantin determiningfuel moisturelevels. On eachsamplingdateandthroughoutthe entire
season,the highestl0-hour fuel moisturelevelstendedto occuralongthe transectinthe Abies
grandisforestseries.Averagebasalareawashighestalongthis transect.Despitethe high
demandfor wateralongthis transectdueto the largeamountof treebiomasspresent,the high
water loss.
andsolarradiation,therebylimiting evaporational
basalareamay reducewindspeeds
(353.3"and 111.7'). As
This sitealsohasthemostnortherlyfacingslopesof thethreetransects
v
impacton a site's moistureregime.
mentionedpreviously,aspectcanhavea considerable
In contrast,the slopeson eithersideof MarbleCreekinthe Abieslasiocarpaforestserieswere
the mostsimilarin aspectandfacedto theeast(87.7" and 121.7'). Ten-hourfuel moisturelevels
tendedto be the loweston all samplingdatesalongthe transectinthe Abieslasiocarpaforest
to bethe mostconsistentat this site both
series.Ten-hourfuel moisturelevelsalsoappeared
acrossthe transectandthroughoutthe season.This consistencyin fuel moistureis a resultof the
reducedimpactthe streamhasat higherelevationsrelativeto lower elevations.Marble Creekis
quite narrow(approximatelyI m) whereit is crossedby the fuel samplingtransectinthe Abies
Iasiocarpaforestseriesandasa result,the influencethe streamexertson the surrounding
vegetationis considerablylessthanat pointsfurtherdownstreamwherethe creekis wider. In
wider(2-3m wide in thevicinity of thetransect
thecreekbecomes
contrast,at lowerelevations
menziesii
fuels,bothliving and
in thePseudotsuga
forestseries)andits effecton the surrounding
morepronounced
asmorewatermovesthroughthesystem.
dead,becomes
v
67
As wasthe casewith overalll0-hourfuel moisturelevels,the lowerriparianfoliar moisture
levelsas comparedto uplandlevelswithin theAbieslasiocarpaforestseriesarea reflectionof .
the lesserinfluencethe streamhasat higherelevations.Apparentlysomeotherfactor,suchas an
undergroundspringin the areawherethe uplandfoliagesampleswerecollected,exerteda
greaterinfluenceon foliar moisturelevelsthanthe creekitself. Compositionalandquantitative
differencesin vegetationbetweenthe areadirectlyadjacentto the creekandareasfurtherupslope
becomemore apparentat lowerelevationsandtendto manifestthemselvesin higherriparian
foliar moisturesascomparedto uplandvalues.Thesedifferencesare,at leastin part,the result
of differencesin the moistureregimeat eachelevation.Althoughno generalinferences
regardingriparianversusuplandfoliar moisturelevelscanbe drawnfrom the presentstudyof
from onedrainageat onepoint in time, the resultssuggestthat at
threesetsof measurements
lower elevations,understoryriparianvegetationcontainsmoremoistureand is thereforeless
likely to ignitethanupslopeunderstoryvegetation.Differencesin ripariananduplandoverstory
foliar moisturetendto be muchlessthanunderstorydifferences.The flammabilityof the
overstory,andthereforethecrown fire spreadhazard,maynot differ betweenriparianandupland
locations,but with increasedmoisturein the understoryfuels,crownfire ignition haz.ard
is likely
lower in riparianstands,particularlyat lower elevationsandalonglargerstreams.Under
exceptionallydry conditionshowever,understoryfuelsmaycureandresultin higherfireline
to crown fire ignitionthan
intensitieswithin the riparianzoneandthereforeposea greaterhaz-ard
in uplandstands.However,asthe resultsof this studyshow,fuel moistureis site-specificand
manyfactorsotherthanproximityto a watersourcemaybe importantin determiningfire hazard
at any particularlocation.
Foliar HeatContent
pineandDouglas-firwerewithin l.l0 and 1.96absolute
Meanfoliar ashcontentsfor ponderosa
respectively(Susott1982,van Wagtendonket
percentof valuesreportedby otherinvestigators,
al. 1998)(Table24). Overaltmeanfoliar heatcontentswith ashwerewithin 1.4MJ kgt of
pine,Douglas-firandgrand/whitefir (Susottet
in otherstudiesfor ponderosa
valuesdetermined
et al. 1998)(Table25). Meanfoliarheatcontents
al.1975,Kelseyetal.1979,vanWagtendonk
pine,0.6MJ kg-rfor Douglas-fir
and 1.0MJ
withoutashwerewithin2.0MJ kg-rfor ponderosa
68
v
kgr for grand/white
fir of previouslyreportedvalues(Susott1982,van Wagtendonk
et al. 1998)
(Table26). Previousresearchhasfoundregionaldifferencesin foliar heatcontents(e.g.van
differences
resultingfrom increases
Wagtendonk
et al. 1998)aswell asseasonal
in levelsof
etherextractives(oils, waxes,fats andterpenes)in foliageasthe fire seasonprogresses
(e.g.
PhilpotandMutch l97l). However,this studycannotattributedifferencesin foliar heatcontent
within speciesto differencesin locationor time of sampling.Foliar sampleswerecollected
throughoutthe summerandthereforeit is not possibleto distinguishlocationaldifferencesin
.-foliar heatcontentfrom seasonal
differences.Sampleswerealsocollectedfrom eachlocation
only once,so it is not possibleto follow trendsin foliar heatcontentoverthe courseof the
seasonat any particularlocation. However,in all casesmeanheatcontentsfor l+ yearold
valuesof 18.0MJ kg't and 18.61MJ kg-l usedin fire behavior
foliageexceeded
the standard
predictioncalculations
Much of the energyreleasedduringcrownfires is the resultof the consumptionof living foliage
(PhilpotandMutch 1971,Chrosciewicz
1986).Basedon the resultsof this studyit appears
that,
!
not play a
at leastin termsof foliar heatcontent,the speciescompositionof a stand'does
significantrole in determiningpotentialcrownfire spreadrates. However,the heatcontent
differencesfound in this studycouldhavean impacton crownfire hazardandcrowning
propagationratesin differentlocations.
Althoughthe BEHAVE fire-behaviorpredictionsystemcannotbe usedto predictcrownfire or
otherseverefire behavior,predictionsofsurfacefire behaviorcanbe usedto predictthe
initiationof crown fire activity(Rothermel1983).The BEHAVE systemdoesnot takeinto
of fire behaviornor doesit predictactivecrowning,
accountcrownfuelsin its predictions
howeveraveragevaluesfor low heatcontentwith ashin this studyexceededthe standardlow
heatcontentwith ashvalueusedin theBEHAVEmodel(18.61MJ kg-')by 10.0%- 10.6%.
Valuesfor low heatcontentwith ashdetermined
in this studyexceeded
thevalueusedin
FARSITE(18.0MJ kg'') by 13J% - 14.4%.Foliarashcontentsdetermined
in this studyfell
(5.55%)by relativedifferences
valueusedin fire behaviorcalculations
of at
belowthestandard
least2.0%o
andas muchas37.1%.Thesedifferences
couldhavean impacton crownfire
intensityandradiantlreatloademittedtowardsunburned
foliage.
v
69
o
The useof liffer andduff heatcontentshigherthanthe standardvalueof 18.61MJ kgl andash
cont€ntslower thanthe standardvalueof 5.55Yoin fire behaviorpredictioncalculationswill
longerflame lengths' Althoughthe
resultin greaterfireline intensitiesandconsequently,
differencesaresmall,theselongerflame lengthscouldincreasecrown fire initiation hazard.For
example,a l0% increasein heatcontentwould leadto an increaseof over 20% in fireline
intensityanda nearl0oloincreasein flame length(Byram1959,Rothermel1972,Albini 1976).
Table24. Percentashcontentsreportedin previousstudiesfor Pinuspondetosaand
Pseudotsugamenziesiifo Ii age.
Pinusponderosa
b
This study
3.49
Pinusponderosa
2.39-3.75
Pinusponderosa
4.t6
Pseudo6ugamenziesii
4.96
Pseudotsugamenziesii
4.25
Pseudotsugamenziesii
6.92
Washington,USA
not stated
Susott(1982)
SienaNevad4
USA
OregonWashington,USA
not stated
van Wagtendonket al. (1998)
SienaNevad4
USA
van Wagtendonket al. (1998)
This study
susotr(1982)
70
Table25. Low heatcontentswith ashreportedin previousstudies(or calculatedftomreported
menziesii,Abies concolor,and
Pseudotsuga
high heatcontentvalues)for Pinusponderosa,
Abies grandisfoliage.
Pinusponderosa
Low heatcontentwith ash
(MIKE')
20.59
pinusponderosa
19.21
pinusponderosa
20.27
pinusponderosa
20.9
menziesii
Pseudotsuga
20.55
pseudotsuga
menziesii
19.98
menziesii
Pseudotsuga
20.29
Abiesgrandidconcolor
20.47
Abiesconcolor
19.4
Abi* grandis
20.83
Species
Location
OregonWashington,USA
SierraNevadq
USA
not stated
This study
northernRocky
Mountains,USA
OregonWeshlngton,USA
SierraNevad4
USA
northernRoclg
Mountains,USA
OregonWashington,USA
SierraNcvad4
USA
northemRocky
Mountains,USA
Kelseyct d. (1979)
van Wagtendonket al. (1998)
Susottet al. (1975)
This study
van Wagtendonket al. (1998)
Kelseyet al' (1979)
This study
van Wagtendonket al. (1998)
v
Kelseyet al. (1979)
v
7l
Table26. Low heat contentswithout ashreported in previousstudies(or calculatedfrom
menziesii,and Abies
reportedhigh heatcontentvalues)for Pinusponderos4Pseudotsuga
concolorfoliage.
Species
Low heat content without ash
(MI kgr)
Pittusponderosa
21.33
Pinusponderosa
19-29- 21.65
Pinusponderosa
20.11
menziesii
Pseudotsuga
21.62
menziesii
Pseudotsuga
21.04
menziesii
Pseudotsuga
21.57
Abiesgrandis/concolor
21.65
Abiesconcolor
20.63
Location
OregonWashington,USA
not stated
This study
SierraNevad4
USA
OregonWashington,USA
not stated
van Wagtendonket al. (1998)
SierraNevad4
USA
OregonWashington,USA
SierraNevad4
USA
Susott(1982)
This study
Spsott(19E2)
van Wagtendonket al. ( 1998)
This study
van Wagtendonket al. (1998)
RiparianandUplandStandStructure
Only threestructuralattributeswerefoundto be significantlydifferentbetweenriparianand
uplandplotsacrossall forestseries.Theseattributeswerebasalarea,standdensity,andcanopy
foliageweight. In everycasethe averagevaluesfor riparianbasalarea,standdensity,and
canopyfoliageweightwerehigherthanthe averagevaluesfound in associated
uplandstands.In
contrast,no attributeswerefoundto be consistentlydifferentbetweenstreamordersacrossall
forestseries.In general,within a forestseries,thedifferences
betweenripariananduplandplots
tendedto be greaterthanthe differencesbetweenstreamorders.
Crown Fire Ignition and Spread
Nearly allstands sampledin this study, regardlessof forest seriesor slope position, were found
to be at risk to the vertical spreadof fire into the crowns and thereforehad a significant chanceof
72
passivecrown fire ignitionas a resultof surfacefire behavior.The potentialfor suchwidespread
torchingactivity is likely markedlydifferentthantheconditionsthat existedhistorically. Prior to
the dry forestsof the southernBlue Mountainswere characterized
Europeansettlement,
by a fire
returnintervalofapproximately
12years.In thelatelgtl'centuryfire recurrence
decreased
in the
BlueMountainsbeginningwith a periodof highprecipitation
in the 1880s-l9l0sandhas
continuedthroughthis centurydueto variouslandusesandfire exclusion(Heyerdahl1997).
Althoughreconstruction
of historicstandstructureswasbeyondthe scopeof this study,current
standstructuresarelikely very differentthanthosethat existedprior to the turn of the century.
The high numberof standsin this studyat risk to torchingin the crownsis a resultof the
'structural andcompositionalchangesthat haveoccurredin theseforest'sover the last 100years.
It appearsthat at present,riparianstandsfaceno greaterhazardofcrown-fire spreadthanupland
standsdespitethe fact that in all forestseriesriparianstandssupportedhighertreedensitiesand
greateramountsof basalareaandfoliagethanuplandstands.Of the 15 standsat risk to active
crownfire spreadunder97thpercentileweatherconditions,8 wereriparianstandsand7 were
uplandstands.Forestseriesappeared
to be a betterindicatorof crown-firespreadhazardthan
slopepositionwith l0 of the 15standsat risk to activecrownfire spreadfoundinthe Abies
lasiocarpaforestseries.Thesesubalpineforestshavehistoricallybeencharacterized
by a highseverityfire regime,burninginfrequently,but with greatintensityandwould havefaced,as is the
casetoday,the greatesthazardfor activecrowningbehaviorprior to 1900. In contrastto the
torchingpotentialthat appearsto haveincreased
this century,particularlyin the drier forest
series,currentactivecrown-firespreadpotentialmaynot be substantiallydifferentthanbefore
,Furopeansettlement.It is importantto notethat althoughfew standswere foundto be at risk to
activecrownfire behavior,the effectsof a fire burningunderextremeweatherconditionswill
likely still be severein mostof thestandssampleddueto passivetorchingof thecrowns.
Little FrenchCreek StandReconstruction
Severalpossibilitiesexist that could explain why active crown fire behaviorwas not predictedin
the riparian standalong Little FrenchCreek. Pre-firefuel loading information was not available
for the Little FrenchCreek areaand as a consequencefuel loadswere reconstructedbasedon the
73
I
post-fireconditions.Theseapproximations
mayhaveunderestimated
actualfuel conditions
resultingin erroneouspredictedfire behavior.Anotherpossibilityis that actualweather
conditionsrnayhaveexceeded
theconditionsthatwerethoughtto haveexistedduringthe fire.
Windsmay havebeenaccelerated
in the narrowvalleybottom. A minimummidflamewindspeed
of 15km h-r would be necessary
to maintainactivecrowninggiventhe catculatedcrown bulk
densities.A third possibilitymay bethat the fire thatspreadthroughthe riparianareawasa very
intensepassivecrownfire andnot an activecrownfire at all.
Perhapsmore importantthanthe fact that activecrownfire spreadwas'notpredictedwithin the
riparianforestalongis the evidenceof rwo very differentdisturbancehistoriesalongLittle
FrenchCreek. The upslopeforestappearsto burnmorefrequentlyihanthe riparianforestand
with stand-replacement
severity.The riparianforestdoesnot appearto haveburnedin eitherthe
1933or 1900fires and,prior to the fire in 1994,wasnot subjectto disturbances
of standreplacementseverity.At the time of the fire in 1994,fuel loadswerehigh in the riparianforest
asa resultof extensiveinsectmortality. In contrast,fuel loadsin the upslopeforestweresparse
andcould not supportfire activity. Thesefindingssuggestthat prior disturbancepatternsmay
havebeenmoreimportantfactorsthanstandstructurein influencingthe unusualfire behavior
that occurredalongLiffle FrenchCreek.
InternetSurvey
The mostimportantfactor in determiningthe crownfire ignitionor torchingpotentialof a stand
is the heightto live crownof the standin question.While determiningthe heightto live crown
for single-layered
standsmay be relativelystraightforward,makingthis determinationin stands
with multiplecanopylayerscanbe quitediffrcult. The lackof consensus
on heightto live crown
estimateswithin any foresttype in the Internetsurveyreflectsthe difficulty encountered
even
amongfire professionals
just wherethe live crownactuallybeginsin a stand.The
in detennining
smallestrangeof,estimates
for anyphotograph
was3 m. A differenceof 3 m wouldgreatly
affecttlrecalculated
valuefor thecriticalfirelineintensityrequiredfor crownfire initiationto
;
occur. Any numberof criteriamaybe usedin determining
a standsheightto live crown.
74
Y
However,without an agreeduponstandard,makingaccuratecrownfire hazardpredictions
will
be difficult andmakingcrownfirehazardcomparisons
will benextto impossible.
Aerial PhotoInterpretation
The resultsof the examinationandanalysisof aerialphotographs
from recentlyburnedareasin
the Blue Mountainsshowthat burnseverityis independent
of slopeposition. The relative
-frequenciesof burn severitywerenot significantlydifferentbetweenplot positions
in eitherfire
.-despitethe fact that overallfire severitywasgreateron the Twin Lakesfire. One
contributing
*factorleadingto the increasedfire severit5r
experienced
on the Twin Lakesburn wasthe elevated
fuel loadingin that arearesultingfrom a largeEngelmannsprucebarkbeetleoutbreak
in the
early 1980s(J. Szymoniakpersonalcommunication).The resultsof the interpretation
of aerial
photographs
of actualfires areconsistentwith the resultsof the portionof this study
on crown
fire ignition hazafi. In both investigations
therewerefew differencesfoundbetweenriparian
anduplandplots in termsof risk of torchingin the crownsregardless
of streamorder. It was not
possibleto differentiatebetweenpassiveandactivecrownfire behaviorfrom
the photographs,
so
no comparisons
canbe madeto the portionsof this studyon predictedfire behaviorand
crown
fire spreadhazard.It shouldbe notedthat forestserieswasnot takeninto consideration
in
analyzingrecent
fire behaviorandthat this analysisis basedsolelyon examinationof aerial
photographs.
A moredetailedinvestigation
includingcollectionof dataat the areassampledon
the photographs
and stratificationof plotsby forestserieswould likely leadto a greater
v
ofthe relativehazardsfacedin differentforesttypes.
_understanding
v
75
NEEDS
CHapTER7: RESPARCH
This studyhasmerelyscratchedthe surfacewith respectto a numberof topicsthat wanant
furtherinvestigation.In termsof overstoryfoliar heatcontent,it would be usefulto conduct
repeatedsamplingat severallocationsoverat leastonefire seasonand ideally over several
to determineif the differencesin heatcontentfoundwithin speciesin this studywerea
seasons
resultof locationaldifferencesor collectiondate. This informationcould be usefulin conducting
Similarly,detailedmonitoringof both living
regionallyspecificcrown fire hazardassessments.
anddeadfuel moistureacrossriparianzonescouldbe usedin determiningmoreprecise
of fire hazardin particularlysensitiveareassuchas sourcesof municipalwater
measurements
suppliesor critical wildlife habitats.
of fuel characteristics
andfuel loadingscould leadto
The useof moredetailedmeasurements
differentestimationsof fireline intensity,flamelength,andratesof spread.Thesedifferent
of the hazardof both crown
estimationscouldthen in turn producemoreprecisemeasurements
fire ignition andcrown fire spread.However,of greaterimportanceis the fact that Van
Wagner'scrown fire theoryis basedon very little empiricalinformation. Althoughthe theoryis
the "stateof the art" in crown fire modeling,it remainslargely
widely utilized andrepresents
untested.Opportunitiesfor crownfire behaviorresearchare limited, howeverwithout more
areopento question.Further
empiricaldata,the accuracyof crown ftehazard assessments
crownfire researchmay also leadto a bettermethodof estimatingthe heightto live crown in
structurallycomplexforeststands.
76
CHePrpn8: MeNecET,mNn
IvpLICATIoNS
Althoughthis studydid not find a substantial
numberof standsat risk to activecrownfire
behavior,the vastmajorityof standssampled(over90%)werefoundto be at risk to torchingand
thereforeat risk to passivecrownfire behavior.With limited fundingavailablefor restorationto
returnstandsto more"natural"and"fire-safe"conditions,priority for treatmentshouldtherefore
+befocusedon uplandstandsin the driestforestseries.These
standsfacethe greatesthazardof
'surface
fire ignition andspreadandarethoughtto havesupportedlittle'torchingactivity
historically. Thesestandsalsocontaina greaterfire-resistanttreecomponentthanstandsin
wetterforestseries.Althoughriparianstandsmayoccasionallyexperiencehigh-intensityfires,
aswasthe casealongLittle FrenchCreek,thesemay in fact be exceptionalcasesdueto unique
disturbancehistoriesandunusualweatherconditions.It would not be practicalor, in many
evendesirableto attemptto reduceripariancrownfire hazardin anticipationof
instances,
extremeweatherconditions.Evenwhereriparianforestsmay be at risk to crown fire, reducing
v
the hazardin the adjacentstandswhereignition is morelikely will lessenthe possibilityof fire
spreadfrom uplandstandsandreducethe overallhazardof high-intensityfire behavior.By
focusingtreatmentson uplandareas,negativeimpactsof restoration(suchas soil compaction
from harvestingequipment)will be minimizedin riparianforests.Reducingcrownfire hazardin
uplandareaswill alsoprotectriparianforestsandassociated
aquaticsystemsindirectlyby
ieducingthe impactsof erosion,whichcanbeseverefollowingintensewildfires(Beschta1990,
Wirr.a. et al. l994,RiemanandClayton lgg7).
Denselystockedstandscombinedwith higherthanhistoriclevelsof largediameterwoodyfuels
haveplacedtheseforestsat greatriskto stand-replacement
fire (Hall 1980,Arno andBrown
1991,Covingtonet al. 1994).Thedensenatureof thesestandsandthe resultingcompetitionfor
limitednutrientandwaterresources
havealsocreatedforestsof highlystressed
low-vigor
(Oliverl98l). Consequently
individuals
theseforestsarecurrentlyat highriskto disease
and
insectattack,greatlyjeopardizing
desiredforestfunctionssuchasresourceproduction,
recreation,
andprovidingwildlifehabitat.Wickmanet al. (1994)suggest
thatin theabsence
of
v
77
fire, insectsanddiseasehavetakenoverthe role regulatingforeststructureandcompositionin
the Blue Mountains.
tendedto focuson short-termsolutionsto problemssuchas fire exclusionand
Pastmanagement
chemicaland biologicalcontrolto reduceinsectpopulations.While theseapproaches
may be
theygenerallyonly maintaincurrentstandconditionsandmay
warrantedin certaininstances,
actuallyexacerbatefutureinsectandfire hazards(Gastet al. 1991,Everettet al. 1994).
Historically,frequentlow-intensityfire andsmall,localizeddiseaseand insectoutbreaksplayed
importantroles in the establishmentdevelopment,
andmaintenance
of-seralforestcommunities
in the InlandNorthwest(Harvey1994).In a sense,theselow-intensitydisturbances
actedto turn
clock" andpreventedthe widespreadestablishment
backthe "successional
of laterseralforest
types. Successfulcontrolof bothhigh-severityfire andinsectoutbreakswill requirea meansof
turningbackthe clock andundoingthe effectsof pastmanagement.Returningfire to the
will be an importantaspectin forestrestoration.Beforeany actioncanbe taken,
Iandscape
however,it is vital that we havea clearunderstanding
of the disturbanceprocesses
that created
havechangedoverthe last
andmaintainedtheseforestshistoricallyandhow theseprocesses
century.
Oncehistoric standconditionsanddisturbanceregimesaredetermined,strategiesto return
alteredforeststo a somewhatmore"natural" statecanbe developed.It will not be possibleto
recreatethe conditionsthat existedprior to Europeansettlementfor a numberof reasons.As
Sprugel(1991)pointsout,everypointin time is ecologicallyuniquedueto a varietyof everchangingfactorssuchasclimate. Evenin the absenceof the human-caused
changesthat have
the forestsof the InlandNorthwestwould likely be differenttoday
occurredfollowing settlement,
thana centuryago. Certainlandusesmayalsohaveresultedin irreversiblechanges,precluding
the possibilityof restorationto more"natural"conditions.Finally, societymayview certain
changesas beneficialandmaynot wish to attemptrestorationon all forestlands. However,
maintaininga varietyof conditions
thoughtto haveoccurredwithin a forest'shistoricrangeof
variabilitybetterensures
thesustainability
andproductivityof the forestoverthe longterm
(Johnson
et al. 1999).
78
"
Knowledgeof the detrimentaleffectsof fire exclusionis by no meansa new development
(e.g.
Leopold1924,Weaver1943).However,it maynot be possibleto merelyreinkoducefire in
someforesttypesdueto high densitiesof understoryregeneration
andexcessivefuel loading.
Evenundercontrolledconditions,reintroductionof fire alonemay in somecasesleadto fires of
high severityandresultin heavymortalityin all treesizeclasses.Considerable
silvicultural
(e.g.thinning,pruning)maybe desirablein manyareasbeforefire is reintroduced.
,manipulation
Thinningcanbe usedto retum currentalteredforeststo conditionsmorecloselyresembling
historic conditionsin termsof speciescomposition,standstructure,aridstanddensity. A number
of recentstudieshavestressed
the needfor activemanagement
in reducingthe fire and insect
hazardsin westernforeststhat are largelyconsequences
(e.g.van
of pastmanagement
1996,GaraandWilson 1998,Johnsonet al. 1998,WilsonandBaker1998,Wilson
Wagtendonk
et al. 1998,Ageeet al. in press).Restorationwill be a slow, labor-intensive,
andcostlyprocess.
Marketsmaynot exist for materialremovedfrom treatedstands.Short-termbenefitswill likely
needto be sacrificedin orderto achievethe long-termgoalof truly sustainableforests.Due to
the high costs,standswill likely needto beprioritizedfor treatment.By merelybreakingup the
continuityof at-riskstandshowever,overallsusceptibilityto fire and insects,andtherefore
hazard,will bereduced.
Presentconditionshavedevelopedovera periodof almosta century. Restorationwill likewise
takedecades.Short-termsolutionsto fire andinsectproblemshavetheir place,but mustbe
implemented
within the frameworkof a longer-termapproach.Quantitativeassessments
of
changesin disturbancepatternsandthe resultingchangesin forestcommunitycompositionand
structurewill providea betterunderstanding
of pastmanagement's
impactson theseforestsand
providestartingpointsfor restoration.With this understanding,
theseforestscanadministeredin
a moreecologicallysoundmanner,incorporating
disturbance
processes
into management
planning.
J
79
LITERATURECITED
K.J.,ed.
dynamicsin forestriparianzones.In: Raedeke,
Agee,J.K. 1988.Successional
p. 3l-45.
Streamside
management:
riparianwildlife andforestryinteractions:
Seattle,WA: Instituteof ForestResources,
Universityof Washington.
Agee,J.K. 1990.Thehistoricalroleof fire in PacificNorthwestforests.In: Walstad,J.D.,S.R.
RadosevichandD.V. Sandberg,
eds.,Naturalandprescribedfire in Pacific
p.
Northwestforests: 25-38.Corvallis,OR: OregonStateUniversityPress.
DC: lslandPress.493p.
Agee,J.K. 1993.Fireecologyof PacificNorthwestforests.Washington;
in terrestrialecosystems
of the easternCascades.
Agee,J.K. 1994.Fire andweatherdisturbances
USDA ForestService,GeneralTechnicalReportPNW-GTR-320.
Seventeenth
Agee,J.K. 1996.The influenceof foreststructureon fire behavior.In: Proceedings,
AnnualForestVegetationManagement
Conference,Redding,CA. 6-18January,
1996.p. 52-68.
I
weatherwildfire- too hotto handle?NorthwestScience.
7l(1):153Agee,J.K. lggT.Thesevere
I 56.
Agee,J.K. 1998.The landscapeecologyof westernforest fire regimes.Northwest Science.
72(specialissue):24-34.
Agee,J.K., B. Bahro, M.A. Finney, P.N. Omi, D.B. Sapsis,C.N. Skinner,J.W. van Wagtendonk
and C.P. Weatherspoon.(in press).The use of shadedfuelbreaksin landscape
fire management.Forest Ecology and Management.
Albini, F.A.1976. Estimatingwildfire behaviorand effects.USDA Forest Service,General
Technical Report INT-GTR-3 0.
Albini, F.A. and R.G. Baughman.1979.Estimatingwindspeedsfor predicting wildland fire
behavior.USDA ForestService,ResearchPaperINT-221.
Albini, F.A. and B.J. Stocks. 1986.Predictedand observedratesof spreadof crown fires in
immaturejack pine. CombustionScienceand Technology.4S:65-74.
Alexander,M.E. 1982.Calculatingand interpretingforestfire intensities.CanadianJournalof
Botanv. 60:349-357.
80
Alexander,M.E. 1988.Helpwith makingcrownfire hazardassessments.
In: Fischer,W.C.and
S.F.Arno, eds.,Protectingpeopleandhomesfrom wildfire in the interiorwest:
p.147-156.USDA ForestService,GeneralTechnicalReportINT-GTR-251.
Anderson,H.E. 1982.Aidsto determining
fuel modelsfor estimating
fire behavior.USDA Forest
Service,GeneralTephnicalReportINT-GTR-I 22.
Anderson,L., C.E.CarlsonandR.H. Wakimoto.1987.Forestfire frequencyandwesternspruce
budwormin westernMontana.ForestEcolory andManagement.22:251-260.
Andrews,P.L. 1986.BEFIAVE:fire behaviorpredictionandfuel modelingsystem- BURN
subsystem,
part l. USDA ForestService,GeneralTechnicalReportINT-GTR194.
''Andrews,
P.L.andC.H.Chase.1989.BEHAVE:fire behaviorpredictionandfuel modeling
system- BURN subsystem,
part2. USDA ForestService,GeneralTechnical
ReportINT-GTR-260.
Anonymous.1978.Instructions
for the l24l and 1242adiabaticcalorimeters.ParrInstrument
Company,TechnicalManualNo. 153.
Arno, M.K. 1996.Reestablishing
fire-adaptedcommunitiesto riparianforestsin the ponderosa
pinezone.In:Hardy,c.c. andS.F.Arno, eds.,The useof fire in forest
restoration:p.4243. USDA ForestService,GeneralTechnicalReportINTGTR-341.
Arno, S.F.andJ.K. Brown.1991.Overcoming
theparadoxin managingwildlandfire. Western
Wildlands.l7(l):40-46.
Arno, S.F.,H.Y. SmithandM.A. Krebs.1997.Old growthponderosa
pineandwesternlarch
standstructures:influencesof pre-I900fires andfire exclusion.USDA Forest
Service,Research
PaperINT-495.
Attiwill, P.M. 1994.Thedisturbance
of forestecosystems:
the ecologicalbasisfor conservative
management.
ForestEcologyandManagement.63:247-300.
Babbitt,B. lgg7.A coordinated
campaign:
fight fire with fire. I I February,1997.Speechgiven
at BoiseStateUniversity,Boise,ID.
Baker,W.L. 1992.Effectsof settlement
andfire suppression
on landscape
structure.Ecology.
73(5):I 879-l887.
Baker,W.L. 1992.The landscape
ecoloryof largedisturbances
in thedesignandmanagement
of
naturereserves.
Landscape
Ecology.7(3):I g l -194.
-
8l
- fire management
policies,directives,
Barney,R.J.andD.F.Aldrich. 1980.Landmanagement
andguidesin the nationalforestsystem:a reviewandcommentary.
USDA
ForestService,GeneralTechnicalReportINT-GTR-76.
effectson forestsuccession
within a centralIdaho
Barrett,S.W. 1988.Fire suppression's
wilderness.
WesternJournalof AppliedForestry.3(3):76-80.
pine
Barrett,S.W.,S.F.Arno andC.H.Key. 1991.Fireregimesof westernlarch-lodgepole
forestsin GlacierNationalPark,Montana.CanadianJournalof ForestResearch.
2l:l7ll-1720.
timber.Fire Management
Beighley,M. andJ. Bishop.1990.Firebehaviorin high-elevation
Notes.5l(2):23-28.
Belsky,A.J. andD.M. Blumenthal.1997.Effectsof livestockgrazingonstanddynamicsand
Biology.1l(2):315-327.
soilsin uplandforestsof theinteriorwest.Conservation
Beschta,R.L. 1990.Effectsof fire on waterquantityandquality.In: Walstad,J.D.,S.R.
andD.V. Sandberg,
eds.,Naturalandprescribed
fire in Pacific
Radosevich
Northwestforests:p.219-232.Corvallis,OR: OregonStateUniversityPress.
of fuelsandweatheron fire
Bessie,W.C. andE.A. Johnson.1995.Therelativeimportance
forests.Ecology.76(3):747-762.
behaviorin subalpine
betweenaquaticandterrestrialsystems.
In: Raedeke,
K.J.,ed.
Bilby, R.E. 1988.Interactions
p. 13-29.
management:
Streamside
riparianwildlife andforestryinteractions:Seattle,WA: Instituteof ForestResources,
Universityof Washington.
Bisson,P.A.,R.E.Bilby,M.D. Bryant,C.A.Dolloff,G.B.Grette,R.A.House,M.L. Murphy,
woodydebrisin forestedstreamsin the
K.V. Koski andJ.R.Sedell.1987.Large
PacificNorthwest:past,present,
andfuture.[n: Salo,E.O.andT.W. Cundy,eds.,
management:
p. 143-190.Seattle,
Streamside
forestryandfisheryinteractions:
WA: Instituteof ForestResources,
Universityof Washington.
Brown,A.A. andK.P. Davis.1973.Forestfire: controlanduse.2nd ed.,New York, NY:
McGrawHill, Inc.686p.
In: Wild Trout IV Symposium,
Brown,J.K. 1989.Effectsof fire on aquaticsystems.
Yellowstone
NationalPark,Mammoth,WY. Sept.l8-19, 1989.p. 106-l10.
82
U
Bryce,S.A.andJ.M.Omernik.1997.Level[V ecoregions
of theBlueMountainsecoregion
of
Oregon,Washington,
andldaho.In:Clarke,S.E.andS.A. Bryce,eds.,
Hierarchical
subdivisions
of theColumbiaPlateauandBlue Mountain
ecoregions,
p. 24-55.USDA ForestService,General
OregonandWashington:
TechnicalReportPNW-GTR-395.
Burgan,R.E.andR.C.Rothermel.1984.BEHAVE:Firebehaviorpredictionandfuel modeling
system- FUEL subsystem.
USDA ForestService,GeneralTechnicalReport
INT-GTR.I67.
**byram,
G.M. 1959.Combustion
of forestfuels.In: Davis,K.P.,ed.Forestfire: controlanduse:
p. 61-89.New York, NY: McGraw-Hill,Inc.
tc"rnp,
A., C.Oliver,P. Hessburg
andR. Evereff.1997.Predictinglate-successional
fire refugia
predatingEuropeansettlementin the Wenatchee
Mountains.ForestEcologyand
Management.95:63-77.
Carleson,D. andL. Wilson. 1985.Reportof theriparianhabitattechnicaltaskforce.Final report
to OregonDepartmentof ForestryandOregonDepartmentof Fish andWildlife.
Carlson,C.E.,W.C.Schmidt,D.G.Fellin andN.W. Wulf. 1985.Silviculturalapproaches
to
westernsprucebudwormmanagement
in the northernU.S. RockyMountains.ln:
Sanders,
C.J.,R.W. Stark,E.J.Mullins andJ. Murphy,eds.,Recentadvancesin
p.281-300.Ottawa,ONT: Canadian
sprucebudwormsresearch:
Forestry
Service.
J
Castello,J.D.,D.J.LeopoldandP.J.Smallidge.1995.Pathogens,
pafferns,
in
andprocesses
forestecosystems.
BioScience.
45(l):16-23.
Chandler,C., P. Cheney,P. Thomas,L. TrabaudandD. Williams.1983.Fire in forestry.Volume
''
II: forestfire management
andorganization.
New York, NY: JohnWiley and
Sons,Inc. 298p.
z, Z. 1986.Foliar
Chrosciewic
heatcontentvariationsin four coniferoustreespeciesof central
Alberta.Canadian
Journalof ForestResearch.
16:.152-157.
C.M. 1982.Physicalcharacteristics
Countryman,
of somenorthernCaliforniabrushfuels.USDA
ForestService,GeneralTechnicalReportPSW-GTR-61.
Covington,W.W.,R.L.Everett,R. Steele,L.L. Irwin,T.A. DaerandA.N.D.Auclair.1994.
Historicalandanticipated
changes
in forestecosystems
of the inlandwestof the
UnitedStates.
Journalof Sustainable
Forestry.
2(l/2):13-63.
v
83
Covington,W.W. andM.M. Moore. 1994.Postsettlement
changesin naturalfire regimesand
foreststructure:ecologicalrestorationof old-growthponderosapine forests.
Journalof Sustainable
Forestry.2(l l2):l53- | 8l .
Cowlin,R.W., P.A. BrieglebandF.L. Moravets.1942.Forestresourcesof the ponderosapine
regionof WashingtonandOregon.USDA ForestService,Miscellaneous
Publication
No.490.
Cz.ech,
B. 1996.Challengesto establishingandimplementingsoundnaturalfire policy.
Renewable
Resources
Journal.A(2):14-19.
R. 1966.Vegetation:identification
Daubenmire,
of typalcommunities.
Science.15l,291-298.
Davis,K.M., B.D. ClaytonandW.C.Fischer.1980.Fireecoloryof Lqlo NationalForesthabitat
types.USDA ForestService,GeneralTechnical
ReportINT-GTR-79.
DeBruin,H.W. 1974.Fromfire controlto fire management,
a major policy changein the Forest
Service.In:Proceedings,
Tall TimbersFireEcoloryConference,
No. 14,
Missoula,
MT. 8-10October,1974.p.l l-17.
!
Deeming,J.E.,R.E. BurganandJ.D. Cohen.1977.Thenationalfire-dangerrating system-1978.
USDA ForestService,GeneralTechnicalReportINT-GTR-39.
Evans,J.W. 1990.Powerfulrockey:the Blue Mountainsandthe OregonTrail. La Grande,OR:
EasternOregonStateCollege.349p.
Evereff,R., P. Ilessburg,M. JensenandB. Bormann.1994.VolumeI: executivesummary.
USDA ForestService,GeneralTechnicalReportPNW-GTR-317.
Everett,R., D. Schellhaas,
D. Spurbeck,
P. Ohlson,D. KeenumandT. Anderson.1997.Structure
of northernspottedowl neststandsandtheir historicalconditionson the eastern
slopeof the PacificNorthwestCascades,
USA. ForestEcologyandManagement.
94:l-14.
G.R. 1970.Two keysfor appraisingforestfire fuels.USDA ForestService,
Fahnestock,
ResearchPaperPNW-99.
Finney,M.A. 1998.FARSITE:fire areasimulator- modeldevelopment
andevaluation.
USDA
ForestService,ResearchPaperRMRS-4.
Fischer,W.C. 1980.Prescribed
fire andbarkbeetleattackin ponderosa
pineforests.Fire
Management
Notes.a I Q): | 0- 12.
Fischer,W.C.andC.E.Hardy.1976.Fire-weather
observers'
handbook.U.S.Department
of
Agriculture,ForestServiceHandbookNo. 494.
;
84
Fowler,P.M. andD.O.Asleson.1984.The locationof lightning-caused
wildlandfires,northern
Idaho.PhysicalGeography.
5:240-252.
Franklin,J.F. 1992.Scientificbasisfor newperspectives
in forestsandstreams.
[n: Naiman,R.,
ed. Watershedmanagement,
balancingsustainabilityandenvironmentalchange:
p.25-72.New York,NY: Springer-Verlag.
Fryer,G.I. andE.A. Johnson.1988.Reconstructing
fire behaviourandeffectsin a subalpine
forest.Journalof AppliedEcologa.25:1063-1072.
andforestfires.Weatherwise.
15(4):148-152.
.juquay, D.M. 1962.Mountainthunderstorms
Gara,R.I.,W.R.Littke,J.K.Agee,D.R.Geiszler,J.D.StuartandC.H.Driver. 1985.Influenceof
fires,fungi, andmountainpinebeetleson developmentof a lodgepolepine forest
in south-centralOregon.In:
Baumgartner,
D.M., R.G.Krebill, J.T.Arnott and
G.F.Gordon,eds.,l,odgepole
pine:thespeciesandits management:
p. 153-162.
Pullman,WA: WashingtonStateUniversity.
Gara,R.[. andJ.S.Wilson.1998.Relationships
betweenfire andinsectsin forestsof thePacific
Northwest.In: SeminirioSul-AmericanoSobreControlede Inc€ndiosFlorestais
e 5a ReuniSoT6cnicaConjuntaSIF/FUPEF/IPEF
SobreControle,deInc6ndios
Florestais,
Brazil.29 June- 2 July, 1998.Universidade
de Federalde Vigosa.p.
198-221.
\_
V
Gast,W.R.,Jr.,D.W. Scott,C. Schmitt,D. Clemens,S. Howes,C.G.Johnson,
Jr.,R. Mason,F.
Mohr andR.A. Clapp,Jr. 1991.BlueMountainsforesthealthreport:new
perspectives
in foresthealth.USDA ForestService.
Gisborne,H.T. 1950.Forestprotection.
In: Winters,R.K.,ed.Fiffy yearsof forestryin the
U.S.A.:p. 30-64.Washington,
DC: Societyof AmericanForesters.
borbatova,N.G. 1964.Calorificvalueof certainvarietiesof forestfuels.In: Kurbatskii,N.P.,ed.
Sovietprogress
in forestfire control:p. 35-38.New York,NY: Consultants
BureauEnterprise,Inc.
Graham,R.T. 1994.Silviculture,fire, andecosystem
management.
JournalofSustainable
-3
Forestry.2(l l 2):339 5 L
Gregory,S.V.,F.J.Swanson,
W.A. McKeeandK.W. Cummins.1991.An ecosystem
perspective
of riparianzones.
Bioscience.
4l :540-55
l.
Habeck,J.R.andR.W.Mutch. 1973.Fire-dependent
forestsin the northernRockyMountains.
3: 408-424.
QuaternaryResearch.
v
o
85
topography,
andforeststructurein the development
Hadley,K.S. 1994.The role of disturbance,
of a montaneforestlandscape.
Bulletinof theTorey BotanicalClub. 121(l):4761.
andwildlandfires:a dangerous
combination.
Fire Management
Haines,D.A. 1988.Downbursts
Notes.49(3):8-10.
Oregon.In: Firehistoryworkshop:p. 75-81.
Hall, F.C. 1980.Firehistory- BlueMountains,
Tucson,AZ: USDA ForestService,GeneralTechnicalReportRM-GTR-81.
P. Sollins,S.V.Gregory,J.D.Laffin,N.H. Anderson,
Harmon,M.E., J.F.Franklin,F.J.Swanson,
S.P.Cline,N.G. Aumen,J.R.Sedell,G.W.Lienkaemper,
K. Cromack,Jr. and
K.W. Cummins.1986.Ecologyof coarsewoodydebrisin temperateecosystems.
Advancesin EcologicalResearch.
15:133-302.
Harrington,M.G. 1996.Prescribedfire applications:restoringecologicalstructureandprocessin
ponderosa
pine forests.In: Hardy,C.C.andS.F.Amo, eds.,The useof fire in
forestrestoration:p.41. USDA ForestService,GeneralTechnicalReportINTGTR-341.
rolesfor insects,diseases,
anddecomposers
in fire dominated
Harvey,A.B.1994.lntegrated
forestsof the inlandwesternUnited States:past,present,andfutureforest
health.Journalof Sustainable
Forestry.2(l/2):2|l-220.
Heinselman,M.L. 1973.Fire in the virgin forestsof the BoundaryWatersCanoeArea,
Minnesota.QuaternaryResearch.
3:329-382.
E.K. 1997.Spatialandtemporalvariationin historicalfire regimesof the Blue
Heyerdahl,
Mountains,OregonandWashington:
the influenceof climate.Ph.D.dissertation.
Seattle,WA: Universityof Washington.224 p.
by ungulates.
Journalof Wildlife Management.
Hobbs,J.T.1996.Modificationof ecosystems
60(4):695-713.
Hough,W.A. 1969.Caloricvalueof someforestfuelsof the southernUnitedStates.USDA
ForestService,Research
Note SE-I20.
Huff, M. 1988.MountRainier:fire andice.ParkScience.8(3):22-23.
followingwildfiresin thewestern
Huff, M.H. 1995.Forestagestructureanddevelopment
OlympicMountains,Washington.EcologicalApplication
s. 5(2):47| -483.
!
Huff; M.H., J.K. Agee,M. GraczandM. Finney.1989.Fuelandfire behaviorpredictionsin
subalpine
forestsof PacificNorthwestnationalparks.Collegeof Forest
Resources,
Universityof Washington,
NationalParkServiceCooperative
Park
StudiesReportCPSU/UW89-4.
86
U
Johnson,
C.G.,Jr.,R.R.Clausnitzer,
P.J.MehringerandC.D.Oliver. 1994.Biotic andabiotic
processes
of eastsideecosystems:
the effectsof management
on plantand
communityecology,andon standandlandscape
vegetationdynamics.USDA
ForestService,GeneralTechnicalReportPNW-GTR-322.
K.N., J. Agee,R. Beschta,
Johnson,
V. Dale,L. Hardesty,
J. Long,L. Nielsen,B. Noon,R.
Sedjo,M. Shannon,
R. Trosper,C. WilkinsonandJ. Wondolleck.1999.
.
Sustainingthe people'slands:recommendations
for stewardshipof the national
forestsandgrasslands
into the nextcentury.Washington,DC: U.S. Department
of Agriculture.
t''Jolrnroo,
K.N., J. Sessions,
J. FranklinandJ. Gabriel.1998.Integratingwildfire into strategic
planningfor SierraNevadaForests.Journalof Forestry.96(l):4249.
Kauffman,J.B. 1988.The statusof riparianhabitatsin PacificNorthwestforests.In: Raedeke,
K.J.,ed. Streamside
managementriparianwildlife and forestryinteractions:p.
45-55.Seattle,WA: Instituteof ForestResources,
Universityof Washington.
Kelsey,R.G.,F. Shafizadeh
andD.P.Lowery. l979.Heat contentof bark,twigs, andfoliageof
ninespecies
of westernconifers.USDA ForestService,Research
NoteINT-261.
Keyes,C.R. 1996.Standstructuresandsilviculturalstrategies
to preventcrown fires in northern
RockyMountainforests.M.S.thesis.Missoula,MT: Universityof Montana.116
p.
J
J.W. 1970.Timelagusefulin fire dangerrating.FireControlNotes.31(3):6-8.
Lancaster,
Leopold,A. 1924.Grass,brush,timberandfire in southernArizona.Journalof Forestry.
22(6):r-r0.
policyof theU.S.ForestService.Journalof
ioveridge, E.W. 1944.Thefire suppression
Forestry.42(8):549-554.
;,
Martin,R.E. 1990.Goals,methods,
andelements
of prescribed
burning.In: Walstad,J.D.,S.R.
Radosevich
andD.V. Sandberg,
eds.,Naturalandprescribedfire in Pacific
Northwestforests:p. 55-66.Corvallis,OR: OregonStateUniversityPress.
Maruoka,K.R. 1994.Fire historyof Pseudotsuga
menziesiiandAbiesgrandis standsin the Blue
Mountainsof OregonandWashington.
M.S.Thesis.Seattle,WA: Universityof
Washington
.73 p.
McAlpine,R.S.andM.W. Hobbs.1994.Predicting
theheightto livecrownbasein plantations
of
fourborealforest
species.
InternationalJournalof
WildlandFire.4(2):103-106.
v
87
McCune,B. 1983.Fire frequencyreducedtwo ordersof magnitudein the BitterrootCanyons,
Montana.CanadianJournalof ForestResearch.13:212-218.
Minore,D. and H.G. Weatherly.1994.Ripariantrees,shrubs,andforestregenerationin the
coastalmountains
of Oregon.New Forests.S:249-263.
stream
Minshall,G.W.,J.T.BrockandJ.D.Varley.1989.WildfiresandYellowstone's
39(10):7
07-7| 5.
ecosystems.
BioScience.
New York,NY: VanNostrandReinhold.722
Mitsch,W.J. andJ.G.Gosselink.1993.Wetlands.
p.
Moeur,M. 1985.COVER:a user'sguideto the CANOPY andSHRUBSextensionof the stand
prognosismodel.USDA ForestService,GeneralTechnicalReportINT-GTR190.
WesternWildlands.1(3):11-15.
Moore,W.R. 1974.Fromfire controlto fire management.
Morris, W.G. 1934.Lightningstormsandfires on the nationalforestsof Oregonand
Washington.USDA ForestService,PacificNorthwestExperimentStation.
1993.Forest
Mutch,R.W., S.F.Arno,J.K.Brown,C.E.Carlson,R.D.OttmarandJ.L.Peterson.
healthin the Blue Mountains:a management
strategyfor fire-adapted
ecosystems.
USDA ForestService,GeneralTechnicalReportPNW-GTR-310.
Naiman,R.J.,H. DecampsandM. Pollock.1993.The roleof ripariancorridorsin maintaining
regionalbiodiversity. EcologicalApplications. 3(2):209-212.
in North Americafollowingmajordisturbances.
Forest
Oliver,C.D. 1981.Forestdevelopment
EcoloryandManagernent.
3: I 53-l 68.
Oliver, C.D., C. Harrington,M. Bickford,R. Gara,W. Knapp,G. LightnerandL. Hicks. 1994.
Maintainingandcreatingold-growthstructuralfeaturesin previouslydisturbed
standstypicaloftheeasternWashington
Cascades.
Journalof Sustainable
Forestry.2(3I4):353-387.
W.T. andD.L. Corell. 1984.Nutrientdynamicsin an agriculturalwatershed:
Peterjohn,
on theroleof a riparianforest.Ecology.65:1466-1475.
observations
pineandwhiteleaf
Philpot,C.W. 1965.Diurnalfluctuationin moisturecontentof ponderosa
manzanita
leaves.
USDA ForestService,Research
NotePSW-67.
plantmaterials.
andpyrolysisof selected
USDA Forest
Philpot,C.W. 1968.Mineralcontent
Note INT-84.
Service.Reserarch
\,
88
Philpot,C.W. 1970.Influenceof mineralcontenton thepyrolysisof plantmaterials.
Forest
Science.16(4'1:461-47
l.
Philpot,C.W. andR.W.Mutch.1971.Theseasonal
trendsin moisturecontent,etherextractives,
andenergyof ponderosa
pineandDouglas-firneedles.
USDA ForestService,
Research
PaperINT-102.
Pickett,S.T.A.andP.S.White.1985.Patchdynamics:
a synthesis.
In: Pickett,S.T.A.andP.S.
White,eds.,Theecoloryof naturaldisturbance
andpatchdynamics:p. 371-384.
New York, NY: AcademicPress,Inc.
-Tickford,
S.G.,G.R.Fahnestock
andR. Ottmar.1980.Weather,fuel, andlightningfires in
'
OlympicNationalPark.NorthwestScience.54(2):92-105.
-Powell,
D.C. lgg4.Effectsof the 1980swesternsprucebudwormoutbreakon the Malheur
NationalForestin northeastern
Oregon.USDA ForestService,Technical
PublicationR6-FI&D-TP-12-94.
Pyne,S.J.1997.Firein America.Seattle,
WA: Universityof Washington
Press.654p.
Pyne,S.J.,P.L. AndrewsandR.D.Laven.l996.Introductionto wildlandfire. 2nded.,New
York,NY: JohnWiley andSons,Inc.769p.
V
K.J. 1988.Introduction.In:
Raedeke,
Raedeke,
K.J.,ed.Streamside
management
riparian
wildlife andforestryinteractions:p. xiii-xvi. Seattle,WA: Instituteof Forest
Resources,
Universityof Washington.
Rieman,B. andJ. Clayton.1997.Wildfireandnativefish: issuesof foresthealthand
conservation
of sensitivespecies.
Fisheries.
22(l l):6-15.
Robinson,G.O. 1975.TheForestService.Baltimore,MD: JohnsHopkinsUniversityPress.337
p.
''-Rog".s,
P. 1996.Disturbanceecolory andforestmanagement:
a reviewof the literature.USDA
ForestService,GeneralTechnicalReportINT-GTR-336.
Romme,W.H. andD.H.Knight.1981.Firefrequencyandsubalpineforestsuccession
alonga
gradientin Wyoming.Ecolory.62:319-326.
topographic
R.C.1972.A mathematical
Rothermel,
modelfor predictingfire spreadin wildlandfuels.USDA
ForestService,Research
PaperINT-l15.
Rothermel,
R.C. 1983.How to predictthespreadandintensityof forestandrangefires.USDA
ForestService,
GeneralTechnicalReport
INT-GTR-I43.
-V
89
In: Proceedings,
Eleventh
Rothermel,R.C. 1991.Crownfire analysisandinterpretation.
Missoula,MT. 16-19April, 1991.
Conference
on FireandForestMeteorology,
p.253-263.
Societyof AmericanForesters.
Rothermel,R.C. 199I . Predictingbehaviorandsizeof crownfires in the northernRocky
Mountains.USDA ForestService,Research
PaperINT-438.
R.N.,D.L. Adams,S.S.Hamilton,S.P.Mealey,R. SteeleandD. Van De Graaff.1994.
Sampson,
healthin the inlandwest.Journalof Sustainable
Assessingforestecosystem
Forestry.2(ll2):3-10.
in fire management.In:
Proceedings,
J.E.1974.Fire suppression
Tall TimbersFire
Sanderson,
EcologyConference,
No. 14,Missoula,MT. 8-10October,1974.p. l9-31.
Schroeder,M.J. andC.C.Buck. 1970.Fire weather.USDA ForestService,Agriculture
Handbook360.
Scott,D.W. andC.L. Schmitt.1996.Foresthealthon nationalforestlandsin the Blue Mountains
USDA ForestService,ReportBt\M-96-12.
1990-1996:insectsanddiseases.
Sedell,J.R.,D.C.Lee,B.E.Rieman,R.F.ThurowandJ.E.Williams.1997.Effectsof proposed
alternativeson aquatichabitatsandnativefishes.In: Quigley,T.M., K.M. Lee
and S.J.Arbelbide,eds.,Evaluationof the EIS alternativesby the science
integrationteam,volumeI: p. 435-528.PacificNorthwestResearchStation,
Portland,OR: USDA ForestService.
patternsof a pinyonpine
Segura,G. andL.C. Snook.1992.Standdynamicsandregeneration
forestin eastcentralMexico.ForestEcologyand Management.4T:175-194.
of hourcontrolfor adequate
fire protection
Show,S.B.andE.I. Kotok. 1930.Thedetermination
in the majorcovertypesof the Californiapine region.U.S. Departmentof
Agriculture,TechnicalBulletinNo. 209.
variability:whatis "natural"
equilibrium,andenvironmental
Sprugel,D.G. 1991.Disturbance,
BiologicalConservation.
58(l):l-18.
vegetationin a changingenvironment?
in theforest.Journalof Forestry.32:462-467.
Starker,T.J. 1934.Fire resistance
of the thermalpropertiesof forestfuels by combustiblegas
Susott,R.A. 1982.Characterization
28(2):404-420.
analysis.ForestScience.
1975.Heatcontentof naturalfuels.Journalof
Susott,R.A.,W.F. DeGrootandF. Shafizadeh.
-325.
FireandFlammability
. 6:31|
F.J.,T.K. Kratz,N.CaineandR.G.Woodmansee.
19E8.Landformeffectson
Swanson,
patterns
processes.
BioScience.
and
38(2):92-98.
ecosystem
90
T.W. andA.M. Lynch.1989.A tree-ringreconstruction
Swetnam,
of westernsprucebudworm
historyin thesouthernRockyMountains.
ForestScience.35(4):962-986.
T.W. andA.M. Lynch.1993.Multicentury,regional-scale
patternsof westernspruce
Swetnam,
budwormoutbreaks.
gical
(4)
Ecolo
Monographs
. 63 :399-424.
T.W.,B.E. Wickman,H.G.PaulandC.H.Baisan.1995.Historicalpatternsof western
Swetnam,
sprucebudwormandDouglas-firtussockmothoutbreaksin the northernBlue
Mountains,OregonsinceA.D. 1700.USDAForestService,Research
Paper
PNW-484.
Tanaka,J.A.,G.L. Star andT.M. Quigley.1995.Strategies
andrecommendations
for addressing
foresthealthissuesin the Blue Mountainsof OregondndWashington.USDA
ForestService,GeneralTechnicalReportPNW-GTR-350.
Taylor,A.R. 1973.Ecologicalaspects
of lightningin forests.In:Proceedings,
Tall TimbersFire
EcologyConference,
No. 13,Tallahassee,
FL.p. 455-482.
lf\o
t>
Turner,M.G. andW.H. Romme.1994.
Landscape
dynamicsin crownfire systems.
Landscape
Ecolory.9(l):59-77.
-
USDA. 1992.Restoringecosystems
in thetBlueMountains:a reportto theregionalforesterand
the forestsupervisors
of theBlue Mountainforests.'USDA
ForestService.
USDA andUSDI. 1994.Draftenvironmental
assessment.
Interimstrategies
for managing
anadromous
fish-producingwatersheds
federal
on
landsin easternOregonand
Washington,Idaho,
andportionsof California.Washington,
DC: USDA Forest
Service,USDI Bureauof Land Management.
USDA andUSDI. 1995.Federalwildland
policyandprogramreview.
fire management
Washington,
DC: U.S.Department
of Agriculture,U.S.Department
of the
Interior.
Van Wagner,C.E. 1977.Conditionsfor thestartandspreadof crownfire. CanadianJournalof
ForestResearch.
7:23-34.
Van Wagner,C.E. 1993.Predictionof crown fire behaviorin two standsofjack pine. Canadian
Journal of ForestResearch.23:442-449.
van Wagtendonk,J.W. 1996.Use of a deterministicfire growth model to test fueltreatments. In:
SierraNevadaEcosystemProject: final reportto Congress,volume 2,
assessments
andscientificbasisfor management
options:p. I155-l165. Davis,
CA: University of California, Centersfor Water and Wildland Resources.
v
7
9l
vanWagtendonk,
J.W.,W.M. SydoriakandJ.M. Benedict.1998.Heatcontentvariationof Sierra
Nevadaconifers.International
Journalof WildlandFire.8(3):I 47-I 58.
Veblen,T.T., K.S. Hadley,E.M.Nel,T. Kitzberger,
M. ReidandR. Villalba. 1994.Disturbance
regimeanddisturbance
interactions
in a RockyMountainsubalpine
forest.
Journalof Ecology.82:125-135.
Weaver,H. 1943.Fire asan ecological
andsilviculturalfactorin theponderosa-pine
regionof
thePacificslope.Journal
of Forestry.
4l(l):7-15.
Weaver,H. 1959.Ecologicalchanges
in theponderosa
pineforestof theWarmSpringsIndian
Reservation
in Oregon.Journalof Forestry.57(l): l5-20.
Whelan,R.J. 1995.Theecologyof fire.Cambridge,
UK: Cambridge
UpiversityPress.346p.
White,P.S.1979.Pattern,process,
andnaturaldisturbance
in vegetation.
BotanicalReview.
45:229-299.
White,P'S.andS.T.A.Pickett.1985.Naturaldisturbance
andpatchdynamics:an introduction.
In: Pickett,S.T.A.andP.S.White,eds.,The ecologyof naturaldisturbance
and
patchdynamics:p. 3-13.New York,NY: Academicpress,Inc.
Wickman,B.E.1992.Foresthealthin theBlueMountains:the influenceof insectsanddiseases.
USDA ForestService,GeneralTechnicalReportPNW-GTR-295.
Wickman,B.E.,R.R.MasonandT.W. Swetnam.1994.Searching
for long-termpatternsof forest
insectoutbreaks.In:
Leather,s.R.,A.D. watt, N.J. Mills andK.F.A. walters,
eds.,Individuals,
populations
andpatternsin ecolory:p.251-261.Andover,UK:
Intercept.
Wilson,J'S.andP.J.Baker.1998.Mitigatingfire risk to late-successionat
forestreserves
on the
eastslopeof the washingtoncascadeRange,uSA. ForestEcologyand
Management.
1I 0:59-75.
Wilson,J.S.,E.S.IsaacandR.I. Gara.1998.Impactsof mountainpinebeetle(Dendroctonus
ponderosae)(Col.,Scolytidae)infestationon future landscapesusceptibilityto
the westernsprucebudworm(Choristoneuraoccidentatis)(Lep.,Tortricidae)in
northcentralWashington.
Journalof Applied Entomology
-245.
. 122:239
wissmar,R.c., J.E.smith,B.A.Mclntosh,
H.w. Li, G.H.Reeves
andJ.R.Seddell.1994.
Ecologicalhealthof riverbasinsin forestedregionsof easternWashington
and
Oregon.USDA ForestService,GeneralTechnicalReportPNW-GTR-326.
Woodard,
P.M.,J.A.BentzandT. VanNest.1983.Producing
a prescribed
crownfire in a
subalpineforestwith an aerialdrip torch.Fire Management
Notes.44(4):24-28.
\.
-
/\
92
a
Wright, H.E., Jr. andM.L. Heinselman.1973.The ecologicalrole of fire in naturalconifer
forestsof westernandnorthernNorth America:introduction.Quaternary
Research.
3:317-328.
Wykofi W.R.,N.L. CrookstonandA.R. Stage.1982.User'sguideto the standprognosismodel.
USDA ForestServioe,GeneralTechnicalReportINT-GTR-I33.
Young,M.K. 1994.Movementandcharacteristics
of sfeam-bornecoarsewoody debrisin
adjacentburnedandundisturbedwatersheds
in Wyoming.CanadianJournalof
ForestResearch.
24:1933-1938.
7-ar,J.H. 1996.BiostatisticalAnalysis.3rd ed.,UpperSaddleRiver,NJ: PrenticeHall. 662p.
J
J
lz
93
APPENDIXA: SyTT,TsoLs
Useo IN TEXT
Symbol
CBD
CBDo
CBH
CBH.
E
h
FMC
I
Io
R
Ro
S
U
Definition
.
Uutt Otntiry
critical bulk densityof crown (kg m'') requiredfor crown fire spread
live crownbaseheight(m)
critical live crown baseheight (m) requiredfor crown fire ignition
net horizontal heatflux (kW mo)
heatof ignition(kJ kg't)
foliar moisturecont€nt(percentdry werght)
fireline intensity(kW m t)
critical surfacefire intensityrequiredfor crown fire initiation (kW m't)
rateofspread(m sect)
critical minimumrateof spreadrequiredfor sustained
crown fire behavior(m sec'r)
massflow rate (kg m'2seir)
94
,
AppeNox B: ScIeNTT,ICANDCoMMoN NAMESoF SpeCITsUSEDTNTEXT
Trees
Scientificname
Abies amabilis
Abies concolor
Abies grandis
Abies lasiocarpa
Abies magnifica
Junip ents occidentalis
Larix occidentalis
Picea engelmannii
Pinus albicaulis
Pinus contorta
Pinus ponderosa
Pseudotsugamenziesii
Tsuga heterophylla
Tsugamertensiana
Insects
Scientificname
Chr or istoneura occidentalis
D endroctonusp onderosae
D endroctonus p seudotsugae
D endroctonus rufip ennis
Scolytus ventralis
Commonname
Pacificsilverfir
white fir
grandfir
subalpinefir
red fir
westernjuniper
westernlarch
Engelmannspruce.
whitebarkpine
lodgepolepine
ponderosa
pine
Douglas-fir
westernhemlock
mountainhemlock
Commonname
westernsprucebudworm
mountainpinebeetle
Douglas-firbark beetle
Engelmannsprucebarkbeetle
fir engraver
J
,7
I
a'
95
APPENDIX C: STRUCTURALDATA FORRIPARIANAJPIENO STEUO COMPARISONS
o
h
O\ n
\O \O l'-
n
O\ €
\O C.l €
a
O
F- r
-
S$hFATFESSgRS
PR33F$
RG F8€KS$F3$ERfr
FRS8Sfl
C.l €
O
h
\O {
r
d
€
h
a9 \9
+
a
\O -a r
ol
r
o
a == RneR aei RsxK eedK == F rs re = g x R* irF eR s Nt*
bo
c.l
o
d;
q!P
l#
ohooooonoooooooh
ooci-JOO.-joJoOooooo
e
pSRB
xc.l€o
E$$;gFg$$SB$RiEE
sFan;n*s;$EFcnn;
$e
a4
R
ohhooohoooooohoo
<tciooooooooo.-:oooo
hoho
oooo
6=S9
€B
'al
r:oq qq
d 6 o n
-A
6\o
6r
{€
-: I
Q n
a
q . . -1 c . ] . +
-: o9e
o - o
qn
@ oqa
N q €
v! - €
q
- d
ri
oo
@ o
o *
@ r
c'l €
h
o F <t h
Oi
i
o d N rA
o r^
;
90
:+
I o il !.| 9 I-a Cr
fi F gSHe=F=R9HRrruE$F!KtsS9!F!e=eSS=geSNqF
tr-
-o
CJ I
o i t o €
qt qr a Q I
s
-
q)
L
;s
r
h
o
c.t r
o
o
@ h
o €
h a
@ €
€
h @ 6
0
Q q
v'r €
q .vi.)A o I
I
.c q 9 93 \
9 !l a') or
-
9
e
o
\o -
n
$$dsE*5sB*r$s6seBsssssessR+aRsHF$;Ee!+n$
;t
L
3
I
*
o. \
V)
\
o
DO
R
r ct o .1 I
= ;=
v)
!') q n .1 n 9 \
e- c! n -
g;S=
! R9R 9;=
e q c'l'1
I
-
:
= =9 9:
SGs*
99.:N
I
99+
r 999
= 9=oi
A
s
iJ
\
\i
L
.:s
L
\
9
N
q
9
cl 9
er o
e 9
"{
9 -
9
n 9
"{
@ €
N c'l 9
"'r
ur rrr r! (r) rrl r! (ll rll
t!
t!
cl trl
tll lrl
EEEEEEEE
EE
EE
EE
c'r 9
c'r 9
B < - o x x +AAAF
; FFddut6sAAtsAAtxAAss I
o
U)
o
$t s < < < <
u)
o
ol!vv
sEsdsE
'
x
F
E
E
F
F
d
E
X
H
E
d
E
E
E
t
E
S
8
5
8
8
5
F
*
E
(
<
X
X
<
<
X
X
< <HH <
\ \ o . o . o .o . r Lo . * * {
xcacacaca
A
E
h
a4
\
\)
o
o
-dddN
Q
P
"s
ddo6--oodNc.lc.t
--c{N-ii-dN
(t)
p
.t)
5s
Eo
F= 5: F= Ep Ep Ep Fp F: Ep EB E: E: E: Ee E=
BFEgE
FTgEFCg4FEFBFEFEFB$EFEFBFEFggE
F
a
o0
e
dd
eo
N
N
o
E
ssEEEE** -*fi{ggFF,igrrsp::EE,:$?
gsgs
gs
$g$EsE
Eggggg
*FFFFE
ii3i:iF*
*stsgi
I
96
c9
H,q
=
g EE
--\OO€
-Nr€6*€SO
c{ hr@
S
9rhrr@9@rrr€Er€€rrrrrrr9r€h€<rts
n 9 e
.n
q
h
a'
-v.
9
q
F
!.1 .'! q q n
r+
@
-o
O
e{
NdN
c{
oq .l
h
6
NN6
!.1 <? d! 1
c{
O
N
@
H
tf
N
cq q
g
h
N
O
r
-:
\
d
-
\q !.r q
€
N
6
-
N
sEsFl
h@+€n
t€-O€@d
n
{
d
q g
\
o
t
rN
g
O
m
-
n
o
-N
n
€
-
cl -.:
n
-
@
r
o
E;
rlP
to
OO\O
o.-: o
OO O OhO
$ --: o o -.: o
Q O O a -O
o o o ci ci o
h
o
OO
o o
O O h
J o o
O O O
...; o'-:
.
&E
au
EF
F! -
\
d]
d]
ol
t:
*
o9 I
\
ct
9
cl
v'! -
oq q
vl
9
s 8 $ 8 8 8 R i S $ $ + d S F R- -S- dSs FS- - eN -g6 -d R S
el
Vl Q
EF
A<
o h o N € F 6 €'1
s m o
o ri oi ki Fi Fi qi ri )q J ci d
nsr+@nha=hhoo6qr6n-ordoo
SrE
LE
9F
<i5
\q q
€ f
c9 \
h f
o9 q
€ 6
\
O
c.l cl
+
n
d
N
J
r
ri
h
ri
-..: cl
n o c!
-'.;ONO
N - d d
r
s
oi
q n
9.^
o\ o\ € + o
o.1
d t3
o
<j
o
oi
vl
€
\9
h
o9 \
t
O
c!
6
e 9
-'O
d N - - v - 6 F - N r - -
-E
E.e
o9
tv)
Eg
!A
e&
=
\jq)
,>l
I
==*=l
NNN-I
99
o e 9 9 9 n !ee
ll.lr!
e 9 - 99!
e c . rc o c r 9 n
tlqJ
|rltjlr{ql
Z d x x l ' . * x x * * <<Z Z x x x x d d ? d x x
RXEEHXHEXEdd*REHHE*R*REE
XX<<
ooao--dNo6--
--tnall
o o\ F
ooo-l
-Fd-i-d-mNn€
gE
ciodcjl
gurgnFEBsE
gFFR$E=nE
$PaPF
REHEI
q
E>
- \o* rl
".=*.1
::::l
""":l
===rl
c0c0c0lot
ddq6a{Ne{d
FP EP Ep Fp Ep Fp F:
E: F:
E= F9 FE
<<<<l
F-
\
a)
-o
R
E
ta
--ddl
sp Epl
t:
FCFEF"*FEFEFEF€FBFEgBFEFBsBFBI
$
ls€t
GG
'6 '6
,ge
o
ttl
B
> - ?-i
vv;r
x
iaEEggFEEE
EEgetnn{tt
,qi
!r
x
ggggt r i'sE'E
E.e
r i'q,q,c
tt
;F5sg
====E 6 6 6 = = --sF3€ q ??? ? !' r.,
5€€€
-
i
-
i
i
Erv
e :€€
c'i
6
6.9.9xx
i{ttlEt#
sggsls
EEEE9gg$g9P&E&E3,EEEEEEEE
97
FORRIPARIAN/UPIaNo STAND coMPARISoNS
APPENDIX D: SAUPT.TNGPLOT CHARACTERISTICS
Table 27. Sampling plot characteristicsfor riparian/upland stand comparisons.
Site Name
Bamett Spring
BarnettSpring
BearCreek
BearCreek
Clear Creek
ClearCreek
Cold Spring
Cold Spring
CraneCreek lst
CraneCreeklst
CraneCreek2nd
CraneCreek2nd
CraneCreek3rd
CraneCreek3rd
DugoutCreek
DugoutCreek
Elk Creek
Elk Creek
FopianCreek
FopianCreek
HalfivayCreek
Halfivay Creek
Creek
Horseshoe
Creek
Horseshoe
Spring
Horseshoe
Spring
Horseshoe
HuckleberryCreek
HuckleberryCreek
HunterCreek
HunterCreek
IndianSpring
IndianSpring
LakeCreeklst
Lake Creeklst
LakeCreek2nd
LakeCreek2nd
Latitude
Longitude Slope
(degrees)
(degrees)
(o/ol
N44"09.830 wl l8'23.482 35
N44.09.817 wl18.23.649 13
N44.15.981w118"42.979 32
N44015.928wl18.43.055 23
N44"27.932 wl 18'27.620 57
N44"28.022 w1t8027,475 37
N44.10.905w l 1 8 ' 1 8 . 3 1 3 4 0
N44.11.047wl l8'18.289 20
N44.08.752 w118"26.621 37
N44.08.784 wl18.26.678 25
N44.08.516wl 18'26.140 46
N44008.511wl18026.343 50
N44'09.812wl 18'22.509 53
N44.09.599 wt18"22.452 55
N44.11.954wl 18'22.600 28
N44012.033wl 18'22.540 40
N44.14.770wt 18.24.489 15
N44.14.589wl18024.515 45
N44.15.903w l 1 8 " 2 3 . 4 7 1 3 0
N44.15.798w1t8"23.342 30
N44.09.552wl18'25.641 50
N44'09.533 wl 18'25.580 25
N44"19.337w l 1 8 ' 2 5 . 5 3 0 1 9
N44'19.371w I 1 8 . 2 5 . 5 0 9 I I
N44'13.210wt18'22.706
60
N44.13.130wl18.22.685 25
N44.18.830wl l8'23.319 30
N44.18.871wl 18.23.248 30
N44.14.709w l 1 8 . 1 8 . 8 0 7 l 8
N44"14.757 w l 1 8 . 1 8 . 7 0 5 4 5
N44.15.714w l l 8 ' 4 1 . 8 7 7 1 5
N44.15.678wl18"42.035 20
N44"16.940w l 1 8 . 4 1 . 1 6 7 2 2
N44'16.941w l 1 8 . 4 1 . 2 5 1 3 8
N44.16.570wl l8'40.999 t2
N44.16.661w l 1 8 " 4 1 . 0 8 4 l 6
Aspect
(degrees)
55
55
75
95
2t0
2t5
185
185
150
165
160
145
350
340
190
190
70
60
305
315
290
290
350
30
295
310
240
220
305
265
t20
l45
115
90
90
120
Elevation
(m)
1524
1554
1969
l98l
1658
l6E9
1640
1670
ls73
1603
r524
1567
t396
t420
1548
1579
t573
1597
1603
t622
1603
1628
t7t3
1725
1469
1524
1798
1829
t573
1597
2134
2l s 8
2231
22s6
2r40
2152
I
a
98
Table 28. Continued.
Latitude
lSiteN"
titti;C"-eCteek
Little CraneCreek
Little Malheur(E facing)
Little Mallieur(E facing)
Little Malheu-r(W facing)
Little Malheur(W facing)
MeadowFork Big Creek
MeadowFork Big Creek
North Fork Elk Creek
North Fork Elk Creek
North Fork Mhlheur(E facing)
North Fork Malheur@ facing)
North Fork Malheur(W facing)
North Fork Malheur(W facing)
North ReynoldsCreek
North ReynoldsCreek
ReynoldsCreeklst
ReynoldsCreeklst
ReynoldsCreek2nd
ReynoldsCreek2nd
ReynoldsCreek3rd
ReynoldsCreek3rd
RockSpring
RockSpring
RootSpringRootSpring;.
,
SouthForkEIk Creek
SouthForkElk Creek
SpringCreek
SpringCreek
SquawCreek
SquawCreek
StationCreek
StationCreek
StinkCreek
StinkCreek
Strawberry
Lake lst
Lake lst
Strawberry
Strawberry
Lake2nd
StrawberrvLake2nd
Longitude
Slope
tt+qptt.:f5 Wl 18.24.733 t7
N44"11.243Wt 18"24.814 30
N44"15.018Wl lg"l8.794 55
N44.15.016
Wl18.18.798 50
N44.15.067Wl18.18.925 25
N 4 4 . 1 5 . 1 4 7W l 1 8 . 1 8 . 8 0 8 5 5
.N44'15.761Wl18"38.079 20
Nl|4.15.891Wl18.38.207 20
N44'14.851Wl18"24.575 l0
N44.14.809Wl18.24.630 45
N4409.225 Wl18.21.895 50
N44"09.212 Wtt822.O2l
55
N44"11.021Wt1922.624 55
N44"11.049Wl18"22.458 26
N44"27.304.Wl18.30.873 70
N44"27.135Wl18"30.769 50
N44.26.587Wtt9.27.470 40
N44.26.681W118"27.435 55
'N44"27.387 Wl19"30.002 55
N44.27.353Wl18030.080 75
N44"25.277Wl18.31.338 25
N44.25.152 Wl I 8.3I .368 55
N44"19.061Wl lg.l8.l77
30
'
N44"19.13W
3 l18"18.309 23
N 4 4 " 1 . 1 3 5 W 11 8 " 2 1 . 6 9 5 5 0
N 4 4 . 1 1 . 2 6 7W l 1 9 " 2 1 . 5 0 7 4 0
N44"14.603Wl18"24.832 25
N44.14.643Wl18"24.893 22
N44.16.721W1t8"22.296 40
N44"16.740.Wtt8"22.232 40
N 4 4 . 1 4 . 0 7 4W l 1 8 . 1 4 . 0 1 6 3 5
N 4 4 . 1 3 . 0 6 1W l 1 8 " 1 4 . 0 8 8 4 5
N44"09.339Wl18"21.466 35
N 4 4 . 0 9 . 2 6 6W l l g . 2 l . 3 1 4 l 8
N44.t2.428Wl18.22.550 30
N44.12.525W1t9"22.646 32
N 4 4 " 1 8 . 3 3W
3 l18"41.138 55
N44"18.294
W' l 1 8 " 4 1 . 1 5 7 4 5
N 4 4 " 1 8 . 1 9W
4 l lg.4l.3l5 25
N44"18.215
Wl18.41.377 54
Aspect
Elevation
80
80
40
45
220
240
85
60
135
70
60
50
270
290
310
320
170
145
345
340
110
130
l9s
215
290
290
155
100
240
255
t20
t20
300
285
160
r60
100
105
95
t20
t65Z
t676
1567
I 585
r567
r597
t920
t926
ts97
t634
1396
1426
1390
r426
t4t4
t445
t725
1774
t463
r5 l 8
t295
1323
2t95
2207
I585
1609
1725
t73l
1652
1676
l4s l
1469
I 384
1408
t439
t469
t926
t932
t939
1975
.r.