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Home My WebLink AboutAPA1321NAY1 71962"{I.S.D('P'U'!.'U1CBtoft~\%Illh.:r1.orT/<1'I,J5'~Q~.)(/ALASKAPOWERAUTHORITYSUSITNAHYDROELECTRICPROJECTENVIRONMENTALSTUDIES-SUBTASK7.12PLANTECOLOGYSTUDIESPHASEIFINALREPORTApri11982ByUNIVERSITYOFALASKAAgriculturalExperimentStationPalmer,Alaska99645-~:<t::;:;vr?tJ./3",....,.PrincipalInvestigator:ProjectLeader:PlantSynecologist:Coordinator:EndangeredSpeciesSpecialist:JayMcKendrickWilliamCollinsDotHelmJosephMcMullenJohnKorandaJ:'ARLISAlaskaResources"&InfonnationSeTvlcesochorage,Alaska PROPOSEDDEVELOPMENTIntheproposedplanforfullbasindevelopment,twomajorreservoirswillbeformed.Thelargerreservoirextends48milesupstreamoftheWatanasiteandhasanaveragewidthofaboutonemileandamaximumwidthoffivemiles.TheWatanareservoirhasasurfaceareaof38,000acresandamaximumdepthofabout680feetatnormaloperatinglevel.TheDevilCanyonreservoirisabout26mileslongandone-halfmilewideatitswidestpoint.Asurfaceareaof7,800acresandamaximumdepthofabout550feetrepresentconditionsatnormaloperatinglevel.Stageddevelopmentisplanned.Aninitialinstallmentof680-MWofcapacityatWatanawillbeavailabletothesystemin1993and340MWwillbeaddedin1994.Ifthemid-rangeforecastingrowthinenergydemandisrealized,DevilCanyonwillbecompletedby2002withaninstalledcapacityof600MW.TheWatanadamwillbeanearthfillstructurewithamaximumheightof885feet,acrestlengthof4,100feet,andatotalvolumeofabout62,000,000cubicyards.Duringconstruction,theriverwillbedivertedthroughtwoconcrete-lineddiversiontunnels,each38feetindiameter,inthenorthbankoftheriver.Upstreamanddownstreamcofferdamswillprotectthedamconstructionarea.Thepowerintakeincludesanapproachchannelinrockonthenorthbank.Amulti-level,reinforcedconcrete,gatedintakestructurecapableofoperatingoverafull140-feetdrawdownrangewillbeconstructed.TheDevilCanyondamwillbeadouble-curvedarchstructurewithamaximumheightofabout645feetandacrestelevationof1463feet.Thecrestwillbeauniform20-footwidthandthemaximumbasewidthwillbe90feet.Arock-fillsaddledamonthesouthbankoftheriverwillbeconstructedtoamaximumheightofabout245feetabovefoundationlevel.Thepowerintakeonthenorthbankwillincludeanapproachchannelinrockleadingtoareinforcedconcretegatestructurewhichwillaccomodateamaximumdrawdownof55feet.Flowconstructionwillbedivertedthroughasingle30-footdiameterconcrete-linedpressuretunnelinthesouthbank.Cofferdamsandthediversiontunnelprovideprotectionduringconstructionagainstfloods.About21/2yearsofaveragestreamflowisrequiredtofilltheWatanareservoir.Fillingwillcommenceafterdamconstructionproceedstoapointwhereimpoundmentconcurrentwithcontinuedconstructioncanbeaccomodated.Post-projectflowswillbelowerinsummerandhigherinwinterthancurrentconditions.Asoneproceedsdownstreamoftheproject,differencesbetweenpre-andpost-projectflowconditionsbecomelesspronounced,astheentireupperbasincontributeslessthan20%ofthetotaldischargeintoCookInlet.TheselectedaccessplanconsistsofaroadfromtherailheadatGoldCreektoDevilCanyononthesouthsideoftheriver.AtDevilCanyoni theroadcrossestheSusitnaandproceedseasttotheWatanasiteonthenorthsideoftheriver.TheplanalsoincludesaccessbyToadconnectingGoldCreektotheParksHighway.LimitedaccessbetweenGoldCreekandtheWatanasitebywayofapioneerroadwillcommenceinmid-1983.RoadaccessfromtheParksHighwaywillbedeferreduntilafterawardofafederallicensefortheproject,andthepioneerroadwillberenderedimpassableiftheproject.doesnotproceed.TheselectedtransmissionlinerouteassociatedwiththeSusitnaprojectroughlyparallels,butisnotadjacentto,theaccessroutebetweenGoldCreekandtheWatanadamsite.AtGoldCreek,itconnectsintotheRailbeltIntertie.BetweenWillowandAnchorage,therouteextendsinasoutherlydirectiontoapointwestofAnchorage,whereunderseacableswillcrossKnikArm.BetweenWillowandHealy,theroutewouldutilizethetransmissioncorridorpreviouslyselectedbythePowerAuthorityfortheRailbeltIntertie.i i SUMMARYTheplantecologygroupwasresponsibleformappingintheupperSusitnaRiverbasinandalongtransmissioncorridorsanddescribingvegetationintheupperbasinanddownstreamareas.Thevegetation/habitattypesfoundintheupperSusitnaRiverbasinandthefloodplaindowntoTalkeetnaweredescribed,classified,andmapped.Manylocationsthroughoutthestudyareawerereconnaissancedinsummer1980toobtaininformationonspeciescompositionandcommunitystructure.Ocularestimatesofthecoverofeachspeciesineachlayerofvegetationweremade,andthesedatawereusedtoclassifythevegetationaccordingtothesystemdevelopedbyViereckandDyrness(1980).Highaltitude(U2)colorinfraredphotographyandLANDSATimagerywereusedtomapthevegetationcovertypes.Mapswereproducedatthescalesof1:250,000and1:24,000fortheentirebasinanddirectimpactareas,respectively.Additionally,theareaextending16kminanydirectionfromtheupperSusitnaRiverfromGoldCreektothemouthoftheMaclarenwasmappedatascaleof1:63,360.A1:24,000scalemapofapparentwetlandswasalsoproduced,basedonthe1:24,000scalevegetationmapandthewetlandsclassificationsystem(Cowardineta1.1979)usedbytheU.S.FishandWildlifeService.Two·additional--l:63,360scalemapswereproducedforthenorthern·andsoutherntransmissioncorridors.Thecentraltransmissioncorridorisincludedonthe1:63,360-scaledmapofportionsoftheupperbasin.VegetationsuccessionalstudieswereconducteddownstreambetweentheDeshkaRiverandGoldCreek.Vegetationstandsatdifferentstagesofdevelopmentinthreesectionsoftheriverwereselectedonthebasisofaerialphotographyandfieldreconnaissance.Theseareasweresampledquantitativelytoobtainvegetationcoverestimatesforallspecies,density,ages,heights,crownlengthandwidth(shrubs),diameterbreastheight(trees),andcrowndominancemeasuresforwoodyspecies.Resultsofreconnaissancesurveysofthevegetation/habitattypesshowthatatleast255vascularplantspeciesin134generaand56familiesarepresentintheupperSusitnaRiverbasin.Ofthesespecies,21representedextensionsofthepreviouslyknownrangesofthespecies.Downstreamareascontained76identifiedvascularplantspeciesin63generain30families.NinespeciesrepresentedrangeextensionsaccordingtoHulten(1968).Overall,277specieswereobservedwhichrepresented140generain56families.Twenty-eightappeartoberangeextensions.SpecialeffortwasmadetolocateanyspecieswhicharecurrentlyunderreviewbytheU.S.FishandWildlifeServiceforpossiblestatusasendangeredorthreatened.Althoughsomepotentialhabitatsofthesespecieswerelocated,noneofthespecieswerefound.Footandhelicoptersurveyswerealsomadeofseverallakesandpondswithinandadjacenttothedirectimpactareastodeterminethecompositionandstructureofplantcommunitiesoccurringinornearthewater.iii Themajorvegetation/habitattypesfoundintheupperbasinstudyareaarelowmixedshrub,woodlandandopenblackspruce,sedge-grasstundra,matandcushiontundra,andbirchshrub.Thesevegetation/habitattypesaretypicalofwhatisfoundcoveringvastareasofAlaskaandnorthernCanada.CharacteristicallY,thesetypesarefoundoncold,wetsoilsandproducevegetationthatgrowsslowlyandoftenappearsstunted.Naturaloccurrencesofwildfireiscommontothesetypesandactstoreversesuccessiontolowerstageswhicharebelievedtoproducemoreannualgrowthofbrowseandherbaceousplantsthanthelatersuccessionalstages.Lessthan3%oftheareaisvegetatedbydeciduousormixedconifer-deciduousforestswhich,bycontrast,havemorerobustgrowthcharacteristics.Deciduousandmixedconifer-deciduousforestsoccurprimarilYalongtheSusitnaRiverwheresoilsarebetterdrainedandalongergrowing·seasonexists.Thedominantvegetationonthedownstreamfloodplainwasmatureforest.consistingofmaturebalsampoplarandmixedbirch-spruce.AlderwasimportantbelowTalkeetnabutwaslesswidespreadabovethisareawheretheriverismorechannelized.Earlysuccessionalstagesincludedhorsetail,willows,andyoungbalsampoplaronsandyandsiltyareaswithdryasoncobb1yareas.Middlesuccessionalstagesincludedalderandimmaturebalsampoplar.Laterstagesincludedpredominantlymaturebalsampoplarandbirch-sprucewithsomebogs.PrimaryvegetationlossesintheWatanadamandimpoundmentareawillbeinwoodlandandopensprucestandsandopenmixedforests~hi1etheDevilCanyonfacilitywillimpactopenandclosedmixedforestsandopenspruceforests.TheWatanaimpoundmentisexpectedtoimpact14,691hawhiletheDevilCanyonimpoundmentmayimpact3,214haofvegetation/habitattypes.Alargeproportionofthedeciduousandmixedforestsinthestudyareawillbedestroyedbytheimpoundments.OthertypesthatwillbeaffectedwillinvolvesmallareasrelativetotheiravailabilityacrosstheentireupperSusitnaRiverbasin.Ifvegetation/habitattypesthatmightbedestroyedareimportantassourcesofbrowseformoose,replacementbrowsesuppliesinadjacentareasmaybecreatedbyburningorbyclearingtostimulateregrowthofpalatableshrubs.ThecompletedevelopmentofallborrowareasatbothDevilCanyonandWatanawilldestroyanestimated1,751haofvegetation/habitattypes.Woodlandandopenspruce,lowmixedshrub,andbirchshrubwillbetheprincipaltypesaffected.Manyoftheseareas,alongwithconstructionsitesandroads,mayberevegetatedbymulchingandseedingwithnativespeciestoquicklyrestoregroundcover.Naturalrevegetationfollowingfertilizationalsoappearspromisinginmitigatingtemporarylossesofvegetation.Decreasedflowratesdownstreamduringtheperiodofreservoirfillingandduringtheperiodofoperationandmaintenancewillallowvegetationtooccupypreviouslybareareasbecauseofthelackoffloodingandwillallownewunvegetatedareastobecomestabilized.Lackofseasonalfloodswillpermitsomesitesinearlysuccessionalstagesofvegetationtoadvancetolatersuccessionalstages.iv Itisdifficulttoidentifyhowlongittakesanareatobecome"stabilized".Vegetationmaydevelop,besiltedunder,andresurfaceanunlimitednumberoftimes.Above-groundagesofwoodyspeciesinearlysuccessionalstagesweregenerallylessthan10years.Tentofifteenyearsafterabove-groundgrowthbegins,aldermaybecomethedominantvegetation.Sincetheamountofnewlyexposedlandatlowerflowratesdoesnotappeartovarydirectlywiththeflowrate,itisdifficulttoestimatehowmuchnewareawouldbegainedbyreducedflowratesandhowmuchwouldbelosttoadvancedstages.TheareabetweenWhiskersCreekandtheChulitnaRiverwouldappeartogainabout40haofnewlandwhile50haofexistingbarelandwouldhaveearlysuccessionalstandsesta-blished.SomefluvialandfloodingprocessesdampenedbythedamscouldbelargelyobviatedbytheinputsfromtheChulitnaandTalkeetnaRiversbelowthethreeriversconfluencenearthetownofTalkeetna.v PROPOSEDDEVELOPMENTSUMMARYLISTOFTABLESLISTOFFIGURESTABLEOFCONTENTSiiiiviiixii-INTRODUCTION------------------------------------------------2-METHODS-----------------------------------------------------22.1-DefinitionofStudyArea----------------------------------22.2-VegetationCover/HabitatMapping---------------------------2.2.3-QualitativeAssessments·---~--------------------------------6(a)SamplingLocationsn________6(b)VegetationCharacteristics---------------------------6(c)Physica1Characteristics------------------------------9(d)WildlifeHabitat-------------------------------------9(e)Wetlands----------------------------------------------92.4-QuantitativeDescriptions----------------------------------102.5-EndangeredandThreatenedSpecies-------------------------123-RESULTS---------------------------~--------------------------133.1-GeneralDescriptionofStudyArea-------------------------133.2-Floristics-------------------------------------------------143.3-Vegetation/HabitatTypeMaps------------------------------25(a)UpperBasin-------------------------------------------25(b)DownstreamFloodplaintoTalkeetna--------------------30(c)TransmissionCorridors--------------------------------30(i )(ii)(iii)Central(DamstoIntertie)---------------------Willow-CookInlet----------------------------Healy-Fairbanks----------------------------3030303.4-Vegetation/HabitatTypeDescriptions----------------------33(a)UpperBasin-------------------------------------------33(i )(i i )(iii)(iv)(v)Forest_TundraTypes----------------------------------ShrubTypes-----------------------------------HerbaceousTypes------------------------------Unvegetated-----------------------------------vi3349556161 (b)DownstreamFloodplain------__________________________62(i )(i i )(iii )(iv)EarlySuccessionalStands_MidSuccessionalStands_LateSuccessionalStands_MooseHabitatCharacteristics_62647581(c)TransmissionCorridors85(i )(ii )(iii )Central(DamstoIntertie)_Willow-CookInlet_Healy-Fairbanks---_8585863.5-Wetlands86(a)IdentificationandMapping__nn__nnn__86·(b)VascularAquaticPlants-----__________________________873.6-ThreatenedorEndangeredSpeciesnnnnn_953.7-NoteworthySpedesnnnnnn________994ANTICIPATEDIMPACTS------------------------------------------1014.1-WatanaDam,Facilities,andImpoundmentnnnn__1014.2-DevilCanyonDam,Facilities,andImpoundment-------------105.4.3-BorrowAreas----------------------------------------------1074.4-AccessRoad-----------------------------------------------1074.5-TransmissionLines----------------------------------------1084.6-DownstreamFloodplain-------------------------------------1134.7-ThreatenedorEndangeredSpecies--------------------------1155-MITIGATION6-REFERENCES1161187 -AUTHORITIESCONTACTED-----------------~---------------------123vii LISTOFTABLESTable1.Vegetation/habitattypes(andsamplelocationnumbers)sampledinupperSusitnaRiverbasin,1980.------------------72.Preliminarylistofplantspeciesidentifiedduringsummersof1980and1981inupperSusitnaRiverbasin(U)anddownstreamfloodplain(D).(10pages)-------------------------153.VascularplantspeciesintheupperSusitnaRiverbasinanddownstreamareaswhichareoutsidetheirrangeasreportedbyHulten(1968).-----------------------------------------------264.Hectaresandpercentageoftotalareacoveredbyvegetation/habitattypesintheupperSusitnaRiverbasin(aboveGoldCreek).------------~-----------------------------------------285.Hectaresandpercentageoftotalareacoveredbyvegetation/habitattypesforthearea16kmoneithersideoftheSusitnaRiverfromGoldCreektotheMaclarenRiver.---------296.Hectaresandpercentoftotalareacoveredbyvegetation/habitattypeswithinthecentraltransmissioncorridor.------317.Hectaresandpercentoftotalareacoveredbyvegetation/habitattypeswithintheWillowtoCookInlettransmission·corridor.----------------------------------------------------328.Hectaresandpercentoftotalareacoveredbyvegetation/habitattypeswithintheHealytoFairbankstransmissioncorridor.----------------------------------------------------349.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinopenconifervegetation/habitattypeinupperSusitnaRiverbasin,summer1980.----------------------3510.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinwoodlandconifervegetation/habitattypeinupperSusitnaRiverbasin,summer1980.----------------------3611..Coverpercentagesfortotalvegetation,verticalstrata,aridplantspeciesinopenblacksprucevegetation/habitattypeinupperSusitnaRiverbasin,summer1980.----------------------3712.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinopenwhitesprucevegetation/habitattypeinupperSusitnaRiverbasin,'summer1980.----------------------38viii 13.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesincloseddeciduousforest(birchandbalsampoplar)vegetation/habitattypeinupperSusitnaRiverbasin,summer1980.-------------------------------------------------4114.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinopenbirchdeciduousforestvegetation/habitattypeinupperSusitnaRiverbasin,summer1980.-------4215.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinclosedbalsampoplarforestvegetation/habitattypeinupperSusitnaRiverbasin,summer1980.-------4416.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinclosedbirchdeciduousforestvegetation/habitattypeinupperSusitnaRiverbasin,summer1980.-------4517.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinclosedaspendeciduousvegetation/habitattypeinupperSusitnaRiverbasin,summer1980.---------------4618.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinclosedmixedconiferdeciduousforestvegetation/habitattypeinupperSusitnaRiverbasin,summer1980.--------------------------------------------------4719.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinopenmixedconiferdeciduousforestvegetation/habitattypeinupperSusitnaRiverbasin,summer1980.-------4820.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinwetsedge-grasstundravegetation/habitattypeinupperSusitnaRiverbasin,summer1980.---------------5121.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinmesicsedge-grasstundravegetation/habitattypeinupperSusitnaRiverbasin,summer1980.---------------5222.PlantspecieslistinherbaceousalpinetundrainupperSusitnaRiverbasin,summer1980..-----------------------------5323.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinclosedmatandcushiontundravegetation/habitattypeinupperSusitnaRiverbasin,summer1980.-------5424.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinclosedtallaldervegetation/habitattypeinupperSusitnaRiverbasin,summer1980.-----------------------5625.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinopentallaldervegetation/habitattypeinupperSusitnaRiverbasin,summer1980.-----------------------58ix Table--26.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinclosedlowshrubvegetation/habitattypeinupperSusitnaRiverbasin,summer1980.-----------------------5927.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinopenlowshrubvegetation/habitattypeinupperSusitnaRiverbasin,summer1980.-----------------------6028.PercentcoveronearlysuccessionalstandsondownstreamfloodplainofSusitnaRiver,summer1981.---------------------6229.Density(stems/ha)ofwoodyspeciesinearlysuccessionalstandsondownstreamfloodplainofSusitnaRiver,summer1981.-6530.CharacteristicsofwoodyspeciesinearlysuccessionalstandsondownstreamfloodplainofSusitnaRiver,summer1981.-------6631.PercentcoveronalderstandsondownstreamfloodplainofSusitnaRiver,summer1981.---------------------------------6732.Density(stems/ha)ofwoodyspeciesinalderstandsondownstreamfloodplainofSusitnaRiver,summer1981.----------6933.CharacteristicsofwoodyspeciesinalderstandsondownstreamfloodplainofSusitnaRiver,summer1981.---------------------7034.PercentcoveronimmaturebalsampoplarstandsondownstreamfloodplainofSusitnaRiver,summer1981.---------------------7135.Density(stems/ha)ofwoodyspeciesinimmaturebalsampoplarstandsondownstreamfloodplainofSusitnaRiver,summer1981.-7236.CharacteristicsofwoodyspeciesinimmaturebalsampoplarstandsondownstreamfloodplainofSusitnaRiver,summer1981.-7337.CharacteristicsoftreesandtallshrubsinimmaturebalsampoplarstandsondownstreamfloodplainofSusitnaRiver,summer1981.--------------------------------------------------7438.PercentcoveronmatureanddecadentbalsampoplarstandsondownstreamfloodplainofSusitnaRiver,summer1981.----------7639.Density(stems/ha)ofwoodyspeciesinmatureanddecadentbalsampoplarstandsondownstreamfloodplainofSusitnaRiver,summer1981.------------------------------------------77x Table40.CharacteristicsofwoodyspeciesinmatureanddecadentbalsampoplarstandsondownstreamfloodplainofSusitnaRiver,summer1981.---------------------------------------7841.CharacteristicsoftreesandtallshrubsinmatureanddecadentbalsampoplarstandsondownstreamfloodplainofSusitnaRiver,summer1981.--------------------------------7942.Percentcoveronbirch-sprucestandsondownstreamfloodplainofSusitnaRiver,summer1981.-----------------------------8043.Characteristicsoftreesandtallshrubsinbirch-sprucestandsondownstreamfloodplainofSusitnaRiver,summer,1981.---------------------------------------------8244.Density(stems/ha)ofwoodyspeciesinbirch-sprucestandsondownstreamfloodplainofSusitnaRiver,summer1981.8345.Characteristicsofwoodyspeciesinbirch-sprucestandsondownstreamfloodplainofSusitnaRiver,summer1981.-------8446.VegetationandwetlandclassesfoundintheproposedSusitnaimpoundmentandborrowareas.---------------------8847.Hectaresofdifferentwetlandtypesbyprojectcomponent.8948.Aquaticplantsurvey,Susitnahydroelectricproject,August1980.(3pages)------------------------------------9249.ListofendangeredandthreatenedplantspeciessoughtintheupperSusitnabasinsurveys.---------------------------9750.HectaresofdifferentvegetationtypestobeimpactedbytheWatanaFacilitycomparedwithtotalhectaresofthattypeintheentireupperbasinandintheareawithin16kmoftheSusitnaRiver.-------------------------------10251.HectaresofdifferentvegetationtypestobeimpactedbytheDevilCanyonFacilitycomparedwithtotalhectaresofthat·typeintheentireupperbasinandtheareawithin16kmoftheSusitnaRiver.------------~------------------10652.Hectaresofdifferentvegetationtypestobeimpactedbytheaccessroadcomparedwithtotalhectaresofthattypeinupperbasinandtheareawithin16kmoftheSusitnaRiver--10953.Hectaresofdifferentvegetationtypestobeimpactedbythetransmissionfacilitycomparedwithtotalhectaresofthattypeintransmissioncorridors.(2pages)-----------------IIIxi LISTOFFIGURESFigure1.LocationofstudyareasinthestateofAlaska.-------------32.VegetationmappingareasofupperSusitnaRiverbasin.------43.Vegetationmappingareasfortransmissioncorridors.--------54.Vegetation/habitattypessamplelocationsinupperSusitnaRiverbasin,1980.------------------------------------------85.LocationsofstandssampledondownstreamfloodplainofSusitnaRiver,1981.----------------------------------------11"6.VegetationmapofupperSusitnaRiverbasin.(scale1:250,000,backpocket)-----------------------------------------------BP7.VegetationmapofproposedWillow-CookInlettransmissioncorridor.(reducedfrom1:63,360,2pages)----------------Appendix8.VegetationmapofproposedHealy-Fairbankstransmission"corridor.(reducedfrom1:63,360,3pages).Appendlx9.VegetationmapofproposedSusitnahydroelectricimpact.area.(reducedfrom1:63,360,3pages)--------------Appendlx10.VegetationmapofproposedSusitnahydroelectricimpactarea.(reducedfrom1:24,000,13pages)------------------Appendix11.WetlandmapofSusitnahydroelectricprojectimpoundmentandborrowareas.(reducedfrom1:24,000,8pages)-------.Appendix12.LocationsoflakesandpondssurveyedforvascularaquaticplantsinAugust1980.-------------~------------------------9013.AschematicrepresentationofthedominantvegetationassociatedwithmanyofthelakesandpondsoftheupperSusitnabasin.----------------------------------------------9614.Projectfacilities.-----------------------------------------103xii 1-INTRODUCTIONTheoverallobjectiveofthePlantEcologyStudieswastomapanddescribethevegetation/habitattypesoccurringintheareastobeaffectedbytheproposedSusitnaHYdroelectricProjectand,forthepurposesofregionalperspective,thesurroundingbasin;topredictimpactsthatwillresultfromtheproposedfacilities;andtoprovidepreliminarymitigationoptions.Specifically,during1980ourobjectivesweretoproducepreliminaryvegetationmapsandqualitativedescriptionsofeachvegetationtypemapped.Objectivesin1980alsoincludedmappingthewetlands.Additionally,weweretosurveytheupperSusitnaRiverimpactareasforplantspeciescurrentlybeingreviewedbytheU.S.FishandWildlifeServiceforprotectionundertheEndangeredSpeciesActof1973.In1981ourmainobjectivewasexpandedtoincludesomequantitativeplantcommunitydescriptionsandpredictsequencesofvegetationsuccessiononthefloodplaindownstreamfromthehydroelectricproject.Mapsofthetransmissioncorridorswerealsotobeproducedin1981. 22 -METHODS2.1-DefinitionofStudyAreaThemainstudyareasincludedtheupperSusitnaRiverbasinanddown-streamfloodplainwhicharelocatedinsouthcentralAlaska(Figure1).TransmissioncorridorsfromWillowtoCookInletandfromHealytoFairbankswerealsostudied.Thestudyareaduring1980includedalloftheupperSusitnaRiverdrainageandthefloodplainoftheSusitnaRiverfromGoldCreektoTalkeetna.Someportionsofthisareawereexaminedmoreintensivelythanothers.ThescaleatwhichthedifferentareasweremappedispresentedinFigure2andgivessomeindicationofhowtheeffortw~sdistributed;moreattentionwasgiventoareasthatweremappedatlargerscales,sincethesearetheareaswhichwillbedirectlyimpactedbytheproposedhydroelectricproject.-During1981,thefloodplainbetweentheDeshkaRiverandGoldCreekwasintensivelystudied.Transmissioncorridors--Central,WillowtoCookInlet,andHealytoFairbanks--weremappedandsomeadditionalvegetationsurveyswereconductedintheupperbasin(Figure3).2.2-VegetationCover/Habitatr·lappingVegetationoftheentireupperSusitnaRiverdrainage(Figure2)wasmappedatascaleof1:250,000.Vegetationadjacenttoandwithin16kmoftheupperSusitnaRiverandwithinthetransmissioncorridors(Figure3)wasmappedatascaleof1:63,360.Thevegetationwithintheproposedimpactareas(i.e.,impoundments,areaswithin0.8kmofimpoundments,floodplainfromPortageCreektoTalkeetna,andborrowsites)wasmappedatascaleof1:24,000.TheclassificationsystempresentedbyViereckandDyrness(1980)wasusedonthemaps.MappingatallthreescalesfortheupperSusitnaRiverbasinbeganbysubdividingtheentireupperdrainageintomajorphysiographicregionsbytheinterpretationofwinterandsummerLANDSATimagery.Vegetationunitson1:120,000scalehighaltitude(U-2)colorinfra-red(CIR)photographyofrepresentativeareasineachphysiographicregionwerethendelineatedandidentifiedaccordingtoViereckandDyrness(1980).The1:120,000scaleprints,withattachedoverlays,weretakenintothefieldandasmanydelineatedvegetationunitsverifiedaspossible.Fieldchecksweredistributedacrosseachofthemajorphysiographicregions,withemphasisbeingplacedonthosevegetationtypeswhichweremostdifficulttointerpretonaerialphotography.Helicopteravailabilityalsowasafactorindetermininghowmanyandwhichareascouldbechecked.TransparentenlargementsofCrRimageryat1:24,000and1:63,360scaleswereobtained.Vegetationunitswerethendelineatedonmylaroverlaysbyusingtheenlargements.The1:250,000scalemappingwasdoneonanoverlayofasummerLANDSATimage;ineachcase,field-checkedcopiesofthe1:120,000scaleCrRimagerywereconsultedforaccuracy.FieldexperienceaidedinterpretatingtonesandtexturesofCIRimageryandthemappingofthevegetation.FinallY,overlaymapsweretracedonsubduedpositivetransparenciesofcorrespondingUSGStopographicmaps.Thesefinalmapswereusedasmastersforduplicatingcopies. FAIRBANKSSCALE:ASSHOWNo2550KM.~ANCHORAGE-FAIRBANKS.TRANSMISSIONLINECORRIDORS....F...I_G_UB,,;;E:....:.-tLOCATIONOFSTUDYAREASINTHESTATEOFALASKA o5101520~KILOMETERSKEYITITIIIJ1/\"--1FIGURE2SCALESI.:24,0001:63,360I:250,000-TOCANTWEWATANADAMSITE")DEVILCANYONDAMSITEITALKEETNAVEGETATIONMAPPINGAREASOFUPPERSUSITNARIVERBASIN ?215 510KILOMETERSFIGURE3t..-</CANTWELL\/(VALDEZANCHORAGE~<l~CI)<l~-\-J(fl<lVEGETATIONMAPPINGAREASFORTRANSMISSIONCORRIDORS 6Duringfieldcheckingoftransmissioncorridors,CIRphotographyatascaleofapproximately1:63,360wasusedfromClear,Alaska,toFairbanks,Alaska,andblackandwhitephotographyatascaleof1:48,000fromHealy,Alaska,toClear,Alaska.TheseblackandwhiteimageswereusedtoalesserextentfromCleartoFairbanks.HighaltitudeCIRtransparencies(1:63,360)wereusedforactualmappinginthelaboratory.Truecolor1:12,000-scaledphotographsoftheAlaskarailroadwereusedtoalimitedextenttoassistinterpretingvegetationintheHealyarea.HighaltitudeCIRprints(1:120,000)wereusedforfieldcheckingandmappingoftheWillowtoCookInletsegment.Arealextentsofvegetation/habitattypesweredeterminedbycuttingeachtypefromapaperreproductionofthemapandweighingthecut-outportionsaccordingtotype.Severalareasofknownsize(about5-10sqmilwerecutout,weighed,averagedtocalculateactualareasfromweights.Percentageswerecomputedasratiosoftheindividualtypestothetotalarea.2.3-~ualitativeAssessments(a)SamplingLocationsEachmajorvegetationtypewassurveyedatthereconnaissancelevel.Areassurveyedwereselectedbasedontheaerialphotography.Someareaswerechosenbecausewewereunsureofwhatvegetationtypewasrepresentedbycertaincolorsandtexturesonthephotographs.Otherswereselectedbecausemoresamplepointswereneededinaparticularvegetationtype.ThedesirednumberofsamplelocationsinavegetationtypewasbasedontheextentofthattypeandonseverityofimpactfromtheproposedSusitnaHYdroelectricProject.Inotherwords,moreareasweresampledinvegetationtypesoflargeextentandintheimpoundmentareas.Thesizeandlocationofanareasampleddependedonthesizeofthehomogeneousarea,thenumberofpeoplesampling,andtimeconstraints.Theareasandtypessampledduringthe1980fieldseason(June,JulY,andAugust)areindicatedonTable1andFigure4.(b)VegetationCharacteristicsForpurposesofdescribingeachvegetation/habitattype,speciescompositionandcommunitystructuredatawerecollectedateachareasampled.Coverofeachplantspeciesineachlayerofvegetationwasobtainedbytheocularestimatemethod.Coveristheverticalprojectionoflivingplantpartsonthegroundandismeasuredasapercentageofareasampled.Thegroundlayerconsistedofallherbaceousspeciesandallwoodyspecieslessthan0.5mtall.Theshrublayerconsistedofwoodyspeciestallerthan0.5mbutlessthan2.5cmdbh(diameterbreastheight).Understoryvegetationwaswoodyspeciesbetween2.5cmand10.0cmdbh.Overstoryvegetationconsistedofspecieslargerthan10.0cmdbh."Shrublayer"referredtoalayerofvegetationwhereastheterm"shrub"referredtothelifeformofwoodyspecies,suchasresinbirch(Betulaglandulosa),dwarfarcticbirch(B.nana),alder(Alnusspp.),crowberry(Empetrumnigrum),andotherswhicharenotconsideredtrees.Sometallshrubssuchasaldermightbetallerthanshorttreessuchasblackspruce(Piceamariana).Hence,heightwasnotagooddistinguishing.characteristicfortheselifeformsinthisvegetation. 7Table1.Vegetation/habitattypes(andsamplelocationnumbers)sampledinupperSusitnaRiverbasin,summer1980.]Vegetation/habitatTypeMatandcushiontundraSedge-grasstundraHerbaceoustundraWetsedge-grassOpenblackspruceWoodlandblackspruceOpenwhitespruceWoodlandwhitespruceClosedbirchforestOpenbirchforestClosedbalsampoplarOpenbalsampoplarClosedaspenClosedmixedconifer-deciduousforestOpenmixedconifer-deciduousforestClosedtallshrubOpenta11shrubLowshrubWi11owshrub~SamplelocationsaregiveninFigure4.SampleLocationNumber~1-89-101112-1415-1718-2223-272829-3233-3435-36373839-4142-4950-525354-6263-64 TOCANTWELL./"'"..........'---J'-~f-./)C/~(~~~~\('-V"~V)62I-.-A)'05101520~KILOMETERSFIGURE4VEGETATION/HABITATTYPESSAMPLELOCATIONSINUPPERSUSITNA RIVERBASIN,1980 9Aspecificwoodyspeciescouldoccurinanyoneorcombinationoflayersinagivenstand.Coverwasalsoestimatedforeachlayerofvegetationdescribed.Covervaluesarenotadditivebecauseofoverlappinglayers.Inotherwords,ifaspecieshas15%shrublayercoveranda10%groundlayercover,itsoverallcoverwouldbeatleast15%butmaybelessthan25%ifpartsofthetallerindividualsoccurabovetheshorterindividuals.Similarly,thesumofthecoverpercentagesinastandmayexceed100%.(c)PhysicalCharacteristicsTheobjectiveofthisportionofthequalitativeassessmentwastocollectdatathatwoulddescribecharacteristicsofthephysicalen-vironmentwhichcouldbecloselyassociatedwiththeoccurrenceofaparticularvegetation/wildlifehabitattype.Onepersononthesurveyteamwasassignedtorecordthephysicalvariablesateachsitewhere.thevegetationwasdescribed.Elevationwasdeterminedfromtopographicmapsorthealtimeterofthehelicopter.DegreeofslopetypicalofthesitewasmeasuredwithanAbneylevel.Aspectwasdeterminedwithacompassandrecordedindegrees.Positionwasalsorecordedaccordingtoelevationandlocationofthesitewithrespecttothelandformonwhichitoccurred(e.g.canyonsite;mid,upper,orlowerlevel;mountaintop).(d)WildlifeHabitatThefocusofthispartofthequalitativeassessmentwasdescribinghabitatvalueofeachcommunity/habitattypeforungulates.Secondarily,signofotherwildlifespecies,suchasbirds,smallmammals,andbearswasrecorded.Availablebrowse,browseutilization,browsevigor,pelletgroups,andcommentsrelativetowildlifehabitatwererecorded.SpecificsarediscussedinthePlantEcologyProceduresManual(AlaskaPowerAuthority1980a).(e)WetlandsAlllandwithintheproposedimpactareaswasalsoclassifiedaccordingtoCowardinetal.(1979)intoappropriatewetlandclasses.Amapdelineatingwetlandtypeswasconstructedusingthevegetation/habitatmapsfollowingthesameproceduresdescribedinSection2.2.Theonlydifferencewasthatthevegetationunitswerereplacedwithappropriatewetlandclasses.Thiswasdonewithlittleconsiderationofsoilmoistureconditions,sincethisinformationwasmostlyunavailableatthetime.Presenceofsteepslopeandlikelygooddrainagewasin-terpretedtoruleoutclassificationaswetlandinsomecaseswherethevegetationcoverdidindicatethepossibilityofwetland.Obviously,thisissomewhatquestionablewithoutactualsoilsdataforinterpretation.Inordertoobtaininformationonaquaticplantspecies,severalpondsandlakesandtheirperipheralwetareaswithintheimpoundmentzoneandadjacentuplandsweresurveyedonfoot.Duringthesurveys,speciescomposition,dominance,andtotalcover(relativetoamountofwater) 10wereestimated.Elevation,estimatedrootingdepth,andwidthofsurroundingwetlandareawererecorded.SurroundingwetlandwaslimitedbydefinitiontotheLacustrine-Limnetic-EmergentWetland-VascularwetlandclassofCowardineta1.(1979).Manyoftheremainingpondsandlakes,notsurveyedon-root,wereexaminedbyhelicopteroverflightstoensuresimilarityamongpondsandtosearchforspeciesnotpre-viouslyencountered.2.4-QuantitativeDescriptionsQuantitativedescriptionsofdownstreamfloodplainplantcommunitieswerebasedonsamplingof29standsbetweentheDeshkaRiverand11kmnorthofTalkeetna(Fi9ure5).ReconnaissanceoftheareainAugust1980andagaininearlysummer1981wasusedtodeterminethetypesoffloodplainvegetationpresent.InJune1981aseriesofpointssys-tematicallyplottedonaerialphotographswasclassifiedbyhelicopter'surveyandusedtodeterminetherelativeavailabilityofeachofthetypes.Samplestandswerethenselectedineachtypeineachofthreereachesoftheriver--DeshkaRivertoSheepCreek,SheepCreektoBirchCreekSlough,andBirchCreekSloughtoChase.Standsofmiddleandlatesuccessionalstageswererequiredtobeofsufficientsizeanduniformitytoallowplacementoffourrandomlyoriented,non-overlapping30-mtransects.Initialdataanalysisindicatedthatmoretransectswereneededforadequatesampling.InAugust,twomoretransectswereusedinmostofthesestands(excepttwoalderstands)andfourmoretransectswereusedinoneofthehighlyvariablebirch-sprucestands(stand4).Earlysuccessionalstandsweresampledwithfourtransectsinahomogeneousareawherepossible.However,manyoftheseareasweretoosmallandasfewastwotransectswereusedinsomeplaces.Sometimesonetransectwouldbetakeninonepatchandanotherinanearby,butnotcontiguous,area.Vegetationcoverbyspecieswasrecordedontwotoeighttransectsatpointsspaced50cmalongatapemeasure.Observationofpointsintheoverstorywasaidedbyuseofasetofcross-hairsinasightingscope.Speciesoccurringwithin5 mofonesideofthetransects,butwhichwerenotencounteredatanyofthepoints,werelisted.Woodyspeclesdensitywasdeterminedbycountingthenumberofindividualsbyheightclassrootedwithinadesignatedplotalongsidethelengthofthetransect.Shrubs<.4m,.4mto2m,and>2mbut<4cmdbhwerecountedinal-mwideplot.Shrubs<0.4mtallwerejudgedunavailableforwinterbrowsebecauseofsnow.Browsablestemswerethoseinsizeclass0.4mto2 mtalland>2mtallbut<4cmdbh.Tallshrubs(>2minheightand>4cmdbh)werecountedina2-mwideplot.Trees(>4minheight)werecountedina5-mwideplot.Anindividualwasdefinedasanystememergingatthesurfaceofthelitter.Age,height,anddbhofimportanttallshrubsandtreesweremeasuredontworandomlyselectedindividualsalongeachtransect.Importantlowshrubswerealsomeasuredforheight,length,andwidth.Heightsoftallindividualsweremeasuredwitharangefinder.Theageofeachmeasuredtreeorshrubwasdeterminedbycountinggrowthringstaken o510~--~I-~~~IFIGURE5LOCATIONSOFSTANDSSAMPLEDONDOWNSTREAMFLOODPLAINOFTHESUSITNJ,RIVER,1981 12fromcrosssectionalcuttingsorcores.Crowndominancewasameasureofwhichspecieswerecapturingthecanopysunlight.Ithadthefollow-ingvalues:(1)opengrown(notencountered),(2)dominant-receivedsunlightfromaboveandthesides,(3)codominant-receivedsunlightfromabove,butnotsides,(4)intermediate-barelyreachingmaincanopy,(5)overtopped-belowgenerallevelofcanopy,(6)subordinate-underovertopped,and(7)ground-lowestlevel.Theelevationofeachstandrelativetotheleveloftheadjacentriverwasmeasuredbyrod-and-leveltechniqueattwoorthreedifferenttimesduringthesummer.Timeofdayforeachmeasurementwasrecordedforlaterreferencetorateofriverflow.2.5-EndangeredandThreatenedSpeciesNoplantspeciesarepresentlyofficiallylistedforAlaskabyfederalorstateauthoritiesasendangeredorthreatened,however,37arecurrentlyunderreviewbytheU.S.FishandWildlifeService(USF&WS1980).MostofthesespecieswerealsodiscussedbyMurray(1980).ThegeneralhabitatrequirementsandoccurrenceoftheseplantspecieswereknownfromprevioustaxonomicandecologicalstudiesinAlaskaandfrominfor-mationontheAlaskanflorabyHulten(1968).Followingareviewofthisinformationandcontactwithlocalexperts,10speciesthatcouldpossiblyoccurinthephytogeographicregionoftheupperSusitnaRiverwereidentified.Potentialhabitatforthesespecieswasthenselectedforcloserinvestigation.InAugust1980andagaininearlyJulY1981,eachoftheselectedareaswassurveyedfromhelicopterandontheground.Spp.cinlnttp.ntionWnSgiventoselectedsiteswherethespeciesinquestionmightoccur.Sincecalciphilicspecieswereincludedinthepotentialendangeredcategory,soilshavingfreecarbonateswerelocatedbyusinggeologicmapsandbytestingrockswith10%hydrochloricacid. 133 -RESULTS3.1-GeneralDescriptionofStudyAreaTheupperSusitnaRiverbasinislocatedinthePacificMountainphysiographicdivisioninsouthcentralAlaska(JFSLUPCA1973).TheSusitnabasinoccurswithinanecoregionclassifiedbyBailey(1976,1978)astheAlaskaRangeProvinceoftheSubarcticDivision.TheSusitnaRiversystemdrainspartsoftheAlaskaRangeonthenorthandpartsoftheTalkeetnaMountainsonthesouth(Figure1).Manyareasalon9theeast-westportionoftheriverbetweentheconfluencesofPortageCreekandtheOshetnaRiveraresteepandcoveredwithconifer,deciduous,andmixedconiferanddeciduousforests.Flatbenchesoccuratthetopsofthesebanksandusuallycontainlowshruborwoodlandconifercommunities.Risingfromthesebenchesarelowmountainscover~dbysedge-grasstundraandmatandcushiontundra.ThesoutheasternportionofthestudyareabetweentheSusitnaRiverandLakeLouiseischaracterizedbyextensiveflatareascoveredwithlowshrublandandwoodlandconifercommunitieswhich,becauseofintergradationsareoftenintermixedanddifficulttodistinguishinthefieldoronaerialphotographs.Tothenortheast,theareaalongtheSusitnaRiverbetweentheMaclarenRiverandtheDenaliHighwayconsistsofwoodlandandopensprucestands.Farthereast,lowshrublandcoverincreases.TheClearwaterMountainsnorthoftheDenaliHighwayhaveextensivetundravegetation.ThefloodplainoftheSusitnaRivernorthoftheDenaliHighwayhaswoodlandspruceandwillowstands,whiletheAlaskaRangecontainsmostofthepermanentsnowfieldsandglaciersinthestudyarea.Steepportionsandsomeadjacentareasalongtheeast-westreachesoftheriverareconsideredtobeintheclosedspruce-hardwoodforesttypeofViereckandLittle(1972),themoderatelYhighmixedevergreenanddeciduousforestmapunitofSpetzman(1963),andtheuplandsprucehardwoodforestbytheJFSLUPCA(1973).Whicheverclassificationonechooses,thistypeofvegetationisfoundmainlyalongriversinthesouthcentralandinteriorregionsofthestate.Thebenchesborderingtheeast-westportionoftheriverandtheareaaroundtheMaclarenRiverareclassifiedasmoisttundrainallthreeofthepreviouslymentionedreferences.Thisclassificationincludesherbaceousmeadowsaswellasshrub-dominatedsites,bothofwhichalsooccuraroundtheBrooksRange,ontheSewardPeninsula,andneartheKilluckMountains.TheextensiveflatsinthelowerOshetnaRiverandLakeLouiseareasinthesoutheasternportionoftheupperbasin,areconsideredopen,lowgrowingspruceforestsbyViereckandLittle(1972),lowmixedevergreenanddeciduousforestsbySpetzman(1963)andlowlandspruce-hardwoodforestsbytheJFSLUPCA(1973).ViereckandLittle's(1972)descriptionappearsmostappropriatesincetheareaiscoveredprimarilybysprucestandswithtreelessbogs. 14ThevegetationalongthelowermountainsandthelowerslopesofthehighermountainswasclassifiedasalpinetundrabyViereckandLittle(1972)andtheJFSLUPCA(1973)andasbarrenandsparsedrytundrabySpetzman(1963).Inthecurrentstudysomeoftheseareasweremappedasrockwhileotherareasweremappedassedge-grasstundraormatandcushiontundra.Onthepreviousmapsrockwasincludedinalpinetundra.Someareaswhichweremappedasrockdohavesomeimportantpioneeringspeciesgrowingincrevices,buttheplantsprovidednegligiblegroundcover.Regardlessofthemappingandclassificationsystemused,thehabitatiscommononmountainsthroughoutthestate.ThedownstreamfloodplainisapartoftheCookInlet-SusitnaLowlands,aportionofthetroughwhichformsamajorbifurcationinthePacificMountainSystem(JFSLUPCA1973).Thisregionisgenerallyflat,occursbelow150minelevationandexperiencesaclimatethatistransitionalbetweenmaritimeandcontinental.Thegrowingseasonisatleastonemonthlongerthanintheupperbasin.Thevegetationofthisregionisconsideredclosedspruce-hardwoodforestbyViereckandLittle(1972),moderatelyhighmixedevergreenanddeciduousforestorhighevergreenspruceforestbySpetzman(1963)anduplandspruce-hardwoodorbottomlandspruce-poplarforestbytheJFSLUPCA(1973).3.2-FloristicsIntheupperSusitnaRiverbasinanddownstreamfloodplaincombined,277vascularplantspecies,occurringin140generain56families,wereidentified(Table2).Twohundredfifty-fivespecieswerefoundintheupperbasinwhileonly76wereidentifieddownstream.Downstreamsiteswereconfinedtothefloodplain;thusrestrictinghabitatandfloristicvariabilityrelativetothediversityintheupperbasinstudy.Fifty-fourspecieswerefoundbothupstreamanddownstream.Although22specieswereencounteredonlydownstream,thedownstreamflorawaspredominantlYasubsetoftheupperbasinflora.Somecollectedspecimenshaveyettobeidentified,andothersneedtobeverifiedbytaxonomicspecialists.ThissituationisparticularlYtruefortheCarexandSalixgenera.ThefamiliesintheupperbasincontainingthemostspecieswereCompositae(Asteraceae),Salicaceae,Rosaceae,Gramineae(Poaceae),Cyperaceae,andEricaceae.TheSalicaceaefamilYwasimportantfromthestandpointofcanopycover,wildlifeusage,andpioneeringongravelbars,whereastheCompositaecontributedrelativelyminorcover.ThegenusSalixcontained17species,tentativelY,whileCarexhad11speciesandSaxifragahadninespecies.Withinthenon-vascularflora,11generaoflichen,whichincludedatleast12species,wereidentifiedinbothareascombined,whileseventaxaofmosseswereidentified.MoreextensiveworkonlichensandmosseswouldundoubtedlYrevealmanymorespecies.ThemajorfloristicandbotanicalfeatureobservedinthestudyoftheupperSusitnaRiverbasinwasatendencYforlowlandandalpinespeciesoftheCookInletandcoastalregiontoextendintotheSusitnaRiver 15Table2.Preliminarylistofplantspecies,identifiedgyringsummersof1980and1981intheupperSusitnaRiverbasin-(U)anddown-streamfloodplain(D).PteridophytaAspidiaceaeDryopterisdilatata(Hoffm.)GrayDryopterisfragrans(L.)SchottGymnocarpiumdryopteris(L.)Newm.AthyriaceaeAthyriumfilix-femina(L.)RothCystopterisfragilis(L.)Bernh.Cystopterismontana(Lam.)Bernh.Matteucciastruthioteris(L.)TodaroWoodsiaalpinaBoltonS.F.GrayEquisetaceaeShieldfernFragrantshield-fernOak-fernLadyfernFragile-fernMountainfragile-fernOstrichfernAlpinewoodsiaU DUU DUDUUDUEquisetumarvenseL..EquisetumfluviatileL.ampl.Ehrh.EquisetumpalustreL.EquisetumpratenseL.EquisetumsilvaticumL.EquisetumvariegatumSchleich.IsoetaceaeMeadowhorsetailUSwamphorsetailUMarshhorsetailD/·leadowhorsetai1 U DWoodlandhorsetailUVariegatedscouring-rushUDIsoetesmuricataDur.LycopodiaceaeLycopodiumalpinumL.LycopodiumannotinumL.LycopodiumclavatumL.LycopodiumcomplanatumL.LycopodiumselagoL.ssp.selagoThelypteridaceaeThelypterisphegopteris(L.)SlossonGymnospermaeCupressaceaeJuniperuscommunisL.PinaceaePiceaglauca(Moench)VossPiceamariana(Mill.)Britt.,--sterns&Pogg.QuillwortAlpineclubmossStiffclubmossRunningclubmossGroundcedarFirclubmossLongbeechfernCommonjuniperWhitespruceBlackspruceUuuUUUUUUDU 16Table2.(Continued,Page2of10)MonocotYledoneaeCyperaceae~CarexaguatilisWahlenb.CarexbigelowiiTorr.CarexcapillarisL.CarexcanescensL.carexconcinnaR.Br.CarexfilifoliaNutt.CarexgarberiFern.CarexlimosaL.CarexloliaceaL.CarexmediaR.Br.exRichards.CarexmembranaceaHook.CarexpodocarpaC. B.ClarkeCarexrhynchophysaC.A.Mey.CarexsaxatilisL.Carexspp.ErlQPhorumangustifoliumHonck.EriophorumscheuchzeriHoppeEriophorumvaginatumL.Eriophorumsp.ScirpusmicrocarpusPresl.Trichophorumcaespitosum(L.)Hartm.Gramineae(Poaceae)Agropyronboreale(Turcz.)DrobovAgropyroncaninum(L.)Beauv.Agropyronmacrourum(Turcz.)DrobovAgropyronsp.AgrostisscabraWilld.Agrostissp.AlopecurusalpinusSm.Arctagrostislatifolia(R.Br.)Griseb.Beckmanniasyzigachne(Steud.)FernCalamagrostiscanadensis(Michx.)Beauv.CalamagrostisururascensR.Br.CinnalatifoliaTrev.Griseb.in-----cecrebDanthoniaintermediaVaseyDeschamps~?atropurpurea(Wahlenb.)Scheele-Deschampsiacaespitosa(L.)Beauv.FestucaaltaicaTrin.FestucarubraL.Coll.Hierochloealpina(Swartz)Roem.&Schult.Hierochloeodorata(L.)Wahlenb.PhleumcommutatumGandogerPoaalpinaL.PoaarcticaR.Br.PoapalustrisL.Trfsetumspicatum(L.)RichterWatersedgeBigelowsedgeHairlikesedgeSilverysedgeLownorthernsedgeThread-leafsedgeSedgeShoresedgeSedgeSedgeFragilesedgeShort-stalksedgeSedgeSedgeSedgeTallcottongrassWhitecottongrassTussockcottongrassCottongrassSmall-fruitbullrushTuftedclubrushNorthernwheatgrassWheatgrassWheatgrassWheatgrassTicklegrassBentgrassMountainfoxtailPolargrassSloughgrassBluejointPurplereedgrassWoodreedTimberoatgrassMountainhairgrassTuftedhairgrassFescuegrassRedfescueAlpineholygrassVani11agrassTimothyAlpinebluegrassArcticbluegrassBluegrassDownyoatgrassuuUDUUDUUUUUUDU DUUUDDUDDDUUDUUUDUDUDUUU DUUUUDUUUUU D WoodrushUNorthernwoodrushUWoodrushUSmall-floweredwoodrushUTundrawoodrushUWahlenbergwoodrushUNuttallpondweedUFiliformpondweedUPondweedUClasping-leafpondweedURobbinspondweedUTable2.(Continued,Page3of10)IridaceaeIrissetosaPellasJuncaceaeJuncusarcticusWilld.JuncuscastaneusSm.JuncusdrummondiiE.Mey.JuncusmertensianusBong.JuncustriglumisL.Luzulacg~pestris(L.)DC.exDC.&Lam.-LuzulaconfusaLindeb.Luzulamultiflora(Retz.)Lej.Luzulaparviflora(Ehrh.)Desv.LuzulatundricolaGorodk.LuzulawahlenbergiiRupr.LiliaceaeLloydiaserotina(L.)Rchb.Streptopusamplexifolius(L.)DC.TofieldiacoccineaRichardsTofieldiapusilla(Michx.)Pers.VeratrumvirideAit.ZygadenuselegansPurshOrchidaceaePlatantheraconvallariaefolia(Fisch.)Lindl.Platantheradilatata(Pursh)Lindl.Platantherahyperborea(L.) Lindl.PotamogetomaceaePotamogetonepihydrousRaf.PotamogetonfiliformisPers.PotamogetongramineusL.PotamogetonperfoliatusL.PotamogetonrobbinsiiOakesSparganiaceaeSparganiumangustifoliumMichx.DicotyledoneaeAraliaceaeEchinopanaxhorridum(Sm.)Decne.&Planch.17WildirisArcticrushChestnutrushDrummondrushr1ertensrushRushAlplilyCucumberrootNorthernasphodelScotchasphodelHeleboreElegantdeathcamasNorthernbog-orchisWhitebog-orchisNorthernbog-orchisNarrow-leavedburreedDevil'sclubuU DUUUUUUDUUUUUUUUUD 18Table2.(Continued,Page4of10)Betu1aceae0Alnuscrispa(Ait.)PurshAlnussinuata(Reg.)Rydb.Alnustenuifo1iaNutt.Betulaglandu10saMichx.BetulananaL.BetulaOCCTdenta1isHook.BetulapapyriferaMarsh.BoraginaceaeMertensiapanicu1ata(Ait.)G.DonMyosotisa1pestrisF.W.SchmidtCa11itrichaceaeCa11itrichehermaphroditicaL.Ca11itrichevernaL.Campanu1aceaeCampanu1a1asiocarpaCham.Caprifo1iaceaeLinnaeaborealisL.Viburnumedu1e(Michx.)Raf.Caryophy11aceaeMinuartiaobtusi10ba(Rydb.)HouseSi1eneacau1isL.Ste11ariasp.Wi1he1msiaphysodes(Fisch.)McNeillCompositae(Asteraceae)AchilleaborealisBong.AchilleasibiricaLedeb.Antennariaa1pina(L.)Gaertn.Antennariamonocepha1aDC.AntennariaroseaGreeneArnicaamp1exlCau1isNutt.ssp.primaMaguireArnicachamissonisLess.(?)ArnicafrigidaC.A.Mey.Arnica1essingiiGreeneArtemisiaa1askanaRydb.ArtemisiaarcticaLess.Artemisiati1esiiLedeb.AstersibiricusL.Erigeronhumi1isGrahamErigeron10nchophy110usHook.AmericangreenalderSitkaalderThin1eafalderResinbirchDwarfarcticbirchWaterbirchPaperbirchTallbluebellForget-me-notWaterstarwortVernalwater-starwortMountainharebellTwin-flowerHighbushcranberryAlpinesandwortMosscampionStarwortMerckiaYarrowSiberianyarrowAlpinepussytoesPussytoesPussytoesArnicaArnicaArnicaArnicaAlaskawormwoodWormwoodWormwoodSiberianasterFleabanedaisyDaisyuU DDUU DUU DU DUUUUUU DUUUUUDU DUUUUDUUUUU DU DUD 19Table2.(Continued,Page5of10)HieraciumtristeWilld.Petasitesfrigidus(L.)Franch.Petasitessagittatus(Banks)GrayPetasitessp.Saussureaangustifolia(Willd.)DC.Senecioatropurpureus(Ledeb.)Fedtsch.SeneciolugensRichards.SeneciosheldonensisPors.SolidagomultiradiataAit.Taraxacumsp.CornaceaeCornuscanadensisL.CrassulaceaeSedumrosea(L.)Scop.Cruciferae(Brassicaceae)CardaminebellidifoliaL.CardaminepratensisL.CardamineumbellataGreeneDrabanivalisLiljebl.DrabastenolobaLedeb.DiapensiaceaeDiapensialapponicaL.ElaeagnaceaeShepherdiacanadensis(L.)Nutt.EmpetraceaeEmpetrumnigrumL.EricaceaeAndromedapolifoliaL.Arctostaphylosalpina(L.)·Spreng.Arctostaphylosrubra(Rehd.&Wilson)Fern.Arctostaphylosuva-ursi(L.)Spreng.Cassiopetetragona(L.)D.DonLedumdecumbens(Ait.)Small~LedumgroenlandicumOederLedumsp.Loiseleuriaprocumbens(L.)Desv.OxycoccusmicrocarpusTurcz.WoollyhawkweedArcticsweetcoltsfootArrowleafsweetcoltsfootSweetcoltsfootSaussureaRagwortRagwortSheldongroundselNortherngoldenrodDandelionBunchberryRoserootAlpinebittercressCuckooflowerBittercressRockcressRockcressDiapensiaSoapberryCrowberryBogrosemaryAlpinebearberryRed-fruitbearberryBearberryFour-anglemountain-heatherNorthernLabradorteaLabradorteaLabradorteaAlpineazaleaSwampcranberryuuuDuuuuU DUU DUUUUUUUU DUUUUUUUUDUU D 20Table2.(Continued,Page6of10)Rhododendronlapponicum(L.)Wahlenb.VacciniumcaespitosumMichx.VacciniumuliginosumL.Vacciniumvitis-idaeaL.FumariaceaeLaplandrosebayDwarfblueberryBogblueberrYMountaincranberryuuU DUCorydalispauciflora(Steph.)Pers.GentianaceaeFew-floweredcorydalisUGentianaglaucaPall.GentianapropinguaRichards.MenyanthestrifoliataL.SwertiaperennisL.GeraniaceaeGeraniumerianthumDC.Ha1oragaceaeHippurisvulgarisL.Leguminosae(Fabaceae)Astragalusaboriginumb¥ichards.AstragalusalpinusL.-AstragalusumbellatusBungeHedysarumalpinumL.LupinusarcticusS.Wats.Oxytropiscampestris(L.)DC.OxytropishuddelsoniiPorsildOxytropismaydellianaTrautv.Oxytropisnigrescens(Pall.)Fisch.OxytropisviscidaNutt.LentibulariaceaePinguiculavillosaL.UtriculariavulgarisL.tlyricaceae~1yrica~L.NymphaceaeNupharpolysepalumEngelm.OnagraceaeGlaucousgentianGentianBuckbeanGentianNortherngeraniumCommonmarestailMilk-vetchMilk-vetchMilk-vetchAlpinesweet-vetchArcticlupineFieldoxytropeHuddelsonoxytropeMaydelloxytropeBlackishoxytropeViscidoxytropeHairybutterwortCommonbladderwortSweetg,aleYellowpondlilyUUUDUUUUUDUU DUDUUUUUUUDUCircaeaalpinaL.EpilobiumangustifoliumL.EpilobiumlatifoliumL.EpilobiumpalustreL.Enchanter'snightshadeDFireweedUDDwarffireweedUDSwampwillow-herbU 21Table2.(Continued,Page7of10)OrobanchaceaeBoschniakiarossica(Cham.&Schlecht.)Fedtsch.PoquePolemoniaceaeUDPolemoniumacutiflorumWilld.PolygonaceaeOxyriadigyna(L.)HillPolygonumbistortaL.PolygonumviviparumL.RumexarcticusTrautv.Rumexsp.PortulacaceaeClaytoniasarmentosaC.A.Mey.PrimulaceaeDodecatheonfrigidumCham.&Schlecht.PrimulacuneifoliaLedeb.TrientaliseuropaeaL.PyrolaceaeJacob'sladderMountainsorrelMeadowbistortAlpinebistortArcticdockDockSpring-beaut.)!NorthernshootingstarWedge-leafprimroseArcticstarflowerU DUUUUUUUUU DMonesesuniflora(L.)GrayPyrolaasarifoliaMichx.PyrolagrandifloraRadiusPyrolaminorL.PyrolasecundaL.RanunculaceaeAeonitumdel/IIIII I U I IUllIActaearubra(Ait.Willd.AnemonenarcissifloraL.·AnemoneparvifloraMichx.AnemonerichardsoniiHookCaltha1eptosepa1aDC..Ranunculusconfervoides(E.Fries)E.FriesRanunculusmacouniiBritt.(maybeR.pacificusorsomethingsimilar)RanunculusnivalisL.RanunculusoccidentalisNutt.RanunculuspygmaeusWahlenb.Ranunculussp.ThalictrumalpinumL.ThalictrumsparsiflorumTurcz.SingledelightUDLiverleafwintergreenDLarge-flowerwintergreenULesserwintergreenUOne-sidedwintergreenU DMonkshoodUBaneberryDAnemoneUNorthernanemoneUAnemoneU DMountainmarsh-marigoldUWatercrowfootU~·1acounbuttercupDSnowbuttercupUWesternbuttercupUPygmybuttercupUButtercupUArcticmeadowrueUFew-flowermeadowrueU D 22Table2.(Continued,Page8of10)RosaceaeDryasdrummondiiRichards.DryasintegrifoliaM.Vahl.DryasoctopetalaL.Geumrossii(R.Br.)Ser.LUetkeapectinata(Pursh)Ktze.PotentillabifloraWilld.PotentillafruticosaL.PotentillahyparcticaMaltePotentillapalustris(L.)Scop.RosaacicularisLindl.RUbUsarcticusL.RubuschamaemorusL.RubusidaeusL.RUbUSpedatusSm.SanguisorbastipulataRaf.SibbaldiaprocumbensL.SorbusscopulinaGreeneSpiraeabeauverdianaSchneid.RubiaceaeGaliumborealeL.GaliumtrifidumL.GaliumtriflorumMichx.Salicaceae0Drummondmountain-avensUDDryasUWhitemountain-avensURossavensULuetkeaUTwo-flowercinquefoilUShrubbycinquefoilUArcticcinquefoilUMarshcinquefoilUDPricklyroseUDNagoonberryUDCloudberryURaspberryUDFive-leafbrambleUSitkaburnetUSibbaldiaUWesternmountainashUBeauverdspireaUDNorthernbedstrawUSma11bedstrawUSweet-scentedbedstrawDPopulusbalsamiferaL.PopulustremuloidesMichx.Salixalaxensis(Anderss.)COy.SalixarbusculoidesAnderss.saTlXarcticaPall.SalixbarclayiAnderss.SalixbrachycarpaNutt.SalixfuscescensAnderss.SalixglaucaL.SalixlanataL.subsp.richardsonii(Hook)A.Skwortz.SalixmonticolaBebbSalixnovae-angliaeAnderss.SalixphlebophyllaAnderss.SalixplanifoliaPurshssp.planifoliaSalixplanifoliaPurshssp.pulchra(Cham.)ArgusSalixpolarisWahlenb.SalixreticulataL.SalixrotundifoliaTrautv.SalixscoulerianaBarrattSalixsp.BalsampoplarQuakingaspenFeltleafwillowLittletreewillowArcticwillowBarelaywi11owBarren-groundwillowAlaskabogwillowGrayleafwi11owRichardsonwillowParkwi11owTallblueberrywillowSkeletonleafwillowPlaneleafwillowDiamondleafwillowPolarwillowNetleafwillowLeastwillowSeoulerwillowWi11owU DUUDU DUUUUDUUUU DUUUUUUUIdD 23Table2.(Continued,Page9of10)SantalaceaeGeocaulonlividum(Richards.)Fern.SaxifragaceaeSandalwoodUBoykiniarichardsonii(Hook.)GrayLeptarrhenapyrolifolia(D.Don)Ser.ParnassiapalustrisL.ParnassiakotzebueiCham.&Schlecht.Parnassiasp.RibeshudsonianumRichards..RibeslaxiflorumPursh(maybeR.--g]andulosum)RibestristePall.saxlfragabronchialisL.SaxifragadavuricaWilld.SaxifragafoliolosaR.Br.SaxifragahieracifoliaWaldst.&Kit.SaxifragalyalliiEnglerSaxifragaoppositifoliaL.SaxifragapunctataL.SaxifragaserpyllifoliaPurshSaxifragatricuspidataRottb.ScrophulariaceaeCastillejacaudata(Pennell)Rebr.PediculariscapitataAdamsPediculariskaneiDurandPedicularislabradoricaWirsingPedicularisparvifloraJ.E.Sm.var.parvifloraPedicularissudeticaWilld.PedicularisverticillataL.VeronicawormskjoldiiRoem.&Schult.RichardsonboykiniaULeather-leafsaxifrageUNorthernGrass-of-ParnassusUKotzebueGrass-of-ParnassusUGrassofParnassus0Northernblackcurrant0Trailingblackcurrant0RedcurrantU 0SpottedsaxifrageUSaxifrageUFoliosesaxifrageUHawkweed-leafsaxifrageURed-stemsaxifrageUPurplemountainsuihageUBrooksaxifrageUThyme-leafsaxifrageUThree-toothsaxifrageUPaleIndianpaintbrushUCapitatelousewortUKanelousewortULabradorlousewortULousewortULousewortUWhorledlousewortUAlpinespeedwellUUmbelliferae(Apiaceae)AngelicalucidaL.HeracleumlanatumMichx.ValerianaceaeValerianacapitataPall.ViolaceaeViolaepipsilaLedeb.ViolalangsdorffiFisch.WildceleryCowparsnipCapitatevalerianMarshvioletVioletUU 0UUU 24Table2.(Continued,Page10of10)NonvascularPlantSpeciesLichensD.Cetrariacucullata(Bell.)Ach.Cetrariaislandica(L.)Ach.Cetrarianivalis(L.)Ach.CetrariarichardsoniiHook.Cetrariaspp.Cladoniaalpetris(L.)Rabenh.CladoniamitisSandst.Cladoniarangiferina(L.)Web.Cladoniaspp.Dactylinaarctica(Hook.)Nyl.Haematommasp.Lobarialinita(Ach)Rabh.Nephromaspp.PeHigeraspp.Rhizocarponeorahicum(L.)DC.StereocaulonpaschaleL.)Hoffm.Thamnoliavermicularis(Sw.)Schaer.Umbilicariasp.MossesUUUUUUUUUUUUUUUDUUClimaciumsp.UHypnumspp.andotherfeathermosn~sUPaludellasguarrosa·(Hedw.)Brid.-UPolytrichumspp.U DPtiliumcrista-castrensis(Hedw.)DeNot.URhacomitriurnspp.UDSphagnumspp.UD~VascularplantspeciesnomenclatureaccordingtoHulten(1968)exceptwherenoted.LichennomenclatureaccordingtoThomson(1979).MossnomenclatureaccordingtoConard(1979).£INomenclatureaccordingtoWelsh(1974).£!NomenclatureaccordingtoViereckandLittle£INomenclatureaccordingtoCrum(1976).(1972). 25drainagefartherthanbotanicalrecordspreviouslyindicated.ActuallY,thisfindingistobeexpectedbecauseofthepaucityofcollectionsintheupperSusitnaRiverbasinpriortothisstudy.AlistofthosespeciesdiscoveredintheupperbasinwhichareoutsideoftherangereportedbyHulten(1968)arelistedinTable3.3.3-Vegetation/HabitatTypeMapsThefollowingvegetation/habitattypemapswereproducedfortheevaluationofimpactsonvegetationresources:a1:250,000scalemapofentireupperbasin(Figure6,backpocket);1:63,360scalemapsoftransmissioncorridors(Figures7and8),accessroute,andthearealocated16kmoneithersideoftheSusitnaRiverbetweenGoldCreekandtheMaclarenRiver(Figure9);anda 1:24,000scalemapofimpoundmentareasand1kmbufferzone,otherdirectimpactareas,andthefloodplainfromDevilCanyontoTalkeetna(Figure10).Awetlandmapwaspreparedfromthe1:24,000scalemapsandispresentedunderSection3.5-Wetlands.Allthevegetation/habitatmaps,exceptthe1:250,000scalemapincludedinthebackpocket,havebeengreatlYreducedinsize.Usersofthemapsareremindedthatthereisseldomadistinctlineofdemarcationbetweenvegetation/habitattypeseitherviewedinthefieldoronaerialphotographs.Delineationofvegetation/habitattypesrequiresconstantjudgmentbythecartographerastotheboundariesofeachtype.Anotherconsiderationisthatthesmallestmappableunitpracticalis260,16,and3hectaresfor1:250,000,1:63,360,and1:24,000scalemaps,respectively.Consequently,somemappingunitsonthelargerscalemaps(1:24,000and1:63,360)aremorespecificthanthoseonthesmallerscalemap(1:250,000).Themaindifferencesresultedbyeliminatingcomplexesanddelineatingforestedareasbydominanttreespeciesonthelargerscalemaps.TheViereckandDyrness(1980)preliminaryvegetationclassificationwasusedforthemappingandofferedastandardnomenclaturewhichotherstudiesontheSusitnaprojectcouldalsouseandhaveconsistentresults.LevelIIInameswereusedinmostcases.However,LevelIVnameswereusedforforestedareasonthe1:24,000and1:63,360scalemaps.InmostcasesthekeypresentedbyViereckandDyrness(1980)wasadequateforclassificationonlyatLevelsIthroughIII,presumablYbecausetheclassificationispreliminaryandlackssufficientinformationtoconsistentlyidentifyvegetationatLevelsIVandV.Also,U-2aerialimageryisnotconsistentlyinterpretableatlowerhierarchicallevelsinthispreliminaryclassification.Forthesereasons,LevelIIIwasused.(a)UpperBasinForest,tundra,andshrublandwerethebasictypesfoundintheupperSusitnaRiverbasin.Forestcommunitieswerethosewithatleast10%coverbytreespeciesregardlessofthetrees'heights.Shrublandcommunitieshadatleast25%coveroferecttodecumbentshrubsbutwerenotlocatedbeyondtheelevationallimitoftrees.Tundrastandswerethosecommunitiesaboveorbeyondtheelevationallimitoftreesandweredominatedbyshruborherbaceousspecies.Al'.S·'v.'\~,,"rr',,,,,,ri-rI!""ARYf)'.11,,','..j'""~dot'~'Lr.1\:.l·.·./I-.'~..,\\·~hJt..l!;;,~k._.-U.S.Dep;:u'''''''''''"<Ii.l/l:$"""'~'.:iF 26Table3.VascularplantspeciesintheupperSusitnaRiverbasinanddownstreamareaswhichareoutsidetheirrangeasreportedbyHulten(1968).UpperBasinExtensions:EquisetumfluviatileLycopodiumselagossp.selagoLycopodiu~cowplanatumPlceamarlana-CarexfilifoliaoanthOniaintermediaLuzulawahlenbergiiVeratrumvirideb/Listeracordata-PlatantheraconvallariaefoliaPlatantherahyperboreaPlatantheradilatataEchinopanaxhorridumSeneciosheJ?onensisMyrica~RanunculusoccidentalisPotentillabif,loraRubusidaeus~RubuspedatusPediculariskaneikaneiPedicularisparvif~PotamogetonrobbinsiiDownstreamExtensions:Echinopanax89rridumRubusidaeusScirpusmicrocarpusGaliumtriflorumAlnustenuifoliaCircaeaalpinaActaearubraRibeshudsonianumE!ArnlCachamissonisSwamphorsetailFirclubmossGroundcedarBlackspruceThread-leafsedgeTimberoatgrassWahlenbergwoodrushHeleboreHeart-leavedtwinbladeNorthernbog-orchisNorthernbog-orchisWhitebog-orchisDevil'sclubSheldongroundselSweetgaleWesternbuttercupTwo-flowercinquefoilRaspberryFive-leafbrambleKanelousewortLousewortRobbinspondweedDevil'sclubRaspberrySmall-fruitbullrushSweet-scentedbedstrawThinleafalderEnchanter'snightshadeBaneberryNorthernblackcurrantArnicatheupperSusitnaRiverbasinin~ViereckandLittle(1972)includetherangeofthisspecies.Q/ThisspecieswasrecordedbythebirdandsmallmammalsurveygroupfromtheUniversityofAlaskaMuseum.£!ViereckandLittle(1972)includedownstreamareaintherangeofthisspecies. 27Figure6illustratesthegeneraloveralldistributionofvegetation/habitattypes,andTable4givesthepercentagesforcoverbyeachtypeintheupperSusitnaRiverbasin.However,itshouldberememberedthatmuchdetailislostattherelativelysmallscaleofFigure6.Figure9islargerscale,providingmoredetailthanFigure6,butitcoversonlytheimpactareasoftheupperbasin.Table5liststhepercentagesforcoveroftypesdelineatedinFigure9.Asa.resultofthesescaledifferences,totalhectaresforsometypesappeartodisagreewhencomputedfromthetwodifferentmaps.Forexample,closedbirchforestswereoftentoosmalltobedelineatedatthesmallerscaleofFigure6butwerecircumscribableatthelargerscaleofFigure9,andthus,thereisanapparentdiscrepancyinthetotalnumberofhectarescomputedfromeachmap.ConiferforestscoverapproximatelY19%oftheupperbasin(Figure6,Table4).Theyoccupyawiderangeofsites,fromthefloodplainstothemountains,butseldomabove975melevation.ConiferforestsarerelativelYmoreextensive(25%oftotalarea)intheimpactareas(Figure9,Table5)thanintheupperbasingenerally.Thisisbecausetheimpactareasarerestrictedtolowerelevationswhereconiferforestsarelocated.Deciduousforests(birch,aspen,andbalsampoplar)andmixedconifer-deciduousforestsaremuchmorerestrictedindistributionthantheconifertypes,togethercoveringonly2.5%ofupperbasin(Figure6,Table4).Thesevegetation/habitattypesarefoundprimarilyonsouth-facingslopesbelow700melevation,andthus,aregenerallYlocatedoncanyonsidesorthefloodplain.Balsampoplarstandsarefoundonlyonthefloodplain(Figure9).Thefactthatdeciduousandmixedconifer-deciduousforestsarerestrictedtotheimpactareasisevidentinthatthesetypesrepresentnearlY6%oftheareadescribedontheimpactareamap(Figure9,Table5).Tundravegetation/habitattypesaregenerallylocatedaboveorbeyond·thelimitofforests.ApproximatelY24%oftheupperbasiniscoveredwithtundra(Figure6,Table4).Mesicorwetsedgegrasstypesdominateroughlyhalfofthetundra.Matandcushiontundraandcomplexesofmatandcushion/sedgegrasstundrarepresentmostoftheremainingtundrasituations.Becausethetundratypesarecharacteristicofhighelevations(>975m)intheregion,theirdistributionisprimarilyassociatedwiththemountainsoftheAlaskaRangeandtheTalkeetnaMountains(Figure6).OnlyinthevicinityofDevilCanyonandJayCreekaretheresubstantialhectareagesoftundraincloseproximitytotheimpactareas(Figure9,Table5).Matandcushiontundraisrelativelymoreabundantintheimpactareathantheupperbasin(14%vs4%)becausenearlyallofthematandcushiontundrafoundintheupperbasinislocatedwithintheboundsoftheareadescribedinFigure9.Shrublandisthelargestoverallgroupofvegetation/habitattypesoccurringintheupperbasin,coveringalmost40%ofthetotalarea(Figure6,Table4):30%iscoveredbyshrubbirchandwillow.Thesetypesarefoundatintermediateandlowelevationsthroughoutthebasin,butprimarilyonthebroadflatareasinthecentral,southernandnortheasternportionsofthebasin.Tallshrub,dominatedbyalder,istheotherprincipalcomponentoftheshrubland,occupying8%and7%of 28Table4.Hectaresandpercentageoftotalareacoveredbyvegetation/habitattypesintheupperSusitnaRiverbasin(aboveGoldCreek).~/b/PercentofVegetation/HabitatTypeHectaresTotalAreaTotalVegetation1,387,60785.08Forest348,23221.35Conifer307,58618.86WoodlandSpruce188,39111.55Openspruce118,8737.29Closedspruce3230.02Deciduous1,2900.08Openbirch9680.06Closedbirch3230.02Mixed"39,3552.41Open23,3871.43Closed15,9680.98Tundra394,68524.20Wetsedge9rass4,8390.30(Mesic)sedge9rass184,35811.30Herbaceousalpine8070.05Matandcushion65,0013.99Matandcushion/sedgegrass139,6808.56Shrub1and644,69039.53Ta11shrub129,0357.91Lowshrub515,65531.62Birch33,5492.06Wi11ow10,6450.65Mixed471,46128.91Unvegetated243,39214.92Water39,8402.44Lakes25,1621.54Rivers14,6780.90Rock113,7126.97Snowandice8918415.51TotalArea1,630,999100.00a/Basedonmapsproducedatascaleof1:250,000.b/DifferencesinresolutionasaresultofdifferencesinscalemayresultinsomediscrepanciesforcommonareasbetweenthesefiguresandthosepresentedinTable5. 29Table5.Hectaresandpercentageoftotalareacoveredbyvegetation/habitattypesforthearea16kmoneithersideoftheSusitnaRiverfromGoldCreektotheMaclarenRiver.~Vegetation/HabitatTypeForestConiferWoodlandspruce-blackWoodlandspruce-whiteOpenspruce-blackOpenspruce-whiteDeciduousOpenbirchClosedbirchClosedbalsampoplarMixedOpenconiferdeciduousClosedconiferdeciduousTundraWetsedgegrassSedgegrassSedgeshrubMatandcushionShrub1andOpentallshrubClosedtallshrubBirchshrubWillowshrubMixedlowshrubHerbaceousGrassland.DisturbedUnvegetatedRockSnowandiceWaterRiverLakeTotalAreab/Hectares142,306115,04862,99313,29128,30410,4604,3931,4982,32457122,8659,63913,226114,7283,51727,50520,07363,633177,26415,52415,76742,8808,23094,863181,0792426,97916,6032494,2365,891462,398PercentofTotalArea30.7524.8713.622.876.122.26.940.320.500.124.942.082.8624.810.765.954.3413.7638.343.363.419.271.7820.520.010.230.015.833.590.050.921.2799.98a/Basedonmapsproducedatascaleof1:63,360.b/DifferencesinresolutionasaresultofdifferencesinmapscalemayresultinsomediscrepanciesforcommonareasbetweenthesefiguresandthosepresentedinTable4. 30theupperbasinrespectively.AlderisfoundinsteepterrainthroughoutthebasinandinlargeexpansesatthewesternendofthebasinnearPortageCreek.Forthemostpart,shrub1andwasequallyimportantinboththeupperbasin(Figure6)andtheimpactarea(Figure9).Fifteenpercentoftheupperbasinisclassifiedasunvegetated(Figure6,Table4).Theseareasconsistprimarilyofrock,snoworiceandweremostcommonatthehighestelevations(i.e.,themountaintops).Thus,relativelYlittleoftheimpactareaisunvegetated.(b)DownstreamFloodplaintoTalkeetnaOpenandclosedbalsampoplarstandsarethepredominantvegetationtypesfoundonthefloodplaindownstreamtoTalkeetna;closedtallshrubisimportanttoalesserextent.Theextentofmapcoverage(Figure10)ofthisareaislimitedtothefloodplain,whichisverynarrowanddiscontinuousinthisreachoftheriver.(c)TransmissionCorridors(i)Centra1(DamstoIntertie)Allthreetransmissioncorridorsweremappedatthe1:63,360scale.However,themapofthecentralcorridorisnotseparatefromthatoftheimpactareamapwhichextends16kminalldirectionsfromtheupperSusitnaRiver.Importantvegetationtypesinthecentraltransmissioncorridorincludedtallshrubonsteepembankments(Figure9,Table6).Openspruceforestsoccurredonslopesandbencheswhereasmixedandbirchforestswerefoundongentleslopesandbenches.Higherelevationtypes includedmatandcushiontundraandsedge-shrubtundra.AreacoveredbyeachtypeispresentedinTable6.(ii)Willow-CookInletTheWillow-CookInletcorridorincludesatotalofapproximately38,000hectares(Table7).ItpassesthroughrelativelYflatterrainwhichis67%forestedpredominantlywithconifer-deciduousforestsinterspersedwithapproximately24%smallandlargewetsedge-grassmeadows(Figure7,Table7).(iii)Healy-FairbanksTheHealy-Fairbankscorridorpassesthroughadissectedplateauinthesouthernsection,theTananaFlatsinthemiddle,andtheChenaRidgeonthenorth.Differentvegetation/habitattypesareassociatedwitheachofthesethreesegments.Thesouthernportionofthecorridorcharacteristicallyhasopenspruceandopenspruce/deciduoustypesalongtheridges,withlowshrubandsedge-grassoccupyingtheflatterareas.Thecentralsegmentiscoveredbyacomplexmosaicofwetvegetationtypes,openspruce,andlowshrub.Thegradationsbetweentypesandmanyunmappab1esmallpatchesofvegetation"madeitnecessarytomapmuchofthisareaascomplexes.TheChenaRidgesegmentispredominantlycoveredbyopenandcloseddeciduousforest(Figure8).Foresttypesaccountedfor 31Table6.Hectaresandpercentoftotalareacoveredbyvegetation/habitattypeswithinthedamtointertie(central)transmissioncorridor.PercentofVegetation/HabitatTypeHectaresTota1AreaForest34,38836.3Woodlandspruce-black3,0283.2Woodlandspruce-white4,9575.2Openspruce-black2,5272.7Openspruce-white4,2844.5Openbirch806.9Closedbirch1,7491.8Closedbalsampoplar449.5Openconifer-deciduous5,1195.4Closedconifer-deciduous11,46912.1Tundra24,97526.3Wetsedge-grass314.3Sedgegrass3,6703.9Sedgeshrub5,8706.2Matandcushion15,12115.9Shrubland31,54833.3Opentallshrub4,7175.0Closedtallshrub5,6966.0Birchshrub10,90911.5Wi11owshrub1,1691.2Mixedlowshrub9,0579.6Grassland109.1Oisturbed10.01Unvegetated3,7784.0Lake698.7River1,4381.5Rock1,6421.7--TotalArea94,808100.0 32Table7.Hectaresandpercentoftotalareacovered'byvegetation/habitattypeswithintheWillowtoCookInlettransmissioncorridor.PercentofVegetation/HabitatTypeHectaresTotalAreaForest25,85167.0Woodlandspruce2,4576.3Openspruce3,4028.8Closedspruce3,2268.4Openbirch16'.04Closedbirch3,6389.4Openbalsampoplar100.3Closedbalsampoplar172.5Openconifer-deciduous1,6974.4Closedconifer-deciduous11,14328.9Wetsedge-grass9,12323.7Shrubland2,2135.7Closedtallshrub92.2Lowmixedshrub2,1215.5Lakes1,0112.6Disturbed3811.0---TotalArea38,579100.0 33almost78%ofthiscorridorwiththeopenforesttypesbeingthedominantform(Table8).Opensprucecovered28.5%ofthearea;opendeciduous11.37%;andopenmixedconifer-deciduous11.2%(Table8).3.4-Vegetation/HabitatTypeDescriptions(a)UpperBasin(i)ForestForestvegetation/habitattypeswerelocatedatthelowerelevationsoftheupperbasin(Figures6and9).Theaverageelevationofsampledareaswas523m.Theseforesttypesweredividedaccordingtothedominanttreetypes(conifer,deciduous,ormixed)andthenbytreecrowncoverpercentage.Deciduousandconifertypeshadatleast75%ofthetreecoverprovidedbyeitherdeciduousorconifertrees,respectively.Thewoodlandtypehadbetween10%and25%treecoverandwasonlyobservedforconiferstands.Openstandscontained25%to50%treecover,whileclosedstandshadover50%treecover.Theboundarypercentagebetweenopenandclosedtypeswas'chosenas50%ratherthanthe60%thatViereckandDyrness(1980)used,sinceitwaseasiertoestimateontheaerialphotographsandinthefield.Fieldestimates.wereperformedbestfromtheairbecausetheVenetianblindeffectofthetreescausedoverestimatesfromtheground.Conifer,deciduous,andmixedstandswereobservedinthefieldwithopencanopieswhileonlydeciduousandmixedstandswithclosedcanopieswerelocatedinthefield.OneclosedconiferareathatappearedontheaerialphotographsintheLakeLouiseareawasnotfieldchecked.Allforestedstandshadalmostcompletevegetationcoverwith80%-95%groundlayercover.-SpruceForestsSprucestandsweredominatedeitherbywhitespruce(Piceaglauca)orblackspruce(Piceamari,ana)andcontainedawell-developedgroundlayer,whichitselfaccountedformostofthevegetationcover(Tables9and10).Thelayerstructureofopenblackandwhitesprucestandswassimilar,exceptthatwhitesprucestandscontainedmoreoverstory,areflectionofthegenerallylargersizeofwhitesprucetrees(Tables11and12).Theseunitsweremappedonlyatthe1:24,000and1:63,360scales(Figures10and9).Anotherdifferencewasthattheoverstoryinopenwhitesprucestandswaslessvariableinheightamongstandsthanwastheoverstoryinblack'sprucestands.Maximumoverstoryheightsoftreesinopenblacksprucetypesvariedfromabout5to11mwhile whitesprucestandsreachedheightsof20m.TheforestcanopY·consistedprimarilyofonespecies,andtreesaveraged15to30cm/dbh.Afewcoresoflargertreesinsomeareasindicatedthatwhitesprucemayrangeinagefrom34to78yearswhilesampledblacksprucemaybe77to171yearsold.Severalwhitesprucestandswereinareasrecoveringfromdisturbances,suchasfire,whileblacksprucestandswerelessrecentlydisturbed,thusaccountingforsomeoftheagedifferences.Opensprucestandswereusuallyfoundonslopesorflatlandsalongthe 34Table8.Hectaresandpercentoftotalareacoveredbyvegetation/habitattypeswithintheHealytoFairbankstransmissioncorridor.a/Vegetation/HabitatType-ForestWoodlandspruceOpenspruceClosedspruceWoodlanddeciduousOpendeciduousCloseddeciduousWoodlandconifer-deciduousOpenconifer-deciduousClosedconifer-deciduousOpenspruce/opendeciduousOpenspruce/wetsedge-grass/opendeciduousOpenspruce/lowshrub/wetsedge-grass/opendeciduousOpenspruce/lowshrubTundraWetsedge-grassSedgegrassSedgeshrubSedge-grass/matandcushionShrublandlowmixedshrubwillowshrublowshrub/wetsedge-grassAgriculturallandDisturbedUnvegetatedLakesRiverGravelTotalAreaHectares86,8301,81231,7391,34799312,55310,38496112,5024,1259481,9937,0084654,4072,2682775661,29617,19915,405581,7361754312,4671962,143128111,509PercentofTotalArea77.91.628.51.2.911.39.30.911.23.70.91.86.30.43.92.00.2.51.215.413.8.051.6.2.42.2.21.9.1100.00a/TheTananaFlatsportionofthetransmissioncorridorisanareaof-extremelycomplexmosaicsofvariousvegetationtypes.Asaresult,variouscomplexeswererecognized. 35-Table9.Coverpercentagesfortotalvegetation,verticalstra~7'andplantspeciesinopenconifervegetation/habitattype-inupperSusitnaRiverbasin,summer1980.CategoryAverageb/Cover(%)-TotalvegetationOverstory(>10cmdbh)PiceaglaucaPiceamarianaUnderstorY(2.5-10cmdbh)PiceaglaucaPiceamarianaWhitespruceBlackspruceWhitespruceBlackspruce98242421032Shrublayer(>0.5mtall,<PiceaglaucaPiceamarianaGroundlayer«0.5mtall)Mosses,unidentifiedFeathermossesPtiliumspp.EmpetrumnigrumLedumdecumbensVacciniumuliginosumVacciniumvitis-idaeaEquisetumarvenseEquisetumsilvaticumLinnaeaborealisPiceamarianaCalamagrostiscanadensis2.5cmdbh)WhitespruceBlackspruceFeathermossCrowberrYNorthernLabradorteaBogblueberryMountaincranberryt-1eadowhorsetailWoodlandhorsetailTwinflowerBlackspruceBluejoint513941129136576688114~Numberofareassampledwas9.Q!Includesonlythosespecieswithatleast5%coverinanyoneareasampled. 36Table10.Coverpercentagesfor.totalvegetation,verticalstrata,g?dplantspeciesinwoodlandconifervegetation/habitattype-inupperSusitnaRiverbasin,summer1980.Shrublayer(>0.5mtall,<2.5cmdbh)PiceamarianaBlackspruceCategoryTotalvegetationOverstory(>10cmdbh)PiceaglaucaUnderstorY(2.5-10cmdbh)PiceamarianaGroundlayer«0.5mtall)FeathermossesSphagnumspp.EmpetrumnigrumLedumdecumbensLedumgroenlandicumVacciniumuliginosumEquisetumsilvaticumRubusarcticusRubuschamaemorusPiceamarianaCarexbigelowiiCarexspp.HhitespruceBlackspruceFeathermossSphagnummossCrowberryNorthernLabradorteaLabradorteaBogblueberryHoodlandhorsetailNagoonberryCloudberryBlackspruceBigelowsedgeSedgeAverageb/Cover(%)-99112111715935628552310155376~Numberofareassampledwas6.Q/Includesonlythosespecieswithatleast5%coverinanyoneareasampled. 37Table11.Coverpercentagesfortotalvegetation,verticalstrata,an?plantspeciesinopenblacksprucevegetation/habitattype~inupperSusitnaRiverbasin,summer1980.CategoryTotalvegetationOverstory(>10cmdbh)PiceaglaucaPiceamarianaUnderstory(2.5-10cmdbh)PiceaglaucaPiceamarianaShrublayer(>0.5mtall,<2.5PiceamarianaSalixspp.Groundlayer«0.5mtall)Mosses,unidentifiedFeathermossesC1adoniaspp.EmpetrumnigrumLedumdecumbensvacclniumu1iginosumVacciniumvitis-idaeaEquisetumsi1vaticumSalixspp.Piceamariana--WhitespruceBlackspruceWhitespruceBlacksprucecmdbh)BlackspruceWi11owFeathermossCrowberryNorthernLabradorteaBogblueberryMountaincranberryWoodlandhorsetailWi11owBlackspruceAverageb/Cover(%)-961413510457829334307141410151274~Numberofareassampledwas3.Q!Includesonlythosespecieswithatleast5%coverinanyoneareasampled. 38Table12.Coverpercentagesfortotalvegetation,verticalstrata,ang/plantspeciesinopenwhitesprucevegetation/habitattype-inupperSusitnaRiverbasin,summer1980.MeadowhorsetailWoodlandhorsetailTwinflowerResinbirchPricklYroseBluejointCategoryTotalvegetationOverstory(>10cmdbh)PiceaglaucaUnderstory(2.5-10cmdbh)PiceaglaucaAliiUSsinuataShrublayer(>0:5mtall,c2.5PiceaglaucaAlnuscrispaRosaadcularisGroundlayer(cO.5mtall)FeathermossesPtiliumspp.EquisetumarvenseEquisetumsilvaticumLinnaeaborealisBetulaglandulosaRosaaciculariscaramagrostiscanadensisWhitespruceWhitespruceSitkaaldercmdbh)WhitespruceAmericangreenPricklyroseFeathermossalderAverageb/Cover(%)-100353511364143943024116156523~Numberofareassampledwas5.£IIncludedonlythosespecieswithatleast5%coverinanyoneareasampled. 39riversatelevationsaveraging487m.Overstoryprovidedalmostone-fourthcoveronopenstandswhichcontainedtreesseveralmeterstall(Table9).Whilethewhitesprucecoverwasconcentratedintheoverstorylayer,mostoftheblacksprucetreecoverwascontainedintheshrublayer(Tables11and12).Blacksprucestandscontainedlowshrubs,suchascrowberry(Emetrumnigrum),northernLabradortea(Ledumdecumbens),bogblueberryVacciniumuliginosum),andmountaincranberry(~;vitis-idaea)inthegroundlayer,whilepricklYrose(Rosaacicularis)andbluejoint(Calamagrostiscanadensis)werethemostimportantgroundlayerspeciesinopenwhitespruce(Tables.11and12).Twin-flower(Linnaeaborealis)wasimportantinthewhitesprucestandsbutwasnotobservedintheblacksprucestands,possiblyreflectingthatgroundspecies'preferenceforbetter-drainedsoils.Ineachofthemappingunits,30to35identifiedspecieswereencountered.Intheseopenwhiteandblacksprucestands,coveroffeathermossesequaledthatofthetrees(Tables11and12).Lowshrubs,suchascrowberry,northernLabradortea,bogblueberry,andmountaincranberryaccountedformuchofthewoodygroundlayer(Tables11and12).Importantherbaceousspeci~sincluded'bluejointandhorsetails(Equisetumspp.)(Tables11and12).NorthernLabradortea,Labradortea(Ledumgroenlandicum),bogblueberry,mountaincranberry,andsphagnumandfeathermosseswerefoundinblackspruceforestsintheupperSusitnaRiverbasinandwereimportantalongtheChenaRiverininteriorAlaska(Viereck1970).Crowberry,nagoon-berryandwoodlandhorsetail(Equisetumsilvaticum)werealsoimportantinblacksprucestands;however,thesespecieswerenotreportedalongtheChenaRiverbyViereck(1970).Meadowhorsetail(Equisetumarvense)andfeathermossesprovidedsignifi-cantamountsofcoverinwhitesprucestandsalongtheChenaRiver(Viereck1970)andintheupperSusitnaRiverbasin,butbluejoint,twin-flower,andthemoSsPtiliumcrista-castrensiswereapparentlymoreimportantalongtheSusitnaRiverthanalongtheChena.HettingerandJanz(1974)reportedthatfeathermosseswereimportantinthegroundlayerofwhitesprucestandsinnortheasternAlaska,whichagreedwithourresults.Theyalsofoundcrowberrytobeanimportantspecies,butthisaccountedforlessthan2%coverintheSusitnastands.Allwoodlandsprucestandsvisitedwereblackspruce.Hereitwasobservedthat,unlikeopensprucestands,woodlandstandswerecomposedofscattered,stuntedtrees,andtheoverstorywasalmostnegligible(Table10).Onereasonforthispatternisthatthisvegetation/habitattypewas'usuallyfoundontherelativelylevelbencheswheresoilswerepoorlydrained.Averageelevationofsampledareaswas620m.Theresultingtreeswereusually,toosmalltoqualifyfortheoverstorylayerbecausetrunkswere<10cmdbh.Maximumheightswerelessthan2minsomeareas.Inthesewoodlandstands,sphagnummosses,notfeathermosses,werethemostimportantcoverspecies;importantgroundlayerspeciesincludedsedges(Carexspp.),woodlandhorsetail,andlowshrubssimilartothosefoundin~opensprucestands(Table10).Slightlyover30identifiedspecieswereencounteredinthewoodlandsprucevegetation/habitattype. 40Woodlandsprucesitesgradedintoboggyareaswheretreecovermightbelessthan10%andthevegetationresembledmuskegs.Lowbirchshrubstandsandwoodlandsprucewerefrequentlydifficulttodistinguishinthefieldbecausebirchstandssometimeshadscatteredtreeswhich,onoccasion,producedalmost10%cover.Onaerialphotographs,theoverallpatterncreatedbysmalltreesproducedsimilartexturesforwoodlandspruceandforlowbirchshrubsites.Thisphenomenon,alongwiththefactthattheseareastookonasimilarcolorwhenphotographed(darkgray),madedistinguishingbetweenthemdifficult.Amongblacksprucestands,thoseoccupyingsignificantslopes(8-10°)appearedtobemoreproductiveofbrowsespeciesand,infact,receivednoticeablYgreaterusebymoosethandidotherblackspruceareas.Comparedtoothervegetationtypes,browseproductionwaslow,butsincethebrowsehadincurredheavyuse,suchstandsappearedtoprovideimportantcoverareasduringsevereweather.Openblacksprucestandsontheflatsweregenerallyverypoorintermsofforageproduction,butsomecaribousignwaspresent.Skoog(1968)consideredthisforesttypetorepresentagoodsupplyofterrestrialforagelichensforcaribouinwinter.-DeciduousForestsBalsampoplar(Poulusbalsamifera),paperbirch(Betulapapyrifera),andtremblingaspenPopulustremuloides)standscomprisedthedeciduoustypes.Theyusuallyhadagreateroverstorycoverthansprucestands,becauseindividualdeciduoustreesproducedmorefoliagecoverthanindividualconifertrees.Thesetypeswererestrictedmostlytothesteepbanksandfloodplainalongtheriver(Figures6and9).Elevationsaveraged582mwithclosedstandsoccurringataverageelevationsof560mandopenstandsat625m.Theyhadalmostcompletevegetationcover,withanespeciallywell-developedgroundlayer.Whiletheoverstorylayerinclosedstandscoveredalmostthree-fourthsofthearea,itonlycoveredaboutthree-eighthsinopenstands(Tables13and14).Overstorywassometimes15mtall,andinthebalsampoplarstandseventaller.Dbh'srangedfrom15to30cm.Paperbirch,tremblingaspen,orbalsampoplardominatedtheforestcanopy,whichconsistedofonespecies.Importantwoodyspeciesinthegroundlayerinbothtypesincludedcrowberry,northernLabradortea,bogblueberry,andmountaincranberry.Openstandsappearedtohavemorewoodycoverinthegroundlayerthandidtheclosedstands,whileclosedstandshadmoreherbaceouscomponents,suchasbunchberry(Cornuscanadensis),bluejoint,andoakfern(Gymnocarpiumdryopteris).Approximately16specieswereidentifiedinopendeciduousforesttypeswhileabout31werefoundincloseddeciduousforests.Closeddeciduousstandswereseparatedonthe1:63,360scalemap(Figure9)accordingtothedominantspecies:balsampoplarandpaperbirch.Smallstandsoftremblingaspenalsooccuredbuttheywereusuallylessthanthesmallestmappableunit.Closedbalsampoplargenerallyoccurredonislandsintheriverorflatareasalongside theriver.Balsampoplarwasusuallythefirsttreeinthesuccessionalstageofvegetation 41Table13.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesincloseddeciduoMlforest(birchandbalsampoplar)vegetation/habitattype-inupperSusitnaRiverbasin,summer1980.CategoryAverageb/Cover(%)-Totalvegetation99764542073415241902659152010538119106CrowberryNorthernLabradorteaBogblueberrYMountaincranberryWoodlandhorsetailBunchberryBalsampoplarBluejointOak-fernTallbluebellWhitesprucePaperbirchBalsampoplarWhitesprucePaperbirchBalsampoplar<2.5cmdbh)WhitesprucePaperbirchBalsampoplarGroundlayer«0.5mtall)Ptiliurnspp.Polytrichumspp.EmpetrumnigrumLedumdecumbensVacciniumuliginosumVacciniumvitis-idaeaEquisetumsilvaticumCornuscanadensisPopulusbalsamiferaCalamagrostiscanadensisGymnocarpiumdryopterisMertensiapaniculataOverstory(>10cmdbh)PiceaglaucaBetulapapyriferaPopulusbalsamiferaUnderstory(2.5-10cmdbh)PiceaglaucaBetulapapyriferaPopulusbalsamiferaShrublayer(>0.5mtall,PiceaglaucaBetUlapapyriferaPopulusbalsamifera~Numberofareassampledwas4.Q!Includesonlythosespecieswithatleast5%coverinanyoneareasampled. 42Table14.Coverpercentagesfortotalvegetation,verticalstrata,andPlan£/speciesinopenbirchdeciduousforestvegetation/habitattype-inupperSusitnaRiverbasin,summer1980.CategoryTotalvegetationOverstory(>10cmdbh)PiceaglaucaBetUlapapyriferaUnderstorY(2.5-10cmdbh)PiceaglaucaBetulapapyriferaShrublayer(>0.5mtall,<2.5PiceaglaucaBetulapapyriferaGroundlayer«0.5mtall)Polytrichumspp.LedumdecumbensLedumgroenlandicumVacciniumuliginosumVacciniumvitis-idaeaCornuscanadensisRosaacicularisP"l"CeaglaucaWhitesprucePaperbirchWhitesprucePaperbirchcmdbh)WhitesprucePaperbirchNorthernLabradorteaLabradorteaBogblueberryMountaincranberryBunchberryPricklYroseWhitespruceAverageb/Cover(%)-99383386165229510201230261153~Numberofareassampledwas2.£IIncludesonlythosespecieswithatleast5%coverinanyoneareasampled. 43developmentonalluvialdeposits.Thebalsampoplartreesprovidedaboutthree-fourthscoverintheoverstorywithrelativelyunimportantunderstoryandshrublayers(Table15).Thegroundlayerwaswelldevelopedandincludedbunchberry,crowberry,northernLabradortea,bogblueberry,andmountaincranberry.Theseareascontained14identifiedspecies.Closedpaperbirchstandsoccurredonsteep,usuallysouth-facingslopes.Theverticallayerstructureissimilartotheclosedbalsampoplarstands:three-fourthsoverstory,awell-developedgroundlayer,andrelativelyunimportantshrubandunderstorylayers(Table16).Paperbirchwasprevalentintheoverstory,withafewscatteredwhitespruce.Themostimportantgroundlayerspecieswerebunchberry,bogblueberry,bluejoint,andoakfern.Approximately25specieswereidentified.Theminor,closedtremblingaspenstandswereusuallyfoundontheupperportionsofdry,south-facingslopes.Thegeneralstructurewassimilartoothercloseddeciduousstandsinthattherewerewell-developedoverstoryandgroundlayersbutinsignificantshrubandunderstorylayers(Table17).Theonestandthatwasvisitedhadagesrangingfrom9to24years.HettingerandJanz(1974)reportedmountaincranberryandbluejointasmajorspeciesinbirchforeststandsinnortheasternAlaska,whichwasinagreementwiththeSusitnaresults.However,feathermossesandaldershrubs,.which.theyalsofound-tobeimportant,wereinsignificantintheupperSusitnaarea.TheundergrowthintheSusitnastandswastallerthanthatpicturedinHettingerandJanz's(1974)publication.TheSusitnastandscontainedbunchberry,northernLabradortea,Labradortea,andbogblueberryasimportantspecieswhichwerenotconsideredimportantintheotherstudy.Bothstudiesreportedthatbirchstandsoccurredondisturbedsiteswithsouthernexposures.-MixedConifer-DeciduousForestsThemixedconifer-deciduousvegetation/habitattypeshadoverstorycoverintermediatebetweenthatforsprucestandsandthatfordeciduousstands.ThistypicalinteriorAlaskaforesttypeisdominatedbywhitespruceandpaperbirch.Elevationsformixedconiferdeciduousforestsaveraged466mwithclosedstandshavingameanelevationnear425mandopenstandsoccurringaround482m.MostofthelargerstandsoccurredonslopesdownstreamfromTsusenaCreek(Figure9).ThesewereprobablYsuccessionalstandswhichdevelopedassprucereplaceddeciduoustrees.Coverinthesevegetation/habitattypeswasalmostcompletewithawell-developedgroundlayercontainingimportantamountsofbluejoint,bunchberry,woodlandhorsetail,andPtilium(Tables18and19).Overstorycoverinclosedmixedstandswasabout60%whilethatinopenmixedstandswas38%.Theheightoftheoverstorywassometimesupto20m.Dbh'sofindividualsinthesetwo-speciesoverstoriesrangedfrom15to30cm. 44Table15.Coverpercentagesfortotalvegetation,verticalstrata,andPlant/speciesinclosedbalsampoplarforestvegetation/habitattype~inupperSusitnaRiverbasin,summer1980.CategoryTotalvegetationCover(%)Q/99Overstory(>10cmdbh)PiceaglaucaPopulusbalsamiferaUnderstory(2.5-10cmdbh)PopulusbalsamiferaWhitespruceBalsampoplarBalsampoplar8017555CrowberryNorthernLabradorteaBogblueberryMountaincranberryBunchberryBalsampoplarBeauverdspiraeaShrublayer(>0.5mtall,<2.5cmdbh)PopulusbalsamiferaBalsampoplarGround1ayer«0.5mtall)Ptiliumspp.Polytrichumspp.EmpetrumnigrumLedumdecumbensvacclniumuliginosumVacciniumvitis-idaeaCornuscanadensisPopulusbalsamiferaSpiraeabeauverdiana£INumberofareassampledwas1.Q/Includesonlythosespecieswithatleast5%cover.10585205304040204015 45Table16.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciea/inclosedbirchdeciduousforestvegetation/habitattype-inupperSusitnaRiverbasin,summer1980.CategoryTotalvegetationOverstory(>10cmdbh)PiceaglaucaBetUlapapyriferaUnderstorY(2.5-10cmdbh)PiceaglaucaBetUlapapyriferaShrublayer(>0.5mtall,<2.5PiceaglaucaBetUlapapyriferaGroundlayer«0.5mtall)Ptiliumspp.Po1ytrichumspp.Vacciniumu1iginosumVacciniumvitis-idaeaEquisetumsilvaticumCornuscanadensisCa1amagrostiscanadensisGymnocarpiumdryopterisMertensiapaniculataWhitesprucePaperbirchWhitesprucePaper·birchcmdbh)WhitesprucePaperbirchBogblueberryMountaincranberryWoodlandhorsetailBunchberryBluejointOak-fernTallb1uebellAverageb/Cover(%)-9973868953313951551551016382010~Numberofareassampledwas2.QIIncludesonlythosespecieswithatleast5%coverinanyoneareasampled. 46Table17.Coverpercentagesfortotalvegetation,verticalstrata,andPlank/speciesinclosedaspendeciduousvegetation/habitattype-inupperSusitnaRiverbasin,summer1980.CategoryTotalvegetationCover(%)QI99Overstory(>10cmdbh)BetulapapyriferaPopulustremuloidesUnderstory(2.5-10cmdbh)BetulapapyriferaPopulustremuloidesShrublayer(>0.5mtall,<2.5cmPiceaglaucaBetUlapapYriferaBetulaglandulosaRosaacicularisSalixspp.POPUlustremuloidesGround1ayer«0.5mtall)Ptiliumspp.Polytrichumspp.LedumdecumbensvaccTniumuliginosumLinnaeaborealisCornuscanadensisMertensiapaniculataEpilobiumangustifoliumGeocaulonlividumSpiraeabeauverdianaVacciniumvitis-idaeaBetulananaViburnuiiledulisLycopodiumannotinumLycopodiumclavatumPaperbirchTremblingaspenPaperbirchTremblingaspendbh)WhitesprucePaperbirchResinbirchPricklyroseWi11owTremblingaspenNorthernLabradorteaBogblueberryTwinflowerBunchberryTallbluebellFireweedSandalwoodBeauverdspiraeaMountaincranberryDwarfarcticbirchHighbushcranberryStiffclubmossRunningclubmoss805805555555555855520.105805555105555~Numberofareassampledwas1.QIIncludesonlythosespecieswithatleast5%cover. 47Table18.Coverpercentagesfortotalvegetation,verticalstrata,andplantspecie~/inclosedmixedconiferdeciduousforestvegetation/habitattype-inupperSusitnaRiverbasin,summer1980.CategoryAverageb/Cover(%)-Totalvegetation98603335834438840382413730CrowberryMountaincranberryWoodlandhorsetailBunchberryNagoonberryBluejointWhitesprucePaperbirchWhitesprucePaperbirchOverstory(>10cmdbh)PiceaglaucaBetulapapyriferaUnderstorY(2.5-10cmdbh)PiceaglaucaBetulapapyriferaShrublayer(>0.5mtall,<2.5cmdbh)PiceaglaucaWhitespruceGroundlayer«0.5mtall)Ptiliumspp.EmpetrumnigrumVacciniumvitis-idaeaEquisetumsilvaticumCornuscanadensisRubusarcticusCalamagrostiscanadensis~Numberofareassampledwas3.£IIncludesonlythosespecieswithatleast5%coverinanyoneareasampled. 48Table19.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciea/inopenmixedconiferdeciduousforestvegetation/habitattype-inupperSusitnaRiverbasin,summer1980.CategoryTotalvegetationOverstory(>10cmdbh)PiceaglaucaBetulapapyriferaUnderstorY(2.5-10cmdbh)PiceaglaucaBetulapapyriferaShrublayer(>0.5mtall,<2.5cmPiceaglaucaBetulapapyriferaSalixnovae-angliaeGroundlayer«0.5mtall)FeathermossesPtiliumspp.EmpetrumnigrumLedumdecumbensvaccrniumuliginosumVacciniumvitis-idaeaEquisetumsilvaticumCornuscanadensisPiceaglaucaCalamagrostiscanadensisGymnocarpiumdryopterisWhitesprucePaperbirchWhitesprucePaperbirchdbh)WhitesprucePaperbirchTallblueberrywillowFeathermossCrowberryNorthernLabradorteaBogblueberryMountaincranberryWoodlandhorsetailBunchberryWhitespruceBluejointOak-fernAverageb/Cover(%)-1003820127511722117918:>4661693132118~Numberofareassampledwas8.Q!Includesonlythosespecieswithatleast5%coverinanyoneareasampled. 49Coresofafewofthelargertreesindicatedthatbirchtreeagesrangedfrom54to111yearswithmostofthemnear90orolder."Whitespruceagesrangedfrom50to204yearswithmosttreesbeingsomewhatover100years.Birchtrees,however,frequentlyhadrottencenterswhichdegradedagingaccuracy.Thus,theiragesmaybemorecomparabletothoseoftheSprucetreesifdeadcenterswereaccountedfor.Theshrublayerwasmoreimportantintheopenstands,mostlyasaresultoftallblueberrywillow(Salixnovae-angliae).Bogblueberrywasanimportantgroundspeciesintheopenmixedstands.Fortyvascularplantspecieswereidentifiedinopenmixedstandswhile29werefoundinclosedmixedstands.GeneralDiscussionofForestTypesForestedcommunitiesintheupperSusitnaRiverbasinweresimilartothosedescribedbyViereck(1975).BlacksprucegenerallYoccurredinwettersitesthanwhitesprucewhiledeciduousormixedforestsoccurredonwarmersites.Closedforestsoccurredonwarmersitesalso.Thedrieroftheseclosedsiteswereusuallydeciduouswhilethemoisteronesweremixedordominatedbyspruce.Deciduousandmixedforeststandswereconsideredearliersuccessionalstagesoftheconiferstands(Viereck1970,1975,andHettingerandJanz1974).Ingeneral,thedeciduousandthemixedconiferanddeciduousforestsappearedtorepresentarelativelypoorforageresourceformooseandcaribou.Thiswasparticularlytrueintheclosedstands.SteepslopesoftenassociatedwiththesetypesmightbepartiallYresponsibleforthelowpreferencebyungulatesaswell.Naturalrecordsofbrowsingintensity,asindicatedbythestructureofpaperbirchsuckers,suggestedthesetypesmayincurheavyuseinseverewinters.Skoog(1968)statedthatthesetypeswerelittleusedbycaribouatanytimeoftheyear.Thefrequencyofberry-filledbearscatsinthistypeinspringsuggesteditmightbeanimportantfoodresourceforblackbearsastheycomeoutofwintertorpor.Theopennatureoftheunderstoryvegetationmadesightingoffecalpileseasierintheseforesttypesandpositivelybiasedcomparisonwithothertypes.PricklYrosewasreportedtobeanimportantspeciesinbalsampoplarstandsalongtheChenaRiver(Viereck1970)andinnortheasternAlaska(HettingerandJanz1974)aswellasinwhitesprucestandsalongtheChenaRiver(Viereck1970).However,itaccountedfor"lessthan8%coverinopenwhitesprucestandsandlessthan5%coverintheclosedbalsampoplarstandsintheupperSusitnaRiverbasin.Hence,pricklYrosedoesnotappeartobeasimportantintheupperSusitnaRiverbasinforesttypesasitisinsomeotherpartsofthestate.(ii)TundraTypesTundracommunitieswhichusuallyoccurredabovethepresentlimitoftreegrowth(Figure6),exhibitedapproximately70identifiedvascularplantspecies.Mostofthewell-vegetatedcommunitiesoccurredonflattogentlyslopingareas,whilesparservegetationoccurredonsteepor 50rockyterrain.Althoughaspectsoftundravegetation/habitattypeswerevariable,fourdistinctsubtypesoccurredinareaslargeenoughtomap:wetsedge-grasstundra,mesicsedge-grasstundra,herbaceousalpinetundra,andclosedmatandcushiontundracommunities.Wetsedge-grasstundracommunitiesoccurredatanaverageelevationof587minwet,depressedareaswithpoordrainage.Theyhadalmostcompletevegetationcover,withmostofitoccurringinthegroundlayer(Table20).Nineteenspecieswereidentified.Themostimportantherbaceousspeciesweretwosedges,especiallywatersedge(Carexaquatilis);bluejoint;andsphagnumaswellasseveralotherunidentifiedmosses.Theshrublayer,whenitwaspresent,containedscatteredindividualwillows(Salixspp.).Wetsedge-grasscommunitiescouldpotentiallycontainupto10%coveroferectshrubs.Therewasusuallyalargeamountoforganicmatterinthesesoilsandsometimestherewasathickorganiclayerontopofmineralsoil.Mesicsedge-grasstundragenerallyoccurredatanelevationof1372monrollinguplandswithwell-drainedsoils.Thesoilswerewell-developedinsomeareas,butinothersthesoiloccurredaspatchesalternatingwithrocks.Ninespecieswereidentifiedwithtotalvegetationcoverbetweenhalfandthree-fourthsofthearea(Table21).Allvegetationwaslowinthegroundlayer,usuallylessthan30cmtall.Bigelowsedge(Carexbigelowii)wasthemostcommonspeciesandaccountedforalmosthalfofthetotalvegetationcover.TwotypesofherbaceousalpinetundraoccurredintheupperSusitnaRiverbasin,althoughonlyone,herb-sedge,occurredinareaslargeenoughtomap.Herb-sedgecommunitiesoccurredatelevationsofaround1295mneartheglaciers,particularlYtheWestForkGlacier,wherethereexistedgentleslopesoffairlywell-drainedandrelativelYwell-developedsoils.Thesewerebasicallymineralsoilscontainingabout5%organicmatter.Someofthesoilmayhavedevelopedfromloess.Vegetationcoverwasalmostcomplete,butcoverwasdispersedevenlyamon9themanyspeciespresentsothatnogroupofspeciesdominatedthearea(Table22).Coverwasnotestimatedbecauseofthecomplexityofthevegetationandfieldtimeconstraints.Allvegetationoccurredinthegroundlayerandapproximately42specieswereidentifiedintheoneareaofherb-sedgetundravisited.Theothertypeofherbaceousalpinecommunitywasfoundinsmall,isolatedrockyareasthatweretoosmalltomaportosample.Smallforbsandsometimesshrubsgrewinthepocketsofmineralsoilimbeddedbetweentherocks.Thefourthmajortypeoftundracommunitywasthematandcushiontundra,whichwasfoundathighelevations(1013m)ondry,windYridges(Figure6).Vegetationcoveredaboutthree-fourthsoftheareaandwasusuallylessthan20to30cmtall(Table23).Lichensandlowmat-formingshrubs,suchasdwarfarcticbirch,crowberry,bearberry,andbogblueberry,dominatedtheseareas.Soilswereshallowandcoarse. 51Table20.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinwetsedge-grasstundravegetation/habitattype~inupperSusitnaRiverbasin,summer1980.CategoryTotalvegetationShrublayer(>0.5mtall,<2.5cmSalixplanifoliasso.pulchraSalixspp..Ground1ayer«0.5mta11)Mosses,unidentifiedSphagnumspp.SalixfuscescenscaTamagrostiscanadensisCarexaguatilisCarexbigelowii~Numberofareassampledwas3.dbh)DiamondleafwillowWi11owSphagnummossAlaskabogwillowBluejointWatersedgeBigelowsedgeAverageCover(%)Q19913858620225143823QIIncludesonlythosespecieswithatleast5%coverinanyoneareasampled. 52Table21.Coverpercentagesfortotalvegetation,verticalstrata,andPlan~/speciesinmesicsedge-grasstundravegetation/habitattype-inupperSusitnaRiverbasin,summer1980.CategoryTotalvegetationGroundlayer«0.5mtall)Polytrichumspp.Salixspp.CarexbigelowiiCarexspp.Hairy-capmossWi11owBigelowsedgeSedgeAverageb/Cover(%)-6565513304~Numberofareassampledwas2.QIIncludesonlythosespecieswithatleast5%coverinanyoneareasampled. 53Table22.Plantspecieslist·inherbaceousg}pinetundrainupperSusitnaRiverbasin,summer1980.-CategoryLycopodiumalpinumLycopodiumannotinumLycopodiumselagoEquisetumsp.CarexbigelowiiCarexfilifoliaErlOPhorumangustifoliumCalamagrostispurpurascensDeschampsiacaespitosaFestucarubraPhleumcommutatumJuncussp.LuzulaconfusaLuzulatundricolaMyosotisalpestrisCampanulalasiocarpaAstersibiricus~isiaarcticaPetasitesfrigidusSenecioatropurpeusSedumroseasr;eneacau1isDiapensialapponicaCassiopetetragonaEpilobiumlatifoliumPolemoniumacutiflorumPolygonumbistortaRumexarcticusACOnftumdelphinifoliumAnemonenarcissifloraCalthaleptosepalaSanguisorbastipulataSibbaldiaprocumbensSalixphlebophyllaSalixpolarisSalixreticulataSalixrotundifoliaBOYklniarichardsoniiSaxifragatricuspidataVeronicawormskjoldiiValerianacapitataPolytrichumspp.~Numberofareassampledwas1.CommonNamesAlpineclubmossStiffclubmossFirclubmossHorsetailBigelowsedgeThread-leafsedgeTallcottongrassPurplereedgrassTuftedhairgrassRedfescueTimothyRushNorthernwoodrushTundrawoodrushForget-me-notMountainharebellSiberianasterWormwoodArcticsweetcoltsfootRagwortRoserootMosscampionDiapensiaFour-anglemountain-heatherDwarffireweedJacob'sladderMeadowbistortArcticdockMonkshoodAnemoneMountainmarsh-marigoldSitkaburnetSibbaldiaSkeletonleafwillowPolarwillowNetleafwillowLeastwillowRichardsonboykiniaThree-toothsaxifrageAlpinespeedwellCapitatevalerianHairY-capmoss 54Table23.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciea/inclosedmatandcushiontundravegetation/habitattype-inupperSusitnaRiverbasin,summer1980.CategoryTotalvegetationGroundlayer«0.5mtall)Lichens,unidentifiedCladoniaspp.EmpetrumnigrumLedumdecumbensvaccrniumuliginosumArctostaphylosspp.BetulaglandulosaBetulanan(jCrowberryNorthernLabradorteaBogblueberryBearberryResinbirchDwarfarcticbirchAverageb/Cover(%)-78781488787610~Numberofareassampledwas8.Q!Includesonlythosespecieswithatleast5%coverinanyoneareasampled. 55Diversewildlifeoccupiedthehighelevationtundracommunitiesinsummer.Mostobviouswerewhimbrel,caribou,blackandbrownbears,ptarmigan,hoarymarmots,andarcticgroundsquirrels.Whimbrelswerefrequentlyspottedhereinearlysummer.Bearscatsindicatedover-winteredberrieswerethemajorattractantofbearsinJunealthoughmanysquirreldenswerefoundwhichhadbeenexcavatedbybears.Caribouweremorefrequentlysightedinthesedge-grasstundrathaninanyothertype.Skoog(1968)consideredsedge-grasstundratobeimportantyear-roundrangeforcaribouinthisregion.Heconsideredmatandcushiontundratobemoreimportantasawinterforagesupply,sinceitswindsweptconditiongenerallykeptitrelativelysnow-free..Wetsedge-grasscommunities,morecommonbelowtreeline,showedusebymoosewherebrowsewasavailable.Otherwise,itsimportancewasmoreimportanttowadingbirdsand,wheretopographyalloweddam-building,beaver.Inmanycases,thewetsedge-grassvegetationwaslikelythe.resultofbeaveractivity.(iii)ShrubTypesShrublandvegetation/habitattypeswerethemostprevalenttypesintheupperSusitnaRiverbasin(Figure6andTable4).Theygenerallyoccurredathigherelevationsthanforestcommunitiesbutatlowerelevationsthantundratypes.Mostareas,particularlythelowshrub,werefoundonextensive,fairlylevelbenchesatmid-elevationsthroughouttheupperbasin.Lessextensiveareas,usuallytallshrub,werefoundonsteepslopesabovetheriver.Twomaintypeswerefound:tallandlowshrub,witheachbeingfurtherdividedbythepercentageshrubcoverintoclosedandopentypes.Approximately65specieswereidentifiedinthisoveralltype.-TallShrubTypesTallshrubcommunitiesweredominatedbySitkaalder(AlnussinuataorAlnuscrispavar.sinuata)andwerefoundmostlyonsteepslopesabovetheriverorsometimesabovetheflatbenchesatanaverageelevationof573m(Figure6).Manyofthesestandswere2to4 minheight.Approx-imately25specieswereidentifiedinthealderstandswhetherclosedoropen.Alderstandsfrequentlyoccurredasstringersthroughothervegetation/habitattypesalongtheslopesbytheriver.ManyareasalsocontainedalderasaringaroundamountainatacertainelevationorinastripalongariverdrainageasatPortageCreek.Theclosedstandshadalmostcompletevegetationcoverwiththegroundlayerandunderstoryaccountingformostofthecover(Table24).Portionsofsomestandswerethickets.Alderprovidedthemostcoverwithbluejointandwoodlandhorsetailaccountingformostofthegroundlayercover.Onlyoneopenalderstandwasvisited.Ithadlessvegetationcoverthantheclosedaldersiteswithmostofthevegetationbeinginthe 56Table24.Coverpercentagesfortotalvegetation,verticalstrata,ay?plantspeciesinclosedtallaldervegetation/habitattype-inupperSusitnaRiverbasin,summer1980.SitkaalderAmericangreenalderWoodlandhorsetailCurrantSitkaalderBluejointCategoryTotalvegetationUnderstory(2.5-10cmdbh)AlnussinuataAlnuscrispaShrub1ayer(>0.5mtall,<2.5AlnussinuataAlnuscrispaRibesspp.Groundlayer«0.5mtall)EguisetumsilvaticumRibesspp.AlTiUSsinuataCalamagrostiscanadensiscmdbh)SitkaalderAmericangreenCurrantalderAverageb/Cover(%)-96572532382810862318735~Numberofareassampledwas3.QIIncludesonlythosespecieswithatleast5%coverinanyoneareasampled. 57understorylayer(Table25).Bluejointwasthemostimportantgroundlayerspecies.Whitesprucewaspresentinboththeoverstoryandunderstory.Thismixtureofalderwithwhitespruceindicatedthatitwasprobablyasuccessionalstand.Hanson's(1953)descriptionofaldertypeswassimilartothosefoundintheupperSusitnabasininthatthesethicketsoccurredonwell-drainedslopesandvariedfrom1to4 minheight.Bluejointdominatedthegroundlayerspeciesinmanycases,whileBeauverdspiraea(Spiraeabeauverdiana)andbogblueberrywereotherimportantspecies.Hanson(1953)alsoobservedbirchshrubs(Betulaspp.)asanimportantspeciesinalderstands,butthealderstandsencounteredintheupperSusitnaRiverbasincontainednobirchshrubs.Incontrast,theSusitnastandscontainedimportantquantitiesofwoodlandhorsetail.AsintheSusitnastudy,HettingerandJanz(1974)observedthatalderstandsoccurredonsteeperslopesandolderripariansites.OnealderstandlocatedonaslopeoftheSusitnacanyon(RllE,T29N)wasveryheavilYusedbymoose(Figure9).Currant(Ribesspp.)appearedtobehighlYpreferredbrowseinthisstand.Willowwasimportantbrowseinallstands,andcertainindividualsofAmericangreenalder(AlnuscrispaorAlnuscrispavar.crispa)wereheavilYbrowsed.-LowShrubTypesAsinearlierstudiesinnorthwesternAlaska(Hanson1953)andinnortheasternAlaska(HettingerandJanz1974),lowshrubvegetation/habitattypeswerecommonintheupperSusitnaRiverbasin.Lowshrubcommunitieswerefoundontheextensiverelativelyflatbencheswheresoilswerefrequentlywetandgleyedbutusuallylackingstandingwater,exceptforwillowtypes.Elevationaveragedabout781m.Over40specieswereidentifiedinthisvegetation/habitattype.Subtypesincludedbirch,willow,andamixtureofthetwo.Becauseofthesubtlegradationsbetweenthesubtypes,descriptionswerekeptverygeneral(Tables26,27).Birchshrubstandswereusuallydominatedbyresinbirch(Betulaglandulosa)about1.0mtallandcontainedseveralotherspeciesoflowshrubs,especiallynorthernLabradortea.Themostimportantassociatedspeciesinthesestandswasbogblueberry,whilemossesandlichenscontributedanimportantamountofcover.Insomestands,therewasabuildupofsoilanddebrisaroundthebasesofeachbirchshrubclump,creatingalargeamountofmicrorelief.Sometimesthestandsweredense,likeathicket,whileothershadlargeopeningsbetweenindivifjualbirchshrubs.Scatteredblackspruceoccurredinsomestandscontributingalmost10%cover.Hence,lowshrubandwoodlandblacksprucestandsweredifficulttodistinguishonthegroundandontheaerialphotographs.Thetwospeciesofbirchshrub,resinanddwarfarcticbirch(Betulanana),weresometimesdifficulttodistinguishbasedonleafshapeandplantheight.Viereck(1966)alsocommentedonthisproblem.Willowwater.formedstandswereusuallyfoundinwetterareas,frequentlywithstandingDiamondleafwillow(Salixplanifoliasubsp.pulchra)sometimesthicketsalongsmallstreamsathighelevations.Watersedgewas Table25.58Coverpercentagesfortotalvegetation,verticalstrata,?ndplantspeciesinopentall'aldervegetation/habitattype~,inupperSusitnaRiverbasin,summer1980.Shrublayer(>0.5mtall,<2.5cmdbh)AlnussinuataSitkaalderCategoryTotalvegetationOverstory(>10cmdbh)PiceaglaucaUnderstory(2.5-10cmdbh)PiceaglaucaAlnussinuataGroundlayer«0.5mtall)LinnaeaborealisAlnussinuatacararnagrostiscanadensisWhitespruceWhitespruceSitkaalderTwinflowerSitkaalderBluejointCover(%)Q!851010455401010255510~Numberofareassampledwas1.Q!Includesonlythosespecieswithatleast5%cover. 59Table26.Coverpercentagesfortotalvegetation,verticalstrata,andplantspeciesinclosedlowshrubvegetation/habitattype~inupperSusitnaRiverbasin,summer1980.CategoryTotalvegetationShrublayer(>0.5mtall,<2.5cmBetulaglandulosaSalixplanifoliassp.pulchraGround1ayer«0.5mta11)Mosses,unidentifiedFeathermossesEmpetrumnigrumLedumdecumbensLedumgroenlandicumVacciniumuliginosumVacciniumvitis-idaeaArctostaphYlosrubraBetulaglandulosaBetulananadbh)ResinbirchDiamondleafwillowFeathermossCrowberryNorthernLabradorteaLabradorteaBogblueberryMountaincranberryRed-fruitbearberryResinbirchDwarfarcticbirchAverageCover(%)Q!9342108521767184886349~Numberofareassampledwas10.Q!Includesonlythosespecieswithatleast5%coverinanyoneareasampled. 60Table27.Coverpercentagesfortotalvegetation,verticalstrataa/andplantspeciesinopenlowshrubvegetation/habitattype-inupperSusitnaRiverbasin,summer1980.TotalvegetationFeathermossLabradorteaBogblueberryResinbirchWatersedgeCategoryShrub1ayer(>0.5mtall,<2.5cmdbh)Betulaglandu10saResinbirchGroundlayer«0.5mtall)FeathermossesLedumgroenlandicumVacciniumuliginosumBetulaglandulosaCarexaguatilisAverageb/Cover(%)-10017583135151543~Numberofareassampledwas2.Q!Includesonlythosespecieswithatleast5%coverinanyoneareasampled. 61theimportantherbaceousspeciesinthesestands.Becauseofthewetness,thesecommunitieswereusuallylessdiversethanbirchshrubstands.Willowfrequentlyhadsoilanddebrisbuiltupatthebasesofthestemswithstandingorrunningwaterinthetroughs.AssociatedspeciessimilartothosenotedbyHanson(1953)andHettingerandJanz(1974)wereobservedintheSusitnaareaandincludednorthernLabradorteaandbogblueberry.CrowberrywasalsocommoninthesestudiesaswellasViereck's(1966)studyontheMuldrowGlacier.Thebirch-willowtypewhichHanson(1953)describedis2to3 mormoretall,whileSusitnabirch-willowstandsandthoseneartheMuldrowGlacierintheInteriorwere1.0to1.5mtall(Viereck1966).MountaincranberrywasimportantinnortheasternAlaskaandtheSusitnaareabutnotinthenorthwesternpartofthestate.Birchshrubcommunitiesapparentlyreceivedmoderateusebymoosemost·oftheyear.However,standswithwillowwerepreferred.Willowstandsreceivedgreaterbrowsingthananyothervegetationtype.Feltleafwillow(Salixalaxensis)anddiamondleafwillowwereheavilyutilizedinmostareas.Caribousignswerealsofrequentinbirchcommunities.Skoog(1968)foundthatleavesofresinbirchwereimportantfoodforcaribouinsummer;andinwinter,lichenswereimportant.Hefoundthatcariboufeedonwillowsinspringandfallandconsideredwillowstandsimportanttotheecologyofcaribou.Weagreewiththis,butspecifythatthisisapparentlytrueonlyforstandsfoundabovetherimoftherivercanyon.(iv)HerbaceousTypesTwoherbaceoustypeswerefoundintheupperbasin.GrasslandsdominatedbybluejointwerepresentonleveltoslopingareasatlowerelevationsalongtheriverandalongthePortageCreekdrainage(Figure6).Herbaceouspioneercommunitieswerepresentongravelandsandbarsthathadrecentlybecomevegetated.Soilsherehadlittleorganicmatterandoftenconsistedofmanycobbles.Pioneerspeciesincludedhorsetails,lupines(Lupinusspp.),andalpinesweetvetch(Hedysarumalpinum).(v)UnvegetatedAreasThreeclassesofunvegetatedareasaredepictedonthemaps(Figures6,9,and10):water,rock,andsnowandice.Lakesandstreamswereincludedinthewatercategory.LakesweregenerallyfoundalongflatbenchesandrangedinsizefromsmallpondstolargelakessuchasBigLake(approximatelY450hal.Rockincorporatedthoseareasofbedrockordepositedgeologicmaterialssupportinglittleornovascularvegetation.Rockoccurredasoutcroppingsathighelevationsoralongsteepcliffsalongtheriverorasunconsolidatedgravelinnewlydepositedriverbars.Snowandiceincludedpermanentsnowfieldsandglaciers.GlaciersandpermanentsQowfieldsweremostcommonatthenorthernendofthestudyareaintheAlaskaRange,althoughsomeoccurrednearthe southernboundaryintheTalkeetnaMountains. 62(b)DownstreamFloodplainTheSusitnaRiver'sstructurediffersmarkedlyamongitsvariousreaches.Currentratesvaryaccordingtothosegradientchanges.Flowvolumesfluctuateseasonallydependinguponairtemperatures,particularlyatthesource,andprecipitationlevelsinsummerandautumn.Twodistinctreachesareapparentinthedownstreamregion:GoldCreektoChulitnaRiver(Talkeetna)andChulitnaRivertoDeshkaRiver(KrotoCreek).TheGoldCreek-ChulitnaRiversectionisrelativelyincisedandwouldbemostaffectedbytheproposedproject.Atsummerflowratesrelativelylittleofthevisiblelandisunvegetated.ThereachbelowTalkeetnaisbraided.However,thepotentialeffectsofthetheprojectbelowTalkeetnawouldbedampenedbytheChulitnaandTalkeetnaRivers.TheSusitnaRiveraboveTalkeetnaaccountsfor37%oftheSusitnaRiverflowjustbelowTalkeetnaandonly17%bythetimeitreachesCookInlet(AlaskaPowerAuthority1980b).Althoughthedownstreamsectionisbraidedandhighlysusceptibletochannelchanges,thepotentialeffectsoftheprojectherewouldbeless.Riverbarsinbraidedstreamsareconstantlybeingreworkedbytheriver.Areasarewashedawayandothersaredeposited.Vegetationisoftendisturbedordestroyedonrecentlydepositedareasevenifthesoilisnoteroded.Vegetationmaydevelopextensivelyonareasthatareundisturbedalthoughfloodsmaylaterdestroythisalso.Flowsarehighestandmostvariableinthesummerandgenerallylowandconstantinthewinter.Thevariablesummerflowsaccountformuchofthevegetationdynamicsinthefloodplain.Springicejams,however,canbesignificantlydisturbingtostream-sidevegetationaboveTalkeetna.Noevidenceoficedamageswereobservedinthelowersection.Balsampoplarisdistinctlyassociatedwiththefloodplainofthisriver.Itoccursonsomeofthemostrecentlydepositedsandbars,aswellasinmiddle-aged,mature,anddecadentstands.However,theoldest,moststableareasareusuallycoveredwithbirch-spruceforest.TheobjectivesofthedownstreamstudYweretostudythevegetationandriverdynamicsandanalyzetheeffectsthatriverdynamicshadonplantcommunities.·(i)EarlySuccessionalStandsEarlysuccessionalcommunitiescommontothelowerSusitnaRiverflood-plainaredominatedbyhorsetail(Euisetum),horsetail-willow,horsetail-balsampoplar,ordryas(Dryasdrummondiiplantcommunities.Thesetypesaccountfor5-10%ofthevegetatedlandonthefloodplainsasdeterminedfromaerialtransectsobservedfromhelicopterinJune,1981.Thesecommunitieshaverelativelylittletotalvegetationcoverandgreaterthan50%bareground(Table28).Plantspeciesinthesetypesaregenerallycharacterizedbyhavingrhizomes,orhorizontalunder-groundstems,whichmayextendformanymetersandareeffectiveinbindingloosesandandsilt.Sproutsgenerallyarisefromtheserhizomes,thusincreasingthevegetationcoverinthearea.Horsetaildominatestheaspectinallbutthedryasplantcommunity,contributinghalfofthetotalcover.Willowandbalsampoplarprovided8and5%cover,respectively(Table28). 63Table28.Percentcoveronearlysuccessionalstands~ondownstreamfloodplainofSusitnaRiver,summer1981.CategoryPhysicalFeaturesWaterBaregroundGravel,cobblesVegetationCategoriesLitterStandingdeadPerennialgrassesPerennialforbsMossesLichensLowshrubsTa11shrubsTreesTotalvegetationMean%+53213+125++4+838VegetationbySpeciesorGenusEquisetumvariegatumPopulusbalsamiferaSalixalaxensisSalixnovae-angliaeSalixarbusculoidesSaTlXsp.Astragalussp.Hedysarumsp.CalamagrostiscanadensisEriophorumsp.Scirpussp.AlnustenuifoliaAlnussinuataArtemisiatelesiiNephromasp.VariegatedhorsetailBalsampoplarFeltleafwillowTallblueberrywillowLittletreewillowWi11ow/·1ilk-vetchSweet-vetchBluejointCottongrassBullrushThinleafalderSitkaalderWormwoodNephroma25841+++++++++++~Earlysuccessionalstandswere20,21,22,and25(Figure5).numbers1,5,6,8,9,13, 14,15,Numberoftransectssampledwas42. 64Willowandbalsampoplarsometimeswerefoundonnewlyformedbarslackinghorsetail,althoughhorsetailappearedtobecomeestablishedfirstusually.Rockyorgravellysitestendedtohavetheleastcoverofhorsetail.Inmostearlysuccessionalstandsbalsampoplaroccurredatgreaterdensitythanotherwoodyspecies(Table29).Theaverageageofthesebalsampoplarswas6years,whereasassociatedfeltleafwillow(Salixalaxensis)andSitkaalder(Alnussinuata)wereboth5years;thinleafaldertypicallYdidnotappearuntil3yearsafterthebalsampoplar.Asindicatedbytheheightsofthesespecies(Table30),alderhadarelativelyrapidgrowthrate,whichallowedittoexceedtheheightofwillowandbalsampoplarwithin2or3years.Alderwasaminorcomponentinthesetypes.Theseearlysuccessionalstagesappearedtolastupto10yearsfromthelastmajordisturbance.Agingofthesestandswasdifficultbecauseafloodmightsiltin,butnotdestroy,establishedvegetationinsome·areas.Thevegetationwouldbeburiedthenresurface.Balsampoplarabout50cminheightmighthave10yearsofgrowthsincethelastmajorsiltingandanother10yearsintheburiedsiltlayer.Thiscyclecouldberepeatedanumberoftimesbeforevegetationsuccessionadvancedtoalaterstage.Thevegetationintheseseralstages10(maybe15)yearsafterstabilizationproducewillowandbalsampoplarbrowsesuitableformoose.Dryasdominatedtheaspectofgravellysites.However,livingdryasaccountedforonly4%cover.Balsampoplaranddryascovered6and8%,respectively.Baregroundwas76%,one-thirdofwhichwascobbles.Dryasisanitrogen-fixingplantandpresumablybenefitsnon-nitrogen-fixingspeciesbyaddingnitrogentothesoil.Evenso,vegetationonthesesitesisslowgrowinguntilsufficientsiltsandsandsaredepositedbywindandwatertoprovideaparentmaterialforsoildevelopment.Dryasisimportantinstabilizingthesedeposits.(ii)MidSuccessionalSiandsDepositionofsandsandsilts,resultingintheelevationofsitesfartherabovetheleveloffrequentflooding,coupledwithfreedomfromdisturbancefromiceandfastwater,appearedtobenecessaryfortransitionofearlysuccessionalvegetationtomid-successionalstages.Thesemid-successionaltypesaccountedforaboutone-fifthofvegetatedlandinthefloodplain.Mid-successionalvegetationwascharacterizedbythinleafalder,orimmaturebalsampoplarwhichhaddevelopedintotallshrubsortrees.Thealdertypeisthefirstphaseofthismid-successionalstageandappearedtolastfrom10to25yearsafterstabilization.Theimmaturebalsampoplarstandsappearedtodominatethevegetation25to55yearsafterstabilizationbutweremuchlessfrequentthanthealderstands.Totalvegetationcoverinalderstandsaveraged87%(Table31);thinleafalderprovided59%,whereasbalsampoplarprovidedonly13%cover.Astrikingdifferencebetweenearlyandmid-successionalstageswasthereductionofbaregroundinmid-successionalstands.Litterandbluejointgrasscoverswere99%and38%,respectively. Table29.Density(stems/ha)ofwoodyspeciesinearlyvegetationsuccessionalstages~ondownstreamfloodplainofSusitnaRiver,summer1981.2 - 4 mTall<.4mTall.4- 2 mTall<4cmdbh>4cmdbh>4 mTallTotalPopulusbalsamiferaBalsampoplar388651103AlnussinuataSitkaalder8643SalixalaxensisFeltleafwillow49298643Salixnovae-angliaeTallblueberrYwillow17621850SalixarcticusArcticwi11ow48Salixsp.Wi11ow----.1Q§.Total45865122874040135215400086911357257237474830558367~Earlysuccessionalstandswerenumbers1,5,6,8,9,13,14,15,20, 21, 22,and25(Figure5).Numberoftransectssampledwas42.Browsablestemswerethosetallerthan.4mbutwithdbh<4cm.0"\c..n Table30.CharacteristicsofwoodysB9ciesinearlyvegetationsuccessionstands~ondownstreamfloodplainofSusitnaRiver,summer1981-.I·leanHeight(cm)t4eanLength(cm)MeanWidth(cm)MeanAgeMeanCrownDominanceNumberofIndividualsSampledSalixalaxensisFeltleafwillow6025185 268Salixnovae-angliaeTallblueberrywillow5218123224Salixspp.Wi11ow683125420~AlnussinuataSitkaalder186 1631455 212AlnustenuifoliaThinleafalder15410087325PopulusbalsamiferaBalsampoplar4424196263.IV~Earlysuccessionalstandswerenumbers1,5,6,8,9,13, 14,15,20,21, 22,and25(Figure5).Numberoftransectssampledwas42..IVOnly62observationsforheight.(J)(J) 67Table31.Percentcoverinalderstands~ondownstreamfloodplainofSusitnaRiver,summer1981.CategoryPhysicalFeaturesBaregroundLitterVegetationCategoriesStandingdeadPerennialgrassesPerennialforbsMossesLichensLowshrubsTa11shrubsTreesTotalvegetationVegetationbySpeciesorGenusCalamagrostiscanadensisAlnustenuifoliaAlnussinuataViburnumeduleEpilobium-angustifoliumPopulusbalsamiferaArtemisiatilesiiSalixalaxensisSalixnovae-angliaeSalixsp.Stellariasp.EpilobiumlatifoliumRosaacicularisRli:i"esspp.Hedysarumsp.RubusarcticusRubusidaeusTrientaliseuropaeaGaliumsp.Poasp.BluejointThinleafalderSitkaalderHighbushcranberryFireweedBalsampoplarWormwoodFeltleafwillowTallblueberrywillowWi11owStarwortDwarffireweedPricklyroseCurrantSweet-vetchNagoonberryRaspberryArcticstarflowerBedstrawBluegrassMean%199+3811++660138738593131335+++++++++++.+~Alderstandswerenumbers2,19,23,and27(Figure5).Numberoftransectssampledwas20. 68Alderdensitygreatlyincreasedoverthatofearlysuccessionalstands"(691upto6682stems/hal,whereasbalsampoplardeclinedfrom40,000to2623stems/ha(Table32).Crowding,competition,andpreferentialbrowsingbymoosemayaccountforsomeofthereductionofbalsampoplar,butmoreimportantly,thefactthatbalsampoplarisshadeintolerantandquicklyovertoppedbyalderisprimarilYresponsibleforitsdecrease.Shadetolerantspeciessuchasraspberry,pricklyrose,andhighbushcranberryappearedinalderstands.Theseproduced200,117,and467browsablestems(>0.4mhigh,<4cmdbh)/ha.Theaverageagesoftallshrub-sizedthinleafalderandbalsampoplarinalderstandswere20and19years,respectively(Table33),indicatingthestandsprobablyaveraged20yearsinage.Balsampoplarandalderheightswerenearlyequal,7.9and7.0m,respectivelyinthealderstands.However,observationofmanydifferentagedalderstandssuggestedthat"oncebalsampoplarreachedthetopofaldercanopies,thebalsampoplarquicklydoubleditsheight,therebyovershadowingthealderanddevelopingintotheimmaturebalsampoplarphaseofthemid-successionalstage.Balsampoplardominatedtheoverstoryofimmaturebalsampoplarstands,producing62%cover(Table34);thinleafalderprovided40%cover.Asinalderstands,therewasessentiallYnobaregroundandlitterandbluejointprovidedmostofthegroundcover.Densityofbalsampoplarandthinleafalderdeclinedfromthatfoundinalderstandssincethebalsampoplartreesgrewlarger(Table35),Sitkaalder,however,tripledindensity(Table35).Feltleafwillowdecreasedfrom3559to352stems/ha.Pricklyroseandhighbushcranberrysubstantiallyincreasedindensity(Table35),andalsodevelopedmuchmorerobustgrowthforms(Table36).Balsampoplartreesinimmaturebalsampoplarstandsaveraged44yearsofage(Table37)and18minheight(morethandoubletheirheightinthealderphase).Alderageswereaboutthesameinboththealderandtheimmaturebalsampoplarphases,suggestingthatapproximately20yearsisthelifeexpectancyofindividualstems.Alderindividualsintheimmaturebalsampoplarstandswouldbesecondgrowth,whereasthebalsampoplarswereamongtheoriginalcolonizers.HeightsofalderwerealsoroughlyequalbetweenthetwophasesanditwasapparentthatthinleafalderattainedagreaterheightthanSitkaalder(Table37).Whitesprucewasfoundasearlyasthealderphase(34stems/hal,withthenumberofindividualsonlyslightlyincreasedintheimmaturebalsampoplarphase(Tables32and35).Agedata(Table37),however,suggestthatmostwhitespruceindividualswereestablishedsometimeafteralderstandsbegandevelopingintotheimmaturebalsampoplarphase.Thisdiscrepancycouldindicatesamplingwasinsufficienttocoverstandvariabilityand/orthatconsiderablemortalityoccurredwithyoungwhitespruceinthisearlyperiodoftheirestablishment.Paperbirchalsowasfoundinbothmid-successionalphases,buttheagedifferencesbetweenphases(Tables32and35)indicatednoincreaseinthenumberofindividualsastheimmaturebalsampoplarphasedeveloped. Table32.Density(stems/ha)ofwoodyspeciesinalderstands~ondownstreamfloodplainofSusitnaRiver,summer1981.2 - 4mTall<.4mTall.4- 2mTall<4cmdbh>4cmdbh>4mTallTotalPopulusbalsamiferaBalsampoplar867900417423972623AlnustenuifoliaThinleafalder483185063398323176266AlnussinuataSitkaalder13333250416SalixalaxensisFeltleafwillow61725171671331253559PiceaglaucaWhitespruce171734EchinopanaxhorridumDevil'sclub133B3RubusidaeusRaspberry9672001167RosaacicularisPricklYrose517117634ViburnumeduleHighbushcranberry467467Salixnovae-angliaeTallblueberrywillow8383RibestristeAmericanredcurrant11331133Salixsp.Wi11ow783-----.1§l------Total5384641712501158308917298m<0~Alderstandswerenumbers2,19,23,and27(Figure5).Numberoftransectssampledwas20.Browsablestemswerethosetallerthan.4mbutwithdbh<4cm. 70Table33.Characteristicsoftreesandtallshrubsinalderstands~ondownstreamfloodplainofSusitnaRiver,summer1981.Mean MeanMeanNumberofHeightdbhMeanCrownIndividuals(m)(cm)AgeDominanceSampledPopulusbalsamiferaBalsampoplar7.97.219228Q1AlnustenuifoliaThinleafalder7.0 7.320240£1AlnussinuataSitkaalder3.93.41754BetulapapyriferaPaperbirch4.94.61344d/PiceaglaucaWhitespruce4.75.01149-~Alderstandswerenumbers2,19,23,and27(Figure5).Numberoftransectssampledwas20.QIOnly27observationsfordbh.y'Only37observationsforage.Q!Only7observationsfordbh. 71Table34.Percentcoverinimmaturebalsampoplarstands~ondownstreamfloodplain,summer1981.CategoryPhysicalFeaturesVegetationCategoriesLitterStandingdeadPerennialgrassesPerennialforbsr10ssesLowshrubsTallshrubsTreesTotalvegetationVegetationbySpeciesorGenusPopulusbalsamiferaAlnustenuifoliaAlnussinuatacaTarnagrostiscanadensisViburnumeduleArtemisiatilesiiHeracleumlanatumMertensiapaniculataRosaacicularisPiceaglaucaSalixnovae-angliaePyrolasecundaPyrolasp.RubusidaeussanguisorbastipulataGaliumsp.MatteucciastruthiopterisStreptopusamplexicaulisBalsampoplarThinleafalderSitkaalderBluejointHighbushcranberryWormwoodCowparsnipTallbluebellPricklyroseWhitespruceTallblueberrywillowOne-sidedwintergreenWintergreenRaspberrySitkaburnetBedstrawOstrichfernCucumber-rootMean%95+239+6486291624082133111+++++++++~Immaturebalsampoplarstandswerenumbers10, 12,and26(Figure5).Numberoftransectssampledwas18. Table35.Density(stems/ha)ofwoodyspeciesinimmaturebalsampoplarstands~ondownstreamfloodplain,summer1981.2-4 mTall<.4mTall.4-2 mTall<4cmdbh>4cmdbh>4 mTallTotalPopulusbalsamiferaBalsampoplar194076191045AlnustenuifoliaThinleafalder74175917045614725065AlnussinuataSitkaalder907426191352SalixalaxensisFeltleafalder352352Salixsp.Willow148148Piceaglauca.Whitespruce3737RubusidaeusRaspberry11851185RosaacicularisPricklyrose103715192556ViburnumeduleHighbushcranberry6304631093Salixnovae-angliaeTallblueberrywillow3737Ribessp.Currant759759Total368552412537675149113629....,N~Immaturebalsampoplarstandswerenumbers10, 12,and26(Figure5).Numberoftransectssampledwas18.Browsab1estemswerethosetallerthan.4mbutlessthan4cmdbh. Table36.Characteristicsofwoodyspeciesinimmaturebalsampoplarstands~ondownstreamfloodplainofSusitnaRiver,summer1981.MeanMeanMeanMeanNumberofHeightLengthWidthMeanCrownIndividuals(cm)(cm) (cm)AgeDominanceSampledSalixnovae~angliaeFeltleafwillow12553459 68Ribessp.Currant4835353 71RubusidaeusRaspberry352921176b/BetulapapyriferaPaperbirch1022522~61-PiceaglaucaWhitespruce10107271AlnussinuataSitkaalder1811531048617YAlnustenuifoliaThinleafalder13973436 6324/PopulusbalsamiferaBalsampoplar18263391568RosaacicularisPricklyrose5640322629ViburnumeduleHighbushcranberry9469515621~Immaturebalsampoplarstandswerenumbers10,12,and26(Figure5).Numberoftransectssampledwas18.'-JwQINoobservationsforage.YOnly13observationsforage.4/Only31observationsforage. Table37.Characteristicsoftreesandtallshrubsinimmaturebalsampoplarstands9!ondownstreamfloodplainofSusitnaRiver,summer1981.MeanMeanMeanNumberofHeightdbhMeanCrownIndividuals(m)(em)AgeDominanceSampledPopulusbalsamiferaBalsampoplar17.724.844236Q!.A1nustenuifo1iaThin1eafalder6.66.922432rdAlnussinuataSitkaalder5.18.52253'11BetulapapyriferaPaperbirch6.212.44341!UPicea9.1auc~Whitespruce2.6--1361if9!Immaturebalsampoplarstandswerenumbers10,12,and26(Figure5).Numberoftransectssampledwas18.Q!Only35observationsforcrowndominance.rdOnly31observationsforage.'"+>'11Have4observationsforage.!UHave2observationsforheight.ifNoobservationsfordbh. 75(iii)LateSuccessionalStandsAsthebalsampoplarstandsmatured,whitespruceoccasionallyappearedinthecanopy.Maturebalsampoplarstandspossiblyoccurred75yearsafterstabilizationandextendedforanother30ormoreyears.Eventually,thebalsampoplarbecomesdecadentleavingspacefordevelopmentofmorebalsampoplarorspruceandbirch,ifnodisturbancesinterrupttheprocess.Thefactorsresponsiblefordevelopmentofthebirch-sprucestandsversuscontinuationofthebalsampoplararestillunclearasisthetimeperiodforitsestablishment.However,geographicandtopo-graphiclocationsandcontinuityofstandssuggestthatbirch-spruceforestoccursonthemoststableandoldestsitescomparedtoeithermatureordecadentbalsampoplarforests.Matureanddecadentbalsampoplarstandscharacterize25to40%ofthevegetatedfloodplainwhilemixedstandsofbirchandspruceoccupy23to32%ofthearea.Matureanddecadentbalsampoplarstands,collectively,averaged90%totalvegetationcover.Balsampoplartrees·provided49%cover,alder44%cover,highbushcranberry21%,pricklyrose15%andbluejoint12%(Table38).Ostrichfern(Matteucciastruthioteris)wasalsoanimportantcomponentoftheunderstory7%covernottypicallYfoundinotherfloodplainplantcommunities.OstrichfernoccurredprimarilyinstandsinmatureanddecadentbalsampoplarstandsnorthofMontanaCreekbutbelowPortageCreek.ItwasusedheavilybymooseinJune.Wehavelaboratorydatafromotherfernspecieswhichindicatethatfernsoftencontainunusuallyhighnitrogenlevelsintheirearlyspringgrowth.Thatfeaturecouldprovideruminantsfeedinguponfernwitharichsourceofproteindependingupondigestibilityofthenitrogencompoundsinthefern.Growthcharacteristicsofpricklyroseandhighbushcranberry,thedominantbrowsespecies,werenotmuchdifferentfromthoseintheimmaturestands(Tables36and39),butdensitiesincreasedfrom2556to12361andfrom1093to23555,respectively(Tables35and40).Thisincreaseinunderstoryislikelyaresultofreducedcompetitionfromtheoverstorybalsampoplar,whichexperiencesnaturalthinning(from1045to294stems/halasitdevelopsintothematureanddecadentstage.Matureanddecadentbalsampoplaraveraged26.4minheightandaveraged98yearsinage,accordingtoourmeasurements(Table41).Thesetreeswereprobablyolderthanrecorded,becausetherottedcenterportionofthetreeswasdifficulttoage.Rotusuallyoccurredat65to80years.Thissameproblemprevented.ouraccuratelyagingsomepaperbirch.OfspecialnotewasthatsomestemsofSitkaalderwereextremelylong-livedrelativetoalderinothersuccessionalstages,andthusthemeanagewas50years.Maximumagesofthesealderapproachedthose(50-70years)weexaminedinanotherstudYduring1980inthelowerSusitnaBasinabovetree-lineneartheCappsglacier.Birch-sprucecommunitieswerecharacterizedby42%coverbypaperbirchand12%coverbywhitespruceintheoverstory(Table42).Tallshrubs,predominantlythinleafalder,accountedfor14%cover.Lowshrubs,forbs,andgrassesprovided40, 44,and18%cover,respectively. 76Table38.Percentcoverinmatureanddecadentbalsampoplarstands~ondownstreamfloodplain,summer1981.CategoryVegetationCategoriesLitterStandingdeadPerennialgrassesPerennialforbsMossesLowshrubsTallshrubsTreesTotalvegetationVegetationbySpeciesorGenusPopulusbalsamiferaAlnustenuifoliaAlnussinuata"iTlbi:irnumeduleRosaacic~scaTamagrostiscanadensisRibesspp.MertensiapaniculataEchinopanaxhorridumRubusidaeusoryopterisdilatataGymnocarpiumsp.MatteucciastruthiopterisStreptopusamplexicaulisPiceaglaucaCornuscanadensisHeracleumlanatumPyrolasp.TrientaliseuropaeaGaliumsp.BalsampoplarThinleafalderSitkaalderHighbushcranberryPricklyroseBluejointCurrantTallbluebellDevil'sclubRaspberrySpinuloseshield-fernOak-fernOstrichfernCucumber-rootWhitespruceBunchberryCowparsnipWintergreenArcticstarflowerBedstraw~1ean%92+1223+3643509049413211512321415711+++++~Matureanddecadentand28(Figure5).balsampoplarstandswerenumbers3,17,24,Numberoftransectssampledwas24. Table39.Characteristicsofwoodyspecies.inmatureanddecadentbalsampoplarstands~ondownstreamfloodplainofSusitnaRiver,summer1981.~1eanMean MeanMeanNumberofHeightLengthHidthMeanCrownIndividuals(cm) (cm)(cm)AgeDominanceSampledRibestristeAmericanredcurrant3829182 716Ribessp.Currant5045253 78RubusidaeusRaspberry6545291 726t.dAlnussinuataSitkaalder24812187968Alnustenuifolia'Thinleafalder20578536 620RosaacicularisPricklyrose6543312 648ViburnumeduleHighbushcranberry8145304648--~Matureanddecadentbalsampoplarstandswerenumbers3,17,24,and28(Figure5).Numberoftransectssampledwas24.t.dOnly24observationsforage."" Table40.Density(stems/ha)ofwoodyspeciesinmatureanddecadentbalsampoplarstands~ondownstreamfloodplain,summer1981.2 - 4 mTall<.4mTall.4- 2 mTall<4cmdbh>4cmdbh>4 mTallTotalPopulusbalsamiferaBalsampoplar294 294AlnustenuifoliaThinleafalder19172236146744841AlnussinuataSitkaalder11127877403PiceaglaucaWhitespruce3 3EchinopanaxhorridumDevil'sclub1410141028RubusidaeusRaspberry218439316115RosaacicularisPricklYrose16111075012361ViburnumeduleHighbushcranberry17222183323555RibestristeAmericanredcurrant65696569------Total121003955625142197855169~Matureanddecadentbalsampoplarstandswerenumbers3,17,24,and28(Figure5).---JNumberof.transectswas24.00Browsablestemswerethosetallerthan0.4mbutwithlessthan4cmdbh. Table41.Characteristicsoftreesandtallshrubsinmatureanddecadentbalsampoplarstands~ondownstreamfloodplainofSusitnaRiver,summer1981.MeanMeanMeanNumberofHeightdbh~leanCrownIndividuals(m)(em)AgeDominanceSampledPopulusbalsamiferaBalsampoplar26.453.29824021AlnustenuifoliaThinleafalder7.17.428542£!AlnussinuataSitkaalder5.316.65052rYBetulapapyriferaPaperbirch14.223.66327'dPiceaglaucal~hitespruce14.023.894316i1~Matureanddecadentbalsampoplarstandswerenumbers3,17,24,and28(Figure5).Numberoftransectssampledwas24.21Only33observationsforageand38forcrowndominance.£!Only32observationsforage.rYOnly1observationforcrowndominance.'dOnly6observationsforageandcrowndominance.fl'-Only14observationsforage......,<.0 80Table42.Percentcoverinbirch-sprucestands~ondownstreamfloodplain,summer1981.CategoryVegetationCategoriesLitterStandingdeadPerennialgrassesPerennia1forbsMossesLowshrubsTa11shrubsTreesTotalvegetationMean%100+1844140145293VegetationbySpeciesorGenusBetulapapyriferaPiceaglaucaAlnustenuifoliaAlnussinuataViburnumeduleRibesspp-.--RosaaciculariscaTamagrostiscanadensisDryopterisdilatataGymnocarpiumsp.EchinopanaxhorridumCornuscanadensisMertensiapaniculataRubusidaeusEPTfObiumangustifoliumEpilobiumlatifoliumSalixnovae-angliaeRubussp.RubuSarcticusTrientaliseuropaeaPaperbirchWhitespruceThinleafalderSitkaalderHighbushcranberryCurrantPricklyroseBluejointSpinuloseshield-fernOak-fernDevil'sclubBunchberryTallbluebellRaspberryFireweedDwarffireweedTallblueberrywillowBrambleNagoonberryArcticstarflower421210519520187441131+++++~Birch-sprucestandswerenumbers4,11,and29(Figure5).Numberoftransectssampledwas20. 81Theaverageheightandapparentageofpaperbirchtreeswas15.5mand72years(Table43).Thisageisalowestimate,sinceunrottedtreetrunksweredifficulttofind.Whitespruceaveraged16.2mand91years.Thinleafalder(>4 mht)averaged5.5mand28years.Thedensityofpaperbirchtreeswas227stems/ha(Table44).Therewere143whitespruce/haand1792alder(allsizes)/ha.Browsablewillow,paperbirch,highbushcranberry,andpricklyrosehaddensitiesof200,750,17050,and16950,respectively.Theseshrubswereabout1mtall(Table45).Birch-sprucestandshadthegreatestvariationinstandstructureofthevegetationtypesfoundonthefloodplain.Therewassomeevidencethatthesestandswereself-perpetuating.Thatis,uponovermaturitythebirch overstoryfalls,makingthesprucemoresusceptibletowind-throwandtherebyallowingapaperbirch"shrub-alder/highbushcranberry-pricklyrosecommunitytoincrease.Theshrubcommunitythenprogressestothebirch-spruceforestconditionagain.Thewoodyspeciescompositionanddensityoftheseralbrushphasemakeitidealmoosehabitat,espe-ciallyasitisinterspersedwiththemorematureforest.(iv)MooseHabitatCharacteristicsHorsetail-willowandhorsetail-balsampoplarplantcommunitiesprovidedasubstantialforageresourceformoose.Closeproximitywithcover(mid-andlate-successionalstands)allowedmostsuchareastoreceiveusebyallageclassesofmooseduringallseasons.However,standswhichwerelocatedfarfromprotectivecovermayonlyhavebeenacceptabletoolderanimals.Horsetailanddryascommunitieswereoflittleornovaluetomooseatanytimeoftheyear,becausethebrowsewaseitherinsufficientortoolow-growing.Mid-successionalplantcommunitiesgenerallyhadfewerstemsofbrowse/haavailabletomoosethanhorsetail-willoworhorsetail-balsampoplarcommunities,butthediversityofbrowsewasgreaterwiththepresenceofshadetolerantspeciessuchashighbushcranberry,raspberry,andpricklyrose.r~id-successionalcommunitiesalsoprovidedamixofforbswhichappearedimportantinthedietsofyoungcalvesandlactatingcows.Bothalderandimmaturebalsampoplarstandsprovideddensehidingandthermalcover.Alderstands,havingverylowbrowsedensities(excludingalder,arelativelYunpalatablespecies),exhibitedextremelyheavyutilizationofbalsampoplar,indicatingmoosemayhavebeenusingthesestandsduringsevereweather.Ouetotheirextensivecoverage,matureanddecadentbalsampoplarandbirch-sprucestandswerethemajorfoodresourceformooselivingonthedownstreamfloodplain.Avarietyofbrowseandforbswerepresentinthesestands.Densitiesofwillowandbalsampoplarwerelessthaninearlysuccessionalstands,butotherspeciessuchashighbushcranberry,pricklyrose,andbirchsaplings(inbirch-sprucestands)wererelativelyabundant.Thedynamicnatureofbirch-sprucestands(i.e.,thecyclingofthestandsfromovermatureoverstorytowind-throwsandbrushfieldsthenbacktomaturebirch-spruce)madethistypeparticularlyattractiveyear-roundhabitatformoose. Table43.Characteristicsoftreesandtallshrubsinbirch-sprucestands~ondownstreamfloodplainofSusitnaRiver,summer1981.MeanMeanMeanNumberofHeightdbhMeanCrownIndividua1s(m)(em)AgeDominanceSampledAlnustenuifoliaThinleafalder5.56.12856AlnussinuataSitkaalder4.37.04550BetulapapyriferaPaperbirch15.529.272230Q!PiceaglaucaWhitespruce16.227.191232~Birchsprucestandswerenumbers4,11,and29(Figure5).Numberoftransectssampledwas20.Q!Only29observationsforageandcrowndominance.00N Table44.Density(stems/ha)ofwoodyspeciesinbirch-sprucestands~ondownstreamfloodplain,summer1981.2-4 mTall<.4mTall.4-2mTall<4cmdbh>4cmdbh>4 mTallTotalAlnustenuifoliaAlnussinuataBetUlapapyriferaPiceaglaucaEchinopanaxhorridumRubusidaeusRosaacicularisiTJ6ijrnumeduleSa1ixnovae:angliaeSpiraeabeauverdianaRibessp.ii:CfiiearubraSalixs-p-.-TotalTh'inleafalderSitkaalderPaperbirchWhitespruceDevil'sclubRaspberryPricklYroseHighbushcranberryTallblueberrywillowBeauverdspiraeaCurrantBaneberryWi11ow5036831671036783-----.lli.14817167173503331183167169501705020010036517103311740013316834242408502271438281608184102765111833850169501721720010010367834675'38870:>w~Birch-sprucestandswerenumbers4,11,and29(Figure5).Numberoftransectssampledwas20.Browsablestemswerethosetallerthan0.4mbutlessthan4cmdbh. Table45.Characteristicsofwoodyspeciesinbirch-sprucestands~ondownstreamfloodplainofSusitnaRiver,summer1981.MeanMeanr,1eanMeanNumberofHeightLength\~idthMeanCrownIndividuals(cm) (cm)(cm)AgeDominanceSampledSalixnovae-ang1iaeTallblueberrywillow1123428663Salixspp.Wi11ow786833761A1nussinuataSitkaalder225101621265Alnustenuifo1iaThin1eafalder226105831158BetulapapyriferaPaperbirch.11666486 69Rosaacicu1arisPri,ck1yrose8149372 637Viburnumedu1eHighbushcranberry9449355640Rubusidaeus-Raspberry5751241716~Birch-sprucestandswerenumbers4,11,and29(Figure5).Numberoftransectssampledwas20.00"" 85(c)TransmissionCorridors(i)Central(DamstoIntertie)Thecentraltransmissioncorridorcrossesadiversenumberofvegetation/habitattypesfoundintheupperbasin(Figure9andTable6).Muchofthediversityresultsfromthelargeelevationdifferencesalongthecorridor.Thepredominanttypesencounteredatthelowerelevations,intheGoldCreekvicinityandinDevilCanyon,areclosedmixedconifer-deciduousforest,closedtallshrub,andclosedbirchforest.Higherelevationsnorthoftheriverarecharacterizedbybirch,lowshrub,sedge-shrubtundra,andmatandcushiontundra.Higherelevationssouthoftheriveralsohaveshrubandtundratypesbutsupportmoreextensivestandsofwoodlandandopenblackspruce.(ii)Willow-CookInletThemappingunitspresentedonFigures7and8andinTables7and8arebasedonvegetationcharacteristicsandnamesaccordingtoViereckandDyrness(1980).Thus,transmissioncorridormappingunitsaresimilartothoseusedintheupperbasin.Deciduousmappingunitsconsistofaspenand/orbirchandcontainbroadleafvegetation.Complexesoftypeswereusedwhereindividualtypesinthefieldweretoosmalltodelineateonthemap.Somecoverclassesmaybeunderestimatedsincetreeshadstartedlosingtheirleaveswhenthecorridorswereflownforfield-checking.TheWillow-CookInlettransmissioncorridorpassesthroughanareadominatedfirstbyclosedbirchandmixedconifer-deciduousforests,nextbylargewetsedge-grassmarshes,andfinallybyopenandclosedsprucestands(Figure7andTable7).TimberedstandsinthisparticularareaoftheSusitnavalleywerecharacterizedbygenerallYgoodstockingofrelativelyhighqualitybirch,whitespruce,andbalsampoplar.However,manyofthestandshavehadpoorregenerationanddevelopedeitherawoodland/shrublandorwoodland/grasslandaspect.Birchwasthepredominantdeciduousspecies.Localizedstandsofbalsampoplarwereassociatedwiththeactiveriverfloodplain(Willowvicinity).Wetsedge-grasswasthesecondmostdominantvegetationtypeinthisarea.Moststandswerequiteextensiveandassociatedwithdiversenetworksofponds,lakes,andmeanderingstreams.Theseareasweregenerallythoughttobeunsupportiveofothertypesofvegetationexceptforscatteredislandsofblackspruceandlowshrubalongdriermargins.WhitesprucedominatedstandcompositionformostofinteriorAlaskabutoccupiedaminoritypositioninthispartoftheSusitnavalley.Thevegetationmapofthiscorridorisnotspecificastosprucespecies.However,mostcommunitiesidentifiedasclosedandopensprucewhichoccurinareasdominatedbymixedconiferdeciduousforestwerelikelywhitespruce.Sprucestandsskirtingwetsedge-grassorlowshrubareasmaybewhiteorblackspruceormixturesofthetwo.Mostwoodlandsprucestandswereblackspruce. 86(iii)Healy-FairbanksThenortherntransmissioncorridorcrossesthreedistinctphysiographi-callyandphytosociologicallydistinctsections:HealytoNenanaRiver,NenanaRivertoTananaRiver,andTananaRivertoFairbanks(Figure8andTable8).TheHealy-to-Nenana-Riversectioncontainsadissectedplateauonthewestside,arelativelyflatareainthemiddle,andtheParksHighwayandNenanaRivertotheeast.Vegetationalongtheridgesleadingfromtheplateauispredominantlyopenspruce,openmixedconifer-deciduous,andopendeciduousforesttypes.TheflatareaispredominantlYlowshrubwithsedge-grassandopenandclosedsprucetypes.Mostofthesprucetreesarerelativelyshortexceptalongthestreams.TheTananaFlatsareaextendsfromjustbeyondtheNenanaRivercrossingtotheTananaRiver.Thissectionischaracterizedbyamosaicofwetvegetationtypesincludingopenspruce(usuallywithlarch(tamarack),.Larixlaricina),lowshrub,andwetsedge-grass.Locationsofmanytypesappeartobecontrolledbyoldstreammeandersanddrainagepatterns.Somepatchesofdeciduousforeststandsalsooccur.Someportionsofthemosaiccouldbedelimitedonthemapwhileothersweretoointermingledtoseparate.Drystreambedshavestringersofothervegetation,suchaslowshrub,throughthem,whichfrequentlycouldnotbedelimitedonthemap.ThesectionfromtheTananaRivertoFairbankspassesthroughrollinghillscoveredpredominantlYwithopendeciduousforestwithsmallareasofsprucelesscommonthanintheprevioussection.Thewoodlandmixedpatchesinthissectionaregenerallycutoverareas.Manyoftheclosedspruceareasproduceveryshort,scrub-liketreesandappearmorelikealowshrubtype.MostspruceareasbetweentheTananaRiverandFairbankscontainonlyspruceandlittlelarch,whileabouthalftheareasintheTananaFlatssectioncontainlarchaswell.Speciesofsprucewerenotcheckedonthegroundbutstandsinlow,poorlydrainedareaswereassumedtobeblackspruce.Individualsinbetterdrainedlocationsmaybeeitherspecies.Thesespeciescouldnotbeseparatedconfidentlywithoutground-checkingmanystands.Therefore,thisvegetationwasmappedasspruce.Thespruce-larchmixturewaseasilyvisiblefromtheairbutcouldnotbedistinguishedontheaerialimagery.Theblackspruce-larchtypewhichisconfinedinAlaskatotheinteriorisgenerallyfoundonlyonwetlowlandsiteswithshallowpermafrost(ViereckandDyrness1980).Larchortamarackisadeciduousconifer.3.5-Wetlands(a)IdentificationandMappingApparentwetlandswithinthedirectimpactareaswereclassifiedandmapped(Figure11)accordingtothatsystem(Cowardinetal.1979)recentlyadoptedbytheU.S.FishandWildlifeService-rUSF&WS1980a). 87Lakes,ponds,rivers,andstreamswerenotspecificallyclassified.Thevegetation/habitatmapswereusedasabasisforpreparingthewetlandsmap.Table46liststhewetlandclassesandcorrespondingvegetationtypes(ViereckandDyrness1980)bythelandscapethatwasactuallymapped.AsindicatedinTable47theremaybeconsiderableamountsofwetlandswithintheprojectarea.Ourestimatesoftotalpalustrinewetlandareas(Table46)wereextremelyliberalsincethewetlandswerehighlyintegratedwithnon-wetlandsandbecausewedidnothavesupportingsoildataforeachofthetypes.Also,althoughthemappingwasperformedusingtheU.S.FishandWildlifeServicesystem,whichisacceptabletotheU.S.ArmyCorpsofEngineersforpermitapPlications,thereareseveralwetlandsmappedunderthissystemthatareoutsideoftheCorp'sjurisdiction.Isolatedwetlands,forexample,withanoutflowoflessthan5cfsareincludedinTable47,butarenotwithintheCorp'sjurisdiction.(b)VascularAquaticPlantsTheobjectiveofthisstudywastoassesstheaquaticvascularplantsgrowingwithinand/oradjacenttopondsandlakes.TheareaofstudyextendedfromDevilCanyontotheconfluenceoftheSusitnaandOshetnaRivers.Selectedpondsandlakeswithintheimpoundmentareaaswellasontheadjacentuplandplateauareaswereevaluated.Twenty-fourlakesandpondswereassessedfromtheground(Figure12).Manyoftheremaininglakesandpondsintheareawereoverflownandinspectedfromtheairtoensuresimilarityamongpondsandtosearchfornewspecies.Thespeciesweredividedinto"true"aquaticsand"bank"species.Althoughthereisnogooddefinitionofaquaticplants,"true"aquaticplantsaredefinedhereasthosegrowingdirectlyinwaterorimmediatelyadjacenttowater.Speciesthatdominatedthebanksorperipheryofthepondsorthatfrequentlyoccurredonfloatingmatswereconsidered"bank"species.Allthespeciesrecordedareconsideredhydrophytes.Thewetlandarea,asdefinedhere,isprimarilyrestrictedtothewetsedge-grasstundratypepresentedinthevegetation/habitatcovermaps,ortheLacustrine-Limnetic-EmergentWetland-VascularwetlandclassofCowardinetll.(1979).TheSusitnaRiveritselfanditstributarieswerenotspecificallyassessedforaquaticplants.Becauseofthehighvelocityofthetributariesandthevelocityandsediment loadofthemainstreamSusitna,theyarenearlydevoidofaquaticvascularplants.However,duringperiodswhenwaterisclear,algalgrowthcanbeofconsiderableimportanceintheSusitnaRiver.Thereareveryfewpondsandlakeswithintheimpoundmentareas.Mostofthewaterbodiesoccurontheuplandplateaubetweentheedgeoftherivercanyonandthesurroundingmountain.ThereareacountlessnumberoflakesinthelargeflatsoftheupperSusitnabasin,suchasthoseinthesoutheasternportionoftheupperbasinintheLakeLouisearea. a/Table47.Hectaresofdifferentwet1andtypesbyprojectcomponent.________WatanaFacilityBorrowAreasImpol.lndmenCCamp,Vi11ageWet1andTypeIDamandSpillwaysandAirstripIA DEFHIPalustrineforested7,408252161338034515Palustrinescrub-shrub1,1261426221219938Palustrineemergent1398 8Lacustrineemergent4Lacustrine548Riverine2,182Tota110,91315032223613327938315OJDevilCanyonFacility<DImpoundment,Wet1andTypeIDamandSpillwaysCampandVillageBorrowAreaKPalustrineforested80011Palustrineshrub-scrub4329Palustrineemergent12LacustrineemergentLacustrine1Riverine810Total1,666-0-40a/WetlandtypesaccordingtoCowardin,etal.(1979).-- 88Table46.VegetationandwetlandclassesfoundintheproposedSusitnaImpoundmentandborrowareas.MappingUnit(Viereck&Dyrness1980)Lakes,pondsRivers,streamsWetsedge-grassLowshrubBirchshrubWi11owshrubOpenblackspruceWoodlandblackspruceOpenwhitespruceClosedwhitespruceOpenbalsampoplarClosedbalsampoplarFWSWetlandClass(Cowardinet~.1979)Lacustrine unconsolidatebottom,aquaticbed,unconsolidatedshoreRiverineUpperPerennialrockbottom,unconsoli-datedbottom,rockyshore,unconsolidatedshorePalustrineorLacustrineemergentPalustrinescrub-shrubPalustrinescrub-shrubPalustrinescrub-shrubPalustrineforestedPalustrineforestedPalustrineforestedPalustrineforestedPalustrineforestedPalustrineforested SUSITNABASINBOUNDARYo510I!IKILOMETERSFIGURE12LOCATIONSOFLAKESandPONDSSURVEYEDFORVASCULARAQUATICPLANTSINAUGUST1980 91MostofthelakesandpondsimmediatelyadjacenttotheimpoundmentareaareclassifiedaccordingtoCowardinetal.(1979)·as:Lacustrine-Limnetic-UnconsolidatedBottomorAquatiC-Bed;orLacustrine-Littoral-AquaticBedorUnconsolidatedBottom.Thedominant"true"aquaticspeciesofthewaterbodieswere:horsetail(Eguisetumfluviatile),burreed(Sparganiumangustifolium),sedge(Carexaguatilis),yellowpondlily(~uPharpolysepalum),mare'stail(Hippurisvulgaris),andbladderwortUtriculariavulgaris)(Table48).BurreedandyellowpondlilyprobablYcontributedmoretototalcoverthanallotherspeciescombined.Yellowpondlily,whichisasubmergedspecieswithlargefloatingleaves,wasparticularlyprominentandformedvastbedsinseveralwaterbodies.Itwasabsentalongtheedgesofpondsbutappearedtogrowbestatdepthsrangingfrom0.6to2.1m.Asaresult,abandofyellowpondlilyfrequentlyoccurredaroundlakesawayfromtheshoresintheareabetweentheshallowsanddeepwater.Burreed,incontrast,frequentlydominatedtheshallowsofthepondswhichwereabout0.15to0.60mindepth.Horsetail,mare'stail,andbladderwortwerealsocommonintheseshallows.Horsetailwascommononrockybottomswherelittleothervegetationoccurred.Bladderwortappearedprominentinshallowshavingamudbottomorabottomoforganicmatter.Dominant"bank"oredgespeciesincluded:horsetail,bluejoint.(Calamarostiscanadensis),cottongrass(Eriohorumspp.),sedge(Carexaquatilis,marshfivefinger(Potentillapalustris,andbuckbeanTMen¥anthestrifoliata).SedgeprobablYcontributedmoretototalcoverthanallotheredgespeciescombined.Itwastheprevalentspeciesofthepondshallowsfromabout0.0-0.3mindepth,alongthepondperiphery,andalsoonfloatingmats,whichweresometimespresent.Thesamespecieswereencounteredinmanyofthewaterbodiesofthearea.TheoneexceptionwastheaquaticvegetationofWatanaLake.ThislakewasdominatedsolelYbypondweed(Potamogetonrobbinsii).Thispondweedisasubmergedrootedaquaticspeciesthatgrewinwaterfromabout1.2to2.4mindepth..Hulten(1968)reportsthatthisspeciesisknownfromhisareaofstudy,butithasonlybeencollectedonceatSummit.Welsh(1974)indicatesthatitisknownfromsouthcentralAlaska,butevidentlyrare.ThereasonforthelackofothervascularplantsinWatanaLakeandthepresenceofPotamogetonrobbinsiiisnotunderstood,althoughat914-melevation,thislakehadthehighestelevationofanywaterbodyassessed.Totalcoverofaquaticvegetationandthewidthofthesurroundingemergentwetlandareavariedfrompondtopond(Table48).Totalcoverappearedtovarydependingupontheproportionateamountofopenwater(ingeneral,morethan2.1mindepth)toshallowwaterpresentineachpond.Thehigherthepercentofshallowwaterthegreatertheareathatsufficientlightcouldpenetratetothebottomand,asaresult,thehigherthecoverofaquaticplants.Thistrendisvalidingeneral,althoughlakesandpondsabove945minelevationusuallyhadsparse Table48AquaticPlantSurvey,SusitnaHydroelectricPrcject,August1980SPECIESPondorLiU<€(#)"1Rl£"Jll)J'\TICS1 2 3 4 5 6 7 8910111213"141516 1718 192C2122 2324Climaciunsp.--Iobssd(a)cIsoetesrruricata--QuillWlrtsEquisetunfluviatile--Horsetaild d dcds sSparganiun~ustifo1iun--Btrrea:!c d d ddd dcdc c d ss c ccf\ltaiDgetonsp.--I'on<I.-eed(nar!U'l-leaved)ccsf\ltamgetonsp.--Pofld...eed(broad-leaved)ssc df\ltamgetonRobbinsii--POI'I:l.eeddf\ltamgetonfilifonnis--I'on<I.-eed'"sSNEriojXlorunspp.--CottongrasssCarexaquatilis--Sedged dc c d dc dNlJI;I1arpolysepalun--Yel1<Joo1pond1ilycdd d d d c d d dd c d d d d dRanunculusconfervoides--Buttercupc d ds ss sPotentillapalustris--MarshfivefingersCallitrichevema--WaterstarWlrtdHippurisvulgaris--Mare'stailcc sdc c s ssM2nyanthestrifo1iata--Buckbeansutriculariavulgaris--BladderWlrtc dc c d ds s da.d"lbninant,c=canmn,s=sparse Table48(Continued,Page2of3)SPECIESPardorLake(#)"iWI("SPECIES1 234 5 6 7 8 9101112131415161718192021 222324\aJSfjlagnunspp.--SfjlagnunI1DSScddEquisetunfluviatile--HorsetaildddslIOOdsiasp.--W:JodsiasCalanagrostiscanadensis--Reedbentg--assd ddccsEriophorunspp.--Cotton9rassd dcdd dcsd cCarexsp.--SedgedddCarexaquatilis--Sedged ddd dd d dddsddd ddd dddCarexrh}flCOjiIysa--Sedgec<DSwIrissetosa--Iriss---Salixsp.--WillowcssPotentillapalustris--Marshfivefingercdccdccdc sscdcI'<1draralapolifo1ia--I'<1drcnEdacM2nyanthestrifo1iata--Buckbeansccds ca.d=dominant,c=common,s=sparse Table48(Continued,Page3of3)Ibrlc:r~(I)2345 67•9101112131415 1617,.19'"21222324(hITotalCover(%)<1<5-0-1-.10-21<50-50-11-51-200-9000-100eD-6O1-50-1>-104D-5O1520-3020-3510-'"Surroundingwetland02-3-:H;6-'l:H;:H;2-9-1>-30l1-31>-253-51>-301>-253D-453-151-22-306-'l12-15:H;2-3Width(Meters)Elevation(Feet)19SO1700mJmJ21802180280019SO19SO1975mJ22802410234018SOmJ;n;oZlSO1800300022502'6025752'60b.datanotrecorded'"-i'> 95aquaticvegetationcoverregardlessofthebottommorphology.Rockysubstrateandrockledgesalsoappearedtolimittheamountofaquaticvegetationcover.Theamountofassociatedemergentwetlandarea,whichwasdominatedbysedgeandothercommonbankspecies,appearedrelatedtosurroundingtopography,bottommorphology,andtheageofthewaterbody.Steepslopesortopographicreliefaroundthewaterbodylimitedtheamountofassociatedemergentwetland.PondsindepressionsonrelativelYflatterrainhadawell-developedassociatedwetlandaroundthem.Organicmatteraccumulatedovertimeandprobablyincreasedtheperipheryareadominatedbyemergentwetlands.Afloatingmatofvegetationwassometimesapartoftheassociatedemergentwetland.Thesematsdevelopedoverwaterandweredominatedbysedge,sphagnummoss,andcommonbankspecies.Asummaryofthedominantaquaticspeciesandfactorsinfluencingtheir"locationinandaroundmanyofthewaterbodiesintheupperSusitnabasinispresentedinFigure13.Theexistenceandsizeofeachzoneindicatedvariesfrompondtopond,althoughthegeneraltrendsoftheareaarepresented.3.6-ThreatenedorEndangeredSpeciesNoplantspeciesarepresentlyofficiallylistedforAlaskabyfederalorstateauthoritiesasendangeredorthreatened;however,37speciesarecurrentlyunderreviewbytheU.S.FishandWildlifeService(USF&WS1980b)forpossibleprotectionundertheEndangeredSpeciesActof1973.InarecentpublicationMurray(1980)discussesthehabitat,distribution,andkeytraitsofmostofthesespecies.Aspecieslist(Table49)extractedfromMurray(1980)wasbelievedtobethemostlikelyplantsofthiscategorytobefoundintheSusitnaRiverdrainage,andinthelandscapetobemodifiedbytheconstructionoftheproposeddamsandassociatedfacilities.Sincetheupperreachesofthedrainagewereexpectedtobetheleastimpacted,themajorportionofthesurveywasdevotedtothestudyofpotentialhabitatsinandaroundtheimpoundments.ThegeneralhabitatrequirementsandoccurrenceoftheseplantspecieswereknownfromprevioustaxonomicandecologicalstudyinAlaska,andfrominformationgivenbyHulten(1968).Severaloftheendangeredspeciesandtheonlythreatenedspecies,(Smelowskiapyriformis),favoredwell-drainedrockyorscreeslopes.PotentialhabitatsweresearchedinAugust,198~andearlyJulY,1981.Threetofourbotanistsandagronomistswerepresentoneachaerialandgroundreconnaissancefieldtrip,thusincreasingtheprobabilityoffindingtheplantspeciesbeingsought.Specificfieldsurveyswereconductedinthefollowingareas:1)theupperdrainagebasin,alpineareasneartheSusitnaandWestForkGlaciers,2)thelowlandsoftheupperdrainagebasin,MaclarenandTyoneRivers,ridges,terraces,andperiglacialfeatures,3)thelowerdrainage,outcrops,andpromontoriesalongtheSusitnaRivernear OPEN WATER ZONE -USUALLY GREATER THAN 2.1 m IN DEPTH -LImE TO NO AQUATIC VEGETATION SCHEMATIC REPRESENTATION DEEP WATER ZONE -WATER FROM 0.6 TO 2.1 m IN DEPTH -USUALLY DOMINATED BY YELLOW POND LILY -SIZE VARIABLE DEPENDING ON BOTTOM MORPHOLOGY SHALLOW WATER ZONE WATER 0.15 TO o.e mIN DEPTH USUALLY DOMINATED BY BUR REED,HORSETAIL. MARE'S TAIL.AND BLADDERWORT -SIZE VARIABLE DEPENDING ON BOTTOM MORPHOLOGY -SPECIES COMPOSITION INFLUENCED BY SUBSTRATE EMERGENT WETLAND PERIPHERY -WATER FROM GROlJN)SURFACE TO a.3m IN DEPTH -MAY CONTAIN A FLOATING MAT OF VEGETATION -DOMINANTS INCLUDE SEDGE,eOTION GRASS,REED BENT GRASS. MARSH FIVEFINGER,BUCKBEAN,AND SPHAGNUM MOSS -SIZE INFLUENCED BY BOTTOM MOllPHOLOGY AND SUflROUNDING TOPOGRAPHY FIGURE 13 A SCt:tEMATIC REPRESENTATION OF THE DOMINANT VEGETATION ASSOCIATED WITH MANY o.F THE LAKES AND PONDS OF THE UPPER SUSITNA BASIN co ()) 97Table49.Listofendangeredandthreatenedplantspecies~/soughtintheuEperSusitnabasinsurveys.inupperKuskokwimR.drainageSpeciesandHabitatSmelowskiapyriformisDrury&NorthAmericaendemiccalcareousscree,talus,RollinsUnofficialStatusQ/ThreatenedspeciesAsteryukonensisCronq.EndangeredspeciesNorthAmericanendemicriverbanks,drystreambeds,riverdeltasandsandgravelsKluaneLake,KoyukukRiverMontiabostockii(A.E.Porsild)S.L.WelshEndangeredspeciesNorthAmericanendemicwet,alpinemeadows,St.EliasMtns.,WrangellMtns.PapaveralboroseumHult.EndangeredspeciesAmphi-Berlngianwell-drainedalpinetundra,WrangellMtns.,St.EliasMtns.CookInletlowlands,AlaskaRangePodisterayukonensisMath&Const.EndangeredspeciesNorthAmericanendemicS.-facingrockyslopes,grasslandsatlowelevations,Eaglearea,YukonborderSmelowskiaborealis(Greene)Drury&RollinsEndangeredspeciesvar.villosaNorthAmericanendemicalpinecalcareousscree,Mt.McKinleyPark,AlaskaRangeTaraxacumcarneocoloratumNels.EndangeredspeciesNorthAmericanendemicalpinerockyslopes,AlaskaRange,YukonOgilvieMtns.OtherEndangeredSpeciesPossibilitiesCryptanthashackletteanaEriogonumflavumvar.aquilinumErysimumasperumvar.angustatumUpperYukonRiverEagle,AlaskaUpperYukonRiver~SpeciesinformationandstatusfromMurray(1980).b/AllspeciesareunderreviewbytheU.S.Fish&WildlifeServicefor-inclusionintheEndangeredSpeciesActof1973. 98WatanaCreek,KosinaCreek,andgravelbarsintheriverbed,4)alternativeaccessroutes,and5)BorrowPit"A"area.Calcareousoutcropareasfoundin1980werere-surveyedatanearlierdatein1981.Aprominentlight-coloredoutcroponthenorthwestflankofMt.Watanasupportedamatandcushionvegetationtypeinwhichmanycalciphilicspecieswerepresent.Theexposedbenchwasbothwell-drainedandcalcareous,requirementsforseveralofthespeciesbeingsought.TheKosinaCreekcalcareousoutcropareawasre-surveyedduringthefirstweekofJulY,198\toobserveatanearlierphenologicaltimethanthe1980survey,andtoobtainfloweringspecimensoftheTaraxacumspeciescollectedpreviously.SeveralfloweringplantsoftheTaraxacumwerecollectedin1981andthepreliminarydeterminationindicatedthatthespecieswas1.alaskanum,acommonspeciesinsomeareas.TheaspectoftheKosinaCreekoutcropsisnorth-facingandthedarksoilaroundthecalcareousrocksisratherfine-grained.TheKosinaCreekoutcropsarealmostaccordantwiththecalcareousoutcropsonthenorthwestsideofMt.Watana,andalsothecalcareouslaggraveldomeswestofWatanaCreek.TheTaraxacumwascollectedinproximitytothecalcareousrocksoftheoutcropandnonewerefoundinthesurroundingvegetationtypes.Thusitmaybeassumedthatthespecieshascalciphilictendencies.SaxifragaoppositifoliaandRhododendronlapponicum,tworecognizedcalciphiles,werenotablyabundantintheKosinaCreekoutcroparea.Thenorthernaccessroadroute(alternativeroutetotheDenaliHighway,nottheproposedroute)totheproposeddamsitewassurveyedinJuly1981bytheplantecologyteam.Twositeswerestudiedonthegroundandtherestoftheroutewasobservedfromlow-levelhelicopterflights.Asandy,blowoutareaonthenorthwestsideofDeadmanMt.onthenorthernaccessroadroutealternativewaschosenforgroundstudy.Thewell-drainedhabitatwasbelievedtobeafavorablesiteforseveraloftheendangeredandthreatenedspecies.Vegetationwasashrubbyheath-birch-willowtype.AsecondsiteonthesouthsideofDeadmanMt.wasstudiedinthesurveyofthenorthaccessroadroute.Aseriesofdryridges,probablyglacialmorainesorterraces,waspresentandthevegetationontwooftheseridgeswassurveyed.Thevegetationwastypicallyamatandcushiontype.AlatersurveywasmadeofthenorthernaccessrouteandagroundstudysitewaschosenontheeastsideofDeadmanMt.nearthe1200-melevation.Theareawascharacterizedbydry,rocky,windblownridgesvegetatedbymatandcushionspecies,andlowshrubwillow-birch-heathvegetationinthemoisterandlowersites.Innoneofthethreesurveyareasonthenorthernaccessroutewereanyofthespeciesinquestionfound.TheotheraccessroutesweresimilarlYsurveyed,buttheplantsinquestionwereapparentlyabsentthereaswell.ThevegetationinthevicinityofBorrowPitAwassurveyedinJulY1981."Thelowridgeareawascharacterizedbyrockyoutcropsintermixed 99withlowareascontainingshrubbyvegetationupto0.5minheight.Inshallowdepressionsorravines,thevegetationcontainedmoreherbsandgrasses,andtallershrubssuchasalder.Nothreatenedorendangeredspecieswerefound.3.7-NoteworthySpeciesTwenty-eightvascularplantspecieswereencounteredduringthesummerof1980intheupperSusitnaRiverbasinandduring1981inthedownstreamareaswhichwereoutsidetherangesindicatedbyHulten(1968)(Table3).Someofthesespeciesmayhavebeenreportedintheareainthe14yearssinceHulten'spublication.Someoftheserangeextensionsaretheresultofmoreintensivebotanicalsurveysintheareawhilesomemayrepresentanactualenlargementoftherangeforsomespecies.BecausetheupperSusitnaRiverdrainageisnotextremelywell-representedinexistingplantcollections,rangeextensions,andsomenewrecordsmaybeexpectedfromanybotanicalsurveysinthearea.TheupperSusitnaRiverdrainagemayrepresentaphytogeographicregioninwhichthelowlandhabitatsoftheCookInletandTalkeetnaRivervalleyextendintotheupperbasinoftheSusitnadrainageandmakecontactwiththearctic-alpinehabitatsandfloraoftheAlaskaRange.AlpinehabitatsclosetomaritimelocationsincentralAlaskahaveuniqueassemblagesofplantspecies,especiallythosecalledtheamphi-Beringianfloristicelement.ArepresentativeexampleofthisfloristictypemaybeseenatHatcherPasSintheTalkeetnaMountains.Twospeciesfoundupstreamrepresentsignificantrangeextensions:SeneciosheldonensisandDanthoniaintermedia.S.sheldonensishadnotpreviouslybeenreportedinthestateexceptpossiblyintheSkagwayarea(Hulten1968).OurspecimenwascollectedinamesicmidgrasscommunityinAugustnearupperPortageCreek,buthasnotyetbeenverified.Thereisatleastoneotherinformalreportofthespeciesoccurringinthestudyarea.Welsh(1974)reportsthatthespeciesoccursinthesouthernYukonandnorthernBritishColumbia.DanthoniaintermediawasfoundinAugustinthegrassportionofamosaicoflowbirchandgrasscommunitiesinthelowshrubareasbetweentheMaclarenRiverandtheDenaliHighway.PreviousrecordingsofthespeciesoccurredneartheupperendofCookInletandtheSkagwayarea(Hulten1968).Moreover,theonlyotherrepresentativeofthegenusinthestate,Q.spicata,hasonlybeenreportedfromnearKetchikan.ThiswouldrepresentasignificantextensionofthegenusalthoughD.intermediawasfoundinonlytheonelocationinourstudyarea.Welsh(1974),incontrast,reportedtheoccurrenceofD.intermediainsouthcentralAlaskawithnospecificlocationsmentioned.Potamogetonrobbinsii,asubmergedrootedaquatic,wasfoundinWatanaLake.TherehasbeenlimitedcollectionofthisspeciesinAlaska.Hulten(1968)reporteditfromhisareaofstudy,butithadonlybeencollectedonceatSummit.Welsh(1974)indicatedthatitisknownfromsouthcentralAlaska,butevidentlYrare. 100ThedistributionofPiceamarianashouldalsobenotedsinceHulten(1968)includedareasnorthandsouthoftheupperSusitnaRiverintherange,butexcludedourstudyarea.ViereckandLittle(1972),however,includedtheSusitnadrainageintheirdistributionmap.Thistreeisoneofthemostcommonspeciesinthestudyarea.Mostotherspeciesontheupperbasinlistrepresentonlyslightrangeextensions.Mostoftheseareextensionstothenorth(moreinland)fromtheirpreviousobservations.ThefindingofPlatantheradilatatarepresentedadeparturefromthepreviouslyreporteddistributionwhichwasstrictlycoastalinAlaska.PlatantherahyperboreaandMyricagaleextensionsincludesitesbetweenareasthatwerepreviouslyincludedintherange.PotentillabifloraandPediculariskaneiDurandkaneiextensionsweresouthofthepreviouslyreportedrange.Bothofthesespecieswerefoundoncalcareousoutcroppings(KosinaCreekandMt.Watana,respectively)whilelookingforendangeredspecies.ThesespeciesareprobablYadaptedtothedrierenvironmentassociatedwiththeinteriororwithcalcareousoutcroppingsintheupperSusitnaRiverbasin.ThedownstreamfloodplaincontainedninespeciesoutsidetheirrangeasreportedbyHulten(1968)(Table3).Twoofthese,devil'sclubandraspberry,wereextensionsintheupperbasinalso,althoughViereckandLittle(1972)includedbothupperandlowerSusitnaRiverintherangeforraspberry.Devil'sclubrepresentsaslightextensionupriver.Themostnotableextensioninthedownstreamportionswassmall-fruitbullrush(Scirpusmicrocarpus)whichhadonlybeenfoundinfourareasoutsidesoutheastAlaska.OneofthosesiteswasneartheconfluenceoftheYentnaandSusitnaRivers.AspecimenwhichappearstobeArnicachamissonis(needstobeverified)representedasignificantextensionfromtheAlaskaPeninsulaandsoutheastAlaska.Thepresenceofenchanter'snightshade(Circaeaalpina)inthedownstreamareawasanextensioninlandfromthecoastalregions.Sweet-scentedbedstraw(Galiumtriflorum)andthinleafalderwereminorextensionswhilebaneberry(Actaearubra)andnorthernblackcurrant(Ribeshudsonianum)wereextensionsfromthesurroundingareasintothebasin.Itshouldberememberedthatmanyoftheserangeextensionsaremerelytheresultofmoreintensivebotanicalcollectionsratherthananactualexpansionofthespectes'range. 1014 -ANTICIPATEDIMPACTSPotentialimpactsonvegetationwereidentifiedbyreviewingpertinentliteratureandbydiscussingwithvariousspecialistsknowledgeableofproblemsassociatedwithhydroelectricdevelopment.Anticipatedimpactareasintheupperbasinandtransmissioncorridorswereidentifiedbyoverlayingexpectedactivitiesonvegetation/habitatmaps.Calculationsofareasizewerebasedonverticalprojection.Becauseofslope,theactualsurfaceareaimpactedwillbesomewhathigherthanthatpresented.ThegenerallocationsoftheprojectcomponentsareindicatedonFigure14.Impactanalysisforthedownstreamfloodplainconsistedofrelatinggeneralchangesinflowduringreservoirfillingandoperationtoplantsuccessiontrends.4.1-WatanaDam,Facilities,andImpoundment(a)ConstructionTheobviousimpactofconstructingthedamandoffillingtheWatanareservoirwillbetheeliminatingofportionsofdifferentvegetation/habitattypes.Thehectaresofeachvegetation/habitataffectedarepresentedincomparisonwiththetotalhectaresofthosetypesintheentireupperSusitnaRiverbasinandinanarea within16kmoftheupperriver(Table50).Atamaximumpoolelevationof666m(2185ft)theWatanaimpoundmentwillinundate approximately14,691ha.Ofthose,12,587haarevegetatedandrepresent0.9%ofallthevegetatedareaoftheupperbasin.Muchoftheimpoundmentareawillbeclassifiedaswetland(Table47).Primarylosseswilloccurinthewoodlandandopensprucestandsandintheopenmixedforests.BirchforestswillbesubstantiallYaffectedbytheimpoundment,relativelymoresothananyothervegetation/habitattype(Table50).TheothertypeswhichwouldexperiencearelativelYmajorimpactareconifer-deciduousforestsandbalsampoplarforests.Additionalimpactonvegetationmayoccurbeyondtheimpoundmentareas,ifroadsorotheractivitiesassociatedwithselectiveclearingofwoodyvegetationfromthedrawdownzonearenotrestrictedtotheimpoundmentzone.Asdiscussedundermitigation(Section5),restrictionofdisturbancetotheimpoundmentareawilllimittheextentofthisimpact.Constructionactivitiesatthedamsite,borrowsites,airstrip,constructioncampandvillagesiteswillresultinalossofadditionalhectaresofvegetation(Table50).Proposedcampandvillagesites,airstripsite,andborrowareaswillbelocatedprimarilyinwoodlandblackspruceandlowshrubstands.BorrowareasDandHalsocoverlargemixedforeststands.BorrowareasmayeventuallyberevegetatedandarediscussedinmoredetailinSection4.3-BorrowAreas.Alloftheaforementionedconstructionactivitieswillbealmostentirelycontainedwithintheareadesignatedasaconstructionzone(Figure14).Thiszonerepresentsthemaximumareaofpotentialconstructiondisturbance. Table50.HectaresofdifferentvegetationtypestobeimpactedbytheWatanafacilitycomparedwithtotal.dintheareawithin16kmoftheSusitnaR',,<::,-LU'<::~v,""UL"J<::."..,,'-..."..........'-,..,..........."'Y<::'•Fac;1;tvC0mD 0nents%DfUpper%Df16kmBorrowAreasBasinArea~./Vegetation/HabitatDamandImpound-Construction1>./TotalForThatTypeSpillwaysmentCampVillageAirstriA0E FHIZone~./TotalForTypeThatTVD'Forest34107841815318081451347825186095.313.1Woodlandspruce-black838701791622425646434}10.2Woodlandspruce-4.2white39771691133 153011.5Openspruce-black28641211514994363}-4.615.4Openspruce-white76926211303107210.2Openbirch1325286611d/63.1d/40.8Closedbirch13460538498-154.2-21.4Closedbalsampoplar33~.5Openconifer-deciduous513373210645317907.718.6Closedconifer-deciduous7759471191549230814.517.5Tundra84708502586.2.5Wetsedge-grass848911753.65.0Sedge-grassSedgeshrub2929b/0.1Matandcushion70382382-:70.7Shrubland4617196362178122419938494266611.03.8Opentallshrub62271227.41.5Closedtallshrub172871122871.8Birchshrub14433435134881952915335810.07.8Willowshrub664172523183.0 3.7Mixed'lowshrub22651292747512421177524260.52.6Herbaceous4545250.0GrasslandDisturbedUnvegetated13210481245625601.09.5Rock1592590.05.36SnowandiceRiver122007287229415.654.2Lake38811692070.83.5Total93146916370173332871802804893413725284161.76.2a/Thisareaencompassesallfacilitycomponentsexcepttheimpoundment,withtheexceptionofminorportionsofBorrowAreasFandI.b/Impoundmentplusconstructionzone.c/Anarea16kmoneithersideoftheSusitnaRiverfromGoldCreektothemouthoftheMaclarenRiver(SeeFigures4through8).711Hectaresofclosedbirchareapparentlygreaterintheimpactareasthanfortheentirebasin,becausethebasinwasmappedatamuchsmallerscale.-andmanyoftheclosedbirchstandsdidnotappearatthatscale.~/AreasofthistypeweretoosmalltobemappedatthescaleofwhichtheupperSusitnaRiverbasinwasmapped. o510I!IKILOMETERSLEGENDCREEKACCESSROAD•ACCESSROADBORROWAREASYARDr:r.CONSTRUCTIONZONEBORROWAREASiiiVILLAGE0CAMP-DAM~IMPOUNDMENT---TRANSMISSION-LINEPROPOSED•••••TRANSMISSION-LINEALTERNATEFIGURE14PROJECTFACILITIES 104Itisunlikelythattheentirezonewillbedirectlyaffected;however,ifallthevegetationisremovedfromthiszone,13,725hectareswillbelostinadditiontothatinthereservoirarealostbyinundation(Table50).Thislossrepresents0.8%oftheentireupperbasin.ReclamationofareasthatwillonlybetemporarilyaffectedwillreducethislossandisdiscussedunderSection5.Thesignificanceoftheselosses,asidefromthevegetationlossitself,willbetheassociatedlossofhabitatforwildlife.Theprincipallossesforbiggamewillbeareducedfoodsupplyforblackbearsandmoose.Browsesuppliesintheimpoundmentareaaremarginalanddonotrepresentalatewinterreserveformoose.Birchandmixedforeststands,however,providebearswithsubstantialberrysuppliesandareparticularlyimportantinthisregardinearlyspring.AmoredetaileddiscussionoftheimpactsonbiggameispresentedinSection3.6(a)(i)(AlaskaPowerAuthority1982).(b)OperationandMaintenanceThepoolelevationoftheWatanaReservoirwillvaryanaverageof27m(90ft),withalowof639m(2095ft)inMay,andagradualincreasetoafullpoolelevationof666meters(2185ft)duringSeptember.Thedrawdownzone(fromfullpooltolowpool)willbeessentiallyunvegetated.Duringdryyears,however,thefullpooltargetelevationmaynotbeattainedandexposedareasthatarenotfloodedmaytemporarilybecomenaturallyrevegetatedwithasparsevegetationcharacterizedbyeasily-dispersed,weedyplantsuntiltheyarefloodedagain.Thegreatestpotentialforthistypeofrevegetationexistsinareasofgentleslope,suchastheWatanaCreekarea.TheWatanaReservoirislocatedinaregionofdiscontinuouspermafrost.Consequently,thereispotentialforearthflowsandslumps,especiallyonnorth-facingslopes,astherelativelywarmreservoirthawsadjacentpermafrost.Thistypeofdisturbancewillmostlikelyoccuronblacksprucesitesandmaylead,inplaces,totheirreplacementbyalderstandsandpossiblybyopenpaperbirchstands.Bankerosionfromwaveactionswillprobablyformterracesatandbelowthefull-poolelevation.AnimpactnotedbyBaxterandGlaude(1980)fornorthernreservoirsisthepotentialforpeatmassestofloattothesurfaceofthereservoir.ThistypeofimpactshouldnotbeextensiveattheWatanareservoir,sinceonlyasmallamountofthepeat-formingwetsedge-grasstypeswillbeinundated.SomepotentialforsuchoccurencesexistsintheWatanaCreekarea.-Therearetwo-otherminorimpactsthatmayoccurduring~heoperationoftheWatanafacility;thepotentialmodificationoflocalclimateandtheicingofvegetationaroundthedamoutflow.Ingeneral,largebodiesofwaterinfluencethelocalclimatebyactingascoldsinksinwinter,therebydelayingtheinitiationofspring,andactasheatsinksinsummer,thusextendinglocalizedwarmweather.Ithasbeenestimatedthatsuchinfluencewillberestrictedtowithin1.6kmofthereservoirshoreline. 105Localclimaticchangesmayresultinminorchangesin·vegetationphenology.Theseverityandextentofthispotentialchangeinvegetationisdifficulttopredict.Theeffectswilllikelybenotedasaslightlaginthephenologicalcycleoftheaffectedarearelativetothesurroundings.Theinfluenceisnotexpectedtoeliminateportionsofthecycle,however.Potentialimpactsonvegetationinthespringmaybemoderatedsomewhat,however,sincethepoolelevationwillbeatitslowestpointthenandthus,thedistancefromthewateredgetothevegetationedgewillbeatitsgreatest.Atthedamoutflow,icefogandwaterspraywillprobablyoccurduringwintermonthswhenthetemperatureisintheapproximaterangeof-120Cto-230C(+100Fto-100F).Thisicefogwillfreezeoncontactwithvegetationandmayaccumulatetocreateloadssufficienttobreaktwigs.Althoughthisimpactwillbeverylocalized,birchtrees,becauseoftheirmanysmallbranches,willbethemostsusceptibletodamage.4.2-DevilCanyonDam,Facilities,andImpoundment(a)ConstructionConstructionandfillingoftheDevilCanyondamandimpoundmentwilleliminateanestimated3214haofvegetation/habitattypes(Table51).Primaryvegetationlosseswillbeofopenandclosedmixedforestsandopenspruceforest.Constructionactivitiesatthedam,camp,andvillagesiteswillfurthereliminateormodifyatleastanother223haofvegetation,primarilyclosedmixedforests.Anestimated1706haofwetlandsarewithinthesedirectimpactareas(Table47).Iftheentireconstructionzone(Figure14)isaffected,5688hawillbelostinadditiontothereservoirarea(Table51).Itshouldbenotedthattheareaoftheconstructionzonerepresentsamaximumpotentialloss;acertainportionofthisareawillprobablynotbedisturbed,andreclamationactivitiescanbeusedtoreclaimareastemporarilyaffected.Themaximumpotentialloss,includingtheconstructionzoneandreservoirarea,represents8884haand0.5%oftheentireupperbasin.VegetationlossesatDevilCanyonwillnotbesignificantintermsofmooseorcaribou,sincemostoftheaffectedareaissituatedonsteepslopeswhicharegenerallyinaccessibletotheseungulates.However,theseareasdoprovidearelativelylargeforagesupplyfor.blackbears.BiggameimpactsaredetailedinSection3.6(b)(i)(AlaskaPowerAuthority1982).(b)OperationandMaintenanceThepoolelevationoftheDevilCanyonreservoirwillfluctuateanaverageof17m(55ft)duringtheyear.Thedrawdownzonecreatedbythisfluctuationwillessentiallybedevoidofvegetation.AsdiscussedfortheWatanareservoir,vegetationmayinvadeinsomeportionsofthiszonewhenthefullpooltargetelevationisnotattained.Incontrast,sincemuchoftheDevilCanyonreservoirisverysteep-sided,thisinvasionmayonlyoccurattheveryupperreachesofthereservoirin FacilitComnonent%ofUpperBasin%of16kmVegetation/HabitatDamandImpound-BorrowConstructionJUTotalArea£!TypeSpll1waysmentCampVi11ageAreaKZone~/TotalForForThatThatTyneT,neForest16228936 39119450467931.94.8Woodlandspruce-black13346179}.3Woodlandspruce-.36white204805003.8Openspruce-black430011785I085t1.63.8Openspruce-white3294748037.7Openblrch5712618318.912.2Closedbirch3430156586<11181<1125.2Openbalsampoplar66elClosedbalsampoplar81422~3.9Openconifer-deciduous72792791.22.9Closedconifer-deciduous272736391082423315019.723.8Tundra112112220.060.2Wetsedge-grass111922034.25.8Sedgegrass1818.01.07Sedgeshrub110.005MatandcushionShrubland70188028720.20.5Opentallshrub2125127.2.8Closedtallshrub11651661.0Birchshrub4918266315.9.7Willowshrub143448.5.6Mixedlow-shrub4212216.05.2HerbaceousGrasslandDisturbedUnvegetated282611171997.43.7Rock15217.02.1SnowandiceRiver18101379476.522.4Lake111132330.130.6Total18319636 39148568888840.51.9Table51.HectaresofdifferentvegetationtypestobeimpactedbytheDevilCanyonfacilitycomparedwithtotalhectaresofthattypeintheentireupperbasinandintheareawithin16kmoftheSusitnaRivera/Thisareaencompassesallfacilitycomponentsexcepttheimpoundment.b/Impoundmentplusconstructionlone.£/Anarea16kmoneithersideoftheSusitnaRiverfromGoldCreektothemouthoftheMaclarenRiver(seeFigures4through8),2../HectaresofclosedbirchareapparentlYgreaterintheimpactareasthanfortheentire'basin,becausethebasinwasmappedatamuchsmallerscale,andmanyoftheclosedbirchstandsdidnotappearatthatscale.~/BalsampoplarstandsweretoosmalltobemappedatthescaleofwhichtheupperSusitnaRiverbasinwasmapped. 107theTsusenaCreekvicinity.AsdiscussedfortheWatanareservoir,erosionofmaterialfromabovethepoolelevationmayoccurafterfilling.Theextentofthisimpactwillvary,dependingonmanyfactors,buttheamountofslumpingwillprobablYbelessthanthatattheWatanareservoir.Soilsurveysareneededtomoreaccuratelypredictsuchoccurences.LocalizedclimaticchangesmayalsooccuraroundtheDevilCanyonreservoir.Becausethereservoirwillbelongandnarrow,theabsolutesurfaceareaofwateradjacenttoanygivenvegetationtypewillberelativelysmall;thustheprobabilityofimpactduetoclimatemodificationoughttobeinsignificant.Finally,theoperationoftheDevilCanyonreservoirwillresultinchangesindownstreamflows,downstreamwatertemperatures,andicecondittons.TheimpactsofthesechangesonvegetationarediscussedinSection4.6-DownstreamFloodplain.4.3-BorrowAreasThecompletedevelopmentofallborrowareasatbothDevilCanyonandWatanawilldestroyanestimated1751haofvegetation/habitattypes(Tables50and51).Thoseportionsoftheborrowareaswithintheimpoundmentandthoseassociatedwithaccessroadconstructionarenotincludedinthisestimate.Thisestimatedoesincludethoseborrowareaswithintheconstructionzonespreviouslydiscussed.Woodlandandopenspruce,lowmixedshrub,andbirchshrubwillbetheprincipaltypesaffected.BorrowAreaK,whichisaquarryassociatedwiththeDevilCanyondam,iscoveredprimarilybymixedforests.Thetotalimpactfromborrowareaswillprobablybelessthanthe1751haestimated,sincecertainareas(possiblyAandH)maynotbeusedandothersmaybeonlypartiallydeveloped.Also,reclamationofalltheseareasispossible(seeSection5).Areasthataredevelopedshouldnot,therefore,bepermanentlydestroyedasaterrestrialhabitatbutmayremainchangedintermsofhabitattypeforalongperiodoftime.Thedevelopmentofborrowareasmayalsoinfluencevegetationinadjacentareasbyloweringthewatertable.ThistypeofimpactwillprobablyonlyoccurtoanynoticeableextentaroundBorrowAreaD,where.adjacentlandtothenorthandwestmaybeinfluenced.Thisimpactwillbelocalized,however,andwillprobablyresultinonlyminorspeciescompositionchangesintheareasaffected.4.4-AccessRoad(a)ConstructionConstructionoftheParksHighway-to-DevilCanyon/Watanaaccessroad(includingrailroadyardandallpotentialborrowareas)willdisturbapproximately900haofvegetation,providingthatmachinerystays 108within30m(100ft)ofthecenterline(Table52).Primarylosseswillbetoopenandclosedconifer-deciduousforestsandlowshrubtypes.Thetotaldirectimpactofthepermanentaccessroadmaybesomewhatlessextensivethantheaforementionedestimate,sincetheroadbedwillonlybeabout14m(45ft)wideandalltheidentifiedborrowareasmaynotbeused.However,thepioneerroadwillprobablycoverseparategroundfromthepermanentaccessrouteincertainareas,andthereforewillresultinadditionaltemporaryimpact.(b)OperationandMaintenanceDuringoperationoftheroad,impactsmayextendbeyondtheroadbaseitself.Wheretheroadrestrictsdrainage,woodyvegetationtypeswillshifttowardsedge-grasstundraandwetsedge-grassconditions.Areaswhicharepresentlywetbutwhichwillbecomedrierwillexperienceagradualinvasionofshrubsandtrees,dependingonspecificsoil/siteconditions.Accumulationsofdustonroadsidevegetationmaycausesnowmelttooccur2-3weeksearlierforadistanceof30-100meithersideoftheroad(CRREL1980).Thisfactor,associatedwithaccumulationsofsomeelements,particularlycalcium,inroaddustandchangesinphotosyn-thesis,maysubstantiallYreducethedensityoffour-an91edcassiope,stiffclubmoss,sphagnummoss,Cladina,andothermossesandlichens;ontheotherhand,cottongrassmayincrease(CRREL1980).Suchshiftsinvegetationcompositionmaybeimperceptibletoanybutthetrainedobserverandshouldnotcauseanysoilerosionproblems.Themostsignificantsourceofimpactassociatedwiththeaccessroadcouldbedamagecausedbyencouragingincreasedoff-roadvehicleuseonsensitivesites(Sparrowet~.1978).Themostextensiveimpactofsuchusewouldbeonwetunstablesoilsandsteepslopes.Levelterrain,rockyandwell-drainedsitesaremostresistant.Userestrictedtotimeswhensoilsarefrozenwouldbeleastdamaging,accordingtoexperiencesintheArctictundratypesoftheNorthSloperegion.Considerablepotentialforfirealsoexists,especiallyduringthespring.Suchaneventcouldbelocalorextendovervastareasdependinguponseveralfactors.Inanyevent,itwouldcausechangesinthevegetationsimilartothosewhichhaveoccurredhistoricallYduetonaturallyoccurringwildfires(i.e.,vegetationwouldbesetbacktoearlysuccessionalstages).Neitherthewetareasnorthesparselyvegetateduplandtundracommunitieswillnormallycarryasignificantfire.However,thebirchandlowmixedshrub,blackandwhitespruce,andmixedconifer-deciduousforesthabitattypesmayigniteintosubstantialfires.Firecouldrevertsuchtypestoseralbrushcommunities,highlyproductiveofmoosebrowse.4.5-TransmissionLines(a)ConstructionConstructionofthetransmissionlineswillresultinlong-termvegetation 109Table52.Hectaresofdifferentvegetationtypestobeimpactedbytheaccessroadcomparedwithtotalhectaresofthattypeintheupperbasinandtheareawithin16kmoftheSusitnaRiver.FacilityComponent%of%ofUpper16kmRail-BasinAreaa/Vegetation/HabitatTypeRight-of-WayBorrowroadofThatofThat(61mwide)AreasYardTotalTypeTypeForestWoodlandspruce2.016.718.7.0010.02Openspruce38.335.573.8.060.2Openbirch10.810.81.00.7Closedbirch4.41.86.22.00.3Closedbalsampoplar14.711.025.74.0Openconifer-deciduous68.74.072.70.7Closedconifer-deciduous163.8141.07.8312.62.0TundraWetsedge-grass8.81.310.10.2 0.3Sedgeshrub17.717.70.09Matandcushion26.526.50.040.04Shrub1andTallshrub63.011.074.00.06 0.03Lowbirchshrub108.032.0140.00.40.33Lowmixedshrub69.03.572.50.010.08Herbaceous-Grassland14.6 14.61.0Disturbed2.07.59.539.0UnvegetatedLakes13.713.70.050.23River2.52.50.020.06Rock1.51.50.0010.01------b/ b/TotalArea613.9266.822.4903.10.06- 0.20-2./Anarea16kmoneithersideoftheSusitnaRiverfromGoldCreektothemouthoftheMaclarenRiver.Q/Thisfigureisnotasummationofthiscolumn,butapercentagedeterminedbydividingthetotalareatobeimpactedbythetotalavailablearea. 110impactswheretowerstructuresandpermanentaccessroadsareplaced.Movementofmachineryoverthegroundwilltemporarilysetbackshrubgrowth.Recoveryfollowingsuchdisturbancesusuallyresultsinimprovedshrubvigorforaperiodoftime.Themajorimpactofconstructionwillbetoreducetheoverstorycoveroftrees.Wheresprucetreesarecut,sprucebarkbeetleproblemsmayarise.IfthedisturbanceoccursduringwinterandthesoilsurfaceisnotsignificantlYexposed,shrubandtreeregenerationcanbeextremelyslow,judgingfromtrailscutinthelowerbasinduringtheoilexplorationperiod.Exposingmineralsoilsintheseareasallowstrees,shrubsandherbaceousbroadleafedplantstoreinvade,andthenaturalforestsucceedsmorequicklYthanwhentheorganicmatisleftintactandonlytreesandshrubsremovedduringright-of-wayclearing.Theestimatedamountsofdifferentvegetationtypesthatwillbewithin.theright-of-wayarepresentedinTable53.Additionalareasmaybeimpactedifaccessroadsareplacedoutsideof.thisright-of-way.Thetransmissionlinebetweenthedamsandtheintertiewillprimarilytraverseclosedconifer-deciduousforestandbirchshrubtype(Table53,Figure9).Utilizationoftheaccessroadtothedamswillhelplimittheimpactinthisarea.FromHealytoFairbanksthetransmissionlinetraversesopenspruceforest,openconifer-deciduousforests,andlowmixedshrubs(Table53,Figure6).ExtensiveclearingwillberequiredfromtheTananaRivertoFairbanks.WithintheroutesegmentfromWillowtoCookInlet(Table53,Figure7),theprimaryvegetationtypesincludeopenspruce,closedconifer-deciduousforest,andwetsedge-grass.Clearingwillalsoberequiredintheforestedareas.Atseveralplaces,thetransmissionlineswillcrosswetlands.TheyareespeciallycommonintheTananaFlatsregionofthenortherncorridor(fromtheNenanacrossingtotheTananaRiver)andalongthesouthernportionoftheWillow-to-CookInletcorridor.Smallwetlandareasmaybespannedwithoutimpact,providingprecautionsaretakenduringconstruction.Largerexpansesofwetlandsthough,willbeadverselyaffected,butimpactscouldbeminimizedifconstruction.timeisrestrictedtowinter.Potentialimpactsincludedirectdisturbanceofwetlandvegetation(andresultantlossofwildlifehabitat)as·wellaschangesindrainagepatternsandpossibleerosionproblems.(b)OperationandMaintenanceMaintenanceofthetransmissionright-of-waymayrequirethetoppingorremovalofthetallertreespecies,suchaswhitespruce,birch,aspen,balsampoplar,andlarch.Periodicclearingoftreesalongtransmissionright-of-wayisexpectedtobenefitwildlifefromthestandpointofincreasedforageproductiononcetheanimalsbecomeaccustomedtothesoundofthelines[seeSection3.6(b)(AlaskaPowerAuthority1982)J.ImpactonvegetationmayalsooccurinthevicinityofthetransmissionlineasaresultofincreasedATVuse.Suchusemaybeespeciallycommonwherethetransmissionlinescrossroadsorotherexistingaccess -_...----..._..--------_.a/HealytoFairbanksDamstoIntertieWillowtoCookInletb/b/b/Tota1Right-of-%ofRight-of-%ofRight-of-%ofRights-Vegetation/HabitatTypeWayCorridorWayCorridorWayCorridorof-WayTable53.Hectaresofdifferentvegetationtypestobeimpactedbythetransmissionfacility1hectaresofthattvpeinthetransmissioncorridForest1533.71.8587.11.7713.52.82834.3Woodlandspruce-black}44.4}2.52.50.1}2D.7}0.8}149.6Woodlandspruce-white82.01.7Openspruce-black}685.2}2.24.90.2}98.D}2.9}812.6Openspruce-white24.50.6Closedspruce74.65.561.71.9136.3Opendeciduous149.71.2149.7Closeddeciduous76.30.776.3Openbirch20.42.520.4..................Closedbirch10.80.6114.83.2125.6Woodlandconifer-deciduous28.83.028.8Openconifer-deciduous251.02.095.41.9111.86.6458.2Closedconifer-deciduous60.21.5346.63.0306.52.8713.3Openspruce/opendeciduous30.83.230.8Openspruce/wetsedge-grass/opendeciduous43.02.243.0Openspruce/lowshrub/wetsedge-grass/opendeciduous70.11.070.1 Table53.(Continued,Page2of2)a/HealytoFairbanksDamstoIntertieWillowtoCookInletb/b/b/TotalRight-of-%ofRight-of-%ofRight-of-%ofRights-Vegetation/HabitatTypeWayCorridorWayCorridorWayCorridorof-WayOpenspruce/lowshrub19.64.219.6Tundra49.61.152.80.2100.61.1203.0Wetsedge-grass29.81.3100.61.1130.4Sedge-grass10.04.410.0Sedgeshrub9.81.752.8O.g62.6Shrubland308.81.8287.20.950.32.4646.3Opentallshrub61.61.361.6Closed,tallshrub34.30.634.3,...,,...,NBirchshrub109.11.0109.1Lowmixedshrub294.11.982.20.950.32.4426.6Lowshrub/wetsedge-grass14.70.914.7Disturbed12.42.912.4Unvegetated18.40.751.30.1219.7Lakes3.71.91.30.125.0River14.70.714.7Total1922.9927.1865.73715.7a/NoneoftheareaeastofCookInletisincludedinthesetotals.b/Theright-of-waywidthwas700feetfortheDevilCanyondamtointertierouteand400feetfortheremainingroutes. 113points.Permanencyofsuchdamageswilllargelybeafunctionofeffectsonsoils.Alterationofthesoilthrougherosionwouldlikelyresultinverylongtermchanges.4.6-DownstreamFloodplain(a)ConstructionDecreasedflowsduringtheperiodoffillingwillenablevegetationtodescendintotheupperportionsofwhatisnowriverchannelbetweentheDevilCanyondamsiteand0.5kmabovetheconfluenceoftheSusitnaandChulitnarivers.However,thedevelopmentofvegetationinthisareawillberelativelynegligible,limitedtofireweed,horsetails,dryas,sweetvetch,andpossiblysomeotherpioneeringspecies.Plantswillberestrictedtointersticesoftherock-armoredchannelbottom.The.periodoffillingwillnotbelongenoughforsufficientwindblownsoiltoaccumulatetoallowforfurthervegetationdevelopment.Becauseofdecreasedflows,areasthatarepresentlyhorsetailcommu-nitiesmayquicklydevelopintobalsampoplarsaplingandwillowcom-munities.Therateofthischangedependsonthesynchronizationofseedcropswithadequateprecipitationandsuitabletemperatures.TheareassupportinghorsetailcommunitiesarerelativelYlimited,however,mostoccurringwithin11kmupstreamoftheconfluenceoftheSusitnaandChulitnarivers.DuringtheperiodofreservoirfillingimpactonvegetationbelowtheSusitna-Chulitnaconfluenceisexpectedtobenegligible.(b)OperationandMaintenanceAtGoldCreek,riverflowsduringthegrowingseason(MaytoSeptember)willbereducedfromanaverageofabout20,000cfstoanaverageofabout10,000cfs.SeasonalfloodswillessentiallYbeeliminated.Asaresult,someofthepresentlyunvegetatedbankareasinthereachfromDevilCanyontotheSusitna-Chulitnaconfluencewillbegintodevelophorsetail,dryas,willow,andbalsampoplarcommunities.Barringdisturbancesbyicejamsandfloods,willowandbalsampoplarrepro-ductionwilldevelopwithinfiveyearsofthelastdisturbinginfluenceonsitespresentlyhavingsandyorsiltysubstrates.Itisestimatedthattheamountofnewlyexposedlandduringthelowerpost-projectflowswillbelessthan50habetweenWhiske~CreekandtheChulitnaRiver.Currentlythereareabout54habarelandexposedatflowsof18,000cfsatGoldCreek.Thiswasestimatedfromaerialphotographstakenat18,000cfs(GoldCreek)onAugust24,1980,andat5,000cfsonOctober19,1981.Theseflowratesareroughapproximationstopre-(20,000cfs)andpost-(10,000cfs)projectflows.Anincreaseinbarelandfrom34hato146hamayoccuronone2.7-mistretchbelowTalkeetnabasedonphotographstakenonAugust24,1981,andAugust24,1980.FlowratesatSusitnaStationonthesedateswere130,000'cfsand119,000cfsrespectively,whichapproximatespre-andpost-projectflows. 114Althoughpost-projectflowsareexpectedtobelower,theyarenotoutsidetherangeofvariabilityforpre-projectflowsbelowTalkeetna.Itshouldbeemphasizedthattheselandestimatesareverycoarseapproximationsbecauseoflimitedphotographyanddifferencesinscaleandqualityofphotographsbetweendates.HYdrologistshaveobservedthataboveTalkeetnatheamountoflanddoesnotvarydirectlywiththeflowrates.Theamountoflandexposedwithanygivendecreaseinflowratedependsuponwhichsideofacertainthresholdthechangeoccurs.ThisisprobablYrelatedtothechannelcross-sectionslope.FlowsconfinedtotheV-shapedportionofthechannelmaydropsubstantiallYwithoutexposingmuchnewground.Whenflowsover-toppinggentlYslopingchannelsidesaredecreased,substantialsurfaceareamaybeexposed.DeterminingtheSusitnaRiver'sflowrateatthebreakbetweenthegentleandsteepslopesofthechannelsideswouldbemostusefulinpredictingeffectsofdownstreamflowsonstreamsidevegetationchanges.Becauseofthelackofinformationonthedownstreamhydrology,estimatesshouldberegardedasverycoarse.Establishmentofsignificantcoveronrockysitesmayrequireseveraldecadestocenturies,andmaybebeyondthescopeofthisproject.Whileadequatewind-blownsandsandsiltsaccumulate,vegetationwillhaveashortstatureforlongperiods.InthedownstreamSusitnaaboveTalkeetna,theareaabovetheleveloftheriverduring40,000cfsflowsisalreadYvegetated.Belowthatlevel,mostofthisareahasarockysubstrate,notconducivetolushgrowth.Consequently,theoverallincreaseinvegetationcoverforthisreachoftheriverwillbeminimalforsometime.BelowTalkeetna,theeffectsofeitherreducedorincreasedflowswillbemoderatedbythecontributionsoftheChulitnaandTalkeetnarivers.Whilethedegreeofmoderationisuncertain,certaintrendsinimpactscanbeexpected.Forexample,theprimaryimpactofdecreasedflowduringsummerbelowTalkeetnawillbetoallowearlysuccessionalvegetationtomovedownontositesthatarepresentlyerodedbyhighsummerflows.Thus,untilanewequilibriumwiththeriverisreached,newearlysuccessionalstandswillmigratetowardthenewlevelofpeakflows,whileolderearlysuccessionalstands(thenlessaffectedbyhighflows)willadvancetoalderandimmaturebalsampoplartypes.Thetimerequiredfordevelopmentofearlysuccessionalvegetationdependsonthefrequencyandseverityofdisturbanceaswellasextentoftheareaandnearnesstoasourceofseedorestablishedvegetation.Techniquesforagingtheearliestherbaceousinvadersareunknown.Woodyindividualswith10yearsofabove-groundgrowthhavebeenfoundinthesestandsalthoughmostwoodyindividualsareinthe4to6-yearoldrange.Individualsmaygrowforanumberofyears,thenbeburiedbysiltandresurface.Approximately10to15yearsafterstabilization,alderbecomesthedominantvegetationandtheimportanceformoosedeclines.Becauseoflimitedknowledgeofriverandvegetationdynamicsintheearlystagesofsuccession,itisdifficulttoestimatehowmuchnewareawouldbegainedandhowmuchearlysuccessionalareawouldbelost. 115FloodsfromtheChulitnaorTalkeetnariversor,inrareinstances,byfloodwaterpassingtheSusitnaprojectmayaltertimeestimates.SucheventsmaymaintainthedistributionofvegetationtypesonthefloodplainbelowTalkeetnasimilartothewayitisatpresent.SincetheDevilCanyon-to-TalkeetnareachoftheriverisexpectedtoremainlargelYice-free,aprincipalenvironmentalforcemaintainingearlysuccessionalvegetationwillbeabsentduringoperation.Thiswillallowpresentearlysuccessionalvegetationtoadvancetolaterforesttypes.DuringsomeWinters,however,accumulationsoficefogonvegetationadjacenttothewidersectionsoftherivermaybreakdowntreesandtallshrubscreatingbrushfieldsofyoungbalsampoplar,willow,andalder.Thiseffectisnotexpectedtoproceedbeyondbank-sidevegetation.4.7-ThreatenedorEndangeredSpeciesNoneoftheplantspeciesunderreviewforpossibleprotectionundertheEndangeredSpeciesActof1973areknowntooccurinthevicinityofanyproposedprojectfacilities,norwereanyofthesespeciesfoundduringsearchesofpotentialhabitat.Althoughsomepotentialhabitatdoesexistintheupperbasin,itisdistantfromanyproposedfacilities.Asaresult,itisnotanticipatedthatanyofthesespecieswillbeadverselyaffectedbyanyprojectactivity. 1165 -HITIGATIONThediscussionof mitigationofimpactsonbotanicalresourcescentersaroundavoidance,minimization,compensation,andrectification.Avoidanceandminimizationare,inmanyinstances,related.Thesetypesofmitigationinvolverefrainingfromunnecessarygrounddisturbanceandregulatingdestructiveactivities,especiallythoseinvolvingheavymachineryandATVusewhensoilsarethawedand/orsaturated.Someofthesefirstmitigationconsiderationshavebeenincorporatedintothetimingofconstruction,thelayout,andthelocationofcertainproposedfacilities.Forexample,placingthetransmissioncorridorclosetotheaccessroadwouldminimizeimpactonvegetationbyencouraginguseoftheroadforaccesstotowerstructures.Winterconstructionwouldalsolimitgrounddisturbance.Locatingsometemporaryfacilitiesorundertakingsomeconstructionactivitieswithinthefutureimpoundmentzonewillalsohelpminimizetheimpactonvegetation.IT,forinstance,accessroadsorotherground-disturbingactivitiesrelatedtotheselectiveclearingofthedrawdownareaarerestrictedtotheimpoundmentzone,whichwilleventuallYbeflooded,thenassociatedimpactswillbelimited.Thelocation,too,withinthereservoirsofseveralofthepotentialborrowareasisanotherexampleofhowthetotalimpactonvegetationcanbeminimized.Asmentionedabove,regulationofATVuseisanimportantaspectofavoidance/minimizationmitigationmethods.Duringtheconstructionperiod,ifATVusefromtheaccessroadisrestricted,thenapotentialimpactonvegetationwillbeminimized.Ifthisrestrictionis·extendedintotheoperationstage(especiallYfromDevilCanyontoWatana)thenimpactwillbefurtherlimited.Anothermitigationtechniqueofthistypeconcernspermafrost.Inareasalongtheaccessroadwheredrainagepatternsmaybechanged,installingculvertsorotherdrainageviaductswillcontrolimpactsassociatedwiththosechanges.Asufficientlythickinsulatinglayerofgravel,placeddirectlyonthevegetationmat,willlimitthepotentialformeltingofpermafrost.ThisstandardArch"c"constructiontechniquewillavoidimpactsonvegetationassociatedwithpermafrostdisturbance.Slashfromsprucetreesthatarecutfromtheaccessroadortransmissionright-of-waywillincreasethepotentialforsprucebarkbeetleinfestation.Theburningofspruceslashwouldlimitorremovethispotential.Inareasthatwillbedirectlyaffected,suchastheimpoundmentzones,damsandspillways,airstripandotherpermanentfacilities,theeliminationofvegetation/habitatareacannotbeavoided.Compensationforlossesofwildlifehabitatcouldbeprovided,inadjacentopenandwoodlandsprucestands,and/ordownstreambalsampoplarstands.Downstreambalsampoplarstands,inparticular,providethegreatestopportunity 117forincreasedbrowseproductionandarelocatedinprimemooserange,whereincreasedbrowseproductioncanbemorefullyutilizedbyaconsistentlY.productiveherd.Compensationtechniquescouldincludeclearing(commercialorotherwise)and/orburningtoenhancesproutingofpoplar,birch,andwillowspecies.Commercialclearing ofdownstreamstandswillbeeconomicallYattractive,willbenefitmoose,andwillprobablyalsoincreasethevalueoftimberinthearea,asdecadentanddiseasedstandsofbalsampoplarandbircharecutandreplacedbyyounger,healthiergrowth.Compensation,asamitigationintechnique,forthebenefitofwildlife~---------------~-sai-sC[fs-s-e-d-i-n-gr-en~-rae-tailintheViildlifeSection3.9(b)(iii)(AlaskaPowerAuthority1982).Althoughpermanentfacilitieswilleliminatecertainareasasvegetation/habitattypes,impactfromtemporaryfacilitiesoractivitiescanbesomewhatrectifiedbyreclamation.Standardconstructionpracticesofeitherrecontouringor creatinggentleslopeswillhelpavoiderosion.problemsandwillaidreclamationefforts.Borrowareas,accessroadcuts,areasofconstructionactivity,andtemporaryfacilitysiteswillberevegetateduponcompletionofconstruction.Thisrevegetationprocesswillbegreatlysimplifiedandacceleratedbystockpilingbothtopsoilandtheorganiclayerduringconstruction.Thestockpilingandredistributionofthismaterialisthemostimportantpartofreclamation.Redistributionofthesematerialsandsubsequentfertilizationwill,inmanyinstances,restorethevegetationcover.Thefirststepin.theprocessistomixorganicmaterialintotheupper10cmofmineralsoils.Adequatefertilizationcanthenbeaccomplishedbyusingfertilizermixtureshighinphosphorus[suchas(N,P,K)10-20-10,8-32-16,etc.]andapplyingthefertilizerataratesufficienttosupply85to110kgofnitrogenperhectare(75to100lbsofnitrogenperacre).Duringthesecondandthirdgrowingseasons,follow-uptreatmentsatone-halftoone-thirdtheoriginalratewillprobablybewarranted.Withtopsoilinplace,fertilizationalonewilloftenprovidethenecessaryimpetusfornaturalrevegetation.Vihereerosionpotentialoraestheticconsiderationsaregreat,however,moreintensiverevegetationpracticesinvolvingmulchingandseeding,preferablywithnativespecies,couldbeemployed.ExperienceinotherregionsofAlaskaindicatesthatarelativelylightseedingrate,whichwouldestablishasparsestandofgrass,isthebestwaytoencouragerapidre-invasionofnativeplants.Tento20well-establishedgrassplantspersquaremeter(oneortwopersquarefoot)wouldbeadequateonsitesnotthreatenedbyerosion. 1186 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119*CRREL.1980.Environmentalengineeringandecologicalbaselineinvesti-gationsalongtheYukonRiver-PrudhoeBayhaulroad.JerryBrownandR.L.Berg(eds).187p.Drury,W.H.,Jr.1956.BogflatsandphysiographicprocessesintheUpperKuskokwimRiverregions,Alaska.ContributionsGrayHerbariumHarvardUniversity.130p.Dyksterhuis,E.J.1958.Ecologicalprinciplesinrangeevaluation.BotanicalReview24:253-272.Gatto,L.W.,C.J.Merry,H.L.McKim,andD.E.Lawson.1980.Environ-mentalanalysisoftheUpperSusitnaRiverBasinusingLANDSATimagery.U.S.ArmyColdRegionsResearchandEngineeringLab.,ReportCRREL80-4,Hanover,N.H.,56p.Goff,F.G.1968.Useofsizestratificationanddifferentialweightingtomeasureforesttrends.AmericanMidlandNaturalist79:402-418.Hanson,H.C.1953.VegetationtypesinnorthwesternAlaskaandcomparisonswithcommunitiesinotherarcticregions.Ecology34:111-140.Haug,P.T.andG.M.VanDyne.1968.Secondarysuccessioninabandonedcultivatedfields:Anannotatedbibiliography.ORNL-TM-2104.p.1-70.(OakRidgeNationalLaboratory,OakRidge,Tenn.)Hegg.K.M.1970.ForestresourcesoftheSusitnaValley,Alaska.UnitedStatesDepartmentofAgriculture,ForestServicePublication.PNW-32.Henry,J.D.andJ.M.A.Swan.1974.Reconstructingforesthistoryfromliveanddeadplantmaterial:AnapproachtothestudyofforestsuccessioninsouthwestNewHampshire.Ecology55:772-783.*Hettinger,L.R.andA.J.Janz.1974.Vegetationandsoilsofnorth-easternAlaska.ArcticGasBiologyReportSeries21.NorthEngineeringServiceCo.,Ltd.Edmonton,Canada.206p.Itow,S.1963.GrasslandvegetationinuplandsofwesternHonshu,Japan.PartII.SuccessionandGrazingIndicators.JapaneseJournalofBotany18:133-167.Leeuwen,G.G.1966.Arelationtheoreticalapproachtopatternandprocessinvegetation:Wentia15:25-46.Mueller-Dombois,D.andH.Ellenberg.1974.Aimsandmethodsofvegetationecology.JohnWileyandSons,NewYork.547p.Pichi-Sermolli,R.E.1948.Anindexforestablishingthedegreeofmaturityinplantcommunities.JournalofEcology36:85-90. 120*Sparrow,S.D.,F.J.Wooding,andE.H.Whiting.1978.Effectsofoff-roadvehicletrafficonsoilsandvegetationintheDenaliHighwayregionofAlaska.JournalofSoilandWaterConservation33:20-27.Spenceley,A.P.1973.Theeffectofthestratificationofvegetationon,theanalysisofsuccessionaldata.JournalofEcology61:767-773.*Viereck,L.A.1966.PlantsuccessionandsoildevelopmentongraveloutwashoftheMuldrowGlacier,Alaska.EcologicalMonographs36:181-199.*Viereck,L.A.1970.ForestsuccessionandsoildevelopmentadjacenttotheChenaRiverininteriorAlaska.ArcticandAlpineResearch2:1-26.*Viereck,L.A.1975.ForestecologyoftheAlaskaTaiga.ProceedingsCircumpolarConferenceonNorthernEcology,1975.Viereck,L.A.,J.Foote,C.T.Dyrness,K.VanCleve,D.Kane,andR.Seifert.1979.PreliminaryresultsofexperimentalfiresintheblacksprucetypeofinteriorAlaska.UnitedStatesDepartmentofAgriculture,ForestServicePublication.PNW-332.Whitford,P.B.1949.Distributionofwoodlandplantsinrelationtosuccessionandclonalgrowth.Ecology30:199-208.Zedler,P.H.andF.G.Goff.1973.SizeassociationanalysisofforestsuccessionaltrendsinWisconsin.EcologicalMonographs43:79-94.RemoteSensing:Hironaka,M.,E.W.Tisdale,andM.A.Fosberg.1976.UseofsatelliteimageryforclassifyingandmonitoringrangelandsinsouthernIdaho.Forest,Wildlife,andRangeExperimentStationBulletinNumber9.UniversityofIdaho..McKendrick,J.D.andP.C.Scorup.1974.Asuperbird'seyeviewofAlaska.Agroborealis6:26-30.Payne,D.P.1975.Introductiontoaerialphotographyfornaturalresourcemanagement.OregonStateUniversityPress.324p.Poulton,C.E.1971.Inventoryandanalysisof'naturalvegetationandrelatedresourcesfromspaceandhighaltitudephotographyannualprogressreport.Calif.Univ.,BerkeleyForestryRemoteSensingLaboratory,UnitedStatesForestService. 121VegetationClassification/MappingAlaskaDistrictCorpsofEngineers.1979.WetlandssurveyoftheWatanaandDevilCanyondamsites.DepartmentoftheArmy,Anchorage,Alaska.*Bailey,R.G.1976.EcoregionsoftheUnitedStates.UnitedStatesDepartmentofAgriculture.ForestService.Ogden,Utah.*Bailey,R.G.1978.DescriptionsoftheecoregionsoftheUnitedStates.UnitedStateDepartmentofAgriculture.ForestService.Ogden,Utah.*Cowardin,L.M.,V.Carter,F.C.Golet,andE.T.LaRoe.1979.Classifi-cationofwetlandsanddeepwaterhabitatsoftheUnitedStates.UnitedStatesFishandWildlifeServicePublicationFWS/BS-79/3J.*JointFederal-StateLandUsePlanningCommissionofAlaska.1973.MajorecosystemsofAlaska(map).Kuchler,A.W.1967.Vegetationmapping.RonaldPress,NewYork.Kuchler,A.W.1964.Whereiswhat?Bio-Science14:39-41.McCormick,J.1978.Ecologyandregulationoffreshwaterwetlands.IN:FreshwaterWetlands:EcologicalProcessesandManagementPotentialTR.E.Good,D.F.Whigham,andR.L.Simpson,eds.),p.341-355.AcademicPress,NewYork.Mueller-Dombois,D.andH.Ellenberg.1974.Aimsandmethodsofvegetationecology.JohnWileyandSons,NewYork.547p.Payne,D.P.1975.Introductiontoaerialphotographyfornaturalresourcemanagement.OregonStateUniversityPress.324p.Sochava,V.1975.Thecontentofvegetationmapsandhowtoenrichit.XIIInternationalBotanicalCongress,Section8,EcologicalBotany.PaperforPresentationatSymposium:LogicalPrinciplesofConstructionandImprovementofInformationContentofVegetationMaps.*Spetzman,L.A.1963.TerrainstudyofAlaska,PartV:Vegetation.EngineerIntelligenceStudy.Office,ChiefofEngineers,DepartmentoftheArmy,Washington,D.C.(map).*UnitedStatesFishandWildlifeService.1980a.Notice.FederalRegister,Vol.45,No.193.*UnitedStatesFishandWildlifeService.1980b.Endangeredandthreat-enedwildlifeandplants:reviewofplanttaxaforlistingasendangeredorthreatenedspecies.Vol.45,No.242.*Viereck,.L.A.andC.T.Dyrness.1980.ApreliminaryclassificationforvegetationofAlaska.PacificNorthwestForestandRangeExperimentStation,GeneralTechnicalReport.PNW-106.38p. 122Walker,D.A.,P.J.Webber,andV.Kom&rkova.1979.Alargescale(1:6000)vegetationmappingmethodfornortherntaiga.InstituteofArcticandAlpineResearch.Unpublishedmanuscript.48p.Other:--*AlaskaPowerAuthority.1980a.SusitnaHYdroelectricProjectEnvironmentalStudiesProceduresManualsubtask7.12:PlantEcologyStudies.SubmittedbyTerrestrialEnvironmentalSpecialists,Inc.andtheUniversityofAlaskatoAcresAmerican,Inc.fortheAlaskaPowerAuthority,Anchorage,Alaska.*AlaskaPowerAuthority.1980b.Studiesidentifychangeindownstreamwaterflow.TheSusitnaHydroStudies.November1980.p.5.*AlaskaPowerAuthority.1982.SusitnaHYdroelectricProject:FeasibilityReport.Volume2:EnvironmentalReport,Sections1-4(FinalDraft).AlaskaPowerAuthority,Anchorage,Alaska.Ballard,W.1980.Upstreammoosestudies.QuarterlYreport,SusitnaHYdroelectricProject,EnvironmentalStudies.Rost,G.R.andJ.A.Bailey.1979.Distributionofmuledeerandelkinrelationtoroads.JournalofWildlifeManagement.43:634-641.*Skoog,R.O.1968.EcologyofthecaribouinAlaska.Ph.D.Dissertation.UniversityofCalifornia,Berkeley.'UnitedStatesArmyCorpsofEngineers.1978.PlanofstudyforSusitnahydropowerfeasibilityanalysis.UnitedStatesArmyCorpsofEngineers,AlaskaDistrict.Wallmo,O.C.,D.F.Reed,andL.H.Carpenter.1976.Alterationofmuledeerhabitatbywildfire,logging,highways,agriculture,andhousingdevelopments,p.37-47.IN:MuledeerdeclineintheWest--Asymposium.UtahAgriculturalExperimentStationPublication.134p.Ward,A.L.1979.Dispersedrecreationimpactonbiggameresource.IN:Dispersedrecreationandnaturalresourcemanagement--Asymposium.CollegeofNaturalResources,UtahStateUniversity,Logan.(inpress).*ReferencesactuallYcitedinthisreport. 1237-AUTHORITIESCONTACTEDFederalAgencies:BureauofLandManagementAnchorage,AlaskaSteveTalbot,Ecologist-LetterfromB.Collins29Sept.1980;requestofplantspecieslistofWatanaMtn.area.PaulaKrebs,RemoteSensingSpecialist-TelephonecallfromB.Collins9July1980;requestforpreliminaryvegetationmapoftheDenalistudy.(CopiesofmapsreceivedAug1980.)ForestService(ForestandRangeExp.Station)Anchorage,AlaskaFredLarson,ResearchForester-VisitfromB.CollinsandP.Scorup8May1980;requestingcooperativeagreementforinventoryandanalysisofplantcommunitiesintheupperSusitnabasin.ForestService(ForestandRangeExp.Station)Fairbanks,AlaskaLeslieViereck,PlantEcologist-21May1980;metwithB.Collins(inAnchorageatALMCTFmeeting)todiscussneedforahierarchicalclassificationofAlaskavegetation.CharlesW.Slaughter,Ecologist- 9Jan.1981;LetterfromB.Collinsrequestingliteraturedealingwithforestandfloodplainsuccession.SoilConservationServiceWeymethLong,DirectorofStateOffice-15May1980;handdeliveredletterofcooperativeagree-menttoobtainapprovalforcooperativestudyofvegetationinupperSusitnabasin.AgriculturalStabilizationandConservationServiceSaltLakeCity,UtahLolaBritton,FileManager- 6May1980;21July1980;ordersforCIRimageryoftheupperSusitnabasin.-19Feb1980;telephonecallfromJ.McKendricktodiscussavailabilityofCIRimagerycoveringupperSusitnabasin.-.10,11,18June1980;telephonecallsfromB.CollinsarrangingforCIRimagery. 124FishandWildlifeServiceKenai,AlaskaWayneRegelin,ResearchBiologist-27May1980;visitfromB.CollinsandJ.McKendrickdiscussingtechniquesforassessmentofmoosebrowseproductionandutilization.StateAgencies:AlaskaDept.ofFishandGamePaulArneson,BiologistSuzanneMiller,Statistician-13May1980;metwithB.CollinstodiscussneedsoflowerSusitnamoosehabitatstudy.-6June1980;metinthefieldwithB.Collinstotesttechniquesforsamplingmoosebrowseproduction/utilization~CharlesSwartz,Biologist-27May1980;metwithB.CollinsandJ.McKendricktodiscussmethodsforevaluatingmoosehabitatandnutritionalvalueofbrowsespecies.KarlSchneider,Biologist5June1981;telephonecalltoB.CollinsconcerningADF&G'sdiscontinuanceofbrowseproduction/utilizationworkinPhaseI.SterlingMiller,Biologist-23Nov.1981;telephonecallfrom.B.CollinsexplaininghowtousethevegetationclassificationbyViereckandLittle(1980),asitpertainedtoourvegetationmaps.ButchYoung,Biologist-June1981;telephonecalltoB.Collinsas~ingforinformationconcerningareasofresearchbeingconductedby·p1antecologystudyteam.Requestedpertinentliteraturereferences.24June1981;letterfromB.Collinsgivingreferencestovegetationsuccessionpapers.LocalAgencies:Matanuska-SusitnaBoroughLeeHyatt,ActingBoroughf.\anarer-8May1980;letterfromB.Collinstorequestcooperativepurchaseof1:63,360scaleCIRphotographyofupperSusitnabasin. sd~W+~+>q~H/uo>+~+a5aAXlON3ddlt OPENSPRu<:£WOOOUHOSPRUCEIVEOETATtoNKEYI3!5MILES2234KILOMETERS~CLOSEDSPRUCEr=:lWETL!!!JSEDGEGRASSr:::lCLOSED~BIRCHFORESToo,~'--:::'1j,I;I,\,~.lI1,.;1IIIt,'-'0IIII'jI"~•,"'r=lOPEN~BIRCHFORESTr:::ICLOSED~BALSAMPOPLAItr::=lOPEN~8A.LSANPOPLARr::::ICLOS£D~MIXEDFOft£ST~OPEN~MIXEDFOft!lT~CLOSED~TALLSHRUBBLOWSHRUB~DISTURBEDQLAKESVEGETATIONMAPOFPROPOSEDWILLOW-COOK'INLETTRANSMISSIONCORRIDORFIGURE7SHEET1of2 ....:!,",..""\;:,,\~1"~i",-::0"_.!",,_t.'~__.:'-ooaZMILES23--I 234!5KILOMETERSyEUTAT!OIfK[{~CLOSEDSHOCI:r::::lWETL!!!JSEOOI:.•IftASlWOOllUHO"'RUCEr::::lelOtED~BIIteHFORESTr:::lOPEN~IlRCHFOREtTr:::ICLOSED~tAU'"POP\.Mr:::'lClOHO~IlIIX1ED'OMITr::::I_N~1IIl)([DFOMIT~CLOSED~TALLSHRUI~LOWIHftUI~DIITURal:DDLAICUVEGETATIONMAPOFPROPOSEDWILLOW·-COOKINLETTRANSMISSIONCORRIDORFIGURE7SHEET2of2 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