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Transcript
ClimateChangeVulnerability
AssessmentforColorado
BureauofLandManagement
December2015 CNHP’s mission is to preserve the natural diversity of life by contributing the essential scientific foundation that leads to lasting conservation of Colorado's biological wealth. ColoradoNaturalHeritageProgram
WarnerCollegeofNaturalResources
ColoradoStateUniversity
1475CampusDelivery
FortCollins,CO80523
(970)491‐7331
ReportPreparedfor:
BureauofLandManagement
ColoradoStateOffice
2850YoungfieldStreet
Lakewood,Colorado80215
RecommendedCitation:
ColoradoNaturalHeritageProgram[CNHP].2015.ClimateChangeVulnerabilityAssessmentfor
ColoradoBureauofLandManagement.K.Decker,L.Grunau,J.Handwerk,andJ.Siemers,editors.
ColoradoNaturalHeritageProgram,ColoradoStateUniversity,FortCollins,Colorado.
Individualchaptersmaybecitedassuggestedbelow.
Frontcover:KnowlesCanyon,photo©PeggyLyon.
Climate Change Vulnerability
Assessment for Colorado Bureau
of Land Management
Colorado Natural Heritage Program Warner College of Natural Resources Colorado State University Fort Collins, Colorado 80523 December2015
EXECUTIVE SUMMARY
TheColoradoofficeoftheBureauofLandManagement(BLM),whichadministers8.4millionacres
ofColorado’ssurfaceacres,andmorethan29millionacresofsub‐surfacemineralestate,hasbeen
chargedwithdevelopingaclimateadaptationstrategyforBLMlandswithinthestate.The
assessmentspresentedhereinpresentastatewideperspectiveonthepotentialfutureinfluencesof
achangingclimateonspeciesandecosystemsofparticularimportancetotheBLM,withthegoalof
facilitatingdevelopmentofthebestpossibleclimateadaptationstrategiestomeetfuture
conditions.
TheColoradoNaturalHeritageProgramconductedclimatechangevulnerabilityassessmentsof
plantandanimalspecies,andterrestrialandfreshwaterecosystems(“targets”)withinatimeframe
ofmid‐21stcentury.Ourassessments1)evaluatethepotentialimpactoffutureclimateconditions
onbothspeciesandecosystemsbyidentifyingthedegreeofchangeexpectedbetweencurrentand
futureclimateconditionswithintheColoradorangeofthetarget,and2)addressthepotential
impactofnon‐climatefactorsthatcanaffecttheresilienceofthetargettoclimatechange,orwhich
arelikelytohaveagreaterimpactduetoclimatechange.Climatechangevulnerabilityassessments
arenotanenduntothemselves,butareintendedtohelpBLMmanagersidentifyareaswhereaction
maymitigatetheeffectsofclimatechange,recognizepotentialnovelconditionsthatmayrequire
additionalanalysis,andcharacterizeuncertaintiesinherentintheprocess.
Ecosystems
Sixteenterrestrialecosystemtypesandsixfreshwaterecosystemgroupswereassessedundera
highradiativeforcingscenario(RCP8.5)fortheirrelativevulnerabilitybymid‐century.Terrestrial
typesincludedsixforestorwoodlandtypes,fourshrublandtypes,fourherbaceousorgrassland
types,andriparianandwetlandareas.Fourterrestrialtypes(pinyon‐juniperwoodland,shortgrass
prairie,andriparianandwetlandareasoftheeasternplains)wererankedwithhighvulnerability,
andasingletype(riparianwoodlandandshrublandoflowerelevationwestslopeareas)was
rankedwithveryhighvulnerability.Mostterrestrialecosystemswererankedwithlowormoderate
vulnerabilitytotheeffectsofclimatechangebymid‐century.
Themajorityofterrestrialecosystemswereevaluatedascurrentlyhavinglowtomoderate
resiliencetoclimateimpacts.Actionsthatincreaseecosystemresilienceandenhancetheadaptive
capacityofthesetargetswillcushiontheirvulnerabilitytochangingclimateconditions,andshould
beaprimaryfocusofmanagementefforts.Forforestandwoodlandecosystems,adaptationactions
arelikelytofocusondisturbancefactorssuchasfireandinsectoutbreak,whileforshrublandand
herbaceousecosystems,reducingtheimpactsofanthropogenicfragmentationanddisturbanceis
centraltoadaptationmanagement.
Freshwaterecosystems(streams,rivers,lakes,andreservoirs)wereevaluatedinrelationtoa
modeledtransitionzonebetweenwarmandcool‐tocold‐waterhabitatsthatcomparedcurrent
ii Colorado Natural Heritage Program © 2015 reachextentineachzonetowhatcouldbeexpectedunderwarmerfutureconditions.Resultswere
summarizedbythreeregions(easternplains,mountain,andwesternvalleys).Overallvulnerability
offreshwaterecosystemswasnoticeablyhigherthanforterrestrialtypes.Fouroftheevaluated
freshwaterecosystems,primarilythoseoflowerelevations,hadvulnerabilityranksofhighorvery
high.Onlystreamsofhigherelevationswereconsideredtohavelowvulnerability.
Nearlyallfreshwaterecosystemshavemoderatetohighexposuretopotentialimpactsfromclimate
change,andgenerallymoderatelevelsofresilienceoradaptivecapacity.Asaresult,mostofthese
typeswillremainmoderatelyvulnerableatbest,evenunderconditionsofimprovedresilience.
Actionsthatmaintainorincreasehydrologicconnectivityandreducenon‐climateimpactsarethe
primarymeansbywhichadaptivecapacityinfreshwaterecosystemscanbemaintainedor
increased.
Species
Ninety‐eightspecies(36animalsand62plants)wereevaluatedforvulnerabilitybymid‐century
usingtheNatureServeClimateChangeVulnerabilityIndex,underahighcumulativecarbon
emissionscenario(SRESA2).
Animalspeciesincludedfouramphibians,thirteenbirds,ninefish,oneinsect,sixmammals,and
threereptiles.Fivespecieswererankedasextremelyvulnerabletoclimatechange.Overall,42%of
theevaluatedanimalspecieswererankedwithhightoextremevulnerabilitytoclimatechangeby
mid‐century.Fish,inparticular,wererankedonthehightoextremelyvulnerableendoftherange;
othertaxonomicgroupsweregenerallymoreevenlydistributedbetweenpresumedstabletohighly
vulnerable.
Nearlyallofthevascularplantspecies(59of62)evaluatedwererankedwithextremelyhigh
vulnerabilitytoclimatechangebymid‐century,generallyduetotheirhighlyrestricted
distributions,naturalbarrierstomovementandrelativelylimiteddispersalabilityand/or
pollinatorspecificity.Restrictiontoaparticularphysiologicalhydrologicalniche,ortouncommon
geologicfeaturesandsubstratesalsotendtoincreasethevulnerabilityofmostofColorado’srare
plants.
Conclusions
Theclimatechangevulnerabilityassessmentspresentedhereinprovideabasicfoundationforthe
developmentofadaptationstrategiesgoingforward.Togetherwithclearlyarticulatedgoalsand
objectivesfortheconservationofimportantBLM‐managedresources,theinformationincludedin
theseassessmentshighlightingthepotentialimpactsofclimatechangeandspecies‐orecosystem‐
specifickeyvulnerabilitiescanbelinkedtospecificmanagementactionsthatareintendedto
addresschangingclimateconditions.
Itisimportanttorecognizethatspeciesassemblagesareverylikelytochangefromwhathasbeen
seeninthehistoricpast,sothattheinvestigationofshiftingdistributions,alteredecological
Climate Change Vulnerability Assessment for Colorado BLM iii functions,andcriticalthresholdsthataretiedtoawarmingclimatewillprovideessentialtoolsfor
adaptationstrategies.
Becauseearlieractionallowsforgreaterimpactandinfluenceonmanagementchallengesbothnow
andinthefuture,wesuggest:





iv UseofstructureddecisionmakingtechniquestofocusandclarifyBLMgoalsandobjectives
forclimatechangeadaptationtargets
Movingaheadwiththedevelopmentofadaptationstrategiesforkeyspeciesand
ecosystems
Prioritizingadaptationeffortsforspeciesandecosystems,takingintoconsiderationboth
thevulnerabilitylevelofthetarget,practicalcriteriaoftimeandresourceavailability,and
trade‐offsorconstraintsthatmaybepresent
Developingandimplementingmethodsformonitoringormeasuringtheresultsof
adaptationactions
Potentiallyrevisitingclimatechangevulnerabilityrankingsasnewinformationbecomes
availableoradditionalconcernsbecomeapparent.
Colorado Natural Heritage Program © 2015 ACKNOWLEDGEMENTS
TheauthorswouldliketoacknowledgethegeneroussupportoftheBureauofLandManagement
ColoradoOffice,whoprovidedfundingforthiseffort.WethanktheBLMstaffwhosharedtheir
extensiveprofessionalexperienceandknowledgethroughouttheprocess.BruceRittenhouse
(BranchChief,NaturalResources),JayThompson(FisheryBiologist),andCarolDawson(Botanist)
actedascoordinatingliaisonsfortheproject.AdditionalBLMpersonnelwhoparticipatedinthe
reviewprocessincludeRobinSell(WildlifeBiologist),andBLMinternsPhilKreningandColleen
Sullivan.
MeganFriggens(ResearchEcologist)withtheUSDAForestServiceGrassland,Shrublandand
DesertEcosystemsProgramoftheRockyMountainResearchStationprovidedvaluablereviewand
inputregardingtheresiliencerankingsofforestandwoodlandecosystems,aswellasreviewofthe
documentasawhole.
WecontinuetoappreciatethehelpofJeffMorisetteandtheNorthCentralClimateScienceCenter
staff,especiallyColinandMarianTalbert,whoprovideduswithessentialtechnicaltoolsfor
accessingandusingclimateprojections.ShannonMcNeelyoftheNCCSCalsoprovidedfeedbackon
thepreliminaryresultsoftheassessment.
Finally,atCNHP,JoannaLemlyprovidedcriticalreviewandinformationaboutwetlandand
riparianhabitats,andRenéeRondeauprovidedadviceandreviewthroughouttheproject.Thank
youall.
Climate Change Vulnerability Assessment for Colorado BLM v Table of Contents Executive Summary ....................................................................................................................................... ii Ecosystems ................................................................................................................................................ ii Species ..................................................................................................................................................... iii Conclusions .............................................................................................................................................. iii Acknowledgements ....................................................................................................................................... v 1 INTRODUCTION .......................................................................................................................................... 1 2 ECOSYSTEMS ............................................................................................................................................ 19 3 ANIMALS ................................................................................................................................................ 173 4 PLANTS ................................................................................................................................................... 325 Appendix A: CCVI Scoring Category Definitions ........................................................................................ 542 Appendix B: Full CCVI Scoring Results ....................................................................................................... 559 vi Colorado Natural Heritage Program © 2015 1 INTRODUCTION
Author
Karin Decker Recommended chapter citation: Decker, K. 2015. Introduction. Chapter 1 In Colorado Natural Heritage Program 2015. Climate Change Vulnerability Assessment for Colorado Bureau of Land Management. K. Decker, L. Grunau, J. Handwerk, and J. Siemers, editors. Colorado Natural Heritage Program, Colorado State University, Fort Collins, Colorado. Climate Change Vulnerability Assessment for Colorado BLM 1 Table of Contents – 1 Introduction Background ................................................................................................................................................... 3 Study area ................................................................................................................................................. 4 Overview ............................................................................................................................................... 4 General climate ..................................................................................................................................... 5 Geology and soils .................................................................................................................................. 5 Land ownership ..................................................................................................................................... 5 Human influence on the landscape ...................................................................................................... 6 Climate Change Vulnerability Assessment .................................................................................................... 8 Uncertainty in climate change vulnerability assessment ......................................................................... 8 Comparing the vulnerability of ecosystems and species .......................................................................... 8 Previous vulnerability assessments in the Colorado region ..................................................................... 9 Climate change in Colorado .................................................................................................................... 15 Literature Cited ....................................................................................................................................... 17 List of Figures and Tables Figure 1.1. Components of vulnerability (Glick et al. 2011). ........................................................................ 4 Figure 1.2. Historical (1990‐2014) Colorado statewide trends for (a) annual mean temperature, (b) annual precipitation, and (c) Palmer Drought Severity Index. Temperature and precipitation are shown as departure from the mean of base period (1901‐2000). Data is from NOAA National Centers for Environmental Information: http://www.ncdc.noaa.gov/cag/data‐info. .................................................. 16 Figure 1.3. Seasonal projected temperature (a) and precipitation (b) changes by mid‐21st century (2050; centered around 2035‐2064 period) for Colorado. .................................................................................... 17 Table 1.1. Summary of climate change vulnerability assessments in the Colorado region that have addressed habitats or species. .................................................................................................................... 10 2 Colorado Natural Heritage Program © 2015 BACKGROUND
TheColoradoofficeoftheBureauofLandManagement(BLM)hasbeenchargedwithdevelopinga
climateadaptationstrategyforBLMlandswithinthestate.Inordertoensurethebestpossible
adaptationstrategies,astatewideperspectiveonthepotentialfutureinfluencesofachanging
climateonspeciesandhabitatsisneeded.ToassisttheBLMinthiseffort,theColoradoNatural
HeritageProgram(CNHP)conductedaclimatechangevulnerabilityassessmentforpriorityspecies
andecosystemswithinatimeframeofmid‐21stcentury.
Thevulnerabilityassessmentisintendedtobepartofadynamic,iterative,multi‐scaleprocessthat
willfocusmanagementactionsonstrategiesthatareeffectiveunderbothcurrentandfuture
climates.ThecomponentsofvulnerabilityweredescribedbyGlicketal.(2011)andconsistof
projectedexposuretoclimatechange,sensitivityofthespeciesorecosystemtoexpectedchanges,
andtheadaptivecapacityofthespeciesorecosystemtorespondtochanges(Figure1.1).Although
thisdiagramisstraightforwardandconceptuallysimple,theindividualcomponentsofexposure,
sensitivity,andadaptivecapacitycanbedifficulttocalculatewithanyprecision.Uncertaintycomes
fromboththedegreeofvariationinthemanyclimateprojectionmodels,andfromthegapsinour
knowledgeofthetargetspeciesorhabitat.Inaddressingthesecomponents,wehopetoidentify
whichecosystemsaremostorleastvulnerabletoclimatechangeaswellasthetypeandspatial
patternofthemostsignificantimpacts.Thisinformationisexpectedtohelplandmanagersidentify
areaswhereactionmaymitigatetheeffectsofclimatechange,recognizepotentialnovelconditions
thatmayrequireadditionalanalysis,andcharacterizeuncertaintiesinherentintheprocess.
OurassessmentisalignedwithexistingandongoingvulnerabilityassessmentsforColoradospecies
andhabitatstomaximizetheefficiencyandeffectivenessofourwork,leveragedatadevelopment,
sharelessonslearned,andcoordinateexpertinputandinterpretation.TheseincludetheGunnison
BasinClimateWorkingGroup,SanJuanClimateInitiative,theStateWildlifeActionPlanrevision
andclimatechangevulnerabilityassessment,andtheColoradoRarePlantConservationInitiative.
Thisanalysisisbasedonarelativelyshorttemporalscale(i.e.,suitedtoagencyplanninghorizons
andattentivetouncertaintylevelsinprojectedclimatemodels)andtheuseofalimitedbut
representativesetofpotentialchangescenarios.
Ourobjectiveswereto:
1. Identifyplantandanimalspecies,andterrestrialandfreshwaterecosystemsofimportance
toBLMmanagementastargetsofouranalysis.
2. Evaluatethepotentialimpactoffutureclimateconditionsonbothspeciesandecosystems
byidentifyingthedegreeofclimatechangeexpectedbetweencurrentandfutureconditions
withintheColoradorangeofthetarget,andincorporatingscientificallydocumented
informationonspeciesorecosystemsresponsetoclimaticfactors.
3. Evaluatethepotentialimpactofnon‐climatefactorsparticulartoeachtargetthatcanaffect
theresilienceofthetargettoclimatechange,orwhicharelikelytohaveagreaterimpact
duetoclimatechange.
4. Producesummaryvulnerabilityrankingsforpriorityspeciesandecosystems.
Climate Change Vulnerability Assessment for Colorado BLM 3 Figure 1.1. Components of vulnerability (Glick et al. 2011). Study area
Overview
Colorado’sboundariesencompasssome66.6millionacres,orover104,000squaremiles.Within
thisarea,thetypeandextentofnaturalvegetationisdeterminedbymanyfactors,including
elevation,climate,soils,disturbancepatterns,andtheecologicalhistoryofthelandscape.Colorado
spansthecontinentaldivideamidthehighestpeaksoftheSouthernRockyMountains.Asaresult,
thestate’stopologyiscomplex.Totheeastofthecontinentaldivide,theeasternplainsrisegently
attherateofabout10feetpermilefromelevationsof3,350‐3,650feetatthestate’seasternedge.
Althoughtheyappearcomparativelyflat,Colorado’seasternplainsboastlittle‐knowndramatic
rivercanyons,shaleoutcropsformingbuttesandscarps,sandystabilizeddunefields,andbasalt‐
cappedmesasthatarelocallandmarksintheeasterncounties.Atelevationsof5,500to6,000feet
nearthemountainfront,theplainstransitionfairlyabruptlytofoothillsandmesasthat,inturn,
quicklyrisetomontaneelevations.Thecentralportionofthestateisdominatedbythepeaksand
rangesoftheSouthernRockyMountains.Here,aseriesofmountainrangestrendinggenerally
north‐southboundastringofhighmountainvalleysorparks,andincludemorethanfiftypeaks
reachingelevationsof14,000feetormore.Tothewest,moremountainsandextensiveplateaus,
heavilydissectedbyravinesandcanyons,formthecharacteristicvalleyandplateauwesternslope
landscape.Nearthewesternborderofthestateelevationsdecreaseagain,reachingalowofabout
4,325feetwheretheColoradoRivercrossestheborderwithUtah.
4 Colorado Natural Heritage Program © 2015 General climate
Colorado’spositionatthehighpointofthecontinentmeansthatseveraldifferentweatherpatterns
influencetheclimateofthestate,andhenceitsvegetation.Ingeneral,higherelevationshavecooler
temperaturesandreceivemoreprecipitation,althoughlocaltopographyhasasignificanteffecton
airmovementscontrollingthesefactors.MoisturemayreachthestatefromeitherthePacificOcean
ortheGulfofMexico,dependingoncurrentaircirculation.Stormsoriginatingtothewestofthe
statedropmuchoftheirmoistureasrainorsnowonthemountainsandwestern‐facingslopes;a
rain‐shadoweffectpreventsmostofthisprecipitationfromreachingtheeasternplains.The
westernpartofColoradoreceivesmostofitsyearlyprecipitationduringwintermonths.Moisture
fromtheGulfofMexicocanproduceheavyprecipitationontheeasternslopeofthedivide,
especiallyinspringandsummer,andtheplainsreceivethemajorityoftheirannualprecipitation
duringthegrowingseason.Southernportionsofthestategenerallyreceivemid‐tolate‐summer
precipitationasthemarginoftheNorthAmericanMonsoonmovesnorth.
Geology and soils
Thelandscapeweseetodayistheproductofbothpastandongoinggeologicprocesses.Theeffects
ofcontinentaldrift,geologicuplifts,volcaniceruption,anderosionhaveresultedinahighly
complexarrangementofrockandsoiltypesthatprovideasubstrateforColorado’snative
vegetation.Colorado’seasternplainsaredominatedbysoilsderivedfromTertiary(2‐65mya)and
Cretaceous(65‐140mya)sedimentaryformations,shapedbytheactionofflowingwaterandwind.
Inthecentralportionofthestate,theColoradoRockyMountainsareformedofigneousand
metamorphicrockthatisthrustupthroughthesedimentarylayerstotheeastandwest.Heresoils
aregenerallylesswelldeveloped,exceptinlow‐lyingareas,whereerosionhasdeposited
substantialsoilmaterial.ThewesternplateausandvalleysarealsoprimarilyformedinTertiary
andCretaceoussubstrates,andmanysoilshavehighconcentrationsofsaltsandmineralsthat
inhibitplantgrowth.Incombinationwithclimatefactors,soilsareagoodindicatorofwhichtypeof
vegetationwilldominatethelandscapeinaparticulararea.
Land ownership
Ownershippatternsreflectthelandusehistoryofthestate,and,togetherwithmanagement
practicesareanimportantfactorindeterminingtheconservationstatusofColorado’slandscape.
Arablelands,especiallyontheeasternplainsandalongriverdrainages,areprimarilyinprivate
ownership.Colorado’smininghistoryhasleftalegacyofprivateinholdingswithinextensivetracts
ofpublicland.Lowerelevationlandsonthewestslopeusedprimarilyforgrazing,mining,oiland
gasextraction,andrecreationaregenerallyadministeredbytheBureauofLandManagement.
Higherelevation(mostlyforested)partsofthestatearelargelyundertheadministrationoftheU.S.
ForestService,whileNationalGrasslandsadministeredbytheU.S.ForestServiceineastern
ColoradowereformedfromfarmlandreclaimedfromtheravagesoftheDustBowldays.The
distributionofstate‐ownedlandstillreflectstheschoollandgrantincludedinthe1875Enabling
ActfortheTerritoryofColorado,whichprovidedthattwosectionsofeverytownship(usually
sections16and36)begrantedforthesupportofpublicschools.
Climate Change Vulnerability Assessment for Colorado BLM 5 About57%ofthestate’ssurfaceacresareprivatelyowned,withtheremainderinfederal,state,
localgovernment,ortribalownership.Federalpubliclandsaccountforalittleover36%of
Coloradoacreage.TheBLMadministers8.4millionacres(13%)ofColorado’ssurfaceacres,aswell
asover29millionacresofsub‐surfacemineralestate.OtherfederallandsinColoradoare
administeredU.S.ForestService(22%ofstateacreage),NationalParkService(1%),andother
federalagenciesincludingtheU.S.FishandWildlifeService,BureauofReclamation,and
DepartmentofDefense(<1%).TheStateofColoradoownsnearly5%oftheacreage,andalsoholds
aboutamillionacresofsub‐surfacemineralestateonlandsinotherownership.Triballands
accountforabout1%ofColorado’sacreage,andtheremainderisownedbygovernmentsatthe
countyandcitylevel.
Human influence on the landscape
Inadditiontonaturaldisturbanceprocessessuchasfire,wind,andflooding,theeffectsofhuman
activitieshavealsochangedpatternsofdisturbanceinColorado.ThesettlementhistoryofColorado
hasresultedinapatternoflandownershipwherepubliclandsareasignificantpartofthe
landscape.
Development Althoughindustrial,urban,suburban,andexurbandevelopmentinColoradoaregenerallynot
occurringonpubliclands,theseactivitiesareasourceofpotentialdisturbancetoadjacentareas.
Colorado’stotalpopulationofover5millionislargelyconcentratedintheFrontRangecorridor
fromPueblonorthtoFortCollinswhere11countiesaccountfor83%ofthestate’spopulation.
LargercitiesoutsidethisareaincludeGrandJunction,Montrose,andDurango.Anetworkof
highways,roads,andothertransportationcorridors,togetherwithutilityright‐of‐waysofvarious
typesconnectspopulatedplaceslargeandsmallthroughoutthestate.Inspiteofthestate’s
increasingpopulation,andpatchworkofprivateandpubliclands,morethan75%ofColorado’s
landscaperemainscoveredbynaturalvegetation,especiallyinhigherelevationareas.
Resource Extraction and Energy Development Miningforcoal,gold,gypsum,limestone,silver,molybdenum,sodaash,sodiumbicarbonate,sand,
gravel,andcrushedstone,aswellastheextractionofpetroleumandnaturalgas,havehada
significantroleinshapingColorado’slandscape.Energydevelopmentisasignificantandexpanding
activityinColorado,especiallyinthenaturalgasandoil‐richareasofthenorthernFrontRangeand
westernslope.Beginninginthe1860s,coalandpetroleumwerethefirstenergyresourcestobe
developedinColorado.Togetherwithnaturalgasandoilshale,thesefossilfuelshavehistorically
constitutedthemajorityofenergydevelopmentinthestate.TheBLMadministersmineralleasing
forallfederallandsinColoradowheresuchrightshavenotbeenwithdrawn,aswellasforsplit‐
estatefederalmineralrightsundernon‐Federallands.Aspartofitstrustresponsibility,theBLM
alsooverseesmineraloperationsontriballands.
RenewableenergyfacilitieshavenotbeendevelopedonBLMlands.Coloradocurrentlyhasover
1,500windturbinesinoperation,primarilyontheeasternplains.Concentratedsolarenergy
facilitiesarealsobeingdevelopedinseveralareasofthestate.However,withtheprojectedfuture
6 Colorado Natural Heritage Program © 2015 growthoftheseindustries,Coloradocanexpecttoseeanincreaseintransmissionlineconstruction
thatmayinvolveBLMadministeredlands.
Agriculture TheoriginalgrasslandsofColorado’seasternplainswerehometolargenumbersofgrazinganimals
includingdeer,pronghorn,elkandbison.WithEuropeansettlement,thesenativegrazerswere
largelyreplacedbydomesticlivestock.Large‐scalegrazingbeganinthe1860s,andquickly
expandedasrailroadsprovidedaccesstoeasternmarkets.BoththeBureauofLandManagement
andtheU.S.ForestServiceissuegrazingpermitsforpubliclandsinColorado,andstate‐owned
landsmayalsobeleasedforgrazing.Cattleandassociatedproductsformthelargestportionof
Colorado’sagriculturalcashreceipts,followedbyfieldcrops(USDANASS2015).Around1900,crop
farmingbegantoexpandinthestate,withwheatandcornastheprimaryproducts.Although
periodicdroughtshaverepeatedlydealthardblowstofarmingandranchinginColorado,theseland
usesstillmakeanimportantcontributiontothestate’seconomy,andhavehadanundeniableeffect
onthearrangementandconditionofColorado’snaturalvegetation.
BLM‐administeredColoradorangelandissubjecttograzingusebypermittedlivestockoperators.
About2,500grazingallotmentsaremanagedbypermitsorleasesthatspecifythekindandnumber
oflivestock,seasonofuse,andamountofusepermittedeachgrazingyear.Permitsorleasesare
subjecttocompliancereviewandpublicscopingpriortorenewal.
Recreation and Conservation Inrecentdecades,recreationhasbecomeanincreasinglyimportantpartoflanduseinColorado.
FromNationalParkstolocalopenspacelands,increasingnumbersofresidentsandvisitorsare
drawntoavarietyofoutdooractivitiessuchashiking,camping,wintersports,hunting,fishing,and
off‐roadvehicleuse.Paradoxically,recreationonColorado’spubliclandscancontributetobothits
conservationanditsdegradation.
AlthoughtheBLMmanagespubliclandsforrecreation,theagencyisalsoresponsiblefor
preservationoftheenvironment,wildlifeandarchaeologicalandpaleontologicalresources;
sustainablenaturalresourceextraction;thevisualappealofpubliclands;andconsidering
socioeconomicimpactsofmanagementdecisions.TheBLM’sapproximatelyonemillionacresof
NationalConservationLandsinColoradoincludetwonationalmonuments,threenational
conservationareas,fivewildernessareas,53wildernessstudyareas,aswellasNationalHistoric
andScenicTrails.TheBLMalsoamanagesanumberofAreasofCriticalEnvironmentalConcernfor
scientific,scenic,ecological,biological,geological,historicalandprehistoricvaluesforpublic
benefit.
Climate Change Vulnerability Assessment for Colorado BLM 7 CLIMATE CHANGE VULNERABILITY ASSESSMENT
Uncertainty in climate change vulnerability assessment
Theincreasingnumberofclimatechangevulnerabilityassessmentstendstoindicatethatmany
entitiesregardtherealityofclimatechangewithahighlevelofcertainty.However,therearea
numberofsourcesthatintroduceuncertaintyofvaryingdegreeintotheseassessments.Frequently
acknowledgedsourcesofuncertaintyorvariationinprojectedoutcomesarethemodeled
componentsofclimatechangeanalysis:theglobalcirculationmodels,hydrologicmodels,species
responsemodels,andsoon.Withallprojectionsoffutureclimateconditionswecannotknowwith
absolutecertaintywhich,ifany,willturnouttobetrue.Downscalingthesemodelsdoesnotremove
inherentuncertainty.
Uncertaintyinthecontextofclimatechangeisnotequivalenttocompletelackofknowledge.
Currentclimatemodelsrepresentthebestavailablescience,yetdonotallagree.Ingeneral,climate
modelsareunderstoodtohavehigherlevelsofcertaintyaboutglobaltemperatureresponsesto
forcingfactorsthantheydoforprecipitationresponse.Boththedirectionofresponse(increaseor
decrease)andthemagnitude(degrees,inches,etc.)ofresponseofclimatefactorsarevariable
amongclimatemodels.Currently,consensusaboutthedirectionoftemperaturechange
(increasing)isgreaterthanforprecipitation.Themagnitudeofexpectedchangeforbothfactorsis
uncertain.
Comparing the vulnerability of ecosystems and species
Althoughwehaveestimatedthevulnerabilitytoclimatechangeofbothecosystemsandthespecies
thatinhabittheminthefollowingchapters,therearedifferencesofbothmethodandscalebetween
theseassessments.
Forecosystems,exposureandsensitivitywerecombinedintoasinglemetricthatwaspairedwitha
resilience‐adaptivecapacitymetricinascoringmatrixtoproduceanoverallvulnerabilityrank.
SpecieswereassessedusingtheNatureServeClimateChangeVulnerabilityIndexmethod(Younget
al.2015),whichtreatsexposureasamodifierofsensitivityandadaptivecapacity(i.e.,low
exposurediscountssensitivity/adaptivecapacityfactors,andhighexposureamplifiesthose
factors).
Ecosystemswereassessedusingtherepresentativeconcentrationpathway(RCP8.5)emissions
scenariomethodoftheIPCCFifthAssessmentReport,whilebothanimalandplantspecieswere
assessedunderA2scenariooftheSpecialReportonEmissionsScenarios(SRES)standards
employedintwopreviousIPCCreports.ThisdifferenceisduetotheuseoftheNatureServeCCVI,
whichisbasedontheearliermethodology,forspeciesonly.Forthemid‐centurytime‐frameofour
assessment,theSRESA2scenarioprojectsCO2concentrationlevelsandtemperatureincreasesthat
areslightlyloweronaveragethanthoseprojectedbytheRCP8.5scenario.However,thetwo
scenariosareapproximatelyequivalentinthattheyarebasedonsimilarunderlyingassumptions
8 Colorado Natural Heritage Program © 2015 aboutfuturedemographicandeconomictrends,andaregenerallyregardedas“worst‐case”
scenarios.Neitherscenarioisconsidered‘better’thantheotherbytheclimatesciencecommunity.
Inaddition,thecorrelationofplantandanimalspecieswithasingleecosystemisrare,especially
formobileanimalspecies.Becauseofthisvariability,andalsobecauseofdifferencesinscale
betweenindividualorganismlife‐cyclefactorsandlandscapelevelprocesses,itispossibleforthe
vulnerabilityofaparticularspeciestobedifferentfromthatofitsprimaryecosystem.
Previous vulnerability assessments in the Colorado region
Priortotheeffortreportedherein,anumberofstudieshaveevaluatedvulnerabilitytochanging
climaticconditionsinandaroundColorado(Table1.1).AdditionalreportsnotincludedinTable1.1
havealsoaddressedthevulnerabilitytoclimatechangeofavarietyofsocio‐economicelements.
Thelistedstudiesemployedanassortmentofqualitativeandquantitativeapproaches;anumberdo
notexplicitlyaddressindividualhabitatsorspecies.Furthermore,spatialscalesoflisted
assessmentsdifferbyonetothreeordersofmagnitude.Anelementthatisconsideredhighly
vulnerabletoextinctioninasmallareamayhavesignificantlyreducedvulnerabilityinother
portionsofitsrange.Consequently,acomparisonofvulnerabilityrankingresultsacrossthese
effortsisproblematic.Nevertheless,afewgeneraltrendsareevidentacrossvulnerability
assessments.Speciesandhabitatsofhigherelevationsareusuallyconsideredmorevulnerablethan
thoseofmid‐elevationareas.Speciesandhabitatsthatareextremelycloselyassociatedwithwater
resourcesaregenerallyexpectedtohavehighervulnerabilitythanthoseinmorexericconditions.
Agreementaboutvulnerabilityforsomedrymid‐to‐lowerelevationhabitatsispoor.Forinstance,
pinyon‐juniperwoodlandsandsagebrushshrublandshavereceivedrankingsrangingfromHighly
VulnerabletoLikelytoIncrease,dependingonthescale,location,andmethodofassessment.This
disagreementillustratestheimportanceofattentiontoscaleandtime‐frameinthedevelopmentof
managementgoalsandobjectivesforclimateadaptationplanning,andhighlightsareaswhere
additionalresearchtoaddresswell‐formulatedquestionsmaybeneeded.
Climate Change Vulnerability Assessment for Colorado BLM 9 Table 1.1. Summary of climate change vulnerability assessments in the Colorado region that have addressed habitats or species. Full Citation
Area
Habitats
Species
Target Time
Methodology
Frame &
Emissions
Scenario
Brown et al. 2008. Climate Change in Rocky Mountain National Park. http://www.nps.gov/romo/parkmgmt/upload/climate_cha
nge_rocky_mountain2.pdf Rocky Mtn. National Park Ray, A.J., J.J. Barsugli, and K.B. Averyt. 2008. Climate change in Colorado: A synthesis to support water resources management and adaptation. Report for Colorado Water Conservation Board. Western Water Assessment http://wwa.colorado.edu/publications/reports/WWA_Clim
ateChangeColoradoReport_2008.pdf Reiman, B.E. and D.J. Isaak. 2010. Climate change, aquatic ecosystems, and fishes in the Rocky Mountain West: Implications and alternatives for management. General Technical Report RMRS‐GTR‐250. USDA Forest Service, Rocky Mountain Research Station. Fort Collins, CO. http://www.fs.fed.us/rm/pubs/rmrs_gtr250.pdf Colorado Natural Heritage Program for Rare Plant Conservation Initiative. 2011. Colorado Wildlife Action Plan: proposed rare plant addendum. Lee Grunau, Jill Handwerk, and Susan Spackman‐Panjabi, eds. Colorado Natural Heritage Program, Colorado State University, Fort Collins, CO. http://www.cnhp.colostate.edu/download/documents/201
1/rareplant_SWAP_final_june_30_2011_formattedv2.pdf Statewide 10 Western Colorado, as part of Rocky Mtn. west Wetlands, lakes & streams, montane, subalpine, alpine Water resources, no individual habitats explicitly addressed Stream environments, including riparian Statewide ‐‐‐‐ Vulnerability
Ranking (see code key below)
‐‐‐‐ None given Qualitative (workshop narrative synthesis) No rankings ‐‐‐‐ Mid‐century. CMIP3 B1, A1B, A2 ensembles Qualitative (narrative synthesis) No rankings Native fishes None given Qualitative (narrative synthesis) No rankings ‐ habitat loss or gain. 121 G1 and G2 plants Mid‐century. A2 Quantitative (NatureServe CCVI) EV/HV/MV/PS/IL
/IE Colorado Natural Heritage Program © 2015 Full Citation
Area
Habitats
Species
Target Time
Frame &
Emissions
Scenario
Methodology
Vulnerability
Ranking (see code key below)
Neely, B., R. Rondeau, J. Sanderson, C. Pague, B. Kuhn, J. Siemers, L. Grunau, J. Robertson, P. McCarthy, J. Barsugli, T. Schulz, and C. Knapp, Eds. 2011. Gunnison Basin: Vulnerability Assessment for the Gunnison Climate Working Group by The Nature Conservancy, Colorado Natural Heritage Program, Western Water Assessment, University of Colorado, Boulder, and University of Alaska, Fairbanks. Project of the Southwest Climate Change Initiative. http://wwa.colorado.edu/publications/reports/TNC‐CNHP‐
WWA‐
UAF_GunnisonClimChangeVulnAssess_Report_2012.pdf Nydick, K., Crawford, J., Bidwell, M., Livensperger, C., Rangwala, I., and Cozetto, K. 2012. Climate Change Assessment for the San Juan Mountain Regions, Southwestern Colorado, USA: A Review of Scientific Research. Prepared by Mountain Studies Institute in cooperation with USDA San Juan National Forest Service and USDOI Bureau of Land Management Tres Rios Field Office. Durango, CO. http://www.mountainstudies.org/s/ClimateResearchRevie
w_SJMs_FINAL.pdf Woodbury, M., M. Baldo, D. Yates, and L. Kaatz. 2012 Joint Front Range Climate Change Vulnerability Study. Water Research Foundation and Tailored Collaboration partners. Denver, CO. http://cwcb.state.co.us/environment/climate‐
change/Pages/JointFrontRangeClimateChangeVulnerability
Study.aspx USDA Forest Service, Region 2. UNPUBLISHED. CCVAs for selected habitats. Decker, K. and R. Rondeau. 2014. San Juan / Tres Rios Climate Change Ecosystem Vulnerability Assessment. Colorado Natural Heritage Program, Colorado State University, Fort Collins, Colorado. http://www.cnhp.colostate.edu/download/documents/201
4/SJRA_ecological_systems_vulnerability_analysis_FINAL.p
df Gunnison Basin 17 terrestrial ecosystems and 7 freshwater 73 species of conservation concern Mid‐century. CMIP3 A2 ‐ Barsugli and Mearns 2010 projected climate scenarios. Qualitative (Manomet‐
MADFW, expert opinion), quantitative (NatureServe CCVI) Uplands: EV/HV/MV/PS/SI.
MI/GI/U Riparian: H/M/L Species: EV/HV/MV/PS/IL
/IE Southwest Colorado Sagebrush, oak, PJ, Ponderosa, Mixed conifer, aspen, subalpine, alpine, riparian, fens & wet meadows 7 taxonomic groups Mid‐century. NARCCAP (CMIP3 A2) Qualitative (narrative relates to regional climate models, and synthesizes work by others) Decrease – no or little change ‐ increase North Central Colorado (Headwaters of South Platte, Arkansas, Colorado rivers) Streams ‐‐‐‐ 2040 and 2070. Selected CMIP3 A2 ensembles Quantitative (models) No rankings 14 upland and 3 wetland/ riparian ecosystems ‐‐‐‐ Mid‐century. Suite of CMIP5 RCP4.5 & 8.5 models ‐ 3 scenarios – Rangwala 2012 Qualitative (modified Manomet‐
MADFW, expert opinion and narrative synthesis) EV/HV/MV/PS/SI
/MI/GI/U Southwest Colorado (San Juan / Tres Rios management area) Climate Change Vulnerability Assessment for Colorado BLM 11 Full Citation
Area
Habitats
Species
Target Time
Frame &
Emissions
Scenario
Methodology
Vulnerability
Ranking (see code key below)
Handwerk, J., B. Kuhn, R. Rondeau, and L. Grunau. 2014. Climate Change Vulnerability Assessment for Rare Plants of the San Juan Region of Colorado. Colorado Natural Heritage Program, Colorado State University, Fort Collins, Colorado. http://www.cnhp.colostate.edu/download/documents/201
4/SanJuan_CCVI_Final_Report.pdf Lukas, J., J. Barsugli, N. Doesken, I. Rangwala, K. Wolter. 2014. Climate change in Colorado: A synthesis to support water resources management and adaptation, 2nd edition. A report for the Colorado Water Conservation Board. Western Water Assessment, Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder. http://cwcbweblink.state.co.us/WebLink/0/doc/191995/Ele
ctronic.aspx?searchid=e3c463e8‐569c‐4359‐8ddd‐
ed50e755d3b7 Decker, K. and M. Fink. 2014. Colorado Wildlife Action Plan Enhancement: Climate change Vulnerability Assessment. Colorado Natural Heritage Program, Colorado State University, Fort Collins, Colorado. http://www.cnhp.colostate.edu/download/documents/201
4/CO_SWAP_Enhancement_CCVA.pdf Pocewicz, A., H.E. Copeland, M.B. Grenier, D.A. Keinath, and L.M. Washkoviak. 2014. Assessing the future vulnerability of Wyoming’s terrestrial wildlife species and habitats. Report prepared by The Nature Conservancy, Wyoming Game and Fish Department and Wyoming Natural Diversity Database. http://www.nature.org/media/wyoming/wyoming‐wildlife‐
vulnerability‐assessment‐June‐2014.pdf Gordon, E. and D. Ojima, eds. 2015. Colorado Climate Change Vulnerability Study. A report by the University of Colorado Boulder and Colorado State University to the Colorado Energy Office. http://wwa.colorado.edu/climate/co2015vulnerability/co_v
ulnerability_report_2015_final.pdf Southwest Colorado (San Juan / Tres Rios management area) ‐‐‐‐ 60 rare plant spp. Mid‐century. CMIP3 A2 Quantitative (NatureServe CCVI) EV/HV/MV/PS/IL
/IE Statewide, and specific subregions Water resources, no individual habitats explicitly addressed ‐‐‐‐ Mid‐century. CMIP3 and CMIP5, pooled RCPs (4.5 & 8.5 discussed) Qualitative (narrative synthesis) No rankings Statewide 13 terrestrial habitats ‐‐‐‐ Mid‐century. BCCA CMIP5 ‐ RCP6.0 Quantitative (models – projected range shift) VH/H/M/L Adjacent to Colorado 11 habitat types, largely analogous to Colorado types 131 Species of greatest conservation need Mid‐century. A2 VH/H/M/L Statewide Broad categories: Alpine, Forests, and Grasslands ‐‐‐‐ Mid‐century? Quantitative (models – annual mean temperature & moisture deficit, NatureServe CCVI) Qualitative (narrative synthesis) 12 No rankings ‐ key vulnerabilities for broad categories Colorado Natural Heritage Program © 2015 Full Citation
Area
Habitats
Species
Target Time
Frame &
Emissions
Scenario
Methodology
Vulnerability
Ranking (see code key below)
Handwerk, J., L. Grunau, and S Spackman‐Panjabi, eds. Colorado Wildlife Action Plan: 2015 Rare Plant Addendum. Colorado Natural Heritage Program, Colorado State University, Fort Collins, Colorado. http://www.cnhp.colostate.edu/download/reports.aspx Statewide ‐‐‐‐ 117 G1 or G2 plants Mid‐century. CMIP3 A2 Quantitative (NatureServe CCVI) EV/HV/MV/PS/IL
/IE Statewide 16 terrestrial habitats and 6 freshwater groups 97 species of conservation concern Mid‐century. NEX‐DCP30 – CMIP5 RCP8.5 & CMIP3 A2 Quantitative (models – out of range conditions, NatureServe CCVI) Ecosystems: VH/H/M/L Species: EV/HV/MV/PS/IL
/IE THIS DOCUMENT (CNHP 2015) Rank
Definition
NatureServe CCVI http://www.natureserve.org/conservation‐tools/climate‐change‐vulnerability‐index (in CNHP RPCI 2011, Neely et al. 2011, Handwerk et al. 2014 & 2015, CNHP 2015) EV ‐ Extremely Vulnerable Abundance and/or range extent within geographical area assessed extremely likely to substantially decrease or disappear by 2050. HV ‐ Highly Vulnerable Abundance and/or range extent within geographical area assessed likely to decrease significantly by 2050. MV ‐ Moderately Vulnerable Abundance and/or range extent within geographical area assessed likely to decrease by 2050. PS ‐ Presumed Stable Available evidence does not suggest that abundance and/or range extent within the geographical area assessed will change (increase/decrease) substantially by 2050. Actual range boundaries may change. IL ‐ Not Vulnerable/Increase Likely Available evidence suggests that abundance and/or range extent within geographical area assessed is likely to increase by 2050. IE ‐ Insufficient Evidence Available information about a species' vulnerability is inadequate to calculate an Index score. Neely et al. (2001), Decker & Rondeau (2014) EV ‐ Extremely Vulnerable Ecosystem at risk of being eliminated from the area as a result of climate change. HV ‐ Highly Vulnerable Majority of ecosystem at risk of being eliminated (i.e., >50% loss) as a result of climate change, but unlikely to be eradicated entirely. For riparian, overall loss of system is expected to be > 50% or ecological process is expected to be severely impacted, e.g., flood frequency occurs 50% less than current flooding regime. MV ‐ Moderately Vulnerable Extent of ecosystem at risk of being moderately reduced (<50% loss) as a result of climate change. For riparian, overall loss of system is expected to be > 50% or ecological process is expected to be severely impacted, e.g., flood frequency occurs 50% less than current flooding regime. LV ‐ Low Vulnerability For riparian only, 0 to 10% loss of area and condition of system remains stable. PS ‐ Presumed Stable Extent of ecosystem approximately the same, but there are significant pattern or condition changes within the area. SI ‐ Slight Increase Ecosystem may become established within the basin from areas outside. MI ‐ Moderate Increase Extent of ecosystem may expand moderately (<50% gain) as a result of climate change. Climate Change Vulnerability Assessment for Colorado BLM 13 Rank
Definition
GI ‐ Greatly Increase U ‐ Unknown Decker & Fink (2014), CNHP (2015) VH ‐ Very High Vulnerability Ecosystem may expand greatly (>50% gain) as a result of climate change. Vulnerability of ecosystem under climate change is uncertain Habitats/ecosystems have high vulnerability to climate change when exposure and sensitivity are high, and adaptive capacity and resilience are low. Transformation of the habitat/ecosystem is most likely to occur in upcoming decades. High vulnerability to climate change results from combining either high or moderate exposure‐sensitivity with low or medium adaptive capacity‐resilience. Under either combination, climate change is likely to have noticeable impact. Moderate vulnerability to climate change results from a variety of combinations for exposure‐sensitivity and adaptive capacity‐resilience. The number of possible combinations indicates a degree of uncertainty in the vulnerability ranking. Under circumstances where the two factors are essentially balanced, vulnerability is thought to be reduced, but still of concern. Low vulnerability to climate change occurs when a habitat combines low exposure and sensitivity with high or moderate adaptive capacity and resilience. For these habitats/ecosystems climate change stress and its effects are expected to be least severe or absent. HV ‐ Highly Vulnerable MV ‐ Moderately Vulnerable LV ‐ Low Vulnerability 14 Colorado Natural Heritage Program © 2015 Climate change in Colorado
AnnualaveragetemperaturesacrossColoradohaveincreasedby2.0°Foverthepast30years
(Figure1.2a).Warmertemperaturesareevidentforallseasons,anddailyhighandlow
temperatureshavealsoincreased(Lucasetal.2014).Incontrast,overtheperiodofrecord,there
arenocomparabletrendsinaverageannualprecipitationinColorado(Figure1.2b),although
snowpacklevelshavebeengenerallybelowaveragesince2000.Thedecreaseinsnowpack,along
withwarmingspringtemperaturesandtheeffectsofincreaseddust‐on‐snowhavecombinedto
shiftthetimingofsnowmeltandpeakrunofffrom1‐4weeksearlier(Lucasetal.2014).Flowering
datesforsomeplantspeciesareoveramonthearlierthantheywereacenturyago(Munsonand
Sher2015).DroughtconditionsasmeasuredbythePalmerDroughtSeverityIndexalsoreflect
warmingtemperaturesandtherecentperiodofbelowaverageprecipitiation(Figure1.2c).
ReconstructionsofdroughtsinwesternNorthAmericashowanumberofdroughtspriortothe
instrumentalrecordthatweremoresevereandlongerlastingthantheworstdroughtsofthepast
century(Woodhouse2004,Stahleetal.2007,Routsonetal.2011),whichillustratestherelatively
narrowviewofvariabilityprovidedbythehistoricalrecord.Bothhistoricandpre‐instrumental‐
recorddroughtshavehadnotableeffectsonvegetationpatterns,andhaveseverelyimpacted
patternsofhumanhabitationandsocialinteraction(Woodhouse2004,Bensonetal.2007).The
possibilityoffuturedroughtsthatgreatlyexceedthemostseveredroughtsofthepastmilleniacan
notbeexcluded(Cooketal.2015).
Projectionsbasedon17models(NASAEarthExchangeDownscaled30Arc‐SecondCMIP5Climate
ProjectionsdatasetfortheconterminousU.S.,Thrasheretal.2013),rununderRCP8.5andRCP4.5
forthe30‐yearperiodcenteredon2050indicatethatallareasofColoradowillexperiencesome
degreeofwarming,andpotentiallychangesinprecipitationaswell.Temperaturechange
projectionsareregardedasmorecertain(Barsuglipers.comm.),andthereisgeneralagreement
thatconditionshavealreadywarmedtosomedegree(Lucasetal.2014);uncertaintyfor
temperaturechangeisgreaterregardingthemagnitudeoftheprojectedchange.Incombination
withexpectedchangesintemperature,however,evenawetterfuturemaynotbesufficientto
maintainrunoffandsoilmoistureconditionssimilartothoseoftherecentpast.Climateprojections
presentedherearesummariesoflong‐termtrendsanddonottrackinter‐annualvariation,which
willremainasourceofvariability,asithasbeeninthepast.Ourecosystemanalysisfocusedona
singlerepresentativeconcentrationpathway(RCP8.5)andalimitedsubsetofavailableglobal
circulationmodels;atthispointintimewehavenowayofknowingifthisisthescenariothatwill
befoundvalidbymid‐century.However,inallscenarios,changesthatinthepastoccurredover
periodsofseveralthousandyearsarenowprojectedtotakeplaceinonlyahundredyears.
ProjectedchangessummarizedinFigure1.3aindicateaverageseasonaltemperatureincreasesof
anywherefromabout3.5‐5.8F,withmeanincreasesofabout4.1‐5.4F.Furthermore,minimum
andmaximumtemperatureincreasesarealsoprojectedforallseasons.Somewhatgreater
increasesareprojectedunderRCP8.5incomparisonwithRCP4.5atmid‐century.Winterminimum
temperaturesareprojectedtohavegreaterincreasesthanwintermaximumtemperatures,butin
allotherseasonsthegreatestincreasesareprojectedinmaximumtemperatures,andtheleastin
Climate Change Vulnerability Assessment for Colorado BLM 15 (a) (b) (c) Figure 1.2. Historical (1990‐2014) Colorado statewide trends for (a) annual mean temperature, (b) annual precipitation, and (c) Palmer Drought Severity Index. Temperature and precipitation are shown as departure from the mean of base period (1901‐2000). Data are from NOAA National Centers for Environmental Information: http://www.ncdc.noaa.gov/cag/data‐info. 16 Colorado Natural Heritage Program © 2015 minimumtemperatures(Figure1.3a).Rangesofprojectedincreaseforallseasonsarebroadly
overlapping.
Meanprojectedprecipitationchangesaregenerallylesscertainthanthosefortemperature,and
maynotbeoutsidetherangeofhistoricvariability,atleastbymid‐century.Seasonalprojected
percentincreasesinprecipitationareonaveragegreatestforwinterandspring(Figure1.3b),while
summerandfallareprojectedtohavedecreasedoressentiallyunchangedprecipitation.However,
rangesforgrowingseasonsincludebothincreasedanddecreasedprecipitation.
(a) (b) Figure 1.3. Seasonal projected temperature (a) and precipitation (b) changes by mid‐21st century (2050; centered around 2035‐2064 period) for Colorado. For temperature (a), the bottom of each bar represents the 10th percentile, and the top of the bar is the 90th. Mean projected change is represented by open diamonds. RCP8.5 statewide projected change in average seasonal temperatures are the top (red) bars, and RCP4.5 are bottom (purple) bars. For precipitation (b), the bottom of each bar represents the 10th percentile, the middle line is the 50th, and the top of the bar is the 90th. RCP8.5 statewide projected percent change in seasonal average precipitation are the left‐hand bars, and RCP4.5 are the right‐hand bars. Seasons are: winter=DJF, spring=MAM, summer=JJA, and fall=SON. A temperature interval of 1°F is equal to an interval of 5⁄9 degrees Celsius. Climate scenarios used were from the NEX‐DCP30 dataset, prepared by the Climate Analytics Group and NASA Ames Research Center using the NASA Earth Exchange, and distributed by the NASA Center for Climate Simulation (NCCS). Literature Cited
Benson,L.,K.Petersen,andJ.Stein.2007.Anasazi(Pre‐ColumbianNative‐American)migrationsduringthemiddle‐12th
andlate‐13thcenturies–weretheydroughtinduced?ClimaticChange83:187‐213.
Cook,B.I.,T.R.Ault,andJ.E.Smerdon.2015.Unprecedented21stcenturydroughtriskintheAmericanSouthwestand
CentralPlains.ScienceAdvances12Feb2015;1:e1400082.
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,K.Wolter.2014.ClimatechangeinColorado:Asynthesistosupportwater
resourcesmanagementandadaptation,2ndedition.AreportfortheColoradoWaterConservationBoard.WesternWater
Assessment,CooperativeInstituteforResearchinEnvironmentalSciences(CIRES),UniversityofColorado,Boulder.
Climate Change Vulnerability Assessment for Colorado BLM 17 Munson,S.M.andA.A.Sher.2015.Long‐termshiftsinthephenologyofrareandendemicRockyMountainplants.
AmericanJournalofBotany102:1‐9.
Routson,C.C.,C.A.Woodhouse,andJ.T.Overpeck.2011.SecondcenturymegadroughtintheRioGrandeheadwaters,
Colorado:Howunusualwasmedievaldrought?GeophysicalResearchLetters38,L22703,doi:10.1029/2011GL050015.
Stahle,D.W.,F.K.Fye,E.R.Cook,R.D.andGriffin.2007.Tree‐ringreconstructedmegadroughtsoverNorthAmericasince
A.D.1300.ClimaticChange83:133‐149.
Thrasher,B.,J.Xiong,W.Wang,F.Melton,A.MichaelisandR.Nemani.2013.DownscaledClimateProjectionsSuitablefor
ResourceManagement.Eos,TransactionsAmericanGeophysicalUnion94:321‐323.
U.S.DepartmentofAgriculture,NationalAgriculturalStatisticsService[USDANASS].2015.2014StateAgricultural
OverviewforColorado.http://www.nass.usda.gov/Quick_Stats/Ag_Overview/stateOverview.php?state=COLORADO
Woodhouse,C.A.2004.ApaleoperspectiveonhydroclimaticvariabilityinthewesternUnitedStates.AquaticSciences
66:346‐356.
Young,B.E.,E.Byers,G.Hammerson,A.Frances,L.Oliver,andA.Treher.2015.GuidelinesforusingtheNatureServe
ClimateChangeVulnerabilityIndex.Release3.0.NatureServe,Arlington,VA.http://www.natureserve.org/biodiversity‐
science/publications/guidelines‐using‐natureserve‐climate‐change‐vulnerability‐index‐0
18 Colorado Natural Heritage Program © 2015 2 ECOSYSTEMS
Authors: Karin Decker Michelle Fink Recommended chapter citation: Decker, K. and M. Fink. 2015. Ecosystems. Chapter 2 In Colorado Natural Heritage Program 2015. Climate Change Vulnerability Assessment for Colorado Bureau of Land Management. K. Decker, L. Grunau, J. Handwerk, and J. Siemers, editors. Colorado Natural Heritage Program, Colorado State University, Fort Collins, Colorado. Climate Change Vulnerability Assessment for Colorado BLM 19 Table of Contents – 2 Ecosystems
Terrestrial Ecosystems – Methods .............................................................................................................. 23 Terrestrial Ecosystems ‐ Results ................................................................................................................. 29 Literature Cited ........................................................................................................................................... 40 Forest and Woodland ................................................................................................................................. 42 Aspen .................................................................................................................................................... 43 Lodgepole ............................................................................................................................................. 50 Mixed conifer ....................................................................................................................................... 56 Pinyon‐Juniper ...................................................................................................................................... 62 Ponderosa ............................................................................................................................................. 70 Spruce‐fir .............................................................................................................................................. 76 Shrubland .................................................................................................................................................... 84 Desert shrubland .................................................................................................................................. 85 Oak & Mixed mountain shrub .............................................................................................................. 91 Sagebrush ............................................................................................................................................. 97 Sandsage ............................................................................................................................................. 103 Grassland or Herbaceous .......................................................................................................................... 108 Alpine .................................................................................................................................................. 109 Montane grasslands ........................................................................................................................... 116 Semi‐desert grassland ........................................................................................................................ 123 Shortgrass prairie ............................................................................................................................... 128 Riparian and Wetland ............................................................................................................................... 136 Riparian woodlands and shrublands .................................................................................................. 137 Wetlands ............................................................................................................................................ 144 Freshwater Ecosystems – Methods .......................................................................................................... 150 Freshwater Ecosystems ‐ Results .............................................................................................................. 158 Streams, Rivers, Lakes, and Reservoirs .............................................................................................. 159 20 Colorado Natural Heritage Program © 2015 List of Figures Figure 2.1. Statewide envelope of projected change in annual mean temperature and precipitation under two emissions scenarios (boxes), in comparison with levels of precipitation increase required to maintain the status quo. ............................................................................................................................. 25 Figure 2.2. Vulnerability ranking matrix. .................................................................................................... 28 Figure 2.3. Projected annual change in Colorado for (a) upland ecosystems, and (b) wetland and riparian ecosystems. Ecosystem means are colored to indicate the degree to which the ecosystem is projected to experience conditions that are out of range of those in its current statewide distribution. ..................... 29 Figure 2.4. Comparison of scores by ecosystem for (a‐e) individual resilience factors, and (f) overall resilience – adaptive capacity score. Background colors reflect the low (red), moderate (orange), and high (green) resilience categories. .............................................................................................................. 30 Figure 2.5. Area of ecosystems mapped at various elevations in Colorado. .............................................. 31 Figure 2.6. Bioclimatic envelope as represented by annual precipitation and mean temperature for ecosystems in Colorado. Error bars represent the 10‐90% range around the mean. ................................ 32 Figure 2.7. Minimum winter and maximum summer temperature ranges for ecosystems in Colorado. Boxes represent the middle quartiles, while whiskers show the 10‐90% range. ....................................... 33 Figure 2.8. Projected seasonal average precipitation and mean temperature trajectories for current upland ecosystem ranges in Colorado by mid‐century under a high radiative forcing scenario (RCP8.5). Circles represent current conditions. ......................................................................................................... 38 Figure 2.9. Projected seasonal average precipitation and mean temperature trajectories for current wetland and riparian ecosystem ranges in Colorado by mid‐century under a high radiative forcing scenario (RCP8.5). Circles represent current conditions. ........................................................................... 39 Figure 2.10. STORET stations with July water temperature readings. ..................................................... 151 Figure 2.11. Prediction Standard Error. .................................................................................................... 151 Figure 2.12. Interpolated water temperature 67 ‐ 69°F filled contour, split into North‐West, North‐
Central, South‐West, and South‐Central sections. Colors represent the mean July air temperature coinciding with each contour section. ...................................................................................................... 152 Figure 2.13. Modeled transition line. ....................................................................................................... 154 Figure 2.14. Decision‐tree for exposure criteria applied to rivers and streams. ...................................... 155 Figure 2.15. Category transitions between current and projected (RCP 8.5) conditions for streams and rivers. ........................................................................................................................................................ 165 Figure 2.16. Comparison of current (top) and projected (bottom) stream temperature classification. . 167 Climate Change Vulnerability Assessment for Colorado BLM 21 List of Tables Table 2.1. Ecosystems assessed for vulnerability to climate change. ........................................................ 23 Table 2.2. Criteria for scoring exposure of terrestrial ecosystems. ............................................................ 25 Table 2.3. Description of factors used to assess resilience‐adaptive capacity in terrestrial ecosystems. . 26 Table 2.4. Vulnerability rank summary for all assessed terrestrial ecosystems. ........................................ 36 Table 2.5. Key vulnerabilities, forest and woodland ecosystems. .............................................................. 42 Table 2.6. Key vulnerabilities, shrubland ecosystems. ............................................................................... 84 Table 2.7. Key vulnerabilities, grassland or other herbaceous ecosystems. ............................................ 108 Table 2.8. Key vulnerabilities, riparian and wetland ecosystems. ............................................................ 136 Table 2.9. Freshwater ecosystem targets. ................................................................................................ 150 Table 2.10. Mean and standard deviation (STD) current July air temperature (°F) values for each contour segment within a section. Values in parentheses are °C. ......................................................................... 153 Table 2.11. Criteria for scoring exposure of lakes and reservoirs freshwater ecosystems. ..................... 155 Table 2.12. Description of factors used to assess resilience‐adaptive capacity in freshwater ecosystems.
.................................................................................................................................................................. 156 Table 2.13. Factors included in TNC freshwater measures of condition database. ................................. 157 Table 2.14. Key vulnerabilities, freshwater ecosystems. .......................................................................... 158 Table 2.15. Vulnerability rank summary for all assessed freshwater ecosystems. .................................. 160 Table 2.16. Representative fish species for freshwater ecosystems. ....................................................... 163 Table 2.17. Reach length statistics (km) for water temperature categories both statewide and by region.
.................................................................................................................................................................. 166 22 Colorado Natural Heritage Program © 2015 TERRESTRIAL ECOSYSTEMS ‐ METHODS
Target selection
InconsultationwithBLM,CNHPidentified16terrestrialecosystemtypesorgroupsofinterestfor
BLMmanagementtobeassessed(Table2.1).Terrestrialecosystemdistributionwasmappedusing
SWReGAP(USGS2004)foruplandecosystems,andNationalWetlandInventorymappingfor
riparianandwetlandecosystems(USFWS1975‐3013).Thevulnerabilityofecosystemswas
assessedundertwoprimaryheadings:exposure‐sensitivity,andresilience‐adaptivecapacity.
Scoresforthesetwofactorswerecombinedtoobtainanoverallvulnerabilityrank.
Table 2.1. Ecosystems assessed for vulnerability to climate change. Terrestrial
Forest and Woodland
Grassland or herbaceous
Aspen forest Alpine Lodgepole pine forest Montane grassland Mixed conifer forest Semi‐desert grassland Pinyon‐Juniper woodland Shortgrass prairie Ponderosa pine forest Spruce‐Fir forest Riparian & Wetland Riparian woodland & shrubland ‐ Eastern Shrubland Riparian woodland & shrubland ‐ Mountain Desert shrubland Riparian woodland & shrubland ‐ Western Oak & mixed mountain shrubland Wetlands ‐ Eastern Sagebrush shrubland Wetlands ‐ Mountain Sandsage shrubland Wetlands ‐ Western Terrestrial ecosystem responses to climate change
Thepredictionofpotentialplantdistributionunderfutureclimateconditionsisbasedonthe
ecologicalprinciplethatthepresenceofaspeciesonthelandscapeiscontrolledbyavarietyof
bioticandabioticfactors,inthecontextofbiogeographicandevolutionaryhistory.Biotic
interactions(e.g.,competition,predation,parasitism,etc.)togetherwithclimateandotherabiotic
componentsacttoinfluencethespatialarrangementofspeciesatlocal,regional,andcontinental
scales.Abioticfactorsthatinfluenceecosystemprocessesandspeciesdistributionsinclude
temperature,water,carbondioxide,nutrients,anddisturbanceregimes(Prenticeetal.1992,
Holling1992).Waterbalance,orthedifferencebetweenprecipitationinputsandwaterlossinthe
formofevapotranspiration,runoff,anddeepdrainage,isaprimarydeterminantofterrestrial
vegetationdistributionintheU.S.(Stephenson1990,Nielsonetal.1992,Nielson1995).
Climate Change Vulnerability Assessment for Colorado BLM 23 Becausecompleteandaccurateknowledgeofdrivingfactorsandhistoryisrarely,ifever,available,
werelyoncorrelativemodelsthatrelateobservedspeciesdistributionwithpastandrecentlevels
ofclimaticvariables.Thepredictiveprocessisfurtherconstrainedbyourinabilitytomeasuresuch
variablesaccuratelyonacontinuousspatialortemporalscale.Asaresult,modelingvariablesare
usuallyanapproximationoftheenvironmentalfactorsthatcontrolspeciesdistribution,using
availabledatathatarelikelyonlysurrogatesfortheactualcontrollingfactors.Furthermore,
becausetherateofvegetationresponsetoenvironmentalshiftsislikelytobelowerthantherateof
climatechangeitself,andbecauserelictreesmayremainfordecades,predictivemodelsaremore
usefulinidentifyingthefuturelocationofsuitablehabitatforaspeciesthaninpredictingtheactual
groundcoverataspecifictimeinaparticularlocation.Finally,althoughwecanestimatethe
climaticrequirementsofagivenspecies,andextrapolatefromthatestimatetheeventual
distributionofanecosystem,itismoredifficulttopredictvegetationdynamicsthataretheresultof
disturbanceeventsorecologicalprocesses(e.g.,drought,fire,snowmelt,herbivory,insect
outbreaks,etc.).Thesefactorsareaddressednarratively,andevaluatedthroughexpertelicitation.
Becauseoftheselimitations,welookedatdegreeofchangeofclimaticvariablesoveran
ecosystem’scurrentrangeasameasureofexposuretoclimatechange,ratherthanattemptto
predictoverallchangesindistribution.
Exposure and sensitivity assessment – terrestrial ecosystems
Weusedspatialanalysismethodstoevaluatetheexposureandsensitivitytoclimatechangefor
eachecosystem.Weusedensembleaveragesof800mNASAEarthExchange(NEX)Downscaled
ClimateProjections(NEX‐DCP30)fortheContinentalUS.Theseaveragesarebasedon34models
developedfortheWorldClimateResearchProgramme's(WCRP)CoupledModelIntercomparison
ProjectPhase5(CMIP5).IndividualmodelsarelistedinAppendixA.
ThereisgeneralagreementthattemperaturesthroughoutColoradoareprojectedtoincrease.
Precipitationmodelsaremuchmorevariable,and,onaveragetendtoshowincreasing
precipitationformostofColorado.However,hydrologicmodelingfortheColoradoRiverandother
basins(e.g.,NashandGleick1991,1993)hasindicatedthat,asageneralizedrule‐of‐thumb,for
each1.8°F(1°C)ofwarming,anapproximate5%increaseinprecipitationwouldberequiredfor
runofflevelstoremainunchanged(SolidlineinFigure2.1).Withprojectedmid‐century
temperaturesincreasing4°Formore,noareasinColoradoareprojectedtoreceivesufficient
compensatoryprecipitation.Inordertoaccountforthepotentialeffectsofwarmertemperatures
onsoilmoistureavailability,anddeterminetheextenttowhicheachecosystemmaybeexposedto
effectivelydrierconditions,wemadeaconservativeapplicationoftheaboverule,toevaluatehow
muchofanecosystemmightreceiveatleastapartial(50%)levelofcompensatoryprecipitation
(dashedlineinFigure2.1).
24 Colorado Natural Heritage Program © 2015 Figure 2.1. Statewide envelope of projected change in annual mean temperature and precipitation under two emissions scenarios (boxes), in comparison with levels of precipitation increase required to maintain the status quo. Foreachecosystem,wecalculatedtheproportionofacreagewhereprojectedannualmean
temperatureformid‐centuryunderRCP8.5wasgreaterthananyannualmeantemperatures
currentlyexperiencedbythatecosystemwithinColorado,ANDprojectedfutureprecipitation
changeswerelessthan5%increaseovercurrentlevels.Ecosystemswerescoredaccordingtothe
scaleshownbelow(Table2.2).Inaddition,anyecosystemwhoseproportionofacreagewith
temperatureswithinthenormalrange,butwithmorethan50%ofthatacreagehavingprojected
futureprecipitationchangeswithlessthan5%increaseovercurrentlevels,wasbumpedtothe
nexthigherexposurecategory.
Itisimportanttonotethattheresultingscoresareintendedtogivearelative,notanabsolute
indicationofthepotentialimpactoffutureclimateconditionsonanecosystem.Thatis,a“Low”
scoredoesnotmeanthatanecosystemisnotvulnerabletoclimatechange,butthattheanalysis
indicatesthatitmaybelessvulnerablethanthoseecosystemswithscoresofModerate,High,or
VeryHigh.Furthermore,underthescoringsystemweused,“Moderate”isabroadcategory,andall
ecosystemswithaModeratevulnerabilityrankarenotnecessarilyequallyvulnerable.
Table 2.2. Criteria for scoring exposure of terrestrial ecosystems. Percent Colorado acres with projected temp > max & ppt delta < 5% 36 – 100% 16 – 35% 0 – 15% High Moderate Low Initial Exposure‐Sensitivity Score Percent Colorado acres with temp <= max & ppt delta < 5% more than 50%? Final Exposure‐Sensitivity Score Yes No Yes No Yes No Very High High High Mod. Mod Low Climate Change Vulnerability Assessment for Colorado BLM 25 Resilience‐adaptive capacity assessment – terrestrial ecosystems
Thisscoresummarizesindirecteffectsandnon‐climatestressorsthatmayinteractwithclimate
changetoinfluencetheadaptivecapacityandresilienceofanecosystem.Factorsevaluatedare
adaptedfromthemethodologyusedbyManometCenterforConservationScienceand
MassachusettsDivisionofFishandWildlife(MCCSandMAFW2010),combinedunderfiveheadings
(Table2.3).Factorswerescoredonascaleof0(lowresilience)to1(highresilience).
Table 2.3. Description of factors used to assess resilience‐adaptive capacity in terrestrial ecosystems. Assessment factor
Description
Bioclimatic envelope and range This factor summarizes the expected effects of limited elevational or bioclimatic ranges for an ecosystem. Suitable conditions for ecosystems at upper elevations may be eliminated. Ecosystems with narrow bioclimatic envelopes may be more vulnerable to climate change. Finally, ecosystems that are at the southern edge of their distribution in Colorado may be eliminated from the state under warming conditions. Growth form and intrinsic dispersal rate This factor summarizes the overall ability of the ecosystem’s component species to shift their ranges in response to climate change relatively quickly. Characteristics of growth form, seed‐dispersal capability, vegetative growth rates, and stress‐tolerance are considered. Vulnerability to increased impact by biological stressors This factor summarizes whether expected future biological stressors (invasive species, grazers and browsers, pests and pathogens) have had, or are likely to have, an increased effect due to interactions with changing climate. Climate change may result in more frequent or more severe outbreaks of these stressors. Ecosystems that are currently vulnerable to these stressors may become more so under climate change. Vulnerability to increased frequency or intensity of extreme events This factor evaluates characteristics of an ecosystem that make it relatively more vulnerable to extreme events (fire, drought, floods, windstorms, dust on snow, etc.) that are projected to become more frequent and/or intense under climate change. Other indirect effects of non‐
climate stressors – landscape condition This factor summarizes the overall condition of the ecosystem at the landscape level across Colorado, and is derived from a landscape integrity score indexing the degree of anthropogenic disturbance (Rondeau et al. 2011, Lemly et al. 2011). Bioclimatic envelope and range
Eachecosystemwasscoredforelevationalrange,southernedgeofrange,annualprecipitation
range,andgrowingdegreedaysrange.Ecosystemsrestrictedtohighelevationsreceivedascoreof
0,otherecosystemsscored1.Likewise,ecosystemsatthesouthernedgeoftheircontinentalrange
inColoradowereassignedascoreof0,andotherecosystemsscored1.Annualprecipitationand
growingdegreedaysrangewerecalculatedastheproportionoftotalvariablerangeinColoradoin
whichtheecosystemhadsignificantpresencemapped.Thesefourscoreswereaveragedtoproduce
asinglescoreforthisfactor.
26 Colorado Natural Heritage Program © 2015 Growth form and intrinsic dispersal rate
Scoresof0(lowresilience),0.5(uncertainormoderateresilience),and1(highresilience)were
assignedtoeachecosystembasedongrowthformofthedominantspecies(i.e.,treesscored0,
shrubsandherbaceousscored1),andotherinformationderivedfromtheliteratureregardingthe
dispersalabilitiesofthosespecies.
Vulnerability to increased attack by biological stressors
Beginningwithadefaultscoreofone,wesubtracted0.2forvulnerabilitytopotentialincreased
effectsofgrazersorbrowsers,and0.3forvulnerabilitytoinvasivespecies.Inaddition,foresttypes
withlevelsofinsectmortalitysufficienttocausedramaticstructuralchangesoveralargearea(>1
millionacresinColorado)receivedascoreof0,andforesttypeswithlowerlevelsofinsect
mortalityreceivedastartingscoreof0.7.Forestscoringwasbasedoncumulativedamagetotals
fromUSFSAerialSurveys(Harris2014).
Vulnerability to increased frequency or intensity of extreme events
Ecosystemsnotespeciallyvulnerabletoincreasedfrequencyorintensityofabioticstressors
receivedadefaultscoreofone.Foresttypesnotadaptedtodryconditionswerescored0.5,to
accountforincreasedsusceptibilitytothecombinedeffectsofdroughtandpotentiallyincreased
wildfire,whilemoredroughttolerantforesttypesscored0.7.Non‐forestecosystemsvulnerableto
droughtwerescored0.5,andecosystemsvulnerableonlytootherabioticstressorsscored0.9.
Landscape condition
Theaveragevalueacrossthestatewidelandscapeintegritymodels(Rondeauetal.2011,Lemlyet
al.2011)foreachecosystemwascalculatedasavaluebetween0and1.
Resilience‐adaptive capacity ranking
Scoresforthefivefactorsarebasedonbothspatialanalysisandliteraturereview.Rankingsforthis
sub‐scoreareoppositetothedirectionoftheexposure‐sensitivityrankingscheme(i.e.,ahigher
valueindicates“better”andalowervalueindicates“worse.”)Theroundedaverageofthefivesub‐
scoresdeterminesthefinalResilience‐AdaptiveCapacityscore.
Average of Resilience‐Adaptive Capacity Scores Overall Resilience‐Adaptive Capacity Score 0 – 0.50 0.51 – 0.70 0.71 – 1.0 Low Moderate High Vulnerability assessment ranking
Overall vulnerability ranking
TheExposure‐SensitivityscoreandtheResilience‐AdaptiveCapacityscorearecombined(Figure
2.2)accordingtotheschemepresentedbelow(Comeretal.2012)toproduceanoverall
vulnerabilityrankforeachecosystem.
Climate Change Vulnerability Assessment for Colorado BLM 27 Exposure‐Sensitivity score / Resilience ‐ Adaptive Capacity score H / H M / H Vulnerability L / H Very High High H / M M / M Moderate L / M Low H / L M / L L / L Figure 2.2. Vulnerability ranking matrix. VeryHigh:Ecosystemshavehighvulnerabilitytoclimatechangewhenexposureand
sensitivityarehigh,andadaptivecapacityandresiliencearelow.Underthesecircumstances,
transformationoftheecosystemismostlikelytooccurinupcomingdecades.
High:Highvulnerabilitytoclimatechangeresultsfromcombiningeitherhighormoderate
exposure‐sensitivitywithlowormediumadaptivecapacity‐resilience.Undereither
combination,climatechangeislikelytohavenoticeableimpact.
Moderate:Moderatevulnerabilitytoclimatechangeresultsfromavarietyofcombinationsfor
exposure‐sensitivityandadaptivecapacity‐resilience.Thescoringmatrixisslightlyweighted
towardincreasedvulnerabilityinthenumberofpossiblecombinationswhichproducea
moderatevulnerabilityranking.Undercircumstanceswherethetwofactorsareessentially
balanced,vulnerabilityisthoughttobereduced,butstillofconcern.
Low:Lowvulnerabilitytoclimatechangeoccurswhenanecosystemisexpectedtoexperience
lowexposureandsensitivityincombinationwithhighormoderateadaptivecapacityand
resilience.Fortheseecosystemsclimatechangestressanditseffectsareexpectedtobeleast
severeorabsent.
28 Colorado Natural Heritage Program © 2015 TERRESTRIAL ECOSYSTEMS ‐ RESULTS
Overview of terrestrial ecosystems
Change in temperature and precipitation by mid‐century
Underthemostseverescenarioecosystemsevaluatedhereinareprojectedtoexperienceannual
meantemperaturesthatare5‐6°Fwarmerthanintherecentpast;atthesametimefuture
precipitationlevelsarenotprojectedtoincreasesufficientlytocompensateevenpartiallyfor
increasedmoisturelossduetowarmertemperatures(dashedlineinFigure2.3).
Figure 2.3. Projected annual change in Colorado for (a) upland ecosystems, and (b) wetland and riparian ecosystems. Ecosystem means are colored to indicate the degree to which the ecosystem is projected to experience conditions that are out of range of those in its current statewide distribution. Resilience factors
ResultsforindividualresiliencefactorsareshowninFigure2.4anddiscussedindetailbelow.
Climate Change Vulnerability Assessment for Colorado BLM 29 (a) Range & environmental envelope rank (b) Dispersal & growth form rank (c) Biological stressors rank (d) Abiotic stressors & Extreme events rank (e) Landscape condition rank (f) Overall Resilience ‐ Adaptive capacity rank Figure 2.4. Comparison of scores by ecosystem for (a‐e) individual resilience factors, and (f) overall resilience – adaptive capacity score. Background colors reflect the low (red), moderate (orange), and high (green) resilience categories. Elevation range and relative abundance
Togetherwithrangeextentandbioclimateenvelope(below),weconsideredelevationasafactor
thatmightdetractfromtheresilienceofanecosystem.EcosystemelevationsinColoradorange
fromabout3,500fttonearly14,000ft(Figure2.5).Theextremehighestelevationsarenon‐
vegetated.Lowelevationsareoccupiedbygrassland,shrubland,andwoodlandecosystems
dominatedbyspeciesadaptedtolowerprecipitationandwarmconditions.Anumberofmontane
tosub‐alpineecosystemsareclusteredtogetheratmiddleelevationsfromabout7,000‐10,000ft.At
higherelevations,subalpineforestandalpinevegetationoccupyfairlydistinctelevationalzones.
30 Colorado Natural Heritage Program © 2015 Figure 2.5. Area of ecosystems mapped at various elevations in Colorado. Bioclimatic envelope
Temperatureandprecipitationvariableswereusedtocharacterizethecurrentbioclimatic
envelopeforeachterrestrialecosystem.Acombinedprecipitationandtemperaturespaceisshown
foreachofthe14uplandecosystemsinFigure2.6.Becauseprecipitationandtemperatureare
highlycorrelatedwithelevation,patternsaresimilartothoseshownunderelevationrangeabove.
Desertshrublandoccupiesthedriestbioclimaticenvelope,whilesandsageandshortgrassprairie
arethewarmest.Statewide,ponderosa,oak‐shrubandsagebrushshrublandarecloselyrelatedin
bioclimaticspace,andshowsubstantialoverlapwiththewarmeranddrierpinyon‐juniperand
semi‐desertgrassland.Abovethesewarmeranddrierecosystems,mixedconifer,aspen,and
lodgepoleforestshareamid‐elevationenvelopewithmontanegrasslands.Thecoldest,wettest
environmentsareoccupiedbyalpinetypes,withspruce‐firforestintermediatebetweenthemiddle
groupandthesehabitats.
Historictemperaturerangesforwinterminimumsandsummermaximumsforeachupland
ecosystemareshowninFigure2.7,andillustratethesamerelationshiptoelevationasdotheother
climatevariables.ThegeographicareacurrentlyoccupiedbyeachecosysteminColoradoislikelyto
experienceashifttowardwarmertemperatures,withtheresultthatbioclimaticenvelopeswillshift
towardhigherelevations.Theacreagethatfallswithinaparticulartemperaturerangewillbe
reducedforcoolertemperaturesandincreasedforwarmertemperatures.
Climate Change Vulnerability Assessment for Colorado BLM 31 Theoverallelevation,range,andbioclimateenveloperesultsareshowninFigure2.4a.
Figure 2.6. Bioclimatic envelope as represented by annual precipitation and mean temperature for ecosystems in Colorado. Error bars represent the 10‐90% range around the mean. 32 Colorado Natural Heritage Program © 2015 Figure 2.7. Minimum winter and maximum summer temperature ranges for ecosystems in Colorado. Boxes represent the middle quartiles, while whiskers show the 10‐90% range. Intrinsic dispersal rate
Mostcharacteristicspeciesofforestorwoodlandecosystemsdonotproducelargenumbersof
seedlingsorspreadquicklyviavegetativegrowth.WiththeexceptionofaspenandGambeloak,
forestandwoodlandtreespeciesaretypicallyslowgrowing,withlimiteddispersalability.Past
migrationratesforNorthAmericantreespeciesinthecurrentinterglacialhavebeenestimatedat
tenstoseveralhundredsofmetersperyear.Althoughthecurrentlyobserveddistributionofa
speciesislikelytolagbehindcurrentclimateconditions,futureconditionsarepredictedtorequire
migrationratesonetofivekilometersperyearinorderforspeciestokeepupwithsuitablehabitat
conditions(Roberts2013).Shrubandgrass‐dominatedecosystemsaresomewhatbetteradaptedto
spreadintoavailablehabitatthroughrelativelyrapidvegetativegrowth.Barrierstoecosystem
movementinColoradoareprimarilythoseduetoelevationalgradientsorhabitatfragmentation,
althoughsoiltypeislikelytoinfluencedispersalandestablishmentpatternsthroughvariable
water‐holdingcapacity.EcosystemranksforthisfactorareshowninFigure2.4b.
Climate Change Vulnerability Assessment for Colorado BLM 33 Biological stressors
BiologicalstressorsforecosystemsinColoradoincludeforestpestsandpathogens,invasive
species,incompatibledomesticlivestockgrazing,andchangesinpatternsofnativeungulate
herbivory.EcosystemranksforthisfactorareshowninFigure2.4c.
Nativeinsectsthatcausetreedamageandmortalityincludebarkbeetles(Dendroctonusspp.,Ips
spp.),westernsprucebudworm(Choristoneuraoccidentalis),andtentcaterpillars(Malacosoma
spp.).Armillariarootdiseaseisasignificantcauseofmortalityinconiferspecies.Pinyonare
susceptibletothefungalpathogenLeptographiumwagenerivar.wageneri,whichcausesblackstain
rootdisease.Five‐needlepines,includinglimberandbristlecone,arethreatenedbywhitepine
blisterrust(WPBR)infectioncausedbytheintroducedfungusCronartiumribicola.
Exoticinvasiveplantspecieswiththepotentialtoalterecosystemfunctioningthatareregionally
widespreadinColoradoincludecheatgrass(Bromustectorum),knapweed(Acroptilonand
Centaureaspp.)Russianolive(Elaeagnusangustifolia)leafyspurge(Euphorbiaesula),andtamarisk
(Tamarixramosissima).Canadathistle(Cirsiumarvense)andmuskthistle(Carduusnatans)arealso
widespread,andother,lessprevalentproblemspeciesincludeoxeyedaisy(Leucanthemum
vulgare) andyellowtoadflax(Linariavulgaris).Mountaingrasslands,lowelevationshrubland,and
riparian/wetlandecosystemsaremostaffected.
Togetherwithlivestockgrazing,overabundanceofnativeungulates(e.g.,deerandelk)andferal
burrosorhorsescanaltervegetation,soils,hydrology,andwildlifespeciescompositionand
abundancesinwaysthatintensifytheeffectsofclimatechangeontheseresources(Beschtaetal.
2013).Forterrestrialecosystems,theprojectedcombinationofincreasingdrought,higher
temperatures,earliersnowmelt,andprecipitationvariabilityinteractingwiththeeffectsof
ungulateusecanresultindecreasedbiodiversity,reducedsoilmoisture,acceleratedsoiland
nutrientloss,andincreasedsedimentation(Beschtaetal.2013).
Extreme events
Extremeeventsthatmayincreaseinfrequencyand/orseverityunderchangingclimaticconditions
includedrought,wildfire,flooding/erosion,andwindstorms.Ecosystemranksforthisfactorare
showninFigure2.4d.
ProlongeddroughthasbeenaperiodicinfluenceinthewesternUnitedStates,includingColorado
(Woodhouse2004).Ecosystemsoflowerelevationsaregenerallydroughttolerant,although
speciescompositionwithinanecosystemislikelytoshiftwithchangingclimatepatterns.Although
wescoredvulnerabilitytoabioticeventsasdistinctfrombiologicalstressors,theinteractionof
wildfireanddroughtwiththeeffectsofthesefactors,especiallyforestmortalityagentslikebark
beetles,blursthedistinctionsomewhat.ThespeciesthatcharacterizeColorado’secosystemshave
varyingtolerancetodrought,however,itislikelythatallspeciesarelessresistanttotheeffectsof
herbivory,pests,andpathogenswhenunderdroughtstress.Widespreadprevalenceofdrought‐
stressedtreesmayprovideenhancedconditionsforstand‐replacingeventssuchasfireorinsect
outbreak(DeRoseandLong2012).Ecosystemsofhigher,wetterelevationshavegenerallybeen
“climate‐limited,”withhighfuelloads,butrarelyhavingdryclimateconditionssuitableforfire
34 Colorado Natural Heritage Program © 2015 spread.Lower,moremesicecosystemshavebeencharacterizedas“fuel‐limited,”withconditions
frequentlysuitableforfire,butlowfuelloadsunlessprioryearshavebeenwet(Whitlocketal.
2010).Withwarmertemperaturesandmorefrequentdrought,higherelevationforestswith
abundantfuelsmayhaveincreasedfirefrequency,whilelowerelevationgrasslandandshrubland
ecosystemsbecomemorefuel‐limitedwithreducedbiomassproduction(Arnoldetal.2014).
Althoughtherearenooverallprecipitationincreasetrendsassociatedwithrecentwarming,there
isevidencethatextremeprecipitationeventshaveincreasedinfrequencyoverthepastseveral
decades(Walshetal.2014).Warmerairandoceantemperaturesallowtheatmospheretohold
moremoisture,whichcanresultinheavyprecipitation,causingmoreextremefloodinganderosion
events,evenifannualprecipitationtotalsdecline.Althoughfuturetrendsinstormoccurrenceare
uncertain,anincreaseinfrequencyofseverestormscouldincreasethefrequencyofwindthrow
eventsinforestedareas.
Non‐climate abiotic stressors
Thecombinedeffectsofhumanactionsthatfragmentlandscapes,alternaturalprocesses,reduce
biodiversity,anddegradeenvironmentalqualityarelikelytoreducetheresilienceofcomplex
adaptiveecosystemstoregimeshiftsunderchangingclimateconditions(Folkeetal.2004).The
cumulativeeffectsofanthropogenicdisturbanceinColoradoareduetohabitatfragmentationand
conversionduetoagriculturaluseaswellasindustrial,residential,resource,andrecreational
developmentactivities.Ourscoringassumesthatecosystemswithhigherlevelsofanthropogenic
disturbancearelikelytobelessresilienttodisturbanceofanykindunderfutureclimateconditions.
Ecosystemsofthehighestelevations,whicharegenerallyinpublicownership,hadthehighest
resilienceratingforthisfactor,whileecosystemsofvalleybottoms,orthoseotherwisefragmented
bylandusehadpoorresilienceratings(Figure2.4e).
Ecosystem vulnerability ranks
Fourofthe20ecosystemsorregionalecosystemsubgroupsassessedhaveanoverallvulnerability
rankofHigh,andoneisrankedVeryHigh(Table2.4).Ingeneral,ecosystemsoftheeasternplains
havethegreatestexposuretochange,andthoseofhigherelevationshavelowerexposure.Undera
longertime‐frame,highelevationareaswouldbesubjecttoincreasedexposure.Mostecosystems
wereassessedashavingmoderateresilience.Asummaryofclimatechangevulnerabilityanalysis
(CCVA)detailsforeachecosystemisprovidedbelow,beginningonpage42.
Climate Change Vulnerability Assessment for Colorado BLM 35 Table 2.4. Vulnerability rank summary for all assessed terrestrial ecosystems. Exposure ‐
Sensitivity final
ranking
Resilience ‐
Adaptive Capacity
final ranking
Combined
ranks
Overall
vulnerability
rank
Aspen forest Low High L/H Low
Lodgepole pine forest Low Low L/L Moderate
Mixed conifer forest Moderate Moderate M/M Moderate
Pinyon‐Juniper woodland Moderate Low M/L High
Ponderosa pine forest Moderate Moderate M/M Moderate
Low Low L/L Moderate
Moderate Moderate M/M Moderate
Low High L/H Low
Sagebrush shrubland Low Moderate L/M Low
Sandsage shrubland High High H/H Moderate
Low Moderate L/M Low
Moderate High M/H Moderate
Semi‐desert grassland Low High L/H Low
Shortgrass prairie High Moderate H/M High
Riparian woodland & shrubland ‐ east High Moderate H/M High
Riparian woodland & shrubland ‐ mountain Low Moderate L/M Low
Riparian woodland & shrubland ‐ west High Low H/L Very High
Wetlands ‐ east High Moderate H/M High
Wetlands ‐ mountain Moderate Moderate M/M Moderate
Wetlands ‐ west Moderate Moderate M/M Moderate
Ecosystem Target
Forest and Woodland
Spruce‐Fir forest Shrubland
Desert shrubland Oak & mixed mountain shrub Grassland or Herbaceous
Alpine Montane grassland Riparian & Wetland
Conclusions
Allecosystemsarelikelytobeaffectedtosomeextentbyclimatechange.Ecosystemswithlow
exposureandhighresiliencecouldbethebeneficiariesoffutureconditions,whilethosewithhigh
exposureandlowresiliencearelikelytoexperiencerangecontractionsand/orsignificantchanges
inspeciescompositionandoverallcondition.Themajorityofhabitattypeswererankedwithlowor
moderatevulnerabilityinouranalysis,however,thegradationsofmoderatelyvulnerable,andthe
transitiontohighlyvulnerablearelessclearthantheseparationbetweenlowandmoderate
vulnerability.Themethodsusedtocombineestimatedexposureandresiliencescoresleavealarge
36 Colorado Natural Heritage Program © 2015 middlegroundwhichcanbeaffectedbyuncertaintyinclimateprojections,currentknowledge,and
ongoingmanagementactions.
Bymid‐century,underbothmoderateandhighradiativeforcingscenarios(RCP4.5andRCP8.5),we
canexpecttoseewarmertemperaturesstatewide,especiallyontheeasternplains.Warmer
temperaturesarelikelytoincludemoreheatwaves,fewercoldsnaps,andgenerallyextendedfrost‐
freeperiods.Althoughtheseconditionscouldbenefitmanyspeciesifprecipitationremains
adequate,thewarmingtrendislikelytobeaccompaniedbyeffectivelydrierconditionsinmany
areas.Evenifprecipitationlevelsathigherelevationsareessentiallyunchanged,warmer
conditionswillleadtomoreprecipitationfallingasraininsteadofsnow,adecreasedsnowpack,
earlierrunoff,andearlierdryconditionsinlatesummer(Lucasetal.2014).Allofthesefactorsmay
interactwithstressorssuchasfire,forestpestsanddiseases,drought,andanthropogenic
disturbancetoalterthefuturetrajectoryofaparticularecosystem.
Comparisonoftherecenthistoricalvaluesofclimatevariableswithprojectedvalueswithinthe
currentColoradodistributionoftheterrestrialecosystems(Figures2.8and2.9)indicatesseasonal
differencesindegreeanddirectionofprojectedchangesintemperatureandprecipitation.For
instance,ecosystemsofhigherelevationsareprojectedtoexperienceagreaterincreaseinwinter
precipitationthanthoseoflowerelevations,althoughtheamountofwarmingissimilarforall
elevations.Projectedchangesinsummerprecipitationaregenerallylessthanforwinter,withsome
ecosystemsseeingaslightincreaseandothersaslightdecrease.
Theinteractionofclimaticconditionswithotherenvironmentalfactorsandbiogeographichistory
shapesthedistributionofecosystemsthatwecurrentlyobserve.Furthermore,thetimelag
betweenwhenclimateconditionsbecomesuitableorunsuitableforaspeciesandtheeventual
colonizationoreliminationofthatspeciesinanareaaddsanotherlevelofuncertaintyto
projectionsoffuturedistribution.Climatechangesoverthepastfewdecadesareprobablyalready
facilitatingagradualshiftofecosystemsthatwillbecomemoreapparentbymid‐century.
Ouranalysisoftherangeoffutureuncertaintyfocusedon“worstcase”(RCP8.5)outcomesinorder
toprovideavulnerabilityprioritizationofkeyecosystemsthatwillfacilitateapragmatic“no‐
regrets”planningstrategyforBLMstaffdealingwiththeongoingeffectsofclimatechangein
Colorado.
Climate Change Vulnerability Assessment for Colorado BLM 37 Figure 2.8. Projected seasonal average precipitation and mean temperature trajectories for current upland ecosystem ranges in Colorado by mid‐century under a high radiative forcing scenario (RCP8.5). Circles represent current conditions. 38 Colorado Natural Heritage Program © 2015 Figure 2.9. Projected seasonal average precipitation and mean temperature trajectories for current wetland and riparian ecosystem ranges in Colorado by mid‐century under a high radiative forcing scenario (RCP8.5). Circles represent current conditions. Climate Change Vulnerability Assessment for Colorado BLM 39 LITERATURE CITED
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Climate Change Vulnerability Assessment for Colorado BLM 41 TERRESTRIAL ECOSYSTEM CCVA SUMMARIES
Forest and Woodland
Table 2.5. Key vulnerabilities, forest and woodland ecosystems. Habitat
Climate factor(s)
Consequences
Other considerations
Aspen Warmer and dry conditions Aspen decline, especially at lower elevations May benefit from fire increase, small patches in conifer forest may expand after conifer mortality Lodgepole Drought, warmer temperatures Fire and insect outbreak; range contraction Mixed Conifer Warmer and dry conditions Change in relative species Diverse species composition abundance or conversion to makes it likely that some other type species will thrive Pinyon‐juniper Warmer and dry conditions Change in relative species Soil types affect distribution abundance favoring juniper; fire and insect outbreak; reduced pinyon pine cone production Ponderosa Drought Fire and insect outbreak Wildland‐Urban Interface complicated management Spruce‐fir Drought Fire and insect outbreak Slow dispersal, short growing season increases vulnerability over time 42 Colorado Natural Heritage Program © 2015 ASPEN
Forestsandwoodlandsdominatedbyquakingaspen
extent exaggerated for display R. Rondeau Climate Vulnerability Rank: Low
Vulnerability summary
Key Vulnerabilities: Hot and dry conditions are likely to lead to aspen decline and mortality at the lowest elevations. However, small aspen patches in conifer forest may benefit from fire increase and expand following conifer mortality. Overallexposuretowarmerandeffectivelydrierconditionsis
lowforthisecosysteminColorado;standsatlowerelevationsare
mostatrisk.Theseforestsaremoderatelyresilient,andin
generallygoodcondition.Aspendynamicsarevariableacrossthe
west,dependingonbothspatialandtemporalscales
(Kulakowski,Kaye,andKashian2013);asaresultthereismuch
uncertaintyaboutthefuturedistributionofthisspecies.Low
elevationstandsimpactedbydroughtarelikelytoexperience
dieback,butinotherareastheinteractionofchangingclimate
anddisturbanceregimesmayfavoraspen(Kulakowski,
Matthews,Jarvis,andVeblen2013).
Distribution
Quakingaspen(Populustremuloides)hasthelargestdistributionofanytreenativetoNorth
America(Little1971).Therangeofthisspecieshasexpandeddramaticallysincetheendofthelast
glacialmaximum,duringwhichthegreaterpartofitsrangewascoveredbytheCordilleranand
Laurentideicesheets.ThiswidespreadecosystemoccursthroughoutmuchofthewesternU.S.and
Climate Change Vulnerability Assessment for Colorado BLM 43 northintoCanada,althoughitismorecommoninthemontaneandsubalpinezonesofthesouthern
andcentralRockyMountains.Theseareuplandforestsandwoodlandsdominatedbyquaking
aspen,orforestsofmixedaspenandconifer,occurringasamosaicofvaryingplantassociations
andadjacenttoadiversearrayofotherecosystems,includingmontanegrasslandsandshrublands,
wetlands,andconiferousforests.InColoradothissystemrangesinelevationfromabout7,500to
10,500feet,andisquitecommononthewestslope,withsmallerstandsrepresentedontheeast
slope.
Characteristic species
Theseforestshaveasomewhatclosedcanopyoftreesof15‐65ft(5‐20m)tall,dominatedby
quakingaspen.Afewconifersmaybepresentincludingwhitefir(Abiesconcolor),subalpinefir
(Abieslasiocarpa),Engelmannspruce(Piceaengelmannii),bluespruce(Piceapungens),ponderosa
pine(Pinusponderosa,)andDouglas‐fir(Pseudotsugamenziesii).Ifconifersmakeupmorethan
15%ofthetreecanopytheoccurrenceisgenerallyconsidereamixedconiferstand.
Theaspencanopytypicallyallowssufficientlightpenetrationforthedevelopmentofalush
understory.Understoriesarehighlyvariableandmaybedominatedbyshrubs,graminoids,or
forbs.CommonshrubsincludeRockyMountainmaple(Acerglabrum),Saskatoonserviceberry
(Amelanchieralnifolia),mountainbigsagebrush(Artemisiatridentatassp.vaseyana),common
juniper(Juniperuscommunis),chokecherry(Prunusvirginiana),Wood’srose(Rosawoodsii),russet
buffaloberry(Shepherdiacanadensis),mountainsnowberry(Symphoricarposoreophilus),andthe
dwarf‐shrubscreepingbarberry(Mahoniarepens)andwhortleberry(Vacciniumspp.).Common
graminoidsincludepinegrass(Calamagrostisrubescens),dryspikesedge(Carexsiccata),Geyer's
sedge(Carexgeyeri),Ross'sedge(Carexrossii),bluewildrye(Elymusglaucus),slenderwheatgrass
(Elymustrachycaulus),Thurberfescue(Festucathurberi),andneedle‐and‐thread(Hesperostipa
comata).ExoticgrassessuchastheperennialsKentuckybluegrass(Poapratensis)andsmooth
brome(Bromusinermis)andtheannualcheatgrass(Bromustectorum)areoftencommonin
occurrencesdisturbedbygrazing.Associatedforbsmayincludecommonyarrow(Achillea
millefolium),Engelmann'saster(Eucephalusengelmannii),larkspur(Delphiniumspp.),Richardson's
geranium(Geraniumrichardsonii),commoncowparsnip(Heracleummaximum),Porter'slicorice‐
root(Ligusticumporteri),silverylupine(Lupinusargenteus),sweetcicely(Osmorhizaberteroi),
westernbrackenfern(Pteridiumaquilinum),Fendler'smeadow‐rue(Thalictrumfendleri),western
valerian(Valerianaoccidentalis),Americanvetch(Viciaamericana),mule‐ears(Wyethia
amplexicaulis),andmanyothers.
Environment
Rangewideelevationsgenerallyrangefrom5,000‐10,000feet(1,525to3,050m),butcanbelower
insomeregions.Topographyisvariable,sitesrangefromleveltosteepslopes.Occurrencesathigh
elevationsarerestrictedbycoldtemperaturesandarefoundonwarmersouthernaspects.Atlower
elevationsoccurrencesarerestrictedbylackofmoistureandarefoundoncoolernorthaspectsand
mesicmicrosites.Thesoilsaretypicallydeepandwelldevelopedwithrockoftenabsent,and
texturerangesfromsandyloamtoclayloams.Parentmaterialsarevariableandmayinclude
sedimentary,metamorphicorigneousrocks,butthistypeappearstogrowbestonlimestone,
basalt,andcalcareousorneutralshales(Mueggler1988).
44 Colorado Natural Heritage Program © 2015 Distributionofaspenforestisprimarilylimitedbyadequatesoilmoisturerequiredtomeetitshigh
evapotranspirationdemand,andsecondarilyislimitedbythelengthofthegrowingseasonorlow
temperatures.Climateistemperatewitharelativelylonggrowingseason,typicallycoldwinters
anddeepsnow.Meanannualprecipitationisgreaterthan15in(38cm)andtypicallygreaterthan
20in(50cm),exceptinsemi‐aridenvironmentswhereoccurrencesarerestrictedtomesic
micrositessuchasseepsorareasthataccumulatelargesnowdrifts.
Dynamics
Aspenisextremelyshadeintolerant,andabletoestablishquicklyoveradisturbedopenareadueto
itsabilitytoreproducebyvegetativesprouting(Howard1996).Thetuftedseedcapsulesproduced
bymatureaspentreesareamenabletowinddispersaloveraconsiderabledistance.Although
quakingaspenestablishmentfromseediscommoninAlaska,northernCanadaandeasternNorth
America,thisislesstrueinthewesternUS,probablybecausegerminatedseedlingsdonotreceive
sufficientmoistureforsurvival(Kay1993).Thereisconflictingevidenceforthefrequencyof
seedlingestablishmentinthewesternUS,however,andquakingaspenmayestablishfromseed
morefrequentlythanpreviouslythought(Howard1996,Rommeetal.1997).
Thereissomeevidenceforsynchronousaspenstandestablishmenteventsoveralargeareaofthe
intermountainwest.Kaye(2011)identifiedtwopeakperiodsofestablishmentviasexual
reproduction,thefirstintheperiod1870‐1890,andtheotherin1970‐1980.Shespeculatesthatthe
earlierestablishmenteventmaybethelegacyofthelastlargefireeventsbeforewidespreadfire
suppressionintheintermountainwest.Thesecondestablishmentpeakcorrespondswithimproved
moistureconditionsduetoashiftinthePacificDecadalOscillationandtheAtlanticMultidecadal
Oscillation.ElliotandBaker(2004)foundthataspenstandsintheSanJuanMountainsare
regeneratingandincreasingindensity.Furthermore,theybelievethataspenincreaseattreelineis
occurringasaresultofestablishmentfromseed.Althoughquakingaspenproducesabundantseeds,
seedlingsurvivalisrarebecausethelongmoistconditionsrequiredtoestablishthemarerarein
thesehabitats.Superficialsoildryingwillkillseedlings(Knight1994).
Aspenforestsandwoodlandsoftenoriginatefrom,andarelikelymaintainedby,stand‐replacing
disturbancessuchascrownfire,diseaseandwindthrow,orclearcuttingbymanorbeaver.The
stemsofthesethin‐barked,clonaltreesareeasilykilledbygroundfires,buttheycanquicklyand
vigorouslyresproutindensitiesofupto30,000stemsperhectare(Knight1994).Thestemsare
relativelyshort‐lived(100‐150years),andtheoccurrencewillsucceedtolonger‐livedconifer
forestifundisturbed.Occurrencesarefavoredbyfireintheconiferzone(Mueggler1988).With
adequatedisturbanceaclonemaylivemanycenturies.
Althoughaspenisnotfiretolerant,itishighlycompetitiveinburnedareasifotherconditionsare
suitable.Aspenclonessurviveintheunderstoryofcool,moistmixedconiferandlowelevation
spruce‐fir,andcanrespondquicklytodisturbances.Instandsaffectedbymultipledisturbance
types(e.g.fire,blowdown,beetle‐kill),aspenregenerationmaybefavoredoverthatofconifers
(Kulakowski,Matthews,Jarvis,andVeblen2013).
Climate Change Vulnerability Assessment for Colorado BLM 45 CCVA Scoring
Exposure‐Sensitivity (Potential Impact) Rank
Percent Colorado acres with projected temp > max & ppt delta < 5% 0.2% Initial Exposure‐Sensitivity Rank Low Percent Colorado acres with temp <= max & ppt delta < 5% more than 50%? No (36.0%) Low Final Exposure‐Sensitivity Rank Exposure to temperature change Underprojectedmid‐centurytemperatures,lessthan1%ofthecurrentrangeofaspenforestin
Coloradowouldexperienceannualmeantemperaturesabovethecurrentstatewidemaximum.
Exposure to precipitation change About36%ofaspenforestecosysteminColoradowillbeexposedtoeffectivelydrierconditions
evenunderunchangedorslightlyincreasedprecipitationprojectedformid‐century.
Sensitivity of ecosystem to temperature and precipitation Quakingaspenisabletogrowonawidevarietyofsites,bothdryandmesic(Mueggler1988).
Climaticconditions,inparticularminimumwintertemperaturesandannualprecipitationamounts
arevariableovertherangeofthespecies(Howard1996).Ingeneral,quakingaspenisfoundwhere
annualprecipitationexceedsevapotranspiration,andthelowerlimitofitsrangecoincideswitha
meanannualtemperatureof45°F(Perala1990).InthecentralRockyMountains,quakingaspen
distributionishighlycorrelatedwithelevation,duetoitsinfluenceontemperatureand
precipitationpatterns.IntheRockyMountainsstandsgenerallyoccurwhereannualprecipitationis
greaterthan14.9in(38cm)peryear(MorelliandCarr2011)andsummertemperaturesare
moderate.
Resilience and Adaptive Capacity Rank
Overall Score: 0.71 Rank: High
Bioclimatic envelope and range Averagedcategoryscore:0.76
Aspenforestsarenotfoundatalpineelevations,butstandsarecommonthroughoutcentraland
westernColoradoatmontanetosubalpineelevations.Aspenforestshavesignificantpresencein
63%ofColorado’soverallprecipitationrange,andin40%ofthestate’sgrowingdegreedaysrange.
QuakingaspenisverywidelydistributedinNorthAmerica,andthesouthernlimitofitsrangeis
currentlywelltothesouthofColorado.
Growth form and intrinsic dispersal rate Score:0.50
46 Colorado Natural Heritage Program © 2015 Quakingaspenisarelativelyfastgrowingspecies,andabletoquicklycolonizedisturbedareasby
vegetativereproduction.However,duetoitstreegrowthform,anduncertaintyaboutseed
dispersalrates,thisecosystemwasscoredashavingintermediateresilienceinthiscategory.
Vulnerability to increased attack by biological stressors Score:0.8
Vulnerabilityofaspentopathogensandherbivores,andsubsequentaspenmortalitymaybe
increasedbyclimatechangeifdroughtandwarmerconditionsincreaseenvironmentalstress
(MorelliandCarr2011).Heavygrazingbyelkincombinationwithdroughtappearstobeleadingto
declineinsomeareas(MorelliandCarr2011).Stressfromgrazingcouldbemitigatedby
managementactions.Cankerinfections,gypsymoth,andforesttentcaterpillaroutbreaksare
tightlyassociatedwithdrierandwarmerconditions(CryerandMurray1992,Johnston2001,Logan
2008,Hoggetal.2001).
Vulnerability to increased frequency or intensity of extreme events Score:0.7
Aspenshaveincreasedsusceptibilitytoepisodicdeclineatlowerelevations,underwarmanddry
conditions(Worralletal.2008).Thisaspendieback(sometimescalledSuddenAspenDecline)
appearstoberelatedtodroughtstress,andistypicallygreatestonthehotteranddrierslopes,
whichareusuallyatthelowestelevationsofastand(Rehfeldtetal.2009).Standsmayundergo
thinning,butthenrecover.Increasingdroughtwithclimatechangeisbelievedtobetheprimary
vulnerabilityofthisecosystem(Worralletal.2013),andsubstantiallossofthistypecanbe
expected.Theeffectsofdroughtarelikelytointeractwithotherstressorssuchasoutbreaksof
pestsanddisease,snowmelttiming,andungulateherbivory.
Theinteractionofclimatechangewithnaturaldisturbancemayalsoaffectthefuturedistributionof
aspen.Althoughaspenisnotfiretolerant,itislikelytoestablishinadjacentforeststhathave
burned,ifotherconditionsaresuitable.
Other indirect effects of non‐climate stressors – landscape condition Score:0.77
AspenforestsinColoradoareingoodconditionandnothighlythreatened.MuchofColorado’s
aspenforestisonfederallandsmanagedbytheU.S.ForestService.Primaryhumanactivitiesinthis
ecosystemincludecattleandsheepgrazing,recreation,andhunting.Someaspenstandsarecutfor
timberproducts.Threatstotheaspenforestsandwoodlandsarecomparativelylow.
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JuanMountains,Colorado,USA.JournalofBiogeography31:733‐745.
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48 Colorado Natural Heritage Program © 2015 Worrall,J.J.,G.E.Rehfeldt,A.Hamann,E.H.Hogg,S.B.Marchetti,M.Michaelian,andL.K.Gray.2013.Recentdeclinesof
PopulustremuloidesinNorthAmericalinkedtoclimate.ForestEcologyandManagement229:35‐51.
Climate Change Vulnerability Assessment for Colorado BLM 49 LODGEPOLE
Forestsdominatedbylodgepolepine
R. Rondeau extent exaggerated for display Climate Vulnerability Rank: Moderate
Vulnerability summary
Key Vulnerabilities: Warmer and drier conditions are likely to increase the impact of fire and insect outbreaks in lodgepole forests. Lodgepole stands near the southern end of the range may be lost. Lodgepolepineforestisrankedmoderatelyvulnerabletothe
effectsofclimatechangebymid‐century.Primaryfactors
contributingtothisrankingareitsvulnerabilitytoforest
disturbancesthatmayincreaseinthefuture,andthefactthatitis
atthesouthernedgeofitsdistributioninColorado.Lodgepole
forestsinColoradohaveexperiencedsignificantmortalitydueto
themountainpinebeetle,andtheinteractionofthisfactorwith
increasedfireanddroughtfrequencyandintensitycouldleadto
conspicuouschangesinthefutureextentandformofthese
forests.
Distribution
ThismatrixformingsystemiswidespreadinuppermontanetosubalpineelevationsoftheRocky
Mountains,Intermountainregion,andnorthintotheCanadianRockies.Lodgepolepinereachesthe
southernextentofitsrangeataboutthemiddleoftheupperGunnisonBasin(Johnston1997),so
thisecosystemisnotfoundinsouthernColorado.
50 Colorado Natural Heritage Program © 2015 Characteristic species
TheseforestsaredominatedbyRockyMountainlodgepolepine(Pinuscontortavar.latifolia)with
shrub,grass,orbarrenunderstories.Manystandsconsistofonlylodgepolepine,butothersare
intermingledwithmixedconiferorquakingaspenstands(thelatteroccurringwithinclusionsof
deeper,typicallyfine‐texturedsoils).Shrubandherbaceouslayersareoftenpoorlydevelopedin
lodgepolepineforests,andplantspeciesdiversityislow.Somecommonunderstoryshrubsinclude
kinnikinnick(Arctostaphylosuva‐ursi),snowbrushceanothus(Ceanothusvelutinus),twinflower
(Linnaeaborealis),creepingbarberry(Mahoniarepens),antelopebitterbrush(Purshiatridentata),
dwarfbilberry(Vacciniumcaespitosum),whortleberry(Vacciniummyrtillus),grousewhortleberry
(Vacciniumscoparium),andcurrant(Ribesspp.).
Environment
Soilssupportingtheseforestsaretypicallywell‐drained,gravelly,havecoarsetextures,areacidic,
andrarelyformedfromcalcareousparentmaterials.InColorado,lodgepolepineforestsgenerally
occurbetween8,000‐10,000feetongentletosteepslopesonallaspects.Somelodgepoleforests
persistonsitesthataretooextremeforotherconiferstoestablish.Theseincludeexcessivelywell‐
drainedpumicedeposits,glacialtillandalluviumonvalleyfloorswherethereiscoldair
accumulation,warmanddroughtyshallowsoilsoverfracturedquartzitebedrock,andshallow
moisture‐deficientsoilswithasignificantcomponentofvolcanicash.
Dynamics
Lodgepolepineisanaggressivelycolonizing,shade‐intolerantconifer.Establishmentisepisodic
andlinkedtostand‐replacingdisturbances,primarilyfire.ThefrequencyofnaturalfiresinRocky
Mountainlodgepolepinestandsrangesfromafewyearsto200ormoreyears(Davisetal.1980).
Lowtomoderateserveritysurfacefiresarelikelytohaveareturnintervalontheorderofafew
decades,whilestand‐replacingfiresaregenerallylessfrequent(Crane1982).
Lodgepolepinesproducebothopenandclosed,serotinouscones,andcanreproducequicklyaftera
fire.Followingstand‐replacingfires,lodgepolepinerapidlycolonizesanddevelopsintodense,
even‐agedstands(sometimesreferredtoas“doghair”stands).Thisfire‐adaptedspecieshasthe
potentialtomoveintoareaswherespruce‐firforestsburn.Theproductionofserotinousconesisa
highlyheritabletraitamongRockyMountainlodgepolepinepopulations(Parchmanetal.2012).
Serotinousconesappeartobestronglyfavoredbyfire,andallowrapidcolonizationoffire‐cleared
substrates(BurnsandHonkala1990),butserotinyisalsoselectedagainstbycontinuousremoval
ofthecanopyseed‐bankbyactiveseedpredators(BenkmanandSiepielski2004).Treeswith
serotinousconesarefavoredunderconditionsofhighfirefrequencyandlowpredation,but
nonserotinyhasanadvantageunderveryhighseedpredation,regardlessoffirefrequency(Talluto
andBenkman2014).
Climate Change Vulnerability Assessment for Colorado BLM 51 CCVA Scoring
Exposure‐Sensitivity (Potential Impact) Rank
Percent Colorado acres with projected temp > max & ppt delta < 5% 0% Initial Exposure‐Sensitivity Rank Low Percent Colorado acres with temp <= max & ppt delta < 5% more than 50%? No (7.3%) Low Final Exposure‐Sensitivity Rank Exposure to temperature change Underprojectedmid‐centurytemperatures,lessthan1%ofthecurrentrangeoflodgepolepine
forestinColoradowouldexperienceannualmeantemperaturesabovethecurrentstatewide
maximum.
Exposure to precipitation change About7%oflodgepoleforestecosysteminColoradowillbeexposedtoeffectivelydrierconditions
evenunderunchangedorslightlyincreasedprecipitationprojectedformid‐century.
Sensitivity of ecosystem to temperature and precipitation Lodgepolepineistolerantofverylowwintertemperatures,andinmanylodgepoleforestssummer
temperaturescanfallbelowfreezing,sothereisnotruefrost‐freeseason(LotanandPerry1983).
Lodgepolepineisalsoabletotakeadvantageofwarmgrowingseasontemperatures,andalonger
growingseasonduetowarmerfalltemperaturescouldfavorthegrowthoflodgepolepine(Villalba
etal.1994,Chhinetal.2008).InsouthernColorado,whitefir(Abiesconcolor)appearstotakethe
placeoflodgepolepineinconiferousforestsofsimilarelevations.Whitefirappearstotolerate
warmertemperaturesthanlodgepolepine(Thompsonetal.2000);underwarmerconditionsit
maybeabletomoveintoareascurrentlyoccupiedbylodgepoleforest.
Lodgepolepineisanorthernspeciesthatdoesexceptionallywellinverycoldclimatesandcan
tolerateawiderangeofannualprecipitationpatterns,fromfairlydrytofairlywet,butgenerally
growsonlywhereannualprecipitationisatleast18‐20inches(Mason1915,LotanandPerry
1983).Lodgepolepineforestsarefoundondriersitesthanspruce‐firforest,althoughsnowfallis
typicallyheavyintheseforests.Summersareoftenquitedry,andlodgepolepineisdependenton
snowmeltmoistureformostofthegrowingseason.Inlowsnowpackyears,growthisreduced(Hu
etal.2010).
Resilience and Adaptive Capacity Rank
Overall Score: 0.35 Rank: Low
Bioclimatic envelope and range Averagedcategoryscore:0.50
52 Colorado Natural Heritage Program © 2015 LodgepolepinesubspeciesarewidelydistributedinNorthAmerica,butRockyMountainlodgepole
reachesthesouthernedgeofitsdistributioninsouth‐centralColorado.Lodgepoleforestsarenot
foundatthehighestelevations,butrangefrommontanetosubalpine.Statewide,theannual
averageprecipitationrangeforlodgepoleforestcoversabout64%ofColorado’soverall
precipitationrange.Growingseasonlengthforlodgepolebroadlyoverlapsthatofthewarmerend
ofthespruce‐firdistribution,andcoversabout35%ofthestatewiderangeofgrowingdegreedays.
Growth form and intrinsic dispersal rate Score:0
Thetreegrowthformandslowdispersalrateoflodgepolepinegivethisecosystemalowresilience
scoreinthiscategory.
Vulnerability to increased attack by biological stressors Score:0
Althoughinvasivespeciesaregenerallynotathreat,lodgepoleforestsarevulnerabletothepest
outbreaksthatappeartoincreasewithwarmer,drier,drought‐proneclimates.Biologicalstressors
thatinteractwithfiredynamicsoflodgepoleforestincludeinfestationsoflodgepolepinedwarf‐
mistletoeandmountainpinebeetle(Anderson2003).Dwarfmistletoereducestreegrowthand
coneproduction,andgenerallyleadstoearliermortality(HawksworthandJohnson1989).
AlthoughlodgepoleforestsarestillcommonacrossColorado,mosthaveexperiencedwidespread
damagefromasevereoutbreakofmountainpinebeetle.Thepinebeetleisanativespecies,and
periodicoutbreaksofthisinsectarepartofthenaturalcyclethatmaintainsColorado’smountain
forests.LodgepoleforestsareexpectedtopersistinColorado(Kaufmannetal.2008),although
foreststructuremaydifferfromwhathasbeenpresenthistorically.
Vulnerability to increased frequency or intensity of extreme events Score:0.5
Warmingtemperaturesandeffectivelydrierconditionsareexpectedtohaveaneffectonfire
frequencyandseverity.Firesuppressioneffectsinlodgepolepineforestsareevidentatalandscape
levelinanoveralllackofvarietyinsuccessionalstages.Individuallodgepolestandsmaynotbe
outsidethenaturalrangeofvariation,butatalandscapelevelfiresuppressionhasprobablyledto
larger,denser,morehomogenouspatchesthataremorefavorableforlargefireandheavy
infestationsofmountainpinebeetle(Keaneetal.2002).Thecurrentoutbreakofmountainpine
beetleappearstobesubsiding,leavingthepotentialforlargefireswithextremebehaviortooccur
inthekilledforests(Kaufmannetal.2008).
Other indirect effects of non‐climate stressors – landscape condition Score:0.75
LodgepoleforestlandscapesinColoradoaregenerallyingoodcondition.Althoughlarge,intact
patchesoflodgepoleforestpersistinColorado,thismaychangeastheeffectsofextensivemountain
pinebeetlemortalityandincreasedfireextentandfrequencyreshapethelodgepolematrix.
Climate Change Vulnerability Assessment for Colorado BLM 53 Developmentofexurbanorrecreationalareasisaminorsourcesofdisturbanceandfragmentation
inlodgepoleforests,asaretheassociatedroadsandutilitycorridors.TimberharvestinColorado’s
lodgepoleforestshasdeclinedsignificantlysincethelate19thcentury,butarecentincreaseinthe
useofbeetle‐killwoodhadmaintainedasmallmarketforthisspecies.Woodharvestactivitiesarea
minorsourceofdisturbanceinthishabitattype,butextensivesalvageloggingandthinningmay
havelocallysevereimpacts.
Literature Cited
Anderson,M.D.2003.Pinuscontortavar.latifolia.In:FireEffectsInformationSystem,[Online].U.S.Departmentof
Agriculture,ForestService,RockyMountainResearchStation,FireSciencesLaboratory(Producer).Available:
http://www.fs.fed.us/database/feis/ Benkman,C.W.andA.M.Siepielski.2004.Akeystoneselectiveagent?Pinesquirrelsandthefrequencyofserotinyin
lodgepolepine.Ecology85:2082‐2087.
Burns,R.M.,andB.H.Honkala,technicalcoordinators.1990a.SilvicsofNorthAmerica:Volume1.Conifers.USDAForest
Service.AgricultureHandbook654.Washington,DC.675pp.
Chhin,S.,E.H.Hogg,V.J.Lieffers,andS.Huang.2008.Influencesofclimateontheradialgrowthoflodgepolepinein
Alberta.Botany86:167‐178.
Crane,M.F.1982.FireecologyofRockyMountainRegionforesthabitattypes.USDAForestServicefinalreport.272pp.
Davis,KathleenM.;Clayton,BruceD.;Fischer,WilliamC.1980.FireecologyofLoloNationalForesthabitattypes.INT‐79.
Ogden,UT:U.S.DepartmentofAgriculture,ForestService,IntermountainForestandRangeExperimentStation.77p.
Hawksworth,F.G.andD.W.Johnson.1989.BiologyandmanagementofdwarfmistletoeinlodgepolepineintheRocky
Mountains.Gen.Tech.Rep.RM‐169.FortCollins,CO:U.S.DepartmentofAgriculture,ForestService,RockyMountain
ForestandRangeExperimentStation.38p.
Hu,J.,D.J.P.Moore,S.P.Burns,andR.K.Monson.2010.Longergrowingseasonsleadtolesscarbonsequestrationbya
subalpineforest.GlobalChangeBiology16:771‐783.
JohnstonB.C.1997.EcologicaltypesoftheUpperGunnisonBasin.Reviewdraft.USDA,ForestService,Gunnison,CO.539
pp.
KaufmannM.R.,G.H.Aplet,M.Babler,W.L.Baker,B.Bentz,M.Harrington,B.C.Hawkes,L.StrohHuckaby,M.J.Jenkins,D.M.
Kashian,R.E.Keane,D.Kulakowski,C.McHugh,J.Negron,J.Popp,W.H.Romme,T.Schoennagel,W.Shepperd,F.W.Smith,
E.KennedySutherland,D.Tinker,andT.T.Veblen.2008.Thestatusofourscientificunderstandingoflodgepolepineand
mountainpinebeetles–afocusonforestecologyandfirebehavior.TheNatureConservancy,Arlington,VA.GFItechnical
report2008‐2.
Lotan,J.E.andD.A.Perry.1983.Ecologyandregenerationoflodgepolepine.Agric.Handb.606.Washington,DC:U.S.
DepartmentofAgriculture,ForestService.51p.
Mason,D.T.1915.LifehistoryoflodgepolepineintheRockyMountains.Bulletin154.Washington,DC:U.S.Departmentof
Agriculture,ForestService.35p.
ParchmanT.L.,Z.Gompert,J.Mudge,F.D.Schilkey,C.W.Benkman,andC.A.Buerkle.2012.Genome‐wideassociation
geneticsofanadaptivetraitinlodgepolepine.MolecularEcology21:2991–3005.
54 Colorado Natural Heritage Program © 2015 Talluto,M.V.andC.W.Benkman.2014.Conflictingselectionfromfireandseedpredationdrivesfine‐scaledphenotypic
variationinawidespreadNorthAmericanconifer.PNAS111:9543‐9548.
Thompson,R.S.,K.H.Anderson,andP.J.Bartlein.2000.Atlasofrelationsbetweenclimaticparametersanddistributions
ofimportanttreesandshrubsinNorthAmerica.U.S.GeologicalSurveyProfessionalPaper1650‐A.
Villalba,R.,T.T.Veblen,andJ.Ogden.1994.ClimaticinfluencesonthegrowthofsubalpinetreesintheColoradoFront
Range.Ecology75:1450‐1462.
Wheeler,N.C.andW.B.Critchfield.1985.Thedistributionandbotanicalcharacteristicsoflodgepolepine:biogeographical
andmanagementimplications.In:Baumgartner,D.M.,R.G.Krebill,J.T.Arnott,andG.F.Weetman,compilersandeditors.
Lodgepolepine:Thespeciesanditsmanagement:Symposiumproceedings;1984May8‐10;Spokane,WA;1984May14‐
16;Vancouver,BC.Pullman,WA:WashingtonStateUniversity,CooperativeExtension:1‐13.
Climate Change Vulnerability Assessment for Colorado BLM 55 MIXED CONIFER
Dry‐mesicandmesicforestsorwoodlandsofDouglasfir,whitefir,otherconiferspecies,and
occasionalaspenstands
R. Rondeau extent exaggerated for display Climate Vulnerability Rank: Moderate
Vulnerability summary
Key Vulnerabilities: Warmer and drier conditions can be expected to change the relative tree species abundance in mixed conifer forests. Although some stands may convert to other types, the diverse species composition of these forests increases the likelihood that some species will benefit under future conditions. Novel mixed conifer types may appear. Theecotonalnatureofmixedconiferstandsincreasesthe
difficultyofinterpretingtheirvulnerabilitytoclimatechange,and
theircapacitytomoveintonewareas.Thediversityofspecies
withinmixedconiferforestmayincreaseitsflexibilityintheface
ofclimatechange.Changingclimateconditionsarelikelytoalter
therelativedominanceofoverstoryspecies,overallspecies
compositionandrelativecover,primarilythroughtheactionof
fire,insectoutbreak,anddrought.Droughtanddisturbance
tolerantspecieswillbefavoredoverdroughtvulnerablespecies.
Speciessuchasbluesprucethatareinfrequentandhavea
narrowbioclimaticenvelopearelikelytodeclineormoveupin
elevation.AbundantspeciesthathaveawidebioclimaticenvelopesuchasGambeloakandaspen
arelikelytoincrease.Outcomesforparticularstandswilldependoncurrentcompositionand
location.Currentstandsofwarm,drymixedconiferbelow8,500ftmaybeathigherriskormay
converttopureponderosapinestandsasfutureprecipitationscenariosfavorrainratherthan
snow.Upwardmigrationintonewareasmaybepossible.
56 Colorado Natural Heritage Program © 2015 Distribution
InColoradothesemixed‐coniferforestsoccuronallaspectsatelevationsrangingfrom4,000to
10,800ft(1,200‐3,300m).Thecompositionandstructureofoverstoryisdependentuponthe
temperatureandmoisturerelationshipsofthesite,andthesuccessionalstatusoftheoccurrence.
Thesecomplexforestandwoodlandcommunitiesareoftenintermingledwithotherforesttypes,
includingponderosapine,aspen,lodgepole,andspruce‐fir,dependingonelevation,andmaybe
adjacenttoshrublandandripariantypesaswell.
Thesimilarenvironmentaltolerancesofmixed‐coniferandaspenforestmeansthatthetwoforest
typesaresomewhatintermixedinmanyareas.Theseforestsappeartorepresentabiophysical
spacewhereanumberofdifferentoverstoryspeciescanbecomeestablishedandgrowtogether.
Localconditions,biogeographichistory,andcompetitiveinteractionsovermanydecadesareprime
determinantsofstandcomposition.
Characteristic species
Severalsub‐typesorphases,representingacontinuumfromwarm‐drytocold‐wethavebeen
describedfortheseforests(Rommeetal.2009),andspeciescomposition,standstructure,andsite
characteristicsvaryaccordingly.
Thesemixed‐speciesforestsmayincludeDouglas‐fir(Pseudotsugamenziesii),whitefir(Abies
concolor),ponderosapine(Pinusponderosa),quakingaspen(Populustremuloides),bluespruce
(Piceapungens),Engelmannspruce(Piceaengelmannii),subalpinefir(Abieslasiocarpa),andlimber
pine(Pinusflexilis),whichreachesthesouthernlimitofitsdistributionintheSanJuanmountains.
Warm‐drysitesarecharacterizedbyDouglas‐fir,oftenwithponderosapineandGambeloak
(Quercusgambelii).Cool‐moiststandsarelikelytobedominatedbyDouglasfir,whitefir,blue
spruceandsomequakingaspen.TypicalunderstoryshrubspeciesincludeRockyMountainmaple
(Acerglabrum),Saskatoonserviceberry(Amelanchieralnifolia),kinnikinnick(Arctostaphylosuva‐
ursi),rockspirea(Holodiscusdumosus),fivepetalcliffbush(Jamesiaamericana),commonjuniper
(Juniperuscommunis),creepingbarberry(Mahoniarepens),Oregonboxleaf(Paxistimamyrsinites),
mountainninebark(Physocarpusmonogynus),mountainsnowberry(Symphoricarposoreophilus),
thimbleberry(Rubusparviflorus),andwhortleberry(Vacciniummyrtillus).Wheresoilmoistureis
favorable,theherbaceouslayermaybequitediverse.
CharacteristicanimalspeciesinmixedconiferforestincludeRuby‐crownedkinglet,Hermitthrush,
Hammond’sflycatcher,Williamson’ssapsucker,Yellow‐rumpedwarbler,Pinesiskin,Red‐breasted
nuthatch,Townsend’ssolitaire,Westerntanager,Browncreeper,Cassin’sfinch,Redcrossbill,Olive‐
sidedflycatcher,Mountainchickadee,Junco,Snowshoehare,Lynx,andPinemarten.
Environment
Thecompositionandstructureofoverstoryisdependentuponthetemperatureandmoisture
relationshipsofthesite,andthesuccessionalstatusoftheoccurrence(DeVeliceetal.1986,
Muldavinetal.1996).Driersites,oftenonsoutherlyaspects,maybesimilartoponderosapine
forest,butwithDouglas‐firandwhitefirasimportantcanopycomponents.Historically,these
standsweresubjecttofairlyfrequentlowtomoderateintensityfire,whichhelpedtomaintaina
Climate Change Vulnerability Assessment for Colorado BLM 57 relativelyopenstructure(Rommeetal.2009).Moremesicstandsarefoundincoolravinesandon
north‐facingslopes,lackponderosapine,andarelikelytobedominatedbyDouglas‐firandwhite
firwithbluespruceorquakingaspenstands,andoccasionalinclusionsofEngelmannspruceor
subalpinefir.Thesecool‐moiststandswouldhavelessfrequentfires,andsoilmoistureconditions
thatallowthegrowthofdensestandsthateventuallyburninahigh‐intensityfire(Rommeetal.
2009).
Soilsofthisecosystemarevariable,andmaybederivedfromparentmaterialsofigneous,
metamorphic,orsedimentaryorigin.Moreopenwoodlandcommunitiesaretypicallyfoundonsoils
thatareshallow,rocky,andwell‐drained.
Dynamics
Long‐termecologicaldynamicsofmixedconiferforestsarerelativelyunderstudied(Rommeetal.
2009).Therehasbeenconsiderablerecentdebateabouthistoricrangeofvariationforstand
densityandhigh‐severityfireincidenceinmixedconiferforests(WilliamsandBaker2012,Fuleet
al.2013,WilliamsandBaker2014).Naturalfireprocessesinthissystemareprobablyhighly
variableinbothreturnintervalandseverity,dependingonstandcomposition,siteconditions,
biogeographichistory,andshort‐andlong‐termclimatepatterns.Forinstance,droughtandhigh
temperaturespriortofireinitiationareassociatedwithlargerburnedareaasfinefuelsbecomedry
(Littelletal.2009).
Althoughcoolmoistmixed‐coniferforestsaregenerallywarmeranddrierthanspruce‐firforests,
thesestandsareofteninrelativelycool‐moistenvironmentswherefireswerehistorically
infrequentwithmixedseverity.Whenstandsareseverelyburned,aspenoftenresprouts.Warm‐
drymixedconiferforestshadahistoricfire‐regimethatwasmorefrequent,withmixedseverity.In
areaswithhighseverityburns,aspenorGambeloakoftenresproutsanddominatesthesitefora
relativelylongperiodoftime.Insomelocations,muchoftheseforestshavebeenloggedorburned
duringEuropeansettlement,andpresent‐dayoccurrencesaresecond‐growthforestsdatingfrom
fire,logging,orotheroccurrence‐replacingdisturbances(MaukandHenderson1984,Chappellet
al.1997).
Additionaldisturbancesinmixedconiferforestsmaybeduetowindstormsorinsect‐pathogen
outbreaks.Sprucebudworminfestationsareamajorsourceoftreemortalityandcanaffect
landscape‐scaledynamicsinmixedconiferforest(Rommeetal.2009).
CCVA Scoring
Exposure‐Sensitivity (Potential Impact) Rank
Percent Colorado acres with projected temp > max & ppt delta < 5% 0.1% Initial Exposure‐Sensitivity Rank Low Percent Colorado acres with temp <= max & ppt delta < 5% more than 50%? Yes (61.0%) Final Exposure‐Sensitivity Rank Moderate 58 Colorado Natural Heritage Program © 2015 Exposure to temperature change Underprojectedmid‐centurytemperatures,lessthan1%ofthecurrentrangeofmixedconifer
forestinColoradowouldexperienceannualmeantemperaturesabovethecurrentstatewide
maximum.
Exposure to precipitation change About61%ofmixedconiferforestecosysteminColoradowillbeexposedtoeffectivelydrier
conditionsevenunderunchangedorslightlyincreasedprecipitationprojectedformid‐century.
Sensitivity of ecosystem to temperature and precipitation Withthevariationfromwarm‐drytypestocool‐moisttypes,mixedconiferforestshaveabroad
ecologicalamplitude,andvariationbetweenstandsisobviouslyinfluencedbybothtemperature
andprecipitation.Theeffectsofclimaticfactorsontheecosystemasawhole,however,arelittle
known,especiallyinColorado.GenerallywarmingconditionsduringtheearlyHoloceneallowedfor
theexpansionofsomemixedconiferforesttreespeciesincludingDouglas‐fir,ponderosapine,and
Gambeloak,andthedevelopmentofmixedconiferforestsinareaspreviouslycharacterizedby
subalpinespecies(Andersonetal.2008).
StudiesfromthesouthwesternUSindicatethatfactorscontrollingthedistributionandpersistence
ofthecomponenttreespeciesinmixedconiferforestsarecomplexandnoteasilyexplainedata
broadclimaticlevel.Forinstance,KaneandKolb(2014)foundthatalthoughdroughtwasan
importantdriverforaspenmortalityinmixedconifer,therewasnosimilareffectforthemuch
slower‐growinglimberpine.Douglas‐firandwhitefirmortalityduringthedroughtwasmoderately
associatedwithpreviousgrowthrate(i.e.,sitequality),indicatingthatlonger‐termprocessessuch
ascompetitionanddisturbancehistorymayalsoplayarole.Cool‐moistmixedconiferforestsof
higherelevationsmaybelesssusceptibletodrought(AdamsandKolb2005),butarenot
completelyprotectedbygenerallycooler,wetterconditions(Kaneetal.2014).
Resilience and Adaptive Capacity Rank
Overall Score: 0.60 Rank: Moderate
Bioclimatic envelope and range Averagedcategoryscore:0.78
Mixedconiferforestsoccuratfoothillandmontaneelevationsthroughoutcentralandwestern
Colorado,andhaveafairlywideecologicalamplitude.Theseforestshavesignificantpresencein
60%ofColorado’soverallprecipitationrange,andin51%ofthestate’sgrowingdegreedaysrange.
Thehighlyvariableandecotonalnatureofmixedconiferforestscontributestothehigherresilience
scoreinthiscategory.
Growth form and intrinsic dispersal rate Score:0
Climate Change Vulnerability Assessment for Colorado BLM 59 Thetreegrowthformandslowdispersalrateofthedominantconiferspeciesgivethisecosystema
lowresiliencescoreinthiscategory.
Vulnerability to increased attack by biological stressors Score:0.7
StandsinthesouthernpartofColoradohavebeenimpactedbythewesternsprucebudwormand
drought.Budwormoutbreaksarepartofanaturalcycleinmixedconiferforest,butmaybe
intensifiedbyincreasingdroughtfrequencyandthegenerallyhighertemperaturesprojectedin
comingdecades.
Vulnerability to increased frequency or intensity of extreme events Score:0.7
Inareasadjacenttodevelopment,mixedconiferstandsmaybepartofthewildland‐urbaninterface,
wheretheyaremostlikelytobethreatenedbytheeffectsoffiresuppression.Theabsenceofa
naturalfireregimeintheseforestshasresultedinincreasedtreedensityandthebuildupofduff
andlitter,whichmayincreasetheseverityoffirewhenitdoesoccur.Asyear‐roundtemperatures
increaseandprecipitationshiftsmoretowardraininsteadofsnow,conditionsfavorablefor
increasingareaburnedmaydevelop(Littelletal.2009).However,manymixedconiferstandsin
Coloradoarenotasseverelyimpactedbyfiresuppression.
Other indirect effects of non‐climate stressors – landscape condition Score:0.81
MixedconiferforestlandscapesinColoradoaregenerallyinverygoodcondition.Exurban
developmentandrecreationalareadevelopmentareathreattotheseforestsalongtheFrontRange
andI‐70corridorinmountainareas.Roadsandutilitycorridorsareasourceofdisturbanceand
fragmentationinmixedconiferforeststatewide,butthesestandsnaturallyoccurinsmallerpatches
thansomeotherforesttypes,sothreatsareminor.Anumberoftreespeciesinmixedconiferare
suitablefortimberharvest,sologgingisanongoingsourceofdisturbanceintheseforests.Threats
fromlivestockgrazingandhuntingorrecreationalactivitiesareminimalformixedconiferforests.
Miningandminetailingsareasmallsourceofdisturbance.
Literature Cited
Adams,H.D.andT.E.Kolb.2005.Treegrowthresponsetodroughtandtemperatureinamountainlandscapeinnorthern
Arizona,USA.JournalofBiogeography32:1629‐1640.
Anderson,R.S.,R.B.Jass,J.L.Toney,C.D.Allen,L.M.Cisneros‐Dozal,M.Hess,J.Heikoop,J.Fessenden.2008.Developmentof
themixedconiferforestinnorthernNewMexicoanditsrelationshiptoHoloceneenvironmentalchange.Quaternary
Research69:263‐275.
Chappell,C.,R.Crawford,J.Kagan,andP.J.Doran.1997.Avegetation,landuse,andhabitatclassificationsystemforthe
terrestrialandaquaticecosystemsofOregonandWashington.UnpublishedreportpreparedforWildlifehabitatand
speciesassociationswithinOregonandWashingtonlandscapes:Buildingacommonunderstandingformanagement.
PreparedbyWashingtonandOregonNaturalHeritagePrograms,OlympiaWA,andPortland,OR.177pp.
60 Colorado Natural Heritage Program © 2015 Crane,M.F.1982.FireecologyofRockyMountainRegionforesthabitattypes.USDAForestServicefinalreport.272pp.
DeVelice,R.L.,J.A.Ludwig,W.H.Moir,andF.Ronco,Jr.1986.AclassificationofforesthabitattypesofnorthernNew
MexicoandsouthernColorado.USDAForestService,RockyMountainForestandRangeExperimentStation.General
TechnicalReportRM‐131.FortCollins,CO.59pp.
Kane,J.M.andT.E.Kolb.2014.Short‐andlong‐termgrowthcharacteristicsassociatedwithtreemortalityinsouthwestern
mixed‐coniferforests.CanadianJournalofForestResearch44:1227‐1235.
Kane,J.M.,T.E.Kolb,andJ.D.McMillin.2014.Stand‐scaletreemortalityfactorsdifferbysiteandspeciesfollowingdrought
insouthwesternmixedconiferforests.ForestEcologyandManagement330:171‐182.
Littell,J.S.,D.McKenzie,D.L.Peterson,andA.L.Westerling.2009.ClimateandwildfireareaburnedinwesternU.S.
ecoprovinces,1916‐2003.EcologicalApplications19:1003‐1021.
Mauk,R.L.andJ.A.Henderson.1984.ConiferousforesthabitattypesofnorthernUtah.USDAForestService,Gen.Tech.
ReportINT‐170,Ogden,Utah.89p.
Muldavin,E.H.,R.L.DeVelice,andF.Ronco,Jr.1996.AclassificationofforesthabitattypessouthernArizonaandportions
oftheColoradoPlateau.USDAForestServiceGeneralTechnicalReportRM‐GTR‐287.RockyMountainForestandRange
ExperimentStation,FortCollins,CO.130pp.
Pfister,R.D.1977.EcologicalclassificationofforestlandinIdahoandMontana.Pages329‐358in:Proceedingsof
EcologicalClassificationofForestLandinCanadaandNorthwesternUSA,UniversityofBritishColumbia,Vancouver.
Romme,W.H.,Floyd,M.L.,Hanna,D.,2009.Historicalrangeofvariabilityandcurrentlandscapeconditionanalysis:South
CentralHighlandssection,SouthwesternColoradoandNorthwesternNewMexico.Col.For.Rest.Inst.,FortCollins,CO.
Steele,R.,R.D.Pfister,R.A.Ryker,andJ.A.Kittams.1981.ForesthabitattypesofcentralIdaho.USDAForestService
GeneralTechnicalReportINT‐114.IntermountainForestandRangeExperimentStation,Ogden,UT.138pp.
Climate Change Vulnerability Assessment for Colorado BLM 61 PINYON‐JUNIPER
Woodlandsandshrublandsdominatedbypinyonpineandjuniperspecies
S. Kettler extent exaggerated for display Climate Vulnerability Rank: High
Vulnerability summary
Key Vulnerabilities: Hot and dry conditions are likely to increase the impact of fire and insect outbreaks, and favor juniper over pinyon pine. Substrates play a key role in determining soil moisture availability for individual stands. Variabledisturbanceandsiteconditionsacrossthedistribution
ofthisecosystemhaveresultedinadynamicmosaicof
interconnectedcommunitiesandsuccessionalstagesacrossthe
landscape.Sincethelastmajorglacialperiod,thedistribution
andrelativeabundanceofpinyonandjuniperhasfluctuatedwith
changingclimaticconditions.Warmingconditionsduringthe
pasttwocenturies,togetherwithchangingfireregime,livestock
grazing,andatmosphericpollutionincreasedtheabilityofthis
ecosystemtoexpandintosomeneighboringcommunities,at
bothhigherandlowerelevations.However,precipitationand
temperaturepatternsareprojectedtochangeinadirectionthat
islessfavorableforpinyon,sothatjunipermaybecomemoredominant,andthesehabitatsare
unabletopersistorexpandintheircurrentform.Primaryfactorscontributingtothehighranking
arethevulnerabilityofthesewoodlandstotheinteractionofdrought,fire,andinsect‐caused
mortality,whichislikelytoincreaseunderchangingclimate,andtheextenttowhichthecurrent
landscapeconditionofthehabitathasbeenimpactedbyanthropogenicdisturbance.
62 Colorado Natural Heritage Program © 2015 Distribution
TheNorthAmericandistributionofthisecosystemiscenteredintheColoradoPlateau,generally
southwestofColorado.Pinyon‐juniperformsthecharacteristicwoodlandofColorado’swestern
mesasandvalleys,whereitistypicallyfoundatlowerelevations(rangingfrom4,900‐8,000ft)on
drymountainsandfoothills.Pinyonandjunipermayformsparseshrublandsorwoodlandson
rockytablelandswherevegetationislargelyconfinedtosmallsoilpocketsinexposedbedrock.
Pinyon‐juniperwoodlandsalsooccurondrymountainsandfoothillsinsouth‐centralandsouth‐
easternColorado,inmountainsandplateausofnorthernNewMexicoandArizona,andextendout
ontoshalebreaksintheGreatPlains.Inthecanyonsandtablelandstothesoutheast,pinyonis
absent,andjuniperaloneformswoodlandsandsavannas.Standsareoftenadjacenttoand
intermingledwithoak,sagebrush,orsaltbushshrubland.
Characteristic species
Pinyonpine(Pinusedulis)andjuniperformthecanopy.Inwesternpinyon‐juniperwoodlandsof
lowerelevations,Utahjuniper(Juniperusosteosperma)isprevalentandRockyMountainjuniper(J.
scopulorum)maycodominateorreplaceitathigherelevations.Insoutheasternpinyon‐juniper
woodlandsone‐seedjuniper(Juniperusmonosperma) replacesUtahjuniper.Theunderstoryis
highlyvariable,andmaybeshrubby,grassy,sparselyvegetated,orrocky.Comeretal.(2003)
separateColorado’spinyon‐juniperintofourecologicalsystems:ColoradoPlateauPinyon‐Juniper
Woodland,ColoradoPlateauPinyon‐JuniperShrubland,ColoradoPlateauMixedBedrockCanyon
andTableland,andSouthernRockyMountainPinyon‐JuniperWoodland.
Pinyon‐juniperwoodlandassociationsarecharacterizedbystandswith25‐60%canopycoverof
treesthataretypically10‐30ft(3‐10m)inheight.Ondryrockymesatopsandslopesthesecanopy
dominantsmaybedwarfed(<3mtall),formingtallshrublands.Onsteepclifffaces,narrow
canyons,andopentablelandsofpredominantlysedimentarysandstone,shale,andlimestone,
pinyonandjunipermayformverysparseshrublandsincracksandpocketswheresoilhas
accumulated.Pinyon‐juniperstandsmaybesolelydominatedbypinyonpine,ormaybeco‐
dominatedbyjuniperspecies.Dependingonsubstrate,theunderstorycanrangefromarelatively
richmixtureofevergreenand/ordeciduousshrubs,toasparsetomoderatelydenseherbaceous
layerdominatedbyperennialgrasses(withorwithoutshrubs),tonovegetationatall(Reidetal.
1999).
Characteristicshrubsanddwarf‐shrubsincludeblacksagebrush(Artemisianova),bigsagebrush
(Artemisiatridentata),Utahserviceberry(Amelanchierutahensis),littleleafmountainmahogany
(Cercocarpusintricatus),mountainmahogany(Cercocarpusmontanus),yellowrabbitbrush
(Chrysothamnusviscidiflorus),mormon‐tea(Ephedraviridis),broomsnakeweed(Gutierrezia
sarothrae),Stansburycliffrose(Purshiastansburiana),antelopebitterbrush(Purshiatridentata),
Gambeloak(Quercusgambelii),andmountainsnowberry(Symphoricarposoreophilus).
Perennialgraminoidsarethemostabundantspeciesinthesparsetomoderatelydenseherbaceous
layer.CharacteristicspeciesincludeIndianricegrass(Achnatherumhymenoides),sideoatsgrama
(Boutelouacurtipendula),bluegrama(Boutelouagracilis),threeawn(Aristidaspp.),Arizonafescue
(Festucaarizonica),needle‐and‐thread(Hesperostipacomata),bluebunchwheatgrass
Climate Change Vulnerability Assessment for Colorado BLM 63 (Pseudoroegneriaspicata),muttongrass(Poafendleriana),James'galleta(Pleuraphisjamesii),and
westernwheatgrass(Pascopyrumsmithii).Theforblayermaybediverse(andmayincludea
numberofrarespecies),butcontributeslittlecover.
Pinyonjay,Plumbeousvireo,Junipertitmouse,Grayflycatcher,Black‐throatedgraywarbler,and
Bushtitaregoodindicatorsfortheecosystem.
Environment
Dependingonsubstrate,pinyon‐juniperstandsarevariableinstructureandcomposition.Stands
occuronavarietyofaspectsandslopes.Slopemayrangefromnearlyleveltosteep(upto80%).
Soilsvaryintexturerangingfromstony,cobbly,gravellysandyloamstoclayloamorclay.Parent
materialslikewisevarywidelyfromgranite,basalt,limestone,andsandstonetomixedalluvium
(Springfield1976).Soildepthsmayrangefromshallowtodeep.
Mesicareasaregenerallypinyon‐dominated,whilejunipersareabletodominateondriersites
(Gottfried1992).Standsvaryconsiderablyinappearanceandcomposition,bothaltitudinallyand
geographically.Junipertendstobemoreabundantatthelowerelevations,pinyontendstobemore
abundantatthehigherelevations,andthetwospeciessharedominancewithinabroadmiddle‐
elevationzone(WoodinandLindsey1954,Heiletal.1993).Standsmayrangefromeven‐agedto
uneven‐agedstands.
Dynamics
Pinyon‐juniperwoodlandsareinfluencedbyclimate,fires,insect‐pathogenoutbreaks,andlivestock
grazing(West1999,Eager1999).Althoughitisclearthatthestructureandconditionofmany
pinyon‐juniperwoodlandshasbeensignificantlyalteredsinceEuropeansettlement(Tausch1999),
inrecentyearstherehasbeenanemergingrecognitionthatnotallofthesewoodlandsare
dramaticallychangedbyanthropogenicinfluence.Increasingdensityofpinyonjuniperwoodlands
andexpansionintoadjacentgrasslandorshrublandarewelldocumentedinsomeareas,butisnota
universalphenomenoninthewesternU.S.(Rommeetal.2009).Furthermore,thetree‐dominated
landscapecharacteristicofpinyon‐juniperwoodlandtodayisnotnecessarilyrepresentativeofthe
typicallandscapeofthepastfewmillennia(Tausch1999).Rommeetal.(2009)distinguishthree
pinyon‐junipertypes(persistentwoodlands,savannas,andwoodedshrublands),using
characteristicsofbasedcanopystructure,understory,anddisturbancehistory.Localsiteconditions
mayresultinafine‐scalemixtureoftypewithinalargermatrixofonetype.Thedifferences
betweenthesetypeshaveimportantimplicationsformanagementactions,andeffortstomaintain
orrestorenaturalprocessesinpinyon‐juniperhabitats.
Bothpinyonpineandjuniperarefairlyslowgrowing,andcanliveforhundredsofyears,alifecycle
thatiswelladaptedtoxerichabitats,butislesssuitableforquicklychangingconditions.Although
individualsofbothspeciesbecomereproductiveafterafewdecades,mostseedproductionisdue
tomaturetreesof75yearsofageorolder(Gottfried1992).Bothspeciesreproduceonlyfrom
seeds,anddonotresproutafterfire.Coneproductionofmaturepinyonpinetakesthreegrowing
seasons,andthelargeseedshaveafairlyshortlifespanof1‐2years(Ronco1990).Junipercones
(oftencalledberries)mayrequire1‐2yearsofripeningbeforetheycangerminate(Gottfried1992).
64 Colorado Natural Heritage Program © 2015 Thesmallerseedsofjuniperaregenerallylong‐lived,survivingaslongas45years.Birdsare
importantdispersersofbothpinyonpineandjuniperseed(Gottfried1992).
Theeffectsoffireinalltypesofpinyon‐juniperdependinpartonfuelprovidedbybothcanopyand
understory,andbyweatherconditionsduringafire(Rommeetal.2009).Sparsewoodlandswith
littleunderstoryvegetationwouldtypicallyhavelimitedfirespreadandlittletreemortality.Astree
densityorunderstorycover(especiallyshrubs)increasesfirespreadisfacilitated,andtree
mortalitybecomesmorelikely.Rommeetal.(2009)concludedthatspreading,low‐intensity
surfacefireshavehistoricallyhadalimitedroleinthisecosystem,andthatinsteadthedominant
fireeffectismortalityofmosttreesandtop‐killofmostshrubswithintheburnedarea,regardless
oftreeorshrubsize.AtMesaVerdeNationalPark,wherepinyon‐juniperwoodlandshaveburnedin
fivelargefiressince1930,treeshavenotyetre‐established.Itisnotknownwhytreeshavenot
beensuccessfulintheseareas,whicharenowoccupiedbyshrubland(Floydetal.2000).
Formanypinyon‐juniperwoodlands,climatefluctuationandinsectordiseaseoutbreakaremore
importantinshapingstandstructurethanfire.Insectanddiseasemortalityisanaturalongoing
process,usuallyatalowlevel,butoccasionallyasmoresevereepisodicoutbreaks.Weather
patternsmayenhancepatternsofmortalityorrecruitment,shiftingstandcompositionand
structureonalocalorregionalscale(Eisenhart2004,Breshearsetal.2005,Shawetal.2005).
CCVA Scoring
Exposure‐Sensitivity (Potential Impact) Rank
Percent Colorado acres with projected temp > max & ppt delta < 5% 20.9% Initial Exposure‐Sensitivity Rank Moderate Percent Colorado acres with temp <= max & ppt delta < 5% more than 50%? No (43.5%) Final Exposure‐Sensitivity Rank Moderate Exposure to temperature change Underprojectedmid‐centurytemperatures,about23%ofthecurrentrangeofpinyon‐juniper
woodlandinColoradowouldexperienceannualmeantemperaturesabovethecurrentstatewide
maximum.
Exposure to precipitation change About64%ofpinyon‐juniperwoodlandinColoradowillbeexposedtoeffectivelydrierconditions
evenunderunchangedorslightlyincreasedprecipitationprojectedformid‐century.
Sensitivity of ecosystem to temperature and precipitation Theseevergreenwoodlandsareadaptedtocoldwinterminimumtemperaturesandlowrainfall,
andareoftentransitionalbetweengrasslandordesertshrublandandmontaneconiferecosystems
(Brown1994,Peet2000).Thepinyon‐juniperecosystemhaslargeecologicalamplitude;warmer
conditionsmayallowexpansion,ashasalreadyoccurredinthepastcenturies,aslongasthereare
periodiccooler,wetteryearsforrecruitment.Increaseddroughtmaydrivefiresandinsect
Climate Change Vulnerability Assessment for Colorado BLM 65 outbreaks,fromwhichthesewoodlandswouldbeslowtorecover.A40%declineinpinyonpine
coneproductionwasassociatedwithanaverage2.3°FincreaseinsummertemperaturesinNew
MexicoandOklahomasites(Redmondetal.2012).Warmingtemperaturesmayreducerecruitment
forpinyonpine,andmightincreasemortalityindrought‐stressedtrees(Adamsetal.2009).
Bargeretal.(2009)foundthatpinyonpinegrowthwasstronglydependentonsufficient
precipitationpriortothegrowingseason(winterthroughearlysummer),andcoolerJune
temperatures.Bothofthesevariablesarepredictedtochangeinadirectionthatislessfavorablefor
pinyonpine.Droughtcanresultinwidespreadtreedie‐off,especiallyofthemoresusceptible
pinyonpine(Breshearsetal.2008).Cliffordetal.(2013)detectedastrongthresholdat23.6in(60
cm)cumulativeprecipitationoveratwo‐yeardroughtperiod(i.e.,essentiallynormalannual
precipitationforpinyonpine).Sitesabovethisthresholdexperiencedlittlepinyondie‐off,while
sitesreceivinglessprecipitationincludedareaswithhighlevelsofmortality.Mortalityofpinyon
treeswasextensiveintheareaduringthe2002‐2003droughtandbarkbeetleoutbreak,butin
areaswherejuniperandshrubspeciesprovidemicrositesforseedlingestablishment,pinyonmay
beabletopersist(RedmondandBarger2013).Patternsofprecipitationandtemperature(i.e.,cool,
wetperiods)appeartobemoreimportantinrecruitmenteventsthanhistoryoflivestockgrazing
(Bargeretal.2009).
Resilience and Adaptive Capacity Rank
Overall Score: 0.41 Rank: Low
Thestatewiderangeofannualaverageprecipitationisabout10‐23in(25‐60cm),withameanof
16in(40cm),similartosagebrushshrubland.Growingseasontemperaturesaregreaterinthe
rangeofpinyon‐juniperthanformanyotherwoodyvegetationtypesinColorado.
Extendeddroughtcanincreasethefrequencyandintensityofinsectoutbreaksandwildfire.Pinyon
aresusceptibletothefungalpathogenLeptographiumwagenerivar.wageneri,whichcausesblack
stainrootdisease,andtoinfestationsofthepinyonipsbarkbeetle(Ipsconfusus)(KearnsandJacobi
2005).Thedifferentialsusceptibilityofpinyonandjunipertodroughtandinsectoutbreakscould
eventuallyresultinthesewoodlandsbeingdominatedbyjuniper.
Bioclimatic envelope and range Averagedcategoryscore:0.76
TheNorthAmericandistributionofthisecosystemiscenteredintheColoradoPlateau,generally
southwestofColorado.Pinyon‐juniperwoodlandsoccuratfoothillandlowermontaneelevations
throughoutcentralandwesternColorado,andhaveafairlywideecologicalamplitude.Statewide,
theannualaverageprecipitationrangeforpinyon‐juniperwoodlandincludesabout44%of
Colorado’soverallprecipitationrange.Growingseasonlengthforthesewoodlandsofwarm,dry
areascoversabout60%ofthestatewiderangeofgrowingdegreedays.
Growth form and intrinsic dispersal rate Score:0
66 Colorado Natural Heritage Program © 2015 Thetreegrowthformandslowdispersalrateofthedominantconiferspeciesgivethisecosystema
lowresiliencescoreinthiscategory.Pinyonpinestandsareslowtorecoverfromintensefires;the
speciesreproducesonlyfromshort‐livedseedsandrecoveryisdependentonseedsourcesand/or
adequatedispersal,aswellassuitablemicrosites(e.g.,undercoveroftreesorshrubs)for
establishment(Floydetal.2015).Junipersarealsoslow‐growing,andsusceptibletobeingkilledby
fire.
Vulnerability to increased attack by biological stressors Score:0
PinyonaresusceptibletothefungalpathogenLeptographiumwagenerivar.wageneri,whichcauses
blackstainrootdisease(primarilyonmoremesicsites),andtoinfestationsofthepinyonipsbark
beetle(Ipsconfusus)(KearnsandJacobi2005),whichhascausedextensivemortalityinpinyon‐
juniperhabitatsinsouthernColorado.Extendeddroughtcanincreasethefrequencyandintensity
ofinsectoutbreaks.
Vulnerability to increased frequency or intensity of extreme events Score:0.7
Pinyonpinestandsareslowtorecoverfromintensefires;thespeciesreproducesonlyfromseed
andrecoveryisdependentonseedsourcesand/oradequatedispersal.Juniperarealsoslow‐
growing,andsusceptibletobeingkilledbyfire.Extendeddroughtcanincreasethefrequencyand
intensityofbothinsectoutbreaksandwildfire.
Other indirect effects of non‐climate stressors – landscape condition Score:0.59
Pinyon‐juniperhabitatsinColoradohavebeenmoderatelyimpactedbyanthropogenicdisturbance.
Ongoingbutlimitedthreatsfromurban,exurban,andcommercialdevelopmentareprimarilyinthe
southcentralandsouthwesternportionsofColorado,wheretowns,roads,andutilitycorridorsare
oftenincloseproximitytopinyon‐juniperwoodlands.Aswithotherhabitatsinthewildland‐urban
interface,areasneardevelopedareasaremostlikelytobethreatenedbytheeffectsoffire
suppression,whilemoreremoteareasaregenerallyingoodcondition.Livestockgrazinghas
degradedtheunderstorygrassesofsomestands,andinvasivecheatgrass(Bromustectorum)has
becomeestablishedinsomeareas.Treeremovalbychaining,orcuttingforfirewoodisaminor
sourceofdisturbancewithinthesewoodlands,butmaydramaticallychangethehabitatwhereit
hasoccurred.MilitarytrainingactivitiesareasourceofdisturbancetothishabitatatFortCarson
andPinyonCanyonManeuverSite.Oilandgasdevelopment,withassociatedroads,pipeline
corridors,andinfrastructure,isanongoingsourceofdisturbanceandfragmentationformost
pinyon‐juniperhabitats.
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Climate Change Vulnerability Assessment for Colorado BLM 69 PONDEROSA
Forestsandwoodlandsdominatedbyponderosapine
S. Neid extent exaggerated for display Climate Vulnerability Rank: Moderate
Vulnerability summary
Key Vulnerabilities: Increased drought intensity and/or frequency is likely to increase the impact of fire and insect outbreaks in ponderosa forests. Areas in the wildland‐urban interface are most problematic. Ponderosapineforestsandwoodlandsarerankedmoderately
vulnerabletotheeffectsofclimatechangebymid‐century.
Primaryfactorscontributingtothisrankingaretheexposureof
largeareasofthishabitattowarmertemperaturesthatarelikely
tointeractwithforeststressors(mountainpinebeetle,drought,
andfire)thatare,inturn,exacerbatedbywarm,dryconditions.
Distribution
ThiswidespreadecosystemismostcommonthroughoutthecordilleraoftheRockyMountains,but
isalsofoundintheColoradoPlateauregion,westintoscatteredlocationsintheGreatBasin,and
northintosouthernBritishColumbia.Thesematrix‐formingwoodlandsoccuratthelower
treeline/ecotonebetweengrasslandorshrublandandmoremesicconiferousforests,typicallyin
warm,dry,exposedsites.
70 Colorado Natural Heritage Program © 2015 Characteristic species
Ponderosapine(Pinusponderosa)isthepredominantconifer;Douglas‐fir(Pseudotsugamenziesii),
pinyonpine(Pinusedulis),andjuniper(Juniperusspp.)mayalsobepresentinthetreecanopy.The
understoryisusuallyshrubby,withSaskatoonservicebery(Amelanchieralnifolia),blacksagebrush
(Artemisianova),bigsagebrush(Artemisiatridentata),kinnikinnick(Arctostaphylosuva‐ursi),
mountainmahogany(Cercocarpusmontanus),chokecherry(Prunusvirginiana),antelope
bitterbrush(Purshiatridentata),Gambeloak(Quercusgambelii),andmountainsnowberry
(Symphoricarposoreophilus)beingcommonspecies.Bunchgrassesincludingbluebunchwheatgrass
(Pseudoroegneriaspicata)andspeciesofneedle‐and‐thread(Hesperostipa),needlegrass
(Achnatherum),fescue(Festuca),muhly(Muhlenbergia),andgrama(Bouteloua)arecommon
understorygrasses.
Grace'swarbler,Pygmynuthatch,andFlammulatedowlareindicatorsofahealthyponderosapine
woodland.
Environment
Thisecosystemoccursatthelowertreeline/ecotonebetweengrasslandorshrublandandmore
mesicconiferousforeststypicallyinwarm,dry,exposedsitesatelevationsrangingfrom6,500‐
9,200ft(1,980‐2,800m).Itcanoccuronallslopesandaspects,however,itcommonlyoccurson
moderatelysteeptoverysteepslopesorridgetops.Thisecosystemoccursonsoilsderivedfrom
igneous,metamorphic,andsedimentarysubstrates(YoungbloodandMauk1985).Characteristic
soilfeaturesincludegoodaerationanddrainage,coarsetextures,circumneutraltoslightlyacidpH,
anabundanceofmineralmaterial,andperiodsofdroughtduringthegrowingseason.Surface
texturesarehighlyvariableinthisecosystemrangingfromsandtoloamandsiltloam.Exposed
rockandbaresoilconsistentlyoccurtosomedegreeinalltheassociations.Annualprecipitationis
8‐24in(25‐60cm),mostlythroughwinterstormsandsomemonsoonalsummerrains.Typicallya
seasonaldroughtperiodoccursthroughoutthissystemaswell.
Dynamics
Ponderosapineisadrought‐resistantandshade‐intolerantconiferwhichoftenformsthelower
treelineinthemajormountainrangesofthewesternUnitedStates.Historically,groundfiresand
droughtwereinfluentialinmaintainingopen‐canopyconditionsinthesewoodlands.With
settlementandsubsequentfiresuppression,occurrenceshavebecomedenser.Presently,many
occurrencescontainunderstoriesofmoreshade‐tolerantspecies,suchasDouglas‐firand/orwhite
fir(Abiesconcolor)aswellasyoungercohortsofponderosapine.Thesestructuralchangeshave
affectedfuelloadsandalteredfireregimes.Presettlementfireregimeswereprimarilyfrequent(5‐
15yearreturnintervals),low‐intensitygroundfirestriggeredbylightningstrikesordeliberately
setfiresbyNativeAmericans.Withfiresuppressionandincreasedfuelloads,fireregimesarenow
lessfrequentandoftenbecomeintensecrownfires,whichcankillmatureponderosapine(Reidet
al.1999).
Climate Change Vulnerability Assessment for Colorado BLM 71 CCVA Scoring
Exposure‐Sensitivity (Potential Impact) Rank
Percent Colorado acres with projected temp > max & ppt delta < 5% 0.9% Initial Exposure‐Sensitivity Rank Low Percent Colorado acres with temp <= max & ppt delta < 5% more than 50%? Yes (69.4%) Final Exposure‐Sensitivity Rank Moderate Exposure to temperature change Underprojectedmid‐centurytemperatures,about1%ofthecurrentrangeofponderosawoodland
inColoradowouldexperienceannualmeantemperaturesabovethecurrentstatewidemaximum.
Exposure to precipitation change About70%ofponderosapinewoodlandinColoradowillbeexposedtoeffectivelydrierconditions
evenunderunchangedorslightlyincreasedprecipitationprojectedformid‐century.
Sensitivity of ecosystem to temperature and precipitation Ponderosapineoccupiesrelativelydry,nutrient‐poorsitescomparedtoothermontaneconifers,
butshowswideecologicalamplitudethroughoutitsdistribution.Rehfeldtetal.(2012)wereableto
predictthedistributionofponderosapinelargelythroughtheuseofsummerandwinter
precipitation,andsummertemperatures(asgrowingdegreedays>5°C).Althoughperiodic
seasonaldroughtischaracteristicacrosstherangeofponderosapine,thisspeciesisgenerally
foundwhereannualprecipitationisatleast13inches(Barrettetal.1980,Thompsonetal.2000).
PonderosastandstothesouthofColoradowereprimarilyreliantonwinterprecipitation
(Kerhoulasetal.2013),whilegrowthofFrontRangestandswascorrelatedwithspringandfall
moisture(LeagueandVeblen2006),indicatingsomevariabilityintheabilityofponderosapineto
takeadvantageofseasonalwateravailability,dependingonsitefactorsandstandhistory.
Consequently,vulnerabilityofponderosaforeststochangesinprecipitationpatternsmaydiffer
accordingtotheirlocationinColorado.
Ponderosapineisabletotoleratefairlywarmtemperaturesaslongasthereisenoughmoisture,
especiallyinthegrowingseason.Optimalgerminationandestablishmentconditionsoccurwhen
temperaturesareabove50°Fandmonthlyprecipitationisgreaterthan1inch(Shepperdand
Battaglia2002).Significantrecruitmenteventsmayoccuronburnedareaswhenconditionsare
wetterthannormalafterafireyear,butnormalprecipitationmayalsobesufficientforseedling
establishmentinsuchcases(Mastetal.1998).Inlowerelevationponderosawoodlandsofthe
ColoradoFrontRange,episodicrecruitmentofponderosapinewasassociatedwithhighspringand
fallmoistureavailabilityduringElNiñoevents(LeagueandVeblen2006).Acorrelationbetween
droughtandlowratesofponderosaseedlingrecruitmenthasalsobeenidentifiedthroughoutthe
westernGreatPlains(Kayeetal.2010).Droughtincombinationwithfutureprojectedhigher
temperaturesislikelytoreduceponderosapineregeneration,especiallyindrier,lowerelevation
areas.TheworkofBrownandWu(2005)suggeststhatcoincidentconditionsofsufficientmoisture
72 Colorado Natural Heritage Program © 2015 andfewerfiresareimportantforwidespreadrecruitmentepisodesofponderosapine;such
conditionsmaybecomelesslikelyunderfutureclimatescenarios.
Increaseddroughtmaydrivefiresandinsectoutbreaks.Relativeproportionsofassociatedspecies
(e.g.,otherconifers,aspen,understoryshrubsandgrasses)inponderosastandsmaychange.This
ecosystemiswelladaptedtowarm,dryconditionsifprecipitationisnottoomuchreduced,and
maybeabletoexpandintohigherelevations.
Althoughclimatechangemayalterfireregimesslightlybyaffectingthecommunitystructure,fireis
notexpectedtohaveasevereimpactinthefutureforthesestands,andmayactuallybebeneficial
insomeareasifitrestoressomepre‐settlementconditions(CovingtonandMoore1994).These
forestsaresusceptibletooutbreaksofthemountainpinebeetleandmistletoeinfestations,bothof
whichmaybeexacerbatedbyincreaseddrought.Impactsofnativegrazersordomesticlivestock
couldalsoalterunderstorystructureandcomposition,andhavethepotentialtonegativelyimpact
soilstability(Allenetal.2002).Whileponderosapineforestsmaybeabletoexpandupwardsin
elevationorremaininthesamevicinityifprecipitationdoesn’tdrasticallychange,thedensityof
somestandsmaydecreaseduetoareductioninavailablesoilmoisture.Standsoflowerelevations
andsouthwestern‐facingslopesaremostlikelytoexperiencereducedextentofponderosapine
forests,withthepotentialforreplacementbygrassland,shrublandorpinyon‐juniperwoodland.
Resilience and Adaptive Capacity Rank
Overall Score: 0.54 Rank: Moderate
Bioclimatic envelope and range Averagedcategoryscore:0.76
Ponderosawoodlandsarenotfoundathighelevations,butinsteadformabroadzoneofconiferous
forestalongthesouthernflankoftheSanJuanMountains,aswellasalongtheeasternmountain
front,generallyatelevationsbetween6,000and9,000ft.Thesewoodlandsareinwithinthecentral
portionoftheirNorthAmericandistributioninColorado.Annualprecipitationissimilartothatfor
oakshrubland,andponderosaforestsarefoundin50%ofColorado’soverallprecipitationrange.
Ponderosaoccursin50%ofgrowingseasonlengthsacrossthestate.
Growth form and intrinsic dispersal rate Score:0
Thetreegrowthformandslowdispersalrateofponderosapinegivethisecosystemalow
resiliencescoreinthiscategory.Althoughseedsaretypicallynotdispersedveryfar,ponderosa
pineisoftenpresentinmixedconiferstands;theseareasmayprovideaseedbankforregeneration
orashifttoponderosapine.Recruitmentisepisodic,dependingonprecipitationanddisturbance
patterns.
Vulnerability to increased attack by biological stressors Score:0.7
Climate Change Vulnerability Assessment for Colorado BLM 73 Theseforestsaresusceptibletooutbreaksofthemountainpinebeetle(Dendroctonusponderosae)
andmistletoeinfestations,bothofwhichmaybeexacerbatedbyincreaseddrought.Mountainpine
beetlehascausedextensivemortalityinponderosapinehabitatsthroughoutColorado,although
thecurrentoutbreakappearstobesubsiding.Impactsofnativegrazersordomesticlivestock,and
thespreadofinvasivegrassescouldalsoalterunderstorystructureandcomposition,withthe
potentialtonegativelyimpactsoilstability(Allenetal.2002).
Vulnerability to increased frequency or intensity of extreme events Score:0.7
Ponderosapineiswelladaptedtosurvivefrequentsurfacefires,andmixed‐severityfiresare
characteristicinthesecommunities(Arno2000).Althoughclimatechangemayalterfireregimes
slightlybyaffectingthecommunitystructure,fireisnotexpectedtohaveasevereimpactinthe
futureforthesestands,andmayactuallybebeneficialinsomeareasifitrestoressomepre‐
settlementconditions(CovingtonandMoore1994).Aprojectedincreaseinthefrequencyof
droughtconditionsislikelytoexacerbatebothfireandinsectoutbreaks,andchangethestructure
andcompositionofponderosawoodlands.
Other indirect effects of non‐climate stressors – landscape condition Score:0.54
PonderosapinelandscapesinColoradohavebeenmoderatelyimpactedbyanthropogenic
activities.Urbanandexurbandevelopmentareaprimarythreattoponderosapinehabitat,
especiallyalongtheFrontRange,butalsoinotherpartsofthestate.Increasingdevelopmenthas
ledtoanextensivewildland‐urbaninterfaceinponderosahabitat,aswellasfragmentationof
standsinexurbanareasduetohousing,roads,andutilitycorridors;thistrendislikelytocontinue
(Theobald2005).Oilandgasdevelopment,mining,andloggingareminorsourcesofdisturbance
andfragmentationinponderosahabitat.
Ponderosaforestandwoodlandhistoricallyexperiencedrelativelyfrequentlowintensityfiresthat
controlledthedensity,age,andstructureofstands.Withfiresuppression,ponderosahasincreased
intofoothillsgrassland,standshavegreatlyincreasedindensity,andopenponderosasavanna
habitathasdecreased.Increasedtreedensityandfuelaccumulationhasresultedinmoresevere
firesinthishabitat,aswellasincreasedoccurrenceofmountainpinebeetleanddwarfmistletoe
infestation.Thealterationofnaturalfireregimesthroughfiresuppressionisanongoingthreatfor
ponderosahabitatwhereitisneardevelopedareas.
Literature Cited
Allen,C.D.,M.Savage,D.A.Falk,K.F.Suckling,T.W.Swetnam,T.Schulke,P.B.Stacey,P.Morgan,M.Hoffman,AndJ.T.
Klingel.2002.Ecologicalrestorationofsouthwesternponderosapineecosystems:abroadperspective.Ecological
Applications12:1418–1433.
Arno,S.F.2000.Fireinwesternforestecosystems.Chapter5inBrown,J.K.andJ.K.Smith,eds.Wildlandfirein
ecosystems:effectsoffireonflora.Gen.Tech.Rep.RMRS‐GTR‐42‐vol.2.Ogden,UT:U.S.DepartmentofAgriculture,Forest
Service,RockyMountainResearchStation.257p.
74 Colorado Natural Heritage Program © 2015 Barrett,J.W.,P.M.McDonald,F.RoncoJr,andR.A.Ryker.1980.Interiorponderosapine.In:Eyer,F.H.,ed.Forestcover
typesoftheUnitedStatesandCanada.Washington,DC:U.S.DepartmentofAgriculture,ForestService:114‐115.
Brown,P.M.andR.Wu.2005.Climateanddisturbanceforcingofepisodictreerecruitmentinasouthwesternponderosa
pinelandscape.Ecology86:3030‐3038.
Covington,W.W.andM.M.Moore.1994.Southwesternponderosaforeststructure:changessinceEuro‐American
settlement.JournalofForestry92:39–47.
KayeM.W.,C.A.WoodhouseandS.T.Jackson.2010.Persistenceandexpansionofponderosapinewoodlandsinthewest‐
centralGreatPlainsduringthepasttwocenturies.JournalofBiogeography37:1668‐1683.
Kerhoulas,L.P.,T.E.Kolb,andG.W.Koch.2013.Treesize,standdensity,andthesourceofwaterusedacrossseasonsby
ponderosapineinnorthernArizona.ForestEcologyandManagement289:425‐433.
League,K.andT.Veblen.2006.ClimaticvariabilityandepisodicPinusponderosaestablishmentalongtheforest‐
grasslandecotonesofColorado.ForestEcologyandManagement228:98‐107.
Mast,J.N.,T.T.Veblen,andY.B.Linhart.1998.Disturbanceandclimaticinfluencesonagestructureofponderosapineat
thepine/grasslandecotone,ColoradoFrontRange.JournalofBiogeography.25:743‐755.
Rehfeldt,G.E.,N.L.Crookston,C.Saenz‐Romero,andE.M.Campbell.2012.NorthAmericanvegetationmodelforland‐use
planninginachangingclimate:asolutionoflargeclassificationproblems.EcologicalApplications22:119‐141.
Reid,M.S.,K.A.Schulz,P.J.Comer,M.H.Schindel,D.R.Culver,D.A.Sarr,andM.C.Damm.1999.Analliancelevel
classificationofvegetationofthecoterminouswesternUnitedStates.UnpublishedfinalreporttotheUniversityofIdaho
CooperativeFishandWildlifeResearchUnitandNationalGapAnalysisProgram,infulfillmentofCooperativeAgreement
1434‐HQ‐97‐AG‐01779.TheNatureConservancy,WesternConservationScienceDepartment,Boulder,CO.
Shepperd,W.D.andM.A.Battaglia.2002.Ecology,Silviculture,andManagementofBlackHillsPonderosaPine.General
TechnicalReportRMRS‐GTR‐97.USDAForestServiceRockyMountainResearchStation,FortCollins,CO.112
Theobald,D.M.2005.LandscapepatternsofexurbangrowthintheUSAfrom1980to2020.EcologyandSociety10:32
Thompson,R.S.,K.H.Anderson,andP.J.Bartlein.2000.Atlasofrelationsbetweenclimaticparametersanddistributionsof
importanttreesandshrubsinNorthAmerica.U.S.GeologicalSurveyProfessionalPaper1650‐A.
Youngblood,A.P.,andR.L.Mauk.1985.ConiferousforesthabitattypesofcentralandsouthernUtah.USDAForest
Service,IntermountainResearchStation.GeneralTechnicalReportINT‐187.Ogden,UT.89pp
Climate Change Vulnerability Assessment for Colorado BLM 75 SPRUCE‐FIR
Dry‐mesicandmesicforestsdominatedbyEngelmannspruceandsubalpinefir
R. Rondeau extent exaggerated for display Climate Vulnerability Rank: Moderate
Vulnerability summary
Key Vulnerabilities: Increased drought intensity and/or frequency is likely to increase the impact of fire and insect outbreaks in subalpine forests. These forests recover slowly due to slow dispersal and a short growing season. Climatechangeprojectionsindicateanincreaseindroughtsand
fastersnowmelt,whichcouldincreaseforestfirefrequencyand
extent,aswellasinsectoutbreakswithinthisecosystem.Itisnot
knownifspruce‐firforestswillbeabletoregenerateundersuch
conditions,especiallyinlowerelevationstands,andthereisa
potentialforareductionorconversiontootherforesttypes,
dependingonlocalsiteconditions.
Thevulnerabilityoftheseforeststowarmertemperatures,
drought,andincreasedmortalityfrominsectoutbreaksare
primaryfactorscontributingtovulnerability.Therestrictionof
thishabitattohigherelevationsanditsrelativelynarrow
biophysicalenvelope,slow‐growth,andpositionnearthe
southernendofitsdistributioninColoradoareadditional
factors.However,theremaybealagtimebeforetheeffectsof
changingclimateareevident.
76 Colorado Natural Heritage Program © 2015 Thelagtimeofthecurrenttreelinepositionbehindclimatechangeisestimatedtobe50‐100+
years,duetotherarityofrecruitmentevents,theslowgrowthandfrequentsetbacksfortreesin
theecotone,andcompetitionwithalreadyestablishedalpinevegetation(Körner2012).However,
onthebasisofhistoricevidence,treelinecanbeexpectedtomigratetohigherelevationsas
temperatureswarm,aspermittedbylocalmicrositeconditions(Smithetal.2003,Richardsonand
Friedland2009,Grafiusetal.2012).Thegradualadvanceoftreelineisalsolikelytodependon
precipitationpatterns,particularlythebalanceofsnowaccumulationandsnowmelt(Rochefortet
al.1994).Ouranalysisindicatedthatspruce‐firforestsinColoradohavemoderatevulnerabilityto
theeffectsofclimatechangebymid‐century.
Distribution
Spruce‐firdry‐mesicandmoist‐mesicforestecosystemsformtheprimarymatrixsystemsofthe
montaneandsubalpinezonesoftheSouthernRockyMountainsecoregion,andaccountfora
substantialpartofthesubalpineforestsoftheCascadesandRockyMountainsfromsouthern
BritishColumbiaeastintoAlberta,southintoNewMexicoandtheIntermountainregion.Spruce‐fir
forestalsoshowschangeswithlatitudeincludingtreelineelevation,speciescomposition,and
dominance.Subalpinefir(Abieslasiocarpa)decreasesinimportancerelativetoEngelmannspruce
(Piceaengelmannii)withincreasingdistancefromtheregionofMontanaandIdahowheremaritime
airmassesinfluencetheclimate.Firincreasesinimportancewithincreasinglatitude,andshares
dominancewithspruceattreelineoverthenorthernhalfoftheSouthernRockyMountains
ecoregion.Treelineoccursatover12,450ft(3800m)atthesouthernendoftheSouthernRocky
Mountainecoregion,butdoesnotexceed11,150ft(3400m)atthenorthernend(Peet1978).
Individualcommunitytypesmaybematrixorlargepatchincharacter,thoughmosttypicallyoccur
asamosaicoflargepatchesacrossthelandscape.Spruce‐firdominatedstandsoccuronallbutthe
mostxericsitesabove10,000ft(3,100m),andincool,shelteredvalleysatelevationsaslowas
8,200ft(2,500m).Therelativedominanceofthetwocanopytreespeciesandtheunderstory
compositionvarysubstantiallyoveragradientfromexcessivelymoisttoxericsites(Peet1981).
Themesicspruce‐firtypeoccursoncool,sheltered,butwell‐drainedsitesabove8,850ft(2,700m).
Openslopesabove9,850ft(3,000m)aretypicallycharacterizedbyamorexericspruce‐firtype,
withvaryingamountsoflodgepoleandlimberpine.
Characteristic species
Engelmannspruceandsubalpinefirdominatethecanopy,eithertogetheroralone.Lodgepolepine
(Pinuscontorta)iscommoninmanyoccurrencesasaremixedconifer/quakingaspen(Populus
tremuloides)stands.UnderstoryspeciesmayincludeGeyer'ssedge(Carexgeyeri),commonjuniper
(Juniperuscommunis),creepingbarberry(Mahoniarepens),Jacob's‐ladder(Polemonium
pulcherrimum)orwhortleberry(Vacciniumspp.).Moremesicunderstorymayincludered
baneberry(Actaearubra),sprucefirfleabane(Erigeroneximius),thimbleberry(Rubusparviflorus),
yellowdotsaxifrage(Saxifragabronchialis),oralpineclover(Trifoliumdasyphyllum),amongother
species.
Climate Change Vulnerability Assessment for Colorado BLM 77 Pinemartensareprimarilyaspruce‐firobligatespeciesthatrequireahealthyandsizeable
occurrenceofmatureforestandareanindicatorofahealthyandviableoccurrenceofthespruce‐fir
ecosystem
Environment
Thesearethematrixforestsofthesubalpinezone,withrangewideelevationsrangingfrom5,000‐
11,000ft(1,525to3,355m).Sitesarecoldyear‐round,andprecipitationispredominantlyinthe
formofsnow,whichmaypersistuntillatesummer.Moist‐mesicoccurrencesaretypicallyfoundin
locationswithcold‐airdrainageorponding,orwheresnowpackslingerlateintothesummer,such
asnorth‐facingslopesandhigh‐elevationravines.Theycanextenddowninelevationbelowthe
subalpinezoneinplaceswherecold‐airpondingoccurs;northerlyandeasterlyaspects
predominate.Theseforestsarefoundongentletoverysteepmountainslopes,high‐elevation
ridgetopsandupperslopes,highplateaus,basins,alluvialterraces,well‐drainedbenches,and
inactivestreamterraces.
Dynamics
Fire,spruce‐beetleoutbreaks,avalanches,andwindthrowallplayanimportantroleinshapingthe
dynamicsofspruce‐firforests.Firesinthesubalpineforestaretypicallystandreplacing,resulting
intheextensiveexposureofmineralsoilandinitiatingthedevelopmentofnewforests.Stand
replacingfiresareestimatedtooccuratintervalsofabout300yearsfordry‐mesicareas,and
longer(350‐400years)formoremesicsites(RommeandKnight1981).Firereturnintervals,
intensity,andextentnaturallydependonavarietyoflocalenvironmentalfactors.Dependingon
siteconditions,spruceorlodgepolepinemayinitiallydominatethepost‐firesite,incombination
withlimberpine,andquakingaspen(DonneganandRebertus1999).Firisgenerallytheleast
abundantforseveraldecadesafterfire,butisabletoestablishinlow‐lightconditionsonforest
litter,andgraduallyincreasesinabundance(Veblenetal.1991).
Sprucebeetle(Dendroctonusrufipennis)outbreaksmaybeevenmoresignificantthanfireinthe
developmentofspruce‐firforests(Weedetal.2013).Whenlargersprucetreesarekilledbyspruce
beetleinfestation,smallerdiametersprucetreesandsubalpinefirtreesareabletoincreasegrowth
andcontinuetodominatethestand(Veblenetal.1991).Inadditiontofiresandbeetlekill,wind
disturbanceinspruce‐firforestshasbeenwelldocumented(Schauppetal.1999).Blowdowns
involvingmultipletreefallsaddtothemosaicofspruce‐firstands.Underanaturaldisturbance
regime,subalpineforestswereprobablycharacterizedbyamosaicofstandsinvariousstagesof
recoveryfromdisturbance,withold‐growthjustonepartofthelargerforestmosaic(Peet1981).
78 Colorado Natural Heritage Program © 2015 CCVA Scoring
Exposure‐Sensitivity (Potential Impact) Rank
Percent Colorado acres with projected temp > max & ppt delta < 5% 0.2% Initial Exposure‐Sensitivity Rank Low Percent Colorado acres with temp <= max & ppt delta < 5% more than 50%? No (40.8%) Low Final Exposure‐Sensitivity Rank Exposure to temperature change Underprojectedmid‐centurytemperatures,lessthan1%ofthecurrentrangeofspruce‐firforestin
Coloradowouldexperienceannualmeantemperaturesabovethecurrentstatewidemaximum.
Exposure to precipitation change About41%ofspruce‐firforestinColoradowillbeexposedtoeffectivelydrierconditionseven
underunchangedorslightlyincreasedprecipitationprojectedformid‐century.
Sensitivity of ecosystem to temperature and precipitation Spruce‐firforesttypicallydominatesthewettestandcoolesthabitatsbelowtreeline.Theseareas
arecharacterizedbylong,coldwinters,heavysnowpack,andshort,coolsummerswherefrostis
common(Uchytil1991).BothEngelmannspruceandsubalpinefiraredependentonsnowmelt
waterformostofthegrowingseason,andinlowsnowpackyearsgrowthisreduced(Huetal.
2010).
Thelengthofthegrowingseasonisparticularlyimportantforbothalpineandsubalpinezones,and
forthetransitionzonebetweenalpinevegetationandclosedforest(treeline).Treeline‐controlling
factorsoperateatdifferentscales,rangingfromthemicrositetothecontinental(Holtmeierand
Broll2005).Onaglobalorcontinentalscale,thereisgeneralagreementthattemperatureisa
primarydeterminantoftreeline.Körner(2012)attributesthedominanceofthermalfactorsatthis
scaletotherelativeconsistencyofatmosphericconditionsoverlargeareas,especiallyin
comparisontomorelocalinfluenceofsoilandmoisturefactors.Furthermore,thereappearstobea
criticaldurationoftemperaturesadequateforthegrowthoftreesinparticular(e.g.,individuals
>3mtall)thatdeterminesthelocationoftreeline.Atmorelocalscales,soilproperties,slope,aspect,
topography,andtheireffectonmoistureavailability,incombinationwithdisturbancessuchas
avalanche,grazing,fire,pests,disease,andhumanimpactsallcontributetotheformationof
treeline(RichardsonandFriedland2009,Körner2012).Patternsofsnowdepthandduration,
wind,insolation,vegetationcover,andtheautecologicaltolerancesofeachtreespeciesinfluence
theestablishmentandsurvivalofindividualswithinthetreelineecotone(Moiretal.2003,
HoltmeierandBroll2005,Smithetal.2009).IntheRockyMountains,treeestablishmentwas
significantlycorrelatedwithwarmerspring(Mar‐May)andcool‐season(Nov‐Apr)minimum
temperaturesaswell(Elliott2012).
Spruce‐firforestscurrentlyoccupycoldareaswithhighprecipitation;warmeranddrierclimate
conditionspredictedbymostmodelscouldresultinanupwardmigrationoftheseforestsintothe
Climate Change Vulnerability Assessment for Colorado BLM 79 alpinezone.However,inCanadianspruce‐firforests,warmerthanaveragesummertemperatures
ledtoadecreaseingrowththefollowingyear(HartandLaroque2013).Sincespruce‐firmaybe
abletotoleratewarmersummertemperatures,thelowerextentofthishabitattypecouldremainat
currentlevelsforsometime,evenifgrowthisreduced.
Thecurrentlocationoftreelineisaresultoftheoperationofclimaticandsite‐specificinfluences
overthepastseveralhundredyears,anddoesnotexactlyreflectthecurrentclimate(Körner2012).
Thetreelinepositionlagtimebehindclimatechangeisestimatedtobe50‐100+years,duetothe
rarityofrecruitmentevents,theslowgrowthandfrequentsetbacksfortreesintheecotone,and
competitionwithalreadyestablishedalpinevegetation(Körner2012).Nevertheless,onthebasisof
historicevidence,treelineisgenerallyexpectedtomigratetohigherelevationsastemperatures
warm,aspermittedbylocalmicrositeconditions(Smithetal.2003,RichardsonandFriedland
2009,Grafiusetal.2012).Infact,treelineadvancehasalreadybeendocumentedatsitesintheSan
JuanMountains(Finketal.2014).
Furthermore,thelagtimeofdecadesorlongerfortreelinetorespondtowarmingtemperatures
mayallowthedevelopmentofnovelvegetationassociations(ChapinandStarfield1997),andmake
itdifficulttoidentifytemperatureconstraintsonthedistributionofthishabitat(Grafiusetal.
2012).Thegradualadvanceoftreelineisalsolikelytodependonprecipitationpatterns.Seedling
establishmentandsurvivalaregreatlyaffectedbythebalanceofsnowaccumulationandsnowmelt.
Soilmoisture,largelyprovidedbysnowmelt,iscrucialforseedgerminationandsurvival.Although
snowpackinsulatesseedlingsandshieldssmalltreesfromwinddesiccation,itspersistence
shortensthegrowingseasonandcanreducerecruitment(Rochefortetal.1994).
Resilience and Adaptive Capacity Rank
Overall Score: 0.34 Rank: Low
Bioclimatic envelope and range Averagedcategoryscore:0.30
Spruce‐firforestsinColoradohaveawideelevationalrange,extendingfromabout8,900ftupto
over12,000ft.Althoughnotasrestrictedasalpinehabitats,spruce‐firforestsaregenerallylimited
tohigher,coolerelevations,andarealsonearthesouthernextentoftheircontinentalrangein
Colorado.Statewide,annualaverageprecipitationisonlyslightlylowerthanthatofalpine,and
theseforestshavesignificantpresencein82%ofColorado’soverallprecipitationrange.Spruce‐fir
requiresalongergrowingseasonthanalpinehabitat,butissuccessfulatmuchcoolertemperatures
thanmostotherforesttypes,coveringonly38%ofthestate’sgrowingdegreerange.Thesefactors
combinetoproducearelativelypoorresiliencescoreinthiscategory.
Growth form and intrinsic dispersal rate Score:0
Thetreegrowthformandslowdispersalrateofthedominantconiferspeciesgivethisecosystema
lowresiliencescoreinthiscategory.Subalpinefirseedsrequirecold‐moistconditionstotrigger
80 Colorado Natural Heritage Program © 2015 germination(Uchytil1991),andthereissomeindicationthatEngelmannspruceseedsgerminate
fasteratrelativelylowtemperatures(Smith1985),givingitacompetitiveadvantageoverlesscold‐
tolerantspecies.Underwarmerconditions,however,currentspruce‐fircommunitiesmaybe
graduallyreplacedbyamixed‐coniferforest.Therearenoobviousbarrierstothegradualdispersal
ofseedlingsintoadjacent,newlysuitablehabitat,althoughthedominantspeciesaregenerally
slow‐growing.
Vulnerability to increased attack by biological stressors Score:0
Althoughthesesubalpineforestsarenotsusceptibletoincreasedprevalenceofinvasivespecies,
theyarevulnerabletooutbreaksofthenativepestspeciessprucebudwormandsprucebeetle.
Warmertemperatures(bothwinterandsummer)arelikelytofacilitatetheseinfestations.Warmer
wintersarecorrelatedwithreducedbeetlemortality,whilehighersummertemperaturesallowa
greaterproportionofthesprucebeetlepopulationtocompleteagenerationinasingleyear,witha
correspondinglyhigherprobabilityofpopulationoutbreak(Bentzetal.2010).Thecurrent
distributionofspruce‐firhabitatisthereforelikelytobeatincreasedriskofsignificantmortality.
Insectoutbreaksarealsotypicallyassociatedwithdroughts.
Vulnerability to increased frequency or intensity of extreme events Score:0.5
Historicnaturalfire‐returnintervalsintheseforestshavebeenontheorderofseveralhundred
years,andthetreespeciesarenotadaptedtomorefrequentfires.Withanincreaseindroughtsand
fastersnowmelts,wecanexpectanincreaseinforestfirefrequencyandextentwithinthiszoneas
ignitionofheavyfuelloadsbecomeslesslimitedbycool,wetconditions.Itisnotknownifspruce‐
firforestswillbeabletoregenerateundersuchconditions,especiallyinlowerelevationstands,and
thereisapotentialforareductioninspruce‐firforests,atleastintheshortterm.
Other indirect effects of non‐climate stressors – landscape condition Score:0.89
Spruce‐firforestlandscapesinColoradoaregenerallyinverygoodcondition,wellprotected,and
minimallyimpactedbyanthropogenicdisturbance.Becausenaturalfirereturnintervalsinthese
habitatsarelong,firesuppressionhasnothadwidespreadeffectsontheconditionofspruce‐fir
habitat.Atalandscapescale,however,agestructuresofspruce‐firforestareprobablysomewhat
alteredfrompre‐settlementconditions.Spruce‐firforestsaresubjecttodisturbancebyrecreational
use,hunting,livestockgrazing,mining,andlogging,butingeneral,threatsfromhousing,roads,and
recreationaldevelopmentandsimilaranthropogenicdisturbanceareminorforspruce‐firhabitats.
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Climate Change Vulnerability Assessment for Colorado BLM 83 Shrubland
Table 2.6. Key vulnerabilities, shrubland ecosystems. Habitat
Climate factor(s)
Consequences
Other considerations
Desert shrubland Soil moisture Conversion to other type Highly altered Oak & mixed mtn. shrub Drought, last frost date variability Dieback with drought and late frost; may increase by resprouting after fire Anthropogenic disturbance Sagebrush Drought Increase in invasive species such as cheatgrass; fire Variable by subspecies Sandsage Extended drought Soil mobilization Loss of native biodiversity 84 Colorado Natural Heritage Program © 2015 DESERT SHRUBLAND
Shrubland,shrub‐steppe,dwarf‐shrubland,andsparselyvegetatedareascharacterizedbysaltbush,
rabbitbrush,winterfat,andotherxericshrubspecies
extent exaggerated for display CNHP Climate Vulnerability Rank: Moderate
Vulnerability summary
Key Vulnerabilities: The interaction of soil types and precipitation patterns largely determines the composition and extent of these shrublands, which may undergo conversion to other types under future climate conditions. The altered condition of many stands is a confounding factor. Theprimaryfactorcontributingtothemoderatevulnerability
rankingofdesertshrublandsinColoradoistheextenttowhich
standshavebeenimpactedbyanthropogenicdisturbance,with
greatlyalteredspeciescompositioninmanyinstances.The
resiliencescoreforthisecosystemisotherwisehigh,and,since
thesearecommunitiesofaridlandscapes,theycouldbeless
vulnerabletoclimatechangewherestandsareingoodcondition.
However,changingsoilmoisturepatternsmayeventuallyfavor
semi‐desertgrasslandinareascurrentlyoccupiedbydesert
shrubland.
Distribution
DesertshrublandcommunitiesoccurthroughouttheintermountainwesternU.S.,andaretypically
open‐canopiedshrublandsdominatedbysaltbushspeciesorothershrubstolerantofsalineor
alkalinesoilstypicallyderivedfrommarineshales,siltstonesandclay.Forthisassessment,we
groupedshrub‐steppe,mixedsaltdesertshrub,matsaltbushshrublands,andsparselyvegetated
shalebadlandstogetherasdesertshrubland.Thesesparsetomoderatelydenselow‐growing
Climate Change Vulnerability Assessment for Colorado BLM 85 shrublandsarewidespreadatlowerelevationsinColorado’swesternvalleys,butalsooccurtoa
smallerextentontheeasternplains.Desertshrublandsarefoundprimarilybetween4,500and
7,000feet,althoughshrub‐steppemayextendupto9,500feetinsomeareas.Shrub‐steppedoes
notformextensivestandsinColoradoexceptintheSanLuisValley.Pinyon‐juniperwoodlandsand
sagebrushshrublandscommonlyareadjacentattheupperelevations.
Characteristic species
Matsaltbushshrublandtypicallysupportsrelativelypurestandsoflow‐growingmatsaltbush
(Atriplexcorrugata)orGardner'ssaltbush(Atriplexgardneri).Otherdwarf‐shrubspeciesthatmay
bepresentincludebudsagebrush(Picrothamnusdesertorum)andshortspinehorsebrush
(Tetradymiaspinosa).Scatteredperennialforbsoccur,suchasdesertprincesplume(Stanleya
pinnata),eveningprimrose(Oenotheraspp.),andphacelia(Phaceliaspp.).Indianricegrass
(Achnatherumhymenoides)andalkalisacaton(Sporobolusairoides)maybepresentinswales.
Annualsmayincludedeserttrumpet(Eriogonuminflatum),andintroducedspeciessuchasAfrican
mustard(Malcolmiaafricana)andcheatgrass(Bromustectorum).Someareasareessentially
barren,orverysparselyvegetated.
Mixedsaltdesertscrubischaracterizedbythetallersaltbushspeciesshadscalesaltbush(Atriplex
confertifolia)orfourwingsaltbush(Atriplexcanescens),andmayincludewinterfat
(Krascheninnikovialanata),paledesert‐thorn(Lyciumpallidum),horsebrush(Tetradymia
canescens),andvarioussagebrush(Artemisia)species.Grassesandforbsaresparsetomoderately
dense,anddominatedbyspeciestolerantoftheharshsoils.Typicalperennialgrassesinclude
Indianricegrass,bluegrama(Boutelouagracilis),thickspikewheatgrass(Elymuslanceolatusssp.
lanceolatus),westernwheatgrass(Pascopyrumsmithii),James’galleta(Pleuraphisjamesii),
Sandbergbluegrass(Poasecunda),oralkalisacaton.
Colorado’sshrub‐steppesaregrass‐dominatedareaswithanopenshrublayer.Typicalgrass
speciesincludebluegrama,needle‐and‐thread(Hesperostipacomata),James’galleta,saltgrass
(Distichlisspicata),Indianricegrass,andalkalisacaton.Historically,theshrublayerwasdominated
bywinterfat,butthisspecieshasdecreasedundergrazingpressureinmanyareas.Winterfathas
largelybeenreplacedbyrabbitbrush(EricameriaandChrysothamnus)speciesandotherwoody
shrubs.
Environment
Desertshrublandclimateisgenerallyaridorsemi‐aridwithextremetemperaturedifferences
betweensummerandwinter.ForoccurrencesinsouthernColorado,themonsoonalperiodofmid‐
tolatesummernormallyprovidesmostoftheannualmoisture;innorthernareasprecipitationis
moreevenlyspreadthroughouttheyear,includingduringthecoldestmonths.Inthesecolddesert
shrublands,however,theyeartoyearvariationofprecipitationislikelytobegreaterthanseasonal
variablity,withresultanteffectsoninterannualvariabilityingrowthandreproductionofshrubland
species(BlaisdellandHolmgren1984).
Desertshrublandsubstratesaregenerallyshallow,typicallysalineoralkaline,fine‐texturedsoils
developedfromshaleoralluvium.Suchsoilsarepoorlydeveloped,duetothearidclimate,with
86 Colorado Natural Heritage Program © 2015 verylowinfiltrationrates(West1983).Unvegetatedsubstrateiscommon,and,ifundisturbed,is
oftencoveredbyabiologicalsoilcrust.Althoughperennialspeciestendtosortoutalonga
moisture/salinitygradientaccordingtoindividualspeciestolerances(West1983),theredonot
appeartobeanyexceptionallynarrowtolerancesorrequirementsforapartcularsoilfactor
presentintypicaldesertshrublandplants(BlaisdellandHolmgren1984).
Dynamics
Thenaturallysparseplantcovermakestheseshrublandsespeciallyvulnerabletowaterandwind
erosion,especiallyifvegetationhasbeenimpactedbygrazingordisturbancesincludingfire.
Historically,saltdesertshrublandshadlowfirefrequency(Simonin2001),andarecharacterized
bylowfuelmassandlowsoilmoisture,whichtendstomitigatefireimpacts(Allenetal.2011).
However,increasedextentofintroducedannualgrasses,especiallycheatgrass,hasfacilitatedthe
spreadoffirebyprovidingcontinuoussurfacefuelsinmanyareas(West1994,).IntheGreatBasin,
cheatgrasshasdemonstrablyincreasedfireactivityinsagebrushshrublands(Balchetal.2013),but
lessisknownaboutfire‐sensitivityofsalinedeserttypes.FiretoleranceofAtriplexspeciesisvaried;
mostsurvivingindividualsareabletoresprout.FourwingsaltbushinNewMexicohadsevere
mortalityfromfire(62%killed),butsurvivingshrubsquicklyresproutedandeventuallyrecovered
prefirestature(Parmenter2008).Shadscaleisgenerallykilledbyfireandreliesonseedfor
revegetationofburnedareas(West1994).Althoughtheirstudydidnotincludeungrazedplotsfor
comparison,Haubensaketal.(2009)notedthat,afterfire,grazeddesertshrublandshad
significantlylowervegetationcover,andweremoreinvadedbynon‐nativespeciesincomparison
withunburnedplots.
Manyofthedominantshrubsarepalatabletodomesticlivestock,sograzingcanalterspecies
compositionaswellasincreasingerosionpotential.Incombinationwithclimaticvariability,these
disturbancesacttochangefloristiccompositionofdesertshrublandsovertime.Forexample,
winterfatwashistoricallyatypicaldominantinsemi‐desertshrubsteppe.Thispalatableshrubis
consideredadecreaserunderdomesticlivestockgrazing.Asaconsequenceofanthropogenically
inducedchangesingrazingpatterns,Greene'srabbitbrush(Chrysothamnusgreenei)isnow
dominantinSanLuisValleyshrubsteppe,althoughthewetterareasstillhavesignificantamounts
ofwinterfat.
CCVA Scoring
Exposure‐Sensitivity (Potential Impact) Rank
Percent Colorado acres with projected temp > max & ppt delta < 5% 30.6% Initial Exposure‐Sensitivity Rank Moderate Percent Colorado acres with temp <= max & ppt delta < 5% more than 50%? No (48.0%) Final Exposure‐Sensitivity Rank Moderate Climate Change Vulnerability Assessment for Colorado BLM 87 Exposure to temperature change Underprojectedmid‐centurytemperatures,about37%ofthecurrentrangeofdesertshrublandin
Coloradowouldexperienceannualmeantemperaturesabovethecurrentstatewidemaximum.
Exposure to precipitation change About79%ofdesertshrublandinColoradowillbeexposedtoeffectivelydrierconditionseven
underunchangedorslightlyincreasedprecipitationprojectedformid‐century.
Sensitivity of ecosystem to temperature and precipitation Thedominantdesertshrubsareabletogrowwhenevertemperaturesarefavorable,butonlyif
thereissufficientsoilmoisture.Soilmoistureaccumulationisprimarilyinwinter,andinfluences
theamountofspringplantgrowth.Ifnoadditionalmoistureisreceivedinspring,growthends,and
plantsbecomedormant.Laterrainsduringthewarmseasonmayre‐inducegrowth(Blaisdelland
Holmgren1984).Soilsaturationmaycausemortalityofthedominantshrubs(Ewingand
Dobrowolski1992).Thecharacteristicinterannualvariabilityofprecipitationindesertshrubareas,
andthedifferentlifehistorystrategies/phenologyofthecomponentspeciescanproducedramatic
differencesinshrublandappearancefromoneyeartothenext(BlaisdellandHolmgren1984).
Munsonetal.(2011)founddecreasedcanopycoverinAtriplexshrublandswithincreasing
temperature,whichtheyattributedtoincreasedevaporationandreducedwateravailabilityinthe
shale‐derivedsoils.Thus,theseshrublandsmaybeabletotoleratehighertemperaturesonlywhen
precipitationisadequate.However,insomesemi‐aridandaridsystems,temporalvariationin
wateravailabilitymaycreatepositivefeedbacksthatfacilitateencroachmentofC3woodyplant
speciesintoareasformerlydominatedbyC4grasses.Otherdesertshrubspecieswithdeeperroot
systems(e.g.,blackbrush,greasewood,mormontea,sagebrush)arebetteradaptedtoexpandinto
grassyareasthanrelativelyshallow‐rootedAtriplexspecies(Munsonetal.2011).Further
differentiationbetweenshrubspeciesintheabilitytoutilizerainfallduringparticularseasons(Lin
etal.1996)mayleadtochangesinspeciescompositionintheseshrublands.Shadscalesaltbush(A.
confertifolia)andotherdesertshrubsaretypicallydependentonspringsoilmoistureforgrowth,
andhavelowmetabolicactivityduringsummerasthesoildries(Mata‐Gonzálezetal.2014).
Resilience and Adaptive Capacity Rank
Overall Score: 0.69 Rank: Moderate
Bioclimatic envelope and range Averagedcategoryscore:0.72
Desertshrublandsaregenerallyconfinedtowarm,dryhabitatswithinColorado,occupying31%of
Colorado’soverallprecipitationrangeand57%ofthestatewiderangeofgrowingdegreedays.
Theseshrublandsarenotlimitedbyelevationalconstraints,andarenotatthesouthernedgeof
theirrangeinColorado,whichgivesthemagoodresiliencescoreinthiscategory.
Growth form and intrinsic dispersal rate Score:0.5
88 Colorado Natural Heritage Program © 2015 Althoughthedominantshrubspeciesarelikelytobefairlyfastgrowing,lackofinformationabout
thedispersalratesofthesespeciesgivesthisecosystemanintermediateresiliencescoreforthis
category.
Vulnerability to increased attack by biological stressors Score:0.7
Increasedinvasionbynon‐nativeannualgrassesandconsequentincreaseinfirefrequencyislikely
todepressrecruitmentofsaltdesertshrubspecies(Haubensaketal.2009).
Vulnerability to increased frequency or intensity of extreme events Score:1
Theseshrublandsarewelladaptedtodrought,sohaveahighresiliencescoreforthiscategory.
Increasedfireeffectsarescoredinthepreviouscategoryasbeingmediatedbycheatgrassinvasion.
Other indirect effects of non‐climate stressors – landscape condition Score:0.51
DesertshrublandlandscapesinColoradohavebeenmoderatelyimpactedbyanthropogenic
activities.Significantportionshavebeenconvertedtoagriculturaluse,especiallyinvalleybottoms
whereirrigationisavailable.Remainingstandsaregenerallyingoodcondition,exceptforaltered
speciescompositioninareaswheregrazinghasreducedoreliminatedsomenativebunchgrasses.
Ongoinglimitedthreatsfromexurbandevelopmentorconversiontoagricultureareaminorsource
ofdisturbance,fragmentation,andhabitatlossintheremainingextentoftheseshrublands.Oiland
gasdevelopment,withassociatedroads,pipelinecorridors,andinfrastructureistheprimary
ongoingsourceofanthropogenicdisturbance,fragmentation,andlossinthishabitat.Livestock
grazinghasalteredpre‐settlementspeciescomposition,andthistrendislikelytocontinueata
reducedrate.Roadsandutilitycorridors,includingthoseassociatedwithsolarenergydevelopment
intheSanLuisValleyareanongoingsourceofdisturbance,andcanfacilitatethespreadofinvasive
plantspecies,whichhavebecomeestablishedinsomeareas.
Literature Cited
Allen,E.B.,R.J.Steers,andS.J.Dickens.2011.Impactsoffireandinvasivespeciesondesertsoilecology.Rangeland
EcologyandManagement64:450‐462.
Balch,J.K.,B.A.Bradley,C.M.D’Antonio,andJ.Gómez‐Dans.2013.Introducedannualgrassincreasesregionalfireactivity
acrossthearidwesternUSA(1980‐2009).GlobalChangeBiology19:173‐183.
Blaisdell,J.P.andR.C.Holmgren.1984.ManagingIntermountainrangelands‐salt‐desertshrubranges.USDAForest
ServiceGeneralTechnicalReportINT‐163.IntermountainForestandRangeExperimentStation,Ogden,Utah.52pp
Haubensak,K.,C.D’Antonio,andD.Wixon.2009.Effectsoffireandenvironmentalvariablesonplantstructureand
compositioningrazedsaltdesertshrublandsoftheGreatBasin(USA).JournalofAridEnvironments73:643‐650.
Climate Change Vulnerability Assessment for Colorado BLM 89 Lin,G.S.L.Phillips,andJ.R.Ehleringer.1996.Monsoonalprecipitationresponsesofshrubsinacolddesertcommunityon
theColoradoPlateau.Oecologia106:8‐17.
Mata‐GonzálezR.,T.L.Evans,D.W.Martin,T.McLendon,J.S.Noller,C.Wan,andR.E.Sosebee.2014.PatternsofWaterUse
byGreatBasinPlantSpeciesUnderSummerWatering.AridLandResearchandManagement28:428‐446.
Munson,S.M.,J.Belnap,C.D.Schelz,M.Moran,andT.W.Carolin.2011.Onthebrinkofchange:plantresponsestoclimate
ontheColoradoPlateau.Ecosphere2:art68.
Parmenter,R.R.2008.Long‐TermEffectsofaSummerFireonDesertGrasslandPlantDemographicsinNewMexico.
RangelandEcologyandManagement61:156–168.
Simonin,K.A.2001.Atriplexconfertifolia.In:FireEffectsInformationSystem,[Online].U.S.DepartmentofAgriculture,
ForestService,RockyMountainResearchStation,FireSciencesLaboratory(Producer).Available:
http://www.fs.fed.us/database/feis/
West,N.E.1983.Intermountainsaltdesertshrublands.Pages375‐397in:N.E.West,editor.Temperatedesertsandsemi‐
deserts.Ecosystemsoftheworld,Volume5.ElsevierPublishingCompany,Amsterdam.
West,N.E.1994.Effectsoffireonsalt‐desertshrubrangelands.InMonsen,S.B.,S.G.Kitchen,comps.1994.Proceedings‐
ecologyandmanagementofannualrangelands;1992May18‐21;Boise,ID.Gen.Tech.RepINT‐GTR‐313.Ogden,UT:U.S.
DepartmentofAgriculture,ForestService,IntermountainResearchStation.416p.
90 Colorado Natural Heritage Program © 2015 OAK & MIXED MOUNTAIN SHRUB
ShrublandsdominatedbyGambeloakorserviceberryandothermontaneshrubspecies
S. Kettler extent exaggerated for display Climate Vulnerability Rank: Low
Vulnerability summary
Key Vulnerabilities: Oak shrublands are most vulnerable to drought and variability of late frosts. The vulnerability of other mountain shrub species is not well known. The ability to resprout after disturbance increases shrub resilience. Oakandmixedmountainshrublandsarerankedashavinglow
vulnerabilitytotheeffectsofclimatechangebymid‐century.
Primaryfactorscontributingtothisrankingarethewide
ecologicalamplitudeoftheseshrublandsinColorado,andtheir
abilitytowithstandorrecoverfromdisturbancerelatively
quickly,whichoffsetsthelowerlandscapeconditionscoredueto
pastanthropogenicdisturbancelevels.
Distribution
Thislargepatchecosystemoccursinthemountains,plateaus,andfoothillsintheSouthernRocky
MountainsandColoradoPlateauecoregions.Oakandmixedmountainshrublandsarewidespread
inthewesternhalfofColorado,andalongthesouthernstretchofthemountainfront.These
shrublandsaremostcommonlyfoundalongdryfoothillsandlowermountainslopesfrom
approximately6,500to9,500ft(2,000‐2,900m)inelevation,oftensituatedabovepinyon‐juniper
woodlands,andadjacenttoponderosawoodlands.Theremaybeinclusionsofothermesicmontane
Climate Change Vulnerability Assessment for Colorado BLM 91 shrublandswithGambeloak(Quercusgambelii)absentorasarelativelyminorcomponent.This
ecosystemintergradeswiththelowermontane‐foothillsshrublandsystemandsharesmanyofthe
samesitecharacteristics.
Characteristic species
StandsdominatedbyGambeloakarecommoninthesouthernpartofColorado,butarecompletely
interspersedwithstandsdominatedbyothershrubspecies,especiallyserviceberry(Amelanchier
spp.)andmahogany(Cercocarpusspp.)athigherelevations.Thevegetationistypicallydominated
byGambeloakaloneorcodominantwithSaskatoonserviceberry(Amelanchieralnifolia),Utah
serviceberry(Amelanchierutahensis),bigsagegrush(Artemisiatridentata),mountainmahogany
(Cercocarpusmontanus),chokecherry(Prunusvirginiana),Stansburycliffrose(Purshia
stansburiana),antelopebitterbrush(Purshiatridentata),mountainsnowberry(Symphoricarpos
oreophilus),orroundleafsnowberry(Symphoricarposrotundifolius).Vegetationtypesinthissystem
mayoccurassparsetodenseshrublandscomposedofmoderatetotallshrubs.Occurrencesmaybe
multi‐layered,withsomeshortshrubbyspeciesoccurringintheunderstoryofthedominant
overstoryspecies.Occurrencescanrangefromdensethicketswithlittleunderstorytorelatively
mesicmixed‐shrublandswitharichunderstoryofshrubs,grassesandforbs.Theseshrubsoften
haveapatchydistributionwithgrassgrowinginbetween.Scatteredtreesareoccasionallypresent
instandsandtypicallyincludespeciesofpineorjuniper.Annualgrassesandforbsareseasonally
present,andweedyannualsareoftenpresent,atleastseasonally.
Non‐oakdominatedmontaneshrublandsareofvariablespeciescomposition,dependingonsite
conditionssuchaselevation,slope,aspect,soiltype,moistureavailability,andpasthistory.Species
presentmayincludemountainmahogany(Cercocarpusmontanus),skunkbushsumac(Rhus
trilobata),clifffendlerbush(Fendlerarupicola),antelopebitterbrush(Purshiatridentata),wildcrab
apple(Peraphyllumramosissimum),snowberry(Symphoricarposspp.),andserviceberry
(Amelanchierspp.).Mostofthesespeciesreproducebothvegetativelyandbyseedlingrecruitment,
aswellasresproutingeasilyafterfire.Variabledisturbancepatternsmayaccountforthelocal
dominanceofaparticularspecies(Keeley2000).Althoughfireisanobvioussourceofdisturbance
intheseshrublands,snowpackmovements(creep,glide,andslippage)mayalsoprovidesignificant
disturbanceinslide‐proneareas(Jamiesonetal.1996).
Spottedtowhee,Virginiawarblers,Green‐tailedtowhee,Blue‐graygnatcatcher,Turkey,blackbear,
deer,elk,andmountainlionarecharacteristicoftheseshrublands.
Environment
Thisecosystemtypicallyoccupiesthelowerslopepositionsofthefoothillandlowermontanezones
whereitmayoccuronleveltosteepslopes,cliffs,escarpments,rimrockslopes,rockyoutcrops,and
screeslopes.Climateissemi‐aridandcharacterizedbymostlyhot‐drysummerswithmildtocold
wintersandannualprecipitationof10‐27in(25‐70cm).Mostprecipitationoccursaswintersnow
butlatesummermonsoonalrainmaybesignificantinsouthernstands.Substratesarevariableand
includesoiltypesrangingfromcalcareous,heavy,fine‐grainedloamstosandyloams,gravelly
loams,clayloams,deepalluvialsand,orcoarsegravel.Soilsaretypicallypoorlydeveloped,rockyto
veryrocky,andwell‐drained.Parentmaterialsincludealluvium,colluvium,andresiduumderived
92 Colorado Natural Heritage Program © 2015 fromigneous,metamorphic,orsedimentaryrockssuchasgranite,gneiss,limestone,quartz,
monzonite,rhyolite,sandstone,schist,andshale.
Dynamics
Theseshrublandsarehighlyfiretolerant.Firecausesdie‐backofthedominantshrubspeciesin
someareas,promotesstumpsproutingofthedominantshrubsinotherareas,andcontrolsthe
invasionoftreesintotheshrublandsystem.DensityandcoverofGambeloakandserviceberry
oftenincreaseafterfire.Naturalfirestypicallyresultinasystemwithamosaicofdenseshrub
clustersandopeningsdominatedbyherbaceousspecies.Historicnaturalfirereturnintervalswere
ontheorderof100yearsinMesaVerde(Floydetal.2000);undersuchconditionsoflowfire
frequency,vulnerablenewlysproutedstemsareabletopersistandformdensethickets.
InsectpestsaffectingGambeloakincludethewoodborer(Agrilusquercicola)andtheoakleafroller
(Archipssemiferana).Thewesterntentcaterpillar(Malacosomacalifornicum)isacommon
defoliatorofshrubspecies.Largeoutbreaksoftheseinsectshavehistoricallybeeninfrequentin
Coloradooakandmixedmountainshrublands(USDAForestService2010).
Oakandmixedmountainshrublandsareimportanthabitatforwildlife,especiallymuledeer,
turkey,andblackbear(Jesteretal.2012).Becauseoakisgenerallyunpalatabletocattle,livestock
grazingcanfacilitatetheincreaseofoakcoverattheexpenseofunderstorygrasses(Mandanyand
West1983).Nativemuledeer,however,browseoakandmixedmountainshrubspeciesduring
mostseasons(Kufeldetal.1973).
CCVA Scoring
Exposure‐Sensitivity (Potential Impact) Rank
Percent Colorado acres with projected temp > max & ppt delta < 5% 1.8% Initial Exposure‐Sensitivity Rank Low Percent Colorado acres with temp <= max & ppt delta < 5% more than 50%? No (47.0%) Low Final Exposure‐Sensitivity Rank Exposure to temperature change Underprojectedmid‐centurytemperatures,about2%ofthecurrentrangeofoak‐mixedmountain
shrublandinColoradowouldexperienceannualmeantemperaturesabovethecurrentstatewide
maximum.
Exposure to precipitation change About49%ofoak‐mixedmountainshrublandinColoradowillbeexposedtoeffectivelydrier
conditionsevenunderunchangedorslightlyincreasedprecipitationprojectedformid‐century.
Sensitivity of ecosystem to temperature and precipitation Ingeneral,theupperandlowerelevationallimitsofGambeloakshrublandarebelievedtobe
controlledbytemperatureandmoisturestress.NeilsonandWullstein(1983)foundthatseedling
Climate Change Vulnerability Assessment for Colorado BLM 93 mortalitywasprimarilyduetospringfreezing,grazing,orsummerdroughtstress.Atmore
northernlatitudes,thezoneoftolerablecoldstressisfoundatlowerelevations,but,atthesame
time,theareaswheresummermoisturestressistolerableareathigherelevations.Neilsonand
Wullstein(1983)hypothesizethatthenortherndistributionallimitofGambeloakcorrespondsto
thepointwherethesetwoopposingfactorsconverge.Oakshrublandsaretypicallyfoundinareas
withmeanannualtemperaturesbetween45and50F(7‐10C;Harperetal.1985).Athigher,
coolerelevations,acornproductionmaybelimitedbytheshortnessofthegrowingseason,and
mostreproductionislikelytobevegetative(Christensen1949).Warmingtemperaturesmay
increasebothacornproductionandseedlingsurvival.
Althoughoaksaremostlikelytodowellunderclimatechange,droughtsmayreducethefrequency
ofestablishmentthroughseedlingrecruitmentbyreducingseedlingsurvival(Neilsonand
Wullstein1983).Thelargeracorn‐producingstemsalsoappeartobemorevulnerabletodrought
inducedmortality.
Resilience and Adaptive Capacity Rank
Overall Score: 0.85 Rank: High
Bioclimatic envelope and range Averagedcategoryscore:0.76
OakandmixedmountainshrublandsarewidespreadinwesternColorado,andhavearelatively
broadecologicalamplitude.Theseshrublandsarenotconfinedtohighelevations,andarenotatthe
southernedgeoftheirrangeinColorado.Oakandmixedmountainshrublandshavesignificant
presencein52%ofColorado’soverallprecipitationrange,and53%ofthestate’sgrowingdegree
dayrange,resultinginafairlyhighresiliencescoreforthiscategory
Growth form and intrinsic dispersal rate Score:1
Theshrubgrowthformofthedominantspecies,andabilitytoquicklycolonizenewareasgivethis
ecosystemahighresiliencescoreforthiscategory.Gambeloakreproducesprimarilybysprouting
ofnewstems,especiallyafterdisturbancessuchasbrushcontrol,fire,andgrazing,although
recruitmentfromseedlingsdoesoccur(Brown1958,Harperetal.1985).Theextensiveclonalroot
systemofGambeloakisaprimarycontributortoitsabilitytosurviveduringperiodswhenseedling
establishmentisimpossible.
Vulnerability to increased attack by biological stressors Score:1
Ingeneraloakandmixedmountainshrublandsarenothighlyvulnerabletoincreasedeffectsof
biologicalstressors.Insomeareas,oakstandsarevulnerabletoincreasedprevalenceofinvasive
speciessuchascheatgrass(Bromustectorum)andknapweeds(Centaureaspp.).Livestockgrazing
94 Colorado Natural Heritage Program © 2015 hasdegradedtheunderstorygrasscommunityofsomeoakstands,andcheatgrassandknapweed
havebecomeestablishedinsomeareas.Mixedmountainshrublandsarelessimpactedbyinvasives.
Vulnerability to increased frequency or intensity of extreme events Score:1
Theseshrublandsarehighlyfiretolerant.Itispossibleforthissystemtomoveupinelevation,
especiallyiffiresopenupsomeoftheadjacentforestedecosystems.
Other indirect effects of non‐climate stressors – landscape condition Score:4.9
OakandmixedmountainshrublandlandscapesinColoradohavebeenmoderatelyimpactedby
anthropogenicactivities.Ongoingbutlimitedthreatsfromurban,exurban,commercial,andenergy
developmentareprimarilyinthesouthernandwesternportionsofColorado,wheretowns,roads,
andutilitycorridorsareoftenincloseproximitytooakshrublands.Mixedmountainshrublandsare
somewhatlessimpactedbydevelopments,primarilythoseassociatedwithrecreationareasor
exurbanhousing.Fireisasourceofdisturbanceintheseshrublands,andtheyarehighlyfire
tolerant.Aswithotherhabitatsinthewildland‐urbaninterface,areasneardevelopedareasare
mostlikelytobethreatenedbytheeffectsoffiresuppression,whilemoreremoteareasare
generallyingoodcondition.
Literature Cited
Brown,H.E.1958.Gambeloakinwest‐centralColorado.Ecology39:317‐327.
Christensen,E.M.1949.Theecologyandgeographicdistributionofoakbrush(Quercusgambelii)inUtah.Thesis.70p.
UniversityofUtah,SaltLakeCity,UT.
Floyd,M.L.,W.H.Romme,andD.D.Hanna.2000.FirehistoryandvegetationpatterninMesaVerdeNationalPark,
Colorado,USA.EcologicalApplications10:1666‐1680.
Harper,K.T.,F.J.Wagstaff,andL.M.Kunzler.1985.BiologymanagementoftheGambeloakvegetativetype:aliterature
review.Gen.Tech.Rep.INT‐179.Ogden,UT:U.S.DepartmentofAgriculture,ForestService,IntermountainForestand
RangeExperimentStation.31p.
Jamieson,D.W.,W.H.Romme,andP.Somers.1996.Bioticcommunitiesofthecoolmountains.Chapter12inTheWestern
SanJuanMountains:TheirGeology,Ecology,andHumanHistory,R.Blair,ed.UniversityPressofColorado,Niwot,CO.
Jester,N.,K.Rogers,andF.C.Dennis.2012.Gambeloakmanagement.NaturalResourcesSeries‐ForestryFactSheetNo.
6.311.ColoradoStateUniversityExtension,FortCollins,Colorado.
Keeley,J.E.2000.Chaparral.Chapter6inNorthAmericanTerrestrialVegetation,secondedition.M.G.BarbourandW.D.
Billings,eds.CambridgeUniversityPress.
Kufeld,R.C.,O.C.Wallmo,andC.Feddema,.1973.FoodsoftheRockyMountainmuledeer.Res.Pap.RM‐111.FortCollins,
CO:U.S.DepartmentofAgriculture,ForestService,RockyMountainForestandRangeExperimentStation.31p.
Madany,M.H.andN.E.West.1983.Livestockgrazing‐fireregimeinteractionswithinmontaneforestsofZionNational
Park,Utah.Ecology64:661‐667.
Climate Change Vulnerability Assessment for Colorado BLM 95 Neilson,R.P.andL.H.Wullstein.1983.BiogeographyoftwosouthwestAmericanoaksinrelationtoatmospheric
dynamics.JournalofBiogeography10:275‐297.
96 Colorado Natural Heritage Program © 2015 SAGEBRUSH
Shrublandandsteppecharacterizedbysagebrush,includingthreesubspeciesofbigsagebrush,
blacksagebrush,Bigelowsage,andlittlesagebrush
R. Rondeau extent exaggerated for display Climate Vulnerability Rank: Low
Vulnerability summary
Key Vulnerabilities: Increased drought intensity and/or frequency is likely to increase the impacts of fire in sagebrush shrublands, as well as play a role in the spread of invasive species. The vulnerability of sagebrush shrublands is expected to be variable by subspecies. Sagebrushshrublandsarerankedashavinglowvulnerabilityto
theeffectsofclimatechangebymid‐century.Theprimaryfactor
contributingtothisrankingisthecomparativelylowprojected
exposuretowarmeranddrierfutureconditionsinthepartof
Coloradowherethegreaterportionofthishabitatisfound.The
combinationofthethreebigsagebrushsubspeciesinour
analysiscollectivelygivesthishabitattypeawideecological
amplitude.Underalongertimeframe,theseshrublandsmay
havehighervulnerability,similartotheassessmentofPocewicz
etal.(2014)forsagebrushhabitatsinWyoming.Inparticular,the
degradedconditionofsomeareas,andthevulnerabilityofthis
ecosystemtopotentialincreasesinfirefrequencyandseverity,
couldincreasethevulnerabilitytoclimatechange.
Distribution
Asevaluatedherein,thethreesubspeciesofbigsagebrush(basinbigsagebrush,Artemisia
tridentatassp.tridentata,mountainbigsagebrush,A.tridentatassp.vaseyana,andWyomingbig
Climate Change Vulnerability Assessment for Colorado BLM 97 sagebrush,A.tridentatassp.wyomingensis)arecombinedasthesagebrushecosystem.Ingeneral,
Wyomingbigsagebrushisfoundindrier,warmerareaswhereprecipitationismorelikelytobein
theformofrain,whilemountainbigsagebrushisfoundathigher,coolerelevationswheresnowis
thedominantformofprecipitation(Howard1999,Johnson2000).Changesintemperatureand
precipitationpatternsmayresultinshiftsintherelativeabundanceanddistributionofthethree
subspecies.
ThismatrixformingecosystemoccursthroughoutthemuchofwesternU.S.InColorado,thelargest
occurrencesareinthewesternhalfofthestate,butthissystemcanalsobefoundineastern
Colorado.NorthwesternColorado,NorthPark,MiddlePark,andtheupperGunnisonBasinhave
largeandcontinuousstandsofsagebrushshrublands.
Characteristic species
Sagebrushshrublandsoflower,drierelevationsaredominatedbybasinbigsagebrushand/or
Wyomingbigsagebrush.Additionalshrubspeciespresentmayincludesilversagebrush(Artemisia
cana),rabbitbrush(ChrysothamnusorEricameriaspp.),winterfat(Krascheninnikovialanata),and
antelopebitterbrush(Purshiatridentata).Understoriesaretypicallygrassy,andcommon
graminoidspeciesincludeIndianricegrass(Achnatherumhymenoides),bluegrama(Bouteloua
gracilis),Geyer’ssedge(Carexgeyeri),thickspikewheatgrass(Elymuslanceolatus),Idahofescue
(Festucaidahoensis),Thurberfescue(F.thurberi),needle‐and‐thread(Hesperostipacomata),basin
wildrye(Leymuscinereus),westernwheatgrass(Pascopyrumsmithii),James’galleta(Pleuraphis
jamesii),Sandbergbluegrass(Poasecunda),orbluebunchwheatgrass(Pseudoroegneriaspicata).
Perennialforbspeciestypicallycontributelessthan25%vegetativecover.
Montanesagebrushshrublandorsteppeischaracterizedbymountainbigsagebrush,andavariety
ofothershrubsincludingSaskatoonserviceberry(Amelanchieralnifolia),littlesagebrush
(Artemisiaarbuscula),prairiesagewort(Artemisiafrigida),rubberrabbitbrush(Ericameria
nauseosa),yellowrabbitbrush(Chrysothamnusviscidiflorus),mountainsnowberry(Symphoricarpos
oreophilus),antelopebitterbrush,waxcurrant(Ribescereum),andWoods’rose(Rosawoodsii),may
bepresent.Bothforbsandgrassesaretypicallywellrepresentedintheunderstory.Common
graminoidsincludeIdahofescue,Thurberfescue,timberoatgrass(Danthoniaintermedia),Parry’s
oatgrass(Danthoniaparryi),squirreltail(Elymuselymoides),slenderwheatgrass(Elymus
trachycaulus),spikefescue(Leucopoakingii),westernwheatgrass,bluebunchwheatgrass,
muttongrass(Poafendleriana),Sandbergbluegrassanduplandsedges(Carexspp.).Forbspecies
mayincludecommonyarrow(Achilleamillefolium),rosypussytoes(Antennariarosea),white
sagebrush(Artemisialudoviciana),milkvetch(Astragalusspp.),arrowleafbalsamroot
(Balsamorhizasagittata),Indianpaintbrush(Castillejaspp.),fleabane(Erigeronspp.),buckwheat
(Eriogonumspp.),strawberry(Fragariavirginiana),avens(Geumspp.),owl's‐claws(Hymenoxys
hoopesii),lupine(Lupinus,spp.),phlox(Phloxspp.),andcinquefoil(Potentillaspp.).
Sage‐grouse(Centrocercusspp.)isanindicatorofahealthysagebrushshrubland.
98 Colorado Natural Heritage Program © 2015 Environment
Bigsagebrushshrublandsaretypicallyfoundinbroadbasinsbetweenmountainranges,onplains
andfoothills.Sitesaretypicallyflattorollinghillswithdeep,well‐drainedsandyorloamsoils
between7,000to10,000feetinelevation.Mostannualprecipitationfallsassnowinwinter.
Temperaturesexhibitlargeannualanddiurnalvariation.
Dynamics
Althoughsagebrushtoleratesdryconditionsandfairlycooltemperaturesitisnotfireadapted,and
islikelytobeseverelyimpactedbyintensefiresthatenhancewinderosionandeliminatetheseed
bank(Schlaepferetal.2014).Increasedfirefrequencyandseverityintheseshrublandscouldresult
increasingareadominatedbyexoticgrasses,especiallycheatgrass(Bromustectorum)(D’Antonio
andVitousek1992,ShinnemanandBaker2009).Warmer,driersites(typicallyfoundatlower
elevations)aremoreinvasiblebycheatgrass(Chambersetal.2007).Thereisamoderatepotential
forinvasionbyknapweedspecies,oxeyedaisy,leafyspurge,andyellowtoadflaxunderchanging
climaticconditions,andapotentialforchangingfiredynamicstoaffecttheecosystem.Thereisno
informationonthevulnerabilityofthisecosysteminColoradotoinsectordiseaseoutbreak,
althoughsevereoutbreaksofthesagebrush‐defoliatingmothArogawebsterihavebeenrecorded
furtherwestintheGreatBasin(Bentzetal.2008).Grazingbylargeungulates(bothwildlifeand
domesticlivestock)canchangethestructureandnutrientcyclingofsagebrushshrublands(Manier
andHobbs2007),buttheinteractionofgrazingwithotherdisturbancessuchasfireandinvasive
speciesunderchangingclimaticconditionsappearscomplex(e.g.Daviesetal.2009)andnotwell
studiedinColorado.
CCVA Scoring
Exposure‐Sensitivity (Potential Impact) Rank
Percent Colorado acres with projected temp > max & ppt delta < 5% 3.7% Initial Exposure‐Sensitivity Rank Low Percent Colorado acres with temp <= max & ppt delta < 5% more than 50%? No (22.1%) Low Final Exposure‐Sensitivity Rank Exposure to temperature change Underprojectedmid‐centurytemperatures,about5%ofthecurrentrangeofsagebrushshrubland
inColoradowouldexperienceannualmeantemperaturesabovethecurrentstatewidemaximum.
Exposure to precipitation change About26%ofsagebrushshrublandinColoradowillbeexposedtoeffectivelydrierconditionseven
underunchangedorslightlyincreasedprecipitationprojectedformid‐century.
Sensitivity of ecosystem to temperature and precipitation Bradley(2010)pointsoutthatsagebrushshrublandsinthewesternU.S.arecurrentlyfoundacross
awidelatitudinalgradient(fromabout35to48degreesnorthlatitude),whichsuggestsadaptation
toacorrespondinglywiderangeoftemperatureconditions.However,becausetheseshrublandsare
Climate Change Vulnerability Assessment for Colorado BLM 99 apparentlyabletodominateazoneofprecipitationbetweendriersaltbushshrublandsandhigher,
somewhatmoremesicpinyon‐juniperwoodland,thedistributionofsagebrushshrublandsislikely
tobeaffectedbychangesinprecipitationpatterns(Bradley2010).Seasonaltimingofprecipitation
isimportantforsagebrushhabitats;summermoisturestressmaybelimitingifwinterprecipitation
islow(GerminoandReinhardt2014).Seedlingsofmountainbigsagebrusharemoresensitiveto
freezingunderreducedsoilmoistureconditions(Lambrechtetal.2007).Wintersnowpackis
criticalforsagebrushgrowth;lowerelevationsareprobablymoreatriskfromtemperatureimpacts
incomparisontoupperelevationsduetolesssnow,andconsequentlygreaterwaterstress.
Underexperimentalwarmingconditionsinahigh‐elevationpopulation,mountainbigsagebrush
hadincreasedgrowth,suggestingthatlongergrowingseasonlengthcouldfacilitatetheexpansion
ofsagebrushhabitatintoareasthatwereformerlytoocoldfortheshrub(Perforsetal.2003).
However,Pooreetal.(2009)foundthathighsummertemperaturesresultedinlowergrowthrate,
duetoincreasedwaterstress.
Schlaepferetal.(2012)modeledfuturedistributionofthebigsagebrushecosysteminthewestern
U.S.Overtheentirestudyarea,sagebrushdistributionwaspredictedtodecrease,especiallyunder
higherCO2emissionsscenarios.Thestrongestdecreasesareinthesouthernpartoftherange
(includingsouthwesternColorado),whilethedistributionispredictedtoincreaseathigher
elevationsandinareasfartothenorthofColorado.
Resilience and Adaptive Capacity Rank
Overall Score: 0.61 Rank: Moderate
Bioclimatic envelope and range Averagedcategoryscore:0.83
Theseshrublandsareprimarilyfoundinthewesternpartofthestate,atelevationsfromabout
5,000to9,500ft,andarenotrestrictedtohighelevations.TheNorthAmericandistributionof
sagebrushhabitatislargelytothewestandnorthofColorado.Thethreesubspeciesofbig
sagebrushshowanelevationalseparation,withmountainbigsagebrushinwetter,cooler
conditionsofhigherelevations,andWyomingbigsagebrushinthewarmestanddriestconditions
atlowerelevations(Howard1999).Duetotheadaptationsofthevarioussubspecies,therangeof
annualaverageprecipitationforsagebrushhabitatsisfairlywide,fromabout8‐40in(20‐100cm),
withameanof18in(45cm),covering64%ofthestatewideprecipitationrange.Growingseason
heataccumulationisalsohighlyvariableacrosstherangeofthehabitat,forthesamereason,and
covers67%ofthestatewiderange.Thiscombinationoffactorsgivessagebrushshrublandsahigh
resiliencescoreinthiscategory.
Growth form and intrinsic dispersal rate Score:0.5
Sagebrushreceivedanintermediateresiliencescoreduetoitsgenerallyslowergrowthratesand
inabilitytoresproutafterfire.Sagebrushisgenerallyapoorseeder,withsmalldispersaldistances,
100 Colorado Natural Heritage Program © 2015 however,therearenoapparentbarrierstodispersalfortheseshrublands.Thesestandsmayalso
besomewhatvulnerabletochangesinphenology.
Vulnerability to increased attack by biological stressors Score:0.7
Otherstressorsforsagebrushshrublandsareinvasionbycheatgrassandexpansionofpinyon‐
juniperwoodlands.Thereisamoderatepotentialforinvasionbyknapweedspecies,oxeyedaisy,
leafyspurge,andyellowtoadflaxunderchangingclimaticconditions,andapotentialforchanging
firedynamicstoaffecttheecosystem.Thereisnoinformationonthevulnerabilityofthisecosystem
toinsectordiseaseoutbreak.
Grazingbylargeungulates(bothwildlifeanddomesticlivestock)canchangethestructureand
nutrientcyclingofsagebrushshrublands(ManierandHobbs2007),buttheinteractionofgrazing
withotherdisturbancessuchasfireandinvasivespeciesunderchangingclimaticconditions
appearscomplex(e.g.Daviesetal.2009)andnotwellstudiedinColorado.
Vulnerability to increased frequency or intensity of extreme events Score:0.5
Althoughsagebrushtoleratesdryconditionsandfairlycooltemperaturesitisnotfireadapted,and
noneofthesubspeciesresproutafterfire(Tirmenstein1999).Sagebrushshrublandislikelytobe
severelyimpactedbyintensefiresthatenhancewinderosionandeliminatetheseedbank(Young
andEvans1989).Increaseddroughtmayincreasefirefrequencyandseverity,eliminating
sagebrushinsomeareas,especiallyatdriersitesoflowerelevations.Increasedfirefrequencyand
severityintheseshrublandsmayresultintheirconversiontograsslandsdominatedbyexotic
species.
Other indirect effects of non‐climate stressors – landscape condition Score:0.53
SagebrushshrublandlandscapesinColoradohavebeenmoderatelyimpactedbyanthropogenic
disturbance.Threatstosagebrushshrublandsfromexurbanorrecreationalareadevelopmentare
limited,butongoingataverylowlevel.Huntingandrecreationareminorsourcesofdisturbancein
thishabitat.Chainingorothershrubremovalformownhay,andtoalesserextentconversionto
croplandisasubstantialthreatinnorthwesternColorado.Largecoalminingoperationsthat
completelyremovethishabitatpriortoreclamationactivityareanongoingthreattothe
connectivityandqualityoftheseshrublands.Oilandgasdevelopment,withassociatedroads,
pipelinecorridors,andinfrastructureisanotherongoingsourceofanthropogenicdisturbance,
fragmentation,andlossinthishabitatinnorthwesternColorado.
Literature Cited
Bentz,B.,D.Alston,andT.Evans.2008.GreatBasininsectoutbreaks.In:Chambers,J.C.,N.Devoe,andA.Evenden,eds.
CollaborativemanagementandresearchintheGreatBasin‐examiningtheissuesanddevelopingaframeworkforaction.
Climate Change Vulnerability Assessment for Colorado BLM 101 Gen.Tech.Rep.RMRS‐GTR‐204.FortCollins,CO:U.S.DepartmentofAgriculture,ForestService,RockyMountainResearch
Station.p.45‐48.
Bradley,B.A.2010.Assessingecosystemthreatsfromglobalandregionalchange:hierarchicalmodelingofriskto
sagebrushecosystemsfromclimatechange,landuseandinvasivespeciesinNevada,USA.Ecography33:198‐208.
Chambers,J.C.,B.A.Roundy,R.R.Blank,S.E.Meyer,andA.Whittaker.2007.WhatmakesGreatBasinsagebrush
ecosystemsinvasiblebyBromustectorum?EcologicalMonographs77:117‐145.
D’Antonio,C.M.andP.M.Vitousek.1992.Biologicalinvasionsbyexoticgrasses,thegrass/firecycle,andglobalchange.
AnnualReviewofEcologyandSystematics23:63–87.
Davies,K.E.,T.J.Sevjcar,andJ.D.Bates.2009.Interactionofhistoricalandnonhistoricaldisturbancesmaintainsnative
plantcommunities.EcologicalApplications19:1536‐1545.
Germino,M.J.andK.Reinhardt.2014.Desertshrubresponsestoexperimentalmodificationofprecipitationseasonality
andsoildepth:relationshiptothetwo‐layerhypothesisandecohydrologicalniche.JournalofEcology102:989‐997.
Howard,J.L.1999.Artemisiatridentatasubsp.wyomingensis.In:FireEffectsInformationSystem,[Online].U.S.
DepartmentofAgriculture,ForestService,RockyMountainResearchStation,FireSciencesLaboratory(Producer).
Available:http://www.fs.fed.us/database/feis/
Johnson,K.A.2000.Artemisiatridentatasubsp.vaseyana.In:FireEffectsInformationSystem,[Online].U.S.Departmentof
Agriculture,ForestService,RockyMountainResearchStation,FireSciencesLaboratory(Producer).Available:
http://www.fs.fed.us/database/feis/
Lambrecht,S.C.,A.K.Shattuck,andM.E.Loik.2007.Combineddroughtandepisodicfreezingonseedlingsoflow‐and
high‐elevationsubspeciesofsagebrush(Artemisiatridentata).PhysiologiaPlantarum130:207‐217.
Manier,D.J.andN.T.Hobbs.2007.Largeherbivoresinsagebrushsteppeecosystems:livestockandwildungulates
influencestructureandfunction.Oecologia152:739‐750.
Perfors,T.,J.Harte,andS.E.Alter.2003.Enhancedgrowthofsagebrush(Artemisiatridentata)inresponsetomanipulated
ecosystemwarming.GlobalChangeBiology9:736‐742.
Pocewicz,A.,H.E.Copeland,M.B.Grenier,D.A.Keinath,andL.M.Washkoviak.2014.Assessingthefuturevulnerabilityof
Wyoming’sterrestrialwildlifespeciesandhabitats.ReportpreparedbyTheNatureConservancy,WyomingGameand
FishDepartmentandWyomingNaturalDiversityDatabase.
Poore,R.E.,C.A.Lamanna,J.J.Ebersole,andB.J.Enquist.2009.Controlsonradialgrowthofmountainbigsagebrushand
implicationsforclimatechange.WesternNorthAmericanNaturalist69:556‐562.
Schlaepfer,D.R.,W.K.Lauenroth,andJ.B.Bradford.2012.Effectsofecohydrologicalvariablesoncurrentandfuture
ranges,localsuitabilitypatterns,andmodelaccuracyinbigsagebrush.Ecography35:374‐384.
Shinneman,D.J.andW.L.Baker.2009.Environmentalandclimaticvariablesaspotentialdriversofpost‐firecoverof
cheatgrass(Bromustectorum)inseededandunseededsemiaridecosystems.InternationalJournalofWildlandFire
18:191‐202.
Tirmenstein,D.1999.Artemisiatridentataspp.tridentata.In:FireEffectsInformationSystem,[Online].U.S.Department
ofAgriculture,ForestService,RockyMountainResearchStation,FireSciencesLaboratory(Producer).Available:
http://www.fs.fed.us/database/feis/
Young,J.A.andR.A.Evans.1989.Dispersalandgerminationofbigsagebrush(Artemisiatridentata)seeds.WeedScience
37:201‐206.
102 Colorado Natural Heritage Program © 2015 SANDSAGE
Shrublandorsteppecharacterizedbysandsagebrush
S. Kettler extent exaggerated for display Climate Vulnerability Rank: Moderate
Vulnerability summary
Key Vulnerabilities: Extended periods of drought that decrease levels of vegetation cover would increase the likelihood that sandy substrates will be mobilized. The loss of native plant biodiversity in many stands decreases the available assemblage of drought‐adapted species that can boost resilience to this vulnerability. Sandsageshrublandsarerankedmoderatelyvulnerabletothe
effectsofclimatechangebymid‐century.Thisrankingis
primarilyduetotheconcentrationofgreatestexposureforall
temperaturevariablesontheeasternplainsofColorado,where
thisecosystemisfound.Inaddition,anthropogenicdisturbance
intheseshrublandshasreducedtheoveralllandscapecondition
ofthehabitat.Theseshrublandsarewelladaptedtosandysoils,
andmaybeabletoexpandintoadjacentareasunderwarmer,
drierconditions,dependingondisturbanceinteractions.Overall
conditionandcompositionoftheseshrublandsmaychangewith
changingclimate.
Distribution
Thesandsageecosystemisfoundprimarilyinthesouth‐centralareasoftheWesternGreatPlains.
OccurrencesgenerallyrangefromtheNebraskaSandhillregionsouthtocentralTexas,although
someexamplesmaybefoundasfarnorthastheBadlandsofSouthDakota.Thegreaterpartofthe
ecosystemoccursintheCentralShortgrassPrairieecoregionineasternColorado,westernKansas
Climate Change Vulnerability Assessment for Colorado BLM 103 andsouthwesternNebraska.SandsageshrublanddominatessandysoilsofColorado’seastern
plains,atelevationsgenerallybelow5,500ft.
Theseshrublandshaveoftenbeentreatedasanedaphicvariantofeasternplainsmixed‐grass
prairie(Albertson&Weaver1944,Daley1972),orofshortgrassprairie(Ramaley1939,Simsand
Risser2000).Sandsage(Artemisiafilifolia)formsextensiveopenshrublandsinsandysoilsof
Colorado’seasternplains,andisofparticularimportanceforbothgreaterandlesserprairie
chickenhabitat,aswellasforothergrasslandbirds.IneasternColorado,thissystemisfoundin
extensivetractsonQuaternaryeoliandepositsalongtheSouthPlatte,ArikareeandRepublican
Rivers,betweenBigSandyandRushCreeks,andalongtheArkansasandCimarronRivers,whereit
iscontiguouswithareasinKansasandOklahoma(Comeretal.2003).
Characteristic species
Throughoutitsrange,thissystemischaracterizedbyasparsetomoderatelydensewoodylayer
dominatedbysandsage.Theseshrubsusuallydonotgrowasclumpsbutratherasindividuals,and
theinterveninggroundismostoftendominatedbyasparsetomoderatelydenselayeroftall,mid‐
orshortgrasses.Associatedspeciescanvarywithgeography,precipitation,disturbanceandsoil
texture.Graminoidspeciessuchassandbluestem(Andropogonhallii),threeawn(Aristidaspp.),
grama(Boutelouaspp.),prairiesandreed(Calamovilfalongifolia),needle‐and‐thread(Hesperostipa
comata),andsanddropseed(Sporoboluscryptandrus)aretypical.Othershrubspeciesmayalsobe
presentincludingtreecholla(Cylindropuntiaimbricata),broomsnakeweed(Gutierreziasarothrae),
pricklypear(Opuntiaspp.),westernsandcherry(Prunuspumilavar.besseyi),andsoapweedyucca
(Yuccaglauca).
Greaterandlesserprairie‐chickens,Cassin’ssparrows,andornateboxturtlesareindicatorsofa
healthysandsageprairiesystem.
Environment
Throughoutitsrangeitiscloselytiedtosandysoils,andthisedaphicrestrictionischaracteristicof
largepatchsystems.Littleisknownaboutthetoleranceofsandsageforsoilsotherthanwell‐
drainedsandwithalowsiltandclaycomponent.Suchsoilsareoften“droughty”,withreduced
water‐holdingability,andconsequently,thepotentialforincreasedwaterstresstoresidentplants
(SoilSurveyDivisionStaff1993).RasmussenandBrotherson(1984)speculatedthatsandsageis
adaptedtolessfertilesoilsthanspeciesofadjacentgrasslandcommunities.
Dynamics
Ramaley(1939)indicatedthatthepersistenceofsandsagewasfacilitatedbyfireandlong
overgrazing,intheabsenceofwhichasitewouldtransitiontosandprairie.However,thereisno
evidencetosuggestthat,undercertaincombinationsoftemperature,precipitation,grazing,and
otherdisturbance,sandsagewouldbeunabletoexpandontoothersoiltypes.Firesuppressionmay
alsocontributetoanincreaseinshrubdensityinthishabitat,althoughsandsagequicklyresprouts
afterburning.Disturbancefromgrazing,fire,anddrought,incombinationwithrangeimprovement
practices,haspermittedtheestablishmentandspreadofnon‐nativespecies.
104 Colorado Natural Heritage Program © 2015 Colorado’seasternplainsexhibitclimaticdifferencesfromnorthtosouthwhichmaybereflectedin
thelocalexpressionofsandsageshrubland.OccurrencesinsouthernColoradoexperiencealonger
growingseason,lowerannualprecipitation,anddifferencesinprecipitationpatterns(Western
RegionalClimateCenter2004),andmaybedominatedbydifferentspeciesthannorthernstands.In
thesouthernrangeofthissystem,Havardoak(Quercushavardii)mayalsobepresentand
representsonesuccessionpathwaythatdevelopsovertimefollowingadisturbance.Havardoakis
abletoresproutfollowingafireandthusmaypersistforlongperiodsoftimeonceestablished
(WrightandBailey1982).
Duringthepast10,000years,theseareasarelikelytohavefluctuatedbetweenactivedunefields
andstabilized,vegetateddunes,dependingonclimateanddisturbancepatterns(Formanetal.
2001).Extendedperiodsofseveredroughtorotherdisturbancethatresultsinlossofstabilizing
vegetationcanquicklyleadtosoilmovementandblowoutsthatinhibitvegetationre‐
establishment,andmayeventuallyleadtodramaticallydifferentspeciescomposition.
CCVA Scoring
Exposure‐Sensitivity (Potential Impact) Rank
Percent Colorado acres with projected temp > max & ppt delta < 5% Initial Exposure‐Sensitivity Rank 44.1% High Percent Colorado acres with temp <= max & ppt delta < 5% more than 50%? No (21.3%) High Final Exposure‐Sensitivity Rank Exposure to temperature change Underprojectedmid‐centurytemperatures,about50%ofthecurrentrangeofsandsageshrubland
inColoradowouldexperienceannualmeantemperaturesabovethecurrentstatewidemaximum.
Exposure to precipitation change About65%ofsandsageshrublandinColoradowillbeexposedtoeffectivelydrierconditionseven
underunchangedorslightlyincreasedprecipitationprojectedformid‐century.
Sensitivity of ecosystem to temperature and precipitation Sandsagesharesthedryandwarmclimateofshortgrass.Annualaverageprecipitationisonthe
orderof10‐18inches(25‐47cm),withameanof16in(40cm).Thegrowingseasonisgenerally
long,withfrequenthightemperatures.
SandsageoccurrencesinColoradohavehistoricallyexperiencedseasonaldifferencesin
precipitationpatternsfromnorthtosouth(WesternRegionalClimateCenter2004).North‐south
gradientsintemperatureandprecipitationonColorado’seasternplainsappeartobereflectedin
thespeciescompositionofsandsagehabitat,especiallyinmidgrassspecies(Daley1972),which
maycontributetovariablevulnerabilitybetweennorthernandsouthernstands.
Climate Change Vulnerability Assessment for Colorado BLM 105 Resilience and Adaptive Capacity Rank:
Overall Score: 0.71 Rank: High
Bioclimatic envelope and range Averagedcategoryscore:0.62
Theseshrublandsarenotlimitedtohighelevations,andinColoradoarewellwithintherangeof
continentaldistribution.Thegeneralrestrictionofsandsageshrublandstowarm,dryareason
Colorado’seasternplainsmeansthattheydisplayasomewhatrestrictedecologicalenvelope,
covering18%ofthestatewideprecipitationrange,and57%ofthegrowingdegreedayrange.The
moderateresiliencescoreforthiscategorymaynotreflectthetruecapacityoftheseshrublandsto
adapttochangingclimateconditionsifsuitablesubstratesareavailable.
Growth form and intrinsic dispersal rate Score:1
Sandsageisoftenabletoresproutquicklyafterfire,althoughitmayhavepoordispersalability,
withmostseedslandingclosetotheparentplant(McWilliams2003).Theapparentabilityofthis
speciestoestablishquicklyafterdisturbancegivesitahighresiliencescoreinthiscategory.
Vulnerability to increased attack by biological stressors Score:1
Domesticlivestockgrazingtendstofavortheincreaseofsandsageoverassociatednativegrasses.
Long‐termcontinuousgrazingofdomesticlivestockhascontributedtothealterationofthese
shrublandhabitatsfromtheirpre‐settlementcondition,however,thisfactorisgenerallylessofa
threatthanchangesintemperatureandprecipitation.
Vulnerability to increased frequency or intensity of extreme events Score:0.5
Droughtisthemostimportantextremeeventthatislikelytoalterthecharacterofthese
shrublands.Warmeranddrierconditions,andresultingreducedvegetationcovercouldallow
reactivationofcurrentlystabilizedsandysoilsthroughouteasternColorado.Althoughsandsage
doesnotreproducevegetatively,itisabletoresproutafterfire.Fireextentandintensityare
correlatedwithclimateandgrazingeffectsonfuelloads.Fireandgrazingarebothimportant
disturbanceprocessesforsandsagehabitat,andmayinteractwithdrought,aswellaspermitting
invasiveexoticplantspeciestoestablishandspread.
Other indirect effects of non‐climate stressors – landscape condition Score:0.43
SandsagelandscapesinColoradoaresignificantlyimpactedbyanthropogenicactivities.Insome
casesthishasincreasedtheextentofsandsageshrublandifmidgrassprairieisconvertedto
106 Colorado Natural Heritage Program © 2015 shortgrass‐sandsagecommunity,dueinlargeparttolong‐termcontinuousgrazingbydomestic
livestock(LANDFIRE2006).Sandsageshrublandshavelimitedbutongoingthreatofconversionto
tilledagricultureorurban/exurbanandcommercialdevelopment.Oilandgasdevelopment,and
windturbinefarms,withassociatedroads,utilitycorridors,andinfrastructureisaprimaryongoing
sourceofanthropogenicdisturbance,fragmentation,andlossinthishabitat.
Literature Cited
Albertson,F.W.andJ.E.Weaver.1944.NatureanddegreeofrecoveryofgrasslandfromtheGreatDroughtof1933to
1940.EcologicalMonographs14:393‐479.
Comer,P.,S.Menard,M.Tuffly,K.Kindscher,R.Rondeau,G.Jones,G.Steinuaer,andD.Ode.2003.UplandandWetland
EcologicalSystemsinColorado,Wyoming,SouthDakota,Nebraska,andKansas.Reportandmap(10hectareminimum
mapunit)totheNationalGapAnalysisProgram.Dept.ofInteriorUSGS.NatureServe.
Daley,R.H.1972.ThenativesandsagevegetationofeasternColorado.M.S.Thesis,ColoradoStateUniversity,FortCollins,
Colorado.
Forman,S.L.,R.Oblesby,andR.S.Webb.2001.TemporalandspatialpatternsofHoloceneduneactivityontheGreatPlains
ofNorthAmerica:megadroughtsandclimatelinks.GlobalandPlanetaryChange29:1‐29.
LANDFIRE.2006.LANDFIREBiophysicalSettingModels.BiophysicalSetting3310940,WesternGreatPlainsSandhill
Steppe.USDAForestService;U.S.DepartmentofInterior.Availableat:
http://www.landfire.gov/national_veg_models_op2.php
McWilliams,J.2003.ArtemisiafilifoliaIn:FireEffectsInformationSystem,[Online].U.S.DepartmentofAgriculture,Forest
Service,RockyMountainResearchStation,FireSciencesLaboratory(Producer).Available:
http://www.fs.fed.us/database/feis/
Ramaley,F.1939.Sand‐hillvegetationofnortheasternColorado.EcologicalMonographs9(1):1‐51.
Rasmussen,L.L.andJ.D.Brotherson.1986.Habitatrelationshipsofsandsage(Artemisiafilifolia)insouthernUtah.In:
McArthur,E.D.,andB.L.Welch,compilers.Proceedings‐‐symposiumonthebiologyofArtemisiaandChrysothamnus;
1984July9‐13;Provo,UT.Gen.Tech.Rep.INT‐200.Ogden,UT:U.S.DepartmentofAgriculture,ForestService,
IntermountainResearchStation:58‐66.
Sims,P.L.,andP.G.Risser.2000.Grasslands.In:Barbour,M.G.,andW.D.Billings,eds.,NorthAmericanTerrestrial
Vegetation,SecondEdition.CambridgeUniversityPress,NewYork,pp.323‐356.
SoilSurveyDivisionStaff.1993.Soilsurveymanual.SoilConservationService.U.S.DepartmentofAgricultureHandbook
18.Availableat:http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ref/?cid=nrcs142p2_054261
WesternRegionalClimateCenter[WRCC].2004.ClimateofColoradonarrativeandstateclimatedata.Availableat
http://www.wrcc.dri.edu
Wright,H.A.andA.W.Bailey.1982.Fireecology:UnitedStatesandsouthernCanada.JohnWileyandSons.NY.501p.
Climate Change Vulnerability Assessment for Colorado BLM 107 Grassland or Herbaceous
Table 2.7. Key vulnerabilities, grassland or other herbaceous ecosystems. Habitat
Climate factor(s)
Consequences
Other considerations
Alpine Extended growing season with earlier snowmelt Conversion to other type that includes shrubs or trees Barriers to dispersal Montane grassland Drought, warmer temperatures Woody species invasion, exotics; potential to expand into burned forest areas Highly altered Semi‐desert grassland ‐‐‐‐ May increase Poor connectivity Shortgrass Extended drought, warmer summer nighttime temperatures Change in relative species abundance, woody species invasion, or conversion to other type Anthropogenic disturbance 108 Colorado Natural Heritage Program © 2015 ALPINE
Thisecosystemincludeshigh‐elevationdrytundraturf,dwarf‐shrublands,fellfield,androckand
screecommunities.
Extent exaggerated for display R. Rondeau Climate Vulnerability Rank: Low
Vulnerability summary
Key Vulnerabilities: Warmer conditions leading to earlier snowmelt and an extended growing season in higher elevations are expected to allow the establishment of woody species above current treeline levels, although this process is likely to be slow. Photoperiod cues (not influenced by climate change) for many species could negate the effects of a longer growing season. The ability of most alpine species to disperse across intervening lower elevation habitat is doubtful. Alpinehabitatsarerankedashavinglowvulnerabilitytothe
effectsofclimatechangebymid‐century,duetolimitedexposure
towarmeranddrierconditions.Overall,alpineareasareingood
condition,withmoderateresilience.Becauseoftheshortgrowing
seasonlengthinalpineandsubalpineareas,changeisexpected
tooccurrelativelyslowly.Underalonger‐termevaluationframe,
vulnerabilityofthishabitatisexpectedtobegreater,sincethese
habitatsarerestrictedtothehighestelevationsofColorado,and
consequentlyhaveanarrowbiophysicalenvelope.
Distribution
ThiswidespreadecosystemoccursaboveuppertimberlinethroughouttheRockyMountain
cordillera.Alpinevegetationisfoundatthehighestelevations,usuallyabove11,000feetin
Climate Change Vulnerability Assessment for Colorado BLM 109 Colorado,wherethelongwinters,abundantsnowfall,highwinds,andshortsummerscreatea
harshenvironment.Althoughalpinedryturfformsthematrixofthealpinezone,itintermingles
withbedrockandscree,icefield,fellfield,alpinedwarf‐shrubland,andalpine/subalpinewet
meadowsystems.Areasdominatedbyherbaceouscovermaybedrytundra,cushion‐plant
dominatedfellfield,orwetmeadows.Shrub‐dominatedareasarecharacterizedby ericaceous
dwarf‐shrubsordwarfwillows.
Characteristic species
Alpinedryturfisformedbyadensecoveroflow‐growing,perennialgraminoidsandforbs.
Rhizomatous,sod‐formingsedgesarethedominantgraminoids,andprostrateandmat‐forming
plantswiththickrootstocksortaprootscharacterizetheforbs.Dominantspeciesincludeboreal
sagebrush(Artemisiaarctica),blackrootsedge(Carexelynoides),spikesedge(Carexnardina),
northernsinglespikesedge(Carexscirpoidea),dryspikesedge(Carexsiccata),curlysedge(Carex
rupestris),tuftedhairgrass(Deschampsiacaespitosa),alpinefescue(Festucabrachyphylla),Idaho
fescue(Festucaidahoensis),Ross'avens(Geumrossii),Bellardibogsedge(Kobresiamyosuroides),
cushionphlox(Phloxpulvinata),andalpineclover(Trifoliumdasyphyllum).Dwarf‐shrublandsof
thealpinearecharacterizedbyanintermittentlayerofsnowwilloworericaceousdwarf‐shrubs
lessthan0.5minheight,withamixtureofforbsandgraminoids,especiallysedges.Snowwillow
(Salixnivalis)isatypicaldominantshrub.Blueberry(Vacciniumspp.)andalpinelaurel(Kalmia
microphylla)mayalsobeshrubassociates.
Mostfellfieldplantsarecushionedormatted,frequentlysucculent,low‐growingrosettesandoften
denselyhairedandthicklycutinized.Plantcovermaybesparsetomoderatebetweenexposed
rocks.CommonfellfieldspeciesincludeRoss'avens,Bellardibogsedge,twinflowersandwort
(Minuartiaobtusiloba),Asianforget‐me‐not(Myosotisasiatica),RockyMountainnailwort
(Paronychiapulvinata),cushionphlox(Phloxpulvinata),creepingsibbaldia(Sibbaldiaprocumbens),
mosscampion(Sileneacaulis),alpinecloverandParry’sclover(Trifoliumparryi).Barrenand
sparselyvegetatedalpinesubstratesincludebothbedrockoutcropandscreeslopes,with
nonvascular(lichen)dominatedcommunities.Therecanbesparsecoverofforbs,grasses,lichens
andlowshrubs.ClumpsofColoradobluecolumbine(Aquilegiacaerulea)andmountainthistle
(Cirsiumscopulorum)arecommoninscreeslopes.
Environment
Thedistributionofvegetationtypesinthealpineiscontrolledinpartbylocaltopographythat
influencessnowdepositionandretention,aswellassoildevelopment.Alpineturfisgenerally
foundonmoregentletomoderateslopes,flatridges,valleys,andbasins,wherethesoilhasbecome
relativelystabilizedandthewatersupplyismoreorlessconstant.Alpinedwarf‐shrublandtypically
isfoundinareasoflevelorconcaveglacialtopography,withlate‐lyingsnowandsub‐irrigation
fromsurroundingslopes.Thesemoistbutwell‐drainedareashavedevelopedrelativelystablesoils
thatarestronglyacidic,oftenwithsubstantialpeatlayers.Fellfieldsarerockyandwind‐scoured
areasthatarefreeofsnowinthewinter,suchasridgetopsandexposedsaddles,wherevegetation
isexposedtosevereenvironmentalstress.Soilsonthesewindysitesareshallow,stony,lowin
organicmatter,andpoorlydeveloped;winddeflationoftenresultsinagravellypavement.
110 Colorado Natural Heritage Program © 2015 Thereissomeevidencethatalpinevegetationisresponsivetofine‐scaleenvironmental
heterogeneity,whichmayenhanceitsresiliencetochangingclimateconditionsinsome
topographicallycomplexareas(Spasojevicetal.2013).
Dynamics
Alpineenvironmentsaregenerallynotsusceptibletooutbreaksofpestspeciesordisease,butmay
havesomeslightvulnerabilitytoinvasiveplantspeciessuchasyellowtoadflax(Linariavulgaris),
knapweed(Centaureaspp.),anddandelion(Taraxacumofficinale).Thesetreelessenvironmentsare
notvulnerabletofire,butcouldbecomesoiftreesareabletoestablish.
Patternsofvegetationgrowth,flowering,andsenescenceinalpinehabitatsareprobablydependent
onbothdaylengthandtemperature(BillingsandMooney1968).Thecharacteristicforband
graminoiddominatedtundraisaresultoflowtemperaturesduringthegrowingseasonthatlimit
vegetationgrowthanddecomposition.Withlongerdaylengthandincreasingsolarradiationin
spring,warmerairandsoiltemperatures,togetherwithmoisturefromsnowmeltenabletheonset
ofplantgrowth.Althoughtemperatureappearstobethedominantcontrolondevelopmental
phenology(BillingsandMooney1968),anumberofalpinespeciesareknowntobesensitiveto
day‐length(KellerandKörner2003).Theprevalenceandimportanceofphotoperiodsensitivityin
Colorado’salpinefloraislittleknown.Ifsomealpinespeciesareunabletoquicklyadaptto
changingtemperaturesbecauseofphotoperiodconstraints,thiscouldchangespeciesinteractions
andrelativeabundancesinalpinehabitats,withconsequencesthatarenotwellunderstood(Hülber
etal.2010,Ernakovichetal.2014).
CCVA Scoring
Exposure‐Sensitivity (Potential Impact) Rank
Percent Colorado acres with projected temp > max & ppt delta < 5% 0% Initial Exposure‐Sensitivity Rank Low Percent Colorado acres with temp <= max & ppt delta < 5% more than 50%? No (38.9%) Low Final Exposure‐Sensitivity Rank Exposure to temperature change Underprojectedmid‐centurytemperatures,lessthan1%ofthecurrentrangeofalpinehabitatin
Coloradowouldexperienceannualmeantemperaturesabovethecurrentstatewidemaximum.
Exposure to precipitation change About39%ofalpinehabitatinColoradowillbeexposedtoeffectivelydrierconditionsevenunder
unchangedorslightlyincreasedprecipitationprojectedformid‐century.
Sensitivity of ecosystem to temperature and precipitation Snowpackisacrucialcomponentofalpineecosystems,anddependsonbothprecipitationamounts
andwinter‐springtemperature(Williamsetal.2002).Vegetationinalpineareasiscontrolledby
Climate Change Vulnerability Assessment for Colorado BLM 111 patternsofsnowretention,winddesiccation,permafrost,andashortgrowingseason(Greenland
andLosleben2001).
Thelengthofthegrowingseasonisparticularlyimportantforthealpinezone,andforthetransition
zonebetweenalpineandforest(treeline).Alpineareashavethefewestgrowingdegreedaysand
lowestpotentialevapotranspirationofanyhabitatinColorado.Treeline‐controllingfactorsoperate
atdifferentscales,rangingfromthemicrositetothecontinental(HoltmeierandBroll2005).Ona
globalorcontinentalscale,thereisgeneralagreementthatcoolsummertemperatureisaprimary
determinantoftreeline.Atthisscale,thedistributionofalpineecosystemsisdeterminedbythe
numberofdaysthatarewarmenoughforalpineplantgrowth,butnotsufficientfortreegrowth.
Otheralpineconditionsthatmaintaintreelessvegetationathighelevationsincludelackofsoil
development,persistentsnowpack,steepslopes,wind,anddenseturfthatrestrictstreeseedling
establishmentandsurvivalwithinthetreelineecotone(Moiretal.2003,Smithetal.2003,
HoltmeierandBroll2005).However,increasedextentoftallshrubwillows(e.g.,Salixplanifoliaand
S.glauca)throughclonalgrowthhasalreadyoccurredinsomeareas(Formicaetal.2014).
Onthebasisofhistoricevidence,treelineisgenerallyexpectedtomigratetohigherelevationsas
temperatureswarm,aspermittedbylocalmicrositeconditions(Smithetal.2003,Richardsonand
Friedland2009,Grafiusetal.2012).Itisunlikelythatalpinespecieswouldbeabletomovetoother
alpineareas.Intheshort‐termwithwarmertemperatures,alpineareasmaybeabletopersist,
especiallyinareaswhereitisdifficultfortreestoadvanceupslope.Theslowgrowthofwoody
speciesandrarityofrecruitmenteventsmaydelaytheconversionofalpineareastoforestortall
shrubfor50‐100+afterclimaticconditionshavebecomesuitablefortreegrowth(Körner2012).
Thus,alpineecosystemsmaypersistforawhilebeyondmid‐century,butarelikelytoeventually
largelydisappearfromColorado.
Resilience and Adaptive Capacity Rank:
Overall Score: 0.69 Rank: Moderate
Bioclimatic envelope and range Averagedcategoryscore:0.25
ElevationsofalpinehabitatsinColoradorangefromabout11,000toover14,000ft.,withameanof
about12,000ft.Alpinehabitatsarerestrictedtohighelevations,andarealsonearthesouthern
extentoftheircontinentalrangeinColorado.Althoughalpineareascover74%ofthestatewide
precipitationrange,alpinegrowingseasonsaretheshortestofanyhabitatinColorado,
encompassingonly26%ofthestatewiderangeofgrowingdegreedays.Thesefactorscombineto
givealpineareasalowresiliencescoreinthiscategory.
Growth form and intrinsic dispersal rate Score:0.50
112 Colorado Natural Heritage Program © 2015 Althoughalpineareasaredominatedbyrelativelyquick‐growingforbandgraminoidspecies,the
shortgrowingseasonsarelimiting.Furthermore,thedifficultyofdispersalacrossintervening
lowerelevationhabitatgivesthisecosystemanintermediateresiliencescoreinthiscategory.
Vulnerability to increased attack by biological stressors Score:0.8
Alpineenvironmentsaregenerallynotsusceptibletooutbreaksofpestspeciesordisease,butmay
havesomeslightvulnerabilitytoinvasiveplantspeciessuchasyellowtoadflaxunderfuture
climaticconditions.Thesetreelessenvironmentsarenotvulnerabletofire,butcouldbecomesoif
treesareabletoestablish.Xericalpineenvironmentsarealreadysubjecttoextremeconditions,but
themoremesicareasarevulnerabletodroughtandchangesinsnowmelttiming.Evenunder
increasedsnowpack,warmertemperaturesarelikelytoalterpatternsofsnowmelt,andmay
reduceavailablemoisture.Thesechangesarelikelytoresultinshiftsinspeciescomposition,
perhapswithanincreaseinshrubsonxerictundra.Withwarmingtemperaturesandearlier
snowmelt,however,elkmaybeabletomoveintoalpineareasearlierandstaylonger,thereby
increasingstressonalpinewillowcommunities(Zeigenfussetal.2011).
Vulnerability to increased frequency or intensity of extreme events Score:0.9
Alpinehabitatsarealsoindirectlyaffectedbybothdroughtandland‐usepracticesinupwindareas
thatleadtodustemissions.Whenwind‐blowndustisdepositedonmountainsnowpack,the
resultingdarkeningofthesnowallowsincreasedabsorptionofsolarradiantenergy,andearlier
meltingthanunderdustfreeconditions.Unlikewarmingtemperatures,whichadvanceboth
snowmelttimingandgrowingseasononsetforalpinevegetation,theeffectofdustdepositionon
mountainsnowpackisasourceofearliersnowmeltthatisnotdirectlylinkedtoseasonalshifting
(Steltzeretal.2009).Althoughdustdepositionmaybeasignificantcontributortosoildevelopment
insomeareas(Lawrenceetal.2011),itcanincreaseevapotranspirationanddecreaseannual
runoffflows(Deemsetal.2013).Changesinsoilmoisturelevelsduetoearliersnowmeltmay
interactwithotherclimatechangeeffectstoproducechangesinspeciescompositionandstructure
ofalpinehabitats.
Other indirect effects of non‐climate stressors – landscape condition Score:0.98
AlpinelandscapesinColoradoaregenerallyinexcellentcondition,andwellprotected.Ongoing
threatsfromdevelopmentinalpinehabitatsassociatedwithrecreationareasandactivities,
includingassociatedroadsandinfrastructure;thesearegenerallyarelimitedinextent.Old
privately‐ownedminingclaimsarescatteredthroughout,butthereareveryfewactivemines
operatingtodayInsouthwesternColorado,sheepgrazingandisolatedminingactivityareminor
sourcesofdisturbanceinalpineareas.Anthropogenicnitrogendepositionisanongoinginfluence
onalpinephenology(Smithetal.2012)andspeciesdiversity(Farreretal.2015)whichmay
Climate Change Vulnerability Assessment for Colorado BLM 113 interactwithwarmingtemperatures,althoughthelong‐termeffectsofthisdisturbancearenotwell
known.
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Deems,J.S.,T.H.Painter,J.J.Barsugli,J.Belnap,andB.Udall.2013.Combinedimpactsofcurrentandfuturedustdeposition
andregionalwarmingonColoradoRiverBasinsnowdynamicsandhydrology.Hydrol.EarthSyst.Sci.17:4401‐4413.
Ernakovich,J.G.,K.A.Hopping,A.B.Berdanier,R.T.Simpson,E.J.Kachergis,H.Steltzer,andM.D.Wallenstein.2014.
Predictedresponsesofarcticandalpineecosystemstoalteredseasonalityunderclimatechange.GlobalChangeBiology
20:3256‐3269.
Farrer,E.C.,I.W.Ashton,M.J.Spasojevic,S.Fu,D.J.X.Gonzalez,andK.N.Suding.2015.Indirecteffectsofglobalchange
accumulatetoalterplantdiversitybutnotecosystemfunctioninalpinetundra.JournalofEcology103:351‐360.
Formica,A.,E.C.Farrer,I.W.Ashton,andK.N.Suding.2014.Shrubexpansionoverthepast62yearsinRockyMountain
alpinetundra:possiblecausesandconsequences.Arctic,Antarctic,andAlpineResearch46:616‐631.
Grafius,D.R.,G.P.Malanson,andD.Weiss.2012.SecondarycontrolsofalpinetreelineelevationsinthewesternUSA.
PhysicalGeography33:146‐164.
Greenland,D.andM.Losleben.2001.Climate.Chapter2inBowman,W.D.,andT.R.Seastedt,eds.StructureandFunction
ofanAlpineEcosystem:NiwotRidge,Colorado.NewYork:OxfordUniversityPress.
Holtmeier,F‐K.andG.Broll.2005.Sensitivityandresponseofnorthernhemispherealtitudinalandpolartreelinesto
environmentalchangeatlandscapeandlocallevels.GlobalEcologyandBiogeography14:395‐410.
Hülber,K.,M.Winkler,andG.Grabherr.2010.Intraseasonalclimateandhabitat‐specificvariabilitycontrolstheflowering
phenologyofhighalpineplantspecies.FunctionalEcology24:245‐252.
Keller,F.andC.Körner.2003.Theroleofphotoperiodisminalpineplantdevelopment.Arctic,Antarctic,andAlpine
Research35:361‐368.
Körner,C.2012.Alpinetreelines:functionalecologyoftheglobalhighelevationtreelimits.Springer,Basel,Switzerland.
Lawrence,C.R.,J.C.Neff,andG.L.Farmer.2013.TheaccretionofaeoliandustinsoilsoftheSanJuanMountains,Colorado,
USA.JournalofGeophysicalResearch116,F02013,doi:10.1029/2010JF001899.
Moir,W.H.,S.G.Rochelle,andA.W.Schoettle.1999.Microscalepatternsoftreeestablishmentnearuppertreeline,Snowy
Range,Wyoming.Arctic,Antarctic,andAlpineResearch31:379‐388.
Richardson,A.D.andA.J.Friedland.2009.Areviewofthetheoriestoexplainarcticandalpinetreelinesaroundtheworld.
JournalofSustainableForestry28:218‐242.
Smith,J.G.,W.Sconiers,M.J.Spasojevic,I.W.Ashton,andK.N.Suding.2012.Phenologicalchangesinalpineplantsin
responsetoincreasedsnowpack,temperature,andnitrogen.Arctic,Antarctic,andAlpineResearch44:135‐142.
Smith,W.K.,M.J.Germino,T.E.Hancock,andD.M.Johnson.2003.Anotherperspectiveonaltitudinallimitsofalpine
timberlines.TreePhysiology23:1101‐1112.
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years:Arepatternsacrossaheterogeneouslandscapeconsistentwithpredictions?Ecosphere4:117.
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114 Colorado Natural Heritage Program © 2015 Steltzer,H.,C.Landry,T.H.Painter,J.Anderson,andE.Ayres.2009.Biologicalconsequencesofearliersnowmeltfrom
desertdustdepositioninalpinelandscapes.PNAS106:11629‐11634.
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Climate Change Vulnerability Assessment for Colorado BLM 115 MONTANE GRASSLANDS
Bunch‐grassdominatedgrasslandsatelevationsbetweenfoothillsandsubalpine
Extent exaggerated for display D. Culver Climate Vulnerability Rank: Moderate
Vulnerability summary
Key Vulnerabilities: Warmer and drier conditions are likely to facilitate the spread of invasive species, and may allow woody species to establish in grasslands. An increase in forest fire activity under future conditions may allow grassland to expand into adjacent burned areas. Montanegrasslandsarerankedasmoderatelyvulnerabletothe
effectsofclimatechangebymid‐century.Primaryfactors
contributingtothisrankingarevulnerabilityoftheseareato
invasivespecies,andthegenerallyhighlydisturbedconditionof
occurrences,bothofwhicharelikelytointeractwiththe
significantincreasesintemperatureacrossmuchofthe
distributionofthehabitatinColoradotoreduceresilienceof
thesehabitats.
Distribution
Montane‐subalpinegrasslandsintheColoradoRockiesaretypicallygrasslandsofforestopenings
andpark‐likeexpansesinthemontaneandsubalpineconiferousforestsatelevationsof7,200‐
10,000feet(2,200‐3,000m),intermixedwithstandsofspruce‐fir,lodgepole,ponderosa,andaspen.
AlthoughsmallermontanegrasslandsarescatteredthroughouttheSouthernRockyMountains
ecoregion,thelargestoccurrencebyfar(overamillionacres)isonthevalleyfloorofthelarge
intermountainbasinSouthParkincentralColorado.Thelargestoccurrencesareprimarilywithin
Colorado,butexamplesarescatteredthroughouttheregionfromWyomingtoNewMexico.
116 Colorado Natural Heritage Program © 2015 Characteristic species
Theselargepatchgrasslandsareintermixedwithvarioustypesofforeststands,dependingon
elevation.Withinthesubalpinezone,forbstendtobemoreprominentathigherelevations,and
shrubsatlowerelevations(TurnerandPaulsen1976).Associationsarevariabledependingonsite
factorssuchasslope,aspect,andprecipitation,butgenerallylowerelevationmontanegrasslands
aremorexericanddominatedbymuhly(Muhlenbergiaspp.),bluebunchwheatgrass
(Pseudoroegneriaspicata),Arizonafescue(Festucaarizonica),andIdahofescue(Festuca
idahoensis),whileuppermontaneorsubalpinegrasslandsaremoremesicandmaybedominated
byThurberfescue(Festucathurberi)ortimberoatgrass(Danthoniaintermedia).Parry’soatgrass
(Danthoniaparryi)isfoundacrossmostoftheelevationalrangeofthissystem.Montanegrasslands
intheColoradoFrontRangeareoftendominatedbyspikefescue(Leucopoakingii)ormountain
muhly(Muhlenbergiamontana)(Peet1981).IntheSanJuanMountainsofsouthwesternColorado,
thesegrasslandsaredominatedbyThurberfescueandotherlargebunchgrasses(Jamiesonetal.
1996).Grassesofthefoothillsandpiedmont,suchasbluegrama(Boutelouagracilis),sideoats
grama(Boutelouacurtipendula),needle‐and‐thread(Hesperostipacomata),prairieJunegrass
(Koeleriamacrantha),westernwheatgrass(Pascopyrumsmithii),Sandbergbluegrass(Poasecunda),
andlittlebluestem(Schizachyriumscoparium)maybeincludedinlowerelevationoccurrences.
Higher,moremesiclocationsmaysupportadditionalgraminoidspeciesincludingbentgrass
(Agrostisspp.),sedge(Carexspp.),alpinefescue(Festucabrachyphylla),Drummond'srush(Juncus
drummondii),alpinetimothy(Phleumalpinum),bluegrass(Poaspp.),orspiketrisetum(Trisetum
spicatum).Woodyspeciesaregenerallysparseorabsent,butoccasionalindividualsfromthe
surroundingforestcommunitiesmayoccur.Scattereddwarf‐shrubsmaybefoundinsome
occurrences;speciesvarywithelevationandlocation.Forbsaremorecommonathigherelevations.
Environment
Thisecosystemtypicallyoccursongentletosteepslopes,parks,oronlowersideslopesthataredry,
andmayextendupto11,000ft(3,350m)onwarmaspects.Thegeneralclimateintherangeofthis
ecosystemistypicallymontanetosubalpine,characterizedbycoldwintersandrelativelycool
summers,althoughtemperaturesaremoremoderateatlowerelevations.Precipitationpatterns
differbetweentheeastandwestsidesoftheContinentalDivide.Ingeneral,thesegrasslands
experiencelongwinters,deepsnow,andshortgrowingseasons.Averageannualprecipitation
rangesbetween20to40inches(51‐102cm),andthemajorityofthisfallsassnow(Turnerand
Paulsen1976).SnowcoverinsomeareascanlastfromOctobertoMay,andservestoinsulatethe
plantsbeneathfromperiodicsubzerotemperatures.Otherareasarekeptfreefromsnowbywind.
Rapidspringsnowmeltusuallysaturatesthesoil,andwhentemperaturesriseplantgrowthis
rapid.Precipitationduringthegrowingseasonishighlyvariable,butprovideslessmoisturethan
snowmelt.Growingseasonsareshort,typicallyfromJunethroughAugustatintermediatelocations,
althoughfrostcanoccuratalmostanytime.
ThegeologyoftheSouthernRockyMountainsisextremelycomplex.Notsurprisingly,soilsarealso
highlyvariable,dependingontheparentmaterialsfromwhichtheywerederivedandthe
conditionsunderwhichtheydeveloped.Podzolicsoilshavedevelopedonmosthighmountain
areasasaresultofcooltocoldtemperatures,relativelyabundantmoisture,andthedominant
Climate Change Vulnerability Assessment for Colorado BLM 117 coniferousforestvegetation.Intheintermingledparksandopentreelessslopesorridges,grassland
soilshavedeveloped.Soiltextureisimportantinexplainingtheexistenceofmontane‐subalpine
grasslands(Peet2000).Thesegrasslandsoftenoccupythefine‐texturedalluvialofcolluvialsoilsof
valleybottoms,incontrasttothecoarse,rockymaterialofadjacentforestedslopes(Peet2000).
Soilsareoftensimilartoprairiesoils,withadarkbrownA‐horizonthatisrichinorganicmatter,
welldrained,andslightlyacidic(TurnerandPaulsen1976).Otherfactorsthatmayexplainthe
absenceoftreesinthissystemaresoilmoisture(toomuchortoolittle),competitionfrom
establishedherbaceousspecies,coldairdrainageandfrostpockets,highsnowaccumulation,
beaveractivity,slowrecoveryfromfire,andsnowslides(Daubenmire1943,Knight1994,Peet
2000).Wheregrasslandsoccurintermixedwithforestedareas,thelesspronouncedenvironmental
differencesmeanthattreesaremorelikelytoinvade(TurnerandPaulsen1976).
Dynamics
Avarietyoffactors,includingfire,wind,cold‐airdrainage,climaticvariation,soilproperties,
competition,andgrazinghavebeenproposedasmechanismsthatmaintainopengrasslandsand
parksinforestsurroundings.Observationsandrepeatphotographystudiesinsitesthroughoutthe
southernRockyMountainsindicatethattreesdoinvadeopenareas,butthatthemechanisms
responsibleforthistrendmaydifferfromsitetosite.AndersonandBaker(2005)discountedfire
suppressionasthecauseoftreeinvasionsinWyoming’sMedicineBowMountains,concludingthat
edaphicconditionswerethemostlikelyfactorlimitingtreeestablishment.IntheSanJuan
MountainsofsoutheasternColorado,ZierandBaker(2006)alsofoundthattheprobabilityoftree
invasionvariedwithforesttype.Climaticvariation,fireexclusion,andgrazingappeartointeract
withedaphicfactorstofacilitateorhindertreeinvasioninthesegrasslands(ZierandBaker2006).
IntheGunnisonBasin,Schaueretal.(1998)identifiedseedlingmortalityastheprimaryfactor
preventinginvasionsofEngelmannspruce,butdidnotdetermineifthiswasduetocompetition
fromestablishedgrasslandplants,ortoedaphicconditions.TheworkofCoopandGivnish(2007)
intheJemezMountainsofnorthernNewMexicosuggeststhatbothchangingdisturbanceregimes
andclimaticfactorsarelinkedtotreeestablishmentinsomemontanegrasslands.Pocketgophers
(Thomomysspp.)areawidespreadsourceofdisturbanceinmontane‐subalpinegrasslands.The
activitiesoftheseburrowingmammalsresultinincreasedaeration,mixingofsoil,andinfiltration
ofwater,andareanimportantcomponentofnormalsoilformationanderosion(Ellison1946).In
addition,CantorandWhitham(1989)foundthatbelow‐groundherbivoryofpocketgophers
restrictedestablishmentofaspentorockyareasinArizonamountainmeadows.Theinteractionof
multiplefactorsindicatesthatmanagementforthemaintenanceofthesemontaneandsubalpine
grasslandsmaybecomplex.
Grazingbydomesticlivestockmayacttooverrideormaskwhatevernaturalmechanismis
responsibleformaintaininganoccurrence.Montane‐subalpinegrasslandswerefirstgrazedby
domesticlivestockbeginninginthelate1800’s(TurnerandPaulsen1976).Afterlower‐elevation,
moreaccessiblerangelandswereoverstockedinthe1870’sand1880’s,useofmontaneand
subalpinegrasslandsincreaseddramatically.Bytheturnofthecenturynearlyallgrazablelandwas
beingutilized,andmuchwasalreadyovergrazed(TurnerandPaulsen1976).AsNationalForests
wereestablishedfollowingtheOrganicAdministrationActof1897,regulationofgrazingonthese
highelevationgrasslandswasinstituted.UselevelspeakedneartheendofthefirstWorldWar,and
118 Colorado Natural Heritage Program © 2015 currentuselevelsaresubstantiallylowerthanthehighestpreviouslevel(TurnerandPaulsen
1976).
Floristiccompositioninthesegrasslandsisinfluencedbybothenvironmentalfactorsandgrazing
history.Grazingisgenerallybelievedtoleadtothereplacementofpalatablespecieswithless
palatableonesmoreabletowithstandgrazingpressure(Smith1967,Paulsen1975,Brown1994,
butseeStohlgrenetal.1999).Ingeneral,palatablegrassesarereplacedbynonpalatableforbsor
shrubsundercattlegrazing(Smith1967),whilepalatableforbsarecharacteristicallyabsentfrom
grasslandswithalonghistoryofsheepuse(TurnerandPaulsen1976).Annualspeciesare
uncommonexceptonheavilydisturbedareas.Someoccurrencesaredominatedbyseededpasture
grasses,especiallysmoothbrome(Bromusinermis),timothy(Phleumpratense),andKentucky
bluegrass(Poapratensis).
Historically,soildisturbancewaslargelytheresultofoccasionalconcentrationsoflargenative
herbivores,orthediggingactionoffossorialmammals.Domesticlivestockranchinghaschanged
thetimingandintensityofgrazingdisturbancefromthatofnativeherbivores,withthepotentialto
alterspeciescomposition,soilcompaction,nutrientlevels,andvegetationstructure.Incombination
withgrazingofdomesticlivestock,various“rangeimprovement”activities(e.g.seeding,rodent
control,herbicideapplication)havethepotentialtoalternaturalecosystemprocessesandspecies
composition.Increasingsmall‐acreageexurbandevelopmentwithlivestock(“ranchettes”)appears
tobeincreasingtheincidenceofweedyexoticspeciesinthesehabitats.ExoticsincludeDalmatian
toadflax(Linariadalmatica),knapweed(Centaureaspp.),cheatgrass(Bromustectorum),
sweetclover(Melilotusofficinalis),andothers.
CCVA Scoring
Exposure‐Sensitivity (Potential Impact) Rank
Percent Colorado acres with projected temp > max & ppt delta < 5% 1.0% Initial Exposure‐Sensitivity Rank Low Percent Colorado acres with temp <= max & ppt delta < 5% more than 50%? Yes (79.6%) Final Exposure‐Sensitivity Rank Moderate Exposure to temperature change Underprojectedmid‐centurytemperatures,about1%ofthecurrentrangeofmontanegrasslandin
Coloradowouldexperienceannualmeantemperaturesabovethecurrentstatewidemaximum.
Exposure to precipitation change About81%ofmontanegrasslandinColoradowillbeexposedtoeffectivelydrierconditionseven
underunchangedorslightlyincreasedprecipitationprojectedformid‐century.
Sensitivity of ecosystem to temperature and precipitation Higherelevationgrasslandsarecharacterizedbycoldwintersandrelativelycoolsummers,
althoughtemperaturesaremoremoderateatlowerelevations.
Climate Change Vulnerability Assessment for Colorado BLM 119 Soiltexturehasasignificanteffectonthedistributionandpersistenceofmontane‐subalpine
grasslands(Peet2000),determiningsoilmoistureconditionsthatacttoexcludetrees.Droughtand
warmertemperaturesmaychangespeciescomposition,orallowinvasionbydrought‐tolerant
shrubsorinvasivespeciesinsomeareas.
Resilience and Adaptive Capacity Rank
Overall Score: 0.74 Rank: High
Bioclimatic envelope and range Averagedcategoryscore:0.82
Thesegrasslandsarenotrestrictedtohighelevations,andarewellwithinthecoreareaoftheir
continentaldistributioninColorado.Thevariationpresentinthevariousgrasslandoccurrences
givesthisecosystemawideecologicalamplitude,covering79%ofColorado’soverallprecipitation
range,and48%ofthegrowingdegreerange.Thesefactorscombinetogivemontanegrasslandsa
highresiliencescoreinthiscategory.
Growth form and intrinsic dispersal rate Score:1
Thisecosystemisdominatedbyrelativelyfastgrowinggraminoidandherbaceousspecies,andis
abletodispersetoavailablehabitatquicklyincomparisonwithecosystemsdominatedbywoody
species.
Vulnerability to increased attack by biological stressors Score:0.5
TheworkofCoopandGivnish(2007)intheJemezMountainsofnorthernNewMexicosuggests
thatbothchangingdisturbanceregimesandclimaticfactorsarelinkedtotreeestablishmentin
somemontanegrasslands.Increasedtreeinvasionintomontanegrasslandswasapparentlylinked
tohighersummernighttimetemperatures,andlessfrostdamagetotreeseedlings;thistrendcould
continueunderprojectedfuturetemperatureincreases.Increaseddisturbancemayalsofacilitate
thecontinuedspreadofintroducedexoticspeciesasclimateconditionschange.Theinteractionof
multiplefactorsindicatesthatmanagementforthemaintenanceofthesemontaneandsubalpine
grasslandsmaybecomplex.
Vulnerability to increased frequency or intensity of extreme events Score:1
Althoughincreasedincidenceorseverityofdroughtmayacttohelppreventtreeinvasioninto
montanegrasslands,thereissomeevidencethatwarmer,driersoilconditionscouldfacilitateshrub
growthinmontanemeadowsorotherwisealterspeciescomposition(Perforsetal.2003).
120 Colorado Natural Heritage Program © 2015 Other indirect effects of non‐climate stressors – landscape condition Score:0.37
MontanegrasslandlandscapesinColoradoarehighlyalteredbyanthropogenicdisturbance.Higher
elevationgrasslandsonrelativelyflatsitesareofteninprivateownership,andareoftenvulnerable
tosubdivisionforresidentialdevelopmentand/ortransportationcorridordevelopment.The
extensivegrasslandsofSouthPark,inparticular,arethreatenedbythesubdivisionoflarge
properties,anddevelopmentoftransportationcorridors.Recreationaluse(publicopenspaceuse
inlowerelevations;hunters,packersandsnow‐mobilersinhigherelevations)isanongoingsource
ofdisturbanceinthishabitat.
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BowMountains,Wyoming,USA.LandscapeEcology21:243–258.
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Brown,D.E.1994.Grasslands.Part4inBioticcommunities:southwesternUnitedStatesandnorthwesternMexico.D.E.
Brown,ed.UniversityofUtahPress,SaltLakeCity,UT.
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theVallesCaldera,NewMexico,USA.JournalofBiogeography34:914‐927.
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Daubenmire,R.F.1943.VegetationalzonationintheRockyMountains.BotanicalReview9:325‐393.
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SanJuanMountains:TheirGeology,Ecology,andHumanHistory,R.Blair,ed.UniversityPressofColorado,Niwot,CO.
Knight,D.H.1994.MountainsandPlains:theEcologyofWyomingLandscapes.YaleUniversityPress,NewHavenand
London.338pages.
Paulsen,H.A.,Jr.1969.Foragevaluesonamountaingrassland‐aspenrangeinwesternColorado.JournalofRange
Management22:102–107.
Paulsen,H.A.,Jr.1975.RangemanagementinthecentralandsouthernRockyMountains:asummaryofthestatusofour
knowledgebyrangeecosystems.USDAForestServiceResearchPaperRM‐154.RockyMountainForestandRange
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Peet,R.K.1981.ForestvegetationoftheColoradoFrontRange:compositionanddynamics.Vegetatio45:3‐75.
Climate Change Vulnerability Assessment for Colorado BLM 121 Peet,R.K.2000.ForestsandmeadowsoftheRockyMountains.Chapter3inNorthAmericanTerrestrialVegetation,
secondedition.M.G.BarbourandW.D.Billings,eds.CambridgeUniversityPress.
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Colorado.
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122 Colorado Natural Heritage Program © 2015 SEMI‐DESERT GRASSLAND
Drygrasslandscharacterizedbydrought‐tolerantbunchgrassspeciesandscatteredshrubs
P. Lyon extent exaggerated for display Climate Vulnerability Rank: Low
Vulnerability summary
Key Vulnerabilities: Climate related vulnerability for these grasslands is minimal, but the impacted condition of many stands may inhibit their potential for expansion. Lowexposureandsensitivitytoprojectedconditionsoutsidethe
currentrangeexperiencedbythesegrasslandsistheprimary
factorcontributingtothelowvulnerabilityrankingofthis
ecosystem.Thegenerallyfairtopoorconditionofmany
occurrencesinColoradomaytendtoinhibitthepotentialofthis
ecosystemtoexploitandmoveintonewareasunderfuture
climateconditions.
Distribution
ThesearethedriestgrasslandsoftheintermountainwesternU.S.,occurringinlargepatchesin
mosaicswithshrublandsystemsdominatedbysagebrush,saltbush,blackbrush,mormon‐tea,and
othershrubspecies.Climatesaresemi‐aridtoarid.Colorado’ssemi‐desertgrasslandsarefound
primarilyondryplainsandmesasofthewestslopeatelevationsof4,750‐7,600feet
Characteristic species
Thesegrasslandsaretypicallydominatedbydrought‐resistantperennialbunchgrassessuchas
Indianricegrass(Achnatherumhymenoides),bluegrama(Boutelouagracilis),needle‐and‐thread
Climate Change Vulnerability Assessment for Colorado BLM 123 (Hesperostipacomata),ringmuhly(Muhlenbergiatorreyi),orJames'galleta(Pleuraphisjamesii),or
bluebunchwheatgrass(Pseudoroegneriaspicata).Scatteredshrubsandsub‐shrubsmaybepresent,
includingsagebrush(Artemisiaspp.),saltbush(Atriplexspp.),jointfir(Ephedraspp.),snakeweed
(Gutierreziasarothrae),orwinterfat(Krascheninnikovialanata).Blackbrush(Coleogyne
ramosissima)isuncommoninColoradooccurrences,buttypicalfurtherwest.
Environment
WestSlopelow‐elevationgrasslandsoccurinsemi‐aridtoaridclimateswithcoldtemperate
conditions.Hotsummersandcoldwinterswithfreezingtemperaturesandsnowarecommon.
GrasslandsofthewesternvalleysreceiveasignificantportionofannualprecipitationinJuly
throughOctoberduringthesummermonsoonstorms,withtherestfallingassnowduringthe
winterandearlyspringmonths.Annualprecipitationisusuallyfrom8‐16in(20‐40cm).
Thesegrasslandsoccurinxericlowlandanduplandareasandmayoccupyswales,playas,mesa
tops,plateauparks,alluvialflats,andplains.Substratesaretypicallywell‐drainedsandstone‐or
shale‐derivedsoils.Somesandysoiloccurrenceshaveahighcoverofcryptogamsonthesoil.Soil
salinitydependsontheamountandtimingofprecipitationandflooding.
Dynamics
Thissystemismaintainedbyfrequentfiresthateliminatewoodyplants.Acombinationof
precipitation,temperature,andsoilslimitsthissystemtothelowerelevationswithintheregion.
Thedominantperennialbunchgrassesandshrubswithinthissystemareallverydrought‐resistant
plants.Grassesthatdominatesemi‐aridgrasslandsdevelopadensenetworkofrootsconcentrated
intheupperpartsofthesoilwhererainfallpenetratesmostfrequently.
Thesemi‐desertgrasslandsystemisvulnerabletoinvasionbyexoticspecies,particularly
cheatgrass(Bromustectorum).Althoughfrequentfiresingrasslandsmayhavebeencommon
historically,theintroductionofcheatgrasshasalteredthedynamicsofthesystem,increasingboth
firefrequencyandpost‐firecheatgrassdominance(ShinnemanandBaker2009,Balchetal.2013).
Cheatgrassiseasilyignited,andalsoprovidesanabundanceoffinefuelsthatcarryfire(Knapp
1998).
Floristiccompositioningrasslandsisinfluencedbybothenvironmentalfactorsandgrazinghistory.
Manygrasslandoccurrencesarealreadyhighlyalteredfrompre‐settlementcondition.Grazingis
generallybelievedtoleadtothereplacementofpalatablespecieswithlesspalatableonesmore
abletowithstandgrazingpressure(Smith1967,Paulsen1975,Brown1994,butseeStohlgrenetal.
1999).Grazingbydomesticlivestockmayacttooverrideormaskwhatevernaturalclimaticor
edaphicmechanismisresponsibleformaintaininganoccurrence.Thishabitatisalsoadaptedto
grazingandbrowsingbynativeherbivoresincludingdeer,elk,bison,andpronghorn,aswellas
burrowingandgrazingbysmallmammalssuchasgophers,prairiedogs,rabbits,andground
squirrels.Activitiesoftheseanimalscaninfluencebothvegetationstructureandsoildisturbance,
potentiallysuppressingtreeestablishment.Periodicdroughtiscommonintherangeoffoothilland
semi‐desertgrasslands,butmaynotbeasgreatafactorinthevegetationdynamicsofthissystem
asingrasslandsoftheplains.
124 Colorado Natural Heritage Program © 2015 Remnantstandsofdesertgrasslandshavebeenhighlyalteredbylivestockgrazing,anditislikely
thatgrasslandsformerlyoccupiedsomesitesthatarenowcoveredbypinyon‐juniperorshrubland
(Dick‐Peddie1993).Grazingbydomesticlivestockcanalsoinfluencetherelativeproportionof
cool‐vs.warm‐seasongrasses,orfavortheincreaseofwoodyshrubspecies.
CCVA Scoring
Exposure‐Sensitivity (Potential Impact) Rank
Percent Colorado acres with projected temp > max & ppt delta < 5% Initial Exposure‐Sensitivity Rank 14.0% Low Percent Colorado acres with temp <= max & ppt delta < 5% more than 50%? No (35.2%) Low Final Exposure‐Sensitivity Rank Exposure to temperature change Underprojectedmid‐centurytemperatures,about19%ofthecurrentrangeofsemi‐desert
grasslandinColoradowouldexperienceannualmeantemperaturesabovethecurrentstatewide
maximum.
Exposure to precipitation change About49%ofsemi‐desertgrasslandinColoradowillbeexposedtoeffectivelydrierconditionseven
underunchangedorslightlyincreasedprecipitationprojectedformid‐century.
Sensitivity of ecosystem to temperature and precipitation Semi‐desertgrasslandspeciesaregenerallydroughttolerant(Dick‐Peddie1993),andareadapted
tolowprecipitationlevelsandalonggrowingseason.Soilsaretypicallyaridisols,whicharedryfor
mostoftheyear,evenduringthegrowingseason,andthereislittleinfiltrationofwaterintothesoil
(SimsandRisser2000).Changesinthetimingandamountofprecipitationcanaffectthestructure
andpersistenceofgrasslands.Withtheircomparitivelyshallowerrootsystems,grasseshavean
advantageovershrubsonshallow,poorlydrainedsoils,whereasshrubsarefavoredondeepersoils
wherewinterprecipitationcanpenetratedeeplyintothesoil.BecauseshrubsareC3plantswith
highercool‐seasonactivity(AsnerandHeidebrecht2005)theyareabletoutilizewinter
precipitationtoagreaterextentthanarewarm‐seasongrasses.SimsandRisser(2000)reportthat
ameanannualtemperatureof50F(10C)isathresholdbetweengrasslandsdominatedbycool‐
season(C3)grassesandthosedominatedbywarm‐season(C4)species.However,Munsonetal.
(2011)reportadeclineinperennialvegetationcoveringrasslandsoftheColoradoPlateauwith
increasesintemperature.
Resilience and Adaptive Capacity Rank
Overall Score: 0.72 Rank: High
Bioclimatic envelope and range Averagedcategoryscore:0.59
Climate Change Vulnerability Assessment for Colorado BLM 125 Thesegrasslandsarenotrestrictedtohighelevations,noraretheyatthesouthernendoftheir
continentaldistributioninColorado.However,becausetheyoccurinthewarmestanddriestparts
ofthestate,theyoccupyonly1%ofColorado’soverallprecipitationrange,and34%ofthe
statewidegrowingdegreedayrange.Thesefactorscombinetolowertheoverallresiliencescorein
thiscategory,butmaybesomewhatoverstatedduetothecurrentlimiteddistributionofthistype
inColorado.
Growth form and intrinsic dispersal rate Score:1
Thisecosystemisdominatedbyrelativelyfastgrowinggraminoidandherbaceousspecies,andis
abletodispersetoavailablehabitatquicklyincomparisonwithecosystemsdominatedbywoody
species.
Vulnerability to increased attack by biological stressors Score:0.5
Semi‐desertgrasslandsarevulnerabletoinvasionbyexoticspecies,particularlycheatgrass.
Extendeddroughtcanleadtowidespreadmortalityofperennialgrassesandallowtheinvasionof
cheatgrass.
Vulnerability to increased frequency or intensity of extreme events Score:1
Droughtandwarmertemperaturesmaychangespeciescomposition,orallowinvasionbydrought‐
tolerantwoodyorinvasivespeciesinsomeareas.Droughtcanincreaseextentofbaregroundand
decreaseforbcoverage,especiallyinmorexericgrasslands(Debinskietal.2010).
Althoughfrequentfiresingrasslandsmayhavebeencommonhistorically,theintroductionof
cheatgrasshasalteredthedynamicsofthesystem,andfireoftenresultsincheatgrassdominance.
Onceovertakenbycheatgrass,morefrequentfiresareencouragedbythedryflammablematerial,
leadingtofurtherdominationbycheatgrass.Evenafewcheatgrassplantsinastandwillproduce
enoughseedtodominatethestandwithinafewyearsafterfire.Increasingdroughtislikelyto
facilitatethistrend.
Other indirect effects of non‐climate stressors – landscape condition Score:0.51
Semi‐desertgrasslandlandscapesinColoradohavebeensignificantlyimpactedbyanthropogenic
activity,especiallyconversiontoagricultureinareasnearrivers.Thecurrentrateofconversionof
lowerelevationnativegrasslandtoagricultureislow,butremainsathreatforsomelimitedareas.
Nativegrasslandhabitatcanalsobelostorfragmentedbysuburbanandexurbandevelopment,and
transportation,oilandgas,orutilityinfrastructuredevelopment.
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Smith,D.R.1967.Effectsofcattlegrazingonaponderosapine‐bunchgrassrangeinColorado.USDAForestService
TechnicalBulletinNo.1371.RockyMountainForestandRangeExperimentStation,USDAForestService,FortCollins,
Colorado.
Stohlgren,T.J.,L.D.Schell,andB.VandenHuevel.1999.Howgrazingandsoilqualityaffectnativeandexoticplant
diversityinrockymountaingrasslands.EcologicalApplications9:45‐64.
Climate Change Vulnerability Assessment for Colorado BLM 127 SHORTGRASS PRAIRIE
Grasslandsdominatedbybluegrama
R. Rondeau extent exaggerated for display Climate Vulnerability Rank: High
Vulnerability summary
Key Vulnerabilities: Warmer summer nighttime low temperatures and/or extended periods of drought are likely to change the balance of warm‐ and cool‐season grasses, and, if fire frequency remains low, allow the establishment of woody species, with the potential for conversion to a more arid grassland type or savanna. Shortgrassprairieisrankedashavinghighvulnerabilitytothe
effectsofclimatechangebymid‐century.Primaryfactors
contributingtothisrankingarethefactthatthesegrasslandsare
foundontheeasternplainsofColorado,wherethegreatestlevels
ofexposureforalltemperaturevariablesoccur.Inaddition,
anthropogenicdisturbanceinthesegrasslandshasreducedthe
overalllandscapeconditionofthehabitat,whichislikelyto
reduceitsresilienceinthefaceofincreasingfrequencyof
extremeevents.
Distribution
Shortgrassprairieischaracteristicofthewarm,drysouthwesternportionoftheGreatPlains,lying
totheeastoftheRockyMountains,andrangingfromtheNebraskaPanhandlesouthintoTexasand
NewMexico.ThehighplainsoftheLlanoestacadodefinethesouthernextentoftheshortgrass
prairie,boundedbyescarpmentsformedintheOgalallaCaprock(calledtheMescaleroescarpment
tothewestandtheCaprockescarpmentontheeast).Theeasternboundaryoftheshortgrass
prairieisafluctuatingecotoneontheeast‐westprecipitationgradientbetweenshortandmidgrass
128 Colorado Natural Heritage Program © 2015 prairie,definedbyatransitionareawhereprecipitationbecomesinsufficienttoprovidesoil
moistureforthetallergrasses(Shantz1923,Carpenter1940).Thenorthernboundaryrepresents
thetransitiontocooler,moremesicmixed‐grasstypes,generallyoccuringinsoutheastern
WyomingandsouthwesternNebraska,althoughoccasionalshortgrassstandsmaybefoundfurther
north.Inspiteofextensiveconversiontoagricultureorotheruses,shortgrassprairiestillforms
extensivetractsontheeasternplainsofColorado,atelevationsbelow6,000feet.
Characteristic species
Thissystemspansawiderangeandthustherecanbesomedifferencesintherelativedominanceof
somespeciesfromnorthtosouthandfromeasttowest.
Priortosettlement,theshortgrassprairiewasagenerallytreelesslandscapecharacterizedbyblue
grama(Boutelouagracilis)andbuffalograss(Buchloedactyloides).Inmuchofitsrange,shortgrass
prairieformsthematrixvegetationwithbluegramadominant.Othergrassesincludethree‐awn
(Aristidapurpurea),side‐oatsgrama(Boutelouacurtipendula),hairygrama(Bouteloua
hirsuta),needle‐and‐thread(Hesperostipacomata),Junegrass(Koeleriamacrantha),western
wheatgrass(Pascopyrumsmithii),James'galleta(Pleuraphisjamesii),alkalisacaton(Sporobolus
airoides),andsanddropseed(Sporoboluscryptandrus).Localinclusionsofmesicorsandysoilsmay
supporttallergrassspeciesincludingsandbluestem(Andropogonhallii),littlebluestem
(Schizachyriumscoparium),Indiangrass(Sorghastrumnutans),andprairiesandreed(Calamovilfa
longifolia),aswellasscatteredshrubspeciesincludingsandsage(Artemisiafilifolia),prairie
sagewort(Artemisiafrigida),fourwingsaltbush(Atriplexcanescens),treecholla(Cylindroputia
imbricata),spreadingbuckwheat(Eriogonumeffusum),snakeweed(Gutierreziasarothrae),pale
wolfberry(Lyciumpallidum),andsoapweedyucca(Yuccaglauca)mayalsobepresent.One‐seed
juniper(Juniperusmonosperma)andoccasionalpinyonpine(Pinusedulis)treesareoftenpresent
onshalebreakswithintheshortgrassprairiematrix.
Thisecosystem,incombinationwiththeassociatedwetlandsystems,representsoneoftherichest
areasintheUnitedStatesforlargemammals.Ahealthyshortgrassprairiesystemshouldsupport
endemicgrasslandbirds,prairiedogcomplexes,viablepopulationsofpronghorn,andotherGreat
Plainsmammals.Historically,suchareaswouldalsohavebeenpopulatedbybisoninsufficient
numberstosupportpopulationsofwolves.Grasslandbirdspeciesmayconstituteoneofthefastest
decliningvertebratepopulationsinNorthAmerica(Knopf1996).
Environment
Theclimateoftheshortgrassprairieischaracterizedbylargeseasonalcontrasts,aswellas
interannualandlongertermvariability(PielkeandDoesken2008).Wintersintheshortgrass
prairiecanbemildanddrywhenPacificairmassesareblockedbytheRockyMountainsunder
zonalflowconditions,orcoldandsnowyundermeridionalflowpatternsthatbringarcticairor
upslopesnow.Springistransitionalwithwarmingconditionsandlingeringarcticairandpossible
heavysnow.Springwarmingbringsthermalinstabilityandatmosphericmixingproducingwindy
conditions,andthunderstormsbecomecommon.Tornadosandslow‐movingstormsproducing
heavyprecipitationmayalsooccur.InsummeradrylineseparatinghumidGulfairfromdrydesert
southwestairformsinthewesternplains,andthunderstormsoftenformalongthisboundary.
Climate Change Vulnerability Assessment for Colorado BLM 129 Summerthunderstormscanproducelocallyheavyprecipitation.Inlatesummer,theNorth
Americanmonsooncanbringmoisturefromthesouthwest.Typicalautumnweatherinthe
shortgrassregionisrelativelyfairanddry,withperiodiccool,wetweatherandthepossibilityof
earlysnow(PielkeandDoesken2008).
Thesegrasslandsoccurprimarilyonflattorollinguplandswithloamy,ustic(dry,butusuallywith
adequatemoistureduringgrowingseason)soilsrangingfromsandytoclayey,atelevations
generallybelow6,000feet(1,830m).Organicmatteraccumulationinshortgrassprairiesoilsis
primarilyconfinedtotheupper8in(20cm,Kellyetal.2008).Theactionofafreeze‐thawcycleon
thesegrasslandsoilsincreasestheirvulnerabilitytowinderosioninlatewinterandspring(Pielke
andDoesken2008).
Dynamics
Large‐scaleprocessessuchasclimate,fireandgrazinginfluencethissystem.Theroleoffirein
maintainingherbaceouscoverandsuppressingwoodyvegetationiswelldemonstratedinmost
prairietypes.Althoughfireisofsomewhatlesserimportanceinshortgrassprairiecomparedto
otherprairietypes,itisstillasignificantsourceofdisturbance(Engleetal.2008),anddocumented
historicfireswereoftenexpansive.Bothfloraandfaunaoftheshortgrassprairiearesensitiveto
theseasonalityandfrequencyoffire(FordandMcPherson1997).Largescaleclimaticconditions
acttodetermineseasonalityandfrequencyofwildfireontheshortgrassprairie,whileextentand
localfireeffectsaredependentontopographicandedaphicconditions.Thexericclimateofthe
shortgrassreducesoverallfuelloads,butalsodriesvegetationsufficientlyforittobecome
flammable.Thegenerallyopen,rollingplainsandoftenwindyconditionsintheshortgrassprairie
facilitatethespreadoffirewhenfuelloadsaresufficient(Axelrod1985).Conversly,breaksand
rockyareasthatareprotectedfromfireareabletosupportwoodyvegetation,eveninthedry
conditionstypicaloftheregion(Wells1965).
Theshortgrassesthatdominatethissystemareextremelydrought‐andgrazing‐tolerant.These
speciesevolvedwithdroughtandlargeherbivoresand,becauseoftheirstature,arerelatively
resistanttoovergrazing.
CCVA Scoring
Exposure‐Sensitivity (Potential Impact) Rank:
Percent Colorado acres with projected temp > max & ppt delta < 5% Initial Exposure‐Sensitivity Rank 58.3% High Percent Colorado acres with temp <= max & ppt delta < 5% more than 50%? No (20.2%) High Final Exposure‐Sensitivity Rank Exposure to temperature change Underprojectedmid‐centurytemperatures,about57%ofthecurrentrangeofshortgrassprairiein
Coloradowouldexperienceannualmeantemperaturesabovethecurrentstatewidemaximum.
130 Colorado Natural Heritage Program © 2015 Exposure to precipitation change About78%ofshortgrassprairieinColoradowillbeexposedtoeffectivelydrierconditionseven
underunchangedorslightlyincreasedprecipitationprojectedformid‐century.
Sensitivity of ecosystem to temperature and precipitation Temperaturesintheshortgrassregionshowsignificantvariationbothdailyandseasonally.
Averagedailytemperaturespansare25‐30°F,anddiurnalvariationisgenerallygreatestin
summer.Wintertemperaturesarecold,withnightsbelowfreezingandchillydaytime
temperatures.Seasonalextremelowsbelow‐20°F(‐29°C)havebeenrecordedthroughoutmostof
theregion(WRCC2014).Ingeneral,thenumberoffrostfreedaysisgreaterinmoresouthern
latitudes,althoughfreezingtemperatureshavebeenrecordedinallmonthsexceptJulyandAugust.
Summermaximumtemperaturesarefrequentlyinthe90’s,especiallyinsouthernlocations;
temperaturesof100°F(38°C)orabovehavebeenrecordedeveninthenorthernpartofthe
shortgrassprairie(WRCC2014).
Grasslandsinareaswheremeanannualtemperatureisabove50°F(10°C)aregenerallydominated
byC4(warm‐season)grassspecies,whicharetolerantofwarmertemperaturesandmoreefficient
inwateruse(SimsandRisser2000).InColorado,shortgrassprairiehasahistoricannualmean
temperatureslightlygreaterthan50°F,althoughtherangeincludesslightlycoolerannualmean
temperaturesaswell.Althoughthesegrasslandsareadaptedtowarm,dryconditions,Alwardetal.
(1999)foundthatwarmingnight‐timetemperaturesinspringweredetrimentaltothegrowthof
bluegrama,andinsteadfavoredcool‐season(C3)species,bothnativeandexotic.Consequently,the
effectofincreasingtemperaturesonshortgrassprairieisdifficulttopredict.
PrecipitationtrendsintheshortgrassprairiearesimilartothoseofthelargerGreatPlainsarea,in
thatwesternareasaredriest.Annualprecipitationisgenerallylessthan20inches(51cm),and
soilsareperiodicallymoistonlyinashallowtoplayertypicallylessthan1‐2feetdeep(Shantz
1923).Meanannualprecipitationvariesfrom20+inchesintheeastto12inches(30cm)insome
westernlocations(PielkeandDoesken2008).Precipitationmaybethemostimportantecological
driverintheshortgrassprairie.LauenrothandSala(1992)foundthatshortgrassproductivitywas
primarilyinfluencedbyprecipitationratherthantemperatureinnortheasternColorado.Alarge
proportion(70‐80%)ofannualprecipitationfallsduringthegrowingseason(WRCC2014),and
mostofthisisreceivedduringalimitednumberoflargerainfallevents(PielkeandDoesken2008).
Dailyprecipitationamountsaretypicallyquitesmall(5mmorless),anddonotcontribute
significantlytosoilwaterrecharge,whichinsteadisprimarilydependentonlargebutinfrequent
rainfallevents(Partonetal.1981,Heisler‐Whiteetal.2008).Snowfallamountsarehighestinthe
north,butgenerallysnowisasmallcomponentofannualprecipitation.Mostoftheannual
precipitationisquicklyevaporatedandtranspiredintotheatmosphereratherthansoakingintothe
soil(PielkeandDoesken2008).Largerrainfalleventspermitdeepermoisturepenetrationinthe
soilprofile,andenableanincreaseinabove‐groundnetprimaryproduction(Heisler‐Whiteetal.
2008).
Soilmoisturelevelisakeydeterminantofthedistributionofshortgrassprairiehabitat;changein
precipitationseasonality,amount,orpatternwillaffectsoilmoisture.Grasslandsgenerallyoccurin
Climate Change Vulnerability Assessment for Colorado BLM 131 areaswherethereisatleastoneannualdryseasonandsoilwateravailabilityislowerthanthat
requiredfortreegrowth(Partonetal.1981,SimsandRisser2000).Soilwateravailabilityactson
bothplantwaterstatusandnutrientcycling(Salaetal.1992).Thedominantshortgrassspecies
bluegramaisabletorespondquicklytoverysmallrainfallevents,althoughthisabilityis
apparentlyreducedduringextendeddroughtperiods(SalaandLauenroth1982,Salaetal.1982,
CherwinandKnapp2012).Nevertheless,bluegramaexhibitedextensivespreadduringthedrought
oftheDustbowlyears(AlbertsonandWeaver1944).Iflargerainfalleventsaremorecommon,the
sensitivityofshortgrassprairieisreduced(CherwinandKnapp2012).
Warmeranddrierconditionswouldbelikelytoreducesoilwateravailabilityandotherwisehave
detrimentaleffectsonecosystemprocesses,whilewarmerandwetterconditionscouldbe
favorable.Furthermore,changingclimatemayleadtoashiftintherelativeabundanceand
dominanceofshortgrassprairiespecies,givingrisetonovelplantcommunities(Polleyetal.2013).
BecausewoodyplantsaremoreresponsivetoelevatedCO2,andmayhavetaprootscapableof
reachingdeepsoilwater(Morganetal.2007),anincreaseofshrubbyspecies(e.g.,cholla,yucca,
snakeweed,sandsage),orinvasiveexoticspecies,especiallyinareasthataredisturbed(for
instance,byheavygrazing)mayalsoresult.
Resilience and Adaptive Capacity Rank
Overall Score: 0.62 Rank: Moderate
Bioclimatic envelope and range Averagedcategoryscore:0.66
Shortgrassprairieexperiencesamuchdrierandwarmerclimatethanmostotherhabitattypesin
Colorado.Annualaverageprecipitationisontheorderof10‐18inches(25‐47cm),withameanof
15in(38cm),andthegrowingseasonisgenerallylong,withfrequenthightemperatures.
Growth form and intrinsic dispersal rate Score:1
Thisecosystemisdominatedbyrelativelyfastgrowinggraminoidandherbaceousspecies,andis
abletodispersetoavailablehabitatquicklyincomparisonwithecosystemsdominatedbywoody
species.
Vulnerability to increased attack by biological stressors Score:0.5
Theshortgrassesthatcharacterizethishabitatareextremelydrought‐andgrazing‐tolerant.These
speciesevolvedwithdroughtandlargeherbivoresand,becauseoftheirstature,arerelatively
resistanttoovergrazing.Grazingbydomesticlivestockistheprimaryuseofremainingshortgrass
prairie.Managementforincreasedlivestockproductiontendstoproduceamorehomogeneous
grasslanddominatedbykeyforagespecies(FuhlendorfandEngle2001),andrequiresadditional
managementefforttorestoreamosaicofhabitatstructuresuitableforcharacteristicwildlife
132 Colorado Natural Heritage Program © 2015 species.Thus,thereisanongoingthreatofhabitatdegradationorlossoffunctionforshortgrass
prairie.Intactshortgrassprairiehasgenerallyresistedinvasionbynon‐nativespecies(Kotanenet
al.1998),includingcheatgrass(Bromustectorum),butdisturbedareasaremoresuceptibleto
invasion.
Vulnerability to increased frequency or intensity of extreme events Score:0.5
Droughthasbeenanaturalprocessinshortgrassprairiebothduringhistoricalrecording,andin
centuriespriortoEuropeansettlement.Moreover,thereisevidencefortheoccurrenceofmega‐
droughtsthatsignificantlyeclipsedtheDustBowlyearsinseverity,duration,andspatialextent
(WoodhouseandOverpeck1998).Althoughshortgrassprairiehasadaptedtoandpersistedunder
conditionsofextremedrought,thedifferentialimpactofdroughtoncomponentspeciesmayalter
speciescomposition(Rondeauetal.2013).Cultivationofmarginallandsmaycompoundthe
vulnerabilityofremainingshortgrassoccurrencestoincreaseddroughtintensityorfrequency.
Dryclimateconditionscandecreasethefuelloadandthustherelativefirefrequencywithinthe
ecosystem.Currently,firesuppressionandcertaingrazingpatternsintheregionhavelikely
decreasedthefirefrequencyevenmore,anditisunlikelythatfirefrequencyandintensitywould
increaseunderprojectedclimateconditions.However,morefrequentoccurrenceofclimate
extremes(e.g.,verywetconditionsfollowedbyverydryconditions)couldincreasethefrequency
andextentofgrasslandwildfires(Polleyetal.2013).
Other indirect effects of non‐climate stressors – landscape condition Score:0.44
ShortgrasslandscapesinColoradohavebeenheavilyimpactedbyanthropogenicdisturbance,
especiallyinthenortheasternpartofthestate.Alargepartoftherangeforthissystemhasbeen
convertedtoagriculture.AreasinsoutheasternColoradohavebeenimpactedbytheunsuccessful
attemptstodevelopdrylandcultivationpreceedingtheDustBowlofthe1930s.Habitatlossisa
continuingthreattoshortgrassprairie.Tilledagriculturehasbeenlargelysurpassedbyincreasing
urbanizationastheprimarysourceofshortgrassprairiehabitatconversion,althoughthereissome
possibilitythatthiscouldreverseifdemandfordrylandbiofuelcropsweretoaccelerate.Inthe
northeasternportionofColorado,patternsofcultivatedlandhavelargelyfragmentedthematrixof
theshortgrassprairie,reducingoreliminatingconnectivityforspeciesthatdependonthem,and
thistrendislikelytocontinue.Residentialandcommercialdevelopmentisasignificantsourceof
habitatlossandfragmentationonthewesternmarginsofColorado’sshortgrassprairie
distribution,lesssoinotherareas,butrarelyentirelyabsent.
Developmentofoilandgasresourcesisongoinginshortgrassprairiehabitat,especiallyinthe
NiobrarashaleoftheDenver‐JulesburgBasinthatliesundermostofthenorthernportionof
shortgrassprairieextentinColorado.Thedensityofassociatedroads,pipelinecorridors,and
infrastructureisaprimaryongoingsourceofanthropogenicdisturbance,fragmentation,andlossin
thishabitat.Disturbancefromrenewableenergydevelopmentremainssmall,andlargelydueto
Climate Change Vulnerability Assessment for Colorado BLM 133 concentratedwindturbine“farms”.Utility‐scalesolarinstallationshavethusfarbeenconfinedto
areasnearurbandevelopment,butthereisapotentialforfuturedisturbancefromthistypeof
facility,whichwouldrequireassociatedutilitycorridordevelopment.
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Climate Change Vulnerability Assessment for Colorado BLM 135 Riparian and Wetland
Table 2.8. Key vulnerabilities, riparian and wetland ecosystems. Habitat
Climate factor(s)
Consequences
Other considerations
Riparian ‐ East Warmer and drier conditions, runoff amount & timing Earlier peak flows, low late summer flows, change in relative species abundance Highly altered due to diversions and dams, agricultural land use patterns Riparian ‐ Mtn. Warmer temperatures, runoff timing Earlier peak flows, low late summer flows, change in relative species abundance Connectivity Riparian ‐ West Warmer and drier conditions, runoff amount & timing Earlier peak flows, low late summer flows, change in relative species abundance Highly altered due to diversions and dams, agricultural land use patterns Wetland ‐ East Warmer, drier conditions Lower water tables, reduced input Strict irrigation control, highly altered Wetland ‐ Mtn. Warmer temperatures, snowmelt timing Potential change in species composition Groundwater‐driven types more stable Wetland ‐ West Drier conditions Lower water tables, reduced input Highly altered 136 Colorado Natural Heritage Program © 2015 RIPARIAN WOODLANDS AND SHRUBLANDS
Areasofgenerallywoodyvegetationassociatedwithmovingwaterandintermittentflooding
extent exaggerated for display K. Carsey Climate Vulnerability Ranks:
High (Eastern), Low (Mountain), Very High (Western)
Vulnerability summary
Key vulnerabilities: Warmer and drier conditions and the consequent change in runoff amount and timing are expected to result in earlier peak flows and low late‐summer flows, which are likely to impact the structure and species composition of riparian vegetation, especially at lower elevations. Riparianwoodlandandshrublandsoftheeasternplainsandwesternareasarerankedashaving
hightoveryhighvulnerabilitytotheeffectsofclimatechangebymid‐century,whilethoseofthe
mountainregionareconsideredtohavecomparativelylowvulnerability.Thevulnerabilityofsome
speciesassemblagesmaybehigherorlowerthanisreflectedbythecollectiveassessment.The
primaryfactorcontributingtotheserankingsisthedegreetowhichriparianwoodlandsatlower
elevationsareexpectedtoexperiencehighertemperatureswithoutcompensatoryprecipitation
increase.Thelowtomoderateresilienceranksreflectthehighlyalteredconditionofmostofthese
habitats,andingeneral,mostriparianwoodlandsandshrublandsthroughoutthestateshould
probablyberegardedashavingsomedegreeofvulnerabilitytoclimatechangethatisnotcaptured
byourbroad‐scaleassessmentmethods.
Distribution
Weassessedtheconditionofriparianwoodlandsandshrublandsineachofthreeregionsin
Colorado,correspondingroughlytoecoregionsasdefinedbyTheNatureConservancy(2009,
modifiedfromBailey1998):theeasternplains(CentralShortgrassPrairieecoregion);mountains
Climate Change Vulnerability Assessment for Colorado BLM 137 (SouthernRockyMountainecoregion);andwesternplateausandvalleys(ColoradoPlateau,
WyomingBasins,andotherecoregions).
RiparianwoodlandsandshrublandsoccurthroughoutColorado.IneasternColoradotheyarefound
alongsmall,mediumandlargestreamsontheplains,includingthewidefloodplainsoftheSouth
PlatteandArkansasRivers.Montanetosubalpineriparianwoodlandsareseasonallyflooded
forestsandwoodlandsthroughouttheRockyMountains.Atmontanetosubalpineelevations,
riparianshrublandsmayoccurasnarrowbandsofshrubsliningstreambanksandalluvialterraces,
orasextensivewillowcarrsinbroadfloodplainsandsubalpinevalleys.Theyincludetheconifer
andaspenwoodlandsthatlinemontanestreams.Theyaremostoftenconfinedtospecific
streamsideenvironments,occurringonfloodplainsorterracesofriversandstreamsorinV‐
shaped,narrowvalleysandcanyons(wherethereiscold‐airdrainage).Lessfrequently,high
elevationriparianwoodlandsarefoundinmoderatetowidevalleybottoms,onlargefloodplains
alongbroad,meanderingrivers,andonpondorlakemargins.Theycanalsobefoundaroundseeps,
fens,andisolatedspringsonhillslopesawayfromvalleybottoms.Atlowerelevationsonthe
westernslope,riparianwoodlandsandshrublandsarefoundwithinthefloodzoneofrivers,on
islands,sandorcobblebars,andimmediatestreambanks.Theyoftenoccurasamosaicofmultiple
communitiesthataretree‐dominatedwithadiverseshrubcomponent.
Characteristic species
Ontheeasternplains,riparianwoodlandsandshrublandsaregenerallydominatedbyplains
cottonwood(Populusdeltoides)andwillow(Salixspp.),butalsooccurasamosaicofmultiple
communitiesinterspersedwithherbaceouspatches.
Dominantshrubswithinthemontanetosubalpineelevationzoneincludealder(Alnustenuifolia),
birch(Betulaoccidentalis),dogwood(Cornussericea),andwillowspecies.Generallytheupland
communitiessurroundingtheseripariansystemsareeitherconiferoraspenforests.
Westernriparianforestsaretypicallydominatedbycottonwood(Populusangustifolia,P.deltoides)
andwillow,butmayincludemaple(Acerglabrum),Douglasfir(Pseudotsugamenziesii),spruce
(Piceaspp.),andjuniper(Juniperusspp.).Shrublandsareprimarilydominatedbywillow,alder,and
birch.
Environment
RiparianareasofColorado’seasternplainsareprimarilyassociatedwithintermittentlyflowing
streamsofsmalltomoderatesize,butalsoincludethelargerfloodplainsofthelargesnowmelt‐fed
rivers(SouthPlatteandArkansas).Smallerstreamsreceivewaterfromprecipitationand
groundwaterinflow,havegreaterseasonalflowvariationthanthelargerrivers,andhaveminimal
ornoflowexceptduringfloods(Covichetal.1997).InmountainousareasofColorado,riparian
areasaremuchmorelikelytobeassociatedwithperenniallyflowingstreams,andtheseplant
communitiesareadaptedtohighwatertablesandperiodicflooding.Runoffandseepagefrom
snowmeltisaprimarysourceofstreamflow.LowerelevationriparianareasinwesternColorado
areadaptedtoperiodicflooddisturbanceandpredominantlyaridconditions.Largerstreamsand
riversaresustainedbyrunofffrommountainareas.Smallerstreamsareprimarilysupportedby
138 Colorado Natural Heritage Program © 2015 groundwaterinflow,oroccasionallargeprecipitationevents,andareoftendryforsomeportionof
theyear.
Dynamics
Riparianwoodlandsaretolerantofperiodicfloodingandhighwatertables.Snowmeltmoisturein
thissystemmaycreateshallowwatertablesorseepsforaportionofthegrowingseason.
Manyhigherelevationriparianshrublandsareassociatedwithbeaver(Castorcanadensis)activity,
whichcanbeimportantformaintainingthehealthoftheriparianecosystem(historicallythis
wouldhavebeentrueforlowerelevationstreamsaswell).Beaverdamsabatechanneldown
cutting,bankerosion,anddownstreammovementofsediment.Beaverdamsalsoraisethewater
tableacrossthefloodplainandprovideyear‐roundsaturatedsoils.Plantestablishmentand
sedimentbuild‐upbehindbeaverdamsraisesthechannelbedandcreatesawetlandenvironment.
Hydrologically,smallerriverstendtohavegreaterseasonalvariationinwaterlevelswithless
developedfloodplainthanthelargerrivers,andcandrydowncompletelyforsomeportionofthe
year.Cottonwooddie‐offsrelatedtoprolonged,intensedroughtandhydrologicalalterationshave
affectedsomestands.
Lowerelevationriparianwoodlandsandshrublandsaredependentonanaturalhydrologicregime,
especiallyannualtoepisodicflooding.Thesewoodlandsandshrublandsgrowwithinacontinually
changingalluvialenvironmentduetotheebbandflowoftheriver,andriparianvegetationis
constantlybeing“re‐set”byfloodingdisturbance.Insomeareas,Russianolive(Elaeagnus
angustifolia),tamarisk(Tamarixspp.),andotherexoticspeciesarecommon.
CCVA Scoring
Exposure‐Sensitivity (Potential Impact) Ranks
Eastern Mountain Western Percent Colorado acres with projected temp > max & ppt delta < 5% 55.5% 1.8% 37.2% High Low High No (6.7%) No (25.3%) No (14.7%) High Low
High
Initial Exposure‐Sensitivity Rank Percent Colorado acres with temp <= max & ppt delta < 5% more than 50%? Final Exposure‐Sensitivity Rank Exposure to temperature change Underprojectedmid‐centurytemperatures,about60%ofthecurrentrangeofriparianwoodland
andshrublandineasternColoradowouldexperienceannualmeantemperaturesabovethecurrent
statewidemaximum.Theproportionissimilar(54%)forwesternriparianareas,butmuchlower
(2%)inmountainareas.
Climate Change Vulnerability Assessment for Colorado BLM 139 Exposure to precipitation change About62%ofriparianwoodlandandshrublandineasternColoradowillbeexposedtoeffectively
drierconditionsevenunderunchangedorslightlyincreasedprecipitationprojectedformid‐
century.Forwesternriparianareas,theproportionisslightlylower(52%),andmountainriparian
areascanexpecttoseeeffectivelydrierconditionsinabout27%oftheirdistribution.
Sensitivity of ecosystem to temperature and precipitation Riparianwoodlandsandshrublandsareadjacenttoandaffectedbysurfaceorgroundwaterof
perennialorephemeralwaterbodies.Theyarecharacterizedbyintermittentfloodinganda
seasonallyhighwatertable.Thecloseassociationofriparianareaswithstreamflowandaquatic
habitatsmeansthatchangingpatternsofprecipitationandrunoffthatalterhydrologicregimesare
likelytohaveadirecteffectonthesehabitats(Caponetal.2013).Inaddition,theinteractionof
increasedgrowthduetoincreasedCO2concentration,warming‐induceddrought,andheat‐stress
withpotentiallyreducedstreamflowsarelikelytoaffectripariancommunitystructureand
composition,especiallyinmorearidareas(Perryetal.2012).
Climateprojectionsformid‐centuryaregenerallyforwarmeranddrieroutcomes,although
precipitationchangeismoreuncertainindirectionandmagnitude(Lucasetal.2014).Annual
runoffandstreamflowareaffectedbybothtemperatureandprecipitation,andeffectsoffuture
changesinthesefactorsaredifficulttoseparate.Warming‐inducedchangesinsnowpackand
snowmelttimingincludeearlierspringsnowmelt,ashifttowardsprecipitationfallingasrain
insteadofsnowinspringandfall,andincreasedsublimationfromthesnowpackthroughoutthe
season.Thesechangesareexpectedtohavegreaterimpactatlowerelevations(Lucasetal.2014).
Theeffectsofwarmingtemperaturesarelikelytochangethehydrologiccyclebyshiftingrunoffand
peakflowstoearlierinthespring,andreducinglatesummer‐earlyautumnflows(Roodetal.
2008).Riparianvegetationisinpartdeterminedbyflowlevels(Aubleetal.1994).Reduced
summerflowsarepredictedtoresultinmorefrequentdroughtstressforriparianhabitats,witha
resultinglossorcontractionofthehabitat(Roodetal.2008).
Resilience and Adaptive Capacity Ranks
Eastern Overall Score: 0.52 Rank: Moderate
Mountain Overall Score: 0.60 Rank: Moderate
Western Overall Score: 0.49 Rank: Low
Bioclimatic envelope and range Scores:0.57(Eastern),0.81(Mountain),0.66(Western)
Theseshrublandsarenotlimitedtohighelevations,andinColoradoarewellwithintherangeof
continentaldistribution.Lowerelevationtypesoftheeastandwestslopehavesomewhatnarrower
bioclimaticrangesthanmontanetypes.
Growth form and intrinsic dispersal rate Score:0.5
140 Colorado Natural Heritage Program © 2015 Themixedgrowth‐forms(trees,shrubs,andherbaceous)thatmaybedominantorcharacteristicof
theseecosystemsgivesthemanintermediateresiliencescoreinthiscategory.
Vulnerability to increased attack by biological stressors Scores:0.5
Seedingwithnon‐nativepasturegrasses,invasionbytamariskandexoticforbshasalreadyaltered
speciescompositioninmanyeasternandwesternriparianecosystem,andwillhavealastingeffect.
Invasivespecieswiththepotentialtoalterecosystemfunction(e.g.,tamarisk)areanongoing
managementchallenge.
Forhigherelevationriparianhabitats,invasivespeciesandgrazingareminorimpacts(Chimneret
al.2010),butthesefactorsareanongoingsourceofdisturbanceinlowermontaneriparianareas.
Manyofthesecommunitieshavedegradedunderstories,withweedyherbaceouslayersand
Russianoliveandtamariskinvadingtheshrublayers.
Vulnerability to increased frequency or intensity of extreme events Scores:0.5
Increasedfrequencyandmagnitudeofdroughtislikelytohavesignificantimpactonthesehabitats.
Althoughfirehasoftennotbeenconsideredanimportantdisturbanceinwetlandandriparian
areas,recentevidencesuggeststhatfiresinmosttypesofadjacentuplandvegetationarelikelyto
burnintothesehabitatsaswell(CharronandJohnson2006,StrombergandRychener2010).
Other indirect effects of non‐climate stressors – landscape condition EasternPlainsScore:0.44
RiparianhabitatsofColorado’seasternplainscontinuetobethreatenedbyurban,exurban,and
recreationaldevelopmentaswellasagriculturalactivities(e.g.,tillageandcropproduction,
livestockgrazing,concentratedanimalfeedingoperations)inadjacentuplandswhoseeffects
contributetoagraduallossofhabitatareaandquality.Landusewithintheriparianareaaswellas
inadjacentanduplandareascanfragmentthelandscapeandreduceconnectivitybetweenriparian
patchesandbetweenripariananduplandareas,adverselyaffectingthemovementofsurface/
groundwater,nutrients,anddispersalofplantsandanimals.Roads,bridges,anddevelopmentcan
alsofragmentbothripariananduplandareas.Gravelminingisanadditionalsourceofdisturbance
tothesehabitats,especiallyalongthelargerrivers.
Alterationofnaturalhydrologicalprocessesbydams,diversions,ditches,roads,etc.,andabiotic
resourceconsumptionthroughgroundwaterpumpinghaveconsiderablyalteredthepresettlement
conditionofthesehabitats,andareanongoingthreat.Dams,reservoirs,diversions,ditchesand
otherhumanlandusesalterthenaturalflowregimeofastream,andcandisrupttheecological
integrityoftheripariansystem.Physicalchangesresultingfromalteredflowregimesinclude
downstreamerosionandchannelization,reducedchannelmorphologydynamics,reducedbase
and/orpeakflows,lowerwatertablesinfloodplains,andreducedsedimentdepositioninthe
floodplain(Poffetal.1997).Mosthydrologicalalterationisduetoagriculturalneeds,exceptin
Climate Change Vulnerability Assessment for Colorado BLM 141 highlydevelopedareasalongthemountainfrontwhereotherusesareovertakingagriculturaluse.
ContinuedgroundwaterpumpingfromtheOgallala‐HighPlainsaquiferhasloweredthewatertable
suchthatmanyformerlyflowingstreamsarenowdryformuchoftheyear(Dodds1997).Flood
controlcangreatlyreducethespatialcomplexityofriparianandwetlandhabitat.
MountainScore:0.69
Riparianareasinmountainareasaregenerallyingoodcondition,althoughnotwithoutimpactfrom
anthropogenicdisturbance.Threatstoriparianwoodlandandshrublandinmountainareasof
Coloradovarywithelevation.Additionalfragmentationandlossofriparianhabitatsatlower
elevationinmountainousareasofColoradoduetourbanizationandagricultureisanongoing
threatinmanyareas.Athigherelevationswherelandsareinpublicownershipthesehabitatsare
mostthreatenedbyrecreationaldevelopmentandusewhereroadsprovideaccessandareasource
ofsedimentationandpollutantrunoff.Exceptatthehighestelevations,fewmountainriparian
habitatsarewithouthydrologicalmodification,andtheongoingstressesfromreservoirs,dams,
diversions,andsimilaralterationsincludedownstreamerosionandchannelization,reduced
channelmorphologydynamics,reducedbaseand/orpeakflows,lowerwatertablesinfloodplains,
andreducedsedimentdepositioninthefloodplain(Poffetal.1997).
WesternSlopeScore:0.40
RiparianareasinwesternColoradoaregenerallyinfaircondition,andhavebeenheavilyimpacted
byanthropogenicdisturbanceinmanyareas.Threatstoriparianhabitatsfromongoingurbanand
exurbandevelopmentaregenerallylessinmostareasofColorado’swestslopeincomparisonwith
theFrontRange,butnotabsent.Agriculturalactivitiesareubiquitousinlowerelevationriparian
habitats,includingirrigatedtilledanduntilledcrops,anddomesticlivestockgrazing.Gravelmining
iscommonalongthelargerrivers.Thesedisturbancesarelikelytocontinuetoproduceagradual
reductioninhabitatareaandqualityinwestsloperiparianhabitats.
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century:hotspotsforclimatechangeadaptation?Ecosystems16:359‐381.
Charron,I.andE.A.Johnson.2006.Theimportanceoffiresandfloodsontreeagesalongmountainousgravel‐bedstreams.
EcologicalApplications16:1757‐1770.
Chimner,R.A.,J.M.Lemly,andD.J.Cooper.2010.Mountainfendistribution,typesandrestorationpriorities,SanJuan
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142 Colorado Natural Heritage Program © 2015 Covich,A.P.,S.C.Fritz,P.J.Lamb,R.D.Marzolf,W.J.Matthews,K.A.Poiani,E.E.Prepas,M.B.Richman,andT.C.Winter.1997.
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11:993‐1021.
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Perspective.JournaloftheNorthAmericanBenthologicalSociety,16:162‐168.
Holsinger,L.,R.E.Keane,D.J.Isaak,L.Eby,andM.K.Young.2014.Relativeeffectsofclimatechangeandwildfireson
streamtemperatures:asimulationmodelingapproachinarockyMountainwatershed.ClimaticChange124:191‐206.
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waterresourcesmanagementandadaptation.Secondedition.ReportfortheColoradoWaterConservationBoard.
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Boulder.
Perry,L.G.,D.C.Andersen,L.V.Reynolds,S.M.Nelson,andP.B.Shafroth.2012.Vulnerabilityofriparianecosystemsto
elevatedCO2andclimatechangeinaridandsemiaridwesternNorthAmerica.GlobalChangeBiology18:8221‐842.
Poff,N.L.,M.M.Brinson,andJ.W.Day.2002.Aquaticecosystemsandglobalclimatechange:potentialimpactsoninland
freshwaterandcoastalwetlandecosystemsintheUnitedStates.PreparedforthePewCenteronGlobalClimateChange.
Available:http://www.c2es.org/publications/aquatic‐ecosystems‐and‐climate‐change
Rood,S.B.,J.Pan,K.M.Gill,C.G.Franks,G.M.Samuelson,andA.Shepherd.2008.DecliningsummerflowsofRocky
Mountainrivers:changingseasonalhydrologyandprobableimpactsonfloodplainforests.JournalofHydrology349:397‐
410.
Stromberg,J.C.andT.J.Rycheneer.2010.Effectsoffireonriparianforestsalongafree‐flowingdrylandriver.Wetlands
30:75‐86.
TheNatureConservancy[TNC].2009.TerrestrialEcoregionsoftheWorld,digitalvectordata.TheNatureConservancy,
Arlington,Virginia.
Climate Change Vulnerability Assessment for Colorado BLM 143 WETLANDS
Herbaceousvegetationdominatedareascharacterizedbywatersaturationandhydricsoils
G. Doyle extent exaggerated for display Climate Vulnerability Ranks:
High (Eastern), Moderate (Mountain and Western)
Vulnerability summary
Key vulnerabilities: Warmer and drier conditions for lower elevation wetlands are likely to result in reduced inputs to these habitats, and lower groundwater levels in general that may reduce the extent and degrade the condition of wetlands. In higher elevations warmer temperatures and consequent earlier snowmelt may influence the species composition of wetland habitats. Ground‐water dependent wetlands at higher elevations are expected to be somewhat buffered from hydrologic change. Wetlandhabitatsofthewesternvalleysandmountainareasarerankedashavingmoderate
vulnerabilitytotheeffectsofclimatechangebymid‐century,whilethoseoftheeasternplainsare
consideredhighlyvulnerable.Theprimaryfactorcontributingtothehigherrankingforeastern
plainswetlandsisthedegreeofincreasedtemperatureprojectedforthatregion,incomparison
withtheotherregions.Thevulnerabilityofsomespeciesassemblagesmaybehigherthanis
reflectedbythecollectiveassessment.Themoderateresilienceranksreflectthehighlyaltered
conditionofmostofthesehabitats,andingeneral,allwetlandsthroughoutthestateshould
probablyberegardedashavingsomedegreeofvulnerabilitytoclimatechangethatisnotcaptured
byourbroad‐scaleassessmentmethods.
Distribution
Weassessedtheconditionofnon‐riparianwetlandsineachofthreesectionsofColorado,
correspondingapproximatelytoecoregionsasdefinedbyTheNatureConservancy(2009,modified
fromBailey1998):theeasternplains(CentralShortgrassPrairieecoregion);mountains(Southern
144 Colorado Natural Heritage Program © 2015 RockyMountainecoregion);andwesternplateausandvalleys(ColoradoPlateau,WyomingBasins,
andotherecoregions).Asconsideredherein,wetlandsareareascharacterizedbywatersaturation
andhydricsoilstypicallysupportinghydrophyticvegetation.
InColorado,non‐riparianwetlandhabitatsincludemoisttowetmeadows,emergentmarshes,fens,
andseepsandsprings.Non‐riparianwetlandsofColorado’seasternplainsandwesternvalleysare
primarilymarshes,seepsandsprings,andwetmeadows.Playas(shallow,temporarywetlands)are
scatteredthroughouttheeasternplains,andoccurinlimiteddistributiononthewesternslopeas
well.Althoughnaturalmarshesandwetmeadowsareprimarilyfoundathigherelevations,
irrigationpractices(directfloodapplication,irrigationtailwaters,elevatedgroundwaterlevels,
etc.)havegreatlyincreasedtheincidenceofwetmeadowsontheeasternplains(Sueltenfussetal.
2013).Mostofthestate’swetmeadowsoccurinmountainousareasofColorado,andmarshesare
generallylesscommon.Fensarealsocharacteristicofthemountainregion.
Characteristic species
Naturalwetmeadowsaredominatedbynativesedgesandgrasses,whilethoseinfluencedby
irrigationmaybedominatedbynon‐nativepasturegrasses.Seepsandspringshavegenerally
similarvegetationtowetmeadows.
Standingwaterinemergentmarshesrestrictsthedominantspeciestorobustwetlandplants,such
ascattail(Typha),bulrush(ScirpusandSchoenoplectusspp.),andlargesedges(Carexspp.).Atlower
elevations,marshescanbecomedenselyvegetatediftheyarenotperiodicallyflushedby
floodwaterormechanicalthinning.
Fenvegetationisgenerallycharacterizedbyadensecoverofsedgesandmoss,oftenintermixed
withforbsandshorttodwarfshrubssuchaswillowandbogbirch(Betulanana).
Environment
MeadowsoccurthroughoutColorado,butmostnaturalwetmeadowsarefoundwithinthemontane
tosubalpinezone.Naturalwetmeadowsaretightlyassociatedwithsnowmeltorsubsurface
groundwaterdischargeandtypicallynotsubjectedtohighdisturbanceeventssuchasflooding.
Withinmountainvalleysandatlowerelevations,extensiveacresofwetmeadowsarealsolinkedto
irrigationpractices,includingfloodirrigationandseepagefromirrigationditches.
Emergentmarshesarewetlandsthatexperiencefrequentorprolongedponding.Marshesoccurin
depressionsandkettleponds,asfringesaroundlakes,alongstreamsandrivers,andbehindmany
typesofimpoundments.Theycanbefoundatallelevations,butaremorecommonatmidtolower
elevations.
Fensarewetlandswiththickorganicsoilsthataresupportedbystablegroundwaterdischarge.
Fensaretypicallyfoundwithinthemontanetosubalpinezone,generallyabove7,000ft.,andcan
formalongtheedgesofvalleybottoms,atbreaksinslope,aroundhillslopeseeps,inshallowbasins
oranywherewheresufficientgroundwateremergestoperenniallysaturatesoils.Fensare
Climate Change Vulnerability Assessment for Colorado BLM 145 considered“oldgrowth”wetlands,astheaccumulationofthickorganicsoilscantakethousandsof
years.
Seepsandspringsincludesmallwetlandsthatarehydrologicallysupportedbygroundwater
discharge.TheyarefoundthroughoutColoradoandcanbeacomponentofthepreviously
describedwetlandtypes,butaremostnotablewithinthecliffandcanyoncountryoftheColorado
PlateauandtheLowerArkansasbasin.
Dynamics
Hydrologyistheprimarydeterminantofthedevelopmentandpersistenceofwetlandecosystems,
andvariationsintiminganddurationofinundationlargelydeterminethetypeofwetland.The
waterbudgetorhydroperiodofawetlandincludesprecipitation,evapotranspiration,andboth
surfaceflowandgroundwater.Althoughwatermaynotbecontinuouslypresentinwetlands,asa
generalruleofthumbinundationduringatleast14consecutivegrowingseasondaysissufficientto
exertasignificantinfluenceonwetlandprocesses(CulverandLemly2013).
CCVA Scoring
Exposure‐Sensitivity (Potential Impact) Rank
Eastern Mountain Western Percent Colorado acres with projected temp > max & ppt delta < 5% 37.2% 0.8% 15.3% High Low Moderate No (11.3%) Yes (54.5%) No (43.5%) High Moderate
Moderate
Initial Exposure‐Sensitivity Rank Percent Colorado acres with temp <= max & ppt delta < 5% more than 50%? Final Exposure‐Sensitivity Rank Exposure to temperature change Underprojectedmid‐centurytemperatures,about43%ofthecurrentrangeofwetlandecosystem
ineasternColoradowouldexperienceannualmeantemperaturesabovethecurrentstatewide
maximum.Theproportionislower(19%)forwesternwetlands,andquitelow(1%)inmountain
areas.
Exposure to precipitation change About49%ofwetlandhabitatsineasternColoradowillbeexposedtoeffectivelydrierconditions
evenunderunchangedorslightlyincreasedprecipitationprojectedformid‐century.Forwestern
wetlandecosystems,theproportionissomewhathigher(59%),andmountainwetlandscanalso
expecttoseeeffectivelydrierconditionsinabout55%oftheirdistribution.
Sensitivity of ecosystem to temperature and precipitation Bothtemperatureandprecipitationcanaffectthepresenceandextentofwetlandsonthe
landscape.Warmer,drierconditionsarelikelytoleadtolowergroundwaterlevels,atleastduring
certainseasons,andcanhaveanegativeimpactontheseecosystems.Earlierspringrun‐offwould
146 Colorado Natural Heritage Program © 2015 resultindryingconditionsbylatesummer,possiblyreducingthesizeofexistingwetlands.
Similarly,wetlandscurrentlysupportedbylate‐meltingsnowfieldsarelikelytodrysoonerthan
undercurrentconditions.
Effectsofclimatechangeonwetlandsareexpectedtobelargelymediatedthroughthesourceof
water,eitherprecipitation,groundwaterdischarge,or,forwetlandsassociatedwithriparianareas,
surfaceflow(Winter2000).Precipitationsupportedwetlandsarethoughttobemostvulnerableto
drierclimaticoutcomes,butdecreasingprecipitationwouldalsobelikelytolowerwatertable
levelsandleadtocontractionofgroundwater‐fedwetlands(Winter2000,Poffetal.2002).Under
wetterconditions,somewetlandtypesmaybeabletoexpandoratleastmaintaincurrentextents.
Considerationoftheeffectsofchangingprecipitationisfurthercomplicatedbythefactthat
wetlandsmayreceivewaterinputfromthesurroundingbasin,notjusttheimmediateenvirons
(Gitayetal.2001).
Temperatureaffectswetlanddistributionandfunctionprimarilythroughitseffectsonratesof
chemical,physicalandbiologicalprocesses(GageandCooper2007).Althoughwetlandsareto
someextentbufferedfromtheimmediateeffectsofwarmingonwatertemperature,warmingcould
increasebothplantgrowthandmicrobialactivitydrivingdecomposition(Fischlinetal.2007).
Temperatureisalsoadriverofevapotranspirationrate,andthewatercycleingeneral(Gitayetal.
2001).
Variationinclimaticconditionsaffectsgroundwaterlevelsbothdirectlyviarechargerates,and
indirectlythroughchangesinpatternsofgroundwateruse,especiallyirrigation(Tayloretal.2012).
Drierfutureconditionsarelikelytoresultintightercontrolsonirrigationseepage,anda
consequentreductioninwetlandacressupportedbythissource.Althoughclimatechangeis
expectedtohaveasignificanteffectonwetlandsthroughchangesintheseasonalityandvariability
ofprecipitationandextremeevents(Gitayetal.2005),changingwaterusepatternsinresponseto
climatechangearealsolikelytoplayamajorroleinthefutureofwetlands(Tayloretal.2012).
Resilience and Adaptive Capacity Rank
Eastern Overall Score: 0.52 Rank: Moderate
Mountain Overall Score: 0.59 Rank: Moderate
Western Overall Score: 0.52 Rank: Moderate
Bioclimatic envelope and range Scores:0.66(Eastern),0.77(Mountain),0.69(Western)
Mostwetlandsarenotlimitedtohighelevations,andinColoradoarewellwithintherangeof
continentaldistribution.Lowerelevationtypesoftheeastandwestslopehavesomewhatnarrower
bioclimaticrangesthanmontanetypes.
Growth form and intrinsic dispersal rate Score:0.5
Climate Change Vulnerability Assessment for Colorado BLM 147 Thisecosystemisdominatedbyrelativelyfastgrowinggraminoidandherbaceousspecies,butmay
berestrictedindispersalabilityifhabitatsareisolatedwithinthelandscape.
Vulnerability to increased attack by biological stressors Scores:0.5
Forhigherelevationwetlands,invasivespeciesandgrazingareminorimpacts(Chimneretal.
2010),butthesefactorsareanongoingsourceofdisturbanceinlowerelevationwetlandsthat
lowertheresilienceoftheseoccurrences.Invasivespecieswiththepotentialtoalterecosystem
functionareanongoingmanagementchallenge.Impactedwetlandsmaybemorevulnerableto
invasionbyexoticspecies.
Vulnerability to increased frequency or intensity of extreme events Scores:0.5
Increasedfrequencyandmagnitudeofdroughtislikelytohavesignificantimpactonthesehabitats.
Eventualimpactsofclimatechangeonaquifersourceofwatercouldeventuallyeliminatesome
types(seeps)fromsomeareas.
Other indirect effects of non‐climate stressors – landscape condition EasternPlainsScore:0.43
WetlandsofColorado’seasternplainscontinuetobethreatenedbyurbanandexurban
developmentaswellasagriculturalactivities(e.g.,tillageandcropproduction,livestockgrazing,
concentratedanimalfeedingoperations)inadjacentuplandswhoseeffectscontributetoagradual
lossofhabitatareaandquality.Theincidentalcreationofwetlandsthroughwatermanagement
activitiesisgenerallynotsufficienttocompensateforlossesinthisecosystem.
MountainScore:0.67
WiththeexceptionoftheextensivewetlandsoftheSanLuisValley,wherewaterdevelopmentfor
agriculturaluseisextensive,wetlandhabitatsinmountainareasofColoradoaregenerallyingood
condition,withfeweranthropogenicimpacts,andareoveralllessthreatenedbydevelopmentand
agriculturethanthoseinlowerelevationsofthestate.
WesternSlopeScore:0.41
WetlandhabitatsinwesternColoradohavebeenheavilyimpactedbyanthropogenicactivities,and
areofteninonlyfaircondition.Alteredhydrologyduetodams,diversions,andgroundwater
pumpingmayinteractwithwarmingtemperaturesandchangesinprecipitationpatterntoalter
groundwaterrechargerates,andleadtodryingorcontractionofwetlands.Hanginggardensarean
especiallyfragilewetlandtypeofthewesternslope.Wheretheyareaccessibletofoottrafficor
livestock,erosion,trampling,andintroductionofexoticspeciesareanongoingthreat.
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Gitay,H.,S.Brown,W.EasterlingandB.Jallow.2001.Ecosystemsandtheirgoodsandservices.ClimateChange2001:
Impacts,Adaptation,andVulnerability.ContributionofWorkingGroupIItotheThirdAssessmentReportofthe
IntergovernmentalPanelonClimateChange,J.J.McCarthy,O.F.Canziani,N.A.Leary,D.J.DokkenandK.S.White,Eds.,
CambridgeUniversityPress,Cambridge,237‐342.
Poff,N.L.,M.M.Brinson,andJ.W.Day.2002.Aquaticecosystemsandglobalclimatechange:potentialimpactsoninland
freshwaterandcoastalwetlandecosystemsintheUnitedStates.PreparedforthePewCenteronGlobalClimateChange.
Available:http://www.c2es.org/publications/aquatic‐ecosystems‐and‐climate‐change
Sueltenfuss,J.P.,D.J.Cooper,R.L.Knight,andR.M.Waskom.2013.Thecreationandmaintenanceofwetlandecosystems
fromirrigationcanalandreservoirseepageinasemi‐aridlandscape.Wetlands33:799‐810.
Taylor,R.G.,B.Scanlon,P.Dölletal.2012.Groundwaterandclimatechange.NatureClimateChange3:322‐329.
TheNatureConservancy[TNC].2009.TerrestrialEcoregionsoftheWorld,digitalvectordata.TheNatureConservancy,
Arlington,Virginia.
Winter,T.C.2000.Thevulnerabilityofwetlandstoclimatechange:ahydrologiclandscapeperspective.Journalofthe
AmericanWaterResourcesAssociation.36:305‐311.
Climate Change Vulnerability Assessment for Colorado BLM 149 FRESHWATER ECOSYSTEMS – METHODS
InconsultationwithBLM,CNHPidentifiedsixfreshwaterecosystemgroupstobeassessed(Table
2.9).Ouranalysisevaluatedtheassociatedwetlandandriparianecosystemsseparately,sothat
vulnerabilityresultsherearenotnecessarilytiedtotheassessmentspresentedabove.
Table 2.9. Freshwater ecosystem targets. Freshwater Ecosystems
Streams – high elevation (>6,500 ft) cold water Rivers Streams – mid elevation (<6,500 ft) cool and warmer water Lakes Cool to coldwater transitional stream areas Reservoirs Thevulnerabilityoffreshwaterecosystemstoclimatechangebymid‐centurywasevaluated
throughacombinationofspatialandnarrativemethods.Theprimarymethodofspatialevaluation
isbasedonamodelofprojectedchangeinwatertemperaturearoundacoldtocool‐waterfisheries
transitionline.
Transition line model
STORETwatertemperaturedatawithinColoradoweredownloadedfromtheEPAwebsite.Sample
datesrangedfrom1964to2013duringalltimesofyearandday.Thenumberofdatarecordsper
stationrangesfrom1tonearly2,000.Julywasassumedtobethecriticalmonthduringwhichwater
temperaturesreaching68°F(20°C)couldnegativelyimpactcoldwaterfishes.Fromthefulldataset
(68,948records),7,373datapointsfrom1,413stationsweretakenduringthemonthofJuly,
rangingover1964‐1984.Julysamplestationsarenotevenlydistributedacrossthestate,with
relativelyfewacrosstheeasternplainsandneartheWyomingborder,andwithgenerallyclumped
spacing(Figure2.10).
MultipleJulydatarecordsforasinglestationwereaveraged.MeanJulywatertemperatureper
stationrangedfrom33.8‐87.1°F(1‐30.6°C).
A2‐power,cross‐validatedlocalpolynomialinterpolationwascalculatedonthemeanJulywater
temperaturestoderivewatertemperaturecontourlinesacrossthestate.Temperaturevalueswere
weightedbynumberofsamplerecordsperstation,togivehigherweighttothemorecertainvalues.
Notsurprisingly,modelfitwaspoorinthoseareaswithfewdatapoints,butwasexcellenttogood
inthoseareasmostlikelytorepresentthetemperaturetransitionline(Figure2.11),sowedeemed
themodelacceptableforthecurrentpurpose.
150 Colorado Natural Heritage Program © 2015 Figure 2.10. STORET stations with July water temperature readings.
Figure 2.11. Prediction Standard Error. Climate Change Vulnerability Assessment for Colorado BLM 151 AfilledcontourforJulywatertemperaturesbetween67‐69°F(19.5‐20.5°C)wasgeneratedfrom
thelocalpolynomialinterpolationpredictionsurface(Figure2.12).Projectedfuturetemperatureis
availableassurfaceairtemperature,andthereisnotaone‐to‐onerelationshipbetweenairand
watertemperaturesoverColorado'scomplextopographical,elevational,andlatitudinalranges.To
accountfornorth‐southandeast‐westgradientsintranslatingthewatertemperaturecontourtoair
temperature,wedividedthestateintosixequalsections.Foreachoffoursections(thetwoeastern
sectionswerenotusedduetolackofdata)wecalculatedthemeanandstandarddeviationofthe
currentmeanJulyairtemperatureforeachwatertemperaturecontoursegmentwithinthesection
(theSouth‐CentralsectionhastwoseparatecontourstodistinguishtheconditionswithintheSan
LuisValley(Figure2.12).
Figure 2.12. Interpolated water temperature 67 ‐ 69°F filled contour, split into North‐West, North‐Central, South‐
West, and South‐Central sections. Colors represent the mean July air temperature coinciding with each contour section. Eachfilledcontoursectionisnotasinglelinebutanarea.Airtemperaturesbelowthemeancanbe
thoughtofasrepresentingthe"leading"edgeofthetransitionbetweencoldandcool‐water
fisheries,whilevaluesabovethemeanwouldrepresentthe"trailing"edgeforthetransitionfrom
cooltowarm‐waterfisheries.Ouranalysisfocusedonmeanvalues(Table2.10)asthebest
representationoftheoveralltransitionarea.
Foreachcontoursegmentshownabove(NW,NC,SW,SC,andtheSanLuisValley),wegenerateda
contourofthecurrentJulyairtemperaturemeanvalue(tablecolumnshadedinblue).Thesefive
sectionalcontourswerethenmanuallystitchedtogetherintoasinglecohesivetemperature
152 Colorado Natural Heritage Program © 2015 contourforthestate,representingthecurrentcoldtowarm‐waterfisheriestransitionline.The
sameprocedurewasfollowedtocreateprojectedfuturetransitionlinesforRCP4.5andRCP8.5
(Figure2.13).ThevulnerabilityanalysiswasmadebycomparingthecurrentandRCP8.5lines,to
maintainconsistencywiththeterrestrialecosystemevaluation.Notethat,becauseweareusingair
temperatureasaproxyforwatertemperature,cold‐waterreleasesfromreservoirstoragearenot
accountedforinthemodel.
Table 2.10. Mean and standard deviation (STD) current July air temperature (°F) values for each contour segment within a section. Values in parentheses are °C. Section
Mean
STD
SC, valley 63.4 (17.4) 2.78 (1.55) NW 66.7 (19.3) 3.61 (2.00) SC, east 68.6 (20.3) 4.76 (2.64) SW 69.6 (20.9) 3.49 (1.94) NC 69.8 (21.0) 3.13 (1.74) Themodeledtransitionlinewasusedtoassignstreamandriverreachestocold,transitional,or
warmwatercategories.Transitionalreachesarethoselyingwithinapproximately0.5kmoneither
sideofthetransitionline;exactdistancesaresomewhatvariabledependingonlocalstream
morphologyandreachsegmentlength.
Exposuretoclimatechangewasevaluatedbycomparingthetotalstreamlengthcurrentlyfallingin
eachcategorywiththetotalsunderprojectedmid‐centuryconditions.Percentchangebetween
categoriesissummarizedbyregion(Eastern,Mountain,Western),usingthesamedivisionsthat
wereappliedtowetlandandriparianecosystems.
Tofocusthevulnerabilityanalysisonthelossofcoldwaterandtransitionalreaches,weuseda
decision‐treebasedoncurrentandprojectedstreamlengthsinthesecategoriestoassignexposure
ranksforstreamsandrivers(Figure2.14).Vulnerabilityishighestinregionswherecurrently
existingcoldwaterandtransitionalreachesareessentiallyentirelyeliminated.Inregionswhere
currentpresenceofcoldortransitionalreachesisalreadyverylow,vulnerabilityismoderate,in
thatlossesareminimal,butalreadywarmreachesareexposedtoadditionalwarminganddrying.
Vulnerabilityisalsomoderateinareaswherelengthsofcoldandtransitionalreacheswilldecline
substantially,butremainpresent.Areaswherecoldandtransitionalreachesremainpresentin
substantiallengthshavecomparativelylowvulnerability.
Climate Change Vulnerability Assessment for Colorado BLM 153 Figure 2.13. Modeled transition line.
154 Colorado Natural Heritage Program © 2015 Cold + Transitional reaches currently > 50km ? No
Yes
Moderate Cold + Transitional reaches in mid‐century > 50km? No
Yes
High Cold + Transitional reaches in mid‐century > 500km? No
Yes
Moderate Cold + Transitional reaches in mid‐century > 10,000km? No
Yes
Moderate Low Figure 2.14. Decision‐tree for exposure criteria applied to rivers and streams. LakesandreservoirsarepoorlydistinguishedinmostGISdata,andtherearefewnaturallakesin
Coloradothathavenotbeenmodifiedtosomeextentforwaterstorage.Weconsideredanywater
bodywithsurfaceareagreaterthanorequalto3km2areservoir,andsmallerwaterbodieswere
classifiedaslakes.Bothlakesandreservoirsweredesignatedaseither“high”or“low”elevation,
accordingtotheirpositioninrelationtothemodeledtransitionaltemperatureline.GISmetrics
werecalculatedusingthesamesixdivisionsofthestateshowninFigure2.12,toaccountfornorth‐
southandeast‐westtemperaturedifferencesinherentinColorado.Exposurewascalculatedfor
lakesandreservoirsusingmethodssimilarforthoseusedinevaluatingterrestrialecosystems
(proportionofacreagewhereprojectedannualmeantemperatureformid‐centuryunderRCP8.5
wasgreaterthananyannualmeantemperaturescurrentlyexperiencedbythatecosystemwithin
Colorado,ANDprojectedfutureprecipitationchangeswerelessthan5%increaseovercurrent
levels,butwithoutadditionalmodifiers(Table2.11).
Table 2.11. Criteria for scoring exposure of lakes and reservoirs freshwater ecosystems. Percent Colorado acres with projected temp > max & ppt delta < 5% Initial Exposure‐Sensitivity Score 36 – 100% 16 – 35% 0 – 15% High Moderate Low Resilience‐Adaptive Capacity Assessment – Freshwater Ecosystems
Thisscoresummarizesindirecteffectsandnon‐climatestressorsthatmayinteractwithclimate
changetoinfluencetheadaptivecapacityandresilienceofanecosystem.Factorsevaluatedare
adaptedfromthemethodologyusedbyManometCenterforConservationScienceand
MassachusettsDivisionofFishandWildlife(MCCSandMAFW2010),combinedunderfiveheadings
(Table2.12).Factorswerescoredonascaleof0(lowresilience)to1(highresilience).
Climate Change Vulnerability Assessment for Colorado BLM 155 Table 2.12. Description of factors used to assess resilience‐adaptive capacity in freshwater ecosystems. Assessment factor
Description
Restriction to specific hydro‐
geomorphic setting Fundamental geomorphic characteristics that define stream and wetland systems (elevation, slope, drainage area) do not change appreciably over decades. However, headwater streams are constrained by upper limits to watersheds, some larger streams or rivers are constrained at their lower limits by the presence of water bodies, including large reservoirs, and lakes or reservoirs are fixed in location. In addition, increasing temperature and accompanying changes in hydrology and water quality could result in the transition of one stream or river type to another. Vulnerability to change in snowmelt timing and magnitude, and/or decreasing baseflows The timing and magnitude of snowmelt runoff provide a key habitat component for some aquatic species. Earlier peak flows, reduced flows, changes in flood frequency or magnitude, and the overall shape of the hydrograph may change under projected climatic conditions. Effects could include shifts in spawning behavior, as well as loss or displacement of spawning beds and other important habitat structure. Lower base flows, and reduced groundwater discharge are possible under projected increased temperatures. These changes can reduce habitat area, as well as increasing habitat vulnerability to temperature and water quality stress. Finally, if overall water supplies decrease, anthropogenic efforts to divert and store water are likely to increase the level of hydrologic modification in these ecosystems. Vulnerability to increased impact by biological stressors This factor summarizes whether expected future biological stressors (invasive species, pests and pathogens) have had, or are likely to have, an increased effect due to interactions with changing climate. Climate change may result in more frequent or more severe outbreaks of these stressors. Ecosystems that are currently vulnerable to these stressors may become more so under climate change. Aquatic pathogens of concern include whirling disease, giardia, and cryptosporidium. Increased temperatures and the resulting hydrologic changes may make freshwater ecosystems more susceptible to invasion by non‐native species, including quagga mussel, New Zealand mudsnail, rusty crayfish, Eurasian millefoil, and others. Finally, native species (e.g., the alga Didymosphenia geminata) can proliferate as nuisance species under changing climatic conditions. Vulnerability to increased frequency or intensity of extreme events This factor evaluates characteristics of an ecosystem that make it relatively more vulnerable to extreme events (floods, drought, fire) that are projected to become more frequent and/or intense under climate change. Flooding and drought frequency may alter geomorphic processes, sedimentation, water quality, and the stability of small populations. An increase in large fires may change sediment loads and water quality. Other indirect effects of non‐
climate stressors This factor summarizes the overall condition of the ecosystem at the landscape level across Colorado, and is derived from a summary impact score indexing the degree of hydrological modification and anthropogenic disturbance (TNC 2012). 156 Colorado Natural Heritage Program © 2015 Restriction to specific hydro‐geomorphic setting
Scoresof0=lowresilience,0.5=intermediateoruncertainresilience,and1=highresiliencewere
assigned,basedonbestprofessionaljudgementfocusedontherelativevulnerabilityofeachtypein
comparisonwithothertypes.
Vulnerability to change in snowmelt timing and magnitude, and/or decreasing baseflows
Scoresof0=lowresilience,0.5=intermediateoruncertainresilience,and1=highresiliencewere
assigned,basedonbestprofessionaljudgementfocusedontherelativevulnerabilityofeachtypein
comparisonwithothertypes.
Vulnerability to increased impact by biological stressors
Foreachbiologicalstressor(invasivespeciesandpathogens‐pests)towhichanecosystemis
believedvulnerable,0.5wassubtractedfromadefaultscoreof1,toproducethefinalecosystem
score.
Vulnerability to increased frequency or intensity of extreme events
Foreachnon‐biologicalstressor(drought,flooding,andfire)towhichanecosystemisbelieved
vulnerable,0.33wassubtractedfromadefaultscoreof1,toproducethefinalecosystemscore.
Other indirect effects of non‐climate stressors
Resiliencetoclimatechangewasevaluatedusingthemeasuresofaquaticresourcecondition
databaseforColoradodevelopedbyTheNatureConservancy(2012).Thedatabaseincludesa
metricthatsummarizesconditionfactorsunderfiveprimaryheadingsasshowninTable2.13for
eachstreamreach.Thesummarymeasurerangesfrom1(verygoodcondition,littleornoimpact)
to4(poorcondition,heavilyimpacted).Wereportthelength‐weightedaverageofthesummary
metricbystreamorrivercategorywithinthesamethreeregions(Eastern,Mountain,Western)
describedabove.
Table 2.13. Factors included in TNC freshwater measures of condition database. Natural Flow Regime
Riparian Condition
Development
Connectivity
Water Quality
 Consumptive Use (Agricultural Use, Municipal Use, Transbasin Diversions)  Reservoir Storage  Riparian Land Use  Non‐native Plants – Tamarisk – in the Riparian Vegetation 




 Instream Barriers to Fish Movement  Streams with a 303d and/or Monitoring and Evaluation Designation Land Use Road Density Road Crossings Oil and Gas Mining Vulnerability Assessment Ranking
Overall Vulnerability Ranking
TheExposure‐SensitivityscoreandtheResilience‐AdaptiveCapacityscorearecombinedinthe
samewayasforterrestrialecosystems(Figure2.2)toproduceanoverallvulnerabilityrankfor
eachfreshwaterecosystem.
Climate Change Vulnerability Assessment for Colorado BLM 157 FRESHWATER ECOSYSTEMS ‐ RESULTS
Table 2.14. Key vulnerabilities, freshwater ecosystems. Habitat
Climate factor(s)
Consequences
Other considerations
Streams ‐ west Warming water temps Loss of cool‐water reaches Connectivity; altered hydrology due to diversions Streams ‐ mtn. Timing and amount of snowmelt/runoff Altered hydrographs Connectivity (including transbasin diversion), potential for increased wildfire disturbance Streams ‐ east Warmer and drier conditions Loss of perennial reaches Connectivity; altered hydrology due to diversions Rivers ‐ west Warming water temps Loss of cool‐water reaches, low summer flows Connectivity (including transbasin diversion), potential for increased wildfire disturbance Rivers ‐ mtn. Timing and amount of runoff Altered hydrographs Connectivity (including transbasin diversion) Rivers ‐ east Timing and amount of runoff Altered hydrographs Connectivity; altered hydrology due to dams and diversions Lakes, high Warmer and drier conditions Reduced water quality Nitrogen deposition Lakes, low Warmer and drier conditions Low water levels Municipal & agricultural supply pressure Reservoirs, high Timing and amount of snowmelt/runoff Earlier high water levels Flood control releases, reduced later storage Reservoirs, low Warmer and drier conditions Low water levels Municipal & agricultural supply pressure 158 Colorado Natural Heritage Program © 2015 STREAMS, RIVERS, LAKES, AND RESERVOIRS
FreshwaterecosystemsinColoradoincludebothcold‐andwarm‐waterstreamsandrivers,aswell
astransitionalcool‐waterstreamandriverreaches.Lakesandreservoirsarealsoincludedinour
analysis.
CNHP photos Climate Vulnerability Ranks:
Threeofthe10regionalecosystemsubtypesassessedhaveanoverallvulnerabilityrankofHigh,
andtwoarerankedVeryHigh(Table2.15).Theprimaryfactorcontributingtothehighexposure
rankingsforriversistheessentiallycompletelossofcurrentcoldandtransitionalreaches.Lakes
andreservoirsatallelevationsareprojectedtoexperiencetemperaturesoutsidethecurrentrange,
aswellaseffectivelydrierconditions.Mostecosystemsubtypeswereassessedashavingmoderate
resilience,withonlymountainstreamshavinghighresilienceandlowoverallvulnerabilitybymid‐
century.
Climate Change Vulnerability Assessment for Colorado BLM 159 Table 2.15. Vulnerability rank summary for all assessed freshwater ecosystems. Freshwater Ecosystem Target
Streams West Exposure ‐
Resilience ‐
Combined
Sensitivity final Adaptive capacity
ranks
ranking
final ranking
Overall
vulnerability
rank
Moderate Moderate M/M Moderate Low High L/H Low Moderate Moderate M/M Moderate High Moderate H/M High Moderate Moderate M/M Moderate High Moderate H/M High Lakes ‐ high High High H/M Moderate Lakes ‐ low High Low H/L Very High Reservoirs ‐ high Moderate Moderate M/M Moderate Reservoirs ‐ low High Low H/L Very High Streams Mountain Streams East Rivers West Rivers Mountain Rivers East Vulnerability summary
Key vulnerabilities: Rivers and Streams Warming water temperatures are expected to lead to loss of cool‐water reaches in both rivers and streams in western Colorado, and to lower summer flows. Warmer temperatures will generally result in earlier snowmelt and runoff for mountain streams and rivers. In eastern Colorado, warmer and drier conditions are likely to reduce the extent of perennial stream reaches, and alter the hydrographs of large rivers that depend on snowmelt. Nearly all river and stream habitats are already impacted by dams and diversions that have degraded the connectivity and hydrology of the ecosystem. Lakes and Reservoirs Warmer and drier conditions for lower elevation lakes and reservoirs are likely to result in generally lower water levels under pressure from municipal and agricultural consumers. High elevation lakes may see reduced water quality as temperatures warm; some areas are already affected by nitrogen deposition. Changes in timing and amount of snowmelt runoff may change storage patterns in higher elevation reservoirs; early flood control releases may lead to reduced late‐season water levels. Smallerloticecosystems(streams)havegenerallylowervulnerability,especiallyathigher
elevationswherecoldwaterreachesarelikelytoremainviable.Theprimaryfactorcontributingto
highorveryhighvulnerabilityranksforfreshwaterecosystemsistheprojectedchangeinthe
transitionzonebetweenwarmandcoldwaterareas.Mostfreshwaterecosystemswererankedas
moderatelyresilient,indicatingthattherearelikelytobemanagementopportunitiestomitigate
someeffectsofexposuretowarmerconditions.
160 Colorado Natural Heritage Program © 2015 Distribution
FreshwaterecosystemsinColoradoarefoundthroughoutthestate,althoughperennialstreamsand
lakesaremorecommonathigherelevations.WiththeexceptionoftheGreenRiver,whichcrosses
thenorthwesterncornerofthestate,allofColorado’smajorriversoriginatewithinthestateand
flowawayfromthecontinentaldivide.Totheeastofthedivide,streamsandriversdraintoward
theGulfofMexico.Onthewesternslope,flowingwatersaretributarytotheColoradoRiver,
drainingtowardthePacificOcean.ConditionsinColoradowatershedsaffectmanydownstream
users,bothwithinthestate’sbordersandbeyond.WaterdistributioninColoradohasevolveda
complexsystemofdiversions,irrigationwells,andwaterstoragefacilitiesthathavealteredthe
originalhydrologicregimeofmanyareas.
Environment
Freshwaterecosystemsasevaluatedinthisassessmentareallpartofaninterconnectedhydrologic
networkthatincludesbothsurfaceandgroundwater.Forthepurposesofourassessment,we
dividethesurfacewatersofthisnetworkintoseveralbroadtypesbysize,flowpatterns,and
location.Flowingwatersofstreamorder5through7(thelargestinColorado)arediscussedherein
as“rivers”,whileflowingwatersoflowerorderaretermed“streams.”Underthisgrouping,rivers
includethelargerperennialstreamreaches,togetherwiththeirmajortributaries,thatdrain
watershedsontheorder10,000+squaremilesinextent.Streamsincludeallothersmallerreaches
bothperennialandintermittent,fromheadwaterstotheirjunctionwithrivers,ifany.
Lakesandreservoirsarealsopartofthehydrologicnetwork,buthavegenerallymuchslower
current,suchthattheygenerallyappearasstandingbodiesofwater,andmaybeisolatedfrom
perennialsurfaceflow.Becausemanylakeshavebeenmodifiedtosomeextenttoregulatewater
flow,wegroupedlargerimpoundments(greaterthanorequalto3km2inarea)togetheras
reservoirs,andsmallerwaterbodies(lessthan3km2inarea)aslakes,regardlessofmodification.
Finally,weassessedfreshwaterhabitatsaccordingtoelevationandregionallocationwithinthe
state.
Dynamics
BaronandPoff(2004)identifiedfivedynamicfactorsthatshapethestructureandfunctionof
freshwaterecosystems:theflowpatternofwaterthroughthesystem,inputsofsedimentand
organicmatter,nutrientandchemicalconditions,temperatureandlightlevels,andplantand
animalassemblages.
Flowpatternsdescribethewaywaterpassesintoandoutofstreams,rivers,lakesandassociated
wetlands.Importantcharacteristicsincludebaseflowlevels,theperiodicityandmagnitudeofboth
annualorfrequentfloodsandrareandextremefloodevents,seasonalityofflows,andannual
variability(BaronandPoff2004).Patternsofwaterflowandtheirinteractionwithlocallandforms
andsubstratesatavarietyofscalesaretheprimarydeterminantofphysicalhabitatforriver
organisms.Aquaticorganismsevolvedwithandareadaptedtothecharacteristicnaturalflow
regimeoftheirhabitat;changesinflowregimecancauseseriousdisruptiontothereproduction
andsurvivalofmanyaquaticspecies,leadingtoaneventuallossofbiodiversity(Bunnand
Arthington2002).Reducedconnectivityinaquatichabitats,bothin‐streamandbetweentheriver
Climate Change Vulnerability Assessment for Colorado BLM 161 channelandassociatedfloodplainhabitats,reduceshabitatavailabilityanddiversity,with
consequentnegativeeffectsonthepopulationviabilityofaquaticspecies.Alteredflowregimes,and
transbasindiversionscanfacilitatetheinvasionandestablishmentofexoticspecies(Bunnand
Arthington2002).Finally,riverinesystemsacttointegrateandcollecttheeffectsofdisturbances
withinthecatchment,includingthoseduetoflowmodification(Naimanetal.2002).
Sedimentandorganicmatterinputstofreshwaterecosystemsmayincludebothnaturaland
anthropogenicsources.Thearrivalofnaturalorganicmatter(e.g.,plantmaterial)fromadjacent
uplandareasisaregularseasonaloccurrence,andsedimentmovementsoccurnaturallywith
seasonalandinterannualvariationinwaterflow.Manyplantandanimalspeciesofthesehabitats
arecloselyadaptedtospecificsedimentandorganicmatterconditions,andareeasilyeliminatedby
changesintheenvironment(BaronandPoff2004).Anthropogenicdisturbancessuchas
agriculture,logging,roadconstruction,dams,anddiversionshavehighlymodifiedthenatural
sedimentandorganicinputoffreshwaterecosystems.Unmodifiedstreamsdisplayamosaicof
habitatscreatedbyflowandsedimentationpatterns.Extensiveremovalofbeaverthroughout
Coloradointhefirsthalfofthe19thcenturyprobablyhadaconsiderableeffectonchannel
structure,diversity,andstability,aswellassedimentlevelsinmountainstreams(Wohl2006).
Placerminingwasanevenstrongeragentofhydrologicmodificationinmanyareas.Diversion
damstendtoshifthabitattowardslowerflowandincreasedfinesedimentation(Bakeretal.2011).
Thelegacyofthesehistoricanthropogenicdisturbancesisreducedhabitatsuitabilityfornative
species.
Naturalnutrientandchemicalconditionsinfreshwaterecosystemsarelargelydeterminedby
climate,bedrock,soil,vegetation,andtopographyinthevicinity,andareconsequentlyhighly
variablebylocale(BaronandPoff2004).Humanactivitiescanaddnutrients(eutrophication),ora
varietyofman‐madechemicals(herbicides,pesticides,pharmaceuticals,etc.)thatchangethe
speciescompositionandqualityofthesehabitats(Carpenter1998).
Watertemperatureiskeyindeterminingoxygenconcentrationandthelifeprocessesofaquatic
organisms.Patternsoftemperatureandsolarenergyabsorptiondifferbetweenmovingandstill
waters.Thereleaseofcoldwaterfromreservoirstorageinterruptsthenaturaltemperature
patternsimmediatelydownstream.
Changingclimateconditionscanaffectallthesefactors,butdirectlyactthroughtemperatureand
flow.
Characteristic species
Thecompletebioticcommunityofanaquaticecosystemincludesplantsandalgae,aswellas
invertebrateandvertebrateanimals.Environmentalconditionsanddynamicsinpartdeterminethe
plantandanimalassemblagesthatwillbeassociatedwithaparticularfreshwaterecosystem.In
turn,thebiotaareactiveparticipantsinecologicalprocesses.Acompletedescriptionofspecies
characteristicofColorado’sfreshwaterecosystemsisbeyondthescopeofthisassessment,but
commonandimportantmacroinvertebratesincludecrustaceansandspeciesofEphemeroptera,
Plecoptera,Trichoptera,andOdonata,amongothers.
162 Colorado Natural Heritage Program © 2015 FishofColorado’sfreshwaterecosystemsincludebothnativeandintroducedspecies.Fishspecies
showninTable2.16arerepresentativeofsomeofthefreshwaterecosystemsevaluated.
Vulnerabilityresultsfromspecies‐specificClimateChangeVulnerabilityIndexanalysis(seeChapter
3)areshown,ifavailable.
Table 2.16. Representative fish species for freshwater ecosystems. Warm
Water
Representative fish
species
CCVI rank
Rivers
Streams
Rivers
Streams
Lakes ‐ high
Streams
Transitional
Rivers
Cold Water
Colorado River Cutthroat Extremely vulnerable X X X X X Greenback Cutthroat X X X X X Rio Grande Cutthroat Extremely vulnerable X X X X X Mottled sculpin X X X X Speckled dace X X X X Brown trout X X Bluehead sucker Highly vulnerable X X X X Flannelmouth sucker Highly vulnerable X X X X Roundtail Chub Highly vulnerable X X X X Bonytail chub Extremely vulnerable X X Colorado pikeminnow Extremely vulnerable X X Humpback chub Extremely vulnerable X X Razorback sucker Highly vulnerable X X Climate Change Vulnerability Assessment for Colorado BLM 163 CCVA Scoring
Exposure‐Sensitivity (Potential Impact) Ranks
Ecosystem
Method
Score
Streams West Decision tree Moderate Streams Mountain Decision tree Low Streams East Decision tree Moderate Rivers West Decision tree High Rivers Mountain Decision tree Moderate Rivers East Decision tree High Lakes – high elev. Avg. “out of range” High Lakes – low elev. Avg. “out of range” High Reservoirs – high elev. Avg. “out of range” Moderate Reservoirs – low elev. Avg. “out of range” High Underthescopeofouranalysis,thetotalstreamandriverlengthpresentinthestateisassumedto
remainconstantbetweenthepresentandmid‐century.Theeffectsofwarmingtemperatureare
measuredbycomparingtheproportionofstreamandriverreachesthatmovefromonecategoryto
thenext.Undertheconstraintsofthetechnique,areachcanremaininthesamecategory,ormove
toawarmercategory,butnevermovetoacoolercategory.
Asexpected,bothstreamsandriversinthemountainregionarecurrentlydominatedbycoldwater
reaches,andtherearelimitedcoldwaterreachespresentinboththeeasternandwesternregions
(Figure2.15,Table2.17).Cooltocoldwatertransitionreachesarecurrentlymostcommonin
westernriversandstreams.Botheasternandwesternriversandstreamscurrentlyhavea
significantproportionofwarmwaterreaches.
StatewidepatternsoftransitionareshowninFigure2.16.Anoverallretreatofcoldwater
conditionstohigherelevationsisevident.Majorriversonboththeeastandwestslopeare
projectedtoseewarmerwatertemperaturesfarupstream.Thiseffectisparticularlyevidentonthe
westernrivers.
Underprojectedwarmingwatertemperaturesatmid‐century,forallregionstheproportionof
warmwaterreachlengthincreases.Transitionalareasgenerallymoveupinelevation,andbecome
concentratedinthemountainregion.Withoutaccountingforwatertemperaturesmaintainedby
storagerelease,coldwaterreachesessentiallydisappearfromthelowerelevationsofbotheastern
andwesternColorado.
164 Colorado Natural Heritage Program © 2015 Exposureto“outofrange”conditionsforlakesandreservoirswaslowestforhighelevation
reservoirs.Bothlowandhighelevationlakeswereinthemoderatelyvulnerablecategory,although
higherelevationlakeshadslightlylessexposure.Lowelevationreservoirshadhighestexposure
underprojectedmid‐centuryclimateconditions.
Figure 2.15. Category transitions between current and projected (RCP 8.5) conditions for streams and rivers. Climate Change Vulnerability Assessment for Colorado BLM 165 Table 2.17. Reach length statistics (km) for water temperature categories both statewide and by region. Cold Water
Transitional
Warm Water
Statewide:
Rivers
Streams
Rivers Streams
Rivers Streams
Current 1,394
64,728
395
12,342 4,480 63,386
% Total 1%
44%
0%
8%
3% 43%
RCP 8.5 560
36,882
117
14,227 5,591 89,348
% Total 0.4%
25%
0.1%
10%
4% 61%
% change from Current ‐60%
‐43%
‐70%
15%
25% 41%
By Region:
West Slope Current 58
0.2%
0
0%
‐100%
% Total RCP 8.5 % Total % change from Current Southern Rocky Mountains
Current % Total RCP 8.5 % Total % change from Current Eastern Plains
Current % Total RCP 8.5 % Total % change from Current 3,044
11%
20
0.07%
‐99%
1,321
2%
560
1%
‐58%
59,640
84%
36,862
52%
‐38%
15
0.03%
0
0%
‐100%
2,044
4%
0
0%
‐100%
129
0.5%
0
0%
‐100%
245
0%
117
0.2%
‐52%
14
0.03%
0
0%
‐100%
4,564
16%
362
1%
‐92%
1,408 5% 1,596 6% 13% 5,640
8%
13,663
19%
142%
18,515
67%
25,741
93%
39%
569 1% 1,456 2% 156% 3,547
5%
18,303
26%
416%
2,138
4%
201
0.4%
‐91%
2,510 5% 2,539 5% 1% 41,324
86%
45,304
94%
10%
166 Colorado Natural Heritage Program © 2015 Figure 2.16. Comparison of current (top) and projected (bottom) stream temperature classification. Climate Change Vulnerability Assessment for Colorado BLM 167 Resilience and Adaptive Capacity Ranks
Ecosystem
Score
Rank
Streams West 0.54 Moderate Streams Mountain 0.71 High Streams East 0.61 Moderate Rivers West 0.49 Moderate Rivers Mountain 0.58 Moderate Rivers East 0.66 Moderate Lakes ‐ high 0.68 High Lakes ‐ low 0.39 Low Reservoirs ‐ high 0.59 Moderate Reservoirs ‐ low 0.27 Low Restriction to specific hydro‐geomorphic setting Highelevationlakesarescoredasmostrestrictedbytheirlocation.Otherwaterbodiesarescored
asintermediateinlocationrestriction,asarehigherelevationstreamsandrivers.Lowerelevation
streamsandriversarepresumedtobeunrestricted.
Score
Ecosystem
Streams West 1 Streams Mountain 0.5 Streams East 1 Rivers West 1 Rivers Mountain 0.5 Rivers East 1 Lakes – high elev. 0 Lakes – low elev. 0.5 Reservoirs – high elev. 0.5 Reservoirs – low elev. 0.5 168 Colorado Natural Heritage Program © 2015 Vulnerability to change in snowmelt timing and magnitude, and/or decreasing baseflows Streams,lakes,andreservoirsofhighelevationsarescoredasleastvulnerabletochangesin
snowmelttimingandmagnitude,andwithlessvulnerabilitytodecreasingbaseflows,underthe
assumptionthathigherelevationsarelesslikelytoseeeffectivelydrierconditionsbymid‐century.
Streams,rivers,andlakesoflowerelevationsarescoredashavingintermediatevulnerabilityfor
thesefactors,basedontheassumptionthattheeffectsofincreasingtemperaturesandeffectively
drierconditionswilltendtoaccumulateinthesedownstreamreaches.Lowelevationreservoirsare
assumedtobemostvulnerable.
Score
Ecosystem
Streams West 0.5 Streams Mountain 1 Streams East 0.5 Rivers West 0.5 Rivers Mountain 0.5 Rivers East 1 Lakes – high elev. 1 Lakes – low elev. 0.5 Reservoirs – high elev. 1 Reservoirs – low elev. 0 Vulnerability to increased impact by biological stressors Ingeneral,freshwaterhabitatsofthehighestelevationsarescoredasnotvulnerabletoincreased
impactbypathogensorinvasives,duetocomparativelycoolertemperaturesintheseareas,andthe
currentlowlevelsofsuchstressors.Lowelevationecosystemsarescoredasmorevulnerableto
invasivespeciesandpathogens,duetothewarmertemperatures,andthefactthatsomeinvasives
andpathogensarealreadypresentinthesehabitats.
Ecosystem
Streams West Streams Mountain Streams East Score
Factors
0.5 Pathogens 1 ‐‐‐ 0.5 Invasives Rivers West 0 Pathogens & Invasives Rivers Mountain 1 ‐‐‐ Rivers East 0.5 Invasives Lakes – high elev. 1 Lakes – low elev. 0 ‐‐‐ Pathogens & Invasives Climate Change Vulnerability Assessment for Colorado BLM 169 Score
Factors
Reservoirs – high elev. 0.5 Invasives Reservoirs – low elev. 0 Pathogens & Invasives Ecosystem
Vulnerability to increased frequency or intensity of extreme events Increasingfrequencyandseverityofdroughtistheprimaryfactorthatislikelytoincrease
vulnerabilityoffreshwaterecosystems.Streamsinwesternandmountainareasarescoredasbeing
vulnerabletoincreasedsedimentationfollowingapotentialincreaseinfirefrequency.Mountain
riversarescoredasvulnerabletoapotentialincreaseinextremeprecipitationevents.High
elevationlakesarenotthoughttobevulnerableinthiscategory.
Score
Factors
Streams West 0.33 Drought, fire Streams Mountain 0.67 Fire Streams East 0.67 Drought Ecosystem
Rivers West 0.67 Drought Rivers Mountain 0.67 Flooding Rivers East 0.67 Drought Lakes – high elev. 1 ‐‐‐ Lakes – low elev. 0.67 Drought Reservoirs – high elev. 0.67 Drought Reservoirs – low elev. 0.67 Drought Other indirect effects of non‐climate stressors Thelength‐weightedmeanscorebyregionforthesummaryconditionfactor(TNC2012)was
convertedtoaproportionofpotentialbestscore(4)usingtheformula:1–((regionmean‐1)/3).A
lowermeanbeforescoreconversionindicatesbettercondition,andhigherresilience.Ingeneral,
higherelevationareasareinbettercondition.
Ecosystem
Mean
Score
Streams West 2.57 0.48 Streams Mountain 2.45 2.57 0.52 0.48 Rivers West 2.94 0.35 Rivers Mountain 3.08 0.31 3.53 0.16 2.34 0.55 2.80 0.40 Streams East Rivers East Lakes – high elev. Lakes – low elev. 170 Colorado Natural Heritage Program © 2015 Ecosystem
Mean
Score
Reservoirs – high elev. 2.94 0.35 Reservoirs – low elev. 3.25 0.25 Conclusions
Allfreshwaterecosystemsareexpectedtobeaffectedtosomeextentbyclimatechange.Aswater
temperatureschange,somewarm‐waterhabitattypesmayexpandattheexpenseofcool‐orcold‐
watertypes.Nearlyallevaluatedfreshwatertypeswererankedwithmoderatetoveryhigh
vulnerabilityinouranalysis,withreasonablecertaintythatthesehabitatswillbeimpactedby
climatechange.Althoughwedidnotincorporatefreshwaterfishspecies‐specificscoringintoour
vulnerabilityanalysis,thoseresults(Chapter3)tendtosupportthegenerallyhighervulnerability
levelsforfreshwaterecosystems.Uncertaintyintheevaluationisduetouncertaintyinclimate
projections,thescopeofcurrentknowledge,andongoingmanagementactions.
Thereisevidencefrommonitoringrecordsthatwarmerairtemperatureshavealreadyaffected
watertemperaturesandhydrographsinmountainstreams(Isaaketal.2012).Bymid‐century,
underbothmoderateandhighradiativeforcingscenarios(RCP4.5andRCP8.5),wecanexpectto
seeevenwarmertemperaturesstatewide,especiallyontheeasternplains.Warmerair
temperaturesareexpectedtoleadtowarmerwatertemperatures,earliersnowmelt,lossof
permanenticefields,andpossiblydrierconditions.Evenifprecipitationlevelsathigherelevations
areessentiallyunchanged,warmerconditionswillleadtomoreprecipitationfallingasraininstead
ofsnow,adecreasedsnowpack,earlierrunoff,andearlierdryconditionsinlatesummer(Lucaset
al.2014).Allofthesefactorsarelikelytointeractwithstressesarisingfromalteredhydrology
(dams,diversions,etc.),andsocio‐economicdemandsforcontinuedwateravailabilityatpreviously
establishedlevels.
ThehighlymanagednatureofwaterresourcesinColoradotosomeextentconfoundsour
preliminaryevaluationofvulnerabilitytoclimatechangefortheseecosystems.Waterstorageand
releasepatternsdonotalwaysmimicconditionsthatwouldbefoundonanunmanipulatedreach,
andthismaybenefitsomespecieswhileharmingothers.Furthermore,theimpactsofwarming
temperaturesandpotentiallychangingprecipitationpatternsonfreshwaterecosystemscanbe
enhancedbyfragmentationormitigatedbyincreasedconnectivityintheseinterconnected
networksofhabitats.Formostspecies,intactconnectivitywithinthehydrologicnetworkwillbe
crucialforadaptationtochangingconditions;however,speciesassemblagesarelikelytochangeas
lessmobilecommunitymembersareeliminated.Enhancingconnectivitywithconcomitant
reductioninanthropogenicstressesislikelytobethemostproductiveapproachforconserving
freshwaterecosystemsunderfutureclimaticconditions(Khamisetal.2014).
Strategiesformeetingthechallengesoffutureconditionsareperhapsmostcomplexandyetmost
urgentforfreshwaterecosystems.Althoughdaunting,earlieractionislikelytoallowincreased
opportunityforfutureadaptivemanagementthandelayorinaction.
Climate Change Vulnerability Assessment for Colorado BLM 171 Literature Cited
Baker,D.W.,B.P.Bledsoe,C.M.Albano,andN.L.Poff.2011.Downstreameffectsofdiversiondamsonsedimentand
hydraulicconditionsofRockyMountainStreams.RiverResearchandApplications27:388‐401.
Baron,J.S.andN.L.Poff.2004.Sustaininghealthyfreshwaterecosystems.UniversitiesCouncilonWaterResources,Water
ResourcesUpdate127:52‐58.
Bunn,S.E.andA.H.Arthington.2002.Basicprinciplesandecologicalconsequencesofalteredflowregimesforaquatic
biodiversity.EnvironmentalManagement30:492‐507.
Carpenter,S.R.,N.F.Caraco,D.L.Correll,R.W.Howarth,A.N.Sharpley,andV.H.Smith.1998.Nonpointpollutionofsurface
waterswithphosphorusandnitrogen.EcologicalApplications8:559‐568.
Isaak,D.J.,C.C.Huhlfeld,A.S.Todd.R.Al‐Chokhachy,J.Roberts,J.L.Kershner,K.D.Fausch,andS.W.Hostetler.2012.The
pastaspreludetothefutureforunderstanding21st‐centuryclimateeffectsonRockyMountaintrout.Fisheries37:542‐
556.
Khamis,K.,D.M.Hannah,M.HillClarvis,L.E.Brown,E.Castella,andA.M.Milner.Alpineaquaticecosystemconservation
policyinachangingclimate.EnvironmentalScience&Policy43:39‐55.
Lucas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter.2014.ClimateChangeinColorado:asynthesistosupport
waterresourcesmanagementandadaptation.Secondedition.ReportfortheColoradoWaterConservationBoard.
WesternWaterAssessment,CooperativeInstituteforResearchinEnvironmentalSciences(CIRES),UniversityofColorado
Boulder.
Naiman,R.J.,S.E.Bunn,C.Nilsson,G.E.Petts,G.Pinay,L.C.Thompson.2002.Legitimizingfluvialecosystemsasusersof
water:anoverview.EnvironmentalManagement30:455‐467
TheNatureConservancy[TNC].2012.FreshwatermeasuresofconditionforColorado.Geodatabase.
Wohl,E.2006.Humanimpactstomountainstreams.Geomorphology79:217‐248.
172 Colorado Natural Heritage Program © 2015 3 ANIMALS
Authors:
Jeremy Siemers Bernadette Kuhn Brad Lambert Robert Schorr John Sovell Recommended chapter citation: Siemers, J., B. Kuhn, B. Lambert, R. Schorr, and J. Sovell 2015. Animals. Chapter 3 In Colorado Natural Heritage Program 2015. Climate Change Vulnerability Assessment for Colorado Bureau of Land Management. K. Decker, L. Grunau, J. Handwerk, and J. Siemers, editors. Colorado Natural Heritage Program, Colorado State University, Fort Collins, Colorado. Climate Change Vulnerability Assessment for Colorado BLM 173 Table of Contents – 3 Animals Methods .................................................................................................................................................... 176 Results ....................................................................................................................................................... 180 Animal Species CCVA Summaries ............................................................................................................. 182 Boreal toad ................................................................................................................................................ 183 Canyon Treefrog........................................................................................................................................ 187 Great Basin Spadefoot .............................................................................................................................. 191 Northern Leopard Frog ............................................................................................................................. 195 American Peregrine Falcon ....................................................................................................................... 199 Black Swift ................................................................................................................................................. 203 Brewer’s Sparrow ...................................................................................................................................... 206 Burrowing Owl .......................................................................................................................................... 210 Golden Eagle ............................................................................................................................................. 214 Greater sage‐grouse ................................................................................................................................. 218 Gunnison sage‐grouse............................................................................................................................... 222 Long‐Billed Curlew .................................................................................................................................... 226 Mountain Plover ....................................................................................................................................... 230 Northern Goshawk .................................................................................................................................... 235 Western Snowy Plover .............................................................................................................................. 239 Western Yellow‐billed Cuckoo .................................................................................................................. 243 White‐faced Ibis ........................................................................................................................................ 247 Bluehead Sucker ....................................................................................................................................... 251 Bonytail Chub ............................................................................................................................................ 256 Colorado pikeminnow ............................................................................................................................... 260 Colorado River Cutthroat Trout ................................................................................................................ 265 Flannelmouth Sucker ................................................................................................................................ 270 Humpback Chub ........................................................................................................................................ 274 Razorback Sucker ...................................................................................................................................... 278 Rio Grande Cutthroat Trout ...................................................................................................................... 282 Roundtail Chub ......................................................................................................................................... 286 Great Basin Silverspot ............................................................................................................................... 290 American beaver ....................................................................................................................................... 294 Desert Bighorn Sheep ............................................................................................................................... 297 174 Colorado Natural Heritage Program © 2015 Fringed Myotis .......................................................................................................................................... 301 Gunnison Prairie Dog ................................................................................................................................ 304 Townsend’s big‐eared bat ......................................................................................................................... 308 White‐tailed prairie dog ............................................................................................................................ 311 Desert spiny lizard ..................................................................................................................................... 314 Longnose leopard lizard ............................................................................................................................ 318 Midget faded rattlesnake ......................................................................................................................... 321 List of Figures and Tables Figure 3.1. Summary of climate change vulnerability scores for animal species. EV = Extremely Vulnerable; HV = Highly Vulnerable; MV = Moderately Vulnerable; PS = Presumed Stable; IL = Increase Likely. ........................................................................................................................................................ 181 Table 3.1. Climate change vulnerability scores for animal species. EV = Extremely Vulnerable; HV = Highly Vulnerable; MV = Moderately Vulnerable; PS = Presumed Stable; IL = Increase Likely. ............... 180 Climate Change Vulnerability Assessment for Colorado BLM 175 METHODS
NatureServe Climate Change Vulnerability Index
Overview
Thisoverviewhasbeensynthesizedandreprinted,withpermission,fromYoungetal.(2011).The
ClimateChangeVulnerabilityIndex(CCVI),developedbyNatureServe,isaMicrosoftExcel‐based
toolthatfacilitatesrapidassessmentofthevulnerabilityofplantandanimalspeciestoclimate
changewithinadefinedgeographicarea.Inaccordancewithwell‐establishedpractices(Schneider
etal.2007,Williamsetal.2008),theCCVIdividesvulnerabilityintotwocomponents:
exposuretoclimatechangewithintheassessmentarea(e.g.,ahighlysensitivespecieswill
notsufferiftheclimatewhereitoccursremainsstable).
sensitivityofthespeciestoclimatechange(e.g.,anadaptablespecieswillnotdeclineeven
inthefaceofsignificantchangesintemperatureand/orprecipitation).
Exposuretoclimatechangeismeasuredbyexaminingthemagnitudeofpredictedtemperatureand
moisturechangeacrossthespecies’distributionwithinthestudyarea.CCVIguidelinessuggest
usingthedownscaleddatafromClimateWizard(http://climatewizard.org)forpredictedchangein
temperature.ProjectionsforchangesinprecipitationareavailableinClimateWizard,but
precipitationestimatesaloneareoftenanunreliableindicatorofmoistureavailabilitybecause
increasingtemperaturespromotehigherratesofevaporationandevapotranspiration.Moisture
availability,ratherthanprecipitationperse,isacriticalresourceforplantsandanimalsand
thereforeformstheotherpartoftheexposuremeasurewithintheCCVI,togetherwith
temperature.Topredictchangesinmoistureavailability,NatureServeandpartnersdevelopedthe
HamonAET:PETmoisturemetricaspartoftheCCVI.Themetricrepresentstheratioofactual
evapotranspiration(i.e.,theamountofwaterlostfromasurfacethroughevaporationand
transpirationbyplants)topotentialevapotranspiration(i.e.,thetotalamountofwaterthatcould
beevaporatedundercurrentenvironmentalconditions,ifunlimitedwaterwasavailable).Negative
valuesrepresentdryingconditions.
Sensitivityisassessedusing20factorsdividedintotwocategories:1)indirectexposuretoclimate
change;and2)speciesspecificfactors(includingdispersalability,temperatureandprecipitation
sensitivity,physicalhabitatspecificity,interspecificinteractions,andgeneticfactors).Foreach
factor,speciesarescoredonaslidingscalefromgreatlyincreasing,tohavingnoeffecton,to
decreasingvulnerability.TheCCVIaccommodatesmorethanoneanswerperfactorinorderto
addresspoordataorahighlevelofuncertaintyforthatfactor.Thescoringsystemintegratesall
exposureandsensitivitymeasuresintoanoverallvulnerabilityscorethatindicatesrelative
vulnerabilitycomparedtootherspeciesandtherelativeimportanceofthefactorscontributingto
vulnerability.
176 Colorado Natural Heritage Program © 2015 TheIndextreatsexposuretoclimatechangeasamodifierofsensitivity.Iftheclimateinagiven
assessmentareawillnotchangemuch,noneofthesensitivityfactorswillweighheavily,anda
speciesislikelytoscoreattheNotVulnerableendoftherange.Alargechangeintemperatureor
moistureavailabilitywillamplifytheeffectofanyrelatedsensitivity,andwillcontributetoascore
reflectinghighervulnerabilitytoclimatechange.Inmostcases,changesintemperatureand
moistureavailabilitywillcombinetomodifysensitivityfactors.However,forfactorssuchas
sensitivitytotemperaturechange(factor2a)orprecipitation/moistureregime(2b),onlythe
specifiedclimatedriverwillhaveamodifyingeffect.
Thesixpossiblescoresare:
ExtremelyVulnerable:Abundanceand/orrangeextentwithingeographicalareaassessed
extremelylikelytosubstantiallydecreaseordisappearby2050.
HighlyVulnerable:Abundanceand/orrangeextentwithingeographicalareaassessedlikelyto
decreasesignificantlyby2050.
ModeratelyVulnerable:Abundanceand/orrangeextentwithingeographicalareaassessedlikely
todecreaseby2050.
NotVulnerable/PresumedStable:Availableevidencedoesnotsuggestthatabundanceand/or
rangeextentwithinthegeographicalareaassessedwillchange(increase/decrease)substantially
by2050.Actualrangeboundariesmaychange.
NotVulnerable/IncreaseLikely:Availableevidencesuggeststhatabundanceand/orrangeextent
withingeographicalareaassessedislikelytoincreaseby2050.
InsufficientEvidence:Availableinformationaboutaspecies'vulnerabilityisinadequateto
calculateanIndexscore.
Scoring Factors in the CCVI
ThefactorsusedtogeneratetheCCVIscorearelistedinthefollowingsection.Detaileddefinitions
ofscoringcategoriesarelistedinAppendixB.
A. Exposure to Local Climate Change 1.
2.
B. Temperature
Moisture
Indirect Exposure to Climate Change 1.
2.
Exposuretosealevelrise.(NotapplicabletoColorado)
Distributionrelativetonaturalandanthropogenicbarriers.
Climate Change Vulnerability Assessment for Colorado BLM 177 3.
C. Sensitivity 1.
2.
3.
4.
5.
6.
D. Predictedimpactoflandusechangesresultingfromhumanresponsestoclimate
change.
Dispersalandmovements.
Predictedsensitivitytotemperatureandmoisturechanges.
a.Predictedsensitivitytochangesintemperature.
b.Predictedsensitivitytochangesinprecipitation,hydrology,ormoisture
regime.
c.Dependenceonaspecificdisturbanceregimelikelytobeimpactedby
climatechange.
d.Dependenceonice,ice‐edge,orsnow‐coverhabitats.
Restrictiontouncommongeologicalfeaturesorderivatives.
Relianceoninterspecificinteractions.
a.Dependenceonotherspeciestogeneratehabitat.
b.Dietaryversatility(animalsonly).
c.Pollinatorversatility(plantsonly).
d.Dependenceonotherspeciesforpropaguledispersal.
e.FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.
Geneticfactors.
a.Measuredgeneticvariation.
b.Occurrenceofbottlenecksinrecentevolutionaryhistory.
Phenologicalresponsetochangingseasonaltemperatureandprecipitation
dynamics.
Documented or Modeled Response to Climate Change 1.
2.
3.
4.
Documentedresponsetorecentclimatechange.
Modeledfuturechangeinrangeorpopulationsize.
Overlapofmodeledfuturerangewithcurrentrange.
Occurrenceofprotectedareasinmodeledfuturedistribution.
Factorsnotconsidered—TheIndexdevelopmentteamdidnotincludefactorsthatarealready
consideredinconservationstatusassessments.Thesefactorsincludepopulationsize,rangesize,
anddemographicfactors.ThegoalisfortheNatureServeClimateChangeVulnerabilityIndexto
complementNatureServeConservationStatusRanksandnottopartiallyduplicatefactors.Ideally,
Indexvaluesandstatusranksshouldbeusedinconcerttodetermineconservationpriorities.
Application of Climate Data
Scoringfactorsrelatedtohistoricandpredictedfutureclimate(temperature,precipitation,and
moistureavailability,FactorsA1,A2,C2ai,andC2biintheCCVI)werecalculatedinGISusingthe
178 Colorado Natural Heritage Program © 2015 methodsdescribedbelow.Refertothespeciesprofilesinthefollowingsectionofthisreportfor
detailsonscoringrationaleandreferencesforallotherfactors.
Exposuretopredictedtemperatureincreasewascalculatedusingspeciesdistributiondataandan
ensembleaverageof16CMIP3climatepredictionmodels(seeAppendixA)averagedoverthe
summerseason(June–August)usingthehigh(A2)CO2emissionsscenario.Thehighemissions
scenariowasusedbecauseitismostsimilartocurrentemissions.DatawereobtainedfromClimate
Wizard,andtheanalysisperiodwastotheyear2050(whichisactuallyanaverageofprojections
foryears2040–2069).Thesummerseason–growingseasonforplants,breedingseasonfor
animals–wasusedbecauseitwasconsideredthemostcriticaltimeperiodformostspecies.
Exposuretoprojecteddrying(integrationofprojectedtemperatureandprecipitationchange,i.e.,
theHamonAET:PETmoisturemetric)wascalculatedusingthedatasetcreatedbyNatureServeas
partoftheCCVI.NotethatNatureServebasedtheirmoisturemetriccalculationsonthesame
ClimateWizarddatasetasabove,exceptthattheyusedtheA1Bcarbondioxideemissionsscenario.
BecausethemodelingmethodsusedbyNatureServewerenotavailable,wewereunableto
recalculateusingtheA2scenario.Thus,weusedthedataasprovided,whichweconsidereda
reasonablealternativesincetheA1BandA2scenariospredictsimilarchangesthroughthemid‐21st
Century,theperiodusedinthisanalysis.Wecalculatedthepercentofeachspecies’range/
distributionthatfallswithineachratingcategory.Allcalculationsusedthe“summer”(June–
August)datasubset.
Thehistoricalthermalnichefactormeasureslarge‐scaletemperaturevariationthataspecieshas
experiencedinrecenthistoricaltimes(i.e.,thepast50years),asapproximatedbymeanseasonal
temperaturevariation(differencebetweenhighestmeanmonthlymaximumtemperatureand
lowestmeanmonthlyminimumtemperature).Itisaproxyforspecies'temperaturetoleranceata
broadscale.ThisfactorwascalculatedinGISbyassessingtherelationshipbetweenspecies’
distributionsandhistoricaltemperaturevariationdatadownloadedfromNatureServe.Historical
temperaturevariationwasmeasuredasthemeanJulyhighminusthemeanJanuarylow,using
PRISMdatafrom1951‐2006,expressedasasingleaveragedvaluefortheentirespeciesrange.
Thehistoricalhydrologicalnichefactormeasureslarge‐scaleprecipitationvariationthataspecies
hasexperiencedinrecenthistoricaltimes(i.e.,thepast50years),asapproximatedbymeanannual
precipitationvariationacrossoccupiedcellswithintheassessmentarea.Ratingsforthisfactor
werecalculatedinGISbyoverlayingthespecies’distributionsonmeanannualprecipitationdata
(PRISM4kmannualaverageprecipitation,ininches,1951‐2006)downloadedfromClimateWizard,
andsubtractingthelowestpixelvaluefromthehighestvalue.
Representing Species’ Distributions
Avarietyofsourceswereusedforanimalspecies,includingelementoccurrencerecordsand/or
observationdatafromCNHP’sdatabases,onlinedistributiondatafromCPW,existingspecies
distributionmodels,rangemapsfrompublishedliterature,andcriticalhabitatmaps.
Climate Change Vulnerability Assessment for Colorado BLM 179 Thelistofanimalspeciesincludedinthisclimatechangevulnerabilityassessmentwasdeveloped
throughconsultationwithBLMstaff,usingtheBLMSensitiveSpecieslistasastartingpoint.This
listincludesallfederallylistedspecies.TheentireBLMsensitivelistwasbeyondthescopeofthe
project,sospecieswereprioritizedaccordingtothelevelofpriorworkavailableandthe
managementimportanceofthespecies.Afewwide‐rangingspeciesofparticularmanagement
interestthatarenotontheBLMsensitivelistwereincluded.
RESULTS
CCVIresultsaresummarizedinTable3.1,andpresentedinfullinAppendixC.Animal species results
are sorted alphabetically by common name within taxonomic group.Therationaleforscoringand
literaturecitationsareincludedinthefollowingspeciesprofiles.
Table 3.9. Climate change vulnerability scores for animal species. EV = Extremely Vulnerable; HV = Highly Vulnerable; MV = Moderately Vulnerable; PS = Presumed Stable; IL = Increase Likely. Taxonomic Group
English Name
Species
Amphibian Boreal Toad Anaxyrus boreas boreas HV
Amphibian Canyon Treefrog Hyla arenicolor MV Amphibian Great Basin Spadefoot Spea intermontana PS Amphibian Northern Leopard Frog Lithobates pipiens MV Bird American Peregrine Falcon Falco peregrinus anatum PS Bird Black Swift Cypseloides niger PS Bird Brewer's Sparrow Spizella breweri PS Bird Burrowing Owl Athene cunicularia hypugaea MV
Bird Golden Eagle Aquila chrysaetos MV Bird Greater sage‐grouse Centrocercus urophasianus HV Bird Gunnison Sage‐grouse Centrocercus minimus HV
Bird Long‐billed Curlew Numenius americanus HV
Bird Mountain Plover Charadrius montanus PS Bird Norhern Goshawk Accipiter gentilis MV Bird Western Snowy Plover Charadrius alexandrinus nivosus HV
Bird Western Yellow‐billed Cuckoo Coccyzus americanus occidentalis MV Bird White‐faced Ibis Plegadis chihi MV Fish Bluehead Sucker Catostomus discolobus HV Fish Bonytail Chub Gila elegans EV
Fish Colorado Pikeminnow Ptychocheilus lucius EV
Fish Colorado River Cutthroat Trout Oncorhynchus clarkii pleuriticus EV Fish Flannelmouth Sucker Catostomus latipinnis HV Fish Humpback Chub Gila cypha EV
Fish Razorback Sucker Xyrauchen texanus HV
180 Score
Colorado Natural Heritage Program © 2015 Taxonomic Group
English Name
Species
Score
Fish Rio Grande Cutthroat Trout Onchorhynchus clarkii virginalis EV
Fish Roundtail Chub Gila robusta HV
Invert‐Insect Great Basin Silverspot Speyeria nokomis nokomis HV
Mammal American Beaver Castor canadensis MV Mammal Desert Bighorn Sheep Ovis canadensis nelsoni MV Mammal Fringed Myotis Myotis thysanodes PS Mammal Gunnison's Prairie Dog Cynomys gunnisoni PS Mammal Townsend's Big‐eared Bat Corynorhinus townsendii PS Mammal White‐tailed Prairie Dog Cynomys leucurus PS Reptile Desert Spiny Lizard Sceloporus magister PS Reptile Longnose Leopard Lizard Gambelia wislizenii PS Reptile Midget Faded Rattlesnake Crotalus oreganus concolor HV
Animalspeciesincludedfouramphibians,thirteenbirds,ninefish,oneinsect,sixmammals,and
threereptiles.Fivespecieswererankedasextremelyvulnerabletoclimatechange.Fish,in
particular,wererankedonthehightoextremelyvulnerableendoftherange(Figure3.1);other
taxonomicgroupsweregenerallymoreevenlydistributedbetweenpresumedstabletohighly
vulnerable.Noevaluatedspecieswereassessedaslikelytoincreaseunderfutureconditions.
Figure 3.1. Summary of climate change vulnerability scores for animal species. EV = Extremely Vulnerable; HV = Highly Vulnerable; MV = Moderately Vulnerable; PS = Presumed Stable; IL = Increase Likely. Climate Change Vulnerability Assessment for Colorado BLM 181 ANIMAL SPECIES CCVI SUMMARIES
182 Colorado Natural Heritage Program © 2015 Boreal toad
Anaxyrusboreasboreas
G4T1/S1
Family:Bufonidae
Climate Vulnerability Rank: Highly Vulnerable
ThisColoradostate‐widerankisbasedon:themajorityofborealtoadpopulationsinColorado
beingborderedbyhighmountainsthatactasnaturalbarriers,whichcouldlimittheabilityofthis
speciestoshiftitsrangeinresponsetoclimatechange;thephysiologicalnicheofthisspeciesbeing
coolerhighelevationareaswheresnowfallandsummerevaporationcouldaffectseasonalwetland
breedinghabitat;thedependenceofthisspeciesonspecifichydrologyforbreedingandthe
potentialdisruptionofthetimingofbreedingandlarvaldevelopmentbyclimatechange.Additional
importantrankingfactorsincludetheimportanceofsnowpacklevelsforbreedingpondwater
levelsandasaninsulatorforhibernation.Borealtoadsarealsooftendependentonbeaversto
createandmaintainbreedinghabitat.
Distribution:BorealtoadswerefoundhistoricallythroughoutthemountainousareasofColorado,
buthavenotbeenreportedfromtheSangreDeCristoMountainRange,WetMountains,orthePikes
Peakregion(Hammerson1999).BorealToadsarealsoabsentfromtheLaPlataMountainsand
UncompahgrePlateauinSouthwestColorado(CNHP2014).Habitat:Borealtoadsarerestrictedto
montanehabitatsatelevationsof8,000–12,200feet(2,400–3,400meters).Commonhabitats
includebeaverponds,wetmeadows,glacialkettlepondsandlakesinsubalpineforests
(Hammerson1999).Breedingoccursalongthemarginsofshallowpondsinstillwater.
Occasionally,floodedtireruts,man‐madepondsandstreambackflowsareusedaswellfor
breeding(Loeffler2001).
CCVI Scoring
Temperature:CalculatedusingClimateWizard:ensembleaverage,highemissionscenario(A2),
mid‐centurytimeframe,averageannualchange.InColoradobymid‐centurythisspeciesisexpected
Climate Change Vulnerability Assessment for Colorado BLM 183 tobeexposedtomeanannualtemperatureincreasesof5.0oFto5.5oFover100percentofitsrange
(NatureServe2012).
Moisture:CalculatedinGISusingNatureServeHamonAET:PETmoisturemetricdata(thisindex
integratesprojectedtemperatureandprecipitationchangestoindicatehowmuchdryingwilltake
place).Rangewidethisspeciesispredictedtobeexposedtonetdryingofgreaterthan11.9percent
on17percentofitsrange,9.7to11.9percentdryingon49percentofitsrangeand7.4to9.6
percentdryingon32percentofitsrange(NatureServe2012).
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Increase.Mountainrangeswithhigh,>12,500ft.
passesshouldbeconsideredasnaturalbarriersforborealtoadmovement(NatureServe2014).The
majorityofborealtoadpopulationsinColoradoaremostlyborderedbyhighmountains.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Intensiveresidentialor
commercialdevelopmentandhightrafficvolumehighwayscouldbeconsideredasanthropogenic
barriers(NatureServe2014).ThemajorityofborealtoadpopulationsoccuronUSFSmanagedland
wheredevelopmentisverylow.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.
Somewhatincreasetoneutral.Landalterationssuchas,timberharvest,grazing,recreationand
waterdevelopmentwouldlikelynotbebeneficialforborealtoadhabitat,buthavenotbeenshown
asprimarycausativeagentsfordeclinesinthesouthernRockyMountains(Loeffler2001).Landuse
changesassociatedwithclimatechangemaybeconsideredathreatbutthescopeandtypeof
changeintherangeoftheborealtoadishardtopredict.
C1)Dispersalandmovements.Somewhatdecreasetoneutral.Borealtoadsaredependentupon
breeding,foragingandhibernatinghabitat,whichencompassesbothwetlandanduplandhabitat
(Adamsetal.2005).Theevidenceshowsseasonalvariabilityintoadmovementsandindividual
movementsandindividualtoadsmaymove4kmormorebetweenbreedingandnonbreeding
habitat(Hammerson1999;Jones2000)anduptoapproximately7.6kmforanadultmale(Lambert
andSchneider2013).
C2ai)Predictedsensitivitytotemperature:historicthermalniche.Neutral.Therangeoccupied
bytheborealtoadintheassessedareahasexperiencedaverage(57.1‐77°F/31.8‐43°C)mean
seasonaltemperaturevariationinthelast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.:Somewhatincrease.
TherangeofthisspeciesinColoradoisrestrictedtocoolerhighelevationareas.Reducedsnowfall
andincreasedsummerevaporationcouldhavedramaticeffectsonthedurationoroccurrenceof
seasonalwetlands(Corn2005).Longeractiveseasonswerefoundtoincreaserecruitmentattwo
breedingsitesinChaffeeCounty,Colorado(Lambertetal.InPrep),e.g.,increasedtemperatureswill
allowforearlierdevelopmentofyoungwithlargermetamorphsenteringhibernationthus
increasingoverwintersurvival.
184 Colorado Natural Heritage Program © 2015 C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Somewhatdecrease.Thisspecieshasundergonegreaterthan
average(>40inches/1,016mm)precipitationvariationoverthelast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.Theborealtoadishighlydependentofspecific
hydrologyforbreeding.Holland(2002)foundthatborealtoadtadpolesinColoradoexperienced
thatgreatestlarvalgrowthratesatbreedingsiteswiththewarmestandleastvariablewater
temperatures.Timingofbreedingandtimeforlarvaldevelopmentcouldalsobeimpactedby
changesinhydrologicallevels(Corn2005).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.Theborealtoadisnotdependentuponspecificdisturbanceregimessuchasfires,floods,
severewinds,pathogenoutbreaks,orsimilarevents.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Somewhatincrease.Borealtoad
breedingpondsoftendependonsnowpackmelttomaintainwaterlevelsforbreeding.Depthof
Snowpackcanbeimportantinprotectinghibernatingtoadsfromfreezing(Campbell1970;Corn
2003;Schereretal.2005).
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.Borealtoadsarenot
dependentonanyspecificgeologicfeature.
C4a)Dependenceonotherspeciestogeneratehabitat.Increase.Borealtoadbreedingponds
arecommonlyfoundinbeaverpondcomplexes(Hammerson1999;Holland2002)andareoften
dependentonbeaverstomaintainbreedinghabitat.
C4b)Dietaryversatility(animals).Neutral.Borealtoadsfeedonawidevarietyofinvertebrates
(Hammerson1999).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.Theborealtoadisaself‐
disperser.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.Neutral.Noother
interspecificinteractionsareimportanttothepersistenceoftheborealtoad.
C5a)Measuredgeneticvariation.Somewhatdecrease.Switzeretal.(2009)foundpatternsof
highlevelsofgeneticdifferentiationamongrelativelyclosebreedingsitesofborealtoadsandfound
thepopulationswithinthesouthernRockyMountainstobeisolatedwithlimitedgeneflowamong
populations.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Neutral.Thereisnoevidence
thatthetotalpopulationofborealtoadswerereducedto<1000individualsortheoccupiedarea
wasreducedby>30%overthelast500years.
Climate Change Vulnerability Assessment for Colorado BLM 185 C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Neutral.Theeffectsofchangesintemperatureandprecipitationmayhavealargeeffectonthe
timingofbreedingforamphibians(Corn2005)andhasbeenobservedinsomespecies(Blaustein
etal.2001).
Literature Cited
Adams,S.B.,D.S.Schmetterling,andM.K.Young.2005.Instreammovementsbyborealtoads.HerpetologicalReview
36(1):27‐33.
Blaustein,A.R.,L.K.Belden,D.H.Olson,D.M.Green,T.L.Root,andJ.M.Kiesecker.2001.Amphibianbreedingandclimate
change.ConservationBiology15:1804‐1809.
Campbell,J.B.1970.Life‐historyofBufoboreasboreasintheColoradoFrontRange.Ph.D.thesis,UniversityofColorado,
Boulder,CO.
Corn,P.S.2003.Amphibianbreedingandclimatechange:Importanceofsnowinthemountains.ConservationBiology
17(2):622‐625.
Corn,P.S.2005.Climatechangeandamphibians.AnimalBiodiversityandConservation28(1):59‐67.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins,CO.
Hammerson,G.A.1999.AmphibiansandreptilesinColorado.Seconded.UniversityPressofColoradoandColorado
DivisionofWildlife.
Holland,A.A.2002.EvaluatingBorealToad(Bufoboreas)BreedingHabitatSuitability.M.S.Thesis,ColoradoState
University,FortCollins,CO.
Jones,M.S.,J.P.Goettl,K.L.Scherff‐Norris,S.Brinkman,L.J.Livo,A.M.Goebel.1998.ColoradoDivisionofWildlifeBoreal
ToadResearchProgressReport1995‐1997.UnpublishedreportColoradoDivisionofWildlife,Denver,CO.
Lambert,B.andS.Schneider.2013.ColoradoNaturalHeritageProgramborealtoadsurveyandmonitoringproject
summary1999‐2012.UnpublishedreporttotheColoradoDivisionofWildlife,FortCollins,CO.
Loeffler,C.(ed.),2001.ConservationplanandagreementforthemanagementandrecoveryofthesouthernRocky
Mountainpopulationoftheborealtoad(Bufoboreasboreas),BorealToadRecoveryTeam.76pp.+appendices.
NatureServe2012.ClimateChangeVulnerabilityAssessmentTool,version2.1.Availableonlineat
https://connect.natureserve.org/science/climate‐change/ccvi.
NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org.Accessed2014.
Scherer,R.D.,E.Muths,B.R.Noon,andP.S.Corn.2005.Anevaluationofweatheranddiseaseascausesofdeclineintwo
populationsofborealtoads.EcologicalApplications15(6):2150‐2160.
Switzer,J.F.,R.Johnson,B.A.Lubinski,andT.L.King.2009.GeneticstructureintheAnaxyrusboreasspeciesgroup(Anura,
Bufonidae):anevaluationoftheSouthernRockyMountainspopulation.FinalReportSubmittedtotheU.S.Fishand
WildlifeService.
186 Colorado Natural Heritage Program © 2015 Canyon Treefrog
Hylaarenicolor
G5/S2
Family:Hylidae
Photo:CopyrightbyLaurenJ.Livoand
SteveWilcox
Climate Vulnerability Rank: Moderately Vulnerable
ThisColoradostate‐widerankisbasedon:themajorityofcanyontreefrogpopulationsinColorado
beingrestrictedtorockycanyonsandcanyon‐bottompoolsthatactasnaturalbarriers,whichcould
limittheabilityofthisspeciestoshiftitsrangeinresponsetoclimatechange;Thecanyontreefrog
ishighlydependentonspecifichydrology(rainfall)forbreedingandthepotentialdisruptionofthe
timingofbreedingandlarvaldevelopmentbyclimatechangeisaconcern.
Distribution:CanyontreefrogsoccurinwesternColoradoatelevationsrangingfromabout4,500‐
6,300ft.alongthesouthernedgeoftheColoradoRivervalleyandalongtheDoloresRiverandits
tributariessouthtoSanMiguelCounty,(Hammerson1999).ThereisanisolatedpopulationinLas
AnimasCountyatMesadeMaya(CNHP2014).Habitat:Canyontreefrogsarefoundalong
intermittentstreamsindeeprockycanyons(Hammerson1999).
CCVI Scoring
Temperature:CalculatedusingClimateWizard:ensembleaverage,highemissionscenario(A2),
mid‐centurytimeframe,averageannualchange.InColoradobymid‐centurythisspeciesisexpected
tobeexposedtomeanannualtemperatureincreasesof5.0oFto5.5oFover100percentofitsrange
(NatureServe2012).
Moisture:CalculatedinGISusingNatureServeHamonAET:PETmoisturemetricdata(thisindex
integratesprojectedtemperatureandprecipitationchangestoindicatehowmuchdryingwilltake
place).Rangewidethisspeciesispredictedtobeexposedtonetdryingofgreaterthan11.9percent
on12.1percentofitsrange,9.7to11.9percentdryingon43.2percentofitsrangeand7.4to9.6
Climate Change Vulnerability Assessment for Colorado BLM 187 percentdryingon31.3percentofitsrangeand5.1to7.3percentdryingon13percentofitsrange
(NatureServe2012).
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Somewhatincreasevulnerability.InColorado,
thisspeciesisrestrictedtorockycanyonsandbreedsincanyonbottompools(Hammerson1999).
Geneticanalysissuggeststhatgeographicbarriersareresponsibleforphylogeographicpatternsin
canyontreefrogsfromArizonaandNewMexico(Barber1999).
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Intensiveresidentialor
commercialdevelopmentandhightrafficvolumehighwayscouldbeconsideredasanthropogenic
barriers(NatureServe2014).Themajorityofcanyontreefrogpopulationsoccuronfederally
managedlandsindeepcanyonswheredevelopmentisverylow.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
Landalterationssuchas,timberharvest,grazing,recreationandwaterdevelopmentwouldlikely
notbebeneficialforcanyontreefroghabitat,buttheremotenessofoccurrencesmakesitunlikely
areasforfuturehumandisturbances.Landusechangesassociatedwithclimatechangemaybe
consideredathreatbutthescopeandtypeofchangeintherangeofthecanyontreefrogishardto
predict.
C1)Dispersalandmovements.Neutral.Canyontreefrogsaredependentonrockycanyonslopes
andbottomsforbreeding,foragingandhibernatinghabitat(Hammerson1999).Hylidsgenerally
exhibitlimitedmovementsonashort‐termbasis(NatureServe2014).Exceptforwarmrainy
nights,canyontreefrogsdonotrangefarfromcanyon‐bottompools(Hammerson1999).
C2ai)Predictedsensitivitytotemperature:historicthermalniche.Neutral.Therangeoccupied
bythecanyontreefrogintheassessedareahasexperiencedaverage(57.1‐77°F/31.8‐43°C)
meanseasonaltemperaturevariationinthelast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Somewhatdecrease.
Thisspeciesshowsapreferenceforenvironmentswithwarmertemperatures(Synderand
Hammerson1993).
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Neutral.Thisspecieshasundergoneaverage(21‐40inches/509‐
1,016mm)precipitationvariationoverthelast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.Thecanyontreefrogishighlydependentonspecific
hydrology(rainfall)forbreeding(Hammerson1999).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.Thecanyontreefrogisnotdependentuponspecificdisturbanceregimessuchasfires,
floods,severewinds,pathogenoutbreaks,orsimilarevents.
188 Colorado Natural Heritage Program © 2015 C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Canyontreefrogsdonot
dependoniceorsnow‐coverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Somewhatincrease.Canyon
treefrogsareassociatedwithrockycanyonbottomswheretheyperchonsolidrocksurfacesandat
nightretreattorockcrevices(Hammerson1999).
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Canyontreefrogsdonotrelyon
otherspeciestogeneratehabitat.
C4b)Dietaryversatility(animals).Neutral.Canyontreefrogsfeedonawidevarietyof
invertebrates(Hammerson1999).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.Thecanyontreefrogisa
self‐disperser.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.Neutral.Noother
interspecificinteractionsareimportanttothepersistenceofthecanyontreefrog.
C5a)Measuredgeneticvariation.Somewhatincrease.Barber(1999)foundlowgeneticvariation
fromdifferencesamongpopulationsinArizonaandNewMexico.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Neutral.Thereisnoevidence
thatthetotalpopulationofcanyontreefrogswerereducedto<1000individualsortheoccupied
areawasreducedby>30%overthelast500years.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Neutral.Theeffectsofchangesintemperatureandprecipitationmayhavealargeeffectonthe
timingofbreedingforamphibians(Blausteinetal.2001;Corn2005),buthasnotbeenreportedfor
canyontreefrogs. Literature Cited
Barber,P.H.1999.Patternsofgeneflowandpopulationgeneticstructureinthecanyontreefrog,Hylaarenicolor.
MolecularEcology8:563‐576.
Blaustein,A.R.,L.K.Belden,D.H.Olson,D.M.Green,T.L.Root,andJ.M.Kiesecker.2001.Amphibianbreedingandclimate
change.ConservationBiology15:1804‐1809.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins,CO.
Corn,P.S.2005.Climatechangeandamphibians.AnimalBiodiversityandConservation28(1):59‐67.
Hammerson,G.A.1999.AmphibiansandreptilesinColorado.Seconded.UniversityPressofColoradoandColorado
DivisionofWildlife.
NatureServe2012.ClimateChangeVulnerabilityAssessmentTool,version2.1.Availableonlineat
https://connect.natureserve.org/science/climate‐change/ccvi.
Climate Change Vulnerability Assessment for Colorado BLM 189 NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org.Accessed2014.
Snyder,G.K.andG.A.Hammerson.1993.Interrelationshipsbetweenwatereconomyandthermoregulationinthecanyon
treefrogHylaarenicolor.JournalofAridEnvironments25:321‐329.
190 Colorado Natural Heritage Program © 2015 Great Basin Spadefoot
Speaintermontana
G5/S3
Family:Scaphiopodidae
Photo:CopyrightbyLaurenJ.
LivoandSteveWilcox
Climate Vulnerability Rank: Not Vulnerable/Presumed Stable
ThisColoradostate‐widerankisbasedon:Theonlymetricthatincreasedthevulnerabilityfor
GreatBasinspadefootswastheirdependenceonspecifichydrology(ephemeralandpermanent
watersources)forbreedingandthepotentialdisruptionofthetimingofbreedingandlarval
developmentbyclimatechange.Therestofthescoringfactorswereneutral.Thehabitatthis
speciesinhabitsisdiverseanddevoidofnaturalbarriers;withintherangeofthisspeciesin
Colorado,oilandgasdevelopmentcouldimpacthabitat,buttherehasnotbeenanyevidenceofthat
occurring.Irrigatedagriculturemaybebeneficialincreatingbreedinghabitat(Leonardetal.1996).
GreatBasinspadefootsoccurinprettyremoteareasofColoradoandareatalowriskofthreats
fromurbandevelopment.
Distribution:GreatBasinspadefootsoccurinnorthwesternColorado,northoftheUncompahgre
Plateau(Hammerson1999).Habitat:GreatBasinspadefootsarefoundinwidevarietyofhabitats
inColoradoatelevationsbelow7,000ft.(Hammerson1999).TypicalhabitattypesinColoradofor
GreatBasinspadefootsarepinyon‐juniperwoodlands,sagebrushandsemidesertshrublands
(Hammerson1999).Breedingoccursintemporarypoolsfromheavyrains(Hammerson1999)and
occasionallyinpermanentshallowponds(Hovinghetal.1995).
CCVI Scoring
Temperature:CalculatedusingClimateWizard:ensembleaverage,highemissionscenario(A2),
mid‐centurytimeframe,averageannualchange.InColoradobymid‐centurythisspeciesisexpected
tobeexposedtomeanannualtemperatureincreasesof5.0oFto5.5oFover100percentofitsrange
(NatureServe2012).
Climate Change Vulnerability Assessment for Colorado BLM 191 Moisture:CalculatedinGISusingNatureServeHamonAET:PETmoisturemetricdata(thisindex
integratesprojectedtemperatureandprecipitationchangestoindicatehowmuchdryingwilltake
place).Rangewidethisspeciesispredictedtobeexposedtonetdryingofgreaterthan11.9percent
on9.1percentofitsrange,9.7to11.9percentdryingon55.1percentofitsrangeand7.4to9.6
percentdryingon22.6percentofitsrangeand5.1–7.3on12.7percentofitsrange(NatureServe
2012).
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral.InColorado,thisspeciesinhabits
sagebrushflats,pinyon‐juniperwoodlandandsemi‐desertshrublands(Hammerson1999),areas
thataretypicallydevoidofnaturalbarriersforspadefoottoads.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Intensiveresidentialor
commercialdevelopmentandhightrafficvolumehighwayscouldbeconsideredasanthropogenic
barriers(NatureServe2014),butformostoftheGreatBasinspadefootsrangeinColoradourban
developmentislow.Theremaybebreedinghabitatcreationfromirrigatedagriculture,butinsome
casesgrainfieldscouldeliminatebreedingponds(Leonardetal.1996).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
Landalterationssuchas,timberharvest,grazing,recreationandwaterdevelopmentwouldlikely
notbebeneficialforGreatBasinspadefoots,buttheremotenessofoccurrencesmakesitunlikely
areasforfuturehumandisturbances.Landusechangesassociatedwithclimatechangemaybe
consideredathreatbutthescopeandtypeofchangeintherangeofthecanyontreefrogishardto
predict.
C1)Dispersalandmovements.Neutral.GreatBasinspadefootsaredependenton
sagebrush/semi‐desertshrublandhabitatwithtemporarypoolsforbreedingandforaging
(Hammerson1999).Specificdispersaldataforthisspeciesislackingbutingeneralspadefoottoads
exhibithighfidelitytobreedingsitewithmovementsuptoseveralhundredmetersfrombreeding
sites(NatureServe2014).Therehavebeenreportsofadultsmigratingupto100metersbetween
breedingpoolsandnon‐breedinghabitat(Busecketal.2005).
C2ai)Predictedsensitivitytotemperature:historicthermalniche.Neutral.Therangeoccupied
bytheborealtoadintheassessedareahasexperiencedaverage(57.1‐77°F/31.8‐43°C)mean
seasonaltemperaturevariationinthelast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Thisspecies
isnotrestrictedtocoldenvironmentsthatarevulnerabletoclimatechange.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Neutral.Thisspecieshasundergoneaverage(21‐40inches/509‐
1,016mm)precipitationvariationoverthelast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.Thegreatbasinspadefootishighlydependenton
192 Colorado Natural Heritage Program © 2015 specifichydrology(ephemeralandpermanentwatersources)forbreeding(Hovinghetal.1995;
Hammerson1999;Busecketal.2005).Timingofbreedingandtimeforlarvaldevelopmentin
amphibianscouldalsobeimpactedbychangesinhydrologicallevels(Corn2005).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.Thegreatbasinspadefootisnotdependentuponspecificdisturbanceregimessuchas
fires,floods,severewinds,pathogenoutbreaks,orsimilarevents.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.GreatBasinspadefootsdo
notdependoniceorsnow‐coverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.GreatBasin
spadefootsarenotdependentonanyspecificgeologicfeature.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.GreatBasinspadefootsdonot
relyonotherspeciestogeneratehabitat.
C4b)Dietaryversatility(animals).Neutral.GreatBasinspadefootsfeedonawidevarietyof
invertebrates(Hammerson1999).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.TheGreatBasinspadefoot
isaself‐disperser.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.Neutral.Noother
interspecificinteractionsareimportanttothepersistenceoftheGreatBasinspadefoot.
C5a)Measuredgeneticvariation.Neutral.PhylogeneticanalysisontwopopulationsofGreat
Basinspadefootssuggestedpossiblegeographicvariationwithinthespecies(WiensandTitus
1991).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Neutral.Thereisnoevidence
thatthetotalpopulationofGreatBasinspadefootswerereducedto<1000individualsorthe
occupiedareawasreducedby>30%overthelast500years.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Neutral.Theeffectsofchangesintemperatureandprecipitationmayhavealargeeffectonthe
timingofbreedingforamphibians(Corn2005)andhasbeenobservedinsomespecies(Blaustein
etal.2001). Literature Cited
Blaustein,A.R.,L.K.Belden,D.H.Olson,D.M.Green,T.L.Root,andJ.M.Kiesecker.2001.Amphibianbreedingandclimate
change.ConservationBiology15:1804‐1809.
Buseck,R.S.,D.A.Keinath,andM.Geraud.2005.SpeciesAssessmentforGreatBasinSpadefootToad(Speaintermontana)
inWyoming.TechnicalreportforBureauofLandManagement,Cheyenne,Wyoming.
Corn,P.S.2005.Climatechangeandamphibians.AnimalBiodiversityandConservation28(1):59‐67.
Climate Change Vulnerability Assessment for Colorado BLM 193 Hammerson,G.A.1999.AmphibiansandreptilesinColorado.Seconded.UniversityPressofColoradoandColorado
DivisionofWildlife.
Hovingh,P.,B.Benton,andD.Bornholdt.1995.Aquaticparametersandlifehistoryobservationsofthegreatbasin
spadefoottoadinUtah.GreatBasinNaturalist45:22‐30.
Leonard,W.P,H.A.Brown,LL.C.Jones,K.R.McAllisterandR.M.Storm.1996.AmphibiansofWashingtonandOregon.
SeattleAudubonSociety,Seattle,Washington.
NatureServe2012.ClimateChangeVulnerabilityAssessmentTool,version2.1.Availableonlineat
https://connect.natureserve.org/science/climate‐change/ccvi.
NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org.Accessed2014.
Wiens,J.J.andT.A.Titus.1991.AphylogeneticanalysisofSpea(Anura:Pelobatidae).Herpetologica.47(1):21‐28.
194 Colorado Natural Heritage Program © 2015 Northern Leopard Frog
Lithobatespipiens
G5/S3
Family:Ranidae
Climate Vulnerability Rank: Moderately Vulnerable
ThisColoradostate‐widerankisbasedon:thenorthernleopardfrog’sdependenceonspecific
hydrologyforbreedingandthepotentialdisruptionofthetimingofbreedingandlarval
developmentbyclimatechange.ThepredictedeffectsofclimatechangeintheWestincludea
reducedsnowpackandshorterperiodsofsnowcover,snowmeltthatoccursearlierintheseason,a
hydrologiccyclethatismoredynamicasextremerainfalleventsoccurwithgreaterfrequencyand
anoverallwarmer,drier,andmoredrought‐likeconditions(Melilloetal.2014).Climatechangehas
thepotentialtoalterthetimingofpondbreedingamphibians(Blausteinetal.2001).Additional
importantrankingfactorsincludethevulnerabilityofnorthernleopardfrogstodevelopmentand
habitatfragmentationfrombusypavedroads.
Distribution:NorthernleopardfrogsoccurthroughoutColorado,excludingmostofthe
southeasternandeasteast‐centralportionofthestate(Hammerson1999).Habitat:Northern
leopardfrogsarefoundinwidevarietyofhabitatsinColoradoatelevationsrangingfrom3,500ft.
to11,000ft.(Hammerson1999).TypicallyinColorado,northernleopardfrogsarefoundinwet
meadows,marshes,ponds,streams,lakesandreservoirs.Breedingoccursinmid‐sizedponds
(Merrell1997)andshallowareasofpermanentpondsandinseasonallyfloodedareasadjacentto
permanentpoolsorstreams(Hammerson1999).
CCVI Scoring
Temperature:CalculatedusingClimateWizard:ensembleaverage,mediumemissionscenario
(A1B),mid‐centurytimeframe,averageannualchange.InColoradobymid‐centurythisspeciesis
expectedtobeexposedtomeanannualtemperatureincreasesof5.0oFto5.5oFover100percentof
itsrange(NatureServe2012).
Climate Change Vulnerability Assessment for Colorado BLM 195 Moisture:CalculatedinGISusingNatureServeHamonAET:PETmoisturemetricdata(thisindex
integratesprojectedtemperatureandprecipitationchangestoindicatehowmuchdryingwilltake
place).Rangewidethisspeciesispredictedtobeexposedtonetdryingofgreaterthan11.9percent
on12.6percentofitsrange,9.7to11.9percentdryingon52.8percentofitsrangeand7.4to9.6
percentdryingon29.1percentofitsrangeand5.1–7.3on5.4percentofitsrange(NatureServe
2012).
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral.Thenorthernleopardfrogoccupiesa
varietyofhabitattypesandiswidelydistributedinColorado(Hammerson1999).Whilepatchiness
occurs,therearefewnaturalbarrierstotheirdispersaltootherlandscapes.Riverscouldbea
barrierdependingonwidthandflowdynamics(NatureServe2014).
B2b)Distributionrelativetoanthropogenicbarriers.Somewhatincrease.Intensiveresidential
orcommercialdevelopmentandhightrafficvolumehighwayscouldbeconsideredas
anthropogenicbarriers(NatureServe2014).Disturbedareasdevoidofcoverdisruptedtheability
fornorthernleopardfrogstoreachhabitatpatchesinNewBrunswick(MazerolleandDesrochers
(2005).Bouchardetal.(2009)foundthatleopardfrogswerehighlyvulnerabletoroadmortality.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.
Somewhatincreasetoneutral.ThenortheasternColoradohabitatofthisspeciesissusceptibleto
potentialdevelopmentofwindfarms/solarfarmsandbiofuelsproduction.Inthefaceofrising
climatechangeandcoststoextractfossilfuels,windenergydevelopmentisexpectedtoincrease
withintherangeofthenorthernleopardfroginColorado(NRDC2014).
C1)Dispersalandmovements.Somewhatdecreasetoneutral.Northernleopardfrogshavegood
movementanddispersalcapabilityastheyaredependentuponbreeding,foragingandhibernating
habitat,whichencompassesbothwetlandanduplandhabitat(Hammerson1999;NatureServe
2014).Theevidenceshowsseasonalvariabilityinleopardfrogmovementsandindividual
movementsupto4kmforadults(Seburnetal.1997)and5.2kmforjuveniles(Dole1971)in
AlbertaandMichiganrespectively.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.Neutral.Therangeoccupied
bytheborealtoadintheassessedareahasexperiencedaverage(57.1‐77°F/31.8‐43°C)mean
seasonaltemperaturevariationinthelast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Increase.Somewhat
Increase.TherangeofthisspeciesinColoradoincludessomehigherelevationmontaneareas.
Reducedsnowfallandincreasedsummerevaporationcouldhavedramaticeffectsontheduration
oroccurrenceofseasonalwetlands(Corn2005).
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Somewhatdecrease.Thisspecieshasundergonegreaterthan
average(>40inches/1,016mm)precipitationvariationoverthelast50years.
196 Colorado Natural Heritage Program © 2015 C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.Thenorthernleopardfrogishighlydependenton
specifichydrologyforbreeding.Reproductivesuccessistiedtoappropriatetemperaturein
breedingsites(shallowponds);timingofthiswouldchangewithearlysnowmeltandwarmer
temperatures(SmithandKeinath2007).Timingofbreedingandtimeforlarvaldevelopmentcould
alsobeimpactedbychangesinhydrologicallevels(Corn2005).Increaseddroughtcouldcause
reductionsinhabitatandpotentiallyincreasemortalityfromeggtoadult.Droughtwasresponsible
fortheextirpationofapopulationofleopardfrogsinLarimerCounty,Colorado(Cornand
Fogleman1984).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.Thenorthernleopardfrogisnotdependentuponspecificdisturbanceregimessuchas
fires,floods,severewinds,pathogenoutbreaks,orsimilarevents.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Northernleopardfrogs
inhabitawiderangeofhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.Northernleopard
frogsarenotdependentonanyspecificgeologicfeature.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutraltosomewhatincrease.Northern
leopardfrogssometimesusebeaverpondsforbreeding(Hammerson1999).
C4b)Dietaryversatility(animals).Neutral.Northernleopardfrogsfeedonawidevarietyof
invertebrates(Hammerson1999).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.Thenorthernleopardfrog
isaself‐disperser.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.Neutral.Noother
interspecificinteractionsareimportanttothepersistenceofthenorthernleopardfrog.
C5a)Measuredgeneticvariation.Somewhatdecrease.Mushetetal.(2013)foundhighlevelsof
geneticdiversityinpopulationsofnorthernleopardfrogsinNorthDakota.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Neutral.Thereisnoevidence
thatthetotalpopulationofnorthernleopardfrogswerereducedto<1000individualsorthe
occupiedareawasreducedby>30%overthelast500years.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Neutral.Theeffectsofchangesintemperatureandprecipitationmayhavealargeeffectonthe
timingofbreedingforamphibians(Corn2005)andhasbeenobservedinsomespecies(Blaustein
etal.2001). Literature Cited
Alford,RossA.2011.Bleakfutureforamphibians.Nature480:461‐462.
Climate Change Vulnerability Assessment for Colorado BLM 197 Blaustein,A.R.,L.K.Belden,D.H.Olson,D.M.Green,T.L.Root,andJ.M.Kiesecker.2001.Amphibianbreedingandclimate
change.ConservationBiology15:1804‐1809.
Bouchard,J.,A.T.Ford,F.E.Eigenbrod,andL.Fahrig.2009.Behavioralresponsesofnorthernleopardfrogs(Ranapipiens)
toroadsandtraffic:Implicationsforpopulationpersistence.EcologyandSociety14(2):23.
Corn,P.S.andJ.C.Fogleman.1984.Extinctionofmontanepopulationsofthenorthernleopardfrog(Ranapipiens)in
Colorado.JournalofHerpetology18(2):147‐152.
Corn,P.S.2005.Climatechangeandamphibians.AnimalBiodiversityandConservation28(1):59‐67.
Dole,J.W.1971.Dispersalofrecentlymetamorphosedleopardfrogs,Ranapipiens.Copeia1971:221‐228.
Hammerson,G.A.1999.AmphibiansandreptilesinColorado.Seconded.UniversityPressofColoradoandColorado
DivisionofWildlife.
Mazerolle,M.J.andA.Desrochers.2005.Landscaperesistancetofrogmovements.CanadianJournalofZoology83:455‐
464.
Melillo,J.M.,T.C.Richmond,andG.W.Yohe,Eds.2014.ClimateChangeImpactsintheUnitedStates:TheThirdNational
ClimateAssessment.U.S.GlobalChangeResearchProgram,841pp.doi:10.7930/J0Z31WJ2.
Merrell,D.J.1977.Lifehistoryoftheleopardfrog,Ranapipiens,inMinnesota.BellMuseumofNaturalHistoryOccasional
PapersNo.15:1‐23.
Mushet,D.M.,N.H.Euliss,Y.ChenandC.A.Stockwell.2013.Complexspatialdynamicsmaintainnorthernleopardfrog
(Lithobatespipiens)geneticdiversityinatemporaryvaryinglandscape.HerpetologicalConservationandBiology
8(1):163‐175.
NaturalResourceDefenseCouncil[NRDC].2014.RenewableEnergyforAmerica,harvestingthebenefitsofhomegrown
renewableenergy[Online].http://www.nrdc.org/energy/renewables/technologies.asp
NatureServe2012.ClimateChangeVulnerabilityAssessmentTool,version2.1.Availableonlineat
https://connect.natureserve.org/science/climate‐change/ccvi.
NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org.Accessed2014.
Seburn,C.N.L.,D.C.SeburnandC.A.Paszkowski.1997.Northernleopardfrog(Ranapipiens)dispersalinrelationto
habitat.Pp.64‐72inGreen,D.M.,ed.AmphibiansinDecline:CanadianStudiesofaGlobalProblem.SocietyfortheStudy
ofAmphibiansandReptiles,HerpetologicalConservationNumberOne.St.Louis,Missouri.
Smith,B.E.andD.A.Keinath.2007.NorthernLeopardFrog(Ranapipiens):atechnicalconservationassessment.[Online].
USDAForestService,RockyMountainRegion.Available:http://www.fs.fed.us/r2/
projects/scp/assessments/northernleopardfrog.pdf
198 Colorado Natural Heritage Program © 2015 American Peregrine Falcon
Falcoperegrinusanatum
G4T4/S2B
Family:Falconidae
Climate Vulnerability Rank: Not Vulnerable/Presumed Stable
ThisColoradostatewiderankisbasedon:theextensivedispersalandmigratoryabilitiesofthis
raptor,thelackofimpactsfromlandusechangesassociatedwithclimatechange,theaverage
geneticvariationmeasuredforthespeciesinNorthAmerica,andthepredicted68percent
expansionofthePeregrinefalconswinterrangeinresponsetoclimatechange.Climatemodels
projectincreasedwarminganddroughtacrosstheassessedareawithannualaveragetemperatures
risingby2.5°Fto5.5°Fby2041‐2070andby5.5°Fto9.5°Fby2070‐2099withcontinuedgrowth
inglobalemissions(A2emissionsscenario),withthegreatestincreasesinthesummerandfall
(Melilloetal.2014).Projectionsofprecipitationchangesarelesscertain,butunderacontinuation
ofcurrentrisingemissionstrends(A2),reducedwinterandspringprecipitationisconsistently
projectedforthesouthernpartoftheSouthwestby2100(Melilloetal.2014).Theseprojected
changesinclimatearenotexpectedtohaveimportantnegativeimpactstothePeregrinefalcon
withintheassessmentarea.
Distribution:PeregrineFalconsbreedalongthefoothillsofColorado'sFrontRangeand(inhigher
concentrations)intherivervalleysandcanyonsoftheWesternSlope(Kingery1998).Habitat:
PeregrineFalconsnestonledgesofhighcliffsinthefoothillsandmountainsfrom4,500toover
9,000feet(1,388to2,776m)inelevation(U.S.FishandWildlifeService1984).Thesteepestand
mostinaccessiblelocationsonthetallestcliffsarepreferred;especiallythosethatofferflat,
protectedledgesatleast18incheswide,withsheerrockaboveandbelow(Johnsgard2009).In
Colorado,pinyon/juniperwoodlandoccursinthevicinityofabouthalfofallPeregrineFalconnest
sites,andponderosapinewoodlandorforestisfoundataboutone‐quarterofthesites(Kingery
1998).
Climate Change Vulnerability Assessment for Colorado BLM 199 CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral.Significantnaturalbarriersdonotexist
forthisspecies.ThePeregrinefalconisavolantlongdistantmigratorthatcantraversemountain
rangesandlargebodiesofwater.
B2b)Distributionrelativetoanthropogenicbarriers.Increase.Neutral.Significant
anthropogenicbarriersdonotexistforthisspecies.Thisraptorisavolantspeciesthatcanflyover
oraroundpotentialanthropogenicbarriers.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
AlthoughraptorsandPeregrinefalconshavebeenreportedtobeatriskofcollisionwithwind
turbinesanddisturbedbytheirconstructionduringbrooding(NHFG2005)duringmigrationonly
about10%oftheirrangeintheassessedareaissuitableforwindenergydevelopment(NRDC
2014).Thisisalowconcernfortheraptorwithintheassessedarea.
C1)Dispersalandmovements.Decrease.Althoughmalestendnottodispersefarfromtheirnatal
sites,femalesareknowntodisperse100sofkmfromnatalsites(Whiteetal.2002).Additionally,
PeregrinefalconshavelargehomerangeswithestimatesinColoradorangingfrom358–1,508km2
(EndersonandCraig1997).Finally,thePeregrinefalconislongdistantmigratorandcantravel
over10,000kilometersduringmigration(Whiteetal.2002).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Therange
occupiedbythePeregrinefalconintheassessedareahasexperiencedanaverage(51.7‐77°F/31.8
‐43.0°C)zonalmeanseasonaltemperatureoverthelast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Thereisno
directevidencethatPeregrinesrequirecoolmicroclimatesfornesting.Theygenerallymakea
scrapeonaledgewithshading,sheltering,oroverhangs,andtrendtosouth‐orwest‐facing
orientationinhighlatitudesbutmorerandomdirectionsinlowerlatitudes.Presumablyorientation
orothermicro‐featuresofeyrieprotectyoungfromtemperatureextremes(Whiteetal.2002)
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Somewhatdecrease.TherangeoccupiedbythePeregrinefalconin
theassessedareahasexperiencedgreaterthanaverage(>40inches/1,016mm)precipitation
variationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Neutral.ThePeregrinefalconhasnodependenceonastrongly
seasonalhydrologicregimeand/oraspecificaquatic/wetlandhabitatorlocalizedmoistureregime
thatishighlyvulnerabletolossorreductionwithclimatechange.
200 Colorado Natural Heritage Program © 2015 C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.ThePeregrinefalconisnotdependentuponspecificdisturbanceregimessuchasfires,
floods,severewinds,pathogenoutbreaks,orsimilarevents.
C2d)Dependenceonsnow‐coveredhabitats.Neutral.ThePeregrinefalconisnotdependenton
habitatswithice,snow,oronsnowpack.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Somewhatincreaseto
increase.Peregrinefalconshavepreferencefornestingoncliffs,althoughtheywilluseartificial
structuressuchassmokestacksandbuildings(Whiteetal.2002).
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.ThePeregrinefalconisnot
dependentonanyotherspeciestocreatesuitablehabitatforitsexistence
C4b)Dietaryversatility.Neutral.Withintheassessedareaperegrinefalconsmainlyfeedonbirds
includingcolumbids(e.g.,Zenaida),swifts,andpasserines,butmayoccasionallyfeedonmammals,
amphibians,fish,andinsects(Whiteetal.2002).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.ThePeregrinefalconisa
self‐disperser.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Neutral.Noother
interspecificinteractionsareimportanttothepersistenceofthePeregrinefalcon.
C5a)Measuredgeneticvariation.Neutral.Theperegrinefalconexhibitsaveragegeneticdiversity
acrosspopulationsinNorthAmericawithobservedandexpectedheterozygositiesbeingnearly
equivalent(Johnsonetal.2010).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Decrease.Itisprojectedthattherewill
beadecreaseinathreattothePeregrinefalconswinterrangeduetoclimatechange.Rangewide,
modelspredictedtoincreaseby69%by2080inthefalconswinterrange(NAS2014).Thisincludes
predictionsofanexpansionofthewinterrangeintheassessedarea.Modelsoftheimpactof
climatechangeonthefalcon’spopulationsizearenotavailablefortheassessedarea.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Climate Change Vulnerability Assessment for Colorado BLM 201 Literature Cited
Enderson,J.H.andG.R.Craig.1997.WiderangingbynestingPeregrinefalcons(Falcoperegrinus)determinedby
radiotelemetry.JournalofRaptorResearch,31:333‐338.
Johnsgard,P.A.2009.BirdsoftheGreatPlains–BreedingSpeciesandtheirDistribution:NewExpandedEdition(2009).
546p.Univ.ofNebr.Press,LincolnandLondon.
Johnson,J.A.,S.L.Talbot,G.K.Sage,K.K.Burnham,J.W.Brown,T.L.Maechtle,W.S.Seeger,M.A.Yates,B.AndersonandD.P.
Mondell.2010.PLoSone,5:1‐15.Available:
http://www.plosone.org/article/fetchObject.action?uri=info:doi/10.1371/journal.pone.0014042&representation=PDF
[2/5/2015].
Kingery,H.E.(editor)1998.Coloradobreedingbirdatlas.ColoradoBreedingBirdAtlasPartnership,Denver.Colorado.
Melillo,J.M.,T.C.Richmond,andG.W.Yohe,Eds.,2014:ClimateChangeImpactsintheUnitedStates:TheThirdNational
ClimateAssessment.U.S.GlobalChangeResearchProgram,841pp.doi:10.7930/J0Z31WJ2.
NationalAudubonSociety(NAS).2014.Audubon’sBirdsandClimateChangeReport:APrimerforPractitioners.National
AudubonSociety,NewYork.Contributors:GaryLangham,JustinSchuetz,CandanSoykan,ChadWilsey,TomAuer,Geoff
LeBaron,ConnieSanchez,TrishDistler.Version1.2.Available:http://climate.audubon.org/birds/perfal/peregrine‐falcon
[1/29/2015].
NewHampshireFishandGame(NHFG).2005.NewHampshirewildlifeactionplan.NewHampshireFishandGame
Department,Concord,NewHampshire.
NaturalResourcesDefenseCouncil(NRDC).2014.RenewableenergyforAmerica.Available:
http://www.nrdc.org/energy/renewables/energymap.asp[2/6/2015].
U.S.FishandWildlifeService1984.AmericanPeregrineFalconRecoveryPlan(RockyMountainSouthwestPopulations).
White,C.M.,N.J.Clum,T.J.CadeandW.GraingerHunt.2002.PeregrineFalcon(Falcoperegrinus),TheBirdsofNorth
AmericaOnline(A.Poole,Ed.).Ithaca:CornellLabofOrnithology;RetrievedfromtheBirdsofNorthAmericaOnline:
http://bna.birds.cornell.edu/bna/species/660.
202 Colorado Natural Heritage Program © 2015 Black Swift
Cypseloidesniger
G4/S3B
Family:Apodidae
Climate Vulnerability Rank: Not Vulnerable/Presumed Stable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)fewtonobarrierstomovement;
2)associationwithwaterfallsfornestingthatmaybevulnerabletodryingunderprojected
increasesintemperatureduetoclimatechange.
Distribution:InColorado,BlackSwiftsbreedprimarilyintheSanJuanMountainswithpopulations
concentratedinthesouthwestcornerofthestate.BreedinglocationsarealsofoundintheSangre
deCristo,FlatTops,Gore,andFrontrangesnorthtonorthernRouttCounty(ColoradoBirdAtlas
Partnership1998;Levadetal.2008).Habitat:InColorado,BlackSwiftsnestonclifffaceswith
waterfallsandinsomecases,wetcaves(ColoradoBirdAtlasPartnership1998;Levadetal.2008).
Elevation:Nestinglocationsrangefrom6,640to11,680feetinelevation,withameanof9,957feet
(Levadetal.2008).
EcologicalSystem:Cliffandcanyon
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral.Volant–nobarriers
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Volant–nobarriers
Climate Change Vulnerability Assessment for Colorado BLM 203 B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.It
isunlikelythatanymitigation‐relatedlandusechangeswilloccurwithinthisspecies’rangewithin
Colorado.
C1)Dispersalandmovements.Decrease.BlackSwiftsbreedinColoradoandundertakelong,
seasonalmigrations.Dispersalabilityisgreat.
C2)Sensitivitytotemperatureandmoisturechanges.Thisspecies'closeassociationwith
waterfallsfornestsites(LowtherandCollins2002)greatlyincreasesitsvulnerability;this
associationwithinColoradoaffectsitsscoreinboththehydrologicandgeologicsections.
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.BlackSwifts
prefercoolsitesnearwaterfallsfornesting,butthesemicroclimatesarenotlikelytobeaffected
directlybyclimatechange.
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Neutral
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.Thedegreetowhichstreamsonwhichthese
waterfallsarefoundwillbeaffectedbyclimatechangeisuncertain;Knorr(1961)firstsuggested
thatthisspecieswillnotnestonintermittentstreamsandthatevenindroughtyearswherethe
streamwasreducedtoatrickle,birdsreturnedtotheirnestingsites(Knorr1961;Knorr1993).The
degreetowhichperennialstreamsthatfeedwaterfallswithnestingsitesbecomeintermittentdue
toclimatechangeseemstobetheprimaryfactorindetermininghowvulnerablenestingsitesmay
be.Levadetal.(2008)didfindthatincreasedstreamflowcontributedtoahigherprobabilitythata
waterfallwouldbeoccupied.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.
C2d)Dependenceonsnow‐coveredhabitats.Neutral.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.SomewhatIncrease.This
species'closeassociationwithwaterfallsfornestsites(LowtherandCollins2002)increasesits
vulnerability.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.
C4b)Dietaryversatility.Neutral. Diet items are diverse, but primarily limited to flying insects
(Lowther and Collins 2002).
C4c)Pollinatorversatility(Plantsonly,notapplicable).
204 Colorado Natural Heritage Program © 2015 C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Unknown.
C5a)Measuredgeneticvariation.Unknown.MoreinformationisneededonBlackSwiftgenetics.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
ColoradoBirdAtlasPartnership,RadeauxandColoradoDivisionofWildlife.1998.ColoradoBreedingBirdAtlas.Denver,
Colorado:ColoradoBirdAtlasPartnership.636pg.
Knorr,O.A.1961.ThegeographicalandecologicaldistributionoftheBlackSwiftinColorado.WilsonBulletin73:155‐170.
Knorr,O.A.1993.BreedingoftheBlackSwiftintheGreatBasin.WesternBirds24:197‐198.
Levad,R.G.,K.M.Potter,C.W.Schultz,C.Gunn,andJ.G.Doerr.2008.Distribution,abundance,andnest‐sitecharacteristics
ofBlackSwiftsintheSouthernRockyMountainsofColoradoandNewMexico.TheWilsonJournalofOrnithology
120:331‐338.
Lowther,P.E.,andC.T.Collins.2002.BlackSwift(Cypseloidesniger).InTheBirdsofNorthAmerica,No.676(A.Pooleand
F.Gill,eds.).TheBirdsofNorthAmerica,Inc.,Philadelphia,PA.
Climate Change Vulnerability Assessment for Colorado BLM 205 Brewer’s Sparrow
Spizellabreweri
G5/S4B
Family:Emberizidae
Climate Vulnerability Rank: Not Vulnerable/Presumed Stable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)potentialincreasehabitat
degradationdueoilandgasdevelopmentinBrewer’ssparrowhabitat;2)relianceonsagebrush
habitats;and3)positivecorrelationbetweenwinterprecipitationandclutchsize.TheBrewer’s
Sparrowmaybelessvulnerablethanotherbirdspeciesassessedinthisreportduetothelackof
barrierstomovement,highgeneticvariation,highdietaryversatility,andlongdistancemovement
patterns.
Distribution:Brewer’sSparrowsareoccurthroughoutmostofColorado,butarenotablyabsent
fromtheSanJuanBasin(ColoradoBirdAtlasPartnership1998;BoyleandReeder2005).Breeding
Brewer’sSparrowsaremostcommoninthemesasandfoothillsofwesternColorado,withthe
highestabundanceestimatesoccurringinthenorthwesterncornerofthestate(Lambeth1998).
Habitat:InColorado,Brewer’sSparrowsaremostfrequentlydocumentedinmountainbig
sagebrushhabitats(ColoradoBirdAtlasPartnership1998).Theyalsooccurinthefollowing
vegetationtypesasdefinedbytheColoradoBreedingBirdAtlas(1998):lowlandsagebrush,tall
desertshrub,shortgrassortallgrass/sandsage,montanegrassland,mountainshrub,pinyon‐juniper
woodland.Elevation:Commonlynestingbetween5,000and7,500ft(AndrewsandRighter1992).
EcologicalSystem:Sagebrushshrubland,Sandsage,DesertShrublands,Pinyon‐Juniper
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
206 Colorado Natural Heritage Program © 2015 B2a)Distributionrelativetonaturalbarriers.Neutral.Brewer'sSparrowsarefoundonboththe
EastandWestSlopeofColorado,fromlowelevationareasontheplains,tohighelevationsitesnear
timberline(11,400feet)(HansleyandBeauvais2004).
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Thisspeciesoccupiesabroad
geographicandelevationrangeinCO.Noanthropogenicbarriershavebeenreportedforthe
species(HansleyandBeauvais2004).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.
SomewhatIncrease.Brewer'sSparrowsareconsideredsagebrushobligates.NWColorado,
includingRioBlancoCounty,containslargeexpansesofsagebrushshrublands.Atotalof2,915
activenaturalgaswellsarecurrentlyoperatinginRioBlancoCounty(COGCC2015).Aprojected
1,845newwellswillbedrilledinRioBlancoCountyin2035tomeetenergydemandsinColorado
(BBC2008).Increasedenergydevelopmentinthisareawillresultinfurtherhabitatfragmentation
forBrewer'sSparrow.
C1)Dispersalandmovements.Decrease.Brewer'sSparrowsmigratelongdistancesacrossthe
WesternUS,winteringinTexas,California,andNevada,andtravelingnorthtoCanada,Wyoming,
Colorado,andtheGreatPlainstobreed(ColoradoBirdAtlasPartnership2008).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Lessthan
10%ofsagebrushecosystemsinColoradoareprojectedtobeoutsideofitscurrentclimatic
envelope(SeeEcosystemSectionofreport).
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.SomewhatDecrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,thespecieshasexperiencedgreaterthanaverage(>40
inches/1,016mm)precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Neutral.Thisspeciesdoesnotrelyonastronglyseasonal
hydrologicregime.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.Thisspeciesdoesnotrelyonaspecificdisturbanceregimethatwillbeimpactedbyclimate
change.
C2d)Dependenceonsnow‐coveredhabitats.SomewhatIncrease.Clutchsizeappearstobe
positivelycorrelatedwithwinterprecipitation(PetersonandBest1986;Lack1966).
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.
Climate Change Vulnerability Assessment for Colorado BLM 207 C4a)Dependenceonotherspeciestogeneratehabitat.GreatlyIncrease.Thisspeciesismost
frequentlyassociatedwithmountainbigsagebrushhabitatsinColorado.
C4b)Dietaryversatility.Neutral.Brewer'sSparrowseatawidevarietyofinsects(Petersonand
Best1986).Duringmigration,Brewer'sSparrowsrelymainlyonseedsandseedheadsforfood,
withinsectscomprisingonly10%oftheirdiet(Short1984).
C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Unknown.
C5a)Measuredgeneticvariation.Neutral.Geneticvariationorinbreedingdepressionhasnot
beenidentifiedasaconcernforBrewer'sSparrow(HansleyandBeauvais2004).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
Andrews,R.andR.Righter.1992.Coloradobirds:areferencetotheirdistributionandhabitat.Denver:DenverMuseumof
NaturalHistory.
BBCResearchandConsulting.2008.NorthwestColoradoSocioeconomicAnalysisandForecasts.Reportpreparedfor
AssociatedGovernmentsofNorthwestColorado.179pg.Availableonlineat
http://www.colorado.gov/cs/Satellite?blobcol=urldata&blobheadername1=ContentDisposition&blobheadername2=Cont
entType&blobheadervalue1=inline%3B+filename%3D%22Full+Report.pdf%22&blobheadervalue2=application%2Fpdf&
blobkey=id&blobtable=MungoBlobs&blobwhere=1251731958720&ssbinary=true.
Boyle,S.A.andD.R.Reeder.2005.Coloradosagebrush:aconservationassessmentandstrategy.GrandJunction:Colorado
DivisionofWildlife.
ColoradoBirdAtlasPartnership,RadeauxandColoradoDivisionofWildlife.1998.ColoradoBreedingBirdAtlas.Denver,
Colorado:ColoradoBirdAtlasPartnership.636pg.
ColoradoOilandGasCommission(COGCC).2015.WeeklyOilandGasStatisticsforFeb2,2015.AccessedonlineFeb21,
2015atwww.colorado.gov/cogcc.
208 Colorado Natural Heritage Program © 2015 Hansley,P.L.andG.P.Beauvais.2004.SpeciesAssessmentforBrewer'sSparrow(Spizellabreweri)inWyoming.Prepared
fortheBLM.49pages.
Lack,D.1966.Populationstudiesofbirds.ClarendonPress,Oxford,UK.
Lambeth,R.1998.Brewer'ssparrow(Spizellabreweri).InColoradoBreedingBirdAtlas,editedbyH.E.Kingery.Denver:
ColoradoBirdAtlasPartnership&ColoradoDiv.ofWildlife.
Petersen,K.L.andL.B.Best.1986.DietsofnestlingSageSparrowsandBrewer’sSparrowsinanIdahosagebrush
community.JournalofFieldOrnithology57:283‐294.
Short,H.L.1984.HabitatSuitabilityIndexmodels:Brewer’sSparrow.USDIFishandWildlifeServiceBiologicalReport
FWS/OBS‐82/10.83.
Climate Change Vulnerability Assessment for Colorado BLM 209 Burrowing Owl
Athenecuniculariahypugaea
G4/S4B
Family:Strigidae
©DonBaccus
Climate Vulnerability Rank: Moderately Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)dependenceonprairiedogsand
othermammalstocreatesuitablenestinghabitat;2)lowlevelsofgeneticdiversity;3)lackof
protectiononprivatelands;4)predictedlossof77%ofcurrentbreedingrangeduetoclimate
change(AudubonSociety2015).
Distribution:Breedingrecordscovermuchofthestate,althoughitismorecommonontheplains
ofeasternColorado(AndrewsandRighter1992,ColoradoBirdAtlasPartnership1998).Habitat:
Thisspeciesisfoundindryopentreelessareasandisassociatedwithburrowingmammals.
Burrowsareusuallysurroundedbybaregroundandprovideprotectionfromweatherextremes
(Haugetal.1993).Althoughcapableofdiggingtheirownburrowswhereburrowingmammalsare
absent,burrowingowlsusuallyuseexistingburrows,particularlythoseofprairiedogs.
EcologicalSystem:ShortgrassPrairie
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.
SomewhatIncrease.AccordingtoDepartmentofEnergywindresourcemaps,theeasternquarterof
210 Colorado Natural Heritage Program © 2015 ColoradoneartheNewMexicoandNebraskabordershasexcellentwindresources(DOE2004).
Windturbinescancausedirectimpactstobirdsviacollisionsthatresultininjuryormortality
(Kunzetal.2007;Kuvleskyetal.2007),aswellasindirectimpactsviahabitatlossandbarriersto
movement(DrewittandLangston2006;Kuvleskyetal.2007;Pruettetal.2009;Kieseckeretal.
2011).ResultsfromastudyatawindfarminCaliforniasuggestthatwindturbinesannuallykill
betweenone‐fifthandnearlytwicethenumberofestimatedowlsintheavailablehabitatarea
(Smallwoodetal.2010).
C1)Dispersalandmovements.Decrease.TheBurrowingOwliscapableoflongdistance
migration,andBurrowingOwlsbandedinAlberta,CanadahavebeenrecoveredinMexico(USFWS
2003).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Thisspecies
isassociatedwithshortgrassprairieinColoradoandisnotlimitedtocoolorcoldhabitats
(ColoradoBirdAtlasPartnership1998).
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.SomewhatDecrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,thespecieshasexperiencedgreaterthanaverage(>40
inches/1,016mm)precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Neutral.StudiesonthePawneeNationalGrasslandshowed
decreasedsurvivalinowletsduringwetsummers(Conrey2010).Preypopulationsmayrespond
positivelytoincreasedrainfall,butBurrowingOwlstypicallydonothuntinwetweather(Conrey
2010).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.
C2d)Dependenceonsnow‐coveredhabitats.Neutral.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.Sandysoilsmay
permiteasierdiggingforprairiedogs,badgers,andBurrowingOwlsthatcreateburrowsinthe
shortgrassprairie.
C4a)Dependenceonotherspeciestogeneratehabitat.SomewhatIncrease.BurrowingOwls
nestinburrowsthatarecreatedbyprairiedogsandothermammals(ColoradoBirdAtlas
Partnership1998).
Climate Change Vulnerability Assessment for Colorado BLM 211 C4b)Dietaryversatility.Neutral.BurrowingOwlsonthePawneeGrasslandatebeetles,
grasshoppers,ants,rodents,andsongbirds;insectscomprised95%oftheirdietbynumberand
only11%bybiomass(Conrey2010).
C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Neutral.
C5a)Measuredgeneticvariation.Increase.Lowlevelsofgeneticvariationhavebeendocumented
inBurrowingOwls,basedonmicrosatellitedatafrompopulationsdistributedthroughoutNorth
America(Macias‐Duarteetal.2010).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Neutral.
D2)Modeledfuturechangeinpopulationorrangesize.Increase.AudubonSociety’sclimate
modelspredictthatby2080,BurrowingOwlscouldlose77%oftheircurrentbreedingrange
(AudubonSociety2015).
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Increase.InColorado,mostareasontheeasternplainsinBurrowingOwl
habitatareonprivatelands.
Literature Cited
Andrews,R.A.,andR.Righter.1992.Coloradobirds.DenverMuseumofNaturalHistory.Denver,Co.Pp363
AudubonSociety.2015.ClimateModelsforBurrowingOwl.Onlineat
http://climate.audubon.org/birds/burowl/burrowing‐owl.AccessedFeb21,2015.
ColoradoBirdAtlasPartnership,RadeauxandColoradoDivisionofWildlife.1998.ColoradoBreedingBirdAtlas.Denver,
Colorado:ColoradoBirdAtlasPartnership.636pg.
Conrey,R.Y.2010.Breedingsuccess,preyuse,andmark–resightestimationofburrowingowlsnestingonblack‐tailed
prairiedogtowns:Plagueaffectsanon‐susceptibleraptor.Ph.D.dissertation,ColoradoStateUniversity,FortCollins,CO.
DepartmentofEnergy(DOE).2004.WINDExchange.ColoradoWindResourceMap.Availableonlineat
http://apps2.eere.energy.gov/wind/windexchange/wind_resource_maps.asp?stateab=co.AccessedFeb2,2015
Drewitt,A.L.andR.H.W.Langston.2006.AssessingtheImpactsofWindFarmsonBirds.Ibis148:29‐42.
Haug,E.A.,B.AMillsap,andM.S.Martell.1993.BurrowingOwl(Speotytocunicularia),inTheBirdsofNorthAmerica(A.
PooleandF.Gill,eds.),no.61.Acad.Nat.Sci.,Philadelphia
212 Colorado Natural Heritage Program © 2015 Kiesecker,J.M.,J.S.Evans,J.Fargione,K.Doherty,K.R.Foresman,T.H.Kunz,D.Naugle,N.P.Nibbelink,andN.D.Nieumuth.
2011.Win‐winforwindandwildlife:avisiontofacilitatesustainabledevelopment.PlosONE6:e17566.
Kunz,T.H.,E.B.Arnett,B.M.Cooper,W.P.Erickson,R.P.Larkin,T.Mabee,M.L.Morrison,M.D.Strickland,andJ.M.
Szewczak.2007.Assessingimpactsofwind‐energydevelopmentonnocturnallyactivebirdsandbats:aguidance
document.JournalofWildlifeManagement71:2449–4486.Available:http://www.wind‐watch.org/documents/wp‐
content/uploads/wild‐71‐08‐45.pdf.
Kuvlesky,W.P.Jr.,L.A.Brennan,M.L.Morrison,K.K.Boydston,B.M.BallardandF.C.Bryant.2007.WindEnergy
DevelopmentandWildlifeConservation:ChallengesandOpportunities.JournalofWildlifeManagement71(8):2487‐
2498.
Macias‐Duarte,A.,C.J.Conway,A.Munguia‐Vega,andM.Culver.2010.NovelmicrosatellitelocifortheBurrowingOwl,
Athenecunicularia.ConservationGeneticsResources2:67‐69.
Pruett,C.L.,M.A.Patten,andD.H.Wolfe.2009.AvoidanceBehaviorbyPrairieGrouse:ImplicationsforDevelopmentof
WindEnergy.ConservationBiology23(5)1253‐1259.
Smallwood,K.S.,C.G.Thelander,M.L.Morrison,L.M.Rugge.2010.BurrowingOwlMortalityintheAltamontPassWind
ResourceArea.TheJournalofWildlifeManagement71(5):1513‐1524).
U.S.FishandWildlifeService.2003.StatusAssessmentandConservationPlanfortheWesternBurrowingOwlinthe
UnitedStates.BiologicalTechnicalPublicationR6001‐2003.120pg.
Climate Change Vulnerability Assessment for Colorado BLM 213 Golden Eagle
Aquilachrysaetos
G5/S3S4B,S4N
Family:Accipitridae
Climate Vulnerability Rank: Moderately Vulnerable
ThisColoradostatewiderankisbasedon:theprojectedincreasesintemperaturefortheassessed
area,increasedwindenergydevelopmentandthegreaterrisktomortalityfromwindturbinesthan
otherraptors,limitedprecipitationvariationtheeaglehashistoricallyexperienced,limitednumber
ofpreyspeciestheeagledependsupon,andapredicteddecreaseinbreedingrange.Climate
projectionssuggestthatsummertemperaturesacrosstherangeoftheGoldenEagleintheassessed
areawillincrease6°Fbytheendofthecenturyunderaloweremissionsscenario,withincreasesof
morethan10°Fbytheendofthecenturyunderahigheremissionsscenario(Karletal.2009).
Distribution:InColorado,goldeneaglesbreedprimarilyinmontanehabitatsinthewestand
canyonhabitatsinthesoutheast.ThereissomelimitedbreedinginnortheastColorado.Inwinter,
goldeneaglesrangemorewidelyandoccurcommonlythroughoutColorado.Habitat:Golden
eaglesuseaverywiderangeofhabitats.Fornestingtheymostfrequentlyusecliffsbutwillalso
nestintrees.Becauseoftheirlargesizeandpredatorynature,theyrequirelargeareasofforaging
habitat.Forforagingtheyusehigh‐andmid‐elevationpineforest,piñon‐juniperwoodlands,
sagebrushandothershrubhabitats,grassland,andagriculturalhabitatsareallusedbyGolden
eagles.
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
214 Colorado Natural Heritage Program © 2015 B2a)Distributionrelativetonaturalbarriers.Neutral.Significantnaturalbarriersdonotexist
forthisspecies.Thisraptorisavolantspeciesthatcantraversemountainrangesandlargebodies
ofwater.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Significantanthropogenic
barriersdonotexistforthisspecies.Thisraptorisavolantspeciesthatcanflyoveroraround
potentialanthropogenicbarriers.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.
Somewhatincrease.GoldenEaglesareatgreaterrisktomortalityfromwindturbinesthanother
raptors(USFWS2011).Windenergydevelopmentisexpectedtoincreasewithintherangeofthe
GoldenEagleinColorado(NRDC2014).
C1)Dispersalandmovements.Decrease.GoldenEaglesreadilydispersemorethan10kilometers
fromhatchingsitetobreedingareas(Kochertetal.2002)
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Therange
occupiedbytheGoldeneagleintheassessedareahasexperiencedanaverage(51.7‐77°F/31.8‐
43.0°C)zonalmeanseasonaltemperatureoverthelast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Somewhatincrease.
InNorthAmerica,GoldenEagle'sbreedingsuccessappearstobecompromisedbythenumberof
extremelyhotdaysduringthebroodrearingperiod(Steenhofetal.1997).Climateprojections
suggestthatsummertemperaturesacrosstherangeoftheGoldenEagleintheassessedareawill
increase6°Fbytheendofthecenturyunderaloweremissionsscenario,withincreasesofmore
than10°Fbytheendofthecenturyunderahigheremissionsscenario(Karletal.2009)
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Somewhatincrease.WithintheassessedareatheGoldenEaglehas
experiencedslightlylowerthanaverage(20‐30inches/255‐508mm)precipitationvariationinthe
past50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Neutral.GoldenEaglereproductivesuccessappearstobe
independentofanyparticularprecipitationregime(Steenhofetal.1997andCrandall2005).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.TheGoldenEagleisnotdependentonanydisturbanceregimesuchasfireorfloodingand
aremostdependentuponsuitablepreypopulationsinforagingareas(Steenhofetal.1997and
Crandall2005).
C2d)Dependenceonsnow‐coveredhabitats.Neutral.TheGoldenEagleisnotdependenton
habitatswithice,snow,oronsnowpack.
Climate Change Vulnerability Assessment for Colorado BLM 215 C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.TheGoldenEagleis
notdependentuponanyuncommongeologicalelements.However,theyoftennestoncliffs,butalso
willnestintreesandontheground,riverbanksandhumanstructures(Kochertetal.2002).
Climatechangeshouldnotimpacttheavailabilityofsuitablecliffsitesfornesting.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.TheGoldenEagleisnot
dependentonanyotherspeciestocreatesuitablehabitatforitsexistence.
C4b)Dietaryversatility.Somewhatincrease.TheGoldenEagledependsuponafewsmall
mammalaspreyincludinghares(Lepusspp.)andrabbits(Sylvilagusspp.);alsogroundsquirrels
(Spermophilusspp.),prairiedogs(Cynomysspp.)andmarmots(Marmotaspp.)(Kochertetal.
2002).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.TheGoldenEagleisaself‐
disperser.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Neutral.Noother
interspecificinteractions,otherthanthosediscussedabove,areimportanttothepersistenceofthe
GoldenEagle.
C5a)Measuredgeneticvariation.Neutral.Thegeneticdiversityofthegoldeneaglehasbeen
reportedtobeaverage(Doyleetal.2014).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Increase.Thepredictedbreedingrange
oftheGoldenEagleintheassessedareaispredictedtodeclineby79percent(NationalAudubon
Society2013).
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
Crandall,R.H.2005.IdentifyingenvironmentalfactorsinfluencingGoldenEaglepresenceandreproductivesuccess.
Master'sthesis,UniversityofMontana.
DoyleJM,KatznerTE,BloomPH,JiY,WijayawardenaBK,etal.(2014)TheGenomeSequenceofaWidespreadApex
Predator,theGoldenEagle(Aquilachrysaetos).PLoSONE9(4):e95599.doi:10.1371/journal.pone.0095599
216 Colorado Natural Heritage Program © 2015 Karl,T.R.,J.M.Melillo,andT.C.Peterson,(eds.).2009.GlobalClimateChangeImpactsintheUnitedStates.Cambridge
UniversityPress.
Kochert,M.N.,K.Steenhof,CL.McintyreandE.H.Craig.2002.GoldenEagle(Aquilachrysaetos),TheBirdsofNorth
AmericaOnline(A.Poole,Ed.).Ithaca:CornellLabofOrnithology;RetrievedfromtheBirdsofNorthAmericaOnline:
http://bna.birds.cornell.edu/bna/species/684doi:10.2173/bna.684"
NationalAudubonSociety.2013.DevelopingaManagementModeloftheEffectsofFutureClimateChangeonSpecies:A
ToolfortheLandscapeConservationCooperatives.UnpublishedreportpreparedfortheU.S.FishandWildlifeService.
NaturalResourcesDefenseCouncil(NRDC).2014.RenewableenergyforAmerica.
http://www.nrdc.org/energy/renewables/energymap.asp
Steenhof,K.,M.N.KochertandT.L.McDonald.1997.InteractiveEffectsofPreyandWeatheronGoldenEagle
Reproduction.JournalofAnimalEcology,66:350‐362.
U.S.FishandWildlifeService(USFWS).2011.DraftEagleConservationPlanGuidance.
Climate Change Vulnerability Assessment for Colorado BLM 217 Greater Sage‐grouse
Centrocercusurophasianus
G3G4/S4
Family:Phasianidae
Climate Vulnerability Rank: Highly Vulnerable
ThisColoradostate‐widerankofHighlyVulnerableisbasedonthefollowingfactors:1)lessthan
10%ofsagebrushecosystemsinCOareprojectedtobeoutsideofcurrentclimaticenvelope(see
Ecosystemschapter);2)outsideoftheirrelianceonsagebrushforcoverandfood,thisspecieshas
fewrestrictionstouncommongeologicfeatures,norelianceonintraspecificrelationships;3)
GreaterSage‐grouse(GrSG)arecapableofmovingseveralkilometers;4)GrSGhaveexperienced
averagetemperaturevariationinthepast50years;5)geneticvariationinColoradoishigherthan
otherpartsoftheGrSGrange.
Distribution:Greatersage‐grouseoccurintheWesternUnitedStatesandCanada.Coloradoison
thesoutheasternedgeofthecurrentGrSGrange(ColoradoGreaterSage‐grouseSteering
Committee[CGSGSC]2008).WithinColorado,theoccupiedrangeofGrSGisinthenorthwestcorner
ofthestateinthefollowingcounties:Eagle,Garfield,Grand,Jackson,Larimer,Mesa,Moffat,Rio
Blanco,Routt,andSummit.Habitat:TheGrSGaredependentonsagebrushyeararoundforfood
andcover.Femalesandbroodsmayselectriparianhabitatsinthesagebrushtypethatcontainhigh
coverofforbsandabundantmoisture(seeCGSGSC2008fordiscussionofseasonalhabitatuse
withinsagebrushshrublands).Elevation:7,900‐9,500feet.
EcologicalSystem:Sagebrushshrubland
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
218
Colorado Natural Heritage Program © 2015 B2a)Distributionrelativetonaturalbarriers.SomewhatIncrease.Severalpopulationsonthe
easternedgeofoccupiedhabitatinCOareseparatedbytheParkRange.Thesehighalpineareas
andruggedpeaksmayactasanaturalbarrierformovement.
B2b)Distributionrelativetoanthropogenicbarriers.SomewhatIncrease.Thismountainrange
isapotentialnaturalbarrierforGrSG.RivervalleysandlargeagriculturalareasinAlberta,
Saskatchewan,Montana,andWyomingweresignificantbarrierstoGrSGmovement(Bushetal.
2011).TheeasternandsouthernedgesofGrSGrangeinColoradocontainirrigatedanddryland
agriculturalfieldsthatmayserveasbarrierstoGrSGmovement(USGSNationalGapAnalysis
Program2004).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.
SomewhatIncrease.GrSGareconsideredsagebrushobligates.NWColorado,includingRioBlanco
County,containslargeexpansesofsagebrushshrublands.Atotalof2,915activenaturalgaswells
arecurrentlyoperatinginRioBlancoCounty(COGCC2015).Aprojected1,845newwellswillbe
drilledinRioBlancoCountyin2035tomeetenergydemandsinColorado(BBC2008).Increased
energydevelopmentinthisareawillresultinfurtherhabitatfragmentationforGrSG.Lessthanone
percentoffederallandsinColoradocontainwindenergydevelopmentright‐of‐wayswithin
PriorityAreasforGrSGConservationinColorado(LeBeauetal.2014).
C1)Dispersalandmovements.Decrease.Averagenest‐to‐wintermovementsinGrSGinWyoming
averaged14.4kminarecentstudy(Fedyetal.2012).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,GrSGhasexperiencedaverage(57.1‐77°
F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Lessthan
10%ofsagebrushecosystemsinColoradoareprojectedtobeoutsideofitscurrentclimatic
envelope(SeeEcosystemSectionofreport).
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.SomewhatDecrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,GrSGhasexperiencedgreaterthanaverage(>40inches/1,016
mm)precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.GreatlyIncrease.Highqualitybrood‐rearinghabitatsareoften
locatedinmesicareaslikestreambedsandwetmeadows(Connellyetal.2000).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncrease.FireisconsideredoneofthetopthreatstoGrSG.Althoughhistoricallynatural
fireswereoftenlargeandsevere,theyweretypicallyinfrequentinGrSGhabitat(Brooksetal.
2015).However,duringrecentdecades,fireprobabilityandoccurrencehasincreasedacrossGrSG
Climate Change Vulnerability Assessment for Colorado BLM 219 habitat,hinderingtherecoveryofsagebrush,andposingathreattoGrSGhabitat(Brooksetal
2015.)
C2d)Dependenceonsnow‐coveredhabitats.Neutral.Thisspeciesmakessnowroostsand
burrows(Backetal.1987),butisnotcompletelydependentonsnowcoverforsurvival.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.SomewhatDecrease.This
speciesisnotrestrictedtouncommongeologicfeatures.
C4a)Dependenceonotherspeciestogeneratehabitat.GreatlyIncrease.TheGrSGrelyon
sagebrushyear‐roundforfoodandcover.
C4b)Dietaryversatility.SomewhatIncrease.Duringthespringandsummer,GrSGconsume
insectsandforbs;theirfallandwinterdietiscomprisedentirelyofsagebrush(CGSGSC2008).
C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Unknown.
C5a)Measuredgeneticvariation.Neutral.NorthPark,MiddlePark,andEaglepopulationsin
high‐elevationvalleyinColoradoaregeneticallydistinctfrompopulationsintheWyomingBasin
thataremorewide‐spread(Oyler‐McCanceetal.2005).NopopulationsinColoradohavebeen
identifiedashavinganextremelylownumberofhaplotypes,ascomparedtothoseintheColumbia
Basin(Oyler‐Mccanceetal.2005).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Neutral.Geneticstestingacross
therangeofGrSGdidnotrevealanypopulationbottlenecksinColoradopopulations(Oyler‐
Mccanceetal.2005).C6)Phenologicalresponsetochangingseasonaltemperatureand
precipitationdynamics.Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
Back,G.N.,M.R.Barrington,andJ.K.McAdoo.1987.SageGrouseuseofsnowburrowsinnortheasternNevada.Wilson
Bulletin99:488‐490.
BBCResearchandConsulting.2008.NorthwestColoradoSocioeconomicAnalysisandForecasts.Reportpreparedfor
AssociatedGovernmentsofNorthwestColorado.179pg.Availableonlineat
http://www.colorado.gov/cs/Satellite?blobcol=urldata&blobheadername1=ContentDisposition&blobheadername2=Cont
220 Colorado Natural Heritage Program © 2015 entType&blobheadervalue1=inline%3B+filename%3D%22Full+Report.pdf%22&blobheadervalue2=application%2Fpdf&
blobkey=id&blobtable=MungoBlobs&blobwhere=1251731958720&ssbinary=true.
Brooks,M.L.,J.R.Matchett,D.J.Shinneman,andP.S.Coates.2015.Firepatternsintherangeofgreatersage‐grouse,1984–
2013‐Implicationsforconservationandmanagement:U.S.GeologicalSurveyOpen‐FileReport2015‐1167,66p.
Bush,K.L.,C.K.Dyte,B.J.Moynahan,C.L.Aldridge,H.S.Sauls,A.M.Battazzo,B.L.Walker,K.E.Doherty,J.Tack,J.Carlson,D.
Eslinger,J.Nicholson,M.S.Boyce,D.E.Naugle,C.A.Paszkowski,andD.W.Coltman.2011.Populationstructureandgenetic
diversityofgreatersage‐grouse(Centrocercusurophasianus)infragmentedlandscapesatthenorthernedgeoftheir
range.ConservationGenetics12:527‐542
ColoradoGreaterSage‐grouseSteeringCommittee[CGSGSC].2008.Coloradogreatersage‐grouseconservationplan.
ColoradoDivisionofWildlife,Denver,Colorado,USA.
ColoradoOilandGasCommission(COGCC).2015.WeeklyOilandGasStatisticsforFeb2,2015.AccessedonlineFeb21,
2015atwww.colorado.gov/cogcc.
Connelly,J.W.,M.A.Schroeder,A.R.Sands,andC.E.Braun.2000.Guidelinestomanagesagegrousepopulationsandtheir
habitats.WildlifeSocietyBulletin28:967‐985.
Fedy,B.C.,C.L.Aldridge,K.E.Doherty,M.O’Donnell,J.L.Beck,B.Bedrosian,M.J.Holloran,G.D.Johnson,N.W.Kaczor,C.P.
Kirol,C.A.Mandich,D.Marshall,G.McKee,C.Olson,C.C.Swanson,andB.Walker.2012.Interseasonalmovementsof
greatersage‐grouse,migratorybehaviour,andanassessmentofthecoreregionsconceptinWyoming.JournalofWildlife
Management76(5):1062‐1071.
LeBeau,C.,J.Fruhwirth,J.R.Boehrs.2014.AnalysisoftheOverlapbetweenPriorityGreaterSage‐GrouseHabitatsand
ExistingandPotentialEnergyDevelopmentAcrosstheWest.FinalReportforWesternValuesProject.Preparedby
WesternEcoSystemsTechnology,Inc.36pg.Onlineat:http://westernvaluesproject.org/wp‐
content/uploads/2014/10/Greater‐Sage‐Grouse‐Priority‐Habitats‐and‐Energy‐Development.pdf.
Oyler‐McCance,S.J.,S.E.Taylor,andT.W.Quinn.2005.Amultilocusgeneticsurveyofgreatersage‐grouseacrosstheir
range.MolecularEcology14:1293‐1310.
USGSNationalGapAnalysisProgram.2004.ProvisionalDigitalLandCoverMapfortheSouthwesternUnitedStates.
Version1.0.RS/GISLaboratory,CollegeofNaturalResources,UtahStateUniversity.
Climate Change Vulnerability Assessment for Colorado BLM 221 Gunnison Sage‐grouse
Centrocercusminimus
G1/S1
ListedThreatened
Family:Phasianidae
Climate Vulnerability Rank: Highly Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)barrierstomovement;2)
potentialdecreaseingrowthofmountainbigsagebrushduetoclimatechange;3)relianceonmesic
habitattypesforbrood‐rearinghabitat;4)lackofgeneticdiversity;5)potentialincreaseinfire
frequencyinsagebrushhabitatsduetoprojectedtemperatureincreases.
Distribution:LimitedtosouthwestColoradoandsoutheastUtah.InColorado,Gunnison‐sage‐
grouseoccurinthefollowingcounties:Delta,Dolores,Gunnison,Hinsdale,Mesa,Montrose,San
Miguel,andSaguache(USFWS2014).Habitat:Gunnisonsage‐grouserelyonlargeexpansesof
sagebrushhabitatforfoodandcover;mesicareasalongripariancorridors,aswellaswetmeadows
providebrood‐rearinghabitat(USFWS2014).
EcologicalSystem:Sagebrushshrubland
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.SomewhatIncrease.Gunnisonsage‐grouserely
onlarge,continuous,unfragmentedlandscapesforsurvival(GSGRSC2005).Theglobaldistribution
ofGunnisonsage‐grouseislimitedtosevenpopulations,sixofwhicharelocatedinColorado.The
remainingpopulationstraddlestheUtah/Coloradoborder.Gunnisonsage‐grouseoccurinareas
222
Colorado Natural Heritage Program © 2015 withelevationsrangingfrom2,300to2,900m(7,500to9,5000ft)ofelevation.Areasbetween
manyoftheColoradopopulationsdonotcontainsuitablehabitatandhaveelevationsmuchhigher
thanthedocumentedrangepreferredbythespecies.TheGunnisonRiverandtheBlackCanyon
mayalsoposeanaturalbarriertomovement.
B2b)Distributionrelativetoanthropogenicbarriers.Increase/SomewhatIncrease.Asnoted
aboveinB2a,Gunnisonsage‐grouserelyonlarge,continuous,unfragmentedlandscapesfor
survival(GSGRSC2005).Humanpopulationsandassociateddevelopmentareprojectedtoincrease
nearmostGunnisonsage‐grousepopulations(USFWS2014).Habitatdeclinefromdisturbanceand
fragmentationcausedbyroadsandpowerlinesisacurrentandfuturethreattothesurvivalof
Gunnisonsage‐grouseinColorado(USFWS2014).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
GeothermaldevelopmentpotentialishighintheGunnisonBasin,andifdevelopmentincreasedin
theBasin,itcouldaffectthelong‐termviabilityofGunnisonsage‐grousewithintheBasin(USFWS
2014).Noexisting,pending,orauthorizedwindenergysitesarewithintheColoradoportionof
occupiedGunnisonsage‐grousehabitat(USFWS2014).Noinformationregardingsolarenergy
developmentwasincludedinthefinalruleissuedbyUSFWSin2014,soitislikelynotathreatin
occupiedGunnisonsage‐grousehabitat.
C1)Dispersalandmovements.SomewhatDecrease.Gunnisonsage‐grousearegenerally
considerednonmigratory,butsomeseasonalmovementshavebeendocumented.IntheGunnison
Basin,individualsgenerallymovelessthan10km(GSGRSC2005),butmovementsasgreatas56
kmhavealsobeenreportedintheBasin(Phillips2013).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.SomewhatIncrease.
PredictingtemperaturesinoccupiedhabitatforGunnisonsage‐grouseischallenging.Inone
scenario,averagesummertemperaturesarepredictedtoincreaseinwesternColoradoby2.8˚Cby
2050(UCAR2009),andaveragewintertemperaturescouldincreaseby2.2˚Cby2050(UCAR
2009).Overtime,increasedtemperaturescouldreducegrowthofmountainbigsagebrush,
resultinginareductionofsuitablehabitatforGunnisonsage‐grouse(USFWS2014).
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Neutral.Consideringtherangeofmeanannualprecipitationacross
occupiedcells,thespecieshasexperiencedaverage(21‐40inches/509‐1,016mm)precipitation
variationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.GreatlyIncrease.Highqualitybrood‐rearinghabitatincludes
mesicmeadows,springs,seeps,andlowvegetationriparianareas,alldependentonadequate
Climate Change Vulnerability Assessment for Colorado BLM 223 moisture(GSGRSC2005;USFWS2014).Thesehabitatstypesarehighlyvulnerabletoclimate
change.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncrease.Inpreviousreports(TNCetal.2011),firehasbeencitedasanaturally
occurringeventthatbenefitsGunnisonsage‐grousebycreatingapatchworkoflowerandhigher
densitysagebrush,andthatclimatechangeislikelytoalterfireregimestherebyreducinghigh‐
qualityhabitatforthespecies.MorerecentreportsindicatethattheimpactsoffireonGunnison
sage‐grousehabitatarenotwellunderstood.However,itisgenerallyacceptedthatfirecancause
anincreaseinweedyplantspeciessuchascheatgrass,andcankillmountainbigsagebrush,
resultingindirectlossofhabitatduetoreducedcoverandforage(CallandMaser1985;USFWS
2014).FireisnotconsideredacurrentthreattoGunnisonsage‐grouse,butbestavailable
informationonclimatechangeindicatesthatfirefrequencyislikelyafuturethreattothespeciesif
firefrequencyincreasesaspredictedbyclimatechangemodels(Lukasetal.2014;USFWS2014).
C2d)Dependenceonsnow‐coveredhabitats.Neutral.Thisspeciesisnotdirectlydependenton
snoworiceforsurvival.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.
C4a)Dependenceonotherspeciestogeneratehabitat.GreatlyIncrease.Thisspeciesrelieson
sage‐brushasacriticalcomponentoftheirdiet,aswellasforcoverthroughallseasons(GSGRSC
2005).
C4b)Dietaryversatility.Increase.Gunnison’sSage‐grouserelyonsage‐brush(Artemisiaspp.)asa
criticalcomponentoftheirdietthroughoutallseasons;theyalsofeedonalargenumberofgrasses,
forbs,buds,andinsectswhenavailable(GSGRSC2005).Theyalsodependonherbsandforbsinthe
summeralongwiththeinsectsthatusethesamehabitat(importantforchickgrowth);factorsthat
couldbeimpactedbyclimatechangetothedegreethatitincludesdroughtsandhotspells(TNCet
al.2011).
C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.GreatlyIncrease.Thisspeciesrelies
onsage‐brushasacriticalcomponentoftheirdiet,aswellasforcoverthroughallseasons(GSGRSC
2005).
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Unknown.
C5a)Measuredgeneticvariation.Increase/SomewhatIncrease.GeneticdiversityinGunnison
sage‐grousehasbeeninvestigatedusingmitochondrialDNAandnuclearmicrosatellitedata(Oyler‐
McCanceetal.2005).Resultsindicatelowlevelsofdiversity,especiallyincomparisontodiversity
foundingreatersage‐grouse(Oyler‐McCanceetal.2005).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
224 Colorado Natural Heritage Program © 2015 C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Neutral.AcrosstheentirerangeofoccupiedhabitatforGunnisonsage‐
grouse,54percentoccursonFederallands,43percentonprivatelands,and3percentonstate
lands(USFWS2014).
Literature Cited
Call,M.W.andC.Maser1985.Call,M.W.andC.Maser.1985.Wildlifehabitatsinmanagedrangelands‐‐thegreatbasinof
southeasternOregon:Sagegrouse.Gen.Tech.Rep.PNW‐GTR‐187.Portland,OR:U.S.DepartmentofAgriculture,Forest
Service,PacificNorthwestResearchStation.
GunnisonSage‐grouseRangewideSteeringCommittee(GSGRSC).2005.Gunnisonsage‐grouserangewideconservation
plan.ColoradoDivisionofWildlife,Denver,Colorado.USA.
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter.2014.ClimateChangeinColorado:ASynthesistoSupport
WaterResourcesManagementandAdaptation.AReportfortheColoradoWaterConservationBoard.WesternWater
Assessment.
Oyler‐McCance,S.J.,J.St.John,S.E.Taylor,A.D.Apa,andT.W.Quinn.2005.PopulationgeneticsofGunnisonSage‐Grouse:
ImplicationsforManagement.JournalofWildlifeManagement69(2):630‐637.
Phillips,M.2013.PreliminarydataonGunnisonsage‐grousemovement,citedinUSFWS2014(seebelow).ColoradoParks
andWildlife.
TheNatureConservancy(TNC).2011.Gunnisonbasin:climatevulnerabilityassessmentreviewworkshop,Gunnison
climateworkinggroup,May12‐13,2011.130pp.
UniversityCorporationforAtmosphericResearch(UCAR).2009.RCPMdataandanalysisprovidedbytheInstituteforthe
StudyofSocietyandEnvironment(ISSE)attheNationalCenterforAtmosphericResearch(NCAR),basedonmodeldata
fromtheWorldClimateResearchProgramme'sCoupledModelIntercomparisonProjectphase3(WCRPCMIP3)multi‐
modeldataset.[http://rcpm.ucar.edu].
U.S.FishandWildlifeService(USFWS).2014.FinalRule,EndangeredandThreatenedWildlifeandPlants;Threatened
StatusforGunnisonSage‐Grouse.FederalRegisterVol79,No.224,Nov.20,2014.DepartmentoftheInterior.
Climate Change Vulnerability Assessment for Colorado BLM 225 Long‐Billed Curlew
Numeniusamericanus
G5/S2B
Family:Scolopacidae
Climate Vulnerability Rank: Highly Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)potentialincreaseinwind
energydevelopmentinLong‐BilledCurlewbreedinghabitatand2)relianceonwetlands,pondsand
playasthatmaybevulnerabletodryingunderprojectedincreasesintemperatureduetoclimate
change.
Distribution:InColorado,Long‐BilledCurlewbreedontheeasternplainswithpopulations
concentratedinthesoutheastcornerofthestate(ColoradoPartnersinFlight2000;ColoradoBird
AtlasPartnership1998).Habitat:InColorado,Long‐BilledCurlewsbreedinshortgrassandmixed‐
grassprairiehabitats,usuallyincloseproximitytowater(ColoradoBirdAtlasPartnership1998).
Elevation:Noinformationonspecificelevationrangesisavailable,butduetotheirpresenceonthe
easternplains,itislikelythattheLong‐BilledCurlewismostcommonlyfoundbetween4,000and
7,000ft.
EcologicalSystem:ShortgrassPrairie,Mixed‐GrassPrairie
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.SomewhatIncrease.TheRockyMountainsmay
actasabarriertomigration(Pageetal.2014).
B2b)Distributionrelativetoanthropogenicbarriers.SomewhatIncrease.Largetractsof
Colorado’sshortgrassprairiehavebeenconvertedtocropland.Long‐BilledCurlewusecropland
226 Colorado Natural Heritage Program © 2015 lessthanexpectedbasedonavailability(Dechantetal.1999).Whilethisspeciesishighlymobile
andcapableofflyingovertheseareas,theremaybeenergeticcostsassociatedwithcrossingthese
croplandsinordertoreachmoresuitablehabitatinshortgrassprairie.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.
SomewhatIncrease.Long‐BilledCurlewnestprimarilyineasternColoradoinshortgrassprairies,
withasmallcontingentinMesaCountyontheWesternSlope(ColoradoBirdAtlasPartnership
1998).AccordingtoDepartmentofEnergywindresourcemaps,theeasternquarterofColorado
neartheNewMexicoandNebraskabordershasexcellentwindresources(DOE2004).Wind
turbinescancausedirectimpactstobirdsviacollisionsthatresultininjuryormortality(Kunzetal.
2007;Kuvleskyetal.2007),aswellasindirectimpactsviahabitatlossandbarrierstomovement
(DrewittandLangston2006;Kuvleskyetal.2007;Pruettetal.2009;Kieseckeretal.2011).
C1)Dispersalandmovements.Decrease.Long‐BilledCurlewbreedinColoradoandundertake
long,seasonalmigrations.
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Thisspecies
isassociatedwithshortgrassprairieinColoradoandisnotlimitedtocoolorcoldhabitats
(ColoradoBirdAtlasPartnership1998).
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Neutral.Consideringtherangeofmeanannualprecipitationacross
occupiedcells,thespecieshasexperiencedaverage(21‐40inches/509‐1,016mm)precipitation
variationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.Thisspeciesreliesonbothdryandwetareasinthe
shortgrassprairie.GrassyfloodplainsalongcreeksinColoradoprovidenestinghabitatforLong‐
BilledCurlewinColorado;wetmeadowsareoftenusedasforagingareas(Davis1949;Johnsgard
1979and1980).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncrease.Long‐BilledCurlewrelyonponds,playas,andlakesforfeeding,bathingand
drinking(ColoradoBirdAtlasPartnership1998).Ontheshortgrassprairie,manyofthesearetied
toseasonalprecipitationsuchasspringandsummerrainevents.
C2d)Dependenceonsnow‐coveredhabitats.Neutral.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.SomewhatIncrease.Long‐
BilledCurlewusewetmeadowsandplayasineasternColorado,whichcanbeunusualfeaturesin
manycountieswhereshortgrassprairiehasbeenconvertedtocropland.
Climate Change Vulnerability Assessment for Colorado BLM 227 C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.
C4b)Dietaryversatility.Neutral.TheLong‐BilledCurlewispredominantlycarnivorous,and
consumessmallinvertebrates(grasshoppers,beetles,earthworms,spiders)aswellassomewild
fruits(DuggerandDugger2002;seeallauthorsinDark‐SmileyandKeinath2004).Largerprey
itemsincludetoadsandsnails,whichareconsumedduringmigration(RedmondandJenni1986).
C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Unknown.
C5a)Measuredgeneticvariation.Unknown.MoreinformationisneededonLong‐BilledCurlew
genetics.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
ColoradoBirdAtlasPartnership,RadeauxandColoradoDivisionofWildlife.1998.ColoradoBreedingBirdAtlas.Denver,
Colorado:ColoradoBirdAtlasPartnership.636pg.
ColoradoPartnersInFlight[CoPIF].2000.ColoradoLandbirdConservationPlan.Available:www.rmbo.org/pif/bcp/
Dark‐Smiley,D.N.andD.A.Keinath.2004.SpeciesAssessmentforLong‐BilledCurlew(Numeniusamericanus)inWyoming.
PreparedfortheBureauofLandManagement,Cheyenne,Wyoming.WyomingNaturalDiversityDatabaseReport,60
pages.
Davis,W.B.1949.Long‐billedCurlewbreedinginColorado.Auk66:202.
Dechant,J.A.,M.L.Sondreal,D.H.Johnson,L.D.Igl,C.M.Goldade,P.A.Rabie,andB.R.Euliss.1999(revised2003).Effectsof
managementpracticesongrasslandbirds:Long‐billedCurlew.NorthernPrairieWildlifeResearchCenter,Jamestown,ND.
19pages.
DepartmentofEnergy(DOE).2004.WINDExchange.ColoradoWindResourceMap.Availableonlineat
http://apps2.eere.energy.gov/wind/windexchange/wind_resource_maps.asp?stateab=co.AccessedFeb2,2015.
Drewitt,A.L.andR.H.W.Langston.2006.AssessingtheImpactsofWindFarmsonBirds.Ibis148:29‐42.
228 Colorado Natural Heritage Program © 2015 Dugger.B.D.,andK.M.Dugger.2002.Long‐billedCurlew(Numeniusamericanus).InTheBirdsofNorthAmerica,No.628
(A.PooleandF.Gill,eds.).TheBirdsofNorthAmerica,Inc.,Philadelphia,PA.
Johnsgard,P.A.1979.BirdsoftheGreatPlains.UniversityofNebraskaPress,Lincoln,Nebraska.539pages.
Johnsgard,P.A.1980.ApreliminarylistofthebirdsofNebraskaandadjacentPlainsstates.UniversityofNebraska,
Lincoln,Nebraska.156pages.
Kiesecker,J.M.,J.S.Evans,J.Fargione,K.Doherty,K.R.Foresman,T.H.Kunz,D.Naugle,N..Nibbelink,andN.D.Nieumuth.
2011.Win‐winforwindandwildlife:avisiontofacilitatesustainabledevelopment.PlosONE6:e17566.
Kunz,T.H.,E.B.Arnett,B.M.Cooper,W.P.Erickson,R..Larkin,T.Mabee,M.L.Morrison,M.D.Strickland,andJ.M.Szewczak.
2007a.Assessingimpactsofwind‐energydevelopmentonnocturnallyactivebirdsandbats:aguidancedocument.
JournalofWildlifeManagement71:2449–4486.Available:http://www.wind‐watch.org/documents/wp‐
content/uploads/wild‐71‐08‐45.pdf.
Kuvlesky,W.P.Jr.,L.A.Brennan,M.L.Morrison,K.K.Boydston,B.M.BallardandF.C.Bryant.2007.WindEnergy
DevelopmentandWildlifeConservation:ChallengesandOpportunities.JournalofWildlifeManagement71(8):2487‐
2498.
Page,G.W.,N.Warnock,T.L.Tibbitts,D.Jorgensen,C.A.Hartman,andL.E.Stenzel.2014.Annualmigratorypatternsof
Long‐BilledCurlewsintheAmericanWest.TheCondor116(1):50‐61.
Pruett,C.L.,M.A.Patten,andD.H.Wolfe.2009.AvoidanceBehaviorbyPrairieGrouse:ImplicationsforDevelopmentof
WindEnergy.ConservationBiology23(5)1253‐1259.
Redmond,R.L.,andD.A.Jenni.1986.PopulationecologyoftheLong‐billedCurlew(Numeniusamericanus)inwestern
Idaho.Auk103:755‐767.
Climate Change Vulnerability Assessment for Colorado BLM 229 Mountain Plover
Charadriusmontanus
G3/S2B
Family:Charadriidae
Climate Vulnerability Rank: Not Vulnerable/Presumed Stable
ThisColoradostatewiderankisbasedon:thelackofnaturaloranthropogenicbarriersforthis
highlyvagilebird,theircapabilitytoengageinlongdistancedispersalandmovementsallowingthe
plovertotrackshiftingclimateenvelopes,theirpreferenceforburnedsites(AugustineandDerner
2012)coupledwithincreasedfirefrequencyprojectedduetoclimatechange,highratesofadult
survivalandnestsuccessratesduringperiodsofdroughtthatisprojectedtoincreasedueto
climatechange,andthehighgeneticvariabilityexhibitedwithinMountainploverpopulationsthat
shouldincreasetheirabilitytoadapttoclimatechange.Climatemodelsprojectincreasedwarming
anddroughtacrosstheassessedareawithannualaveragetemperaturesrisingby2.5°Fto5.5°Fby
2041‐2070andby5.5°Fto9.5°Fby2070‐2099withcontinuedgrowthinglobalemissions(A2
emissionsscenario),withthegreatestincreasesinthesummerbreedingseasonandduringfall
(Melilloetal.2014).
Distribution:InColorado,thegreatestnumbersofbreedingMountainPloversoccurinWeld
County(GraulandWebster1976).Thebreedingrangeofthisspecieshasundergoneadramatic
long‐termcontraction,bothinColorado(AndrewsandRighter1992)andthroughoutthewestern
GreatPlains(GraulandWebster1976).Habitat:BreedingMountainPloversoccupyopenhabitats
withlow‐growingvegetation,especiallyshortgrassprairiecharacterizedbythepresenceofblue
gramagrassandbuffalograss(Graul1975,GraulandWebster1976,KnopfandMiller1994).In
grasslandswherevegetationgrowstallerthanapproximatelythreeinchesinheight,Mountain
Ploversuseintensivelygrazedareas(GraulandWebster1976,Knopf1996),prairiedogtowns
(Knowlesetal.1982;KnowlesandKnowles1984,OlsonandEdge1985,Shackford1991),and
falloworrecentlyplowedagriculturalfields(Shackford1991,Shackfordetal.1999).
230 Colorado Natural Heritage Program © 2015 CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers..Neutral.Significantnaturalbarriersdonotexist
forthisspecies.TheMountainPloverisaGreatPlainsinhabitantandishighlyvolant,capableof
traversingmountainrangesandlargebodiesofwater.Itisaseasonalmigrant,whosehomeranges
averageover50hectaresinsize(KnopfandRupert1996).
B2b)Distributionrelativetoanthropogenicbarriers.Increase.Neutral.Significant
anthropogenicbarriersdonotexistforthisspecies.Thisbirdisavolantspeciesthatcanflyoveror
aroundpotentialanthropogenicbarriers.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Increase.
ThehabitatofthisGreatPlainsspeciesishighlysusceptibletopotentialdevelopmentofwind
farms/solarfarmsandbiofuelsproduction(AndresandStone2010).Inthefaceofrisingclimate
changeandcoststoextractfossilfuels,windenergydevelopmentisexpectedtoincreasewithinthe
rangeoftheMountainPloverinColorado(NRDC2014).
C1)Dispersalandmovements.Decrease.MountainPloverareknowntodisperseupto50
kilometersfromtheirnatalregions(KnopfandWunder2006).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Therange
occupiedbytheMountainploverintheassessedareahasexperiencedanaverage(51.7‐77°
F/31.8‐43.0°C)zonalmeanseasonaltemperatureoverthelast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Somewhatincrease.
Adultsactivelyshadechicksonhotdays,andadultsandchicksoftenseekshade(Knopfand
Wunder2006).Increasedtemperaturesassociatedwithclimatechangeintheassessedarea
(Melilloetal.2014)couldleadtoincreasedbroodrearingstressforMountainPlover.
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Somewhatdecrease.WithintheassessedareatheMountainPlover
hasexperiencedgreaterthanaverage(>40inches/1,016mm)precipitationvariationinthepast50
years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Somewhatdecrease.Adultsurvivalandnestsuccessishighest
duringdroughtperiods,butnestsuccessisalsoenhancedbycoolertemperatures(Dinsmore2008,
Dreitzetal.2012).Inthefuture,climatechangeisprojectedtoincreasetemperatures,butitwill
alsoincreasedroughtfrequency(Melilloetal.2014),whichmayincreaseadultsurvivaland
recruitmentofyoungMountainPlover.However,theinterplayofclimatechangeinduceddrought
andwarmingwithinprairieecosystemswillbedynamic,makingitdifficulttoassesshowthiswill
impactMountainploverpopulationtrendsovertime.
Climate Change Vulnerability Assessment for Colorado BLM 231 C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Somewhatdecrease.MountainPloverreactfavorablytofire,andwiththepredictedincreasein
wildfireintheassessedareaduetoclimatechange(Melilloetal.2014),thisshouldleadto
somewhatofadecreaseintheirvulnerabilitytohowclimatechangewillimpactthisindexfactor.In
somepartsoftheirrange,MountainPloversareattractedtoburnedgrasslandsinbreedingareas
fornestingandinnonbreedingareasforforagingandnightroosting(WunderandKnopf2003,
Knopf2008).MountainPloverresponsetoburnsisoftenquick,withbirdsappearingonfields
wherefiresarestillsmoldering(KnopfandWunder2006).Increaseddroughtassociatedwith
climatechangeintheaccessedareaisexpectedtoincreasewildfirefrequency(Melilloetal.2014),
potentiallybenefittingMountainPlover.
C2d)Dependenceonsnow‐coveredhabitats.Neutral.TheMountainPloverisnotdependenton
habitatswithice,snow,oronsnowpack.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.TheMountainPlover
isnotdependentuponanyuncommongeologicalelements.
C4a)Dependenceonotherspeciestogeneratehabitat.SomewhatIncrease.TheMountain
Ploverusesareasofshortgrassesthathavebeengrazedbyprairiedogs,cattleandother
herbivores(Dinsmore2003).
C4b)Dietaryversatility.Neutral.MountainPloverareopportunisticforagersthatfeedonabroad
rangeofinsects(KnopfandWunder2006).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.TheMountainPloverisa
self‐disperser.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Neutral.Noother
interspecificinteractionsareimportanttothepersistenceoftheMountainPlover.
C5a)Measuredgeneticvariation.SomewhatDecrease.MountainPloverpopulationsexhibit
considerablegeneticmixing,whichresultsinhighgeneticvariabilitywithinpopulations(Oyler‐
McCanceetal.2005).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
232 Colorado Natural Heritage Program © 2015 Literature Cited
Andres,B.A.,andK.L.Stone.2010.ConservationPlanfortheMountainPlover(Charadriusmontanus),Version1.1.
ManometCenterforConservationSciences,Manomet,Massachusetts.
Andrews,R.,andR.Righter.1992.Coloradobirds:areferencetotheirdistributionandhabitat.DenverMus.Nat.Hist.,
Denver.442pp.
Augustine,D.J.,andJ.D.Derner.2012.DisturbanceRegimesandMountainPloverHabitatinShortgrassSteppe:Large
HerbivoreGrazingDoesNotSubstituteforPrairieDogGrazingorFire.ManagementandConservation76:721‐728.
Dinsmore,S.J.2003.MountainPlover(Charadriusmontanus):atechnicalconservationassessment.[Online].USDAForest
Service,RockyMountainRegion.Available:http://www.fs.fed.us/r2/projects/scp/assessments/mountainplover.pdf
[1/23/2015].
Dinsmore,S.T.2008.InfluenceofdroughtonannualsurvivaloftheMountainPlover.TheCondor,110:45–54.
Dreitz,V.J.,R.Y.Conrey,andS.K.Skagen.2012.Droughtandcoolertemperaturesareassociatedwithhighernestsurvival
inMountainPlovers.AvianConservationandEcology:[online]URL:http://www.ace‐eco.org/vol7/iss1/art6/.
Graul,W.D.1975.BreedingbiologyoftheMountainPlover.WilsonBull.87:6‐31
Graul,W.D.,andL.E.Webster.1976.BreedingstatusoftheMountainPlover.Condor78:265‐267.
Knopf,F.L.1996.MountainPlover(Charadriusmontanus).inTheBirdsofNorthAmerica,No.211(A.PooleandF.Gill,
eds.).TheAcademyofNaturalSciences,Philadelphia,PA,andTheAmericanOrnithologists’Union,Washington,D.C.
Knopf,F.L.2008.MountainPloverstudies,PawneeNationalGrassland,1985–2007.Unpublishedreport,Colorado
DivisionofWildlife,Denver,CO.
Knopf,F.L.,andB.J.Miller.1994.Charadriusmontanus‐montane,grassland,orbare‐groundplover?Auk111:504‐506.
Knopf,F.L.andJ.R.Rupert.1996.ReproductionandmovementsofMountainPloversbreedinginColorado.Wilson
Bulletin108:28‐35.
Knopf,F.L.andM.B.Wunder.2006.MountainPlover(Charadriusmontanus),TheBirdsofNorthAmericaOnline(A.Poole,
Ed.).Ithaca:CornellLabofOrnithology;RetrievedfromtheBirdsofNorthAmericaOnline:
http://bna.birds.cornell.edu/bna/species/211doi:10.2173/bna.211.
Knowles,C.J.,andP.R.Knowles.1984.AdditionalrecordsofMountainPloversusingprairiedogtownsinMontana.Prairie
Naturalist16:183‐186.
Knowles,C.J.,C.J.Stoner,andS.P.Gieb.1982.Selectiveuseofblack‐tailedprairiedogtownsbyMountainPlovers.Condor
84:71‐74.
Melillo,J.M.,T.C.Richmond,andG.W.Yohe,Eds.,2014:ClimateChangeImpactsintheUnitedStates:TheThirdNational
ClimateAssessment.U.S.GlobalChangeResearchProgram,841pp.doi:10.7930/J0Z31WJ2.
NaturalResourcesDefenseCouncil(NRDC).2014.RenewableenergyforAmerica.
http://www.nrdc.org/energy/renewables/energymap.asp
Olson,S.L.,andD.Edge.1985.NestsiteselectionbyMountainPloversinnorthcentralMontana.J.RangeManage.38:280‐
282.
Oyler‐McCance,S.J.,J.St.John,F.L.Knopf,andT.W.Quinn.2005.PopulationgeneticanalysisofMountainPloverusing
mitochondrialDNAsequencedata.Condor107:354–362.
Climate Change Vulnerability Assessment for Colorado BLM 233 Shackford,J.S.1991.BreedingecologyoftheMountainPloverinOklahoma.Bull.OklahomaOrnithol.Soc.24:9‐13.
Shackford,J.S.,D.M.Leslie,Jr.,andW.D.Harden.1999.Range‐wideuseofcultivatedfieldsbyMountainPloversduring
thebreedingseason.J.FieldOrnithol.70:114‐120.
Wunder,M.B.,andF.L.Knopf.2003.TheImperialValleyofCaliforniaiscriticaltowinteringMountainPlovers.Journalof
FieldOrnithology74:74–80.
234 Colorado Natural Heritage Program © 2015 Northern Goshawk
Accipitergentilis
G5/S3B
Family:Accipitridae
Climate Vulnerability Rank: Moderately Vulnerable
ThisColoradostatewiderankisbasedon:theprojectedincreaseintemperatureanddroughtfor
theassessedarea,selectionofcoolmicroclimatesfornestplacement,dependenceonold‐forest
structurethatmaybethreatenedbyincreasedfrequencyofwildfirecausedbydroughtand
warming,andlowlevelsofgeneticvariabilityquestioningthegoshawksadaptabilitytoachanging
environment.Regionalannualaveragetemperaturesareprojectedtoriseby2.5°Fto5.5°Fby
2041‐2070andby5.5°Fto9.5°Fby2070‐2099withcontinuedgrowthinglobalemissions(A2
emissionsscenario),withthegreatestincreasesinthesummerandfall(Melilloetal.2014).Under
acontinuationofcurrentrisingemissionstrends(A2),reducedwinterandspringprecipitationis
consistentlyprojectedforthesouthernpartoftheSouthwestby2100elevatingthepotentialfor
wildfire(Melilloetal.2014).
Distribution:TheNortherngoshawkisfoundthroughoutthestateofColoradoabove7500feetin
elevation(AndrewsandRighter1992).TheColoradoBreedingBirdAtlas(Kingery1998)shows
goshawkstobewelldistributedintheSanJuanMountainsandacrossthenorthernmountain
ranges.Habitat:InnorthwesternColorado,northerngoshawkstypicallynestinaspen,sometimes
inconiferstandslessthan100yearsold,andupto10,000feetinelevation(Kingery1998).
Goshawkstendtochoosenesttreesonshallowslopes,flatbenchesinsteepcountry,andfluvial
pansonsmallstreamjunctions(Kingery1998).
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
Climate Change Vulnerability Assessment for Colorado BLM 235 B2a)Distributionrelativetonaturalbarriers..Neutral.Significantnaturalbarriersdonotexist
forthisspecies.Thisraptorisavolantspeciesthatcantraversemountainrangesandlargebodies
ofwater(NatureServe2014).
B2b)Distributionrelativetoanthropogenicbarriers..Neutral.Significantanthropogenic
barriersdonotexistforthisspecies.Thisraptorisavolantspeciesthatcanflyoveroraround
potentialanthropogenicbarriers(NatureServe2014).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
AlthoughNorthernGoshawkhavebeenreportedtobeatriskofcollisionwithwindturbinesduring
migration(Brandes2005)onlyasmallportionoftheirrangeintheassessedareaissuitablefor
windenergydevelopmentandtherearenotimportantflywaysforthisraptorwithinthepotential
areasofwinddevelopment(NRDC2014).Thisisalowconcernfortheraptorwithintheassessed
area.
C1)Dispersalandmovements.Decrease.NorthernGoshawksreadilydispersemorethan10
kilometersfromhatchingsitetobreedingareasandhavehomerangesthatarefromthe100sto
1000sofhectaresinsize(SquiresandReynolds1997).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Therange
occupiedbytheNortherngoshawkintheassessedareahasexperiencedanaverage(51.7‐77°
F/31.8‐43.0°C)zonalmeanseasonaltemperatureoverthelast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Somewhatincrease.
InsouthernportionsoftheGoshawkrangeincludingtheassessedareagoshawknestareas
typicallyhavenortherlyaspectsindicatingaselectionforcoolermicroclimates(USFWS1998).
Climateprojectionssuggestthatsummertemperaturesintheassessedareawillincreasefrom6°F
morethan10°Fbytheendofthecenturyunderahigheremissionsscenario(Karletal.2009),
whichcouldmakethegoshawkmorevulnerabletoclimatechangeintheassessedarea.
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Somewhatincrease.WithintheassessedareatheNorthern
Goshawkhasexperiencedslightlylowerthanaverage(20‐30inches/255‐508mm)precipitation
variationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Somewhatdecrease.Reproductivesuccessseemstobe
negativelyimpactedbyincreasedspringprecipitationandpositivelyinfluencedbywarmer
temperatures(Kennedy2003,Patla2997)andwithincreasingtemperaturesanddroughtprojected
fortheassessedarea(Karletal.2009)thiscouldpositivelyimpactrecruitment.However,
populationgrowthratesaremostsensitivetochangesinadultsurvivalratesandchangesthat
influenceadultsurvivalwouldprobablyhaveagreaterinfluenceonpopulationpersistence
(Kennedy2003).
236 Colorado Natural Heritage Program © 2015 C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.Thegoshawkisnot
dependentuponanyuncommongeologicalelements.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Increase.Goshawksaredependentonold‐foreststructureanddecliningprecipitationcoupledwith
increasingtemperaturesanddroughtintheassessedareaisprojectedtoincreasetheareaburned
bywildfire(Karletal.2009).Thispotentialthreattooldgrowthforestisaconcernforgoshawks
(Boyceetal.2006).
C2d)Dependenceonsnow‐coveredhabitats.Neutral.Thegoshawkisnotdependentonhabitats
withice,snow,oronsnowpack.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.Thegoshawkisnot
dependentuponanyuncommongeologicalelements.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thegoshawkisnotdependent
onanyotherspeciestocreatesuitablehabitatforitsexistence.
C4b)Dietaryversatility.Neutral.Thegoshawkcapturesawidevarietyofpreyandisclassifiedas
apreygeneralist(SquiresandReynolds1997),typicallypreyingonasuiteof8to15species
(Reynoldsetal.1992).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.Thegoshawkisaself‐
disperser.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Neutral.Noother
interspecificinteractionsareimportanttothepersistenceofthegoshawk.
C5a)Measuredgeneticvariation.SomewhatIncrease.Thegoshawkexhibitshighhaplotype
diversityacrosspopulationsinNorthAmerica,butlownucleotidediversitywithinpopulations
includingtheRockyMountainpopulation,whichisgeneticallydifferentiatedfromeasternand
otherwesternpopulationsoftheraptor(BayarddeVoloetal.2013).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Climate Change Vulnerability Assessment for Colorado BLM 237 Literature Cited
Andrews,R.,andR.Righter.1992.Coloradobirds:areferencetotheirdistributionandhabitat.DenverMus.Nat.Hist.,
Denver.442pp.
BayarddeVolo,S.,R.T.Reynolds,S.A.Sonsthagen,S.L.TalbotandM.F.Antolin.2013.Phylogeny,postglacialgeneflow,and
populationhistoryofNorthAmericanNorthernGoshawk(Accipitergentilis).TheAuk130:342−354.
Boyce,D.A.,Jr.,R.T.ReynoldsandR.T.Graham.2006.Goshawkstatusandmanagement:Whatdoweknow,whathavewe
done,wherearewegoing?In:Morrison,Michael,ed.Thenortherngoshawk:atechnicalassessmentofitsstatusecology,
andmanagement.StudiesinAvianBiology.31:312‐325.
Brandes,D.2005.WindpowerdevelopmentandraptormigrationintheCentralAppalachians.HawkMigrationStudies
Spring2005:20‐25.
Karl,T.R.,J.M.Melillo,andT.C.Peterson,(eds.).2009.GlobalClimateChangeImpactsintheUnitedStates.Cambridge
UniversityPress.
Kennedy,P.L.2003.NorthernGoshawk(Accipitergentilesatricapillus):atechnicalconservationassessment.[Online].
USDAForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/northerngoshawk.pdf[1/22/2015].
Kingery,H.E.(editor)1998.Coloradobreedingbirdatlas.ColoradoBreedingBirdAtlasPartnership,Denver.Colorado.
Melillo,J.M.,T.C.Richmond,andG.W.Yohe,Eds.,2014:ClimateChangeImpactsintheUnitedStates:TheThirdNational
ClimateAssessment.U.S.GlobalChangeResearchProgram,841pp.doi:10.7930/J0Z31WJ2.
NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org.(Accessed:January21,2015).
NRDC(NaturalResourcesDefenseCouncil).2014.RenewableenergyforAmerica.
http://www.nrdc.org/energy/renewables/energymap.asp
Patla,S.M.1997.Nestingecologyandhabitatofthenortherngoshawkinundisturbedandtimberharvestareasonthe
TargheeNationalForest,GreaterYellowstoneecosystem.M.S.Thesis,IdahoStateUniversity,Pocatello,ID.
Reynolds,R.T.,R.T.Graham,M.H.Reiser,RL.Bassett,P.L.Kennedy,D.A.Boyce,G.Goodwin,R.Smith,andE.L.Fisher.1992.
ManagementrecommendationsforthenortherngoshawkinthesouthwesternUnitedStates.U.S.D.A.For.Serv.Gen.Tech.
Rep.RM‐217.RockyMt.For.andRangeExp.Stn.FortCollins,CO
Squires,J.R.andR.T.Reynolds.1997.NorthernGoshawk(Accipitergentilis),TheBirdsofNorthAmericaOnline(A.Poole,
Ed.).Ithaca:CornellLabofOrnithology;RetrievedfromtheBirdsofNorthAmericaOnline:
http://bna.birds.cornell.edu/bna/species/298doi:10.2173/bna.298
U.S.FishandWildlifeService(USFWS).1998.Statusreviewofthenortherngoshawkintheforestedwest.Unpublished
Report.OfficeofTechnicalSupport,ForestResources,PortlandOregon.Alsoavailableonlineat
http://pacific.fws.gov/news/pdf/gh_sr.pdf.
238 Colorado Natural Heritage Program © 2015 Western Snowy Plover
Charadriusalexandrinusnivosus
G3T3/S1B
Family:Charadriidae
Climate Vulnerability Rank: Highly Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)naturalbarrierstomovement;
2)potentialincreaseinwindenergydevelopmentinbreedinghabitat;3)relianceonalkali‐covered
playasandsandymarginsofreservoirsthatmaybevulnerabletodryingduetoprojectedwarmer
temperatures;4)potentialrelianceonseasonalwetlandscreatedbyspringrunoffthatmaybe
alteredduetoclimatechange;5)lowamountsofgeneticdifferentiation.
Distribution:TheWesternSnowyPlover(SnowyPloverhereafter)isasmallshorebirdthatbreeds
onthePacificcoastfromsouthernWashingtontosouthernBajaCalifornia,Mexico,andininterior
westernstatesincludingUtah,Idaho,NevadaandColorado(USFWS2012).InColorado,Snowy
Ploversnestonalkali‐coveredplayasintheSanLuisValley,aswellasalongsandyshoresof
constructedreservoirsinthesoutheasterncornerofthestateintheLowerArkansasRiverBasin
(AndrewsandRighter1992;ColoradoBirdAtlasPartnership1998).Theytypicallyarrivein
Coloradoinmid‐Aprilanddepartstartingfrommid‐JulyintoOctober(AndrewsandRighter1992).
Habitat:InColorado,SnowyPloversnestonalkali‐coveredplayasintheSanLuisValley,aswellas
alongsandyshoresofreservoirsintheLowerArkansasRiverBasin.Elevation:Noinformationis
availableontheelevationrangeofSnowyPloverinColorado,butbasedondistribution,thespecies
likelybreedsatelevationsrangingfrom4,000ftto8,000ft.
EcologicalSystem:ShortgrassPrairie,GreasewoodShrublands
Climate Change Vulnerability Assessment for Colorado BLM 239 CCVI Scoring
B1)Exposuretosealevelrise.Neutral.Sandyoceanbeachesofferhabitatforsnowyplover,and
thesemaybelosttosealevelrise.However,theassessmentareaforthisCCVIislimitedto
Colorado,sosealevelriseisnotconsideredhere.
B2a)Distributionrelativetonaturalbarriers.Neutral.Thisspeciesishighlymobile.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Thisspeciesishighlymobile.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.
SomewhatIncrease.SnowyPloverareknowntonestintheSanLuisValleyandineasternColorado
alongtheArkansasRiver(ColoradoBirdAtlasPartnership1998).AccordingtoDepartmentof
Energywindresourcemaps,theeasternquarterofColoradoneartheNewMexicoandNebraska
bordershaveexcellentwindresources(DOE2004).Windturbinescancausedirectimpactstobirds
viacollisionsthatresultininjuryormortality(Kunzetal.2007;Kuvleskyetal.2007),aswellas
indirectimpactsviahabitatlossandbarrierstomovement(DrewittandLangston2006;Kuvlesky
etal.2007;Pruettetal.2009;Kieseckeretal.2011).
C1)Dispersalandmovements.Decrease.Thisspeciesishighlymobile.SnowyPloversthatbreed
intheGreatPlainswinterontheGulfofMexicocoast(Pageetal.2009).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Thisspecies
isnotlimitedtocoolorcoldhabitats.
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.SomewhatDecrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,thespecieshasexperiencedgreaterthanaverage(>40
inches/1,016mm)precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.GreatlyIncrease.SnowyPloversnestonalkali‐coveredplayas
intheSanLuisValley,aswellasalongsandyshoresofreservoirsintheLowerArkansasRiver
Basin.TheSanLuisValleyislocatedintheRioGrandeRiverBasin.Manywetlandsinthisbasinare
dependentonsnow‐meltfromthesurroundingmountains,andthesewetlandsareexpectedtobe
moreacutelyaffectedthanotherecosystemsinthearea(USFWS2012).Climatemodelsprojecta
rangeof‐28%to+11%inannualrunofffortheRioGrandeBasin,andarangeof‐10%to+19%for
theArkansasRiverBasinformid‐century(Lukasetal.2014).Furthermore,changingdemandsfor
waterintheseriverbasinsmayresultingreaterfluctuationsinreservoirlevelsintheseareas,
whichinturncouldleadtothefloodingofreservoirshorelinesandresultinglossofSnowyPlover
nestinghabitat.Lastly,increasedgroundwaterpumpingforagriculturecouldleadtoareductionin
availablesurfacewaterandalossofSnowyPlovernestinghabitat(Busby2002).
240 Colorado Natural Heritage Program © 2015 C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncrease.SnowyPloversintheArkansasBasinhavebeendocumentednestingonthe
shorelinesofconstructedreservoirs,butintheSanLuisValley,thealkaliflatsthatprovidenesting
habitatarelikelytiedtomoreseasonalhydroperiodsassociatedwithspringrunoff.
C2d)Dependenceonsnow‐coveredhabitats.SomewhatIncrease.IntheSanLuisValley,runoff
fromsnowmeltprovidesflowstowetlandsthatprovidehabitatforSnowyPlover(Laubhanand
Gammonley2000).
C3)Restrictiontouncommongeologicalfeaturesorderivatives.SomewhatIncrease.The
SnowyPloveroccursonalkaliflatsaroundreservoirsduringthebreedingseason,whilemigrants
occuronmudflatsandsandyshorelines(AndrewsandRighter1992).Furthermore,SnowyPlovers
intheGreatPlainsfrequentlynestnearwaterbodiesthatcontainhighsalinitylevels,whichthey
mayuseforevaporativecoolingduringperiodsofhightemperatures(Purdue1976).
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.
C4b)Dietaryversatility.Neutral.IntheGreatPlains,SnowyPloverfeedonavarietyof
invertebratesincludingflies(Ephydrasp.),beetles(Blediussp.,Cicindelasp.),andmanyterrestrial
insectsblownfromsurroundingareasincludinggrasshoppers,lepidopterans,andbeetles(Busby
2002;Purdue1976,GroverandKnopf1982).
C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Unknown.
C5a)Measuredgeneticvariation.SomewhatIncrease.Geneticstudieshaverevealedlowamounts
ofgeneticdifferentiationamongpopulationsofSnowyPlovers,withalmostallvariabilityfound
withinpopulations(Funketal.2007).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Neutral.Noevidencefora
populationbottleneckwasfoundinageneticstudyofGreatBasin,Midwest,GulfCoast,andPacific
CoastSnowyPloverpopulations(Funketal.2007).
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
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Busby,W.H.2002.KansasRecoveryPlanfortheSnowyPlover(Charadriusalexandrinus).KansasBiologicalSurveyReport
toKansasDepartmentofWildlifeandParks.44pg.
ColoradoBirdAtlasPartnership,RadeauxandColoradoDivisionofWildlife.1998.ColoradoBreedingBirdAtlas.Denver,
Colorado:ColoradoBirdAtlasPartnership.636pg.
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http://apps2.eere.energy.gov/wind/windexchange/wind_resource_maps.asp?stateab=co.AccessedFeb2,2015.
Drewitt,A.L.andR.H.W.Langston.2006.AssessingtheImpactsofWindFarmsonBirds.Ibis148:29‐42.
Funk,W.C.,T.D.Mullins,andS.M.Haig.2007.Conservationgeneticsofsnowyplovers(Charadriusalexandrinus)inthe
WesternHemisphere:populationgeneticstructureanddelineationofsubspecies.ConservationGenetics8:1287–1309.
Grover,P.B.,andF.L.Knopf.1982.HabitatrequirementsandbreedingsuccessofCharadriaformbirdsnestingatSalt
PlainsNationalWildlifeRefuge,Oklahoma.JournalofFieldOrnithology53:139‐148.
Kiesecker,J.M.,J.S.Evans,J.Fargione,K.Doherty,K.R.Foresman,T.H.Kunz,D.Naugle,N.P.Nibbelink,andN.D.Nieumuth.
2011.Win‐winforwindandwildlife:avisiontofacilitatesustainabledevelopment.PlosONE6:e17566.
Kunz,T.H.,E.B.Arnett,B.M.Cooper,W.P.Erickson,R.P.Larkin,T.Mabee,M.L.Morrison,M.D.Strickland,andJ.M.
Szewczak.2007.Assessingimpactsofwind‐energydevelopmentonnocturnallyactivebirdsandbats:aguidance
document.JournalofWildlifeManagement71:2449–4486.http://www.wind‐watch.org/documents/wp‐
content/uploads/wild‐71‐08‐45.pdf.
Kuvlesky,W.P.Jr.,L.A.Brennan,M.L.Morrison,K.K.Boydston,B.M.BallardandF.C.Bryant.2007.WindEnergy
DevelopmentandWildlifeConservation:ChallengesandOpportunities.JournalofWildlifeManagement71(8):2487‐
2498.
Laubhan,M.K.,andJ.H.Gammonley.2000.DensityandforaginghabitatselectionofwaterbirdsbreedingintheSanLuis
ValleyofColorado.JournalofWildlifeManagement64:808‐819.
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter.2014.ClimateChangeinColorado:ASynthesistoSupport
WaterResourcesManagementandAdaptation.AReportfortheColoradoWaterConservationBoard.WesternWater
Assessment.
Page,G.W.,L.E.Stenzel,G.W.Page,J.S.Warriner,J.C.WarrinerandP.W.Paton.2009.SnowyPlover(Charadrius
alexandrinus),TheBirdsofNorthAmericaOnline(A.Poole,Ed.).Ithaca:CornellLabofOrnithology;Retrievedfromthe
BirdsofNorthAmericaOnline:http://bna.birds.cornell.edu/bna/species/154.
Pruett,C.L.,M.A.Patten,andD.H.Wolfe.2009.AvoidanceBehaviorbyPrairieGrouse:ImplicationsforDevelopmentof
WindEnergy.ConservationBiology23(5)1253‐1259.
Purdue,J.R.1976.AdaptationsoftheSnowyPloverontheGreatSaltPlains,Oklahoma.SouthwesternNaturalist.21:347‐
357.
U.S.FishandWildlifeService.SanLuisValleyConservationArea,ColoradoandNewMexico.2012.DraftEnvironmental
AssessmentandLandProtectionPlan.MountainPrairieRegion.Availableonlineathttps://www.fws.gov/mountain‐
prairie/refuges/lpp_PDFs/slv_lppdraft_all.pdf
242 Colorado Natural Heritage Program © 2015 Western Yellow‐billed Cuckoo
Coccyzusamericanusoccidentalis
G5T2T3/S1B
Family:Cuculidae
Climate Vulnerability Rank: Moderately Vulnerable
ThisColoradostatewiderankisbasedon:narrowhabitatrequirementsanddifficultiesindispersal
byjuvenilesandadultsbetweenpatchesofsuitableriparianhabitat,increaseddryinganddrought
projectedduetoclimatechangefortheassessedarea,dryingassociatedwithglobalclimatechange
causingincreasedwaterwithdrawalforhumanconsumptionresultinginadditionallossand
fragmentationofriparianbreedinghabitat,increasedwildfireduetoincreasedfrequencyof
droughtinhistoricallywildfirefreeriparianhabitat,andprojectedincreasesintamariskinvasion
intosuitableriparianhabitatduetoclimatechange.Climatemodelsprojectincreasedwarmingand
droughtacrosstheassessedareawithannualaveragetemperaturesrisingby2.5°Fto5.5°Fby
2041‐2070andby5.5°Fto9.5°Fby2070‐2099withcontinuedgrowthinglobalemissions(A2
emissionsscenario),withthegreatestincreasesinthesummerandfall(Melilloetal.2014).
Projectionsofprecipitationchangesarelesscertain,butunderacontinuationofcurrentrising
emissionstrends(A2),reducedwinterandspringprecipitationisconsistentlyprojectedforthe
southernpartoftheSouthwestby2100(Melilloetal.2014).Theseprojectedchangesinclimateare
predictedtohavedramaticeffectsonthedistribution,quantity,andqualityofsuitableriparian
habitatavailableforbreeding,negativelyimpactingpopulationsofthecuckoowithintheassessed
area.
Distribution:TheRockyMountainBirdObservatoryconductedsurveysforcuckoosinwestern
Coloradoduringthesummersof2008through2011andfoundthemalongtheNorthForkofthe
GunnisonRiver(DeltaCounty),theColoradoRiver(MesaCounty),nearNucla(MontroseCounty),
andtheYampaRiver(MoffatCounty)(Beason2012).Ahandfulofincidentaldetectionswerealso
recordedduringthistime,butitwasconcludedthatthespeciesisaveryrarebreederinwestern
Coloradoaftersurveyswerecompleted.Habitat:Ariparianspecies,thewesternyellow‐billed
Climate Change Vulnerability Assessment for Colorado BLM 243 cuckoobreedsinlow‐tomoderate‐elevationnativeforestsliningtheriversandstreamsofthe
westernUnitedStates.Cottonwoodwillowforests(Populusspp.‐Salixspp.)aremostoftenused,
althoughotherripariantreespeciescanbeimportantcomponentsofbreedinghabitataswell,such
asalder(Alnusspp.),boxelder(Acernegundo),mesquite(Prosopisspp.),Arizonawalnut(Juglans
major),Arizonasycamore(Platanuswrightii),oak(Quercusspp.),netleafhackberry(Celtis
reticulata),velvetash(Fraxinusvelutina),Mexicanelderberry(Sambucusmexicanus),seepwillow
(Baccharisglutinosa),andoccasionally,tamarisk(Tamarixspp.).
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers..Neutral.Significantnaturalbarriersdonotexist
forthisspecies.Thecuckooisavolantlongdistantmigratorthatcantraversemountainrangesand
largebodiesofwater.
B2b)Distributionrelativetoanthropogenicbarriers.Increase.Somewhatincreasetoincrease.
Habitatdestruction,modification,anddegradationfromdamconstructionandoperations;water
diversions;riverflowmanagement;streamchannelizationandstabilization;conversionto
agriculturaluses,suchascropsandlivestockgrazingintheassessmentareaareconsidered
barrierstodispersalbyjuvenileandadultyellow‐billedcuckoos(USFWS2014).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Increase.
Modificationstohydrology(impoundments,channelization,andalterationofriverflows,and
surfaceandgroundwaterwithdrawal)resultincuckoohabitatlossandfragmentation(USFWS
2014).Thedryingtrendassociatedwithglobalclimatechangemayresultinmoredams,levees,
waterwithdrawalsorotheractivitiestoensurefreshwaterforhumanconsumption,whichmay
resultinadditionalhabitatlossandfragmentation(USFWS2014).
C1)Dispersalandmovements.Somewhatdecreasetodecrease.Limiteddataondispersal
suggestshighsitefidelitywithmatingbirdsreturningtotheirpastnestingsiteswhilenatalbirdsdo
disperseupto205metersformalesand33,315metersforfemales(McNeiletal.2013).
Additionallycuckoosarelong‐distancemigrants,althoughdetailsoftheirmigrationpatternsare
notwellknown(Hughes1999).Matedpairsalsohavelargehomerangesthatvaryinsizefrom6‐
55hectares(Halterman2009).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Therange
occupiedbytheWestern‐yellowbilledcuckoointheassessedareahasexperiencedanaverage
(51.7‐77°F/31.8‐43.0°C)zonalmeanseasonaltemperatureoverthelast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Somewhatincrease
toincrease.Thereisnodirectevidencethatcuckoosrequirecoolmicroclimatesfornesting,butin
thewesternU.S.theyarerestrictedtoriparianhabitatswiththickshadedoverstorythatareof
higherhumiditythanthesurroundingaridlandscape(Hughs1999,Wiggins2005).
244 Colorado Natural Heritage Program © 2015 C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Somewhatdecrease.Therangeoccupiedbythecuckoointhe
assessedareahasexperiencedgreaterthanaverage(>40inches/1,016mm)precipitation
variationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Greatlyincrease.inthewesternU.S.thecuckooisrestrictedto
riparianhabitatswiththickshadedoverstorythatareofhigherhumiditythanthesurroundingarid
landscape(Hughs1999,Wiggins2005).Thehighersummertemperatures,earlierspringsnowmelt,
andlowersummerflowscausedbyclimatechange(Melilloetal.2014),willresultinbothshort‐
termandlong‐termlossofrequiredriparianhabitatfromexcessivewinterscouring,summer
drying,andwildfire(USFWS2014).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Somewhatincrease.Thedryingprojectedfortheassessmentareaduetoclimatechangeisexpected
toincreasethefrequencyofwildfire(Melilloetal.2014).Historically,wildfirewasuncommonin
nativeriparianwoodlands(BuschandSmith1993)andtheexpectedincreasedincidenceof
wildfireintocuckoohabitatwillfurtherdegrade,isolate,orfragmentcuckoohabitat(USFWS2014).
C2d)Dependenceonsnow‐coveredhabitats.Neutral.Thecuckooisnotdependentonhabitats
withice,snow,oronsnowpack.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.Thecuckooisnot
dependentuponanyuncommongeologicalelements.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thecuckooisnotdependenton
anyotherspeciestocreatesuitablehabitatforitsexistence.
C4b)Dietaryversatility.Neutraltosomewhatincrease.Cuckoosfeedonabroadrangeofitems,
butprimarilyonslowmovinginsectsincludinggrasshoppers,butterfliesandmoths,hemipteraand
beetles.However,larvaeofthefamilySphingidae(sphinxmoths)havebeennotedasanimportant
foodsourceforyellow‐billedcuckoos,andthelackofsuchpreyhasbeenimplicatedinthedecline
ofthewesternsubspecies.(Wiggins2005).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.Thecuckooisaself‐
disperser.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Somewhatincrease.
Throughoutmostofitsrange,habitatfortheWesternyellow‐billedcuckooisthreatenedbythe
conversionofnativeriparianwoodlandstoriparianvegetationdominatedbytamariskandother
nonnativevegetation(USFWS2014).Modelsbasedonprojectedclimatechangepredictthatthis
invasivetamariskwillbecomemoredominantinthisregionoverthenext100years(Kernsetal.
2009).
C5a)Measuredgeneticvariation.Unknown.
Climate Change Vulnerability Assessment for Colorado BLM 245 C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Decrease.Winterrangeispredictedto
increaseby69%by2080(NAS2014).
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
Beason,J.P.2012.2011SurveysforYellow‐billedCuckoosinWesternColorado.TechRep.R‐YBCUUSFWS‐09‐3.Rocky
MountainBirdObservatory,Brighton,Colorado.30pp.
Busch,D.E.andS.D.Smith.1993.Effectsoffireonwatersalinityrelationsofriparianwoodytaxa.Oecologia94a:186‐194
Halterman,M.M.2009.SexualDimorphism,DetectionProbability,HomeRange,andParentalCareintheYellow‐billed
Cuckoo.UniversityofNevadaPhD.Dissertation.Accessedonline[2/4/2015]at
http://search.proquest.com/docview/304943422.
Hughes,J.M.1999.Yellow‐billedCuckoo(Coccyzusamericanus),TheBirdsofNorthAmericaOnline(A.Poole,Ed.).Ithaca:
CornellLabofOrnithology;RetrievedfromtheBirdsofNorthAmericaOnline:
http://bna.birds.cornell.edu/bna/species/418
Kerns,B.K.,B.J.Naylor,M.Buonopane,C.G.ParksandB.Rogers.2009.Modelingtamarisk(Tamarixspp.)habitatand
climatechangeeffectsintheNorthwesternUnitedStates.InvasivePlantScienceandManagement,2:200‐215.
McNeil,S.E.,D.Tracy,J.R.StanekandJ.E.Stanek.2013.Yellow‐billedcuckoodistribution,abundanceandhabitatuseon
theLowerColoradoRivertributaries:2008‐2012summaryreport.LowerColoradoRiverMulti‐SpeciesConservation
Program.BureauofReclamation,
Melillo,J.M.,T.C.Richmond,andG.W.Yohe,Eds.,2014:ClimateChangeImpactsintheUnitedStates:TheThirdNational
ClimateAssessment.U.S.GlobalChangeResearchProgram,841pp.doi:10.7930/J0Z31WJ2.
NationalAudubonSociety(NAS).2014.Audubon’sBirdsandClimateChangeReport:APrimerforPractitioners.National
AudubonSociety,NewYork.Contributors:GaryLangham,JustinSchuetz,CandanSoykan,ChadWilsey,TomAuer,Geoff
LeBaron,ConnieSanchez,TrishDistler.Version1.2.Available:http://climate.audubon.org/birds/goleag/golden‐eagle
[1/29/2015].
Wiggins,D.2005.Yellow‐billedCuckoo(Coccyzusamericanus):atechnicalconservationassessment.[Online].USDA
ForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/yellowbilledcuckoo.pdf[2/4/2015].
U.S.FishandWildlifeService(USFWS).2014.EndangeredandThreatenedWildlifeandPlants;ProposedThreatened
StatusfortheWesternDistinctPopulationSegmentoftheYellow‐billedCuckoo(Coccyzusamericanus);FinalRule.
FederalRegister79(192:59992‐60038).
246 Colorado Natural Heritage Program © 2015 White‐faced Ibis
Plegadischihi
G5/S2B
Family:Threskiornithidae
©John Breltsch Climate Vulnerability Rank: Moderately Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)potentialwindfarm
developmentonColorado’seasternplainsand2)potentialdecreaseinrunoffandprecipitationthat
servesasawatersourceforwetlandsintheSanLuisValley.
Distribution:InColorado,individualsprimarilynestintheSanLuisValleyandonportionsofthe
easternplains,andaretypicallymigrantsintheeasternplainsandmountainparks(Andrewsand
Righter1992).Habitat:TheWhite‐FacedIbisisalarge,long‐leggedbirdthatinhabitsfreshwater
wetlandsandmarshes(FieldGuidetotheBirdsofNorthAmerica1999,Dark‐SmileyKeinath2003).
EcologicalSystem:ShortgrassPrairie;Wetlands
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral.White‐facedIbisareahighlymobile
species,andindividualsthatsummerinColoradoundertakelongmigrationstowinterinsouthern
California,Louisiana,andMexico(Rosenbergetal.1991).
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.SeeB2aabove.Thisspeciesis
highlymobile.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.
SomewhatIncrease.White‐facedIbisareknowntonestintheSanLuisValleyandontheeastern
plainsofColorado(AndrewsandRighter1992).AccordingtoDepartmentofEnergywindresource
maps,theeasternquarterofColoradoneartheNewMexicoandNebraskabordershaveexcellent
Climate Change Vulnerability Assessment for Colorado BLM 247 windresources(DOE2004).Windturbinescancausedirectimpactstobirdsviacollisionsthat
resultininjuryormortality(Kunzetal.2007;Kuvleskyetal.2007),aswellasindirectimpactsvia
habitatlossandbarrierstomovement(DrewittandLangston2006;Kuvleskyetal.2007;Pruettet
al.2009;Kieseckeretal.2011).
C1)Dispersalandmovements.Decrease.SeeB2a.Thisspeciesishighlymobile,andindividuals
thatsummerinColoradotravellongdistancestospendthewinterinthesouthernU.S.andMexico
(Rosenbergetal.1991).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,White‐FacedIbisinColoradohas
experiencedaverage(57.1‐77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Thisspecies
isnotlimitedtocoolorcoldenvironments.Droughtcouldaffecttheavailabilityofwetlandhabitats,
butthisisvulnerabilityisscoredunderC2bii.
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Increase.Consideringtherangeofmeanannualprecipitationacross
occupiedcells,White‐FacedIbishasexperiencedsmall(4‐10inches/100‐254mm)precipitation
variationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.Thisspeciesisawetlandobligatethatprefers(almost
exclusively)wetlandswithemergentvegetation(Dark‐SmileyandKeinath2003).Drought
conditionscancausedryingofemergentvegetationandsuitablenestinghabitats,causingbreeding
adultstorelocate.Furthermore,droughtcanmakeibiseggsandyoungmoresusceptibleto
predation(Dark‐SmileyandKeinath2003).InRioGrandeBasin,wetlandsdependentonsnow‐melt
fromthesurroundingmountains,areexpectedtobemoreacutelyaffectedthanotherecosystemsin
thearea(USFWS2012).Climatemodelsprojectarangeof‐28%to+11%inannualrunoffforthe
RioGrandeBasinformid‐century(Lukasetal.2014).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncrease.Shallow,seasonallyfloodedwetlandscanprovideforaginghabitatforWhite‐
FaceIbis(LaubhanandGammonley2000).
C2d)Dependenceonsnow‐coveredhabitats.SomewhatIncrease.IntheSanLuisValley,runoff
fromsnowmeltprovidesflowstowetlandsthatprovidehabitatforWhite‐FacedIbis(Laubhanand
Gammonley2000).
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.
C4b)Dietaryversatility.Neutral.TheWhite‐FacedIbisfeedsprimarilyoncrustaceans,
earthworms,andaquaticinsects(SmileyandKeinath2003).
248 Colorado Natural Heritage Program © 2015 C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Unknown.
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
Andrews,R.A.,andR.Righter.1992.Coloradobirds.DenverMuseumofNaturalHistory.Denver,Co.Pp27.
Dark‐Smiley,D.D.andD.A.Keinath.2003.SpeciesAssessmentforWhite‐FacedIbis(PlegadisChihi)inWyoming.Prepared
forU.S.DepartmentoftheInterior.Cheyenne,Wyoming.59pp.
DepartmentofEnergy(DOE).2004.WINDExchange.ColoradoWindResourceMap.Availableonlineat
http://apps2.eere.energy.gov/wind/windexchange/wind_resource_maps.asp?stateab=co.AccessedFeb2,2015.
Drewitt,A.L.andR.H.W.Langston.2006.AssessingtheImpactsofWindFarmsonBirds.Ibis148:29‐42.
FieldGuidetotheBirdsofNorthAmerica,ThirdEdition.1999.NationalGeographicSociety,Washington,D.C.
Kiesecker,J.M.,J.S.Evans,J.Fargione,K.Doherty,K.R.Foresman,T.H.Kunz,D.Naugle,N.P.Nibbelink,andN.D.Nieumuth.
2011.Win‐winforwindandwildlife:avisiontofacilitatesustainabledevelopment.PlosONE6:e17566.
Kunz,T.H.,E.B.Arnett,B.M.Cooper,W.P.Erickson,R.P.Larkin,T.Mabee,M.L.Morrison,M.D.Strickland,andJ.M.
Szewczak.2007.Assessingimpactsofwind‐energydevelopmentonnocturnallyactivebirdsandbats:aguidance
document.JournalofWildlifeManagement71:2449–4486.http://www.wind‐watch.org/documents/wp‐
content/uploads/wild‐71‐08‐45.pdf.
Kuvlesky,W.P.Jr.,L.A.Brennan,M.L.Morrison,K.K.Boydston,B.M.BallardandF.C.Bryant.2007.WindEnergy
DevelopmentandWildlifeConservation:ChallengesandOpportunities.JournalofWildlifeManagement71(8):2487‐
2498.
Laubhan,M.K.,andJ.H.Gammonley.2000.DensityandforaginghabitatselectionofwaterbirdsbreedingintheSanLuis
ValleyofColorado.JournalofWildlifeManagement64:808‐819.
Climate Change Vulnerability Assessment for Colorado BLM 249 Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter.2014.ClimateChangeinColorado:ASynthesistoSupport
WaterResourcesManagementandAdaptation.AReportfortheColoradoWaterConservationBoard.WesternWater
Assessment.
Pruett,C.L.,M.A.Patten,andD.H.Wolfe.2009.AvoidanceBehaviorbyPrairieGrouse:ImplicationsforDevelopmentof
WindEnergy.ConservationBiology23(5)1253‐1259.
Rosenberg,K.V.,R.D.Ohmart,W.C.Hunter,andB.W.Anderson.1991.BirdsofthelowerColoradoRiverValley.University
U.S.FishandWildlifeService.SanLuisValleyConservationArea,ColoradoandNewMexico.2012.DraftEnvironmental
AssessmentandLandProtectionPlan.MountainPrairieRegion.Availableonlineathttps://www.fws.gov/mountain‐
prairie/refuges/lpp_PDFs/slv_lppdraft_all.pdf.
250 Colorado Natural Heritage Program © 2015 Bluehead Sucker
Catostomusdiscobolus
G4/S4
Family:Catostomidae
Climate Vulnerability Rank: Highly Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)barrierstomovement;2)
warmingstreamtemperaturesmayaffectblueheadsuckerthatgenerallyinhabitcoolstreams3)
potentialdeclineinrunoffandsubsequentdecreaseinflowsintheUpperColoradoRiverBasin;4)
relianceongravelbarsforspawning;5)lackofvariabilityinannualprecipitationinlast50years;
6)hybridizationwiththenonnativewhitesuckercouldaffectthegeneticintegrityofthespecies.
Distribution:InColorado,theblueheadsuckerisfoundthroughouttheUpperColoradoRiver
drainage.Habitat:InColorado,adultblueheadsuckermostoftenarefoundinswifter,higher
gradientstreams;larvalfishinhabitnear‐shore,lowvelocityhabitats(Childsetal.1998).Riffles
andpoolssupportalgaeandmacroinvertebratesthatareconsumedbyblueheadsuckers(Sigler
andSigler1996).Blueheadsuckeroccupywarmtocoolstreams(20˚C)withrockysubstrates
(SiglerandSigler1996;Bestgen2000).
EcologicalSystem:Streams
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Increase.Blueheadsuckerarefoundinthe
mainstemandtributariesoftheColoradoRiverwithinthestateofColorado(MillerandRees2000).
Thespeciescanoccurinhighgradientstreams.Waterfallscouldcreateupstreammovements
withinthesestreams.Althoughtheexactleapingabilitiesofblueheadsuckerarenotknown,many
Climate Change Vulnerability Assessment for Colorado BLM 251 streamfishesarenotabletojumpaboveheightsof1.0‐1.5m(BjornnandReiser1991;Holtheetal.
2005).
B2b)Distributionrelativetoanthropogenicbarriers.Increase.Damsandimpoundmentsalong
theColoradoRiveranditstributariescreatebarriersforblueheadsuckermovement.Thisspecies
prefersswiftervelocity,highergradientstreamsanddoesnotdowellinimpoundments
(BezzeridesandBestgen2002).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
C1)Dispersalandmovements.SomewhatDecrease.Morestudiesareneededtoinvestigate
movementpatternsofblueheadsucker.Someinvestigatorshavereportedthatthespecies
relativelysedentary,movingonlyafewkilometers(Vanicek1967,ReesandMiller2001),while
othersreportrecapturingindividuals19kmfromoriginalcapturelocations(HoldenandCrist
1981).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.SomewhatIncrease.
Blueheadsuckerinhabitawidevarietyofriversystemsfromsmallcreekstolargerivers.Although
generallyinhabitingstreamswithcooltemperatures,theyhavebeenfoundinsmallcreekswith
highwatertemperatures(28degreesC)(Ptaceketal.2005,Smith1966).
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.SomewhatDecrease.Speciesshowsapreferenceforenvironments
towardthewarmerendofthespectrum
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.SomewhatIncrease.Highbaseflowsareimportantforthe
reproductionsuccessofblueheadsucker(AndersonandStewart2007).Mostpublishedresearch
indicatesadeclineinrunoffintheUpperColoradoRiverBasinbythemid‐to‐late21stcentury(Ray
etal.2008,Lukasetal.2014).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncrease.Highbaseflowsareimportantforthereproductionsuccessofblueheadsucker
(AndersonandStewart2007).MostpublishedresearchindicatesadeclineinrunoffintheUpper
ColoradoRiverBasinbythemid‐to‐late21stcentury(Rayetal.2008,Lukasetal.2014).
C2d)Dependenceonsnow‐coveredhabitats.Neutral
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral
252 Colorado Natural Heritage Program © 2015 C4b)Dietaryversatility.Neutral.Blueheadsuckerlarvaefeedondiatoms,zooplankton,and
dipteranlarvae(Carteretal.1986;MuthandSnyder1995;Ptaceketal.2005).Adultsandjuveniles
feedonmacroinvertebrates,algae,andinsectlarvae(Vanicek1967,Childsetal.1998,Osmundson
1999).
C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Unknown
C5a)Measuredgeneticvariation.Increase.Althoughstudieshaveshownhighgeneticdiversityin
blueheadsuckeracrossthespeciesrange(Douglasetal.2009),hybridizationwiththenonnative
whitesuckercouldaffectthegeneticintegrityofthespecies.Hybridizationbetweenthenon‐native
whitesucker(Catostomuscommersoni)andblueheadsuckerhasbeendocumented,aswellas
individualswithgeneticcontributionsfromthewhitesucker,blueheadsucker,andnative
flannelmouthsucker(Catostomuslatipinnus)(McDonaldetal.2008).Thenon‐nativewhitesucker
hasfacilitatedintrogressionbetweentwonativespecies,andthereforethreatensthegenetic
integrityoftheblueheadandflannelmouthsuckers.Ageneticstudyofthespeciesrevealedthree
distinctgeographicareasthatareevolutionarilysignificantformaintainingthegeneticintegrityof
theblueheadsucker(referredtoasevolutionarilysignificantunits):theBonnevilleBasin,the
UpperLittleColoradoRiver,andtheColoradoRiver(Hopkenetal.2013).Allblueheadsucker
populationsinthestateofColoradobelongtotheColoradoRiverunit(Hopkenetal.2013).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
Anderson,R.M.andG.Stewart.2007.Fish‐FlowInvestigation:II.Impactsofstreamflowalterationsonthenativefish
assemblageandtheirhabitatavailabilityasdeterminedby2Dmodelingandtheuseoffishpopulationdatatosupport
instreamflowrecommendationsforthesectionsoftheYampa,Colorado,GunnisonandDoloresRiversinColorado.
ColoradoDivisionofWildlifeSpecialReportNo.80,DOW‐R‐S‐80‐07.FortCollins.
Beatty,R.J.,F.J.Rahel,andW.A.Hubert.2009.Complexinfluencesoflow‐headdamsandartificialwetlandsonfishesina
ColoradoRivertributarysystem.FisheriesManagementandEcology16:457‐467.
Climate Change Vulnerability Assessment for Colorado BLM 253 Bestgen,K.R.2000.PersonalcommunicationwithDirectorofColoradoStateUniversity’sLarvalFishLabtoColorado
ParksandWildlife,FortCollins,Colorado.
Bezzerides,N.andK.Bestgen.2002.StatusreviewofroundtailchubGilarobusta,flannelmouthsuckerCatostomus
latipinnis,andblueheadsuckerCatostomusdiscobolusintheColoradoRiverbasin.2002.ColoradoStateUniversityLarval
FishLaboratory,FortCollins,CO.
BjornnT.C.&ReiserD.W.1991.Habitatrequirementsofsalmonidsinstreams.Bethesda,MD:AmericanFisheriesSociety
SpecialPublication19:83–138.
Carter,J.G.,V.A.Lamarra,andR.J.Ryel.1986.DriftoflarvalfishesintheupperColoradoRiver.JournalofFreshwater
Ecology3:567‐577.
Childs,M.R.,R.W.Clarkson,andA.T.Robinson.1998.ResourceusebylarvalandearlyjuvenilenativefishesintheLittle
ColoradoRiver,GrandCanyon,Arizona.TransactionsoftheAmericanFisheriesSociety127:620‐629.
Douglas,M.R.,M.E.Douglas,andM.W.Hopken.2009.PopulationGeneticAnalysisofBlueheadSucker[Catostomus
(Pantosteusdiscobolus]AcrosstheSpecies’Range.Onlineat
http://www.fws.gov/southwest/es/NewMexico/documents/ZBSESD/Douglas_et_al_2013.pdf
Holden,P.B.andL.W.Crist.1981.DocumentationofchangesinthemacroinvertebrateandfishpopulationsintheGreen
RiverduetoinletmodificationofFlamingGorgeDam.ContractNo.0‐07‐40‐S1357forWaterandPowerResources
Service.Bio/West,Inc.,Logan,UT.
HoltheE.,E.Lund,B.Finstad,E.B.Thorstad,andR.S.McKinley.2005.Afishselectiveobstacletopreventdispersionofan
unwantedfishspecies,basedonleapingcapabilities.FisheriesManagementandEcology12,143–147.
Hopken,M.W.,M.R.Douglas,andM.E.Douglas.2013.StreamhierarchydefinesriverscapegeneticsofaNorthAmerican
desertfish.MolecularEcology22:956–971.
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter.2014.ClimateChangeinColorado:ASynthesistoSupport
WaterResourcesManagementandAdaptation.AReportfortheColoradoWaterConservationBoard.WesternWater
Assessment.
McDonald,D.B.,T.L.Parchman,M.R.Bower,W.A.Hubert,andF.J.Rahel.2008.Anintroducedandanativevertebrate
hybridizetoformageneticbridgetoasecondnativespecies.Proc.Natl.Sci.USA.105:10842‐10847.
Miller,W.J.andD.E.Rees.2000.IchthyofaunalsurveysoftributariesoftheSanJuanRiver,NewMexico.MillerEcological
Consultants,Inc.,FortCollins,CO.
Muth,R.T.andD.E.Snyder.1995.DietsofyoungColoradosquawfishandothersmallfishinbackwatersoftheGreen
River,ColoradoandUtah.GreatBasinNaturalist55:95‐104.
Osmundson,D.B.1999.LongitudinalvariationinfishcommunitystructureandwatertemperatureintheupperColorado
River:implicationsforColoradopikeminnowhabitatsuitability.FinalReportforRecoveryImplementationProgram,
ProjectNo.48.U.S.FishandWildlifeService,GrandJunction,CO.
Ptacek,J.A.,D.E.Rees,andW.J.Miller.2005.Blueheadsucker(Catostomusdiscobolus):atechnicalconservation
assessment.USDAForestService,RockyMountainRegion,FortCollins,Colorado.
Ray,A.J.,J.Barsugli,andK.Avery.2008.ClimateChangeinColorado:ASynthesistoSupportWaterResources
ManagementandAdaptation.ReporttotheColoradoWaterConservationBoard.
Rees,D.E.andW.J.Miller.2001.HabitatselectionandmovementofnativefishintheColoradoRiver,Colorado.Miller
EcologicalConsultants,Inc.,FortCollins,CO.
254 Colorado Natural Heritage Program © 2015 Sigler,W.F.andJ.W.Sigler.1996.FishesofUtah;anaturalhistory.UniversityofUtahPress,SaltLakeCity,UT.
Smith,G.R.1966.DistributionandevolutionoftheNorthAmericanCatostomidfishesofSubgenusPantosteus,Genus
Catostomus.MiscellaneousPublicationsoftheMuseumofZoology,UniversityofMichigan,No.129.Universityof
Michigan,AnnArbor,MI.
Vanicek,C.D.1967.EcologicalstudiesofnativeGreenRiverfishesbelowFlamingGorgeDam,1964‐1966.Ph.D.Thesis,
UtahStateUniversity,Logan,UT.
Climate Change Vulnerability Assessment for Colorado BLM 255 Bonytail Chub
Gilaelegans
G1/SX
ListedEndangered
Family:Cyprinidae
No photo available Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)barrierstomovement;2)
potentialdeclineinrunoffandsubsequentdecreaseinflowsintheUpperColoradoRiverBasin;3)
relianceonrockysubstratesandgravelbarsforspawning;4)lackofvariabilityinannual
precipitationinlast50years;5)lackofgeneticvariation.
Distribution:ThebonytailchubisconsideredfunctionallyextinctinColorado(CarlsonandMuth
1989).NoverifiableoccurrencesofwildbonytailchubhavebeendocumentedinColoradosince
1984whenoneindividualwascaughtintheBlackRocksareanearGrandJunction,Colorado
(Kaedingetal.1986).Acaptivebroodstockwasestablishedfromsomeofthelastwildbonytail
collected,andstockingofcaptive‐rearedindividualsisaprimaryrecoverystrategy(Nesleretal.
2003).ThedistributionmapaboverepresentscriticalhabitatasdesignatedbyUSFWS(2003).
Habitat:Bonytailchubpreferbackwaterswithrockyormuddybottomsandflowingpools,but
reportssuggesttheycanalsooccurinstreamreacheswithswiftcurrents(USFWS2012).
EcologicalSystem:Streams
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral/SomewhatIncrease.Naturalphysical
barrierstomovementintheColoradoRiveranditstributariesarenaturalrapidsandswift
256 Colorado Natural Heritage Program © 2015 turbulentflows,andthesearelikelytofluctuatedependingonflows(U.S.FishandWildlifeService
2002).
B2b)Distributionrelativetoanthropogenicbarriers.Increase.Damsandimpoundmentsalong
theColoradoRiveranditstributariescreatebarriersforbonytailchubmovement,andaffect
seasonalavailabilityofhabitat(U.S.FishandWildlifeService2002).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
C1)Dispersalandmovements.Decrease.Littleinformationisknownregardingthelifehistory
andmovementsofbonytailchub,butfishreleasedinNevadatraveledasmuchas56km(Marsh
andMueller1999).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Thebonytail
chubisadaptedtothelarge,warm‐waterriversandstreamsoftheColoradoRiverBasin.Changes
tothermalhabitatshaveoccurredduetothein‐riverhypolimneticdamreleasesandthelossof
warm,floodplainwetlands(Kappenmanetal.2012).
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Increase.Consideringtherangeofmeanannualprecipitationacross
occupiedcells,thespecieshasexperiencedsmall(4‐10inches/100‐254mm)precipitation
variationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.SomewhatIncrease.Maintenanceofstreamflowisimportant
fortherecoveryandconservationofbonytailchub,aspeciesnowconsideredfunctionallyextinctin
theUpperColoradoRiverSub‐basin(USFWS2012).Mostpublishedresearchindicatesadeclinein
runoffintheUpperColoradoRiverBasinbythemid‐to‐late21stcentury(Rayetal.2008,Lukaset
al.2014).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Increase.Littleisknownaboutspawningrequirementsforbonytailchub,butitislikelythatlike
othermembersofthegenusGila,theyspawninrockysubstrates(USFWS2002).Pulsesinspring
flowsareimportantforcreatingcobblebarsaswellasforfloodingbottomlandthatserveas
nurseryhabitatforyoung(USFWS2002).Adequatebaseflowsarenecessaryforthecreationand
maintenanceofbonytailchubhabitat.Mostpublishedresearchindicatesadeclineinrunoffinthe
UpperColoradoRiverBasinbythemid‐to‐late21stcentury(Rayetal.2008,Lukasetal.2014),
whichcouldleadtofurtherlossanddegradationofhabitatforrazorbacksuckers.Increase.(USFWS
2002).
C2d)Dependenceonsnow‐coveredhabitats.Neutral.
Climate Change Vulnerability Assessment for Colorado BLM 257 C3)Restrictiontouncommongeologicalfeaturesorderivatives.Increase.Rockysubstrates
andgravelbarsmaybeimportantspawninghabitatforbonytailchub(USFWS2002).Thecreation
andmaintenanceofthesehabitatsarejeopardizedbydamsandimpoundmentsthatalternatural
hydrologicregimes.
C4a)Dependenceonotherspeciestogeneratehabitat.Unknown.
C4b)Dietaryversatility.Neutral.Bonytailchubareomnivorous,andconsumeorganicmaterial,
aquaticmacrophytes,invertebrates,bullfrogs,andfish(Marshetal.2013).
C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Unknown.
C5a)Measuredgeneticvariation.Increase.Historicgeneticdiversityofthebonytailchubis
unknown,andsofewwildindividualsareleftthattheerosionofgeneticvariabilitymayhave
alreadyoccurred(USFWS2002).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
Carlson,C.A.,andR.T.Muth.1989.TheColoradoRiver:lifelineoftheAmericanSouthwest.CanadianSpecialPublication,
FisheriesandAquaticSciences106:220–239.Keppenman,K.M.,E.S.Cureton,J.Ilgen,M.Toner,W.C.Fraser,andG.A.
Kaeding,L.R.,B.D.Burdick,P.A.Schrader,andW.R.Noonan.1986.Recentcaptureofabonytail(Gilaelegans)and
observationsonthisnearlyextinctcyprinidfromtheColoradoRiver.Copeia4:1021‐1023.
Kappenman,K.M.,E.S.Cureton,J.Ilgen,M.Toner,W.C.Fraser,andG.A.Kindschi.2012.ThermalRequirementsofthe
Bonytail(Gilaelegans):ApplicationtoPropagationandThermal‐RegimeManagementofRiversoftheColoradoRiver
Basin.TheSouthwesternNaturalist57(4):421‐429.
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter.2014.ClimateChangeinColorado:ASynthesistoSupport
WaterResourcesManagementandAdaptation.AReportfortheColoradoWaterConservationBoard.WesternWater
Assessment.
258 Colorado Natural Heritage Program © 2015 Marsh,P.C.,G.A.Mueller,andJ.D.Schooley.2013.SpringtimeFoodsofBonytail(Cyprinidae:Gilaelegans)InALower
ColoradoRiverBackwater.TheSouthwesternNaturalist,58(4):512‐516.
Marsh,P.C.andG.Mueller.1999.Spring‐summermovementsofBonytailinaColoradoRiverreservoir,LakeMohave,
ArizonaandNevada.U.S.GeologicalSurvey.Open‐FileReport99‐103.FortCollins,CO:U.S.GeologicalSurvey.42p.
Nesler,T.P.,K.Christopherson,J.M.Hudson,C.W.McAda,F.Pfeifer,andT.E.Czapla.2003.Anintegratedstockingplanfor
RazorbackSucker,Bonytail,andColoradoPikeminnowfortheUpperColoradoRiverendangeredfishrecoveryprogram.
Ray,A.J.,J.Barsugli,andK.Avery.2008.ClimateChangeinColorado:ASynthesistoSupportWaterResources
ManagementandAdaptation.ReporttotheColoradoWaterConservationBoard.
U.S.FishandWildlifeService.2002.Bonytail(Gilaelegans)RecoveryGoals:amendmentandsupplementtotheBonytail
ChubRecoveryPlan.U.S.FishandWildlifeService,Mountain‐PrairieRegion(6),Denver,Colorado.
U.S.FishandWildlifeService.2003.Bonytail(Gilaelegans)CriticalHabitatshapefile.U.S.FishandWildlifeService,
Mountain‐PrairieRegion(6),Denver,Colorado.Availableonlineathttps://catalog.data.gov/dataset/final‐critical‐habitat‐
for‐the‐bonytail‐chub‐gila‐elegans.
U.S.FishandWildlifeService.2012.Bonytail(Gilaelegans)5‐YearReview:SummaryandEvaluation.U.S.Fishand
WildlifeService,UpperColoradoRiverEndangeredFishRecoveryProgram.Denver,Colorado.July2012,29pp.
Climate Change Vulnerability Assessment for Colorado BLM 259 Colorado Pikeminnow
Ptychocheiluslucius
G1/S1
ListedEndangered
Family:Cyprinidae
Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)barrierstomovement;2)
potentialdeclineinrunoffandsubsequentdecreaseinflowsintheUpperColoradoRiverBasin;3)
relianceongravel‐cobblesubstratesinhighgradientstreamsforspawning;4)lackofvariabilityin
annualprecipitationinlast50years;5)lackofgeneticvariation.
Distribution:TheColoradopikeminnownowoccursinapproximately1,090milesofriverhabitat
intheupperColoradoRiverBasinaboveLakePowellintheGreenRiver,upperColoradoRiver,and
SanJuanRiversub‐basins(USFWS2011).Thedistributionmapprovidedaboveisbasedoncritical
habitatdesignatedbyUSFWS(2013).Habitat:Coloradopikeminnowadultsarelong‐distance
migratorsthatrequireuninterruptedreachesofmediumtolargeriverswithpools,deeprunsand
eddyhabitatsmaintainedbyhighspringflows(USFWS2011).Gravelandcobbledepositsareused
forspawninghabitat;watertemperaturesduringspawningaretypically18to23˚C(USFWS2011).
EcologicalSystem:Streams
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral/SomewhatIncrease.Historically,
Coloradopikeminnowmigratedlongdistancestoandfromspawningsites(Tyus1991).Rapidsand
260
Colorado Natural Heritage Program © 2015 swiftturbulentflowscancreatenaturalbarrierstomovementofColoradopikeminnowduringhigh
flows,butthesebarriersarelikelyseasonal(USFWS2002).
B2b)Distributionrelativetoanthropogenicbarriers.Increase.Extensivedambuildinginthe
1930sthroughthe1960shasbeencitedastheprimarycausefortheextirpationofColorado
pikeminnowinthelowerColoradoRiverbasin(MuellerandMarsh2002,Osmundson2011).
AlthoughthespeciesstillpersistsintheupperColoradoRiverbasin,damshaveblockedupstream
passage,convertedfree‐flowingriverinesegmentsintolenticreservoirhabitat,andcooled
downstreamreacheswithhypolimneticreleases(Osmundson2011).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
C1)Dispersalandmovements.Decrease.ColoradopikeminnowintheSanJuanRiverregularly
travelanaverageof4to62km(DurstandFranssen2014).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Somewhat
Increase/Neutral.Coloradopikeminnowevolvedinwarm‐waterriversandtributariesinthe
ColoradoRiverBasin.Evidencefromrecentstudiessuggestthatwarmerstreamtemperaturesin
theSanJuanRiverSub‐basincontributetofastergrowthandmaturityinColoradopikeminnowas
comparedtocolderstreamtemperaturesintheUpperColoradoRiverSub‐basin(Durstand
Franssen2014).Warmerstreamtemperaturesasaresultofclimatechangecouldresultinhigher
ratesofrecruitmentforColoradopikeminnow.
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.SomewhatIncrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,thespecieshasexperiencedslightlylowerthanaverage(11‐20
inches/255‐508mm)precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.SomewhatIncrease/Neutral.Coloradopikeminnowadults
requirepools,deepruns,andeddyhabitatsthatarecreatedandmaintainedbyhighspringflows.
Theseasonalhighflowscreatedbyspringrunoff“maintainchannelandhabitatdiversity,flush
sedimentsfromspawningareas,rejuvenatefoodproduction,formgravelandcobbledepositsused
forspawning,andrejuvenatebackwaternurseryhabitats”(USFWS2002).Mostpublishedresearch
indicatesadeclineinrunoffintheUpperColoradoRiverBasinbythemid‐to‐late21stcentury(Ray
etal.2008,Lukasetal.2014).Lowerflowscouldresultinafurtherdeclineinthecreationand
maintenanceofColoradopikeminnowhabitat.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Increase.AdultColoradopikeminnowarepiscivorous.Historically,thespeciesreliedonnativeprey
fishesasamajorfoodsource.ThesenativefishesspawninMayandJuneduringhighspringflows.
Coloradopikeminnowpreyonthesmallyoungoftheyeargeneratedfromthesespawningevents,
Climate Change Vulnerability Assessment for Colorado BLM 261 andspawnoncetheyarelargeenough(approx.50mmtotallength)intheearlytomid‐summer
(Nesleretal.1988,TyusandHaines1991,Franssenetal.2007).Climatemodelsprojectearlier
peaksinstreamflow,andthismayaltertheavailabilityofpreyfishforColoradopikeminnow.
Dependenceonsnow‐coveredhabitats.Neutral.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Increase.Colorado
pikeminnowspawningravel‐cobblesubstratesinhigh‐gradientstreams(Haynesetal.1984;Tyus
andHaines1991);backwatersformedinsilt‐sandbarsareconsideredidealnurseryhabitat
(Osmundsonetal.2002).DamsanddiversionsintheColoradoRiveranditstributarieshavealtered
naturalflowregimes,andlesshigh‐qualityhabitatisavailablefortheColoradopikeminnow.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.
C4b)Dietaryversatility.Neutral.Coloradopikeminnowadultsarepiscivorousandarethemain
nativepredatoroftheColoradoRiverBasinbecauseoftheirlargesizeandlargemouth(Vanicek
andKramer1969,Minckley1973,HoldenandWick1982,USFWS2002).YoungColorado
pikeminnowconsumeinsects,copepods,cladocerans,andmidgelarvae(Vanicek1967,Jacobiand
Jacobi1982,MuthandSnyder1995,USFWS2002).
C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Unknown.
C5a)Measuredgeneticvariation.Increase.GeneticdiversitystudiesofmitochondrialDNAin
hatcherystockandmuseumspecimenshasrevealedlowgeneticdiversityinColoradopikeminnow
(BorleyandWhite2006).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.SomewhatIncrease.Apost‐
Pleistocenegeneticbottleneckhasbeenproposedasthecauseoflowlevelsofgeneticvariationin
Coloradopikeminnow(BorleyandWhite2006).
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
262 Colorado Natural Heritage Program © 2015 Literature Cited
Borley,K.andM.White.2006:MitochondrialDNAvariationintheendangeredColoradopikeminnow:Acomparison
amonghatcherystocksandhistoricspecimens.NorthAmericanJournalofFisheriesManagement26(4):916‐920.
Durst,S.L.andN.R.Franssen.2014.MovementandgrowthofjuvenileColoradoPikeminnows(Ptychocheiluslucius)inthe
SanJuanRiver,NMandUT.TransactionsoftheAmericanFisheriesSociety143:519–527.
Franssen,N.R.,K.B.Gido,andD.L.Propst.2007.Flowregimeaffectsavailabilityofnativeandnonnativepreyofan
endangeredpredator.BiologicalConservation138:330–340.
Haynes,C.M.,T.A.Lytle,E.J.Wick,andR.T.Muth.1984.LarvalColoradosquawfish(Ptychocheiluslucius)intheUpper
ColoradoRiverbasin,Colorado,1979‐1981.TheSouthwesternNaturalist29:21‐33.
Holden,P.B.andE.J.Wick.1982.LifehistoryandprospectsforrecoveryofColoradosquawfish.In:W.H.Miller(ed.),
FishesoftheUpperColoradoRiverSystem:presentandfuture,pp.98‐108.AmericanFisheriesSociety.
Jacobi,G.Z.,andM.D.Jacobi.1982.Fishstomachcontentanalysis.Pages285‐324inColoradoRiverfisheryprojectfinal
report.Part3,Contractedstudies.U.S.FishandWildlifeServiceandBureauofReclamation,SaltLakeCity,UT.
Minckley,W.L1973.FishesofArizona.ArizonaGameandFishDepartment,Phoenix.pp.158‐159.
Mueller,G.A.andP.C.Marsh.2002.Lost,adesertriveranditsnativefishes:ahistoricalperspectiveoftheLowerColorado
River.InformationandTechnologyReportUSBS/BRD/ITR‐2002‐0010,U.S.GovernmentPrintingOffice,Denver,CO.69
pp.
Muth,R.T.andD.E.Snyder.1995.DietsofyoungColoradosquawfishandothersmallfishinbackwatersoftheGreen
River,ColoradoandUtah.TheGreatBasinNaturalist55:95–104.
NeslerT.P.,R.T.Muth,andA.F.Wasowicz1988.EvidenceforbaselineflowspikesasspawningcuesforColorado
SquawfishintheYampaRiver,Colorado.AmericanFisheriesSocietySymposium5:68‐79.
Osmundson,D.B.,R..Ryel,V.L.LamarraandJ.Pitlick.2002.Flowsediment‐biotarelations:implicationsforriver
regulationeffectsonnativefishabundance.EcologicalApplications12:1719‐1739.
Osmundson,D.B.2011.ThermalRegimeSuitability:AssessmentofUpstreamRangeRestorationPotentialforColorado
Pikeminnow,AWarmwaterEndangeredFish.RiverRestorationApplications27:706‐722.
Tyus,H.M.1991.EcologyandmanagementofColoradosquawfish.Pages379–402inW.L.MinckleyandJ.E.Deacon(eds.).
Battleagainstextinction:nativefishmanagementintheAmericanwest.TheUniversityofArizonaPress,Tucson.
Tyus,H.M.,andGB.Haines.1991.Distribution,habitatuse,andgrowthofage‐OColoradosquawfishintheGreenRiver
basin,ColoradoandUtah.TransactionsoftheAmericanFisheriesSociety120:79‐89.
U.S.FishandWildlifeService[USFWS].2002.Coloradopikeminnow(Ptychocheiluslucius)RecoveryGoals:amendment
andsupplementtotheColoradoSquawfishRecoveryPlan.U.S.FishandWildlifeService,Mountain‐PrairieRegion(6),
Denver,Colorado.
U.S.FishandWildlifeService[USFWS].2011.Coloradopikeminnow(Ptychocheiluslucius)5‐yearreview:summaryand
evaluation.USFWS,UpperColoradoRiverEndangeredFishRecoveryProgram,Denver,Colorado.
U.S.FishandWildlifeService[USFWS].2013.Coloradopikeminnow(Ptychocheiluslucius)CriticalHabitatshapefile.U.S.
FishandWildlifeService,Mountain‐PrairieRegion(6),Denver,Colorado.Availableonlineat
https://catalog.data.gov/dataset/final‐critical‐habitat‐for‐the‐colorado‐pikeminnow‐ptychocheilus‐lucius
Climate Change Vulnerability Assessment for Colorado BLM 263 Vanicek,C.D.1967.EcologicalstudiesofnativeGreenRiverfishesbelowFlamingGorgeDam,1964–1966.Unpublished
Ph.D.dissertation,UtahStateUniversity,Logan.i0038‐4909‐49‐2‐203‐Vanicek1
Vanicek,C.D.,andR.Kramer.1969.LifehistoryoftheColoradosquawfish,Ptychocheiluslucius,andtheColoradochub,
Gilarobusta,intheGreenRiverinDinosaurNationalMonument1964–1966.TransactionsoftheAmericanFisheries
Society98:193–208.
264 Colorado Natural Heritage Program © 2015 Colorado River Cutthroat Trout
Oncorhynchusclarkiipleuriticus
G4T3/S3
Family:Salmonidae
Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)barrierstomovement;2)
potentialcomplexeffectsofwarmingstreamtemperaturesthatmayincreaseColoradoRiver
cutthroattrout(CRCThereafter)recruitment,aswellasprovidemoresuitablehabitatfor
nonnativesalmonidsthathybridizeandcompetewithCRCT;3)relianceongravelbarsfor
spawning;4)lackofvariabilityinannualprecipitationinlast50years;5)rainbowtroutandother
subspeciesofcutthroattrouthybridizewithCRCTandcouldthreatenthegeneticintegrityofCRCT.
Distribution:ColoradoRivercutthroattroutarefoundinthefollowingriverbasinsofColorado:
Dolores,Gunnison,UpperGreen,UpperColorado,Yampa,White,andSanJuan(Hirschetal.2013).
Recentgeneticandmeristicstudieshaveidentifiedtwoextantcutthroatlineageswithinthisrange,
provisionallydesignatedtheBlueLineage,nativetotheYampa,GreenandWhiteRiverBasins,and
theGreenLineage,nativetotheUpperColorado,GunnisonandDoloresbasins(Metcalfetal.2012,
Bestgenetal.2013,USFWS2014).AthirdlineagenativetotheSanJuanbasinisevidentlyextinct,
thoughblueandgreenlineagepopulationshavebeenestablishedinthisbasinbystocking.In
keepingwithcurrently‐recognizedinlandcutthroattaxonomy,thisassessmentconsidersall
cutthroatsindigenoustotheWestSlopeasCRCT.Habitat:InColorado,CRCTrequirecool,clear
waterinstreamswithwell‐vegetated,stablebanks;deeppools,boulders,andlogsareimportant
forprovidingcoverforCRCT(Young1995,Youngetal.1998).CRCTalsooccurinlakes,butthese
arerelativelyrare(Hirshetal.2013).Elevation:CRCToccursfrom4,600fttonearly12,500ft
acrossitsrange(Hirshetal.2013).SpecificelevationrangesforColoradoarenotavailable.
EcologicalSystem:MontaneStreams
Climate Change Vulnerability Assessment for Colorado BLM 265 CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral/SomewhatIncrease.Waterfalls,beaver
dams,bedrock,debrisandrapidsarenaturalfeaturesintheriverbasinsthatprovidehabitatfor
CRCT(Hirshetal.2013).Manyofthesefeaturesmayonlyappearduringhighflows.Nonetheless,
theymaycreateseasonalbarrierstomovementforCRCT.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral/SomewhatIncrease.Theeffectof
barrierscanbecomplexforCRCT.Thepresenceofabarriercanblocktheupstreammovementof
nonnativesalmonidsthatnegativelyaffectpopulationsofCRCTthroughhybridization,foodand
spacecompetition,andpredation(AllendorfandLeary1988,ForbesandAllendorf1991,Hirshet
al.2013).DamsandimpoundmentsintheColoradoRiverBasinanditstributariescreatebarriers
toCRCTmovement(Young2008).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
C1)Dispersalandmovements.SomewhatDecrease.EvidencefromYoung(1995)suggeststhat
summerhomerangesforCRCTrangefrom11to652meters.
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Somewhat
Increase/Neutral.ClimatewarmingmayhavecomplexeffectsonCRCTpopulations.ManyCRCT
populationspersistinhigherelevationstreamsbecauseunlikenonnativesalmonids,theycan
toleratecolderwatertemperatures.However,thesecoldtemperaturesmaynotprovideconditions
thatCRCTcanthrivein,andgrowthandrecruitmentmaybehinderedbytheselowtemperatures.
HigherelevationstreamsthatarecurrentlytoocoldtosustainCRCTpopulationsmaywarmenough
inthefuturetoprovidesuitablehabitatforCRCT.Warmerstreamtempscouldresultinearly
spawningandhigheroverwintersurvivalforCRCT.Itisalsopossiblethatthesewarmerstream
temperatureswillprovidesuitablehabitatfornonnativefishaswell.
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.SomewhatIncrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,thespecieshasexperiencedslightlylowerthanaverage(11‐20
inches/255‐508mm)precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.Lackofinstreamflowsduetodroughtconditionsis
consideredthehighestclimatechangeriskfactorforCRCT(Haaketal.2010).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral/SomewhatIncrease.SpawningofCRCTbeginsafterrunoffhaspeakedinspringorearly
266 Colorado Natural Heritage Program © 2015 summer(Young1995).Watertemperaturesmayalsoprovidespawningcues(Young1995).
Temperatureincreasesduetoclimatechangemayleadtoearlierpeakrunoffandwarmerwater
temperatures.ThesemayresultinearlierspawningandhigheroverwintersurvivalforCRCT.
FemaleCRCTdepositeggs10‐25cmdeepinspawninggravel.Naturalhydrologicregimesthathelp
creategravelbarshavebeenalteredbydam‐relatedchangesintimingandflowlevels.Most
publishedresearchindicatesadeclineinrunoffintheUpperColoradoRiverBasinbythemid‐to‐
late21stcentury(Rayetal.2008,Lukasetal.2014),whichcouldleadtofurtherlackofhydrologic
processesrequiredtocreateandmaintainhabitatforCRCT.
C2d)Dependenceonsnow‐coveredhabitats.Neutral.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral/SomewhatIncrease.
Requiresgravelsforspawning,seeaboveexplanationinC2C.
C4)Relianceoninterspecificinteractions.Neutral.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.
C4b)Dietaryversatility.Neutral.Amphipods,plankton,dipterans,andhymenopteransareall
importantcomponentsofCRCTdiet(Colburn1966,Bozeketal.1994).
C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Unknown.
C5a)Measuredgeneticvariation.Increase.Nonnativerainbowtrout(Oncorhynchusmykiss)and
othersubspeciesofcutthroattrout(Oncorhynchusclarkiispp.)havehybridizedwithCRCT,thus
reducingthegeneticintegrityofthesubspecies(AllendorfandLeary1988,ForbesandAllendorf
1991,CRCTConservationTeam2006;Hirschetal.2013).Naturalorconstructedbarriersexistto
limitgeneticmixingofrainbowandothersubspeciesofcutthroattroutandCRCT.However,these
barriersalsoposeathreattoCRCTasitrestrictsindividualstoshort,headwaterstreamsegments
(Young2008).Thisrestrictionrenderspopulationsmorevulnerabletoextirpationfromstochastic
events,andcouldresultinthelongtermlossofgeneticvariability(Young2008,Robertsetal.
2013).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
Climate Change Vulnerability Assessment for Colorado BLM 267 D4)Protectedareas.Unknown.
Literature Cited
Allendorf,F.W.andR.F.Leary.1988.Conservationanddistributionofgeneticvariationinapolytypicspecies,the
cutthroattrout.ConservationBiology2:170‐184.
Bestgen,K.R.,K.B.Rogers,andR.Granger.2013.Phenotypepredictsgenotypeforlineagesofnativecutthroattroutinthe
SouthernRockyMountains.FinalReporttoU.S.FishandWildlifeService,ColoradoFieldOffice,DenverFederalCenter
(MS65412),Denver,CO.LarvalFishLaboratoryContribution177.
Bozek,M.A.,L.D.DeBrey,andJ.A.Lockwood.1994.DietoverlapamongsizeclassesofColoradoRivercutthroattrout
(Oncorhynchusclarkipleuriticus)inahighelevationmountainstream.Hydrobiologia273:9‐17.
Colborn,L.G.1966.ThelimnologyandcutthroattroutfisheryofTrappersLake,Colorado.DepartmentofGame,Fish,and
Parks,Denver,Colorado.FisheriesResearchDivisionSpecialReport9
Coleman,M.A.andK.D.Fausch.2007.Coldsummertemperaturelimitsrecruitmentofage‐0cutthroattroutinhigh‐
elevationColoradostreams.TransactionsoftheAmericanFisheriesSociety136:1231‐1244.
CRCTConservationTeam.2006.ConservationagreementforColoradoRivercutthroattrout(Oncorhynchusclarkii
pleuriticus)intheStatesofColorado,Utah,andWyoming.ColoradoDivisionofWildlife,FortCollins.10p.
Forbes,S.H.andF.W.Allendorf.1991.Mitochondrialgenotypeshavenodetectableeffectsonmeristictraitsincutthroat
trouthybridswarms.Evolution45:1350‐1359.
Haak,A.L.,J.E.Williams,D.Isaak,A.Todd,C.Muhlfeld,J.L.Kershner,R.Gresswell,S.Hostetler,andH.M.Neville.2010.The
potentialinfluenceofchangingclimateonthepersistenceofsalmonidsoftheinlandwest.U.S.GeologicalSurvey,Open‐
FileReport2010‐1236,Reston,Virginia.AccessedNov13,2014.Onlineat:pubs.usgs.gov/of/2010/1236/.
Hirsch,C.L.,M.R.Dare,andS.E.Albeke.2013.Range‐widestatusofColoradoRivercutthroattrout(Oncorhynchusclarkii
pleuriticus):2010.ColoradoRiverCutthroatTroutConservationTeamReport.ColoradoParksandWildlife,FortCollins.
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter.2014.ClimateChangeinColorado:ASynthesistoSupport
WaterResourcesManagementandAdaptation.AReportfortheColoradoWaterConservationBoard.WesternWater
Assessment.
Metcalf,J.L.,S.S.Stowell,C.M.Kennedy,K.B.Rogers,D.McDonald,J.Epp,K.Keepers,A.Cooper,J.J.Austin,andA.P.Martin.
2012.Historicalstockingdataand19thcenturyDNArevealhuman‐inducedchangestonativediversityanddistribution
ofcutthroattrout.MolecularEcology21:5194‐5207.
Ray,A.J.,J.Barsugli,andK.Avery.2008.ClimateChangeinColorado:ASynthesistoSupportWaterResources
ManagementandAdaptation.ReporttotheColoradoWaterConservationBoard.
Roberts,J.J.,K.D.Fausch,D.P.Peterson,andM.B.Hooten.2013.Fragmentationandthermalrisksfromclimatechange
interacttoaffectpersistenceofnativetroutintheColoradoRiverbasin.GlobalChangeBiology19:1383‐1398.
U.S.FishandWildlifeService[USFWS].2014.FinalSummaryReport:GreenbackCutthroatTroutGeneticsandMeristics
StudiesFacilitatedExpertPanelWorkshop.USFWSRegion6,Lakewood,CO,OrderNo.F13PB00113.AccessedNov6,
2014.Available:
http://cpw.state.co.us/Documents/Research/Aquatic/CutthroatTrout/2014GreenbackCutthroatTroutWorkshopSummar
y.pdf.
268 Colorado Natural Heritage Program © 2015 Young,M.K.1995.ColoradoRivercutthroattrout.M.K.Youngtechnicaleditor.Pages16‐23.In:AConservation
AssessmentforInlandCutthroatTrout.USDAForestService,RockyMountainForestandRangeExperimentStation,Fort
Collins,Colorado.GeneralTechnicalReport.RM‐GTR‐256.
Young,M.K.,K.A.Meyer,D.J.Isaak,andR.A.Wilkison.1998.Habitatselectionandmovementbyindividualcutthroattrout
intheabsenceofcompetitors.JournalofFreshwaterEcology13:371‐381.
Young,M.K.2008.ColoradoRiverCutthroatTrout:ATechnicalConservationAssessment.USDAForestService,Rocky
MountainStation,FortCollins,CO.
Climate Change Vulnerability Assessment for Colorado BLM 269 Flannelmouth Sucker
Catostomuslatipinnis
G3G4/S3
Family:Catostomidae
Climate Vulnerability Rank: Highly Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)barrierstomovement;2)
potentialdeclineinrunoffandsubsequentdecreaseinflowsintheUpperColoradoRiverBasin;3)
relianceongravelbarsforspawning;4)lackofgeneticvariation.
Distribution:InColorado,theflannelmouthsuckerisfoundthroughouttheUpperColoradoRiver
drainage.Habitat:InColorado,flannelmouthsuckerresideinmainstemandtributarystreamsin
theUpperColoradoRiverBasin.Theyareopportunisticbenthicfeeders.Adultsoccupydeepriffles
andrunsaswellasdeep,murkypoolswithsparsevegetation(McAda1977;SiglerandSigler1996;
BezzeridesandBestgen2002),whileyoungfisharetypicallyfoundinquiet,shallowrifflesand
near‐shoreeddies(Childsetal.1998).
EcologicalSystem:Streams
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Increase.Flannelmouthsuckeraremost
commonlyfoundinpoolsanddeeperrunsofthemainstemandtributariesoftheColoradoRiver
withinthestateofColorado(BezzeridesandBestgen2002;SiglerandMiller1963;Minckleyand
Holden1980).
270 Colorado Natural Heritage Program © 2015 B2b)Distributionrelativetoanthropogenicbarriers.Increase.Damsandimpoundmentsalong
theColoradoRiveranditstributariescreatebarriersforflannelmouthsuckermovement.This
speciesdoesnotdowellinimpoundments(McAda1977,SiglerandSigler1996,Bezzeridesand
Bestgen2002).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
C1)Dispersalandmovements.Decrease.Flannelmouthsuckerarecapableoflongdistance
movementsasfaras229kilometers(Weiss1993).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral/Somewhat
Increase.Flannelmouthsuckeroccupywarmandcoolwaterreachesofmostmainstemriversand
largetributariesinalltheColoradoRiverBasinsystemsinColoradoincludingthoseintheSanJuan,
Dolores,Gunnison,Colorado,White,Yampa(includingtheLittleSnakeRiver),andGreenRiver
basins(BestgenandZelasko2004;ColoradoParksandWildlife2015).
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.SomewhatDecrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,thespecieshasexperiencedgreaterthanaverage(>40
inches/1,016mm)precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.SomewhatIncrease.Highbaseflowsareimportantforthe
reproductionsuccessofflannelmouthsucker,aswellasblueheadandrazorbacksuckers(Anderson
andStewart2007).MostpublishedresearchindicatesadeclineinrunoffintheUpperColorado
RiverBasinbythemid‐to‐late21stcentury(Lukasetal.2014;Rayetal.2008).Reducedbaseflows
maybeassociatedwithincreasesinthenon‐nativewhitesucker(C.commersonii)populations.
Hybridizationofflannelmouthsuckerandwhitesuckerisaveryseriousthreattoflannelmouth
suckerintheColoradoRiverBasin(AndersonandStewart2007).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.ThisspeciesevolvedintheColoradoRiverBasinandisadaptedtohighspringrunoff(Rees
etal.2005).SpringflowsfortheColoradoRiverareprojectedtopeakearlierandbehigherin2035‐
2064(Lukasetal.2014).
C2d)Dependenceonsnow‐coveredhabitats.Neutral.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral/SomewhatIncrease.
Femalesspawnovergravel(CPW2014).Hydrologicprocessesthathelpcreateandmaintaingravel
barsmaybealteredduettoprojecteddecreasesinflowsintheColoradoRiverBasin(Lukasetal.
2014;Rayetal.2008).
Climate Change Vulnerability Assessment for Colorado BLM 271 C4a)Dependenceonotherspeciestogeneratehabitat.Unknown.
C4b)Dietaryversatility.Neutral.
C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Unknown.
C5a)Measuredgeneticvariation.Increase.Althoughthespeciesiswidespreadthroughoutthe
ColoradoRiverBasin,arecentstudyfoundverylowlevelsofgeneticdiversitybasin‐wide(Douglas
andDouglas2003).Furthermore,hybridsbetweennonnativewhitesucker(Catostomus
commersoni)andflannelmouthsuckerhavebeendocumentedintheColorado,Gunnison,and
Yamparivers(AndersonandStewart2007;DouglasandDouglas2003;Shiozawaetal.2003).
Hybridizationbetweenthenon‐nativewhitesuckerandthenativeblueheadsuckerhasalsobeen
documented,aswellasindividualswithgeneticcontributionsfromthewhitesucker,bluehead
sucker,andnativeflannelmouthsucker(Catostomuslatipinnus)(McDonaldetal.2008).Thenon‐
nativewhitesuckerhasfacilitatedintrogressionbetweentwonativespecies,andtherefore
threatensthegeneticintegrityoftheblueheadandflannelmouthsuckers.Whitesuckershave
becomepervasivethroughouttheColoradoRiverBasin,hybridizingreadilywithflannelmouth
suckers,thuscreatingaseriousextinctionrisktoflannelmouthsuckers(McDonaldetal.2008).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
Anderson,R.M.andG.Stewart.2007.Fish‐FlowInvestigation:II.Impactsofstreamflowalterationsonthenativefish
assemblageandtheirhabitatavailabilityasdeterminedby2Dmodelingandtheuseoffishpopulationdatatosupport
instreamflowrecommendationsforthesectionsoftheYampa,Colorado,GunnisonandDoloresRiversinColorado.
ColoradoDivisionofWildlifeSpecialReportNo.80,DOW‐R‐S‐80‐07.FortCollins.
Bestgen,K.R.,andK.A.Zelasko.2004.DistributionandstatusofnativefishesintheColoradoRiverBasin,Colorado.Final
ReporttoColoradoDivisionofWildlife.FortCollins,CO
Bezzerides,N.,andK.R.Bestgen.2002.StatusReviewofRoundtailChubGilarobusta,FlannelmouthSuckerCatostomus
latipinnis,andBlueheadSuckerCatostomusdiscobolusintheColoradoRiverBasin.Finalreport.SubmittedtoU.S.
272 Colorado Natural Heritage Program © 2015 DepartmentoftheInterior,BureauofReclamation,SaltLakeCity,Utah.LarvalFishLaboratoryContribution118,
ColoradoStateUniversity,Ft.Collins.
Childs,M.R.,R.W.Clarkson,andA.T.Robinson.1998.ResourceusebylarvalandearlyjuvenilenativefishesintheLittle
ColoradoRiver,GrandCanyon,Arizona.TransactionsoftheAmericanFisheriesSociety127:620‐629.
ColoradoParksandWildlife.2015.StateofColoradoConservationandManagementPlanfortheRoundtailChub(Gilia
robusta),BlueheadSucker(Catostomusdiscobolus)andFlannelmouthSucker(Catostomuslatipinnis).UnpublishedDraft.
Douglas,M.R.andM.E.Douglas.2003.YampaRiverhybridsuckergeneticassessment.DepartmentofFisheryandWildlife
Biology,ColoradoStateUniversity,FortCollins,CO.
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter.2014.ClimateChangeinColorado:ASynthesistoSupport
WaterResourcesManagementandAdaptation.AReportfortheColoradoWaterConservationBoard.WesternWater
Assessment.
McAda,C.W.1977.AspectsofthelifehistoryofthreeCatostomidsnativetotheUpperColoradoRiverBasin.Master’s
thesis,UtahStateUniversity,Logan,Utah.
Minckley,W.L.andP.B.Holden.1980.BlueheadsuckerinD.S.Lee,C.R.Gilbert,C.H.Hocutt,R.E.Jenkins,D.E.MacAllister
andJ.R.Stauffer,Jr.,editors.AtlasofNorthAmericanfreshwaterfishes.NorthCarolinaStateMuseumofNaturalHistory,
Columbia.p.377.
Ray,A.J.,J.Barsugli,andK.Avery.2008.ClimateChangeinColorado:ASynthesistoSupportWaterResources
ManagementandAdaptation.ReporttotheColoradoWaterConservationBoard.
Rees,D.E.,J.A.Ptacek,R.J.Carr,andW.J.Miller.2005.FlannelmouthSucker(Catostomuslatipinnis):atechnical
conservationassessment.[Online].USDAForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/flannelmouthsucker.pdf[Jan8,2015].
Sigler,W.F.andR.R.Miller.1963.FishesofUtah.UtahDepartmentofGameandFish,SaltLakeCity,UT.
Sigler,W.F.andJ.W.Sigler.1996.FishesofUtah;anaturalhistory.UniversityofUtahPress,SaltLakeCity,UT.
Weiss,S.J.1993.Spawning,movementandpopulationstructureofflannelmouthsuckerinthePariaRiver.M.S.Thesis.
UniversityofArizona,Tucson,AZ.
Climate Change Vulnerability Assessment for Colorado BLM 273 Humpback Chub
Gilacypha
G1/S1
ListedEndangered
Family:Cyprinidae
No photo available Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)barrierstomovement;2)
potentialdeclineinrunoffandsubsequentdecreaseinflowsintheUpperColoradoRiverBasin;3)
relianceongravelbarsforspawning;4)lackofgeneticvariation.
Distribution:OnlytwohumpbackchubpopulationsstillexistinColorado:theYampaCanyon
populationontheYampaRiverandtheBlackRockspopulationontheColoradoRiver(U.S.Fishand
WildlifeService2002).Thedistributionmapaboveshowscriticalhabitatasdesignatedbythe
USFWS(2003).Habitat:InColorado,adulthumpbackchubresideinswift,turbulenthabitatsand
indeeppoolsincanyons(Kaedingetal.1990;Leeetal.1981).Theyarealsofoundinwhitewaterin
deepeddies(Minckley1991).Juvenilesaregenerallyfoundinmoreshallowareas;youngofthe
yearhavebeendocumentedinshallowareasnearshorewithslowcurrentsandfinecobblesand
boulders(GormanandSeales1995).
EcologicalSystem:Streams
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral/SomewhatIncrease.Rapidsand
waterfallsmaycreatenaturalbarriersintheColorado,Yampa,andGreenrivers.
274 Colorado Natural Heritage Program © 2015 B2b)Distributionrelativetoanthropogenicbarriers.Increase.Damsanddiversionsinthe
ColoradoRiveranditstributariescreatebarrierstohumpbackchubmovement,andcausechanges
inchannelgeomorphology,sedimentregimes,andstreamflows(U.S.FishandWildlifeService
2011).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
C1)Dispersalandmovements.Neutral/SomewhatDecrease.Althoughmanybigriverfishfrom
theColoradoRiverBasintravellongdistances,thehumpbackchubhasbeenreportedtohave
relativelylimitedmovement(Paukertetal.2006).Theaveragespawningdistancesforhumpback
chubintheBlackRocksareaoftheColoradoRiverhasbeenreportedas6.4km(ValdezandRyel
1995).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral/Somewhat
Increase.Thehumpbackchubisadaptedtothelarge,warm‐waterriversandstreamsofthe
ColoradoRiverBasin.Humpbackchubgrowrelativelyquicklyinwarmwatertemperatures,and
coldertemperaturessuchasthosecausedbyhypolimneticdamreleaseshavebeenshownto
significantlylowergrowthrates(ClarksonandChilds2000).Warmerwatertemperaturescaused
byprojectedincreasesintemperaturemayhelpincreaserecruitmentratesinhumpbackchub
populations.
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Increase.Consideringtherangeofmeanannualprecipitationacross
occupiedcells,thespecieshasexperiencedsmall(4‐10inches/100‐254mm)precipitation
variationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.SomewhatIncrease.Maintenanceofstreamflowisimportant
fortherecoveryandconservationofbonytailchub(U.S.FishandWildlifeService2011).Flow
recommendationshavebeendevelopedforhumpbackchubintheGreenRiver(Muthetal.2000),
YampaRiver(Moddeetal.1999),andupperColoradoRiver(McAda2003).However,theremaybe
lesswateravailableinfuturetoprovidetheseflows.Mostpublishedresearchindicatesadeclinein
runoffintheUpperColoradoRiverBasinbythemid‐to‐late21stcentury(Lukasetal.2014;Jayet
al.2008).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Increase.Highspringflowsthatcreateandcleangravelbars,aswellastemporarilyreducenon‐
nativefishpopulations,arepositivelyassociatedwithreproductionofhumpbackchubintheLower
ColoradoRiver(Gorman1994).
C2d)Dependenceonsnow‐coveredhabitats.Neutral.
Climate Change Vulnerability Assessment for Colorado BLM 275 C3)Restrictiontouncommongeologicalfeaturesorderivatives.Increase.Humpbackchubare
associatedwithcleangravelbarsforspawning(Gorman1994;U.S.FishandWildlifeService2002).
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.
C4b)Dietaryversatility.Neutral.Humpbackchubfeedonsmallfishes,diatoms,planktonic
crustaceans,algae,andaquaticandterrestrialarthropods(U.S.FishandWildlifeService2002;
ValdezandRyel1995).
C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Unknown.
C5a)Measuredgeneticvariation.SomewhatIncrease.Geneticdiversityhasbeenidentifiedasan
issueforthehumpbackchub.Recentgeneticstudieshaveattemptedtounravelgeneticdifferences
betweenroundtailchubandhumpbackchub.Resultsindicatethatacrossitsrange,humpbackchub
androundtailchuboccupysixdistinctmanagementunits(DouglasandDouglas2007).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
Clarkson,R.W.,andM.R.Childs.2000.Temperatureeffectsofhypolimnial‐releasedamsonearlylifestagesofColorado
RiverBasinbig‐riverfishes.Copeia2000:402–412.
Douglas,M.R.andM.E.Douglas.2007.GeneticStructureofHumpbackChubGilacyphaandRoundtailChubG.robustain
theColoradoRiverEcosystem.Report.DepartmentofFish,WildlifeandConservationBiology,ColoradoStateUniversity.
99pp.
Gorman,O.T.andSeales,J.M.1995.Habitatusebytheendangeredhumpbackchub(Gilacypha)intheLittleColorado
River,ArizonanearGrandCanyon.ProceedingofDesertFishesCouncil1994annualsymposium.17‐20NovemberDeath
ValleyNationalPark,FurnaceCreek,CA.
Kaeding,L.R.,Burdick,B.D.,andSchraderP.A.1990.Temporalandspatialrelationsbetweenthespawningofhumpback
chubandroundtailchubintheupperColoradoRiver.TransactionsoftheAmericanFisheriesSociety119:135‐144.
276 Colorado Natural Heritage Program © 2015 Lee,D.S.,GilbertC.R.,HocuttC.H.,JenkinsR.E.,CallisterD.E.,andStaufferJ.R.1981.AtlasofNorthAmericanFreshwater
Fishes:NorthCarolina,NorthCarolinaStateMuseumofNaturalHistory,1981,c1980.
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter.2014.ClimateChangeinColorado:ASynthesistoSupport
WaterResourcesManagementandAdaptation.AReportfortheColoradoWaterConservationBoard.WesternWater
Assessment.
McAda,C.W.2003b.FlowrecommendationstobenefitendangeredfishesintheColoradoandGunnisonRivers.U.S.Fish
andWildlifeService,GrandJunction,CO.
Minckley,W.L.1991.Nativefishesofaridlands:Adwindlingresourceofthedesertsouthwest.USDAForestService.
GeneralTechnicalReportRM‐GTR‐206.pp18.
Modde,T.,W.J.Miller,andR.Anderson.1999.Determinationofhabitatavailability,habitatuse,andflowneedsof
endangeredfishesintheYampaRiverbetweenAugustandOctober.FinalReportofU.S.FishandWildlifeService,Vernal,
UtahtoUpperColoradoRiverEndangeredFishRecoveryProgram,Denver,CO.Onlineathttp://www.fws.gov/mountain‐
prairie/crrip/habitat.htm.
Muth,R.T.,L.W.Crist,K.E.LaGory,J.W.Hayse,K.R.Bestgen,T.P.Ryan,J.K.Lyons,andR.A.Valdez.2000.Flowand
temperaturerecommendationsforendangeredfishesintheGreenRiverdownstreamofFlamingGorgeDam.FinalReport
totheUpperColoradoRiverEndangeredFishRecoveryProgram,Denver,CO.
Paukert,C.P.,L.G.JrCoggins,andC.E.Flaccus.2006.DistributionandmovementofhumpbackchubintheColorado
River,GrandCanyon,basedonrecaptures.Trans.Am.Fish.Soc.135:539–544.
Ray,A.J.,J.Barsugli,andK.Avery.2008.ClimateChangeinColorado:ASynthesistoSupportWaterResources
ManagementandAdaptation.ReporttotheColoradoWaterConservationBoard.
U.S.FishandWildlifeService.2002.Humpbackchub(Gilacypha)RecoveryGoals:amendmentandsupplementtothe
HumpbackChubRecoveryPlan.U.S.FishandWildlifeService,Mountain‐PrairieRegion(6),Denver,Colorado.Valdezand
Ryel.1995.
U.S.FishandWildlifeService.2003.Humpbackchub(Gilacypha)CriticalHabitatshapefile.U.S.FishandWildlifeService,
Mountain‐PrairieRegion(6),Denver,Colorado.Availableonlineathttps://data.doi.gov/dataset/final‐critical‐habitat‐for‐
the‐humpback‐chub‐gila‐cypha.
U.S.FishandWildlifeService.2011.Humpbackchub(Gilacypha)5‐YearReview:SummaryandEvaluation.U.S.Fishand
WildlifeService,UpperColoradoRiverEndangeredFishRecoveryProgram.Denver,CO.29pp.
Valdez,R.A.andR.J.Ryel.1995.LifeHistoryandEcologyoftheHumpbackChubintheColoradoRiverinGrandCanyon,
Arizona.InThecontrolledfloodofGrandCanyon,Editedby:Webb,R.H.,Schmidt,J.C.,Marzolf,G.R.andValdez,R.A.
297–307.Washington,D.C.:AmericanGeophysicalUnion.Monograph110.
Climate Change Vulnerability Assessment for Colorado BLM 277 Razorback Sucker
Xyrauchentexanus
G1/S1
ListedEndangered
Family:Catostomidae
Photo: James E. Johnson, U.S. Fish & Wildlife Service Climate Vulnerability Rank: Highly Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)barrierstomovement;2)
potentialdeclineinrunoffandsubsequentdecreaseinflowsintheUpperColoradoRiverBasin;3)
lackofvariationinprecipitationacrossoccupiedhabitatinlast50years;4)requirescleancobble
barsforspawning.
Distribution:RazorbacksuckerarefoundonlyintheupperGreenRiverinUtah,andthelower
YampaRiverinColorado,andoccasionallyintheColoradoRivernearGrandJunction(U.S.Fishand
WildlifeService2002).Habitat:Adultrazorbacksuckeroccupydeepruns,eddies,andflooded
backwaterhabitatsinthesprings;summerhabitatistypicallylow‐velocityruns,pools,andeddies
(USFWS2002).Spawningoccursincobble,gravels,andsand(USFWS2002).Youngrazorback
suckersaretypicallyfoundinquiet,warm,shallowbackwaters(USFWS2002).
EcologicalSystem:Streams
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2)Distributionrelativetobarriers.RazorbacksuckeroccurinthemainstemoftheColorado
Riveraswellasitsmajortributaries(U.S.FishandWildlifeService1998).
B2a)Distributionrelativetonaturalbarriers.Neutral/SomewhatIncrease.Naturalphysical
barrierstomovementintheColoradoRiveranditstributariesarenaturalrapidsandswift
278 Colorado Natural Heritage Program © 2015 turbulentflows,andthesearelikelytofluctuatedependingonflows(U.S.FishandWildlifeService
2002).
B2b)Distributionrelativetoanthropogenicbarriers.Increase.Thedeclineofthespecies
throughouttheColoradoRiverBasinisattributedlargelytoextensivehabitatloss,modification,
andfragmentation,andblockedfishpassagefromdamconstructionandoperations(U.S.Fishand
Wildlife2012).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
C1)Dispersalandmovements.Decrease.Razorbacksuckerarecapableoftravelinglong
distances.Spawningmigrationsof30to106km(oneway)havebeenreportedintheYampaRiver
inDinosaurNationalMonument(Tyus1987;TyusandKarp1990).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Razorback
suckerisawarm‐waterfish,andtheavailabilityofwarm,productivewetlandsmaypromotefaster
growthandhighersurvivaloflarvae(Bestgen2008).
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.SomewhatIncrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,thespecieshasexperiencedslightlylowerthanaverage(11‐20
inches/255‐508mm)precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.SomewhatIncrease.Highspringflowshavebeenreportedtobe
importanttoadultsforfeeding,temperatureregulation,andspawning(TyusandKarp1990).
Spawningmovementsandtheappearanceofripefishwereassociatedwithincreasingspringflows
andaveragewatertemperaturesof14°C(range9‐17°Cor48‐63°F)(TyusandKarp1990).There
maybelesswateravailableinfuturetoprovidetheseflows.Mostpublishedresearchindicatesa
declineinrunoffintheUpperColoradoRiverBasinbythemid‐to‐late21stcentury(Lukasetal.
2014;Rayetal.2008).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Increase/SomewhatIncrease.Adultrazorbacksuckersspawnovercleancobblebarsduringspring
runoff,andtheirlarvaeflowintofloodplainhabitatsinundatedduringthespringfloods(McAdaand
Wydoski1980;U.S.FishandWildlifeService2002;Wicketal.1982).Thedam‐relatedchangesin
timingandflowlevelsontheColoradoRiveranditstributaries,alongwithchannelization,haveled
toalossoffloodplainnurseriesthatarenecessaryforthesurvivalandreproductionofthe
razorbacksucker(McAdaandWydoski1980).Mostpublishedresearchindicatesadeclineinrunoff
intheUpperColoradoRiverBasinbythemid‐to‐late21stcentury(Lukasetal.2014;Rayetal.
2008),whichcouldleadtofurtherlossanddegradationofhabitatforrazorbacksuckers.
Climate Change Vulnerability Assessment for Colorado BLM 279 C2d)Dependenceonsnow‐coveredhabitats.Neutral.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.SomewhatIncrease.SeeC2c.
Adultrazorbacksuckersspawnovercleancobblebarsduringspringrunoff,andtheirlarvaeflow
intofloodplainhabitatsinundatedduringthespringfloods(McAdaandWydoski1980;U.S.Fish
andWildlifeService2002;Wicketal.1982).
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.
C4b)Dietaryversatility.Neutral.Thedietoftherazorbacksuckervariesbylifestage,and
includesinsects,zooplankton,phytoplankton,algae,anddetritus(Bestgen1990;Muthetal.2000).
C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Unknown.
C5a)Measuredgeneticvariation.Neutral.Geneticdiversityhasbeenreportedashighforthe
razorbacksucker(Dowlingetal.1996;Dowlingetal.2005).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
Bestgen,K.R.1990.Statusreviewoftherazorbacksucker,Xyrauchentexanus.FinalReporttoU.S.BureauofReclamation,
SaltLakeCity,Utah.Contribution44,LarvalFishLaboratory,ColoradoStateUniversity,FortCollins.92pp.
Bestgen, K. 2008. Effects of Water Temperature on Growth of Razorback Sucker Larvae. Western North American Naturalist 68 (1): 15‐20. DowlingT.,W.Minckley,andP.Marsh.1996.MitochondrialDNAdiversitywithinandamongpopulationsofrazorback
sucker(Xyrauchentaxanus)asdeterminedbyrestrictionendonucleaseanalysis.Copeia,1996,542–550.
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter.2014.ClimateChangeinColorado:ASynthesistoSupport
WaterResourcesManagementandAdaptation.AReportfortheColoradoWaterConservationBoard.WesternWater
Assessment.
280 Colorado Natural Heritage Program © 2015 McAda,C.W.andR.W.Wydoski.1980.Therazorbacksucker(Xyrauchentexanus)intheUpperColoradoRiverBasin.974‐
976.U.S.FishandWildlifeServiceTechnicalPapers99.
Muth,R.T.,L.W.Crist,K.E.LaGory,J.W.Hayse,K.R.Bestgen,T.PRyan,J.K.Lyons,andR.A.Valdez.2000Flowand
temperaturerecommendationsforendangeredfishesintheGreenRiverdownstreamofFlamingGorgeDam.FinalReport
FG‐53totheUpperColoradoRiverEndangeredFishRecoveryProgram.U.S.FishandWildlifeService,Denver,CO.
Ray,A.J.,J.Barsugli,andK.Avery.2008.ClimateChangeinColorado:ASynthesistoSupportWaterResources
ManagementandAdaptation.ReporttotheColoradoWaterConservationBoard.
Tyus,H.M.,andC.A.Karp.1990.Spawningandmovementsofrazorbacksucker,Xyrauchentexanus,intheGreenRiver
BasinofColoradoandUtah.SouthwesternNaturalist35:427–433.
Tyus,H.M.1987.Distribution,reproduction,andhabitatuseoftherazorbacksuckerintheGreenRiver,Utah,1979–1986.
TransactionsoftheAmericanFisheriesSociety116:111–116.
U.S.FishandWildlifeService.1998.Razorbacksuckerrecoveryplan.U.S.FishandWildlifeService,Region6,Denver,
Colorado.
U.S.FishandWildlifeService.2002.RazorbacksuckerRecoveryGoals:AmendmentandsupplementtotheRazorback
SuckerRecoveryPlan.U.S.FishandWildlifeService,Region6,Denver,Colorado.
U.S.FishandWildlifeService.2012.FiveYearReview:SummaryandEvaluation.UpperColoradoRiverEndangeredFish
RecoveryProgram.Denver,Colorado,July2012.
Wick,E.J.,C.W.McAda,andR.V.Bulkley.1982.Lifehistoryandprospectsforrecoveryoftherazorbacksucker.Pages120‐
126in:W.H.Miller,H.M.Tyus,andC.A.Carlson(editors).FishesoftheupperColoradoRiversystem:presentandfuture.
AmericanFisheriesSociety,Bethesda,Maryland.
Climate Change Vulnerability Assessment for Colorado BLM 281 Rio Grande Cutthroat Trout
Oncorhynchusclarkiivirginalis
G4T3/S3
Family:Salmonidae
No photo available Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)barrierstomovement;2)
potentialdewateringofstreamsintheRioGrandeRiverBasin;3)lackofgeneticdiversity.
Distribution:InColorado,theRioGrandecutthroattroutoccursintheRioGrandeRiverBasin.
Habitat:RioGrandecutthroattroutoccurinclear,cold,highelevationstreams.Adultsusedeep
pools,whilefryusebackwatersandsidechannels(USFWS2014).
EcologicalSystem:Streams
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Increase.Insomeheadwaterstreams,waterfalls,
cascades,bedrockchutes,orsubterraneanreachesmaypresentnaturalbarriersthatblock
movementofRioGrandecutthroattrout(Pritchardetal.2008).
B2b)Distributionrelativetoanthropogenicbarriers.SomewhatIncrease.Damsanddiversions
inoccupiedRioGrandecutthroattrouthabitatcanblockdispersalofpopulations,increasingthe
riskofextinction(Zeigleretal.2012).However,theeffectsofconstructedbarriersarecomplex.
Theyalsoprovideabarriertothemovementofnon‐nativefishspeciesthatcompetewithandprey
onRioGrandecutthroattrout(PritchardandCowley2006).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
282 Colorado Natural Heritage Program © 2015 C1)Dispersalandmovements.SomewhatDecrease.Nodataexistsonaveragemovement
capabilitiesforRioGrandecutthroattrout(PritchardandCowley2006).Cutthroattrouton
Colorado’swestslopewerefoundtomoveamediandistanceof91m‐1.2kmduringthesummer
(SchmetterlingandAdams2004).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.GreatlyIncrease.
DroughtandincreasedstreamtemperatureshavebeenidentifiedasamajorthreattoRioGrande
cutthroattrout(Haaketal.2010).DroughtsinthesouthwesternUnitedStatesareexpectedto
increaseinfrequencyandseverity(HoerlingandEischeid2007).Thiscouldresultinstream
dewateringandadecreaseinavailablehabitat(U.S.FishandWildlifeService2014;Zeigleretal.
2012).AverageannualairtemperaturehasincreasedacrosstherangeofRioGrandecutthroat
troutsincethemid‐20thcentury,andthistrendcouldresultinelevatedstreamtemperaturesthat
areunsuitableforRioGrandecutthroattroutthatrelyoncoldwaterhabitattocompletetheirlife
cycle(U.S.FishandWildlifeService2014;Williamsetal.2009;Ziegleretal.2012).
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.SomewhatDecrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,thespecieshasexperiencedgreaterthanaverage(>40
inches/1,016mm)precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.GreatlyIncrease.Reducedstreamflowhasalreadybeen
observedthroughouttherangeofRioGrandecutthroattrout(Zeigleretal.2012).Recentclimate
modelspredictdecreasesinannualstreamflowintheRioGrandeBasin(Lukasetal.2014).Stream
dryingreducesavailablehabitatforalllifestagesofRioGrandecutthroattrout(seematrixin
USFWS2014).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.RioGrandecutthroattroutarelocatedinheadwaterstreams.Theyspawnfollowingpeak
runofflevelsfromsnowmelt(Behnke2002;PritchardandCowley2006).Climatechangehas
shiftedpeakrunofffromsnowmeltapproximately10daysearlierthan45yearsago(Zeigleretal.
2012).EarlierrunoffcouldposebenefitsandthreatstoRioGrandecutthroattrout.Young‐of‐year
wouldbenefitfromalongergrowingseason,butalongseasonoflowflowscouldleadtoincreased
streamtemperaturesandstreamintermittencyoutsideofthetolerancerangeforthespecies
(USFWS2014).
C2d)Dependenceonsnow‐coveredhabitats.Neutral.AsnotedaboveinC2c,RioGrande
cutthroattroutarelocatedinheadwaterstreams.Theyspawnfollowingpeakrunofflevelsfrom
snowmelt(Behnke2002;PritchardandCowley2006).
Climate Change Vulnerability Assessment for Colorado BLM 283 C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral/SomewhatIncrease.
Sediment‐freegravelsandcobblesarenecessaryforproducingaquaticinsectsforfoodandcreate
spawninghabitats(USFWS2014).
C4a)Dependenceonotherspeciestogeneratehabitat.Unknown.
C4b)Dietaryversatility.Neutral.StudiesofColoradoRiverandRioGrandecutthroattrout
indicatethatmidgelarvae,caddisflies,andmayflies,aswellasarangeofotherbenthicpreyitems
comprisethemaindietofthesenativetroutspecies(Bozeketal.1994;PritchardandCowley2006;
MooreandGregory1988;Youngetal.1997).
C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Neutral.
C5a)Measuredgeneticvariation.Increase.Geneticdiversityisaconservationconcernforthis
speciesthathasexperiencedprecipitousdeclinesinthelastcentury.Recentstudieshaveshown
thattherearetwo“evolutionarysignificantunits”ofRioGrandecutthroattrout:oneintheRio
GrandeBasin,andoneinthePecosandCanadianbasins(Pritchardetal.2009).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
Behnke,R.J.2002.TroutandsalmonofNorthAmerica.FreePress,NewYork.
Bozek,M.A.,L.D.Debrey,andJ.A.Lockwood.1994.DietoverlapamongsizeclassesofColoradoRivercutthroattrout
(Oncorhynchusclarkipleuriticus)inahigh‐elevationmountainstream.Hydrobiologia273:9‐17.
Haak,A.L.,J.E.Williams,D.Isaak,A.Todd,C.Muhlfeld,J.L.Kershner,R.Gresswell,S.Hostetler,andH.M.Neville.2010.
Thepotentialinfluenceofchangingclimateonthepersistenceofsalmonidsoftheinlandwest.U.S.GeologicalSurvey,
Open‐FileReport2010‐1236,Reston,Virginia.AccessedNov13,2014.Onlineat:pubs.usgs.gov/of/2010/1236/.
Hoerling,M.,andJ.Eischeid.2007.PastpeakwaterintheSouthwest.SouthwestHydrology6:18–19,35.
284 Colorado Natural Heritage Program © 2015 Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter.2014.ClimateChangeinColorado:ASynthesistoSupport
WaterResourcesManagementandAdaptation.AReportfortheColoradoWaterConservationBoard.WesternWater
Assessment.
Moore,K.M.S.andS.V.Gregory.1988.SummerhabitatutilizationandecologyofcutthroattroutfrySalmoclarkii.in
CascadeMountainUSAstreams.CanadianJournalofFisheriesandAquaticSciences45:921‐1930.
PritchardV.L.,J.L.Metcalf,K.Jones,A.P.Martin,D.E.Cowley.2008.PopulationstructureandgeneticmanagementofRio
Grandecutthroattrout(Oncorhynchusclarkiivirginalis).ConservationGenetics,10,1209–1221.
Pritchard,V.L.,andD.E.Cowley.2006.RioGrandecutthroattrout(Oncorhynchusclarkiivirginalis):atechnical
conservationassessment.U.S.DepartmentofAgricultureForestService,RockyMountainRegion,SpeciesConservation
Project,FortCollins,Colorado.Available:www.fs.fed.us/r2/projects/scp/assessments.(September2008).
Schmetterling,D.A.andS.B.Adams.2004.Summermovementswithinthefishcommunityofasmallmontanestream.
NorthAmericanJournalofFisheriesManagement24:1163–1172
U.S.FishandWildlifeService.2014.EndangeredandThreatenedWildlifeandPlants;12‐MonthFindingonaPetitionTo
ListRioGrandeCutthroatTroutasanEndangeredorThreatenedSpecies.DocketNo.FWS–R2–ES–2014–0042;
4500030113.
Young,M.K.,Rader,R.B.,andBelish,T.A.1997.“InfluenceofMacroinvertebrateDriftandLightontheActivityand
MovementofColoradoRiverCutthroatTrout.”TransactionsoftheAmericanFisheriesSociety,126,428‐437.
Williams,J.E.,A.L.Haak,H.M.Neville,andW.T.Colyer.2009.Potentialconsequencesofclimatechangetopersistenceof
cutthroattroutpopulations.NorthAmericanJournalofFisheriesManagement29:533–548.
Ziegler,M.P,A.S.Todd,C.A.Caldwell.2012.EvidenceofRecentClimateChangewithintheHistoricRangeofRioGrande
CutthroatTrout:ImplicationsforManagementandFuturePersistence,TransactionsoftheAmericanFisheriesSociety
141(4):1045‐1059.
Climate Change Vulnerability Assessment for Colorado BLM 285 Roundtail Chub
Gilarobusta
G3/S2
Family:Cyprinidae
Climate Vulnerability Rank: Highly Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)barrierstomovement;2)
potentialdeclineinrunoffandsubsequentdecreaseinflowsintheUpperColoradoRiverBasin;3)
potentialshiftintimingofspawningthatcouldleadtolowerrecruitment;4)lackofgenetic
diversity.
Distribution:InColorado,theroundtailchubisfoundontheWesternSlopeintheUpperColorado
RiverBasin.ThemapaboveisbasedoninformationprovidedintheColoradoParksandWildlife
(2015)conservationassessmentplandraft.Habitat:Roundtailchuboccupymainstemand
tributariesstreamsintheUpperColoradoRiverBasin.Adultsuseeddiesandpoolsnearareaswith
strongcurrentsandboulders(CPW2015);whilesjuvenilesaremostfrequentlyfoundinquiet,
shallowbackwaters(Brouderetal.2000).
EcologicalSystem:Streams
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.SomewhatIncrease/Neutral.Adultroundtailchub
occupydeeppoolsandrunsinmainstemandsmallertributarysystemoftheColoradoRiverBasin
(Bestgenetal.2011).Larvaepreferlowvelocitybackwaters,young‐of‐the‐yearoccupyshallow,low
velocityhabitats,andjuvenilesoccupypools(Bestgenetal.2011).Rapids,swiftturbulentflows,
andwaterfallscouldcreatenaturalbarrierstomovementofroundtailchubduringhighflows,but
thesebarriersarelikelyseasonal.HighsalinitylevelsintheDoloresRiverfromParadoxValley
286 Colorado Natural Heritage Program © 2015 downstreamtoSanMiguelcouldalsoposeasanaturalbarrierwhenconcentrationsarehighduring
lowflows(Bestgenetal.2011).
B2b)Distributionrelativetoanthropogenicbarriers.Increase.Theconstructionofdamsalong
themainstemoftheColoradoRiveranditstributarieshasfragmentedandinundatedriverine
habitat;releasedcold,clearwaters;alteredecologicalprocessesandsedimentregimes;affected
seasonalavailabilityofhabitat;andblockedfishpassage(MarshandDouglas1997;Minckleyand
Deacon1968;U.S.FishandWildlifeService2002;ValdezandRyel1995).Roundtailchubdeclines
arecommoninimpoundmentsafterreservoirconstruction(BezzeridesandBestgen2002).
WolfordMountainReservoirhoststheonlyreservoir‐dwellingpopulationofroundtailchubin
Colorado(Ewert2010).Fishpassagewayshavebeencreatedfortheroundtailchubandother
nativefishatdamsitesintheColoradoRivernearPalisadeandontheGunnisonRiver(Landers
2012).TheGreenRiverDaminUtahisslatedforrehabilitation,andthefinalplansforrenovation
includeafishpassagewaytoallowfortheupstreamanddownstreammovementofnativefishes,
includingroundtailchub(U.S.DepartmentofAgriculture2014).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
C1)Dispersalandmovements.Neutral.Roundtailchubtravel5‐80kmduringspawning(Bestgen
etal.2011).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.The
roundtailchubisadaptedtothelarge,warm‐waterriversandstreamsoftheColoradoRiverBasin.
Roundtailchubpreferstreamtemperaturesthatrangefrom18‐20˚C(BezzeridesandBestgen
2002).DamreleaseshaveledtocolderwatertemperaturesintheBasin,andthesearesuggestedas
areasonfortheoveralldeclineinroundtailchubpopulations(Bestgenetal.2011).
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.SomewhatDecrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,thespecieshasexperiencedgreaterthanaverage(>40
inches/1,016mm)precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.SomewhatIncrease.Abundanceofroundtailchubwas
positivelycorrelatedwithmoderatetohighbaseflowsintheColoradoRiverBasin(Andersonand
Stewart2007).However,theremaybelesswateravailableinfuturetoprovidetheseflows.Most
publishedresearchindicatesadeclineinrunoffintheUpperColoradoRiverBasinbythemid‐to‐
late21stcentury(Lukasetal.2014;Jayetal.2008).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Increase.RoundtailchubtypicallyspawninJunetoearlyJulywhenwatertemperaturesrangefrom
16‐22˚C(ColoradoParksandWildlife2015).Mostpublishedresearchindicatesadeclineinrunoff
Climate Change Vulnerability Assessment for Colorado BLM 287 intheUpperColoradoRiverBasinbythemid‐to‐late21stcentury(Lukasetal.2014;Jayetal.
2008).ThiscouldcauselowflowsinAprilandMay,creatingwarmerwatertemperaturesthatcould
prematurelyinitiatespawningofroundtailchub,andsubsequentcoldhighflowscouldkilleggsand
larvae(Bestgenetal.2011).
C2d)Dependenceonsnow‐coveredhabitats.Neutral.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.Roundtailchub
spawnovergravelindeeppoolsandruns(BezzeridesandBestgen2002;Brouderetal.2000).
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.
C4b)Dietaryversatility.Neutral.Roundtailchubfeedonaquaticandterrestrialinsects,fish,
snails,algae,andoccasionallylizards(Bestgen2000;Brouder2001;ColoradoParksandWildlife
2015;Osmundson1999;SiglerandSigler1996).
C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Unknown.
C5a)Measuredgeneticvariation.SomewhatIncrease.Theroundtailchubisverycloselyrelated
tothehumpbackchub,andgeneticdiversityhasbeenidentifiedasaconservationissueforthese
twospecies(Clarksonetal.2012;DouglasandDouglas2007).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
Bestgen,K.R.2000.PersonalcommunicationwithDirectorofColoradoStateUniversity’sLarvalFishLabtoColorado
ParksandWildlife,FortCollins,Colorado.
Bestgen,K.R.,P.Budy,andW.J.Miller.2011.StatusandtrendsofflannelmouthsuckerCatostomuslapipinnis,bluehead
suckerCatostomusdiscobolus,androundtailchubGilarobusta,intheDoloresRiver,Colorado,andopportunitiesfor
populationimprovement:PhaseIIreport.PreparedforLowerDoloresPlanWorkingGroup.Onlineat
http://warnercnr.colostate.edu/docs/fwcb/lfl/PDF/LFL‐166‐Bestgen_et_al‐2011‐Rpt.pdf.
288 Colorado Natural Heritage Program © 2015 Bezzerides,N.,andK.R.Bestgen.2002.StatusReviewofRoundtailChubGilarobusta,FlannelmouthSuckerCatostomus
latipinnis,andBlueheadSuckerCatostomusdiscobolusintheColoradoRiverBasin.Finalreport.SubmittedtoU.S.
DepartmentoftheInterior,BureauofReclamation,SaltLakeCity,Utah.LarvalFishLaboratoryContribution118,
ColoradoStateUniversity,Ft.Collins.
Brouder,M.J.,D.D.Rogers,andL.D.Avenetti.2000.Lifehistoryandecologyoftheroundtailchub(Gilarobusta)fromtwo
streamsintheVerdeRiverBasin.TechnicalGuidanceBulletinNo.3–July2000.ArizonaGameandFishDepartment
ResearchBranch,FederalAidinSportfishRestorationProjectF‐14‐R,Phoenix.
Brouder,M.J.2001.Effectsoffloodingonrecruitmentofroundtailchub,Gilarobusta,inasouthwesternriver.The
SouthwesternNaturalist46(3):302‐310.
Clarkson,R.W.,P.C.MarshandT.E.Dowling.2012.Populationprioritizationforconservationofimperiledwarmwater
fishesinanarid‐regiondrainage.AquaticConservation:MarineandFreshwaterEcosystems22(4):498‐510.
ColoradoParksandWildlife.2015.StateofColoradoConservationandManagementPlanfortheRoundtailChub(Gilia
robusta),BlueheadSucker(Catostomusdiscobolus)andFlannelmouthSucker(Catostomuslatipinnis).UnpublishedDraft.
Douglas,M.R.andM.E.Douglas.2007.GeneticStructureofHumpbackChubGilacyphaandRoundtailChubG.robustain
theColoradoRiverEcosystem.Report.DepartmentofFish,WildlifeandConservationBiology,ColoradoStateUniversity.
99pp.
Ewert,J.2010.WolfordMountainReservoir,fishsurveyandmanagementdata.ColoradoDivisionofWildlife.Available
from
http://cpw.state.co.us/documents/fishing/fisherywatersummaries/summaries/northwest/wolfordmountainreservoir.p
df
Landers,J.2012.ColoradoDamModifiedtoIncludeInnovativeFishwaysandBoatPassage.CivilEngineering82(11):24‐
28.
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter.2014.ClimateChangeinColorado:ASynthesistoSupport
WaterResourcesManagementandAdaptation.AReportfortheColoradoWaterConservationBoard.WesternWater
Assessment.
Marsh,P.C.,andM.E.Douglas.1997.Predationbyintroducedfishesonendangeredhumpbackchubandothernative
speciesintheLittleColoradoRiver,Arizona.TransactionsoftheAmericanFisheriesSociety126:343–346.
Minckley,W.L.,andJ.E.Deacon.1968.Southwesternfishesandtheenigmaof“EndangeredSpecies”:man’sinvasionof
desertscreatesproblemsfornativeanimals,especiallyforfreshwaterfishes.Science,159:1424‐1432.
Osmundson,D.B.1999.LongitudinalvariationinfishcommunitystructureandwatertemperatureintheUpperColorado
River:implicationsforColoradopikeminnowhabitatsuitability.FinalReportforRecoveryImplementationProgram,
ProjectNo.48.U.S.FishandWildlifeService,GrandJunction,Colorado.
Ray,A.J.,J.Barsugli,andK.Avery.2008.ClimateChangeinColorado:ASynthesistoSupportWaterResources
ManagementandAdaptation.ReporttotheColoradoWaterConservationBoard.
Sigler,W.F.andJ.W.Sigler.1996.FishesofUtah:ANaturalHistory.UniversityofUtahPress,SaltLakeCity.
U.S.DepartmentofAgriculture.2014.FinalEnvironmentalImpactStatement.GreenRiverDiversionRehabilitation
Project.AccessedOctober14,2014onlineat
http://www.nrcs.usda.gov/wps/portal/nrcs/detail/ut/programs/planning/ewpp/?cid=nrcs141p2_034037.
Climate Change Vulnerability Assessment for Colorado BLM 289 Great Basin Silverspot
Speyerianokomisnokomis
G3T1/S1
Family:Nymphalidae
Climate Vulnerability Rank: Highly Vulnerable
ThisColoradostatewiderankisbasedon:theprojectedincreaseintemperatureanddroughtinthe
assessedarea,theinabilityofthesilverspottodisperseacrossdrylandscapes,itsdependenceon
wetlandhabitatwithinanaridlandscape,thedryingofitswetlandhabitatduetoprojected
frequenciesofdrought,modificationstohydrology(e.g.,waterdiversionprojects,cappingsprings,
anddrainingwetlands)tosupporttheagricultureandlivestockindustriesastheavailabilityof
waterresourcesdeclines,limitedprecipitationvariationthesilverspothashistoricallyexperienced,
theincreasedthreattosuitablehabitatfromwildfirecausedbydroughtandwarming,dependence
onalarvalhostplantthatisrestrictedtowetlands,andlowlevelsofgeneticvariabilityquestioning
thesilverspotsadaptabilitytoachangingenvironment.Regionalannualaveragetemperaturesare
projectedtoriseby2.5°Fto5.5°Fby2041‐2070andby5.5°Fto9.5°Fby2070‐2099with
continuedgrowthinglobalemissions(A2emissionsscenario),withthegreatestincreasesinthe
summerandfall(Melilloetal.2014).Underacontinuationofcurrentrisingemissionstrends(A2),
reducedwinterandspringprecipitationisconsistentlyprojectedforthesouthernpartofthe
Southwestby2100elevatingthepotentialforwildfire(Melilloetal.2014).
Distribution:InColorado,coloniesoccuratonlyfourpreviouslyknownlocationsinLaPlata,Mesa,
Montrose,andOuraycounties(CNHP2004).Habitat:TheNokomisfritillaryisassociatedwiththe
UpperSonoran(pinyon‐juniper,variousshrubs)andCanadian(fir‐spruce‐tamarack,somepine,
aspen‐maple‐birch‐alder‐hemlock)LifeZonesofthesouthwesternUnitedStatesandnorthern
Mexico(Hammond1974,Scott1986,Selby2007).Habitatsaregenerallydescribedaspermanent
spring‐fedmeadows,seeps,marshes,andboggystreamsidemeadowsassociatedwithflowing
waterinaridcountry(Hammond1974,Scott1986,TildenandSmith1986,OplerandWright1999,
BrockandKaufman2003,Selby2007).
290
Colorado Natural Heritage Program © 2015 CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Increase.Aridlandscapesseparatingdesert
streamsandwetlandsareaseverebarriertothisspecies.GreatBasinsilverspotbutterfliesdonot
migratewithdocumentedroutinedispersaldistancesofonlyupto4km(Fleischmanetal.2002).
Theyrequirestreamsidemeadowsandseepageareasduringtheiradultflightperiodandfortheir
larvalstage.InthearidSouthwest,wherethisbutterflylives,thesehabitatconditionsarewidely
separatedandisolated(Selby2007)andpopulationsatonelocalewillnotcrossaridlandscapesto
distantcoloniesexistingatotherdesertstreams/wetlands.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Anthropogenicbarriersarenot
thoughttobeaconcernforthisspeciesbecauseoftheundevelopeddesertlandscapesthisspecies
inhabits.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Increase.
Modificationstohydrology(e.g.,waterdiversionprojects,cappingsprings,anddrainingwetlands)
tosupporttheagricultureandlivestockindustriesarethegreatesthistoric,current,andfuture
threattothelong‐termsurvivaloftheGreatBasinsilverspotbutterflyintheassessedarea.
Increasedwaterdemand,combinedwithreducedavailabilityduetoclimatechange(Karletal.
2009),willnegativelyimpactthisspecies.
C1)Dispersalandmovements.Neutral.TheGreatbasinsilverspothasbeendocumentedto
routinelydisperseupto4km(2.5miles),andinonestudy26percentoftherecapturedbutterflies
hademigratedfromtheirinitialcapturepatch(Fleischmanetal.2002).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Therange
occupiedbytheGreatBasinsilverspotintheassessedareahasexperiencedanaverage(51.7‐77°
F/31.8‐43.0°C)zonalmeanseasonaltemperatureoverthelast50years
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Somewhatdecrease.
TheGreatBasinSilverspothasapreferenceforwarmerenvironmentsandisassociatedwitharid
desertlandscapesoftheUpperSonoranLifeZone(Selby2007).
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Somewhatdecrease.WithintheassessedareatheGreatBasin
silverspothasexperiencedgreaterthanaverage(>40inches/1,016mm)precipitationvariationin
thepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Greatlyincrease.TheGreatbasinsilverspotiscompletely
dependentuponwidelyseparatedisolatedspotswheretherearepermanentspring‐fedmeadows,
seeps,marshes,andboggystreamsidemeadowsassociatedwithflowingwaterinthemidstof
otherwisearidcountry(Hovanitz1970,BrockandKaufman2003).Inthefuture,climatechangeis
Climate Change Vulnerability Assessment for Colorado BLM 291 projectedtoincreasedroughtfrequency(Melilloetal.2014,whichmayreducethesehabitats
withintheassessedarea.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Increase.Climatechangeisprojectedtoincreasewildfirefrequencyintheassessedarea(Melillo
2014).Firecancausedirectmortalityoflarvaeandeliminaterequiredhostplants.Giventhese
factors,itshouldbeassumedthatextensive(e.g.,burningallormostofthehabitatinanareaatone
time)orfrequent(e.g.,everyonetotwoyears)firesarelikelytonegativelyaffectbutterfly
populations(Selby2007).Alternatively,lowseverityandinfrequent(every5years)firecan
maintainthecomplexofwetmeadows,willows,andotherwoodywetlandspeciesthatprovides
optimalmicroclimatesforthelarvalfoodplant(bogviolet)andadultnectarplantstheGreatBasin
silverspotbutterflyneeds.
C2d)Dependenceonsnow‐coveredhabitats.Neutral.TheGreatBasinsilverspotisnot
dependentonhabitatswithice,snow,oronsnowpack.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.TheGreatBasin
silverspotisnotdependentuponanyuncommongeologicalelements.
C4a)Dependenceonotherspeciestogeneratehabitat.Increase.TheGreatBasinsilverspotis
dependentonthepresenceofanadequatesupplyofthelarvalfoodplant(i.e.,bogviolet[Viola
nephrophylla])(NatureServe2014).Microhabitatconditionsforthebogvioletincludesoggysoil
andshade,oftenundershrubssuchaswillows(Baird1942).Willowsareusuallypresent
(Hammond1974)andprobablyhelptocreatethemicroclimatethatthevioletsneed.Climate
changeisprojectedtoincreasedroughtfrequencywithintheassessedarea(Melilloetal.2014),
reducingthewateravailableforsustainingtheplantcommunitiesthebogvioletdependsupon.
C4b)Dietaryversatility.Bogviolet(Violanephrophylla)istheexclusivelarvalfoodplant.Adults
feedonnectarfromawiderangeoffloweringalpineplants(OplerandWright1999).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.TheGreatBasinfritillaryis
aself‐disperser.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Neutral.Noother
interspecificinteractionsareimportanttothepersistenceoftheGreatBasinfritillary.
C5a)Measuredgeneticvariation.Increase.ColoniesofNokomisfritillarysubspeciestendtobe
small,local,restrictedtoarelativelynarrowelevationrange,andsusceptibletooccasionalsevere
populationdeclines;consequently,lowlevelsofheterozygosityarenotunexpected.Genetic
researchontheGreatBasinsilverspotindicatesthatthereisverylittlegeneticvariationinthese
populations(Selby2007).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
292 Colorado Natural Heritage Program © 2015 C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
Baird,V.B.1942.WildvioletsofNorthAmerica.UniversityofCaliforniaPress,Berkeley,CA.
Brock,J.P.andK.Kaufman.2003.ButterfliesofNorthAmerica.HoughtonMifflin,NewYork,NY.383pp.
ColoradoNaturalHeritageProgram(CNHP).2004.Nokomisfritillaryelementglobalrank(EGR)report.ColoradoNatural
HeritageProgram,FortCollins,CO.
Fleishman,E.,C.Ray,P.Sjögren‐Gulve,C.L.Boggs,andD.D.Murphy.2002.Assessingtherelativerolesofpatchquality,
area,andisolationinpredictingmetapopulationdynamics.ConservationBiology16:706‐716.
Hammond,P.C.1974.AnecologicalsurveyofthenymphalidbutterflygenusSpeyeria.M.S.Thesis,UniversityofNebraska,
Lincoln,NE.
Hovanitz,W.1969(1970).Habitat:Argynnisnokomis.JournalofResearchontheLepidoptera8(1):20.
Karl,T.R.,J.M.Melillo,andT.C.Peterson,(eds.).2009.GlobalClimateChangeImpactsintheUnitedStates.Cambridge
UniversityPress.
Melillo,J.M.,T.C.Richmond,andG.W.Yohe,Eds.,2014:ClimateChangeImpactsintheUnitedStates:TheThirdNational
ClimateAssessment.U.S.GlobalChangeResearchProgram,841pp.doi:10.7930/J0Z31WJ2.
NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org[2/6/2015].
Opler,P.A.andA.BWright.1999.Petersonfieldguidetowesternbutterflies.Revisededition.HoughtonMifflinCo.,
Boston,MA.540pp.
Scott,J.A.1986.ThebutterfliesofNorthAmerica.StanfordUniversityPress,Stanford,CA.583pp.
Selby,G.2007.GreatBasinSilverspotButterfly(Speyerianokomisnokomis[W.H.Edwards]):atechnicalconservation
assessment.[Online].USDAForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/greatbasinsilverspotbutterfly.pdf[1/23/2015].
Tilden,J.W.andA.C.Smith.1986.Afieldguidetowesternbutterflies.Houghton‐MifflinCo.,Boston,MA.370pp.23color
plates.
Climate Change Vulnerability Assessment for Colorado BLM 293 American Beaver
Castorcanadensis
G5/S4
Family:Castoridae
Climate Vulnerability Rank: Moderately Vulnerable
ThisColoradostate‐widerankisbasedon:thelimitedthermalnicheforC.canadensis;C.
canadensis’relianceonaquaticenvironments;andC.canadensis’susceptibilitytovaryingwater
availability.
Distribution:C.canadensisisfoundinnearlyallwaterwaysinColorado.Habitat:C.canadensis
livesandfeedsinandaroundwaterwaysofColorado,butaremostabundantinareaswithaspen,
cottonwood,orwillowespeciallyinbroadglacialvalleyswithlowstreamgradients(Armstronget
al.2011).Elevation:3,300–11,000feet.
EcologicalSystem:Waterwaysandadjacentriparianforests
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral.Therearefewnaturalbarriersfor
beavers.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Becausebeaversareadeptat
colonizingwaterbodiesandareubiquitousinNorthAmerica,therearefewanthropogenicbarriers.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
Thereisnotclimate‐changemitigatingenergydevelopmentthatwilllimitbeaversuccess.
294
Colorado Natural Heritage Program © 2015 C1)Dispersalandmovements.SomewhatDecrease.Femalestypicallydispersefurtherthan
males(10kmvs.3km)(Sunetal.2000).Juvenilesindifferentsystemsmaydispersalless(2–5
km)(McNewandWoolf2005).Dispersaldistancesfortransplantedbeavercanbemuchhigher
(BoyleandOwens2007),butnaturaldispersalistypicallylessthan10km(VanDeelenand
Pletscher1986,Sunetal.2000).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Muchofthe
beaverrangeinColoradofallswithinthe55‐77°Frange.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Increase
Vulnerability.Thermoneutralzoneforbeaversisbetween32‐82°F(MacArthur1989)andthe
speciesspendsmostofitstimeinwaterwherethermoregulationincoolaquaticenvironmentscan
bephysiologicallychallenging(MacArthurandDyck1990).However,beaversaretiedtoaquatic
environmentsthatmaybecomemorescarceandwarminganddryingcontinue.
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.SomewhatIncreaseVulnerability.BasedontheClimateWizard
mapofhistorichydrologicvariation,muchoftherangeinColoradovariesfromthelowestvariation
tomid‐levelsofvariability.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.GreatlyIncreasevulnerability.Beaversare100%relianton
aquaticenvironmentsforsubsistence,anditislikelyasclimatedriesandwarmsthedistribution
(andbeaverabundance)willbereduced.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncreaseVulnerability.Beaversdonotrelyonaparticulardisturbanceregimeanddo
notneedanabsenceofdisturbance.Themostregularnon‐essentialdisturbanceiswater
availability.Populationsofbeaveronlow‐flowstreamswilllikelybethemostdisturbedby
alternationsinhydrology(BoyleandOwens2007).Beaversandtheirhabitatcanbechallengedby
theabsenceofwater(drought)oranabundanceofwater(flooding),butcanmodifytheir
environmenttolimittheimpactofthesestressors.Climatechangeislikelytoincreasethe
frequencyofdroughtandthismaylimitbeaverdistributionandnumbers.
C2d)Dependenceonsnow‐coveredhabitats.Neutral.Thereisnoknownrelationshipofthis
speciestosnoworice‐coveredhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.Thisspeciesisnot
knowntospecializeonuncommongeologicalfeatures.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Beaversgeneratetheirown
habitatviadambuilding.
C4b)Dietaryversatility.Neutral.Beaversaregeneralistherbivoresfeedingoninnerbark,twigs,
leaves,andbudsofdeciduouswoodyplants,andherbaceousandaquaticplants(BoyleandOwens
2007).
Climate Change Vulnerability Assessment for Colorado BLM 295 C5a)Measuredgeneticvariation.Unknown.Nodataareavailableforgeneticvariabilitywithin
NorthAmericanbeavers.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.onlyif5Aisunknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.Nodataavailable.
D1)Responsetorecentclimatechange.Unknown.Nodataavailable.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Neutral.Veryfewrivermilesareconsideredprotected,butwetlandsand
waterwaysreceivelegalprotectionthroughCleanWaterActandotherlegislation.
Literature Cited
Armstrong,D.M.,J.P.Fitzgeraldand,C.A.Meaney.2011.MammalsofColorado,2ndEdition.UniversityPressofColorado.
704pp.
Boyle,S.,andS.Owens.2007.NorthAmericanBeaver(CastorCanadensis):atechnicalconservationassessment.[Online].
USDAForestService,RockyMountainRegion.Available::
http://www.fs.fed.us/r2/projects/scp/assessments/northamericanbeaver.pdf[5January2015].
MacArthur,R.A.1989.Energymetabolismandthermoregulationofbeaver(Castorcanadensis).CanadianJournalof
Zoology67:651‐657.
MacArthur,R.A.,andA.P.Dyck.1990.Aquaticthermoregulationofcaptiveandfree‐rangingbeavers(Castorcanadensis).
CanadianJournalofZoology68:2409‐2416.
McNew,L.B.,Jr.,andA.Woolf.2008.Dispersalandsurvivalofjuvenilebeavers(Castorcanadensis)insouthernIllinois.
AmericanMidlandNaturalist154:217‐228.
Sun,L.,D.Müeller‐Schwarze,B.A.Schulte.2000.Dispersalpatternsandeffectivepopulationsizeofthebeaver.Canadian
JournalofZoology78:393‐398.
VanDeelen,T.R.,andD.H.Pletscher.1996.Dispersalcharacteristicsoftwo‐year‐oldbeavers,Castorcanadensis,inwestern
Montana.CanadianField‐Naturalist110:318‐321.
296
Colorado Natural Heritage Program © 2015 Desert Bighorn Sheep
Oviscanadensisnelsoni
G4/S4
Family:Bovidae
No photo available
Climate Vulnerability Rank: Moderately Vulnerable
ThisColoradostate‐widerankisbasedon:transportationcorridorsthatcanlimitO.canadensis
nelsonidispersal;likelyincreaseindroughtconditionsthroughitsrange;geneticbottlenecks;and
modeledimpactsfromclimatechange.Despitethesethreats,O.canadensisnelsoniarewelladapted
todroughtconditions,havebroadrangesthatmayallowsomepopulationstomigrateawayfrom
inhospitablehabitatsandconditions,andhaveshownflexibilityintimingofparturitionthatmay
bettermatchperiodsofheightenedresourceavailability.
Distribution:O.canadensisnelsoniarefoundinwesternColoradoinafewspecificpopulations
neartheUtahborder.Habitat:canbefoundinavarietyofhabitats,butpreferareaswithhigh‐
visibilitywithgrass,lowshrubs,muchrockcoverandtopographicrelief,andwithabundantopen
areasforescape.Elevation:Varies,buttypicallylessthan10,000feet.
EcologicalSystem:Cliffs,grasslands
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral.Thereissomedesertbighornsheep
habitatnorthofcurrentreintroductionsites(BlackRidge,Uncompahgre,andDoloresRiver
populations),butitisseparatedbylowerelevationvalleys.Givenbighornsheepabilitytoutilize
lowerelevationhabitats(KrausmanandBowyer2003),populationshavethepotentialtomigrate
northasclimateschange.
Climate Change Vulnerability Assessment for Colorado BLM 297 B2b)Distributionrelativetoanthropogenicbarriers.IncreaseVulnerability.Urban,suburban,
andtransportationdevelopmentborderbighornsheeppopulationstothenorth.Thesemaybe
minimallyrestrictiveinsomeareas,butmajortransportationcorridorscanprohibitmovementand
restrictgeneflow(Eppsetal.2005).Additionally,becausehuntedbighornsheepshowagreater
responsetohumandisturbance(Geist1971,KingandWorkman1986)thisdevelopmentpressure
andthehumanpopulationsinproximitytoitmayfurtherprohibitmigration.Becauseitisunclearif
thepotentialisolationandsheepbehaviorareidenticaltothosedocumentedinCalifornia
populations,thisisconsidered“increasevulnerability”insteadof“greatlyincreasevulnerability”.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
Neithersolar,wind,orbiomassenergyproductionappeartobehigh‐rewardtargetsforthisregion
ofwesternColoradobasedonNationalRenewalEnergymaps
(apps1.eere.energy.gov/states/maps.cfm/state=CO).
C1)Dispersalandmovements.DecreaseVulnerability.Bighornsheepcanmoveupto70km
betweenseasonalranges(Beechametal.2007).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Muchofthe
desertbighornrangeinColoradofallswithinthe55‐77°Frange.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.SomewhatDecrease
Vulnerability.Hottertemperaturesdonotappeartochallengebighornphysiology(Turner1973).
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.SomewhatIncreaseVulnerability.BasedontheClimateWizardmap
ofhistorichydrologicvariation,muchofthedesertbighornsheeprangeinColoradovariesfromthe
lowestvariationtomid‐levelsofvariability.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.NeutraltoSomewhatDecrease.Desertbighornsheeparewell
adaptedtoheatanddroughtstress,evenabletoconcentrateurinebetterthancamels(Turner
1973).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncrease.Desertbighornsheepareoccasionallyexposedtoandadaptedtodrought
conditions.However,therecenttrendsinwarminganddroughtmaybeimpactingviability.
Prolongeddroughtcancauseincreasedsheepmortality(Monson1960),impactrecruitment
(Wehausenetal.1987),andcontributetodecreasedpopulationviability(WeaverandMensch
1971).Climatedatasuggestthatdroughtwillpossiblyincreaseinfrequency,intensityandduration.
Diseaseisacommonfactorcausingperiodicdesertbighorndecline(Singeretal.2001).
C2d)Dependenceonsnow‐coveredhabitats.Neutral.Thereisnoknownrelationshipofthis
speciestosnoworice‐coveredhabitats.
298
Colorado Natural Heritage Program © 2015 C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.Thisspeciesisnot
knowntospecializeonuncommongeologicalfeatures.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Norelianceonotherspeciesfor
habitatgeneration.
C4b)Dietaryversatility.Neutral.Desertbighornsheepareherbivorous,feedinglargelyon
grassesandforbs,supplementingthisdietwithsomeshrubs(Armstrongetal.2011).
C5a)Measuredgeneticvariation.Neutral.Geneticdiversityofdesertbighornpopulationsis
relativelyhighinsomepopulations(Gutierrez‐Espeletaetal.2000)whilelowinothers(Hedrick
andWehausen2014).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.SomewhatIncrease
VulnerabilitytoNeutral.Populationisolationandreintroductioneffortswithsmallpopulations
havecreatedgeneticbottlenecksinsomeregions(Rameyetal.2001,Hedricketal.2001).
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
SomewhatDecreaseVulnerabilitytoNeutral.Desertbighornsheephaveshownsite‐specific
variabilityinparturitionthatallowsflexibilitytocapitalizingonavailableresources,butthismay
comewithfitnessconsequencesfornewlyreintroducedpopulations(Whitingetal.2011)
D1)Responsetorecentclimatechange.Neutral.Nothingreported.
D2)Modeledfuturechangeinpopulationorrangesize.SomewhatIncreaseVulnerability.Epps
etal.(2004)modeledthepotentialoffuturepopulationdeclineoverthenext60years.With
minimumtemperaturechangescenariosaverageextinctionprobabilityofpopulationswas20%.
Whencombinedwiththeprojecteddeclineinprecipitationtheprobabilityincreasedto30%.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.Nothingdocumented.
D4)Protectedareas.SomewhatIncreaseVulnerability.Withinthecurrentrangetherearefew
protectedareasthatwouldprotectpopulations.
Literature Cited
Armstrong,D.M.,J.P.Fitzgeraldand,C.A.Meaney.2011.MammalsofColorado,2ndEdition.UniversityPressofColorado.
704pp.
BeechamJr,J.J.,C.P.Collins,andT.D.Reynolds.2007.RockyMountainBighornSheep(OvisCanadensis):atechnical
conservationassessment.[Online].USDAForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/rockymountainbighornsheep.pdf[6January2015].
Epps,C.W.,D.R.McCullough,J.D.Wehausen,V.C.Bleich,andJ.L.Rechel.2004.Effectsofclimatechangeonpopulation
persistenceofdesert‐dwellingmountainsheepinCalifornia.ConservationBiology18:102‐113.
Epps,C.W.,P.J.Palsbell,J.D.Wehausen,G.K.Roderick,R.R.Ramey,andD.R.McCullough.2005.Highwaysblockgeneflow
andcausearapiddeclineingeneticdiversityofdesertbighornsheep.EcologyLetters8:1029‐1038.
Climate Change Vulnerability Assessment for Colorado BLM 299 Geist,V.1971.Mountainsheep:astudyinbehaviorandevolution.UniversityofChicagoPress,Chicago,383pp.
Gutierrez‐Espeleta,G.A.,S.T.Kalinowski,W.M.Boyce,andP.W.Hedrick.2000.Geneticvariationandpopulationstructure
indesertbighornsheep:implicationsforconservation.ConservationGenetics1:3‐15.
Hedrick,P.W.,G.A.Gutierrez‐Espeleta,andR.N.Lee.2001.Foundereffectsinanislandpopulationofbighornsheep.
MolecularEcology10:851‐857.
Hedrick,P.W.,andJ.D.Wehausen.2014.Desertbighornsheep:changesingeneticvariationovertimeandtheimpactof
mergingpopulations.JournalofFishandWildlifeBiology5:3‐13.
King,M.M.,andG.W.Workman.1986.Responseofdesertbighornsheeptohumanharassment:managementimplications.
TransactionsoftheNorthAmericanWildlifeandNaturalResourcesConference51:74‐85.
Krausman,P.R.,andR.T.Bowyer.2003.Mountainsheep,OviscanadensisandO.dalli.Pp.1095‐1115inWildmammalsof
NorthAmerica:biology,management,andeconomics.2nded.(G.A.Feldhamer,B.C.Thompson,andJ.A.Chapman,eds.).
JohnHopkinsUniversityPress,Baltimore,MD.1216pp.
Monson,G.1960.Effectsofclimateondesertbighornnumbers.DesertBighornCouncilTransactions4:12‐14.
Ramey,R.R.,G.Luikart,andF.J.Singer.2001.Geneticbottlenecksresultingfromrestorationefforts:thecaseofthedesert
bighornsheepinBadlandsNationalPark.RestorationEcology8:85‐90.
Singer,F.J.,L.C.Zeigenfuss,andL.Spicer.2001.Roleofpatchsize,disease,andmovementinrapidextinctionofbighorn
sheep.ConservationBiology15:1347‐1354.
Turner,J.C.1973.Water,energyandelectrolytebalanceinthedesertbighornsheep,Oviscanadensis.PhDThesis.
UniversityofCalifornia,Riverside.138pp.
Weaver,R.A.,andJ.L.Mensch.1971.BighornsheepinnortheasternRiversideCounty.Wildlifemanagement
administrativereport71‐1.CaliforniaDepartmentofFishandGame,Sacramento,California.
Wehausen,J.D.,V.C.Bleich,B.Blong,andT.L.Russi.1987.RecruitmentdynamicsinasouthernCaliforniamountain
sheeppopulation.JournalofWildlifeManagement51:86‐98.
Whiting,J.C.,R.T.Bowden,J.T.Flinders,andD.L.Eggert.2011.Reintroductionbighornsheep:fitnessconsequencesof
adjustingparturitiontolocalenvironments.JournalofMammalogy92:213‐220.
300
Colorado Natural Heritage Program © 2015 Fringed Myotis
Myotisthysanodes
G4/S3
Family:Vespertilionidae
Climate Vulnerability Rank: Not Vulnerable/Presumed Stable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)fewtonobarrierstomovement;
2) associationwithcavesandminesasgeologicfeaturesmaybeincreasevulnerabilityunder
projectedincreasesintemperatureduetoclimatechange,howeverthisspeciesisnotfound
exclusivelyincavesandmines.
Distribution:InColorado,Thefringedmyotisthisspecieshasbeenfoundsparinglyonboththe
easternandwesternsidesoftheContinentalDivide(Armstrongetal.2011).Habitat:InColorado,
thefringedmyotisisfoundinconiferouswoodlandsandshrublandssuchasponderosapine,
greasewood,oakbrush,andsaltbrush(Armstrongetal.2011).Elevation:Thisspecieshasbeen
recordedupto7,500feetinColorado(Armstrongetal.2011).
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral.Volant–nobarriers
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Volant–nobarriers
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.It
isunlikelythatanyclimatemitigation‐relatedlandusechangeswilloccurwithinthisspecies’range
withinColorado.
C1)Dispersalandmovements.Decrease.Long‐distancedispersalabilities.
Climate Change Vulnerability Assessment for Colorado BLM 301 C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Neutral.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Somewhatincrease.AdamsandHayes(2008)postulatedthat
theimpactofreducedwaterstoragecapacityasaresultofclimatechangeinthearidwestern
UnitedStateswouldnegativelyimpactlactatingfemalesofthisspecies,especiallyatalocalscale.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.
C2d)Dependenceonsnow‐coveredhabitats.Neutral.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.SomewhatIncrease.Thisbat
isfoundincavesandmines,butinColoradoisnotrestrictedtothesefeatures.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.
C4b)Dietaryversatility.Neutral. This species feeds broadly on moths, beetles, and other flying insects
(Keinath 2004; Armstrong et al. 2011).
C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Unknown.
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
302
Colorado Natural Heritage Program © 2015 Literature Cited
Adams,R.A.andM.A.Hayes.2008.Wateravailabilityandsuccessfullactationbybatsasrelatedtoclimatechangeinarid
regionsofwesternNorthAmerica.JournalofAnimalEcology77:1115‐1121.
Armstrong,D.M.,J.P.Fitzgerald,andC.A.Meaney.2011.MammalsofColorado,2ndedition.DenverMuseumofNatureand
ScienceandUniversityPressofColorado,Boulder,CO.
Keinath,D.A.2004.Fringedmyotis(Myotisthysanodes):atechnicalconservationassessment.[Online].USDAForest
Service,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/townsendsbigearedbat.pdf
Climate Change Vulnerability Assessment for Colorado BLM 303 Gunnison Prairie Dog
Cynomysgunnisoni
G5/S5
Family:Sciuridae
Climate Vulnerability Rank: Not Vulnerable/Presumed Stable
DespiteC.gunnisonibeingrankedasStable,thefactorsthatwouldleadittobemorevulnerableare:
predicteddecreasesinprecipitation;habitatloss;prairiedogsusceptibilitytoplague:andlimited
geneticvariability.Currently,noneoftherankingfactorsconsiderthethreatshighenoughthatC.
gunnisoniwouldbeinimminentthreatfromon‐goingclimatechange.Thespeciesabilityto
disperseanditslackofrelianceofmesichabitatsbufferitfromclimatechangethreats.
Distribution:C.gunnisoniisfoundinsouthwesternandsouth‐centralColoradoingrasslands,and
semi‐desertandmontaneshrublands(Armstrongetal.2011).Habitat:C.gunnisoniarehabitat
architects,modifyingthesoilandvegetativecharacteristicsaroundcolonies.Theyinhabit
shortgrassandmid‐grassprairies,shrublandsinlowvalleys,andwetter,high‐elevationprairies.
Elevation:6000‐12000feet.
EcologicalSystem:Grasslands,Shrublands
CCVI Scoring
B1)Exposuretosealevelrise‐Neutral.
B2a)Distributionrelativetonaturalbarriers.NeutraltoSomewhatIncreaseVulnerability.
TherearevariouslowpassesinandoutofprairiedograngeinColoradothatwillnotpreventthe
GunnisonPrairiedogfromemigrating,butmaylimitdispersalifsubjectedtoclimate‐causedshifts.
Populationsareknowntohaveoccurredashighas~12,000’elevationinColorado(Armstronget
304
Colorado Natural Heritage Program © 2015 al.2011).However,theUSFWS(2010)pointedoutthatnumerouspartsoftherangeareseparated
bymountainrangesthatalmostcompletelylimitprairiedogmovementbetweenthem.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Muchoftheprairiedograngein
Coloradoisonpublicland.FutureplanningscenariosforSouthParksuggestincreasedsuburban
andinfrastructuredevelopmentthatmaylimitdispersalcapacityforpopulationsinthisregion.
Muchoftherangeisnothinderedbyanthropogenicdisturbancetogreatlylimitrangewideclimate‐
causeddispersal.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutralto
SomewhatIncreaseVulnerability.Wind‐energydevelopmentisincreasinginColorado.Alongthe
easternedgesoftheGunnisonandSanLuisvalleyswindspeedsareattractiveandmaytargetwind‐
energydevelopmentinthisareaoftheprairiedogsrange.Similarly,solarenergymaybetargeted
fortheSanLuisValleywheresolarexposureispromising(NaturalResourcesEnergyLaboratory,
ConcentratingSolarPowerEnergymapforColorado,2007andGlobalSolarRadiationatLatitude
TiltmapforColorado,2007).Itisunclearhowthisspeciesrespondstoenergydevelopment,butit
islikelysuchdevelopmentwouldfurthersegmentpopulations.
C1)Dispersalandmovements.SomewhatDecrease.Themovementsanddispersalarepoorly
studiedinthisspecies.However,inotherspeciesofprairiedogsmovementsareknowntobe
around2‐8km(GarrettandFranklin1988;Knowles1985).SeglundandSchnurr(2010)reported
dispersaldistancesaslongas7.7km.
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Basedon
ClimateWizard.orgPastExposureTemperatureVariation,muchofGunnison’sprairiedograngein
Coloradoisfrom55‐77°F.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.NeutraltoSomewhat
IncreaseVulnerability.Becausethisspeciesofprairiedogisanobligatehibernator(Shalawayand
Slobodchikoff1988)itsoverwintersurvivalcanbechallengedifoverwinterthermalconditionsdo
notmaintainlong,stableperiodsofcoldtemperatures(Arnoldetal.1991,Schorretal.2009).Thus,
ifthermalconditionsarenotappropriateforhibernation,survivalmaybedepressed.
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.SomewhatIncrease.BasedonClimateWizard.orgAverageAnnual
Precipitation1951‐2006,muchofGunnison’sprairiedograngeinColoradoismiddle‐to‐low
precipitationvariation.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.NeutraltoSomewhatDecrease.Gunnison’sprairiedogsinhabit
grasslandsandsemidesertandmontaneshrublands(Armstrongetal.2011).Vegetationconditions
ofmanylandswithintherangeofGunnison’sprairiedoghavebeenalteredthroughgrazing
(Fleischner1994).Theprairiedogsarepossiblymoresusceptibletostressfromdroughtwhere
nativevegetationhasbeenseverelyaltered(SeglundandSchnurr2010).Mostvegetationwithin
Climate Change Vulnerability Assessment for Colorado BLM 305 usedhabitathassomeleveloftolerancetoaridconditionsandmaynotbedramaticallyimpacted
byincreaseddryingpredictedbyclimatemodeling.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncreasetoIncrease.Themostdramaticandrecurringdisturbancethatcanimpact
Gunnison’sprairiedogsisplague(Cullyetal.1997).Gunnison’sprairiedogsareoccasionally
exposedtodroughtconditions.Theseconditionscausestressandevenpopulationreduction/local
extirpationintheblack‐tailedprairiedog(Fackaetal.2010).Climatedatasuggestthatdroughtwill
possiblyincreaseinfrequency,intensityandduration.
C2d)Dependenceonsnow‐coveredhabitats.Neutral.Thereisnoknownrelationshipofthis
speciestosnoworice‐coveredhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.Thisspeciesisnot
knowntospecializeonuncommongeologicalfeatures.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Generatesandmodifiesitsown
habitatbyburrowingandgrazing.
C4b)Dietaryversatility.Neutral.Gunnison’sprairiedogisanherbivore,feedinglargelyon
grassesandforbs,supplementingthisdietwithsomeshrubs(FitzgeraldandLechleitner1974;
Longhurst1944).
C5a)Measuredgeneticvariation.NeutraltoSomewhatIncreaseVulnerability.Geneticdiversity
inthisspecieswasdeterminedtobelow(Travisetal.1997).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.onlyif5Aisunknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Neutral.Noobservationsmade.
D1)Responsetorecentclimatechange.Neutral.Nothingreported.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Neutral.
Literature Cited
Armstrong,D.M.,J.P.Fitzgeraldand,C.A.Meaney.2011.MammalsofColorado,2ndEdition.UniversityPressofColorado.
704pp.
Arnold,W.,G.Heldmaier,S.Ortmann,H.Pohl,T.Ruff,andS.Stenlechner.1991.Ambienttemperaturesinhibernaculaand
theirenergeticconsequencesforalpinemarmots(Marmotamarmota).JournalofThermalBiology16:223‐226.
306
Colorado Natural Heritage Program © 2015 Cully,Jr.,J.F.,A.M.Barnes,T.J.Quan,andG.Maupin.1997.DynamicsofplagueinaGunnison’sprairiedogcolonycomplex
fromNewMexico.JournalofWildlifeDiseases33:706‐719.
Facka,A.N.,etal.2010.Droughtleadstocollapseofblack‐tailedprairiedogpopulationsreintroducedtotheChihuahuan
Desert.JournalofWildlifeManagement74:1252‐1762.
Fitzgerald,J.P.andR.R.Lechleitner.1974.ObservationsonthebiologyofGunnison’sprairiedogincentralColorado.J.
Colorado‐WyomingAcad.Sci.21:22.
Fleischner,T.L.1994.EcologicalcostsoflivestockgrazinginwesternNorthAmerica.ConservationBiology8:629‐644.
Garrett,M.G.,andW.L.Franklin.1988.Behavioralecologyofdispersalintheblack‐tailedprairiedog.Journalof
Mammalogy69:236‐250.
Knowles,C.J.1985.ObservationonprairiedogdispersalinMontana.PrairieNaturalist17:33‐40.
Longhurst,W.1944.ObservationsontheecologyoftheGunnisonprairiedoginColorado.JournalofMammalogy25:24‐
36.
Schorr,R.A.,P.M.Lukacs,andG.L.Florant.2009.Bodymassandwinterseverityaspredictorsofoverwintersurvivalin
Preble’smeadowjumpingmouse.JournalofMammalogy90:17‐24.
Seglund,A.E.andP.M.Schnurr.2010.ColoradoGunnison’sandwhite‐tailedprairiedogconservationstrategy.Colorado
DivisionofWildlife,Denver,Colorado,USA.
Shalaway,S.,andC.N.Slobodchikoff.1988.SeasonalchangesinthedietofGunnison’sprairiedog.JournalofMammalogy
69:835‐841.
Travis,S.E.,C.N.Slobodchikoff,andP.Keim.1997.DNAfingerprintingrevealslowgeneticdiversityinGunnison’sprairie
dog(Cynomysgunnisoni).JournalofMammalogy78:725‐732.
U.S.FishandWildlifeService.2010.SpeciesassessmentandlistingpriorityassignmentforCynomysgunnisoni(central
andsouth‐centralColorado,north‐centralNewMexico).Available:
http://ecos.fws.gov/docs/candidate/assessments/2010/r6/A0IB_V01.pdf
Climate Change Vulnerability Assessment for Colorado BLM 307 Townsend’s Big‐eared Bat
Corynorhinustownsendiipallescens
G3G4T3T4/S2
Family:Vespertilionidae
Climate Vulnerability Rank: Not Vulnerable/Presumed Stable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)fewtonobarrierstomovement;
2) associationwithcavesandminesasgeologicfeaturesmaybeincreasevulnerabilityunder
projectedincreasesintemperatureduetoclimatechange.
Distribution:InColorado,Townsend’sbig‐earedbatoccursthroughoutthewesterntwo‐thirdsof
thestate,includingthesoutheasterncanyonlands(Armstrongetal.2011).Habitat:InColorado,
Townsend’sbig‐earedbatsoccurinawiderangeofhabitatsincludingsemi‐desertshrublands,
pinyon‐juniperwoodlands,anddryconiferousforests(Armstrongetal.2011).Itismostoften
foundroostingincavesandmines,butusesbuildings,crevices,andclifffacesduringthesummer
(Armstrongetal.2011).Elevation:Thisspecieshasbeenrecordedupto9,500feetinColorado
(Armstrongetal.2011).
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral.Volant–nobarriers
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Volant–nobarriers
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.It
isunlikelythatanyclimatemitigation‐relatedlandusechangeswilloccurwithinthisspecies’range
withinColorado.
308
Colorado Natural Heritage Program © 2015 C1)Dispersalandmovements.Decrease.Long‐distancedispersalabilities.
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Neutral.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Neutral/Somewhatincrease.AdamsandHayes(2008)
postulatedthattheimpactofreducedwaterstoragecapacityasaresultofclimatechangeinthe
aridwesternUnitedStateswouldnegativelyimpactlactatingfemalesofMyotisthysanodes,
especiallyatalocalscale.ThisproposedimpactcouldaffectotherspeciessuchasCorynorhinus
townsendiiaswell.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.
C2d)Dependenceonsnow‐coveredhabitats.Neutral.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.SomewhatIncrease.Thisbat
isacaveandmineobligate,butinColoradoisfoundinminesmorefrequentlythancaves.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.
C4b)Dietaryversatility.Neutral.Thisspeciesisamothspecialist,butwillfeedopportunistically
onotherflyinginsects(GruverandKeinath2006).
C4c)Pollinatorversatility(Plantsonly,notapplicable).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Unknown.
C5a)Measuredgeneticvariation.NeutraltoSomewhatDecrease.Inananalysisofgenetic
diversityamongsubspeciesofC.townsendii,Piaggioetal.(2009)foundthatC.t.pallescenshada
levelofdiversitysimilartoC.t.townsendiiandbothofthesesubspecieshadagreaterlevelof
diversitythantheendangeredC.t.virginianusasmeasuredbytheaveragenumberofallelesper
locusandaverageallelicrichnessperpopulation.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
Climate Change Vulnerability Assessment for Colorado BLM 309 D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
Adams,R.A.andM.A.Hayes.2008.Wateravailabilityandsuccessfullactationbybatsasrelatedtoclimatechangeinarid
regionsofwesternNorthAmerica.JournalofAnimalEcology77:1115‐1121.
Armstrong,D.M.,J.P.Fitzgerald,andC.A.Meaney.2011.MammalsofColorado,2ndedition.DenverMuseumofNatureand
ScienceandUniversityPressofColorado,Boulder,CO.
Gruver,J.C.,andD.A.Keinath.2006.Townsend’sBig‐earedBat(Corynorhinustownsendii):atechnicalconservation
assessment.[Online].USDAForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/townsendsbigearedbat.pdf
Piaggio,A.J.,K.W.Navo,andC.W.Stihler.2009.Intraspecificcomparisonofpopulationstructure,geneticdiversity,and
dispersalamongthreesubspeciesofTownsend'sbig‐earedbats,Corynorhinustownsendiitownsendii,C.t.pallescens,and
theendangeredC.t.virginianus.ConservationGenetics10:143‐159.
310
Colorado Natural Heritage Program © 2015 White‐tailed Prairie Dog
Cynomysleucurus
G4/S4
Family:Sciuridae
Climate Vulnerability Rank: Not Vulnerable/Presumed Stable
SimilartoC.gunnisoni,C.leucurusisconsideredStable,butthefactorsthatwouldleadittobemore
vulnerableare:predicteddecreasesinprecipitation;necessityforcoldenvironsforhibernation;
habitatloss;prairiedogsusceptibilitytoplague:andlimitedgeneticvariability.Currently,noneof
therankingfactorsconsiderthethreatshighenoughthatC.leucuruswouldbeinimminentthreat
fromon‐goingclimatechange.Thespeciesabilitytodisperseanditslackofrelianceofmesic
habitatsbufferitfromclimatechangethreats.
Distribution:C.leucurusisfoundinnorthwestandwest‐centralColoradoinsemi‐aridgrasslands
andshrublands,andmountainvalleys(Armstrongetal.2011).Habitat:C.leucurusaremoreoften
foundinsemidesertshrublands,butoccasionallyinvadingpasturesandagriculturallandsatlower
elevations(Armstrongetal.2011).Elevation:typicallybelow8,500ft.
EcologicalSystem:Grasslands,Shrublands
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral.Therearenoobviousnaturalbarriersto
white‐tailedprairiedogmovementinColorado.Populationsareknowntohaveoccurredashighas
~10,000’elevationinColorado(Armstrongetal.2011).
Climate Change Vulnerability Assessment for Colorado BLM 311 B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Muchoftheprairiedograngein
Coloradoisonpubliclandandmuchoftherangeisnothinderedbyanthropogenicdisturbanceto
greatlylimitrangewideclimate‐causeddispersal.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
Wind‐energydevelopmentisincreasinginColorado.InnorthwesternColoradowindspeedsmaybe
attractiveforwind‐energydevelopmentinthisareaoftheprairiedogsrange.However,itis
unlikelythatdevelopmentwillsignificantlyimpactbymitigation‐relatedlandusechanges.
C1)Dispersalandmovements.SomewhatDecrease.Maximummovementdistancesdocumented
forwhite‐tailedprairiedogsis8km(Cooke1993,citedinSeglundetal.2006),butmost
documentedmovementsarelessthanthis.
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Basedon
ClimateWizard.orgPastExposureTemperatureVariation,muchofwhite‐tailedprairiedograngein
Coloradoisfrom55‐77°F.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.NeutraltoSomewhat
IncreaseVulnerability.Becausethisspeciesofprairiedogisanobligatehibernator(Harlow1995)
itsoverwintersurvivalcanbechallengedifoverwinterthermalconditionsdonotmaintainlong,
stableperiodsofcoldtemperatures(Arnoldetal.1991,Schorretal.2009).Thus,ifthermal
conditionsarenotappropriateforhibernation,survivalmaybedepressed.
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.SomewhatIncrease.BasedonClimateWizard.orgAverageAnnual
Precipitation1951‐2006,muchofwhite‐tailedprairiedograngeinColoradoismiddle‐to‐low
precipitationvariation.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche..NeutraltoSomewhatDecrease.White‐tailedprairiedogs
inhabitaridgrasslandsandshrublandsinColorado(Armstrongetal.2011).Mostvegetationwithin
usedhabitathassomeleveloftolerancetoaridconditionsandmaynotbedramaticallyimpacted
byincreaseddryingpredictedbyclimatemodeling.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncreasetoIncrease.Themostdramaticandrecurringdisturbancethatcanimpact
white‐tailedprairiedogsisplague(MenkensandAnderson1991).White‐tailedprairiedogsare
occasionallyexposedtodroughtconditions.Theseconditionscausestressandevenpopulation
reduction/localextirpationintheblack‐tailedprairiedog(Fackaetal.2010).Climatedatasuggest
thatdroughtwillpossiblyincreaseinfrequency,intensityandduration.
C2d)Dependenceonsnow‐coveredhabitats.Neutral.Thereisnoknownrelationshipofthis
speciestosnoworice‐coveredhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.Thisspeciesisnot
knowntospecializeonuncommongeologicalfeatures.
312
Colorado Natural Heritage Program © 2015 C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Generatesandmodifiesitsown
habitatbyburrowingandgrazing.
C4b)Dietaryversatility.Neutral.White‐tailedprairiedogslargelyfeedongrassesandforbs,
supplementingthisdietwithsomeshrubs(Armstrongetal.2011).
C5a)Measuredgeneticvariation.NeutraltoSomewhatIncreaseVulnerability.Geneticdiversity
inthisspecieswasdeterminedtobelowcomparetoblack‐tailedprairiedogs(Cooke1993,citedin
Seglundetal.2006).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Onlyif5Aisunknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.Noobservationsmade.
D1)Responsetorecentclimatechange.Unknown.Nothingreported.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Neutral.
Literature Cited
Armstrong,D.M.,J.P.Fitzgeraldand,C.A.Meaney.2011.MammalsofColorado,2ndEdition.UniversityPressofColorado.
704pp.
Arnold,W.,G.Heldmaier,S.Ortmann,H.Pohl,T.Ruff,andS.Stenlechner.1991.Ambienttemperaturesinhibernaculaand
theirenergeticconsequencesforalpinemarmots(Marmotamarmota).JournalofThermalBiology16:223‐226.
Cooke,L.1993.TheroleoflifehistorytraitsintheevolutionofsocialityintheWTPD(Cynomysleucurus).Finalreportto
ArapahoNationalWildlifeRefuge,Walden,CO.CollegeoftheHolyCross,Worchester,MA.
Facka,A.N.,etal.2010.Droughtleadstocollapseofblack‐tailedprairiedogpopulationsreintroducedtotheChihuahuan
Desert.JournalofWildlifeManagement74:1252‐1762.
Harlow,H.J.1995.Fastingbiochemistryofrepresentativespontaneousandfacultativehibernators:thewhite‐tailed
prairiedogandtheblack‐tailedprairiedog.PhysiologicalZoology68:915‐934.
Menkens,Jr.,G.E.,andS.H.Anderson.1991.Populationdynamicsofwhite‐tailedprairiedogsduringanepizooticof
sylvaticplague.JournalofMammalogy72:328‐331.
Schorr,R.A.,P.M.Lukacs,andG.L.Florant.2009.Bodymassandwinterseverityaspredictorsofoverwintersurvivalin
Preble’smeadowjumpingmouse.JournalofMammalogy90:17‐24.
Seglund,A.E.,A.E.Ernst,M.Grenier,B.Luce,A.Puchniak,andP.Schnurr.2006.White‐tailedprairiedogconservation
assessment.WesternAssociationofFishandWildlifeAgencies,Laramie,WY.136pp.
Climate Change Vulnerability Assessment for Colorado BLM 313 Desert Spiny Lizard
Sceloporusmagister
G5/S2
Family:Phrynosomatidae
Climate Vulnerability Rank: Not Vulnerable/Presumed Stable
ThisColoradostatewiderankisbasedon:theDesertspinylizardspreferenceforwarm
temperaturescoupledwiththeincreasingtemperaturesprojectedunderclimatechange,a
thermoregulatoryrangeof27⁰to37⁰C(Brattstrom1965)whichshouldallowthelizardtocope
withrisingtemperatures,thelizard’spreferenceforaridandhotlandscapesthatareactually
expectedtoincreaseinsizewithintheassessedareaduetoincreaseddroughtandtemperatures
projectedunderclimatechange,anda20percentexpansionintherangeofthelizardinthe
assessedareaasaresultofclimatechange(Buckley2010).Climatemodelsprojectincreased
warminganddroughtacrosstheassessedareawithannualaveragetemperaturesrisingby2.5°Fto
5.5°Fby2041‐2070andby5.5°Fto9.5°Fby2070‐2099withcontinuedgrowthinglobalemissions
(A2emissionsscenario),withthegreatestincreasesinthesummerandfall(Melilloetal.2014).
Distribution:InColorado,thislizardoccursintheextremesouthwesterncorneroftheStateat
elevationsbelow5,100feet(Hammerson1999).Habitat:ThehabitatinColoradoincludesshrub‐
covereddirtbanksandsparselyvegetatedrockyareasnearflowingstreamsandarroyos.They
prefersoftsoilsbeneathgreasewood,rabbitbrush,saltcedar,andothershrubsandfrequently
perchonlargerocksorinshrubsandtrees(Hammerson1999).
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral.Largeriversandlakesactaseffective
barriersforthisspeciesasdootherwaterobstructionssuchaspondsandmarshes(NatureServe
314
Colorado Natural Heritage Program © 2015 2014),butsmallerwaterobstacleswouldnotimpedelargescalemigratorymovementslikeshifts
indistributionduetoachangingclimate.However,therearenolargeriversorwaterbodieswithin
theassessmentareathatwouldpreventlargescalemovementsoftheDesertspinylizard.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Busyhighways,highwayswith
obstructions,andurbanareascanactasbarrierstodispersal(NatureServe2014),butinthe
assessmentareatherearenolarge,busyhighwaysorlargeurbancenters,rathertherearefew
roadsandsmallhumanpopulations.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
Changesinlanduseassociatedwithclimatechangearenotconsideredathreat.
C1)Dispersalandmovements.Neutral.Desertspinylizardjuvenileswilldisperseseveral100
metersfromtheirnatalareabeforeestablishingaterritoryoftheirown(TannerandKrogh1973)
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Therange
occupiedbytheDesertspinylizardintheassessedareahasexperiencedanaverage(51.7‐77°
F/31.8‐43.0°C)zonalmeanseasonaltemperatureoverthelast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Somewhatdecrease.
TheDesertspinylizardprefersratherwarmtemperatures,attemptingtothermoregulatesuchthat
ithasameanbodytemperatureofabout35⁰C(range27⁰to37⁰C)(Brattstrom1965).
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Increase.TherangeoccupiedbytheDesertspinylizardinthe
assessedareahasexperiencedaverage(4‐10inches/100‐254mm)precipitationvariationinthe
past50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Neutraltosomewhatdecrease.TheDesertspinylizardis
adaptedtoaridlandscapesinhabitingareasreceivinglessthan30centimetersofrainperyear(Vitt
andOhmart1974)andwiththeincreasedprojectionsfordroughtduetoclimatechangeinthe
assessmentarea(Melilloetal.2014),changingclimatecouldevenbenefitthespecies.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.TheDesertspinylizardisnotdependentuponspecificdisturbanceregimessuchasfires,
floods,severewinds,pathogenoutbreaks,orsimilarevents.
C2d)Dependenceonsnow‐coveredhabitats.Neutral.TheDesertspinylizardisnotdependent
onhabitatswithice,snow,oronsnowpack.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Somewhatincrease.Desert
spinylizardsarerestrictedtosparselyvegetatedrockyareasnearflowingstreamsorarroyos
withintheassessmentarea(Hammerson1999).Suchareas,althoughnothighlyuncommonwithin
theassessmentarea,arecertainlynotadominantlandscapetype
Climate Change Vulnerability Assessment for Colorado BLM 315 C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.TheDesertspinylizardisnot
dependentonanyotherspeciestocreatesuitablehabitatforitsexistence.
C4b)Dietaryversatility.Neutral.Desertspinylizardsareopportunisticpredatorswithaflexible
diet,feedingmainlyonavarietyofinsectswithsomesmalllizardsandplantmaterialalsotaken
(Hammerson1999).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.TheDesertspinylizardisa
self‐disperser.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Neutral.Noother
interspecificinteractionsareimportanttothepersistenceoftheDesertspinylizard.
C5a)Measuredgeneticvariation.Neutral.ThegeneticvariationoftheDesertspinylizardis
aboutaverage,whencomparedtorelatedtaxa(Woodetal.2013).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Somewhatdecrease.Thepredicted
futurerangeoftheDesertspinylizardisexpectedtoincreasewithintheassessmentareabymore
than20percent(Buckley2010).
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
Brattstrom,B.H.1965.BodyTemperaturesofReptiles.AmericanMidlandNaturalist73:376‐422.
Buckley,L.B.2010.Therangeimplicationsoflizardtraitsinchangingenvironments.GlobalEcologyandBiogeography,
19:452‐464.
Hammerson,G.A.1999.AmphibiansandreptilesinColorado.2nded.UniversityPressofColorado,Boulder,Colorado.364
pp.
Melillo,J.M.,T.C.Richmond,andG.W.Yohe,Eds.,2014:ClimateChangeImpactsintheUnitedStates:TheThirdNational
ClimateAssessment.U.S.GlobalChangeResearchProgram,841pp.doi:10.7930/J0Z31WJ2.
NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org.(Accessed:February17,2015).
Tanner,W.W.andJ.E.Krogh.1973.EcologyofSceloporusmagisterataNevadatestsite,NyeCounty,Nebraska.Great
BasinNaturalist,33:133‐146.
316
Colorado Natural Heritage Program © 2015 Vitt,L.J.andR.D.Ohmart.1974.ReproductionandEcologyofaColoradoRiverPopulationofSceloporusmagister(Sauria:
Iguanidae).Herpetologica,30:410‐417.
Wood,D.A.,A.G.Vandergast,K.R.Barr,R.D.Inman,T.C.Esque,K.E.NussearandR.N.Fisher.2013.Comparative
phylogeographyrevealsdeeplineagesandregionalevolutionaryhotspotsintheMojaveandSonoranDeserts.Diversity
andDistributions,19:722–737
Climate Change Vulnerability Assessment for Colorado BLM 317 Longnose Leopard Lizard
Gambeliawislizenii
G5/S1
Family:Crotaphytidae
Climate Vulnerability Rank: Not Vulnerable/Presumed Stable
ThisColoradostate‐widerankisbasedon:G.wislizeniirestrictedtoanareaofColoradothathas
seenlittletemperatureandhydrologicvariabilityandtheirsusceptibilitytohabitatlossfrom
encroachingweedygrasses.However,G.wislizeniiiswell‐adaptedtodroughtstress.
Distribution:G.wislizeniiisattheeasternlimitofitsrangeinwesternandsouthwesternColorado.
Habitat:G.wislizeniicanbefoundinflat,aridandsemiaridplainsandcanyonlandswithvarious
desertshrubs,includingsagebrush,greasewood,saltbush,andjunipers.Elevation:below6,000
feet.
EcologicalSystem:Xericshrublandswithmuchbareground.
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.SomewhatIncreaseVulnerabilitytoNeutral.
Areasofexcessivegrasscovercanprohibitlizarduse(Schorretal.2011),butitisuncleartowhat
degreesuchexpansesofgrassexistaroundhabitatsinColorado.However,somepopulationsin
westernColoradoareborderedtothenorthbylargeriversthatmaybeunpassable.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Therearefewknownhuman
barrierstodispersalwherelizardsarefound.
318
Colorado Natural Heritage Program © 2015 B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
Neithersolar,wind,orbiomassenergyproductionappeartobehigh‐rewardtargetsforthisregion
ofwesternColoradobasedonNationalRenewalEnergymaps
(apps1.eere.energy.gov/states/maps.cfm/state=CO).
C1)Dispersalandmovements.Neutral.Individualscanmoveupto1.5km(ParkerandPianka
1976,SchorrandLambert2010).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Muchofthe
desertbighornrangeinColoradofallswithinthe55‐77°Frange.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.SomewhatDecrease
Vulnerability.Hottertemperaturesdonotappeartochallengelizardphysiology.InColorado,mean
soilsurfacetemperatureswherelizardswerefoundwas100°F(SchorrandLambert2010).
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.IncreaseVulnerability.BasedontheClimateWizardmapofhistoric
hydrologicvariation,muchoftheleopardlizardrangeinColoradoininthelowervariabilityrange.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.NeutraltoSomewhatDecrease.Leopardlizardsareadaptedto
heatanddroughtstress.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
NeutraltoSomewhatIncreaseVulnerability.Leopardlizardsarenotdependentonparticular
disturbanceregimes.However,undisturbedhabitatswithintheirrangeappeartopreventexpanse
ofinvasivegrasses(Westobyetal.1989,Hammerson1999).
C2d)Dependenceonsnow‐coveredhabitats.Neutral.Thereisnoknownrelationshipofthis
speciestosnoworice‐coveredhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.Thisspeciesisnot
knowntospecializeonuncommongeologicalfeatures.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thisspeciesdoesnotrelyon
otherspeciesofhabitatdevelopment.
C4b)Dietaryversatility.Neutral.Leopardlizardsfeedonavarietyofinsectsandsome
vertebrates(Hammerson1999).
C5a)Measuredgeneticvariation.Neutral.Therearenodataonthegeneticvariabilityofthis
species.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.onlyif5Aisunknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Neutral.Therearenodataonseasonaldynamics.
Climate Change Vulnerability Assessment for Colorado BLM 319 D1)Responsetorecentclimatechange.Neutral.Nothingreported.
D2)Modeledfuturechangeinpopulationorrangesize.Unknown.
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Neutral.ThesouthwesternColoradopopulationsexistwithinanational
monument,whilethecentral‐westernColoradopopulationsarewithinunprotectedfederallands.
Literature Cited
Hammerson,G.A.1999.AmphibiansandreptilesinColorado.2nded.UniversityPressofColorado,Boulder,Colorado.364
pp.
Parker,W.S.,andE.R.Pianka.1976.Ecologicalobservationsontheleopardlizard(Crotaphytuswislizenii)indifferent
partsofitsrange.Herpetologica32:95‐114.
Schorr,R.A.,andB.Lambert.2010.Longnoseleopardlizard(Gambeliawislizenii)homerangeandhabitatuseon
CannonballMesa,Colorado.ColoradoNaturalProgramReport.17pp.
Schorr,R.A.,B.A.Lambert,andE.Freels.2011.Habitatuseandhomerangeoflong‐nosedleopardlizards(Gambelia
wislizenii)inCanyonsoftheAncientsNationalMonument,Colorado.HerpetologicalConservationandBiology6:312‐323.
Westoby,M.,B.Walker,andI.Noy‐Meir.1989.Opportunisticmanagementforrangelandsnotatequilibrium.Journalof
RangeManagement42:266‐274.
320
Colorado Natural Heritage Program © 2015 Midget Faded Rattlesnake
Crotalusoreganusconcolor
G5T4/S3?
Family:Viperidae
Climate Vulnerability Rank: Highly Vulnerable
ThisColoradostatewiderankisbasedon:theMidgetfadedrattlesnakesrelianceonrockoutcrops
suitablefordenningandthenarrowtemperaturerangessuitableforhibernatingrattlesnakesat
thosedens,barrierstomovementcreatedbylargeriverswithintheassessedarea,fragmentationof
theassessedareabybothpavedandunpavedroadsthatsignificantlyimpairmovement,thelowto
moderategeneticvariabilityofthesnakelesseningtheadaptabilityofthesnaketoclimatechange,
andtheincreaseintemperaturesprojectedfortheassessedareaduetoclimatechange.Climate
modelsprojectincreasedwarminganddroughtacrosstheassessedareawithannualaverage
temperaturesrisingby2.5°Fto5.5°Fby2041‐2070andby5.5°Fto9.5°Fby2070‐2099with
continuedgrowthinglobalemissions(A2emissionsscenario),withthegreatestincreasesinthe
summerandfall(Melilloetal.2014).
Distribution:Coloradoisattheeasternmarginofthesubspecies'range.InColorado,itoccursin
westcentralColoradoinMesa,Delta,Garfield,Montrose,andSanMiguelcounties(CNHP1998).
Habitat:Midgetfadedrattlesnakesoccurininawidevarietyofterrestrialhabitatsincluding
pinyon‐juniperwoodlands,plainsgrasslands,anddesertandmountainshrublands.Theytendto
preferaridtosemi‐aridsitesandtypicallyavoidwetsites.Theywilloccupysiteswithawiderange
ofsoiltypesfromsandytorocky(Hammerson1999).
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.SomewhatIncreasetoneutral.Large,fastflowing
riversareabarriertothisrattlesnake,riversliketheYampa,Colorado,andothersthatoccurwithin
Climate Change Vulnerability Assessment for Colorado BLM 321 theassessedareashouldbeconsideredbarriers(ReedandDouglas2002).Theseriverswillimpede
distributionalshiftsintheassessmentarea,butwillnotgreatlyorcompletelyimpairdistributional
shiftscausedbyclimatechange.Busyhighways,likeInterstate70thatbisectsthedistributionof
therattlesnakeintheassessedarea,alsoimpedemovements,butdonotcompletelyrestrict
movements(NatureServe2014).
B2b)Distributionrelativetoanthropogenicbarriers.Increase.Somewhatincreasetoneutral.
Roads(bothpavedandunpaved)restrictfine‐scalemovementpatternsoftheMidgetfaded
rattlesnakebutnotbroadscalemovements(Spearetal.2011)anddenselyurbanizedareas
dominatedbybuildingsandpavementaresufficientbarrierstomovementfortherattlesnake
(NatureServe2014).TheonlylargecityintheassessmentareaisGrandJunctionandthissingle
urbancentershouldnotsignificantlyimpedetherattlesnake’sabilitytoshiftitsdistributionwithin
theareainresponsetoclimatechange.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Increase.
Neutral.Changesinlanduseassociatedwithclimatechangearenotconsideredathreat.
C1)Dispersalandmovements.Somewhatdecreasetoneutral.Midgetfadedrattlesnakesare
dependentuponwinterdensandmigratetoandfromthosedensonanannualbasis.Althoughthey
havesomeofthelargestactivityrangesreportedinrattlesnakes,annualmovementsstillonly
movementsaveragearound2000metersperyear,only300metersforgravidfemales(Parkerand
Anderson2007).
C2ai)Predictedsensitivitytotemperature:historicalthermalniche.Neutral.Therange
occupiedbytheMidgetfadedrattlesnakeintheassessedareahasexperiencedanaverage(51.7‐
77°F/31.8‐43.0°C)zonalmeanseasonaltemperatureoverthelast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Increase.TheMidget
fadedrattlesnakeisrestrictedtorockoutcropswheretheirhibernaculaarelocated.Modelingof
denninghabitatindicatesaverynarrowtemperaturerangethatrepresentssuitabilityfor
rattlesnakedenning(Spearetal.2011)suggestingthatincreasingtemperaturesprojectedforthe
assessmentarea(Melilloetal.2014)couldnegativelyimpactcurrentlysuitabledenninghabitat,
influencingthefuturedistributionoftheMidgetfadedrattlesnake.
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Neutral.TherangeoccupiedbytheMidgetfadedrattlesnakeinthe
assessedareahasexperiencedaverage(21‐40inches/509‐1,016mm)precipitationvariationin
thepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Somewhatincreasetoneutral.Thereissomeevidenceto
suggestthatreproductivesuccessispositivelyinfluencedbyprecipitation,butlong‐term
continuousmonitoringisneededtounderstandwhetherprecipitationconsistentlyexplains
reproductiveoutputandtopredictthepotentialeffectsoffutureclimatechangeonrattlesnake
recruitment.(Spearetal.2011).
322
Colorado Natural Heritage Program © 2015 C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.TheMidgetfadedrattlesnakeisnotdependentuponspecificdisturbanceregimessuchas
fires,floods,severewinds,pathogenoutbreaks,orsimilarevents.
C2d)Dependenceonsnow‐coveredhabitats.Neutral.TheMidgetfadedrattlesnakeisnot
dependentonhabitatswithice,snow,oronsnowpack.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Increase.Midgetfaded
rattlesnakesrequirerockoutcropsforhibernacula/denning(ParkerandAnderson2007andSpear
etal.2011).
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.TheMidgetfadedrattlesnakeis
notdependentonanyotherspeciestocreatesuitablehabitatforitsexistence.
C4b)Dietaryversatility.Neutral.Midgetfadedrattlesnakesmainlypreyonlizards,buteatabroad
rangeofpreyincludingsmallmammalsandbirds(ParkerandAnderson2007).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.TheMidgetfaded
rattlesnakeisaself‐disperser.
C4e)Formspartofaninterspecificinteractionnotcoveredby4a‐d.Neutral.Noother
interspecificinteractionsareimportanttothepersistenceoftheMidgetfadedrattlesnake.
C5a)Measuredgeneticvariation.Somewhatincreasetoneutral.Overall,geneticdiversityislow
tointermediateacrossmidgetfadedrattlesnake(Spearetal.2011).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)Responsetorecentclimatechange.Unknown.
D2)Modeledfuturechangeinpopulationorrangesize.Decrease.Winterrangeispredictedto
increaseby69%by2080(NAS2014).
D3)Overlapofmodeledfuturerangewithcurrentrange.Unknown.
D4)Protectedareas.Unknown.
Literature Cited
ColoradoNaturalHeritageProgram(CNHP).1998.Midgetfadedrattlesnakeelementglobalrank(EGR)report.Colorado
NaturalHeritageProgram,FortCollins,CO.
Hammerson,G.A.1999.AmphibiansandreptilesinColorado.2nded.UniversityPressofColorado,Boulder,Colorado.364
pp.
Climate Change Vulnerability Assessment for Colorado BLM 323 Melillo,J.M.,T.C.Richmond,andG.W.Yohe,Eds.,2014:ClimateChangeImpactsintheUnitedStates:TheThirdNational
ClimateAssessment.U.S.GlobalChangeResearchProgram,841pp.doi:10.7930/J0Z31WJ2.
NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org[2/6/2015].
Parker,J.M.andS.H.Anderson.2007.Ecologyandbehaviorofthemidgetfadedrattlesnake(Crotalusoreganusconcolor)
inWyoming.JournalofHerpetology,41:41‐51.
Reed,R.N.,andM.E.Douglas.2002.EcologyoftheGrandCanyonrattlesnake(Crotalusviridisabyssus)intheLittle
ColoradoRivercanyon,Arizona.SouthwesternNaturalist47:30‐39.
Spear,S.F.,J.M.Parker,C.R.PetersonandC.L.Jenkins.2011.Conservationandmanagementofmidgetfadedrattlesnakes:
statewildlifegrantfinalreport.TheOrianneSociety,Clayton,GA.
324
Colorado Natural Heritage Program © 2015 4 PLANTS
Authors:
Jill Handwerk Bernadette Kuhn Delia Malone Recommended chapter citation: Handwerk, J., B. Kuhn, and D. Malone. 2015. Plants. Chapter 4 In Colorado Natural Heritage Program 2015. Climate Change Vulnerability Assessment for Colorado Bureau of Land Management. K. Decker, L. Grunau, J. Handwerk, and J. Siemers, editors. Colorado Natural Heritage Program, Colorado State University, Fort Collins, Colorado. Climate Change Vulnerability Assessment for Colorado BLM 325 Table of Contents – 4 Plants Methods .................................................................................................................................................... 329 Results ....................................................................................................................................................... 333 Plant Species CCVA Summaries................................................................................................................. 336 Aletes latilobus (Lomatium latilobum) ...................................................................................................... 337 Aletes lithophilus (Neoparrya lithophila) .................................................................................................. 340 Amsonia jonesii ......................................................................................................................................... 344 Aquilegia chrysantha var. rydbergii .......................................................................................................... 348 Asclepias uncialis ssp. uncialis .................................................................................................................. 351 Astragalus anisus ....................................................................................................................................... 354 Astragalus debequaeus ............................................................................................................................. 357 Astragalus equisolensis (Astragalus desperatus var. neeseae) ................................................................ 361 Astragalus microcymbus ........................................................................................................................... 364 Astragalus naturitensis ............................................................................................................................. 367 Astragalus osterhoutii ............................................................................................................................... 370 Astragalus piscator .................................................................................................................................... 373 Astragalus rafaelensis ............................................................................................................................... 376 Astragalus ripleyi ....................................................................................................................................... 379 Astragalus tortipes .................................................................................................................................... 383 Bolophyta ligulata (Parthenium ligulatum) ............................................................................................... 386 Camissonia eastwoodiae........................................................................................................................... 390 Cleome (Peristome) multicaulis ................................................................................................................ 393 Corispermum navicula .............................................................................................................................. 396 Cryptogramma stelleri .............................................................................................................................. 399 Erigeron kachinensis ................................................................................................................................. 402 Eriogonum brandegeei.............................................................................................................................. 405 Eriogonum clavellatum ............................................................................................................................. 408 Eriogonum coloradense ............................................................................................................................ 411 Eriogonum contortum............................................................................................................................... 414 Eriogonum ephedroides ............................................................................................................................ 419 Eriogonum pelinophilum .......................................................................................................................... 424 Eutrema penlandii ..................................................................................................................................... 427 Gentianella tortuosa ................................................................................................................................. 430 326 Colorado Natural Heritage Program © 2015 Gilia (Aliciella) stenothyrsa ....................................................................................................................... 435 Gutierrezia elegans ................................................................................................................................... 440 Ipomopsis polyantha ................................................................................................................................. 443 Lomatium concinnum ............................................................................................................................... 446 Lupinus crassus ......................................................................................................................................... 449 Mimulus eastwoodiae ............................................................................................................................... 452 Nuttallia (Mentzelia) chrysantha .............................................................................................................. 455 Nuttallia (Mentzelia) densa ....................................................................................................................... 458 Nuttallia (Mentzelia) rhizomata ................................................................................................................ 461 Oenothera acutissima ............................................................................................................................... 465 Oreocarya (Cryptantha) caespitosa .......................................................................................................... 468 Oreocarya (Cryptantha) osterhoutii ......................................................................................................... 473 Oreocarya revealii (Cryptantha gypsophila) ............................................................................................. 476 Oreocarya (Cryptantha) rollinsii ................................................................................................................ 479 Pediomelum aromaticum ......................................................................................................................... 484 Penstemon debilis ..................................................................................................................................... 487 Penstemon degeneri ................................................................................................................................. 490 Penstemon gibbensii ................................................................................................................................. 493 Penstemon grahamii ................................................................................................................................. 496 Penstemon harringtonii ............................................................................................................................ 499 Penstemon penlandii ................................................................................................................................ 503 Penstemon scariosus var. albifluvis .......................................................................................................... 506 Phacelia formosula .................................................................................................................................... 509 Phacelia submutica ................................................................................................................................... 512 Physaria (Lesquerella) congesta ................................................................................................................ 515 Physaria obcordata ................................................................................................................................... 518 Physaria (Lesquerella) parviflora .............................................................................................................. 521 Physaria (Lesquerella) pruinosa ................................................................................................................ 524 Physaria pulvinata ..................................................................................................................................... 527 Physaria (Lesquerella) vicina ..................................................................................................................... 530 Sclerocactus glaucus ................................................................................................................................. 533 Sisyrinchium pallidum ............................................................................................................................... 536 Thalictrum heliophilum ............................................................................................................................. 539 Climate Change Vulnerability Assessment for Colorado BLM 327 List of Figures and Tables Figure 4.1. Summary of climate change vulnerability scores for plant species. EV = Extremely Vulnerable; HV = Highly Vulnerable; MV = Moderately Vulnerable; PS = Presumed Stable; IL = Increase Likely. ...... 335 Table 4.1. Climate Change Vulnerability Scores for Plant Species. EV = Extremely Vulnerable; HV = Highly Vulnerable; MV = Moderately Vulnerable; PS = Presumed Stable; IL = Increase Likely. .......................... 333 328 Colorado Natural Heritage Program © 2015 METHODS
NatureServe Climate Change Vulnerability Index
Overview
Thisoverviewhasbeensynthesizedandreprinted,withpermission,fromYoungetal.(2011).The
ClimateChangeVulnerabilityIndex(CCVI),developedbyNatureServe,isaMicrosoftExcel‐based
toolthatfacilitatesrapidassessmentofthevulnerabilityofplantandanimalspeciestoclimate
changewithinadefinedgeographicarea.Inaccordancewithwell‐establishedpractices(Schneider
etal.2007,Williamsetal.2008),theCCVIdividesvulnerabilityintotwocomponents:
exposuretoclimatechangewithintheassessmentarea(e.g.,ahighlysensitivespecieswill
notsufferiftheclimatewhereitoccursremainsstable).
sensitivityofthespeciestoclimatechange(e.g.,anadaptablespecieswillnotdeclineeven
inthefaceofsignificantchangesintemperatureand/orprecipitation).
Exposuretoclimatechangeismeasuredbyexaminingthemagnitudeofpredictedtemperatureand
moisturechangeacrossthespecies’distributionwithinthestudyarea.CCVIguidelinessuggest
usingthedownscaleddatafromClimateWizard(http://climatewizard.org)forpredictedchangein
temperature.ProjectionsforchangesinprecipitationareavailableinClimateWizard,but
precipitationestimatesaloneareoftenanunreliableindicatorofmoistureavailabilitybecause
increasingtemperaturespromotehigherratesofevaporationandevapotranspiration.Moisture
availability,ratherthanprecipitationperse,isacriticalresourceforplantsandanimalsand
thereforeformstheotherpartoftheexposuremeasurewithintheCCVI,togetherwith
temperature.Topredictchangesinmoistureavailability,NatureServeandpartnersdevelopedthe
HamonAET:PETmoisturemetricaspartoftheCCVI.Themetricrepresentstheratioofactual
evapotranspiration(i.e.,theamountofwaterlostfromasurfacethroughevaporationand
transpirationbyplants)topotentialevapotranspiration(i.e.,thetotalamountofwaterthatcould
beevaporatedundercurrentenvironmentalconditions,ifunlimitedwaterwasavailable).Negative
valuesrepresentdryingconditions.
Sensitivityisassessedusing20factorsdividedintotwocategories:1)indirectexposuretoclimate
change;and2)speciesspecificfactors(includingdispersalability,temperatureandprecipitation
sensitivity,physicalhabitatspecificity,interspecificinteractions,andgeneticfactors).Foreach
factor,speciesarescoredonaslidingscalefromgreatlyincreasing,tohavingnoeffecton,to
decreasingvulnerability.TheCCVIaccommodatesmorethanoneanswerperfactorinorderto
addresspoordataorahighlevelofuncertaintyforthatfactor.Thescoringsystemintegratesall
exposureandsensitivitymeasuresintoanoverallvulnerabilityscorethatindicatesrelative
vulnerabilitycomparedtootherspeciesandtherelativeimportanceofthefactorscontributingto
vulnerability.
Climate Change Vulnerability Assessment for Colorado BLM 329 TheIndextreatsexposuretoclimatechangeasamodifierofsensitivity.Iftheclimateinagiven
assessmentareawillnotchangemuch,noneofthesensitivityfactorswillweighheavily,anda
speciesislikelytoscoreattheNotVulnerableendoftherange.Alargechangeintemperatureor
moistureavailabilitywillamplifytheeffectofanyrelatedsensitivity,andwillcontributetoascore
reflectinghighervulnerabilitytoclimatechange.Inmostcases,changesintemperatureand
moistureavailabilitywillcombinetomodifysensitivityfactors.However,forfactorssuchas
sensitivitytotemperaturechange(factor2a)orprecipitation/moistureregime(2b),onlythe
specifiedclimatedriverwillhaveamodifyingeffect.
Thesixpossiblescoresare:
ExtremelyVulnerable:Abundanceand/orrangeextentwithingeographicalareaassessed
extremelylikelytosubstantiallydecreaseordisappearby2050.
HighlyVulnerable:Abundanceand/orrangeextentwithingeographicalareaassessedlikelyto
decreasesignificantlyby2050.
ModeratelyVulnerable:Abundanceand/orrangeextentwithingeographicalareaassessedlikely
todecreaseby2050.
NotVulnerable/PresumedStable:Availableevidencedoesnotsuggestthatabundanceand/or
rangeextentwithinthegeographicalareaassessedwillchange(increase/decrease)substantially
by2050.Actualrangeboundariesmaychange.
NotVulnerable/IncreaseLikely:Availableevidencesuggeststhatabundanceand/orrangeextent
withingeographicalareaassessedislikelytoincreaseby2050.
InsufficientEvidence:Availableinformationaboutaspecies'vulnerabilityisinadequateto
calculateanIndexscore.
Scoring Factors in the CCVI
ThefactorsusedtogeneratetheCCVIscorearelistedinthefollowingsection.Detaileddefinitions
ofscoringcategoriesarelistedinAppendixB.
A. Exposure to Local Climate Change 1.
2.
B. Indirect Exposure to Climate Change 1.
2.
330 Temperature
Moisture
Exposuretosealevelrise.(NotapplicabletoColorado)
Distributionrelativetonaturalandanthropogenicbarriers.
Colorado Natural Heritage Program © 2015 3.
C. Sensitivity 1.
2.
3.
4.
5.
6.
D. Predictedimpactoflandusechangesresultingfromhumanresponsestoclimate
change.
Dispersalandmovements.
Predictedsensitivitytotemperatureandmoisturechanges.
a.Predictedsensitivitytochangesintemperature.
b.Predictedsensitivitytochangesinprecipitation,hydrology,ormoisture
regime.
c.Dependenceonaspecificdisturbanceregimelikelytobeimpactedby
climatechange.
d.Dependenceonice,ice‐edge,orsnow‐coverhabitats.
Restrictiontouncommongeologicalfeaturesorderivatives.
Relianceoninterspecificinteractions.
a.Dependenceonotherspeciestogeneratehabitat.
b.Dietaryversatility(animalsonly).
c.Pollinatorversatility(plantsonly).
d.Dependenceonotherspeciesforpropaguledispersal.
e.FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.
Geneticfactors.
a.Measuredgeneticvariation.
b.Occurrenceofbottlenecksinrecentevolutionaryhistory.
Phenologicalresponsetochangingseasonaltemperatureandprecipitation
dynamics.
Documented or Modeled Response to Climate Change 1.
2.
3.
4.
Documentedresponsetorecentclimatechange.
Modeledfuturechangeinrangeorpopulationsize.
Overlapofmodeledfuturerangewithcurrentrange.
Occurrenceofprotectedareasinmodeledfuturedistribution.
Factorsnotconsidered—TheIndexdevelopmentteamdidnotincludefactorsthatarealready
consideredinconservationstatusassessments.Thesefactorsincludepopulationsize,rangesize,
anddemographicfactors.ThegoalisfortheNatureServeClimateChangeVulnerabilityIndexto
complementNatureServeConservationStatusRanksandnottopartiallyduplicatefactors.Ideally,
Indexvaluesandstatusranksshouldbeusedinconcerttodetermineconservationpriorities.
Application of Climate Data
Scoringfactorsrelatedtohistoricandpredictedfutureclimate(temperature,precipitation,and
moistureavailability,FactorsA1,A2,C2ai,andC2biintheCCVI)werecalculatedinGISusingthe
methodsdescribedbelow.Refertothespeciesprofilesinthefollowingsectionofthisreportfor
detailsonscoringrationaleandreferencesforallotherfactors.
Climate Change Vulnerability Assessment for Colorado BLM 331 Exposuretopredictedtemperatureincreasewascalculatedusingspeciesdistributiondataandan
ensembleaverageof16CMIP3climatepredictionmodels(seeAppendixA)averagedoverthe
summerseason(June–August)usingthehigh(A2)CO2emissionsscenario.Thehighemissions
scenariowasusedbecauseitismostsimilartocurrentemissions.DatawasobtainedfromClimate
Wizard,andtheanalysisperiodwastotheyear2050(whichisactuallyanaverageofprojections
foryears2040–2069).Thesummerseason–growingseasonforplants,breedingseasonfor
animals–wasusedbecauseitwasconsideredthemostcriticaltimeperiodformostspecies.
Exposuretoprojecteddrying(integrationofprojectedtemperatureandprecipitationchange,i.e.,
theHamonAET:PETmoisturemetric)wascalculatedusingthedatasetcreatedbyNatureServeas
partoftheCCVI.NotethatNatureServebasedtheirmoisturemetriccalculationsonthesame
ClimateWizarddatasetasabove,exceptthattheyusedtheA1Bcarbondioxideemissionsscenario.
BecausethemodelingmethodsusedbyNatureServewerenotavailable,wewereunableto
recalculateusingtheA2scenario.Thus,weusedthedataasprovided,whichweconsidereda
reasonablealternativesincetheA1BandA2scenariospredictsimilarchangesthroughthemid‐21st
Century,theperiodusedinthisanalysis.Wecalculatedthepercentofeachspecies’
range/distributionthatfallswithineachratingcategory.Allcalculationsusedthe“summer”(June–
August)datasubset.
Thehistoricalthermalnichefactormeasureslarge‐scaletemperaturevariationthataspecieshas
experiencedinrecenthistoricaltimes(i.e.,thepast50years),asapproximatedbymeanseasonal
temperaturevariation(differencebetweenhighestmeanmonthlymaximumtemperatureand
lowestmeanmonthlyminimumtemperature).Itisaproxyforspecies'temperaturetoleranceata
broadscale.ThisfactorwascalculatedinGISbyassessingtherelationshipbetweenspecies’
distributionsandhistoricaltemperaturevariationdatadownloadedfromNatureServe.Historical
temperaturevariationwasmeasuredasthemeanJulyhighminusthemeanJanuarylow,using
PRISMdatafrom1951‐2006,expressedasasingleaveragedvaluefortheentirespeciesrange.
Thehistoricalhydrologicalnichefactormeasureslarge‐scaleprecipitationvariationthataspecies
hasexperiencedinrecenthistoricaltimes(i.e.,thepast50years),asapproximatedbymeanannual
precipitationvariationacrossoccupiedcellswithintheassessmentarea.Ratingsforthisfactor
werecalculatedinGISbyoverlayingthespecies’distributionsonmeanannualprecipitationdata
(PRISM4kmannualaverageprecipitation,ininches,1951‐2006)downloadedfromClimateWizard,
andsubtractingthelowestpixelvaluefromthehighestvalue.
Representing Species’ Distributions
Forplantspecies,weusedelementoccurrencesfromCNHP’sBIOTICSdatabasetogenerate
distributionmapsandperformtheGIScalculationsreferencedabove.
Theplantspeciesincludedinthisclimatechangevulnerabilityassessmentincludeallthefederally
listed(threatened,endangeredandcandidate)speciesknowntooccuronBLMlands.Alsoincluded
arealltheplantspeciesfromtheBLMSensitiveSpecieslist,withtheexceptionof13speciesfor
whichtherewasnotsufficientinformationavailabletoevaluatetheeffectsofclimatechange.The
omittedspecieswere:Arabiscrandallii(Boecheracrandallii),Astragalusmusiniensis,Astragalus
332 Colorado Natural Heritage Program © 2015 sesquiflorus,Cymopterusduchesnensis,Eriogonumacaule,Eriogonumtumulosum,Eriogonum
viridulum,Fraserapaniculata,Lygodesmiadoloresensis,Packerapauciflora,Sphaeromeriacapitata,
Townsendiastrigosa,Trichophorumpumilum(Scirpusrollandii).
RESULTS
CCVIresultsaresummarizedinTable4.1,andpresentedinfullinAppendixC.Plantspeciesresults
aresortedalphabeticallybyscientificname.Therationaleforscoringandliteraturecitationsare
includedinthefollowingspeciesprofiles.
Table 4.10. Climate Change Vulnerability Scores for Plant Species. EV = Extremely Vulnerable; HV = Highly Vulnerable; MV = Moderately Vulnerable; PS = Presumed Stable; IL = Increase Likely. Species
English name
Aletes latilobus (Lomatium latilobum) Canyonlands aletes EV
Aletes lithophilus (Neoparrya lithophila) Rock‐loving neoparrya EV
Amsonia jonesii Jones' bluestar MV Aquilegia chrysantha var. rydbergii Golden columbine EV
Asclepias uncialis ssp. uncialis Dwarf milkweed EV
Astragalus anisus Gunnison milkvetch EV
Astragalus debequaeus DeBeque milkvetch EV
Astragalus equisolensis Horseshoe milkvetch EV
Astragalus microcymbus Skiff milkvetch EV
Astragalus naturitensis Naturita milkvetch EV
Astragalus osterhoutii Kremmling milkvetch EV
Astragalus piscator Fisher Towers milkvetch EV
Astragalus rafaelensis San Rafael milkvetch EV
Astragalus ripleyi Ripley milkvetch EV
Astragalus tortipes Sleeping Ute milkvetch EV
Bolophyta ligulata (Parthenium ligulatum) Ligulate feverfew EV
Camissonia eastwoodiae Eastwood evening primrose HV
Cleome multicaulis Slender spiderflower EV
Corispermum navicula Boat‐shaped bugseed EV
Cryptogramma stelleri Slender rock‐brake EV
Erigeron kachinensis Kachina daisy EV
Eriogonum brandegeei Brandegee wild buckwheat EV
Eriogonum clavellatum Comb Wash buckwheat EV
Eriogonum coloradense Colorado wild buckwheat EV
Eriogonum contortum Twisted Buckwheat EV
Eriogonum pelinophilum Clay‐loving wild buckwheat EV
Climate Change Vulnerability Assessment for Colorado BLM Score
333 Species
English name
Score
Eriogonum ephedroides Ephedra buckwheat EV
Eutrema penlandii Penland alpine fen mustard EV
Gentianella tortuosa Utah gentian EV
Gilia (Aliciella) stenothyrsa Narrow‐stem Gilia EV
Gutierrezia elegans Lone Mesa snakeweed EV
Ipomopsis polyantha Pagosa skyrocket EV
Lomatium concinnum Colorado desert‐parsley EV
Lupinus crassus Payson lupine EV
Mimulus eastwoodiae Eastwood's monkeyflower EV
Nuttallia (Mentzelia) chrysantha Golden blazing star EV
Nuttallia (Mentzelia) densa Arkansas Canyon stickleaf EV
Nuttallia (Mentzelia) rhizomata Roan Cliffs Blazingstar EV
Oenothera acutissima Narrow‐leaf evening primrose HV
Oreocarya (Cryptantha) caespitosa Tufted Cryptanth EV
Oreocarya (Cryptantha) rollinsii Rollins' Cats‐eye EV
Oreocarya osterhoutii (Cryptantha osterhoutii) Osterhout's cat's‐eye EV
Oreocarya revealii (Cryptantha gypsophila) Gypsum Valley cat's‐eye EV
Pediomelum aromaticum Paradox breadroot EV
Penstemon debilis Parachute penstemon EV
Penstemon degeneri Degener beardtongue EV
Penstemon gibbensii Gibben's beardtongue EV
Penstemon grahamii Graham beardtongue EV
Penstemon harringtonii Harrington's beardtongue EV
Penstemon penlandii Penland penstemon EV
Penstemon scariosus var. albifluvis White River penstemon EV
Phacelia formosula North Park phacelia EV
Phacelia submutica DeBeque phacelia EV
Physaria (Lesquerella) congesta Dudley Bluffs bladderpod EV
Physaria (Lesquerella) parviflora Piceance bladderpod EV
Physaria (Lesquerella) pruinosa Pagosa bladderpod EV
Physaria (Lesquerella) vicina Good‐neighbor bladderpod EV
Physaria obcordata Piceance twinpod EV
Physaria pulvinata Cushion bladderpod EV
Sclerocactus glaucus Colorado hookless cactus EV
Sisyrinchium pallidum Pale blue‐eyed grass EV
Thalictrum heliophilum Sun‐loving meadow rue EV
334 Colorado Natural Heritage Program © 2015 Nearlyallofthe62plantspeciesanalyzedscoredasextremelyvulnerabletopredictedclimate
changeinColorado.Onlythreespecies(Amsoniajonesii,CamissoniaeastwoodiaeandOenothera
acutissima)werehighlytomoderatelyvulnerable.Noneoftheplantspeciesscoredaspresumed
stableorlikelytoincreaseundertheclimatechangescenariousedinthisanalysis.(Table4.1).
Factorsthatweremostlikelytocontributetothevulnerabilityofplantsinclude:naturalbarriersto
movementandpoordispersalability,physiologicalhydrologicalniche,restrictiontouncommon
geologicfeaturesorsubstrates,andpollinatorspecificity.Ofthe62plantspeciesevaluatedfor
Coloradotheconfidenceratingswereveryhighforallspecies.
Despitethedevelopmentofnumerousclimatechangemodels,thereremainssomeuncertainty
aboutwhatclimaticchangeswillactuallyoccurandhowspeciesfitnessandpopulationstability
willbeaffected.Whenevaluatedataregional(i.e.,smallerthanstatewide)scale,somespecies
scoredaslessvulnerabletoclimatechange.Forexample,intheSanJuanregionofColorado,
Amsoniajonesiiispresumedstablewheretherearefewnaturaloranthropogenicbarriersto
movementandithasbeenexposedtogreaterhistoricaltemperaturevariation,whereasitscoresas
moderatelyvulnerableonastatewidescalewherethepresenceofnaturalandanthropogenic
barriersincreasesandthereislessexposuretohistorictemperatureextremes.Mimulus
eastwoodiaescoredashighlyvulnerableintheSanJuanregionbutisconsideredextremely
vulnerableonastatewidescaleforthesamereasons,increasedbarrierstomovementandless
exposuretohistorictemperaturevariation.ThesamewastrueforPediomelumaromaticumwhich
ismoderatelyvulnerableintheSanJuan’sandextremelyvulnerablestatewide.Thus,itisimportant
toconsiderthespeciesrangeinrelationtotheassessmentareawhendevelopingadaption
strategies,andtoconsiderhowsuchfactors,suchasprecipitationandtemperatureaveragescan
affectthescoreswhenspeciesareevaluatedatdifferentscales.
Figure 4.1. Summary of climate change vulnerability scores for plant species. EV = Extremely Vulnerable; HV = Highly Vulnerable; MV = Moderately Vulnerable; PS = Presumed Stable; IL = Increase Likely. Climate Change Vulnerability Assessment for Colorado BLM 335 PLANT SPECIES CCVI SUMMARIES
336 Colorado Natural Heritage Program © 2015 Aletes latilobus (Lomatium latilobum) Canyonlandsaletes
G1G2/S1
Family:Apiaceae
Photo: Gina Glenne Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)1)Aleteslatilobushabitatis
surroundedbyanthropogenicandnaturalbarriersthatmayinhibitrangeshift2)potentialincrease
inenergydevelopmentinA.latilobushabitat;3)A.latilobushasexperiencedasmallrangeinmean
annualprecipitationoverthelast50years;4)seeddispersaldistancesareprobablyfairlylimited;
5)potentialdecreaseinsoilmoistureavailabilityunderprojectedwarmertemperatures;6)
restrictiontosandstoneEntradaandNavajoFormations.
Distribution:ColoradoPlateau,NavajoBasin;GrandandSanJuanCounties,Utah,andMesa
County,Colorado.Habitat:OnEntradaSandstoneandNavajoSandstone,betweenfinsandinslot
canyons,insandysoilandincrevices.Surroundingplantcommunitiesaredesertshrub,pinyon‐
juniper,orponderosapine‐mountainbrush.Foundincanyonlandsinpinyon‐juniperanddesert
shrubcommunities;onsandstoneledgesandinsandysoilsderivedfromtheEntradaFormationor
thecontactpointoftheWingateandChinleFormations(Spackmanetal.1997,Ackerfield2012,
WeberandWittmann2012).Elevation:4541‐5807feet.
EcologicalSystem:CliffandCanyon,DesertShrub
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
Climate Change Vulnerability Assessment for Colorado BLM 337 B2a)Distributionrelativetonaturalbarriers.Increase.Rangeshiftinresponsetoclimate
changeisinhibitedbyunsuitablegeologyandtheColoradoRiverValley(tothenorth)thatdonot
containsuitablehabitatforthisspecies(USGS2004).
B2b)Distributionrelativetoanthropogenicbarriers.Increase.Extensivehabitatalterationdue
tooilandgasextractioninandaroundhabitatoccupiedbythisspecies(FracFocusWells2013)
inhibitsrangeshift.Additionally,muchofthelandscapesurroundingoccurrencesofA.latilobushas
beenalteredbylivestockgrazing(CNHP2014).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Increase.
Desertshrublandshavehighpotentialfornaturalgasextraction,andsolarandwindenergy
development(Grunauetal.2011;NRDC2011).
C1)Dispersalandmovements.Increase.Seedslikelyfallclosetoparentplant.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Increase.Cliffand
canyonspecieswererated‘Increase’basedontheassumptionthatthesehabitatsarelikelytobe
alteredasColoradobecomeswarmer.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.GreatlyIncrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,thespecieshasexperiencedverysmall(<4inches/100mm)
precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.Climatemodelsprojecthottertemperaturesfor
Colorado,withtrendstowardmoreseveresoil‐moisturedroughtconditionsinColorado(Lukaset
al.2014).Warmertemperatureswillresultinhigherevapotranspirationratesforplants.A.
latilobusoccursinasemi‐aridclimatewithanaverageof11.33inchesofprecipitationperyear
(WesternRegionalClimateCenter2015).Althoughtolerancelimitsforlackofmoistureare
unknownforthisspecies,ahotterclimatecombinedwithhigherevapotranspirationmayresultin
stressfulconditionsforA.latilobus.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.SomewhatIncrease.
RestrictedtosandstonesoftheEntradaandNavajoFormations(CNHP2014).
338 Colorado Natural Heritage Program © 2015 C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesisdependentonotherspeciestogeneratehabitat.
C4c)PollinatorVersatility.Unknown.
C4d)Dependenceonotherspeciesforpropaguledispersal.Unknown.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.Unknown.
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown. Literature Cited
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Climate Change Vulnerability Assessment for Colorado BLM 339 Aletes lithophilus (Neoparrya lithophila) Rock‐lovingneoparrya
G3/S3
Family:Apiaceae
Photo: Jim McCain
Climate Vulnerability Rank: Highly Vulnerable
ThisColoradostate‐widerankisbasedon:predicteddecreasesinprecipitation;thediscontinuityof
suitablehabitatthatisolatespopulationsandcreatesnaturalbarriersandhabitatalterationthat
resultsfromlivestockgrazingwhichactsasananthropogenicbarriers;possiblewindpower
developmentthatmayoccurincurrentandpotentialfuturerange;limitedsuccessfulseed
dispersal;andalterationofthenaturalfiredisturbanceregime.Suitablehabitatislikelytobe
reducedasthisspecies’rangebecomesdrier.Climatemodelsprojectannualnetdryingacrossthe
rangeofthisspecies(NatureServe2012)withresultingtrendstowardmoreseveresoil‐moisture
droughtconditionsinColorado(Lukasetal.2014)
Distribution:AleteslithophilusisendemictothesouthernRockyMountainswherethisspeciesis
knownfromsevencountiesinsouth‐centralColorado:Chaffee,Conejos,Fremont,Huerfano,
Mineral,RioGrande,andSaguache;andhasalsobeenreportedfromonesiteinnorth‐centralRio
BravoCountyinNewMexico(Anderson2004,SEINet2014).Mostoccurrencesareknownfromthe
westernrimoftheSanLuisValley,butimportantoutlyingoccurrencesarealsofoundinthe
ArkansasValleyintheSalidaareaandatFarisitaDikeinHuerfanoCounty(Anderson2004).
EcologicalSystem/Habitat:AleteslithophilusisfoundintheSouthernRockyMountainSteppe‐
OpenWoodland‐ConiferousForest‐AlpineMeadowProvince(Anderson2004).InthisecosystemN.
lithophilatypicallyoccupiesvolcanicsubstrates,inthecracksorshelvesofmoderatetosteeprock
outcrops,oroutcropsofvolcanicsoils,usuallywithminimaltalusbutisalsoknowntooccuron
sedimentaryrockderivedfromextrusivevolcanics.Habitatsurroundingtherockoutcropsis
typicallygrasslandsorpinon‐juniperwoodlandswithassociatedtaxaoftenincludingFestuca,
Artemisia,Muhlenbergia,Hymenoxys,andRibes(NatureServe2014).Elevation:Reportsdocument
340 Colorado Natural Heritage Program © 2015 thatAleteslithophilusrangesfrom6,700to10,000feet,butismostcommonlyfoundbetween7,280
to9,800feetinelevation(Anderson2004).
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Increase.OccurrencesofAleteslithophilusare
naturallyisolatedbythediscontinuityofsuitablehabitat(Anderson2004).Thisspeciesoccupies
rockoutcrops,dikesandcliffsthataredistributedonthelandscapeasislandssurroundedbyasea
ofgrasslandandwoodlandhabitatswheretheinterveningenvironmentisapparentlyunsuitable
fortheestablishmentofA.lithophilusandactsasbarrierstorangeshift.
B2b)Distributionrelativetoanthropogenicbarriers.Somewhatincrease.Habitatalterationas
aconsequenceoflivestockgrazingbothindirectlyanddirectlyimpairsrangeshiftdrivenbyclimate
change.Aleteslithophilusishighlyvulnerabletohabitatalterationasindicatedbya“coefficientof
conservatism”value(Cvalue)of“9”(Rocchio2007).ThemajorityofA.lithophilusoccurrencesare
eitheronoradjacenttolandthatismanagedforlivestockgrazing(BLM2014,CNHP2014)andthe
majorityofthosegrazingallotmentsarecategorizedas“improve”(BLM2014).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.
Somewhatincrease.NaturalhistoryrequirementsofAleteslithophilusareincompatiblewiththe
landusechangesthatmaypossiblyoccurinitscurrentandfuturerangeasaresultofwindenergy
development.Potentialforwindpowerdevelopmentishighthroughoutthewesternperimeterof
theSanLuisvalley(NRDC2011)wherethemajorityofthedocumentedoccurrencesofN.lithophila
arelocated(CNHP2014).
C1)Dispersalandmovements.Somewhatincrease.Successfulseeddispersalislimitedby
unsuitablehabitat.AlthoughAleteslithophilusseedsmaybedispersedbyavarietyofmechanisms,
includingwindandanimals,withpotentialmaximumdispersaldistancesofupto15and1,500
metersrespectively(JongejansandTelenius2001,VittozandEngler2007),theprobabilityof
dispersaldecreasesrapidlywithincreasingdistancefromthesource(Barbouretal.1987).Flat
areassurroundingtherockoutcropsinhabitedbyN.lithophilapresentunsuitablehabitatthat
undoubtedlyactassinkswhenseedsareblownorwashedontotheseareas(Anderson2004).
C2ai)Predictedsensitivitytotemperature:historicthermalniche.Neutral. Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage
temperaturevariation(57.1‐77oF)inthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Aletes
lithophilusisnotrestrictedtocoolorcoldenvironments.Additionally,habitatpreferences
(Anderson2004)suggestthatA.lithophilusistolerantofwarmertemperatures.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Neutral.Consideringtherangeofmeanannualprecipitationacross
Climate Change Vulnerability Assessment for Colorado BLM 341 occupiedcells,thespecieshasexperiencedaverageprecipitationvariation(36.5inches)inthepast
50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Somewhatincrease.Aleteslithophilusissomewhatdependent
onaseasonalhydrologicregimethatisvulnerabletoalterationwithclimatechangeandassociated
predictedincreasedseverityandfrequencyofdrought(USGCRP2009).AlthoughA.lithophilus
occupiesxericsites,populationmaintenanceviarecruitmentisdependentonseedlingsuccess
whichappearstobedependentonperiodsofoneorseveralwetyearsduringwhichplantscan
becomeestablished(Anderson2004).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Increase.WhileseveredroughtsarealreadypartoftheSouthwestclimate,human‐inducedclimate
changewilllikelyresultinmorefrequentandmoreseveredroughtswithassociatedincreasesin
wildfires(USGCRP2009).Additionally,thepresenceofcheatgrass(Bromustectorum)inmany
occurrencesmayfurtherexacerbateclimatechange‐inducedalterationtonaturalfireregimes.
Increasedfirefrequencywillfavorfire‐dependentorfire‐tolerantspecies,whichthisspeciesisnot
(Anderson2004),leadingtowardchangesinspeciescomposition(Noss2001).
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Somewhatincrease.Aletes
lithophilusisprimarilyrestrictedtoTertiaryvolcanicsubstrateswiththespeciesprimarily
distributedalongtheeasternmarginoftheSanJuanVolcanicArea(Anderson2004).Tertiary
volcanicsubstratesarewidelydistributedinsouthcentralandsouthwesternColoradowith
Tertiaryashflowtuffandpre‐ashflowvolcanicsunderlyingmuchoftheeasternSanJuan
Mountains(Tweto1979,ChronicandWilliams2002).
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Aleteslithophilusisnotknown
tobedependentonotherspeciestogeneratehabitat.
C4c)PollinatorVersatility.Neutral.SpeciesinthefamilyApiaceaehaveahighdegreeoffloral
uniformitywithverylittlefloralspecializationandthusutilizeabroadsuiteofpollinatorsfor
pollenvectors(Anderson2004).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.Aleteslithophilusisnot
knowntobedependentonotherspeciesfordispersal.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.Unknown.
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
342 Colorado Natural Heritage Program © 2015 Literature Cited
Anderson,D.G.2004.NeoparryalithophilaMathias(Bill’sneoparrya):atechnicalconservationassessment.[Online].USDA
ForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/neoparryalithophila.pdf
Barbour,M.G.,J.H.Burk,andW.D.Pitts.1987.TerrestrialPlantEcology.Benjamin/CummingsPublishingCompany,Inc.,
MenloPark,CA.
Chronic,H.andF.Williams.2002.RoadsideGeologyofColorado,2nded.MountainPressPublishingCO.,Missoula,
Montana.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Jongejans,E.andA.Telenius.2001.Fieldexperimentsonseeddispersalbywindintenumbelliferousspecies(Apiaceae).
PlantEcology152:67–78.
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter2014.ClimateChangeinColorado,ASynthesistoSupport
WaterResourcesManagementandAdaptation,SecondEdition.Availableat:
http://wwa.colorado.edu/climate/co2014report/.Accessed:2014.
NatureServe2012.ClimateChangeVulnerabilityAssessmentTool,version2.1.Availableonlineat
https://connect.natureserve.org/science/climate‐change/ccvi.
NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org.(Accessed:November14,2014)
Noss,R.(2001).BeyondKyoto:Forestmanagementinatimeofrapidclimatechange.ConservationBiology15(3):578‐
590.
NRDCRenewableEnergyMapNaturalResourcesDefenseCounsel.2011.RenewableenergyforAmerica:harvestingthe
benefitsofhomegrown,renewableenergy.Online.Available:http://www.nrdc.org/energy/renewables/energymap.asp
(accessed2014).
Rocchio,J.2007.FloristicQualityAssessmentIndicesforColoradoPlantCommunities.ColoradoNaturalHeritage
Program,ColoradoStateUniversity,FortCollins,CO.
SouthwestEnvironmentalInformationNetwork(SEINet).2014.Cryptanthacaespitosa.Availableat:
http://swbiodiversity.org/.Accessed2014.
Tweto,O.1979.GeologicMapofColorado.CompiledbytheU.S.GeologicalSurveywithtechnicalassistancebythe
ColoradoGeologicalSurvey.
U.S.DepartmentoftheInterior,BureauofLandManagement(BLM).2014.Geocommunicator.Availableat:
http://www.geocommunicator.gov/GeoComm/.Accessed:2014.
VittozP.andEnglerR.2007.Seeddispersaldistances:atypologybasedondispersalmodesandplanttraits.Bot.Helv.
117:109–124.
Climate Change Vulnerability Assessment for Colorado BLM 343 Amsonia jonesii Jones’bluestar
G4/S2
Family:Apocynaceae
Photo: Joe Leahy Climate Vulnerability Rank: Moderately Vulnerable
ThisColoradostatewiderankisbasedon:predictedincreasedtemperatureanddecreased
precipitationduringperiodoffloweringandfruiting;thepresenceofhighescarpmentsthatactas
naturalbarriersaswellashabitatalterationthatresultsfromenergyextraction,agricultural
developmentandlivestockgrazingthatactasanthropogenicbarrierstorangeshift;possiblewind
powerdevelopmentwhichmayimpactpotentialfuturerange;alterationtothenaturalfire
disturbanceregime;pollinatorlimitation;predicteddecreaseinmodeledfuturerangewithlittle
habitatincludedinprotectedareas.Suitablehabitatislikelytobelosttothisspeciesand
reproductivesuccessdiminished.Climatemodelsprojectannualnetdryingthroughouttherangeof
thisspecies(NatureServe2012)whichmayimpactrecruitmentandpopulationsurvivability.
Distribution:A.jonesiiisknownfromNEArizona,Utah,NWNewMexico,andSWColoradointhe
UnitedStates(NatureServe2014).InColorado,itisknownfromMesaandMontezumacounties
(USDANRCS2013,CNHP2014).Habitat:Dry,openareaswithclay,sandy,orgravellysoils,in
desert‐steppe,rockydrainagesanddraws(CNHP2014).Elevation:4400‐5800feet.
EcologicalSystem:DesertShrublands,Pinyon‐JuniperWoodlands
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.SomewhatIncrease.Withachangingclimate
Amsoniajonesiiispredictedtomovenorthward,trackingclimatemoresuitabletoitsevolved
environmentaltolerancesandecologicalniche(UVUH2014).Coloradopopulationswillencounter
344 Colorado Natural Heritage Program © 2015 theRoanPlateau,aneast‐westtrendingescarpment,whichpresentsanaturalelevational,
environmentalandhabitatbarrierthatrestrictstheabilityofthisspeciestoshiftrange.
B2b)Distributionrelativetoanthropogenicbarriers.SomewhatIncrease.SomeColorado
populationsinwillbeinhibitedfromrangeshiftbyoilandgasdevelopment(FracFocusWells
2013),habitatconversiontohayagricultureandhabitatalterationbylivestock(USDA2012).
B3)Predictedimpactoflandusechangesresultingfromhumanresponsestoclimatechange.
Neutral.AlthoughportionsofwesternColoradohavehighpotentialforwindandsolarenergy
development,thespeciesisunlikelytobesignificantlyaffectedbymitigation‐relatedlanduse
changesthatmayoccurwithinitscurrentand/orpotentialfuturerange(NRDC2011).
C1)Dispersalandmovements.Somewhatincrease.Similartorelatedspecies,thecylindricaland
corkyseedsofAmsoniajonesiimaybedispersedbywater.Dispersalbywaterishighly
unpredictableandundocumented(VittozandEngler2007)butingeneralmostplantseedsdonot
dispersefartherthan100m(Cainetal.2000).
C2ai)Predictedsensitivitytotemperature:historicthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationovertherangeofthisspecies,Amsoniajonesiihas
experiencedaveragetemperaturevariation(57.1‐77°F)overthepast50years(NatureServe2012). C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Somewhatdecrease.
Thisspeciesisnotrestrictedtocoolorcoldenvironmentsandshowsapreferencefor
environmentstowardthewarmerendofthespectrum.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Neutral.Consideringtherangeofmeanannualprecipitationacross
occupiedcells,A.jonesiihasexperiencedaverage(21‐40inches/509‐1,016mm)precipitation
variationinthepast50years(NatureServe2012).
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.SomewhatIncrease.Speciesisfoundincoarse,sandysoilsoften
inthebottomsofdrawsanddrainages.Predictedclimatedryingduringthespringgrowingseason
willreducethisspeciesrecruitment,abundanceandhabitatsuitability.Longtermsurvivabilitymay
consequentlybediminishedeventhoughincreasedautumnmoisturemayenhancedispersaland
germinationpotential.Duringlatesummerandearlyautumn,A.jonesiiispredictedtobeexposed
toprecipitationdecreasesofupto3percentoverapproximately30percentofitsrangeand
increasesofupto6percentover70percentofitsrange.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Increase.FirefrequenciesinthePinyon‐Juniperwoodlandsandsageanddesertshrublands
occupiedbythisspeciesareexpectedtoincreaseinthefuture,followingtrendsthatalreadyshow
increasedfirefrequencies,areaburnedandfireseverity(Littleetal.2009,Stephens2005,
Westerlingetal.2006,USFSnodate).
Climate Change Vulnerability Assessment for Colorado BLM 345 C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Somewhatdecrease.Speciesis
reportedtobewidelyadaptableinthenurserytrade,andisreportedtogrowonvarioussubstrates.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesdependsonotherspeciestogenerateitshabitat.
C4c)PollinatorVersatility.Neutral.InferredfromarelatedspeciesAmsoniakearneyanawhich
hasawidevarietyofpollinators(USFWS2013).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.Similartootherrelated
species,seedmorphologysuggeststhatthisspeciesmaydispersebywaterandisthusnotlikely
reliantonotherspeciesfordispersal.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.Unknown.
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
D1)DocumentedResponsetoRecentClimateChange(e.g.,rangecontractionorphenology
mismatchwithcriticalresources).Unknown.
D2)ModeledFuture(2050)ChangeinRangeorPopulationSize.Increase.Rangewide
predictedfuturerangerepresentsa20percentto50percentdeclinerelativetocurrentrange
(UVUH2014).
D3)OverlapofModeledFuture(2050)RangewithCurrentRange.Neutral.Predictedfuture
rangeoverlapsthecurrentrangebygreaterthan60percentwithintheassessmentarea(UVUH
2014).
D4)OccurrenceofProtectedAreasinModeledFuture(2050)Distribution.Somewhat
Increase.Fivetothirtypercentofthemodeledfuturedistributionwithintheassessmentareais
encompassedbyoneormoreprotectedareas(USDI2014).
Literature Cited
Cain,M.L.,B.G.Milligan,andA.E.Strand.2000.Long‐distanceSeedDispersalinPlantPopulations.AmericanJournalof
Botany87(9):1217–1227.
ColoradoNaturalHeritageProgram.1997+.ColoradoRarePlantGuide.www.cnhp.colostate.edu.Latestupdate:June30,
2014.
346 Colorado Natural Heritage Program © 2015 ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Littell,J.,D.McKenzie,D.Peterson,andA.Westerling.2009.ClimateandwildfireareaburnedinwesternU.S.
ecoprovinces,1916‐2003.EcologicalApplications19:1003‐1021
NatureServe2012.ClimateChangeVulnerabilityAssessmentTool,version2.1.Availableonlineat
https://connect.natureserve.org/science/climate‐change/ccvi.
NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org.
NRDCRenewableEnergyMapNaturalResourcesDefenseCounsel.2011.RenewableenergyforAmerica:harvestingthe
benefitsofhomegrown,renewableenergy.Online.Available:http://www.nrdc.org/energy/renewables/energymap.asp
(accessed2014).
Stephens,S.L.2005.ForestfirecausesandextentonUnitedStatesForestServicelands.InternationalJournalofWildland
Fire14:213‐222.
U.S.DepartmentofAgriculture(USDA).2012.2012CensusofAgriculture.Availableat:
http://www.agcensus.usda.gov/index.php
U.S.D.A.ForestService(USFS).NoDate.Pinyon‐JuniperNaturalRangeofVariation.Availableat:
http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5434337.pdf.
U.S.DepartmentoftheInterior(USDI),U.S.GeologicalSurvey.2014.NationalGapAnalysisProgram,ProtectedAreasData
Viewer.Availableat:http://gapanalysis.usgs.gov/padus/viewer/
U.S.FishandWildlifeService(USFWS).2013.AmsoniakearneyanaKearneyblue‐star5‐YearReview:Summaryand
Evaluation.ArizonaEcologicalServicesTucsonSub‐office,Tucson,Arizona.
UtahValleyUniversityHerbarium(UVUH).2014.Availableat:http://herbarium.uvu.edu/herbInfo.shtml
VittozP.andEnglerR.2007.Seeddispersaldistances:atypologybasedondispersalmodesandplanttraits.Botanica
Helvetica,117(2),109–124.DOI:10.1007/s00035‐007‐0797‐8
Westerling,A.L.,B.P.Bryant,H.K.Preisler,T.P.Holmes,H.G.Hidalgo,T.Das,andS.R.Shrestha.2011.Climatechangeand
growthscenariosforCaliforniawildfire.ClimaticChange109:445‐463.
Climate Change Vulnerability Assessment for Colorado BLM 347 Aquilegia chrysantha var. rydbergii Goldencolumbine
G4T1Q/S1
Family:Ranunculaceae
Photo: Steve Olson Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widevulnerabilityrankisbasedonthefollowing:1)restrictiontomoistmicro‐
habitatsincliffs,canyons,andseeps2)relianceonhawkmothsasamajorpollinator3)shortseed
dispersaldistances.
Distribution:KnownfromFremont,ElPaso,Jefferson,andLasAnimascounties.ThePlants
Database(USDANRCS2015)showsA.chrysanthavar.rydbergiiinArizona,Colorado,andNew
Mexico.TheFloraofNorthAmerica(Vol.3,1997)statesthatColoradopopulationshavebeencalled
A.chrysanthavar.rydbergiianddoesnotmentionNewMexicoorArizona.ReportsfromNew
MexicoandArizona(USDANRCS2015)areprobablyerroneous,possiblyoriginatingbecauseNM
andAZarelistedintherangeofvar.rydbergiiinthe1985NoticeofReviewforListingas
EndangeredorThreatenedSpecies.Thesereportshavenototherwisebeensubstantiated.Habitat:
Incanyonsandfoothillsalongstreamsorinrockyravines(Spackmanetal.1997,Weberand
Wittmann2012).Aquilegiachrysanthavar.rydbergiigrowsinorganicsoilsandhasalsobeen
observedingravelderivedfromgraniteparentmaterial.Oftenfoundnearthebaseofboulderson
thecanyonsidesandfloor,itmayalsogrowonseep‐fedrockyledges.Itgrowsinshadyandmoist
areasonslopesaboveacreek,alongthesidedrainages,andwithintheriparianareaofaperennial
stream.Elevation:5,000‐8,240feet.
EcologicalSystem:MountainStreams,SeepsandSprings,DouglasFir
348
Colorado Natural Heritage Program © 2015 CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
C1)Dispersalandmovements.Increase.Seedslikelyfallclosetotheparentplant,anddonot
containspecializedstructuresfordispersal.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.SomewhatIncrease.
Consideringthemeanseasonaltemperaturevariationovertherangeofthisspecies,Aquilegia
chrysanthavar.rydbergiihasexperiencedslightlylowerthanaveragetemperaturevariation(47.1‐
57°F)overthepast50years(NatureServe2012).
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Increase.This
speciesoccursincool,shaded,moisthabitatsthatmaybereducedifColoradobecomeswarmerand
drier,asprojectedinmanyclimatemodels.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Increase.Consideringtherangeofmeanannualprecipitationacross
occupiedcellsinColorado,A.chrysanthavar.rydbergiihasexperiencedslightlylowerthanaverage
(15.56inches)precipitationvariationinthepast50years(NatureServe2012).
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.GreatlyIncrease.Thisspeciesoccursincool,shadedareasin
cliffsandcanyons.Thesemicro‐habitatsoftencontainmoistsoilsandseasonalseepsthatmaybe
vulnerabletoclimatechange.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Somewhatdecrease.This
speciesoccursinseveralhabitattypes.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.
C4c)PollinatorVersatility.SomewhatIncrease.Crepuscularhawkmothsserveasamajor
pollinatorforA.chrysanthavar.rydbergiiinthesouthwestU.S.andnorthernMexico(Miller1985).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
Climate Change Vulnerability Assessment for Colorado BLM 349 C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.Neutral.
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown. Literature Cited
ColoradoNaturalHeritageProgram.1997+.ColoradoRarePlantGuide.www.cnhp.colostate.edu.Latestupdate:June30,
2014.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Miller,R.B.HawkmothPollinationofAquilegiachrysantha(Ranunculaceae)inSouthernArizona.TheSouthwestern
Naturalist30(1):69‐76.
NatureServe2012.ClimateChangeVulnerabilityAssessmentTool,version2.1.Availableonlineat
https://connect.natureserve.org/science/climate‐change/ccvi.
NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org.Accessed2014.
Spackman,S.,B.Jennings,J.Coles,C.Dawson,M.Minton,A.Kratz,andC.Spurrier.1997.Coloradorareplantfieldguide.
PreparedforBureauofLandManagement,U.S.ForestServiceandU.S.FishandWildlifeServicebyColoradoNatural
HeritageProgram.
USDA,NRCS.2015.ThePLANTSDatabase(http://plants.usda.gov).NationalPlantDataTeam,Greensboro,NC27401‐
4901USA.
Weber,W.A.andR.C.Wittmann.2012.ColoradoFlora,EasternSlope,AFieldGuidetotheVascularPlants,FourthEdition.
Boulder,Colorado.532pp.
350 Colorado Natural Heritage Program © 2015 Asclepias uncialis ssp. uncialis Dwarfmilkweed
G3G4T2T3/S2
Family:Asclepiadaceae
Photo: Steve Olson Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)lackofvariabilityinmean
annualprecipitationinthepast50years;2)shortseeddispersaldistances;3)croplandandurban
developmentmayactasabarriertoseeddispersal;and4)potentialforwindenergydevelopment
onColorado’seasternplains.
Distribution:Estimatedrangeis71,964squarekilometers(27,785squaremiles),calculatedinGIS
bydrawingaminimumconvexpolygonaroundtheknownoccurrences.Thereispotentiallyabout
40,000squaremilesofhabitatineasternColorado(althoughperhapsasmuchas50%ofthisarea
isnolongersuitablehabitat),roughly45%ofthetotalpotentialrangeofthespecies.Thecurrent
knowndistributionofAsclepiasuncialisssp.uncialisformsanarcalongtheflankoftheSouthern
RockyMountainsfromnortheasternColoradotosouthwesternNewMexicoandadjacent
southeasternArizona.CurrentlyknownfromnineColoradocounties(LasAnimas,Weld,KitCarson,
Huerfano,Pueblo,Otero,Prowers,Fremont,andElPaso),andhistoricallyknownfromatleasteight
additionalcounties(Arapaho,Adams,Baca,Bent,Cheyenne,Larimer,DenverandWashington).
OccurrencesareprimarilyinsoutheasternColorado.Habitat:Asclepiasuncialisssp.uncialisis
primarilyassociatedwithspeciestypicalofshortgrassprairie.Associatedvegetationiscomprised
mostlyofgrasses,withforbs,shrubs,andtreestypicallycomprisinglessthan15%ofthetotal
vegetationcover.Althoughplantsareoftenfoundatthebaseofescarpmentsormesas,thespecies
doesnotoccuronrockledgesoroutcroppings,andisabsentfromhighlydisturbedhabitatssuchas
sanddunes,erosionchannels,washslopes,andbadlands.Occurrencesareknownfromsoils
derivedfromavarietyofsubstrates,includingsandstone,limestone,andshale,butaremostoften
foundinsandyloamsoils.Itdoesnotoccurinpuresand.
Elevation:3890‐7730feet.
Climate Change Vulnerability Assessment for Colorado BLM 351 EcologicalSystem:ShortgrassPrairie,Pinyon‐Juniper
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral.
B2b)Distributionrelativetoanthropogenicbarriers.SomewhatIncrease.Croplandand
urban/ex‐urbandevelopmentintheshortgrassprairiemayactasbarriersforseeddispersal.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Increase.
AccordingtoDepartmentofEnergywindresourcemaps,theeasternquarterofColoradonearthe
NewMexicoandNebraskabordershasexcellentwindresources(DOE2004).Winddevelopment
couldresultinthelossofA.uncialisvar.uncialishabitat.
C1)Dispersalandmovements.SomewhatIncrease.Seedscontainatuftofsilkyhairstoaidin
winddispersal(Decker2006).
C2ai)Predictedsensitivitytotemperature:historicthermalniche.SomewhatDecrease.
Consideringthemeanseasonaltemperaturevariationforoccupiedcells,thespecieshas
experiencedgreaterthanaverage(>77°F/43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Not
restrictedtocoolorcoldclimatesthatareprojectedtobelostduetoclimatechange.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Increase.Consideringtherangeofmeanannualprecipitationacross
occupiedA.uncialisvar.uncialishabitat,thespecieshasexperiencedsmall(4‐10inches/100‐254
mm)precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.Occurrencesare
knownfromsoilsderivedfromavarietyofsubstrates,includingsandstone,limestone,andshale,
butaremostoftenfoundinsandyloamsoils(CNHP2014;Decker2006).Itdoesnotoccurinpure
sand.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesisdependentonotherspeciestogeneratehabitat.
352 Colorado Natural Heritage Program © 2015 C4c)PollinatorVersatility.Neutral.Likelytobepollinatedbygeneralistspecies(Decker2006).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.Neutral.
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown. Literature Cited
ColoradoNaturalHeritageProgram.1997+.ColoradoRarePlantGuide.www.cnhp.colostate.edu.Latestupdate:June30,
2014.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Decker,K.2006.AsclepiasuncialisGreene(wheelmilkweed):atechnicalconservationassessment.[Online].USDAForest
Service,RockyMountainRegion.Available:http://www.fs.fed.us/r2/projects/scp/assessments/asclepiasuncialis.pdf
DepartmentofEnergy(DOE).2004.WINDExchange.ColoradoWindResourceMap.Availableonlineat
http://apps2.eere.energy.gov/wind/windexchange/wind_resource_maps.asp?stateab=co.AccessedFeb2,2015.
NatureServe2012.ClimateChangeVulnerabilityAssessmentTool,version2.1.Availableonlineat
https://connect.natureserve.org/science/climate‐change/ccvi.
NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org.Accessed2014.
Climate Change Vulnerability Assessment for Colorado BLM 353 Astragalus anisus Gunnisonmilkvetch
G2G3/S2S3
Family:Fabaceae
Photo: Lori Brummer Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)highmountainranges
surroundingA.anisuspopulationscreatenaturalbarrierstodispersal;2)probablelimitedseed
dispersaldistances;3)potentialgeothermalenergydevelopmentintheGunnisonBasin;4)species
hasexperiencedasmallrangeofprecipitationinthelast50yearsand5)possiblyrelianceon
nodulization.
Distribution:ThespeciesentireglobalrangeiscontainedwithintheupperGunnisonBasin,in
GunnisonandSaguachecounties,Colorado.Estimatedrangeis1,962squarekilometers(757
squaremiles),calculatedinGISin2008bytheColoradoNaturalHeritageProgrambydrawinga
minimumconvexpolygonaroundtheknownoccurrences.Habitat:Drygravellyflatsandhillsides,
insandyclaysoilsoverlyinggraniticbedrock,usuallyamongorunderlowsagebrush.Elevation:
7500‐8500feet.
EcologicalSystem:Sagebrush
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.SomewhatIncrease.Rangeshiftinresponseto
climatechangeisinhibitedbyhighmountainrangesthatsurroundtheGunnisonBasin.
354 Colorado Natural Heritage Program © 2015 B2b)Distributionrelativetoanthropogenicbarriers.SomewhatIncreaseUrbanandexurban
developmentintheGunnisonBasinactascurrentandpotentialfuturebarrierstoA.anisus
movement.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Increase.
GeothermaldevelopmentpotentialishighintheGunnisonBasin,andifdevelopmentincreasedin
theBasin,itcouldfragmenthabitatintheBasin(USFWS2014).
C1)Dispersalandmovements.Increase.Seedslikelyfallclosetoparentplant,anddonotcontain
specializedstructurestoaidindispersal.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.SomewhatDecrease.
Consideringthemeanseasonaltemperaturevariationforoccupiedcells,A.anisushasexperienced
greaterthanaverage(>77°F/43.0°C)temperaturevariationinthepast50years(NatureServe
2012).
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Basedon
fieldobservations,thisplantiswelladaptedtodroughtandtemperatureextremes(Johnston,pers.
comm.2011).
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Increase.Thespecieshasexperiencedsmall(4‐10inches/100‐254
mm)precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.SomewhatIncrease.Speciesissomewhatdependentona
stronglyseasonalhydrologicregimeorlocalizedmoistureregimethatishighlyvulnerabletoloss
orreductionwithclimatechange.Precipitationamountsarefairlyevenlydistributedthroughout
theseasons,withsomewhatmoremoistureoccurringduringthe“monsoon”seasonofJulyand
August(DeckerandAnderson2004).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncrease.Astragalusanisusrequiresahighqualitymatrixcommunityofsagebrush
shrublandorpinyon‐juniperwoodlandswhichdependonanaturalfireregimetomaintain
appropriatevegetationstructure(NatureServe2014)Further,modeledfuturechangesinfire
probabilityandofvegetationpatternsshowincreasedprobabilityoffirethroughouttheregion
occupiedbythisspecies(Krawchuketal.2009).
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesisdependentonotherspeciestogeneratehabitat.
C4c)PollinatorVersatility.Neutral.Nodata,forcedscore.
Climate Change Vulnerability Assessment for Colorado BLM 355 C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.Nodata,forcedscore.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.SomewhatIncrease.
AlthoughAstragalusanisushasnotbeeninvestigatedfornodulization,noduleshavebeenreported
forseveralotherspeciesinthesubgroupArgophylii(A.crassicarpus,A.missouriensis,A.mollissimus,
andA.purshii),soitispossiblethatA.anisusalsopossessesthisability(DeckerandAnderson
2004).
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown. Literature Cited
ColoradoNaturalHeritageProgram.1997+.ColoradoRarePlantGuide.www.cnhp.colostate.edu.Latestupdate:June30,
2014.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Decker,K.andD.G.Anderson.2004.AstragalusanisusM.E.Jones(Gunnisonmilkvetch):atechnicalconservation
assessment.[Online].USDAForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/astragalusanisus.pdf.[May5,2011].
Johnston,B.2011.PersonalcommunicationatGunnisonClimateChangeWorkshop,May13,2011.Gunnison,Colorado.
KrawchukM.A,M.A.Moritz,M‐A.Parisien,J.VanDorn,K.Hayhoe.2009.GlobalPyrogeography:theCurrentandFuture
DistributionofWildfire.PLoSONE4(4):e5102doi:10.1371/journal.pone.0005102.Availableat:
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0005102#pone‐0005102‐g002
NatureServe2012.ClimateChangeVulnerabilityAssessmentTool,version2.1.Availableonlineat
https://connect.natureserve.org/science/climate‐change/ccvi.
NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org.Accessed2014.
U.S.FishandWildlifeService(USFWS).2014.FinalRule,EndangeredandThreatenedWildlifeandPlants;Threatened
StatusforGunnisonSage‐Grouse.FederalRegisterVol79,No.224,Nov.20,2014.DepartmentoftheInterior.
356 Colorado Natural Heritage Program © 2015 Astragalus debequaeus DeBequemilkvetch
G2/S2
Family:Fabaceae
Photo: Peggy Lyon Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)Astragalusdebequaeushabitatis
surroundedbyanthropogenicandnaturalbarriersthatmayinhibitrangeshift2)potentialincrease
innaturalgasdevelopmentinA.debequaeushabitat;3)A.debequaeushasexperiencedasmall
rangeinmeanannualprecipitationoverthelast50years;4)seeddispersaldistancesareprobably
fairlylimited;5)potentialsymbioticrelationshipwithroot‐nodulatingbacteria.
Distribution:KnownfromDelta,GarfieldandMesacounties,intheColoradoRiverValleynear
DeBeque.Theplant'srangeevidentlycorrespondstotheextentoftheAtwellGulchMemberofthe
WasatchFormation.Estimatedrangeis1,736squarekilometers(670squaremiles),calculatedin
2008bytheColoradoNaturalHeritagePrograminGISbydrawingaminimumconvexpolygon
aroundtheknownoccurrences.Habitat:Astragalusdebequaeusoccursinvari‐colored,fine
textured,seleniferous,andapparentlysalinesoilsoftheWasatchFormation‐AtwellGulchMember
(Welsh1985).Itisfoundinareassurroundedbypinyon‐juniperwoodlandsanddesertshrub
(Scheck1994).Astragalusdebequaeusisfoundonbarrenoutcropsofdarkclayinterspersedwith
lensesofsandstone.Theplantsoccuronsandyspots.Plantsaremostlyclusteredontoeslopesand
alongdrainages,butmanyoccuronsteepsideslopes.Soilsareclayeybutlitteredwithsandstone
fragments.Elevation:4950‐6680feet.
EcologicalSystem:Barrens,Pinyon‐Juniper,DesertShrub,Sagebrush
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
Climate Change Vulnerability Assessment for Colorado BLM 357 B2a)Distributionrelativetonaturalbarriers.Increase.Rangeshiftinresponsetoclimate
changeisinhibitedbyunsuitablegeologyandhighmountainhabitatsthatwouldnotcontain
suitablehabitatforthisspecies(USGS2004).
B2b)Distributionrelativetoanthropogenicbarriers.SomewhatIncrease.Extensivehabitat
alterationduetooilandgasextractioninandaroundhabitatoccupiedbythisspecies(FracFocus
Wells2013)inhibitsrangeshift.Additionally,muchofthelandscapesurroundingoccurrencesofA.
debequaeushasbeenalteredbylivestockgrazing(CNHP2014).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Increase.
ThehabitatofA.debequaeushasahighpotentialfornaturalgasextraction,andmoderatepotential
forsolarandwindenergydevelopment(Grunauetal.2011;NRDC2011).
C1)Dispersalandmovements.Increase.Seeddispersalislikelyfairlylimited,consideringthatA.
debequaeusseedsdonotcontainanyspecializedstructurestoaidindispersal.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.SomewhatDecrease.
Consideringthemeanseasonaltemperaturevariationforoccupiedcells,A.debequaeushas
experiencedgreaterthanaverage(>77°F/43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.A.
debequaeusoccupiesopensitesoverawiderangeofelevations(CNHP2014)withtemperatures
thatvaryadiabaticallywithelevation,suggestingthatthisspeciesisnotlimitedtocool
environments.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Increase.Consideringtherangeofmeanannualprecipitationacross
occupiedcells,A.debequaeushasexperiencedsmall(4‐10inches/100‐254mm)precipitation
variationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.Climatemodelsprojecthottertemperaturesfor
Colorado,withtrendstowardmoreseveresoil‐moisturedroughtconditionsinColorado(Lukaset
al.2014).Warmertemperatureswillresultinhigherevapotranspirationratesforplants.A.
debequaeusoccursinasemi‐aridclimatewithanaverageof11.33inchesofprecipitationperyear
(WesternRegionalClimateCenter2015).Althoughtolerancelimitsforlackofmoistureare
unknownforthisspecies,ahotterclimatecombinedwithhigherevapotranspirationmayresultin
stressfulconditionsforA.debequaeus.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.SomewhatIncrease.Although
thisspeciesoccursinseveralhabitattypesincludingbarrens,pinyon‐juniper,desertshrub,and
358 Colorado Natural Heritage Program © 2015 sagebrush,ithasapreferenceforbarrenoutcropsofdarkclaysoilsoftheAtwellGulchMemberof
the.WasatchFormation‐.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesisdependentonotherspeciestogeneratehabitat.
C4c)PollinatorVersatility.Neutral.AllAstragalusspeciesareranked‘Neutral’basedonUSFS
speciesassessmentsthatindicateseveralwesternAstragalusspeciesarevisitedbyover20species
ofbees(DeckerandAnderson2004).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.SomewhatIncrease.
Astragalus.debequaeushasnotbeeninvestigatedfornodulization.However,noduleshavebeen
reportedforseveralotherspeciesinthesubgroupArgophylii(A.crassicarpus,A.missouriensis,A.
mollissimus,andA.purshii),soitispossiblethatA.equisolensisalsopossessesthisability(Decker
andAnderson2004).
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown. Literature Cited
ColoradoNaturalHeritageProgram.1997+.ColoradoRarePlantGuide.www.cnhp.colostate.edu.Latestupdate:June30,
2014.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Decker,K.andD.G.Anderson.(2004,April21).AstragalusanisusM.E.Jones(Gunnisonmilkvetch):atechnical
conservationassessment.[Online].USDAForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/astragalusanisus.pdf.[May5,2011].
FracFocusWells.2013.MapProvidedbyFracTrackerAllianceonFracTracker.org.Availableat:
http://www.fractracker.org/map/national/
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter2014.ClimateChangeinColorado,ASynthesistoSupport
WaterResourcesManagementandAdaptation,SecondEdition.Availableat:
http://wwa.colorado.edu/climate/co2014report/.Accessed:2014.
NatureServe2012.ClimateChangeVulnerabilityAssessmentTool,version2.1.Availableonlineat
https://connect.natureserve.org/science/climate‐change/ccvi.
NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org.Accessed2014.
Climate Change Vulnerability Assessment for Colorado BLM 359 NRDCRenewableEnergyMapNaturalResourcesDefenseCounsel.2011.RenewableenergyforAmerica:harvestingthe
benefitsofhomegrown,renewableenergy.Online.Available:http://www.nrdc.org/energy/renewables/energymap.asp
(accessed2014).
Scheck,C.1994.SpecialStatusPlantsHandbookGlenwoodSpringsResourceArea.Unpublishedreportpreparedforthe
BureauofLandManagement,GlenwoodSprings,CO.
USGSNationalGapAnalysisProgram.2004.ProvisionalDigitalLandCoverMapfortheSouthwesternUnitedStates.
Version1.0.RS/GISLaboratory,CollegeofNaturalResources,UtahStateUniversity.
Welsh,S.L.1985.NewspeciesofAstragalus(Leguminosae)fromMesaCounty,Colorado.GreatBasinNaturalist45(1):31‐
33.
WesternRegionalClimateCenter.2015.AverageannualprecipitationforGrandJunction,Colorado.
http://www.wrcc.dri.edu/cgi‐bin/cliMAIN.pl?co3488.AccessedFeb24,2015.PeriodofRecord:1900to2015.
360 Colorado Natural Heritage Program © 2015 Astragalus equisolensis (Astragalus desperatus var. neeseae) Horseshoemilkvetch
G5T1/S1
Family:Fabaceae
Photo: Peggy Lyon Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedon:1)A.equisolensishasexperiencedasmallrangeinmean
annualprecipitationoverthelast50years;2)seeddispersaldistancesareprobablyfairlylimited;
3) pinyon‐juniperhabitatsoccupiedbyA.equisolensismaybesubjecttoincreasedwildfiresand
decreasesinsoilmoistureundertheclimatechangeprojectionsofhottertemperatures;4)
potentialsymbioticrelationshipwithroot‐nodulatingbacteria.
Distribution:KnownfromonecountyinUtah(USDANRCS2015)andonecountyinColorado
(CNHP2014).Habitat:A.equisolensisisassociatedwithmixeddesertandsaltdesertshrub
vegetationcommunitiesthataregenerallydominatedbysagebrush,shadscaleandhorsebrush.The
populationsinMesaCountyareinanopenjuniper/blackbrushcommunityonrockyconvexslopes
withredsoils.Elevation:4520‐6030feet.
EcologicalSystem:Pinyon‐JuniperWoodlands
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.SomewhatIncrease/Neutral.Rangeshiftin
responsetoclimatechangeisinhibitedbyunsuitablegeologyandhighmountainhabitatsthat
wouldnotcontainsuitablehabitatforthisspecies(USGS2004).
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.
Climate Change Vulnerability Assessment for Colorado BLM 361 B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.
SomewhatIncrease.Habitatdisturbanceandalterationmayoccurwithincreaseddevelopmentof
uraniumminesinthearea.
C1)Dispersalandmovements.Increase.SeeddispersaldistancesarelikelyshortsinceAstragalus
seedsgenerallydonotcontainspecializedstructurestoaidindispersal.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thisspecieshasexperiencedaverage(57.1
‐77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.A.
equisolensisoccupiesopensitesoverawiderangeofelevations(CNHP2014)withtemperatures
thatvaryadiabaticallywithelevation,suggestingthatthisspeciesisnotlimitedtocool
environments.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Increase.Consideringtherangeofmeanannualprecipitationacross
occupiedcells,thespecieshasexperiencedsmall(4‐10inches/100‐254mm)precipitation
variationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.Climatemodelsprojecthottertemperaturesfor
Colorado,withtrendstowardmoreseveresoil‐moisturedroughtconditionsinColorado(Lukaset
al.2014).Warmertemperatureswillresultinhigherevapotranspirationratesforplants.A.
equisolensisoccursinasemi‐aridclimatewithanaverageof8.7inchesofprecipitationperyear
(WesternRegionalClimateCenter2015).Althoughtolerancelimitsforlackofmoistureare
unknownforthisspecies,ahotterclimatecombinedwithhigherevapotranspirationmayresultin
stressfulconditionsforA.equisolensis.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncrease.A.equisolensisoccursinpinyon‐juniperhabitats.Thesehabitatsaremorelikely
toburnwithincreasedtemperaturesandanincreaseinweedyspeciesthatcomprisethe
understory,suchascheatgrass.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesisdependentonotherspeciestogeneratehabitat.
C4c)PollinatorVersatility.Neutral.AllAstragalusspeciesareranked‘Neutral’basedonUSFS
speciesassessmentsthatindicateseveralwesternAstragalusspeciesarevisitedbyover20species
ofbees(DeckerandAnderson2004).
362 Colorado Natural Heritage Program © 2015 C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.SomewhatIncrease.
Astragalusequisolensishasnotbeeninvestigatedfornodulization.However,noduleshavebeen
reportedforseveralotherspeciesinthesubgroupArgophylii(A.crassicarpus,A.missouriensis,A.
mollissimus,andA.purshii),soitispossiblethatA.equisolensisalsopossessesthisability(Decker
andAnderson2004).
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown. Literature Cited
ColoradoNaturalHeritageProgram.1997+.ColoradoRarePlantGuide.www.cnhp.colostate.edu.Latestupdate:June30,
2014.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Decker,K.andD.G.Anderson.2004.AstragalusanisusM.E.Jones(Gunnisonmilkvetch):atechnicalconservation
assessment.[Online].USDAForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/astragalusanisus.pdf.[May5,2011].
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter2014.ClimateChangeinColorado,ASynthesistoSupport
WaterResourcesManagementandAdaptation,SecondEdition.Availableat:
http://wwa.colorado.edu/climate/co2014report/.Accessed:2014.
NatureServe2012.ClimateChangeVulnerabilityAssessmentTool,version2.1.Availableonlineat
https://connect.natureserve.org/science/climate‐change/ccvi.
NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org.Accessed2014.
USDA,NRCS.2015.ThePLANTSDatabase(http://plants.usda.gov).NationalPlantDataTeam,Greensboro,NC27401‐
4901USA.
USGSNationalGapAnalysisProgram.2004.ProvisionalDigitalLandCoverMapfortheSouthwesternUnitedStates.
Version1.0.RS/GISLaboratory,CollegeofNaturalResources,UtahStateUniversity.
WesternRegionalClimateCenter.2015.AverageannualprecipitationforGateway,Colorado.
http://www.wrcc.dri.edu/cgi‐bin/cliMAIN.pl?co3246.AccessedFeb24,2015.PeriodofRecord:1947to2015.
Climate Change Vulnerability Assessment for Colorado BLM 363 Astragalus microcymbus Skiffmilkvetch
G1/S1
Family:Fabaceae
Photo: Michelle DePrenger‐Levin Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)movementbarriers;2)poor
dispersalcapacity;3)restrictiontospecificgeologicfeatures;4)potentialfuturethreatsfrom
livestockgrazingandgeothermalenergydevelopment;5)potentialincreaseinfirefrequencyin
occupiedhabitat;6)potentialrelianceonseasonalmoistureregimesforfruitproduction.
Distribution:GunnisonCounty,andextendingintotheedgeofSaguacheCounty.Estimatedrange
is168squarekilometers,calculatedinGISbydrawingaminimumconvexpolygonaroundthe
knownoccurrences.Habitat:Opensagebrushorjuniper‐sagebrushcommunitiesonmoderately
steeptosteepslopes.Oftenfoundinrockyareaswithavarietyofsoilconditionsfromclayto
cobbles,graytoreddishincolor.Elevation:7600‐8400feet.
EcologicalSystem:Sagebrush,Pinyon‐Juniper
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.SomewhatIncrease/Neutral.Rangeshiftin
responsetoclimatechangeisinhibitedbyunsuitablegeologyandhighmountainhabitatsthat
wouldnotcontainsuitablehabitatforthisspecies(USGS2004).
B2b)Distributionrelativetoanthropogenicbarriers.SomewhatIncrease/Neutral.The
followingpotentialfactorsthatmayaffectthehabitatorrangeofAstragalusmicrocymbusare(1)
Residentialandurbandevelopment;(2)recreation,roads,andtrails;(3)utilitycorridors;(4)
nonnativeinvasiveplants;(5)wildfire;(6)contourplowingandnonnativeseedings;(7)livestock,
364 Colorado Natural Heritage Program © 2015 deerandelkuseofhabitat;(8)mining,oilandgasleasing;(9)climatechange;and(10)habitat
fragmentationanddegradation(USFWS2010).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Increase.
GeothermaldevelopmentpotentialishighintheGunnisonBasin,andifdevelopmentincreasedin
theBasin,itcouldaffectthelong‐termviabilityofA.microcymbuswithintheBasin(USFWS2014).
C1)Dispersalandmovements.Increase.Seeddispersalislikelyfairlylimited,consideringthatA.
microcymbusseedsdonotcontainanyspecializedstructurestoaidindispersal.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.SomewhatDecrease.A.
microcymbushasexperiencedagreaterthanaveragetemperature(>70°F/43.0°C)variationinthe
past50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.SomewhatIncrease.
Speciesissomewhatrestrictedtocoolorcoldenvironmentsthatmaybelostasaresultofclimate
change.TemperaturesintheAstragalusmicrocymbusoccupiedhabitatcandipbelowfreezingany
monthoftheyear.Climatemodelspredictearlier,fastersnowmeltalongwithdecreasedsummer
precipitationandincreasedsummertemperatures(Barsugli2010).Thiswouldresultin
significantlyloweramountsofwaterstoredinthesoilsduringthesummer.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Increase.Thespecieshasexperiencedsmall(4‐10inches/100‐254
mm)precipitationvariationinthepast50years.
C2bii) Predicted sensitivity to changes in precipitation, hydrology, or moisture regime:
physiologicalhydrologicalniche.SomewhatIncrease.Precipitationinfluencesfruitproductionin
A.microcymbuswithadditionalfruitproducedinyearswithhigherthanaveragewinterprecipitation
(DePrenger‐Levinetal.2013).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncrease.Sagebrushshrublandsandpinyon‐juniperhabitatsmayexperienceincreased
firefrequenciesduetoincreasedtemperatures.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesisdependentonotherspeciestogeneratehabitat.
C4c)PollinatorVersatility.Neutral.AllAstragalusspeciesareranked‘Neutral’basedonUSFS
speciesassessmentsthatindicateseveralwesternAstragalusspeciesarevisitedbyover20species
ofbees(DeckerandAnderson2004).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
Climate Change Vulnerability Assessment for Colorado BLM 365 C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.SomewhatIncrease.
AlthoughA.microcymbushasnotbeenstudiedfornodulization,manyspeciesofAstragalusform
mycorrhizalassociations.
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown. Literature Cited
Barsugli,J.2010.HydrologicProjectionsfortheGunnisonBasin.PresentationatFollow‐upmeetingfortheClimate
ChangeAdaptationWorkshop.Gunnison,Colorado.
ColoradoNaturalHeritageProgram.1997+.ColoradoRarePlantGuide.www.cnhp.colostate.edu.Latestupdate:June30,
2014.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Decker,K.andD.G.Anderson.2004.AstragalusanisusM.E.Jones(Gunnisonmilkvetch):atechnicalconservation
assessment.[Online].USDAForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/astragalusanisus.pdf.[May5,2011].
DePrenger‐Levin,M.,J.M.RampNeale,T.A.GrantIII,C.DawsonandY.E.Baytok.2013.LifeHistoryandDemographyof
AstragalusmicrocymbusBarneby(Fabaceae).2013.NaturalAreasJournal,33(3):264‐275.
U.S.FishandWildlifeService(USFWS).2010.EndangeredandThreatenedWildlifeandPlants;TwelveMonthFindingon
aPetitiontoListAstragalusmicrocymbusandAstragalusschmolliaeasEndangeredorThreatened.FederalRegister:Vol.
75,No.240,December10,2010.
U.S.FishandWildlifeService(USFWS).2014.FinalRule,EndangeredandThreatenedWildlifeandPlants;Threatened
StatusforGunnisonSage‐Grouse.FederalRegisterVol79,No.224,Nov.20,2014.DepartmentoftheInterior.
USGSNationalGapAnalysisProgram.2004.ProvisionalDigitalLandCoverMapfortheSouthwesternUnitedStates.
Version1.0.RS/GISLaboratory,CollegeofNaturalResources,UtahStateUniversity.
366 Colorado Natural Heritage Program © 2015 Astragalus naturitensis Naturitamilkvetch
G2G3/S2S3
Family:Fabaceae
Photo: B. Kuhn Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors1)barrierstomovement;2)limited
seeddispersalcapabilities;3)lackoftemperatureandprecipitationvariabilityinlast50years;4)
potentialdecreaseinsoilmoistureavailabilitywithincreasedtemperatures;5)restrictionto
specificgeologicfeaturesandsoiltypes;6)potentialforincreasedfirefrequencyinoccupiedA.
naturitensishabitat.
Distribution:KnownfromNewMexico,Utah,theNavajoNationandColorado(Garfield,Mesa,
Montezuma,Montrose,andSanMiguelcounties).Habitat:Astragalusnaturitensisoccurson
sandstoneledges,crevicesofsandstonebedrock,dryrockmesas,ledges,anddetritalslopesat
5000‐7000feet.Pinyon‐juniperwoodlandsinareaswithshallowsoilsoverexposedbedrock.
Usuallyitisinsmallsoilpocketsorrockcrevicesinsandstonepavementalongcanyonrims.
Sometimesitisfoundnearbyindeepersandysoilswithorwithoutsoil.Elevation:4830‐7030feet.
EcologicalSystem:CliffandCanyon,Pinyon‐Juniper,Sagebrush
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Increase/SomewhatIncrease.Highmountains,
unsuitablehabitat,andlargerivervalleys(Gunnison,Colorado,andSanMiguelrivers)mayactas
naturalbarriersthatinhibitrangeshiftsassociatedwithclimatechange.
Climate Change Vulnerability Assessment for Colorado BLM 367 B2b)Distributionrelativetoanthropogenicbarriers.SomewhatIncrease/Neutral.Extensive
habitatalterationduetooilandgasextractioninWesternColorado(FracFocusWells2013)
inhibitsrangeshift.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
C1)Dispersalandmovements.Increase.Seeddispersalislikelyfairlylimited,consideringthatA.
naturitensisseedsdonotcontainanyspecializedstructurestoaidindispersal.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.SomewhatDecrease.
Consideringthemeanseasonaltemperaturevariationforoccupiedcells,A.naturitensishas
experiencedgreaterthanaverage(>77°F/43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Increase.
Consideringthemeanseasonaltemperaturevariationforoccupiedcells,A.naturitensishas
experiencedsmall(37‐47°F/20.8‐26.3°C)temperaturevariationinthepast50years.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Increase.Consideringtherangeofmeanannualprecipitationacross
occupiedcells,thespecieshasexperiencedsmall(4‐10inches/100‐254mm)precipitation
variationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.Climatemodelsprojecthottertemperaturesfor
Colorado,withtrendstowardmoreseveresoil‐moisturedroughtconditionsinColorado(Lukaset
al.2014).Warmertemperatureswillresultinhigherevapotranspirationratesforplants.A.
naturitensisoccursinasemi‐aridclimatewithanaverageof11.33inchesofprecipitationperyear
innearbyGrandJunction,CO(WesternRegionalClimateCenter2015).Althoughtolerancelimits
forlackofmoistureareunknownforthisspecies,ahotterclimatecombinedwithhigher
evapotranspirationmayresultinstressfulconditionsforA.naturitensis.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncrease.Sagebrushshrublandsandpinyon‐juniperhabitatsmayexperienceincreased
firefrequenciesduetoincreasedtemperatures.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.SomewhatIncrease.
Astragalusnaturitensisoccursonsandstoneledges,crevicesofsandstonebedrock,dryrockmesas,
ledges,anddetritalslopesat5000‐7000feet(CNHP2014).Itisoftenfoundgrowinginshallowsoils
ontopofsandstoneledgesandslickrock,butoccasionalisfoundindeeper,sandysoils.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesisdependentonotherspeciestogeneratehabitat.
368 Colorado Natural Heritage Program © 2015 C4c)PollinatorVersatility.Neutral.AllAstragalusspeciesareranked‘Neutral’basedonUSFS
speciesassessmentsthatindicateseveralwesternAstragalusspeciesarevisitedbyover20species
ofbees(DeckerandAnderson2004).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.SomewhatIncrease.A.
naturitensishasnotbeeninvestigatedfornodulization.However,noduleshavebeenreportedfor
severalotherspeciesinthesubgroupArgophylii(A.crassicarpus,A.missouriensis,A.mollissimus,
andA.purshii),soitispossiblethatA.naturitensisalsopossessesthisability(DeckerandAnderson
2004).
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown. Literature Cited
ColoradoNaturalHeritageProgram.1997+.ColoradoRarePlantGuide.www.cnhp.colostate.edu.Latestupdate:June30,
2014.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Decker,K.andD.G.Anderson.2004.AstragalusanisusM.E.Jones(Gunnisonmilkvetch):atechnicalconservation
assessment.[Online].USDAForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/astragalusanisus.pdf.[May5,2011].
FracFocusWells.2013.MapProvidedbyFracTrackerAllianceonFracTracker.org.Availableat:
http://www.fractracker.org/map/national/
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter2014.ClimateChangeinColorado,ASynthesistoSupport
WaterResourcesManagementandAdaptation,SecondEdition.Availableat:
http://wwa.colorado.edu/climate/co2014report/.Accessed:2014.
Climate Change Vulnerability Assessment for Colorado BLM 369 Astragalus osterhoutii Kremmlingmilkvetch
G1/S1
ListedEndangered
Family:Fabaceae
Photo: Denise Culver Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)barrierstomovement;2)limited
seeddispersaldistance;3)lackofvariationinannualprecipitationinthelast50years;4)potential
lackofsoilmoistureduetoprojectionsofhottertemperatures;5)potentialincreaseinfire
frequencyinsagebrushecosystems;6)restrictiontohighlyseleniferoussoilsanduniquegeologic
substrates6)potentialsymbioticrelationshipwithroot‐nodulatingbacteria.
Distribution:EndemictoGrandCounty,Colorado.Estimatedrangeis120squarekilometers,
calculatedinGISbydrawingaminimumconvexpolygonaroundtheknownoccurrences.
Impreciselyreportedoccurrencesarenotincluded.Habitat:Highlyseleniferoussoils(grayish‐
brownclay)derivedfromNiobraraShale;sometimesgrowingupthroughsagebrush.Elevation:
7370‐8000feet.
EcologicalSystem:Sagebrush
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.SomewhatIncrease.AccordingtoSWReGAP
vegetationlayers,unsuitablehabitatandgeologysurroundingknownlocationsofA.osterhoutiimay
restrictrangeshiftsduetoclimatechange(USGS2004).
370 Colorado Natural Heritage Program © 2015 B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Housingdevelopment,motorized
recreationareas,oilandgasdrilling,androadsallcreatebarrierstomovementforA.osterhoutii.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.
SomewhatIncrease.IncreasedoilandgasdrillingcouldleadtolossofindividualA.osterhoutii
plants,andincreasedhabitatfragmentationanddegradation.
C1)Dispersalandmovements.Increase.Seeddispersaldistancesarelikelysomewhatlimiteddue
tothelackofspecializedstructurestoaidindispersal.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.SomewhatDecrease.
Consideringthemeanseasonaltemperaturevariationforoccupiedcells,thespecieshas
experiencedgreaterthanaverage(>77°F/43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.A.
osterhoutiiisnotlimitedtocoolorcoldhabitatsthatmaybelosttoclimatechange.Lessthan10%
ofsagebrushecosystemsinColoradoareprojectedtobeoutsideofitscurrentclimaticenvelope
(SeeEcosystemSectionofreport).
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Increase.Consideringtherangeofmeanannualprecipitationacross
occupiedcells,thespecieshasexperiencedsmall(4‐10inches/100‐254mm)precipitation
variationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.SomewhatIncrease.Climatemodelsprojecthotter
temperaturesforColorado,withtrendstowardmoreseveresoil‐moisturedroughtconditionsin
Colorado(Lukasetal.2014).Warmertemperatureswillresultinhigherevapotranspirationrates
forplants.A.osterhoutiioccursinasemi‐aridclimatewithanaverageof11.88inchesof
precipitationperyear(WesternRegionalClimateCenter2015).Althoughtolerancelimitsforlack
ofmoistureareunknownforthisspecies,ahotterclimatecombinedwithhigher
evapotranspirationmayresultinstressfulconditionsforA.osterhoutii.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncrease.ClimatemodelsprojecthottertemperaturesforColorado(Lukasetal.2014),
andthiscouldresultinincreasedfirefrequencyinsagebrushecosystems.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.SomewhatIncrease.Speciesis
restrictedtowhiteshaleoutcropsofNiobrara,Pierre,andTroublesomeFormationsinGrand
County(CNHP2014).Itismostoftenfoundgrowinginhighlyseleniferoussoils.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesisdependentonotherspeciestogeneratehabitat.
Climate Change Vulnerability Assessment for Colorado BLM 371 C4c)PollinatorVersatility.Neutral.
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.SomewhatIncrease.A.
osterhoutiihasnotbeeninvestigatedfornodulization.However,noduleshavebeenreportedfor
severalotherspeciesinthesubgroupArgophylii(A.crassicarpus,A.missouriensis,A.mollissimus,
andA.purshii),soitispossiblethatA.osterhoutiialsopossessesthisability(DeckerandAnderson
2004).
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown. Literature Cited
ColoradoNaturalHeritageProgram.1997+.ColoradoRarePlantGuide.www.cnhp.colostate.edu.Latestupdate:June30,
2014.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Decker,K.andD.G.Anderson.2004.AstragalusanisusM.E.Jones(Gunnisonmilkvetch):atechnicalconservation
assessment.[Online].USDAForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/astragalusanisus.pdf.[May5,2011].
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter2014.ClimateChangeinColorado,ASynthesistoSupport
WaterResourcesManagementandAdaptation,SecondEdition.Availableat:
http://wwa.colorado.edu/climate/co2014report/.Accessed:2014.
USGSNationalGapAnalysisProgram.2004.ProvisionalDigitalLandCoverMapfortheSouthwesternUnitedStates.
Version1.0.RS/GISLaboratory,CollegeofNaturalResources,UtahStateUniversity.
WesternRegionalClimateCenter.2015.AverageannualprecipitationforKremmling,Colorado.
http://www.wrcc.dri.edu/cgi‐bin/cliMAIN.pl?co3488.AccessedFeb24,2015.PeriodofRecord:1908to2015.
372 Colorado Natural Heritage Program © 2015 Astragalus piscator FisherTowersmilkvetch
G2G3/S1
Family:Fabaceae
Photo: Peggy Lyon Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)A.piscatorhasexperienceda
verysmallrangeinmeanannualprecipitationoverthelast50years;2)seeddispersaldistances
areprobablyfairlylimited;3)potentialincreaseinuraniumandvanadiummininginA.piscator
habitat4)pinyon‐juniperhabitatsoccupiedbyA.piscatormaybesubjecttoincreasedwildfires
undertheclimatechangeprojectionsofhottertemperatures;5)potentiallackofavailablesoil
moistureunderprojectedclimatewarming;6)potentialsymbioticrelationshipwithroot‐
nodulatingbacteria.
Distribution:KnownfromoneoccurrenceinMesaCountyinColorado.AlsoknownfromUtah.
Habitat:Insandy,sometimesgypsiferoussoilsofvalleybenchesandgulliedfoothills.InGateway,it
isfoundonslightlygravellysoilswithmixedredandwhiteparticles.Inaddition,itwasoftenfound
onthesidesofdrygullies(Spackmanetal.1997).Elevation:4500‐5580feet.
EcologicalSystem:SandyAreas,DesertShrub,Pinyon‐Juniper
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral.Thisspeciesisknownfromthe
Colorado/Utahborderinruggedcanyonlands.Nomountainrangesorlargerivervalleysoccurhere.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Fewanthropogenicdisturbances
arepresentintheruggedcanyonsnearGateway,Colorado.Roads,railroads,andsparsehousing
Climate Change Vulnerability Assessment for Colorado BLM 373 developmentarethemaindisturbanceslocatednearA.piscatorhabitat,buttheseoccupyafairly
smallfootprint.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Increase.
FutureincreasesinuraniumandvanadiumminingarepossiblewithinA.piscatorhabitat(CNHP
2014).
C1)Dispersalandmovements.Increase.Seedsdonotcontainspecializedstructurestoaidin
dispersal,andlikelyfallclosetoparentplant.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,A.piscatorhasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Thisspecies
isnotlimitedtocoolorcoldenvironments.Itoccursindry,uplandareasdominatedbypinyon‐
juniperanddesertshrubs.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.GreatlyIncrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,A.piscatorhasexperiencedverysmall(<4inches/100mm)
precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.Climatemodelsprojecthottertemperaturesfor
Colorado,withtrendstowardmoreseveresoil‐moisturedroughtconditionsinColorado(Lukaset
al.2014).Warmertemperatureswillresultinhigherevapotranspirationratesforplants.A.piscator
occursinasemi‐aridclimatewithanaverageof8.7inchesofprecipitationperyear(Western
RegionalClimateCenter2015).Althoughtolerancelimitsforlackofmoistureareunknownforthis
species,ahotterclimatecombinedwithhigherevapotranspirationmayresultinstressful
conditionsforA.piscator.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncrease.A.piscatoroccursinpinyon‐juniperhabitats.Thesehabitatsaremorelikelyto
burnwithincreasedtemperaturesandanincreaseinweedyspeciesthatcomprisetheunderstory,
suchascheatgrass.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesisdependentonotherspeciestogeneratehabitat.
374
Colorado Natural Heritage Program © 2015 C4c)PollinatorVersatility.Neutral.AllAstragalusspeciesareranked‘Neutral’basedonUSFS
speciesassessmentsthatindicateseveralwesternAstragalusspeciesarevisitedbyover20species
ofbees(DeckerandAnderson2004).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.SomewhatIncrease.A.
piscatorhasnotbeeninvestigatedfornodulization.However,noduleshavebeenreportedfor
severalotherspeciesinthesubgroupArgophylii(A.crassicarpus,A.missouriensis,A.mollissimus,
andA.purshii),soitispossiblethatA.piscatoralsopossessesthisability(DeckerandAnderson
2004).
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown. Literature Cited
ColoradoNaturalHeritageProgram.1997+.ColoradoRarePlantGuide.www.cnhp.colostate.edu.Latestupdate:June30,
2014.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Decker,K.andD.G.Anderson.2004.AstragalusanisusM.E.Jones(Gunnisonmilkvetch):atechnicalconservation
assessment.[Online].USDAForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/astragalusanisus.pdf.[Feb26,2015].
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter2014.ClimateChangeinColorado,ASynthesistoSupport
WaterResourcesManagementandAdaptation,SecondEdition.Availableat:
http://wwa.colorado.edu/climate/co2014report/.Accessed:2014.
Spackman,S.,B.Jennings,J.Coles,C.Dawson,M.Minton,A.Kratz,andC.Spurrier.1997.Coloradorareplantfieldguide.
PreparedforBureauofLandManagement,U.S.ForestServiceandU.S.FishandWildlifeServicebyColoradoNatural
HeritageProgram.
WesternRegionalClimateCenter.2015.AverageannualprecipitationforGateway,Colorado.
http://www.wrcc.dri.edu/cgi‐bin/cliMAIN.pl?co3246.AccessedFeb24,2015.PeriodofRecord:1947to2015.
Climate Change Vulnerability Assessment for Colorado BLM 375 Astragalus rafaelensis SanRafaelmilkvetch
G2G3/S1
Family:Fabaceae
Photo: Peggy Lyon Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)A.rafaelensishasexperienceda
verysmallrangeinmeanannualprecipitationoverthelast50years;2)seeddispersaldistances
areprobablyfairlylimited;3)pinyon‐juniperhabitatsoccupiedbyA.rafaelensismaybesubjectto
increasedwildfiresundertheclimatechangeprojectionsofhottertemperatures;5)potentiallack
ofavailablesoilmoistureunderprojectedclimatewarming;6)potentialsymbioticrelationship
withroot‐nodulatingbacteria.
Distribution:ThisisaNavajoBasinendemic;EmeryandlesscommonlyinGrandCounty,Utah
(Welshetal.1993),alsoinMontrose,MesaandLaPlatacountiesinColorado(CNHP1998).
Habitat:Gulliedhills,washes,andtalusundercliffs;inseleniferousclayey,silty,orsandysoils.
Sometimescolonialonroadcuts.ColoradoplantsarefoundonsoilsderivedfromtheMorrison
formation,evenwhenthishaswasheddownontoEntradaorChinleformations(Spackmanetal.
1997).Elevation:4720‐6700feet.
EcologicalSystem:Pinyon‐Juniper
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Increase.Rangeshiftinresponsetoclimate
changeisinhibitedbyunsuitablegeologyandhighmountainhabitatsthatwouldnotcontain
suitablehabitatforthisspecies(USGS2004).
376 Colorado Natural Heritage Program © 2015 B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Fewanthropogenicdisturbances
arepresentintheruggedcanyonsnearParadoxandNucla,Colorado.Roads,railroads,andsparse
housingdevelopmentarethemaindisturbanceslocatednearA.rafaelensishabitat,butthese
occupyafairlysmallfootprint.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
C1)Dispersalandmovements.Increase.Seedsdonotcontainspecializedstructurestoaidin
dispersal,andlikelyfallclosetoparentplant.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,A.rafaelensishasexperiencedaverage
(57.1‐77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Thisspecies
isnotlimitedtocoolorcoldenvironments.Itoccursindrywashesandcliffbasesinareas
dominatedbypinyon‐juniper.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.GreatlyIncrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,A.rafaelensishasexperiencedverysmall(<4inches/100mm)
precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.Climatemodelsprojecthottertemperaturesfor
Colorado,withtrendstowardmoreseveresoil‐moisturedroughtconditionsinColorado(Lukaset
al.2014).Warmertemperatureswillresultinhigherevapotranspirationratesforplants.A.
rafaelensisoccursinasemi‐aridclimatewithanaverageof11.73inchesofprecipitationperyear
(WesternRegionalClimateCenter2015).Althoughtolerancelimitsforlackofmoistureare
unknownforthisspecies,ahotterclimatecombinedwithhigherevapotranspirationmayresultin
stressfulconditionsforA.rafaelensis.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncrease.A.rafaelensisoccursinpinyon‐juniperhabitats.Thesehabitatsaremorelikely
toburnwithincreasedtemperaturesandanincreaseinweedyspeciesthatcomprisethe
understory,suchascheatgrass.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesisdependentonotherspeciestogeneratehabitat.
Climate Change Vulnerability Assessment for Colorado BLM 377 C4c)PollinatorVersatility.Neutral.AllAstragalusspeciesareranked‘Neutral’basedonUSFS
speciesassessmentsthatindicateseveralwesternAstragalusspeciesarevisitedbyover20species
ofbees(DeckerandAnderson2004).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.SomewhatIncrease.A.
rafaelensishasnotbeeninvestigatedfornodulization.However,noduleshavebeenreportedfor
severalotherspeciesinthesubgroupArgophylii(A.crassicarpus,A.missouriensis,A.mollissimus,
andA.purshii),soitispossiblethatA.rafaelensisalsopossessesthisability(DeckerandAnderson
2004).
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown. Literature Cited
ColoradoNaturalHeritageProgram.1997+.ColoradoRarePlantGuide.www.cnhp.colostate.edu.Latestupdate:June30,
2014.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Decker,K.andD.G.Anderson.2004.AstragalusanisusM.E.Jones(Gunnisonmilkvetch):atechnicalconservation
assessment.[Online].USDAForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/astragalusanisus.pdf.[May5,2011].
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter2014.ClimateChangeinColorado,ASynthesistoSupport
WaterResourcesManagementandAdaptation,SecondEdition.Availableat:
http://wwa.colorado.edu/climate/co2014report/.Accessed:2014.
Spackman,S.,B.Jennings,J.Coles,C.Dawson,M.Minton,A.Kratz,andC.Spurrier.1997.Coloradorareplantfieldguide.
PreparedforBureauofLandManagement,U.S.ForestServiceandU.S.FishandWildlifeServicebyColoradoNatural
HeritageProgram.
USGSNationalGapAnalysisProgram.2004.ProvisionalDigitalLandCoverMapfortheSouthwesternUnitedStates.
Version1.0.RS/GISLaboratory,CollegeofNaturalResources,UtahStateUniversity.
378 Colorado Natural Heritage Program © 2015 Astragalus ripleyi Ripley’smilkvetch
G3/S2
Family:Fabaceae
Photo: Courtesy of Colorado Natural Areas Program Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedon:predictedprecipitationdecreases;highmountainsthat
actasnaturalbarriersandhabitatalterationthatresultsfromconversiontofarmland,andlivestock
grazing,whichactasanthropogenicbarrierstorangeshift;limitedseeddispersaldistance;
alterationtothenaturalfiredisturbanceregime;restrictiontoasomewhatuncommongeology;
andpollinatorlimitations.Suitablehabitatislikelytobereducedandreproductivesuccess
diminished.Climatemodelsprojectannualnetdryingthroughoutthisspeciesrange(NatureServe
2012)withresultingtrendstowardmoreseveresoil‐moisturedroughtconditionsinColorado
(Lukasetal.2014).
Distribution:AstragalusripleyihasbeenreportedfromColoradoinConejosCounty(Spackman
1997+)andfromNewMexicoinTaosandRioArribaCounties(NMRPTC2014).However,within
theseregions,A.ripleyidoesnotoccupyallpotentialhabitatbutratherisrestrictedtovolcanic‐
derivedsubstrates(Ladyman2003).Habitat:Astragalusripleyiexhibitsahighdegreeofhabitat
specificity.Itisapparentlyrestrictedtovolcanicsubstrates,inopen‐canopyponderosapine‐
Arizonafescuesavannah,oralongtheedgesofmixedconiferouswoodland/forestwhereArizona
fescueisdominant.Elevation:InColorado,8200‐9300ft.(Spackmanetal.1997).
EcologicalSystem:PonderosaPineWoodlands
Climate Change Vulnerability Assessment for Colorado BLM 379 CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Somewhatincrease.Naturalbarriersborderthe
distributionofthisspeciestotheeast,westandnorthimpairingrangeshift.Astragalusripleyi‘s
rangeisborderedtothewestbythehighpeaksofthenorthwest‐southeasttrendingSanJuan
Mountains,totheeastbythenorth‐southtrendingSangredeCristoMountainRangeandtothe
northbytheeast‐westtrendingLaGaritaMountains.Northwardmigrationthroughthecenterof
therangeisinhibitedbyunsuitablehabitatintheSanLuisvalley(USGS2014).
B2b)Distributionrelativetoanthropogenicbarriers.Somewhatincrease.Conversionof
habitattofarmland(USDA2012)andhabitatalterationbylivestockgrazing(USDOIBLM2014)
impairsrangeshift.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
Neitherexistingnorplannedrenewableenergydevelopmentwilllikelyimpactthisspecies(NRDC
2011).
C1)Dispersalandmovements.Somewhatincrease.Limitedandlocalizeddispersaldistancein
combinationwithinfrequentseedlingrecruitmentincreasesthisspeciesvulnerabilitytoclimate
changebydecreasingmigrationandestablishmentpotential.Seedsmaybedispersedbysmall
mammals,antsandwindorwater(Ladyman2003).Windcanresultadispersaldistanceof1‐15
meters,smallmammalsandantsupto15metersandwaterdispersaldistanceishighly
unpredictable(VittozandEngler2007)buttypicallynotfartherthan100m(Cainetal.2000).
C2ai)Predictedsensitivitytotemperature:historicthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationovertherangeofA.ripleyi,thisspecieshasexperienced
averagetemperaturevariation(57.1‐77oF)overthepast50years(NatureServe2012).
C2aii)Physiologicalthermalniche.Neutral.Thisspeciesisnotdependentoncoolorcold
environments.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Neutral.Consideringtherangeofmeanannualprecipitationacross
occupiedcells,thespecieshasexperiencedaverageprecipitationvariation(21‐40inches)overthe
last50years(NatureServe2012).
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.PredictedprecipitationdecreasesfromMarchthrough
Juneduringthisspecies’growthandreproductiveseasonarelikelytoreduceestablishmentand
flowering(Ladyman2003)thusimpactabundance,distributionandhabitatquality.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Increase.AstragalusripleyioftenoccupiesPonderosa(Pinusponderosa)forests(CNHP2014).
Historically,short‐interval,low‐severitysurfacefiresmaintainedsparse,openstandsinmostdry
380 Colorado Natural Heritage Program © 2015 Ponderosapineforests(Schoennageletal.2004).Consequencesofdecadesoffiresuppressionwith
theaccumulationoffuelsincombinationwithimpactsofrecentclimatechangehavecontributedto
analteredfireregimewithunprecedentedlylarge,high‐severitywildfiresthatarebeyondtherange
ofnaturalvariability(Schoennageletal.2004).
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Increase.Astragalusripleyiis
anedaphicendemicthatoccursexclusivelyonvolcanicderivedsoilsassociatedwiththeSanJuan
volcanicfield(NatureServe2014)withacommensuratelylimitedrange.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Astragalusripleyiisnotknown
tobereliantonotherspeciesforhabitatgeneration.
C4c)PollinatorVersatility.Somewhatincrease.Astragalusripleyiappearstobebee‐pollinated.
Beesandantshavebeenobservedonflowersandbumblebees(Bombusternaries)havebeen
reportedasthemostcommonarthropodvisitor(NatureServe2014).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.Littleevidencehasbeen
documentedforanyparticularmethodofdispersal.However,seeddispersalhasbeenspeculatedto
beeffectedbyants,mice,andotherseedstorers,tumblingofdriedplants,andwindorwater
transport(Ladyman2003)andlikelynotdependentonaspecificspecies.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.SomewhatIncrease.A.
rafaelensishasnotbeeninvestigatedfornodulization.However,noduleshavebeenreportedfor
severalotherspeciesinthesubgroupArgophylii(A.crassicarpus,A.missouriensis,A.mollissimus,
andA.purshii),soitispossiblethatA.rafaelensisalsopossessesthisability(DeckerandAnderson
2004).
C5a)Measuredgeneticvariation.Unknown.Nostudieshavebeenundertakentodeterminethe
geneticstructureofeitherrange‐wideorlocalpopulationsalthoughlocallyendemicspeciesof
Astragalustendtoexhibitreducedlevelsofpolymorphismthatmayimplyareducedrobustness
againstenvironmentaluncertainty(Ladyman2003).
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
Literature Cited
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Cain,M.L.,B.G.Milligan,andA.E.Strand.2000.Long‐distanceSeedDispersalinPlantPopulations.AmericanJournalof
Botany87(9):1217–1227.
Climate Change Vulnerability Assessment for Colorado BLM 381 Decker,K.andD.G.Anderson.2004.AstragalusanisusM.E.Jones(Gunnisonmilkvetch):atechnicalconservation
assessment.[Online].USDAForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/astragalusanisus.pdf.[May5,2011].
Ladyman,J.A.R.2003.AstragalusripleyiBarneby(Ripley’smilkvetch):atechnicalconservationassessment.[Online].
USDAForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/astragalusripley.pdf
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,K.Wolter.2014.ClimateChangeinColorado:ASynthesistoSupportWater
ResourcesManagementandAdaptation,SecondEdition.Available
at:http://cwcbweblink.state.co.us/WebLink/ElectronicFile.aspx?docid=191994&searchid=e3c463e8‐569c‐4359‐8ddd‐
ed50e755d3b7&dbid=0
NatureServe2012.ClimateChangeVulnerabilityAssessmentTool,version2.1.Availableonlineat
https://connect.natureserve.org/science/climate‐change/ccvi.
NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org.(Accessed:November14,2014)
NewMexicoRarePlantTechnicalCouncil(NMRPTC).1999.NewMexicoRarePlants.Albuquerque,NM:NewMexicoRare
PlantsHomePage.http://nmrareplants.unm.edu(Latestupdate:16January2014).
NRDCRenewableEnergyMapNaturalResourcesDefenseCounsel.2011.RenewableenergyforAmerica:harvestingthe
benefitsofhomegrown,renewableenergy.Online.Available:http://www.nrdc.org/energy/renewables/energymap.asp
Accessed2014.
Schoennagel,T.,T.T.Veblen,andW.H.Romme.2004.TheInteractionofFire,Fuels,andClimateacrossRockyMountain
Forests.BioScience,Vol.54No.7,661‐675.
Spackman,S.,B.Jennings,J.Coles,C.Dawson,M.Minton,A.Kratz,andC.Spurrier.1997.ColoradoRarePlantFieldGuide.
PreparedfortheBureauofLandManagement,U.S.FishandWildlifeServiceandU.S.ForestServicebytheColorado
NaturalHeritageProgram,FortCollins.
U.S.DepartmentofAgriculture(USDA).2012.2012CensusofAgriculture.Availableat:
http://www.agcensus.usda.gov/index.php
U.S.DepartmentoftheInterior,BureauofLandManagement(BLM).2014.Availableat:
http://www.geocommunicator.gov/GeoComm/.Accessed2014.
U.S.GeologicalSurvey.2014.TheNationalMap.Availableat:http://nationalmap.gov/viewer.html
VittozP.andEnglerR.2007.Seeddispersaldistances:atypologybasedondispersalmodesandplanttraits.Botanica
Helvetica,117(2),109–124.DOI:10.1007/s00035‐007‐0797‐8
382 Colorado Natural Heritage Program © 2015 Astragalus tortipes SleepingUtemilkvetch
G1/S1
Family:Fabaceae
Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedon:1)A.tortipeshasexperiencedaverysmallrangeinmean
annualprecipitationoverthelast50years;2)seeddispersaldistancesareprobablyfairlylimited;
3)barrierstomovement4)shrublandhabitatsoccupiedbyA.tortipesmaybesubjecttoincreased
wildfiresundertheclimatechangeprojectionsofhottertemperatures;5)potentiallackofavailable
soilmoistureunderprojectedclimatewarming;6)potentialsymbioticrelationshipwithroot‐
nodulatingbacteria.
Distribution:Coloradoendemic(UteMountainUteReservation,MontezumaCounty).Estimated
rangeis10squarekilometers(4squaremiles),calculatedinGISbydrawingaminimumconvex
polygonaroundtheknownoccurrences.Habitat:A.tortipesoccursinamixeddesertscrub,
consistingofAtriplexconfertifolia,Chrysothamnusgreenei,andGutierreziasarothrae(Andersonand
Porter1994).Itisendemictogranite‐derivedgravelssouthoftheSleepingUte(ColoradoNational
HeritageProgram1997).Elevationalrange5400‐5700ft(Spackmanetal.1997).Elevation:5450‐
5700feet.
EcologicalSystem:DesertShrub
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Increase/SomewhatIncrease.Highmountains
andunsuitablehabitatssurroundmanyoftheA.tortipesoccurrences.
Climate Change Vulnerability Assessment for Colorado BLM 383 B2b)Distributionrelativetoanthropogenicbarriers.Increase/SomewhatIncrease.Cropland
onthewesternedgeofoccupiedhabitatmayactasabarriertomovementforA.tortipes.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Increase.
Shrublandspecieswereranked‘Increase’duetothepotentialofwindandsolardevelopment.
C1)Dispersalandmovements.Increase.Seedsdonotcontainspecializedstructurestoaidin
dispersal,andlikelyfallclosetoparentplant.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,A.tortipeshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Thisspecies
isnotlimitedtocoolorcoldenvironments.Itoccursindry,uplandareasdominatedbydesert
shrubs.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.GreatlyIncrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,A.tortipeshasexperiencedverysmall(<4inches/100mm)
precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.Climatemodelsprojecthottertemperaturesfor
Colorado,withtrendstowardmoreseveresoil‐moisturedroughtconditionsinColorado(Lukaset
al.2014).Warmertemperatureswillresultinhigherevapotranspirationratesforplants.A.tortipes
occursinasemi‐aridclimatewithanaverageof12.95inchesofprecipitationperyearinnearby
Cortez,CO(WesternRegionalClimateCenter2015).Althoughtolerancelimitsforlackofmoisture
areunknownforthisspecies,ahotterclimatecombinedwithhigherevapotranspirationmayresult
instressfulconditionsforA.tortipes.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncrease.A.tortipesoccursinshrublandhabitats.Thesehabitatsmaybemorelikelyto
burnwithincreasedtemperaturesandanincreaseinweedyspeciesthatcomprisetheunderstory,
suchascheatgrass.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesisdependentonotherspeciestogeneratehabitat.
C4c)PollinatorVersatility.Neutral.AllAstragalusspeciesareranked‘Neutral’basedonUSFS
speciesassessmentsthatindicateseveralwesternAstragalusspeciesarevisitedbyover20species
ofbees(DeckerandAnderson2004).
384 Colorado Natural Heritage Program © 2015 C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.SomewhatIncrease.A.
tortipeshasnotbeeninvestigatedfornodulization.However,noduleshavebeenreportedfor
severalotherspeciesinthesubgroupArgophylii(A.crassicarpus,A.missouriensis,A.mollissimus,
andA.purshii),soitispossiblethatA.tortipesalsopossessesthisability(DeckerandAnderson
2004).
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown. Literature Cited
Anderson,J.L.,andJ.M.Porter.1994.Astragalustortipes(Fabaceae),anewspeciesfromDesertBadlandsinsouthwestern
ColoradoanditsphylogeneticrelationshipswithinAstragalus.SystematicBotany,19(1):116‐125.
ColoradoNaturalHeritageProgram.1997+.ColoradoRarePlantGuide.www.cnhp.colostate.edu.Latestupdate:June30,
2014.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Decker,K.andD.G.Anderson.2004.AstragalusanisusM.E.Jones(Gunnisonmilkvetch):atechnicalconservation
assessment.[Online].USDAForestService,RockyMountainRegion.Available:
http://www.fs.fed.us/r2/projects/scp/assessments/astragalusanisus.pdf.[Feb26,2015].
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter2014.ClimateChangeinColorado,ASynthesistoSupport
WaterResourcesManagementandAdaptation,SecondEdition.Availableat:
http://wwa.colorado.edu/climate/co2014report/.Accessed:2014.
Spackman,S.,B.Jennings,J.Coles,C.Dawson,M.Minton,A.Kratz,andC.Spurrier.1997.Coloradorareplantfieldguide.
PreparedforBureauofLandManagement,U.S.ForestServiceandU.S.FishandWildlifeServicebyColoradoNatural
HeritageProgram.
WesternRegionalClimateCenter.2015.AverageannualprecipitationforCortez,Colorado.http://www.wrcc.dri.edu/cgi‐
bin/cliMAIN.pl?co3246.AccessedFeb24,2015.PeriodofRecord:1911to2015.
Climate Change Vulnerability Assessment for Colorado BLM 385 Bolophyta ligulata (Parthenium ligulatum) Coloradofeverfew
G3/S2
Family:Asteraceae
Photo: Bob Skowron Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedon:predictedtemperatureincreasesandprecipitation
decreases;presenceofhighmountainrangesandescarpmentsthatpresentnaturalbarriers;
habitatalterationrelatedtooilandgasdevelopmentandlivestockgrazing,whichactas
anthropogenicbarriers;possiblewindpowerdevelopmentonpotentialfuturehabitat;limitedseed
dispersaldistance;restrictiontoarelativelyuncommongeology;andpollinatorlimitations.
Suitablehabitatislikelytobereducedandreproductivesuccessdiminishedasthisspecies’range
becomeswarmeranddrier.Climatemodelsprojectannualnetdryingacrosstherangeofthis
species(NatureServe2012)withresultingtrendstowardmoreseveresoil‐moisturedrought
conditionsinColorado(Lukasetal.2014).
Distribution:BolophytaligulatahasbeenreportedfromColoradoinRioBlancoandMoffat
Counties,andfromUtahinEmeryCounty(NatureServe2014,Welshetal.1987).
EcologicalSystem/Habitat:Bolophytaligulataisknownfrombarrenorsemi‐barrencalciferousor
gypsiferousoutcropsoftheGreenRiver,Uinta,Ferron,Summerville,andCarmelformationsinsalt
desertshrub,serviceberry,rabbitbrush,Indianrice‐grass,greasebush,galleta,blacksagebrush,
pygmysagebrush,andpinyon‐junipercommunities(NatureServe2014).Elevation:1705‐2135
meters(NatureServe2014).
CCVI Scoring
Temperature:CalculatedusingClimateWizard:ensembleaverage,mediumemissionscenario
(A1B),mid‐centurytimeframe,averageannualchange.InColorado,thisspeciesisexpectedtobe
exposedtomeanannualtemperatureincreasesof4.5oFbymid‐century(NatureServe2012).
386 Colorado Natural Heritage Program © 2015 Moisture:CalculatedinGISusingNatureServeHamonAET:PETmoisturemetricdata(thisindex
integratesprojectedtemperatureandprecipitationchangestoindicatehowmuchdryingwilltake
place).InColoradothisspeciesispredictedtobeexposedtonetdryingof9.7to11.9percenton2
percentofitsrange,7.4to9.6percentdryingon13percentofitsrange,5.1to7.3percentdryingon
71percentofitsrangeand2.8to5.0percentdryingon14percentofitsrange.
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Somewhatincrease.Severalmountainranges
andescarpments(USGS2014)actasbarrierstoclimatechange‐inducedrangeshiftforthemajority
ofpopulationsofPartheniumligulatum.
B2b)Distributionrelativetoanthropogenicbarriers.Increase.Habitatalterationrelatedto
energyextractionandlivestockgrazingimpairallpopulationsofBolophytaligulatafrom
climatechange–inducedrangeshift.Allpopulationsoccurinornearshaleplaysandbasinsandare
surroundingbyactiveoilandgasdevelopment(FracFocusWells2013).Additionally,themajority
ofthishabitatinspeciesrangeispubliclandmanagedbytheBLMasrangelandforlivestock(BLM
2014).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.
Somewhatincrease.ExistingandplannedwindpowerdevelopmentontheUtah‐Wyomingborder
(NRDC2011)mayalterhabitatonthepotentialfuturerangeofBolophytaligulata.Because
Bolophytaligulataismoderatelyvulnerabletohabitatalteration(Rocchio2007),windpower‐
relateddevelopmentmaynegativelyimpactthisspeciessurvivability.
*Bolophytaligulata’slifehistorystrategiescanbesuggestedbyBolophytaalpina(Parthenium
alpinum)strategies.BolophytaligulataisverycloselyrelatedtoP.alpinum,suchthattheoriginal
taxonomicrankofP.ligulatumwasavarietyofP.alpinumthatwaslaterelevatedtospecieslevel
(HeidelandHandley2004).
C1)Dispersalandmovements.Somewhatincrease.Windisthelikelydispersalagentfor
Bolophytaalpina(Partheniumalpinum),andthusforB.ligulata.AchenesofB.alpinahavefringed,
wing‐likemembranousextensionsofthepappuswhichcanimprovedispersaldistanceupto15
meters(VittozandEngler2007).
C2ai)Predictedsensitivitytotemperature:historicthermalniche. Neutral. Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage
temperaturevariation(57.1‐77oF)inthepast50years(NatureServe2012).
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Somewhatincrease.
Bolophytaligulatamayrequirecoldtemperaturestoinduceflowering.Winterandspring
temperaturesarepredictedtowarmby4.6oFto4.7oF(NatureServe2012)andthusmaybe
inadequatetopromotefloweringorconverselymayprovidemiscuesthatalterflowering
phenology.Timingoflifehistorytraitsiscentraltolifetimefitnessandnowhereisthismore
importantasinthephenologyoffloweringingoverningplantreproductivesuccess(Inouye2008).
Climate Change Vulnerability Assessment for Colorado BLM 387 C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Somewhatincrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,thespecieshasexperiencedsmall(10.1inches)precipitation
variationinthepast50years(NatureServe2014).
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Somewhatincrease.AlthoughBolophytaligulataiswell
adaptedtoenvironmentalextremes,predictedprecipitationdecreasesduringtheperiodof
floweringandfruitingmaydiminishreproductivesuccess.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Unknown.InColorado,Bolophytaligulatatypicallyoccupiessparselyvegetatedsitesthatdonot
carryfirewell.Although,thesesitesarealsotypicallysurroundedbycommunitiessuchassage
shrublandsandpinyon‐juniperwoodlandswherefirefrequenciesareexpectedtoincreaseinthe
future,followingtrendsthatalreadyshowincreasedfirefrequencies,areaburnedandfireseverity
(Stephens2005,Westerlingetal.2006,Littelletal.2009.However,asyet,impactsonB.ligulata
hasnotbeendocumented.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnot
restrictedtoordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Increase.Bolophytaligulatais
edaphicallyrestrictedtocalciferousorgypsiferousoutcropsofshalesandclaysoftheGreenRiver,
Uinta,Ferron,andCarmelformations(Welshetal.1987).
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Bolophytaligulatahasnotbeen
showntobedependentonotherspeciestogeneratehabitat.
C4c)PollinatorVersatility.Somewhatincrease.PollinationofthecloselyrelatedB.alpinamay
requirespecializedpollinationvectors,suggestingsimilarpollinationrequirementsforB.ligulata.
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.Unknown.
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
Literature Cited
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
388 Colorado Natural Heritage Program © 2015 FracFocusWells.2013.MapProvidedbyFracTrackerAllianceonFracTracker.org.Availableat:
http://www.fractracker.org/map/national/
Heidel,B.andJ.Handley.2004.Partheniumalpinum(Nutt.)Torr.&Gray(alpinefeverfew):atechnicalconservation
assessment.[Online].USDAForestService,RockyMountainRegion.
Available:http://www.fs.fed.us/r2/projects/scp/assessments/partheniumalpinum.pdf.Accessed:2014.
Inouye,D.W.2008.Effectsofclimatechangeonphenology,frostdamage,andfloralabundanceofmontanewildflowers.
Ecology89:353–362.http://dx.doi.org/10.1890/06‐2128.1
Littell,J.,D.McKenzie,D.Peterson,andA.Westerling.2009.ClimateandwildfireareaburnedinwesternU.S.
ecoprovinces,1916‐2003.EcologicalApplications19:1003‐1021
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter2014.ClimateChangeinColorado,ASynthesistoSupport
WaterResourcesManagementandAdaptation,SecondEdition.Availableat:
http://wwa.colorado.edu/climate/co2014report/.Accessed:2014.
NatureServe2012.ClimateChangeVulnerabilityAssessmentTool,version2.1.Availableonlineat
https://connect.natureserve.org/science/climate‐change/ccvi.
NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org.Accessed2014.
NRDCRenewableEnergyMapNaturalResourcesDefenseCounsel.2011.RenewableenergyforAmerica:harvestingthe
benefitsofhomegrown,renewableenergy.Online.Available:http://www.nrdc.org/energy/renewables/energymap.asp
(accessed2014).
Rocchio,J.2007.FloristicQualityAssessmentIndicesforColoradoPlantCommunities.ColoradoNaturalHeritage
Program,ColoradoStateUniversity,FortCollins,CO.
Spackman,S.,B.Jennings,J.Coles,C.Dawson,M.Minton,A.Kratz,andC.Spurrier.1997.ColoradoRarePlantFieldGuide.
PreparedfortheBureauofLandManagement,U.S.FishandWildlifeServiceandU.S.ForestServicebytheColorado
NaturalHeritageProgram,FortCollins.
Stephens,S.L.2005.ForestfirecausesandextentonUnitedStatesForestServicelands.InternationalJournalofWildland
Fire14:213‐222.
U.S.GeologicalSurvey(USGS).2014.TheNationalMap.Availableat:http://nationalmap.gov/viewer.html.Accessed2014.
VittozP.andEnglerR.2007.Seeddispersaldistances:atypologybasedondispersalmodesandplanttraits.Bot.Helv.
117:109–124.
Welsh,S.L.,N.D.Atwood,andJ.C.Higgins.1987.GreatBasinNaturalistMemoir,no.9.BrighamYoungUniversity,ISBN0‐
8425‐2260‐3.
Westerling,A.L.,B.P.Bryant,H.K.Preisler,T.P.Holmes,H.G.Hidalgo,T.Das,andS.R.Shrestha.2011.Climatechangeand
growthscenariosforCaliforniawildfire.ClimaticChange109:445‐463.
Climate Change Vulnerability Assessment for Colorado BLM 389 Camissonia eastwoodiae Eastwoodeveningprimrose
G2/S1
Family:Onagraceae
Photo: Janis Huggins Climate Vulnerability Rank: Highly Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)C.eastwoodiaehasexperiencea
smallrangeinprecipitationinthelast50years;2)availablesoilmoisturemaydecreaseif
temperaturesincreaseaspredictedinclimatemodels;3)potentialforincreasedenergy
developmentwithinsuitablehabitat;4)likelihoodofshortseeddispersaldistance;5)potentialfor
increasedfirefrequencyinpinyon‐juniperandshrublandhabitatthatsupportC.eastwoodiae
populations.
Distribution:EndemictotheColoradoPlateau.FoundinUtah(sevencounties),Arizona(2
counties),andColorado(2counties,USDANRCS2012).Habitat:InColoradothisspeciesisfound
onclaysoilsderivedfromMancosshalewithAtriplexgardneriadominantassociate.Elevation:
4,570‐6,050feet.
EcologicalSystem:SaltbushFlatsandFans,Pinyon‐Juniper
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Increase.
AreasofC.eastwoodiaehabitatmayhavepotentialforincreasedoilandgas,aswellaswindand
solardevelopment.
390
Colorado Natural Heritage Program © 2015 C1)Dispersalandmovements.Increase.Seedslikelyfallclosetoparentplant.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.SomewhatDecrease.
Consideringthemeanseasonaltemperaturevariationforoccupiedcells,thespecieshas
experiencedgreaterthanaverage(>77°F/43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Thisspecies
isnotlimitedtocoolorcoldhabitatsthatareexpectedtobelosttoclimatechange.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Increase.Consideringtherangeofmeanannualprecipitationacross
occupiedcells,thespecieshasexperiencedsmall(4‐10inches/100‐254mm)precipitation
variationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.SomewhatIncrease.Climatemodelsprojecthotter
temperaturesforColorado,withtrendstowardmoreseveresoil‐moisturedroughtconditionsin
Colorado(Lukasetal.2014).Warmertemperatureswillresultinhigherevapotranspirationrates
forplants.C.eastwoodiaeoccursinasemi‐aridclimatewithanaverageof11.33inchesof
precipitationperyearinnearbyGrandJunction,CO(WesternRegionalClimateCenter2015).
Althoughtolerancelimitsforlackofmoistureareunknownforthisspecies,ahotterclimate
combinedwithhigherevapotranspirationmayresultinstressfulconditionsforC.eastwoodiae.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncrease.Increasedfirefrequencymayoccurinshrublandsandpinyon‐juniper
ecosystemsthatsupportpopulationsofC.eastwoodiae.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesisdependentonotherspeciestogeneratehabitat.
C4c)PollinatorVersatility.Unknown.
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.Unknown.
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown. Climate Change Vulnerability Assessment for Colorado BLM 391 Literature Cited
ColoradoNaturalHeritageProgram.1997+.ColoradoRarePlantGuide.www.cnhp.colostate.edu.Latestupdate:June30,
2014.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
FracFocusWells.2013.MapProvidedbyFracTrackerAllianceonFracTracker.org.Availableat:
http://www.fractracker.org/map/national/
Littell,J.,D.McKenzie,D.Peterson,andA.Westerling.2009.ClimateandwildfireareaburnedinwesternU.S.
ecoprovinces,1916‐2003.EcologicalApplications19:1003‐1021
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter2014.ClimateChangeinColorado,ASynthesistoSupport
WaterResourcesManagementandAdaptation,SecondEdition.Availableat:
http://wwa.colorado.edu/climate/co2014report/.Accessed:2014.
USDA,NRCS.2012.ThePLANTSDatabase.NationalPlantDataTeam,Greensboro,NC27401‐4901USA.
WesternRegionalClimateCenter.2015.AverageannualprecipitationforGrandJunction,Colorado.
http://www.wrcc.dri.edu/cgi‐bin/cliMAIN.pl?co3488.AccessedFeb24,2015.PeriodofRecord:1900to2015.
392 Colorado Natural Heritage Program © 2015 Cleome (Peristome) multicaulis Slenderspiderflower
G2G3/S2S3
Family:Capparaceae
Photo: Georgia Doyle Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)barrierstomovement;2)
potentialforsolarandwinddevelopmentinSanLuisValley;3)likelihoodoflimitedseeddispersal;
4)specieshasexperienceverysmallprecipitationvariationinlast50years;4)restrictionto
alkalineorsalinesoilsinwetlands.
Distribution:Mexico,Texas,Arizona,NewMexico,Wyoming,andColorado(USDANRCS2013).
WeberandWittmann(2012)reportthatthisspeciesiswidelydistributedinMexico.Habitat:
Cleomemulticaulisisrestrictedtosalineoralkalinesoils,aroundalkalisinks,ponds,alkaline
meadows,oroldlakebeds.Thesurroundingplantcommunityissalinebottomlandshrubland
(dominatedbySarcobatusandChrysothamnus).Theplantoftengrowsinbandsjustaboverushes
(Juncussp.)andmayextendintogreasewoodandsaltgrass(Graff1992,Spackmanetal.1997,
ColoradoNaturalHeritageProgram2014).Elevation:7,500‐8,200feet.
EcologicalSystem:Grass/ForbDominatedWetlands;Playas
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Greatlyincrease.Knownoccurrencesarelimited
totheflooroftheSanLuisValley,andsurroundinghighmountainsmayactasabarriersto
movement.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.
Climate Change Vulnerability Assessment for Colorado BLM 393 B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Increase.
AnincreaseinsolarandwinddevelopmentcouldoccurintheSanLuisValley.
C1)Dispersalandmovements.Increase.Noinformationisavailableondispersal,butseedslikely
fallclosetoparentplants.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.SomewhatDecrease.
Consideringthemeanseasonaltemperaturevariationforoccupiedcells,thespecieshas
experiencedgreaterthanaverage(>77°F/43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Thisspecies
isnotlimitedtocoolorcoldhabitatsthatarelikelytobelosttoclimatechange.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.GreatlyIncrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,thespecieshasexperiencedverysmall(<4inches/100mm)
precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.GreatlyIncrease.Cleomemulticaulisisrestrictedtosalineor
alkalinesoils,aroundalkalisinks,ponds,alkalinemeadows,oroldlakebeds.Thesewetlandsites
occurinthearidclimateSanLuisValley,whereaverageannualprecipitationis9.39inchesinDel
Norte,CO(WesternRegionalClimateCenter2015).
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesisdependentonotherspeciestogeneratehabitat.
C4c)PollinatorVersatility.Unknown.
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.Unknown.
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown. 394 Colorado Natural Heritage Program © 2015 Literature Cited
ColoradoNaturalHeritageProgram.1997+.ColoradoRarePlantGuide.www.cnhp.colostate.edu.Latestupdate:June30,
2014.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Graff,D.1992.StatusreportforCleomemulticaulisonBlancawetlands.BureauofLandManagement,SanLuisResource
Area,Alamosa,CO.
NatureServe2012.ClimateChangeVulnerabilityAssessmentTool,version2.1.Availableonlineat
https://connect.natureserve.org/science/climate‐change/ccvi.
NatureServe.2014.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.1.NatureServe,
Arlington,Virginia.Availablehttp://explorer.natureserve.org.Accessed2014.
Spackman,S.,B.Jennings,J.Coles,C.Dawson,M.Minton,A.Kratz,andC.Spurrier.1997.ColoradoRarePlantFieldGuide.
PreparedfortheBureauofLandManagement,U.S.ForestService,andU.S.FishandWildlifeServicebytheColorado
NaturalHeritageProgram,Ft.Collins,CO.
USDA,NRCS.2013.ThePLANTSDatabase.NationalPlantDataTeam,Greensboro,NC27401‐4901USA.
Weber,W.A.andR.C.Wittmann.2012.ColoradoFlora,EasternSlope,AFieldGuidetotheVascularPlants,FourthEdition.
Boulder,Colorado.555pp.
WesternRegionalClimateCenter.2015.AverageannualprecipitationforDelNorte,Colorado.
http://www.wrcc.dri.edu/cgi‐bin/cliMAIN.pl?co3488.AccessedFeb24,2015.PeriodofRecord:1893to2015.
Climate Change Vulnerability Assessment for Colorado BLM 395 Corispermum navicula Boat‐shapedbugseed
G1?/S1
Family:Chenopodiaceae
Photo: David G. Anderson Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)naturalbarriersthatwould
preventrangeshiftsduetoclimatechange;2)likelihoodofshortseeddispersaldistances;3)
potentiallackofsoilmoistureunderprojectedclimatewarming;4)lackofprecipitationvariability
inlast50years;5)restrictiontouncommongeologicsubstrates.
Distribution:ConsideredaColoradoendemicbasedonrecentgenetictesting,occurringinJackson
County(Nealeetal.2013).GeneticevidencesuggeststhatNorthSandDunespopulationsarea
separatelyevolvingmetapopulationthatiswellsupportedasadistinctspeciescomparedtoC.
americanumandC.villosum.ApopulationpreviouslyconsideredtobeC.naviculaintheEastSand
DunesisconsideredaC.naviculaxC.americanumhybrid(Nealeetal.2013).Estimatedrangeis17
squarekilometers(6squaremiles),calculatedinGISbydrawingaminimumconvexpolygon
aroundtheknownoccurrences(calculatedbytheColoradoNaturalHeritageProgramin2008).
Habitat:Sanddunes(Nealeetal.2013;CNHP2014).Elevation:8,250‐8,730feet.
EcologicalSystem:Barrens,SandyAreas
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Increase.Thisspeciesislimitedtosanddunes,
andsurroundingareascontainunsuitablegeologyandsoils.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.
396 Colorado Natural Heritage Program © 2015 B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
C1)Dispersalandmovements.Increase.Seedslikelyfallclosetoparentplant.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,C.naviculahasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Increase.This
speciesoccursinsanddunesthatmaybecomedrierasaresultofhighertemperatures.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.GreatlyIncrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,thespecieshasexperiencedverysmall(<4inches/100mm)
precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.Climatemodelsprojecthottertemperaturesfor
Colorado,withtrendstowardmoreseveresoil‐moisturedroughtconditionsinColorado(Lukaset
al.2014).Warmertemperatureswillresultinhigherevapotranspirationratesforplants.C.
navicularoccursinasemi‐aridclimatewithanaverageof10.52inchesofprecipitationperyearin
nearbyWalden,CO(WesternRegionalClimateCenter2015).Althoughtolerancelimitsforlackof
moistureareunknownforthisspecies,ahotterclimatecombinedwithhigherevapotranspiration
mayresultinstressfulconditionsforC.navicula.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Increase.C.naviculaisasand
duneendemic(Nealeetal.2013;CNHP2014).
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesisdependentonotherspeciestogeneratehabitat.
C4c)PollinatorVersatility.Unknown.
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.Unknown.
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
Climate Change Vulnerability Assessment for Colorado BLM 397 C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown. Literature Cited
ColoradoNaturalHeritageProgram.1997+.ColoradoRarePlantGuide.www.cnhp.colostate.edu.Latestupdate:June30,
2014.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter2014.ClimateChangeinColorado,ASynthesistoSupport
WaterResourcesManagementandAdaptation,SecondEdition.Availableat:
http://wwa.colorado.edu/climate/co2014report/.Accessed:2014.
Neale,J.,M.Islam,A.Schwabe.2013.TestingthegeneticidentityofCorispermumattheNorthandEastSandDunesof
NorthernColorado.DenverBotanicGardens.ReporttoColoradoNaturalAreasProgram.SubmittedNov.29,2013.24pg.
WesternRegionalClimateCenter.2015.AverageannualprecipitationforWalden,Colorado.
http://www.wrcc.dri.edu/cgi‐bin/cliMAIN.pl?co3488.AccessedFeb24,2015.PeriodofRecord:1897to2015.
398 Colorado Natural Heritage Program © 2015 Cryptogramma stelleri Slenderrock‐brake
G5/S2
BLMsensitive
Family:Pteridaceae
Photo: Peggy Lyon Climate Vulnerability Rank: Extremely Vulnerable
Thisstatewiderankisbasedonrestrictiontocool,shadedclifffaces,thepresenceofcliffsand
canyonsthatserveasnaturalbarriersinsuitablehabitat,restrictiontocalcareousclifffacesand
overhangswithdrippingwater.Climatemodelsprojectannualnetdryingacrosstherangeofthis
species(NatureServe2012)withresultingtrendstowardmoreseveresoil‐moisturedrought
conditionsinColorado(Lukasetal.2014).Thesehotteranddrierconditionsmayresultinalossof
suitablehabitatforC.stelleri.
Distribution:DistributionofC.stelleriisnearlycircumpolar(NatureServe2013).Itiswidespread
throughouttheUnitedStates.InColoradoithasbeenreportedfromArchuleta,Conejos,Garfield,
Grand,Gunnison,Ouray,SanJuan,SanMiguel,andSummitCounties(CNHP2013).Habitat:Occurs
incracksandcrevicesoflimestonecliffsinmoistconiferousforests,generallyassociatedwith
drippingwater.Elevation:4700‐10,900feet.
EcologicalSystem/Habitat:GroundwaterDependentWetlands,CliffandCanyonSeeps
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.SomewhatIncrease.Speciesgrowsoncliffwalls
andinshallowrockoverhangsthatserveasnaturalbarriers.
Climate Change Vulnerability Assessment for Colorado BLM 399 B2b)Distributionrelativetoanthropogenicbarriers.Neutral.Therearenosignificant
anthropogenicbarriersforthisspeciesintheassessmentarea(Radeloffetal.2005).
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
Occurscliffwallsandinshallowrockoverhangs.Werateallcliffandcanyonspecies‘Neutral’based
ontheassumptionthatdevelopmentinthishabitatisunlikelyinmostmitigationscenarios.
C1)Dispersalandmovements.Neutral.Althoughdispersalmechanismsareunknown,windand
waterlikelytransportspores.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.Neutral.Specieshas
experiencedaveragetemperaturevariation(57.1to>77°F/31.8‐43°C)inthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Increase.Speciesthat
occurinseepsincliffsandcanyonswereallrated‘Increase’undertheassumptionthatthishabitat
maybelostasColoradobecomeswarmer,andpresumablydrier.
C2bi)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Somewhatdecrease.Thespecieshasexperiencedgreaterthan
average(>40inches/1,016mm)precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.GreatlyIncrease.Speciesoccursoncliffwallsandinshallow
rockoverhangswithdrippingwater.Weratedcliffandcanyonspeciesthatpreferwettermicro
sitesas‘GreatlyIncrease’basedontheassumptionthatthesehabitatsmaybelostasColorado’s
climatebecomeswarmeranddrier.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.Thespeciesisnotknowntobedependentonaspecificdisturbanceregime,nordoesit
occurinhabitatlikelytobeexposedtoaltereddisturbanceregimesinawaythatwouldaffectthe
rangeorabundanceofthespecies.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Littledependenceonsnow
oricecover.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Increase.Speciesisrestricted
tocalcareouscliffsandcanyons(Hulten1968).
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.
C4c)PollinatorVersatility.Neutral.C.stelleriisafernthatproducesspores,soitdoesnotrelyon
pollinators.
C4d)Dependenceonotherspeciesforpropaguledispersal.Unknown.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.Unknown.
400 Colorado Natural Heritage Program © 2015 C5)Geneticfactors.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown.
Literature Cited
ColoradoNaturalHeritageProgram(CNHP).2013.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Hulten,E.1968.FloraofAlaskaandNeighboringTerritories.StanfordUniversityPress,Stanford,CA.
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,K.Wolter.2014.ClimateChangeinColorado:ASynthesistoSupportWater
ResourcesManagementandAdaptation,SecondEdition.Availableat:
http://cwcbweblink.state.co.us/WebLink/ElectronicFile.aspx?docid=191994&searchid=e3c463e8‐569c‐4359‐8ddd‐
ed50e755d3b7&dbid=0
NatureServe2012.ClimateChangeVulnerabilityAssessmentTool,version2.1.Availableonlineat
https://connect.natureserve.org/science/climate‐change/ccvi.
NatureServe.2013.NatureServeExplorer:Anonlineencyclopediaoflife[webapplication].Version7.0.NatureServe,
Arlington,VA.U.S.A.Availablehttp://www.natureserve.org/explorer.AccessedDecember9,2013.
Radeloff,V.C.,R.B.Hammer,S.IStewart,J.S.Fried,S.S.Holcomb,andJ.F.McKeefry.2005.TheWildlandUrbanInterfacein
theUnitedStates.EcologicalApplications15:799‐805.
Climate Change Vulnerability Assessment for Colorado BLM 401 Erigeron kachinensis Kachinadaisy
G2/S1
Family:Asteraceae
Photo: Lorainne Yeatts Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)barrierstomovement;2)
restrictiontowet,salinesoilsalongcliffandcanyonwallsthatmaybecomehotteranddrier;3)lack
ofvariationinprecipitationinlast50years.
Distribution:EndemictotheColoradoPlateauinColoradoandUtah.Knowfromonecountyin
Utah(SanJuanCounty),andseveralinColorado.Habitat:Occursinwet,salinesoilsinalcoves,
seeps,andhanginggardensonsandstonecliffsandcanyonwalls(Allphin1991,Spackmanetal.
1997,Ackerfield2012,CulverandLemly2013).AssociatedspeciesincludeEpipactisgigantea,
Aquilegiamicrantha,Mimuluseastwoodiae,andCalamagrostis.Surroundingplantcommunities
includePinyon‐juniper,Fraxinus,andSalix(CNHP2014).Elevation:4,700‐6,700feet.
EcologicalSystem:CliffandCanyon
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Increase.E.kachinensisoccursinhanginggardens
andalcovesincanyons.Cliffsandcanyonsthatserveashabitatforthespeciesalsopresentbarriers
tomovement.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.B3)Impactoflandusechanges
resultingfromhumanresponsestoclimatechange.Neutral.
402 Colorado Natural Heritage Program © 2015 C1)Dispersalandmovements.Increase.Seedslikelyfallclosetoparentplant.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Increase.Cliffand
canyonspecies,suchasE.kachinensis,wererated‘Increase’basedontheirrestrictiontocool,moist
pocketsincanyonsthatmaybecomewarmeranddrierduetoclimatechange.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.GreatlyIncrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,thespecieshasexperiencedverysmall(<4inches/100mm)
precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.GreatlyIncrease.E.kachinensisreliesonalocalizedmoisture
regimefromseeps.ClimatemodelsprojecthottertemperaturesforColorado,withtrendstoward
moreseveresoil‐moisturedroughtconditionsinColorado(Lukasetal.2014).Tolerancelevelsfor
E.kachinensisareunknown,butincreasedtemperaturesmayleadtosoildryingandalossof
suitablehabitatforthisrareplantspecies.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.SomewhatIncrease.E.
kachinensisoccursonwet,salinesoilsinalcovesandhanginggardensoncanyonwalls.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesisdependentonotherspeciestogeneratehabitat.
C4c)PollinatorVersatility.Unknown.
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.Unknown.
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown. Climate Change Vulnerability Assessment for Colorado BLM 403 Literature Cited
Ackerfield,J.2012.TheFloraofColorado.ColoradoStateUniversityHerbarium.433pp.
Allphin,L.1991.SurveyofGrandGulchPrimitiveAreaforErigeronkachinensis.
ColoradoNaturalHeritageProgram.1997+.ColoradoRarePlantGuide.www.cnhp.colostate.edu.Latestupdate:June30,
2014.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Culver,D.R.andJ.M.Lemly.2013.FieldGuidetoColorado’sWetlandPlants:Identification,EcologyandConservation.
ColoradoNaturalHeritageProgram,WarnerCollegeofNaturalResources,ColoradoStateUniversity,FortCollins,
Colorado.
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter2014.ClimateChangeinColorado,ASynthesistoSupport
WaterResourcesManagementandAdaptation,SecondEdition.Availableat:
http://wwa.colorado.edu/climate/co2014report/.Accessed:2014.
Spackman,S.,B.Jennings,J.Coles,C.Dawson,M.Minton,A.Kratz,andC.Spurrier.1997.Coloradorareplantfieldguide.
PreparedforBureauofLandManagement,U.S.ForestServiceandU.S.FishandWildlifeServicebyColoradoNatural
HeritageProgram.
404 Colorado Natural Heritage Program © 2015 Eriogonum brandegeei Brandegeewildbuckwheat
G1G2/S1S2
Family:Polygonaceae
Photo: Susan Spackman Panjabi Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)barrierstodispersal;2)lackof
rangeofvariabilityinprecipitationinthepast50years;3)potentialdecreaseinsoilmoisture
availabilitywithincreasedtemperatures;4)restrictiontospecificgeologicfeaturesandsoiltypes.
Distribution:EndemictoColorado;FremontandChaffeecounties.Sixofthenineverified
occurrencesarelocatedwithina5by15mileareaalongtheArkansasRiverinChaffeeCounty.The
otherthreeareabout50milesawayina2by3mileareaatGardenPark,northofCanonCityin
FremontCounty(Anderson2006).QuestionablereportsofE.brandegeeiinotherareasare
consideredtobemislabeled(Anderson2006).Estimatedrangeis6,828squarekilometers(2,636
squaremiles),calculatedinGISbydrawingaminimumconvexpolygonaroundtheknown
occurrences(calculatedbytheColoradoNaturalHeritageProgramin2008).Habitat:Occurrences
ofEriogonumbrandegeeiarelimitedmostlytooutcropsoftheDryUnionFormation(inChaffee
County)andlowermembersoftheMorrisonFormation(inFremontCounty),ortoQuaternary
stratathatarederivedfromtheseformations(O'Kane1988;Spackmanetal.1997;Anderson
2006).Theunifyingfeatureofalltheknownoccurrencesisthepresenceofasignificantportionof
bentoniteclayinthesoil(Anderson2006).Eriogonumbrandegeeiismostcommonlyfoundon
active,verysteepslopes,andlessfrequentlyonflatsites(Anderson2006).Ingeneral,thisspecies
isfoundonbarrenoutcropsofwhitetograyishsoilswithinopensagebrushandpinyon‐juniper
communities.Elevation:5,715‐8,648feet.
EcologicalSystem:Barrens,Sagebrush
Climate Change Vulnerability Assessment for Colorado BLM 405 CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Increase.HighmountainsandtheArkansasRiver
arelocatedbetweenpopulationsofE.brandegeei,andthesemaypresentbarrierstodispersal.
B2b)Distributionrelativetoanthropogenicbarriers.Neutral.
B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Neutral.
Energydevelopmentisunlikelytooccuronthesteepslopesoccupiedbythisspecies.
C1)Dispersalandmovements.SomewhatIncrease/Neutral.Eriogonumspecieshavepotentialfor
effectivedispersalbywind,water,andanimals(Anderson2006).
C2ai)Predictedsensitivitytotemperature:historicthermalniche.Neutral.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.Increase.Consideringtherangeofmeanannualprecipitationacross
occupiedcells,E.brandegeeihasexperiencedsmall(4‐10inches/100‐254mm)precipitation
variationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.Increase.Climatemodelsprojecthottertemperaturesfor
Colorado,withtrendstowardmoreseveresoil‐moisturedroughtconditionsinColorado(Lukaset
al.2014).Warmertemperatureswillresultinhigherevapotranspirationratesforplants.E.
brandegeeioccursinasemi‐aridclimatewithanaverageof12.77inchesofprecipitationperyearin
nearbyCanonCity,CO(WesternRegionalClimateCenter2015).Althoughtolerancelimitsforlack
ofmoistureareunknownforthisspecies,ahotterclimatecombinedwithhigher
evapotranspirationmayresultinstressfulconditionsforE.brandegeei.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
Neutral.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Increase.E.brandegeeioccurs
onoutcropsoftheDryUnionFormationandtheMorrisonFormation,aswellasQuaternarystrata
derivedfromtheseformations;soilsthatsupporttheseoccurrencescontainbentoniteclay(O'Kane
1988;Spackmanetal.1997;Anderson2006).
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesisdependentonotherspeciestogeneratehabitat.
406 Colorado Natural Heritage Program © 2015 C4c)PollinatorVersatility.Neutral.SpeciesofEriogonumaretypicallypollinatedbygeneralist
pollinators(Revealpers.comm.inAnderson2006;Tepedino2002).
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)FormspartofaninterspecificinteractionnotcoveredbyC4a‐d.Unknown.
C5a)Measuredgeneticvariation.Unknown.
C5b)Occurrenceofbottlenecksinrecentevolutionaryhistory.Unknown.
C6)Phenologicalresponsetochangingseasonaltemperatureandprecipitationdynamics.
Unknown. Literature Cited
Anderson,D.G.2006.EriogonumbrandegeeiRydberg(Brandegee’sbuckwheat):atechnicalconservationassessment.
[Online].USDAForestService,RockyMountainRegion.Available:
http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5206849.pdf
ColoradoNaturalHeritageProgram.1997+.ColoradoRarePlantGuide.www.cnhp.colostate.edu.Latestupdate:June30,
2014.
ColoradoNaturalHeritageProgram(CNHP).2014.BiodiversityTrackingandConservationSystem(BIOTICS).Colorado
NaturalHeritageProgram,ColoradoStateUniversity,FortCollins.
Lukas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter2014.ClimateChangeinColorado,ASynthesistoSupport
WaterResourcesManagementandAdaptation,SecondEdition.Availableat:
http://wwa.colorado.edu/climate/co2014report/.Accessed:2014.
O’Kane,S.L.1988.Colorado’srareflora.GreatBasinNaturalist48:434‐484.
Reveal,J.L.2002.PersonalcommunicationwithexpertonEriogonumregardingE.coloradense.
Spackman,S.,B.Jennings,J.Coles,C.Dawson,M.Minton,A.Kratz,andC.Spurrier.1997.Coloradorareplantfieldguide.
PreparedforBureauofLandManagement,U.S.ForestServiceandU.S.FishandWildlifeServicebyColoradoNatural
HeritageProgram.
Tepedino,V.2002.PollinationBiologyResearchinRelationshiptoRarePlants.PresentationtotheColoradoNativePlant
Society’sAnnualMeetingonSeptember21,2002.
WesternRegionalClimateCenter.2015.AverageannualprecipitationforCanonCity,Colorado.
http://www.wrcc.dri.edu/cgi‐bin/cliMAIN.pl?co3488.AccessedFeb24,2015.PeriodofRecord:1948to2005.
Climate Change Vulnerability Assessment for Colorado BLM 407 Eriogonum clavellatum CombWashbuckwheat
G2/S1
Family:Polygonaceae
Photo: Courtsey of the Colorado Natural Areas Program Climate Vulnerability Rank: Extremely Vulnerable
ThisColoradostate‐widerankisbasedonthefollowingfactors:1)barrierstomovement;2)
potentialforwindandsolarenergydevelopmentinE.clavellatumhabitat;3)likelihoodofshort
seeddispersaldistances;4)potentialdecreaseinsoilmoistureduetoprojectedhigher
temperatures;5)lackofvariabilityinannualprecipitationinlast50years;6)potentialincreasein
firefrequencyinE.clavellatumoccupiedhabitat.
Distribution:KnownfromMontezumaCountyinColorado.EstimatedrangeinColoradois117
squarekilometers(45squaremiles),calculatedinGISbydrawingaminimumconvexpolygon
aroundtheknownoccurrences(calculatedbytheColoradoNaturalHeritageProgramin2008).
Habitat:Thisspeciesisfoundinfinetexturedsoils,sandysilttoclaysilt.Dominantplant
communitiesareshadscaleandblackbrushassociations.OtherassociatedspeciesincludeAtriplex
confertifoliaandColeogyneramosissima(Welsh1978).Elevation:4,813‐6,033feet.
EcologicalSystem:DesertShrub,SaltbrushFansandFlats
CCVI Scoring
B1)Exposuretosealevelrise.Neutral.
B2a)Distributionrelativetonaturalbarriers.Neutral.
B2b)Distributionrelativetoanthropogenicbarriers.SomewhatIncrease.Irrigatedcropland
maycreatebarrierstodispersal.
408 Colorado Natural Heritage Program © 2015 B3)Impactoflandusechangesresultingfromhumanresponsestoclimatechange.Increase.
Therelativelyflat,semiaridlandsinSWColoradohavepotentialforsolarandwindenergy
development.
C1)Dispersalandmovements.Increase.Noinformationisavailableonseeddispersaldistances,
butitislikelythatE.clavellatumseedsfallclosetoparentplants.
C2ai)Predictedsensitivitytotemperature:historicthermalniche.Neutral.Consideringthe
meanseasonaltemperaturevariationforoccupiedcells,thespecieshasexperiencedaverage(57.1‐
77°F/31.8‐43.0°C)temperaturevariationinthepast50years.
C2aii)Predictedsensitivitytotemperature:physiologicalthermalniche.Neutral.Thisspecies
occursindry,uplandareasinSWColoradoandisnotrestrictedtocoolorcoldclimates.
C2bi) Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
historicalhydrologicalniche.GreatlyIncrease.Consideringtherangeofmeanannual
precipitationacrossoccupiedcells,thespecieshasexperiencedverysmall(<4inches/100mm)
precipitationvariationinthepast50years.
C2bii)Predictedsensitivitytochangesinprecipitation,hydrology,ormoistureregime:
physiologicalhydrologicalniche.SomewhatIncrease.Climatemodelsprojecthotter
temperaturesforColorado,withtrendstowardmoreseveresoil‐moisturedroughtconditionsin
Colorado(Lukasetal.2014).Warmertemperatureswillresultinhigherevapotranspirationrates
forplants.E.clavellatumoccursinasemi‐aridclimatewithanaverageof12.95inchesof
precipitationperyearinnearbyCortez,CO(WesternRegionalClimateCenter2015).Although
tolerancelimitsforlackofmoistureareunknownforthisspecies,ahotterclimatecombinedwith
higherevapotranspirationmayresultinstressfulconditionsforE.clavellatum.
C2c)Dependenceonaspecificdisturbanceregimelikelytobeimpactedbyclimatechange.
SomewhatIncrease.Shrublandsmayexperiencemorefrequentwildfiresiftemperaturesincrease
asprojected.
C2d)Dependenceonice,ice‐edge,orsnowcoverhabitats.Neutral.Thisspeciesisnotrestricted
toordependentoniceorsnowcoverhabitats.
C3)Restrictiontouncommongeologicalfeaturesorderivatives.Neutral.
C4a)Dependenceonotherspeciestogeneratehabitat.Neutral.Thereisnoevidencethatthis
speciesisdependentonotherspeciestogeneratehabitat.
C4c)PollinatorVersatility.Unknown.
C4d)Dependenceonotherspeciesforpropaguledispersal.Neutral.
C4e)Formspartofaninterspecificinteractionn