Colorado Wildlife Action Plan Enhancement: Climate Change ... · Colorado Wildlife Action Plan Enhancement:Climate Change Vulnerability Assessment 2014 9 Acknowledgements The authors

ColoradoWildlifeActionPlanEnhancement:ClimateChangeVulnerabilityAssessment

December2014

KarinDeckerandMichelleFink

ColoradoNaturalHeritageProgramColoradoStateUniversityFortCollins,Colorado80523‐1475

ColoradoWildlifeActionPlanEnhancement: ClimateChangeVulnerabilityAssessment 2014

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Table of Contents

TableofContents......................................................................................................................................................2

ListofFigures........................................................................................................................................................6

ListofTables..........................................................................................................................................................7

ListofAcronymsandAbbreviations................................................................................................................8

Acknowledgements.................................................................................................................................................9

Introduction.............................................................................................................................................................10

Methods.....................................................................................................................................................................12

ExposureandSensitivityAssessment.....................................................................................................12

Currentdistributionmodels...................................................................................................................12

Mid‐centuryclimateprojections...........................................................................................................16

Exposuretoclimateenvelopeshiftforimportantvariables....................................................12

Resilience‐AdaptiveCapacityAssessment............................................................................................20

Bioclimaticenvelopeandrange............................................................................................................20

Growthformandintrinsicdispersalrate..........................................................................................21

Vulnerabilitytoincreasedattackbybiologicalstressors..........................................................21

Vulnerabilitytoincreasedfrequencyorintensityofextremeevents..................................21

Landscapecondition..................................................................................................................................21

VulnerabilityAssessmentRanking...........................................................................................................21

Exposure‐SensitivityRanking................................................................................................................21

Resilience‐AdaptiveCapacityRanking...............................................................................................22

OverallVulnerabilityRanking................................................................................................................22

Results........................................................................................................................................................................24

Statewidepatternsofmid‐centuryclimatechangeinColorado..................................................24

Temperature..................................................................................................................................................24

Precipitation..................................................................................................................................................25

Habitat‐specificpatternsofmid‐centuryclimatechangeinColorado......................................32

Habitatvulnerabilityranks..........................................................................................................................36


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Potentialbiomeshifts.....................................................................................................................................37

Conclusions..............................................................................................................................................................39

LiteratureCited......................................................................................................................................................41

TERRESTRIALECOSYSTEMVULNERABILITYASSESSMENTSUMMARIES................................44

LODGEPOLE.............................................................................................................................................................45

ClimateInfluences............................................................................................................................................45

ExposureandSensitivitySummary..........................................................................................................45

ResilienceComponents..................................................................................................................................46

AdaptiveCapacitySummary........................................................................................................................47

VulnerabilitytoClimateChange................................................................................................................47

PINYON‐JUNIPER..................................................................................................................................................52






PONDEROSA............................................................................................................................................................59






SPRUCE‐FIR.............................................................................................................................................................66






OAK‐MIXEDMOUNTAINSHRUB....................................................................................................................74


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SAGEBRUSH.............................................................................................................................................................81






SANDSAGE................................................................................................................................................................89






FOOTHILLANDMOUNTAINGRASSLAND..................................................................................................96






SHORTGRASSPRAIRIE......................................................................................................................................101

ClimateInfluences..........................................................................................................................................101

ExposureandSensitivitySummary........................................................................................................102

ResilienceComponents................................................................................................................................102

AdaptiveCapacitySummary......................................................................................................................103

VulnerabilitytoClimateChange..............................................................................................................103


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PLAYAS.....................................................................................................................................................................108






RIPARIANWOODLANDSANDSHRUBLANDS.........................................................................................112






WETLANDS...............................................................................................................................................................117






ALPINE.....................................................................................................................................................................122







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List of Figures

Figure1.Componentsofvulnerability Glicketal.2011 ..................................................................11

Figure2.Illustrationofmethodforsummarizingthe12climateprojectionmodels.............18

Figure3.Generallizedexampleofassessingtherangeshiftfortemperatureorprecipitationvariables.Thedashedlineindicatesthelimitofthecurrentrangeforthatvariablewithinaspecifichabitat..............................................................................................................................14

Figure4.Vulnerabilityrankingmatrix.........................................................................................................22

Figure5.Annualmeantemperature,comparisonofhistoricnormalswithprojectedconditionsatmid‐21stcenturyforbestandworstcaseendsofmodelrange.....................26

Figure6.Meansummertemperature,comparisonofhistoricnormalswithprojectedconditionsatmid‐21stcenturyforbestandworstcaseendsofmodelrange...................27

Figure7.Meanwintertemperature,comparisonofhistoricnormalswithprojectedconditionsatmid‐21stcenturyforbestandworstcaseendsofmodelrange.....................28

Figure8.Annualprecipitation,comparisonofhistoricnormalswithprojectedconditionsatmid‐21stcenturyforbestandworstcaseendsofmodelrange.................................................29

Figure9.Summerprecipitation,comparisonofhistoricnormalswithprojectedconditionsatmid‐21stcenturyforbestandworstcaseendsofmodelrange............................................30

Figure10.Winterprecipitation,comparisonofhistoricnormalswithprojectedconditionsatmid‐21stcenturyforbestandworstcaseendsofmodelrange............................................31

Figure11.CurrentColoradoannualmeantemperatureandprecipitationforninehabitattypesandprojectedmid‐centuryregionofchange.Circlesrepresenthistoricmeanswitherrorbarsrepresentingonestd.dev.Squaresrepresentthemiddle80%percentoftherangeofprojectedmid‐centurychange 12modelsunderRCP6 ...................................33

Figure12.CurrentColoradosummermeantemperatureandprecipitationforninehabitattypesandprojectedmid‐centuryregionofchange.Circlesrepresenthistoricmeanswitherrorbarsrepresentingonestd.dev.Squaresrepresentthemiddle80%percentoftherangeofprojectedmid‐centurychange 12modelsunderRCP6 ...................................34

Figure13.CurrentColoradomeanwinterminimumtemperatureandprecipitationforninehabitattypesandprojectedmid‐centuryregionofchange.Circlesrepresenthistoricmeanswitherrorbarsrepresentingonestd.dev.Squaresrepresentthemiddle80%percentoftherangeofprojectedmid‐centurychange 12modelsunderRCP6 .............35

Figure14.Potentialbiomeshiftsby2060 Rehfeldtetal.2012 ....................................................38


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Figure15.Exposure‐SensitivityandResilience‐Adaptivecapacityscoresforhabitatsincludedinthisevaluation.VulnerabilityranksofLow,Moderate,andHigharerelativecategoriesindicatinganapproximatepriorityofeachhabitatformanagementandplanningforclimatechange......................................................................................................................39

List of Tables

Table1.Habitatsassessedforvulnerabilitytoclimatechange.Habitatsmarkedwithanasteriskwereaddressedwithanarrativeemphasis,duetospatialdatalimitations.....12

Table2.Metricsusedinhabitatmodels.Unlessotherwisenoted,metricswerecalculatedforeachyearinthetimerange the32yearperiod1980‐2012 ,andthenaveragedoverallyears..................................................................................................................................................15

Table3.Variablegroupsusedindistributionmodeling......................................................................16

Table4.BCCACMIP5Modelsusedforanalysis.......................................................................................17

Table5.Climatevariablesusedtoassesseachhabitat.........................................................................19

Table6.Descriptionoffactorsusedtoassessresilience‐adaptivecapacity...............................20

Table7.Projectedchanges relativeto1980‐2012 bymid‐21stcentury 30‐yearperiodcenteredaround2050 forColoradoasawhole,shownasstatewidemean stdev ....24

Table8.Vulnerabilityranksummaryforallassessedhabitats........................................................36


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List of Acronyms and Abbreviations

SWAP StateWildlifeActionPlan

AFWA AssociationofFishandWildlifeAgencies

AUC Areaundercurve

BCCA BiasCorrectedConstructedAnalogs

BOR BureauofReclamation

BRT BoostedRegressionTrees

CIRES CooperativeInstituteforResearchinEnvironmentalSciences,UniversityofColoradoBoulder

CMIP ClimateModelDiagnosisandIntercomparisonProject Phase3publishedin2007,Phase5publishedin2013

CNHP ColoradoNaturalHeritageProgram

CPW ColoradoParksandWildlife

DJF Wintermonths

JJA Summermonths

MAFW MassachusettsDivisionofFishandWildlife

MAM Springmonths

MCCS ManometCenterforConservationScience

NCCSC NorthCentralClimateScienceCenter

NRCS NaturalResourcesConservationService

NOAA NationalOceanicandAtmosphericAdministration

ppm partspermillion

ppt precipitation

RCP Representativeconcentrationpathway

SAHM SoftwareforAssistedHabitatModeling

SON Fallmonths

SSURGO SoilSurveyGeographicdatabase

STATSGO StateSoilGeographicdatabase

USGS UnitedStatesGeologicalSurvey


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Acknowledgements

TheauthorswouldliketoacknowledgethegeneroussupportofColoradoParksandWildlife,whoprovidedfundingforthiseffort.NumerousCPWstaffsharedtheirextensiveprofessionalexperienceandknowledgethroughouttheprocess.InparticularwethankEricOdell,FranciePusateri,SethMcClean,JimGarner,CaseyCooley,TrevorBalzer,TrentVerquer,HarryCrockett,TinaJackson,andBrianSullivanfortheirassistance.

ThisprojectwouldnothavebeenpossiblewithoutthesupportandcollaborationoftheNorthCentralClimateScienceCenter.ThesharedexpertiseofJeffMorisette,ColinTalbert,MarianTalbert,andBrianMillerattheNCCSCprovideduswithessentialtechnicaltoolsaswellasinteractionwithlocalclimatescientiststhatwouldhavebeendifficultifnotimpossibleforustoacquirewithouttheirassistance.JoeBarsugli CIRES andAndreaRayNOAA providedcrucialfeedbackonourclimatedataselectionandinterpretation.

Finally,atCNHP,JoannaLemlyprovidedcriticalreviewandinformationaboutwetlandandriparianhabitats,RenéeRondeauprovidedadviceandreviewthroughouttheproject,andLeeGrunauperformedprodigiousfeatsofprojectorganization,asusual,thatenabledustocompletethiswork.Thankyouall.


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Introduction

Statewildlifeactionplans SWAPs wereoriginallydevelopedin2005byall50statesandfiveU.S.territoriesasaprerequisiteforthereceiptoffederalfundsthroughtheWildlifeConservationandRestorationProgramandtheStateWildlifeGrantsProgram.TheseplanscompilestepsandstrategiesnecessarytoconservewildlifespeciesandtheirhabitatssothatadequatemanagementactionisundertakenbeforefederalactionundertheESAisrequired.SWAPsareintendedto“assessthehealthofthestate’swildlifeandhabitats,identifytheproblemstheyface,andoutlinetheactionsthatareneededtoconservethemoverthelongterm” AFWA2006 .ASWAPisrequiredtoaddresseightkeyelements,includingdescriptionsofthedistribution,abundance,andconditionofspeciesandtheirhabitats,researchandconservationactionpriorities,monitoringandreview,andbroadpublicparticipation.

MostoftheoriginalSWAPsdidnotaddressclimatechange.Inrecognitionofthegrowingthreatposedbythisfactor,theAssociationofFishandWildlifeAgencies AFWA hasrecommendedthatstatesincorporatetheimpactsofclimatechangeintotheten‐yearSWAPrevisionsrequiredtobecompletedby2015,andprovidedguidanceforthistaskAFWA2009,2012 .AsrecommendedintheAFWAbest‐practicesdocument,therevisedSWAPwilladdresspotentialimpacts,opportunitiesandvulnerabilitiesunderlikelyfutureclimaticconditions.Theintegrationofclimatechangeisintendedtobepartofadynamic,iterative,multi‐scaleprocessthatwillfocusmanagementactionsonstrategiesthatareeffectiveunderbothcurrentandfutureclimates.Thisanalysisisbasedonarelativelyshorttemporalscale i.e.,suitedtoagencyplanninghorizonsandattentivetouncertaintylevelsinprojectedclimatemodels andtheuseofalimitedbutrepresentativesetofpotentialchangescenarios.

AprimarytoolrecommendedbytheAFWAbest‐practicesisthevulnerabilityassessmentforecosystemresponsestoclimatechange.ThecomponentsofvulnerabilityweredescribedbyGlicketal. 2011 andconsistofprojectedexposuretoclimatechange,sensitivityofthespeciesorecosystemtoexpectedchanges,andtheadaptivecapacityofthespeciesorecosystemtorespondtochanges Figure1 .Althoughthisdiagramisstraightforwardandconceptuallysimple,theindividualcomponentsofexposure,sensitivity,andadaptivecapacitycanbedifficulttocalculatewithanyprecision.Uncertaintycomesfromboththedegreeofvariationinthemanyclimateprojectionmodels,andfromthegapsinourknowledgeofthetargetspeciesorhabitat.Inaddressingthesecomponents,wehopetoidentifywhichecosystemsaremostorleastvulnerabletoclimatechangeaswellasthetypeandspatialpatternofthemostsignificantimpacts.Thisinformationisexpectedtohelplandmanagersidentifyareaswhereactionmaymitigate


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theeffectsofclimatechange,recognizepotentialnovelconditionsthatmayrequireadditionalanalysis,andcharacterizeuncertaintiesinherentintheprocess.

Figure 1. Components of vulnerability (Glick et al. 2011).

DuringtherevisionofColorado’scurrentSWAP,theColoradoNaturalHeritageProgramCNHP ,ColoradoParksandWildlife CPW ,NorthCentralClimateScienceCenterandU.S.GeologicalServiceFortCollinsResearchCentercollaboratedtoproduceclimatechangevulnerabilityassessmentsforhighprioritywildlifehabitatsinthestate.Ourobjectiveswereto:

1. Evaluateexposureandsensitivityofpriorityhabitatsbyidentifyingthedegreeofclimatechangeexpectedbetweencurrentandfutureconditionsforclimatefactorsbelievedtoinfluencethedistributionofthehabitat.

2. Evaluateadaptivecapacityofeachhabitatbyassessingfactorsthataffecttheresilienceofthehabitattochangeinlandscapecondition,invasiveorproblematicnativespeciespresence,dynamicprocessalterationbetweenpastandcurrentconditions,andthecharacteristicbioclimaticenvelopeofthehabitat.

3. Producesummaryvulnerabilityratingsforpriorityhabitats.


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Methods

InconsultationwithCPW,CNHPidentified13targethabitatstobeassessed Table1 .TheselectionofhabitatswasbasedontheirimportancetoColoradowildlifeSpeciesofGreatestConservationNeed previouslyidentifiedinthe2005SWAPprocess .Thevulnerabilityofhabitatswasassessedundertwoprimaryheadings:exposure‐sensitivity,andresilience‐adaptivecapacity.Scoresforthesetwofactorswerecombinedtoobtainanoverallvulnerabilityrank.

Table 1. Habitats assessed for vulnerability to climate change. Habitats marked with an asterisk were not modeled.

Target Habitats

Forest and Woodland Grassland

Lodgepole pine forest Foothill & mountain grassland*

Pinyon‐Juniper woodland Shortgrass prairie

Ponderosa pine forest Riparian & Wetland

Spruce‐Fir forest Playas*

Shrubland Riparian woodland & shrubland *

Oak & mixed mountain shrubland Wetlands*

Sagebrush shrubland Other

Sandsage shrubland Alpine

Exposure and Sensitivity Assessment

Weusedspatialanalysismethodstoevaluatetheexposureandsensitivitytoclimatechangeforeachhabitat.ClimatedatawasacquiredwiththeassistanceoftheUSGSFortCollinsScienceCenterandtheNorthCentralClimateScienceCenter.Foreachhabitat,projectedchangeissummarizedbothnarrativelyandgraphically,wherepossible.

Exposure to climate envelope shift for important variables

Ourgoalwastoidentifyclimatevariablesthatweremostinfluentialindeterminingthedistributionofahabitatandevaluateprojectedfuturechangebymid‐centuryforeachvariable.Weusedthreesourcesofinformationforthis:1 habitatdistributionmodelingforasubsetofhabitattypes ;2 expertreview;and3 literaturereview.Fornineoftheuplandhabitattypes,weusedmodelsofcurrentdistributionforeachhabitattoidentifyimportantclimatevariablesforthathabitat.Duetolimitationsintheresolutionofclimatedata,nomodelswereconstructedforthefouradditionalhabitattypes markedby*in


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Table1 .VariablesusedandimportanceranksforeachhabitatmodelwerereviewedbyCPWhabitatmanagersandCNHPecologists,inconjunctionwithaliteraturereview.Insomeinstances,modelswerere‐runtoincorporatefeedbackreceivedorapplicablepublisheddata.Becauseofthehighcorrelationbetweenmanyvariables,thehighAUCvaluesofallmodelsregardlessofwhichcorrelatedvalueswerechosen,andthedifficultyofinterpretingsomemetrics,wedidnotrelysolelyonthemodelingprocesstoidentifyimportantvariablesforeachhabitat.Toclarifyinterpretation,wechosetofocusthefinalanalysisonvariablesthatrepresentedseasonalratherthanmonthlyclimateinformation,andwesubstitutedmeansforvariablesbasedonthestandarddeviationofameanoriginallyusedtoinvestigatevariability .

Fiveclimatevariablesperhabitatwereusedtoevaluateexposureandsensitivity Table5 byassessingthedegreetowhichfutureconditionswithinthecurrentmappeddistributionofahabitatwereprojectedtobeoutsidethecorerangeofcurrentconditions,i.e.,the“rangeshift” Figure3 .Foreachvariable,thepercentofcurrentmappedacreagethatisprojectedtofallbeloworabove dependingonthedirectionofgreateststressinthe“worstcase”–e.g.,eitherwarmestordriestconditions thecurrentrangeiscalculated.Exposure‐sensitivityranksarecalculatedfromtheaverageofthefiverangeshiftproportions.Uncertaintyinthisprocesscomesfromtheprobabilitythatthereareimportantclimatevariablesthatweeitherdon’tknowabout,orcan’tmodel.Additionally,criticalvariablescontrollingthedistributionofahabitatmaynotbeclimaterelated e.g.,soils .Ourintentwastousethebestcurrentlyavailableinformationtomakeabestestimateofvulnerabilitywithavailableinformation.

Current distribution models

ModelingmethodsweredevelopedwiththeassistanceofUSGSFortCollinsScienceCenterandtheNorthCentralClimateScienceCenter.PresencepointsforeachmodeledhabitattypewerederivedfromplotlocationsintheVegBankdatabase Peetetal.2013 andfromplotlocationscollectedbyCNHPandothersinpastvegetationinventoryandsurveyprojects.Pointlocationswereconvertedtocentroidsonthe1kmreferencegridusedastheprojecttemplate;onlycellswithasinglehabitattypewereretained,toavoidecotonalareastransitionalbetweenhabitattypes.Pointsforallhabitatswerecheckedagainstgroundappearancesonrecentaerialimagery,andwithreferencetotheknowndistributionofsignificantpatchesofthishabitattype.Foreachhabitat,thepointsofalltheothertypeswereusedasabsencepoints.ModelingwasperformedwiththeSAHM Morisetteetal.2013 packageinVisTrails NYU‐PolyandUniv.ofUT2014 .


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Figure 3. Generalized example of assessing the range shift for temperature or precipitation variables. The dashed line indicates the limit of the current range for that variable within a specific habitat.

Althoughsomeapparentlycausalrelationshipsbetweenenvironmentalvariablesandthepresenceofprimarycomponent‐speciesaredocumentedformostofourhabitats,thereissubstantialuncertaintyremaining,aswellasalackofdatathatcouldbeusedtomodelsomeofthevariablesknowntobeimportant.Wehadavailablespatialdatafor44climatevariablesand5soilvariablesforthestudyarea Table2 .Climatevariablesweregeneratedfrom1kmDaymet1980‐2012normals Thorntonetal.2012 ;soilvariablesweregeneratedfromSTATSGOandSSURGOdatabases NRCS1994,2012 andconvertedto1kmrasters.Asexpected,acorrelationanalysisshowedhighcollinearitybetweentemperaturevariables,betweenprecipitationvariables,andbetweensoilvariables.Beingmindfulofthepotentialforclimatefactorschosenincurrentmodelstoexhibitdifferentpatternsinfutureprojectionsascomparedtothecurrentnormalperiod Braunischetal.2013 ,wewerereluctanttoretainonlyasinglevariableeachforprecipitationandtemperature.Inanefforttoretainrepresentativeclimatevariablesatdifferenttemporalscales e.g.monthly,seasonally,annually wegroupedour44climatevariablesinto11categories Table3 .Collinearitywasgreatlyreduced althoughnotentirelyeliminated bytheprocedureofselectingasinglevariablefromeachofthegroups.Additionalvariablesineachgroupwereretainedformodelinitiationifbelow0.75correlation.

Wetestedfourmodellingtechniques:boostedregressiontrees BRT ,generalizedlinearmodels,multivariateadaptiveregressionsplines,andrandomforests.Althoughall


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techniquesproducedmodelswithveryhighAUCvalues,wechosetouseBRTasprovidingthebestspatialresultswithregardtotheknownpresentdistributionofeachhabitattype.

Table 2. Metrics used in habitat models. Unless otherwise noted, metrics were calculated for each year in the time range (the 32 year period 1980‐2012), and then averaged over all years.

Metric Description

Temperature

Mean January temperature ((tmax+tmin)/2)

Mean July temperature ((tmax+tmin)/2)

Total annual growing degree days, base 0°C daily ((tmax+tmin)/2) summed across all days where this number is above 0°C

Annual frost free days days/year where tmin > 0°C

Annual very hot days days/year where tmax > 38°C

Annual very cold days days/year where tmin < ‐34°C

Date of first frost Julian date where tmin first <= 0°C in the summer/fall

Variability of first frost standard deviation of first frost over the full time range

Date of last frost Julian date where tmin last <= 0°C in the spring/summer

Variability of last frost standard deviation of last frost over the full time range

Mean summer temperature ((tmax+tmin)/2) averaged over June‐August

Maximum summer temperature tmax averaged over June‐August

Mean winter temperature ((tmax+tmin)/2) averaged over December‐February

Minimum winter temperature tmin averaged over December‐February

Precipitation

Total precipitation for each month (12 metrics) sum of daily precipitation for the month

Total precipitation for each season (4 metrics) sum of the daily precipitation for the 3 month period

Variability of seasonal precipitation (4 metrics) standard deviation of seasonal ppt over the full time range

Total annual precipitation sum of daily precipitation for the year

Variability of annual precipitation standard deviation of annual ppt over the full time range

Seasonal drought days (4 metrics) days/season where ppt < 5mm

Annual drought days days/year where ppt < 5mm


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Metric Description

Annual heavy precipitation days days/year where ppt > 25mm

Total heavy precipitation days total days where ppt > 25mm over the full time period

Total measurable precipitation days total days where ppt > 10mm over the full time period

Soil

Soil depth (cm) Due to the coarse scale of STATSGO and the incomplete nature of SSURGO in Colorado, soil depth and composition were derived from both STATSGO alone and a combination of STATSGO and SSURGO. Whichever version explained the most variation in each model was chosen.

Percent sand

Percent clay

Percent silt

Table 3. Variable groups used in distribution modeling.

Precipitation

Monthly mean precipitation warm months (AMJJA)

Monthly mean precipitation cold months (SONDJF) average

Annual/seasonal (DJF, MAM, JJA, SON) precipitation totals or drought

Variability of annual/seasonal precipitation totals or drought

Extreme precipitation events

Multi‐year precipitation totals

Temperature

Growing season indicators (growing degree days, frostfree days, first and last frost days and variability, temperatures of warmest or coldest months)

Variability of first and last frost dates

Extreme cold events

Extreme hot events

Soil

Soil depth and composition (sand/silt/clay %)

Mid-century climate projections

Projectedfutureandmodeledhistoricbiascorrected,1/8degreestatisticallydownscaleddailyclimatedata BOR2013 forthetopvariables totalingatleast75%oftherelativeinfluenceinthefinalmodel,oridentifiedasimportantbyothersources werecalculated


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usingtheGeoDataPortalpackage Talbert2014 ofVisTrailsandadhocpythoncodeprovidedbytheNCCSC.Weused12models Table4 ,averagedover1980‐2005torepresent"historic"or“current”normals,andaveragedover2035‐2060undertheCMIP5RCP6scenariotorepresentmid‐centuryprojections 2050;BCCA2013 .An1/8degreeresolutionisapproximately12km.Thisisthefinestresolutioncurrentlyavailableforprojecteddailydata.RCP6isthesecondhighestRepresentativeConcentrationPathwayvanVuurenetal.2011 usedintheClimateModelDiagnosisandIntercomparisonProject,phase5 CMIP5 ,estimatingtheequivalentof850ppmofCO2beyondtheyear2100,makingitlooselyequivalenttotheA2emissionsscenariofromCMIP3 830ppmCO2by2100.Note,however,thatRCPsuseradiativeforcinginsteadofCO2emissionsandsoarenotdirectlycomparable .CPWpersonnelselectedRCP6foruseinthisproject.The12modelschosenareallclimateprojectionmodelscalculatedunderRCP6.

Table 4. BCCA CMIP5 Models used for analysis.

Modeling Center (or Group) Institute ID Model Name

Beijing Climate Center, China Meteorological Administration

BCC bcc‐csm1‐1_rcp60_r1i1p1

National Center for Atmospheric Research NCAR CCSM4_rcp60_r1i1p1

NOAA Geophysical Fluid Dynamics Laboratory NOAA GFDL GFDL‐CM3_rcp60_r1i1p1

GFDL‐ESM2G_rcp60_r1i1p1

GFDL‐ESM2M_rcp60_r1i1p1

Institut Pierre ‐ Simon Laplace IPSL IPSL‐CM5A‐LR_rcp60_r1i1p1

IPSL‐CM5A‐MR_rcp60_r1i1p1

Atmosphere and Ocean Research Institute (The University of Tokyo), National Institute for Environmental Studies, and Japan Agency for Marine ‐ Earth Science and Technology

MIROC MIROC5_rcp60_r1i1p1

Japan Agency for Marine ‐ Earth Science and Technology, Atmosphere and Ocean Research Institute (The University of Tokyo), and National Institute for Environmental Studies

MIROC MIROC‐ESM_rcp60_r1i1p1

MIROC‐ESM‐CHEM_rcp60_r1i1p1

Meteorological Research Institute MRI MRI‐CGCM3_rcp60_r1i1p1

Norwegian Climate Centre NCC NorESM1‐M_rcp60_r1i1p1

We acknowledge the World Climate Research Programme's Working Group on Coupled Modelling, which is responsible for

CMIP, and we thank the climate modeling groups (listed in the above table) for producing and making available their model

output. For CMIP, the U.S. Department of Energy's Program for Climate Model Diagnosis and Intercomparison provides

coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth

System Science Portals.


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Thedifferentinitialconditionsandforcingalgorithmsusedbyeachmodelingcenterresultinarangeofoutcomesfromthedifferentmodels,reflectingtheinherentuncertaintyinprojectingfutureclimaticconditions.Precipitationprojectionsinparticularvarywidelyfrommodeltomodel.Tocapturetherangeofuncertaintyinthemostusefulwaypossible,thecentral80%ofthe12‐modelrangewaschosentorepresentthe"reasonablerange"ofpossiblefutureclimateforeachmetric Figure2 .Arasterforthelowerendofeachmetricwasproducedbyadding10%oftherangetotheminimumcellvalue,andforthehigherendbysubtracting10%oftherangefromthemaximumcellvalue.Inevaluatinghabitatexposuretoclimatechange,wegenerallyconcentratedonthe“worstcase”endoftherange,representingeitherthewarmestprojectedconditionsfortemperaturevariablesorthedriestprojectedconditionsforprecipitationvariables.Althoughanumberofmodelsprojectincreasedprecipitationforourarea,wefocusedonpotentiallydrieralternativestoaccountforthedryingeffectsofincreasingtemperature.Thisgivesmanagerstheoptiontoplanforthe"worstcase"changeinclimate.

Figure 2. Illustration of method for summarizing the 12 climate projection models.


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Table 5. Climate variables used to assess each habitat (shaded cells).

Habitat Target

Winter ppt

Spring ppt

Summer ppt

Fall ppt

Annual ppt

Heavy ppt days

Drought days

Date of last frost

Date of first frost

Winter min tem

p

Winter avg temp

Spring avg temp

Summer avg tem

p

Annual avg tem

p

GDD (base 0)

Very hot days

Very cold days

Forest and Woodland

Lodgepole pine forest

Pinyon‐Juniper woodland

Ponderosa pine forest

Spruce‐Fir forest

Shrubland

Oak & mixed mountain shrub

Sagebrush shrubland

Sandsage shrubland

Grassland

Foothill & mountain grassland

Shortgrass prairie

Riparian & Wetland

Playas

Riparian woodland & shrubland Wetlands

West

Mountains

East

Other

Alpine


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Resilience-Adaptive Capacity Assessment

Thisranksummarizesindirecteffectsandnon‐climatestressorsthatmayinteractwithclimatechangetoinfluencetheadaptivecapacityandresilienceofahabitat.FactorsevaluatedareadaptedfromthemethodologyusedbyManometCenterforConservationScienceandMassachusettsDivisionofFishandWildlife MCCSandMAFW2010 ,combinedunderfiveheadings Table6 .Factorswerescoredonascaleof0 lowresilience to1 highresilience .

Table 6. Description of factors used to assess resilience‐adaptive capacity.

Assessment factor Description

Bioclimatic envelope and range

This factor summarizes the expected effects of limited elevational or bioclimatic ranges for a habitat. Suitable conditions for habitats at upper elevations may be eliminated. Habitats with narrow bioclimatic envelopes may be more vulnerable to climate change. Finally, habitats 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 habitat’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. Habitats 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 a habitat 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 habitat 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

Eachhabitatwasscoredforelevationexposure,southernedgeofrange,annualprecipitationrange,andgrowingdegreedaysrange.Habitatsrestrictedtohighelevationsreceivedascoreof0,otherhabitatsscored1.Likewise,habitatsatthesouthernedgeoftheircontinentalrangeinColoradowereassignedascoreof0,andotherhabitatsscored1.


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AnnualprecipitationandgrowingdegreedaysrangewerecalculatedastheproportionoftotalvariablerangeinColoradoinwhichthehabitathadsignificantpresencemapped.Thesefourscoreswereaveragedtoproduceasinglescoreforthisfactor.

Growth form and intrinsic dispersal rate

Scoresof0 lowresilience ,0.5 uncertainormoderateresilience ,and1 highresilience wereassignedtoeachhabitatbasedongrowthformofthedominantspecies i.e.,treesscored0,shrubsandherbaceousscored1 ,andotherinformationderivedfromtheliteratureregardingthedispersalabilitiesofthosespecies.

Vulnerability to increased attack by biological stressors

Foreachbiologicalstressortowhichahabitatisbelievedvulnerable,0.33wassubtractedfromadefaultscoreof1,toproducethefinalhabitatscore.

Vulnerability to increased frequency or intensity of extreme events

Foreachnon‐biologicalstressortowhichahabitatisbelievedvulnerable,0.33wassubtractedfromadefaultscoreof1,toproducethefinalhabitatscore.

Landscape condition

Theaveragevalueacrossthestatewidelandscapeintegritymodels Rondeauetal.2011,Lemlyetal.2011 foreachhabitatwascalculatedasavaluebetween0and1.

Vulnerability Assessment Ranking

WelooselyfollowedthemethodologyoftheNatureServeHabitatClimateChangeVulnerabilityIndex Comeretal.2012 .Foreachhabitat,itsprojectedexposuretoclimatechangeanditspresumedsensitivitytothatchangearecombinedintoasinglerank.Thisrankincorporatestheprojecteddegreeofchange exposure forfiveclimatevariablesbelievedtobeimportantindeterminingthedistributionofthathabitat sensitivity .Theexposure‐sensitivityrankiscombinedwitharanksummarizingtheresilienceandadaptivecapacityofthehabitat.

Exposure-Sensitivity Ranking

Thisranksummarizesthedegreeofprojectedchange exposure forfiveclimatevariablesperhabitat.Variablesarethosetowhichthehabitatissensitive,basedonourthreesourcesofinformation.Foreachvariable,thepercentofcurrentmappedacreagethatisprojectedtofallbeloworabove dependingonthedirectionofgreateststressinthe“worstcase”


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scenario–e.g.,eitherwarmestordriestconditions onestandarddeviationofthecurrentmeaniscomparedwiththepercentageundercurrentconditions.Anegativevalueindicatesimprovingconditionsforthathabitat,whileapositivevalueindicatesexposureconditionsthatarepresumedtobemorestressful.Thevaluesareaveragedforacombinedscorethatisintendedtoindicatetherelativedegreeofimpacttothehabitatfromchangingclimate.

Resilience-Adaptive Capacity Ranking

Scoresforthefivefactorsarebasedonbothspatialanalysisandliteraturereview.Rankingsforthissub‐scoreareoppositetothedirectionoftheexposure‐sensitivityrankingscheme i.e.,apositivevalueindicates“better”andanegativevalueindicates“worse.” Theroundedaverageofthefivesub‐rankingsdeterminesthefinalResilience‐AdaptiveCapacityrank.

Overall Vulnerability Ranking

TheExposure‐SensitivityrankandtheResilience‐AdaptiveCapacityrankarecombinedFigure4 accordingtotheschemepresentedbelow Comeretal.2012 .

Exposure‐Sensitivity rank / Resilience ‐ Adaptive capacity rank

Vulnerability

H / H M / H L / H

Very High

High

Moderate

Low

H / M M / M L / M

H / L M / L L / L

Figure 4. Vulnerability ranking matrix.

VeryHigh:Habitatshavehighvulnerabilitytoclimatechangewhenexposureandsensitivityarehigh,andadaptivecapacityandresiliencearelow.Underthesecircumstances,transformationofthehabitatismostlikelytooccurinupcomingdecades.


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High:Highvulnerabilitytoclimatechangeresultsfromcombiningeitherhighormoderateexposure‐sensitivitywithlowormediumadaptivecapacity‐resilience.Undereithercombination,climatechangeislikelytohavenoticeableimpact.

Moderate:Moderatevulnerabilitytoclimatechangeresultsfromavarietyofcombinationsforexposure‐sensitivityandadaptivecapacity‐resilience.Thenumberofpossiblecombinationsindicatesadegreeofuncertaintyinthevulnerabilityranking.Undercircumstanceswherethetwofactorsareessentiallybalanced,vulnerabilityisthoughttobereduced,butstillofconcern.

Low:Lowvulnerabilitytoclimatechangeoccurswhenahabitatcombineslowexposureandsensitivitywithhighormoderateadaptivecapacityandresilience.Forthesehabitatsclimatechangestressanditseffectsareexpectedtobeleastsevereorabsent.


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Results

Statewide patterns of mid-century climate change in Colorado

Projectionsbasedon12modelsrununderRCP6forthe30‐yearperiodcenteredon2050indicatethatallareasofColoradowillexperiencesomedegreeofwarming Table7,Figures5‐7 ,andpotentiallychangesinpecipitationaswell.Temperaturechangeprojectionsareregardedasmorecertain Barsuglipers.comm. ,andthereisgeneralagreementthatconditionshavealreadywarmedtosomedegree Lucasetal.2014 ;uncertaintyfortemperaturechangeislargelyregardingthemagnitudeoftheprojectedchange.PrecipitationprojectionsforColoradoaremorevariablethanthosefortemperature.Somemodelprojectionsaredrierthancurrentconditionsandsomearewetter Figures8‐10 ;statewidepatternsofprecipitationarealsovariablebetweenmodels.Incombinationwithexpectedchangesintemperature,however,evenawetterscenariomaynotbesufficienttomaintainrunoffandsoilmoistureconditionssimilartothoseoftherecentpast.Climateprojectionspresentedherearesummariesoflongtermtrendsanddonottrackinter‐annualvariation,whichwillremainasourceofvariability,asithasbeeninthepast.Ouranalysisfocusedonasinglerepresentativeconcentrationpathwayandalimitedsubsetofavailableglobalcirculationmodels;atthispointintimewehavenowayofknowingifthisisthescenariothatwillbefoundvalidbymid‐century.

Table 7. Projected changes (relative to 1980‐2012) by mid‐21st century (30‐year period centered around 2050) for Colorado as a whole, shown as statewide mean (stdev).

Projected changes by

mid‐21st century*

Lower (10%) range

Upper (90%) range

Change in annual avg. temperature 1.04C (0.04) 1.87F (0.07) 2.28C (0.11) 4.10F (0.20)

Change in summer avg. temperature 1.30C (0.07) 2.34F (0.13) 2.78C (0.15) 5.00F (0.27)

Change in winter avg. temperature 0.59C (0.15) 1.06F (0.27) 2.52C (0.15) 4.54F (0.27)

Change in annual precipitation ‐41.73 mm (26.54) ‐1.64 in (1.04) 53.70 mm (25.59) 2.11 in (1.01)

Change in summer precipitation ‐29.86 mm (17.26) ‐1.18 in (0.68) 8.60 mm (4.87) 0.34 in (0.19)

Change in winter precipitation ‐8.44 mm (9.39) ‐0.33 in (0.37) 17.34 mm (14.12) 0.68 in (0.56)

*Projections are based on 12 BCCA CMIP5 RCP6 models

Temperature Statewide,annualmeantemperaturesunderthewarmestprojectedconditionswouldincreasebyatleast2C 3.6°F .Ingeneral,mountainousareas,includingtheSanLuisValley,willwarmslightlyless 0.2‐0.3C;0.4‐0.5°F thanelsewhere.Temperaturesin


25

northeasternandnorthwesternColoradoareprojectedtoincreasebyaround2.4C 4.3°F ,withincreasesofaround2.0C 3.6°F incentralpartsofthestate.Wintertemperaturesshowasimilarpattern,withthegreatestpotentialwarming 2.6‐2.8C;4.7‐5.0°F projectedfornon‐mountainousareasinthenorthernhalfofthestate.Althoughaveragewinterminimumtemperaturesremainbelowfreezingstatewide,increasingmeanwintertemperaturesarelikelytogreatlyexpandtheareaexperiencingwintermeansabovefreezing.Projectedincreasesinsummermeantemperaturesaregreatestontheeasternplains 2.6‐3.1C;4.7‐5.6°F ,andareleastinmountainousareasunderthewarmestscenario.Summerminimumtemperatures i.e.,warmnights arealsoprojectedtoincrease.CurrentlymostofColorado’salpineareashaveaveragesummerminimumtemperaturesthatdipbelowfreezing.Underthewarmestscenario,thesecoldsummernighttemperatureswouldbelargelyeliminatedfrommanypartsofthestate.

Precipitation

Incontrasttotemperatureprojections,changesinprecipitationcouldbepositiveornegative.Underthedriestprojectedconditions,easternColorado,thesouthernSanJuanMountains,andtheSanLuisValleycouldseedecreasesof1‐4inchesormoreinannualprecipitation.Underthewettestprojectedconditions,mostareaswouldexperienceanincreaseinannualprecipitation,especiallythenorthernandcentralmountains.Underprojectedwetterconditions,mountainareasaremostlikelytoseeanincreaseinwinterprecipitation,andthefareasternplainsmostlikelytoseesomewhatmoresummerprecipitation.Underprojecteddrierconditions,thegreatestdecreaseinwinterprecipitationisforthesouthwesternpartofthestate,andsummerdecreasesaregreatestontheeasternplains.Projectedstatewidepatternsofprecipitationaregenerallysimilartothoseobservedintherecentpast,butwithaslighttendancyforeasternandsouthernpartsofthestatetoberelativelydrierthantheyhavebeen.ThelocaleffectsofColorado’scomplextopographyaddanadditionalelementofuncertaintytoprojectionsofprecipitationthathaveanunderlyingresolutionof1/8thdegree ~12km .


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Figure 5. Annual mean temperature, comparison of historic normals with projected conditions at mid‐21st century for best and worst case ends of model range.


27

Figure 6. Mean summer temperature, comparison of historic normals with projected conditions at mid‐21st century for best and worst case ends of model range.


28

Figure 7. Mean winter temperature, comparison of historic normals with projected conditions at mid‐21st century for best and worst case ends of model range.


29

Figure 8. Annual precipitation, comparison of historic normals with projected conditions at mid‐21st century for best and worst case ends of model range.


30

Figure 9. Summer precipitation, comparison of historic normals with projected conditions at mid‐21st century for best and worst case ends of model range.


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Figure 10. Winter precipitation, comparison of historic normals with projected conditions at mid‐21st century for best and worst case ends of model range.


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Habitat-specific patterns of mid-century climate change in Colorado

Acomparisonofthecurrentclimateenvelopeforannualandseasonalpatternsoftemperatureandprecipitationwithprojectedvalues Figure11 showsthatfutureconditionsformosthabitatsintheircurrentlyoccupiedrangewillbewarmer,butprobablystillwithintherangeoftoleranceformostconstituentspecies.Theprojectedrangeoffutureprecipitationtendstowardswetterforhigherelevationhabitats,anddrierforlowerelevationhabitats.Habitatsoftheeasternplainsaregenerallyprojectedtobedrierandwarmer.Duetoincreasingtemperaturepatterns,evenaslightincreaseinprecipitationmayresultinoveralldrierconditionsforsoilmoisture.

Seasonalpatternsoftemperatureandprecipitationshowdifferentpatterns.Theelevationalseparationofhabitatsisnotevidentforsummerprecipitation,althoughtemperaturegradientsremain Figure12 .Warmingtrendsaresimilartothoseseenintheannualsummary,butprecipitationtendstowarddrierconditionsincomparisonwiththerecentpast.Projectedchangesforwintertemperatureandprecipitationmeansshowlesspotentialwarming,andmorepotentialincreaseinprecipitation Figure13 .

Withinthetimeframeandemissionsscenariousedforouranalysis,theprojectedclimateconditionsforourfocalhabitatsindicatethatbymid‐centuryhabitatenvelopesareshifting,butmaystillbewithintherangeoftheconstituentorganisms,atleastinpart.Ingeneral,mosthabitatswillnotshiftquickly,butwewilllikelybegintoseealteredcompositionandpotentialfornovelcombinations.


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(a)

(b)

Figure 11. Current Colorado annual mean temperature and precipitation and projected mid‐century region of change for (a) upland habitats and (b) wetland and riparian habitats. Circles represent historic means with error bars representing one std. dev. Squares represent the middle 80% percent of the range of projected mid‐century change (12 models under RCP6).


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(a)

(b)

Figure 12. Current Colorado summer mean temperature and precipitation and projected mid‐century region of change for (a) upland habitats and (b) wetland and riparian habitats. Circles represent historic means with error bars representing one std. dev. Squares represent the middle 80% percent of the range of projected mid‐century change (12 models under RCP6).


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(a)

(b)

Figure 13. Current Colorado mean winter minimum temperature and precipitation and projected mid‐century region of change for (a) upland habitats and (b) wetland and riparian habitats. Circles represent historic means with error bars representing one std. dev. Squares represent the middle 80% percent of the range of projected mid‐century change (12 models under RCP6).


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Habitat vulnerability ranks

Threeofthe18habitatsorhabitatsubgroupsassessedhaveanoverallvulnerabilityrankofHigh Table8 .Ingeneral,habitatsoftheeasternplainshavethegreatestexposuretochange,andthoseofhigherelevationsaremoderatelyexposed.Underamoresevereemissionsscenario,andlongertime‐frame,thesehabitatswouldbesubjecttoincreasedexposure.Mosthabitatswereassessedashavingmoderateresilience.Additionaldiscussionforindividualhabitatsisprovidedbelow.

Table 8. Vulnerability rank summary for all assessed habitats.

Habitat Target Exposure ‐

Sensitivity final ranking

Resilience ‐ Adaptive capacity

final ranking

Combined ranks

Overall vulnerability

rank

Forest and Woodland

Lodgepole pine forest Low Low L/L Moderate

Pinyon‐Juniper woodland Low Low L/L Moderate

Ponderosa pine forest Moderate Moderate M/M Moderate

Spruce‐Fir forest Moderate Moderate M/M Moderate

Shrubland

Oak & mixed mountain shrub Low High L/H Low

Sagebrush shrubland Low Moderate L/M Low

Sandsage shrubland High High H/H Moderate

Grassland

Foothill & mountain grassland ‐ high Moderate Moderate M/M Moderate

Foothill & mountain grassland ‐ low High Moderate H/M High

Shortgrass prairie High Moderate H/M High

Riparian & Wetland

Playas Moderate Low M/L High

Riparian woodland & shrubland ‐ west Low Low L/L Moderate

Riparian woodland & shrubland ‐ mountain Low Moderate L/M Low

Riparian woodland & shrubland ‐ east Low Moderate L/M Low

Wetlands ‐ west Low Moderate L/M Low

Wetlands ‐ mountain Low Moderate L/M Low

Wetlands ‐ east Moderate Moderate M/M Moderate

Other

Alpine Moderate Moderate M/M Moderate


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Potential biome shifts

Rehfeldtetal. 2012 modeledtheNorthAmericanbiomesofBrownetal. 1998 forfutureclimatescenarios.WithinColorado,recentpastconditionsaresuitableforeightbiometypes,approximatelycorrespondingtothealpine,spruce‐fir,montaneconiferencompassingponderosa,mixedconifer,andaspen,withinclusionsofothermontanenon‐treedvegetationtypes ,oak‐mixedmountainshrub,pinyon‐juniperwoodland,sage‐desertgrassland,shortgrass,anddesertshrubland Figure14 .Aspredictedbythemodelconsensusfor2060,biomesinthestateareexpectedtoshifttotheextentthatsuitableareaforalpineiseliminatedinfavorofspruce‐fir,togetherwithapotentialfornovelcombinationsofconifersatelevationspreviouslydominatedbyspruce‐firforests.Thezonesuitableforthevariousconiferandaspentypesispredictedtoexpandsubstantially,potentiallymovingintosouthernareascurrentlyoccupiedbyoak‐mixedmountainshrubland.Areasfavorabletooak‐mixedmountainshrublandarealsoprojectedtoexpandnorthward,intoareascurrentlyoccupiedbypinyon‐juniperand/orsagebrushgrassland.Conditionssuitablefordesertshrublandarealsopredictedtoexpandconsiderablyintoareascurrentlyoccupiedbysagebrush‐grassland oragriculture .Inthesouthernplains,someareaisprojectedtobecomedryenoughforsemi‐desertgrasslandstodisplaceshortgrass.

Becausewedidnotmodelprojectedfuturedistributionofhabitats,acomparisonofthebiomemodelsofRehfeldtetal. 2012 withourresultsisnotstraightforward.Furthermore,modeledbiometypesdonotcrosswalktoourhabitattypesinaclearone‐to‐onerelationship;anumberoftypesaresimplynotaddressedwellbyaparticularbiome.However,projectedbiomechangesareinbroadagreementwithouranalysisofColorado’smoreextensivehabitats,exceptforthoseoftheeasternplains.Ourlowexposurerankingofpinyon‐juniperandoak‐mixedmountainshrubcorrespondswiththeprojectedexpansionofthesebiomesintoareasthatarecurrentlycoolerthanfutureprojections.ModerateexposurerankingsformostofColorado’sconiferousforesttypesarereflectedintheprojectedrearrangementofbiometypeswhereconditionsinalpineareasbecomefavorablefortreegrowth,andlowerelevationforestsarelikelytochangeinstructureandcompositionastheyexpandintoadditionalhabitat.Thehighexposurerankingforhabitatsoftheeasternplainsisnotmatchedbyamodeledbiomeshift,exceptinthesouthernplainswhereshortgrassprairiemayunabletomaintainitscurrentdistribution.


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Figure 14. Potential biome shifts by 2060 (Rehfeldt et al. 2012).


39

Conclusions

Themajorityofhabitattypeswererankedasmoderatelyvulnerableinouranalysis,however,thedivisionbetweenmoderatelyandhighlyvulnerableislessclearthantheseparationbetweenlowandmoderatevulnerability Figure15 .Thetruevulnerabilitylevelofhabitatsnearthemoderate‐highdivisionislikelytobedeterminedbytheirdegreeofadaptivecapacity,whichwewerenotabletoevaluatewithprecision,andwhichcanbeaffectedbymanagementactionstosomeextent.

Figure 15. Exposure‐Sensitivity versus Resilience‐Adaptive capacity scores for habitats included in this evaluation. Vulnerability ranks of Low, Moderate, and High are relative categories indicating an approximate priority of each habitat for management and planning for climate change.

Bymid‐century,underamedium‐highradiativeforcingscenario RCP6.0 ,wecanexpecttoseewarmertemperaturesstatewide,especiallyontheeasternplains.Warmertemperaturesarelikelytoincludemoreheatwaves,fewercoldsnaps,andgenerallyextendedfrost‐freeperiods.Althoughtheseconditionscouldbenefitmanyspeciesif


40

precipitationremainsadequate,thewarmingtrendislikelytobeaccompaniedbydrierconditionsinmanyareas.Evenifprecipitationlevelsathigherelevationsareessentiallyunchanged,warmerconditionswillleadtomoreprecipitationfallingasraininsteadofsnow,adecreasedsnowpack,earlierrunoff,andearlierdryconditionsinlatesummerLucasetal.2014 .Allofthesefactorsmayinteractwithstressorssuchasfire,forestpestsanddiseases,drought,andanthropogenicdisturbancetoalterthefuturetrajectoryofaparticularhabitat.

Comparisonofthecurrentrangeofclimatevariableswiththeprojectedrange Figures11‐13above indicatessubstantialcurrentandfutureoverlapofclimaticconditionsforsomehabitatgroups.Forinstance,alpine,spruce‐fire,and,insomecaseslodgepolepine,areclearlycloseinclimatictolerance,whileponderosapine,oak‐shrub,andsagebrushformagroupsharingsimilarclimaticconditionsatlowerelevations.Theinteractionofclimaticconditionswithotherenvironmentalfactorsandbiogeographichistoryshapesthedistributionofhabitatsthatwecurrentlyobserve.Furthermore,thetimelagbetweenwhenclimateconditionsbecomesuitableorunsuitableforaspeciesandtheeventualcolonizationoreliminationofthatspeciesinanareaaddsanotherlevelofuncertaintytoprojectionsoffuturehabitatdistribution.Climatechangesoverthepastfewdecadesareprobablyalreadyfacilitatingagradualshiftofhabitatsthatwillbecomemoreapparentbymid‐century.

Ouranalysisoftherangeoffutureuncertaintyfocusedon“worstcase”outcomesinordertoprovideavulnerabilityprioritizationofkeyhabitatsthatwillfacilitateapragmatic“no‐regrets”planningstrategyforCPWstaffdealingwiththeongoingeffectsofclimatechangeinColorado.


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Lemly,J.,L.Gilligan,andM.Fink.2011.StatewideStrategiestoImproveEffectivenessinProtectingandRestoringColorado’sWetlandResourceIncludingtheRioGrandeHeadwatersPilotWetlandConditionAssessment.ReportpreparedforColoradoParksandWildlifeandU.S.EnvironmentalProtectionAgency.ColoradoNaturalHeritageProgram,ColoradoStateUniversity,FortCollins,CO.

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TERRESTRIAL ECOSYSTEM VULNERABILITY ASSESSMENT SUMMARIES

Forest and Woodland Habitats

Lodgepoleforest

Pinyon‐juniperwoodland

Ponderosapineforestandwoodland

Spruce‐firforest

Shrubland Habitats

Oak‐mixedmountainshrubland

Sagebrushshrubland

Sandsageshrubland

Grassland Habitats

Foothill‐montanegrassland

Shortgrassprairie

Riparian and Wetland Habitats

Playas

RiparianWoodlandsandShrublands

Wetlands

Other Habitats

Alpine


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LODGEPOLE

Climate Influences

Lodgepolepine Pinuscontorta isanorthernspeciesthatdoesexceptionallywellinverycoldclimatesandcantolerateawiderangeofannualprecipitationpatterns,fromfairlydrytofairlywet,butgenerallygrowsonlywhereannualprecipitationisatleast18‐20inchesMason1915,LotanandPerry1983 .Lodgepolepineforestsarefoundondriersitesthanspruce‐firforest,althoughsnowfallistypicallyheavyintheseforests.Summersareoftenquitedry,andlodgepolepineisdependentonsnowmeltmoistureformostofthegrowingseason.Inlowsnowpackyears,growthisreduced Huetal.2101 .

Lodgepolepineistolerantofverylowwintertemperatures,andinmanylodgepoleforestssummertemperaturescanfallbelowfreezing,sothereisnotruefrost‐freeseason LotanandPerry1983 .Lodgepolepineisalsoabletotakeadvantageofwarmgrowingseasontemperatures,andalongergrowingseasonduetowarmerfalltemperaturescouldfavorthegrowthoflodgepolepine Villalbaetal.1994,Chhinetal.2008 .InsouthernColorado,whitefir Abiesconcolor appearstotaketheplaceoflodgepolepineinconiferousforestsofsimilarelevations.Whitefirappearstotoleratewarmertemperaturesthanlodgepolepine Thompsonetal.2000 ;underwarmerconditionsitmaybeabletomoveintoareascurrentlyoccupiedbylodgepoleforest.

Exposure and Sensitivity Summary

Lodgepolepineforestsareprojectedtoexperiencewintertemperatureswarmerthanthecurrentinaboutonequarterofthecurrentdistribution.Projectedwinterandspringprecipitationlevelsaregenerallywithinthecurrentrange,butsummerprecipitationfor21%ofthecurrentdistributionisprojectedtobelowerthanthedriestendofthecurrentrange.


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Lodgepole

Climate variable

(sources: M=model, E = expert review, L = literature review)

% projected

range shift

Winter precipitation (L) 0%

Spring precipitation (M) 3%

Summer precipitation (M) 21%

Mean winter temperature (E) 25%

Very cold days (E) 25%

Average range shift 14.9%

Rank L

Exposure‐Sensitivity level Low

Resilience Components

LodgepolepinesubspeciesarewidelydistributedinNorthAmerica,butRockyMountainlodgepolereachesthesouthernedgeofitsdistributioninsouth‐centralColorado.InColorado,lodgepolepineforestsrangefromabout8,500‐11,000ft.inelevation.Statewide,theannualaverageprecipitationrangeforlodgepoleforestisabout13.5‐41in. 35‐105cm ,withameanof25” 64cm .Lodgepolepineisabletotoleratemuchwarmertemperaturesthanspruce‐firforest.Growingseasonlengthforlodgepolebroadlyoverlapsthatofthewarmerendofthespruce‐firdistribution.

Manylodgepoleforestsdevelopedfollowingfires.Lodgepolepinesproducebothopenandserotinouscones,andcanreproducequicklyafterafire.Followingstand‐replacingfires,lodgepolepinerapidlycolonizesanddevelopsintodense,even‐agedstands sometimesreferredtoas“doghair”stands .Thisfire‐adaptedspecieshasthepotentialtomoveintoareaswherespruce‐firforestsburn.

Althoughinvasivespeciesaregenerallynotathreat,lodgepoleforestsarevulnerabletothepestoutbreaksthatappeartoincreasewithwarmer,drier,drought‐proneclimates.Biologicalstressorsthatinteractwithfiredynamicsoflodgepoleforestincludeinfestationsoflodgepolepinedwarf‐mistletoeandmountainpinebeetle Anderson2003 .Dwarfmistletoereducestreegrowthandconeproduction,andgenerallyleadstoearliermortalityHawksworthandJohnson1989 .AlthoughlodgepoleforestsarestillcommonacrossColorado,mostareexperiencingwidespreaddamagefromasevereoutbreakofmountainpinebeetle.Thepinebeetleisanativespecies,andperiodicoutbreaksofthisinsectare


47

partofthenaturalcyclethatmaintainsColorado’smountainforests.LodgepoleforestsareexpectedtopersistinColorado Kaufmannetal.2008 .

Adaptive Capacity Summary

Range and biophysical envelope

Dispersal & growth form

Biological stressors

Extreme events

Landscape condition

Resilience ‐ Adaptive capacity score Rank

Resilience Level

Lodgepole 0.60 0 0.67 0.33 0.75 0.45 L Low

Vulnerability to Climate Change

Exposure ‐ Sensitivity

Resilience – Adaptive Capacity

Combined rank

Overall vulnerability to climate change

Lodgepole pine forest Low Low L/L Moderate

Lodgepolepineforestisrankedmoderatelyvulnerabletotheeffectsofclimatechangebymid‐centuryunderamoderateemissionsscenario.Primaryfactorscontributingtothisrankingareitsvulnerabilitytoforestdisturbancesthatmayincreaseinthefuture,andthefactthatitisatthesouthernedgeofitsdistributioninColorado.

Mapsbelowillustratethespatialpatternofexposureundertheworstcasescenarioforthefiveclimatevariablesassessedforlodgepolepineforest.Legendpointersindicatetherangeofchangeforthishabitatwithinthestatewideextentofchange.Forwinterprecipitation,areasinthesouthernandwesternedgeoftheColoradodistributionaremostexposed.Forspringandsummerprecipitation,areasalongtheFrontRangearemostexposedtodrierconditions.WarmingduringthegrowingseasonisprojectedtoexperiencethegreatestincreaseintheeasternportionoftheColoradodistribution,andthenumberofverycolddaysinwinterisprojectedtoreducethemostinthesouth‐westernpartofthedistribution.


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49


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References:

Anderson,M.D.2003.Pinuscontortavar.latifolia.In:FireEffectsInformationSystem,Online .U.S.DepartmentofAgriculture,ForestService,RockyMountainResearchStation,FireSciencesLaboratory Producer .Available:http://www.fs.fed.us/database/feis/

Chhin,S.,E.H.Hogg,V.J.Lieffers,andS.Huang.2008.InfluencesofclimateontheradialgrowthoflodgepolepineinAlberta.Botany86:167‐178.

Hawksworth,F.G.andD.W.Johnson.1989.BiologyandmanagementofdwarfmistletoeinlodgepolepineintheRockyMountains.Gen.Tech.Rep.RM‐169.FortCollins,CO:U.S.DepartmentofAgriculture,ForestService,RockyMountainForestandRangeExperimentStation.38p.

Hu,J.,D.J.P.Moore,S.P.Burns,andR.K.Monson.2010.Longergrowingseasonsleadtolesscarbonsequestrationbyasubalpineforest.GlobalChangeBiology16:771‐783.

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.Kennedy


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Sutherland,D.Tinker,andT.T.Veblen.2008.Thestatusofourscientificunderstandingoflodgepolepineandmountainpinebeetles–afocusonforestecologyandfirebehavior.TheNatureConservancy,Arlington,VA.GFItechnicalreport2008‐2.

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.DepartmentofAgriculture,ForestService.35p.

Thompson,R.S.,K.H.Anderson,andP.J.Bartlein.2000.AtlasofrelationsbetweenclimaticparametersanddistributionsofimportanttreesandshrubsinNorthAmerica.U.S.GeologicalSurveyProfessionalPaper1650‐A.

Villalba,R.,T.T.Veblen,andJ.Ogden.1994.ClimaticinfluencesonthegrowthofsubalpinetreesintheColoradoFrontRange.Ecology75:1450‐1462


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PINYON-JUNIPER

Climate Influences

Theseevergreenwoodlandsareadaptedtocoldwinterminimumtemperaturesandlowrainfall,andareoftentransitionalbetweengrasslandordesertshrublandandmontaneconiferecosystem Brown1994,Peet2000 .Sincethelastmajorglacialperiod,thedistributionandrelativeabundanceofthecharacteristictreespecieshasfluctuateddynamicallywithchangingclimaticconditions.Warmingconditionsduringthepasttwocenturies,togetherwithchangingfireregime,livestockgrazing,andatmosphericpollutionincreasedtheabilityofthisecosystemtoexpandintoneighboringcommunities,atbothhigherandlowerelevations Tausch1999 .Variabledisturbanceandsiteconditionsacrossthedistributionofthisecosystemhaveresultedinadynamicmosaicofinterconnectedcommunitiesandsuccessionalstagesthatmaybenaturallyresilient.

Bargeretal. 2009 foundthatpinyonpine Pinusedulis growthwasstronglydependentonsufficientprecipitationpriortothegrowingseason winterthroughearlysummer ,andcoolerJunetemperatures.Bothofthesevariablesarepredictedtochangeinadirectionthatislessfavorableforpinyonpine.Droughtcanresultinwidespreadtreedie‐off,especiallyofthemoresusceptiblepinyonpine Breshearsetal.2008 .Cliffordetal. 2013 detectedastrongthresholdat60cmcumulativeprecipitationoveratwo‐yeardroughtperiod i.e.,essentiallynormalannualprecipitationforpinyonpine .Sitesabovethisthresholdexperiencedlittlepinyondie‐off,whilesitesreceivinglessprecipitationincludedareaswithhighlevelsofmortality.Mortalityofpinyontreeswasextensiveintheareaduringthe2002‐2003droughtandbarkbeetleoutbreak,butinareaswherejuniperJuniperusspp. andshrubspeciesprovidemicrositesforseedlingestablishment,pinyonmaybeabletopersist RedmondandBarger2013 .Patternsofprecipitationandtemperature i.e.,cool,wetperiods appeartobemoreimportantinrecruitmenteventsthanhistoryoflivestockgrazing Bargeretal.2009 .

Thepinyon‐juniperhabitathaslargeecologicalamplitude;warmerconditionsmayallowexpansion,ashasalreadyoccurredinthepastcenturies,aslongasthereareperiodiccooler,wetteryearsforrecruitment.Increaseddroughtmaydrivefiresandinsectoutbreaks,fromwhichthesewoodlandswouldbeslowtorecover.


Pinyon‐juniperwoodlandsareprojectedtoexperiencesummertemperatureswarmerthanthecurrentrangeinmorethanonethirdofthecurrentdistribution.Projectedwinter


53

precipitationlevelsaregenerallywithinthecurrentrange,butspringandsummerprecipitationfor9‐16%ofthecurrentdistributionareprojectedtobelowerthanthedriestendofthecurrentrange.

Pinyon‐juniper

Climate variable


% projected

range shift


Spring precipitation (M, L) 16%

Summer precipitation (M, E, L) 9%

Mean summer temperature (M, E) 38%

Very cold days (M, E) 3%


Rank L



Pinyon‐juniper,whichformsthecharacteristicwoodlandofwarm,drylowerelevationsfromabout4,600to8,500ft.,iswidespreadinColorado’swesterncanyonsandvalleys,aswellasinthesouthernmountains.TheNorthAmericandistributionofthishabitatiscenteredintheColoradoPlateau,generallysouthwestofColorado.Standsareoftenadjacenttoandintermingledwithoak,sagebrush,orsaltbushshrubland.Thestatewiderangeofannualaverageprecipitationisabout10‐23in 25‐60cm ,withameanof16in40cm ,similartosagebrushshrubland.Growingseasontemperaturesaregreaterintherangeofpinyon‐juniperthanformanyotherwoodyvegetationtypesinColorado.

Extendeddroughtcanincreasethefrequencyandintensityofinsectoutbreaksandwildfire.PinyonaresusceptibletothefungalpathogenLeptographiumwagenerivar.wageneri,whichcausesblackstainrootdisease,andtoinfestationsofthepinyonipsbarkbeetle Ipsconfusus KearnsandJacobi2005 .Thedifferentialsusceptibilityofpinyonandjunipertodroughtandinsectoutbreakscouldeventuallyresultinthesewoodlandsbeingdominatedbyjuniper.

Pinyonpinestandsareslowtorecoverfromintensefires;thespeciesreproducesonlyfromseedandrecoveryisdependentonseedsourcesand/oradequatedispersal.Junipersarealsoslow‐growing,andsusceptibletobeingkilledbyfire.AtMesaVerdeNationalPark,


54

wherepinyon‐juniperwoodlandshaveburnedinfivelargefiressince1930,treeshavenotyetre‐established.Itisnotknownwhytreeshavenotbeensuccessfulintheseareas,whicharenowoccupiedbyshrubland Floydetal.2000 .



Dispersal &

growth form


Extreme events

Landscape condition


Resilience Level

Pinyon‐juniper 0.87 0 0.67 0.33 0.592 0.47 L Low




Combined rank


Pinyon‐Juniper woodland Low Low L/L Moderate

Pinyon‐juniperwoodlandsarerankedmoderatelyvulnerabletotheeffectsofclimatechangebymid‐centuryunderamoderateemissionsscenario.Primaryfactorscontributingtothisrankingarethevulnerabilityofthesewoodlandstostressorsthatarelikelytoincreaseunderchangingclimate,andtheextenttowhichthecurrentlandscapeconditionofthehabitathasbeenimpactedbyanthropogenicdisturbance.

Mapsbelowillustratethespatialpatternofexposureundertheworstcasescenarioforthefiveclimatevariablesassessedforpinyon‐juniper.Legendpointersindicatetherangeofchangeforthishabitatwithinthestatewideextentofchange.Areasinthesouthernpartofthestatearemostexposedtopotentiallydrierconditions,especiallyforsummerprecipitation.Temperaturechangedoesnotshowaclearpattern.


55


56


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References:

Barger,N.N.,H.D.Adams;C.Woodhouse,J.C.Neff,andG.P.Asner.2009.Influenceoflivestockgrazingandclimateonpiñonpine Pinusedulis dynamics.RangelandEcologyandManagement62:531–539.

Breshears,D.D.,O.B.Myers,C.W.Meyer,F.J.Barnes,C.B.Zou,C.D.Allen,N.G.McDowell,andW.T.Pockman.2008.Treedie‐offinresponsetoglobalchange‐typedrought:mortalityinsightsfromadecadeofplantwaterpotentialmeasurements.FrontiersinEcologyandtheEnvironment7:185‐189.

Brown,D.E.1994.GreatBasinConiferWoodland.InBioticcommunities:southwesternUnitedStatesandnorthwesternMexico.D.E.Brown,ed.UniversityofUtahPress,SaltLakeCity,UT.

Clifford,M.J.,P.D.Royer,N.S.Cobb,D.D.Breshears,andP.L.Ford.2013.Precipitationthresholdsanddrought‐inducedtreedie‐off:insightsfrompatternsofPinusedulismortalityalonganenvironmentalstressgradient.NewPhytologist200:413‐421.

Floyd,M.L.,W.H.Romme,andD.D.Hanna.2000.FirehistoryandvegetationpatterninMesaVerdeNationalPark,Colorado,USA.EcologicalApplications10:1666‐1680.


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Kearns,H.S.J.andW.R.Jacobi.2005.Impactsofblackstainrootdiseaseinrecentlyformedmortalitycentersinthepiñon‐juniperwoodlandsofsouthwesternColorado.Can.J.For.Res.35:461‐471.

Peet,R.K.2000.ForestsandmeadowsoftheRockyMountains.Chapter3inNorthAmericanTerrestrialVegetation,secondedition.M.G.BarbourandW.D.Billings,eds.CambridgeUniversityPress.

Redmond,M.D.andN.N.Barger.2013.Treeregenerationfollowingdrought‐andinsect‐inducedmortalityinpiñon‐juniperwoodlands.NewPhytologist200:402‐412.

TauschR.J.1999.Historicpinyonandjuniperwoodlanddevelopment.In:S.B.MonsenandR.Stevens eds. .ProceedingsoftheConferenceonEcologyandManagementofPinyon‐JuniperCommunitieswithintheInteriorWest.Ogden,UT,USA:USDepartmentofAgriculture,ForestService,RockyMountainResearchStation.p.12–19.


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PONDEROSA

Climate Influences

Ponderosapine Pinusponderosa occupiesrelativelydry,nutrient‐poorsitescomparedtoothermontaneconifers,butshowswideecologicalamplitudethroughoutitsdistribution.Rehfeldtetal. 2012 wereabletopredictthedistributionofponderosapinelargelythroughtheuseofsummerandwinterprecipitation,andsummertemperatures asgrowingdegreedays 5C .Althoughperiodicseasonaldroughtischaracteristicacrosstherangeofponderosapine,thisspeciesisgenerallyfoundwhereannualprecipitationisatleast13inches Barrettetal.1980,Thompsonetal.2000 .PonderosastandstothesouthofColoradowereprimarilyreliantonwinterprecipitation Kerhoulasetal.2013 ,whilegrowthofFrontRangestandswascorrelatedwithspringandfallmoisture LeagueandVeblen2006 ,indicatingsomevariabilityintheabilityofponderosapinetotakeadvantageofseasonalwateravailability,dependingonsitefactorsandstandhistory.Consequently,vulnerabilityofponderosaforeststochangesinprecipitationpatternsmaydifferaccordingtotheirlocationinColorado.

Ponderosapineisabletotoleratefairlywarmtemperaturesaslongasthereisenoughmoisture,especiallyinthegrowingseason.Optimalgerminationandestablishmentconditionsoccurwhentemperaturesareabove50°Fandmonthlyprecipitationisgreaterthan1inch ShepperdandBattaglia2002 .Significantrecruitmenteventsmayoccuronburnedareaswhenconditionsarewetwetterthannormalafterafireyear,butnormalprecipitationmayalsobesufficientforseedlingestablishmentinsuchcases Mastetal.1998 .InlowerelevationponderosawoodlandsoftheColoradoFrontRange,episodicrecruitmentofponderosapinewasassociatedwithhighspringandfallmoistureavailabilityduringElNiñoevents LeagueandVeblen2006 .AcorrelationbetweendroughtandlowratesofponderosaseedlingrecruitmenthasalsobeenidentifiedthroughoutthewesternGreatPlains Kayeetal.2010 .Droughtincombinationwithfutureprojectedhighertemperaturesislikelytoreduceponderosapineregeneration,especiallyindrier,lowerelevationareas.TheworkofBrownandWu 2005 suggeststhatcoincidentconditionsofsufficientmoistureandfewerfiresareimportantforwidespreadrecruitmentepisodesofponderosapine;suchconditionsmaybecomelesslikelyunderfutureclimatescenarios.

Increaseddroughtmaydrivefiresandinsectoutbreaks.Relativeproportionsofassociatedspecies e.g.,otherconifers,aspen,understoryshrubsandgrasses inponderosastands


60

maychange.Thishabitatiswelladaptedtowarm,dryconditionsifprecipitationisnottoomuchreduced,andmaybeabletoexpandintohigherelevations.


Ponderosapineforestandwoodlandsareprojectedtoexperiencesummertemperatureswarmerthanthecurrentrangeinmorethanonethirdofthecurrentdistribution,andprojectedwintertemperaturesarewarmerthanthecurrentrangeformorethanaquarterofthedistribution.Projectedsummerandfallprecipitationlevelsareprojectedtobelowerthanthedriestendofthecurrentrangefornearlyaquarterofthecurrentdistribution.

Ponderosa

Climate variable


% projected

range shift


Fall precipitation (L) 23%

Mean winter minimum temperature (M, E) 27%

Mean summer temperature (E) 39%

Very hot days (E) 32%


Rank M

Exposure‐Sensitivity level Moderate


Ponderosawoodlandsarenotfoundathighelevations,butinsteadformabroadzoneofconiferousforestalongthesouthernflankoftheSanJuanMountains,aswellasalongtheeasternmountainfront,generallyatelevationsbetween6,000and9,000ft.ThesehabitatsareinwithinthecentralportionoftheirNorthAmericandistributioninColorado.Annualprecipitationissimilartothatforoakshrubland,witharangeof18.9‐35.8in 30‐80cm andameanof20in 51cm .Ponderosaoccursinabroadmiddlerangeofgrowingseasonlengthsacrossthestate.

Althoughseedsaretypicallynotdispersedveryfar,ponderosapineisoftenpresentinmixedconiferstands;theseareasmayprovideaseedbankforregenerationorashifttoponderosapine.Recruitmentisepisodic,dependingonprecipitationanddisturbancepatterns.Theseforestsaresusceptibletooutbreaksofthemountainpinebeetle


61

Dendroctonusponderosae andmistletoeinfestations,bothofwhichmaybeexacerbatedbyincreaseddrought.Impactsofnativegrazersordomesticlivestockcouldalsoalterunderstorystructureandcomposition.

Ponderosapineiswelladaptedtosurvivefrequentsurfacefires,andmixed‐severityfiresarecharacteristicinthesecommunities Arno2000 .Althoughclimatechangemayalterfireregimesslightlybyaffectingthecommunitystructure,fireisnotexpectedtohaveasevereimpactinthefutureforthesestands,andmayactuallybebeneficialinsomeareas.





Extreme events

Landscape condition


Resilience Level

Ponderosa 0.87 0 0.67 0.67 0.54 0.53 M Moderate




Combined rank


Ponderosa pine forest & woodland Moderate Moderate M/M Moderate

Ponderosapineforestsandwoodlandsarerankedmoderatelyvulnerabletotheeffectsofclimatechangebymid‐centuryunderamoderateemissionsscenario.Primaryfactorscontributingtothisrankingaretheexposureoflargeareasofthishabitattowarmertemperaturesthatarelikelytointeractwithforestdisturbancesthatare,inturn,exacerbatedbywarm,dryconditions.

Mapsbelowillustratethespatialpatternofexposureundertheworstcasescenarioforthefiveclimatevariablesassessedforponderosahabitats.Legendpointersindicatetherangeofchangeforthishabitatwithinthestatewideextentofchange.Areasalongthemountainfrontareprojectedtoseethemostdecreaseinsummerandfallprecipitation.ThenorthernFrontRangeportionofthedistributionisprojectedtoexperiencethemostwarming.Veryhotdays whichmaycontributetofiredanger mayincreaseslightlythroughoutthedistributionofponderosa.


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63


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References:

Arno,S.F.2000.Fireinwesternforestecosystems.Chapter5inBrown,J.K.andJ.K.Smith,eds.Wildlandfireinecosystems:effectsoffireonflora.Gen.Tech.Rep.RMRS‐GTR‐42‐vol.2.Ogden,UT:U.S.DepartmentofAgriculture,ForestService,RockyMountainResearchStation.257p.

Barrett,J.W.,P.M.McDonald,F.RoncoJr,andR.A.Ryker.1980.Interiorponderosapine.In:Eyer,F.H.,ed.ForestcovertypesoftheUnitedStatesandCanada.Washington,DC:U.S.DepartmentofAgriculture,ForestService:114‐115.

Brown,P.M.andR.Wu.2005.Climateanddisturbanceforcingofepisodictreerecruitmentinasouthwesternponderosapinelandscape.Ecology86:3030‐3038.

Howard,J.L.2003.Pinusponderosavar.scopulorum.In:FireEffectsInformationSystem,Online .U.S.DepartmentofAgriculture,ForestService,RockyMountainResearchStation,FireSciencesLaboratory Producer .Available:http://www.fs.fed.us/database/feis/


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KayeM.W.,C.A.WoodhouseandS.T.Jackson.2010.Persistenceandexpansionofponderosapinewoodlandsinthewest‐centralGreatPlainsduringthepasttwocenturies.JournalofBiogeography37:1668‐1683.

League,K.andT.Veblen.2006.ClimaticvariabilityandepisodicPinusponderosaestablishmentalongtheforest‐grasslandecotonesofColorado.ForestEcologyandManagement228:98‐107.

Mast,J.N.,T.T.Veblen,andY.B.Linhart.1998.Disturbanceandclimaticinfluencesonagestructureofponderosapineatthepine/grasslandecotone,ColoradoFrontRange.JournalofBiogeography.25:743‐755.

Oliver,W.W.,andR.A.Ryker.1990.PinusponderosaDougl.exLaws.Ponderosapine.p.413‐424.In:Burns,R.M.andB.H.Honkala tech.coord. SilvicsofNorthAmericaVolume1,Conifers.USDAFor.Serv.Agric.Handb.654.Availableat:http://www.na.fs.fed.us/pubs/silvics_manual/Volume_1/pinus/ponderosa.htm

Shepperd,W.D.andM.A.Battaglia.2002.Ecology,Silviculture,andManagementofBlackHillsPonderosaPine.GeneralTechnicalReportRMRS‐GTR‐97.USDAForestServiceRockyMountainResearchStation,FortCollins,CO.112p.

Thompson,R.S.,K.H.Anderson,andP.J.Bartlein.2000.AtlasofrelationsbetweenclimaticparametersanddistributionsofimportanttreesandshrubsinNorthAmerica.U.S.GeologicalSurveyProfessionalPaper1650‐A.


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SPRUCE-FIR

Climate Influences

Spruce‐firforesttypicallydominatesthewettestandcoolesthabitatsbelowtreeline.Theseareasarecharacterizedbylong,coldwinters,heavysnowpack,andshort,coolsummerswherefrostiscommon Uchytil1991 .BothEngelmannspruce Piceaengelmannii andsubalpinefir Abieslasiocarpa aredependentonsnowmeltwaterformostofthegrowingseason,andinlowsnowpackyearsgrowthisreduced Huetal.2101 .

Thelengthofthegrowingseasonisparticularlyimportantforbothalpineandsubalpinezones,andforthetransitionzonebetweenalpinevegetationandclosedforest treeline .Treeline‐controllingfactorsoperateatdifferentscales,rangingfromthemicrositetothecontinental HoltmeierandBroll2005 .Onaglobalorcontinentalscale,thereisgeneralagreementthattemperatureisaprimarydeterminantoftreeline.Körner 2012 attributesthedominanceofthermalfactorsatthisscaletotherelativeconsistencyofatmosphericconditionsoverlargeareas,especiallyincomparisontomorelocalinfluenceofsoilandmoisturefactors.Furthermore,thereappearstobeacriticaldurationoftemperaturesadequateforthegrowthoftreesinparticular e.g.individuals 3mtall thatdeterminesthelocationoftreeline.Atmorelocalscales,soilproperties,slope,aspect,topography,andtheireffectonmoistureavailability,incombinationwithdisturbancessuchasavalanche,grazing,fire,pests,disease,andhumanimpactsallcontributetotheformationoftreelineRichardsonandFriedland2009,Körner2012 .Patternsofsnowdepthandduration,wind,insolation,vegetationcover,andtheautecologicaltolerancesofeachtreespeciesinfluencetheestablishmentandsurvivalofindividualswithinthetreelineecotone Moiretal.2003,HoltmeierandBroll2005,Smithetal.2009 .IntheRockyMountains,treeestablishmentwassignificantlycorrelatedwithwarmerspring Mar‐May andcool‐seasonNov‐Apr minimumtemperaturesaswell Elliott2012 .

Spruce‐firforestscurrentlyoccupycoldareaswithhighprecipitation;warmeranddrierclimateconditionspredictedbymostmodelscouldresultinanupwardmigrationoftheseforestsintothealpinezone.However,inCanadianspruce‐firforests,warmerthanaveragesummertemperaturesledtoadecreaseingrowththefollowingyear HartandLaroque2013 .Sincespruce‐firmaybeabletotoleratewarmersummertemperatures,thelowerextentofthishabitattypecouldremainatcurrentlevelsforsometime,evenifgrowthisreduced.


67

Thecurrentlocationoftreelineisaresultoftheoperationofclimaticandsite‐specificinfluencesoverthepastseveralhundredyears,anddoesnotexactlyreflectthecurrentclimate Körner2012 .Thetreelinepositionlagtimebehindclimatechangeisestimatedtobe50‐100 years,duetotherarityofrecruitmentevents,theslowgrowthandfrequentsetbacksfortreesintheecotone,andcompetitionwithalreadyestablishedalpinevegetation Körner2012 .Nevertheless,onthebasisofhistoricevidence,treelineisgenerallyexpectedtomigratetohigherelevationsastemperatureswarm,aspermittedbylocalmicrositeconditions Smithetal.2003,RichardsonandFriedland2009,Grafiusetal.2012 .

Furthermore,thelagtimeofdecadesorlongerfortreelinetorespondtowarmingtemperaturesmayallowthedevelopmentofnovelvegetationassociations ChapinandStarfield ,andmakeitdifficulttoidentifytemperatureconstraintsonthedistributionofthishabitat Grafiusetal.2012 .Thegradualadvanceoftreelineisalsolikelytodependonprecipitationpatterns.Seedlingestablishmentandsurvivalaregreatlyaffectedbythebalanceofsnowaccumulationandsnowmelt.Soilmoisture,largelyprovidedbysnowmelt,iscrucialforseedgerminationandsurvival.Althoughsnowpackinsulatesseedlingsandshieldssmalltreesfromwinddesiccation,itspersistenceshortensthegrowingseasonandcanreducerecruitment Rochefortetal.1994 .


Spruce‐firforestsareprojectedtoexperiencewinterandsummertemperatureswarmerthanthecurrentrangeinasignificantportionoftheircurrentdistribution.Projectedwinterandspringprecipitationlevelsaregenerallywithintherangeofthecurrentdistribution.


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Spruce‐fir

Climate variable


% projected

range shift


Spring precipitation (M, E) 5%

Mean winter minimum temperature (E) 31%

Mean summer temperature (M, E, L) 43%

Growing degree days ‐ base 0 (L) 43%


Rank M



Spruce‐firforestsinColoradohaveawideelevationalrange,extendingfromabout8,900ft.uptoover12,000ft.Althoughnotasrestrictedasalpinehabitats,spruce‐firforestsaregenerallylimitedtohigher,coolerelevations,andarealsonearthesouthernextentoftheircontinentalrangeinColorado.Statewide,annualaverageprecipitationisslightlylowerthanforalpinewitharangeofabout16‐47in. 40‐120cm andameanof31in. 80cm .Spruce‐firrequiresalongergrowingseasonthanalpinehabitat,butissuccessfulatmuchcoolertemperaturesthanmostotherforesttypes.Spruce‐firforestsaccumulatemoreannualgrowingdegreedaysthanalpineareas,butfewerthanforotherforestedtypes.

Subalpinefirseedsrequirecold‐moistconditionstotriggergermination Uchytil1991 ,andthereissomeindicationthatEngelmannspruceseedsgerminatefasteratrelativelylowtemperatures Smith1985 ,givingitacompetitiveadvantageoverlesscold‐tolerantspecies.Underwarmerconditions,however,currentspruce‐fircommunitiesmaybegraduallyreplacedbyamixed‐coniferforest.Therearenoobviousbarrierstothegradualdispersalofseedlingsintoadjacent,newlysuitablehabitat,althoughthedominantspeciesaregenerallyslow‐growing.

Althoughthesesubalpineforestsarenotsusceptibletoincreasedprevalenceofinvasivespecies,theyarevulnerabletooutbreaksofthenativepestspeciessprucebudwormandsprucebeetle.Warmertemperatures bothwinterandsummer arelikelytofacilitatetheseinfestations;currentdistributionofspruce‐firhabitatmaythereforebeatincreasedriskofsignificantmortality.Insectoutbreaksarealsotypicallyassociatedwithdroughts.


69

Historicnaturalfire‐returnintervalsintheseforestshavebeenontheorderofseveralhundredyears,andthetreespeciesarenotadaptedtomorefrequentfires.Withanincreaseindroughtsandfastersnowmelts,wemightexpectanincreaseinforestfirefrequencyandextentwithinthiszone.Itisnotknownifspruce‐firforestswillbeabletoregenerateundersuchconditions,especiallyinlowerelevationstands,andthereisapotentialforareductioninspruce‐firforests,atleastintheshortterm.





Extreme events

Landscape condition


Resilience Level

Spruce‐fir 0.37 0 0.67 0.67 0.89 0.51 M Moderate




Combined rank


Spruce‐Fir forest Moderate Moderate M/M Moderate

Spruce‐firforestsarerankedmoderatelyvulnerabletotheeffectsofclimatechangebymid‐centuryunderamoderateemissionsscenario.PrimaryfactorscontributingtothisrankingaretherestrictionofthesehabitatstohigherelevationsinColorado,andtherelativelynarrowbiophysicalenvelope.ThemajorityoftheNorthAmericandistributionofEngelmannspruceandsubalpinefiristothenorthofColorado.Theslowgrowthanddispersaloftheseforestsalsocontributestotheirvulnerability.

Mapsbelowillustratethespatialpatternofexposureundertheworstcasescenarioforthefiveclimatevariablesassessedforspruce‐firhabitats.Legendpointersindicatetherangeofchangeforthishabitatwithinthestatewideextentofchange.AreasonthesouthernflankoftheSanJuanMountainsareprojectedtoexperiencethegreatestreductionsinwinterandspringprecipitationunderadryscenario,whilenorthernportionsoftherangearelittlechanged.Winterminimumtemperaturesareprojectedtowarmbyatleast2°Cthroughouttherange,andsummermeantemperaturesmayincreaseevenmore,especiallyinnorthernColorado.Overall,thegrowingseasonforspruce‐firforestsinthestateisexpectedtoincrease,whichcouldeventuallyfacilitatethemigrationofthishabitattohigherelevations.


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References:

Alexander,R.R.1987.Ecology,silviculture,andmanagementoftheEngelmannspruce‐subalpinefirtypeinthecentralandsouthernRockyMountains.Agric.Handb.659.Washington,DC:U.S.DepartmentofAgriculture,ForestService.144p.

Chapin,F.S.andA.M.Starfield.1997.TimelagsandnovelecosystemsinresponsetotransientclimaticchangeinarcticAlaska.Climaticchange35:449‐461.

Elliott,G.P.2012.ExtrinsicregimeshiftsdriveabruptchangesinregenerationdynamicsatuppertreelineintheRockyMountains,USA.Ecology93:1614‐1625.

Grafius,D.R.,G.P.Malanson,andD.Weiss.2012.SecondarycontrolsofalpinetreelineelevationsinthewesternUSA.PhysicalGeography33:146‐164.

Hart,S.J.andC.P.Laroque.2013.Searchingforthresholdsinclimate‐radialgrowthrelationshipsofEngelmannspruceandsubalpinefir,JasperNationalPark,Alberta,Canada.Dendrochronologia31:9‐15.


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Holtmeier,F‐K.andG.Broll.2005.Sensitivityandresponseofnorthernhemispherealtitudinalandpolartreelinestoenvironmentalchangeatlandscapeandlocallevels.Global

Hu,J.,D.J.P.Moore,S.P.Burns,andR.K.Monson.2010.Longergrowingseasonsleadtolesscarbonsequestrationbyasubalpineforest.GlobalChangeBiology16:771‐783.

Körner,C.2012.Alpinetreelines:functionalecologyoftheglobalhighelevationtreelimits.Springer,Basel,Switzerland.

Moir,W.H.,S.G.Rochelle,andA.W.Schoettle.1999.Microscalepatternsoftreeestablishmentnearuppertreeline,SnowyRange,Wyoming.Arctic,Antarctic,andAlpineResearch31:379‐388.

Richardson,A.D.andA.J.Friedland.2009.Areviewofthetheoriestoexplainarcticandalpinetreelinesaroundtheworld.JournalofSustainableForestry28:218‐242.

Rochefort,R.M.,R.L.Little,A.Woodward,andD.L.Peterson.1994.Changesinsub‐alpinetreedistributioninwesternNorthAmerica:areviewofclimaticandothercausalfactors.TheHolocene4:89‐100.

Smith,W.K.1985.Westernmontaneforests.Chapter5inChabot,R.F.andH.A.Money,eds.,PhysiologicalEcologyofNorthAmericanPlantCommunities.ChapmanandHall,NewYork,351pp.

Smith,W.K.,M.J.Germino,T.E.Hancock,andD.M.Johnson.2003.Anotherperspectiveonaltitudinallimitsofalpinetimberlines.TreePhysiology23:1101‐1112.

Uchytil,R.J.1991.PiceaengelmanniiandAbieslasiocarpa.In:FireEffectsInformationSystem, Online .U.S.DepartmentofAgriculture,ForestService,RockyMountainResearchStation,FireSciencesLaboratory Producer .Available:http://www.fs.fed.us/database/feis/


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OAK-MIXED MOUNTAIN SHRUB

Climate Influences

Ingeneral,theupperandlowerelevationallimitsofGambeloak Quercusgambelii shrublandarebelievedtobecontrolledbytemperatureandmoisturestress.NeilsonandWullstein 1983 foundthatseedlingmortalitywasprimarilyduetospringfreezing,grazing,orsummerdroughtstress.Atmorenorthernlatitudes,thezoneoftolerablecoldstressisfoundatlowerelevations,but,atthesametime,theareaswheresummermoisturestressistolerableareathigherelevations.NeilsonandWullstein 1983 hypothesizethatthenortherndistributionallimitofGambeloakcorrespondstothepointwherethesetwoopposingfactorsconverge.Oakshrublandsaretypicallyfoundinareaswithmeanannualtemperaturesbetween7and10C 12.6‐18.0F;Harperetal.1985 .Athigher,coolerelevations,acornproductionmaybelimitedbytheshortnessofthegrowingseason,andmostreproductionislikelytobevegetative Christensen1949 .Warmingtemperaturesmayincreasebothacornproductionandseedlingsurvival.

Oaksaremostlikelytodowellunderwarmertemperatures,althoughdroughtsandlatefrostsmayaffectthefrequencyofestablishmentthroughseedlingrecruitmentbyreducingtheacorncropinsomeyears.


Oakandmixedmountainshrublandsareprojectedtoexperiencetemperatureswarmerthanthecurrentrangeinmorethanonethirdofthecurrentdistribution,aswellasashifttoearlierdateoflastspringfrostinsomeareas.Projectedspringandsummerprecipitationlevelsareprojectedtobelowerthanthedriestendofthecurrentrangeforasmallpartofthecurrentdistribution.


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Oak

Climate variable


% projected

range shift

Spring precipitation (M, E) 8%


Drought days (M, L) 6%

Date of last frost in spring (M, E, L) ‐8%

Mean annual temperature (L) 38%


Rank L



OakandmixedmountainshrublandsarewidespreadinthewesternhalfofColorado,andalongthesouthernstretchofthemountainfrontatelevationsfromabout6,000‐9,000feet.Theelevationrangeofthishabitatissimilartothatofponderosapine,andthesehabitatsareoftenadjacent.StandsdominatedbyGambeloakarecommoninthesouthernpartofColorado,butarecompletelyinterspersedwithstandsdominatedbyothershrubspecies,especiallyserviceberry Amelanchierspp. withmahogany Cercocarpusspp. athigherelevations.Thesehabitatsarenotlimitedtohigherelevations,andarenotatthesouthernextentoftheirNorthAmericandistributioninColorado.Averageannualprecipitationforoakshrublandisabout12‐32in 30‐80cm ,withameanof21.5in 52cm .Precipitationamountsformixedmountainshrublandareprobablyslightlyhigher.Growingseasonissimilartothatofponderosaandhigherelevationsagebrush.

Gambeloakreproducesprimarilybysproutingofnewstems,especiallyafterdisturbancessuchaslogging,fire,andgrazing,althoughrecruitmentfromseedlingsdoesoccur Brown1958,Harperetal.1985 .TheextensiveclonalrootsystemofGambeloakisaprimarycontributortoitsabilitytosurviveduringperiodswhenseedlingestablishmentisimpossible.Historicnaturalfirereturnintervalswereontheorderof100yearsinMesaVerde Floydetal.2000 ;undersuchconditionsoflowfirefrequency,vulnerablenewlysproutedstemsareabletopersistandformdensethickets.

Non‐oakdominatedmontaneshrublandsareofvariablespeciescomposition,dependingonsiteconditionssuchaselevation,slope,aspect,soiltype,moistureavailability,andpasthistory.Speciespresentmayincludemountainmahogany Cercocarpusmontanus ,


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skunkbushsumac Rhustrilobata ,clifffendlerbush Fendlerarupicola ,antelopebitterbrush Purshiatridentata ,wildcrabapple Peraphyllumramosissimum ,snowberrySymphoricarposspp. ,andserviceberry Amelanchierspp. .Mostofthesespeciesreproducebothvegetativelyandbyseedlingrecruitment,aswellasresproutingeasilyafterfire.Variabledisturbancepatternsmayaccountforthelocaldominanceofaparticularspecies Keeley2000 .Althoughfireisanobvioussourceofdisturbanceintheseshrublands,snowpackmovements creep,glide,andslippage mayalsoprovidesignificantdisturbanceinslide‐proneareas Jamiesonetal.1996 .

Insomeareas,oakstandsarevulnerabletoincreasedprevalenceofinvasivespeciessuchascheatgrassandknapweeds.Currentlytherearefewinvasivesinthestandsdominatedbyserviceberryandmahogany.Theseshrublandsarehighlyfiretolerant.Itispossibleforthissystemtomoveupinelevation,especiallyiffiresopenupsomeoftheadjacentforestedecosystems.





Extreme events

Landscape condition


Resilience Level

Oak 0.89 1 1 1 0.49 0.85 H High




Combined rank


Oak & mixed mountain shrub Low High L/H Low

Oakandmixedmountainshrublandsarerankedashavinglowvulnerabilitytotheeffectsofclimatechangebymid‐centuryunderamoderateemissionsscenario.PrimaryfactorscontributingtothisrankingarethewideecologicalamplitudeoftheseshrublandsinColorado,andtheirabilitytowithstandorrecoverfromdisturbancerelativelyquickly,whichoffsetsthelowerlandscapeconditionscoreduetopastanthropogenicdisturbancelevels.

Mapsbelowillustratethespatialpatternofexposureundertheworstcasescenarioforthefiveclimatevariablesassessedforoakandmixedmountainshrubhabitats.Legend


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pointersindicatetherangeofchangeforthishabitatwithinthestatewideextentofchange.PrecipitationduringthegrowingseasonisprojectedtodecreasemostinthesouthernandeasternportionsofthedistributionofthishabitatwithinColorado,althoughitislikelytoremainwellwithinthetoleranceoftheseshrublands.Theprojectedshiftto1‐2weeksearlierlastfrostsinspringwouldbebeneficialforthishabitat,andalthoughannualmeantemperaturesareprojectedtoincreasebyatleast2°Cinthehottestscenario,thisisalsolikelytoremainwithinthetoleranceofmostoccurrences.


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References:

Brown,H.E.1958.Gambeloakinwest‐centralColorado.Ecology39:317‐327.

Christensen,E.M.1949.Theecologyandgeographicdistributionofoakbrush Quercusgambelii inUtah.SaltLakeCity,UT:UniversityofUtah.70p.Thesis.

Clary,W.P.andA.R.Tiedemann.1992.EcologyandvaluesofGambeloakwoodlands.In:Ffolliott,P.F.,G.J.Gottfried,D.A.Bennett andothers ,technicalcoordinators.Ecologyandmanagementofoaksandassociatedwoodlands:perspectivesinthesouthwesternUnitedStatesandnorthernMexico:Proceedings;1992April27‐30;SierraVista,AZ.Gen.Tech.Rep.RM‐218.FortCollins,CO:U.S.DepartmentofAgriculture,ForestService,RockyMountainForestandRangeExperimentStation:87‐95

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:aliteraturereview.Gen.Tech.Rep.INT‐179.Ogden,UT:U.S.DepartmentofAgriculture,ForestService,IntermountainForestandRangeExperimentStation.31p.

Jamieson,D.W.,W.H.Romme,andP.Somers.1996.Bioticcommunitiesofthecoolmountains.Chapter12inTheWesternSanJuanMountains:TheirGeology,Ecology,andHumanHistory,R.Blair,ed.UniversityPressofColorado,Niwot,CO.

Keeley,J.E.2000.Chaparral.Chapter6inNorthAmericanTerrestrialVegetation,secondedition.M.G.BarbourandW.D.Billings,eds.CambridgeUniversityPress.

Neilson,R.P.andL.H.Wullstein.1983.BiogeographyoftwosouthwestAmericanoaksinrelationtoatmosphericdynamics.JournalofBiogeography10:275‐297.


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SAGEBRUSH

Climate Influences

Asevaluatedherein,thethreesubspeciesofbigsagebrush basinbigsagebrush,Artemisiatridentatassp.tridentata,mountainbigsagebrush,A.tridentatassp.vaseyana,andWyomingbigsagebrush,A.tridentatassp.wyomingensis arecombinedassagebrushhabitat.Ingeneral,Wyomingbigsagebrushisfoundindrier,warmerareaswhereprecipitationismorelikelytobeintheformofrain,whilemountainbigsagebrushisfoundathigher,coolerelevationswheresnowisthedominantformofprecipitation Howard1999,Johnson2000 .Changesintemperatureandprecipitationpatternsmayresultinshiftsintherelativeabundanceanddistributionofthethreesubspecies.

Bradley 2010 pointsoutthatsagebrushshrublandsinthewesternU.S.arecurrentlyfoundacrossawidelatitudinalgradient fromabout35to48degreesnorthlatitude ,whichsuggestsadaptationtoacorrespondinglywiderangeoftemperatureconditions.However,becausetheseshrublandsareapparentlyabletodominateazoneofprecipitationbetweendriersaltbushshrublandsandhigher,somewhatmoremesicpinyon‐juniperwoodland,thedistributionofsagebrushshrublandsislikelytobeaffectedbychangesinprecipitationpatterns Bradley2010 .Seasonaltimingofprecipitationisimportantforsagebrushhabitats;summermoisturestressmaybelimitingifwinterprecipitationislowGerminoandReinhardt2014 .Seedlingsofmountainbigsagebrushweremoresensitivetofreezingunderreducedsoilmoistureconditions Lambrechtetal.2007 .

Underexperimentalwarmingconditionsinahigh‐elevationpopulation,mountainbigsagebrushhadincreasedgrowth,suggestingthatlongergrowingseasonlengthcouldfacilitatetheexpansionofsagebrushhabitatintoareasthatwereformerlytoocoldfortheshrub Perforsetal.2003 .However,Pooreetal. 2009 foundthathighsummertemperaturesresultedinlowergrowthrate,duetoincreasedwaterstress.Wintersnowpackwascriticalforsagebrushgrowth;lowerelevationsareprobablyatmoreriskfromtemperatureimpactsincomparisontoupperelevationsduetolesssnowand,consequentlygreaterwaterstress.

Schlaepferetal. 2012 modeledfuturedistributionofthebigsagebrushecosysteminthewesternU.S.Overtheentirestudyarea,sagebrushdistributionwaspredictedtodecrease,especiallyunderhigherCO2emissionsscenarios.Thestrongestdecreasesareinthesouthernpartoftherange,whilethedistributionispredictedtoincreaseathigherelevationsandinmorenorthernareas.


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Sagebrushshrublandsareprojectedtoexperienceanincreaseinnumberofveryhotdaysincomparisonwiththecurrentrangeinmorethanonequarterofthecurrentdistribution,andfallfrostdatesarelikelytobelaterforsomeareasaswell.Projectedwinterprecipitationlevelsaregenerallywithinthecurrentrange,butspringandsummerprecipitationfor6‐12%ofthecurrentdistributionareprojectedtobelowerthanthedriestendofthecurrentrange.

Sagebrush

Climate variable


% projected

range shift


Spring precipitation (E, L) 6%


Date of first frost in fall (E) 13%

Very hot days (M) 27%


Rank L



Theseshrublandsareprimarilyfoundinthewesternpartofthestate,atelevationsfromabout5,000to9,500ft.TheNorthAmericandistributionofsagebrushhabitatislargelytothewestandnorthofColorado.Thethreesubspeciesofbigsagebrushshowanelevationalseparation,withmountainbigsagebrushinwetter,coolerconditionsofhigherelevations,andWyomingbigsagebrushinthewarmestanddriestconditionsatlowerelevationsHoward1999 .Duetotheadaptationsofthevarioussubspecies,therangeofannualaverageprecipitationforsagebrushhabitatsisfairlywide,fromabout8‐40in 20‐100cm ,withameanof18in 45cm .Growingseasonheataccumulationisalsohighlyvariableacrosstherangeofthehabitat,forthesamereason.

Becausethesearegenerallyshrublandsoflowerelevations,theyarenotexpectedtobelimitedbyarequirementforcooler,highelevationhabitat.Althoughsagebrushisgenerallyapoorseeder,withsmalldispersaldistances,therearenoapparentbarrierstodispersal


83

fortheseshrublands.Thesestandsmayalsobesomewhatvulnerabletochangesinphenology.

Otherstressorsforsagebrushshrublandsareinvasionbycheatgrassandexpansionofpinyon‐juniperwoodlands.Thereisamoderatepotentialforinvasionbyknapweedspecies,oxeyedaisy,leafyspurge,andyellowtoadflaxunderchangingclimaticconditions,andapotentialforchangingfiredynamicstoaffecttheecosystem.Thereisnoinformationonthevulnerabilityofthisecosystemtoinsectordiseaseoutbreak.

Althoughsagebrushtoleratesdryconditionsandfairlycooltemperaturesitisnotfireadapted,andnoneofthesubspeciesresproutafterfire Tirmenstein1999 .Sagebrushshrublandislikelytobeseverelyimpactedbyintensefiresthatenhancewinderosionandeliminatetheseedbank YoungandEvans1989 .Increaseddroughtmayincreasefirefrequencyandseverity,eliminatingsagebrushinsomeareas,especiallyatdriersitesoflowerelevations.Increasedfirefrequencyandseverityintheseshrublandsmayresultintheirconversiontograsslandsdominatedbyexoticspecies.





Extreme events

Landscape condition


Resilience Level

Sagebrush 0.93 0.5 0.67 0.33 0.53 0.57 M Moderate




Combined rank


Sagebrush shrubland Low Moderate L/M Low

Sagebrushshrublandsarerankedashavinglowvulnerabilitytotheeffectsofclimatechangebymid‐centuryunderamoderateemissionsscenario.TheprimaryfactorcontributingtothisrankingistheprojectedlowexposuretowarmeranddrierfutureconditionsinthepartofColoradowherethegreaterportionofthishabitatisfound.Thecombinationofthethreebigsagebrushsubspeciesinouranalysiscollectivelygivesthishabitattypeawideecologicalamplitude.Underamoresevereemissionsscenario,these


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shrublandswouldhavehighervulnerability,similartotheassessmentofPocewiczetal.2014 forsagebrushhabitatsinWyoming.

Mapsbelowillustratethespatialpatternofexposureundertheworstcasescenarioforthefiveclimatevariablesassessedforsagebrushhabitats.Legendpointersindicatetherangeofchangeforthishabitatwithinthestatewideextentofchange.WinterandspringprecipitationlevelsareprojectedtodecreasethemostinthesouthwesternpartoftheColoradodistributionofsagebrush,whilethemajorityoftheseshrublandsinnorthwesternColoradomayseelittlechange.Summerprecipitationshowsthegreatestprojecteddecreaseintheeasternpartsofthehabitatdistribution,especiallyinthehighintermountainvalleys.InportionsofthedistributionfromtheGunnisonvalleyuptoNorthPark,averagedatesoffirstfallfrostcouldbeshifted1‐4weekslaterthancurrentmeans.WiththeexceptionoftheextremesouthwestcornerofColorado,sagebrushshrublandsinthestatemayexperienceonlyaslightincreaseinthenumberofveryhotdays.ThesetrendstendtoindicatethatlowerelevationsagebrushstandsinthesouthernpartofColoradoaremostvulnerable.


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References:

Bradley,B.A.2010.Assessingecosystemthreatsfromglobalandregionalchange:hierarchicalmodelingofrisktosagebrushecosystemsfromclimatechange,landuseandinvasivespeciesinNevada,USA.Ecography33:198‐208.

Germino,M.J.andK.Reinhardt.2014.Desertshrubresponsestoexperimentalmodificationofprecipitationseasonalityandsoildepth: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.DepartmentofAgriculture,ForestService,RockyMountainResearchStation,FireSciencesLaboratory Producer .Available:http://www.fs.fed.us/database/feis/

Lambrecht,S.C.,A.K.Shattuck,andM.E.Loik.2007.Combineddroughtandepisodicfreezingonseedlingsoflow‐andhigh‐elevationsubspeciesofsagebrush Artemisiatridentata .PhysiologiaPlantarum130:207‐217.

Perfors,T.,J.Harte,andS.E.Alter.2003.Enhancedgrowthofsagebrush Artemisiatridentata inresponsetomanipulatedecosystemwarming.GlobalChangeBiology9:736‐742.

Pocewicz,A.,H.E.Copeland,M.B.Grenier,D.A.Keinath,andL.M.Waskoviak.2014.AssessingthefuturevulnerabilityofWyoming’sterrestrialwildlifespeciesandhabitats.ReportpreparedbyTheNatureConservancy,WyomingGameandFishDepartmentandWyomingNaturalDiversityDatabase.

Poore,R.E.,C.A.Lamanna,J.J.Ebersole,andB.J.Enquist.2009.Controlsonradialgrowthofmountainbigsagebrushandimplicationsforclimatechange.WesternNorthAmericanNaturalist69:556‐562.

Schlaepfer,D.R.,W.K.Lauenroth,andJ.B.Bradford.2012.Effectsofecohydrologicalvariablesoncurrentandfutureranges,localsuitabilitypatterns,andmodelaccuracyinbigsagebrush.Ecography35:374‐384.

Tirmenstein,D.1999.Artemisiatridentataspp.tridentata.In:FireEffectsInformationSystem, Online .U.S.DepartmentofAgriculture,ForestService,RockyMountain


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ResearchStation,FireSciencesLaboratory Producer .Available:http://www.fs.fed.us/database/feis/

Young,J.A.andR.A.Evans.1989.Dispersalandgerminationofbigsagebrush Artemisiatridentata seeds.WeedScience37:201‐206.


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SANDSAGE

Climate Influences

Thishabitathasoftenbeentreatedasanedaphicvariantofeasternplainsmixed‐grassprairie Albertson&Weaver1944,Daley1972, ,orofshortgrassprairie Ramaley1939,SimsandRisser2000 .Sandsage Artemisiafilifolia formsextensiveopenshrublandsinsandysoilsofColorado’seasternplains,andisofparticularimportanceforbothgreaterandlesserprairiechickenhabitat,aswellasforothergrasslandbirds.IneasternColorado,thissystemisfoundinextensivetractsonQuaternaryeoliandepositsalongtheSouthPlatte,ArikareeandRepublicanRivers,betweenBigSandyandRushCreeks,andalongtheArkansasandCimarronRivers,whereitiscontiguouswithareasinKansasandOklahomaComeretal.2003 .Duringthepast10,000years,theseareasarelikelytohavefluctuatedbetweenactivedunefieldsandstabilized,vegetateddunes,dependingonclimateanddisturbancepatterns Formanetal.2001 .Extendedperiodsofseveredroughtorotherdisturbancethatresultsinlossofstabilizingvegetationcanquicklyleadtosoilmovementandblowoutsthatinhibitvegetationre‐establishment,andmayeventuallyleadtodramaticallydifferentspeciescomposition.

Littleisknownaboutthetoleranceofsandsageforsoilsotherthanwell‐drainedsandwithalowsiltandclaycomponent.Suchsoilsareoften“droughty”,withreducedwater‐holdingability,andconsequently,thepotentialforincreasedwaterstresstoresidentplants SoilSurveyDivisionStaff1993 .RasmussenandBrotherson 1984 speculatedthatsandsageisadaptedtolessfertilesoilsthanspeciesofadjacentgrasslandcommunities.Ramaley1939 indicatedthatthepersistenceofsandsagewasfacilitatedbyfireandlongovergrazing,intheabsenceofwhichasitewouldtransitiontosandprairie.However,thereisnoevidencetosuggestthat,undercertaincombinationsoftemperature,precipitation,grazing,andotherdisturbance,sandsagewouldbeunabletoexpandontoothersoiltypes.

SandsageoccurrencesinsouthernColoradohavehistoricallyexperiencedalonggrowingseason,lowannualprecipitation,andseasonaldifferencesinprecipitationpatternsfromnorthtosouth WesternRegionalClimateCenter2004 .North‐southgradientsintemperatureandprecipitationonColorado’seasternplainsappeartobereflectedinthespeciescompositionofsandsagehabitat,especiallyinmidgrassspecies Daley1972 ,whichmaycontributetovariablevulnerabilitybetweennorthernandsouthernstands.

Thishabitatiswelladaptedtosandysoils,andmaybeabletoexpandintoadjacentareasunderwarmer,drierconditions,dependingondisturbanceinteractions.Overallconditionandcompositionoftheseshrublandsmaychangewithchangingclimate.


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Sandsageshrublandsareprojectedtoexperiencetemperatureswarmerthanthecurrentrangeinmostofthecurrentdistribution,includinganincreaseinnumberofveryhotdays.Projectedwinterandspringprecipitationlevelsareprojectedtobelowerthanthedriestendofthecurrentrangefor15‐19%ofthedistribution,anddroughtdaysareprojectedtoincreaseinadditionalareas.

Sandsage

Climate variable


% projected

range shift

Winter precipitation (M, E) 19%

Spring precipitation (E) 15%

Drought days (M) 29%


Very hot days (L) 87%


Rank H

Exposure‐Sensitivity level High


SandsagehabitatdominatessandysoilsofColorado’seasternplains,atelevationsgenerallybelow5,500ft.Inotherstates,sandsageisknowntooccurupto6,000ft. McWilliams2003 .Sandsagesharesthedryandwarmclimateofshortgrass.Annualaverageprecipitationisontheorderof10‐18inches 25‐47cm ,withameanof16in 40cm .Thegrowingseasonisgenerallylong,withfrequenthightemperatures.

Sagebrushspeciesingeneralhavepoordispersalability,withmostseedslandingclosetotheparentplant McWilliams2003 .Althoughsandsagedoesnotreproducevegetatively,itisabletoresproutafterfire.Fireextentandintensityarecorrelatedwithclimateandgrazingeffectsonfuelloads.Fireandgrazingarebothimportantdisturbanceprocessesforsandsagehabitat,andmayinteractwithdrought,aswellaspermittinginvasiveexoticplantspeciestoestablishandspread.Asignificantportionofthishabitathasbeenconvertedfrommidgrasstoshortgrasssandsagecommunity,inlargepartduetolong‐termcontinuousgrazingbydomesticlivestock LANDFIRE2006 .


91





Extreme events

Landscape condition


Resilience Level

Sandsage 0.65 1 0.67 1 0.43 0.74 H High




Combined rank


Sandsage shrubland High High H/H Moderate

Sandsageshrublandsarerankedmoderatelyvulnerabletotheeffectsofclimatechangebymid‐centuryunderamoderateemissionsscenario.ThisrankingisprimarilyduetotheconcentrationofgreatestexposureforalltemperaturevariablesontheeasternplainsofColorado,wherethesehabitatsarefound.Inaddition,anthropogenicdisturbanceintheseshrublandshasreducedtheoveralllandscapeconditionofthehabitat.

Mapsbelowillustratethespatialpatternofexposureundertheworstcasescenarioforthefiveclimatevariablesassessedforsandsagehabitats.Legendpointersindicatetherangeofchangeforthishabitatwithinthestatewideextentofchange.Underthedriestfutureprojections,decreaseinwinterprecipitationisgenerallylessthan1cm,withintherangeoftheseshrublandsinColorado,whilethedecreaseinspringprecipitationisgreater,at1‐2cm.Easternsandsagestandsmayexperienceseveralfewerdaysofmeasurableprecipitationperyear.ThegreatestprojectedchangeforsandsageshrublandsinColoradoisinveryhotdaysandgrowingseasonlength,bothofwhichshowasubstantialincrease,especiallyinthesoutheasternpartofthestate.


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93


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References:

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Comer,P.,S.Menard,M.Tuffly,K.Kindscher,R.Rondeau,G.Jones,G.Steinuaer,andD.Ode.2003.UplandandWetlandEcologicalSystemsinColorado,Wyoming,SouthDakota,Nebraska,andKansas.Reportandmap 10hectareminimummapunit totheNationalGapAnalysisProgram.Dept.ofInteriorUSGS.NatureServe.

Daley,R.H.1972.ThenativesandsagevegetationofeasternColorado.M.S.Thesis,ColoradoStateUniversity,FortCollins,Colorado.

Forman,S.L.,R.Oblesby,andR.S.Webb.2001.TemporalandspatialpatternsofHoloceneduneactivityontheGreatPlainsofNorthAmerica:megadroughtsandclimatelinks.GlobalandPlanetaryChange29:1‐29.

LANDFIRE.2006.LANDFIREBiophysicalSettingModels.BiophysicalSetting3310940,WesternGreatPlainsSandhillSteppe.USDAForestService;U.S.DepartmentofInterior.Availableat:http://www.landfire.gov/national_veg_models_op2.php


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McWilliams,J.2003.ArtemisiafilifoliaIn:FireEffectsInformationSystem, Online .U.S.DepartmentofAgriculture,ForestService,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.,NorthAmericanTerrestrialVegetation,SecondEdition.CambridgeUniversityPress,NewYork,pp.323‐356.

SoilSurveyDivisionStaff.1993.Soilsurveymanual.SoilConservationService.U.S.DepartmentofAgricultureHandbook18.Availableat:http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ref/?cid nrcs142p2_054261

WesternRegionalClimateCenter WRCC .2004.ClimateofColoradonarrativeandstateclimatedata.Availableathttp://www.wrcc.dri.edu


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FOOTHILL AND MOUNTAIN GRASSLAND

Climate Influences

Colorado’snon‐shortgrassprairiegrasslandsarehighlyvariable,dependingonelevationandlatitude.FoothillorpiedmontgrasslandsarefoundattheextremewesternedgeoftheGreatPlainsatelevationsbetween5,250and7,200feet,whereincreasingelevationandprecipitationfacilitatethedevelopmentofmixedtotallgrassassociationsoncertainsoils.Montane‐subalpinegrasslandsintheColoradoRockiesarefoundatelevationsof7,200‐10,000feet,intermixedwithstandsofspruce‐fir,lodgepole,ponderosa,andaspen,orasthematrixcommunityinthelargeintermountainbasinofSouthPark.Semi‐desertgrasslandsarefoundprimarilyondryplainsandmesasinwesternColoradoatelevationsof4,750‐7,600feet.Ourvulnerabilityanalysisdividedgrasslandsintothoseaboveandbelow7,500feet,roughlydividingmontane‐subalpineoccurrencesfromtheeasternandwesternlowerelevationgrasslandtypes.

Higherelevationgrasslandsarecharacterizedbycoldwintersandrelativelycoolsummers,althoughtemperaturesaremoremoderateatlowerelevations.Soiltextureisimportantinexplainingtheexistenceofmontane‐subalpinegrasslands Peet2000 .Montanegrasslandsoftenoccupythefine‐texturedalluvialorcolluvialsoilsofvalleybottoms,incontrasttothecoarse,rockymaterialofadjacentforestedslopes Peet2000 .Otherfactorsthatmayexplaintheabsenceoftreesinthissystemaresoilmoisture toomuchortoolittle ,competitionfromestablishedherbaceousspecies,coldairdrainageandfrostpockets,highsnowaccumulation,beaveractivity,slowrecoveryfromfire,andsnowslides Daubenmire1943,Knight1994,Peet2000 .Wheregrasslandsoccurintermixedwithforestedareas,thelesspronouncedenvironmentaldifferencesmeanthattreesaremorelikelytoinvadeTurnerandPaulsen1976 .

WestSlopelow‐elevationgrasslandsoccurinsemi‐aridtoaridclimateswithcoldtemperateconditions.Hotsummersandcoldwinterswithfreezingtemperaturesandsnowarecommon.GrasslandsofthewesternvalleysreceiveasignificantportionofannualprecipitationinJulythroughOctoberduringthesummermonsoonstorms,withtherestfallingassnowduringthewinterandearlyspringmonths.Foothillgrasslandsoftheeasternmountainfronthaveacontinentalclimatewithbotheast‐westandnorth‐southgradients.Alongthewesternedgeoftheplains,theRockyMountainscreatearainshadowtotheeast.Precipitationrapidlyincreaseswithincreasingelevation.SeveredroughtisalsoacommonphenomenonintheWesternGreatPlains Borchert1950,StocktonandMeko1983,Covitchetal.1997 .Temperaturevariationinthefoothillzoneislessthanonthe


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plains,withlowersummertemperaturesandhigherwintertemperaturesproducingaclimateismoremoderatethanthatforgrasslandstotheeast WesternRegionalClimateCenter2004 .

Droughtandwarmertemperaturesmaychangespeciescomposition,orallowinvasionbydrought‐toleranttrees/shrubsorinvasivespeciesinsomeareas.Droughtcanincreaseextentofbaregroundanddecreaseforbcoverage,especiallyinmorexericgrasslandsDebinskietal2010 ,whichcouldresultinatransformationtoasemi‐desertgrasslandtype.


Foothillandmontanegrasslandsareprojectedtoexperiencebothsummerandwintertemperaturesthatarewarmerthanthecurrentrangeinabouthalfofthecurrentdistribution,moresoinlowerelevationgrasslands.Althoughprojectedwinterprecipitationlevelsaregenerallywithinthecurrentrange,annualprecipitationlevelsareprojectedtobelowerthanthedriestendofthecurrentrangefornearlyhalfofthelowerelevationdistribution,anddroughtdaysareprojectedtoincreaseinadditionalareas.

High elevation grasslands

Low elevation grasslands

Climate variable % projected

range shift

Winter precipitation 0% 1%

Annual precipitation 7% 44%

Drought days 5% 22%

Mean winter temperature 44% 64%

Mean summer temperature 55% 65%

Average range shift 22.1% 39.1%

Rank M H

Exposure‐Sensitivity level Moderate High


Thesefoothillandmontanegrasslandsarenotrestrictedtohighelevations,andarenotatthesouthernedgeoftheirNorthAmericandistributioninColorado.


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Climaticvariation,fireexclusion,andgrazingappeartointeractwithedaphicfactorstofacilitateorhindertreeinvasioninthesegrasslands ZierandBaker2006 .TheworkofCoopandGivnish 2007 intheJemezMountainsofnorthernNewMexicosuggeststhatbothchangingdisturbanceregimesandclimaticfactorsarelinkedtotreeestablishmentinsomemontanegrasslands.Increasedtreeinvasionintomontanegrasslandswasapparentlylinkedtohighersummernighttimetemperatures,andlessfrostdamagetotreeseedlings;thistrendcouldcontinueunderprojectedfuturetemperatureincreases.Theinteractionofmultiplefactorsindicatesthatmanagementforthemaintenanceofthesemontaneandsubalpinegrasslandsmaybecomplex.

Floristiccompositioningrasslandsisinfluencedbybothenvironmentalfactorsandgrazinghistory.Manygrasslandoccurrencesarealreadyhighlyalteredfrompre‐settlementcondition.Grazingisgenerallybelievedtoleadtothereplacementofpalatablespecieswithlesspalatableonesmoreabletowithstandgrazingpressure Smith1967,Paulsen1975,Brown1994,butseeStohlgrenetal.1999 .Grazingbydomesticlivestockmayacttooverrideormaskwhatevernaturalclimaticoredaphicmechanismisresponsibleformaintaininganoccurrence.Thishabitatisalsoadaptedtograzingandbrowsingbynativeherbivoresincludingdeer,elk,bison,andpronghorn,aswellasburrowingandgrazingbysmallmammalssuchasgophers,prairiedogs,rabbits,andgroundsquirrels.Activitiesoftheseanimalscaninfluencebothvegetationstructureandsoildisturbance,potentiallysuppressingtreeestablishment.Periodicdroughtiscommonintherangeoffoothillandsemi‐desertgrasslands,butmaynotbeasgreatafactorinthevegetationdynamicsofthissystemasingrasslandsoftheplains.



Dispersal &

growth form


Extreme events

Landscape condition


Resilience Level

High elevation grasslands 0.82 1 0.33 0.67 0.37 0.64 M Moderate

Low elevation grasslands 0.71 1 0.33 0.67 0.37 0.62 M Moderate


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Foothill & mountain grassland Exposure ‐ SensitivityResilience – Adaptive

Capacity Combined

rank Overall vulnerability to

climate change

High elevation Moderate Moderate M/M Moderate

Low elevation High Moderate H/M High

Foothillandmountaingrasslandsofelevationsabove7,500ft.arerankedasmoderatelyvulnerabletotheeffectsofclimatechangebymid‐centuryunderamoderateemissionsscenario,andthosebelow7,500ft.havehighvulnerability.Primaryfactorscontributingtothisrankingarevulnerabilityoftheseareatoinvasivespecies,andthegenerallyhighlydisturbedconditionofoccurrences,bothofwhicharelikelytointeractwiththesignificantincreasesintemperatureacrossmuchofthedistributionofthehabitatinColoradotoreduceresilienceofthesehabitats.

NOTE:duetothegenerallysmallsizeofmontane‐foothillgrasslandoccurrences,exposuremapswerenotproducedforthishabitat.

References:

Borchert,J.R.1950.TheclimateofthecentralNorthAmericangrassland.AnnalsoftheAssociationofAmericanGeographers40:1‐39.

Brown,D.E.1994.Grasslands.InBioticcommunities:southwesternUnitedStatesandnorthwesternMexico.D.E.Brown,ed.UniversityofUtahPress,SaltLakeCity,Utah.

Coop,J.D.andT.J.Givnish.2007.SpatialandtemporalpatternsofrecentforestencroachmentinmontanegrasslandsoftheVallesCaldera,NewMexico,USA.JournalofBiogeography34:914‐927.

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.PotentialeffectsofclimatechangeonaquaticecosystemsoftheGreatPlainsofNorthAmerica.HydrologicalProcesses11:993‐1021.

Daubenmire,R.F.1943.VegetationalzonationintheRockyMountains.BotanicalReview9:325‐393.

Debinski,D.M.,H.Wickham,K.Kindscher,J.C.Caruthers,andM.Germino.2010.Montanemeadowchangeduringdroughtvarieswithbackgroundhydrologicregimeandplantfunctionalgroup.Ecology91:1672‐1681.


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Knight,D.H.1994.MountainsandPlains:theEcologyofWyomingLandscapes.YaleUniversityPress,NewHavenandLondon.338pages.

Paulsen,H.A.,Jr.1975.RangemanagementinthecentralandsouthernRockyMountains:asummaryofthestatusofourknowledgebyrangeecosystems.USDAForestServiceResearchPaperRM‐154.RockyMountainForestandRangeExperimentStation,USDAForestService,FortCollins,Colorado.

Peet,R.K.2000.ForestsandmeadowsoftheRockyMountains.Chapter3inNorthAmericanTerrestrialVegetation,secondedition.M.G.BarbourandW.D.Billings,eds.CambridgeUniversityPress.

Smith,D.R.1967.Effectsofcattlegrazingonaponderosapine‐bunchgrassrangeinColorado.USDAForestServiceTechnicalBulletinNo.1371.RockyMountainForestandRangeExperimentStation,USDAForestService,FortCollins,Colorado.

Stockton,C.W.andD.M.Meko.1983.DroughtreoccurrenceintheGreatPlainsasreconstructedfromlong‐termtree‐ringrecords.JournalofClimateandAppliedMeteorology22:17‐29.

Stohlgren,T.J.,L.D.Schell,andB.VandenHuevel.1999.Howgrazingandsoilqualityaffectnativeandexoticplantdiversityinrockymountaingrasslands.EcologicalApplications9:45‐64.

Turner,G.T.,andH.A.Paulsen,Jr.1976.ManagementofMountainGrasslandsintheCentralRockies:TheStatusofOurKnowledge.USDAForestServiceResearchPaperRM‐161.RockyMountainForestandRangeExperimentStation,USDAForestService,FortCollins,Colorado.

WesternRegionalClimateCenter WRCC .2004.ClimateofColoradonarrativeandstateclimatedata.Availableathttp://www.wrcc.dri.edu

Zier,J.L.andW.L.Baker.2006.AcenturyofvegetationchangeintheSanJuanMountains,Colorado:Ananalysisusingrepeatphotography.ForestEcologyandManagement228:251–262.


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SHORTGRASS PRAIRIE

Climate Influences

Soilmoisturelevelisakeydeterminantofthedistributionofshortgrassprairiehabitat;changeinprecipitationseasonality,amount,orpatternwillaffectsoilmoisture.Grasslandsgenerallyoccurinareaswherethereisatleastoneannualdryseasonandsoilwateravailabilityislowerthanthatrequiredfortreegrowth Partonetal.1981,SimsandRisser2000 .Soilwateravailabilityactsonbothplantwaterstatusandnutrientcycling Salaetal.1992 .Thishabitatreceivesmostofitsannualprecipitationduringthespringandsummergrowingseason.Dailyprecipitationamountsaretypicallyquitesmall 5mmorless ,anddonotcontributesignificantlytosoilwaterrecharge,whichinsteadisprimarilydependentonlargebutinfrequentrainfallevents Partonetal.1981,Heisler‐Whiteetal.2008 .Largerrainfalleventspermitdeepermoisturepenetrationinthesoilprofile,andenableanincreaseinabove‐groundnetprimaryproduction Heisler‐Whiteetal.2008 .Thedominantshortgrassspeciesbluegrama Boutelouagracilis isabletorespondquicklytoverysmallrainfallevents,althoughthisabilityisapparentlyreducedduringextendeddroughtperiods SalaandLauenroth1982,Salaetal.1982,CherwinandKnapp2012 .Nevertheless,bluegramaexhibitedextensivespreadduringthedroughtoftheDustbowlyears AlbertsonandWeaver1944 .Iflargerainfalleventsaremorecommon,thesensitivityofshortgrassprairieisreduced CherwinandKnapp2012 .

Grasslandsinareaswheremeanannualtemperatureisabove10°CaregenerallydominatedbyC4 warm‐season grassspecies,whicharetolerantofwarmertemperaturesandmoreefficientinwateruse SimsandRisser2000 .InColorado,shortgrassprairiehasahistoricannualmeantemperatureslightlygreaterthan10°C,althoughtherangeincludesslightlycoolerannualmeantemperaturesaswell.Althoughthesegrasslandsareadaptedtowarm,dryconditions,Alwardetal. 1999 foundthatwarmingnight‐timetemperaturesinspringweredetrimentaltothegrowthofbluegrama,andinsteadfavoredcool‐season C3 species,bothnativeandexotic.Consequently,theeffectofincreasingtemperaturesonshortgrassprairieisdifficulttopredict.

Warmeranddrierconditionswouldbelikelytoreducesoilwateravailabilityandotherwisehavedetrimentaleffectsonecosystemprocesses,whilewarmerandwetterconditionscouldbefavorable.Furthermore,changingclimatemayleadtoashiftintherelativeabundanceanddominanceofshortgrassprairiespecies,givingrisetonovelplantcommunities Polleyetal.2013 .BecausewoodyplantsaremoreresponsivetoelevatedCO2,andmayhavetaprootscapableofreachingdeepsoilwater Morganetal.2007 ,anincreaseofshrubbyspecies e.g.,cholla,yucca,snakeweed,sandsage ,orinvasiveexotic


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species,especiallyinareasthataredisturbed forinstance,byheavygrazing mayalsoresult.


Shortgrassprairieisprojectedtoexperiencespringandsummertemperaturesthatarewarmerthanthecurrentrangeinthemajorityofthecurrentdistribution.Projectedprecipitationlevelsareprojectedtobelowerthanthedriestendofthecurrentrangefornearlyhalfofthelowerelevationdistribution.Anincreaseindroughtdays,andfewerdayswithlargeprecipitationeventsareprojectedforasubstantialportionofthecurrentdistributionaswell.

Shortgrass prairie

Climate variable


% projected

range shift

Annual precipitation (L) 43%

Days with heavy precipitation (L) 30%

Drought days (M, E, L) 38%

Mean spring temperature (L) 58%

Mean summer temperature (L) 67%


Rank H

Exposure‐Sensitivity level High


Inspiteofextensiveconversiontoagricultureorotheruses,shortgrassprairiestillformsextensivetractsontheeasternplainsofColorado,atelevationsbelow6,000feet.ColoradoaccountsforasubstantialportionoftheNorthAmericandistributionofthesegrasslands,whichextendfromTexastoWyoming.ShortgrassprairieexperiencesamuchdrierandwarmerclimatethanmostotherhabitattypesinColorado.Annualaverageprecipitationisontheorderof10‐18inches 25‐47cm ,withameanof15in 38cm ,andthegrowingseasonisgenerallylong,withfrequenthightemperatures.

Theshortgrassesthatcharacterizethishabitatareextremelydrought‐andgrazing‐tolerant.Thesespeciesevolvedwithdroughtandlargeherbivoresand,becauseoftheirstature,arerelativelyresistanttoovergrazing.Fireislessimportantthanherbivoryin


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shortgrasshabitat;thetypicallywarmanddryclimateconditionsacttodecreasethefuelloadandthustherelativefirefrequencywithinthehabitat.Historically,firesthatdidoccurwereoftenextensive;firesuppressionandgrazinghavegreatlychangedthistendency.Morefrequentoccurrenceofclimateextremes e.g.verywetconditionsfollowedbyverydryconditions couldincreasethefrequencyandextentofgrasslandwildfires Polleyetal.2013 .





Extreme events

Landscape condition


Resilience Level

Shortgrass 0.69 1 0.33 0.67 0.44 0.62 M Moderate




Combined rank


Shortgrass prairie High Moderate H/M High

Shortgrassprairieisrankedashavinghighvulnerabilitytotheeffectsofclimatechangebymid‐centuryunderamoderateemissionsscenario.PrimaryfactorscontributingtothisrankingarethefactthatthesegrasslandsarefoundontheeasternplainsofColorado,wherethegreatestlevelsofexposureforalltemperaturevariablesoccur.Inaddition,anthropogenicdisturbanceinthesegrasslandshasreducedtheoveralllandscapeconditionofthehabitat,whichislikelytoreduceitsresilienceinthefaceofincreasingfrequencyofextremeevents.

Mapsbelowillustratethespatialpatternofexposureundertheworstcasescenarioforthefiveclimatevariablesassessedforshortgrasshabitats.Legendpointersindicatetherangeofchangeforthishabitatwithinthestatewideextentofchange.Forthedriestprojection,annualprecipitationcouldbe4‐8cmlessthancurrentlevels,withareductioninheavyprecipitationeventsevenunderwetterscenarios,andincreaseindayswithlittletonomeasurableprecipitation.Springandsummertemperaturesareprojectedtoincreaseby2.5‐3°Cinthewarmestscenarioacrossthedistributionofthishabitat,whichislikelytoincreasedroughtstressforshortgrassprairie.


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105


106

References:

Albertson,F.W.,andJ.E.Weaver.1944.NatureanddegreeofrecoveryofgrasslandfromtheGreatDroughtof1933to1940.EcologicalMonographs14:393‐479.

Alward,R.D.,J.K.Detling,andD.G.Milchunas.1999.Grasslandvegetationchangesandnocturnalglobalwarming.Science238 5399 :229‐231.

Cherwin,K.,andA.Knapp.2012.Unexpectedpatternsofsensitivitytodroughtinthreesemi‐aridgrasslands.Oecologia169:845‐852.

Heisler‐White,J.L.,A.K.Knapp,andE.F.Kelly.2008.Increasingprecipitationeventsizeincreasesabovegroundnetprimaryproductivityinasemi‐aridgrassland.Oecologia158:129‐140.

Morgan,J.A.,D.G.Milchunas,D.R.LeCain,M.West,andA.R.Mosier.2007.Carbondioxideenrichmentaltersplantcommunitystructureandacceleratesshrubgrowthintheshortgrasssteppe.PNAS104:14724‐14729.

Parton,W.J.,W.K.Lauenroth,andF.M.Smith.1981.Waterlossfromashortgrasssteppe.AgriculturalMeteorology24:97‐109.


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Polley,H.W.,D.D.Briske,J.A.Morgan,K.Wolter,D.W.Bailey,andJ.R.Brown.2013.ClimatechangeandNorthAmericanrangelands:trends,projections,andimplications.RangelandEcology&Management66:493‐511.

Sala,O.E.,andW.K.Lauenroth.1982.Smallrainfallevents:anecologicalroleinsemiaridregions.Oecologia53:301‐304.

Sala,O.E.,W.K.Lauenroth,andW.J.Parton.1982.Plantrecoveryfollowingprolongeddroughtinashortgrasssteppe.AgriculturalMeteorology27:49‐58.

Sala,O.E.,W.K.Lauenroth,andW.J.Parton.1992.Long‐termsoilwaterdynamicsintheshortgrasssteppe.Ecology73:1175‐1181.

Sims,P.L.,andP.G.Risser.2000.Grasslands.In:Barbour,M.G.,andW.D.Billings,eds.,NorthAmericanTerrestrialVegetation,SecondEdition.CambridgeUniversityPress,NewYork,pp.323‐356.


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PLAYAS

Climate Influences

PlayasofColorado’seasternplainsaresmall,shallow,isolatedtemporarywetlands,eachwithinaclosedwatershed.Intheabsenceofanthropogenicdisturbance,playasreceivewateronlyfromprecipitationandassociatedrunoff,andwaterislostthroughevaporation,transpiration,andinfiltration HaukosandSmith2003 .Wetanddryperiodsaredependentonlocalpatternsofprecipitationandtemperaturebothseasonallyandfromyeartoyear.Incommonwiththesurroundingshortgrassprairiehabitat,playasineasternColoradoreceivemostoftheirlimitedannualprecipitationintheformofrainduringtheperiodAprilthroughSeptember WRCC2004 .Unmodifiedplayasarenormallydryinlatewinterandearlyspring Bolenetal.1989 .Mostprecipitationeventsaresmall 5mmorless ,butinfrequentheavyrainfalleventsarecharacteristicoftheregion.Thebiodiversityofaplayainagivenyearisaproductofbothcurrentandpastconditionsthatpermitthegrowthofvegetationfromtheseedbank,andsupportassociatedfauna HaukosandSmith1993 .

Colorado’seasternplainsgenerallyexperiencealargedailyrangeintemperature,andsummertemperaturesaregenerallyhigherthaninotherareasofthestate,orequivalenttothewarmestlow‐elevationareasinsouthwestColorado.Thewarm,dryconditionsoflatesummerfacilitatetheevaporationofstandingwater,aswellastranspirationbyplayavegetation.Extendedperiodsofdrought,andattendantduststormsarecharacteristicoftheregion WRCC2004 .

Changesintheamountandtimingofprecipitation,aswellastheeffectofincreasingtemperatureonevapotranspirationratesarelikelytoalterthehydroperiodofindividualplayas,and,inaggregate,thenumberanddistributionofplayasonthelandscapeMatthews2008 .Decreasesinprecipitationarelikelytoincreasefragmentationofplayalakesasalandscapelevelhabitatresource,suchthatspeciesutilizingthesehabitatswillfaceincreaseddifficultyinmovingbetweenplayas McIntyreetal.2014,Ruizetal.2014 .


Projectedprecipitationlevelsforplayasaregenerallywithinthecurrentrange.Springandsummertemperaturesareprojectedtobewarmerthanthecurrentrangeinmorethanhalfofthedistributionofthishabitat.


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Playas


range shift

Spring precipitation 0%

Summer precipitation 0%

Drought days 0%

Mean spring temperature 58%

Mean summer temperature 56%

Average range shift 23%

Rank M



PlayasineasternColoradoarenotrestrictedtohighelevations,andarenotatthesouthernedgeoftheirrange.However,thesefactorsmaynotbeasrelevanttodeterminingvulnerabilityforthesesmall,isolatedhabitatpatchesasforlarger,morecontiguoushabitattypes.PlayasineasternColoradooccurinarelativelysmallrangeofprecipitationandgrowingseasonconditions.Furthermore,thesmallsize,isolation,anddynamicnatureofthesehabitatsmeansthatconnectivityanddispersalarecriticalpointsofvulnerabilityinthepersistenceofthesehabitatsandthespeciesthatrelyonthem.

Increasedsedimentationthroughwatererosionofadjacentcultivatedlandsandactivefillingofdepressionalwetlandshasbeentheprimarythreattothepersistenceofplayahabitats HaukosandSmith2003 .Farfewerthan1%ofextantplayasarewithoutmodification,eithertothewetlanditself,ortoitswatershed Johnsonetal.2012 .Anthropogenicalterationstohydrologywithinindividualplayasincludetilling,pitexcavationtoincreasewaterstorage,runoffdiversion,andpumpingforirrigation.Additionallandusepracticeswithintheimmediatewatershedmayincludecropcultivation,livestockgrazing,development,andotherpracticesthatincreasesedimentaccumulationintheplaya Luoetal.1997,Johnsonetal.2012 .Impactstoplayasfromconversiontocroplandaresignificant,andtendtodecreasetheresilienceoftheplayahabitat.TillingdecreasestheabilityofaplayadepressiontomaintainnaturalhydroperiodTsaietal.2007 ,andincreasesthechanceofcolonizationbyexoticspecies Tsaietal.2012 .Thehighlyalteredconditionofplayahabitatislikelytosignificantlydegradetheabilityofthesewetlandstoadapttoclimatechange.


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Extreme events

Landscape condition


Resilience Level

Playas 0.62 0.00 0.33 0.67 0.57 0.44 L Low




Combined rank


Playas Moderate Low M/L High

Playasarerankedashavinghighvulnerabilitytotheeffectsofclimatechangebymid‐centuryunderamoderateemissionsscenario.PrimaryfactorscontributingtothisrankingarethefactthattheseisolatedwetlandsarefoundontheeasternplainsofColorado,wherethegreatestlevelsofexposureforalltemperaturevariablesoccur.Inaddition,anthropogenicdisturbanceinthesehasreducedtheoveralllandscapeconditionandconnectivityofthehabitat,whichislikelytoreduceitsresilienceinthefaceofincreasingfrequencyofextremeevents,andgenerallywarmer,drierconditions.

NOTE:duetothegenerallysmallsizeofplayaoccurrences,exposuremapswerenotproducedforthishabitat.

References:

Bolen,E.G.,L.M.Smith,andH.L.SchrammJr.1989.Playalakes:prairiewetlandsoftheSouthernHighPlains.BioScience39:615‐623.

Haukos,D.A.,andL.M.Smith.1993.Seed‐bankcompositionandpredictiveabilityoffieldvegetationinplayalakes.Wetlands13:32‐40.

Haukos,D.A.,andL.M.Smith.2003.PastandfutureimpactsofwetlandregulationsonplayaecologyinthesouthernGreatPlains.Wetlands23:577‐589.

Johnson,L.A.,D.A.Haukos,L.M.Smith,andS.T.McMurry.2012.PhysicallossandmodificationofSouthernGreatPlainsplayas.JournalofEnvironmentalManagement112:275‐283.


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Luo,H.,L.M.Smith,B.L.AllenandD.A.Haukos.1997.Effectsofsedimentationonplayawetlandvolume.EcologicalApplications7:247‐252.

Matthews,J.H.2008.AnthropogenicclimatechangeinthePlayaLakesJointVentureRegion:understandingimpacts,discerningtrends,anddevelopingresponses.ReportpreparedforthePlayaLakesJointVenture.Available:http://www.pljv.org/documents/science/PLJV_climate_change_review.pdf

McIntyre,N.E.,C.K.Wright,S.Swain,K.Hayhoe,G.Liu,F.W.Swartz,andG.M.Henebry.2014.ClimateforcingofwetlandlandscapeconnectivityintheGreatPlains.FrontiersinEcologyandtheEnvironment12:59‐64.

Ruiz,L,N.Parikh,L.J.Heintzman,S.D.Collins,S.M.Starr,C.K.Wright,G.M.Henebry,N.vanGestel,andN.E.McIntyre.2014.DynamicconnectivityoftemporarywetlandsinthesouthernGreatPlains.LandscapeEcology29:507‐516.

Tsai,J.,L.S.Venne,S.T.McMurry,andL.M.Smith.2007.InfluencesoflanduseandwetlandcharacteristicsonwaterlossratesandhydroperiodsofplayasintheSouthernHighPlains,USA.Wetlands27:683‐692.

Tsai,J.,L.S.Venne,S.T.McMurry,andL.M.Smith.2012.Localandlandscapeinfluencesonplantcommunitiesinplayawetlands.JournalofAppliedEcology49:174‐181.

WesternRegionalClimateCenter WRCC .2004.HistoricalClimateInformation,NarrativesbyState.ClimateofColorado.Availableat:http://www.wrcc.dri.edu/narratives/colorado/


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RIPARIAN WOODLANDS AND SHRUBLANDS

Climate Influences

WeassessedtheconditionofriparianwoodlandsandshrublandsineachofthreeregionsinColorado,correspondingroughlytoecoregionsasdefinedbyTheNatureConservancy2009,modifiedfromBailey1998 :theeasternplains CentralShortgrassPrairieecoregion ;mountains SouthernRockyMountainecoregion ;andwesternplateausandvalleys ColoradoPlateau,WyomingBasins,andotherecoregions .

RiparianareasofColorado’seasternplainsareprimarilyassociatedwithintermittentlyflowingstreamsofsmalltomoderatesize,butalsoincludethelargerfloodplainsofthelargesnowmelt‐fedrivers SouthPlatteandArkansas .Smallerstreamsreceivewaterfromprecipitationandgroundwaterinflow,havegreaterseasonalflowvariationthanthelargerrivers,andhaveminimalornoflowexceptduringfloods Covichetal.1997 .InmountainousareasofColorado,riparianareasaremuchmorelikelytobeassociatedwithperenniallyflowingstreams,andtheseplantcommunitiesareadaptedtohighwatertablesandperiodicflooding.Runoffandseepagefromsnowmeltisaprimarysourceofstreamflow.LowerelevationriparianareasinwesternColoradoareadaptedtoperiodicflooddisturbanceandpredominantlyaridconditions.Largerstreamsandriversaresustainedbyrunofffrommountainareas.Smallerstreamsareprimarilysupportedbygroundwaterinflow,oroccasionallargeprecipitationevents,andareoftendryforsomeportionoftheyear.

Riparianwoodlandsandshrublandsareadjacenttoandaffectedbysurfaceorgroundwaterofperennialorephemeralwaterbodies.Theyarecharacterizedbyintermittentfloodingandaseasonallyhighwatertable.Thecloseassociationofriparianareaswithstreamflowandaquatichabitatsmeansthatchangingpatternsofprecipitationandrunoffthatalterhydrologicregimesarelikelytohaveadirecteffectonthesehabitats Caponetal.2013 .Inaddition,theinteractionofincreasedgrowthduetoincreasedCO2concentration,warming‐induceddroughtandheat‐stresswithpotentiallyreducedstreamflowsarelikelytoaffectripariancommunitystructureandcomposition,especiallyinmorearidareasPerryetal.2012 .

Climateprojectionsformid‐centuryaregenerallyforwarmeranddrieroutcomes,althoughprecipitationchangeismoreuncertainindirectionandmagnitude Lucasetal.2014 .Annualrunoffandstreamflowareaffectedbybothtemperatureandprecipitation,andeffectsoffuturechangesinthesefactorsaredifficulttoseparate.Warmingtemperaturesarelikelytoaffectthehydrologiccyclebyshiftingrunoffandpeakflowstoearlierinthe


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spring,andreducinglatesummer‐earlyautumnflows Roodetal.2008 .Riparianvegetationisinpartdeterminedbyflowlevels Aubleetal.1994 .Reducedsummerflowsarepredictedtoresultinmorefrequentdroughtstressforriparianhabitats,witharesultinglossorcontractionofthehabitat Roodetal.2008 .Warming‐inducedchangesinsnowpackandsnowmelttimingincludeearlierspringsnowmelt,ashifttowardsprecipitationfallingasraininsteadofsnowinspringandfall,andincreasedsublimationfromthesnowpackthroughouttheseason.Thesechangesareexpectedtohavegreaterimpactatlowerelevations Lucasetal.2014 .


Becauseofthewidespreadnatureandgenerallywideecologicaltolerancesofthisdiversegroupofplantcommunitiesasawhole,projectedtemperatureandprecipitationconditionsacrossthecompletecurrentdistributionaregenerallywithinthecurrentrange.RiparianwoodlandsandshrublandsinwesternColoradoareprojectedtoexperiencesummertemperaturesthatarewarmerthanthecurrentrangeinnearlyhalfofthecurrentdistribution.IneasternColorado,projectedprecipitationlevelsareprojectedtobelowerthanthedriestendofthecurrentrangefor15%ofthecurrentdistribution,anddroughtdaysareprojectedtoincreaseaswell.

Riparian woodland and shrubland West Mountain East


range shift

Winter precipitation 0%

Spring precipitation 0% 15%

Summer precipitation 0% 0%

Fall precipitation 0%

Days with heavy precipitation 0%

Drought days 38%

Mean winter temperature 0%

Mean spring temperature 0% 0% 0%


Very hot days 0%

Average range shift 9% 0% 11%

Rank L L L

Exposure‐Sensitivity level Low Low Low


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RiparianareashaveawideecologicalamplitudeinColorado,andarenotrestrictedbyelevationoredge‐of‐rangefactors.However,thestructureandcompositionofriparianhabitatsiscloselytiedtolocalaswellasupstreamenvironmentalconditions,andisconsequentlyhighlyvariablefromonepartofthestatetoanother.Changingclimatescouldhavedramaticeffectsonthecomponentspeciesandarrangementofriparianhabitats;theconsequencesofthesechangesforhabitatfunctionandpersistencearelittleknown.

Dominantriparianspeciesareoftendependentonperiodicflooddisturbancefordispersalandregeneration.Alteredhydrologyduetodams,diversions,andgroundwaterpumpingmayinteractwithwarmingtemperaturesandchangesinprecipitationpatterntoalterfluvialregimes.Suchchangesmayincreasevulnerabilityofriparianhabitatstoinvasionbyexoticspecies,especiallyafterextremeevents Caponetal.2013 .Increasedfrequencyandmagnitudeofdroughtislikelytohavemoreimpactonthesehabitatsthanstreamwarmingorwildfire,atleastatregionalscales Holsingeretal.2014 .Climatechangeinwatersourceareasaswellasinadjacenthabitatscouldhavesignificantimpactonriparianhabitats,potentiallyreducingvegetativecover,andalteringspeciescomposition.


Riparian woodland and shrubland




Extreme events

Landscape condition


Resilience Level

West 0.57 0.50 0.33 0.67 0.40 0.50 L Low

Mountain 0.81 0.50 0.33 0.67 0.69 0.60 M Moderate

East 0.64 0.50 0.33 0.67 0.44 0.52 M Moderate


Riparian woodland & shrubland Exposure ‐ SensitivityResilience – Adaptive

Capacity Combined

rank Overall vulnerability to

climate change

West Low Low L/L Moderate

Mountain Low Moderate L/M Low

East Low Moderate L/M Low


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Riparianwoodlandandshrublandsoftheeasternplainsandmountainareasarerankedashavinglowvulnerabilitytotheeffectsofclimatechangebymid‐centuryunderamoderateemissionsscenario,whilethoseofthewesternvalleysareconsideredmoderatelyvulnerable.PrimaryfactorscontributingtotheserankingsarethewideecologicalamplitudeanddistributionofriparianhabitatsthroughoutColorado,althoughthevulnerabilityofsomespeciesassemblagesmaybehigherthanisreflectedbythecollectiveassessment.Thelowtomoderateresilienceranksreflectthehighlyalteredconditionofmostofthesehabitats,andingeneral,riparianwoodlandsandshrublandsthroughoutthestateshouldprobablyberegardedashavingsomedegreeofvulnerabilitytoclimatechangethatisnotcapturedbyourbroad‐scaleassessmentmethods.

NOTE:duetotherelativelysmallsizeofriparianoccurrences,exposuremapswerenotproducedforthishabitat.

References:

Auble,G.T.,J.M.Friedman,andM.L.Scott.1994.Relatingriparianvegetationtopresentandfuturestreamflows.EcologicalApplications4:544‐554.

Bailey,R.1998.EcoregionsmapofNorthAmerica:Explanatorynote.USDAForestService,Misc.Publicationno.1548.10pp. mapscale1:15,000,000

Capon,S.J.,L.E.Chambers,R.MacNally,R.J.Naiman,P.Davies,N.Marshall,J.Pittock,M.Reid,T.Capon,M.Douglas,J.Catford,D.S.Baldwin,M.Stewardson,J.Roberts,M.parsons,andS.E.Williams.2013.Riparianecosystemsinthe21stcentury:hotspotsforclimatechangeadaptation?Ecosystems16:359‐381.

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.PotentialeffectsofclimatechangeonaquaticecosystemsoftheGreatPlainsofNorthAmerica.HydrologicalProcesses11:993‐1021.

Holsinger,L.,R.E.Keane,D.J.Isaak,L.Eby,andM.K.Young.2014.Relativeeffectsofclimatechangeandwildfiresonstreamtemperatures:asimulationmodelingapproachinarockyMountainwatershed.ClimaticChange124:191‐206.

Lucas,J.,J.Barsugli,N.Doesken,I.Rangwala,andK.Wolter.2014.ClimateChangeinColorado:asynthesistosupportwaterresourcesmanagementandadaptation.Secondedition.ReportfortheColoradoWaterConservationBoard.WesternWaterAssessment,CooperativeInstituteforResearchinEnvironmentalSciences CIRES ,UniversityofColoradoBoulder.


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Perry,L.G.,D.C.Andersen,L.V.Reynolds,S.M.Nelson,andP.B.Shafroth.2012.VulnerabilityofriparianecosystemstoelevatedCO2andclimatechangeinaridandsemiaridwesternNorthAmerica.GlobalChangeBiology18:8221‐842.

Rood,S.B.,J.Pan,K.M.Gill,C.G.Franks,G.M.Samuelson,andA.Shepherd.2008.DecliningsummerflowsofRockyMountainrivers:changingseasonalhydrologyandprobableimpactsonfloodplainforests.JournalofHydrology349:397‐410.

TheNatureConservancy TNC .2009.TerrestrialEcoregionsoftheWorld,digitalvectordata.TheNatureConservancy,Arlington,Virginia.


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WETLANDS

Climate Influences

Weassessedtheconditionofnon‐riparianwetlandsineachofthreesectionsofColorado,correspondingapproximatelytoecoregionsasdefinedbyTheNatureConservancy 2009,modifiedfromBailey1998 :theeasternplains CentralShortgrassPrairieecoregion ;mountains SouthernRockyMountainecoregion ;andwesternplateausandvalleysColoradoPlateau,WyomingBasins,andotherecoregions .

Asconsideredherein,wetlandsareareascharacterizedbywatersaturationandhydricsoilstypicallysupportinghydrophyticvegetation.Non‐riparianwetlandsofColorado’seasternplainsandwesternvalleysareprimarilymarshes,seeps,andsprings,andwetmeadows.Althoughnaturalmarshesandwetmeadowsareprimarilyfoundathigherelevations,irrigationpractices directfloodapplication,irrigationtailwaters,elevatedgroundwaterlevels,etc. havegreatlyincreasedtheincidenceofwetmeadowsontheeasternplains Sueltenfussetal.2013 .Playasareconsideredseparatelyabove.Mostofthestate’swetmeadowsoccurinmountainousareasofColorado,andmarshesaregenerallylesscommon.Fensarealsocharacteristicofthemountainregion.

Effectsofclimatechangeonwetlandsareexpectedtobelargelymediatedthroughthesourceofwater,eitherprecipitation,groundwaterdischarge,or,forwetlandsassociatedwithriparianareas,surfaceflow Winter2000 .Precipitationsupportedwetlandsarethoughttobemostvulnerabletodrierclimaticoutcomes,butdecreasingprecipitationwouldalsobelikelytolowerwatertablelevelsandleadtocontractionofgroundwater‐fedwetlands Winter2000,Poffetal.2002 .Underwetterconditions,somewetlandtypesmaybeabletoexpandoratleastmaintaincurrentextents.Considerationoftheeffectsofchangingprecipitationisfurthercomplicatedbythefactthatwetlandsmayreceivewaterinputfromthesurroundingbasin,notjusttheimmediateenvirons Gitayetal.2001 .

Temperatureaffectswetlanddistributionandfunctionprimarilythroughitseffectsonratesofchemical,physicalandbiologicalprocesses GageandCooper2007 .Althoughwetlandsaretosomeextentbufferedfromtheimmediateeffectsofwarmingonwatertemperature,warmingcouldincreasebothplantgrowthandmicrobialactivitydrivingdecomposition Fischlinetal.2007 .Temperatureisalsoadriverofevapotranspirationrate,andthewatercycleingeneral Gitayetal.2001 .

Variationinclimaticconditionsaffectsgroundwaterlevelsbothdirectlyviarechargerates,andindirectlythroughchangesinpatternsofgroundwateruse,especiallyirrigation


118

Tayloretal.2012 .Drierfutureconditionsarelikelytoresultintightercontrolsonirrigationseepage,andaconsequentreductioninwetlandacressupportedbythissource.Althoughclimatechangeisexpectedtohaveasignificanteffectonwetlandsthroughchangesintheseasonalityandvariabilityofprecipitationandextremeevents Gitayetal.2005 ,changingwaterusepatternsinresponsetoclimatechangearealsolikelytoplayamajorroleinthefutureofwetlands Tayloretal.2012 .


ThesehabitatshaveawidedistributioninColorado,andasawholearegenerallylessexposedthanareindividualwetlandoccurrences.InwesternColorado,projectedsummerandfallprecipitationaredrierthanconditionsforthecurrentdistributioninsomeareas,andthenumberofveryhotdaysislikelytoincreaseforaboutathirdofthedistributionthere.Wetlandsinthemountainareasofthestatearemostlikelytoseedrierthancurrentconditionsinthewinterandspring.Wetlandhabitatsoftheeasternplainsaremostlikelytoseesummertemperatureswarmerthanthecurrentrange,drierspringandsummer,andincreaseddroughtdaysincomparisontothecurrentrange.

Wetland West Mountain East


range shift

Winter precipitation 19%

Spring precipitation 4% 6%

Summer precipitation 14% 12%

Fall precipitation 6%

Days with heavy precipitation 0%

Drought days 29%

Mean winter temperature 0%

Mean spring temperature 0% 0% 0%


Very hot days 32%

Average range shift 10% 5% 23%

Rank L L M

Exposure‐Sensitivity level Low Low Moderate


119


WetlandshaveawideecologicalamplitudeinColorado,andarenotrestrictedbyelevationoredge‐of‐rangefactors.Thepotentialaggregationofbasinwideeffectsintowetlandareasincreasesthechanceforchangestohaveanimpactoverconsiderabledistances.Changingclimatescouldhavedramaticeffectsonthecomponentspeciesandhydrologiccyclesofwetlands;theconsequencesofthesechangesforhabitatfunctionandpersistencearelikelytobesignificant.Becausemanywetlandsaresmallandrelativelyisolatedwithinthelandscape,habitatconnectivityandspeciesdispersalareapointofvulnerability.

Wetlandhabitatshavebeenheavilyimpactedbyanthropogenicactivities,especiallywatermanagement GageandCooper2007 .Alteredhydrologyduetodams,diversions,andgroundwaterpumpingmayinteractwithwarmingtemperaturesandchangesinprecipitationpatterntoaltergroundwaterrechargerates,andleadtodryingorcontractionofwetlands.Impactedwetlandsmaybemorevulnerabletoinvasionbyexoticspecies.Increasedfrequencyandmagnitudeofdroughtislikelytohavesignificantimpactonthesehabitats.Climatechangeinwatersourceareasaswellasinadjacenthabitatscouldhavesignificantimpactonwetlands.


Wetlands Range and biophysical envelope



Extreme events

Landscape condition


Resilience Level

West 0.69 0.50 0.33 0.67 0.41 0.52 M Moderate

Mountain 0.90 0.50 0.33 0.67 0.67 0.61 M Moderate

East 0.66 0.50 0.33 0.67 0.43 0.52 M Moderate


Wetlands Exposure ‐ Sensitivity

Resilience – Adaptive Capacity Combined rank


West Low Moderate L/M Low

Mountain Low Moderate L/M Low

East Moderate Moderate M/M Moderate


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Wetlandhabitatsofthewesternvalleysandmountainareasarerankedashavinglowvulnerabilitytotheeffectsofclimatechangebymid‐centuryunderamoderateemissionsscenario,whilethoseoftheeasternplainsareconsideredmoderatelyvulnerable.PrimaryfactorscontributingtotheserankingsarethewideecologicalamplitudeanddistributionofwetlandhabitatsthroughoutColorado,althoughthevulnerabilityofsomespeciesassemblagesmaybehigherthanisreflectedbythecollectiveassessment.Themoderateresilienceranksreflectthehighlyalteredconditionofmostofthesehabitats,andingeneral,wetlandsthroughoutthestateshouldprobablyberegardedashavingsomedegreeofvulnerabilitytoclimatechangethatisnotcapturedbyourbroad‐scaleassessmentmethods.

NOTE:duetothegenerallysmallsizeofwetlandoccurrences,exposuremapswerenotproducedforthishabitat.

References:

Bailey,R.1998.EcoregionsmapofNorthAmerica:Explanatorynote.USDAForestService,Misc.Publicationno.1548.10pp. mapscale1:15,000,000

Fischlin,A.,G.F.Midgley,J.T.Price,R.Leemans,B.Gopal,C.Turley,M.D.A.Rounsevell,O.P.Dube,J.Tarazona,A.A.Velichko.2007.Ecosystems,theirproperties,goods,andservices.ClimateChange2007:Impacts,AdaptationandVulnerability.ContributionofWorkingGroupIItotheFourthAssessmentReportoftheIntergovernmentalPanelonClimateChange,M.L.Parry,O.F.Canziani,J.P.Palutikof,P.J.vanderLindenandC.E.Hanson,Eds.,CambridgeUniversityPress,Cambridge,211‐272.

Gage,E.,andD.J.Cooper.2007.Historicrangeofvariationassessmentforwetlandandriparianecosystems,U.S.ForestServiceRegion2.PreparedforUSDAForestService,RockyMountainRegion.DepartmentofForest,RangelandandWatershedStewardship,ColoradoStateUniversity,FortCollins,Colorado.

Gitay,H.,A.SuarezandR.T.Watson.2002.ClimateChangeandBiodiversity.IPCCTechnicalPaper,IntergovernmentalPanelonClimateChange,Geneva,77pp.

Gitay,H.,S.Brown,W.EasterlingandB.Jallow.2001.Ecosystemsandtheirgoodsandservices.ClimateChange2001:Impacts,Adaptation,andVulnerability.ContributionofWorkingGroupIItotheThirdAssessmentReportoftheIntergovernmentalPanelonClimateChange,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:potentialimpactsoninlandfreshwaterandcoastalwetlandecosystemsintheUnited


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States.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.Thecreationandmaintenanceofwetlandecosystemsfromirrigationcanalandreservoirseepageinasemi‐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.JournaloftheAmericanWaterResourcesAssociation.36:305‐311.


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ALPINE

Climate Influences

Snowpackisacrucialcomponentofalpineecosystems,anddependsonbothprecipitationamountsandwinter‐springtemperature Williamsetal.2002 .Vegetationinalpineareasiscontrolledbypatternsofsnowretention,winddesiccation,permafrost,andashortgrowingseason GreenlandandLosleben2001 .Dryerareasareoftencharacterizedbyadensecoveroflow‐growing,perennialgraminoidsandforbs.Rhizomatous,sod‐formingsedgesarethedominantgraminoids,andprostrateandmat‐formingplantswiththickrootstocksortaprootscharacterizetheforbs.Low‐growingshrublandscharacterizedbyanintermittentlayerofsnowwillowordwarf‐shrubslessthan0.5minheight,withamixtureofforbsandgraminoids especiallysedges aretypicallyisfoundinareasoflevelorconcaveglacialtopography,withlate‐lyingsnowandsubirrigationfromsurroundingslopes.

Thelengthofthegrowingseasonisparticularlyimportantforthealpinezone,andforthetransitionzonebetweenalpineandforest treeline .AlpineareashavethefewestgrowingdegreedaysandlowestpotentialevapotranspirationofanyhabitatinColorado.Treeline‐controllingfactorsoperateatdifferentscales,rangingfromthemicrositetothecontinentalHoltmeierandBroll2005 .Onaglobalorcontinentalscale,thereisgeneralagreementthattemperatureisaprimarydeterminantoftreeline.Atthisscale,thedistributionofalpineecosystemsisdeterminedbythenumberofdaysthatarewarmenoughforalpineplantgrowth,butnotsufficientfortreegrowth.Otheralpineconditionsthatmaintaintreelessvegetationathighelevationsincludelackofsoildevelopment,persistentsnowpack,steepslopes,wind,anddenseturfthatrestrictstreeseedlingestablishmentandsurvivalwithinthetreelineecotone Moiretal.2003,Smithetal.2003,HoltmeierandBroll2005 .

Onthebasisofhistoricevidence,treelineisgenerallyexpectedtomigratetohigherelevationsastemperatureswarm,aspermittedbylocalmicrositeconditions Smithetal.2003,RichardsonandFriedland2009,Grafiusetal.2012 .Itisunlikelythatalpinespecieswouldbeabletomovetootheralpineareas.Intheshort‐termwithwarmertemperatures,alpineareasmaybeabletopersist,especiallyinareaswhereitisdifficultfortreestoadvanceupslope.Theslowgrowthofwoodyspeciesandrarityofrecruitmenteventsmaydelaytheconversionofalpineareastoforestfor50‐100 afterclimaticconditionshavebecomesuitablefortreegrowth Körner2012 .Thus,alpineecosystemsmaypersistforawhilebeyondmid‐century,butarelikelytoeventuallylargelydisappearfromColoradointhelongrun.


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Alpinehabitatsareprojectedtoexperiencetemperatureswarmerthanthecurrentrangeinmorethanhalfoftheircurrentdistribution.Projectedwinterandspringprecipitationlevelsaregenerallywithintherangeofthecurrentdistribution.

Alpine

Climate variable


% projected

range shift

Winter precipitation (M, L) 0%

Spring precipitation (M) 4%

Days with heavy precipitation (M, L) 0%

Mean summer temperature (M, L) 56%



Rank M



ElevationsofalpinehabitatsinColoradorangefromabout11,000toover14,000ft.,withameanofabout12,000ft.Alpinehabitatsarerestrictedtohighelevations,andarealsonearthesouthernextentoftheircontinentalrangeinColorado.Statewide,theannualaverageprecipitationrangeisabout20‐60in 50‐150cm withameanof36in 92.5cm .AlpinegrowingseasonsaretheshortestofanyhabitatinColorado.

Alpineenvironmentsaregenerallynotsusceptibletooutbreaksofpestspeciesordisease,butmayhavesomeslightvulnerabilitytoinvasiveplantspeciessuchasyellowtoadflax.Thesetreelessenvironmentsarenotvulnerabletofire,butcouldbecomesoiftreesareabletoestablish.Xericalpineenvironmentsarealreadysubjecttoextremeconditions,butthemoremesicareasarevulnerabletodroughtandchangesinsnowmelttiming.Evenunderincreasedsnowpack,warmertemperaturesarelikelytoalterpatternsofsnowmelt,andmayreduceavailablemoisture.Thesechangesarelikelytoresultinshiftsinspeciescomposition,perhapswithanincreaseinshrubsonxerictundra.Withwarmingtemperaturesandearliersnowmelt,however,elkmaybeabletomoveintoalpineareas


124

earlierandstaylonger,therebyincreasingstressonalpinewillowcommunitiesZeigenfussetal.2011 .

Alpinehabitatsarealsoindirectlyaffectedbybothdroughtandland‐usepracticesinupwindareasthatleadtodustemissions.Whenwind‐blowndustisdepositedonmountainsnowpack,theresultingdarkeningofthesnowallowsincreasedabsorptionofsolarradiantenergy,andearliermeltingthanunderdustfreeconditions.Unlikewarmingtemperatures,whichadvancebothsnowmelttimingandgrowingseasononsetforalpinevegetation,theeffectofdustdepositiononmountainsnowpackisalsoasourceofearliersnowmelt,andisnotdirectlylinkedtoseasonalwarming Steltzeretal.2009 .Althoughdustdepositionmaybeasignificantcontributortosoildevelopmentinsomeareas Lawrenceetal.2011 ,itcanincreaseevapotranspirationanddecreaseannualrunoffflows Deemsetal.2013 .Changesinsoilmoisturelevelsduetoearliersnowmeltmayinteractwithotherclimatechangeeffectstoproducechangesinspeciescompositionandstructureofalpinehabitats.





Extreme events

Landscape condition


Resilience Level

Alpine 0.32 0.5 0.67 0.67 0.98 0.61 M Moderate




Combined rank


Alpine Moderate Moderate M/M Moderate

Alpinehabitatsarerankedmoderatelyvulnerabletotheeffectsofclimatechangebymid‐centuryunderamoderateemissionsscenario.PrimaryfactorscontributingtothisrankingarethefactthatthesehabitatsarerestrictedtothehighestelevationsofColorado,andconsequentlyhaveanarrowbiophysicalenvelope.ManyoftheconstituentspeciesareatthesouthernedgeoftheirdistributioninColorado.Underalonger‐termevaluationframe,vulnerabilityofthishabitatisexpectedtobegreater.

Mapsbelowillustratethespatialpatternofexposureundertheworstcasescenarioforthefiveclimatevariablesassessedforalpinehabitats.Legendpointersindicatetherangeof


125

changeforthishabitatwithinthestatewideextentofchange.AlpineareasintheSanJuanMountainsaregenerallymostexposedtodrierconditions.Underawetterscenario,however,somepartsthesouthernmountainsmayexperienceanincreaseinlargeprecipitationevents.Temperaturepatternsarelessclear;allareasareprojectedtoundergowarmingtosomedegree,althoughtoalesserextentthanisprojectedforlowerelevationhabitats.


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References:

Deems,J.S.,T.H.Painter,J.J.Barsugli,J.Belnap,andB.Udall.2013.CombinedimpactsofcurrentandfuturedustdepositionandregionalwarmingonColoradoRiverBasinsnowdynamicsandhydrology.Hydrol.EarthSyst.Sci.17:4401‐4413.

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.StructureandFunctionofanAlpineEcosystem:NiwotRidge,Colorado.NewYork:OxfordUniversityPress.

Holtmeier,F‐K.andG.Broll.2005.Sensitivityandresponseofnorthernhemispherealtitudinalandpolartreelinestoenvironmentalchangeatlandscapeandlocallevels.GlobalEcologyandBiogeography14:395‐410.

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,SnowyRange,Wyoming.Arctic,Antarctic,andAlpineResearch31:379‐388.

Richardson,A.D.andA.J.Friedland.2009.Areviewofthetheoriestoexplainarcticandalpinetreelinesaroundtheworld.JournalofSustainableForestry28:218‐242.

Smith,W.K.,M.J.Germino,T.E.Hancock,andD.M.Johnson.2003.Anotherperspectiveonaltitudinallimitsofalpinetimberlines.TreePhysiology23:1101‐1112.

Steltzer,H.,C.Landry,T.H.Painter,J.Anderson,andE.Ayres.2009.Biologicalconsequencesofearliersnowmeltfromdesertdustdepositioninalpinelandscapes.PNAS106:11629‐11634.

Williams,M.E.,M.V.Losleben,andH.B.Hamann.2002.AlpineareasintheColoradoFrontRangeasmonitorsofclimatechangeandecosystemresponse.GeographicalReview92:180‐191.


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Zeigenfuss,L.C.,K.A.Schonecker,andL.K.VanAmburg.2011.UngulateherbivoryonalpinewillowintheSangredeCristoMountainsofColorado.WesternNorthAmericanNaturalist71:86‐96.

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Colorado Wildlife Action Plan Enhancement: Climate Change ... · Colorado Wildlife Action Plan Enhancement:Climate Change Vulnerability Assessment 2014 9 Acknowledgements The authors