TheRelationshipbetweenland-coverandaquaticmacroinvertebratecommunities

offourwaterbodiesinWesternMontana,USA

AnastassiaRyanUNDERCWest2016

Abstract

Thehealthandbiodiversityofstreamsisinvaluablefrombothlandmanagement

andwildlifepreservationperspectives.Wesampled5river,creek,andmanmade

ditchsitesinwesternMontanatoassesswaterqualityandrelatemacroinvertebrate

communitydiversitytoadjacentlandcover.Inthisstudywequantitativelyand

qualitativelydescribedthebenthicmacroinvertebratecommunitiesoffourdifferent

loticsystems.DiversityindexeswerecalculatedincludingSimpsons(asthebaseline

responsevariable),richness,andPercentModelAffinity(PMA)alongwithseveral

othersandusedinastepwiseregressiontodeterminethebestmodeltopredict

Simpson’sDiversity.AquaticmacroinvertebraterichnessandPMAwerethebest

predictorsofSimpson’sDiversitybasedonp-ValuesandtheAIC.Futurestudies

shouldinvestigatebothlandcoverandthephysicalandchemicalcharacteristicsin

thewaterbodiesstudied.

Introduction

Streams are the blood vessels of the terrestrial ecosystem. Streams play a role in

nutrient cycling and decomposition of plant material, and provide habitat to a variety of

species of fish and macroinvertebrates. Streams are an important source of biodiversity

within different landscapes, and benthic macroinvertebrates contribute to this biodiversity

(Tonkin 2014). Biodiversity of streams provides an important food source for terrestrial

animals, such as mink, which feed on freshwater mussels and crayfish, and bears, which

prey on salmonid fish. A large portion of fish diet consists of macroinvertebrates, as

different kinds of fish feed on various kinds of aquatic invertebrates. There is an evident

biological cascade that depends on the large diversity provided a healthy stream

ecosystem and good water quality. From headwaters to lower reaches, different

communities of benthic macroinvertebrates exist (e.g., shredders such as stoneflies in

headwaters, or caddisfly collector-gatherers in mid- and lower reaches). These

communities contribute to the processing and downstream transport of dissolved organic

matter (DOM) and fine particulate organic matter (FPOM) (Vannote et al. 1980)

contributing to the cleanliness and health of the stream environment.

TheMoieseValleyisalargeagriculturalcommunityinWesternMontanaon

theFlatheadReservationwherelikeeverywhereinthewesternUnitedStatesis

concernedaboutwaterqualityinthecurrentenvironmentalclimate.The

agricultureintheareaislargelyindustrialcattle,wheat,andhayallofwhichrequire

largesumsofwatertoproduce(Vorosmartyetal.2000).Theseindustriesalsohave

astresseffectonthelocalwaterqualityduetothenutrientloadingproducedfrom

runoffoffertilizersormanureintostreamsorbodiesofwater.Today’sindustrial

agricultureusesavarietyofharmfulmethodsintryingtomaximizetheiryieldsand

profits.Pesticidesareintendedtokillinsectsindiscriminately,herbicidesintended

tokillweedsmayalsodamagethediversityofthenativeflora,andfungicidesare

useddirectlyinwaterways.Alloftheseindustrialagriculturemeasuresareharmful

totheadjoinedaquaticsystems.

Agoodindicatorofecologicalhealthisthediversityofspeciesthatthe

ecosystemhouses.Whentoomanystressorsenteraripariansystemthewater

qualitygoesdownandthesensitivemacroinvertebratescannotsurviveinthe

systemanylonger(Palmeretal.2010).AccordingtotheHilsenhoffBioticIndex

(Barbouretal.)caddisfy’sandstonefly’saresensitivetopollution,right-handed

snailsandcrawlingwaterbeetlesarefacultative,andleft-handedsnailsandworms

arepollutiontolerant.Thereareseveralbiodiversityindexesorequationsmeantto

calculatewaterqualitywitharatingsystemsuchasHilsenhoff’s(HIB),thereisalso

percentEphemeroptera,Plecoptera,Trichoptera(EPT)(DeWaltetal.1999)percent

modelaffinity(PMA)(Novak&Bode1992),percentChironomidae,abundance,and

richness.

Anotherpossibleindicatorofstreamhealthistheadjacentlandcover.Along

thesamelinesasthediversityoftaxawithinthestreamindicatinggoodquality

water,thediversityoffloraabuttingastreamwouldbeasignalofahealthyriparian

ecosystem.Wesampledfiveriver,creek,andmanmadeditchsitesinwestern

Montanatoassesswaterqualityandrelatemacroinvertebratecommunitydiversity

toadjacentland-cover(Weigeletal.1999).Theassessmentconsistedofa

quantitativeandqualitativestudydescribingthebenthicmacroinvertebrate

communitiesinfourdifferentloticsystems.Usingthequantitativedatadifferent

metricswerecalculated(suchastheHBI,EPT,richness,etc.).Alongwithourdataa

land-coverdatabaseprovidedbytheMontanaStateGovernmentwebsitewasused

toassesstherelationshipbetweenwaterqualitywithinthesystemandthe

borderingenvironment.

Methods

SamplingSites:

Fivelocationswithina15-kilometerradiusofTheNationalBisonRange

weresampledwiththekicknetmethod.Thelocationswerechosentorepresent

variouslevelsofwaterqualitywithdistinctadjacentlandcover.Threeofthesites

arelocatedintwoofthetributariestotheFlatheadRiver,theMissionRiverandthe

JockoRiver.Theothertwositesaremanmadeeitheracanaloraditchusedfor

agriculturalirrigation.

TheNinepipelocationisthenorthernmostlocationitisawetland

conservationsiteusedasfloodcontrol.ThereisacanaloriginatingfromThe

NinepipeWildlifeNationalRefugeusedforirrigationintheMoieseagricultural

valley.Thisisamanmadecanalwherethesubstrateissiltandvegetation,andthe

adjacentland-coveriscompletelygrassland.

TheMissionRiversiteselectedisrightunderwheretheMoieseWetland

Restorationsiteemptiesintotheriver.Therestorationconsistsofseveralwetlands

meanttotakewastewaterfromtheMoieseValleyindustrialagriculturalditchesand

filteroutthepollution.Thisparticularlocationisofinterestforthepeopleofthe

FlatheadReservationbecauseoftheinvestmentmadetobuildthewetland

restorationsiteandthequalityoftheirwater.TheMissionsiteislargestriver

sampledwithvarioussizedcoblesubstrateandtheadjacentland-coverishalf

grasslandandhalfriparianwoodlandandshurbland.

TheJockoRiverwassampledattwospots,theUpperJockositeisan

upstream-isolated-bradedlocationandtheLowerJockositeisdownstreaminmore

developedarea.TheregioninWesternMontanawheretheJockorunsismostly

agriculturalandthereareirrigationditchesthatenterandexitbetweenthetwo

selectedsamplingsites.Theadjacentland-covertotheUpperJockoisgrassland,

openeddeveloped,andriparianwoodlandandshrublandwhiletheland-coveron

theLowerJockoisclassifiedasmajorroads,andriparianwoodlandandshrubland.

Jerry’sDitchisasitethatrunsthougharanchingpropertyinDixion,

Montana.Theassumptionforthissiteisthatthewaterqualityisimpaireddueto

thenutrientloadingproducedbythecattleontheproperty.ThesubstrateinJerry’s

DitchissimilartoNinepipe,entirelycomposedofsiltandvegetation.Theland-cover

adjacenttotheditchisclassifiedaslowintensityresidentialandcultivatedcrops.

Alltheland-covertypeclassificationscanbeseenonthemapintheappendix(figure

1).

SamplingMethods:

Eachofthefivesitesweresampledthreetimesondifferentdates:27June

2016,5July2016,and20July2016.Everysamplingeventconsistedofthreekick

netsweepswitha150meshkicknet.TheJockolocationswheretherewasdiverse

substrateadditionalsamplesweretaken.Threekicknetsweepsweretakenina

riffle,run,andpoolontheJockoRiverateithertheupperorlowerlocationtoget

comprehensivesamplesoftheentireriversystem.Eachsamplewasstrainedand

preservedin%95ReagentAlcohol.Eachsamplewasprocessedunder

magnification;everymacroinvertebratewithinthesedimentandvegetative

materialwascollected,identifiedtoorderaccordingtoDr.J.ReeseVoshell,Jr.’s‘A

GuideToCommonFreshwaterInvertebratesofNorthAmerica’andcountedas

presentwiththestreamthesamplewastakenfrom(Table2,Figures2-6).

StatisticalAnalysis:

GPScoordinatestakenateachsamplinglocationwereusedinArcMap(Esri

2013)alongwithland-coverclassificationdataobtainedfromtheMontana

Governmentwebsite.Thebuffertoolwasusedtocreatea15-meterradiusbuffer

aroundthesamplingsites.Thentheland-coverclassificationlayerwasclippedto

justthe15-meterradiustoobtainthepercentageofland-covertypedirectly

adjacenttoeachsamplingsite.Thereweresevenland-covertypesforallfiveofthe

samplinglocations:Type1isNorthernRockyMountainlowermontaneriparian

woolandandshrubland,Type2isRockyMountainlowermontanefoothillandvalley

grassland,Type3iscultivatedcrops,Type4isopenwater,Type5ismajorroads,

Type6lowintensityresidential,andType7isopendeveloped.

Severalmetricswerecalculatedpriortostatisticalanalysisfromtheraw

macroinvertebratecountdata.Allthemetricsarediversityindexesintendedto

relatethequalityofthewaterorthestreamhealthtothediversityandabundance

ofpresentmacroinvertebrates.ThebaselinemetricusedwasSimpsonsindexbut

alsocalculatedforcomparison:HBI,EPT,PMA,percentChironomidae,abundance,

andrichness.

Thetypeland-coverpercentagesandeachofthemetricsareusedtopreform

aforwardstepwiseregressionanalysisinSystatVersion13toobtaintheAkaike

InformationCriterion(AIC)valuesgiveninTable1.UsingSimpsonsdiversityindex

asourstandardforgoodqualitywaterandahealthystreamhabitat,wecompared

boththeland-covertypesandthecalculatedmetricsagainstitasourinitialanalysis.

Asfollowupanalysiswetookland-covertypeandcalculatedmetricsasindividual

categoriesandpreformedtheforwardstepwiseregressiononthemindividually.A

principlecomponentsanalysiswasalsopreformedinSystatVersion13tovisualize

therelationshipsamongallofthevariables(figure8).InRpackage“mvabund”

(Wangetal.2016)wepreformedanordinationandageneralizedlinearmodelon

therawmacroinvertebratecountdatatovisualizethesimilaritiesbygroupings

(figure9).Becausethisisabundancedata,whichistypicallynon-normal“mvabund”

takesthatintoaccountandisabletosortthroughthenon-normalcyaccordingly.

Results

TheordinationraninRshowscleargroupingsbasedonsimilaritiesinthe

rawcountdata.Eachsitehaddistincttaxanomicgroupsandvaryingabundance.The

dominantfamilyintheorderDipteraintheLowerJocko,UpperJocko,andinJerry’s

DitchwastheChironomidae.Jerry’sDitchhadtheleasttotalabundancewithonly

70specimenscollected,theUpperJockohadthemostabundancewith1067

specimenscollected.TheMissionsitewasthesecondmostabundantwith735

collectedspecimenswiththedominantorderbeingTrichoptera.

Thestepwiseregressionusingallofthefactors(land-covertypeandthe

calculatedmetrics)gavePMAandrichnessastheleadingpredictorvariablesin

determiningwaterquality(Simpsonsdiversity)(Table1).

Thenwewantedtoseewhattheleadingpredictorvariablewouldbeifwe

lookedateachcategoryindividually,land-covertypeandcalculatedmetrics.When

takingonlythecalculatedmetricsforstepwiseregressionagainsttheSimpsons

responsevariablebothrichnesswithap-Valueof0.00andaPMAp-Valueof0.048

gaveusthelowestAICvalueof-71.177.Whentakingland-covertypeastheonly

predictorvariables,Type1isthestrongestpredictorvariablewithap-Valueof

0.004andanAICvalueof-49.771.ThePCAshowsaclearrelationshipbetween

Simpsons,richness,abundance,Type1,andType7.

Discussion

ThereisaclearpositiverelationshipbetweenSimpsons,richness,andType1

land-cover.ThismeansthattheNorthernRockyMountainlowermontaneriparian

woodlandandshrublandland-covertypeispositivelycorrelatedwithhigher

diversityofmacroinvertebratepopulation.ThehighertheSimpsonsdiversityvalue

orrichnessofspeciesinastreamsystemwouldindicategoodwaterqualityanda

healthyaquaticecology.

ItisnaturalthatwhenanalyzingallofthefactorsagainsttheSimpsons

responsevariabletherichnessandPMAaretheleadingpredictorvariables.When

analyzingonlythecalculatedmetricsagainstSimpsonsitmakessensethatrichness

andPMAwouldalsobethestrongestpredictorvariables.Thefactthatrichnessgot

ap-Valueof0.00whencomparedwithSimpsonsdiversityindexmeansthatbecause

richnessisafactorincalculatingSimpsonsindexyouwouldexpecttheretobea

directrelationshipbetweenthetwometrics.Sincethetwo,Simpsonsandrichness

aresosimilaronecoulduserichnessinplaceofSimpsonsasaquickestimateofthe

healthofastreamandinturnwaterqualityinthestreamsystem(McGuire2006).

ThePrincipalComponentsAnalysisalsoshowsthattherearesimilaritiesin

Simpsons,richness,PMA,andType1butsuggeststhatType7,abundance,EPT,and

Chiromayalsobegoodindicatorsofdiversityandwaterquality(figure8).While

theordinationconfirmsthatthemacroinvertebratepopulationsareconsistent

withineachsamplinglocationduringthethreeseparatesamplingevents.

UpperJockoprovedtobethemostabundantsiteandthisislikelybecause

thereweredistinctsubstrateareassampledseparatelybutwechosetoincludethe

samplesinourstatisticalmodelstoenhancethestrengthoftheanalysisbyutilizing

allofthedatawecollected.Thustherewasavarietyofmicrohabitatsthatcouldbe

utilizedbyadiverseassemblageofbenthicinvertebrates.TheMissionhadalarge

numberofTrichoptera,whichareasensitivetaxa.TheUpperJockoandMissionhad

thehighestSimpsonsscoresrespectively(Table2).TheUpperJockohadtheleast

alteredland-coverandwasinanareaclassifiedasNorthernRockyMountainlower

montaneriparianwoodlandandshurblandwhichwastheland-covertypefoundto

havethemostinfluenceonthemacroinvertebratediversity.TheMissionsitewasin

anareathathadbeendevelopedasawetlandrestorationsitesothefactthatithas

thesecondbestSimpsonsscoresandahighnumberofthesensitivetaxa

Trichopterasuggeststhatthewaterqualitythereisbetterthanateitheragricultural

site(Jerry’sDitchandNinepipe).

Clearlythereisarelationshipbetweenland-covertypeandthehealthofa

loticsystem(Wangetal.2011).Whenchoosingoursiteswewentoutphysicallyand

lookedfordifferenttypesofloticsystemstocompare.Infuturestudiesitwouldbe

interestingtofindmultiplelocationswithacertainland-coverclassificationanddo

replicatesandthencomparewithotherland-covertypereplicates.Alsowewerenot

ablecollectothermetricssuchasvelocity,temperature,dissolvedoxygen,etc.that

wouldbeimportantintellingthewholestoryofwhatisgoingoninariversystem.

Acknowledgements

IwouldliketothankmyMentorKathrineBarrettforteachingmeeverything

Iknowaboutmacroinvertebratesandforherinfectiousenthusiasm.Iwouldliketo

thankDr.GaryBelovskyandJenifferBelovskyforgivingmethiswonderful

opportunityandexperience.DavidFlagelformakingallthearrangementstogetthis

projectdone.TotheUniversityofNotreDameforhavingsuchagreatprogramfor

studentstoliveandlearninthefield.

References

Barbour,M.T.,Graves,C.G.,Plafkin,J.L.,Wisseman,R.W.andBradley,B.P.1992.EvaluationofEPA'srapidbioassessmentbenthicmetrics:Metricredundancyandvariabilityamongreferencestreamsites.EnvironmentalToxicologyandChemistry11:437–449.DeWalt,R.E.,Webb,D.W.Webb,Harris,M.A.1999.SummerEphemeroptera,Plecoptera,andTrichoptera(EPT)speciesrichnessandcommunitystructureinthelowerIllinoisRiverbasinofIllinois.GreatLakesEntomologist3:115-132.McGuireD.L.2007.ClarkForkRiverBiomonitoringMacroinvertebrateCommunityAssessments.UnitedStatesEnvironmentalProtectionAgencyRegion8.Novak,M.A.,Bode,R.W.1992.Percentmodelaffinity:anewmeasureofmacroinvertebratecommunitycomposition.JournaloftheNorthAmericanBenthologicalSociety11:80-85.Palmer,M.A.,Menninger,H.L.,Bernhardt,E.2010.RiverRestoration,habitatheterogeneityandbiodiversity:afailureoftheoryorpractice.FreshwaterBiology55:205-222.Tonkin,J.D.2014.Driversofmacroinvertebratecommunitystructureinunmodifiedstreams.PeerJ2:e465;DOI10.7717/peerj.465.Vannote,R.L.,G.W.Minshall,K.W.Cummins,J.R.Sedell,ANDC.E.Gushing.1980.TheRiverContinuumConcept.Can.J.Fish.Aquat.Sci.37:130-137.Vorosmarty,C.J.,Green,P.,Salisbury,S.,Lammers,R.B.2000.GlobalWaterResouces:VulnerabilityfromClimateChangeandPopulationGrowth.Science5477:284-288.Voshell,J.R.2002.AGuideToCommonFreshwaterInvertebratesofNorthAmerica.DepartmentofEntomologyCollegeofAgricultureandLiveSciencesVirginiaTech.Wang,L.,Lyons,J.,Kanehl,P.,Gatti,R.2011.InfluencesofWatershedLandUseonHabitatQualityandBioticIntegrityinWisconsinStreams.Fisheries22:2-12.Wang,Y.,Naumann,U.,Wright,S.,Eddelbuettel,D.,Warton,D.2016.StatisticalMethodsforAnalysingMultivariateAbundanceData.3.11.9.Weigel,B.M.,Lyons,J.,Palne,L.K.,Dodson,S.I.,Undersander,D.J.1999.UsingStreamMacroinvertebratestoCompareRiparianLandUsePracticesonCattleFarmsinSouthwesternWisconsin.JournalofFreshwaterEcology15:93-106.

TablesTable1:ThistablegivestheresultsofeachforwardstepwiseregressiondonewiththeSimpson’sDiversityIndexastheresponsevariableandLand-coverTypes[Type1-NorthernRockyMountainlowermontaneriparianwoolandandshrubland,Type2-RockyMountainlowermontanefoothillandvalleygrassland,Type3-cultivatedcrops,Type4-openwater,Type5-majorroads,Type6-lowintensityresidential,Type7-opendeveloped]andCalculatedMetrics[EPT,PMA,HBI,percentChironomidae,abundance,andrichness]asthepredictorvariables.

Table2:Showsthenumberofeachmajorfamilyofmacroinvertebratecountedateachlocation.Thesenumberswereusedtomakethepiecharts(figures1-5).TherangeofSimpsonsvaluesaregiven,theSimpsonsDiversityIndexwascalculatedindividuallyforeachofthethreesamplingeventsateachlocation.

Figures

Figure1:Mapofsamplingsiteswithland-covertypesateachsite.

LowerJocko

Chironomidae

Coleoptera

Diptera

Ephemeroptera

Plecoptera

Trichoptera

Worm

UpperJocko

Chironomidae

Coleoptera

Diptera

Ephemeroptera

Plecoptera

Trichoptera

Worm

Jerry'sDitch

Chironomidae

Coleoptera

Diptera

Ephemeroptera

Plecoptera

Trichoptera

Figures2-6:Anindividualpiechartforthemostabundantfamiliesfoundateachsite.TheJockoRiverandJerry’sditcharesimilarinthatthemostabundantmacroinvertebratefoundatthosesitesaretheChironomidaewhicharemostlyfacultative.AtNinepipethedominatingmacroinvertebrateareScudswhicharealsomostlyfacultative.InMissionTrichopteraarethedominanttaxawhicharesensitivetopollution.

Ninepipe

Chironomidae

Coleoptera

Diptera

Ephemeroptera

Plecoptera

Trichoptera

Worm

Scud

Mission

Chironomidae

Coleoptera

Diptera

Ephemeroptera

Plecoptera

Trichoptera

Worm

Scud

Figure7:Theresultoftheforwardstepwiseregressionwithinputsofallthefactorsi.e.land-covertypeandcalculatedmetrics,showingthatrichnessandPMAarethestrongestpredictorvariablesindeterminingSimpsonsdiversity.

Figure8:PrincipleComponentsAnalysispreformedinSystat.ThisgraphshowsthattherearestrongsimilartiesbetweenSimpsons,Type1land-cover,andrichnessatoursitesbutthereseemstobeaweakeryetstillpresentrelationshipbetweenthepreviousmentionedmetricsandEPTandPMA.

Figure9:InRpackage“mvabund”wepreformedanordinationandageneralizedlinearmodelontherawmacroinvertebratecountdatatovisualizethesimilaritiesbygrouping.Thesitesarecolorcoded:Mission-grey,Ninepipe-red,JockoUpper-green,Jerry’sDitch-purple,JockoLower-blue.Therearespatialdistinctionsfromeachsamplecollectedateachsite.Themacroinvertebratecommunitiesremainedconstantthroughoutthesamplingperiod(lateJunetolateJuly2016).