LessonPlanforSantaRitaExperimentalRangeVegetationMonitoring
MarthaGebhardt,OutreachCoordinator
Objectives:
Part1:
StudentswilllearnaboutcommonplantspeciesonSRERthroughvegetationmonitoringtechniques
usingthebelttransectmethod.
StudentswillanalyzeandpresentdatacollectedinPart1byclassifyingplantspeciesbasedongrowth
habits(grasses,forbs,shrubs)
Part2:
UsetheScientificMethodto:
Makepredictionsaboutplantspeciesatdifferentlocationsontherange
Analyzeplantspeciesovertimeusingpastdatarecordsandphotographsofthetransects
Comparevegetationtrendstoprecipitationandgrazinghistory
Compare/Contrastresultstootherlocationsontherange
Part1:
Materials
Clipboard,penorpencil,andpaperforrecordingdata
Measuringtapethatisatleast100ftlong
1ftruler
Surveyflags(apx.10)
SRERplantguide
Additionalplantguide(s)[optional]
Background
TherewillbealocationpredesignatedonSRERwherestudentscangotakevegetationmeasurements
withoutdisturbingotherscienceexperimentsthatareongoing.
Explainthatsince1972,everythreeyearsplantdensitymeasurementshavebeenrecordedonSRER.
Today,wewillrecordthisdatausingthesameproceduresscientistsuse.Wewillbeusingabelttransect
method.Wewillmeasureout100ft.withmeasuringtape.Plantdensitythatiswithin1ftofthe
measuringtapewillberecorded.Counteachplantspeciesonlyonce.
BeltTransectImage:
Procedure
1.Separateclassinto3-4groupsdependingonsizeofclass.Usuallyabout4-5students/groupensures
everyonewillhavetasksthroughoutthelesson.
2.Markastartinglocationforeachgroup.Makesuregroupsdon’tendupoverlappingeachotherwhen
theymeasureouttheirtransects.Trytouseavarietyoflocations---havegroupsgooffindifferent
directions,ifthere’sanelevationchangehavesomegroupssurveyalongitandothersnot,aimfora
varietyofvegetation,ifpossible.
3.Haveeachgroupmeasureout100ft.andmarktheendinglocationwithasurveyflag.
4.Havestudentsrecordimportantinformationabouttheirtransect.Someusefulinformationthatmight
affectvegetationincludes:pastweather(ifknown),locationoftransect,orevidenceofpredators(scat,
fur,etc.)
5.Countallplantspecieswithinthetransectusingtheplantspeciesguide.Don’tworrytoomuchabout
makingsureyouhavetherightspeciesifit’shardtotell.Differentgrassspeciescanbedifficultto
distinguish.Itismoreimportanttocounttheindividualthanitistoaccuratelyidentifyit.
ExampleDatasheet:
note—thisisahypotheticaldatasheetforpurposesofprovidinganexample
6.Sumandcategorizetheplantsineachtransectaseither:grasses,forbs,orshrubs
DefinitionsofGrasses,Forbs,andShrubs:
Grasses-vegetationconsistingoftypicallyshortplantswithlongnarrowleaves,growingwildor
cultivatedonlawnsandpasture
Forbs-vascular(havingtissuethatconductwater,sap,andnutrients)plantswithoutsignificantwoody
tissueabovetheground.
Shrubs-perennial(plantthatlivesmorethan2years),multi-stemmedwoodyplantthatisusuallyless
than4-5metersinheight.Shrubstypicallyhaveseveralstemsarisingfromorneartheground.(cactus
andchollaareshrubs)
ExampleDatasheet:
note—thisisahypotheticaldatasheetforpurposesofprovidinganexample
7.Presentandcomparegroupresults.Questionstoconsider:
-Whydoyouthinkyourgroupgothigh/lownumbersofgrasses,forbs,orshrubs?
-Whydidothergroupsgethigher/lowernumbersofgrasses,forbs,orshrubs?
-Whichgrouphadthegreatestoveralldiversityofplantspecies?
-Whichgrouphadtheleastoveralldiversityofplantspecies?
-Whichgrouphadthehighestdensityordiversityofgrass,forb,and/orshrubspecies?Why?
-Whichgrouphadthelowestdensityordiversityofgrass,forb,and/orshrubspecies?Why?
Part2:
Site
Location
Elevation(m) Materials
Penorpencil
paper
SRERplantguide
Additionalplantguide(s)[optional]
Datasets—4total
Graphingpaperorcomputerwithexcel
Calculator
Background
Vegetationtransectshavebeenongoingat132sitesonSRERsince1972(greenpointsonmap).Density
wasmeasuredevery3yearsbetween1972-1984and1991-2015.Today,wewillanalyzethedata
collectedat4ofthesesites(yellowstarsonmap).Oneofthesesiteshadafirein1994(siteontheeast).
Wewillanalyzethenumberofgrasses,forbs,andshrubsateachofthesites.Wewillanalyzetrendsin
vegetationandmakeinferencesaboutwhetherornotthesetrendscanbeexplainedbypast
precipitationorcattlegrazingrecords.Wewillcomparevegetationacrossthesitesandseetheeffects
firehadonvegetation.
MapofvegetationtransectsatSRER:
Site3
Site2
Site4
Site1
1
2
3
4
Pasture8Transect14
Pasture12BTransect7W
Pasture5NTransect11W
Pasture6ATransect1
1269
981
883
1284
Procedure
1.Separateclassinto4groupsandgiveeachgroupadataset.
Notesondatasets:
Eachdatasetcontains:plantdensitydata,planttransectphotos,precipitationdata,andcattlegrazing
data
PlantDensityData
-Thisisthetotalnumberofeachplantspeciesoccurringinthebelttransectperformedateachsite.
-“xxx”valuesmeannodataisavailablebecauseareadingwasnotmade.Assumeallofthesevalues
equal0whenanalyzingdata.
PlantTransectPhotos
-Theseareallavailablephotosoftheplanttransects.Someofthephotodatesmightnotalignwith
sampledates,butyoushouldstillbeabletovisualizedifferencesinvegetationovertime.
PrecipitationData
-Thesereadingaretakenfromtheraingaugelocatednearesttoyoursite(seeimagebelow)
CattleGrazingData
-Asweknow,manyresearchersatSRERarestudyingcattlegrazing.Thisdataisthetotalnumberof
cowspresentinthesiteforeachyear.
MapofraingaugesatSRER:
NWraingauge
SWraingauge
RUELAraingauge
FORESraingauge
2.Formahypothesesabouttheplantdensitydatausingif,then,becausestatements.Forexample,if
thereismorecowsinthesiteforacertainyear,thentherewillbelessgrassdensity,becausecowseat
grass.Asagroupdevelop2hypotheses:1foryoursiteand1acrosssites
Thingstoconsider:findingsfromPart1,elevationateachsite,Whateffectdoyouthinkcattlegrazingor
precipitationwillhaveonvegetation?WhatdoyouknowaboutthevegetationhistoryofSRER?How
willfireaffectvegetation?
3.Analyzethedataforyoursite
-Classifyeachplantspeciesasgrass,forb,orshrubusingthedefinitionsprovidedinPart1andtheSRER
plantspeciesguide.
-Sumthetotalnumberofgrasses,forbs,andshrubsforeachyear.
-Ifpossible,graphthesevaluesovertime
-Lookatdiversity:Bothwithineachoftheseclassificationsandtheoverallplantdiversityatthesite
-Arethereanysurprises?
-Howdidthevegetationchangeovertime?
-Compareresultstotheplanttransectphotos.Canyouseehowtheresultscomparetoactual
photographs?
-Compareresultstothecattlegrazingandprecipitationdata.Aretheresimilaritiesordifferences?For
example,dohigherlevelsofcowsaffectvegetation?Doesmoreorlessrainforaspecifictimehavean
effectonvegetationtrends?
4.Re-visitthehypothesisforyoursite
-Doyourresultssupportorrejectyourinitialhypothesis?
-Haveyoulearnedmoreinformationthatmighthelpexplainwhytheresultssupport(orreject)your
hypothesis.Forexample,didtheprecipitationandcattlegrazingdatahelpyouexplainthevegetation
densitydata?
-Areyouconvincedbytheresults?Doyouneedmoreinformationtosaywhetherornotyour
hypothesiswassupportedorrejected?(ThinkaboutPart1:Howsimilarordifferentwaseachgroup’s
results?)
-Whataresomeadditionalquestionsthathavearisenthroughthisanalysis?
-Doyouhaveideasforfuturequestionsorresearch?
4.Shareresults.Haveeachgrouppresenttheirinitialhypothesis,vegetationdensitydataovertime,and
theirconclusions(#4).Remindstudentstoconsidertheir“acrosssites”hypotheses.Aseachgroup
presents,encouragestudentstoaskquestionsthatwillhelpthemdecideiftheir“acrosssites”
hypothesisissupportedorrejected.Forexample,ifGroupAdevelopedan“acrosssites”hypothesisthat
involvedcattlegrazingandthegrouppresenting(GroupB)didnotincludethisdata,GroupAshouldask
GroupBwhattheircattlegrazingdatawasandhowitcomparedtotheirvegetationdensitydata.
5.Getbackintogroupsandgivestudents5minutestodecideiftheir“acrosssites”hypothesiswas
supportedorrejectsbytheinformationtheyheard.Re-visitthepointsin#4.
6.Haveeachgroupsharetheirfinalconclusions.Wastheir“acrosssites”hypothesissupportedornot
andwhy?