Evapotranspiration from cypress (Taxodium ascendens) wetlands and slash pine (Pinus elliottii) uplands in north-central Florida

276 Pages·1996·9.1 MB·English

by  Liu, Shuguang

EVAPOTRANSPIRATIONFROMCYPRESS(Taxodiumascendens)WETLANDS
ANDSLASHPINE{Pirnselliottii)UPLANDSINNORTH-CENTRALFLORIDA
By
SHUGUANGLIU
ADISSERTATIONPRESENTEDTOTHEGRADUATESCHOOLOF
THEUNIVERSITYOFFLORIDA
INPARTL\LFULFILLMENTOFTHEREQUIREMENTSFORTHE
DEGREEOFDOCTOROFPHILOSOPHY
UNIVERSITYOFFLORIDA
1996
ACKNOWLEDGEMENTS
I am especially grateful to my major advisor, Dr. Hans Riekerk, for his
encouragement,guidanceandpatience.Itishisvision,helpandconfidenceinmethat
makesmystudyanddissertationintheUnitedStatespossible.
Iamalsoverygratefultomysupervisorycommittee. Dr. HeiuyGholz, Dr.
Loukas Arvanitis, Dr. Ken Campbell, and Dr. Allen Smajstrla, for their many
suggestions.Dr.HenryGholzadvisedontheinitialtakingoffofthecampaignonstomatal
conductancemeasurements, andallowedmetousetheindependentlymeasurededdy
COvariancedatatoverifymymodels.
IwouldliketothankDr.WendellCropper,Jr.,forhistremendoushelpwhenhe
was working attheUniversityofFloridaandservedonmycommittee. Now, heis
workingattheUniversityofMiami,Florida.
I am indebtedtomy friends andcolleagues, especially Larry Korhnak, who
collectedall the longtermfielddata includingwatertablefluctuations andweather
informationduringtheseyears.WillieWoodhelpedwithdatacollectiononlitterfalland
throughfall.KenClarkrantheEddysolSystemforeddycorrelationdata.RobertHamlin
climbedthetowerswithmetomeasuretranspirationandstomatalconductance.GeSun
helpedinsettinguptheaccesstowersandgettingthetruckoutofswan:q)swhensmck.
Finally,Iwanttothankmywife,HongmeiLuo,forherfullsupportandpatience.
ii
ThisresearchwassupportedbyUSDAForestServiceGrantContractNo.A8FS-
91961:EvapotranspirationProcessesinPine-cypressFlatwoodsWetlands,HansRiekerk,
principalinvestigator,andconductedonthelandsmadeavailablebytheGeorgia-Pacific
Corporation.
iii
TABLEOFCONTENTS
Page
ACKNOWLEDGEMENTS
ii
LISTOFTABLES vii
LISTOFFIGURES ix
ABSTRACT xv
CHAPTERS
1 INTRODUCTION 1
2 LITERATUREREVIEW 5
EvapotranspirationFromFloridaFlatwoods 5
SingleLayerModels 8
Multi-LayerModels 11
CouplingBetweenVegetationandAtmosphere 14
ModelingStomatalConductanceattheLeafLevel 16
CanopyStomatalConductance 19
LeafAreaIndexandRadiationTransferinForestCanopy 20
RainfallInterception 23
CanopyStorageCapacity 23
EvaporationFromtheWetCanopy 25
PredictiveModels 25
3 MATERL\LSANDMETHODS 29
StudySites 29
EcosystemStructure 31
PlantInventory 31
OverstoryLeafAreaIndex 32
UnderstoryLeafAreaIndex 34
iv
StomatalConductance 35
FieldMeasurement 35
ModelingStomatalConductanceattheLeaf/NeedleLevel 37
MeasurementofRainfallInterception 39
StorageCapacity 39
RainfallInterception 42
EvaporationFromStandingWaterinWetlands 46
SoilMoistureContent 47
EstimationofETfromWaterLevelFluctuations 47
SpecificYield 48
EstimatingEvapotranspiration 49
StatisticalAnalysis 51
DevelopmentofanEvapotranspirationModel 52
DerivationofaNewInterceptionModel 52
TranspirationModels 61
EvaporationfromSoilorWaterSurfaces 69
EXPERIMENTALRESULTSANDDISCUSSION 71
StandStrucmreandRadiation 71
PlantInventory 71
DynamicsofLitterfallandLeafAreaIndex 77
RadiationTransferandVerticalDistributionof
LeafAreaIndex 86
RainfallInterception 96
StorageCapacity 96
RainfallCanopyInterception 100
Discussion 104
EvaporationFromtheSurfaceofStandingWater
inCypressWetlands 110
RelationshipBetweenWaterLevelandWaterSurface
AreainWetlands 110
WaterSurfaceEvaporationinWetlands 114
EvaporationFromStandingWaterinWetlands 114
DailyPatternofTranspirationandStomatalConductance
attheLeaf/NeedleLevel 119
RelationshipsamongStomatalConductanceand
EnvironmentalVariables 121
ComparisonofTranspirationandStomatalConductance
betweenSpeciesattheLeaf/NeedleLevel 126
EstimationofEvapotranspirationfromWaterLevelFluctuations .. 126
InCypressWetlands 126
IntheUplands 130
V
5 MODELINGRESULTSANDDISCUSSION 135
StomatalConductance 135
Results 135
Discussion 138
RainfallInterception 142
Transpiration,CanopyConductanceandtheCouplingof
theForestwiththeAtmosphere 149
VerificationoftheTranspirationModel 149
TranspirationandConductanceattheCanopyLevel 149
ComparisonBetweenTranspirationSubmodels 164
HysteresisintheChangeofEnvironmentalVariables 165
HysteresisintheResponseofTranspirationand
StomatalConductancetoEnvironmentalVariables 167
DegreeoftheCanopy-AtmosphereCoupling 173
EvapotranspirationfromCypressWetlandsandSlashPineUplands 178
ComparisonofEvapotranspirationinTimeandSpace 178
SensitivityAnalysis 181
MaximumEvapotranspirationoftheEcosystems 188
6 SUMMARY 190
OriginalityoftheResearch 190
SuggestionsforFutureResearch 194
APPENDICES 196
I QBASICSCRIPTSOFETM 196
nm IONUPTUPTUFTIFLIELSETSOFERTOMMETM 223460
LISTOFREFERENCES 244
BIOGRAPHICALSKETCH 258
vi
USTOFTABLES
Table Page
4-1 Speciescompositionandtheirimportanceincypresswetlands 73
4-2 GeneralcharacteristicsofthestudycypresswetlandsC,KandN,and
othersimilarcypresswetlandsinFlorida 75
4-3 LeaflitterfallandLAIofthestudycypresswetlandsC,KandN,and
othersimilarcypresswetlandsinFlorida 76
4-4 Treeandstandcharacteristicsofslashpineuplands 77
4-5 Cumulativeleaf/needlefallfromApril1,1993,toMarch31,1994 78
4-6 RegressioncoefficientsfornormalizedLAIofslashpine,cypress
andblackgimi 86
4-7 LeafAreaIndexofpahnettoinpineuplands 87
4-8 Regressioncoefficientsofthepolynomialequationsdescribing
thenormalizedverticaldistributionofleafareaindexinthecanopies 95
4-9 Estimatedstoragecapacitiesofthefoliage,branchesandstems
inthecanopies 97
4-10 Measuredrainfallandinterception,inmm,fi-omApril1993to
March1994 100
4-11 Coefficientsintheempiricalregressionequationsofinterceptionand
rainfallandtemperature 103
4-12 ComparisonofCanopyRainfallStorageCapacitiesofForests 108
4-13 Comparisonofannualinterceptionlossofcypresswetlandswith
otherforestecosystems Ill
vii
4-14 Wetlanddepth,wetlandarea,andcoefficientsai,ajandajofthe
polynomialregressionequationdescribingtherelationshipbetween
thesurfaceareaofthestandingwaterandthewaterlevelinwetlands 112
4-15 Estimatedannualevaporation(mm)fromthesurfaceofstandingwater
inwetlands 119
4-16 Comparisonoftranspkationandg,betweenpondcypressandslashpine 127
5-1 Resultsofforwardstepwisemultiplelinearregressionanalysisofg^for
thetwotreespecies 135
5-2 Optimizedcoefficientsofstomatalconductancemodelsof T.ascendens
andP.elliottiifoliage 137
5-3 ComparisonoftheperformanceofJarvistypeofstomatalconductance
model 141
5-4 ComparisonofpredictedrainfallinterceptionusingtheGash,Mulder
andnewLiumodel 146
5-5 Comparisonofsomeinterceptionmodels 147
5-6 Comparisonofannualtranspirationpredictedbydifferentmodels 166
5-7 Transpiration,rainfallinterception,substrateevaporationandtotalET
FromFloridaflatwoodsecosystems 179
5-8 Annualevapotranspirationinpercentofannualrainfall 181
5-9 SensitivityanalysisontheevapotranspirationmodelETM 187
viii
LISTOFFIGURES
Figure Page
2-1 Therelationshipbetweencanopyheight(h),roughnesslength(Zg),
zerodisplacementheight(d),andwindspeed(u(z))inaforest 10
2-2 ExampleofestimationcanopyrainfallstoragecapacityC„using
theLeytonmethod 24
3-1 LocationofthesmdywetlandsC,KandNwithinthe50x50m^
gridsystem 30
3-2 Determinationofrainfallretentioncapacitybywettinganddrying
branschesandstemsinthelaboratory 41
3-3 Mapoftrees,tower,littertrapsandthroughfalltroughsinthe
Cuplandplot 43
3-4 Mapoftrees,tower,littertrapsandthroughfalltroughsinthe
Kuplandplot 44
3-5 Mapoftrees,tower,littertrapsandthroughfalltroughsinthe
Nuplandplot 45
3-6 ThestrucmreofoftheevapotranspirationmodelETM 53
3-7 Electricalanalogueoftheexchangeofsensibleheatandlatentheat
withinaforestcanopy 62
4-1 Relativeimportanceoftreespeciesincypresswetlands 72
4-2 Monthlyandcumulativeleaflitterfallofcypressinwetlands 79
4-3 Monthlyandcumulativeleaflitterfallofblackguminwetlands 80
4-4 Monthlyandcumulativepineneedlelitterfallinbothuplands
andwetlands 81
ix
4-5 Temporalchangeofleafareaindexofcypresswetlandsand
slashpineuplandsduring1993 83
4-6 Normalizedtemporalchangeofleafareaindexofslashpine,
cypressandblackgumin1993 85
4-7 Verticaldistributionofphotosyntheticallyactiveradiationinthe
crownsofsixindividualslashpineandfivecypresstrees 88
4-8 Leafangledistributionofcypressleavesinwetlands 89
4-9 Penetrationofphotosyntheticallyactiveradiationincypresscanopies .... 90
4-10 Comparisonofdirectandindirectestimatesofleafareaindex 92
4-11 ComparisonofLAI-2000measurementswithdirectestimatesof
leafareaindexinforeststands 93
4-12 Verticaldistributionofcumulativesurfaceareaindex(CSAI)incypress
wetlandsandslashpineuplands 94
4-13 Surfaceretentioncapacityofbranchesandstemsasafunctionof
diameterandtreespecies 97
4-14 Relationshipbetweenmonthlyinterceptionandrainfallmeasured
incypresswetlandsandslashpineuplandsfromApril1of1993
toMarch31of1994 102
4-15 Seasonalchangesofrainfallandinterceptionincypresswetlands
andslashpineuplandsmeasuredfromApril1of1993toMarch31
of1994 105
4-16 Seasonalchangesoftheinterceptionratioincypresswetlandsand
slashpineuplandsmeasuredfromApril1of1993toMarch31
of1994 106
4-17 Surfaceareaofstandingwaterasafunctionofwaterlevelin
cypresswetlands 113
4-18 Temporalchangeoftheratioofpanevaporationincypress
wetlandstoopenpanevaporationatastandardweatherstation
from1993to1994 115
x