Oaks/GrassSavannaAmeriFluxSiteinCalifornia

DennisBaldocchiSiyanMaandJoeVerfaillie

UniversityofCalifornia,Berkeley

ECOSTRESSMee?ng,UCDavis,May16,2017

Objec?ves

•  GiveOverviewofResourcesandMetadata•  Reportonfindingsfrom16+yearsofcon?nuouscarbon,waterandenergyfluxesmeasuredoverOaksavannaandannualgrassland

TonziRanch,US-Ton,AmeriFluxTower

Dis?nctWetandDryPeriods,toStudyEffectsofVaryingSoilMoistureonCarbonandWaterExchangeExperienceswiderangeofTemperature(0-40C),tostudyeffectsofWarmingonEcosystemProcessesExperienceswiderangeofAnnualPrecipita?on(300-1000mm),tostudynon-lineareffectsofrainfallonecosystemmetabolismOpenStructureChallengesassump?onsofSimpleBig-LeafModels

OakSavannaisPerfectLaboratoryforStudyingEcosystem-ClimateInterac?ons

Camp Pardee

ppt mm

200 400 600 800 1000 1200

Cou

nt

0

2

4

6

8

10

12

14

16

18

20

InterannualVariabilityofRainatTonzi/VairaRanches

We’veExperiencedAverageandExtremelyWetandDryYearsoverthepast16years2012/13weredrybutweexperiencedDryyearsbeforeOaksareadaptedtodryyearsandcansurvive2dryyearsinarow.Whatabout3dryyearsinarow?Theytendtooccurrarely.

Ione, CA

End of Hydrological Year

2000 2002 2004 2006 2008 2010 2012 2014 2016

Pre

cipi

tatio

n (m

m/y

)

300

400

500

600

700

800

900

1000

savanna

Griffin+Anchuka?s,2015GRL

Liu,Y.,M.J.Hill,X.Zhang,Z.Wang,A.D.Richardson,K.Huiens,G.Filippa,D.D.Baldocchi,S.Ma,J.Verfaillie,andC.B.Schaaf.2017.UsingdatafromLandsat,MODIS,VIIRSandPhenoCamstomonitorthephenologyofCaliforniaoak/grasssavannaandopengrasslandacrossspa?alscales.AgriculturalandForestMeteorology237–238:311-325.

ModisOperandi

•  DirectCarbon,WaterandEnergyFluxMeasurementswithEddyCovariance

•  Spa?alUpscalingwithRemoteSensing–  TerrestrialandAirborneLIDAR,IKONOS(1-4mresolu?on)

•  TemporalUpscalingwithDigitalCamerasandVegIndices–  PhenologyandDynamicsofLeafAreaIndex

•  Mechanis?cUnderstandingofEcophysiologicalProcesses–  UnderstoryeddyfluxsystemandsoilCO2probesforfluxpar??oning–  EcosystemModeling,CANOAK-3D–  PhysiologicalMeasurementsofPre-DawnWaterpoten?aland

photosynthe?ccapacity,TRY–  Soilmoisturenetworks,COSMOS,SMAP,ISMN–  RootandSoilDepth,withGPR

EddyFluxInstrumenta?on

3dSonicAnemometerNonDispersiveInfraredGasSpectrometerforCO2andH2O

EddyCovariance

F w c= ' '

Mean

Fluctuation

RepositoryofRemoteSensingData•  Ikonos:07/22/2001•  Avris:2005,2006,2009•  CASI:•  AirborneLIDAR:2003,2009•  TerrestrialLidar:2014•  MODISTimeSeries…•  UpwardLookingDigitalCamera?meseries:2006-•  LED/NDVI?meseries:2006->•  HighResolu?onspectralreflectance?meseries(2006-)•  UnderstoryTramSystem(PARandRninx):2006-2015•  Tower-basedDigitalWebCamera:2005->

TonziRanchOakSavanna,nearIone

IKONOS

CanopyStructure:LaserAl?meterData

Chenetal

LIDAR Measurements of Tree HeightOak Savanna, Ione, CA

Tree Height, m

0 10 20 30 40 50 60

pdf

0.0

0.1

0.2

0.3

0.4

2003, ave ht = 9.62 m2009, ave ht = 10.64 m

LIDAR, Oak Savanna, Ione, CA

Crown Diameter, m

0 5 10 15 20 25 30pd

f0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

2003: 8.06 m 2009: 8.79 m

Belandetal

MonitorSurfacePhenologywithaSuiteofOp?calSensors

LEDNDVISensor

FluxTowerwithDigitalCamera

Hyper-spectralspectrometerUpwardLookingCamera

GapFrac?onPhenologywithUpwardLookingCamerasunderOakSavanna

CanDetectStartandEndofGrowingSeasonwithPrecision

SoilDepthwithGroundPenetra?ngRadar

Raz-Yaseefetal,2013JGRBiogeoscience

Roots!

Oak Savanna 2005

Day

0 50 100 150 200 250 300 350 400

Soi

l Moi

stur

e ( c

m3/

cm3)

0

10

20

30

40

50

0-15 cm15-30 cm30-45 cm45-60 cm

SeasonalityofSoilMoisture

MonitoringDepthtoGroundWater

Maetal.2016AgForMetMilleretal,2010,WRR

Day

100 120 140 160 180 200 220 240 260 280

Vcmax

0

20

40

60

80

100

120

140

SeasonalityofPhotosynthe?cCapacity

InterannualVariabilityofNetEcosystemCarbonExchange

VairaRanch

TonziRanch

GrasslandisCarbonNeutral,aslightsource:27gCm-2y-1SavannaisamodestSink,:-157gCm-2y-1

Ione, CA

Hydrological Year

2000 2002 2004 2006 2008 2010 2012 2014 2016 2018

NE

E (g

C m

-2 y

-1)

-300

-200

-100

0

100

200

300

SavannaGrassland

EffectofDrought

2013wasNormalun?laboutD120,thenSystemshutdown,Physiologically

Savanna

Day

0 50 100 150 200 250 300 350

NE

E (g

C m

-2 d

-1)

-4

-2

0

2

4NEE Ave (2001-2013)2013

Varia?oninGrossPrimaryProduc?vity

Savanna(1060gCm-2y-1)wasmoreproduc?ve,by40%,thantheGrassland(665gCm-2y-1)

Ione, CA

Hydrological Year

2000 2002 2004 2006 2008 2010 2012 2014 2016

GP

P (g

C m

-2 y

-1)

400

600

800

1000

1200

1400

1600

Savannaannual grassland

Varia?oninEcosystemRespira?on

The‘cost’ofamoreProduc?veSystem

Ione, CA

Hydrological Year

2000 2002 2004 2006 2008 2010 2012 2014 2016

Rec

o (g

C m

-2 y

-1)

400

600

800

1000

1200

1400

oak savannaannual grassland

RainandEvapora?on SavannaET:404+/-64mmy-1AnnualGrassET:323+/-26mmy-1ppt:542+/-173mmy-1

Ione, CA

End of Hydrological Year

2000 2002 2004 2006 2008 2010 2012 2014 2016

Wat

er F

lux

(mm

/y)

200

300

400

500

600

700

800

900

1000

savannagrasslandprecipitation

On-GoingWork

WorkCon?nuesatpartofAmeriFluxandFLUXNETnetworksUseTerrestrialLidartoCharacterizeCanopyandApply3-dModelstoSimulateLight,carbonandWaterExchangeCollabora?ngwithCOSMOSandSMAPprojectsTodetectsoilmoisturedynamicswithremoteSensingandmicrowavebandradarDataareWidelyUsedinValida?ngModels,RemoteSensingProductsandCrossSiteSyntheses

LifeasaBlueOak:FirngthroughtheEvolu?onaryEye

oftheNeedle

Savanna vs Grassland

Savanna

400 600 800 1000 1200 1400 1600

Gra

ssla

nd

300

400

500

600

700

800

900

1000

1100

GPP; r2 = 0.53Reco; r2 = 0.72Plot 1 Regr

CarbonFluxesattheSavannaandGrasslandareinSynch

Year to Year Changes in Productivity

dGPP (gC m-2 y-1)

-600 -400 -200 0 200 400 600

dRec

o (g

C m

-2 y

-1)

-400

-200

0

200

400

600SavannaAnnual GrasslandPlot 1 RegrCoefficients:

b[0] 18.51b[1] 0.658r ≤ 0.727

YearsthatPromoteProduc?vity,rela?vetothePrioryearComeattheCostofMoreRespira?on,

AndViceVersa

ClimateTrends:Pardee,CA

TemperatureIncreasedbyabout1.25Cover60Years

Precipita?onisHighlyVariableandNeartheBorderlinetoSustainForestsvsGrass

Camp Pardee

Year

1920 1940 1960 1980 2000 2020

Tair

(c)

14.5

15.0

15.5

16.0

16.5

17.0

17.5

18.0

18.5

Camp Pardee

Year

1920 1940 1960 1980 2000 2020

annu

al P

reci

p (m

m)

0

200

400

600

800

1000

1200

mean: 518 mmstddev: 193

-124 -123 -122 -121 -120 -119 -118 -117 -116 -115Longitude

33

34

35

36

37

38

39

40

41

42

Latit

ude

Quercus douglasii Range

FieldSites,nearIone

BlueOakRange