Linking Economic Models to Linking Economic Models to Ecosystem Models: Biofuel Ecosystem Models: Biofuel

ExamplesExamples

Bill PartonBill PartonSteve Del GrossoSteve Del Grosso

Sarah DavisSarah DavisBruce McCarlBruce McCarlSteve WilliamsSteve Williams

Steve OgleSteve Ogle

OutlineOutline Ecosystem ModelsEcosystem Models

DayCent model description & testingDayCent model description & testing EPIC, DNDC, BIOM-BGCEPIC, DNDC, BIOM-BGC

Linking to Economic ModelsLinking to Economic Models Fully linkedFully linked Economic Economic → Ecosystem→ Ecosystem Ecosystem → EconomicEcosystem → Economic

Biofuel Ecosystem Model ResultsBiofuel Ecosystem Model Results PennsylvaniaPennsylvania IllinoisIllinois

ConclusionsConclusions

CH4 Validaions

0

10

20

30

0 10 20 30observed CH4 gC ha-1 d-1

sim

ua

lted

CH

4 g

C h

a-1 d

-1

intensive ag

dryland ag

short grass

coniferous

decidous

tropical

N2O Validations

-1

0

1

2

3

4

-1 0 1 2 3 4ln(observed N2O - gN ha-1 d-1)

ln(s

imu

alte

d N

2 O -

gN

ha-1

d-1

) deciduous forest

dryland ag

grassland

intensive ag

organic ag

DAYCENT vs NASS County Level Yields

y = 0.9067x + 24.511

R2 = 0.7109

0

200

400

600

800

0 200 400 600 800observed gC m-2 yr-1

sim

ula

ted

gC

m-2

yr-1

Compare Nitrate Export

0

10

20

30

40

50

60

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

year

kg

N/h

a/y

r

Observed

Simulated

Compare Water Drainage

01020304050607080

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

year

wa

ter

yie

ld c

m

Observed

Simulated

Fully Linked Economic and Fully Linked Economic and Ecological ModelsEcological Models

Economic Model

Land Use Change and Ag Management

Optimal Land Use Practice

Ecological Model Assessment•NPP•Greenhouse Gas Fluxes

AdvantagesAdvantages All land use options can be assessedAll land use options can be assessed

DisadvantagesDisadvantages Complex modelComplex model Excess computer timeExcess computer time Vulnerable to errorsVulnerable to errors

Economic Models Drive Ecological Economic Models Drive Ecological ModelsModels

Use FASM U.S. Agricultural Model to Use FASM U.S. Agricultural Model to predict biofuel land use changepredict biofuel land use change

Expansion of ag land into:Expansion of ag land into:1.1. CRPCRP

2.2. GrasslandGrassland

3.3. ForestsForests

Economic Models Drive Ecological Economic Models Drive Ecological ModelsModels

DayCent Model simulated ecosystem DayCent Model simulated ecosystem responseresponse

Plant productionPlant production NN22O fluxesO fluxes Soil C changesSoil C changes

Change in crop acreageChange in crop acreage Corn vs. Soybean vs. WheatCorn vs. Soybean vs. Wheat

Corn/Soybean Net Soil Greenhouse Gas

-30

-20

-10

0

10

20

30

40

50

60

70

Cropland CTCorn/Soy

CRP CTCorn/Soy

GrasslandCT Corn/Soy

CRP to NTCorn/Soy

Grassland toNT Corn/Soy

Corn/Soy toSwitchgrass

g C

O2-C

eq

. m

-2 y

r-1

Cropland to Biofuels

-20

0

20

40

60

80

delta SOC N2O GHGnet ANPP

g C

O2-

C e

q. m

-2 y

r-1

CT corn/soy corn/soy to NT corn/soy corn/soy to cont. CT corn

corn/soy to cont. NT corn corn/soy to switchgrass

AN

PP

gC

m-2

yr-1

* 0

.1

-50

-40

-30

-20

-10

0

10

20

30

40

50

GHGnet ANPP

g C

O2-C

eq

. m-2

yr-1

prairie prairie harvested prairie harvested + N prairie to switchgrass

AN

PP

gC

m-2

yr-1

* 0

.1Grassland/Degraded LandGrassland/Degraded Land

Ecological Models Drive Economic Ecological Models Drive Economic ModelsModels

Use ecological models to drive response Use ecological models to drive response surfaces used in economic modelssurfaces used in economic models NN22O vs. FertilizerO vs. Fertilizer Yield vs. FertilizerYield vs. Fertilizer Soil C vs. Land Use and FertilizerSoil C vs. Land Use and Fertilizer

Response Surface ModelingResponse Surface Modeling

0.4

0.3

0.2

0.1

0.0

N2O Flux

Clay

0.1 0.2 0.3 0.4 0.5Fertilizer

05

1015

2025

Clay

0.1 0.2 0.30.4 0.5

Fertilizer010

3020

1.0

0.5

0.0

NO Flux

Clay

0.1 0.2 0.3 0.4 0.5Fertilizer0

10

3020

Clay

0.1 0.2 0.30.4 0.5

Fertilizer010

3020

0.3

0.2

0.1

CH40.40.30.20.10.0

0.50.60.70.80.91.0

N2 Flux

CORN

0.4

0.3

0.2

0.1

0.0

N2O Flux

0.4

0.3

0.2

0.1

0.0

0.4

0.3

0.2

0.1

0.0

N2O Flux

Clay

0.1 0.2 0.3 0.4 0.5Clay

0.1 0.2 0.3 0.4 0.5Fertilizer

05

1015

2025

Fertilizer0

510

1520

25

05

1015

2025

Clay

0.1 0.2 0.30.4 0.5

Clay

0.1 0.2 0.30.4 0.5

Fertilizer010

3020

Fertilizer010

3020

1.0

0.5

0.0

NO Flux

1.0

0.5

0.0

NO Flux

Clay

0.1 0.2 0.3 0.4 0.5Clay

0.1 0.2 0.3 0.4 0.5Fertilizer0

10

3020

Fertilizer010

3020

Clay

0.1 0.2 0.30.4 0.5

Clay

0.1 0.2 0.30.4 0.5

Fertilizer010

3020

Fertilizer010

3020

0.3

0.2

0.1

CH4

0.3

0.2

0.1

CH40.40.30.20.10.0

0.50.60.70.80.91.0

N2 Flux0.40.30.20.10.0

0.50.60.70.80.91.0

0.40.30.20.10.0

0.50.60.70.80.91.0

N2 Flux

CORN

Clay

0.1 0.2 0.3 0.4 0.5PET Ann

8090

100110

120130

N2O Flux

0.20

0.15

0.10

0.05

0.00

0.25

Clay

0.1 0.2 0.3 0.4 0.5PET Ann

8090

100110

120130

0.0

0.1

0.2

0.3

0.4

0.5

0.6

NO Flux

Clay

0.1 0.2 0.30.4 0.5

PET Ann80

90100

110120

130

0.3

0.2

0.1

CH4

Clay

0.1 0.2 0.3 0.4 0.5

PET Ann80

90100

110120

130

0.4

0.3

0.2

0.1

0.0

0.5

0.60.7

N2 Flux

SOYBEAN

Clay

0.1 0.2 0.3 0.4 0.5Clay

0.1 0.2 0.3 0.4 0.5PET Ann

8090

100110

120130

PET Ann80

90100

110120

130

N2O Flux

0.20

0.15

0.10

0.05

0.00

0.25

N2O Flux

0.20

0.15

0.10

0.05

0.00

0.25

0.20

0.15

0.10

0.05

0.00

0.25

Clay

0.1 0.2 0.3 0.4 0.5Clay

0.1 0.2 0.3 0.4 0.5PET Ann

8090

100110

120130

PET Ann80

90100

110120

130

8090

100110

120130

0.0

0.1

0.2

0.3

0.4

0.5

0.6

NO Flux

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.0

0.1

0.2

0.3

0.4

0.5

0.6

NO Flux

Clay

0.1 0.2 0.30.4 0.5

Clay

0.1 0.2 0.30.4 0.5

PET Ann80

90100

110120

130

PET Ann80

90100

110120

130

0.3

0.2

0.1

CH4

0.3

0.2

0.1

CH4

Clay

0.1 0.2 0.3 0.4 0.5Clay

0.1 0.2 0.3 0.4 0.5

PET Ann80

90100

110120

130

PET Ann80

90100

110120

130

0.4

0.3

0.2

0.1

0.0

0.5

0.60.7

N2 Flux 0.4

0.3

0.2

0.1

0.0

0.5

0.60.7

0.4

0.3

0.2

0.1

0.0

0.5

0.60.7

N2 Flux

SOYBEAN

0.4

0.3

0.2

0.1

0.0

N2O Flux

Clay

0.1 0.2 0.3 0.4 0.5Fertilizer

05

1015

2025

1.0

0.5

0.0

N2 Flux

Clay

0.1 0.2 0.30.4 0.5

Fertilizer0

510

1520

25

NO Flux 0.4

0.3

0.2

0.10.0

0.5

0.6

0.7

Clay

0.1 0.2 0.3 0.4 0.5Fertilizer0

510

1520

25

0.3

0.2

0.1

CH4

Clay

0.1 0.20.3 0.4 0.5

Fertilizer05

1015

2025

WHEAT

0.4

0.3

0.2

0.1

0.0

N2O Flux

0.4

0.3

0.2

0.1

0.0

0.4

0.3

0.2

0.1

0.0

N2O Flux

Clay

0.1 0.2 0.3 0.4 0.5Clay

0.1 0.2 0.3 0.4 0.5Fertilizer

05

1015

2025

Fertilizer0

510

1520

25

05

1015

2025

1.0

0.5

0.0

N2 Flux

1.0

0.5

0.0

N2 Flux

Clay

0.1 0.2 0.30.4 0.5

Clay

0.1 0.2 0.30.4 0.5

Fertilizer0

510

1520

25

Fertilizer0

510

1520

25

05

1015

2025

NO Flux 0.4

0.3

0.2

0.10.0

0.5

0.6

0.7

NO Flux 0.4

0.3

0.2

0.10.0

0.5

0.6

0.7

0.4

0.3

0.2

0.10.0

0.5

0.6

0.7

Clay

0.1 0.2 0.3 0.4 0.5Clay

0.1 0.2 0.3 0.4 0.5Fertilizer0

510

1520

25

Fertilizer05

1015

2025

05

1015

2025

0.3

0.2

0.1

CH4

0.3

0.2

0.1

CH4

Clay

0.1 0.20.3 0.4 0.5

Clay

0.1 0.20.3 0.4 0.5

Fertilizer05

1015

2025

Fertilizer05

1015

2025

05

1015

2025

WHEAT

Clay

0.1 0.2 0.3 0.4 0.5

Fertilizer0

1020

3040

50

N2O Flux0.4

0.3

0.2

0.1

0.0

0.5

0.6

Clay

0.1 0.2 0.30.4 0.5

Fertilizer010

2030

4050

1.0

0.5

0.0

NO Flux

1.5

Clay

0.1 0.2 0.3 0.4 0.5

0.3

0.2

0.1

CH4

Fertilizer0

1020

3040

50

Clay

0.1 0.2 0.30.4 0.5

2

1

0

N2 Flux

Fertilizer0

1020

3040

50

GRASS HAY

Clay

0.1 0.2 0.3 0.4 0.5Clay

0.1 0.2 0.3 0.4 0.5

Fertilizer0

1020

3040

50

Fertilizer0

1020

3040

50

010

2030

4050

N2O Flux0.4

0.3

0.2

0.1

0.0

0.5

0.6

N2O Flux0.4

0.3

0.2

0.1

0.0

0.5

0.6

0.4

0.3

0.2

0.1

0.0

0.5

0.6

Clay

0.1 0.2 0.30.4 0.5

Clay

0.1 0.2 0.30.4 0.5

Fertilizer010

2030

4050

Fertilizer010

2030

4050

010

2030

4050

1.0

0.5

0.0

NO Flux

1.5

1.0

0.5

0.0

NO Flux

1.5

Clay

0.1 0.2 0.3 0.4 0.5Clay

0.1 0.2 0.3 0.4 0.5

0.3

0.2

0.1

CH4

0.3

0.2

0.1

CH4

Fertilizer0

1020

3040

50

Fertilizer0

1020

3040

50

010

2030

4050

Clay

0.1 0.2 0.30.4 0.5

Clay

0.1 0.2 0.30.4 0.5

2

1

0

N2 Flux

2

1

0

N2 Flux

Fertilizer0

1020

3040

50

Fertilizer0

1020

3040

50

010

2030

4050

GRASS HAY

Global Model ResultsGlobal Model Results

-60

-50

-40

-30

-20

-10

0

10

nitrif inhib split N fert 70%N no till no till+nitinhib

% d

elta

bas

e

grain yield

N2O total

GHG net

Beach, R.H., B.J. DeAngelo, S. Rose, C. Li, W. Salas, S.J. DelGrosso. 2008. Mitigation potential and costs for global agricultural greenhouse gas emissions. Agricultural Economics 38: 109–115.

Biofuel Crop Specific Greenhouse Biofuel Crop Specific Greenhouse Gas BudgetGas Budget

PennsylvaniaPennsylvania SwitchgrassSwitchgrass Corn/SoybeanCorn/Soybean PopularPopular

Illinois/IowaIllinois/Iowa SwitchgrassSwitchgrass MiscanthusMiscanthus

Adler, P.R., S.J. Del Grosso, and W.J. Parton. 2007. Life cycle assessment of net greenhouse gas flux for bioenergy cropping systems. Ecol. Appl. 17(3):675–691.

Greenhouse gas sources and sinks from Greenhouse gas sources and sinks from bioenergy cropping systems in the near-bioenergy cropping systems in the near-

termterm

-150

-100

-50

0

50

100

Gre

enh

ou

se g

as f

luxe

s (g

CO

2e-

C m

-2y-1

)

-150

-100

-50

0

50

100

Ag. machineryChemical inputNitrous oxideMethaneBiofuel conversionSoil CGHGnet

SWG

CS-CT

RCG CSA-CT

CS-NT

HP

CSA-NT

Near-term

Adler, P.R., S.J. Del Grosso, and W.J. Parton. 2007. Life cycle assessment of net greenhouse gas flux for bioenergy cropping systems. Ecol. Appl. 17(3):675–691.

2005

0

2

4

6

8

10

alfalfa canary grass corn switchgrass soy

N2O

gN

ha-1

d-1

obs

sim

2006

0

2

4

6

8

10

alfalfa canary grass corn switchgrass soy

N2O

gN

ha-1

d-1

obs

sim

Observed and DAYCENT NObserved and DAYCENT N22O for Biofuel O for Biofuel

Cropping Systems in PennsylvaniaCropping Systems in Pennsylvania

Ames, Iowa - Switchgass Yields

0

2

4

6

8

10

12

14

16

0 60 120 180 240 300

N fert kg/ha

biom

ass

Mg/

ha

observed

DAYCENT

Ames, Iowa - Switchgass NO3 Leaching

0

50

100

150

200

250

0 60 120 180 240 300

N fert kg/ha

kg N

/ha

DAYCENT

S. C. Davis

S. C. Davis

S. C. Davis

S. C. Davis

SummarySummary

Fully linked models are difficult to useFully linked models are difficult to use Offline linking of models works wellOffline linking of models works well Net greenhouse gas balances are a Net greenhouse gas balances are a

function of:function of: Specific biofuel cropSpecific biofuel crop

• Perennial vs. annualPerennial vs. annual Land use prior to start of biofuel cropLand use prior to start of biofuel crop

• Existing croplandExisting cropland• CRP/mature grassland?CRP/mature grassland?

Tillage and fertilizing practiceTillage and fertilizing practice