Use of Biome-BGC with the ChEAS flux tower network to address scaling issues

Faith Ann HeinschNTSG, School of Forestry

The University of Montana

ChEAS MeetingJuly 1, 2003

BIOME-BGC estimates fluxes and storage of energy, water, carbon, and nitrogen for vegetation and soil on a daily basis.

Model algorithms represent physical and biological processes that control fluxes of energy and mass:

• New leaf growth and old leaf litterfall • Sunlight interception by leaves, and penetration to the ground • Precipitation routing to leaves and soil • Snow (SWE) accumulation and melting • Drainage and runoff of soil water • Evaporation of water from soil and wet leaves • Transpiration of soil water through leaf stomata • Photosynthetic fixation of carbon from CO2 in the air • N uptake from the soil • Distribution of C and N to growing plant parts • Decomposition of fresh plant litter and old soil organic matter • Plant mortality• Plant phenology • Fire/disturbance

The BIOME-BGC Terrestrial Ecosystem Process Model

• Daily time step (day/night partitioning based on daily information)

• Single, uniform soil layer hydrology (bucket model)

• 1 uniform snow layer of SWE (no canopy snow interception/losses)

• 1 canopy layer (sunlit/shaded leaf partitioning)

• Dynamic phenology and C/N allocation (e.g. LAI, biomass, soil and

litter)

• Disturbance (fire) and mortality functions

• Variable litter and soil C decomposition rates (3 litter and 4 soil C

pools)

Major Features:

BIOME-BGC

Meteorological Parameters Required by Biome-BGC

• Daily maximum temperature (°C) • Daily minimum temperature (°C) • Daylight average temperature (°C) • Daily total precipitation (cm)

• Daylight average partial pressure of water vapor (Pa)

• Daylight average shortwave radiant flux density (W/m2)

• Daylength (s)

 

     

          Site DataSite DataLatitudeElevation

Slope/AspectSoil Depth

Soil Texture

 

Atmospheric Atmospheric CO2CO2

PlantPlant

Soil Organic Soil Organic MatterMatter

Atmospheric NAtmospheric N

Soil Mineral NSoil Mineral N

Allocation to Allocation to New growthNew growth

N N UptakUptak

ee

MRMR

LitterLitter

PSNPSNGRGR

HRHR

Meteorological Meteorological DataData

Air TemperatureRadiation

PrecipitationHumidity

Atmospheric CO2

Evaporation/ Evaporation/ TranspirationTranspiration

PhotosynthesisPhotosynthesis

Total Total RespirationRespiration

Soil and Litter Soil and Litter RespirationRespiration

LAILAI

SnowSnow

SoilSoil

OutflowOutflow

TemperatureTemperature

CC

Annual InputAnnual InputN DepositionN Fixation

Daily - AnnualDaily - AnnualPhotosynthesisEvapotranspirationRespirationAbsorbed PAR 

Daily - Annual Daily - Annual AllocationAllocation Carbon, Nitrogen -leaf (LAI) -stem -coarse root -fine root  

N FluxN FluxC FluxC Flux

HH22OO

CC

CC

Periodic Periodic InputInput Disturbance -fire -harvest -grazing -agriculture

 

     

         

HH22OO

HH22OO

HH22OO

HH22OO

BIOME-BGC Eco-physiological ParametersBiome-BGC uses a list of 43 parameters to differentiate biomes.

• general eco-physiological characteristics• must be specified prior to each model

simulation• can be measured in the field, obtained from the

literature or derived from other measurements.

Default Biome types with defined parameters•Deciduous Broadleaf Forest (temperate)

•Deciduous Needleleaf forest (larch)

•Evergreen Broadleaf Forest (subtropical/tropical)

•Evergreen Needleleaf Forest

•Evergreen Shrubland

•C3 Grassland

•C4 Grassland

BiomeBGC

Landcoverdatabase

Other inputs:soils, elevation,

N-deposition

Surfaceweatherdatabase

Disturbancehistory

database

Vegetation

parameter

database

Integration

Model Estimates of:Outflow

SnowET

Rh

NEE NPP

Soil CfPAR

Biomass

LAISimulation

Validation

Hydrographdata

SNOTELdata

Flux towerdata

Ancillarymeasurements

at flux sites

Satellite data(MODIS,AVHRR)

FIA, FHM,Ecodata

(Inventory)

BIOME-BGC Simulated Daily Carbon and Water Exchange(1Barrow Tussock / Wet Sedge Tundra Site, 2000)

Daily C BudgetDaily 1Meteorology

1 Daily meteorological data obtained from Barrow W Post Station, 71.28N 156.76W

-15

-10

-5

0

5

10

15

deg

C

0

50

100

150

200

250

300

cmTav Tsoil (Biome-BGC) Snow_z

-0.0020

-0.0010

0.0000

0.0010

0.0020

0.0030

0.0040

0.0050

0.0060

1/11/21

2/103/1

3/214/10

4/305/20

6/96/29

7/198/8

8/289/17

10/710/27

11/1612/6

12/26

kg C

m-2

day

-1

NEE GPP R_autotrophic R_heterotrophic

-50

-40

-30

-20

-10

0

10

20

30

1/12/1

3/14/1

5/16/1

7/18/1

9/110/1

11/112/1

g C

m-2

1996 1997 1999 2000 2001

BIOME-BGC Simulated Cumulative Net Carbon Exchange(1Barrow Tussock / Wet Sedge Tundra Site)

C sink (+)

C source (-)

1 Daily meteorological data obtained from Barrow W Post Station, 71.28N 156.76W

2001 BIOME-BGC Cumulative Net C exchange(Boreal ENF Forest)

-250

-200

-150

-100

-50

0

50

100

150

200

250

Date

g C

m-2

Bonanza Creek Kenai Coldfoot Atigun

C source (+)

C sink (+)

2000 BIOME-BGC Cumulative Net C exchange(Boreal ENF Forest)

-250

-200

-150

-100

-50

0

50

100

150

200

250

Date

g C

m-2

Bonanza Creek Kenai Coldfoot Atigun

C source (+)

C sink (+)Alaska Study Region

Biome-BGC runsfor 4 areas in Alaska

Site Name LatitudeKenai AK 60.18N

Bonanza Creek AK 64.70N

Coldfoot AK 67.15N

Atigun AK 68.02N

Biome-BGC Estimates of LAIPark Falls, WI

Biome-BGC Estimate of NPP for Park Falls, 2001Maximum LAI = 3.2

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

0 30 60 90 120 150 180 210 240 270 300 330 360

Day of Year

NP

P (

gC

m-2

d-1

)

Biome-BGC Estimate of NPP for Park Falls, 2002Maximum LAI = 3.3

0.00.51.01.52.02.53.03.54.0

0 30 60 90 120 150 180 210 240 270 300 330 360

Day of Year

NP

P (

gC

m-2

d-1

)

Biome-BGC Estimates of NEE and GPP

Julian Day0 60 120 180 240 300 360

GP

P (

gC m

-2 d

-1)

0.0

2.5

5.0

7.5

10.0

12.5

15.0

17.5

Park Falls, WI

Julian Day

0 60 120 180 240 300 360

NE

E (

gC m

-2 d

-1)

-7.5

-5.0

-2.5

0.0

2.5

5.0

7.5

Biome-BGC with DBFBiome-BGC with Mixed ForestTower

Suggested Improvementsto

Biome-BGCSimulations at ChEAS Flux

Tower Sites

Wetland-BGC

• Presently being tested in Barrow, AK and the Niyak floodplain near Glacier Park, MT

• Dynamic groundwater component– Previously 1 soil layer, now 2

(saturated/unsaturated)

• Designed to be require minimal additional data

• Methane??

Unique Site Disturbance History

• Natural Disturbances– Timing– Intensity– Examples

• Fire• Blowdown

• Managed Disturbances– Timing– Intensity– Examples

• Fertilization• Harvest• Slash burn• Plant

Ensembling of Simulations

• Temporal– Necessary for historic

disturbances• 1 simulation for each

year of the meteorological record

• Obscures effects of meteorology to allow recovery to be seen

• Spatial– Non-interactive

• Age class– Old growth forests– Selective harvest

and replant • Vegetation Type

– ENF vs. DBF

• Hydrology– Upland vs. wetland

Disturbance History

Credit: P. Thornton, NCAR

Seasonal Cycle of GEP

Credit: P. Thornton, NCAR

Annual LAI in Final Simulation Year

Credit: P. Thornton, NCAR

Annual NEE in Final Simulation Year

Credit: P. Thornton, NCAR

Annual ET in Final Simulation Year

Credit: P. Thornton, NCAR

Suggested Improvements

• Difficult to attribute discrepancies to either the model or measurements

• Probably a combination of:– Site-specific parameterization

• Low maximum stomatal conductance

• Incorrect treatment of respiration at low Tair

– Site-specific measurement biases• Undermeasurement of warm season respiration

– Need to find a way to decompose NEE

Biome-BGC Default Eco-physiological Parameters: Evergreen Needleleaf Forest

value units description 1 (flag) 1 = WOODY 0 = NON-WOODY 1 (flag) 1 = EVERGREEN 0 = DECIDUOUS 1 (flag) 1 = C3 PSN 0 = C4 PSN 1 (flag) 1 = MODEL PHENOLOGY 0 = USER-SPECIFIED --- (yday) yearday to start new growth (when phenology flag = 0) --- (yday) yearday to end litterfall (when phenology flag = 0) 0.2 (prop.) transfer growth period as fraction of growing season 0.2 (prop.) litterfall as fraction of growing season 0.26 (1/yr) annual leaf and fine root turnover fraction 0.7 (1/yr) annual live wood turnover fraction 0.005 (1/yr) annual whole-plant mortality fraction 0.005 (1/yr) annual fire mortality fraction 1.4 (ratio) (ALLOCATION) new fine root C : new leaf C 2.2 (ratio) (ALLOCATION) new stem C : new leaf C 0.071 (ratio) (ALLOCATION) new live wood C : new total wood C 0.29 (ratio) (ALLOCATION) new croot C : new stem C 0.5 (prop.) (ALLOCATION) current growth proportion 42.0 (kgC/kgN) C:N of leaves 93.0 (kgC/kgN) C:N of leaf litter, after retranslocation 58.0 (kgC/kgN) C:N of fine roots 50.0 (kgC/kgN) C:N of live wood 730.0 (kgC/kgN) C:N of dead wood 0.31 (DIM) leaf litter labile proportion 0.45 (DIM) leaf litter cellulose proportion 0.24 (DIM) leaf litter lignin proportion 0.34 (DIM) fine root labile proportion 0.44 (DIM) fine root cellulose proportion 0.22 (DIM) fine root lignin proportion 0.71 (DIM) dead wood cellulose proportion 0.29 (DIM) dead wood lignin proportion 0.01 (1/LAI/d) canopy water interception coefficient 0.51 (DIM) canopy light extinction coefficient 2.6 (DIM) all-sided to projected leaf area ratio 8.2 (m2/kgC) canopy average specific leaf area (projected area basis) 2.0 (DIM) ratio of shaded SLA to sunlit SLA 0.033 (DIM) fraction of leaf N in Rubisco 0.004 (m/s) maximum stomatal conductance (projected area basis)

0.00004(m/s) cuticular conductance (projected area basis)

MET_INPUT (keyword) start of meteorology file control block metdata/TDE.mtc41 meteorology input filename 4 (int) header lines in met file RESTART (keyword) start of restart control block 1 (flag) 1 = read restart file 0 = don't read restart file 0 (flag) 1 = write restart file 0 = don't write restart file 0 (flag) 1 = use restart metyear 0 = reset metyear restart/TDE_n.endpoint input restart filename restart/TDE.endpoint output restart filename TIME_DEFINE (keyword - do not remove) 8 (int) number of meteorological data years 8 (int) number of simulation years 1993 (int) first simulation year 0 (flag) 1 = spinup simulation 0 = normal simulation 6000 (int) maximum number of spinup years (if spinup simulation) CLIM_CHANGE (keyword - do not remove) 0.0 (deg C) offset for Tmax 0.0 (deg C) offset for Tmin 1.0 (DIM) multiplier for Prcp 1.0 (DIM) multiplier for VPD 1.0 (DIM) multiplier for shortwave radiation CO2_CONTROL (keyword - do not remove) 1 (flag) 0=constant 1=vary with file 2=constant, file for Ndep 356.0 (ppm) constant atmospheric CO2 concentration TDE_co2.txt (file) annual variable CO2 filename SITE (keyword) start of site physical constants block 0.765 (m) effective soil depth (corrected for rock fraction) 28.0 (%) sand percentage by volume in rock-free soil 64.0 (%) silt percentage by volume in rock-free soil 8.0 (%) clay percentage by volume in rock-free soil 290.0 (m) site elevation 35.95 (degrees) site latitude (- for S.Hem.) 0.2 (DIM) site shortwave albedo 0.0005 (kgN/m2/yr) wet+dry atmospheric deposition of N 0.0004 (kgN/m2/yr) symbiotic+asymbiotic fixation of N

BIOME-BGCExample InitializationFile

RAMP_NDEP (keyword - do not remove) 0 (flag) do a ramped N-deposition run? 0=no, 1=yes 2099 (int) reference year for industrial N deposition 0.0001 (kgN/m2/yr) industrial N deposition value EPC_FILE (keyword - do not remove) dbf.epc (file) TDE DBF ecophysiological constants W_STATE (keyword) start of water state variable initialization block 0.0 (kg/m2) water stored in snowpack 0.5 (DIM) initial soil water as a proportion of saturation C_STATE (keyword) start of carbon state variable initialization block 0.001 (kgC/m2) first-year maximum leaf carbon 0.0 (kgC/m2) first-year maximum stem carbon 0.0 (kgC/m2) coarse woody debris carbon 0.0 (kgC/m2) litter carbon, labile pool 0.0 (kgC/m2) litter carbon, unshielded cellulose pool 0.0 (kgC/m2) litter carbon, shielded cellulose pool 0.0 (kgC/m2) litter carbon, lignin pool 0.0 (kgC/m2) soil carbon, fast microbial recycling pool 0.0 (kgC/m2) soil carbon, medium microbial recycling pool 0.0 (kgC/m2) soil carbon, slow microbial recycling pool 0.0 (kgC/m2) soil carbon, recalcitrant SOM (slowest) N_STATE (keyword) start of nitrogen state variable initialization block 0.0 (kgN/m2) litter nitrogen, labile pool 0.0 (kgN/m2) soil nitrogen, mineral pool OUTPUT_CONTROL (keyword - do not remove) outputs/TDE_out (text) prefix for output files 1 (flag) 1 = write daily output 0 = no daily output 0 (flag) 1 = monthly avg of daily variables 0 = no monthly avg 0 (flag) 1 = annual avg of daily variables 0 = no annual avg 1 (flag) 1 = write annual output 0 = no annual output 1 (flag) for on-screen progress indicator DAILY_OUTPUT (keyword) 3 (int) number of daily variables to output 516 0 epv.vwc (%) 43 1 wf.soilw_trans (kg m-̂2) 38 2 wf.canopyw_evap (kg m-̂2) ANNUAL_OUTPUT (keyword) 2 (int) number of annual output variables 545 0 annual maximum projected LAI 636 1 vegetation C END_INIT (keyword) indicates the end of the initialization file

BIOME-BGCExample Initialization File (cont.)

What if Some Met Data is Missing?

• Use a nearby weather station

• Use MT-CLIM to estimate radiation and humidity measurements from Tmax, Tmin– designed to handle complex terrain– uses a base station to calculate “site” data

• Use DAYMET (conterminous U.S. only)– uses several met stations surrounding site– data available from 1980-1997– takes into account complex terrain

-5

-4.5

-4

-3.5

-3

-2.5

-2

-1.5

-1

-0.5

0

0 10 20 30 40 50

soilw

PS

I

-5

-4.5

-4

-3.5

-3

-2.5

-2

-1.5

-1

-0.5

0

0 10 20 30 40 50

soilw

PS

I

-5

-4.5

-4

-3.5

-3

-2.5

-2

-1.5

-1

-0.5

0

0 10 20 30 40 50

soilw

PS

I

(%)

(MP

a)

Soil Class Silt loam Silt Loamβ-value -4.625 -3.84 -5.275VWC_sat 0.48 0.48 0.41PSI_sat -0.0073 -0.0078 -0.0013

BIOME-BGC 1Soil Water – Soil Water Potential Curves

1after Cosby et al., 1984

BIOME-BGC Environmental Controls on Canopy Conductance (Walker Branch Site)

M_total,sun,shade = (MPPFD,sun,shade * MTmin * MVPD * MPSI)

where multipliers range from 0 (full Gs reduction) to 1 (no effect)

Gs, sun,shade = Gs,max * M_total, sun,shade

M_TMIN

0

0.2

0.4

0.6

0.8

1

-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1

TMIN (degC)

M_VPD

0

0.2

0.4

0.6

0.8

1

900 1200 15001800 2100 24002700 3000 33003600 39004200

VPD (Pa)

M_PPFD

0

0.2

0.4

0.6

0.8

1

0 150 300 450 600 750 900 10501200135015001650

PPFD (umol/m2/s)

M_PSI

0

0.2

0.4

0.6

0.8

1

-0.5 -0.7 -0.8 -1 -1.1 -1.3 -1.4 -1.6 -1.7 -1.9 -2 -2.2 -2.3

PSI (MPa)

MODIS vs. Biome-BGC LAI

MODIS LAI vs BIOME BGC LAI Walker Branch, TN 2001 (Mixed Deciduous Hardwood Forest)

0

1

2

3

4

5

6

7

1 31 61 91 121 151 181 211 241 271 301 331 361

DOY

LA

I (m

2/m

2)

MODIS LAI BGC Proj LAI

Mixed Forest, Park Falls, WI2001

0

1

2

3

4

5

6

7

0 30 60 90 120 150 180 210 240 270 300 330 360

Julian Day

LA

I (m

2 m

-2)

Coll. 3 Coll. 4

Corn Cropland, Bondville, IL2001

0

1

2

3

4

5

6

7

0 30 60 90 120 150 180 210 240 270 300 330 360

Julian Day

LA

I (m

2 m

-2)

Coll. 3 Coll. 4

Loblolly Pine, Duke Forest, NC2001

0

1

2

3

4

5

6

7

0 30 60 90 120 150 180 210 240 270 300 330 360

Julian Day

LA

I (m

2 m

-2)

Coll. 3 Coll. 4

Deciduous Broadleaf Forest, Morgan Monroe State Forest, IN2001

0

1

2

3

4

5

6

7

0 30 60 90 120 150 180 210 240 270 300 330 360

Julian Day

LA

I (m

2 m

-2)

Coll. 3 Coll. 4

GPP Estimates of 5X5 km Grid

Tower Site Name

BO

RE

AS

_S

SA

_O

AB

OR

EA

S_

SS

A_

OB

SB

OR

EA

S_

SS

A_

OJP

BO

RE

AS

_N

SA

_1

96

3B

OR

EA

S_

NS

A_

19

81

BO

RE

AS

_N

SA

_1

98

9B

OR

EA

S_

NS

A_

19

98

BO

RE

AS

_N

SA

_O

BS

BO

RE

AS

_N

SA

_U

BS

Ca

mp

_R

ive

r_C

CC

am

p_

Riv

er_

MF

Ca

mp

_R

ive

r_Y

PB

lod

ge

ttN

iwo

t_R

idg

e_

1N

iwo

t_R

idg

e_

2G

ain

es_

Miz

eM

eto

lius_

Inte

rM

eto

lius_

Old

Me

toliu

s_

Yn

gW

ind

_R

ive

rS

an

tare

m_

67

Sa

nta

rem

_7

7S

an

tare

m_

83

NA

SA

_p

ine

Ga

ine

s_

AC

Me

r_B

leu

eN

orf

olk

Mo

rg_

Mo

nH

arv

ard

Sm

ith

so

nia

nW

alk

_B

ran

Ho

wla

nd

_H

Ho

wla

nd

_M

TH

ow

lan

d_

WT

N_

Mic

hS

ylv

an

iaU

MB

SD

uke

_H

dw

dD

uke

_P

ine

Du

ke

_O

pe

nL

ost_

Cre

ek

WL

EF

Will

ow

_C

ree

kN

rn_

Pla

ins

La

_P

az

Sky_

Oa

ks_

Old

SK

y_

Oa

ks_

Yn

gS

iste

rsB

lack_

Hill

sU

tah

_W

he

atg

rass

Uta

h_

Ju

nip

er

Uta

h_

Sa

ge

bru

sh

Gla

cie

r_L

ake

Ja

sp

er_

Rid

ge

Va

ira

_R

an

ch

To

nzi_

Ra

nch

Le

htb

rid

ge

Ko

nza

_P

rair

ieR

an

ne

lls_

gr

Ra

nn

ells

_u

nW

aln

ut_

Rvr

Fo

rt_

Pe

ck

Ce

rra

do

Su

ga

r_C

an

eC

am

p_

Bo

rde

nN

AS

A_

oa

kG

ain

es_

Dld

Bo

nd

evill

eM

an

ha

tta

nC

ub

_H

illM

ea

d_

irri

Me

ad

_ro

taM

ea

d_

rain

Srn

_G

rt_

Pla

in

GP

P (

gC

m-2)

0

500

1000

1500

2000

2500

3000ENF

EBF

DBF

Mixed Forest

Open Shrubland

Woody Savannas

Savannas

Grasslands

Cropland

Park Falls/WLEF, WIMODIS GPP (DAO) = 1497.36 gC m-2

MODIS GPP (TOW) = 1078.91 gC m-2

Tower GPP = 1036.52 gC m-2

Julian Day0 30 60 90 120 150 180 210 240 270 300 330 360

GP

P (

gC

m-2

d-1

)

0

2

4

6

8

10

12

Park Falls/WLEF, WI: Tower vs. DAO

Tavg-Tower

-20 -10 0 10 20 30

Tav

g-D

AO

-20

-10

0

10

20

30

Tmin-Tower

-30 -20 -10 0 10 20 30

Tm

in-D

AO

-30

-20

-10

0

10

20

30

VPDavg-Tower0 500 1000 1500

VP

Dav

g-D

AO

0

500

1000

1500

SWRad-Tower0 5 10 15 20 25 30

SW

Rad

-DA

O

0

5

10

15

20

25

30

Tower GPP (gC m-2 d-1)

0 500 1000 1500 2000

MO

DIS

GP

P (

gC

m-2

d-1

)

0

500

1000

1500

2000R2 = 0.61

DBF

ENF

Grassland

MIxed Forest

Open Shrubland

GPP from MOD17A2 Algorithm Default (DAO) Data As Input Meteorology

GPP from MOD17A2 Algorithm Tower Data As Input Meteorology

Tower GPP (gC m-2 yr-1)

0 500 1000 1500 2000

MO

D1

7A

2 G

PP

(g

C m

-2 y

-1)

0

500

1000

1500

2000R2 = 0.74

DBFENFGrasslandMixed ForestOpen Shrubland

Spring

Tower GPP (gC m-2)

0 100 200 300 400 500 600

MO

DIS

GP

P (

gC

m-2

)

0

100

200

300

400

500

600Winter

Tower GPP (gC m-2)

0 50 100 150 200 250 300

MO

DIS

GP

P (

gC

m-2

)

0

50

100

150

200

250

300

Autumn

Tower GPP (gC m-2)0 100 200 300 400 500

MO

DIS

GP

P (

gC

m-2

)

0

100

200

300

400

500Summer

Tower GPP (gC m-2)0 200 400 600 800 10001200

MO

DIS

GP

P (

gC

m-2

)

0

200

400

600

800

1000

1200

MOD17A2with

TowerMeteorology

DBFENFGrasslandMixed ForestOpen Shrubland

Spring

Tower GPP (gC m-2)0 100 200 300 400 500 600

MO

DIS

GP

P (

gC

m-2

)

0

100

200

300

400

500

600Winter

Tower GPP (gC m-2)0 50 100 150 200 250 300

MO

DIS

GP

P (

gC

m-2

)

0

50

100

150

200

250

300

Autumn

Tower GPP (gC m-2)0 100 200 300 400 500

MO

DIS

GP

P (

gC

m-2

)

0

100

200

300

400

500Summer

Tower GPP (gC m-2)0 200 400 600 800 1000 1200

MO

DIS

GP

P (

gC

m-2

)

0

200

400

600

800

1000

1200

MOD17A2with

Default (DAO)Meteorology

DBFENFGrasslandMixed ForestOpen Shrubland