Use of Biome-BGC with the
ChEAS flux tower network
to address scaling issues
Faith Ann Heinsch
NTSG, School of Forestry
The University of Montana
ChEAS Meeting
July 1, 2003
The BIOME-BGC Terrestrial Ecosystem Process Model
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
BIOME-BGC
Major Features:
• 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)
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 Data
Latitude
Elevation
Slope/Aspect
Soil Depth
Soil Texture
Meteorological
Data
Air Temperature
Radiation
Precipitation
Humidity
Atmospheric CO2
Evaporation/
Transpiration
Temperature
H2O
H2O
Snow
Photosynthesis
Atmospheric
CO2
PSN
GR
Periodic
Input
Disturbance
-fire
-harvest
-grazing
-agriculture
MR
HR
Allocation to
New growth
Plant
C
H2O
Annual Input
N Deposition
N Fixation
LAI
Soil
H2O
Outflow
H2O
Daily - Annual
Photosynthesis
Evapotranspiration
Respiration
Absorbed PAR
Total
Respiration
C
Soil and Litter
Respiration
C
Daily - Annual
Allocation
Carbon,
Nitrogen
-leaf (LAI)
-stem
-coarse root
-fine root
N
Uptak
e
Litter
Soil Organic
Matter
Soil Mineral N
Atmospheric N
C Flux
N Flux
BIOME-BGC Eco-physiological Parameters
Biome-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
Integration
Surface
weather
database
Landcover
database
Simulation
Model Estimates of:
Outflow
Snow
Hydrograph
data
Rh
ET
LAI
Soil C
NEE
Flux tower
data
SNOTEL
data
Other inputs:
soils, elevation,
N-deposition
Biome
BGC
NPP
Biomass
Ancillary
measurements
at flux sites
Validation
fPAR
Satellite data
(MODIS,
AVHRR)
FIA, FHM,
Ecodata
(Inventory)
BIOME-BGC Simulated Daily Carbon and Water Exchange
(1Barrow Tussock / Wet Sedge Tundra Site, 2000)
Daily 1Meteorology
Daily C Budget
15
300
0.0060
10
250
0.0050
5
200
150
-5
100
-10
50
kg C m-2 day-1
0
cm
deg C
0.0040
0.0030
0.0020
0.0010
0.0000
-0.0010
-15
0
R_autotrophic
meteorological data obtained from Barrow W Post Station, 71.28N 156.76W
6
/2
12
/6
12
6
/1
11
7
/2
10
/7
10
17
9/
28
8/
GPP
8
8/
19
7/
29
6/
NEE
9
6/
20
5/
30
4/
10
4/
21
3/
1
3/
10
2/
21
1/
1
1/
2
/1
27
Snow_z
10
9/
12
28
13
29
14
Tsoil (Biome-BGC)
9/
8/
8/
7/
7/
29
14
30
15
1 Daily
6/
6/
5/
5/
Tav
-0.0020
R_heterotrophic
BIOME-BGC Simulated Cumulative Net Carbon Exchange
(1Barrow Tussock / Wet Sedge Tundra Site)
30
C sink (+)
20
10
g C m-2
0
-10
-20
-30
-40
C source (-)
-50
12
11
/1
/1
/1
2000
10
1
9/
1999
1
8/
1
7/
1997
1
6/
1 Daily
1
5/
1
4/
1
3/
1
2/
1
1/
1996
2001
meteorological data obtained from Barrow W Post Station, 71.28N 156.76W
2000 BIOME-BGC Cumulative Net C exchange
(Boreal ENF Forest)
Biome-BGC runs
for 4 areas in Alaska
250
C source (+)
200
150
gCm
-2
100
50
0
-50
-100
-150
Alaska Study Region
-200
C sink (+)
-250
12
11
10
/1
/1
/1
1
9/
1
8/
1
7/
1
6/
1
5/
1
4/
1
3/
1
2/
1
1/
Date
Bonanza Creek
Kenai
Coldfoot
Atigun
2001 BIOME-BGC Cumulative Net C exchange
(Boreal ENF Forest)
250
C source (+)
200
150
gCm
-2
100
50
Site Name
Kenai AK
Latitude
60.18N
Bonanza Creek AK
64.70N
-150
Coldfoot AK
67.15N
-250
Atigun AK
68.02N
0
-50
-100
-200
C sink (+)
12
11
10
Bonanza Creek
Kenai
Coldfoot
Atigun
/1
/1
/1
1
9/
1
8/
1
7/
1
6/
1
5/
1
4/
1
3/
1
2/
1
1/
Date
Biome-BGC Estimates of LAI
Park Falls, WI
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0
30
60
90
120 150 180 210 240 270 300 330 360
Day of Year
Biome-BGC Estimate of NPP for Park Falls, 2002
Maximum LAI = 3.3
NPP (gC m -2 d-1)
NPP (gC m -2 d-1)
Biome-BGC Estimate of NPP for Park Falls, 2001
Maximum LAI = 3.2
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0
30
60
90
120 150 180 210 240 270 300 330 360
Day of Year
Biome-BGC Estimates of NEE and GPP
Park Falls, WI
7.5
17.5
15.0
-1
GPP (gC m d )
2.5
-2
-2
-1
NEE (gC m d )
5.0
0.0
-2.5
-5.0
12.5
10.0
7.5
5.0
2.5
-7.5
0.0
0
60
120
180
240
300
360
0
60
120
180
Julian Day
Julian Day
Biome-BGC with DBF
Biome-BGC with Mixed Forest
Tower
240
300
360
Suggested Improvements
to
Biome-BGC
Simulations 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 Ecophysiological Parameters:
Evergreen Needleleaf Forest
value
1
1
1
1
----0.2
0.2
0.26
0.7
0.005
0.005
1.4
2.2
0.071
0.29
0.5
42.0
93.0
58.0
50.0
730.0
0.31
0.45
0.24
0.34
0.44
0.22
0.71
0.29
0.01
0.51
2.6
8.2
2.0
0.033
0.004
0.00004
units
(flag)
(flag)
(flag)
(flag)
(yday)
(yday)
(prop.)
(prop.)
(1/yr)
(1/yr)
(1/yr)
(1/yr)
(ratio)
(ratio)
(ratio)
(ratio)
(prop.)
(kgC/kgN)
(kgC/kgN)
(kgC/kgN)
(kgC/kgN)
(kgC/kgN)
(DIM)
(DIM)
(DIM)
(DIM)
(DIM)
(DIM)
(DIM)
(DIM)
(1/LAI/d)
(DIM)
(DIM)
(m2/kgC)
(DIM)
(DIM)
(m/s)
(m/s)
description
1 = WOODY 0 = NON-WOODY
1 = EVERGREEN 0 = DECIDUOUS
1 = C3 PSN 0 = C4 PSN
1 = MODEL PHENOLOGY 0 = USER-SPECIFIED
yearday to start new growth (when phenology flag = 0)
yearday to end litterfall (when phenology flag = 0)
transfer growth period as fraction of growing season
litterfall as fraction of growing season
annual leaf and fine root turnover fraction
annual live wood turnover fraction
annual whole-plant mortality fraction
annual fire mortality fraction
(ALLOCATION) new fine root C : new leaf C
(ALLOCATION) new stem C : new leaf C
(ALLOCATION) new live wood C : new total wood C
(ALLOCATION) new croot C : new stem C
(ALLOCATION) current growth proportion
C:N of leaves
C:N of leaf litter, after retranslocation
C:N of fine roots
C:N of live wood
C:N of dead wood
leaf litter labile proportion
leaf litter cellulose proportion
leaf litter lignin proportion
fine root labile proportion
fine root cellulose proportion
fine root lignin proportion
dead wood cellulose proportion
dead wood lignin proportion
canopy water interception coefficient
canopy light extinction coefficient
all-sided to projected leaf area ratio
canopy average specific leaf area (projected area basis)
ratio of shaded SLA to sunlit SLA
fraction of leaf N in Rubisco
maximum stomatal conductance (projected area basis)
cuticular conductance (projected area basis)
BIOME-BGC
Example Initialization
File
MET_INPUT
(keyword) start of meteorology file control block
metdata/TDE.mtc41 meteorology input filename
4
(int)
header lines in met file
RESTART
(keyword)
1
(flag)
restart file
0
(flag)
restart file
0
(flag)
restart/TDE_n.endpoint
restart/TDE.endpoint
TIME_DEFINE
8
8
1993
0
simulation
6000
simulation)
CLIM_CHANGE
0.0
0.0
1.0
1.0
1.0
start of restart control block
1 = read restart file
0 = don't read
1 = write restart file
0 = don't write
1 = use restart metyear
input restart filename
output restart filename
0 = reset metyear
(keyword - do not remove)
(int)
number of meteorological data years
(int)
number of simulation years
(int)
first simulation year
(flag)
1 = spinup simulation
0 = normal
(int)
maximum number of spinup years (if spinup
(keyword - do not remove)
(deg C)
offset for Tmax
(deg C)
offset for Tmin
(DIM)
multiplier for Prcp
(DIM)
multiplier for VPD
(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
0.765
fraction)
28.0
64.0
8.0
290.0
35.95
0.2
0.0005
0.0004
(keyword) start of site physical constants block
(m)
effective soil depth (corrected for rock
(%)
sand percentage by volume in rock-free soil
(%)
silt percentage by volume in rock-free soil
(%)
clay percentage by volume in rock-free soil
(m)
site elevation
(degrees) site latitude (- for S.Hem.)
(DIM)
site shortwave albedo
(kgN/m2/yr) wet+dry atmospheric deposition of N
(kgN/m2/yr) symbiotic+asymbiotic fixation of N
BIOME-BGC
Example Initialization
File (cont.)
RAMP_NDEP
0
2099
0.0001
EPC_FILE
dbf.epc
(keyword - do not remove)
(flag) do a ramped -deposition
N
run? 0=no, 1=yes
(int) reference year for industrial N deposition
(kgN/m2/yr) industrial N deposition value
(keyword- do not remove)
(file) TDE DBF ecophysiological constants
W_STATE
0.0
0.5
(keyword) start of water state variable initialization block
(kg/m2)
water stored in snowpack
(DIM)
initial soil water as a proportion ofturation
sa
C_STATE
0.001
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
(keyword) start of carbon state variable initialization block
(kgC/m2) first
-year maximum leaf carbon
(kgC/m2) first
-year maximum stem carbon
(kgC/m2) coarse woody debris carbon
(kgC/m2) litter carbon, labile pool
(kgC/m2) litter carbon, unshielded cellulose pool
(kgC/m2) litter carbon, shielded cellulose pool
(kgC/m2) litter carbon, lignin pool
(kgC/m2) soil carbon, fast microbial recycling pool
(kgC/m2) soil carbon, medium microbial recycling pool
(kgC/m2) soil carbon, slow microbial recycling pool
(kgC/m2) soil carbon, recalcitrant SOM (slowest)
N_STATE
0.0
0.0
(keyword) start of nitrogen state variable initialization block
(kgN/m2) litter nitrogen, labile pool
(kgN/m2) soil nitrogen, mineral pool
OUTPUT_CONTROL
outputs/TDE_out
1
(flag) 1 =
0
(flag) 1 =
0
(flag) 1 =
1
(flag) 1 =
1
(flag) for
(keyword- do not remove)
(text) pr
efix for output files
write daily output
0 = no daily output
monthly avg of daily variables 0 = no monthly avg
annual avg of daily variables
0 = no annual avg
write annual output 0 =
no annual output
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
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
BIOME-BGC 1Soil Water –
Soil Water Potential Curves
0
-0.5
PSI (MPa)
-1
-1.5
-2
-2.5
-3
-3.5
-4
-4.5
-5
0
10
30
30
20
40
40
50
50
soilw (%)
Soil Class
β-value
VWC_sat
PSI_sat
Silt loam
-4.625
0.48
-0.0073
Silt
-3.84
0.48
-0.0078
Loam
-5.275
0.41
-0.0013
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_VPD
1
0.8
0.6
0.4
M_PPFD
M_PSI
0.2
1
1
0
900 1200 1500 1800 2100 2400 2700 3000 3300 3600 3900 4200
0.8
0.8
VPD (Pa)
0.6
0.6
0.4
0.4
0.2
0.2
M_TMIN
0
-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)
0
1
0
150 300 450 600 750 900 10501200135015001650
PPFD (umol/m2/s)
0.8
0.6
0.4
0.2
0
-10
-9
-8
-7
-6
-5
-4
TMIN (degC)
-3
-2
-1
0
1
MODIS vs. Biome-BGC LAI
MODIS LAI vs BIOME BGC LAI
Walker Branch, TN 2001 (Mixed Deciduous Hardwood Forest)
7
6
LAI (m2/m2)
5
4
3
2
1
0
1
31
61
91
121
151
181
211
241
271
DOY
MODIS LAI
BGC Proj LAI
301
331
361
Mixed Forest, Park Falls, WI
2001
7
6
LAI (m2 m-2)
5
4
3
2
1
0
0
30
60
90
120
150
180
210
Julian Day
Coll. 3
Coll. 4
240
270
300
330
360
Corn Cropland, Bondville, IL
2001
7
6
LAI (m2 m-2)
5
4
3
2
1
0
0
30
60
90
120
150
180
210
Julian Day
Coll. 3
Coll. 4
240
270
300
330
360
Loblolly Pine, Duke Forest, NC
2001
7
6
LAI (m2 m-2)
5
4
3
2
1
0
0
30
60
90
120
150
180
210
Julian Day
Coll. 3
Coll. 4
240
270
300
330
360
Deciduous Broadleaf Forest, Morgan Monroe State Forest, IN
2001
7
6
LAI (m2 m-2)
5
4
3
2
1
0
0
30
60
90
120
150
180
210
Julian Day
Coll. 3
Coll. 4
240
270
300
330
360
0
BOREAS_SSA_OA
BOREAS_SSA_OBS
BOREAS_SSA_OJP
BOREAS_NSA_1963
BOREAS_NSA_1981
BOREAS_NSA_1989
BOREAS_NSA_1998
BOREAS_NSA_OBS
BOREAS_NSA_UBS
Camp_River_CC
Camp_River_MF
Camp_River_YP
Blodgett
Niwot_Ridge_1
Niwot_Ridge_2
Gaines_Mize
Metolius_Inter
Metolius_Old
Metolius_Yng
Wind_River
Santarem_67
Santarem_77
Santarem_83
NASA_pine
Gaines_AC
Mer_Bleue
Norfolk
Morg_Mon
Harvard
Smithsonian
Walk_Bran
Howland_H
Howland_MT
Howland_WT
N_Mich
Sylvania
UMBS
Duke_Hdwd
Duke_Pine
Duke_Open
Lost_Creek
WLEF
Willow_Creek
Nrn_Plains
La_Paz
Sky_Oaks_Old
SKy_Oaks_Yng
Sisters
Black_Hills
Utah_Wheatgrass
Utah_Juniper
Utah_Sagebrush
Glacier_Lake
Jasper_Ridge
Vaira_Ranch
Tonzi_Ranch
Lehtbridge
Konza_Prairie
Rannells_gr
Rannells_un
Walnut_Rvr
Fort_Peck
Cerrado
Sugar_Cane
Camp_Borden
NASA_oak
Gaines_Dld
Bondeville
Manhattan
Cub_Hill
Mead_irri
Mead_rota
Mead_rain
Srn_Grt_Plain
GPP (gC m-2)
GPP Estimates of 5X5 km Grid
3000
ENF
EBF
DBF
2500
Mixed Forest
Open Shrubland
Woody Savannas
2000
Savannas
Grasslands
Cropland
1500
1000
500
Tower Site Name
Park Falls/WLEF, WI
MODIS GPP (DAO) = 1497.36 gC m-2
MODIS GPP (TOW) = 1078.91 gC m-2
Tower GPP = 1036.52 gC m-2
12
GPP (gC m-2 d-1)
10
8
6
4
2
0
0
30
60
90
120
150
180
210
Julian Day
240
270
300
330
360
30
30
20
20
Tmin-DAO
Tavg-DAO
Park Falls/WLEF, WI: Tower vs. DAO
10
0
-10
0
-10
-20
-20
-20
-10
0
10
20
-30
-30
30
Tavg-Tower
-20
1000
500
-10
0
10
20
30
25
30
Tmin-Tower
30
SWRad-DAO
1500
VPDavg-DAO
10
25
20
15
10
5
0
0
0
500
1000
VPDavg-Tower
1500
0
5
10
15
20
SWRad-Tower
GPP from MOD17A2 Algorithm
Default (DAO) Data As Input Meteorology
R2 = 0.61
-2
-1
MODIS GPP (gC m d )
2000
1500
1000
DBF
ENF
Grassland
MIxed Forest
Open Shrubland
500
0
0
500
1000
1500
Tower GPP (gC m-2 d-1)
2000
2000
R2 = 0.74
-2
-1
MOD17A2 GPP (gC m y )
GPP from MOD17A2 Algorithm
Tower Data As Input Meteorology
1500
1000
DBF
ENF
Grassland
Mixed Forest
Open Shrubland
500
0
0
500
1000
1500
Tower GPP (gC m-2 yr-1)
2000
Winter
Spring
600
MODIS GPP (gC m )
250
-2
-2
MODIS GPP (gC m )
300
200
150
100
50
0
MOD17A2
with
Tower
Meteorology
500
400
300
200
100
0
0
50 100 150 200 250 300
0
-2
Tower GPP (gC m )
Tower GPP (gC m-2)
Summer
Autumn
500
-2
MODIS GPP (gC m )
-2
MODIS GPP (gC m )
1200
100 200 300 400 500 600
1000
800
600
400
200
0
400
DBF
ENF
Grassland
Mixed Forest
Open Shrubland
300
200
100
0
0
200 400 600 800 1000 1200
Tower GPP (gC m-2)
0
100
200
300
400
Tower GPP (gC m-2)
500
Winter
Spring
600
MODIS GPP (gC m )
250
-2
-2
MODIS GPP (gC m )
300
200
150
100
50
0
MOD17A2
with
Default (DAO)
Meteorology
500
400
300
200
100
0
0
50
100 150 200 250 300
0
-2
-2
Tower GPP (gC m )
Autumn
500
MODIS GPP (gC m )
1000
-2
-2
MODIS GPP (gC m )
Tower GPP (gC m )
Summer
1200
100 200 300 400 500 600
800
600
400
200
0
400
DBF
ENF
Grassland
Mixed Forest
Open Shrubland
300
200
100
0
0
200 400 600 800 1000 1200
-2
Tower GPP (gC m )
0
100
200
300
400
-2
Tower GPP (gC m )
500