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Perspectives on modeling biogeochemistry of agriculture on drained peat soils
Narasinha Shurpali
Biogeochemistry research group Department of Environmental Science
A presentation at the Nordic seminar on peatland drainage and environment in Kuopio on 05.11.2013
Key advantages to ecosystem modeling
• Systematically organize our current knowledge of the ecology of the ecosystems
• Quantitative estimates that we can test in the field.
• We can use a model to get a glimpse of the future and help prepare for it.
• These models will challenge us to think more specifically about the effects of climate change
on boreal ecosystems
• All the above are possible once underlying ecological principles have been validated in the model
by successful field tests
05.11.2013 Modelling GHG emissions on organic soils/Shurpali 2
DISCLAIMER: These perspectives are from a model user point of view and NOT of a model developer
9.12.2013 3 Modelling GHG emissions on organic soils/Shurpali
Off-the-shelf ecosystem biogeochemical models • DNDC family of models • CoupModel • APSIM • Daycent • Ecosse
CoupModel - Underlying principles
Royal Institute of Technology, Sweden Dr. Per-Erik Jansson Mineral and Organic soils
9.12.2013 Esityksen nimi / Tekijä 5
CoupModel – Plant growth and C and N dynamics
9.12.2013 Esityksen nimi / Tekijä 6
APSIM was developed to simulate biophysical processes in agricultural systems, particularly as it relates to the economic and ecological outcomes of management practices in the face of climate risk Developed by CSIRO Australia Mineral Soils
Climate
- Temperature - Precipitation - N deposition
Soil properties - Texture - Organic matter - Bulk density - pH
Management - Crop rotation - Tillage - Fertilization - Manure use - Irrigation - Grazing
DNDC
1. Soil water movement
2. Plant-soil C dynamics
3. N transformation
Availability of water, NH4, NO3, and DOC
Used by
soil microbes
Used by plants
Emissions of
N2O, NO, N2, CH4 and CO2
Growth of crop biomass
Competition
DNDC bridges between inputs and outputs
INPUT INPUT INPUT OUTPUT PROCESSES
N leaching
A snaposhot of the DNDC model in action
05.11.2013 Modelling GHG emissions on organic soils/Shurpali 9
Grassland site in Jokioinen
05.11.2013 Modelling GHG emissions on organic soils/Shurpali 10
Afforested agricultural soil, Birch, 18 year old stand, 50-90 cm peat depth, C:N 12 High emitter : 21 kg N/ ha
05.11.2013 Modelling GHG emissions on organic soils/Shurpali 11
Abandoned agricultural soil in the Kannus region, 30 cm peat depth, C:N 18 High emitter : 3.4 kg N/ ha
05.11.2013 Modelling GHG emissions on organic soils/Shurpali 12
Year. Day of year
2004 2005 2006 2007 2008
GP
P,
kg C
ha
-1 d
-1
-250
-200
-150
-100
-50
0
50
GPP_Field
GPP_DNDC
Year, Day of year
2004 2005 2006 2007 2008
TE
R,
kg C
ha
-1 d
-1
0
20
40
60
80
100
120
TER_field
TER_DNDC
Year, Day of year
2004 2005 2006 2007 2008
NE
E,
kg C
ha
-1 d
-1
-120
-100
-80
-60
-40
-20
0
20
40
NEE_field
NEE_DNDC
05.11.2013 Modelling GHG emissions on organic soils/Shurpali 13
Year, Day of year
2004 2005 2006 2007 2008
Soi
l T 5
cm
-15
-10
-5
0
5
10
15
20
25
ST5_DNDC
ST5_field_est
year, Day of year
2004 2005 2006 2007 2008
Soi
l T, 15
/16
cm d
epth
-5
0
5
10
15
20
ST15_DNDC
ST16_field
Year, Day of year
2004 2005 2006 2007 2008
Soi
l T, 3
0/32
cm
dee
p
-2
0
2
4
6
8
10
12
14
16
ST30_DNDC
ST32_field
Year, Day of year
2004 2005 2006 2007 2008
Soi
l T, 48
/50
cm d
eep
0
2
4
6
8
10
12
14
ST50_DNDC
ST48_Fld_Est
05.11.2013 Modelling GHG emissions on organic soils/Shurpali 14
year, Day of year
2004 2005 2006 2007 2008
VM
C-F
ield
, W
FP
S-M
odel
0.0
0.2
0.4
0.6
0.8
1.0
WFPS_DNDC
VMC2_field
05.11.2013 Modelling GHG emissions on organic soils/Shurpali 15
Year, Day of year
2004 2005 2006 2007 2008
CH
4 E
mis
sio
ns, kg
C h
a-1
d-1
-20
0
20
40
60
80
100
CH4_Field
CH4_DNDC
05.11.2013 Modelling GHG emissions on organic soils/Shurpali 16
Year, Day of year
2004 2005 2006 2007 2008
N2O
em
issio
ns, g
N h
a-1
d-1
0
10
20
30
40
N2O
Em
issio
ns, g
N h
a-1
d-1
0
1000
2000
3000
4000
5000
N2O_Field
N2O_DNDC
05.11.2013 Modelling GHG emissions on organic soils/Shurpali 17
Year, Day of year
2004 2005 2006 2007 2008
Sno
wd
ep
th, m
m
0
200
400
600
800
SnowDepth_field
SnowDepth_DNDC
05.11.2013 Modelling GHG emissions on organic soils/Shurpali 18
J. Gong et al. / Agricultural and Forest Meteorology 180 (2013) 225– 235
05.11.2013 Modelling GHG emissions on organic soils/Shurpali 19
J. Gong et al. / Agricultural and Forest Meteorology 180 (2013) 225– 235
05.11.2013 Modelling GHG emissions on organic soils/Shurpali 20
• DNDC performance – soil climate, CO2 exchange
• DNDC responded well in terms of N2O emissions changes in response to the prevailing climatic conditions during the growing season
• DNDC mimicked observed N2O emission patterns as affected by fertilizer applications
• Nonetheless, the timing and magnitudes of emission dynamics were different enough to cause large differences in the observed and modeled seasonal sums
• It failed to correctly reproduce winter time soil conditions and associated winter emissions
• In view of Koponen et al. (2006a and 2006b) and Marja Maljanen’s work on winter time N2O emissions from drained organic soils, such a model behavior could underestimate N2O emissions by as much as 90%
• Finland has a wealth of data from different types of organic soils. The scope for utilising these data for model validation is wide. A research programme in itself. THANKS
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