Perspectives on modeling biogeochemistry of …Perspectives on modeling biogeochemistry of...

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


Grassland site in Jokioinen


Afforested agricultural soil, Birch, 18 year old stand, 50-90 cm peat depth, C:N 12 High emitter : 21 kg N/ ha


Abandoned agricultural soil in the Kannus region, 30 cm peat depth, C:N 18 High emitter : 3.4 kg N/ ha


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


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


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


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


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


Year, Day of year

2004 2005 2006 2007 2008

Sno

wd

ep

th, m

m

0

200

400

600

800

SnowDepth_field

SnowDepth_DNDC


J. Gong et al. / Agricultural and Forest Meteorology 180 (2013) 225– 235


• 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

Perspectives on modeling biogeochemistry of …Perspectives on modeling biogeochemistry of...

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