By Åsa Kasimir, Jessica Coria, Hongxing He, Xiangping Liu, Anna Nordén and Magnus Svensson, at the young researchers meeting on multifunctional landscapes, Gothenburg June 7-8, 2016.

1. AN ECOLOGICAL–ECONOMIC ANALYSIS OF CLIMATE
MITIGATION THROUGH REWETTING PREVIOUSLY
DRAINED HEMIBOREAL PEATLANDS
Åsa Kasimir, Jessica Coria, Hongxing He, Xiangping Liu, Anna Nordén and
Magnus Svensson
Department of Earth Sciences
asa.kasimir@gu.se
Biodiversity and Ecosystem
services in a Changing Climate

2. 11 Tg CO2e yr-1 18 Tg CO2e yr-1
≈
≈

3. Wetlands store carbon and plant
nutrients
But release some methane
C
N
N2O ≈ zero
CH4
CO2
Peat
asa.kasimir@gu.se

4. When drained; carbon dioxide and
nitrous oxide emissions
• Aerated soil makes agriculture and forestry
possible.
• Decomposition of peat, the source for CO2 and
N2O emission.
• Continues as long as the soil is drained or all
peat has disappeared.
C
N
Ditch CO2 N2O
asa.kasimir@gvc.gu.se

5. • Soils contain three times more C than living biomass.
• Peatlands contain nearly 30% of the world’s soil carbon
covering 3% of the earth’s land area.
• Land use contribute 24% of anthropogenic GHG
emissions

6. Skogaryd
• Spruce forest on drained soil earlier used for agriculture
• >1 m deep fertile peat
• A lot of measurement data

7. Climate data - drives the modell
• Precipitation
• Air temperature
• Relative humidity
• Global radiation
• Wind speed
Calibration; data 2007-2009
• Net solar radiation
• NEE
• Soil emission N2O and CO2
• Soil temperature
• Soil water
• GWL
• Soil energy flow
Skogaryd, drained peat soil CoupModell
Water and energy flow
Plant module
C and N flow module
P.-E. Jansson & D.S. Moon 2001.
P.-E. Jansson 2012.
Hongxing He et al. 2016. Factors
controlling Nitrous Oxide emission from a
spruce forest ecosystem on drained
organic soil, derived using the
CoupModel. Ecological Modelling

8. Simulated total GHG balance for the forest ecosystem from 1951 to
2011 and extended to 2031. Note that the GHG balance presented
assumes no final harvest.
Hongxing He et al. (2016) Forests on drained agricultural
peatland are potentially large sources of greenhouse gases –
insights from a full rotation period simulation.
Biogeosciences 13, 2305–231

9. Four scenarios modelled by Coup
aim; to assess emissions and economy
•80 year rotation
1. Spruce, GWL ~40 cm depth (business as usual scenario),
2. Salix, GWL ~20 cm depth,
3. Reed Canary Grass, GWL ~10 cm depth,
4. Rewetting, GWL in the soil surface (~0 cm)

10. Vegetation Norway spruce Willow RCG Wetland
Average GWL set cm -40 -20 -10 0
Average GWL obtained -48 -22 -13 0
Biomass growth
m3 ha-1 yr-1
Mg CO2 ha-1 yr-1
15.9
11.0
13.6
10.0
26.6
9.7 1.31
Emissions: Mg CO2eq ha-1 yr-1
CO2 emission 20.1 13.1 6.4 1
N2O emission 3.0 2.4 <0.01 0
CH4 emission (0.2) (0.2) (0.2) 2.6
Leaching:
Leaching of nitrate kg N ha-1 yr-1 32 6.9 5.1 0
Leaching of DON kg N ha-1 yr-1 8.7 4.5 3.7 0
Leaching N into N2O Mg CO2eq ha-1 yr-1 0.3 0.1 0.1
Leaching of DOC Mg CO2 ha-1 yr-1 0.11 0.04 0.01 ~0
Mineralized DOC in lakes2 Mg CO2 ha-1 yr-1 0.2 0.1 0.02
Total GHG emissions3 Mg CO2eq ha-1 yr-1 24 16 6.7 1.3
CoupModel simulation results.

11. GHG mitigation by rewetting and vegetation change
Year
1950 1970 1990 2010 2030
MgCO2ha
-1
-2000
-1500
-1000
-500
0
Spruce -40 cm groundwater level
Willow -20 cm groundwater level
Reed Caney Grass - 10 cm groundwater level
Rewetting to 0 cm groundwater level
by
-33%
by
-72%
by
-89%
fromsprucetowillow
fromsprucetoRCG
fromsprucetorewet
Modelled accumulated soil carbon loss

12. 12
Economics
Products sold on the market minus management cost 3384 1847 1697 0
Concrete /steel replacement
Replacement of fossil fuels
1250
530
0
1031
0
704
0
0
Ecosystem Services - Biodiversity 0 0 0 1517
CO2 emission -4371 -3248 -1814 96
CH4 emission -46 -46 -46 -463
N2O emission -741 -660 -1 0
N2O due to nitrate leaching -39 -8 -5 0
CO2 from DOC leaching to water -89 -33 -5 0
Cost of management of ditches/ restoring wetland -14 -14 -14 -404
Net Annuity Value (SEK ha-1 year-1) -136 -1131 516 746
Benefits (SEK ha-1 year-1) (+)
Costs (SEK ha-1 year-1) (-)
Marginal damage costs, Social Cost of Carbon SCC= 175.2 SEK ton-1 CO2eq

13. GWL, cm
0 10 20 30 40 50 60
BiomassgrowthorGHGsoilemission,MgCO2eqha
-1
yr
-1
0
5
10
15
20
25
30
35
Spruce growth
Willow growth
RCG growth
Spruce soil GHG
Willow soil GHG
RCG soil GHG
GWL Sensitivity of Biomass and GHG emission
for scenario 1, 2 and 3

14. Emission factors, IPCC default and estimated in
this project
IPCCEF
IPCCEF
IPCC EF are for drained wetlands in Temperate climate

15. Where to find forest
on drained peat:
Ernfors et al. 2007
In Sweden; 500 kha forest on fertile
drained peat with a peat depth larger
than 30 cm, like in Skogaryd.
Based on our modeled GHG emissions
these areas emit 12 Tg CO2eq every
year, possible to reduce by 33%, 72% or
89%.
Wetlands; 1/5 of Sweden area

16. 11 Tg CO2e yr-1 18 Tg CO2e yr-1
≈
≈
1.2 Mha forest and
200 kha agriculture