This presentation was presented during the 2 Parallel session on Theme 3.1, Managing SOC in: Soils with high SOC – peatlands, permafrost, and black soils, of the Global Symposium on Soil Organic Carbon that took place in Rome 21-23 March 2017. The presentation was made by Ms. Michelle Garneau from Université du Québec á Montréal - Canada, in FAO Hq, Rome

1. Quantifying terrestrial ecosystem carbon stocks for
future GHG mitigation, sustainable land-use planning
and adaptation to climate change,
Québec, Canada
Michelle Garneau, Professor
Simon van Bellen, Associate professor
Geotop Research Center
Université du Québec à Montréal, Montréal, Canada
Global Symposium on Soil Organic Carbon
FAO, Rome – 22 March 2017

2. Distribution of peatlands in the Canadian boreal belt
after Tarnocai, 2011
0
50,000
100,000
150,000
200,000
250,000
300,000
350,000
400,000
British-Columbia
Alberta
Saskatchewan
Manitoba
Ontario
Quebec
New-Brunswick
Nova-Scotia
Prince-Edward-…
Newfoundland-…
Yukon
Northwest-…
Nunavut
Area (km²)
Frozen Fens
Frozen Bogs
Unfrozen Fens
Unfrozen Bogs
• 2nd largest country (9.9 million km2)
• Peatlands: 13-17% of terrestrial surface
• ≥ 150 Gt of carbon (Tarnocai, 2011)
• 64% in the boreal and 33% in the
subarctic regions

3. Northern ecosystem carbon cycle
Global boreal forests store ~272
Gt C (Pan et al., 2011)
• Carbon accumulation is
mostly cyclic
• Large emissions of CO2 and
CH4 linked with natural
disturbance (fires) and
human intervention
Northern peatlands represent
500-600 Gt C or ~30% of the
terrestrial carbon stock (Yu, 2012;
Turetsky et al., 2015)
• Accumulation mostly since
the last glaciation
• Sinks of carbon, but
sources of methane (CH4)
Peatlands have had a net cooling effect on the global climat during the Holocene, removing
CO2 from the atmosphere: -0.22 to -0.56 W m-2 (Frolking & Roulet, 2007)2007)
O2
CO2
C
C
C
C
Photosynthesis
CO2
C
Forest stand
CH4
C
C
C
C C
C
Forest stand life
cycle = decades
to a few centuries
C C
CH4
CC
CC
CC
C
Peatland
CH4
CH4CO2
Photosynthesis
CO2
C
C
C
C
C
C
O2
C
Peatland life cycle
= millennia
CO2
CC

4. Carbon stock inventory
• Agriculture Canada: Tarnocai, 2011
• Natural Resources Canada (CFS): CaMP for
CBM-CFS
• Ministère Développement durable,
Environnement et de la Lutte contre les
changements climatiques (MDDELCC)
• Québec:
• First extensive carbon stock inventory
• Plan Nord: harmonizing the economic,
social and environmental aspects on the
northern territory
• 2035: 50 % territory for conservation
purposes: conservation target
• Biodiversity
• Carbon stocks for climate change
mitigation (Climate Change Action
Plan 2013-2020)GoogleEarth

5. Temporal trends in carbon accumulation
Garneau et al., 2014
Overall slowdown of carbon accumulation linked with Neoglacial cooling,
based on the analysis of six ecoregions and various peatland types
Insolation June (W m-2)
Carbon accumulation rate

6. Spatial trends in carbon accumulation
• Spatial database from the
MDDELCC Ecological
Inventory: 92 natural regions,
average area - 17 660 km2
• Peatland carbon density
(kg C m-2) for 30 sites
0 200100 Kilometers
N

7. Carbon density modelling including environmental variables
Cumulative shortwave
radiation
Growing-
season
precipitation
Latitude
Climatic/spatial variables:
• Mean annual temperature
• Annual precipitation
• Growing-season precipitation
• Growing-degree days above 0ºC
• Growing-season cumulative shortwave radiation
• Growing-season average shortwave radiation
• Latitude
Predictive model: r2 of
0.55 and RMSE of
38.6 kg C m-2

8. Correcting bias created by the use of central cores
Mean = 0.65

9. est soil carbon density (kg C m-2) and environmental variables
Carbon density quantified
separately for organic and mineral
horizons
• managed forests: 284 soil pedons
• unmanaged forests: 52
observations of carbon density
Organic horizons more vulnerable to
release, through fire and climate
change

10. Peatlands Forest soils
Boreal carbon density patterns in Quebec
Carbon stock:
7.9 Gt C (5.6-10.6)
Total area:
92 500 km2
(MDDELCC, 2016)
Mean carbon density:
85.5 kg C m-2
Carbon stock:
6.2 Gt C
Total area:
416 800 km2 of
managed forests and
139 700 km2 of
unmanaged forests
(MDDELCC, 2016)
Mean carbon density:
10.9 kg C m-2, 11.7 kg
m-2 in managed forests
and 9.4 kg m-2 in
unmanaged forests

11. Peatland carbon stocks exceed forest soil stocks,
despite their lower areal coverage
6.7 5.6
85.5
5.0 3.9
PEATLANDS MANAGED
FORESTS
UNMANAGED
FORESTS
CARBONDENSITY(KGM-2)
2.79
0.78
7.91 2.10
0.54
PEATLANDS MANAGED
FORESTS
UNMANAGED
FORESTS
CARBONSTOCK(GT)
Mineral horizon Organic horizon

12. +6ºC
+3ºC
+1.5 - 2ºC
Hiver
+0.3 mm jr-1
-0.3 mm jr-1
Longer growing seasons and positive moisture balance: increased
potential for carbon sequestration
Warming and negative moisture balance: decreased potential for carbon
sequestration
Soil moisture balance (P-ET)Temperature
+2.5ºC
Projected changes in summer climate and
peatland carbon dynamics (2041-2070)
Ouranos, 2016

13. +3ºC
+1,5 - 2ºC +0,3 mm jr-1
-0,3 mm jr-1
Soil moisture balance (P-ET)Temperature
+2,5ºC
Climate change and permafrost peatlands
Permafrost degradation:
• Palsa collapse
• Increased emission of CH4
• Gradual drying, return of
xerophilous Sphagnum moss
• Return of net accumulation
~50-70 years until return of
net carbon accumulation
(Turetsky et al., 2007,
Sanderson, 2016, Lamarre
et al., 2012)
Ouranos, 2016

14. +6ºC
Hiver
Warming and negative moisture balance: increased fire
severity, especially in western Quebec
Projected changes in summer climate and
forest soil carbon (2041-2070)
+3ºC
+1,5 - 2ºC +0,3 mm jr-1
-0,3 mm jr-1
Soil moisture balance (P-ET)Temperature
+2,5ºC
Ouranos, 2016

15. Peatland carbon density
(kg C m-2) is 7 to 8 times
higher than those of the
forest soil: 85.5 kg C m-2
vs. 10.9 kg C m-2
The total boreal forest soil and
peatland carbon stock is
estimated at 14.1 Gt C
Carbon stocks vs. anthropogenic emissions

16. • The Quebec boreal forest soil and peatland carbon stock is estimated at 14.1 Gt C
• At 7.9 Gt C, peatlands represent more than half of this stock
• Boreal forest soils store around 6.2 Gt C, with 79% in managed forest soils (vs. 21% in
unmanaged forest soils) and 57% in mineral horizons (vs. 43% in organic horizons)
• Future GHG mitigation policies and sustainable land-use planning should be
supported by an increase in investments in peatland, wetland and forest
conservation, management and rehabilitation to limit greenhouse gas emissions
Thank you for your attention