CMOS Bulletin SCMO
Vol. 45, No.2
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50th Anniversary: Interviews
a model called the Peatland Carbon Model (PCARS), published in 2001 and 2002. Subsequently, we
developed the McGill Wetland Model (MWM) as part of the development of the Canadian Earth System Model.
Just recently the scientists at the Canadian Centre for Climate Modelling and Analysis (CCCma) have
developed a full carbon land surface scheme based on this work and our subsequent peatland models (Wu et
al., 2016).
Our work with MWM is:
Wu, J. and N. T. Roulet (2014). "Climate change reduces the capacity of northern peatlands to absorb the
atmospheric carbon dioxide: The different responses of bogs and fens." Global Biogeochemical Cycles 28(10):
1005-1024.
Wu, J., N. T. Roulet, T. R. Moore, P. Lafleur and E. Humphreys (2011). "Dealing with microtopography of an
ombrotrophic bog for simulating ecosystem-level CO2 exchanges." Ecological Modelling 222(4): 1038-1047.
Wu, J., N. T. Roulet, M. Nilsson, P. Lafleur and E. Humphreys (2012). "Simulating the carbon cycling of
northern peatlands using a land surface scheme coupled to a wetland carbon model (CLASS3W-MWM)."
Atmosphere - Ocean 50(4): 487-506.
Wu, J., J. Sagerfors, M. Nilsson and N. Roulet (in review). "Six Years Simulation of Carbon Fluxes for a
Minerotrophic Mire (poor fen) in Northern Sweden using the McGill Wetland Model (MWM)." Journal of
Geophysical Research - Biogeoscience.
Most of the citations for our paper have been
from other modelling groups struggling to get
peatlands into their climate models and land
surface schemes.
Q: What do you think is the main message
from this body of research?
This work has told us that we should attempt to
keep peatlands intact and not affect their
hydrology if we want the carbon stored in them
to remain stored.
Q: What are your research plans for the
future?
We will continue to work on this problem. We
have developed a simpler version for running
long-term climate studies over the Holocene
and we continue to refine our McGill Wetland
Model. We are modifying it to include dynamic
vegetation and nitrogen and phosphorus
cycles.
Q: What are your hopes for land surface-
atmosphere research in general, in the
future?
I hope the models begin to incorporate land-
use change, because over 75% of terrestrial
landscapes are influenced in some way by
human activities and these changes make the
surface much more sensitive to change – i.e.
they lose their natural resilience.
Peatlands collapsing due to permafrost thaw.
CMOS Bulletin SCMO
Vol. 45, No.2
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50th Anniversary: Interviews
Q: Climate change is a political, social and environmental focal point of this century. What is your
opinion on what should be prioritized?
We need to build in resilience into all the decisions we make. Making the systems we rely on too brittle is
definitely going the wrong direction. We have to develop a way to incorporate adaptive management into all
our decisions. We manage far too linearly and ignore the fact that most of the system we rely on are complex
systems.
Reference
Wu, Y., D. L. Verseghy and J. R. Melton (2016). "Integrating peatlands into the coupled Canadian Land Surface Scheme (CLASS)
v3.6 and the Canadian Terrestrial Ecosystem Model (CTEM) v2.0." Geoscientific Model Development 9(8): 2639-2663.
About Nigel
Dr. Nigel T. Roulet is a James McGill Professor of Biogeosciences and Chair of
the Department of Geography, McGill University. Nigel’s research interests
focus on the interactions among hydrology, climatology, and ecosystems
processes in peatlands and forested catchments of the temperate, boreal, and
arctic regions. He has published over 200 scientific papers, book chapters and
monographs and was a contributing author to the 2nd through 4th scientific
assessments of climate change by the United Nation’s Intergovernmental
Panel on Climate Change. He is currently an Associate Editor of Global
Biogeochemical Cycles, Hydrological Processes, and Ecosystems and has
been an associate editor of Wetlands and the Journal of Geophysical Research
– Biogeosciences. In November 2014 Nigel was inducted as a member of the
Academy of Science of the Royal Society of Canada.
Paper Summary
Parameterization of peatland hydraulic properties for the Canadian Land Surface Scheme
: Letts, M.G.,
Roulet, N.T., Comer, N.T., Skarupa, M.R. Verseghy, D.L., 2000.
The authors write on the development of the organic soil parameters for the Canadian Land Surface Scheme
(CLASS). Most land surface packages for climate models assume the soils comprise sand, silt and clay, but
much of the northern latitudes are covered with soils that are largely made up of organic material. For
example, twelve percent of the land surface of Canada, and similar areas of Fennoscandinavia and Russia,
are covered with peatlands. The thermal and hydraulic properties of organic matter are very different than
those of mineral soils largely due to the high porosity of organic matter. At the time this was the first inclusion
of organic matter into a land surface package, but many climate models now use a similar parameters set.
Without the inclusion of organic matter in climate models the presence and absence of permafrost and the an-
nual thermal cycle cannot be simulated with any degree of confidence.