Presented at the 3rd ICOS Science Conference in Prague, Czech Republic, 11-13 Sep 2018.

1. Disaggregating the impacts of human activities and
natural disturbances on reported greenhouse gas
emissions and removals in Canada’s managed forest
Werner A. Kurz
Natural Resources Canada
Canadian Forest Service
ICOS 2018
Prague, Sept 11 2018

2. Canadian Journal of Forest Research, 2018
http://dx.doi.org/10.1139/cjfr-2018-0176
Published yesterday!
Acknowledgements
The approach presented here is the result of the collaboration between the Canadian
Forest Service of Natural Resources Canada and the Pollutant Inventories and Reporting
Division of Environment and Climate Change Canada.
Many thanks also to:
Tony Lemprière, Karin Simonson, Scott Morken, Carolyn Smyth, Eric Neilson, Alison
Beatch and Ana Blondel
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3. Background
Managed Land Proxy (MLP):
 The IPCC Managed Land Proxy specifies that for greenhouse gas
reporting, emissions and removals from anthropogenic activities in
the land sector are those that occur on managed lands.
 But …
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4. IPCC 2010 Conclusions
 [T]he managed land proxy has several shortcomings
 For some countries and circumstances, use of the managed land
proxy may lead to emission and removal estimates dominated by
natural effects occurring on managed land and this would need to
be recognised where inventory estimates were used in estimates of
anthropogenic or management effects.
 [T]here is also a requirement to be able to identify the impact of
mitigation and management efforts even where these are
overwhelmed by the impacts of natural processes (e.g. natural
disturbances) or where these are obscured by inter-annual variations
in greenhouse gas fluxes.
 [F]urther work by the scientific community will result in more
mature approaches which can be assessed at a later date.
IPCC 2010, Revisiting the Use of Managed Land as a Proxy for Estimating National Anthropogenic
Emissions and Removals, eds: Eggleston H.S., Srivastava N., Tanabe K., Baasansuren J. Meeting
Report, 5 -7 May, 2009, INPE, São José dos Campos, Brazil, Pub. IGES, Japan 2010
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5. Motivation
To develop methods to separate in the reporting for the managed forest
 emissions and subsequent removals resulting from uncontrollable
natural disturbances such as wildfire, insects and storms from
 all other emissions and subsequent removals of greenhouse gases
resulting from human activities.
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6. 6
226 million ha
Managed Forest in Canada
Ogle et al. 2018, Carb. Bal. Mgmt.

7. 7
Fire Data
Most fires (area burned) caused
by lightning
Large variation in area burned
 0.23 – 7.6 Mha (1970 – 2015)
 Avg. 2.2 Mha/yr in managed and
unmanaged forests (NFDP)
Fire size
 3% of fires are >200 ha
 represent 97% of area burned
Efforts to control fires
 Costs of fire fighting: $500
million - $1 billion + per year

8. Carbon Budget Model of the
Canadian Forest Sector (CBM-CFS3)
 An operational-scale model of forest C dynamics.
 Builds on 25+ years of experience
 Allows assessment of forest management impacts on C
 Core model of Canada’s forest GHG reporting system
 Available at carbon.cfs.nrcan.gc.ca

9. CBM-CFS3: Data Integration Framework
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Land-use change data
Forest inventory and growth & yield data
Natural disturbance monitoring data
Forest management activity data
Ecological modelling parameters
CBM-CFS3

10. Hierarchy of Spatial Scales
Canada:
18 Reporting Zones
60 Reconciliation Units
634 Spatial Units
~ 3 million stands

11. Disaggregation of fluxes into natural and
anthropogenic components
 Stands affected by wildfires are transferred to the natural
disturbance component where the direct and post-fire emissions as
well as subsequent removals are reported for 40 to 100 years (burn
area weighted average 84.3 years). Note that this includes lands
burned prior to 1990.
 Stands affected by insect disturbances after 1990 causing more than
20% biomass mortality are transferred to the natural disturbance
component until biomass has regrown to the pre-disturbance levels.
 Once the respective age of commercial maturity or biomass thresholds
have been reached, the stands are transferred back to the
anthropogenic component.
 Forest management activities on naturally disturbed lands, e.g.,
salvage logging transfers the stand to the anthropogenic component.
 The sum of the two components is consistent with the reported forest
land (FL-FL) values in previous national forest GHG inventories.
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12. Areas with natural and anthropogenic impacts
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Area dominated by
natural disturbances:
54 Mha + 5%
Area dominated by
anthropogenic impacts:
172 Mha + 4%
Note that stands regrowing
following pre-1990 wildfires are
reported in the natural disturbance
component (until they reach the
age threshold).
The area totals of each component are fairly stable over time.

13. The natural disturbance component includes areas that
are sources and those that are sinks!
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Note that stands regrowing following pre-1990 wildfires are reported in
the natural disturbance component (until they reach the age threshold).

14. Total flux disaggregated to natural disturbance and
anthropogenic components
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15. Total flux disaggregated to natural disturbance and
anthropogenic components
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 The total is the managed forest flux (FL-FL) previously reported
under the Managed Land Proxy

16. The anthropogenic component is correlated with the
area affected by forestry activities
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 Forestry activities include clearcut logging, partical cutting and harvest
residue burning. Declining sink with increasing area disturbed.
 HWP = net emissions from the harvested wood product sector.

17. Discussion
 New reporting approach greatly reduces inter-annual variation in
emissions and focuses on impacts of forest management.
 Better reflects how changes in forest management and mitigation
efforts affect emissions
 But need to track both components, in particular as emissions from
wildfires have been increasing dramatically in recent years.
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18. Next Steps
 We are working on a spatially-explicit approach (1 ha resolution) at
the national scale using next generation tools (GCBM/FLINT).
 This approach will further increase “transparency” by documenting
areas that are reported in the two land components.
 And it will enable better documentation of the outcomes of
investments into forest sector mitigation activities.
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19. Landsat-derived annual time series of land-
cover change with attribution 1985 - 2011:
Source:Mike Wulder and Joanne White: http://forests.foundryspatial.com
Source: Hermosilla, T, M.A. Wulder, J.C. White, N.C. Coops, G.W. Hobart, Rem.Sens. Env., 170: 121-132.
http://dx.doi.org/10.1016/j.rse.2015.09.004
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20.  Disaggregating the impacts of natural disturbances in reported forest
sector GHG emission inventories improves the reporting of the
anthropogenic fluxes by reducing interannual variability and trends.
 This enables estimation of changes in emissions associated with
changes in forest management.
 Achieves greater transparency in reporting outcomes of mitigation
activities and investments in forest sector mitigation.
 Approach used since NIR2017.
Conclusions
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21. Thank you
Werner.Kurz@canada.ca
Paper at
http://dx.doi.org/10.1139/cjfr-2018-0176
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22. Decision tree for the separation of lands
 All stands in FL-FL are established either following a stand replacing
natural disturbance (ND) or following harvest.
Stand
established
following
ND?
Include in reporting
Stand
reached
pre ND
biomass
stocks?
>= 60
years since
ND?
Partial ND
with > 20%
mortality?
Exclude from reporting
Yes
Yes
No
No
Yes No
Has any
FM activity
occurred
since ND?
No
No
Yes
Yes
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23. IPCC methodological options
The 2010 IPCC report from the Expert
Meeting Report on “Revisiting the
Use of Managed Land as a Proxy for
Estimating National Anthropogenic
Emissions and Removals”:
 reviewed the MLP shortcomings,
 introduced five possible
approaches to estimating
anthropogenic emissions in the
land sector, and
 concluded that further work is
required before any alternative to
the MLP can be recommended.
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24. A new reporting approach
 We have modified the GHG estimation process in the CBM-CFS3
such that we can disaggregate emissions and subsequent removals in
eight land categories which we then sum to:
1. Emissions and removals on lands subject to forest management, and
2. Emissions and removals on lands affected by natural disturbances
(causing >20% biomass mortality).
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25. Outline
Background
Motivation
Methods
Results
Discussion
Conclusions
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26. Outline
Background
Motivation
Methods
Results
Discussion
Conclusions
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27. Outline
Background
Motivation
Methods
Results
Discussion
Conclusions
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28. Outline
Background
Motivation
Methods
Results
Discussion
Conclusions
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29. Outline
Background
Motivation
Methods
Results
Discussion
Conclusions
29