TECHNICAL ASPECTS OF THE FOREST
CARBON INVENTORY OF THE
UNITED STATES: RECENT PAST AND
NEAR FUTURE
Christopher W. Woodall, Research Forester, U.S. Forest Service, St. Paul, MN
GRANT DOMKE
SEAN HEALEY
JOHN COULSTON
JAMES SMITH
ANDREW GRAY
Co-Authors
Outline
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Where we’ve been…
Where we are at…
Where we want to go…
FIA Carbon/Biomass Goal
“Improve forest biomass/carbon estimates using the
sound science in concert with our external
partners/scientists. Just as we try to provide the
best volume estimates across the country, we should
produce the best biomass/carbon estimates”
State of Accounting in 2010
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Live Tree = Field Measurement
Standing Dead Tree = Model
Litter = Model
Downed Dead Wood = Model
Soil Organic Carbon = Model
Belowground = Model
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Data Delivery = FIA vs NGHGI Tools
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Vs.
* Used in 2009 National Greenhouse Gas Inventory of Forests (LULUCF)
Problem with Models
Do trees really
grow/die in such a
stable manner?
How about invasive
earthworms and
warming temperature
impact on litter depth?
How about western tree mortality
and fires?
Problem with Models
e.g., 1,000
year ice
storm
Improvements in 2011
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Jenkins to Component
Ratio Method
Phase 2 standing dead
Released to Public in April
2012
Improvements in 2012
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Phase 3 Down Woody
Materials
Released to Public in April
2013
CRM vs. Jenkins
Jenkins
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Nationally consistent method
Tree component estimates
Single field-based
parameter: dbh
Useful at large scales
Not linked to tree volume
Relies on external stump
equation
Component Ratio Method (CRM)
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Nationally consistent method
Standardized use of regional
volume equations
Utilizes dbh and height
measurements
Requires Jenkins to estimate
component biomass
Incorporates rotten and
missing cull deductions
Relies on external stump
equation
CRM vs. Jenkins
Bole
Method
Jenkins:
CRM:
79.5 kg C
70.0 kg C
Top and limbs
Stump
25.0 kg C 4.9 kg C
21.7 kg C 4.3 kg C
Total AG carbon
109.4 kg C
96.0 kg C
CRM vs. Jenkins
Douglas-fir
Quaking Aspen
9 inch tree biomass by tree height across United States
CRM vs. Jenkins
Woodall, C.W., Heath, L.S., Domke, G.M., Nichols,
M.C. 2011. Methods and equations for estimating
aboveground volume, biomass, and carbon for trees
in the U.S. forest inventory, 2010. Gen. Tech. Rep.
NRS-88. Newtown Square, PA: U.S. Department of
Agriculture, Forest Service, Northern Research
Station. 30 p.
Domke, G.M., Woodall, C.W., Smith, J.E.,
Westfall, J.A., McRoberts, R.E. 2012.
Consequences of alternative tree-level
biomass estimation procedures on U.S. forest
carbon stock estimates. Forest Ecology and
Management. 270: 108-116.
National Volume/Biomass Effort
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Consortium
Collect Data Progressively Through Species
Standing Dead Trees Inventory Plots
Standing Dead Wood
Wood density
Structural loss
Density Reduction Factors
Density Reduction Factors
Structural Loss Adjustment
Models vs. Measurements
Models may not
account for recent
disturbance
mortality such as
fire or insects
Western State Standing Dead Trees
C
Wilson et al. In Review
Standing Dead Research
Domke, G.M., Woodall, C.W., Smith, J.E. 2011.
Accounting for density reduction and structural loss
in standing dead trees: Implications for forest
biomass and carbon stock estimates in the United
States. Carbon Balance and Management 6: 14.
Woodall, C.W., Domke, G.M., MacFarlane, D.W.,
Oswalt, C.M. 2012. Comparing field- and modelbased standing dead tree carbon stock estimates
across forests of the United States. Forestry. 85:
125-133.
Implications of Changes to 2012 US
LULUCF
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Not all changes are due to the revised estimation procedures
for live and standing dead trees (e.g., new inventories).
Reduction in US C stocks by 6.7% (3,232 Tg C)
Increase in US C annual sequestration (2009 inventory year)
by 3.5% (8.3 Tg C/yr)
CRM adoption was partially responsible for reducing AG live
tree stocks (2010) by 15.2% (2,606 Tg C). However, annual
stock change (2009) increased by 0.9% (1.2 Tg C/yr)
Using FIA Phase 2 standing dead trees reduced standing
dead tree US stocks (2010) by 14.8% (458 Tg C). However,
annual stock change (2009) increased by 122.2% (11.0 Tg
C/yr).
Phase 2 vs Phase 3 Plots
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Phase 2
1 per 6,000 acres
Phase 3
1 per 96,000 acres
Soils
Downed
Woody
Materials
(DWM)
Forest Floor
Understory
Vegetation
DWM Plots
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27,000+
plots
Sampled
20022010
Unique DWM Considerations (i.e., Decay)
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Height collapse
(volume)
Case hardening
Density reductions
Harmon et al. 2008
(NRS-GTR-29)
Downed Dead Biomass
Prior NGHGI Model
Smith et al. 2006
Live Tree Biomass
DWM P3 vs. NGHGI Model
Estimated CWD C density (Tg)
Field-based
Model: Carbon calculation tool
Domke et al. In review
DWM P3 vs. NGHGI Model
Domke et al. In review
Live versus Dead versus Area
Woodall et al.
In Review.
Bringing it All Together: A Cohesive
View of C Across Pools and US
Wilson et al.
In Review
Future Work
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Interior Alaska and Managed Land
Definition
Missing Data and 1990 Baseline
CCT for National Forest System
Soil Organic Carbon and Forest
Floor
Belowground
Unity among on-line reporting tools
Volume/Biomass research
And so on…
Summary
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Improving estimation of each
pool…step by step
CRM adoption and standing dead
refinements in 2011
Downed dead wood in 2012 (right
now)
Soil organic carbon and forest floor
in 2013
Small group that tries to leverage
the community of carbon scientists
THANK YOU!!!
cwoodall@fs.fed.us