The Technical Specifications of the US Forest Carbon Inventory: Recent Past and Near Future

1. The Technical Specifications of the US Forest Carbon Inventory: Recent Past and Near Future Christopher W. Woodall, Research Forester, U.S. Forest Service, St. Paul, MN

2. Co-Authors • Grant Domke • James Smith • John Coulston • Sean Healey • Andy Gray

3. Outline • Why Inventory? • Coordination within FIA • 2011 Accomplishments • CRM vs Jenkins • Standing Dead • 2012 and Beyond

4. Why Inventory? Accounts for majority of carbon sequestration in U.S.

5. Flux Related to U.S. Emissions 12 % Offset

6. UNFCCC Information • United Nations Framework Convention on Climate Change: www.unfccc.int • Land Use, Land Use Change, and Forestry: LULUCF • Report Forest Area, Carbon Stocks, and Stock Change Annually back to 1990 • How Many States did the FIA inventory in 1990? 2

7. Carbon Pools = Biomass • Aboveground biomass • Belowground biomass • Dead wood • Litter • Soil organic carbon

8. Aboveground Live Tree Biomass

9. Aboveground Carbon Flux

10. Organization within FIA • National Carbon Accounting Steering Committee • Representatives from each FIA unit • Serve as liaisons to their regional units • Northern Research Station Carbon Group • Prepare UNFCCC inventory • Facilitate techniques integration into FIA tools/documentation • Leads on accounting research

11. Brief History of C Accounting • Prior to Annual FIA • Almost pure modeling effort • No P3 data • Missing reserved land information • Now in a period of transition from pure models of past and annual inventory • Incorporation of P3 data • Refined tree component estimation

12. State of Accounting in 2010 • Live Tree = Field Measurement • Standing Dead Tree = Model • Litter = Model • Downed Dead Wood = Model • Soil Organic Carbon = Model • Belowground = Model Vs. * Used in 2009 National Greenhouse Gas Inventory of Forests (LULUCF)

13. 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?

14. Improvements in 2011 • Jenkins to Component Ratio Method • Phase 2 standing dead • Released to Public in April 2012

15. CRM and Jenkins: 2 Accounting Books Resource Protection Act Report to Congress Volume and Biomass EPA National Greenhouse Gas Inventory Forest Carbon x 0.5 ≠ “Gaming the System?”

16. CRM vs. Jenkins • Jenkins • 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 • Component Ratio Method (CRM) 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

17. CRM vs. Jenkins Bole Top and limbs Stump Total AG carbon Method Jenkins: CRM: 79.5 kg C 70.0 kg C 25.0 kg C 21.7 kg C 4.9 kg C 4.3 kg C 109.4 kg C 96.0 kg C

18. CRM vs. Jenkins Douglas-fir Quaking Aspen 9 inch tree biomass by tree height across United States

19. CRM vs. Jenkins * For 20 most abundant hwd/sftwd species by region

20. 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.

21. CRM vs. Jenkins 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.

22. Standing Dead Wood Wood density Structural loss

23. Density Reduction Factors

24. Density Reduction Factors

25. Structural Loss Adjustment Cline et al. 1980

26. Structural Loss Adjustment

27. Structural Loss Adjustment *Paper birch in New Hampshire

28. Models vs. Measurements Models may not account for recent disturbance mortality such as fire or insects

29. 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 model-based standing dead tree carbon stock estimates across forests of the United States. Forestry. 85: 125-133.

30. Implications of Changes to 2012 US LULUCF • 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).

31. Baseline Trend Recalculations

32. Mid-Term Changes • Phase 3 downed dead wood • Changes to FIADB being currently implemented • Refined AK managed lands layers • Released to public in 2013

33. Longer Term Changes • Improved individual tree volume/biomass models • Meshing remotely sensed imagery/models with soil measurements • Belowground and foliage model improvements • Phase 3 forest floor • Biomass GRM

34. Summary • Improving estimation of each pool…step by step • CRM adoption and standing dead refinements first • Dead wood next • Continued P3 sampling and success of volume/biomass study essential

35. Thank You!!!