TECHNICAL ASPECTS OF THE FOREST CARBON INVENTORY OF THE UNITED STATES: RECENT PAST AND NEAR FUTURE

1. 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

2. Grant DomkeSean HealeyJohn CoulstonJames SmithAndrew Gray Co-Authors

3. Outline • Where we’ve been… • Where we are at… • Where we want to go…

4. 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”

5. 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 • Data Delivery = FIA vs NGHGI Tools Vs. * Used in 2009 National Greenhouse Gas Inventory of Forests (LULUCF)

6. 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?

7. Problem with Models e.g., 1,000 year ice storm

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

9. Improvements in 2012 • Phase 3 Down Woody Materials • Released to Public in April 2013

10. 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

11. 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

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

13. 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.

14. National Volume/Biomass Effort • Consortium • Collect Data Progressively Through Species

15. Standing Dead Trees Inventory Plots

16. Standing Dead Wood Wood density Structural loss

17. Density Reduction Factors

18. Density Reduction Factors

19. Structural Loss Adjustment

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

21. Western State Standing Dead Trees C Wilson et al. In Review

22. 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.

23. 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).

24. Phase 2 vs Phase 3 Plots • Soils • Downed Woody Materials (DWM) • Forest Floor • Understory Vegetation Phase 2 1 per 6,000 acres Phase 3 1 per 96,000 acres

25. DWM Plots • 27,000+ plots • Sampled 2002-2010

26. Unique DWM Considerations (i.e., Decay) • Height collapse (volume) • Case hardening • Density reductions • Harmon et al. 2008 (NRS-GTR-29)

27. Prior NGHGI Model Downed Dead Biomass Live Tree Biomass Smith et al. 2006

28. DWM P3 vs. NGHGI Model Estimated CWD C density (Tg) Field-based Model: Carbon calculation tool Domke et al. In review

29. DWM P3 vs. NGHGI Model Domke et al. In review

30. Live versus Dead versus Area Woodall et al. In Review.

31. Bringing it All Together: A Cohesive View of C Across Pools and US Wilson et al. In Review

32. Future Work • 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…

33. Summary • 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

34. Thank You!!! cwoodall@fs.fed.us