1. Forest Inventory Methods and Carbon Analysis Linda S. Heath Richard A. Birdsey USDA Forest Service Northeastern Research Station In Support of the United States Submission on Land-Use, Land-Use Change, and Forestry Lyon, France 9 September 2000

2. Outline of Presentation The United States Forest Inventory Methods to Estimate Carbon in Forests Estimates for Article 3.3 of the Kyoto Protocol – Afforestation, Deforestation, and Reforestation Estimates for Article 3.4 of the Kyoto Protocol – Forest Management Activities

4. Inventory Sample Design Phase One – Remote Sensing to Stratify Forest Area –3,000,000 forest sample points, each equals 100 ha Phase Two – Ground Sampling of Forest Attributes –120,000 forest sample points, each equals 2200 ha Phase Three – Forest Health Monitoring –4,500 forest sample points, each equals 38,500 ha

5. Phase One – Remote Sensing Source: NAPP 1:40,000 color infrared photography Sample Points: 16 photo points located systematically over the “effective area” of each photo. Measurement: land cover Note: in process of shifting to satellite data

6. Phase Two – Field Sampling Sample Intensity = 1 sample location per 6,000 acres of land Inventory Cycle Length = Five years or 20 percent of the sample locations each year Year One Year Two Year Three Year Four Year Five Five-Year Panel

7. Phase Two Sample Location Design Plot measurements: age, disturbance, owner, physiography, etc. Tree measurements: species, dimensions, damage, etc.

8. Phase Three – Forest Health Monitoring FHM and FIA sample locations are co-located Additional data: crown condition, soils, understory, coarse woody debris, etc.

9. Forest Inventory Estimates as a Basis for Carbon Analysis (Trends by State and Region) Area by land class (reconciled with NRI) Area by forest type, owner, age class Tree volume by species and size class Tree biomass by species and size class

10. Methods to estimate carbon I.Calculating carbon based using inventory data II.Estimating forest sector carbon III.Uncertainty

11. Basic estimation of carbon stocks and stock changes Carbon stock = CARBON/AREA times AREA Carbon stock change = C stock at time 2 minus C stock at time 1 Divide by length of period = carbon/year  Estimated values can be obtained from measured data or from using models 

12. How to calculate carbon stock estimates from forest inventory data? Calculate biomass and convert to carbon (carbon = 50% of dry weight biomass) Estimate forest floor carbon using simple relationships Estimate soil carbon based on USDA State Soil Geographic database (STATSGO), coupled with historical land use change knowledge and assumptions of soil dynamics following land use change and disturbance Sum carbon pools

13. Example: Average forest C budget for one rotation of pine on a high site in the SE

14. Example: Average forest C stock changes on one rotation of pine on a high site in the SE 0-45-910-1415-1920-2425-2930-3435-3940-44

15. Example: Two rotations of pine on a high site in SE Forest C and disposition of C in harvested wood 406020 Carbon (MT/ha) 080 Age NOTE: Energy and emissions are releases of C to the atmosphere

16. Disposition of carbon in harvested wood – U.S. average Source: Heath and others, 1996; Skog and Nicholson, 1998

17. Major characteristics that affect forest C budgets Region (Ex: Northeast, Pacific Northwest) Forest Type (Ex:Douglas-fir, Oak/Hickory) Site Quality (High, Medium, Low) Prior Land Use (Cropland, Pasture, Forest) Age or Volume

18. Regions of the U.S.

19. Overall review: illustration of significant C stocks and changes Growth Removals Litterfall, Mortality Treefall Harvest residue Humification Decomposition SOIL COARSE WOODY DEBRIS FOREST FLOOR ATMOSPHERE STANDING DEAD HARVESTED CARBON BIOMASS Above and Below LANDFILLS ENERGY Imports/ Exports PRODUCTS Mortality Recycling decay processing burning disposalburning decay

20. Forest sector system of models and data for C estimates and projections of managed U.S. forests

21. Assumptions for Base projection Assumptions involve factors about U.S. Forest growth Population Income Economic activity Utilization factors

22. What is uncertainty? – IPCC guidelines Generic definition of uncertainty IPCC guidelines suggest that it is more useful to express uncertainty quantitatively and systematically in the form of well-developed confidence intervals.

23. Uncertainty - definition and method Uncertainty: an expression of likely values for an estimate when the true value is not exactly known. Methods: We use Monte Carlo simulations to represent uncertainty as probability distributions

24. Uncertainty represented by a probability distribution CONFIDENCE INTERVAL 95 %

25. Source: (Smith and Heath, in press ) Projected inventory of privately owned managed forests of US

26. Absolute and relative uncertainty C estimates on private managed forests of the U.S. Inventory: 80% confidence interval 22,400 +/- 950 MMT 22,400 +/- 4% MMT Flux: 80% confidence interval 74 +/- 11.5 MMT 74 +/- 15% MMT Source: Smith and Heath, in press; C in harvests not included in these estimates; also based on older inventory data.

27. Summary of methods for Articles 3.3 and 3.4 Followed IPCC definitions and accounting All C pools included where appropriate Estimates based on comprehensive forest inventory data and carbon estimation models Used multiple strata (region, owner, forest type,..) Used projection models and adjusted periodic estimates to required reporting dates

28. Identification of Kyoto Lands (FAO Definitions) DataProjections

29. Average C Uptake on Land by Region and Age - Regeneration After Harvest (Includes decay of logging debris)

30. Characteristics of Several Accounting Approaches Reforestation includes: Accounting Approach: Afforestation + Deforestation Forest Regrowth Decay of Logging Debris Harvest Emissions IPCC Land Based Yes FAO Activity Based Yes FAO Land Based II Yes FAO Land Based I Yes

31. Average Annual Carbon Stock Changes by Reporting Period and Accounting Framework

32. U.S. submission for Article 3.4 Proposes inclusion of three broad land management activities: Forest Management, Cropland Management, and Grazing Land Management Proposes a comprehensive land-based accounting system

33. Definition of managed forests Forest management is an activity involving the: Regeneration, tending, protection Harvest, access, and utilization of forest resources to meet the purposes of the forest landowner.

34. Comparison of managed and all forests Where are unmanaged forests? Almost half in Alaska Almost 40% in Rocky Mountain region and California

35. Carbon stocks and area estimates, 1990 (Table II) In 1990, managed forests in the U.S. covered 198,611,000 hectares and contained 36,203 +/- 6% MMT of C Does not include carbon in existing forest products.

36. Managed forest lands, US, 2008-2012 Avg. annual C stock change C taken up by trees in managed forests 381.9 C released by harvesting trees-276.0 Net C taken up in Soil52.4 Net C taken up in Floor12.8 Net C taken up in Understory0.7 Net C accrued in live biomass & soil 171.8 C increase in logging residue26.1 C in products in use39.1 C in products in landfills51.3 C stored in products & landfills90.4 Net C removals related to managed forests 288 +/- 15% MMT/yr

37. Trend of carbon sequestration on managed forests, U.S. Data Projections