1. Modelling C sequestration following afforestation/reforestation Preliminary simulations using GRC3 FORESTRY AND FOREST PRODUCTS Keryn Paul Phil Polglase Gary Richards NATIONAL CARBON ACCOUNTING SYSTEM

2. Background CSIRO FFP Soil

3. GRC3 structure

4. Process

5. Objective Preliminary testing of GRC3… 1.Development of model structure 2.Identify important pools for sequestration of C 3.Improved knowledge for: - Application of model (avoid misuse) -Management of plantations for C sequestration -Clarify expectations of the role of plantations and soil under a C trading system (set default values)

6. Preliminary simulations 7 case studies in Australia Model calibrated to: –Growth –Above and/or below ground biomass –Litter fall –Litter layer mass Model run to generate unverified outputs for soil C

7. Case studies Annual rainfall (mm) 4 sites 5 sites 29 sites 3 sites 14 sites 2 sites 3 sites

8. Deriving allocation of NPP to stems ObservedPredicted

9. Deriving allocation of NPP to roots

10. Deriving allocation of NPP to foliage

11. Deriving allocation of NPP to foliage & litter decomposition

12. Pinus radiata, SA

13. E. globulus, low rainfall WA

14. E. globulus, SE Vic.

15. C removed from atmosphere

16. C removed in products

17. Change in soil C ?

18. ?

19. Importantprocesses

20. NPP StemsBranchesBarkFoliageF. rootsC. roots 3-PG Tree Debris Soil Empirical litter decomp. submodel better?

21. Importantprocesses

22. NPP StemsBranchesBarkFoliageF. rootsC. roots DeRe Sol.Cel. Lig. 3-PG GENDEC Tree Debris Soil CO 2

23. humification of plant cellulose and lignin pools Little available information on change in soil C following afforestation

24. Further work… Development of models for decomposition and humification of litter Verification of soil C sub-models –Paired pasture/plantation sites –Soil fractionation

25. Summary Potentially large influences of management and climate on C sequestration following afforestation Most C is sequestered by tree biomass Changes in soil C appear be relatively minor, but this needs to be tested

26. E. grandis, Q’ld

27. P. radiata, NSW

28. E. nitens, Tas

29. NPP StemsBranchesBarkFoliageF. rootsC. roots DeRe 3-PG Roth-C Tree Debris Soil De Re CO 2 RPMDPMHUM CO 2 ? ? ?