1. Sustainable Production Forestry THE JOINT FORCES OF CSIRO & SCION Application of the New Zealand Douglas-fir stand-level growth model to data from the PNW Leith Knowles and Lars Hansen

2. THE JOINT FORCES OF CSIRO & SCION

6. NZ stand-level growth model (DF NAT)  Based on data from 1600 permanent plots  MTH = fn(SI, age and latitude)  Current annual BA increment = fn(SBAP, age, crown, competition)  Mortality = fn(stocking, DBH) based on Reineke’s 3/2 rule  BA after thinning: BA2 = BA1*(N2/N1) a

7. THE JOINT FORCES OF CSIRO & SCION PNW validation data Jim Flewelling facilitated access to data from the Stand Management Cooperative, University of Washington 27 silvicultural trials (installations) 303 sample plots Stands 3-28 yrs of age Roger Fight, US Forest Service, PNW Research Station also contributed to the study

8. THE JOINT FORCES OF CSIRO & SCION Fit of PNW data against NZ ht/age curves

9. THE JOINT FORCES OF CSIRO & SCION Ht/age curves refitted to PNW data

10. THE JOINT FORCES OF CSIRO & SCION New PNW ht/age curves

11. THE JOINT FORCES OF CSIRO & SCION Cumulative distribution of Site Index NZ PNW

12. THE JOINT FORCES OF CSIRO & SCION In PNW, SI increases with stocking

13. THE JOINT FORCES OF CSIRO & SCION NZ mortality function slightly underpredicts for PNW

14. THE JOINT FORCES OF CSIRO & SCION Different definitions for height to crown base  PNW: height above ground to lowest whorl where 3 out of 4 quadrants contain live branches  NZ: the average of height above ground to lowest live branch, and height above ground to lowest whorl with majority of branches live

15. THE JOINT FORCES OF CSIRO & SCION Predicted vs observed crown length for PNW data

16. THE JOINT FORCES OF CSIRO & SCION Thinning coefficient fitted for each thinning on each plot BA after thinning: BA2 = BA1*(N2/N1) a  PNW first thinning a = 0.77  PNW second thinning a = 0.82  Average NZ a = 0.71  Average GB a = 0.66  Average Germany a = 0.83

17. THE JOINT FORCES OF CSIRO & SCION SBAP sets BA ‘level’

18. THE JOINT FORCES OF CSIRO & SCION Cumulative distribution of SBAP NZ PNW

19. THE JOINT FORCES OF CSIRO & SCION SBAP in PNW trials independent of stocking

20. THE JOINT FORCES OF CSIRO & SCION Site Index and BA potential are poorly correlated

21. THE JOINT FORCES OF CSIRO & SCION 500-Index Volume MAI (m 3 /ha/yr) for a stand that has been thinned to waste to 500 stems/ha by 15m MTH, and grown on to age 40 years  Best growth installation 717: 17.4 m 3 /ha/yr  Poorest growth installation 501: 5.5 m 3 /ha/yr  Average for 27 installations: 12.4 m 3 /ha/yr  Compares to NZ average of 18.4 m 3 /ha/yr

22. THE JOINT FORCES OF CSIRO & SCION 500 index for 27 PNW installations

23. THE JOINT FORCES OF CSIRO & SCION Overall, DF NAT works well against PNW data

24. THE JOINT FORCES OF CSIRO & SCION Conclusions  SI similar (32m @ 40 years)  SBAP higher in NZ (1.88) vs PNW (1.2)  500-index higher in NZ (18.4) vs PNW (12.4)  Slightly higher mortality in PNW  DF NAT needed new height-to-crown-base prediction function  Despite productivity differences (BA not SI), DF NAT works well in PNW  Valuable to repeat the exercise in 5-10 years

25. THE JOINT FORCES OF CSIRO & SCION Questions and answers