1. Diameter-free Growth Modelling and other Heresies Oscar Garcia University of Northern British Columbia

2. Themes Resolution, science vs. technology Stem dbh as growth driver Stochastics

3. Model Uses Decision-making (prediction) Research (understanding)

4. Prediction Precision Controllable variables Match: Available input info Required output info Management Decision-making

5. “Process models” Mechanistic, realistic Detailed Qualitative behavior Generate questions Scientific Research

6. Science vs. Technology N, S, W, E Journal of Applied Forestry

7. Science vs. Technology N, S, W, E Journal of Applied Forestry

8. Prediction Tree-level model tree list

9. Prediction Inventory Tree-level model (B,N,H) tree list

10. Prediction Inventory Application Tree-level model (B,N,H) tree list (B,N,H)

11. Prediction Inventory Application Tree-level model (B,N,H) tree list (B,N,H) Stand-level model

12. Complexity, Resolution Level

13. “Model at one level of detail below the level desired for prediction” Complexity, Resolution Level

14. “Model at one level of detail below the level desired for prediction” Understanding: Two levels higher? Prediction: Same level Complexity, Resolution Level

15. “Model at one level of detail below the level desired for prediction” Understanding: Two levels higher? Prediction: Same level Links Complexity, Resolution Level

16. Growth Drivers  v = f(age, dbh, site) ?

17. Growth Drivers  v = f( age, dbh, {site}) ? height

18. Growth Drivers  v = f(height, dbh) Growth driven by stem thickness?

19. Growth Drivers  v = f(height, dbh) Growth driven by stem thickness??  v = f(height, resources captured)

20. TASS Mitchell 1975

21. Stand-level  V /  H = f(H, N, C)(Eichhorn 1904)  N /  H = g(H, N, C)  C /  H = h(H, N, C)

22. C vs. H

24. Stochastic Models Convenient for the modeller Variability info? In practice, single realization

25. Gross Increment

26. Stochastic Models Convenient for the modeller Variability info? In practice, single realization Worse of both worlds?

27. Mind the Users! web.unbc.ca/~garcia