1. Silvics of Western Hemlock
Second-Growth Western Hemlock Product Yields Related to Differences in Stand Density
Les Jozsa
Research Scientist Emeritus

2. Vancouver Island and the Lower Mainland of BC
Sampling Locations of Second-Growth Western Hemlock (90 years of age)
650/ s/h
1000 s/h
1700 s/h (50)
1000 s/h (50)
986 s/h
440 s/h
840 stems/ha

3. Port Hardy 580 s/ha western hemlock at age 90
Site index of 39m, at age 50, is less than 1% of the coastal western hemlock region!

4. Not the edge of wheat-field, but 930 s/ha hemlock stand

5. Sampling Plan of Stem-Wood Characterization

6. Old-Growth Reference Values of Wood Density

7. Perspective on Second-Growth Wood Density

8. Western Hemlock is an INDETERMINATE Species

9. Density Distribution in Western Hemlock

10. Average Ring Density Trends

11. Average Ring Width Trends
6 rings/ inch
8 rings/ inch

12. Pith-to-Bark Ring Density Trends

13. 440 Stem per Hectare at Age 90

14. 1000 Stems per Hectare at Age 90

15. Stem Shapes and Density Zones at Age 60 and 90

16. Where do your logs fit within the cube?

17. Harvesting cost & lumber recovery factor by DBH

18. Standing Volume at 50 Years of Age ~ 1000 & 1700 s/h

19. Log Value in Old- Growth and Second- Growth Wh

20. Strength and Stiffness of 105x105 mm Squares
MOE values from two 930 s/ha stands, in all DBH classes (30, 35, 40, and 45 cm) met or exceeded Select Structural code values for Hem-Fir.
Lumber from 580 s/ha did not meet SS, but did meet or exceed the No.1/No.2 code values up to 50cm DBH

21. STRENGTH & STIFFNESS – a primer

22. Equilibrium Moisture Contents & Relative Humidity

23. High-Value Hemlock Moulding Rejects (CW)

24. Along-the-grain shrinkage in compression wood

25. Pulp and Paper Quality

26. Second-Growth Western Hemlock Wood Quality
Log and Lumber Grades
Lumber Structural Properties
Mechanical Properties of Small Clears
Treatability
Machining Properties
Veneer and LVL
Pulp properties and Yields

27. Stand, Tree, Log, Lumber, Wood, Ring, Fibre Quality