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

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

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!

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

Sampling Plan of Stem-Wood Characterization

Old-Growth Reference Values of Wood Density

Perspective on Second-Growth Wood Density

Western Hemlock is an INDETERMINATE Species

Density Distribution in Western Hemlock

Average Ring Density Trends

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

Pith-to-Bark Ring Density Trends

440 Stem per Hectare at Age 90

1000 Stems per Hectare at Age 90

Stem Shapes and Density Zones at Age 60 and 90

Where do your logs fit within the cube?

Harvesting cost & lumber recovery factor by DBH

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

Log Value in Old- Growth and Second- Growth Wh

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

STRENGTH & STIFFNESS – a primer

Equilibrium Moisture Contents & Relative Humidity

High-Value Hemlock Moulding Rejects (CW)

Along-the-grain shrinkage in compression wood

Pulp and Paper Quality

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

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