Levels-of-Growing-Stock Study (LOGS)

• Levels-Of-Growing-Stock (L.O.G.S.) Cooperative Study in Douglas-fir
• About the LOGS Cooperative
• Study objectives
• LOGS partners
• Study results for the CFS-BCMOF LOGS installations
• Future potential...

---

Study results for the CFS-BCMOF LOGS installations

The results-to-date for the two Canadian studies are similar to the other installations with gross basal area and volume increments directly related to basal area growing stock. With the passage of time and the aging of the stands, suppression mortality, present only in the control plots, has reduced the net total tree volume increment of the controls to less than those of some of the lightest thinning treatments, and continues to play an increasingly important factor in the comparison of treatments versus control.

Cumulative total tree volume production of the controls has exceeded that of all treatments with the exception of the “dense” treatment at Shawnigan Lake; however, when measured in merchantable volume, several thinning treatments exceed the net merchantable volume production of the controls. This difference between cumulative total tree and merchantable volume production is expected to increase as the stands age and the effects of suppression-related mortality in the controls and the gradual increase in growing stock of the thinned treatments take effect.

Thinning has markedly increased diameter growth resulting in dramatically different diameter and volume distributions among treatments.

In summary, gross total tree volume increment increases with stocking, though at a decreasing rate, up to a point at which suppression-related mortality becomes important. In thinning, one trades reduced gross total tree volume growth for increased diameter growth, improved stem quality and improved resistance to wind and snow damage.

---