Preliminary outturn studies in E. regnans.  J.E. Opie.  January 1972.  7 pp. (unpubl.)

SUMMARY

This records the results of exploratory studies of exploratory studies of product outturn for Eucalyptus regnans in Toolangi Forest district. Effects of tree size on the yield per tree of sawlog and pulpwood, each expressed as a percentage of gross bole volume, are defined. Some effects of age are also indicated. The effects of tree size and age on outturn percentage for both sawlogs and total produce are indicated graphically and as mathematical functions. In broad terms, the form of the curves is as follows: from the zero point at the minimum merchantable DBHOB, the outturn percentage rises very steeply with increase in DBHOB until a stage is reached, at about twice the minimum merchantable DBHOB, when further increase in DBHOB has little effect. The outturn values asymptote towards about 70% for sawlogs and nearly 100% for total produce. Stand age appears to affect both the slope of the curves and the level of the asymptotes.

Further studies are required to define age effects more clearly, and to examine the economic and human factors. Sampling of particularly defective stands is also desirable.