Productivity of seedling and coppice eucalypt crops over short rotations.  W. D. Incoll.  June 1983.  12 pp. (unpubl.)

SUMMARY

This study investigated the productivity of plantation-grown eucalypts at rotations of up to 10 years of age. Two trials were established, one in 1969 and the other in 1971. The 1969 trial contained two species, Eucalyptus viminalis Labill. (manna gum) and Eucalyptus globulus Labill. ssp. bicostata (Maid. et al.) Kirkp. (Gippsland blue gum), at two spacings of 0.31 m x 0.31 m and 0.62 m x 0.62 m, two fertiliser treatments, and three rotation lengths (three, six and nine years) in an incomplete factorial design; unfortunately, this trial was damaged by snow and could not provide reliable productivity data. The 1971 trial was larger and contained E. globulus ssp. bicostata at two spacings of 2.43 m x 0.31 m and 2.43 m x 0.62 m, three seedling rotation lengths (four, seven and ten years) and three coppice rotations (three, six and nine years).

The stands were measured before each harvest to estimate stand parameters and the harvested trees were sampled to estimate under and overbark volumes and the above-ground biomass of stemwood, stembark, branches and foliage.

At ten years of age, the 1971 trial produced 192 m³ ha^-1 of overbark stem volume and 106 t ha^-1 of above-ground biomass. Mean annual increment of overbark stem volume increased with age up to a maximum value of 19.2 m³ ha^-1 an^-1 and 10.6 t ha^-1 an^-1 of above-ground biomass at an age of ten years.

Approximately 66% of stumps coppiced successfully after the first seedling rotation of three years and about 90% of these stumps coppiced after a subsequent coppice rotation of three years. The productivity of volume and dry matter of these coppice rotations was less than that of the preceding seedling rotation.

The paper-making properties of material from both trials were tested by the Division of Chemical Technology, CSIRO, who found that the material harvested was quite suitable for making paper, provided leaf material was excluded.