More than 25 researchers and plantation managers attended a
Programme 2 workshop and field tour in December to review CRC
silvicultural research that has examined production of sawlogs and
veneer logs in Eucalyptus globulus and E. nitens.
The two-day event included workshop sessions at Churchill,
Victoria, and visits to two research field trials within the
Gippsland eucalypt plantation estate of Hancock Victoria
Plantations.
The silvicultural research trial at Carrajung, in the Strzelecki
Ranges, examines the combined influences of pruning, thinning and
fertiliser treatments, imposed at three years of age, on the growth
and water use of E. nitens on a highly productive
site. University of Melbourne researcher Dr David Forrester,
who led the study, explained that pruning leads to a greater
reduction of growth in thinned stands because lower canopies of
unpruned trees in the unthinned stands are shaded and contribute
less to tree growth than lower canopies in the thinned stands.
Nonetheless, thinning had the greatest impact on tree growth in
this experiment. Five years after thinning, the dominant
‘final crop’ trees in the thinned, unfertilised
treatment area were larger in diameter than those in the unthinned,
unpruned fertilised treatment. The study shows how these treatments
could be applied to design more efficient and faster growing
plantations.
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 Measuring
log straightness in E. globulus using image-processing
software
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By the age of nine years, the trees on this highly productive site
had attained an impressive size. Dr Forrester is now researching
how different silvicultural treatments interact on less productive
sites. Other presentations during the workshop also focused on the
effects of thinning, pruning and fertiliser on wood properties and
log value.
Participants also visited an interesting trial of
E.
globulus near Boolarra, conducted by the Southern Tree
Breeding Association. The area had been thinned and pruned at four
years of age to convert it to a ‘sawlog’ regime in
order to study the genetic control of sawlog and veneer traits. CRC
researchers from the University of Tasmania and the University of
Melbourne have assessed stem straightness in this trial, and in a
sister trial in western Victoria. UTAS researcher David Blackburn
reported that there are good prospects to improve straightness in
E. globulus plantations grown for solid wood by breeding
– an important finding as log straightness can enhance wood
recovery and value in this species. Newly developed methods for
objective assessment of log straightness were presented.
These important field trials will increase our understanding of how
silviculture and genetics determine log, stand and product value.
CRC participants can access the workshop presentations on the
Members Website.
