Eucalypt Study Finds Quality Timber

By GALLOWAY, Jill

James Milner is looking not so much for the fastest growing of the 12 different species of eucalyptus trees on Massey University’s Tuapaka sheep and beef farm at Aokautere, but more at the growth rate of the species that produce better timber.

The lecturer in the University’s Institute of Natural Resources was put through his paces by a group of around 45 farm foresters who gathered at the farm last week to look at Mr Milner’s eucalyptus trials and other trees on the 428 hectare research farm.

He started the project in 1995, planting trees on four micro sites – the top and bottom of a hill and the shady face and sunny face.

“What I’m looking for is the relative performance of each of the 12 species on each of those (micro sites).”

They are E.agglomerata, E.baxteri, E.botryoides, E.cladocalyx, E.globoidea, E.microcorys, E.mulleriana, E.nitens, E.obliqua, E.pilularis, E.regnans and E.saligna.

The results are predictable.

“The species that we traditionally associate with good performance like E.nitens and E. regnans are the best in terms of fast growing.

“But we’re more interested in some of the species which perhaps have intermediate growth performance, but better wood quality.”

The study identifies the stringybarks like E agglomerata, E. mulleriana, E. baxteri, E.pilularis and E.globoidea.

“They’re slower growing, but they have wood which is much harder, has good natural durability and is easier to mill.” Mr Milner said.

“It doesn’t split, warp, twist or degrade during milling whereas many of the others do,” he said.

He hopes the varieties that mill more easily will be worth more.

“The market for eucalypt timber is at the moment undeveloped or unsophisticated. A better quality wood should be worth more”.

Mr Milner believes that eventually the stringybarks will be the only eucalypts with a market, because wood that isn’t easily millable doesn’t really fit anywhere.

The windy sites at Tuapaka were not good for any species of eucalyptus tried out. Generally, the trees preferred the sun to the shady sites.

“They performed better in both height and diameter when they weren’t on shady sites.”

During the winter coming, he said, he will measure the diameter of the trees again and assess things like the natural branch shed.

He will then thin the block, leaving just a couple of the best growing treesand milling the rest.

There are 40-50 hectares of trees planted at Tuapaka, mostly on the front escarpment of the property. Most of it is Pinus radiata.

Gorse remains a problem on the farm and some new stands planted after harvesting of radiata in 2002 have a “magnificent stand of gorse,” he said.

“I don’t know how the pruners will get on. If it was me, I’d take one look at be out of there,” he laughed.

Tuapaka has 1-2 hectares of Cupressus lusitanica.

There was a steep hill face, showing scars of many past slips which the farm foresters noted.

“Why isn’t that face planted up?” one asked.

He was told the paddock is used as a holding block for the woolshed and yards.

“It’s not holding very well, is it?” was the retort. A ripple of laughter went through farm forestry group.

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(c) 2007 Evening Standard; Palmerston North, New Zealand. Provided by ProQuest Information and Learning. All rights Reserved.