Revisiting eucalypts—a strategic assessment

A prolonged recession is as good a time as any to re-examine one’s premises: to identify what is excellent and what is failing. For too long pine foresters have been involved in an industry that – like airlines, computer hardware and semiconductors – it has on aggregate suffered a loss of capital during the last decade. Over the last 50 years the State has invested $1 billion on forest R&D – and most of that on pine. This has not provided the expected returns because it failed to appreciate the huge natural variability with respect to wood quality, and especially in the corewood of pine. The intrinsic wood properties of today’s pine are little better than that of 80 years ago. The belated recognition that all species are unimproved with regard to intrinsic wood properties puts eucalypt and pine on an equal footing in that both face the same challenge of getting the best out of the existing resource, as well as of developing greatly improved breeds. Eucalypts, and alternative species generally, have been ignored by most forest companies with support coming largely from farm foresters and small investors. Many have been on the receiving end of the question “Why bother?” when pressing the case for the possibility of planting eucalypts. Too often this is followed by a condescending explanation of past failures, and that in the old days the Forest Service tested hundreds of species and that radiata pine was the winner. We tried, they did not work out. Yet any professional gambler will tell you that “you don't bet on the horse you think is gonna win, you bet on the horse that’s got the best odds”; and that you spread your bets/investments (alternative species) and hedge against uncertainties. Our failure to develop a large eucalypt estate is in stark contrast to other Southern Hemisphere countries (Table 1), both in temperate and sub-tropical regions. Most of these plantations are being established by the private sector, which is looking to maximize profit. Many of the new projects involve very high biomass productivity (either for pulp or energy production). These are cutthroat businesses where New Zealand has little prospect of competing on equal terms with countries like Brazil or Uruguay. However around the world there has been less progress with solid wood products and therein lies an opportunity

Variations in the dynamic modulus of elasticity with proximity to the stand edge in radiata pine stands on the Canterbury Plains, New Zealand

To explore the effects of wind on tree form and wood quality, 30 transects were placed across each of three relatively narrow stands of Pinus radiata, aged 11, 17 and 25 years old, on the Canterbury Plains, New Zealand. The experimental design assumed that the major influence on stand edges to be the prevailing strong north-westerly winds that blow across this region. Outerwood dynamic modulus of elasticity (Ed) and tree height increased with distance from the stand edge, while taper reduced. The negative effect of wind extended into the stand the equivalent of one tree height, regardless of the age of the stand, with the least stiff trees (i.e., those with the lowest Ed) located at the stand edge. Surprisingly, larger effects were observed at the downwind edge of these stands, although the reasons for this are not clear. Results from this study indicate that for those stands investigated trees located at the stand edge, or within a distance equivalent to one tree height from the edge, may be of marginal value for structural timber

Very early screening of wood quality for radiata pine: pushing the envelope

For many years, breeding of Pinus radiata for structural wood relied on improving basic density assessed at age 7 or 8 years old, with little progress. Current efforts have moved to acoustic screening for stiffness at similar age. Breeding cycles are still too long. An alternative is to screen out the worst trees even earlier: shorter breeding cycles should outweigh the lower accuracy due to early selection. Besides genetic effects, there is also evidence that wood stiffness is affected by wind, particularly for stands with low stocking and trees in forest margins. A glasshouse experiment was setup for early selection considering two factors: tree position and clone. Tree positions were straight (control), leaning (30° from the vertical) and rocked (15 minutes every hour, simulating 10 km h-1 wind). Four clones were used covering a range of wood stiffness and replication was 12 plants per treatment. The response variables at 8 months were squared acoustic velocity (v2, surrogate of stiffness), basic density, collar diameter, diameter asymmetry and compression wood. There were significant differences of v2 for treatments and clones. Straight trees had the higher v2 (2.15 km2 s-2), followed by leaning trees (1.95 km2 s-2) and rocked trees (1.74 km2 s-2). The 19% v2 reduction from straight to rocking trees is consistent with observations on the effect of forest margins. Clonal means ranged from 1.53 to 2.11 km2 s-2. Basic density showed significant differences between treatments but not for clones, with higher values for leaning trees (408.0 kg m-3), followed by rocked trees (370.2 kg m-3) and straight trees (358.3 kg m-3). There was zero correlation between v2 and basic density. Straight and rocked trees formed little compression wood in thin arcs at random within the cross-section. Leaning trees formed continuous compression wood on the underside of the leaning stem. We discuss the implications for tree improvement

Effet des pourritures brunes sur l’adsorption de l’eau et la composition chimique du bois de Coeur du pin sylvestre

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