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NZJFS - Volume 25
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Competitive positioning strategy for New Zealand Pinus radiata in selected United Kingdom sawn timber markets
Author(s) R. J. Cooper, S. P. Kalafatis and A. J. McPherson ISSN 0048-0134 File size 1.4 mb Pages 379-407 Issue 3 Volume 25 Product positioning in industrial markets is an important consideration when new materials or products are introduced into a mature market. An investigation was carried out into the position of established timber species as perceived by UK end-users of timber. Multi-dimensional scaling techniques were employed in obtaining and explaining the perceptual patterns of four market segments (ie, general furniture, furniture frames, general joiner, and mouldings). The potential position of P. radiata D.Don was determined by overimposing objective measures of its physical properties. The findings indicateds that although there were differences in the perceptions of the end-use segments, all four segments shared a common element in their differentiation of species as hardwoods or softwoods. It was proposed that P. radiata should be positioned amongst the premium softwoods. Therefore, promotional efforts should emphasise its superior finishing properties and should be supported by a unique selling proposition centred around the sustainable availability of long and wide clear lengths. Efforts should be aimed at end-users who exhibit diversity in their utilisation of species eg manufacturers of mouldings. -
Grading random-width lumber by computer
Author(s) C. L. Todoroki ISSN 0048-0134 File size 779.3 kb Pages 367-378 Issue 3 Volume 25 A computer program, FLGRADE, has been developed that can grade random-width factory lumber to the US Western Lumber Grading Rules. FLGRADE uses data obtained from digitized boards. Board profile (including wane) is represented using a series of line segments which combine to form a polygon. All other defect data are represented using diagonal coordinates representing the smallest encompassing rectangle. The algorithm creates a list of cuttings by considering areas of placement. Using dynamic programming, an initial 2-stage solution is generated based on the rip-first cutting procedure. Alternative solutions which allow more flexible cutting sequences (i.e. either rip first or cross-cut first) and which do not restrict the number of stages are then generated to determine whether a higher percentage of cuttings, and hence a higher grade, can be obtained. Grades generated by FLGRADE for a set of boards for which defect data had previously been digitized, resulted in 80% receiving the same grade as had been manually assigned. Of the remaining boards, approximately 6% received a higher grade and 14% a lower grade. All computer assignments agreed with manual assignments within one factory lumber grade. -
Spiral grain in Canterbury Pinus radiata: within- and between-tree variations and effect on mechanical properties
Author(s) A. Tsehaye and J. C. F. Walker ISSN 0048-0134 File size 433.4 kb Pages 358-366 Issue 3 Volume 25 A study of spiral grain in 25-yr-old plantation grown Pinus radiata in Canterbury, New Zealand, showed that the angle of spiral grain measured in dried, dressed and machine stress graded boards from different positions in the tree with respect to log height and distance from the pith, varied significantly both within the tree and between trees. Strength properties (modulus of elasticity, tensile strength, bending strength) and wood density were also measured on the boards, and correlations with the angle of spiral grain investigated. Bending strength and stiffness decreased with an increase in the angle of spiral grain, corewood stiffness was less sensitive to spiral grain than outerwood stiffness, and spiral grain downgraded a significant proportion of sawmill output. -
Free shrinkage of Pinus radiata at an elevated temperature
Author(s) A. M. Carrington, R. B. Keey and J. C. F. Walker ISSN 0048-0134 Pages 348-357 Issue 3 Volume 25 Preliminary tests to measure free shrinkage strain on Pinus radiata at increased temperatures (dry-bulb 70 deg C, wet-bulb 43-68 deg C) were conducted on discs taken from an internodal portion of the stem of an 8-yr-old tree from a plantation at Rolleston, SE of Christchurch, New Zealand. Radial, tangential, and sectional shrinkage strains were determined against the moisture content. These tests showed unexpected scatter due to large and variable amounts of compression wood in the disks. There was little correlation between the measured strains and the percentage of latewood or the density of the samples. The tests were therefore repeated using wood slats 10 mm thick from a tree grown in an environment which reduced the amount of compression wood (in Southland which is less windy than the area in the Canterbury region where the test discs originated). These tests indicated that a very small strain appeared at high volume-averaged moisture contents (greater than the fibre saturation point). This may have been due to contraction of the surface layers which had dried below the fibre saturation point. However, significant strains began at a volume-averaged moisture content of 33% (dry basis). Of particular significance is the development of a new technique to measure strain continuously at higher temperatures which should be useful for kiln-drying studies. -
Examination of crop typing in forest estate modelling
Author(s) L. Te Morenga, B. Manley and S. Wakelin ISSN 0048-0134 File size 1.2 mb Pages 328-347 Issue 3 Volume 25 Alternative strategies for aggregating stands into croptyes were evaluated. Strategies tested included traditional grid methods, clustering methods, and a variable resolution approach. A benchmark stand-level model was developed within the FOLPI forest estate modelling system for a 231 stand estate. Croptying strategies were evaluated for their ability to match the results from this stand-level model. Comparisons were made in terms of the variation within croptypes, objective function value, forecast cash flows and woodflow volumes, stands specified for harvest over the short term, and problem size. The best croptyping strategy was the variable resolution approach in which the unique identity of the 41 stands within 6 yr of harvesting was preserved while the 190 younger stands were aggregated into croptypes. This hierarchical approach represents a compromise between the need for short-term detail and the desirability of modelling long-term consequences within the same model. -
Development of a composite taper equation to predict over- and under-bark diameter and volume of Eucalyptus saligna in New Zealand
Author(s) A. D. Gordon, C. Lundgren and E. Hay ISSN 0048-0134 File size 532.4 kb Issue 3 Volume 25 Development of a composite taper equation to predict over- and under-bark diameter and volume of Eucalyptus saligna in New Zealand. -
Understorey species composition patterns in a Pinus radiata plantation on the central North Island volcanic plateau, New Zealand
Author(s) R. B. Allen, K. H. Platt and R. E. J. Coker ISSN 0048-0134 Pages 301-317 Issue 3 Volume 25 -
Growth and predicted timber value of Pinus radiata cuttings and seedlings on a fertile farm site
Author(s) D. G. Holden, B. K. Klomp, S. O. Hong and M. I. Menzies ISSN 0048-0134 File size 1.1 mb Pages 283-300 Issue 3 Volume 25 Pinus radiata D. Don cuttings from 3-yr-old donor trees were compared with seedlings in a spacing trial planted on farmland near Rotorua and grown on a direct sawlog regime. At age 7 yr, the cuttings were taller but slimmer and had less taper than the seedlings. Closer spacing at planting enhanced height but not diameter growth for both stock types. The most pronounced contrast between the two stock types was the better resistance to toppling and superior form, particularly straightness, of the cuttings. This trend had a marked effect on crop selection raitos, resulting in the need to plant at least double the number of seedlings to approach the crop quality of the cuttings. PC-STANDPAK was used to model results at plantation age 28 yr. It was predicted that the superior shape and form of the butt log of the cuttings would result in a substantially higher recoverable volume of clear grade timber than the seedlings. Consequently, the value of pruned logs per hectare for the cuttings was predicted to be 20% higher than that for the seedlings. This trial was planted on a fertile site, and early differences in form between seedlings and cuttings were more pronounced than observed at less fertile sites. However, the results observed here could be expected on other highly fertile sites. -
Phosphorus levels in topsoils under conifer plantations in Canterbury high country grasslands
Author(s) M. C. Belton, K. F. O'Connor and A. B. Robson ISSN 0048-0134 Pages 265-282 Issue 3 Volume 25 There was a significant enhancement of 'plant available' topsoil phosphorus by conifer plantations in the montane zone across a wide precipitation range. Despite the high variability, this enhancement appeared to be of similar magnitude along the whole precipitation range sampled, a situation apparently diferent from that outlined for 'inorganic phosphorus'. -
Cross-grain effect on tensile strength and bending stiffness of Pinus radiata structural lumber
Author(s) D.J. Cown, B. Walford, and M.O. Kimberley ISSN 0048-0134 File size 449.8 kb Pages 256-262 Issue 2 Volume 25 -
Log rotation effect on carriage sawing of swept logs
Author(s) C. L. Todoroki ISSN 0048-0134 File size 510.0 kb Pages 246-255 Issue 2 Volume 25 A computer sawing system, which simulated a multiple saw edger, was used to investigate the effect of log rotation on the timber conversions of logs with sweep of three size-classes. A sample of 100 logs was stratified with respect to both log size and sweep, and four sawing methods (half-taper live sawing, half-taper cant sawing, offset live sawing, and offset cant sawing) were applied with the computer sawing simulation system AUTOSAW to each log at 37 positions representing rotation at 10 deg intervals from 0 deg (equivalent to the 'sweep up' position) to 360 deg inclusive. All 14 800 simulations used the same carriage configuration, saw kerfs, and target dimensions and the timber conversion percentage was determined for each. The results suggest that, under the conditions selected for the simulations, any log rotation can be used with half-taper cant sawing without sacrifice of substantial volume, but rotation is more important with offset cant sawing. Increased conversions were obtained when the log rotation was approximately 145 deg , i.e. midway between the 'sweep in' and 'sweep down' positions. For every angle, half-taper sawing obtained conversions that were at least equal to, if not greater than, those obtained with offset sawing. Results were consistent with the general rule of thumb that each 0.1 increase in the sweep:diameter ratio (deviation : s.e.d.) leads to a 5% decrease in timber recovery. -
Split- versus full-taper sawing of pruned plantation-grown logs
Author(s) J. C. Park ISSN 0048-0134 File size 81.9 kb Pages 231-245 Issue 2 Volume 25 Trials in three sawmills directly compared conversion of pruned, plantation-grown (in New Zealand), Pinus radiata logs by split-taper and full-taper sawing systems. No decided advantage from either system was found in recovery of defect-free clears, either by volume or by lengths. Full-taper sawing reduced total conversion by 3.4-4.7%, conversion to combined clears grades by 2.2-6.5%, and gross log values by 4.9-10.9%. Full-taper sawing was more difficult to implement, required additional cutting to square cants and blocks, and was estimated to lower mill production rates by 5-20%. Combined results proved full-taper sawing inappropriate for conversion of pruned plantation-grown logs. -
Modelling of Pinus radiata wood properties. part 2: basic density
Author(s) X. Tian, D. J. Cown and D. L. McConchie ISSN 0048-0134 Pages 214-230 Issue 2 Volume 25 -
Modelling of Pinus radiata wood properties. part 1: spiral grain
Author(s) X. Tian, D. J. Cown and M. J. F. Lausberg ISSN 0048-0134 Pages 200-213 Issue 2 Volume 25 -
Physiological ageing and site effects on wood properties of Pinus radiata
Author(s) M. J. F. Lausberg, D.J Cown, K.F.Gilchrist, J. H. Skipwith, and C.R.Treloar ISSN 0048-0134 File size 569.9 kb Pages 189-199 Issue 2 Volume 25 -
Clonal variation of wood density variables in Pinus radiata
Author(s) L. A. Donaldson, R. Evans, D. J. Cown and M. J. F. Lausberg ISSN 0048-0134 File size 646.7 kb Pages 175-188 Issue 2 Volume 25 -
Wood properties of Eucalyptus nitens grown in New Zealand
Author(s) M. J. F. Lausberg, K. F. Gilchrist and J. H. Skipwith ISSN 0048-0134 File size 1.0 mb Pages 147-163 Issue 2 Volume 25 Some evaluations of solid wood samples (including internal checking assessment, shrinkage, collapse and tension tests) were carried out on 15-year-old Eucalyptus nitens trees grown in the Kaingaroa Forest, New Zealand. There were significant differences between the stand density classes in basic density and moisture content, with the low density class having significantly lower earlywood density than the medium and high density classes. Significant differences were observed between all three classes in average ring density and latewood percentage. The extent of the internal checking observed will present a definite problem to many solid wood products. Collapse occurred readily and could be severe, but steaming effectively restored the collapse. The scanner used gave an accurate and reliable estimate of radial and tangential shrinkage combined. The tension test results were positively correlated with density and moisture content. -
Variation in some wood properties of Pseudotsuga menziesii provenances grown in New Zealand
Author(s) M. J. F. Lausberg, D.J Cown, D.L.McConchie and J. H. Skipwith ISSN 0048-0134 File size 715.7 kb Pages 133-146 Issue 2 Volume 25 -
Volume estimation of export pulplogs
Author(s) J. C. Ellis and M. O. Kimberley ISSN 0048-0134 File size 583.7 kb Pages 123-132 Issue 2 Volume 25 Stratified sampling has been applied to the estimation of volume in export consignments of pulplogs from New Zealand. Minimal bias and greatly improved precision were demonstrated when this type of sampling was compared with the alternative cluster sampling procedure. Adoption of stratified sampling techniques has reduced the cost and increased the precision of average piece volume estimates used to derive overall volumes from a total piece count. -
Intensive site-preparation to control armillaria root disease in second-rotation Pinus radiata
Author(s) M. Self and M. MacKenzie ISSN 0048-0134 File size 341.6 kb Pages 111-116 Issue 1 Volume 25 Stump removal and windrowing were used as a site-preparation technique to control infection by Armillaria spp. in two second-rotation P. radiata stands. Significant reductions in mortality due to Armillaria spp. from 10% to <1%, and from 22% to 5% at 5 years from planting were achieved. Parasitic sub-lethal infection at age 8 years in the same stands was reduced from 85% to 10% and 67% to 31%. An economic cost-benefit analysis was carried out. -
Mycological records: 4. Vizella tunicata sp. nov.
Author(s) P. D. Gadgil ISSN 0048-0134 File size 650.4 kb Pages 107-110 Issue 1 Volume 25 A new species of Vizella, V. tunicata, distinguished from other Vizella species by the gelatinous coat surrounding each ascospore, is described. The fungus is parasitic on leaves of Pittosporum tenuifolium and Myrsine australis. -
Mycological records: 3. Coniothyrium ovatum Swart.
Author(s) G. S. Ridley ISSN 0048-0134 File size 107.9 kb Pages 105-106 Issue 1 Volume 25 Coniothyrium ovatum occurring on leaves of Eucalyptus leucoxylon is reported as a new host record and a new fungus record for New Zealand -
Appropriate age for selection of final-crop Pinus radiata
Author(s) J. P. Maclaren ISSN 0048-0134 File size 1.3 mb Pages 91-104 Issue 1 Volume 25 Results from four trials indicated that tree selection which takes place during the normal pruning phase of P. radiata (ages 3 to 10 years) is inefficacious. At these early ages it is not possible to identify many of those trees that are likely to be of superior form or size at the age of clearfelling. Accuracy of prediction improved with age, and by the time of production thinning (age 12-14) a manager can place considerable reliance in the choice of crop trees. Change of dominance appears to be more pronounced in lower-stocked stands. -
Height growth of Pinus radiata as affected by stocking
Author(s) J. P. Maclaren, J. C. Grace, M. O. Kimberley, R. L. Knowles and G. G. West ISSN 0048-0134 File size 978.1 kb Pages 73-90 Issue 1 Volume 25 Results from 29 semi-mature trails of New Zealand P. radiata indicate that height growth is positively correlated with final-crop stocking in certain circumstances, and where stockings are less than 800 stems/ha (higher stockings were not analysed). A subsidiary dataset, with ages from planting to 7 years, gave results that confirmed these. For 12 of these trials there was an average height loss of 0.13 m/year after thinning to final stockings, or approximately 2 m over one typical rotation, for every halving in stocking. One possibility is that this effect is due to wind: lower stockings incur greater wind turbulence, which reduces height growth. In order to standardise descriptions of stand height a new equation was calculated to predict mean top height from predominant mean height. -
Micronutrient and macronutrient uptake by Pinus radiata, and soil boron fractions, as affected by added nitrogen and boron
Author(s) S. T. Olykan, J. A. Adams, A. H. Nordmeyer and R. G. McLaren ISSN 0048-0134 File size 734.2 kb Pages 61-72 Issue 1 Volume 25 Changes in soil boron fractions, dry weights of biomass components (needles, branches, stem bark, stem wood) and uptake of nitrogen, phosphorus, potassium, calcium, magnesium, boron, copper, and a zinc were studied in a 4-year-old Pinus radiata stand in Ashley Forest, North Canterbury, 1 year after application of urea at 0 and 400 kg N/ha and/or ulexite at 0 and 7.4 kg B/ha. Significant responses to both the applied nitrogen and boron were measured in total above-ground tree biomass. The needle, branch, and stem components were significantly heavier in the trees fertilized with boron alone, but only the needle component was significantly heavier where nitrogen fertilizer has been added alone. Increased tree growth was associated with increased total uptake of all nutrients except phosphorus and potassium which increased only in trees treated with ulexite. Increased nutrient uptake was measured mainly in needles of trees treated with urea, but in needles and branches of those to which ulexite was applied. Nutrient concentrations of non-fertilizer elements remained similar or declined in trees to which fertilizer was applied. This was attributed to dilution effects and/or internal translocation between biomass components. Boron application significantly increased boron concentrations in the current and 1-year-old needles whereas nitrogen application had no effect on nitrogen concentrations. Some of the added boron was retained in plant-available fractions in the top 20 cm of the soil 1 years after application and this, together with the potential retranslocation of boron within the ulexite-treated trees, will provide a future supply of boron for tree growth. The results confirmed that ulexite is a suitable long-term supplier of fertiliser boron to P. radiata growing in low rainfall areas. -
Pinus radiata seedling growth and micronutrient uptake in a sand culture experiment, as affected by the form of nitrogen
Author(s) S. T. Olykan and J. A. Adams ISSN 0048-0134 File size 726.0 kb Pages 49-59 Issue 1 Volume 25 A pot trial was used to investigate the effect of the form of nitrogen (ammonium or nitrate) and the rate of nitrogen addition, at 1, 2.5, or 5 mM (14, 35, and 70 micro g/ml respectively), on Pinus radiata seedlings grown in sand culture. Ammonium-fed seedlings were taller and had heavier shoots and roots than nitrate-fed seedlings, particularly at the highest rate of nitrogen addition. The ammonium-fed seedlings contained greater total amounts of copper and boron and had a higher percentage of copper, boron, and iron in the shoots than nitrate-fed seedlings. The nitrate-fed seedlings contained significantly more iron. Increasing the rate of nitrogen addition from 14 to 35 micro g/ml increased shoot weights in the ammonium-fed seedlings, increased shoot height in the nitrate-fed seedlings, and increased shoot:root ratios for both forms of nitrogen. Shoot heights of ammonium-fed seedlings increased when the rate of nitrogen increased from 14 to 70 micro g/ml. Within each nitrogen form, the rate of nitrogen addition did not generally affect micronutrient concentrations in the shoots or roots. The concentrations of boron and iron (at all nitrogen rates) and copper (at 70 micro g N/ml) were higher in the nitrate-fed roots than in the ammonium-fed roots but the concentrations of iron and copper (at all nitrogen rates) in the nitrate-fed shoots were significantly less than ammonium-fed shots. The nitrate-fed roots were darker in colour and were more branched and finer than ammonium-fed roots. Organic acids, produced during nitrate reductase activity, may have a role in these differences. -
Magnesium nutrition and dry matter allocation patterns in Pinus radiata
Author(s) T. W. Payn, D. J. Mead, G. M. Will and I. R. Hunter ISSN 0048-0134 File size 642.5 kb Pages 39-48 Issue 1 Volume 25 Pinus radiata seedlings grown in a range of magnesium solution concentrations showed differences in root:shoot ratios, with those exhibiting magnesium deficiency symptoms allocating proportionately less resources to the roots than healthy seedlings. A foliar spray of 2% magnesium solution with 0.2% PulseTM in water alleviated the deficiency symptoms and improved dry matter allocation to the roots. In a 7-year-old P. radiata fertilizer trial, magnesium fertilizer treatments caused no improvement in basal area or height after 6 years but foliar magnesium concentrations had been raised above the critical level. Trees with adequate foliar magnesium had nearly double the fine root biomass of those with inadequate concentrations. This suggested that below-ground dry matter allocation was decreased in deficient trees, and that the noted slow growth response of P. radiata to magnesium fertilizer may be due to the need to rebuild the root system before an above-ground response occurs. However, while fine root (<1 mm) biomass was increased in 3-year-old trees treated 18 months previously with magnesium fertilizer, no relationship between root:shoot ratio and magnesium application was found. It was suggested that the changes in root:shoot ratio may develop over a period longer than 3 years. -
Preferences for land-use options involving forestry in the Mackenzie/Waitaki Basin
Author(s) J. R. Fairweather and S. R. Swaffield ISSN 0048-0134 File size 81.9 kb Pages 20-38 Issue 1 Volume 25 The New Zealand Resource Management Act 1991 emphasises the importance of assessing the potential environmental effects of land-use change. Forestry is a potential land-use in the Mackenzie/Waitaki Basin but its effects are not acceptable to everyone. The preferences of stakeholders were investigated for different land-use options involving forestry. Using a 'Q sort' technique, stakeholders expressed preferences for cards that presented environmental effects of a range of technically feasible land-use options, including forestry, agriculture, and conservation. Analysis of the results identified several clear "themes', or sets of preferences, characterized by a distinctive set of preferred land-use options, and a distinctive combination of effects. Each theme has specific criteria for judging acceptability. -
Protective value of regenerating tea tree stands on erosion-prone hill country, East Coast, North Island, New Zealand
Author(s) D. O. Bergin, M. O. Kimberley and M. Marden ISSN 0048-0134 File size 893.3 kb Pages 3-19 Issue 1 Volume 25 The effect of pasture reversion to tea tree communities (comprising Leptospermum scoparium and/or Kunzea ericoides var. ericoides of varying ages) on landslide damage resulting from Cyclone Bola was studied in hill country on the East Coast of the North Island, New Zealand. Eighteen sites containing areas of both pasture and regenerating forest aged 6-79 years were selected from areas of steep, colluvial-covered slopes prone to shallow landslipping. Vegetation composition and stand dynamics were ascertained from sample plots, and aerial photographs were used to measure landslide damage. Manuka dominated younger stands but within 20-30 years of establishment, kanuka had become dominant. Landslide damage showed a rapid and high significant reduction against increasing age of tea tree stands and was estimated to be 65% less than pasture at 10 years and 90% less at 20 years.
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