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NZJFS - Volume 20 (1990)
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Corrigendum (Note) for Frederick, D. J., Madgwick, H. A. I., Jurgensen, M. F., & Oliver, G. R., 1985: Dry matter, energy, and nutrient contents of 8-year-old stands of Eucalyptus regnans, Acacia dealbata, and Pinus radiata in New Zealand. 15(2), 142-157.
D.J. Frederick, H.A.I. Madgewick, M.F. Jurgensen, and G.R. Oliver
Issue 3. 01/01/2011. 353.
[72.4 KB]. -
Pyrolysis products of Pinus contorta bark
T.D. Lomax and R.A. Franich
Issue 3. 349-352.
ISSN 0048-0134. [395.9 KB].The yields of char, tar, and non-condensible gases from the pyrolysis of Pinus contorta Loudon bark were measured. The major components of the pyrolysis tar (5.5% yield) were catechol and 2-methyl catechol. Pyrolysis gave 45% char with ash content 3.5% (mainly aluminium, calcium, potassium, and silica). -
AUTOSAW system for sawing simulation
C. L. Todoroki
Issue 3. 332-348.
ISSN 0048-0134. [1.4 MB].A PC-based system, comprising three programs, has been developed to simulate the sawing of pruned logs. Timber grades, conversions, and values may be produced for both individual logs and batches of logs. The number of logs which may be processed in any given batch is unrestricted. Simulations may be performed either interactively or as part of an automated process. Automated sessions require 8 to 16 seconds to process each log whilst interactive sessions, which provide graphic images of the log at each stage of the simulation, may be interrupted at any stage. -
Linear programming and related approaches in forest planning
O. Garcia
Issue 3. 307-331.
ISSN 0048-0134. [2.9 MB].A number of approaches to forest management planning are surveyed and analysed. A unified treatment of the various models and optimisation techniques is attempted, aiming at a better understanding of their essential characteristics and interrelationships. Ways of improving computational efficiency are examined. Structures for the forestry submodel are classified into three basic types, and interpreted in terms of network flows. A utilisation / economics submodel, comprising an objective function and constraints representing supply requirements, yield regulation, terminal conditions, and other aspects of the management problem, completes the formulation. A new criterion for yield regulation, based on irreversible investment concepts, is discussed in detail. The optimisation methods proposed in the literature for solving forest planning problems are evaluated, together with other potentially useful techniques and strategies. Topics covered include the use of standard Linear Programming packages, the prospects of decomposition and partitioning methods, the potential for utilising oldest-first and other cutting priorities, the explicit use of time structure in Dynamic Linear Programming and Optimal Control Theory algorithms, and the Hoganson-Rose procedure and its relationship to Lagrangian relaxation. -
Triclopyr : the forest managers' alternative to 2 4 5-T?
J. M. Balneaves and N. A. Davenhill
Issue 3. 295-306.
ISSN 0048-0134. [1.2 MB].Two triclopyr formulations (3,5,6-tricloro-2-pyridyloxyacetic acid) were evaluated at various rates sprayed over three tree species (Pinus radiata D. Don, Cupressus macrocarpa Hartweg, Pseudotsuga menziesii (Mirbel) Franco), and the likely impact on gorse (Ulex europaeus L.) regrowth after initial land clearing was assessed. Post-plant release spraying with triclopyr is feasible if rates do not exceed 0.6 kg/ha. Release spraying should be carried out before the flush of new growth in the spring (for Ps. menziesii, before bud swell) to avoid apical death, multi-leadering, and reduced growth. Triclopyr should be used in preference to triclopyr + picloram as it is less damaging to tree seedlings and gives more effective gorse suppression for the first year after tree planting. -
Offspring sex ratios of Bracon phylacteophagus as influenced by host size and maternal age.
W. Faulds
Issue 3. 290-294.
ISSN 0048-0134. [435.4 KB].Laboratory studies of Bracon phylacteophagus Austin (Hym: Braconidae) showed that significantly higher offspring sex ratios (male: female) were produced from small hosts than from large hosts and evidence suggests that selective oviposition was the main factor influencing this relationship. Females produced a higher ratio of male offspring later in life than they did earlier in life from large hosts. -
Selection of special-purpose species effect of pests and diseases
I. Nicholas and E. Hay
Issue 3. 279-289.
ISSN 0048-0134. [1.3 MB].Special-purpose timber species are being grown in New Zealand for high-quality end-uses, especially furniture, joinery, and veneers. The main species are Acacia melanoxylon R. Br., Juglans nigra L., Cupressus macrocarpa Hartw., C. lusitanica Mill., Eucalyptus regnans F. Muell., E. delegatensis R. Baker., E. saligna Smith., E. fastigata Deane & Maiden, and E. botryoides Smith. These species suffer attack from a range of wood- and foliage-damaging insects and fungi; however, none is severe enough to restrict a species' growth, lower its wood quality, or limit its planting. Foliage-attacking insects have increased in the last decade, with the eucalypts being the main hosts because of the close proximity to Australia and the favourable wind flows. Success has been achieved with biological control programmes on two pests which were potentially limiting for eucalypt planting. Fungal health problems, although apparent at times, have yet to prove to be major limiting factors. Further research is required to evaluate the effect of insect damage on the end wood product. Current experience in growing special-purpose species indicates that the original species selection is still sound from the health perspective. -
Response of young Pinus radiata to cultivation and fertiliser near Motueka, New Zealand
D. J. Mead
Issue 3. 268-278.
ISSN 0048-0134. [1.2 MB].Heavy broadcast applications of superphosphate (112 kg P/ha at planting and 75 kg P/ha at age 7) improved growth rates of Pinus radiata D. Don during the 11-year study period by two or three times over the untreated plots. However, even these rates were unable to maintain phosphorus concentrations at non-limiting levels for more than a few years after application. Boron fertiliser prevented dieback, although there was no response in tree volume. Individual-tree doses of nitrogen fertiliser (17 g/tree) applied along with phosphorus and boron in the first two growing seasons, resulted by age 5 years in a 0.6-m height growth increase over plots treated with phosphorus and boron alone. However, a volume response was not detectable at age 7. Application of 150 kg N/ha with phosphorus and boron after thinning at age 7 years led to a 12% volume response over the phosphorus plus boron treatment by age 11 years. However, this response was only short-lived. There was no response to nitrogen in the absence of phosphorus and boron. Associated with the response to phosphorus were increases in branch size. Ripping to 0.75 m improved growth rates but discing had no effect. The response in volume to ripping was 13 and 27 m3/ha at ages 7 and 11 years, respectively. -
Water potential and subsequent growth of Pinus radiata seedlings influence of lifting, packaging and storage conditions
J. M. Balneaves and M. I. Menzies
Issue 3. 257-267.
ISSN 0048-0134. [984.1 KB].The integrated system widely used in New Zealand for planting out Pinus radiata D. Don seedlings minimises handling and facilitates the smooth flow of tree stocks from nursery to field, reducing the time between lifting and planting. However, some instances of desiccation have been reported, especially in seedlings at the top of cartons, and so various methods of minimising this problem were evaluated. Where soil conditions are dry, irrigation of nursery beds can help minimise the early afternoon water deficit. Seedlings lifted early in the morning or late in the afternoon, with their roots dipped in water, and with overnight cool storing, gave the best growth after planting. In one trial, dipping the roots of the seedlings from the top third of the carton in water, spraying the roots with water, and folding plastic flaps over the roots in cartons were all beneficial compared with no watering. In another trial where seedlings were dipped in water, a wet hessian blanket over the roots was slightly more effective than a plastic liner, and both were significantly better than no extra protection. -
Nematodes in New Zealand forest nurseries
G. W. Yeates
Issue 3. 249-256.
ISSN 0048-0134. [865.7 KB].A survey of nine nurseries (36 blocks) yielded no nematode populations at damaging levels. Rotylenchus robustus (de Man) Filipjev was recorded, as were total populations of root-feeding, fungal-feeding, bacterial-feeding, and omnivorous nematodes. Current management practices of rotation and tillage appear to be keeping populations of Trichodorus, Rotylenchus, Pratylenchus, and Paratylenchus spp. below levels at which they may cause economic damage. -
Book review - Davis, T.D., Haissig, B.E. & Sankhla, N. (Eds.) 1988: Adventitious root formation in cuttings.
Menzies, M.
Issue 2. 01/01/2011. 245-246.
ISSN 0048-0134. [163.3 KB]. -
Changes in transverse wood permeability during the drying of Dacrydium cupressinum and Pinus radiata
R. E. Booker
Issue 2. 231-244.
ISSN 0048-0134. [3.6 MB].When softwoods are dried and subsequently impregnated with waterborne preservatives two problems frequently occur—preservative screening of multi-salt preservatives and difficult re-drying. To study the causes, the permeability of Dacrydium cupressinum Lamb, (rimu) and Pinus radiata D. Don wood was measured along the three principal directions. These two softwood species are anatomically very similar, but differ in that rimu has no resin canals. The radial and tangential permeabilities of the green sapwood of the two species were similar and of the order of 10-16 m2. The transverse permeability of the green rimu intermediate wood was lower and of the order of 10-17 m2. After drying andresaturation the radial and tangential permeability of the rimu intermediate wood were practically unchanged, while the transverse permeability of the sapwood dropped to that of the intermediate wood. For P. radiata sapwood the tangential permeability decreased to 10-18 m2. In contrast, after drying and resaturation the radial permeability of P. radiata sapwood was of the order of 10-14 m2, two orders of magnitude greater than for the green wood. This increase in radial permeability was caused by an interplay of flow along the radial and axial resin canals. It is believed that the absence of preservative screening in P. radiata sapwood during impregnation is due to rapid dispersal of preservative solution along the resin canals, followed by movement into the tracheids where the preservative fixes to the cell walls. This mechanism cannot operate in rimu wood as it does not have resin canals, and so preservative screening occurs. -
Provenance variation in wood properties of Pinus caribaea var hondurensis
J. A. Wright
Issue 2. 220-230.
ISSN 0048-0134. [122.0 KB].Variation in the densitometry traits of wood density (DEN) and within-sample density variation (VAR) of 11 provenances of Pinus caribaea var. hondurensis Barr. and Golf, at 11 sites was studied. The analysis of variance revealed significant differences (p 0.001) between sites and provenances for DEN and VAR, with site accounting for more of the variance than provenance. The site x provenance interaction term was not statistically significant and accounted for none of the variance. Thus, provenances were consistently ranked for DEN and VAR regardless of site. The lowest values for DEN and VAR were at sites with higher altitude ( 1000 m). Coastal provenances were generally lower for DEN and VAR than inland provenances but these differences were not significant. -
Spring needle-cast of Pinus radiata in Tasmania: II. Effects of fertilisers and thinning on disease severity, and the impact of disease on growth
F. D. Podger and T. J. Wardlaw
Issue 2. 206-219.
ISSN 0048-0134. [1.6 MB].Four field experiments were established in closed stands of Pinus radiata D. Don in north-western Tasmania to test the effectiveness of soil applications of nitrogen, phosphorus, sulphur, and a comprehensive fertiliser formulation in correcting or preventing the development of the defoliating disease "spring needle-cast" (SNC). They provided no support for hypotheses that chronic nutrient deficiencies contribute to the disease. The possibility that seasonal but ephemeral deficiency in one or more nutrients might predispose susceptible individuals to SNC remains to be tested. Over a 4-year period, between 9 and 13 years after planting, the diameter growth of SNC-affected trees in an unthinned stand was reduced by 14% for each 10% increase in defoliation. This is comparable to that reported for Dothistroma needle blight and Cyclaneusma needle-cast in New Zealand. In a younger stand the impact on diameter growth was less but increased over successive measurement intervals. In stands thinned prior to the onset of SNC the development of significant disease was delayed by 2-5 years. -
Spring needle-cast of Pinus radiata in Tasmania: I. Symptoms, distribution, and association with Cyclaneusma minus
F. D. Podger and T. J. Wardlaw
Issue 2. 184-205.
ISSN 0048-0134. [2.4 MB]."Spring needle-cast" (SNC) is an undiagnosed disease of Pinus radiata D. Don which causes a rapid browning and collapse of mesophyll tissues of 1 -year-old needles in spring and is followed by premature and heavy casting of needles. It first appears about the time of canopy closure and affects between 40% and 80% of trees randomly distributed in closed stands in areas of Tasmania which receive between 1200 and 2000 mm annual rainfall. The incidence and severity of disease appear not to be highly sensitive to local topographic variation and remain relatively constant from year to year. SNC is distinguished from other foliar diseases and disorders of P. radiata in Tasmania, including Dothistroma septospora Morelet, on the basis of gross symptoms and the phenology of their development. Three common needle-inhabiting fungi, Cyclaneusma minus (Butin) DiCosmo Peredo & Minter, Lophodermiumpinastri (Schard. ex Fr.) Chev., and Strasseria geniculata (Berk. & Br.) Hohn., were ubiquitous on fallen dead needles, but none was constantly associated with recently cast needles on SNC-affected trees. Complete foliar sprays with chlorothalinol (500 g a.i./L) at intervals of 6 weeks for the first 6 months of one growing season markedly improved needle retention. -
Growth of pampas grass (Cortaderia spp.) in New Zealand Pinus radiata forests
R. L. Gadgil, P. G. Barton, P. J. Allen and A. M. Sandberg
Issue 2. 176-183.
ISSN 0048-0134. [664.1 KB].Rate of pampas (Cortaderia selloana (Schult.) Asch. et Graeb. and C. jubata (Lem.) Stapf) growth in five Pinus radiata D. Don forests was only slightly less than in managed agricultural pampas plantations. Number of plants per unit area tended to be higher on phosphate-amended clay soils than on pumice or coastal sands, but the maximum rate of above-ground dry matter accumulation on these soils was similar (7-8 t/ha/year). Greatest accumulation of pampas dry matter (55 t/ha at age 4) was recorded on a coastal sand in an area where no trees were present. The highest dry matter accumulation recorded in a tree stand was 46 t/ha on a pumice soil. -
Herbicides increase growth responses to fertilizer in a 5-year-old Eucalyptus regnans plantation
M. G. Messina
Issue 2. 168-175.
ISSN 0048-0134. [899.0 KB].A 5-year-old Eucalyptus regnans F. Muell. plantation in the Napier district of the North Island of New Zealand was treated with 200 kg diammonium phosphate (DAP) + 250 kg urea/ha or 200 kg DAP + 500 kg urea/ha, and with a 2% solution of glyphosate applied at a rate of approximately 3L/a.i./ha, in an incomplete factorial design. Reduction of herbaceous/shrubby competition significantly (p = 0.05) increased 20-month diameterat-breast-height and volume increments but did not affect height increment. Fertiliser significantly influenced height increment, but did not affect diameter and volume increment over the 20-month study period. Neither herbicide nor fertiliser treatment significantly influenced foliar nutrient concentrations. The study showed that weed control can be as important as fertiliser in enhancing eucalypt growth. -
Diameter growth of Eucalyptus grandis under conditions of extreme suppression
B. V. Bredenkamp and H. E. Burkhart
Issue 2. 162-167.
ISSN 0048-0134. [578.6 KB].Investigation of Eucalyptus grandis Maiden stands under conditions of extreme suppression indicated that diameter growth of dominant individuals continues even when that of suppressed individuals ceases altogether and mean diameter growth of the stand is minimal. An increase in the mean diameter of the suppressed stand is due to a real increase in the size of the mean tree and is not merely an artifact of mortality amongst the lower size classes. -
Early growth of Eucalyptus delegatensis provenances in four field trials in south-eastern Australia
G. F. Moran, R. I. Forrester and A. F. Rout
Issue 2. 148-161.
ISSN 0048-0134. [1.5 MB].Investigation of Eucalyptus grandis Maiden stands under conditions of extreme suppression indicated that diameter growth of dominant individuals continues even when that of suppressed individuals ceases altogether and mean diameter growth of the stand is minimal. An increase in the mean diameter of the suppressed stand is due to a real increase in the size of the mean tree and is not merely an artifact of mortality amongst the lower size classes. -
Internode length of hoop pine genetic parameters and prospects for developing a long internode breed
M. J. J. Dieters, R. R. Woolaston and D. G. Nikles
Issue 2. 138-147.
ISSN 0048-0134. [877.6 KB].Internode length of Araucana cunninghamii Ait. ex D. Don (hoop pine) is moderately to strongly inherited (average h2=0.48), but shows no strong genetic correlations with vigour or stem straightness traits. Although it is feasible to develop a long-internode breed through recurrent selection and conventional multiclonal seed orchards, the addition of an extra selection criteria to those of the main breed, in the absence of favourable genetic correlations, may result in some loss of gain in growth rate and stem straightness compared to the main breed. -
Strangulation of pre-treatment effect on the development and rooting of fascicle cuttings of Pinus radiata
D. S. Koh, M. I. Menzies and S. O. Hong
Issue 2. 129-137.
ISSN 0048-0134. [1010.7 KB].The effect of strangulation of the stems of 2- and 7-year-old Pinus radiata D. Don trees on the development and rootability of fascicle shoots was examined. Strangulation of the stems of juvenile P. radiata may be beneficial, in terms of subsequent development of shoots from needle fascicles, and speed and percentage of rooting. Both the development and rootability of needle fascicle shoots declined with increased spacing of strangulation along the stem. Strangulation of stems of 7-year-old trees was done at different crown positions, using clones that were easy and difficult to root as stem cuttings. Fascicle bud development was better in the upper part of the crown but strangulation had no significant effect. Needle fascicle development varied with clone, and there was no significant difference between easy- and difficult-to-root clones. None of the fascicle buds from 7-year-old trees had rooted 90 days after setting. -
Area conservation mechanisms associated with forest management
L. R. Broad
Issue 1. 120-126.
ISSN 0048-0134. [717.8 KB].Two area conservation mechanisms that are examined are commonly used within mathematical programming formulations of forest management problems. The mechanisms associated acyclic networks. That each mechanism allows for differing management alternatives is readily apparent from the network structures. Each mechanism is consistent with networks familiar to operations research, that is multi-item replacement networks. The network structures can be used with network programming and decomposition techniques to facilitate solutions to forest management problems. -
Analysis and simulation of a logging weighbridge installation
D. C. McNickle and R. C. Woollons
Issue 1. 111-119.
ISSN 0048-0134. [887.7 KB].Queuing theory and simulation methods were used to quickly and inexpensively estimate waiting times at a forest industry weighbridge system. Arrival, beginning, and finishing times of trucks were measured over 2 days. Inter-arrival times were exponentially distributed, allowing the system to be approximated by a simple queuing model. Estimates of queue waiting times agreed well with observed values. The models suggested that if a second weighbridge were installed it could save over 50 hours of truck time per day. They were also used to demonstrate that the system then in use was operating at close to its maximum capacity. A simulation model written in GPSS validated the approximations that had been used to fit the queuing formulas. The simulation also demonstrated the difficulty of estimating mean waiting times accurately by observation, in systems where the traffic intensity is high. There may be other areas in forestry research which would benefit from similar analyses, probably leading to increased efficiency. -
Structural root morphology and biomass of three age-classes of Pinus radiata
A. Watson and C. O'Loughlin
Issue 1. 97-110.
ISSN 0048-0134. [1.4 MB].The root systems of 13 Pinus radiata D. Don. trees from three age-classes in Mangatu Forest were hydraulically excavated. Each system was drawn in plan and elevation, then dissected and sorted into six diameter-classes for weight and length measurements to obtain information on changes in root biomass and root extension with time. Lateral roots had a maximum length of 4.7, 6.4, and 10.4 m at ages 8, 16, and 25 years respectively. Vertical roots grew to depths of 2.1, 2.6, and 3.1 m for the three age-classes respectively. At 8 years the root bole contained 40% of the total root weight. This increased to approximately 50% after 16 years. Stand biomass of roots was 9, 67, and 151 tonnes/ha at a stocking rate of 253 stems/ha for the three age-classes respectively. Total root weight (kg) was regressed on diameter at breast height (cm) to give the relationship: loge(total root weight) = 2.24 loge(dbh) - 2.68 (r2 = 0.99), which can be used to estimate the below-ground biomass from dbh. -
Species associations in Ips grandicollis galleries in Pinus taeda
C. Stone and J. A. Simpson
Issue 1. 75-96.
ISSN 0048-0134. [2.2 MB].This 15-month study examined the species composition and abundance of communities of invertebrates and fungi in Ips grandicollis Eichhoff galleries in billets of Pinus taeda L. from two localities in north-eastern New South Wales, Australia. Based on monthly sampling of billets which were examined 30 to 60 days after felling, a total of 32 species of insects, six species of Collembola, 30 species of mites, 15 species of nematodes, and 14 species of fungi were recovered. Species constellations were produced for each locality. Species phoretically or parasitically associated with / grandicollis formed a colonising guild, while those species not known to possess such host relationships formed a decay guild. Fungal species had the greatest number of positive associations with species of insects, mites, and nematodes associated with /. grandicollis. Total number of mites and of nematodes per unit sampling area was positively correlated to the development stage of I. grandicollis. The relationship between billet aspect and percentage moisture content of bark plus cambium influenced gallery nematode counts. -
Leaf-inhabiting fungi of eucalypts in New Zealand. II.
M. Dick
Issue 1. 65-74.
ISSN 0048-0134. [1.1 MB].Elsinoe eucalypti Hansford, Macrohilum eucalypti Swart, Microsphaeropsis conielloides Sutton, Pachysacca pusilla Swart, Seimatosporium cylindrosporum Swart, S. falcatum (Sutton) Shoemaker, S. fusisporum Swart & Griffiths, and Vermisporium obtusum Swart & Williamson are reported on Eucalyptus spp. leaves for the first time in New Zealand. Coccomyces globosus Johnston, which is known on three indigenous hosts, has been found on four species of Eucalyptus. Species of Hendersonia previously reported on Eucalyptus in New Zealand are now placed in the genus Sonderhenia. Mycosphaerella swartii Park & Keane, the teleomorph of Sonderhenia eucalyptorum (Hansford) Swart & J. Walker, is reported for the first time. New host records are listed for six other fungi on Eucalyptus. -
Introduction into New Zealand of Bracon phylacteophagus, a biocontrol agent of Phylacteophaga froggatti, eucalyptus leaf-mining sawfly
W. Faulds
Issue 1. 54-64.
ISSN 0048-0134. [1.1 MB].A braconid was imported into New Zealand from Australia to control the introduced Eucalyptus leaf-mining sawfly Phylacteophaga froggatti Riek (Hym. : Pergidae). Difficulties in rearing the parasite in quarantine facilities were overcome after it was discovered that the imported material included two closely related Bracon spp. with different mating requirements. The principal parasite (subsequently described as Bracon phylacteophagus Austin (Hym.: Braconidae)) was released and is now well established in some localities. Early results show a very rapid spread of the parasite with up to 98% parasitism and indicate that the sawfly population should be considerably reduced by late summer 1990. -
Planting density effects on water use efficiency of trees and pasture in an agroforestry experiment
J. Eastham, C. W. Rose, D. A. Charles-Edwards, D. M. Cameron and S. J. Rance
Issue 1. 39-53.
ISSN 0048-0134. [1.5 MB].Water use of trees and pasture were studied at three tree densities in an agroforestry experiment where trees were planted at densities of approximately 2150, 304, and 82 stems/ha in a Nelder design. Tree transpiration and pasture evaporation were related to their respective biomass production to estimate water use efficiencies at each tree density over a 2-year study period throughout 1985 and 1986. Tree planting density was found to modify productivity and water use of both trees and pasture. During dry conditions biomass production per tree was lowest at high tree densities being 19 g/day compared with 69 and 45 g/day at medium and low tree densities respectively. Transpiration rates per tree were also lowest at high tree densities being 12.9 x 10-3 m3/day compared with 54.5 and 72.9 x 10-3 m3/day from medium and low densities respectively. However, water use efficiency was found to be highest in the densely planted trees where mean values for 1985 and 1986 were 4.6 and 3.9 kg/m3 respectively in 1986. Pasture evaporation was generally lowest under the densely planted trees where soil water contents in the pasture root zone were lowest. Pasture production was greatest at the intermediate tree density and this was associated with a higher water use efficiency than was found from pasture under high and low tree densities. -
Variation in nutrient concentrations within Pinus radiata trees and their relationship to tree size
H. A. I. Madgwick and D. J. Mead
Issue 1. 29-38.
ISSN 0048-0134. [868.5 KB].Twelve Pinus radiata D. Don trees were sampled for concentrations of nitrogen, phosphorus, potassium, calcium, and magnesium in foliage by age and crown location, in branches by age, and in stem sections. Crown component nutrient concentrations were more highly correlated with diameter breast height than with either total height or height increment. Foliar nitrogen and phosphorus decreased and calcium and magnesium increased down the crown. Foliar nitrogen and phosphorus decreased and calcium increased with needle age. Branch nitrogen, phosphorus, and potassium decreased and calcium increased with both branch age and stem diameter. Coefficients of variation in foliar nutrients tended to be lowest in 1-year-old foliage. Among nutrients the coefficients were lowest for nitrogen and phosphorus and highest for calcium and magnesium. -
Growth effects of large gaps in Pinus radiata plantations
G. Minko and G. Hepworth
Issue 1. 22-28.
ISSN 0048-0134. [653.8 KB].Effects of circular gaps exceeding 100 m2 in area, on height, diameter, form, and branch size of the gap-edge and non-edge trees in Pinus radiata D. Don plantations were examined at Myrtleford in Victoria, south-eastern Australia. There was little difference between the trees around gaps 6.1m in radius (area 117 m2) and trees further inside the stand. For gaps 9.1 m or greater in radius (area >263 m2), distance from the gap centre had no effect on tree height but, up to a distance of three trees from the gap edge, was negatively related to diameter and volume. Trees located on the sunnier side of gaps had greater diameter and volume than trees on the more shaded side. Edge trees had larger diameter, volume, and more branches with diameter above 2.5 cm than trees inside the stands. The results indicate that for this site and for the particular local market, pruning of edge trees appears necessary to maintain log quality where the gap area approaches or exceeds 250 m2. -
Allozyme analysis in seed and tree identification in New Zealand
H. L. Billington, G. B. Sweet and P. Bolton
Issue 1. 16-21.
ISSN 0048-0134. [612.6 KB].Allozyme analysis by electrophoresis has the potential for many practical uses in tree breeding programmes, orchard management, and seed or clone identification. Of two studies carried out in New Zealand, one was on identification of the race to which three unidentified Pinus muricata D. Don seedlots belonged. The other involved identification of a mislabelled seed orchard clone of Pinus radiata D. Don. -
General and specific combining ability in families of Pinus radiata in New South Wales Australia
I. G. Johnson
Issue 1. 3-15.
ISSN 0048-0134. [1.3 MB].Diameter at 1.3 m and total height were assessed at HV2 years from planting in a control-pollinated progeny test of Pinus radiata D. Don in New South Wales, Australia. The material represented an 18-female x 4-male North Carolina II mating design, with eight crosses missing. The stem diameter and height of each tree were combined in a measure of conic volume. General combining ability (GCA) and specific combining ability (SCA) variances were estimated as measures of additive genetic and dominance variances respectively. Ratios of estimated GCA to SC A for the traits diameter and volume were low (0.4 to 0.5), while that for height was high (3.0). Individual heritability estimates were low (0.07 to 0.09) and imprecise for diameter and volume, but that for height was moderate (0.24). Additive genetic correlations between pairs of growth traits were positive, and relatively high. The over-all agreement in rank between observed means of crosses and values from parental GCAs was such that actual crosses between the few highest-GCA females and males also included a high proportion of the top-ranked families. These results support a "general combiner" strategy of mating parents on the basis of GCA, in control pollinated seed orchards, over the operationally more expensive alternative of reproducing tested crosses.
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