NZJFS - Volume 9 (1979)
Corrigendum for Swanson et al. 1979: Transpiration in mountain beech estimated simultaneously by heat-pulse velocity and climatised cuvette. 9 (2), 170-176Swanson, R. H., Benecke, U. & Havranek, W. M.
Corrigendum for NZJFS 9 (2): 170-176.
The paper which this Corrigendum refers to is available here: Transpiration in mountain beech estimated simultaneously by heat-pulse velocity and climatised cuvette
Potential of unmodified and copper-modified alkylammonium compounds as groundline preservativesButcher, J. A., Preston, A. F., & Drysdale, J.
Pinus radiata D.Don (radiata pine) and Betula alba L. (silver birch) sapwood stakes were exposed for periods of up to 12 months in a fungus cellar after treatment with various unmodified and copper-modified alkylammonium compounds. In general, diaJkyldimethyl ammonium salts performed best, followed by benzalkonium chloride. Primary and tertiary amine salts failed to afford any significant protection from fungal attack. Amendment of treatment solutions with copper salts extended performance of all alkylammonium compounds. Results are discussed in conjunction with short-term field trials, and predictions of long-term field performance are attempted. It is concluded that quaternary ammonium compounds, and in particular dialkyldimethyl compounds, show considerable potential for protection of radiata pine in ground contact. This potential is further extended when treated solutions are modified by addition of cupric salts. None of the preservative formulations tested protected silver birch stakes from soft rot, although some performed as well as copperchrome-arsenate preservative.
Endogone flammicorona as a mycorrhizal symbiont of Douglas-fir in New ZealandChu-chou, M., & Grace, L. J.
Sporocarps of Endogone flammicorona Trappe & Gerdemann were found to be associated with roots of Douglas fir (Pseudotsuga menziesii (Mirb.)Franco) from its seedling stage to trees over 70 years of age. Seedlings of Douglas fir inoculated with pieces of sporocarps of E. flammicorona formed simple, unbranched ectomycorrhizas on short roots. The mycorrhizal seedlings were significantly taller and heavier than the control seedlings. This is the first report of the occurrence of E. flammicorona in New Zealand and of its association as an ectomycorrhizal fungus of Douglas fir in this country.
Seed storage of several New Zealand indigenous trees Part 1: Kauri (Agathis australis)Preest, D.
The viability of kauri seed is ephemeral under ambient conditions. Since collection is difficult, hazardous, and therefore expensive, a satisfactory method of storing seed surplus to requirements would be valuable.
Kauri seed was stored in air-tight containers for up to 11.7 years at moisture contents of 6%, 10%, 15%, and 20% oven-dry weight and at constant temperatures of — 10°, 5°, 10°, 15° and 20°C. Seed longevity was heavily dependent on both these factors, though moisture content was the more critical. The optimum moisture content appeared to be around 6%. For short- to medium-term storage (up to 6 years) the optimum temperature was about 5°C. For longer storage or higher moisture content (10%) the results suggested that the optimum temperature was below freezing point.
This experiment showed that kauri seed can be kept for 5-6 years with viability little impaired, and probably in excess of 12 years with fair viability retained, if stored air-tight under conditions of low moisture content and temperature.
The nutritional role of Lupinus arboreus in coastal sand dune forestry 4: Nitrogen distribution in the ecosystem for the first 5 years after tree plantingGadgil, R. L.
An age sequence of Pinus radiata D. Don stands was studied at Woodhill State Forest, where trees are planted at a nominal 1730 stems/ha into coastal sand which has been partly stabilised with marram grass and perennial tree lupin. During the first 5 years of tree growth the dynamics of dry matter and nitrogen accumulation in the ecosystem were dominated by changes which occurred in the herbaceous vegetation.
Crushing during tree planting and spray releasing of trees during the first year had a profound effect on both lupins and marram grass with the result that litter, rather than lupin plant tops, became the largest contributor to total dry matter and its nitrogen content for the remainder of the study period.
Lupins regenerated to 85% of their former productivity during the second year of tree growth but declined between years two and five. The marram component showed a much slower rate of decline during the same period.
There was no overall increase in dry matter or nitrogen content of the ecosystem between years two and five and it is inferred that the chief source of nitrogen for tree growth was the nitrogen fixed by the lupin and stored in the herbaceous plants and their litter.
Early patterns of Armillaria root rot in New Zealand pine plantations converted from indigenous forest - an alternative interpretationRoth, L. F., Shaw III, C. G., MacKenzie, M., & Crockett, F.
Patchy occurrence of root rot in pine plantations aggravates economic loss by removing land from production. On sites of former indigenous forest in the North Island of New Zealand, patches of Armillaria root rot develop within the rooting area of former large trees, especially Beilschmiedia tawa (A. Cunn.) Ben th. et Hook. f. ex Kirk and Podocarpaceae. Seedlings planted near larger infected roots of the old tree die quickly and almost concurrently at and away from the stump. Later a zone of peak mortality progresses successively from the stump outward as the seedling stand is depleted near the stump and as distances between seedlings and infectious main roots away from the stump become greater. An impression of indeterminate, rapid, patch enlargement results which may be misleading. Until the dynamics of patch development are better understood, quantitative prediction of any losses that might accompany aging of the patches should be made with caution.
Root anchorage and root morphology of Pinus radiata on a range of ripping treatmentsSomerville, A.
The root anchoring properties of 11 1/2-year-old Pinus radiata D. Don, grown at Eyrewell State Forest after a range of ground preparation treatments, were tested by winching over sample trees and recording resistance with a strain gauge. The study included naturally regenerated and hand-planted stock on unripped ground, and machine-planted stock on ripped ground that had been treated in four different ways. Altogether 62 trees were winched over during February and March 1978. An increase in anchoring ability of roots in deep rips (to 120 cm) resulted in a tendency towards stem failure rather than the uprooting that characterised other treatments and which is the usual mode of failure in windthrow on the Canterbury Plains.
Sixty-one root systems were excavated in April and May 1978 and measured to examine the main differences between treatments. Natural regeneration had a greater total root weight than did planted stock. Laterals contributed two-thirds of the total root weight in all treatments and were mostly located near the surface. Deep ripping treatments markedly altered root distribution but not total root weights. The greatest differences between treatments were in the sinker roots. Increased depth of ripping resulted in redistribution of sinker roots downwards which accounted for the increased root anchorage of the trees in these treatments. While regeneration tended to form large straight-grained tap roots where soil conditions permitted, nursery stock (particularly 2/0 stock) formed few tap roots and a number of smaller diameter sinkers which often fractured at the base of the stem when under stress. Roots were significantly aligned along rips. Some treatments showed evidence of a slight asymmetrical root development associated with the north-west wind.
Root-wood strength deterioration in radiata pine after clearfellingO'Loughlin, C., & Watson, A.
The tensile wood strength (kPa) of small roots of Pinus radiata D.Don (radiata pine) sampled from living trees and from stumps cut 3, 9, 14, and 29 months prior to sampling, was examined. Mean live root-wood strength was 17 600 kPa which is considerably less than the wood strengths of similar-sized roots from other species studied overseas. Mean root-wood tensile strength declined in an exponential manner after felling of the parent trees. Calculated time to half strength was only 14 months.
Fungicidal control of Phaeocryptopus gaeumannii infection in a 19-year-old Douglas-fir standHood, I. A., & van der Pas, J. B.
Sixty-eight trees in a stand of unhealthy 19-year-old Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) were treated with fungicides either by spraying twiceyearly for 2 years, or by injection three times during 4 years. Handspraying crown foliage to beyond run-off point during the growing season with separate applications of 0.05% copper (as copper oxychloride; 0.1% Multifilm X-77 added) and/or 0.02% triforine reduced plot mean current-needle infection by Phaeocryptopus gaeumannii (Rohde) Petrak from ≥ 99% to 42% or less. Helicopter spraying with these chemicals at about 2240 litres/ha/application was ineffective mean infection ≥ 96%) and cannot yet be recommended for the control of P. gaeumantiii in forest management. Trunk injections of 0.35% carbendazim in N/10 HCi at a rate of 3-4 litres/tree/injection reduced plot mean infection 13% or less after two seasons. Positive responses in growth (all injection plots) and needle retention (one plot) were indicated 2 and 4 years, respectively, after injection plots were first treated. Most trees handsprayed with copper and several injected trees developed phototoxicity symptoms after treatment.
Surface area of needles in Pinus radiata - variation with respect to age and crown positionBenecke, U.
Needle weight per unit surface-area was determined for Pinus radiata D.Don fascicles by coating needles with glass balls suspended in a fluidised bed. Within a tree-crown, weight/area of needles increased with age and declined strongly with increasing shade. In an unthinned canopy the decline from sun- to shadecrown was 31%, while in an open thinned canopy it was 26%. Fascicle position within the crown, therefore, requires recognition when determining foliage surface-area from needle mass by the method described.
The peppermint group of eucalyptsWilcox, M. D.
The peppermints constitute a distinctive natural group of 10 eucalypts of the subgenus Monocalyptus. They share several morphological features of bark, seedling characteristics, timber properties, fruits and buds, and are especially characterised by high concentrations of essential oil in the leaves.
While none of these eucalypts is commercially important for forestry in New Zealand, most have been planted on a small scale, and some make handsome ornamentals. The group is currently being comprehensively tested for suitability in soil erosion control in the Wairarapa district.
An early progeny trial in Pinus radiata 2: Subjective assessment of crookednessBannister, M. H.
Five independent observers assessed more than 1600 stems of Pinus radiata D.Don for crookedness on a 0-9 scale. Inconsistencies in the scoring of individual observers resulted in erratic changes in the mean and the variance as the work progressed; this was probably the origin of four distinct interactions, which contributed a small but statistically significant part of the total variance. The error variance of the individual observer was about 0.5 and constituted about 32% of the total variance.
The frequency distributions of the errors generally showed significant departures from the normal, but for no consistent reason. In some there was skewness, in some positive kurtosis, and most showed apparently anomalous frequencies in some classes. As expected, the mean score of five observers per tree was greatly superior in its statistical properties to the single scores, the departure of its frequency distribution from the normal falling well short of the 5% significance level.
The variance of the errors showed significant heterogeneity and were to some extent correlated with the means. Attempts to eliminate these undesirable features by transformations were only partly successful; but, despite rather severe changes brought about by the transformation, the analyses of variance made before and after transformation gave essentially the same results.
The data were analysed as five separate sets (one from each observer) and as a single set combining the five scores for each tree. The results consistently indicated the presence of a substantial families component in the total variance (P <
A method for assessment of recoverable volume by log typesDeadman, M. W., & Goulding, C. J.
This paper describes a method for assessing the recoverable volume by log types of a single species stand of trees shortly before harvesting. The method takes into account the influences on yield of stem quality and malformation, and of log specifications and preferences. Trees are cruised for quality and malformation. No attempt is made to divide trees into logs in the field. During computer analysis of the inventory data, lists of log specifications and values control a dynamic programming optimisation process which estimates the potential yield from each stem. A test of the method at ten clear felling sites indicated that good results were attainable, the overall error in recovered volume being 3.7 percent. An operational system based on the method is now being used by the N.Z. Forest Service.
Fluctuation in opossum populations along the north bank of the Taramakau Catchment and its effect on the forest canopy. See Corrigendum, 11(1), 1.Pekelharing, C. J.
Fluctuations in density patterns of opossum populations were studied by faecal pellet counts, along the North Bank of the Taramakau catchment from 1970 to 1977. The study area contained two major vegetation associations, rata/kamahi forest and red beech forest. Variations in density patterns over the years indicated that peak population numbers in the beech forests were approximately half those in the rata/kamahi forests. The upper transitional forests above both major forest types, however, reached similar peak densities. Canopy defoliation was studied by aerial photography in 1980 and in 1973. Within 13 years over 40% of the canopy in these protection forests was defoliated. This large-scale defoliation coincided with a build-up and peaking of the opossum population.
In the winter of 1974 the whole area was poisoned by air with 1080 (sodium monofluoroacetate) impregnated carrot. Approximately 85% of the opossum population was removed by this operation. The greatest decline in pellet densities was recorded in the lower and mid-forest strata.
A Corrigendum to this paper is available here: Fluctuation in opossum populations along the north bank of the Taramakau Catchment and its effect on the forest canopy
Sustained growth responses to superphosphate applied to established stands of Pinus radiataFlinn, D. W., Moller, I. M., & Hopmans, P.
Growth responses to superphosphate broadcast applied at 630 and 1260 kg ha-1 to 9- to 18-year-old unthinned stands of Pinus radiata at three sites in the Scarsdale plantation (Victoria) have been measured for up to 13 years after treatment. A substantial basal area response was found for both rates of superphosphate and there is evidence that on at least two of the sites the responses will continue through to rotation age with a commensurate increase in site productivity. Sectional measurements showed that form factor of the co-dominant and partly suppressed trees was not significantly influenced by fertiliser addition.
Basal area growth curves together with favourable soil P retention characteristics and differential soil and foliar P levels between treatments indicated that the higher application rate of superphosphate will provide substantially higher yields at rotation age than the lower rate. Responses to the higher rate represented an increase in standing volume of at last 100 m3 ha-1 at all sites over the 11-13 year period after treatment and reduced the time taken to obtain the equivalent basal area growth on unfertilised sites by over four years.
Foliar and soil analyses showed that the sites were not only P deficient but also low in Ca and high in Al. Correction of mild Ca deficiency and alleviation of the adverse effects of Al on the P nutrition of P. radiata by the application of superphosphate probably contributed to the substantial responses obtained.
Seedling growth in tanekaha (Phyllocladus trichomanoides): effects of shade and other seedling speciesPook, E. W.
Seedlings of tanekaha (Phyllocladus frichomanoides) were grown alone and in a mixture with kauri (Agathis australis), mapau (Myrsine australis) and lancewood (Pseudopanax crassifolius) seedlings under four levels of shading in a glasshouse. Growth response of tanekaha was similar in both experiments. Seedling dry weight increment was linearly related to light intensity for all four species in the range 1.7% to 33% full daylight. Growth rates of the shrub hardwood species (mapau and lancewood) were superior to those of the softwoods (tanekaha and kauri) over the whole range of illumination. It is suggested that the very slow growth rates of the softwoods under shaded conditions, compared to many hardwoods, partly explain the general failure of softwood regeneration in mature primary forest and their patterns of establishment in secondary scrub and forest communities.
Nutritional basis for feeding zone preference of Arhopalus ferus (Coleoptera: Cerambycidae)Hosking, G. P., & Hutcheson, J. A.
The inner bark and sapwood of Pinus radiata are compared regarding their nutritional value to larvae of the cerambycid Arhopalus ferus. Larvae feeding in the inner bark, for which they show a strong preference under field conditions, had a relative growth rate four times that of sapwood-fed individuals (48.7 and 11.3mg/g/day respectively). Nitrogen concentration was much higher in the inner bark than in the sapwood, as were soluble carbohydrate levels. Food consumption, growth, and food utilisation indices are presented for bark-fed larvae as well as estimated nitrogen assimilation.
Changes within tree crowns following thinning of young Douglas-fir infected by Phaeocryptopus gaeumanniiHood, I. A., & Sandberg, C. J.
A survey was carried out of tree crowns in a 22-year-old stand of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) in order to study changes following thinning five years earlier. Thinning to 220 and 740 stems/ha did not increase foliage retention or needle density, and had, at most, only a slight effect on mean infection of Phaeocryptopus gaeumannii (Rohde) Petrak, which was not less than 79% at different crown levels. In the lower crown region of unthinned trees ninth whorl branches retained needles longer, but showed less shoot extension over the last two years, than equivalent, unsuppressed branches of thinned trees. Thinned trees developed deeper crowns. An adjacent, 24-year-old stand thinned to 220 stems/ha 12 years previously still retained a high infection (more than 98%), and foliage retention and density were no greater than on trees of the same stocking in the more recently thinned stand.
Transpiration in mountain beech estimated simultaneously by heat-pulse velocity and climatised cuvette. See Corrigendum, 9 (3), 360-361Swanson, R. H., Benecke, U., & Havranek, W. M.
Water vapour loss as measured for foliage in a climatised cuvette and xylem sap-flow as calculated from stem heat-pulse velocity (HpV) measurements in mountain beech (Nothofagus solandri var. clifiorlioides Hook. F. poole) are compared over a seven-hour period.
A close correlation was obtained between branch transpiration and heatpulse velocity uuder the prevailing conditions of low moisture stress. The Hpv technique appears to be appücable to mountain beech, a hardwood with a difiuse-porous vascular transport system. Tentative extrapolation of results to total crown transpiration and total stem sap-flow gave similar results.
A Corrigendum to this paper is available here: Corrigendum for Swanson et al. 1979: Transpiration in mountain beech estimated simultaneously by heat-pulse velocity and climatised cuvette
Growth of Eucalyptus regnans in a plot at RotoruaWilcox, M. D., & Thulin, I. J.
At age 13 years, a 0.156-ha plot of Eucalyptus regnans has attained a mean height of 28.5 m, a mean diameter (at 1.4 m) of 40.7 cm, a total stand volume of 307 m3/ha, a mean annual total volume increment of 23.6 m3/ha/year, and a basal area of 30.8 m2/ha. Since the plot had no surround or buffer zone, the volume increment and basal area would be inflated.
The initial stocking of the stand was 5357 stems/ha, and was reduced to 1178 stems/ha at age 4 years and to 237 stems/ha at age 7 years.
The seed came from Mt Erica, Victoria.
Bud morphogenesis of Pinus radiata in New Zealand 2: The seasonal shoot growth pattern of seven clones at four sitesBollmann, M. P., & Sweet, G. B.
Primordial initiation and development of branch buds were studied in seven clones at each of four locations in the North Island of New Zealand.
Initiation of the annual shoot primordia had started by mid-September at all sites. Growth differences due to site began to appear in January, when extension and primordial differentiation of the new season's shoot was starting.
At the warmer sites initiation continued until late autumn or early winter while at the colder sites it ceased earlier. Consequently the annual shoots collected in September from the coastal Te Teko seed orchard contained 220 to 241 more primordia than those from the other three sites. Shoot extension by September was also higher there (1.3 mm per internode as compared with 0.5 mm at the inland location of Waimihia). Te Teko was also the site where needle growth was most rapid and the number of cycles in the annual shoot was greatest.
The results generally confirm the pattern of shoot growth previously demonstrated for the leading shoot of a single clone.
Generalisation of multi-trait selection indices using information from several sitesBurdon, R. D.
A multi-trait selection index is formulated for selecting parents using half-sib progeny test information, to illustrate the approach of treating the expressions of any one trait at different sites as being effectively several distinct traits. This involves analysing data from one site at a time and linking results from different sites in a separate but minor operation. The proposed approach is highly robust with respect to the statistical properties of data and offers great flexibility in assessment procedures and the assignment of economic weights.
The ash group of eucalyptsWilcox, M. D.
The ash group comprises 42 taxa of the genus Eucalyptus. These eucalypts form Pryor and Johnson's informal series OBLIQUAE of the subgenus Monocalyptus.
All described species and subspecies are listed and briefly discussed. The group includes several well-known large timber trees for which species and provenance trials have recently been established. Genetic improvement programmes based on comprehensive provenance testing and local selection have been initiated for E. regnans, E. fastigata and E. delegatensis. Provenance tests of a limited range of seedlots have been established for E. obliqua, E. oreades, E. fraxinoides and E. sieberi.
Breeding of the clerid Thanasimus formicarius for the control of the bark beetles Hylastes ater and Hylurgus ligniperda in New ZealandZondag, R.
In September 1976, 214 adults and 165 larvae of the predatory clerid Thanasimus formicarius L. were received from the Commonwealth Institute of Biological Control station in Austria. A successful breeding and rearing technique was developed; by July 1977, 364 adults had been reared and by June 1978 a further 1081. Liberations have been made in several forests in the North Island (176 adults were released in 1977 and 616 in 1978) but no field recoveries have yet been made, and the breeding will continue for at least another year.
The difficulties encountered with the breeding are discussed, and suggestions are made on how the technique could be improved.
Book review - Meyland, B.A., & Butterfield, B.G. 1978: The structure of New Zealand woodsHarris, J. M.
Review of "The structure of New Zealand woods", by Meyland, B.A., & Butterfield, B.G. 1978: NZJFS 9(1), 124.
Trans-Tasman forest products trade after a decade of NAFTA 1966-75Fenton, R.
General trans-Tasman trade has increased in real-term values by over 75% from Australia and 100% from New Zealand but forest products have only increased 3 and 14% respectively. Australia still supplies 15-20% of New Zealand's forest products imports, while the New Zealand share of the much larger Australian imports decreased from c. 17 to 13%. New Zealand has failed to substitute seasoned pine framing for North American softwood imports. Neither has the finger-jointed sawnwood potential of the "old-crop" plantations been exploited.
Expansion of New Zealand newsprint production ill accords with both forest supply potential in the next 15 years, and with Australian plans for increased production. Results apparent from joint forest consultations are limited, and mutual competition for forest products within Australasia appears to be increasing.
NAFTA failed to expand forest products trade in the decade. Australian forest areas appear to be large enough for export surpluses in the year 2000 and the Australasian countries will be mutually competitive on third markets. Increased afforestation will accentuate this.
Cubic spline curves and calculation of volume of sectionally measured treesGoulding, C. J.
When stem volume is estimated from measurements of cross-sectional area using Smalian's composite formula and data from Pinus radiata in New Zealand errors in volume rapidly increase as intensity of measurement decreases, exceeding 8% when the interval between measurements is greater than 5 m. Newton's composite formula or Romberg's method can halve this error but are applicable only when the intervals between measurements are uniform. Integrating a cubic spline curve fitted through the data points can estimate volume with only 60% of the error of Smalian's formula. This function is suited for use with dendrometer measurements of standing trees and, provided that the distances between measurements are less than 5 m, errors can be confined to less than 5% of the volume.
Movement of marked sika (Cervus nippon) and red deer (Cervus elaphus) in central North Island, New ZealandDavidson, M. M.
Movement of sika deer (Cervus nippon), within the area from the 1905 liberation point in the northern Kaimanawa Forest to the Ruahine Range some 90 km south, was studied over the period 1964-74 using self-tagging collars. Fiftyfour sika and 30 red deer (Cervus elaphus), mostly hunter-killed, were recovered. For sika deer, the average distance travelled from tagging to kill site was 2.2 km after an average of 16.9 months
Control of Sirex noctilio F. with Deladenus siricidicola bedding part 2: Introductions and establishments in the South Island 1968-75Zondag, R.
The nematode, Deladenus siricidicola Bedding, which sterilises adult female Sirex noctilio F. and is regarded as being the most important controlling agent of the woodwasp in the North Island, has been successfully introduced into several South Island forests. It is well established in the northern parts of Nelson Conservancy and there has spread naturally to forests where it was not introduced. In Canterbury Conservancy it has been recovered from two of the six forests in which it was introduced, and in Southland Conservancy from five of the eight forests.
Details are given of the methods used for the introductions and the establishment checks.
Transformation of nitrogen fertilisers and movement of nutrients from the surface of a rhyolitic pumice forest soilBallard, R.
The transformations and movement of urea, diammonium phosphate (DAP), ammonium sulphate (AS), ammonium nitrate (AN), calcium ammonium nitrate (CAN), sulphur-coated urea (SCU) and isobutylidene diurea (IBDU) were followed over a 16-week period using intact cores from the surface 10 cm of a rhyolitic pumice forest soil. Fertiliser was applied at equivalent to 200 kg N/ha and the cores were leached with 5 cm of distilled water per week.
AS, AN and CAN exhibited similar, rapid leaching rates with over 90% of the applied N passing through the cores in 10 weeks: 50% of the N applied as NH4-N passed through in this form while the remainder was nitrified and passed through as N03-N. Urea and DAP showed a slower initial leaching, but this increased as nitrification peaked at 7 weeks. After 16 weeks about 70% of the N applied in urea and DAP had passed through the cores with about 70% of this as N03-N. The two slow-release fertilisers, SCU and IBDU showed steady leaching patterns, identical to each other. About 50% of their N was leached over the 16 week period, nearly all as N03-N. Very little unhydrolysed urea was leached from any of the urea-based sources. The bulk of the residual fertiliser N appeared to be in organic form, but it was readily mineraliseable.
All fertilisers greatly increased the leaching rate of Ca, Mg and K, with AS having the greatest and DAP the least effect. The fertilisers had little effect on the movement of P in this soil.
The practical implications of the results are discussed.
Ester formulation and surfactant affect response of radiata pine and gorse seedlings to 2,4,5-TPreest, D.
In a replicated 2 (ester) x 4 (rate) x 2 (surfactant) factorial experiment the iso-octyl ester of 2,4,5-T was found to be more effective in controlling seedling gorse (Ulex europaeus L.) and less damaging to radiata pine (Pinus radiata D.Don) seedlings than the butyl ester. The addition of 0.5% v/v surfactant significantly enhanced the activity of the iso-octyl ester against the gorse, but not that of the butyl ester, and resulted in marginally less tree growth suppression by 2,4,5-T. Further investigation of the effects of ester formulation and surfactant on 2,4,5-T activity in relation to gorse control and tree selectivity appears warranted.
Changes in the carbohydrate concentration of pine seedlings after cool storageMcCracken, I. J.
Seedlings of Pinus mugo and Pinus radiata were cool stored for 0, 6, 12 and 18 weeks and analysed for carbohydrate (as soluble sugars and starch) on removal from storage and after six weeks subsequent growth in controlled environment.
Concentrations of carbohydrate were highest at lifting (10-14% of seedling dry weight) and declined steadily through 6, 12 and 18 weeks' cool storage in both species. Pinus mugo seedlings retained higher concentrations in stem and root than P. radiata during cool storage and these were depleted during subsequent growth. Pinus radiata showed a similar pattern of depletion during growth following 0 and 6 weeks' cool storage but results suggests that alternative resources were utilised following 12 and 18 weeks' storage, resulting in a decline in vigour. A pre-treatment of root wrenching had no significant effect on carbohydrate concentrations in either species.
A physiological study of seed cone production in Pinus radiataSweet, G. B.
Individual grafts in two Pinus radiata seed orchards were categorised (a) as being "good flowerers", or (b) as flowering poorly, either because (i) many of their long shoots failed to develop ("non-developers") or because (ii) most of their long shoots differentiated into branches ("mainly branch"). At one site buds in trees of the 3 categories were treated with a mixture of gibberellin A4/7 with naphthaleneacetic acid (GA/NAA) at the stage of long shoot differentiation. At the second site buds were harvested at that stage and extracted to assay for endogenous gibberellins and cytokinins, carbohydrates, nitrogen and amino acids.
In all categories of tree an increased number of seed cones were differentiated following GA/NAA application. This resulted in part from an increase in total long shoot numbers, and in part through a developmental "switch" from branches to seed cones.
Buds of good flowering trees had high levels of soluble carbohydrates and amino acids, but low levels of total and non-polar gibberellins, and cytokinins, relative to trees whose long shoots mostly developed into branches.
The hypothesis is proposed that undifferentiated long shoot primordia tend to differentiate as seed cones rather than as branches when their rate of growth is high. Treatments which increase seed cone differentiation may involve a temporary diversion of metabolites from the apical meristem of a bud to its developing long shoots at the time when differentiation is occurring.
Growth and wood properties of Pinus radiata in relation to applied ethyleneBarker, J. E.
Ethylene in the form of Ethrel was applied as a band to boles of Pinus radiata. A large, localised diameter growth response occurred which was linearly related to the logarithm of the concentration applied. The growth response was due to increased cell division. The water-soluble extractive content, the basic density, amount of ray tissue and tracheid wall thickness were increased. Tracheid length and wood strength were decreased. Volumetric shrinkage and lignin content were not influenced.
Ammonium uptake from dilute solutions by Pinus radiata seedlingsFlewelling, J. W.
The rate of ammonium ion uptake by seven-week-old seedlings of Pinus radiata from complete nutrient solutions, when described in terms of the carrier hypothesis and the analogous theory of enzyme kinetics, had a Michaelis-Menten constant (KM) of 15.3 mM/litre with a standard error of the mean equal to 5.6 mM/litre. Although uptake rates at concentrations up to 110 mM/litre were in accord with the Michaelis-Menten equation, anomalously high rates of uptake were observed at 230 mM/litre.
A repellent to protect radiata pine seedlings from browsing by sheepKnowles, R. L., & Tahau, F.
Repellents containing either thiram or egg, together with acrylic adhesive and red dye, were sprayed on 1-year-old radiata pine seedlings.
Browsing damage on the seedlings by sheep was compared, together with that on untreated seedlings, over a six-month period.
Formulations containing egg significantly reduced the incidence of browsing for 3-4 months but mixtures containing thiram, or acrylic adhesive and red dye without egg were not effective repellents.
Where radiata pine is planted on pasture and sheep are grazed amongst the seedlings, egg-based repellents may be useful in reducing spring and early summer browsing damage. They could also be used on forest sites to protect seedlings from sheep introduced to control weeds such as bracken fern.