Showing papers on "Pinus radiata published in 1978"

Comparison of the pilodyn and torsiometer methods for the rapid assessment of wood density in living trees

Abstract: Two experiments were carried out to evaluate the "Pilodyn Wood Tester" (which operates by measuring the penetration of a steel striker pin) for nondestructive assessment of wood density in living trees. Results were compared with those from the recently developed Torsiometer method as regards accuracy for predicting the wood density measured from increment cores. In the first trial, 10-year-old radiata pine clones were tested (25 clones, 5 ramets/clone, 2 measurements/ramet). The Pilodyn was by far the most rapid method and the penetration data gave a correlation coefficient of —0.96 with wood density on a clone mean basis. The Torsiometer gave a correlation of 0.78. The second study was in a 31-year-old radiata pine plantation where 25 stems were assessed at four breast height sampling points by the three methods used in the first trial. Again the Pilodyn results were obtained more rapidly and were more closely related to mean tree outerwood density (r = —0.86 as compared to 0.79 for the Torsiometer). The Pilodyn Wood Tester appears to have a high potential for the rapid measurement of wood density in large numbers of stems and would be particularly useful for ranking groups of trees such as clones or families by density classes. INTRODUCTION Wood density is an important timber characteristic which is being increasingly considered in radiata pine tree breeding programmes along with vigour, form, branching and health. However, because it is by far the most expensive of these traits to measure on a large scale, on account of the time involved, it is often not assessed. Rapid methods of measuring wood density in standing trees are much sought after and recent years have seen the development of the Torsiometer technique (Fig. 1) whereby the force required to turn an increment borer is recorded with the aid of a torque-measuring device (Polge and Keller, 1970; Harris et al., 1976a; Nicholls and Roget, 1977; Young, 1977). This system still necessitates the use of an increment borer in the field but greatly reduces the laboratory workload. The Pilodyn Wood Tester (Fig. 1) was originally developed in Switzerland to obtain quantitative data on the degree of soft rot in wooden poles. The test involves N.Z. J. For . Sci. 8(3): 384-91 (1978). No. 3 Cown — Assessment of Wood Density in Living Trees 385 FIG. 1 (Upper)-Torsiometer attached to increment borer bit (Lower) Pilodyn Wood Tester. 386 New Zealand Journal of Forestry Science Vol. 8 injecting a spring-loaded striker pin into the wood and reading the depth of penetration off a scale on the body of the instrument. Hoffmeyer (1978) reported results of a smallscale trial using the Pilodyn to estimate the wood density of Abies alba trees. A correlation coefficient of 0.71 was obtained for the data relating penetration depth to the density of increment cores. This principle is attractive in that it is rapid, does not require the use of an increment borer, and should be free of operator bias. The following studies were undertaken to examine the relationship between penetration depth and wood density of standing trees of Pinus radiata D. Don, using a Pilodyn with a 6-joule spring and 2.5-mm diameter striker pin. MATERIALS AND METHODS 1. Assessment on 10-year-old Trees Ramets from 206 radiata pine clones were established in Cpt. 1350, Kaingaroa Forest in 1968 in randomised blocks. Thus at the time of the current assessment the cuttings had been in the field for 10 years. Density values were calculated from increment cores at a 1974 measurement (Wilcox et al., 1975) and these data were used as a basis for the selection of 25 clones covering the full range of densities in the trial. Five ramets from each of the 25 clones were identified at random on a plan of the area and these were to be tested with the Pilodyn, Torsiometer and increment cores. At each ramet, two bark strips (20 mm X 50 mm) were removed from opposite sides of the stem at breast height and this defined the test areas within which all measurements and cores were foken. Three of the clones had to be subsequently discarded due to high mortality. In the laboratory the outer three complete growth rings were assessed for wood density by the maximum moisture content method (Smith, 1954). 2. Assessment in a 51-year-old Stand As the Pilodyn operates by penetration, there was a suspicion that its action might be affected by the number of latewood bands encountered, as latewood density in radiata pine is appreciably greater than that of the earlywood, and the contrast increases with distance from the pith. A 31-year-old stand in Cpt. 10 Whakarewarewa State Forest Park was chosen to test the suitability of the instrument for assessing density in older stands. Methods adopted were the same as for Experiment 1 except that four sample points per tree were tested from each of 25 stems in order to compare the ranking of individual trees by density with the Pilodyn and Torsiometer results. In the laboratory the outer 20 mm of each increment core were used for density determination.

Water Uptake by Mycorrhizal Roots of Radiata Pine Seedlings.

Abstract: Seedlings of radiata pine (Pinus radiata D. Don) grown in a sandy soil inoculated with Rhizopogon luteolus had 72% of their short roots mycorrhizal at age 5 months whereas the uninoculated controls had only 6.0 %. When water was withheld from the soil and soil water matric potential became more negative, the leaf water potential of both inoculated and uninoculated plants became more negative, transpiration rate was reduced, and the derived resistance of the plant plus soil to the flow of water increased. There was no significant difference between inoculated and uninoculated plants in transpiration rate, but leaf water potential was more negative and consequently the derived resistance of plant plus soil was greater in the inoculated plants. The resistance of plant plus soil was partitioned using a simple whole-plant model. Resistance within the soil was considered more significant than that in the plant, and the greater soil resistance associated with the inoculated plants was considered to be due to differences in root geometry.

Nutrient deficiencies in pinus radiata in new zealand

Abstract: Deficiencies of N, P, K, Ca, Mg, B, Cu, Zn, and Fe have been found in nurseries and/or plantations of Pinus radiata in New Zealand. The visual symptoms are described and details of the soil types on which they occur are given. Deficiency-like symptoms due to other causes are described. While visual symptoms give an immediate and usually reliable indication of the presence of a nutrient deficiency, confirmation by foliage analysis is recommended. Deficiency foliage levels of each nutrient are given.

Influence of clearfelling on decomposition of pinus radiata litter

Abstract: Two experiments investigating the effect of clearfelling on decomposition of Pinus radiata D.Don litter are described. The first was a field trial in which P. radiata trees were felled without disturbance to the litter layer. Small plots were laid out in the clearfelled area and in an adjacent closed-canopy stand. Screens of shade cloth were erected over the plots. Of the litter originally present Degree of shading had no effect on litter decomposition. In the second experiment, cuttings of P. radiata were planted in troughs designed to expose weighed experi­ mental litter to the influence of plant roots but not to the influence of plant tops. Shades were placed over the trough surfaces and the plants grown until mycelial wefts were visible in the litter. Twenty-four troughs were then selected and plants in 12 of them were severed at litter level. Six troughs containing a growing plant and six with a "felled" plant were placed in a growth room simulating the climate of an open, clearfelled area. A similar set was placed in another room simulating the climate under a closed-canopy pine stand. Shades were removed from the troughs in the "open" climate room. All troughs were watered to field capacity daily. After 6 months, significantly more litter remained in the troughs with intact plants than in those where the plants had been "felled", irrespective of whether they were in the "open" or in the "forest" climate room. The first experiment suggested and the second experiment confirmed that the biological changes resulting from clearfel;ing, including the removal of mycorrhizal root influence, were more important in increasing litter decomposition than the physical effect of the change in climate.

Comparison of Establishment Methods for Pinus radiata on a Former P. pinaster Site

Abstract: SUMMARY The effects of three site preparation methods involving retention of logging residue, burning and cultivation together with seven fertiliser/weedicide treatments on establishment of P. radiata on a former P. pinaster site were examined. Evidence is presented to show that early growth is enhanced by retaining litter and logging residue from the first crop compared with the more commonly used methods of broadcast or windrow burning followed by ploughing. Conservation of soil moisture through the mulching effect of litter and residue is considered to be the main factor responsible for the differences in early growth between the site preparation methods tested. A statistically significant growth response to chemical weed control was observed on burnt and cultivated sites but not on sites where residue was retained. The response to fertilisers in the presence of weed control varied according to the site preparation method, with a significant response to P on unburnt sites and to N + P + Zn on windrow b...

Effects of root residues on growth ofPinus radiata seedlings and a mycorrhizal fungus

Abstract: SUMMARY The height of Pinus radiata Don seedlings grown on soils incorporating different proportions of root tissues (25 and 50%) was shown to be reduced by 20–80%. Seedlings watered with aqueous extracts from soil/root mixtures also showed a significant reduction in growth. This growth-retarding effect was partially overcome by the addition of nutrients or by soil sterilisation. It is postulated that growth retardation was caused not only by nutrient deficiency resulting from the addition of organic matter with a high C/N ratio, but also by phytotoxic substances present in the root tissue. The effect of water extracts of roots from old P. radiata trees on the growth of young P. radiata seedlings and on a mycorrhizal fungus (Rhizopogon sp.) under aseptic conditions was also studied. Extracts from the inner bark of roots caused complete growth inhibition of the mycorrhizal fungus as well as root necrosis and wilting of P. radiata seedlings. A water-soluble substance or substances, toxic both to the roots of P. radiata and to its mycorrhizal fungus, is postulated as the causal agent.

Nutrient movement into soils beneath eucalypt and exotic conifer forests in southern central Victoria

Abstract: Above-ground nutrient return to the soil was estimated by studying forest floor leachates for up to 2 years in two eucalypt forests (Eucalyptus obliqua and E regnans) and two nearby conifer plantations (Pinus radiata and Pseudotsuga menziesii) near Narbethong in southern central Victoria Forest floor leachate volumes were recorded approximately once a month and samples were analysed for pH and potassium, sodium, magnesium, and calcium concentrations The volume of forest floor leachate was greater in the eucalypts than in the conifers This was attributed to greater interception losses of water by the conifers Forest floor leachate chemistry underwent regular seasonal fluctuations which were similar for each of the four forest types Acidity was highest in spring and autumn and lowest in summer Cation concentrations were highest in autumn and lowest in spring This behaviour was attributed to changes in climate and in rates of litter decomposition In contrast to cation concentrations, cation quantities entering the soil in forest floor leachate showed no pronounced seasonal variations although they tended to be high in winter The quantities of cations added to the soil in forest floor leachate varied with forest type, and were significantly higher in E obliqua than in the comparable P radiata stand Greater quantities of acid were added to the soil under P radiata The P radiata soil contained lower quantities of exchangeable cations than the E obliqua soil This was consistent with the observed differences in forest floor leachate chemistry Unlike the P radiata soil, the P menziesii soil did not appear to be depleted in exchangeable cations It was concluded that P radiata had depleted the exchangeable cation reserves in the soil studied but that the full significance of this is still unknown

Root biomass of Pinus radiata D. Don.

Abstract: Summary Root biomass of 20 trees of Pinus radiata at Jonkershoek State forest. Cape Province, R.S.A., was measured. Oven-dry weight of 10 of these trees, 27 year old (“young” trees), ranged between 66,9 kg and 231,0 kg. Oven-dry weight of the other 10 trees measured, 36–39 year old (“old” trees) ranged between 149,2 kg and 491,4 kg. Oven-dry weight (kg) of root biomass of the “old” trees (Y) regressed over DBH over-bark (x) in ern, gave Y = 11,934 X – 267,207 with r2 = 0,856, while oven-dry root weight (Y) in kg of the same trees, regressed over diameter (ern) under bark of the stump, 20 cm above the ground, gave: Y = 12,130 X – 267,633 with r2 = 0,931. Thus, it is possible to evaluate root biomass of P. radiata of similar age and site conditions, by an above-ground parameter such as stump diameter or DBH. Root mass was related to basal diameter, to evaluate missing roots. This also provided data for evaluating fine root ( <5 mm diameter) weight. Quantity and percentage of total fine roots of P. radiata, ...

A biomass study in Pinus radiata D. Don

Abstract: This paper deals with a preliminary study of the aboveground biomass of Pinus radiata in the Jonkershoek State Forest. A sample of 25 twenty-nine year old trees was selected from comp. 35A. The oven-dry stem mass was estimated by subsampling each stem and regressing the estimated oven-dry mass on DBH (r = 0,9767). Similarly, a sample of branches, representing the range of branch diameters, was drawn, their oven-dry mass was determined and subsequently regressed on branch diameter (r = 0,9751). Branch mass per tree was estimated by sampling the distribution of branch diameters for each tree separately. A reliable estimate of crown mass (r = 0,8385) and total aerial mass (r = 0,9776) from DBH is also made. Total estimated above-ground biomass for the stand amounted to 184860 kg ha-1 , of which 89 per cent was stem wood and the remainder crown.

The life history and behaviour of chlenias sp., a geometrid defoliator of radiata pine in tasmania

Abstract: Larvae of a species of Chlenias (Lepidoptera: Geometridae) which normally feed on Eucalyptus spp, extensively defoliated Pinus radiata regeneration at Pittwater, Tasmania from 1968–1971. Pupation occurred beneath the litter and adults emerged from mid April to mid July when dusk temperatures were consistently below 4.5°C. The location of mates by flying males involved the release of pheromone(s) by female moths whose wings were expanded during copulation. Eggs were deposited in clusters on the terminal and youngest shoots of host trees. Incubation was approximately 70–80 days. There were six larval instars and defoliation became severe during the fourth and subsequent instars. Pupation occurred in a silken sand cocoon from early November to December. There was one generation per year.

Effect of Storage in Different Seasons on Sapstain and Decay of Pinus radiata D. Don in N.S.W.

Abstract: SUMMARY The effect of storage in different seasons on the incidence of sapstain and decay has been examined in Pinus radiata D. Don. Logs were cut in spring, summer, autumn and winter and left with or without bark in a forest near Oberon, west of Sydney. After one, two and three months storage, the logs were converted to boards that were strip stacked for air drying. The only safe season for storage of P. radiata logs was winter when logs could be left in the forest for one month without decay, or sapstain, to any significant depth. In all seasons degrade in debarked logs was usually more severe than in logs with bark intact. Sapstain and a few decay fungi were isolated from boards cut from logs prestored in the forest. The most prevalent sapstain fungi were Diplodia pinea (Desm.) Kickx in summer, and in winter Aureobasidium pullulans (De Bary) Arn., an unidentified Ascomycete, and less frequently Graphium sp. The decay-causing fungus Peniophora gigantea (Fr.) Massee was isolated from logs following three...

Wood properties of pinus radiata infected with dothistroma pini

Abstract: Wood properties were measured on 10 nine-year-old trees from each of the four spraying treatments (aqueous solutions of copper-based fungicides) applied to control Dothisfroma pini infection of radiata pine in Sample Plot R919, Kaingaroa Forest. Wood samples were cut from levels in the stems corresponding to seven and four annual growth layers, and these were examined for wood density, shrinkage, green moisture content, growth rate, tracheid length, grain angle, resin content, pith diameter and bark thickness. Significant differences in wood properties that could be related to the spray treatments were limited to some loss of diameter growth in unsprayed, heavily defoliated trees (more apparent in the upper than in the lower stem), and also a trend to increasing wood density in outer growth layers following severe defoliation.

Edge Effects in Pinus radiata

Abstract: SUMMARY A sample of 25 tree diameters was taken in each of the outer 6 rows of 20 stands of Pinus radiata and analyzed with respect to mean diameter and variance. The relationship between mean diameter and row location was satisfactorily expressed by an asymptotic regression. Surrounds, consisting of three rows will largely eliminate edge effects due to inequal competition and the data suggest that in some cases two rows might be sufficient.

Growing Nursery Plants in Soil-less Media from Sawmill Refuse

Abstract: In an effort to reduce the use of nursery soil, old pine bark, fresh pine bark and a composted mixture of pine sawdust and shavings were tested as soil-less media for raising seedlings of Pinus radiata and Eucalyptus diversicolor. The admixtures of organic and slow release fertilizers, mainly sources of N and P, also of superphosphate and rockphosphate, were tested against pure media. The results proved highly significant superiority of old bark over other media, and of organic over inorganic fertilizers.

Predicting the impact of silvicultural treatment on the wood characteristics of pinus radiata

Abstract: The impact of silviculture on intrinsic wood properties can be estimated by separating the analysis into two stages: predicting the impact of silviculture on the distribution of volume according to the physiological age of the wood; and predicting mean-tree wood properties from the mean physiological age of the tree. A simple growth model provided satisfactory estimates of mean physio­ logical age of trees in two heavily thinned plots of Pinus radiata D.Don. The model was used to predict the mean physiological age of trees from selected regimes.