Showing papers on "Pinus radiata published in 1990"

Increases in Phosphorus Requirements for CO2-Enriched Pine Species

Abstract: Pinus radiata D. Don (half-sib families 20010 and 20062) and Pinus caribaea var hondurensis (an open-pollinated family) were grown for 49 weeks at seven levels of phosphorus and at CO2 concentrations of either 340 or 660 microliters per liter, to establish if the phosphorus requirements differed between the CO2 concentrations and if mycorrhizal associations were affected. When soil phosphorus availability was low, phosphorus uptake was increased by elevated CO2. This may have been related to changes in mycorrhizal competition. When the phosphorus concentration in the youngest fully expanded needles was above 600 milligrams per kilogram the shoot weight of all pine families was greater at high CO2 due to increases in rates of photosynthesis. More dry weight was partitioned to the stems of P. radiata family 20010 and P. caribaea. At foliar phosphorus concentrations above 1000 milligrams per kilogram (P. radiata) and 700 milligrams per kilogram (P. caribaea), growth did not increase at 340 microliters of CO2 per liter. Soluble sugar levels in the same needles mirrored the growth response, but the starch concentration declined with increasing phosphorus. At 660 microliters of CO2 per liter, shoot weight and soluble sugar concentrations were still increasing up to a foliar P concentration of 1800 milligrams per kilogram for P. radiata and 1600 milligrams per kilogram for P. caribaea. The starch concentrations did not decline. These results indicate that higher foliar phosphorus concentrations are required to realize the maximum growth potential of pines at elevated CO2.

Transpiration of plantation pinus radiata estimated by the heat pulse method and the bowen ratio

Abstract: The heat pulse method was used to estimate stand transpiration from a radiata pine (Pinus radiata) plantation in southeastern Australia over a period of four days. The diurnal pattern of sapflow was related to net radiation with a time lag of about 1.5 hours. Despite high soil moisture levels, sapflow did not keep up with evaporative demand in the afternoon. Sapflow estimates of transpiration exceeded estimates for evaporation based on Bowen ratio measurements for all four days of the study. Copyright © 1990 John Wiley & Sons, Ltd

Growth, dry weight partitioning and wood properties of Pinus radiata D. Don after 2 years of CO2 enrichment

Abstract: Advanced selections (families 20010 and 20062) of P. radiata D. Don were exposed to either 340 or 660 μmol CO2 mol 1 for 2 years to establish if growth responses to high CO2 would persist during the development of woody tissues. The experiment was carried out in glasshouses and some of the trees at each CO2 concentration were subjected to phosphorus deficiency and to periodic drought. CO2 enrichment increased whole-plant dry matter production irrespective of water availability, but only when phosphorus supply was adequate. The greatest increase occurred during the exponential period of growth and appeared to be tied to increased rates of photosynthesis, which caused accelerated production of leaf area. The increase in whole-plant dry matter production was similar for both families; however, family 20010 partitioned larger amounts of dry weight to the trunks than family 20062. which favoured the roots and branches. Wood density was generally increased by elevated CO2 and for family 20010 this increase was due to thickening of the tracheid walls. Tracheid length was similar at both CO2 levels but differed between families. These results suggest that, as the atmospheric CO2 concentration rises, field-grown P. radiata should produce more dry weight at sites where phosphorus is not acutely deficient, even where drought limits growth; however, increases in wood production are likely only for genotypes which continue to partition at least the same proportion of dry weight to wood in the trunk.

Partitioning of rainfall in a eucalypt forest and pine plantation in southeastern australia: II stemflow and factors affecting stemflow in a dry sclerophyll eucalypt forest and a pinus radiata plantation

Abstract: Stemflow of a dry sclerophyll eucalypt forest and a nearby Pinus radiata plantation was studied on a rainfall event basis. The stemflow yields of the forests are quantified, compared, and presented on an annual basis for four years. Yields of the individual eucalypt species are compared and the tree characteristics responsible for the yield differences are discussed. The influence of event size, type, and season on stemflow are also shown. Rainfall angle is shown to have a significant effect on stemflow yield.

Ectomycorrhiza formation in Eucalyptus.: IV. Ectomycorrhizas in the sporocarps of the hypogeous fungi Mesophellia and Castorium in Eucalypt forests of Western Australia.

Abstract: SUMMARY Ectomycorrhiza formation by 11, geographically distinct Eucalyptus species and Pinus radiata with 23 diverse ectomycorrhizal fungi was examined in pure culture syntheses. Few differences occurred between the Eucalyptus species in their ability to form ectomycorrhizas with several fungi, thus indicating no evidence for host-fungus specificity within Eucalyptus. Pinus radiata and most Eucalyptus species formed ectomycorrhizas in common with several broad-host-ranging fungi. However, fungus species which are known to associate exclusively with members of the Pinaceae, e.g. Suillus and Rhizopogon species, did not form ectomycorrhizas with any Eucalyptus species and vice versa. Possible incompatibility between several host-fungus combinations was characterized by host accumulation of phenolic compounds in epidermal and cortical cells. These results are discussed relevant to better understanding degrees and processes of ectomycorrhiza host-fungus specificity and compatibility and to practical considerations in reforestation of exotic plantations.

Extended Host Range of Agrobacterium tumefaciens in the Genus Pinus

Abstract: Two-to 4-month-old seedlings of nine pine species (Pinus eldarica Medw., Pinus elliottii Engelm., Pinus jeffreyi Grev. & Balf., Pinus lambertiana Dougl., Pinus ponderosa Laws., Pinus radiata D. Don, Pinus sylvestris L., Pinus taeda L., Pinus virginiana Mill), Douglas fir (Pseudotsuaa menziesii (Mirb.) Franco) and incense cedar (Libocedrus decurrens Torr.) were inoculated with five strains of Agrobacterium tumefaciens. Transformation occurred in all conifer species tested as determined by gall formation and opine production. The frequency of gall formation varied by host species, by bacterial strain, and was related to the age of the stem when inoculated. Galls were visible 8 to 12 weeks after inoculation and were small (often less than 2.5 millimeters in diameter). Fewer than half (230 of 502) of the galls originally formed on the trees were present after 1 year, and 26 of these grew to diameters greater than 2 centimeters. The majority of these larger galls (18 of 26) were found in P. radiata. Bacterial strain-specific opines were found in 67 of the 81 gall tissues sampled.

Structural root morphology and biomass of three age-classes of Pinus radiata.

Abstract: 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.

Changes in transverse wood permeability during the drying of Dacrydium cupressinum and Pinus radiata.

Abstract: 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 m. The transverse permeability of the green rimu intermediate wood was lower and of the order of 10\" m. 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 IO m. In contrast, after drying and resaturation the radial permeability of P. radiata sapwood was of the order of 10~ m, 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.

The formulation and commercialization of glulam pine tannin adhesives in Chile

Abstract: The results of fingerjointing and glulam industrial trials in Chile using a “honeymoon” fast-set adhesive system manufactured using commercially-produced mildly-sulphited pine tannin extract are reported. The results obtained satisfy the relevant international standards specifications and constitute the first occasion that a commercially produced pine tannin adhesive has been used succesfully in industrial productions runs. This pine tannin adhesive is now available commercially in Chile for fully-exterior, structural-grade, solid timber applications. A new “honeymoon” type adhesive formulation had to be developed due to the peculiar gelling of the pine tannin extract used. The Chilean pine tannin extracted from a mixture of Pinus insignis and Pinus radiata shows gel times longer than what reported for other conifer tannins with the exception of Pinus brutia. Such differences in curing rate are tentatively reported to be related to the relative branching of the different conifer tannins.

Mycorrhizal fungi of radiata pine seedlings in nurseries and trees in forests

Abstract: The relationship of mycorrhizal fungi of radiata pine (Pinus radiata D. Don) seedlings in nurseries and trees in forests was studied. The results showed that in most cases the dominant mycorrhizal fungi did not change when nursery seedlings are transplanted into forest soil but in some cases the dominant mycorrhizal fungi changed dramatically. There was some evidence that soil type and soil fertility could have played important roles in these changes.

Modelling stand growth of radiata pine thinned to varying densities

Abstract: Growth trends in a radiata pine thinning experiment established 18 years ago in Kaingaroa Forest, New Zealand, are portrayed and analyzed. The six thinnings, to 200, 300, 400, 500, 600, and 700/ha,...

IgE-binding proteins from pine (Pinus radiata D. Don) pollen: evidence for cross-reactivity with ryegrass (Lolium perenne).

Abstract: A complex mixture of pine ( Pinus radiata D. Don) pollen proteins are rapidly released into aqueous solutions. IgE-binding proteins have been identified in these extracts using combi

Status and management of insect pests and diseases in Victorian softwood plantations

Abstract: Insect pests and diseases destructive to Pinus radiata and other exotic conifers in State-owned plantations (approximately 100 000 ha) and in pine nurseries are reviewed, as are the control measure...

Phenology of Pinus radiata log colonization and reproduction by the European bark beetle Orthotomicus erosus (Wollaston) (Coleoptera: Scolytidae) in the south-western Cape Province.

Abstract: The temporal distribution of Orthotomicus erosus (Woll.) beetles within a Pinus radiata plantation near Grabouw was recorded from weekly trap logs over a period of five years. O. erosus is summer active. The number of eggs and larvae produced by these beetles was monitored for two years and showed that colonization is followed immediately by brood production.

Poor tree form of Pinus radiata D. Don on former pasture sites in New South Wales.

Abstract: Summary The merchantable timber yield from Pinus radiata plantations established on former pastures is reduced compared with stands on ex-native forest sites in comparable areas because the trees develop numerous defects including sinuous stems, multiple leaders and heavy branches. The causative factors have not been identified, but deformation is most severe on highly improved sites where the soils have a high nitrification potential. In NSW, other site-specific nutritional factors including boron and sulphur deficiencies also appear to be involved in the development of “poor form” on ex-pastures. The availability to trees of several elements including phosphorus, boron, sulphur, aluminium and manganese is affected by previous land use. Most plantations on previous pastures in NSW are of pre-commercial age so the major impact on timber yields has yet to be realized. Over the past decade there has been a steady increase in the area and proportion of plantations established each year on pasture country. Of...

An examination of the browsing animal problem in australian eucalypt and pine plantations

Abstract: Author(s): Montague, Thomas L.; Pollock, David C.; Wright, Wendy | Abstract: The severity and extent of browsing damage to pine and eucalypt plantations and possible solutions are examined. Twenty-six percent of all trees surviving 9 months after planting were browsed yet only six percent had more than 50% of foliage damaged. The most common form of damage was for the foliage to be browsed or the tree bitten off with browsing damage implicated in the mortality of the 24% of trees that died. No difference in the extent of damage between Pinus radiata and eucalypts was detected. Slight differences between three Eucalypt species and two ages of seedlings were detected; however, these differences in damage levels were insufficient to afford adequate protection through appropriate selection of species and type of nursery stock. Most of the damage was attributed to the Swamp Wallaby (Wallabia bicolor) and the European rabbit (Oryctolagus cuniculus). The use of electric or rotonet fencing and repellents containing chili or dog-urine extracts seem to offer the only nondestructive ways of minimising browsing damage. The development of less palatable species and types of nursery stock is dependent on other considerations including general suitability, but warrants further research.

Phenology of Pinus radiata log colonization by the pine bark beetle Hylastes angustatus (Herbst) (Coleoptera: scolytidae) in the south-western Cape Province

Abstract: Phenology of Pinus radiata log colonization by Hylastes angustatus was recorded at Grabouw by means of weekly trap logs. Over the five year study period, 95% of all beetles were captured in September and October. This study facilitates correct timing of insecticide treatments to protect pine seedlings from attack.

Spring needle-cast of Pinus radiata in Tasmania: I. Symptoms, distribution, and association with Cyclaneusma minus.

Abstract: 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.//) at intervals of 6 weeks for the first 6 months of one growing season markedly improved needle retention. It is postulated that SNC is due to the secondary pathogenic activity of one or a suite of endophytic fungi following as yet unidentified seasonal but ephemeral stress.

Water potential and subsequent growth of Pinus radiata seedlings: influence of lifting, packaging and storage conditions.

Abstract: 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.

Variation in nutrient concentrations within Pinus radiata trees and their relationship to tree size.

Abstract: 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.

Competition for nitrogen and moisture in a Pinus radiata-pasture agroforestry system

Abstract: A 3 x 2 factorial experiment was conducted to examine the outcome and some of the competitive mechanisms between P. radiata (D. Don) and pasture for N and soil moisture. The factors examined were the monthly addition of 30 kg N/ha versus no additional N, and the manipulation of the level of pasture competition by spraying and simulated-grazing to give three levels of pasture competition. The experiment coincided with a period of severe drought which greatly increased the competition for soil moisture. Removal of pasture competition by spraying released a large amount of N into the soil mineral N pool. It also reduced overall demand for N and water because of the reduction in competition resulting in improved tree growth and greater N uptake by trees. However, it was apparent that moisture was the main limiting factor for tree growth in the plus-pasture treatments because, whilst trees did take up some of the applied N in the plus-pasture treatments, they showed no increase in growth and N uptake. A localized effect of trees on pasture dry matter production and N content occurred. Directly beneath trees and in the area predominantly occupied by tree roots competition for water and N was intense. Pasture response to N was greatest away from the tree rooting zone. Pasture appeared to compete successfully due to the nature of its root system which consists of a large biomass of very fine roots compared to the small biomass of fine pine roots in the surface soil. Competition between pasture and trees was further examined using the stable isotope 15N to trace a single 15N-labelled application of N fertilizer in spring. Recovery of 15N during the split fertilizer application program was assessed by periodic pasture harvests in the simulated-grazing treatment and by obtaining a complete balance sheet after 249 days. The dynamics of plant availability of applied 15N and retention of 15N in the soil was also followed. The recovery and retention of 15N03and 15NH4 + in particular were compared in the simulated-grazing treatment. Larger quantities of 15N03remained available to plants than 15NH4 + and 15N was still found in the KCl-extractable mineral N pool at 154 and 249 days after application. P. radiata assimilated the same amount of 15N when added as 15N03 or 15NH4 + in the simulated-grazing treatment but uptake into the aboveground biomass of pasture was greater for 15N03 than for 15NH4 +. However, pasture uptake of 15N03and 15NH4 + was not significantly different when pasture stubble and roots were include in the total recovery for all harvests. Removal of pasture competition increased the availability of 15N for the period just after application but 15N uptake by P. radiata was only doubled.