Showing papers in "Australian Forestry in 1991"
TL;DR: In silviculturally treated and fast grown trees, the reduced longitudinal growth strain gradient, along a radius from pith to outer xylem, would decrease splitting of wood during conversion.
Abstract: Summary The effect of a number of silvicultural treatments on peripheral longitudinal growth strains and wood properties was examined at breast height (1.3 m) in 12.5-year-old plantation trees of Eucalyptus grandis (Hill) Maiden. These treatments included: untreated control (C); thinning (T); fertiliser and thinning (F); and fertiliser, weeding, insecticide and thinning (A). Strain was measured using electronic strain gauges glued to the outer xylem. Stem diameter was progressively greater and growth strain lower in treatments C, T, F and A respectively. Compared to treatment C, treatment A increased diameter at breast height by 190% and reduced longitudinal growth strain by 40%. However, within treatments, the level of growth strain was not related to growth rate. In silviculturally treated and fast grown trees, the reduced longitudinal growth strain gradient, along a radius from pith to outer xylem, would decrease splitting of wood during conversion. A positive relationship was found between growth stra...
39 citations
TL;DR: Bark samples of 30 individual trees were collected from six potentially important Acacia species and the yields, Stiasny values, and the polyflavanoid contents of the hot water extractives were determined, finding the bark quality of A. parramattensis for wood adhesives would be comparable to thatof A. mearnsii provenances in New South Wales, Australia.
Abstract: Summary Bark samples of 30 individual trees were collected from six potentially important Acacia species; A. falciformis, A. implexa, A leucoclada, A. parramattensis, A. sylvestris and A. trachyphloia in New South Wales and Australian Capital Territory, Australia, and the yields, Stiasny values, and the polyflavanoid contents of the hot water extractives were determined. The bark samples from A. parramattensis gave the highest mean (50.2% of bark dry weight) of the extractives yield, while the lowest mean (21.9%) was obtained from barks of A. leucoclada. The two highest mean Stiasny values from A. falciformis (88.0%) and from A. parramattensis (82.8%) were not significantly different. The highest mean polyflavanoid content from A. parramattensis (41.7%) was significantly different from others. The bark quality of A. parramattensis for wood adhesives would be comparable to that of A. mearnsii provenances in New South Wales, Australia.
36 citations
TL;DR: The incidence of mistletoe plants on eucalypt trees in dry sclerophyll forest was recorded in Eden Forestry Region, New South Wales and the number of bird foraging acorns and birds foraging in mistle toe flowers were compared to determine the use of these resources.
Abstract: Summary The incidence of mistletoe plants on eucalypt trees in dry sclerophyll forest was recorded in Eden Forestry Region, New South Wales. Before logging there were 210 trees per hectare over 10 cms diameter breast height. On average 2.8 trees per hectare carried mistletoe at the rate of 5.0 mistletoe plants per hectare. In similar forest logged to 91 trees per hectare there remained 1.8 trees per ha carrying 2.3 mistletoe plants per ha. Yertchuk, Eucalyptus consideniana, Maiden, was the most common tree and had the most mistletoe plants in the study area with an average of 1.7 plants per tree. Birds foraging in mistletoe flowers were compared with birds foraging in eucalypt blossom to determine the use of these resources. Out of 180 plots 41 individuals were recorded as foraging in mistletoe while only eleven birds were recorded feeding amongst blossom of Eucalyptus sieberi L. Johnson. Logging reduced the number of trees per ha and therefore of mistletoe plants per ha and the number of bird foraging ac...
25 citations
TL;DR: A series of plots comparing 1) irrigation at 12.5 mm per week 2) normal rainfall and 3) artificial drought was established in a 9-year old stand of Pinus radiata D. Don. near Canberra, A.C.T. showed that drought-induced dieback was inversely proportional to water supply.
Abstract: Summary A series of plots comparing 1) irrigation at 12.5 mm per week 2) normal rainfall and 3) artificial drought was established in a 9-year old stand of Pinus radiata D. Don. near Canberra, A.C.T. The degree of drought-induced dieback was inversely proportional to water supply. Mortality was at first greatest on the draughted plots but later these plots became more resistant to mortality caused by natural drought than plots which received normal rainfall. After 12 years of treatment total basal area production was 64, 46, and 33 m2 ha-1 on the irrigated, normal and draughted plots respectively. Self-thinning maintained live basal area at about 35 m2 ha′ on the normal plots and 25 m2 ha-1 on the draughted plots. Although there was some mortality on the irrigated plots there was no indication of an upper limit for carrying capacity for live basal area. The cessation of irrigation was followed by substantial deaths which reduced live basal area to a level comparable with the normal plots. Examination of s...
25 citations
TL;DR: Soil and foliar chemistry data showed that stem and branch deformities increased with increasing site fertility, and that deformity was directly correlated with soil mineral-N concentrations.
Abstract: Summary The growth and form of 20-year-old radiata pine stands were assessed in relation to previous land use in Sunny Corner State Forest, near Lithgow, N.S.W. Basal area and merchantable volume were higher in ex-pasture (grazed land) and ex-improved pasture (grazed and cropped sites) than in an ex-native forest site, but the trees on former pastures were more deformed. A range of defects including multiple leaders, forks, stem sinuosity, butt sweep and heavy branching were most prevalent in the ex-improved pasture site. Up to 44% of trees in the ex-improved pasture were severely deformed and less than 50 stem ha−1 were considered suitable as sawlog quality trees. Only 12% of trees in the ex-native forest site had severe defects. Soil and foliar chemistry data showed that stem and branch deformities increased with increasing site fertility, and that deformity was directly correlated with soil mineral-N concentrations. Deformity was also correlated with foliar manganese, aluminium and calcium, and some de...
23 citations
TL;DR: The Department of Conservation and Environment in the State of Victoria addresses silvicultural research: to sustain wood production in second and subsequent rotations of pine plantations; and to balance sustained wood production and ecosystem conservation in native forests.
Abstract: Summary In the last decade, greatly increased public and political awareness of the need for biosphere conservation has placed strict controls on the productive use of Australia's already limited forest resource. The challenge is considerable. Ultimately, it could mean that much of Australia's native forests will no longer be available for wood production either directly or indirectly through conversion to plantations of pine of eucalyptus. This paper describes how the Department of Conservation and Environment in the State of Victoria is meeting this challenge for forested public land. Specifically, it addresses silvicultural research: to sustain wood production in second and subsequent rotations of pine plantations; and to balance sustained wood production and ecosystem conservation in native forests. From a review of field trials and fundamental studies motivated by reports of a “2R-decline” in wood production on sandy soils in South Australia, it is concluded that a serious irreversible decline is unl...
22 citations
TL;DR: The results of this investigation suggest that there is scope for selecting genotypes that can penetrate and grow in clay layers of high strength or low aeration.
Abstract: Summary The penetration and growth of roots of different genotypes of Pinus radiata into Stockdale loamy sand (it has a clay layer at 55–70 cm depth) at different soil strength and aeration were investigated. Soil aeration below 10% air-filled pore space significantly retarded root growth. There were significant differences between Pinus radiata families in root growth in the clay layer at high soil strength and low aeration. Families also differed in their sensitivity towards high soil strength and low aeration conditions in the clay layer. The results of this investigation suggest that there is scope for selecting genotypes that can penetrate and grow in clay layers of high strength or low aeration.
22 citations
TL;DR: Three modelled sequences of estimated average monthly flows of the River Murray were used to study the likely effects of river management on the frequency and duration of flooding of the river red gum forests at Barmah in northern Victoria.
Abstract: Summary Three modelled sequences of estimated average monthly flows of the River Murray were used to study the likely effects of river management on the frequency and duration of flooding of the river red gum forests at Barmah in northern Victoria. One model gave monthly flows in the River Murray at Yarrawonga from 1890 to the present with no regulation or diversions. The second model gave flows with Hume Dam regulation and diversion. The third model gave flow with Dartmouth and Hume Dam regulation and diversion. This corresponds to “current” regulation. The Hume Dam (only) sequence was regarded as the one that corresponded best to the state of the river for which forest flooding data were available. A relation between the average monthly flow (expressed in gigalitres per day) and the percentage of forest flooded was used to transform the historical sequences of monthly flows into the corresponding maximum monthly percentages of forest flooded. This, in turn, was used as input in a grid cell model of the ...
22 citations
Abstract: Summary In Queensland, comprehensive site capability information is used to guide planning for Pinus plantation establishment. Prior to dealing for plantation establishment, field surveys are used to provide information for site suitability and site capability assessment. Knowledge of site capability is used as an input into selection of site preparation systems, site preparation design, taxon selection and fertilizer prescription. The information collected in, and the site capability knowledge inferred from, field surveys are described in this paper.
18 citations
TL;DR: It is suggested that splitting of wood during conversion would be less likely in trees with faster rates of growth, due to a lower longitudinal strain gradient along a radius from pith to outer xylem.
Abstract: Summary Using electronic strain gauges, longitudinal peripheral growth strain was measured at 1.6 m height in fifty 22-year-old plantation grown trees of Eucalyptus grandis (Hill) Maiden. The extent of peripheral growth strain was not found to be related to rate of growth. This result and measurements of internal growth strains in five 32-year-old trees suggested that splitting of wood during conversion would be less likely in trees with faster rates of growth, due to a lower longitudinal strain gradient along a radius from pith to outer xylem.
15 citations
TL;DR: The 0.9 m Growtube provided an advantage over the nil Growtube, however, further research is required in order to determine an optimum Growtube length and to explore the full potential of these treeshelters.
Abstract: Summary The effects of the commercial treeshelter ‘Growtube®’ on the growth of Eucalyptus cloeziana, Grevillea robusta, Araucaria cunninghamii and Casuarina cunninghamiana seedlings are reported. Twelve months growth data were analysed for seedlings grown in nil, 0.9 m, 1.9 m and 2.9 m lengths of Growtube. While differences between treatments were significant, the pattern of responses was similar for all species. Increasing the Growtube length resulted in increased height growth and a change in stem form. The use of 1.9 m and 2.9 m lengths of Growtube induced a columnar stem form which results in tree instability, thus long lengths of Growtube cannot be recommended for routine use. The 0.9 m Growtube provided an advantage over the nil Growtube, however, further research is required in order to determine an optimum Growtube length and to explore the full potential of these treeshelters.
TL;DR: Almost 80 ha of warm temperate rainforest in far East Gippsland was severely burnt in February 1983 and five years after the fire, the vegetation composition was dominated by species which characterise mature rainforest.
Abstract: Summary Approximately 80 ha of warm temperate rainforest in far East Gippsland was severely burnt in February 1983. A study to assess the impact of a wildfire commenced under the National Rainforest Conservation Programme in 1987. Seventy seven permanent Quadrats were established on a grid to monitor vegetation changes, and the numbers and areas occupied by trees, shrubs and seedlings were determined. Five years after the fire, the vegetation composition was dominated by species which characterise mature rainforest. Large increases also occurred in the populations of Acacia melanoxylon, Eucalyptus sp., sclerophyll shrubs and a number of disturbance dependent herbs. Rainforest species recovered through both seedlings and epicormic sprouts. Few species were obligate seed regenerators and these included species restricted to early regeneration stages, as well as uncommon rainforest overstorey species. Populations of several epiphytic species uncommon before the fire may have been reduced, and Cyathea leichha...
TL;DR: Responses of Eucalyptus species planted on farmland in the south-west of Western Australia to nitrogen (N) and phosphorus (P) fertilisation were investigated over two and three year periods.
Abstract: Summary Responses of Eucalyptus species planted on farmland in the south-west of Western Australia to nitrogen (N) and phosphorus (P) fertilisation were investigated over two and three year periods. Factorial combinations of N (0, 6, 17 and 34 g per seedling) and P (0, 5, 12 and 24 g per seedling) in mostly water soluble (quick release) compounds were applied within a month of planting. On well drained soils growth of E. globulus exceeded that of E sideroxylon and E. microcarpa by a considerable margin. After three years there were significant (p 0 g were ...
TL;DR: In this article, a specific silvicultural system, which incorporates measures for soil conservation and environmental protection, is prescribed for each SPC, and the object is to optimise Pinus productivity within the constraints of minimising soil loss and not exceeding a prescribed tolerable soil loss limit.
Abstract: Summary The silviculture of Pinus plantation establishment in Queensland is site-based. Knowledge of both Pinus growth requirements and site capability are used to define site preparation classes (SPCs), the basic planning units used in plantation development. A specific silvicultural system, which incorporates measures for soil conservation and environmental protection, is prescribed for each SPC. The object is to optimise Pinus productivity within the constraints of minimising soil loss and not exceeding a prescribed tolerable soil loss limit.
TL;DR: Sixty-nine Eucalyptus amplifolia seedlots were established in September 1986 at Gainesville, Florida, measured periodically for growth and frost-tolerance, and converted in August 1989 to a seedling seed orchard on the basis of sib and individual superiority.
Abstract: Summary Sixty-nine Eucalyptus amplifolia seedlots (four previously tested provenances and 65 half-sib progenies from selected trees in 11 Australian provenances) were established in September 1986 at Gainesville, Florida, measured periodically for growth and frost-tolerance, and converted in August 1989 to a seedling seed orchard on the basis of sib and individual superiority. Provenance variability was significant for seedling and second-coppice survivals but especially for frost-tolerance. The provenances represented by the 65 progenies were notably better than previously tested provenances. No new provenance was superior in all critical traits, but each had at least one progeny with good tree size and acceptable frost-tolerance. Individual and family heritabilities were moderate, and seedlings from the seed orchard should have about 30% better growth and frost-tolerance. Selected progenies also performed well in additional field studies. The resilience of E. amplifolia progenies in a freezing chamber t...
TL;DR: In Queensland, site preparation design is the stage of planning for Pinus plantation establishment, during which both watershed protection and runoff management needs are met, and runoff control systems and the boundaries for different site preparation systems are located in the field.
Abstract: Summary In Queensland, site preparation design is the stage of planning for Pinus plantation establishment, during which both watershed protection and runoff management needs are met, and runoff control systems and the boundaries for different site preparation systems are located in the field. The aims and methods of site preparation design are described in this paper.
TL;DR: Growth of several first-generation seed orchard seedlots of Pinus radiata was compared with that of genetically unimproved routine seedlOTS at ages six to 15 years, in six seed source (yield) trials and eight progeny tests in New South Wales.
Abstract: Summary Growth of several first-generation seed orchard seedlots of Pinus radiata was compared with that of genetically unimproved routine seedlots at ages six to 15 years, in six seed source (yield) trials and eight progeny tests in New South Wales. The seed orchard seedlots were collected from three New South Wales, three interstate, and two overseas orchards, while the routine seedlots were mostly collected from final crop trees during first rotation clearfelling. At age 6–8 years, on average, stock from the eight seed orchards grew faster than the routines at all sites, with an overall mean gain of 8.5% for diameter and 19.9% for tree volume. Although there were some cases of seed orchard stock growing more slowly than routine stock, the great majority of samples tested were superior, i.e. 85% of the comparisons of diameter growth and 75% of comparisons of volume. In well over half of the comparisons, growth of stock from individual seed orchards exceeded that of the routines by at least 10%. The Tall...
TL;DR: In this paper, the authors estimate the cost of the current commitment to protect non-wood values by retaining ecologically sensitive areas in a selectively logged blackbutt forest (Eucalyptus pilularis Sm.) in N.S.
Abstract: Summary This case study estimates the cost (in terms of reduced royalty) of the current commitment to protecting non-wood values by retaining ecologically sensitive areas in a selectively logged blackbutt forest (Eucalyptus pilularis Sm.) Blackbutt is the most important native timber-producing species in N.S.W. Within these forests, which frequently have a history of relatively low impact logging (group selection), reserved or low-disturbance areas have been set in place to safeguard ecologically “sensitive areas”. These retained areas are expected to complement and interact with the selectively logged forest to improve the maintenance of non-wood values and provide a reference for the long-term impacts of logging. The current forms and extent of reserves and low disturbance areas are examined in the Coffs Harbour Management Area on the north coast of N.S.W. To broadly estimate some of the cost attributable to the commitment to non-wood values, the current royalty value of the harvestable timber set aside...
TL;DR: Assessment and selection for root parameters could be carried out in any season as long as soil conditions at the time are suitable for expression of variation between genotypes, but significant site × family × season interactions suggest that sampling times need to be chosen carefully.
Abstract: Summary The effect of genotype, site and season in the expression of root characteristics such as fine root length, proportion of active roots, short root density and per cent mycorrhiza, were studied on six Pinus radiata families growing on four different sites. Genetic differences occurred between the families in the expression of root characteristics. There was a strong family × site interaction indicating that particular genotypes may express their root characteristics differently in different environments. There were significant differences in the expression of root characteristics between different sampling times. However, generally there was no significant family × season interaction. This suggests that assessment and selection for root parameters could be carried out in any season as long as soil conditions at the time are suitable for expression of variation between genotypes. However significant site × family × season interactions suggest that sampling times need to be chosen carefully for propo...
TL;DR: Nematode levels were assessed for woodchips taken from sirex-infested trees in South Australia during July 1988 and knowledge of this relationship will allow an assessment of the nematode level in a plantation immediately before the inoculation period.
Abstract: Summary Nematode levels were assessed for woodchips taken from sirex-infested trees in South Australia during July 1988. These trees were sampled to determine the percentage of sirex infected with nematodes that emerged during January to April 1989. A logistic equation was fitted to the data from 20 trees to quantify the relationship between the nematode level for woodchips and the percentage of sirex infected with nematodes. Knowledge of this relationship will allow an assessment of the nematode level in a plantation immediately before the inoculation period. Managers can prescribe nematode inoculations based on these results. An operational procedure for woodchip sampling is suggested. However, further testing is needed to verify the relationship in other regions and to determine a reliable period for sampling.
TL;DR: Bark samples of Acacia mearnsii trees from 18 provenances in Australia were analysed by the hide-powder method, and the total solids, insolubles, soluble solids and non-tannin contents of the barks were determined so that the tannin values could be calculated.
Abstract: Summary Bark samples of Acacia mearnsii trees from 18 provenances in Australia were analysed by the hide-powder method, and the total solids, insolubles, soluble solids and non-tannin contents of the barks were determined so that the tannin contents of the barks could be calculated. Mean values of total solids, soluble solids and tannin contents for the barks obtained from the Tasmanian and Victorian provenances differed significantly from those of the South Australian and New South Wales provenances. The mean values of tannin contents in the barks from provenances in Tasmania, Victoria, South Australia and New South Wales were 46.9, 46.6, 39.4 and 38.8%, respectively. Statistical analysis revealed that there was no significant relationship between the results from the hide-powder and the Stiasny methods.
TL;DR: A simple mechanical device is used in the field to measure the angle at which freshly cast needles fracture, which is strongly related to their moisture content, and this technique has potential for application to other forest litter types.
Abstract: Summary Knowing fuel moisture content is important for predicting the behaviour of forest fires. This paper presents a method for quickly and inexpensively estimating the moisture content of pine (Pinus pinaster) needle litter. A simple mechanical device is used in the field to measure the angle at which freshly cast needles fracture, which is strongly related to their moisture content. This technique has potential for application to other forest litter types.
TL;DR: In this paper, six published algorithms for estimating the true height within stem-analyzed sections were compared by locating the position of the growing tip in 30 karri regrowth logs.
Abstract: Summary Height/age data recorded from tree stem analysis can be biased if the height of the cross-cut is taken as the tree height for a given age, because of the presence of a “hidden tip” above the cross-cut. Six published algorithms for estimating the true height within stem-analyzed sections were compared by locating the position of the growing tip in 30 karri regrowth logs. Uncorrected data significantly (P < 0.05) underestimated the length of the hidden tip within a stem section by up to 2 metres, whilst methods proposed by Carmean (1972) and Lenhart (1972) produced unbiased, accurate tree heights. Either of these algorithms appear suitable for karri stem analysis data.
TL;DR: In this paper, the contribution of River Murray tributaries to the flooding of the Barmah river red gum forest was examined and the main stem of the River Murray above Lake Hume was the major source.
Abstract: Summary The contribution of River Murray tributaries to the flooding of the Barmah river red gum forest was examined. The main stem of the River Murray above Lake Hume was the major source. Removal of this would lead to a 55% decrease in forest flooding. Removal of either the Ovens or the Mitta Mitta Rivers would give a 30% reduction in flooding. Removal of the Kiewa River would give a 15% reduction in flooding. All tributaries act to some extent in concert. A backwater influence due to high water levels at the downstream confluence of the Goulburn and Murray Rivers may cause high water levels at Barmah. Because of the short-lived nature of these high water levels it is unlikely that such floods penetrate far into the forest.
TL;DR: Overall, the most satisfactory long-term weed control and tree response was achieved with oryzalin, while diphenamid gave greater pre-emergence control of grass weeds, whileoryzalin was more effective against the broad-leaved weeds.
Abstract: Summary In a glasshouse pot trial, applications of the pre-emergence herbicide oryzalin at rates equivalent to 4 and 8 kg a.i. ha−1 were toxic to germinating seeds of Eucalyptus maculata, Casuarina glauca and Acacia saligna. The pre-emergence herbicide diphenamid was toxic at rates of 7 and 14 kg a.i. ha−1 to germinating C. glauca and A. saligna, but not to E. maculata. Both oryzalin and diphenamid were selective at these rates when applied over newly-planted seedlings of Eucalyptus melliodora, Casuarina cunninghamiana and Acacia baileyana on a former pasture site. Diphenamid gave greater pre-emergence control of grass weeds, while oryzalin was more effective against the broad-leaved weeds. Overall, the most satisfactory long-term weed control and tree response was achieved with oryzalin. The post-emergence herbicides fluazifop-butyl at 0.6 and 1.2 kg a.e. ha−1 and clopyralid at 0.25 and 0.5 kg a.e. ha−1, were mostly selective to the planted seedlings on the former pasture site, but they gave unsatisfacto...
TL;DR: In this paper, the effect of stocking (stems/ha) on growth in predominant height of young Caribbean pine (Pinus caribaea Morelet var hondurensis Barr, and Golf.) in coastal Queensland was examined.
Abstract: Summary The effect of stocking (stems/ha) on growth in predominant height of young Caribbean pine (Pinus caribaea Morelet var hondurensis Barr, and Golf.) in coastal Queensland was examined. A strong negative relationship was found in most cases from about five to eleven years. The potential implications for management are discussed.
TL;DR: A cutting device hoisted by a helium-filled balloon was developed for sampling leaves or other material in tall tree canopies and was found to perform well when used to obtain leaves at a height of 30 m in a Eucalyptus grandis canopy.
Abstract: Summary A cutting device hoisted by a helium-filled balloon was developed for sampling leaves or other material in tall tree canopies. The apparatus was found to perform well when used to obtain leaves at a height of 30 m in a Eucalyptus grandis canopy. Full details of the design and construction of the balloon and cutter are given.
TL;DR: Applications developed at the Forest Research Institute for portable field computers in forest management are reviewed, software development methods are discussed, and some criteria for evaluating new hardware are presented.
Abstract: Summary Modern portable field computers are flexible and powerful machines with a wide range of uses. They now have the ability to provide a great deal of on-site support to forest management personnel. In this paper applications developed at the Forest Research Institute for portable field computers in forest management are reviewed, software development methods are discussed, and some criteria for evaluating new hardware are presented.