Showing papers in "Australian Forestry in 1987"
TL;DR: The biology, economic importance, causes of outbreaks and possible control strategies are briefly reviewed for bark beetles generally, and in particular, for the introduced species Hylastes ater, Hylurgus ligniperda, and Ips grandicollis in commercial plantations of Pinus spp.
Abstract: Summary Aspects of the biology, economic importance, causes of outbreaks and possible control strategies are briefly reviewed for bark beetles generally, and in particular, for the introduced species Hylastes ater, Hylurgus ligniperda, and Ips grandicollis in commercial plantations of Pinus spp., and for Phloeosinus cupressi and Scolytus multistrialus on ornamental cypress and elm respectively. The extensive plantations of Pinus radiata in Australia are believed to be especially susceptible to damage by bark beetles. Ips grandicollis can cause tree mortality and contribute to blue-staining in sapwood of pine, S. multistrialus is being monitored for a possible association with Ceralocystis ulmi (the causal agent of the devastating Dutch elm disease in Western Europe and North America), while H. ater, H. ligniperda and P. cupressi have low economic potential. Stringent plant quarantine measures need to continue at Australian ports of entry for timber and wood products, so that the risk of additional acciden...
40 citations
TL;DR: Responses by quarantine and forestry authorities to the inadvertent introduction to Australia of seven economically important pests and pathogens of forest trees, or forest products, from the time of introduction to the present are described.
Abstract: Summary Responses by quarantine and forestry authorities to the inadvertent introduction to Australia of seven economically important pests and pathogens of forest trees, or forest products, from the time of introduction to the present are described. Eradication was achieved only in the case of European house borer (Hylotrupes bajulus). but not for West Indian drywood termite (Cryptotermes brevis), five-spined bark beetle (Ips grandicollis). Sirex wood wasp (Sirex noctilio), poplar rusts (Melampsora medusae and M. larici-populina) and Dothistroma needle blight (Dothistroma septospora). It has not been possible to quantify the economic cost of eradication attempts, or of control measures including research, for any of the case histories presented. It is argued that the Australian Agricultural Health and Quarantine Service should be actively involved in control campaigns until effective pest or disease management strategies have been developed.
34 citations
TL;DR: In this paper, the effect of an aerial drop of a solution of ammonium sulphate and kelzan, commonly used as a retardant mixture for the suppression of bushfires, was examined on the foliage of a eucalypt forest in the Blue Mountains near Sydney.
Abstract: Summary The effect of an aerial drop of a solution of ammonium sulphate and kelzan, commonly used as a retardant mixture for the suppression of bushfires, was examined on the foliage of a eucalypt forest in the Blue Mountains near Sydney. Observations were carried out over a one year period. Damage to the overstorey was estimated and litter-fall and changes in cover of understorey and ground cover species were measured. In the field, immediate and widespread leaf death occurred, in trees, shrubs and ground cover. The overstorey recovered rapidly but recovery in the understorey took much longer. Variations in the rate and ability to recover were found amongst understorey species. An increase in litterfall from trees and shrubs occurred during the first few months after treatment. However total litterfall over the year did not differ between the treated and an untreated area. Trials with seedlings of four shrub species in a glasshouse, showed that leaf death was caused solely by the ammonium sulphate compon...
24 citations
TL;DR: The growth pattern and the optimum thinning range for 60-year-old white cypress pine stands differed from that previously reported for this species and was determined to be within the range 6 to 10 m2 ha−1.
Abstract: Summary The growth of 60-year-old white cypress pine stands at five locations in the Pilliga Management Area of N.S.W. is analysed over a 20 year period following thinning. The growth pattern and the optimum thinning range differed from that previously reported for this species. At four of the five locations stand basal area increment was independent of basal area for a range of values forming a ‘plateau’ of maximum increment. For these sites, no stand basal area increment rise or decline was detected with increasing residual basal area, over the range 6 to 18 m2 ha−1. The other location exhibited a growth pattern akin to the phenomenon of “lock-up” where increment did not “plateau” but peaked at a basal area of about 8 m2 ha−1 and then declined markedly at higher basal area without corresponding mortality. The optimum thinning range, where both tree size and site utilisation are maximised, was determined to be within the range 6 to 10 m2 ha−1. Maximum basal area increment ranged from 0.30 to 0.40 m2 ha−1...
19 citations
TL;DR: Factors which may influence the early detection and identification of exotic insect pests of trees and timber in Australia are discussed, with examples from Queensland.
Abstract: Summary Factors which may influence the early detection and identification of exotic insect pests of trees and timber in Australia are discussed, with examples from Queensland. Sixty-seven species of wood-boring insects are listed which were intercepted at the Port of Brisbane or detected subsequent to entry during the period 1977 to 1985. The modes of entry and countries of origin of these insects (grouped by families) are presented. Avenues for improving the efficacy of present detection and identification approaches are suggested. The application of stringent quarantine measures at ports of entry is still considered to be our best means of preventing problems with exotic pests in forests and in timber.
18 citations
TL;DR: Several of the biological features of Araucaria cunninghamii have had a major impact on the development of techniques for the production of high quality seed, including the rigidly defined branching system, wide interclonal variation in flowering season, intermittent flowering, the pollination mechanism, seed structure and grafting incompatibility.
Abstract: Summary Several of the biological features of Araucaria cunninghamii have had a major impact on the development of techniques for the production of high quality seed. These include the rigidly defined branching system, a long juvenile period with respect to the production of pollen cones, wide interclonal variation in flowering season, intermittent flowering, the pollination mechanism, seed structure and grafting incompatibility. The significance of these features in relation to seed orchard design, establishment and management, and to seed collectior processing and storage is discussed. Major outstanding problems are indicated, and potentially productive avenues of research outlined
15 citations
TL;DR: In this article, seasons of increased bushfire activity in New South Wales, Victoria and Tasmania are shown to be significantly related to the occurrence of El Nino/Southern Oscillation (ENSO) events in the equatorial Pacific Ocean.
Abstract: Summary Seasons of increased bushfire activity in New South Wales, Victoria and Tasmania are shown to be significantly related to the occurrence of El Nino/Southern Oscillation (ENSO) events in the equatorial Pacific Ocean. ENSO events can be predicted up to 18 months before they occur using meteorological satellites and ship weather observations. Bushfire fighting authorities and the public can therefore be warned of the forthcoming seasonal bushfire hazard, which may lead to reduced bushfire damage and decreased public expenditure on fire fighting.
14 citations
TL;DR: The effects of the five-spined bark beetle Ips grandicollis on the incidence and spread of bluestain fungi in billets of Pinus elliottii over 60 days were studied in summer 1986 near Coffs Harbour.
Abstract: The effects of the five-spined bark beetle Ips grandicollis on the incidence and spread of bluestain fungi in billets of Pinus elliottii over 60 days were studied in summer 1986 near Coffs Harbour,...
13 citations
TL;DR: The yield of veneer and sawn timber from 36-year-old plantation-grown radiata pine trees of cutting and seedling origin were compared in a mill study in order to determine the quality and volume of products recovered.
Abstract: Summary The yield of veneer and sawn timber from 36-year-old plantation-grown radiata pine trees of cutting and seedling origin were compared in a mill study. The cuttings had been taken from 6-year-old trees (7 years from seed) of good vigour, stem form and branching, and of the same seed source as used to grow the trees of seedling origin in the study. The total volume of logs harvested from the cuttings and seedlings was about the same (59.0 m3 c.f. 57.1 m3) but the volume of products recovered was higher in logs derived from the cuttings (24.4 m3 c.f. 20.1 m3). A higher proportion of the logs harvested from the cuttings was accepted for peeling (41.2% c.f. 31.8%).The overall yield in volume of veneer was 43% greater for the cuttings (11.1 m3 c.f. 7.8 m3) and the quality was better, also the number of face-grade veneer sheets from the cuttings billets was twice that from the seedlings. Though the remaining volume of logs from the cuttings sent to the sawmill was lower than that from the seedlings (34.7...
13 citations
TL;DR: In this article, the results from an experiment in partial cutting conducted in 12.7 ha of multi-aged stands of E. delegatensis situated on private property in central Tasmania were reported.
Abstract: Summary This paper reports the results from an experiment in partial cutting conducted in 12.7 ha of multi-aged stands of E. delegatensis situated on private property in central Tasmania. The objective of management is to maximise sustained yield of sawlogs, with a variable yield of pulpwood. Following a precise survey of the positions of all trees greater than 20 cm dbh, the stands were partially cut. Nearly all trees that were sound, of good form, and therefore considered likely to appreciate in value, were retained; defective and overmature trees were removed regardless of size. The degree of release of retained trees was calculated as the change, before and after felling, in a competition index that was derived from the relative size and distance apart of subject and competing trees. Regression analysis of diameter increment against per cent reduction in competition index explained 63 per cent of variation in growth in trees less than 30 cm dbh, but less than 15 per cent variation in growth in trees g...
12 citations
TL;DR: Results indicate that in the mixed eucalypt forests of central Victoria, regrowth responded to the reduction in competition, with the magnitude of the response in bai and height increment generally increasing with the degree of release and increasing crown dominance.
Abstract: Summary The response in basal area and height of messmate stringybark regrowth stems to release from competition over a period of ten years was examined in irregular stands of mixed eucalypts in the Wombat and Creswick Forests. These stands contained a mixture of small trees (dbhob <30 cm) less than 40 years old (regrowth), with larger trees (dbhob to 80 cm) 80 to 100 years old (overwood). Competing stems were identified by the ‘zone count’ method using a 9.2 m2 ha-1 optical wedge. Basal area increment (bai) and height increment of regrowth stems was reduced by competing overwood and regrowth, but regrowth stems retained a capacity to respond when released from this competition. Regardless of crown position within the regrowth stratum, regrowth responded to the reduction in competition, with the magnitude of the response in bai and height increment generally increasing with the degree of release and increasing crown dominance. These results indicate that in the mixed eucalypt forests of central Victoria, ...
TL;DR: In this article, the mass propagation of superior full-sib families and outstanding individual genotypes by means of seeds and/or cuttings, which would result in significant increases in gains above the levels achieved by conventional seed orchard methods, are discussed for Araucaria cunninghamii, Pinus caribaea var. hondurensis and F1 hybrids of the latter with P. elliottii and P. tecunumanii.
Abstract: Summary Methods for the mass propagation of superior full-sib families and outstanding individual genotypes by means of seeds and/or cuttings, which would result in significant increases in gains above the levels achieved by conventional seed orchard methods, are discussed for Araucaria cunninghamii, Pinus caribaea var. hondurensis and F1 hybrids of the latter with P. elliottii and P. tecunumanii. Biological features which influence the choice of technique for the various species include: incidence of grafting incompatibility, time taken for grafts to commence flowering, coincidence of flowering times, levels of seed set and viability, and the vegetative multiplication rates obtainable. For the Pinus taxa, the preferred approach to the production of tested superior full-sib families is by a combination of fully controlled pollination in clone banks, followed by vegetative multiplication at a moderately high rate. For A. cunninghamii, the most flexible strategy is considered to be mass pollination in young...
TL;DR: The atmosphere beyond the year 2000 will be different from any experienced since before the last glaciation, more than 100 000 years ago, and this will profoundly affect forestry locally and globally.
Abstract: Summary The atmosphere beyond the year 2000 will be different from any experienced since before the last glaciation, more than 100 000 years ago. This will profoundly affect forestry locally and globally. Large percentage increases in carbon dioxide and other greenhouse gases will cause temperatures at a given location to be far higher than any in human history, and large local changes in rainfall and humidity. These will greatly affect tree growth, species composition in natural forests, and fire frequencies. In addition, higher carbon dioxide concentrations in the air will increase the potential growth rates of trees, which will be more limited by other factors such as water stress and nutrient supply. Other environmental factors affecting forests include possible destruction of the stratospheric ozone layer, which would lead to increased ultraviolet radiation which is detrimental to tree growth. The cumulative effects of local air pollution, including acid rain and smog, may also continue to seriously ...
TL;DR: The use of Landsat and other types of remotely sensed imagery by forest managers in Australia should become more widespread with improvements in sensors and computer algorithms and the increasing availability of cheaper computing facilities, including microcomputers, to analyse data.
Abstract: Summary Landsat and other remotely sensed digital data offer many advantages for forest managers. Researchers and land managers have used Landsat to inventory forests, detect and monitor fire boundaries and clearing of forests, and monitor the spread of major forest pests. In North America, and to some extent in Australia, Landsat data are used operationally for some of these functions. The use of Landsat and other types of remotely sensed imagery by forest managers in Australia should become more widespread with improvements in sensors and computer algorithms and the increasing availability of cheaper computing facilities, including microcomputers, to analyse data.
TL;DR: Case histories of the initial detection and spread of several introduced tree diseases are analysed to show difficulties which can arise in early detection of outbreaks and proposed eradication campaigns.
Abstract: Summary In Australia, native and introduced trees are at risk from many exotic diseases, both known and unknown. To exclude these diseases effectively, quarantine must be based on sound biological principles. The influence on quarantine of several biological factors is discussed; those considered include life cycle of the pathogen, alternate hosts, methods of introduction, the lag period between introduction of a pathogen and its detection, deficiencies in disease records, taxonomic resources for identification and others. The close relationship between quarantine measures for agricultural, horticultural, forestry and native plants, and the need for co-ordination in these fields, is stressed. Case histories of the initial detection and spread of several introduced tree diseases are analysed to show difficulties which can arise in early detection of outbreaks and proposed eradication campaigns. Whilst contingency plans for disease outbreaks must be developed, it is concluded that the cheapest and most effe...
TL;DR: In this article, the authors present some preliminary ideas on the present position of private forestry in Australia and suggest that despite a plethora of incentive schemes, relatively little effort is put into assistance for anything but core forestry.
Abstract: Summary This paper presents some preliminary ideas on the present position of private forestry in Australia. The broad term, private forestry, is disaggregated down into various components, to determine what is being done in each and by whom, the kinds of assistance available and from whom, and the major incentives and disincentives. Six groups of private forest owners are identified, each motivated by different objectives and with different available resources. We suggest though, that despite a plethora of incentive schemes, relatively little effort is put into assistance for anything but ‘core forestry’ Core forestry is what State forest services concentrate on—industrial plantations and managing native forests primarily for wood production, with hired or contracted labour and management. We suggest that incentive schemes designed to promote private forestry have often not addressed real constraints because they were never designed from the roots up, with the client—a prospective forest owner—in mind. T...
TL;DR: In this article, the authors discuss the problem of resolving conflicts in resource use in the Australian Forest Service and propose a solution to resolve conflicts in the forest management: fighting over the forests.
Abstract: (1987). Fighting over the forests: resolving conflicts in resource use. Australian Forestry: Vol. 50, No. 3, pp. 144-146.
TL;DR: In this paper, the authors argue that retention of existing vegetation may be a better option in many cases than planting new trees, and propose a system of financial, technical and social support for such a strategy.
Abstract: Summary Over two thirds of Australia's woodland and forests have been cleared for conversion to agriculture and pasture since 1965. Programs to combat tree decline, particularly to retain and restore native vegetation are urgently needed to maintain the productivity of much of Australia's farmlands. Such efforts to date have been reviewed. Incentive schemes promoting trees on farms have concentrated on tree planting although we argue that retention of existing vegetation may be a better option in many cases. As with incentive schemes for private timber production, many schemes have been ineffective because of a failure to appreciate the landowners' financial situation and the bases of existing land use. Although there are vast regional differences throughout Australia, many farmers are now actively interested in forestry to sustain and improve agricultural productivity, to minimise land degradation and enhance environmental values. We propose a system of financial, technical and social support for such la...
TL;DR: Although subject to cyclone hazard, the Pinus and other exotic forests on Melville Island are sufficiently well established that the future of the project seems assured and it seems unlikely that any other land use could possibly match commercial pine forestry at this location.
Abstract: Summary The establishment of large plantations of Pinus caribaea on Melville Island under the direction of the Northern Territory Conservation Commission ultimately envisages a viable forestry enterprise run by the indigenous Tiwi producing saw lumber for the virtually captive Darwin market. Key aspects of the project are compared with experience and practice in the Caribbean, to which the species is native. Although subject to cyclone hazard, the Pinus and other exotic forests on Melville Island are sufficiently well established that the future of the project seems assured. From economic, environmental and conservation points of view, it seems unlikely that any other land use could possibly match commercial pine forestry at this location.
TL;DR: Manual and computer based methods for generating random number lists for use in conducting 3P sample surveys are described and a procedure for selecting from pages of computer generated output the most satisfactory page of random numbers is outlined.
Abstract: Summary This article describes manual and computer based methods for generating random number lists for use in conducting 3P sample surveys. It outlines a procedure for selecting from pages of computer generated output the most satisfactory page of random numbers to use for selecting the 3P sample when the number of units (trees, plots, etc.) to be assessed is small, e.g., <500.
TL;DR: In this paper, the authors investigated the travel times of articulated logging trucks along varying classes of road in the Circular Head region of North West Tasmania and developed a road classification system to relate the performance of such trucks to roads of different standards.
Abstract: Summary The travel times of articulated logging trucks along varying classes of road in the Circular Head region of North West Tasmania were investigated. A road classification system was developed to relate the performance of such trucks to roads of different standards. Using this system, models were tested to predict travel times over any specified route for both unloaded and loaded travel. By using one of these models, fixed, variable and total haulage costs per tonne could be estimated for a vehicle travelling over one or more of eleven defined classes of road. This approach illustrates how costs estimates can be made, more equitably than those currently in force, without necessarily changing total haulage costs, since variations in road conditions along different haulage routes can be taken into account.
TL;DR: In this article, the strength of six dominant class trees of Douglas fir (Pseudotsuga menziesii), aged about 55 years, from plantations in each of four localities (Macedon, Otway Ranges, Bright and Beechworth) were tested for physical and mechanical strength properties in both the green and dried (12% moisture content) condition.
Abstract: Summary Wood samples from six dominant class trees of Douglas fir (Pseudotsuga menziesii), aged about 55 years, from plantations in each of four localities (Macedon. Otway Ranges, Bright and Beechworth) were tested for physical and mechanical strength properties in both the green and dried (12% moisture content) condition. Differences were found in the strength of wood from the four locations according to static strength tests on green material for a number of properties. Wood from Bright and Beechworth had significantly lower strength values than that from Macedon and the Otway Ranges, and wood from Bright had consistently lower strength values than that from the other three localities. The results from impact tests on green material from the four locations were not significantly different. For timber dried to 12% moisture content, strength did not differ with location. Strength values of wood from the samples of 55 year-old Douglas fir grown in Victoria were similar to those reported from similar aged s...
TL;DR: A system based on debarking in the stand immediately after felling, forwarder extraction and chipping at the landing would probably produce chips most cheaply overall, mainly because the transport and disposal costs associated with removal of bark and the cost of replacing the nutrients it contains would be avoided.
Abstract: Summary A major constraint on the use of thinnings from young regrowth eucalypt stands for pulpwood is the lack of commercially proven debarking processes. Some types of debarking equipment which, with further development, may be suitable are discussed briefly. Six systems of felling, debarking, transporting and chipping small-diameter eucalypt stems were examined to compare delivered costs of chips at the pulp mill. The systems differed in terms of debarking processes, and debarking and chipping locations. On the assumption that eucalypt bark has no economic value at the mill, a system based on debarking in the stand immediately after felling, forwarder extraction and chipping at the landing would probably produce chips most cheaply overall, mainly because the transport and disposal costs associated with removal of bark and the cost of replacing the nutrients it contains would be avoided.
TL;DR: The way that the wood supply/demand outlook in the Pacific Region is evolving means that the future of forestry in Australia will be determined more by what happens outside Australia than within this article.
Abstract: Summary The way that the wood supply/demand outlook in the Pacific Region is evolving means that the future of forestry in Australia will be determined more by what happens outside Australia than within. Most of the presently accepted premises underlying forest policies in Australia will be obsolete within a decade or so. Only a drastic re-structuring to cost-effective market-directed policy can avert yet another crisis.
TL;DR: The integration of quarantine, contingency planning and forest health surveillance is seen as the major strength of forest insect and disease protection in New Zealand as mentioned in this paper, and a Forest Disease Contingency Plan, the most recent addition to the forest protection system, facilitates rapid and considered response to new pest and disease outbreaks without compromising the quality of decision making.
Abstract: Summary The integration of quarantine, contingency planning and forest health surveillance is seen as the major strength of forest insect and disease protection in New Zealand. A Forest Disease Contingency Plan, the most recent addition to the forest protection system, facilitates rapid and considered response to new pest and disease outbreaks without compromising the quality of decision making. Its recent use against the leaf blister sawfly, Phylacteophaga froggatti, well illustrates the benefits of such a plan.
TL;DR: The successful development of a machine to prune pines between 2 m and 6 m could result in a reduction of high pruning costs by $222 000 or more a year in Australia, and allow pruning in other areas that may otherwise remain unpruned.
Abstract: Summary A conceptual design for a machine to prune pines between 2 m and 6 m is presented. Computer-aided-design illustrations of some machine features are presented. The proposed machine attaches to an excavator prime-mover, and uses an octagon of milling cutters to machine away branches. It is estimated the machine (excluding the prime-mover) would cost about $65 000 and be able to prune one tree per minute. The pruning cost would then be 95C per tree. This is less than the cost of doing it manually. For comparison, the cost of high-pruning when using mobile platforms is also estimated and found to be greater than the cost of manual pruning. The number of machines required to carry out all high-pruning in Australia is estimated to be between 20 and 30. The successful development of the machine could result in a reduction of high pruning costs by $222 000 or more a year in Australia, and allow pruning in other areas that may otherwise remain unpruned.