Showing papers in "Australian Forestry in 2001"
TL;DR: In this article, the authors discuss three bushfire incidents in Australia where firefighters were trapped and killed, and the development of fire spread in forest fuels from a line start, and a table illustrates the distance that a line fire can travel in five minutes under different fire danger conditions.
Abstract: Summary Firefighters engaged in parallel or indirect attack are working in a “dead-man zone” if they do not appreciate the time and space required to find a safe refuge. In this zone, if the wind direction changes, the fire can advance so rapidly that the firefighters have very little time to seek refuge in the burnt area behind a suppressed portion of line, or egress elsewhere, before the fire overwhelms them. We discuss three bushfire incidents in Australia where firefighters were trapped and killed, and the development of fire spread in forest fuels from a line start. A table illustrating the distance that a line fire can travel in five minutes under different fire danger conditions is presented. Factors that affect the speed of the firefighter's reaction to changed circumstances, and safe work practices, arc discussed.
67 citations
TL;DR: Generally, new leaves exhibited lower SLWs and higher water contents than old leaves irrespective of watering regime or provenance, and the importance of leaf “toughness” (as indicated by SLW) to insect herbivory, and therefore its relevance to plantation managers, is discussed.
Abstract: Summary The influence of watering regime, provenance and leaf-age were studied in relation to specific leaf weight (abbreviated SLW; inversely correlated with percentage leaf water) of juvenile leaves of Eucalyptus globulus subspecies globulus. SLW provides a physiological estimate of leaf “toughness” relevant to studies of insect herbivory. Leaves from saplings given continuous access to water had lower SLWs and higher water contents than leaves from saplings that were drip irrigated. Saplings of the King Island provenance produced leaves of consistently lower SLW compared with leaves from saplings of the Geeveston provenance irrespective of watering regime. Furthermore, leaves from the King Island provenance saplings exhibited less variation with respect to water content than leaves from the Geeveston saplings irrespective of watering regime. Generally, new leaves exhibited lower SLWs and higher water contents than old leaves irrespective of watering regime or provenance. The importance of leaf “toughne...
53 citations
TL;DR: In this article, a brief background to growth stress, its undesired effects on sawlog utilization, and the methods that have been developed to counter these effects is provided, along with three major methods used at present for growth strain measurement on tree or log surfaces.
Abstract: Summary This paper provides a brief, general background to growth stress, its undesired effects on sawlog utilization, and the methods that have been developed to counter these effects. The paper also describes three major methods used at present for growth strain measurement on tree or log surfaces, and discusses the need for an improved understanding of these methods.
53 citations
TL;DR: Progress on breeding radiata pine for stiffness in New Zealand is reviewed, with a briefer account of work in Australia, and several direct and indirect methods to improve stiffness are described.
Abstract: Summary Radiata pine is widely planted in the southern hemisphere, and has a versatile timber. The mature wood of this species is strong and stiff enough for a number of industrial uses, but current trends of harvesting at below 30 years result in a high proportion of low-stiffness juvenile wood. Radiata pine breeders have countered this reduction, indirectly, by selecting progenies for dense juvenile wood. However there is evidence now that improving juvenile wood density may not be sufficient to fully address low stiffness. This has led to work on assessing stiffness itself, and to studies on using microfibril angle in the tree improvement program. Progress on breeding radiata pine for stiffness in New Zealand is reviewed in this paper, with a briefer account of work in Australia. Several direct and indirect methods to improve stiffness arc described. These include static bending tests on boards and small clear specimens, acoustic and stress wave methods, and microfibril angle, in addition to density an...
50 citations
TL;DR: In this paper, the effects of chemical fertilizer, spacing, and interplanted nitrogen-fixing trees on wood density and diameter growth of 15-year-old Eucalyptus saligna trees were evaluated.
Abstract: Summary We evaluated effects of chemical fertilizer, spacing, and interplanted nitrogen-fixing trees on wood density and diameter growth of 15-year-old Eucalyptus saligna trees. The trees were grown in silvicultural trials established on former sugarcane land on the island of Hawaii. Elevation was 480 m, slopes were gentle, and annual rainfall averaged 4600 mm at the trial locations. Breast-high increment core samples were obtained by boring more than 100 dominant and codominant trees. Diameters of individual trees ranged from 16.4 to 45.9 cm, and cross-sectional wood densities from 349 to 496 kg m−3. Silvicultural treatment means for 15-year diameter ranged from 24.2 to 35.6 cm, and means for cross-sectional wood density from 400 to 424 kg m−3. Wider spacing (4 m by 4 m vs. 2 m by 2 m) increased mean diameter by 34% without decreasing, and may have increased, wood density. Level of chemical fertilization did not affect wood density, and mean diameter of trees sampled in the two fertilizer treatments was ...
48 citations
TL;DR: Options for control of psyllids are discussed to enable landholders and forest plantation managers to make more informed decisions on ways of dealing with outbreaks on eucalypts, particulary E. camaldulensis.
Abstract: Summary Psyllids are one of the most devastating insect pest groups in Australia, affecting both native forests and eucalypt plantations. They feed on a wide variety of eucalypt host species, with some psyllid species restricted to a single eucalypt host species or to a group of closely related species. Predominant amongst eucalypt species attacked by psyllids is Eucalyptus camaldulensis Dehnh., an important tree species for a variety of reasons including the insect and decay resistance of the timber, its role in reducing water table levels and minimising erosion along streams and rivers, its adaption to soils with significant salt content, and its importance as a habitat for native wildlife. In recent years it has become a candidate species for plantation forestry, especially in the northern irrigation areas of Victoria. This paper briefly examines the biology of psyllids, covering their identification, description and life-cycles, and providing a brief history of major psyllid outbreaks in Australia. Th...
39 citations
TL;DR: This paper revisited a series of trials carried out over the last two decades in an attempt to evaluate the long-term effects of land preparation at re-establishment on the productivity of fast growing hardwoods (Acacia mearnsii and Eucalyptus spp.).
Abstract: Appropriate land preparation at re-establishment is of major importance to forest managers to ensure maximum survival and vigorous early growth of South African plantation forests. This work revisits a series of trials carried out over the last two decades in an attempt to evaluate the long-term effects of land preparation at re-establishment on the productivity of fast—growing hardwoods (Acacia mearnsii and Eucalyptus spp.). A wide range of land preparation techniques was tested: ploughing, ripping, subsoiling, ridging and complete site preparation (de-stumping, ripping and discing) inter alia. Of the eleven trials originally planted, five reached rotation age (between 9 and 11 years) and, apart from one which was destroyed by a storm at 5 years, the rest, at time of writing, were close to clearfelling. With the exception of one trial where significant growth responses were recorded, and apart from a few significant lower-order interactions, final survival, basal area and volume were not affecte...
38 citations
TL;DR: Following harvesting, retained eucalypt stems will exert a suppressive influence on regrowth in terms of stocking, and height and volume growth, which has been the subject of several studies in Australia.
Abstract: Summary Competition between trees for resources such as light, nutrients and water is a significant process in a forest. Because these resources are limited, a forest site has a maximum productive capacity, and its resources must be shared between all trees. This sharing is not necessarily equal, with canopy position and the ability of a tree to capture resources dictating its competitive status in the stand. As a result, a tree with a favourable position or size advantage can ultimately suppress its neighbours. Similarly, following harvesting, retained eucalypt stems will exert a suppressive influence on regrowth in terms of stocking, and height and volume growth. This effect has been the subject of several studies in Australia, aimed primarily at quantifying it in terms of a ‘zone of influence’ or loss of potential biological and commercial productivity. These studies have shown that the zone of influence on regrowth around a retained eucalypt tree following harvesting is typically 1.7 to 3.0 times its ...
26 citations
TL;DR: Bat activity was recorded in eight paired coupes of unlogged forest and 22-year-old regrowth forest, near Eden in southern New South Wales, suggesting roads and tracks provide linear edge habitat that may be an important ameliorative measure allowing a range of bat species to exploit habitat otherwise too cluttered for foraging.
Abstract: Summary Bat activity was recorded in eight paired coupes of unlogged forest and 22-year-old regrowth forest, near Eden in southern New South Wales. Regrowth coupes had been clearfelled in 1976, with no retention of habitat trees or riparian buffers on minor forest streams. Ultrasonic detectors (Anabat) positioned off-flyways recorded an average of 87 passes in the first two hours after dark in unlogged coupes compared to 36 passes in regrowth coupes. This difference was probably due to considerable ‘clutter’ in the regrowth compared to the open forest structure of unlogged coupes. The overall rate of feeding (feeding buzzes/total passes) was very low in this study (3% in unlogged, 0.9% in logged). Low activity in regrowth was consistent for less maneuverable bat species, although those with a large body size were too rare to be tested. Despite low activity in regrowth, trapping rate on tracks was high, although 20% less than in unlogged coupes. Across the logged/unlogged mosaic, 11 bats were caught per ha...
25 citations
TL;DR: Results suggest that significant improvements in local and regional prediction of forest growth may be gained by augmenting information derived from aerial photography and limited field inventory, with predictions made from process models such as 3-PG.
Abstract: Summary In this paper predictions from a process model, based on the Physiological Principel Predicting Growth (3-PG) model, are compared with those of two conventional growth and yield models. A number of forest growth variables are compared including the standing volume, mean diameter at breast height (DBH), and stocking over 50 000 ha of native eucalypt forest in south-eastern Australia. Stand variable predictions at 22 permanent plot locations, using a locally calibrated empirical growth model and 3-PG were highly correlated with field estimates derived from plot data. 3-PG predictions of standing volume, diameter at breast height (DBH) and stocking explained 86%, 59% and 89% of the variance respectively, compared to the local empirical model which explained 84%, 59% and 78% of the variance in predictions of the same variables. A generic forest growth model explained only 6% of the variance in standing volume predictions. A number of methods of estimating maximum potential standing volume across the l...
23 citations
TL;DR: In this article, the relationship between variation in wood shrinkage and cellulose crystallite width determined by X-ray diffraction was assessed using SilviScan-2 (a system developed at CSIRO for rapid assessment of wood microstructure).
Abstract: Summary The relationship between variation in wood shrinkage and cellulose crystallite width determined by X-ray diffraction was assessed using SilviScan-2 (a system developed at CSIRO for rapid assessment of wood microstructure). Cellulose crystallite width, density and microfibril angle were determined for 600μm wide zones on small wood samples with known tangential shrinkage. The tangential shrinkage measurements included shrinkage to 12% moisture content after reconditioning (MC AR); and a shrinkage differential calculated from tangential shrinkage to 12% MC AR recorded for each zone; and the minimum shrinkage recorded in adjacent wood of similar cambial age. Spearman correlations and forward stepwise regressions showed that the cellulose crystallite width was a good predictor of the shrinkage measures and that density was a minor predictor. Together, cellulose crystallite width and density could explain 75% of the variation in tangential shrinkage for randomly selected locations throughout the tree, ...
TL;DR: Molecular markers have provided evidence that the canopy position from which open-pollinated seed is harvested in Eucalyptus globulus can markedly affect its outcrossing rate, indicating the importance of sampling position within the canopy when collecting open- Pollinated seed for deployment or genetic evaluation.
Abstract: Molecular markers have provided evidence that the canopy position from which open-pollinated seed is harvested in Eucalyptus globulus can markedly affect its outcrossing rate. Outcrossing rates were higher and more uniform in upper canopy samples. As expected, no significant differences in outcrossing rate were found between top and bottom canopy samples of self-incompatible trees, but differences were large between top and bottom samples of self-compatible trees. In one tree, 73% of the open-pollinated progenies at the bottom of the canopy were selfed compared to 26% at the top. Such selfing can severely reduce survival and growth. This result clearly indicates the importance of sampling position within the canopy when collecting open-pollinated seed for deployment or genetic evaluation.
TL;DR: A comprehensive study was conducted on three provenances of ten-year-old Eucalyptus globulus grown on two sites near Mount Gambier, South Australia to assess wood properties as they relate to the end-use as sawn timber, and to examine differences in wood properties between provenances and sites.
Abstract: Summary A comprehensive study was conducted on three provenances of ten-year-old Eucalyptus globulus grown on two sites near Mount Gambier, South Australia to assess wood properties as they relate to the end-use as sawn timber, and to examine differences in wood properties between provenances and sites. Ten trees with relatively good form and growth were selected from each provenance at each site. Growth strain was measured on both standing trees and the harvested logs. Data analysis of longitudinal growth strain showed that: (1) mean growth strain throughout the stem at the first site (Johnstons Block) was higher in all three provenances than at the second site (Heath Block), in particular for SE Tasmania provenance; (2) King Island provenance had significantly lower growth strain than the Jeeralang and SE Tasmania provenances; (3) there were no significant differences in mean growth strain with sampling heights up the stem; (4) Jeeralang provenance had higher between-tree and within-tree variation in gr...
TL;DR: Bennett et al. as mentioned in this paper found that low levels of phosphorus were correlated with increased susceptibility of Eucalyptus globulus to infection by Mycosphaerella cryptica compared with trees given high amounts of phosphorus fertiliser.
Abstract: Summary Leaf disease caused by Mycosphaerella cryptica was assessed on the adult foliage of a 6-year-old Eucalyptus globulus fertiliser trial in south-eastern Australia. The trial consisted of 16 treatments of various combinations of nitrogen, phosphorus, potassium and trace elements, originally established to determine the effects of these additions on tree growth. Disease was assessed as the proportion of the whole crown with leaf spot caused by M. cryptica. The trial had previously been measured for growth parameters (Bennett et al. 1997). The results from our study provide evidence that low levels of phosphorus were correlated with increased susceptibility of E. globulus to infection by M. cryptica compared with trees given high levels of phosphorus fertiliser. Treatments with no phosphorus added were significantly more diseased than those with up to 200 kg ha−1 added phosphorus. Neither the addition of nitrogen, potassium nor a combination of trace elements had a significant effect on disease severit...
TL;DR: This paper attempts to define forest sustainability in the contemporary usage and is hoped that the paper will help clarify related policy issues and the processes required to plan and monitor forest sustainability.
Abstract: Summary Misunderstandings have arisen in the Comprehensive Regional Assessments (CRA) leading up to the Regional Forest Agreements (RFA) on the utilisation and management of Australian native forests, due to different perceptions held by stakeholder groups on what constitutes forest sustainability. In the CRA process, terms such as ‘sustained yield’, ‘sustainable yield’, ‘sustainable forest management’, ‘multiple-use forestry’, ‘ecologically sustainable forest management’ and ‘adaptive forest management’ have been used indiscriminately, adding to the confusion. This paper attempts to define forest sustainability in the contemporary usage. It is hoped that the paper will help clarify related policy issues and the processes required to plan and monitor forest sustainability. These processes address goals over a long time horizon, and these goals in turn provide a framework for guiding and constraining detailed short-term planning.
TL;DR: The amount of suitable nesting substrate did not appear to be a factor limiting populations in either the dry or wet sclerophyll forest, and C. lepidus was captured in all ages of regrowth and in both partially logged and old-growth forest.
Abstract: Summary Occurrence and nest site use by pygmy possums were investigated in dry and wet sclerophyll forest in Tasmania. There were four silvicultural treatments in the dry sclerophyll forest (a clearfelled coupe with 17-year-old regrowth, two partially logged coupes and old-growth forest) and four in the wet sclerophyll forest (4- and 20-year-old regrowth resulting from clearfelling, 80-year-old natural regrowth and old-growth forest). Cercartetus lepidus was captured in all ages of regrowth and in both partially logged and old-growth forest. C. nanus was captured only in 20- and 80-year-old regrowth in wet sclerophyll forest. Partially decayed logs were important nest sites for C. lepidus. Fissures in live trees associated with fire scars and hollows in stumps were also used as nests. All three nests of C. nanus were located in stumps. The amount of suitable nesting substrate did not appear to be a factor limiting populations in either the dry or wet sclerophyll forest.
TL;DR: A trial designed to measure benefits to growth of post—establishment weed control and fertiliser application in a young Eucalyptus dunnii plantation was used to test whether young trees benefiting from such silvicultural practices were more resilient to stress from waterlogging and insect damage.
Abstract: Summary A trial designed to measure benefits to growth of post—establishment weed control and fertiliser (diammonium phosphate, DAP) application in a young Eucalyptus dunnii plantation was used to test whether young trees benefiting from such silvicultural practices were more resilient to stress from waterlogging and insect damage. Chlorophyll fluorescence (Fv/Fm) was used as the measure of tree stress. Both the weed control and fertiliser treatments had significant beneficial effects on diameter and height of surviving trees. Tree growth response was greater for weed control than fertiliser application. Neither treatment, however, appeared to alleviate the impact of flooding on tree mortality. Insect damage, in particular from the leaf blister sawfly Phylacteophaga froggatti, was negatively correlated with tree size, which in turn was directly influenced by the degree of soil inundation, weed control and fertiliser application. It is argued that growth results from a balance of beneficial conditions and ...
TL;DR: The first published study quantifying the effects of a poisoning operation on the densities of mammalian herbivores both on a poisoned plantation and in the surrounding environment is presented.
Abstract: Tasmanian forestry companies commonly manage browsing damage to seedlings on plantations through the lethal control of native mammalian herbivores, using '1080' (sodium monofluoroacetate). Although this practice is controversial, there is a lack of published quantitative data on its success in reducing animal numbers. We present the first published study quantifying the effects of a poisoning operation on the densities of mammalian herbivores both on a poisoned plantation and in the surrounding environment. Line transect surveys were used to monitor species densities before and after poisoning. The species targetted by the poisoning operation were the red-bellied pademelon (Thylogale billardierii), the red-necked wallaby (Macropus rufogriseus subspecies M. r. rufogriseus), the common brushtail possum (Trichosurus vulpecula) and European rabbit (Oryctolagus cuniculus). One non-target species, the common wombat (Vombatus ursinus), was also monitored. Poisoning significantly reduced pademelon density on the poisoned plantation (decline of 98%). A significant decrease in red-necked wallaby density was also detected at this time (decline of 60%) but a general declining trend was present within the data, so we interpret this result with caution. No significant effects were detected for possums, rabbits or wombats. The high kill-rate for pademelons may reflect the dominance of this species over others at bait stations and/or greater sensitivity to 1080. Six weeks after poisoning, the density of pademelons on the treated plantation had increased but was still significantly lower than before poisoning. At the same time, red-necked wallaby density on the treated plantation had increased, with animals moving onto the plantation from surrounding habitats. The decline of pademelons was hypothesized to enable an influx of red-necked wallabies onto the poisoned site, through reduced inter-specific dominance behaviour.
TL;DR: On this stressful site the indigenous species have been resilient to serious perturbations of the environment, and it seems likely that, for the retention of species on a site, frequencies of fires and droughts may be more critical than the occasional exceptionally severe event.
Abstract: Summary Species on Mt Towrong are distributed along soil moisture gradients which are dictated chiefly by aspect, altitude, soil depth and proximity to drainage lines. On the warm and dry western aspect large areas of shallow, rocky soils alternate with bands of deeper soils. On the cooler eastern aspect, soils are relatively deep throughout. Drought damage has occurred on the rocky soils of the western aspect six times in the last 25 years, whenever the annual rainfall was less than about 50% of the long-term mean. Fires are also recurrent perturbations that are most severe in drought years, especially when accompanied by hot NW winds. The fire of 1983 caused severe damage over the whole western aspect of Mt Towrong. Damage on the eastern lee slope was much less severe. An assessment of relative recovery of tree species from these perturbations was based on various combinations of species pairs growing in close proximity to one another. Hie rank order of drought resistance was Allocasuarina verticillata ...
TL;DR: The root: shoot ratio was consistently higher in seedlings from seasonally dry sites compared to those from semi-arid sites, and is likely to be beneficial as it allows an adequate water supply for longer during the dry period.
Abstract: Summary To gain a better understanding of those parameters that control growth and productivity of Eucalyptus microtheca populations from seasonally dry to semi-arid sites in Australia we measured their total plant biomass, allocation of dry matter to roots and shoots, specific leaf area (SLA) and water use. For this purpose the seedlings were raised up to five months under three different pot moisture conditions applied by cyclical watering regimes. Young seedlings of six provenances of Eucalyptus microtheca fell generally into two groups, the Rockhampton, Walgett and Maree provenances which evolved in evenly distributed, though erratic, rainfall conditions at semi-arid sites, and the Pilbara, West Kimberleys and Camooweal provenances which evolved in seasonally dry sites with a reliable monsoon. The former group had the greater leaf area and total plant biomass. Specific leaf area correlated positively with leaf area and total plant biomass at various times across the experimental period. However, as on...
TL;DR: Exotic species of Cedrela grown on the New South Wales mid-north coast of Australia are not attacked by the shootborer Hypsipyla robusta whereas Australian red cedar grown in plantation in the same location is heavily attacked.
Abstract: Summary Exotic species of Cedrela (C. odorata C. de Canodolle and C. fissilis Vel.) grown on the New South Wales mid-north coast of Australia are not attacked by the shootborer Hypsipyla robusta whereas Australian red cedar (Toona ciliata) grown in plantation in the same location is heavily attacked. In an extension of our earlier study, further grafts were constructed using C. odorata and C. fissilis as scion and T. ciliata as rootstock. Tree height and degree of shootborer attack were monitored over a four-year period. Grafts of C. odorata on T. ciliata were attacked but not those of C. fissilis on T. ciliata, revealing further insights into the host preference of Hypsipyla. Possible reasons for the observed differences in susceptibility to attack between the two graft types are discussed.
TL;DR: Tree diversity was significantly lower after high impact/intensity logging in comparison to low impact/ intensity logging and unlogged forest, and the implications for sustainable forest management and forest conservation in Papua New Guinea are discussed.
Abstract: Summary Portable sawmill logging in Papua New Guinea is widely advocated by ecoforestry organisations as an ecologically improved method of rainforest exploitation because of its reduced impact on biodiversity. Here the impacts of conventional high impact/intensity conventional logging, and low impact/intensity portable sawmill logging on tree diversity six years after harvest are compared based on current operational practices. Tree diversity was significantly lower after high impact/intensity logging in comparison to low impact/intensity logging and unlogged forest. Low impact logging resulted in a reduction in tree diversity of 5 % and 25 % for the Shannon Wiener index (H') and Simpson's index (D) of diversity, respectively, in comparison to unlogged forest. Conventional logging resulted in a reduction in diversity of 25 % (H') and 48 % (D) in comparison to unlogged forest. Based on comparisons with other studies high reductions in tree diversity after conventional high impact logging are attributed to...
TL;DR: It is concluded that a low density koala population persists in the regional forests and that purported evidence of decline in the population is unconvincing.
Abstract: Summary A survey conducted by playing pre-recorded calls of a male koala and listening for responses was used to further assess the distribution of koalas in south-eastern New South Wales. Fourteen koalas were recorded from 388 sample sites. This detection rate (4%) was low compared to detection rates in north-eastern New South Wales. Insufficient data were generated to allow analysis of koala distribution in relation to environmental variables. The koalas were scattered through the region on various land tenures. The results suggest that conclusions regarding the distribution of koalas, based on previous records, may reflect uneven survey effort. The data from this survey and from other contemporary sources show the continued presence of koalas at localities where they had previously been reported as extinct. It is concluded that a low density koala population persists in the regional forests and that purported evidence of decline in the population is unconvincing. There were no significant differences i...
TL;DR: In this article, the authors used a small section of one-metre resolution airborne data to calibrate a moderate spatial resolution model based on Landsat Thematic Mapper data to estimate canopy structural properties in St Marys State Forest, near Maryborough, south-eastern Queensland.
Abstract: Accurate habitat mapping is critical to landscape ecological studies such as required for developing and testing Montreal Process indicator 1.1e, fragmentation of forest types. This task poses a major challenge to remote sensing, especially in mixedspecies, variable-age forests such as dry eucalypt forests of subtropical eastern Australia. In this paper, we apply an innovative approach that uses a small section of one-metre resolution airborne data to calibrate a moderate spatial resolution model (30 m resolution; scale 1:50 000) based on Landsat Thematic Mapper data to estimate canopy structural properties in St Marys State Forest, near Maryborough, south-eastern Queensland. The approach applies an image-processing model that assumes each image pixel is significantly larger than individual tree crowns and gaps to estimate crown-cover percentage, stem density and mean crown diameter. These parameters were classified into three discrete habitat classes to match the ecology of four exudivorous arboreal species (yellowbellied glider Petaurus australis, sugar glider P. breviceps, squirrel glider P. norfolcensis , and feathertail glider Acrobates pygmaeus), and one folivorous arboreal marsupial, the greater glider Petauroides volans. These species were targeted due to the known ecological preference for old trees with hollows, and differences in their home range requirements. The overall mapping accuracy, visually assessed against transects (n = 93) interpreted from a digital orthophoto and validated in the field, was 79% (KHAT statistic = 0.72). The KHAT statistic serves as an indicator of the extent that the percentage correct values of the error matrix are due to ‘true’ agreement verses ‘chance’ agreement. This means that we are able to reliably report on the effect of habitat loss on target species, especially those with a large home range size (e.g. yellow-bellied glider). However, the classified habitat map failed to accurately capture the spatial patterning (e.g. patch size and shape) of stands with a trace or sub-dominance of senescent trees. This outcome makes the reporting of the effects of habitat fragmentation more problematic, especially for species with a small home range size (e.g. feathertail glider). With further model refinement and validation, however, this moderateresolution approach offers an important, cost eff e c t i v e advancement in mapping the age of dry eucalypt forests in the region.
Journal Article•
TL;DR: The methodology used for acquiring ground information, satellite image production and the processing techniques to produce the forest cover map is described and issues associated with determination of the forest/savannah boundary and the effect of fire on the reliability of mapping are considered.
Abstract: Summary About half the total forest area of Australia lies north of the Tropic of Capricorn. Improved information about northern forest and woodlands is required for national level statistics, forest policy development, reserve system planning and for ongoing management by relevant State and Territory agencies. NORFOR, an initiative of National Forest Inventory (NFI), addresses this need. It involves a partnership between Western Australia, Northern Territory and Queensland in the development of a common system for processing of satellite remote sensing data to achieve a consistent product that reliably details the extent of forest cover and broad forest types across northern Australia. For the purpose of the project three locations across northern Australia were selected to trial the agreed methodology: the Kimberley region of Western Australia, the Daly Basin of Northern Territory and the Einasleigh Uplands of Queensland. This paper reports on the work in the Kimberley region and describes the methodolo...
TL;DR: Two retrospective studies were conducted in the coarse-textured, coastal lowland soils of south-eastern Queensland to provide a preliminary assessment of compaction affects on the productivity of Pinus plantations, finding a clear link between persistent compaction, reduced root development and reduced wood production.
Abstract: Summary Two retrospective studies were conducted in the coarse-textured, coastal lowland soils of south-eastern Queensland to provide a preliminary assessment of compaction affects on the productivity of Pinus plantations. In the first study, stem wood volume of a 9-year-old plantation established on a site used as a log dump during clearfell harvest of the first rotation was reduced by 40.3%. There was a clear link between persistent compaction, reduced root development and reduced wood production. Standard site preparation and cultivation operations used at the time of second rotation establishment did not ameliorate compaction damage. A number of operational measures are suggested for minimising the impact of log dumps on plantation productivity. In the second study, dendro-chronological techniques were used to determine annual basal area increments (BAIs) of crop trees following thinning operations that resulted in rut compaction of various intensities. The methodology allowed both positive growth res...
TL;DR: In this paper, the authors evaluated the net present value and internal rate of return of investing in N fertilization of eucalypt plantations managed for pulpwood, particularly around the period of canopy closure.
Abstract: Summary We evaluated the net present value and internal rate of return of investing in N fertilization of eucalypt plantations managed for pulpwood, particularly around the period of canopy closure. We found that, given our base case assumptions, N fertilization is currently profitable when applied to plantations expected to have a medium-to-high response in wood yield. Furthermore, even though our analysis was limited to pre-tax stumpage values, our results suggested that the investment would be profitable on a wider range of sites for many combinations of variables if there were favourable movements of key variables from current values within realistic ranges, for example, for wood value and the cost of fertilizer. However, actual growth responses need to be quantified more precisely for a range of conditions and care should be taken to select the most responsive sites to be fertilized. Estate-wide optimization of the investment and prevailing economic circumstances should also be considered.
TL;DR: A series of experimental trials was established in order to determine the most satisfactory method of seedbed preparation that would ensure adequate regeneration in an area considered as "typical" of the dry lowland forest of the cast coast of Tasmania as mentioned in this paper.
Abstract: Summary During the 1970s and early 1980s the clcarfell burn and sow silvicultural system was seen as the best means of replacing the previously degraded stands in dry lowland forest in Tasmania with a vigorous rcgrowth forest. During the 1980s a number of problems were experienced in obtaining adequate regeneration on some of these dry forest coupes. In 1991 and 1992 a series of experimental trials was established in order to determine the most satisfactory method of seedbed preparation that would ensure adequate regeneration in an area considered as ‘typical’ of the dry lowland forest of the cast coast of Tasmania. A variety of seedbed preparation techniques was used in association with a seedtree partial logging system. These included pre—or post—harvest burning, pre—or post—harvest cultivation, and normal logging disturbance. The results indicate that pre-harvest cultivation is the most effective treatment as measured by the fraction of plots stocked and density of seedlings. The cost of pre-harvest cu...