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The successful manufacturing of glulam from several important Australian commercial timbers is quite challenging due to difficulties in gluing. Improvements in adhesive bond performance of spotted gum, Darwin stringybark, and southern pine timber have been achieved using alternative pre-gluing surface machining methods, e.g., face milling and sanding-post planing, when compared to conventional planing methods. In order to improve the understanding of the effects that different surface machining methods have on adhesive bond performance, this study used micro X-ray computed tomography and microscopy to assess key adhesive bond criteria. There was a considerable loss in the amount of adhesive after the wet and dry test cycles for all species. There was also an extremely high frequency of voids in the glue lines for all species, which would negatively impact bond strength and durability. Face mill prepared timber boards resulted in thicker glue lines and greater resistance to adhesion loss, compared to boards prepared via planing. For the two hardwood species, face milling also resulted in greater adhesive penetration; however, for southern pine, there were no significant differences in adhesive penetration between the three surface machining treatments. Adhesive penetration was much deeper in southern pine compared to spotted gum and Darwin stringybark.

This project to identify the causes of Stringybark forest dieback we are witnessing and provide land managers with recommendations to enable them to maintain ecological function and to ensure that the forest cover of the Adelaide Hills can be sustained into the future. Refereed/Peer-reviewed

The 2-ha 20-minute bird survey method was used to survey bird assemblages in the Darwin Stringybark Eucalyptus tetrodonta forest of the Weipa bauxite plateau, Cape York Peninsula, Queensland. A standardised method was preferred so that bird data could be compared with bird data collected in post-mining rehabilitation sites. Thirty-six native forest survey sites were selected using stratification (8 vegetation types) and replication. Over 16 months, eight surveys were conducted at each site, amounting to a total of 160 minutes of survey effort per site. No single site had the full complement of native-forest bird species. A minimum of 14 sites, including seven of the eight site types, was required for all 79 species to be recorded at least once. Sufficient bird data were obtained to conduct statistical analyses, but the species list remained incomplete compared with an estimate of asymptotic species richness.

Botanical essential oils have been successfully used in controlling insect pests. In the present study, insecticidal activity of essential oil extracted from the leaves of messmate stringybark [Eucalyptus procera Dehnh. (Myrtales: Myrtaceae)] were investigated through contact and fumigant toxicity against the cowpea weevil [Callosobruchus maculatus (F.) (Coleoptera: Bruchidae)] and the red flour beetle [Tribolium castaneum Herbst (Coleoptera: Tenebrionidae)]. Chemical analysis of the essential oil by Gas chromatography-Mass spectrometry proved 1,8-cineole (45.0 %), α-pinene (28.6 %) and viridiflorol (5.7 %) were major constituents of the oil. The essential oil comprises 98.3 % terpenic compound including 31.4 % monoterpene hydrocarbons, 55.8 % oxygenated monoterpenes, 2.2 % sesquiterpene hydrocarbons and 8.9 % oxygenated sesquiterpenes. Results showed that C. maculatus and T. castaneum were very susceptible to the essential oil of E. procera in both contact and fumigant bioassays. 24 h-LC values w...

Dormant buds such as lignotuberous and epicormic buds are adaptations possessed by plants growing in stressful environments. Eucalyptus obliqua is a species occupying a wide range of habitats in south-eastern Australia, which displays ecotypic diversity. Seedlings of E. obliqua from provenances with and without lignotubers were subject to heat stress at 40–100°C for durations ranging from 2 to 128 min. Seedlings from a single population were also stressed by decapitation, which left two, four or eight leaves intact. While the upper stems and leaves of the heated seedlings from different provenances reacted in the same way to the treatments imposed, seedlings that lacked lignotubers died at lower temperatures and at shorter durations than seedlings that possessed lignotubers. Production of lignotuberous shoots did not necessarily guarantee seedling survival as the mortality rates of lignotuberous shoots were high, ranging from 55% to 100%. The recoveries of the heated and decapitated seedlings were similar...

Eucalyptus expressa, a new tall forest tree species from sheltered gullies in the sandstone ranges north-west of Sydney, is described and illustrated, and notes on affinities, distribution, ecology and conservation status provided. A key to the stringybarks (E. ser. Pachyphloius) of the Sydney Basin is also presented

Foliar nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) concentrations of 5 Symphyomyrtus (E. botryoides, E. cladocalyx, E. microcorys, E. nitens, E. saligna) and 7 Monocalyptus (E. agglomerata, E. baxteri, E. globoidea, E. muelleriana, E. obliqua, E. pilularis, E. regnans) species were determined for each of four hill country microsites; upper shady, lower shady, upper sunny and lower sunny slopes. ANOVA and correlation analysis were used to identify species and microsite effects, and nutrient associations. Significant (P ≤ 0.0014) species differences were identified for all nutrients, E. botryoides and E. saligna generally had high nutrient concentrations while stringybark species were low, particularly for N and K. Subgeneric contrasts revealed that Symphyomyrtus species had significantly higher concentrations of P (P = 0.05) N, K and Ca (P < 0.0001) but lower Mg (P < 0.0001) than Monocalyptus. Microsite had less influence on nutrient concentrations than species. N was strongly positively correlated with P and K in most Symphyomyrtus species but was not correlated with P in Monocalyptus. Mg was positively correlated with Ca but negatively correlated with K in most species. The results indicate that Monocalyptus and Symphyomyrtus species differ in ability to accumulate key macronutrients.

Sampling arthropods in the upper canopy of tall trees presents a range of challenges associated with portability, cost, placement, replication and collection. Detailed schematics and instructions are presented here for three trap designs: sticky CD cases, plastic bottle hanging flight-intercept traps and drink bottleneck funnel crawl traps. By using simple and salvageable materials such as plastic drink bottles and compact disc cases, the financial cost of an arthropod sampling regime in the crowns of old-growth Tasmanian stringybark trees Eucalyptus obliqua (L'Herit) was kept to a minimum. The traps collected comparatively diverse communities: the sticky traps catching high levels of Diptera, Hymenoptera and Coleoptera; the funnel traps catching Diptera, Hemiptera and Coleoptera; and the hanging traps catching Diptera, Coleoptera and Lepidoptera. The sticky traps were ranked best, and the funnels worst, when integrating relative merits of cost, transport, durability, construction, placement, retrieval, sorting and arthropod condition.

Summary Ground surveys were conducted in the coastal and inland mixed—species eucalypt forests of East Gippsland from 2003 to 2006, using ten permanent forest health assessment sites across the region, to determine the cause, extent and severity of extensive defoliation first observed in late 2003. The primary cause of defoliation in the 2003 and 2005 outbreaks were Doratifera spp. (cup moth) and Uraba lugens (gumleaf skeletoniser) respectively. Eucalyptus globoidea (white stringybark) and E. elata (river peppermint) appeared most susceptible while E. cypellocarpa (mountain grey gum), E. obliqua (messmate) and E. sieberi (silvertop) were generally more resistant to defoliation by these insect species. The initial assessment in November 2003 indicated high levels of defoliation with a mean of 71% (range: 30–85%) across all ten sites. Re-assessment of the sites in March 2004 indicated active defoliation had ceased and that foliage cover in the trees had improved with mean defoliation of 34% (range: 15–60%),...

Clear-fell logging around small headwater streams in Tasmanian wet eucalypt forests was predicted to affect both the retention of leaf litter and the composition and size of leaf packs. Retention structures were surveyed in six natural streams and six streams in forest regenerated 3–5 years after clear-fell and burn logging. Logged streams had more wood, but retained less leaves than natural streams, and consequently had fewer and smaller leaf packs. Leaf packs from natural streams contained 200% more leaves, bark and twigs than packs from logged streams. The effect of buoyancy on leaf retention was assessed with release and recapture of marked Eucalyptus obliqua and Nothofagus cunninghamii leaves. Eucalypt leaves were more likely to be trapped by retention structures on the bed of the stream, while smaller, more buoyant N. cunninghamii leaves were mainly trapped by leaf packs. Leaf packs in natural streams were formed on a matrix of small twigs and long strips of bark, shed from the upper branches of mature stringybark eucalypts, while leaf retention was reduced in logged streams because there are no mature trees to provide effective retention structures. Changes to the channel form increase both discharge and sedimentation. These factors have strong implications for downstream nutrient processing and riverine food webs.

Ptychaphelenchus eucalypticola gen. nov., sp. nov. is described from the bark of Eucalyptus macrorhynca, at Mount Ainslie, ACT, Australia. The new genus is characterised by small ventrolateral flaps midway between the cloaca and tail tip in adult males, a variable overhanging anterior lip of the vulva in adult females, and three rounded unfringed tubercles on the tail tip. In addition to the generic characteristics, the new species has a stylet 15µm long with large basal swelling, two to three lateral lines, and a short reflexure of the anterior of the gonad. The new genus has characteristics of several genera within Aphelenchoididae as well as novel features, which suggest that the evolutionary relationships within the superfamily may require re-evaluation.

More than half of western Cape York Peninsula experiences fire every dry season, and the effects of this on the bauxite are twofold: gibbsite is dehydrated to boehmite or alumina and Fe-oxyhydroxides are converted to maghemite. Effects are most significant on the earthen materials of termite nests, particularly those coating the trunks of the common Eucalyptus tetrodonta (Darwin stringybark), and where dead trunks, branches and roots have burnt. Fire-induced dehydration of ooliths in termite nests is suggested as the source of the high-boehmite redsoil in the Weipa Bauxite deposit.

The findings of an investigation into the microwave (MW) modification and conventional kiln drying of backsawn/flatsawn messmate stringybark (Eucalyptus obliqua L'Herit) are summarized. The project was conducted in two parts. Part 1, the subject of this article, investigates whether low-intensity microwave modification results in more or less check formation than occurs during conventional drying of eucalypts. Part 2 of the investigation will determine the acceleration in kiln drying that can be achieved through microwave modification of the wood structure and in turn improving permeability. Significant improvement in microwave modified samples compared to controls in relation to check (internal/honeycombing and surface) formation during drying was observed, with Schedule 1 (70 kWh/m3) having 55% of samples without checks compared to the control samples at 31%. The study also found that there is a significant reduction in surface checking (number and depth) in MW modified boards compared to the controls. ...

Summary The woods of yellow stringybark (Eucalyptus muelleriana) and silvertop ash (E. sieberi) are both used for the manufacture of flooring, but yellow stringybark is the preferred species because it contains fewer natural defects and dries faster and with less degrade than silvertop ash. Sometimes companies manufacturing flooring from yellow stringybark find that the wood they process contains higher levels of natural defects than expected, possibly due to the presence of silvertop ash in the wood that they receive from sawmills. It is difficult to prove this, however, because timber from both species looks similar in the rough-sawn condition and is similar anatomically. Hence, a reliable method of identifying the two species is needed. This study used canonical variate analysis to analyse linear combinations of quantitative indicators of ray anatomy in an attempt to clearly separate the wood of the two species. Canonical variate analysis scores derived from the analysis of ray height and cell number, ...

We quantified the foraging ecology of the White-throated Treecreeper (Cormobates leucophaeus) in the Australian Capital Territory (ACT), south-eastern Australia, where it is the sole species of treecreeper present, and where a rough-barked eucalypt (Red Stringybark (Eucalyptus macrorhyncha)) and a smooth-barked eucalypt (Inland Scribbly Gum (Eucalyptus rossii)) are the dominant tree species. We examined relationships among foraging observations and variables including tree species, tree size, part of tree (substrate), time of day and month. We also quantified the kinds of foraging techniques used by the White-throated Treecreeper on different type and sizes of trees and at different times of the year. The White-throated Treecreeper more commonly foraged on Red Stringybark than on Inland Scribbly Gum. On Red Stringybark, the birds foraged more frequently on the trunk (above 4 m) and large branches than on other substrates. This trend was less marked on Inland Scribbly Gum, where dead branches were most often used for foraging. Foraging techniques that allowed rapid searching of each tree were those employed most commonly. Of these techniques, gleaning was most common (>50% of foraging time), but peering also was common. Drilling was most commonly performed on dead substrates. Foraging techniques employed by the White-throated Treecreeper changed significantly from morning to afternoon, with an increase in peering in afternoons. An increase in peering was observed for both sexes in April, but the magnitude of the increase was greater for females. White-throated Treecreepers in the ACT foraged more commonly on rough-barked eucalypts and exhibited less intraspecific resource partitioning between sexes than reported from other regions. Some of these differences may be related to contrasts in bird assemblages, particularly the absence of other bark-foraging species which may, in turn, reduce levels of intraspecific (gender-based) competition and resource partitioning. They also may be associated with differences in habitat attributes and resource availability between study areas.

Total stand above-ground biomass (AGB) was measured at three sites of varying productivity in the Batemans Bay region of NSW. All trees with diameter at breast height (dbh) >10 cm on three plots of 0.4-0.6 ha were weighed. Spotted gum was the dominant tree species across all sites. The basal area ranged from 29 to 43 m2 ha{-1} depending on site quality. The total dry AGB was 220, 287 and 397 t ha{-1} for the low, medium and high-quality sites (LQS, MQS and HQS), respectively. Spotted gum accounted for 66-79% of the AGB. The proportion of AGB in larger trees (dbh > 50 cm) increased significantly with increased site quality. Bark accounted for about 7% of the weight of all spotted gum logs. The only significant differences in the proportion of bark in the logs were between trees with dbh >70 cm and those with dbh < 40 cm. Ironbark had the highest proportion of the log biomass in the bark (12.4%). The mean moisture content of spotted gum logs was similar to that of Sydney blue gum and yellow stringybark logs. The moisture content of ironbark logs was significantly lower than that of all other species tested, whereas its basic density was higher than that of all other species. A strong correlation (r2 = 0.947) was found between tree diameter and AGB for spotted gum across all sites. Most trees on all sites were < 30 cm in diameter (particularly at the low-quality site), and the variance of AGB increased with tree size. The fraction of biomass in all spotted gum commercial logs was 58.2%. The biomass in commercial logs at the MQS was significantly greater than that at both the LQS and the HQS. An average 0.8 t of residues was generated per tree as a result of selective harvesting of commercial spotted gum forests. The largest fraction of biomass in commercial spotted gum logs (64.1%) was found in large trees (55-65 cm dbh), although the only significant differences were between trees with dbh between 35 and 40 cm and those with dbh between 55 and 65 cm. Pulp logs accounted for 55% of the AGB harvested in spotted gum commercial logs. The proportion of higher-quality commercial logs increased with increased site quality.

Summary Isolated trees and small patches of trees – paddock trees – are a prominent feature of agricultural landscapes in Australia, but are declining in many areas due to natural senescence, clearing, dieback and the general absence of recruitment. We assessed the importance of paddock trees for woodland conservation in a 30 000 ha sample of the New South Wales (NSW) South-west Slopes using Satellite Pour l’Observation de la Terre (SPOT) panchromatic satellite imagery combined with models predicting the original distribution of vegetation communities. Tree-cover occurred over 12% of the study area. The patch-size distribution of vegetation in the study area varied between woodland types. For woodland communities that were confined to hills and ridges, most tree-cover occurred as few, large remnants. For woodland communities of the foothills and plains (Blakely's Red Gum, Eucalyptus blakelyi and Yellow Box, Eucalyptus melliodora, or White Box, Eucalyptus albens and Red Stringybark), 54% of remnant tree-cover occurred as patches < 1 ha. The loss of paddock trees will cause substantial reductions to some woodland communities. For example, the loss of patches < 1 ha in woodlands dominated by Blakely's Red Gum and Yellow Box would reduce this association from 7.4% to 3.4% of its predicted pre-1750 distribution. Mean distance to tree-cover across the study area increased almost fourfold if patches < 1 ha were removed from the landscape, which may have consequences for movements of some flora and fauna. Failure to protect and perpetuate paddock trees will diminish the likelihood of achieving the conservation objectives of comprehensiveness, adequacy and representativeness in agricultural landscapes.

Summary Eucalyptus sieberi L.Johnson (silvertop ash) and E. globoidea Blakely (white stringybark) are two important timber species from East Gippsland, Victoria, where their regeneration following timber harvesting is usually attempted using the seed tree silvicultural system. Their seed crop development processes have not been well documented, however, and the information available for E. globoidea appears to contain inconsistencies. Consequently, this study was initiated, during the establishment of the Silvicultural Systems Project experiment near Cabbage Tree Creek, East Gippsland, to describe the morphological development of seed crops in the two species, and to determine the quantities, variation and losses associated with each stage in that development. Eight funnel seed traps were located on a duplex soil site which supported a stand composed of 67% E. sieberi and 33% E. globoidea, by basal area. They were monitored at intervals of about a fortnight over the period from February 1989 to November 1...

In Australia the stringybark group of eucalypts comprises at least 25 species of Eucalyptus from the botanical series Capitellatae. The species are abundant in south-eastern Australia, and four groups (white, yellow, brown and red) of the commercial timber come mainly from Victoria and New South Wales and these include E. baxteri (Benth.) Maiden, E. globoidea Blakely & Blakely, E. macrorhyncha F. Muell. ex Benth., and E. muelleriana Howitt. As with the ‘ash group’ of eucalypts, the timbers are similar in appearance, and although they are heavier than the ash group, there are some overlapping characteristics. Two additional species, E. consideniana Maiden (yertchuk) and E. sieberi L.A.S. Johnson (silvertop ash), outside the stringybark group, were studied as their woods also closely resemble those from the stringybark group. Differences were found between the species in vessel diameter and density, ray content, amount of axial parenchyma, distinctness of growth rings, basic density and wood colour. Most of the useful differences arise from extremes of these characteristics. Eucalyptus macrorhyncha (red stringybark) can be identified when the pore number is greater than 15/mm2, the average maximum tangential diameter is less than 140 μm, by ray width and content and from the definite pink-reddish colour. Eucalyptus sieberi can be distinguished definitely from E. muelleriana, and fairly certainly from E. globoidea and E. baxteri by uniformly distributed deposits in the rays. Considerable overlap in wood structure exists among E. muelleriana, E. globoidea and E. baxteri making their separation on wood characteristics impractical. Photomicrographs illustrating various points have been included together with a key for separation between the species studied. Similarities to other species including E. acmenoides, E. microcorys, E. obliqua, E. phaeotricha, and E. pilularis are discussed.

Messmate stringybark is common in forests across south-eastern Australia. The bark of these trees is persistent and produces firebrands that contribute to house loss and the difficulty of fire suppression during wildfires. The trees typically survive fire with the amount of bark depleted. We compared two common methods to assess messmate bark fuels: (1) field-based hazard assessment, and (2) desk-based assessment using mapped time since fire. Our measurements included space-for-time field surveys and laboratory flammability tests. Although several physical properties of bark could be approximated from both assessment methods, some bark properties important to flammability were not captured. Ignitability was found to be dependent on the amount of char on bark fragments and could be predicted by the site assessment methods, whereas sustainability was dependent on bark fragment dimensions and could not be predicted by current methods. Bark fragment properties were found to be partially a function of tree size. Overall, these findings indicate that current bark assessment methods do not capture all the key bark properties that contribute to messmate bark’s flammability. Further research is warranted to improve bark assessment methods so they better reflect bark’s contribution to fire behaviour.

We describe the relationships between the number, size and type of cavities in six species of eucalypt trees from southern New South Wales (south-eastern Australia) and tree diameter, tree height, tree species and other measures. The eucalypt species studied were:-Narrow-leaved Peppermint ( Eucalyptus radiata ), Mountain Swamp Gum ( Eucalyptus camphora ), Mountain Gum ( Eucalyptus dalrympleana ), Red Stringybark ( Eucalyptus macrorhyncha ), Ribbon Gum ( Eucalyptus viminalis ), and, Broad-leaved Peppermint ( Eucalyptus dives ). E. radiata and E. macrorhyncha supported almost twice the proportion of branch-end hollows than cavities assigned to other categories. Cavities in the main trunk were the predominant hollow class in E. viminalis and E. dalrympleana . Large diameter trees were characterised by more branch-end hollows, whereas main trunk cavities were typically the most prevalent cavity type in smaller diameter stems. We identified a simple, general rule that highlights the relationships between cavities and readily measured tree attributes. Our data show that, in general, both the number of cavities and cavity size were directly proportional to tree diameter, but inversely proportional to the square root of tree height. This proportionality changed between different tree species. E. dives and E. viminalis supported, on average, larger cavities than other species, whereas the cavities in E. macrorhyncha were smaller than the other taxa sampled. This simple general relationship may make it possible to make rapid crude estimates of cavity abundance across large areas of forest by measuring simple tree attributes such as tree diameter and tree height.

We characterized the day roost sites of four pairs and one solitary tawny frogmouth Podargus strigoides in a woodland in south-eastern Australia. The birds were equipped with radio transmitters which enabled us to locate them daily from autumn 1997 to late summer 1998. Tree species, tree size, roost height and orientation of the roosting bird were recorded. Over the study period tawny frogmouths frequented a large number of day roosts (up to 71 per pair). Birds rarely used the same roost over extended time periods and most roosts were used for less than 3 days. Mature trees with a girth of more than 0.5 m were preferred as day roosts. Tawny frogmouths exhibited a significant preference for the coarse and dark-barked stringybark trees, but other tree species such as the smooth-barked, light-coloured gums were also frequented. However, when roosting in gum trees, dead branches were preferred, presumably as these have a coarser appearance than living branches and therefore provided better camouflaging. Especially during winter, the birds showed a significant selection of branches on the northern side of roost trees presumably to maximize sun exposure. During summer, two pairs maintained a significant northerly preference, whereas the others used roosts with random orientations. Small-scale seasonal movements in the area used for day roosting were also observed, with two pairs selecting a distinct area with a south-westerly aspect during summer which appeared to have less sun exposure. Our study suggests that tawny frogmouths select roosts to (1) minimize visibility from day predators and (2) to facilitate passive thermoregulation by sun-basking.

Plant community composition and its likely environmental controls were investigated for 200 sample plots (each 100 m2) from Mediterranean-type vegetation in the Little Desert National Park, Victoria. twinspan classification revealed four readily identifiable vegetation types; mallee-broombush, heathland, stringybark open woodland, and an assemblage intermediate between mallee-broombush and heathland referred to here as broom-heath. Mallee-broombush was found on Parilla Sands characterized by high Ca levels relative to heathland and stringybark open woodlands on unconsolidated Lowan Sands. The first axis of a 2 dimensional non-metric MDS ordination also divided heathlands (high axis scores) from mallee-broombush (low scores), while the second separated these vegetation types from stringybark woodlands and broom-heath. Vector-fitting revealed significant correlations between the locations of samples in ordination space and exchangeable soil Ca, soil colour, aspect and Shannon–Weiner diversity. Highest species richness/diversity was associated with the ecotonal area between Parilla and Lowan Sands (i.e. broom-heath) where a number of species characteristic of different assemblages had overlapping ranges. The fire-sensitive conifer, Callitris rhomboidea, was preferentially located in stringybark woodland and broom-heath vegetation types. Its presence was positively associated with high species richness and aspects having a southerly component. Four Callitris stands sampled for population structure were all > 40 years old and showed evidence of interfire recruitment from seeds released by old, serotinous cones. Overall, results suggest that variations in plant community composition and structure in the eastern block of the Little Desert are primarily due to variations in soil properties associated with the distribution of the two dominant substrate types, Parilla Sand and Lowan Sand. However, the interplay of topography and fire behaviour has probably been more important than substrate type in determining the distribution and population structure of longer-lived, fire-sensitive species such as Callitris rhomboidea.

[Extract] The sap of the Red Stringybark or Red Mahogany Eucalyptus resinifera is an important dietary component for the northern race of the Yellow-bellied Glider Petaurus australis reginae, locally named the Fluffy Glider (Quin 1996). In north-east Queensland, Yellow-bellied Gliders are classified as vulnerable, with a distribution limited to the wet sclerophyll forests at the western edge of the rainforest, between Daintree and Cardwell (Maxwell et al.1996). Harrington & Sanderson (1994) have shown that these wet sclerophyll forests have contracted by more than 50% in the past 50 years due to logging and invasion by rainforest. Yellow-bellied Gliders emerge at night to forage on sap, which is obtained by biting out small patches of bark from the trunk or main branches. Only E.resinifera is exploited in this way in north-east Queensland whereas a number of species of eucalypt are used in other parts of Australia (Russell 1995). Sap continues to exude during the day and birds regularly feed at the active sap-scars, an event that has been reported only by Russell (1981) in north-east Queensland. Goldingay (1996) briefly mentions diurnal use of the sap-feeding wounds but provides no details. This paper reports our observations of the species of bird using sap-scars; we discuss this behaviour and the factors influencing its occurrence.

An investigation has been carried out into whether the internal moisture movement inside Australian hardwood timber is best described by a diffusion model with driving forces based on gradients in moisture content or in partial pressure of water vapour. Experimental data from two sets of drying schedules applied to timber from three species of Australian hardwoods (yellow stringybark, spotted gum and ironbark) reported in Langrish et al. (1997) have been used to assess the use of the two driving forces, and the standard error has been used as the criterion for goodness of fit. Moisture-content driving forces have fitted the data better than a model based on vapour-pressure driving forces alone. The use of moisture-content driving forces with diffusion parameters obtained from data from one drying schedule is also better in predicting the drying behaviour with another schedule than vapour-pressure driving forces for yellow stringybark and ironbark. These results may be due to the complexity of the moisture-movement process through timber, with more than one moisture-transport mechanism being active, so that the use of only one driving force for moisture movement is at best only an approximation to the true behaviour.

Summary A bioclimatic analysis was undertaken for four commercially valuable wood production trees from south-eastern Australia: -Eucalyptus regnans (mountain ash, swamp gum or stringy gum); Eucalyptus delegatensis (alpine ash, white-top stringybark or gum-top stringy bark); Eucalyptus nitens (shining gum or silvertop) and Eucalyptus fustigata (brown barrel or cut-tail). A reference resource for forest managers is presented that includes summary information on a range of bioclimatic conditions which characterise the extant distribution of each tree species. These data were used to map the predicted potential bioclimatic domains of the four species. In each case, areas were identified with marginally suitable bioclimatic conditions that extended beyond the present known distributions of the species, while the core bioclimatic domain of each species often conformed more closely to its known range. The results of our investigation highlighted some clear differences in the bioclimatic regimes occupied by the ...

Summary On 14 October 1988 a major wildfire occurred in the Bemm River area, 33 km east of Orbost in the East Gippsland region of Victoria. The weather was dominated by wind speeds of gale force strength. The fire burnt under “very high” to “extreme” fire danger conditions with a maximum McArthur fire danger index of 82, a maximum mean forward rate of spread between 3.5 and 4.0 km/h and a maximum mean fireline intensity in the range 31,200 to 35,500 kW/m. The final area of the wildfire was 5,670 ha and the perimeter was 80 km. A highly significant influence on fire behaviour was the layer of aerated, highly flammable shrub fuel. This was combined in the coastal forests of the Bemm River area with high quantities of litter and the high spotting potential of the stringybark eucalypts. Total fine fuel loads averaged about 20 t/ha. The rate of spread predicted by the McArthur Mk 5 Forest Fire Danger Meter during the initial two hour period of the wildfire was 2.0 km/h and the observed mean rate of spread was ...

The quantification of particle emission factors under controlled laboratory conditions for burning of the following five common tree species found in South East Queensland forests has been studied: Spotted Gum (Corymbia citriodora), Blue Gum (Eucalyptus tereticornis), Bloodwood (Eucalyptus intermedia), Iron Bark (Eucalyptus crebra), and Stringybark (Eucalyptus umbra). The results of the study show that the particle number emission factors and PM2.5 mass emission factors depend on the type of tree and the burning rate. For fast burning conditions, the average particle number emission factors are in the range of 3.3-5.7 x 10(15) particles/kg for woods and 0.5-6.9 x 10(15) particles/kg for leaves and branches, and the PM2.5 emission factors are in the range of 140-210 mg/kg for woods and 450-4700 mg/kg for leaves and branches. For slow burning conditions, the average particle number emission factors are in the range of 2.8-44.8 x 10(13) particles/kg for woods and 0.5-9.3 x 10(13) particles/kg for leaves and branches, and the PM2.5 emissions factors are in the range of 120-480 mg/kg for woods and 3300-4900 mg/kg for leaves and branches.

The bark of eucalypt trees is a significant habitat attribute of forests and woodlands, with different bark types supporting varying populations of invertebrate and vertebrate fauna. Bark also contributes to fuel load in wildfires and hazard reduction burning, with a concomitant loss of habitat and modification of habitat resources. We compared the composition and abundance of tree trunk invertebrates inhabiting four eucalypt bark types and determined the impact of burning the bark on population abundance and community composition. Trees of four bark types (gum, box, stringybark, ironbark) were selected at three sites and arthropod traps placed on burnt and unburnt trees of each type. Traps were left in place for 12 days and arthropod preferences for the four bark types (burnt and unburnt) were analysed. The total number of arthropods differed between bark types, with stringybark and ironbark supporting the largest numbers of invertebrates and the most diverse communities. Burnt stringybark and gum bark had reduced arthropod abundance compared to unburnt bark. The study highlights an ecological consequence of fire on an aspect of invertebrate habitat, with flow-on effects for vertebrates, that should be considered in fire management, as greater areas of land are subject to frequent hazard reduction burning in eastern Australia.

In south-eastern Australia, bark of the ‘stringybark’ eucalypt group, and notably that of messmate (Eucalyptus obliqua L’Hér.), is notorious for intense spotting and it is likely that firebrands of this type contribute significantly to loss of life and property during major wildfires. The fuelbed ignition potential by glowing samples was laboratory tested on excised sections of Pinus radiata D. Don litterbed at moisture contents between 2 and 8% and for ‘no-wind’ or for ‘wind’ of 1 m s–1. Prepared samples of outer bark between 0.5 and 1.6 g were combusted until they attained ~20% of initial mass before placement. For ‘no-wind’, flaming ignition did not occur and the probability of glowing ignition appeared to depend on the chance of contact with needles. For ‘wind’, the probability of flaming ignition was a function of sample glowing mass and fuelbed moisture content. Its ignition probability, weight-for-weight, appears to exceed that reported for other forest firebrands, including bark of E. globulus Labill. However, it is likely that the notoriety of messmate bark is also due, in part, to its morphology and in-flight behaviour. It is argued that firebrand laboratory tests to date may poorly reflect the ignition potential of similar samples after flight.

While assessing the corrosive properties of some eucalypts, it has been observed that timbers belonging to the “stringybark” group appear to be more corrosive than others. Research has been carried out therefore on the main stringybark species and major commercial brands of steel which are used for the manufacture of bandsaw blades. This study demonstrated that stringybark wood is considerably more corrosive than expected. The average corrosiveness of stringybarks is shown to be some 126% greater than that of other eucalypts. Such high corrosiveness is detrimental in woodworking, papermaking and building industries and can generally create serious problems in many wood-metal situations.

Tree species preferences of a koala population inhabiting a small area of forest and woodland in the Campbelltown area, south-west of Sydney, were investigated over a two-year period. In total, 2499 trees from 45 independent field sites were assessed, with tree species preferences determined on the basis of a comparative analysis of proportional data relating to the presence/absence of koala faecal pellets. The results established that grey gum (Eucalyptus punctata) and blue-leaved stringybark (E. agglomerata) were most preferred by koalas in the study area, but only when growing on shale-based substrates. The preferential utilisation of E. punctata and E. agglomerata on substrates derived from shales, compared with that recorded for the same species on sandstones, suggests that their use by koalas was influenced by differences in nutrient status between substrates. Regression analyses further identified a trend for use of at least one of the preferred species (E. punctata) to be more commonly associated with larger trees. Results are discussed in terms of their relevance to issues of resource availability and the need to reconsider, by way of a hierarchical approach, the use of food trees by koalas generally. The presence of E. punctata and E. agglomerata and their occurrence in conjunction with shale-based substrates are considered to be important limiting factors affecting the present-day distribution and abundance of koalas in the Campbelltown area.

The large-scale dynamics of bird communities in central Victoria, Australia, were studied in relation to eucalypt flowering by recording community changes throughout the annual cycle in sites north and south of the Great Dividing Range (GDR). Two kinds of forest habitat were considered, one of which flowers profusely in winter ('ironbark') while the other flowers little but over the warmer months ('stringybark'). There were eight sites, two of each habitat in both the northern and southern regions. In the absence of flowering in ironbark sites during summer, the avian communities of both kinds of habitat are virtually the same in each region. However, the sets of communities in each region differ significantly from one another at this time. With the onset of winter flowering, avian community composition in ironbark habitats in each region diverges greatly from the non-flowering ironbark and stringybark communities, but converges back to those communities as flowering declines. Most of these changes are due to the influx of high densities of nectarivores, especially honeyeaters and lorikeets. Such influxes in stringybark habitats did not occur, probably because the flowering intensity was at most an order of magnitude less than that in ironbark sites. The results show the dramatic impact that eucalypt flowering has on avian communities in south-eastern Australia, and the influence of habitat differences. Thus, although nectarivores move into the northern region of the study area to capitalize on winter flowering, they show high habitat specificity and virtually avoid the non-flowering stringybark habitats. The results are discussed in terms of landscape and regional dynamics of birds and the possible interactions among avian sub-communities (the 'nectarivores' and 'non-nectarivores').

Regeneration of susceptible species following a major decline in the population and distribution of the pathogen Phytophthora cinnamomi Rands is reported from a reassessment of infested plots in open forest, woodland and heathland of the Grampians. The distribution of P. cinnamomi and changes in the vegetation were measured on quadrats set up in 1976 and 1977 and checked biennially until 1984. In 1995, P. cinnamomi was detected in only 15.6% of the 345 soil and root samples tested and was present in only 28.6% of the infested quadrats compared with 100% of the samples and infested quadrats in all previous assessments. Both the restricted distribution and the isolation of P. cinnamomi from susceptible species without symptoms were evidence of changes in the disease which may have been associated with factors such as a reduced supply of susceptible host roots or an alteration in pathogenicity or in the environment. Changes were recorded in structure and species composition of infested plant communities compared with those that remained pathogen-free, but few recent deaths or dieback symptoms were observed in 1995. On the infested plots, several mature stringybark eucalypts such as Eucalyptus baxteri and E. obliqua had died, and the survivors had reduced crown density and dieback of the major branches. However, regeneration in the form of 8-year-old saplings and young seedlings showed few or no symptoms despite the isolation of P. cinnamomi from the roots. The understorey of infested plots comprised a dense growth of field-resistant plants such as Leptospermum spp. and sedges entwined with dodder laurel, whereas the uninfested plots contained a species-rich heath flora of which 54% were known to be susceptible to P. cinnamomi. Regeneration and continuing survival of 24 susceptible species from 11 different families were recorded as small plants on various infested quadrats. However, 12 susceptible species from 7 different families had failed to regenerate. Pathogen populations may increase with the renewed supply of susceptible roots, but independent of pathogen potential, the emerging susceptible species may not be able to compete effectively against the dense field-resistant understorey in infested plots in order to re-establish the original diverse heathland understorey.

The diet of the yellow-bellied glider (Petaurus australis) was examined at a site in north Queensland by extensive observation of individuals from 10 glider groups. The diet was assessed in four seasons over 12 months by collating large numbers of qualitative feeding observations and by analysis of faeces. Data were also collected on flowering and bark shedding in the forest. Sap feeding accounted for more than 80% of the feeding observations throughout the year. Nectar and pollen of eucalypts (Eucalyptus spp.) and banksias (Banksia spp.) accounted for much of the remainder of the diet although arthropods and honeydew were present in spring and summer. Faecal analysis was based on much smaller sample sizes but confirmed the qualitative result obtained from direct observations. It also revealed the presence of a wide variety of pollen types. Many of these could be attributed to incidental ingestion but at least six rain forest genera were moderately common in faeces, which is consistent with observations of brief and infrequent visits by gliders to these trees. Examination of eucalypt, banksia and other pollen types showed that 60-70% of pollen was devoid of cell contents, supporting earlier suggestions that gliders obtained protein from pollen digestion, but at this site also from harvesting arthropods. This study confirms the dependence of the yellow-bellied glider in north Queensland on the sap of the red stringybark (Eucalyptus resinifera) and that conservation of the yellow-bellied glider is intimately associated with the management of this tree species. The use of various species for nectar and pollen suggests that the yellow-bellied glider may be an important pollinator in these forests. Moreover, sap from the wounds created by gliders is used by a range of other animal species. These observations suggest that the yellow-bellied glider is likely to be a keystone species in the open-forest ecosystems of north Queensland and that it deserves special emphasis in management.

Changes in the distribution of both pathogen and flora provided data on pathogen decline and on survival, colonisation and regeneration of plant species in defined plots in open dry sclerophyll forests of the Brisbane Ranges 23-30 years after invasion by Phytophthora cinnamomi. The density of the stringybark eucalypts (Eucalyptus informal subgenus Monocalyptus) which dominate the overstorey was halved on some plots. The survivors now show vigorous crown growth but few seedlings are present. Regeneration of the understorey occurred in three stages. Firstly, resistant sedges and then seedlings of resistant opportunists rapidly colonised ground left vacant by the destruction of the dominant understorey species, Xanthorrhoea australis. In the second stage, moderately susceptible species such as Banksia marginata and Grevillea steiglitziana resprouted from old stumps and prostrate legumes increased their ground cover. In the third stage some highly susceptible species, such as X. australis, Dillwynia glaberrima, Hibbertia stricta and Monotoca scoparia have regenerated from seed on sites previously badly affected by the pathogen. Some plants of these species have survived for 10 years, despite the continued presence of scattered pockets infected with of P. cinnamomi. However, Isopogon ceratophyllus, frequent in the understorey of the plot prior to disease, has not regenerated.

In the stringybark eucalypts, the baxteri clade consists of E. arenacea, from South Australia and northwestern Victoria, E. baxteri, mainly from the Great Dividing Range of Victoria, and E. alpina, an endemic taxon from the Grampian Ranges of Victoria. Populations of these taxa were sampled from across their geographic and morphological ranges. Phenetic and phylogenetic analyses were undertaken of the leaf volatile oil composition of the sampled plants. On the basis of these analyses, E. arenacea emerges as a cohesive, monophyletic species, while E. baxteri is a variable and probably paraphyletic species. Populations on Kangaroo Island, South Australia, are variable and intermediate, and may represent recent intergradation between the two species. Populations of E. baxteri from the Grampians are distinctive chemically, but not morphologically, within the species. Recent hybridisation between this form of E. baxteri and E. alpina was shown to be occuning within the Grampians. E. alpina is a highly variable taxon, and probably polyphyletic as currently recognised. Three distinct forms were recognised within E. alpina. The first, and most distinctive, is from the southern Serra Range; the second is from the northern Serra Range and Wonderland Range; the third, and most similar to E. baxteri, is from the Victoria Range.

Populations of stringybark trees from East Gippsland, with affinities to Eucalyptus macrorhyncha, were studied by pattern analyses of adult and seedling morphology, leaf volatile oils and flavonoid composition. They had previously been determined as hybrids, or as referable to an undescribed taxon. Samples of E. deuaensis, E. globoidea, E. macrorhyncha and E. muelleriana were included to assess the affinities of E. aff. macrorhyncha to other stringybark taxa. No evidence was found to support a hybrid origin of E. aff. macrorhyncha, and it is described as E. mackintii sp. nov. In adult morphology E. mackintii is similar to, but distinct from E. macrorhyncha, whereas in seedling morphology the two are indistinguishable. Two chemical forms of E. mackintii were detected in the leaf volatile oils, both of which have also been reported to occur in E. deuaensis and E. macrorhyncha. The leaf flavonoid composition of the new species is similar to that of E. macrorhyncha, although some differences between the two were observed. The inclusion of E. mackintii in a cladistic analysis of the informal superseries Capitellaticae Ladiges & Humphries resulted in the taxon forming an unresolved basal trichotomy within the infraseries Capitllatae.

Summary The basal area increment (b.a.i.) of trees in two stands of Eucalyptus obliqua L'Herit. (messmate stringybark) in central Victoria was studied for periods of 7–8 years after wildfire. There was an appreciable temporary reduction in b.a.i. only in stems receiving more than 50% crown scorch. These stems resumed normal increment within three to four years of the fire, this being coincident with full restoration of foliage.

Summary Sixteen months after an intense wildfire in September 1973 in a eucalypt forest in eastern Victoria, up to 50% of Eucalyptus sieberi (silvertop) and E. globoidea (white stringybark) trees were dead and a significant proportion of the remainder which had produced epicormic shoots, were dying. In an attempt to explain this abnormal occurrence, the historical and current development of dieback in this forest was studied in relation to Phytophthora cinnamomi (phytophthora root rot), logging, the wildfire, rainfall, and soil temperature. Examination of aerial photographs taken in 1941, 1961, 1973 and 1975 revealed that a substantial increase in the area occupied by dead trees occurred between 1973 (pre-fire) and 1975. On an observation plot established in the burned forest in July 1975, and monitored over seven years, epicormic development and diameter and height growth were poor, and most of the surviving trees did not regain normal crown volume. It is postulated that the dieback was due to P. cinnamo...

Soil baiting techniques identified the presence of five fungal genera capable of causing pre- and post-emergent damping-off in two eucalypt species [Eucalyptus obliqua (messmate stringybark) and E. radiata (narrow leaf peppermint)] under laboratory conditions.

A study was conducted into the conservation requirements of the isolated population of the Red-tailed Black-Cockatoo Calyptorhynchus rnagnificus in southeastern South Australia and south-western Victoria. The range and status of the population are clarified and earlier suggestions of the population's dependence on Brown Stringybark Eucalyptus baxteri are confirmed. An additional food source, Bulloak Casuarina luehmannii is reported. The population's breeding requirements are still poorly known, Clearing of E. baxteri is the main threat to the population's existence.

Preliminary investigations of the interaction occurring between different timber species and various types of steel used for sawblade manufacture, have indicated clearly the practical importance of the process of stress corrosion cracking (Krilov 1986). Based on eight timber species and four types of steel, these have confirmed the previous findings, indicating that the losses of material can be very extensive. The results of the combined effects of corrosion and wear produced steel losses ranging from 3.3 to 8.4 g/m2/h in weight and 0.0008 to 0.002 mm/h in thickness of the sawblade. The interaction between timber species and the types of steel was highly significant. The corrosion losses caused by the ‘stringybark’ species, Eucalyptus obliqua, E. muellerana and E. macrorhynca were >37% greater than those produced by species not belonging to this botanical classification. Both timber and steels were ranked by Duncan's multiple-range test according to their corrosive properties, which differed at 5% probability level. These findings have practical applications in the woodworking industry and related fields.

Most of the increase in deflection with time that occurs during the drying of initially green beams under load is known to be due more to the change in moisture content (a mechanosorptive phenomenon) than to the passage of time. A first approximation rheological model for this deflection is presented. The validity of the model was assessed by tests on small messmate stringybark (Eucalyptus obliqua) beams. It was found that during the initial drying about 85% of the total deformation was attributable to the proposed first approximation rheological model.

An investigation was undertaken with plain shank nails, to establish the effect of heat energy on their static withdrawal resistance. This energy was conducted along the embedded shank and dissipated into the surrounding timber fibres. The study was undertaken using three Australian timbers viz., Radiata Pine, Messmate Stringybark and Blackbutt. It included an examination of density, moisture content and levels of thermal induction. A statistical study was undertaken to determine the relationship between nail diameter, penetration and maximum withdrawal resistance. This paper discusses the findings of the investigation. Equations have been determined that link diameter and penetration of a plain shank nail with its withdrawal resistance value for varying thermal levels, timber densities and moisture conditions.

Summary The instrument consists of a modified solid brass cylinder through which moves a plunger tipped with a blunt needle. The needle is pushed through the bark to the wood surface and the depth of penetration is read from a scale on the barrel. The instrument enables fast and accurate measurements of bark thickness to be made on gum, peppermint and stringybark eucalypts. The measuring technique is virtually non-destructive and is simpler and more accurate and precise than other commonly used techniques, including the Swedish bark gauge.

Dominance of herbaceous species was examined in relation to tree cover in lightly grazed stringybark Eucalyptus laevopinea open-forest recovering from ringbarking and logging on the Northern Tablelands of New South Wales (NSW). The dominant herb was recorded in 121 quadrats (0.25 m2) in 24 plots (10 × 10) stratified by tree cover (beneath trees, away from trees, and amongst small sapling stands). Aristida ramosa dominated the grassy understorey in interspaces, whereas Microlaena stipoides was the most frequent dominant beneath and near tree cover. Poa sieberiana was also more abundant beneath trees. Dominance varied in sapling stands between these three species, suggesting that tree invasion triggers herbaceous succession away from A. ramosa towards M. stipoides and P. sieberiana. It is suggested that year-long green, shade-tolerant grasses such as M. stipoides are better suited to the shaded, fertile, frost-protected environment beneath mature tree canopies, and deep-rooted, summer-active grasses such as A. ramosa are favoured away from the canopies and root zones of trees.