Influence of cyclonic winds on the performance of hardwood plantations in tropical north Queensland.

Severe Tropical Cyclone Yasi crossed the far north Queensland coast at Mission Beach on February 3rd, 2011, shattering the regions developing hardwood plantation industry. The cyclone’s path covered the primary areas of hardwood and softwood plantations in this region, causing widespread destruction. The extent of cyclone damage, coupled with the weak international economy has resulted in a severe decline in industry confidence for the future of timber plantations in this region. This report reviews the impacts of Severe TC Yasi on the performance of key hardwood plantation species in north Queensland. It summarises the influence of species, genetics, plantation design, management and age on plantation resilience. The information will contribute to a “Best Practice Guide for Timber Plantations in Cyclonic Areas” to be produced by Timber Queensland. This will assist companies with future plantation investment decisions in the tropical cyclone zone. 2 200 trees were assessed, including 44 species at 32 localities located from Daintree to Townsville. Data are also presented for a post-cyclone assessment of 5 900 African mahogany trees on four sites in the Ingham region. A report prepared for the Timber Queensland project: Best Practice Guide for Timber Plantations in Cyclonic Areas.

Influence of Corymbia hybridisation on crown damage by three arthropod herbivores.

Three common pests (eucalypt tortoise beetle Paropsis atomaria, leaf blister sawfly Phylacteophaga froggatti and eriophyid mites) of commercial spotted gum plantations were assessed for their crown damage levels on parent and hybrid Corymbia taxa ( Corymbia torelliana, C. citriodora subsp. variegata and their hybrid) at three common-garden field sites. Damage levels differed significantly between sites for all three herbivore species, and between taxa for eriophyid mites and P. atomaria. However, herbivore response to hybridisation only differed for P. atomaria between sites, even where damage levels did not. Hybrids exhibited three common patterns of susceptibility relative to parent taxa, being most commonly intermediate to their parents for crown damage (additive resistance pattern), or no difference between parents and hybrids, or with one incidence of dominance for susceptibility.

White shark (Carcharodon carcharias) microsatellite genotypes (six loci) from regions along Australia's southern and eastern coastline.

Despite international protection of white sharks (Carcharodon carcharias), important conservation parameters such as abundance, population structure and genetic diversity are largely unknown. The tissue of 97 predominately juvenile white sharks sampled from spatially distant eastern and southwestern Australian coastlines was sequenced for the mitochondrial DNA (mtDNA) control region and genotyped with six nuclear-encoded microsatellite loci. MtDNA population structure was found between the eastern and southwestern coasts (FST = 0.142, p < 0.001), implying female natal philopatry. This concords with recent satellite and acoustic tracking findings which suggest the sustained presence of discrete east coast nursery areas. Furthermore, population subdivision was found between the same regions with biparentally inherited microsatellite markers (FST = 0.009, p <0.05), suggesting that males may also exhibit some degree of reproductive philopatry. Five sharks captured along the east coast had mtDNA haplotypes that resembled western Indian Ocean sharks more closely than Australian/New Zealand sharks, suggesting that transoceanic dispersal or migration resulting in breeding may occur sporadically. Our most robust estimate of contemporary genetic effective population size was low and below the threshold at which adaptive potential may be lost. For a variety of reasons, these contemporary estimates were at least one, possibly two orders of magnitude below our historical effective size estimates. Further population decline could expose these genetically isolated populations to detrimental genetic effects. Regional Australian white shark conservation management units should be implemented until genetic population structure, size and diversity can be investigated in more detail. Reference: Blower, D. C., Pandolfi, J. M., Gomez-Cabrera, M. del C., Bruce, B. D. & Ovenden, J. R. (In press - April 2012). Population genetics of Australian white sharks reveals fine-scale spatial structure, transoceanic dispersal events and low effective population sizes. Marine Ecology Progress Series.

Southern scallop (Pecten fumatus) microsatellite genotypes (fifteen loci) from eighteen locations along the coastline of south-eastern Australia

Microsatellite genotypes of individual scallops

Corymbia leaf oils, latitude, hybrids and herbivory: a test using common-garden field trials

Foliar oils, particularly monoterpenes, can influence the susceptibility of plants to herbivory. In plants, including eucalypts, monoterpenes are often associated with plant defence. A recent analysis revealed an increase in foliar oil content with increasing latitudinal endemism, and we tested this pattern using three eucalypt taxa comprising a latitudinal replacement cline. We also examined the relative concentrations of two monoterpenes (alpha-pinene and 1,8-cineole), for which meta-analyses also showed latitudinal variation, using hybrids of these three taxa with Corymbia torelliana. These, and pure C. torelliana, were then assessed in common-garden field plots for the abundance and distribution of herbivory by four distinct herbivore taxa. Differing feeding strategies among these herbivores allowed us to test hypotheses regarding heritability of susceptibility and relationships to alpha-pinene and 1,8-cineole. We found no support for an increase in foliar oil content with increasing latitude, nor did our analysis support predictions for consistent variation in alpha-pinene and 1,8-cineole contents with latitude. However, herbivore species showed differential responses to different taxa and monoterpene contents. For example, eriophyid mites, the most monophagous of our censused herbivores, avoided the pure species, but fed on hybrid taxa, supporting hypotheses on hybrid susceptibility. The most polyphagous herbivore (leaf blister sawfly Phylacteophaga froggatti) showed no evidence of response to plant secondary metabolites, while the distribution and abundance patterns of Paropsis atomaria showed some relationship to monoterpene yields.

Mass transfer properties (permeability and mass diffusivity) of four Australian hardwood species

Characterisation of mass transfer properties was achieved in the longitudinal, radial, and tangential directions for four Australian hardwood species: spotted gum, blackbutt, jarrah and messmate. Measurement of mass transfer properties for these species was necessary to complement current vacuum drying modelling research. Water-vapour diffusivity was determined in steady state using a specific vapometer. Permeability values of some species and material directions were extremely low and undetectable by the mass flow meter device. Hence, a custom system based on volume evolution was conceived to determine very low, previously unpublished, wood permeability values. Mass diffusivity and permeability were lowest for spotted gum and highest for messmate. Except for messmate, in the radial direction, the four species measured were less permeable in all directions than the lowest published figures, demonstrating the high impermeability of Australian hardwoods and partly accounting for their relatively slow drying rates. Premeability, water-vapour diffusivity, and associated anisotropic ratio data obtained for messmate were extreme or did not follow typical trends and is consequently the most difficult of the four woods to dry in terms of collapse and checkinng degradation.

Rotary veneering of plantation-grown spotted gum (Corymbia citriodora subsp. variegata) and Dunn's white gum (Eucalyptus dunnii)

This report evaluates the wood and veneer properties of plantation-grown spotted gum (Corymbia citriodora subsp. variegata, or CCV) and Dunn's white gum (Eucalyptus dunnii), grown at different stockings, in thinning trials near Ellangowan in north-east New South Wales (mean annual rainfall 1050 mm) and Kingaroy in south-east Queensland (mean annual rainfall 873 mm). Thinning trials were established at age seven years. Both species showed a significant increase in stem diameter growth of the dominant trees in response to thinning. At age 10 years, trees from the unthinned (950–1270 stems ha-1) and 300 stems ha-1 treatments were selected for veneering. Five dominant trees were felled from each combination of species x sites x thinning treatment. Diameter at breast height over bark of the selected trees ranged from 20 cm to 27 cm at Ellangowan, and 19 cm to 26 cm at Kingaroy. From each tree, 1.5 m long billets were removed at two positions: a butt billet from 0.3–1.8 m above ground and a top billet from approximately 5.5–7.0 m. Log end splitting was assessed 24 hours after harvesting and again after steaming, approximately four days after harvesting. Disks from just above both billets were collected for assessment of wood properties. Billets were peeled on a spindleless veneer lathe to produce a full veneer ribbon with a target green thickness of 2.8 to 3.0 mm. The 1.55 m wide (tangential dimension) veneer sheets were dried and graded according to AS/NZ Standard 2269:2008, which describes four veneer grades. Veneer samples taken along the length of the veneer ribbon, at regular intervals of 1.55 m, were tested for stiffness, shrinkage and density. Veneer length measurements were used to calculate the radial distance of each sample from the central axis of the billet. Overall veneer gross recoveries ranged from 50% to 70%. They were significantly lower at the Kingaroy site, for both species. The veneer recoveries achieved were 2–3 times higher than typical green off saw recoveries from small plantation hardwood logs of similar diameter. Most of the veneer recovered was classified as D-grade. CCV trees from the Ellangowan site yielded up to 38% of the better C-grade and higher grade veneers. The main limiting factors that prevented veneer from meeting higher grades were the presence of kino defects and encased knots. Splits in E. dunnii veneer also contributed to reduced grade quality. Log end splits were higher for E. dunnii than for CCV, and logs from Ellangowan exhibited more severe splitting. Split index was generally higher for top than for butt billets. Split index was strongly correlated with the average veneer grade from corresponding billets. The Ellangowan site, where rainfall was higher and trees grew faster, yielded significantly denser and stiffer veneers than did the drier sites near Kingaroy, where tree growth was slower. The difference was more pronounced for E. dunnii than for CCV. Differences in measured wood properties between thinned and unthinned treatments were generally small and not significant. On average, 10% of billet volume was lost during the peeling rounding-up process. Much of the wood laid down following thinning was removed during rounding-up, meaning the effect of thinning on veneer properties could not be effectively assessed. CCV was confirmed as having high veneer density and very good veneer stiffness, exceeding 15 GPa, making it very suitable for structural products. E. dunnii also demonstrated good potential as a useful structural plywood resource, achieving stiffness above 10 GPa. Veneer stiffness and density in CCV increased from pith to bark at both sites, while for E. dunnii there was a radial increase in these properties at the Ellangowan site only. At the drier Kingaroy site, veneer stiffness and density declined from mid-radius to the log periphery. This may be associated with prolonged drought from 2005 to 2009, corresponding to the later years of tree growth at the Kingaroy site. CCV appeared to be less sensitive to drought conditions. Standing tree acoustic velocity, determined by the Fakopp time-of-flight method, provided a reliable prediction of average veneer stiffness for both species (R2=0.78 for CCV and R2=0.90 for E. dunnii) suggesting that the Fakopp method may be a useful indicator of tree and stand quality, in terms of veneer stiffness in standing trees.

Using fire in spotted gum - ironbark forests for production and biodiversity outcomes. Guidelines for landholders

This guide applies to spotted gum - ironbark forests and woodlands. Topics covered in the guide include: *The spotted gum - ironbark ecosystem; *General effects of burning practices; *Understandinng the effects of fire management; *Timber production; *Livestock grazing production; *Balancing production and biodiversity; *Fire management planning for the property; *Recommendtaions for landholders. These guidelines have been prepared for spotted gum - ironbark forests and woodlands and are not necessarily applicable to other forest and woodland ecosystems. The recommendations provided in these guidelines should be used as a guide only.

The wood properties of subtropical and tropical hardwood plantation timber grown for high-value products in Australia

Wood quality and properties of plantation grown trees differ from those from mature, natural grown trees and this has implications for processing, manufacturing and product performance. The wood properties of genetically improved and syliculturally managed plantation trees are affected by their faster growth rates younger harvest age. This report summarises the key wood properties of species that are the primary candidates for plantation forestry in the subtropical to tropical region of eastern Australia. The planned end uses for these trees vary from short-rotation pulp to high-value products such as poles, sawn timber for appearance products and engineered wood products including structural plywood and laminated veneer lumber (LVL).

The Queensland forest industry

An overview of the commercial growing, management and processing of forest products in Queensland.

Evaluation of super-heated steam vacuum drying viability and development of a predictive drying model for four Australian hardwood species.

The results of drying trials show that vacuum drying produces material of the same or better quality than is currently being produced by conventional methods within 41 to 66 % of the drying time, depending on the species. Economic analysis indicates positive or negative results depending on the species and the size of drying operation. Definite economic benefits exist by vacuum drying over conventional drying for all operation sizes, in terms of drying quality, time and economic viability, for E. marginata and E. pilularis. The same applies for vacuum drying C. citriodora and E. obliqua in larger drying operations (kiln capacity 50 m3 or above), but not for smaller operations at this stage. Further schedule refinement has the ability to reduce drying times further and may improve the vacuum drying viability of the latter species in smaller operations.

Processing small diameter logs from sub-tropical species

Small spindleless veneer lathe technology was used to produce veneer sheets as an alternative processing option to optimise the use of small log plantation resource. Thinned (300 spha) and unthinned control (1000 spha) plantings of 10.5-year-old Corymbia citriodora ssp. variegata (CCV) and E. dunnii (Dunn’s white gum) grown in two contrasting sites from climatic regions with large annual rainfall differences were studied. Overall veneer gross recoveries ranged from 50% to 70%, which were up to 3 times higher than typical sawn green-off saw recoveries from small plantation hardwood logs of similar diameter. Major limiting factors preventing veneer from meeting higher grades were the presence of kino defects and encased knots. Splits in E. dunnii veneer also contributed to reduced grade quality. Differences between two thinning treatments for veneer properties and grade recovery were generally small. There was significant evidence of site and species differences on veneer quality. The good quality site with higher rainfall in northern New South Wales produced denser and stiffer veneers with higher grade recoveries. CCV is a superior structural veneer species with high wood density and hardness as well as very good veneer stiffness exceeding 15,000 MPa but Dunn’s white gum has also demonstrated good potential as a useful structural plywood resource. Results indicate that relatively high veneer recoveries were achieved for the sub-tropical plantation hardwoods combined with very superior mechanical properties which suggest that veneer production have suitable attributes for a range of engineered wood products including plywood and laminated veneer lumber.

African mahogany (Khaya senegalensis) plantations in Australia - status, needs and progress

The Australian African mahogany estate comprises over 12,000 ha of industrial plantations, farm-forestry plots and trials, virtually all derived from Africa-sourced wild seed. However, the better trees have given high-value products such as veneers, high-grade boards and award-winning furniture. Collaborative conservation and improvement by the Northern Territory (NT) and Queensland governments since 2000 realised seed orchards, hedge gardens and genetic tests revealing promising clones and families. Private sector R&D since the mid 2000s includes silvicultural-management and wood studies, participatory testing of government material and establishing over 90 African provenances and many single-tree seedlots in multisite provenance and family trials. Recent, mainly public sector research included a 5-agency project of 2009-12 resulting in advanced propagation technologies and greater knowledge of biology, wood properties and processing. Operational priority in the short term should focus on developing seed production areas and ‘rolling front’ clonal seed orchards. R&D priorities should include: developing and implementing a collaborative improvement strategy based on pooled resources; developing non-destructive evaluation of select-tree wood properties, micropropagation (including field testing of material from this source) to ‘industry ready’ and a select-tree index; optimising seed production in orchards; advancing controlled pollination techniques; and maximising benefits from the progeny, clone and provenance trials. Australia leads the world in improvement and ex situ conservation of African mahogany based on the governments’ 13-year program and more recent industry inputs such that accumulated genetic resources total over 120 provenances and many families from 15 of the 19 African countries of its range. Having built valuable genetic resources, expertise, technologies and knowledge, the species is almost ‘industry ready’. The industry will benefit if it exploits the comparative advantage these assets provide. However the status of much of the diverse germplasm introduced since the mid 2000s is uncertain due to changes in ownership. Further, recent reductions of government investment in forestry R&D will be detrimental unless the industry fills the funding gaps. Expansion and sustainability of the embryonic industry must capitalise on past and current R&D, while initiating and sustaining critical new work through all-stakeholder collaboration.

Development of a productivity asessment toll for native spotted gum forest on private land based on estimates of forest growth on Crown land.

Reliable estimates of forest productivity are essential for improved predictions of timber yields for the private native spotted gum resource in southern Qld and northern NSW. The aim of this research was to estimate the potential productivity of native spotted gum forests on private land by making use of available inventory data collated from Qld and northern NSW for spotted gum forest on Crown land (i.e. state forests). We measured a range of site-related factors to determine their relative importance in predicting productivity of spotted gum forest. While measures such as stand height and height-diameter relationships are known to be useful predictors of productivity, we aimed to determine productivity for a site where this information was not available. Through estimation of stand growth rates we developed a spotted gum productivity assessment tool (SPAT) for use by landholders and extension officers. We aimed to develop a tool to allow private landholders to see the benefits of maintaining their timber resource. This paper summarises the information used to develop the SPAT with a particular focus on forest growth relationships.

Processing Tomato Production in the Burdekin: Opportunities and Risks for Growers

The research undertaken here was in response to a decision by a major food producer in about 2009 to consider establishing processing tomato production in northern Australia. This was in response to a lack of water availability in the Goulburn Valley region following the extensive drought that continued until 2011. The high price of water and the uncertainty that went with it was important in making the decision to look at sites within Queensland. This presented an opportunity to develop a tomato production model for the varieties used in the processing industry and to use this as a case study along with rice and cotton production. Following some unsuccessful early trials and difficulties associated with the Global Financial Crisis, large scale studies by the food producer were abandoned. This report uses the data that was collected prior to this decision and contrasts the use of crop modelling with simpler climatic analyses that can be undertaken to investigate the impact of climate change on production systems. Crop modelling can make a significant contribution to our understanding of the impacts of climate variability and climate change because it harnesses the detailed understanding of physiology of the crop in a way that statistical or other analytical approaches cannot do. There is a high overhead, but given that trials are being conducted for a wide range of crops for a variety of purposes, breeding, fertiliser trials etc., it would appear to be profitable to link researchers with modelling expertise with those undertaking field trials. There are few more cost-effective approaches than modelling that can provide a pathway to understanding future climates and their impact on food production.