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Genetics, genetics x environment (GGE) biplot analysis is an effective method, based on principal component analysis, to fully explore multi-environment trial data. It allows visual examination of the relationships among the test environments, genotypes, and the genotype x environment (GxE) interactions. Data from multi-environment trials of 'P. radiata' D. Don containing 165 to 216 families in five environments were used to demonstrate the results and application of GGE biplot analysis. There were non-overlapping clusters of two and three sites, which indicated two distinct environments. The best family for both of the distinct environments was also identified. Genetic correlations among sites ranged from 0.98 to -0.50, indicating that there were large GxE interactions among the test environments.

The stability of biochar carbon (C) is the major determinant of its value for long-term C sequestration in soil. A long-term (5 year) laboratory experiment was conducted under controlled conditions using 11 biochars made from five C3 biomass feedstocks (Eucalyptus saligna wood and leaves, papermill sludge, poultry litter, cow manure) at 400 and/or 550 °C. The biochars were incubated in a vertisol containing organic C from a predominantly C4-vegetation source, and total CO₂-C and associated δ¹³C were periodically measured. Between 0.5% and 8.9% of the biochar C was mineralized over 5 years. The C in manure-based biochars mineralized faster than that in plant-based biochars, and C in 400 °C biochars mineralized faster than that in corresponding 550 °C biochars. The estimated mean residence time (MRT) of C in biochars varied between 90 and 1600 years. These are conservative estimates because they represent MRT of relatively labile and intermediate-stability biochar C components. Furthermore, biochar C MRT is likely to be higher under field conditions of lower moisture, lower temperatures or nutrient availability constraints. Strong relationships of biochar C stability with the initial proportion of nonaromatic C and degree of aromatic C condensation in biochar support the use of these properties to predict biochar C stability in soil.

Biomass energy (bioenergy) could play a significant role in meeting global energy demands. But this would entail a substantial increase in the scale and intensity of biomass production, which could have negative implications for soil health. Bioenergy can contribute to climate change mitigation through displacement of fossil fuels and potentially through sequestration of carbon. Conversely, the required expansion of bioenergy feedstock production could lead to emissions through loss of soil carbon, especially through indirect land use change (iLUC). The gain or loss of terrestrial carbon is determined by the LUC and systems used for biomass production. In this chapter, we first define bioenergy systems and outline their potential to deliver low-carbon energy. We then describe the opportunities and risks to soil health from bioenergy systems, and finally discuss measures by which these risks can be minimised, and biomass can be produced while protecting and ideally enhancing soil health. While our focus is on the interaction between bioenergy systems and soil health predominantly at a local scale, we also discuss larger scale issues including the intensification of production and how biomass supply will need to meet developing sustainability systems to meet different social and environmental constraints.

Norfolk Island pine ('Araucaria heterophylla' - formerly known as 'A. execlsa') is native to Norfolk Island and is used there as a structural and decorative timber. Improved utilisation can be made of the timber once its structural properties are known. This paper reports on unique in-grade structural testing of the timber. No significant structural testing has been done on Norfolk Island pine in the past, and certainly there is no evidence of in-grade testing. Previous attempts at grading were based on using small, clear specimens. This project involved testing full-size specimens of randomly selected timber that was grown and milled on Norfolk Island. The work was undertaken in accordance with AS/ NZ4063: 1992. Preliminary results indicated higher shear and compressive strengths but lower bending and tensile strengths and modulus of elasticity than expected. The timber is weakest in tension. The presence of knots has a significant effect on strength. Knot reduction through improved silvicultural techniques and/ or knot excision and re-jointing will substantially improve utilisation of the species. Careful selection and grading of timber will be needed for specific structural applications.

Aboveground biomass was twice as high in mixtures of 'Eucalyptus globulus' and 'Acacia mearnsii' when compared to 'E. globulus' monocultures after 11 years. This was attributed to increased nutrient availability and accelerated rates of N and P cycling in mixtures. This study examined whether the increase in aboveground biomass production was associated with an increase in total productivity (both above- and belowground), a change in C partitioning (from below to aboveground) or both. Total annual belowground C allocation (TBCA) was determined during year 11 in a mixed-species trial near Cann River, southeastern Australia. Monocultures of 'E. globulus' (100%E) and 'A. mearnsii' (100%A) and mixtures of these species (50%E:50%A) were planted in a replacement series. Using a conservation of mass approach, TBCA was estimated as soil carbon dioxide (CO₂) efflux C minus the C input from aboveground litter plus changes in the C stored in soil, roots and the forest floor litter layer. Aboveground net primary production (ANPP) was also estimated to enable comparison of ratios of above and belowground fluxes between treatments. TBCA ranged from 14.6 to 16.3 Mg C ha⁻¹ year⁻¹ and was not significantly different in 100%E, 50%E:50%A and 100%A. Higher ratios of ANPP:TBCA in the mixtures (0.41) than in either monoculture (100%A:0.28 100%E:0.31) indicated that trees in mixture partitioned a lower proportion of assimilated C belowground than those in monocultures. Since the mixture was as productive as monocultures belowground but more productive aboveground, it appears to be more productive overall and thus have the potential to increase C sequestration above that of monocultures.

Approximately 3.1 Mt of forest products are discarded in Australian landfills annually, with only limited knowledge on the extent of decay for the various products. As organic materials decay in landfills they release methane and carbon dioxide. The main aim of this study was to improve understanding of the extent of decomposition of wood and paper products in landfills in Australia, based on the analysis of carbon dynamics in forest products excavated from landfills in New South Wales and Queensland, and investigations of the fate of carbon in forest products under controlled laboratory conditions designed to optimise anaerobic decay.

There was typically little or no decay in the wood samples from the landfills in Sydney. Although there was significant decay in rainforest wood excavated from Cairns, decay levels for other wood types found both in Cairns and Sydney landfills were lower (0.7-9.0%). Climate did not influence decay in wood and engineered wood products (EWP). Microscopic analyses revealed that most decay patterns in wood analysed from Sydney MSW landfills were consistent with aerobic fungal decay. Estimated carbon loss ranged from 0.6 to 9.0% for EWPs and 0 to 58.9% for paper. Papers produced from mechanical pulp had lower carbon loss than those produced via chemical processes. Climate impacted on decay levels for papers made from chemical pulp. Lower carbon losses were observed for EWP and paper excavated from the C&D landfill compared with MSW landfills. Decay factors for paper should therefore reflect pulp type, climate and landfill type.

Carbon losses ranged from 0.2-3.8% for wood species tested in the reactor studies. The suggested factor for carbon loss for wood in landfills in Australia is 1.4%. Microscopy analyses in the wood revealed evidence of bacterial attack only. Addition of copy paper did not increase carbon loss for the wood species tested. Carbon losses for particleboard and MDF ranged from 0.7-1.6%. Carbon losses for bamboo (11.4%) were significantly higher than for EWPs. Carbon losses for the three types of copy paper ranged from 72.4 – to 82.5 %, and were significantly higher than for cardboard (43.8%). Differences in carbon loss between paper types were statistically significant. A decay factor for combined EWPs and wood in landfills in Australia of 1.3% and for paper products of 47.7% is proposed. The new suggested decay factors represent a significant reduction from factors currently used for forest products, with substantial impacts on greenhouse gas estimation from landfills.

In their recent editorial, Schulze and colleagues (Schulze et al., 2012) discuss the implications of a large-scale increase in the harvest of forest biomass to provide 20% of the current global primary energy supply. They present several well-founded concerns regarding the economic and ecological sustainability of such a scenario, concerns we largely share. However, the authors express particular apprehension regarding greenhouse gas (GHG) consequences of expanded forest bioenergy production that we do not entirely share. GHGs - while important - should not be the sole evaluation criterion when the objective is climate protection. The peer reviewed literature provides important insights beyond that presented which warrants additional commentary in order to give a more holistic and balanced perspective on the subject of forest bioenergy and climate.

Environmental change is altering forest insect dynamics worldwide. As these systems change, they pose significant ecological, social, and economic risk through, for example, the loss of valuable habitat, green space, and timber. Our understanding of such systems is often limited by the complexity of multiple interacting taxa. As a consequence, studies assessing the ecology, physiology, and genomics of each key organism in such systems are increasingly important for developing appropriate management strategies. Here we summarize the genetic and genomic contributions made by the TRIA project - a long-term study of the mountain pine beetle (Dendroctonus ponderosae Hopkins) system encompassing beetle, fungi, and pine. Contributions include genetic and genomic resources for species identification, sex determination, detection of selection, functional genetic analysis, mating system confirmation, hybrid stability tests, and integrated genetic studies of multiple taxa. These resources and subsequent findings have accelerated our understanding of the mountain pine beetle system, facilitating improved management strategies (e.g., enhancements to stand susceptibility indices and predictive models) and highlighting mechanisms for promoting resilient forests. Further, work from the TRIA project serves as a model for the increasing number and severity of invasive and native forest insect outbreaks globally (e.g., Dutch elm disease and thousand cankers disease).

Three landfill sites that had been closed for 19, 29 and 46 years and had been operated under different management systems were excavated in Sydney. The mean moisture content of the wood samples ranged from 41.6% to 66.8%. The wood products recovered were identified to species, and their carbon, cellulose, hemicellulose and lignin concentration were determined and compared to those of matched samples of the same species. No significant loss of dry mass was measured in wood products buried for 19 and 29 years, but where refuse had been buried for 46 years, the measured loss of carbon (as a percentage of dry biomass) was 8.7% for hardwoods and 9.1% for softwoods, equating to 18% and 17% of their original carbon content, respectively. The results indicate that published decomposition factors based on laboratory research significantly overestimate the decomposition of wood products in landfill.

Terrestrial laser scanning (TLS) data provide 3-D measurements of vegetation structure and have the potential to support the calibration and validation of satellite and airborne sensors. The increasing range of different commercial and scientific TLS instruments holds challenges for data and instrument interoperability. Using data from various TLS sources will be critical to upscale study areas or compare data. In this paper, we provide a general framework to compare the interoperability of TLS instruments. We compare three TLS instruments that are the same make and model, the RIEGL VZ-400. We compare the range accuracy and evaluate the manufacturer's radiometric calibration for the uncalibrated return intensities. Our results show that the range accuracy between instruments is comparable and within the manufacturer's specifications. This means that the spatial XYZ data of different instruments can be combined into a single data set. Our findings demonstrate that radiometric calibration is instrument specific and needs to be carried out for each instrument individually before including reflectanceinformation in TLS analysis. We show that the residuals between the calibrated reflectance panels and the apparent reflectance measured by the instrument are greatest for highest reflectance panels (residuals ranging from 0.058 to 0.312).

In 1966 there was issued by the Melbourne University Press one of the most distinctive and finest - as well as perhaps the most unlikely in its authorship - of the Australian regional histories to be produced in the middle third of the twentieth century. Its creator was an American woman of a well-to-do New York family, Louise Tiffany Daley (1895-1978), who had come to Australia in 1946 and settled in Alstonville. Both the style and the circumstances of her life to that point were unlikely for an 'Australian (regional) historian', to say the least, and they contributed to making this book and her pattern of intuitions and of passionate interests, as well as the style of writing, very much ones that were, and still are, 'sui generis'. Her actual text - and it is a record of much insight, fascination and power - was the resultant of several catalysing compulsions, which are discussed in the accompanying biography of the author in this edition.

Phylogeography infers patterns of migration, demography, and historical relationships from genetic data. Such studies have been particularly useful in understanding vicariance and colonization processes in pest species. Using a low-density single-nucleotide polymorphism (SNP) data set we investigated the range-wide phylogeography of mountain pine beetle (Dendroctonus poderosae Hopk., Coleoptera: Curculionidae) in North America using approximate Bayesian computation (ABC) methods. Our data suggest early divergence events occurred to the south and east of the Great Basin Desert, with populations further west and north of the Great Basin Desert arising later. Further, high levels of genetic differentiation among populations on either side of the basin appear consistent with previous studies. Above the Great Basin Desert, several populations exhibit high rates of migration and admixture. These data further support the idea that Canadian populations have spread from multiple source populations and suggest that small populations of mountain pine beetle may have been present in northern Canada for many decades. These findings further our understanding of the spatiotemporal history of mountain pine beetle in North America and suggest that the species is capable of continued, rapid range expansion from relatively few founding individuals.

In breeding forest trees, as for livestock, the goal is to capture as much genetic gain as possible for the breeding objective, while limiting longand short-term inbreeding. The Southern Tree Breeding Association STBA) is responsible for breeding Australia's two main commercial forest tree species and has adopted algorithms and methods commonly used in animal breeding to achieve this balance. Discrete generation breeding is the norm for most tree breeding programmes. However, the STBA uses an overlapping generation strategy, with a new stream of breeding initiated each year. A feature of the species bred by the STBA ('Pinus radiata' and 'Eucalyptus globulus') is the long interval (up to 7 years) between when an individual is mated and when its progeny is first assessed in field trials and performance data included in the national performance database. Mate selection methods must therefore recognize the large pool of unmeasured progeny generated over recent years of crossing. In addition, the substantial delay between when an individual is selected in a field trial and when it is clonally copied into a mating facility (breeding arboretum) means that selection and mating must occur as a two-step process. In this article, we describe modifications to preselection and mate selection algorithms that allow unmeasured progeny (juveniles) to be recognized. We also demonstrate that the addition of hypothetical new progeny to the juvenile pool is important for computing the increase in average co-ancestry in the population. Methods outlined in this article may have relevance to animal breeding programmes where between mating and progeny measurement, new rounds of mating are initiated.

A stem-diameter data set of five combined trials of 'Pinus radiata' D. Don was used to identify and determine the nature of genetics by environment (GxE) interaction. The restricted maximum likelihood approach was applied to handle the main issues of the multi-environment trial analysis: (1) Testing sources of heterogeneity of variance and lack of between-sites genetic correlation; (2) Modelling the heterogeneity of error variance among trials and micro-environmental variation within each trial; and (3) Selecting the best model for prediction of breeding values. Model comparison was based on the criterion of log-likelihood. The significance of variance components was tested by the likelihood ratio test which showed that all sources of GxE interactions were highly significant, indicating that GxE interactions occurred in these five trials due to both the heterogeneity of variances and the lack of correlation. Estimates of Type B genetic correlations were increased slightly by correcting for the heterogeneity of variances. The full model, which accommodated heterogeneity of error variances between trials, spatial variation within trials, and fitting a separate GxE interaction variance for each trial, was superior to other models for this multi-environment trial.

The eastern Australian temperate biota harbours many plants with fragmented geographic ranges distributed over 1000s of kilometres, yet the spatial genetic structure of their populations remains largely unstudied. In this study, we investigated genetic variation of the nuclear internal transcribed spacer (ITS) and chloroplast DNA sequences to disentangle the phylogeography of two widely distributed but highly fragmented eastern Australian fire-sensitive temperate conifers: Callitris oblonga (12 populations and 121 individuals) and C. rhomboidea (22 populations and 263 individuals). The three highly disjunct populations of C. oblonga all had unique chloroplast and ITS haplotypes consistent with the classification of these three populations as distinct subspecies. Molecular dating indicates that divergences of these populations occurred pre- to mid- Pleistocene (2.66 to 1.08 mya). Callitris rhomboidea showed greater diversity of chloroplast haplotypes which was strongly phylogeographically structured (Gst = 0.972), with haplotypes unique to specific geographic regions. ITS haplotype diversity was far higher than in C. oblonga with 38 haplotypes displaying high geographic structuring (Gst = 0.387) with many population-specific haplotypes. A phylogeographic break was identified between populations north and south of eastern Victoria dated at 0.43-0.47 mya. In both species, the strong genetic structuring of both chloroplast and ITS haplotypes provides evidence that their widespread ranges have resulted from long term persistence in low fire frequency refugia combined with poor dispersal. Any loss of populations due to increasing fire frequency or habitat loss is likely to result in a reduction of genetic diversity.

'Cadellia pentastylis' F.Muell., (family Surianaceae), a dry rainforest tree with a conservation listing of Vulnerable at state and national levels, was first collected from the Gunnedah area by the botanical collector J.L. Boorman in 1907. We report the first record of 'Cadellia pentastylis' from the Gunnedah area (30°58'49"S, 150°15'15"E) since 1907, and provide details of the community and habitat where it occurs, on the lower slopes of Black Jack Mountain. Although this population is one of the smallest in New South Wales, it is significant as it is at its southern distributional limit, and is found adjacent to semi-evergreen vine thicket, another type of dry rainforest, on the same hillslope. We list the New South Wales occurrences of this species and discuss aspects of its flowering phenology.

Genetic surveys of the population structure of species can be used as resources for exploring their genomic architecture. By adjusting filtering assumptions, genome-wide single-nucleotide polymorphism (SNP) datasets can be reused to give new insights into the genetic basis of divergence and speciation without targeted resampling of specimens. Filtering only for missing data and minor allele frequency, we used a combination of principal components analysis and linkage disequilibrium network analysis to distinguish three cohorts of variable SNPs in the mountain pine beetle in western Canada, including one that was sex-linked and one that was geographically associated. These marker cohorts indicate genomically localized differentiation, and their detection demonstrates an accessible and intuitive method for discovering potential islands of genomic divergence without a priori knowledge of a species' genomic architecture. Thus, this method has utility for directly addressing the genomic architecture of species and generating new hypotheses for functional research.

From our meta-analysis of worldwide data, soil carbon content decreased following land use change from pasture to conifer plantation. However, carbon stored in litter on the forest floor may balance the carbon lost from mineral soil. A paired study (a native pasture with 'Themeda triandra' dominant, and a 16-year-old 'Pinus radiata' plantation) at Kowen Forests, ACT, Australia, assessed the soil carbon change, carbon accumulation in litter on the forest floor and annual carbon return to soil surface via litterfall after land use change from native pasture to pine plantation. Results show that carbon stocks in the top 1 m mineral soil had decreased by 18% from 75 to 61 t/ha, 16 years after the land use change. However, approximately 10 t C/ha in litter had accumulated on the forest floor (including 3.2 t/ha in woody debris mostly from pruning/thinning). In the last two (local drought) years (July 2002-June 2004) approximately 2 t C/ha/yr returned to the soil surface via litterfall. Hence, C in the litter pool could substantially compensate the C loss from soil. Thus, considering the significant amount of carbon likely to be stored in plant biomass, a pine ecosystem planted onto prior pasture should be a net sink for C despite possible losses in soil C.

Whitewood ('Endospermum medullosum') is native to Vanuatu and has been designated as a priority species for plantation development by the Vanuatu Government for timber production after exhaustion of available natural forest supplies. Domestication is well advanced, with first and second-generation seed orchards and considerable silvicultural research having been accomplished, yet development of a plantation estate has been slow. This study analyses the value chain of whitewood on the two main islands of Efate and Santo that have land suitable for growing whitewood, most of the existing processing facilities and the main markets for whitewood products. The value chain is described and pricing along the chain is presented. Interviews with stakeholders identified impediments to the expansion and development of whitewood plantations. Despite a value-added chain existing, the price available to growers often reflects native forest timber prices that are inadequate given the input costs associated with plantation development, therefore providing little motivation to grow whitewood. There is a trend in the market for the highest profits to be taken by owners of key timber processing plant such as portable sawmills, kiln dryers and preservation vessels. However, prices achieved for processed whitewood products generally do not match those of radiata pine products, indicating potential for greater returns for growers and other stakeholders. As a result, landholder participation in plantation establishment is low and is dispersed as many small woodlots. Small-scale growers and processors face technical challenges, including growing of high quality and value stems and timely treatment of sawn timber. Greater capacity for consistency of product quality and the development of new products to maximise utilisation will improve revenue flows to growers.