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The Millennium Drought lasted more than a decade and is notable for causing persistent shifts in the relationship between rainfall and runoff in many southeastern Australian catchments. Research to date has successfully characterised where and when shifts occurred and explored relationships with potential drivers, but a convincing physical explanation for observed changes in catchment behaviour is still lacking. Originating from a large multi-disciplinary workshop, this paper presents and evaluates a range of hypothesised process explanations of flow response to the Millennium Drought. The hypotheses consider climatic forcing, vegetation, soil moisture dynamics, groundwater, and anthropogenic influence. The hypotheses are assessed against evidence both temporally (e.g. why was the Millennium Drought different to previous droughts?) and spatially (e.g. why did rainfall–runoff relationships shift in some catchments but not in others?). Thus, the strength of this work is a large-scale assessment of hydrologic changes and potential drivers. Of 24 hypotheses, 3 are considered plausible, 10 are considered inconsistent with evidence, and 11 are in a category in between, whereby they are plausible yet with reservations (e.g. applicable in some catchments but not others). The results point to the unprecedented length of the drought as the primary climatic driver, paired with interrelated groundwater processes, including declines in groundwater storage, altered recharge associated with vadose zone expansion, and reduced connection between subsurface and surface water processes. Other causes include increased evaporative demand and harvesting of runoff by small private dams. Finally, we discuss the need for long-term field monitoring, particularly targeting internal catchment processes and subsurface dynamics. We recommend continued investment in the understanding of hydrological shifts, particularly given their relevance to water planning under climate variability and change. [ABSTRACT FROM AUTHOR]

Context: Knowledge gaps exist for the interference of Avena ludoviciana and Argemone mexicana in chickpea grown in eastern Australia. Aims: This research aimed to examine the effect of different interference levels of A. ludoviciana and A. mexicana for their potential to cause yield loss in chickpea. Methods: Experiments were conducted in a randomised complete block design with five weed infestation levels of both weeds (none, low, medium, high, and very high) in three replications. Key results: Infestations of A. ludoviciana and A. mexicana at 15 and 17 plants m−2 caused an 83 and 48% reduction in chickpea yield, respectively, compared with weed-free situations. Based on the regression model, a 50% yield reduction of chickpea occurred at 10 and 17 plants m−2 of A. ludoviciana and A. mexicana , respectively. Based on the modified hyperbolic model, maximum seed production of A. ludoviciana and A. mexicana in chickpea at an infestation level of 1 plant m−2 was estimated at 366 and 7800 seeds m−2, respectively. At crop harvest, seed retention of A. ludoviciana and A. mexicana was greater than 50 and 90%, respectively. Conclusions: A. ludoviciana and A. mexicana infestation in chickpea caused a substantial reduction in crop yield. High seed retention in A. mexicana and A. ludoviciana in chickpea suggests the possibility to manage these two weeds through harvest weed seed control. Implications: The information generated from this study could help in strengthening integrated weed management in chickpea. Knowledge gaps exist for the interference of Avena ludoviciana and Argemone mexicana in chickpea in Australia. About 50% yield reduction of chickpea occurred at 10 and 17 plants m−2 of A. ludoviciana and A. mexicana , respectively. High seed retention in A. mexicana and A. ludoviciana in chickpea suggests the possibility to manage these two weeds through harvest weed seed control for strengthening integrated weed management. [ABSTRACT FROM AUTHOR]

Rainwater tanks are a fundamental component of integrated water cycle management, but the quality of harvested water is little understood and is potentially affected by many factors such as roofing material, site temperature, frequency of tank use, and surrounding land use. There has been limited study of the first flush, overflow water and harvested water quality from rainwater tanks in Australia. This paper presents the water quality results of a yearlong data collection and analysis study involving five rainwater tanks located in Western Sydney, Australia. The results show that tank water quality was impacted by the construction materials used to fabricate both the tanks and roofs. Furthermore, the overflow and first flush water quality were found to be of a lower standard than the tank samples, with implications for the cleaning of the first flush device and overflow diversion. Finally, the issues identified with the maintenance of the tanks are highlighted and discussed. [ABSTRACT FROM AUTHOR]

This paper reviews practical policy lessons from trade in a dietary supplement (or nutraceutical) processed from Terminal/a ferdinandiana (Combretaceae), which contains extremely high levels of natural ascorbic acid (vitamin C). Most production is from wild harvest by Aboriginal people, who get USD 14 per kilogram (kg) for picked, sorted fruit. However, the main Australian company involved is struggling to get the 12 tons/year it requires, and could market much more. Although Aboriginal people ideally should benefit economically from harvest of T. ferdinandiana, there are major challenges to this objective, including Australia's high labor costs compared to Asia, Africa, and Latin America where T. ferdinandiana can be grown. In addition, although Australia is a signatory to and plays a leading role in the international Convention on Biodiversity (CBD), this has meant lithe in practice so far. "Cultural branding" and certification of organic, wild harvested T. ferdinandiana fruit collected by Aboriginal people working in partnership with commercial companies offers a possibility for Aboriginal people to continue to benefit from wild harvest or enrichment plantings. However, even the establishment of commercial horticultural production within Australia faces several challenges. For Australia to maintain and develop the international market, future development of this bush food must include: (a) implementation of existing international and national policies on protection of genetic resources; (b) formation of a producer association to increase production efficiencies; (c) functioning partnerships between Aboriginal producers and commercial partners that guarantee and expand reliable supply and develop cultural branding and certification as marketing tools; and (d) scientific research into improving I ferdinandiana fruit yields and production methods, based on improved resource management and efficient processing methods. [ABSTRACT FROM AUTHOR]

This paper focuses on the adverse effects of soil sodicity and alkalinity on the growth of barley (Hordeum vulgare L.) in a rainfed environment in south-western Australia. These conditions cause the accumulation of salt (called 'transient salinity') in the root zone, which decreases the solute potential of the soil solution, particularly at the end of the growing season as the soil dries. We hypothesized that two approaches could help overcome this stress: (a) improved micro-water harvesting at the soil surface, which would help maintain soil hydration, decreasing the salinity of the soil solution, and (b) soil amelioration using small amounts of gypsum, elemental sulfur or gypsum plus elemental sulfur, which would ensure greater salt leaching. In our experiments, improved micro-water harvesting was achieved using a tillage technique consisting of exaggerated mounds between furrows and the covering of these mounds with plastic sheeting. The combination of the mounds and the application of a low rate of gypsum in the furrow (50 kg ha−1) increased yields of barley grain by 70% in 2019 and by 57% in 2020, relative to a control treatment with conventional tillage, no plastic sheeting and no amendment. These increases in yield were related to changes in ion concentrations in the soil and to changes in apparent electrical conductivity measured with the EM38. [ABSTRACT FROM AUTHOR]

Aim: Well‐managed semi‐arid forests help offset global change by storing significant amounts of carbon above‐ and belowground and maintaining hydrological cycles. Larger trees have been the focus of many studies due to their carbon storage and habitat quality, yet recruitment and small trees are important components of ecosystem resilience and recovery. Here, we study the impacts of disturbances (including harvesting) on recruitment, mortality and growth for a mixed conifer‐broadleaf semi‐arid forest type using long‐term data. Location: Pilliga Forest in New South Wales, inland eastern Australia. Taxon: Callitris‐Eucalyptus forests. Methods: We used data from permanent sample plots (PSPs) spanning 55 years, calculated stand structure, gains and losses and determined reasons for tree death (harvesting, fire, wind, drought and other effects). We extracted climate and fire data for the PSP locations using spatial analysis. Results: Stocking of studied forests remained stable (modest increase in basal area and stem density), despite harvesting and wildfires over 6 decades. Compared to stands in the 1940s and prior to European settlement, current forests are composed of more trees per unit area, and these trees have smaller diameters. Recruitment and sustained presence of small trees have buffered impacts of recurring drought, fire and harvesting. Fires are a common feature of the studied ecosystems and fire impacts have increased in the past 20 years, especially in unmanaged stands, where fires have reduced tree carbon by >50%. Main conclusions Recruitment and growth of small trees are critical to offset carbon losses due to fire, drought and harvesting. All size classes have important ecological values in semi‐arid forests and must be included in long‐term monitoring programmes. Long‐term data offer unique insights into combined effects of climate change, management and disturbances, especially for fire‐prone ecosystems, where small trees are often susceptible to fire. [ABSTRACT FROM AUTHOR]

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Forest industry is one of the high-risk industries. Machine operators and forestry workers are a vital part of the forest industry and their health and well-being can greatly impact their work quality and efficiency. It is important to consider the safety of the cabins of harvesting machines, as machine operators spend a long time there during their work. Different guidelines, protective structures, codes of practices and standards applied in Australia were reviewed in this article. Details on chain shot issue and safety recommendations are provided for felling/processing, primary timber transportation, in-field chipping, loading and transportation. Most of the forestry cabins have windows made of polycarbonate, a heavy-duty plastic that provides protection from heat, air, dust and noise. This review indicates that most of the Australian codes of practices provide general information on safety regulations thus the focus was made on finding the relevant available guidelines/standards on the physical and structural requirements and new technological development trends on protection structures. Summarised guidelines and information could be of use to the industry and academic users working on the cabin protection. [ABSTRACT FROM AUTHOR]

Development of the Australian food composition program, focussing on the enablers and barriers to progress, is reviewed following a process of reference harvesting and unstructured interviews with experts. Strong growth in new data and publications during the 1930s and 1970/80s was followed by more stagnant periods, particularly during the 1990s, enabled by data needs for national nutrition surveys, labelling requirements and national policy needs. From the late 1980s there was a move from paper to computerised tables and then to online databases in the 2000s. Australia's food composition tables have evolved in line with international developments in science and changed data publication methods. Maintaining the timeliness of these databases requires significant investment in new analytical data and skilled scientists to drive this process. [ABSTRACT FROM AUTHOR]

Abstract: While Australia has lifted its outright ban on banana imports, very strict pre-entry requirements remain in place making it prohibitively expensive for foreign suppliers to land product in Australia. These include the establishment and maintenance of areas of low pest prevalence (following guidelines described in FAO, 2005; FAO, 2007, respectively), trash minimization procedures and post-harvest fungicide treatments (Biosecurity Australia, 2008). Strict though these import requirements are and small the risk of exotic disease transference may be, the potential consequences of some disease outbreaks to the Australian banana industry is potentially huge. In this paper we provide quantitative estimates of these potential damages (in Australian dollars, A$) and discuss the implications for Australia's import risk assessment process using the example of black Sigatoka. In 2001 this disease was detected in the Tully region of Queensland, a major banana production region. The cause of the outbreak remains unknown (Molina et al., 2005), but it was detected early enough to be eradicated at a cost A$17 million (Sosnowski et al., 2009). This outbreak has failed to quell calls to relax banana import requirements further, and criticism continues to be directed at Australia's import risk assessment process and its associated appropriate level of protection (Javelosa and Schmitz, 2006; Leroux and Maclaren, 2011). This is a locus of disease arrival probabilities and outbreak consequences with a unique product which forms a maximum expected damage a product entering the country can pose before violating Australian quarantine regulations. However, in practice the appropriate level of protection is not stated in quantitative terms, but is instead defined in rather ambiguous qualitative terms as very low. Our analysis provides quantitative evidence suggesting that in the case of banana imports, the appropriate level of protection corresponds to an expected damage of A$60 million per annum. This suggests that although current quarantine regulations are trade-restrictive, the appropriate level of protection corresponds to a relatively severe level of damage. [Copyright &y& Elsevier]

Abstract: Maturity index (MI) is a key determinant of pea softness and ultimately retail value. Pea seed development goes through the optimal market stage for human consumption about a week before harvest. MI increases rapidly during the last 3–4 days prior to the optimal harvest which is when there is a need for better forecasting capability. Extensive field sampling is currently used to track MI in each of the individual paddocks, though it has limited ability to predict MI more than a day ahead. We developed an Artificial Neural Network (ANN) model that complements field sampling by forecasting the MI trend several days ahead. It was built using historical harvest information along with weather and climate forecasts. We implement and evaluate the ANN in a large pea growing region in Tasmania, Australia, and this paper highlights key results. The ANN produced an average error of 31.8MI units when forecasting MI at harvest with a 7-day lead time versus the current manual method which produced an average error of 36.6MI units for a lead time of 2 days. This means the model provides the ability to not only harvest peas closer to their ideal MI but also plan harvesting and transport logistics with a much greater lead time. [Copyright &y& Elsevier]

The Australian sugar industry is seeking to increase profitability through better integration across a value chain fragmented among many owners. Within the cane harvesting and transport sectors, many existing inefficiencies are a result of excessive numbers of harvesting machines owned by harvester contractors and growers, and the fact that most harvesters operate within a short time window each day. In order to improve the complex system from a tactical and strategic planning perspective, leading to reduced costs of production, a modelling framework identifying the key drivers and links must first be developed. Upon developing the framework, techniques in operations research, financial modelling, and simulation can be applied to investigate opportunities to enhance the system in partnership with industry. This paper describes the development of such a framework through participation with two case-study mill areas within the Australian sugar industry, along with its application to improve the efficiency of the harvesting and transport system. Through reducing the number of harvesters in the region and implementing best practice principles for harvesting, one of the case study mills showed potential gains in profitability of up to AU$1 million per annum. Implementation took place in one of the case study regions during the 2003 harvest season for which the region is now pursuing further adoption in 2004. [Copyright &y& Elsevier]

Biodiversity monitoring is recognised as a key action for ecologically sustainable land use, but there are few examples of landscape programmes. We outline the first five years of biodiversity monitoring focusing on insectivorous bats in low rainfall, multiple‐use forests and woodlands of the Pilliga, Australia. Using ultrasonic sampling over multiple nights, both on‐ and off‐tracks, we identify annual trends in bat activity and occupancy and environmental covariates. Trends differed depending on whether occupancy or bat activity was the response variable. Site occupancy was almost 100% and remained stable and/or did not decline for most species nor diversity over the monitoring period, suggesting little variation in bat populations. In comparison, total activity was initially very high (567 passes night−1 on‐track) and then declined by up to 40% in the following three years, but then fully recovered in the fifth year. This general pattern was evident both on‐ and off‐tracks for most taxa, though activity was three times greater on‐ than off‐track, highlighting the importance of these distinct habitat features for bats. Multivariate state‐space (MARSS) models predicted, unexpectedly, that high winter rainfall prior to our surveys was negatively related to activity for many taxa. In contrast, disturbance from timber harvesting or fire had weak or no identifiable effects on trends in activity for most taxa. One exception was Chalinolobus picatus (threatened), whose occupancy off‐tracks was negatively related to the extent of recent (<5 years) fire and to harvesting, though at the landscape scale, occupancy remained stable. This result, together with patterns for other bat taxa, suggests that disturbance effects were short‐lived/dispersed and/or environmental mitigations were effective at maintaining bat populations at a landscape level. Annual monitoring highlighted annual variation in activity and its implications when setting a baseline for monitoring. We also discuss modifications to future monitoring effort, based on the existing five years of data. [ABSTRACT FROM AUTHOR]

On-board spindle and brush type stripper round module harvest systems were evaluated on commercial field scale for dryland Upland cotton in Australia over two harvest seasons. Observations on harvester performance, including harvesting efficiency, harvest loss, seed cotton yield and lint turn out were conducted at three locations, during the 2017 and 2018 cotton growing seasons, with a single variety. Fibre quality was measured by High Volume Instrumentation (HVI™) and Advanced Fiber Information System (AFIS) and analysed to determine if there were any significant differences between the two harvesting systems. The stripper harvesters had higher productivity (i.e. hectares per hour), harvested more material with lower harvest loss than the spindle harvesters. The seed cotton harvested by the stripper systems contained plant material which resulted in a lower lint turn out than the spindle harvester although the yield in bales ha−1 was still higher. There were no significant differences in fibre quality as measured by the HVI except for colour and trash. The significant differences in colour and trash did not affect the economic return to the grower as the visual colour and trash grades were below, i.e. better than, the Australian base grade. There were also no significant differences in the fibre quality as measured by AFIS. It is hypothesised that the reasons for this was due to the appropriate timing and application of defoliation, harvesting when moisture content ≤ 12%, reduced leaf allowing for gentler ginning and mature fibre. [ABSTRACT FROM AUTHOR]

The article presents a summary of five research projects on different biomass harvesting systems in Australian plantations. The first trial assessed the productivity and cost of slash-bundling the harvesting residues in clear felled area using Pinox slash-bundler in Eucalypt plantation in Tasmania. Second project investigated the efficiency of a European mobile chipper to collect pine harvesting residues Green Triangle (Victoria) while in the third project a conventional forwarder was studied to recover pine residues logs (called Fibre plus material) as an integrated biomass operation in Western Australia. The product quality and fuel consumption of the biomass harvesting systems were also assessed within the trials. Whole tree biomass harvesting (including feller-buncher, grapple skidder and chipper) was another trial carried out in low-productivity Eucalypt stands in Western Australia to produce biomass chips for bioenergy purposes. Where bioenergy markets are strong, thinning materials (e.g. large branches) may also be utilised as a source for bioenergy. The operating costs and environmental impacts (including remaining residues assessment to sustain soil quality in biomass recovery operations) of different technologies were compared/discussed in this article. [ABSTRACT FROM AUTHOR]

Abstract: Aims: Bryophyte re‐colonization after disturbance is largely governed by environmental conditions within disturbed forests. In particular, distance to a forest edge is an important predictor of bryophyte community re‐colonization, through either direct constraints, such as dispersal limitation, or indirectly by altering environmental conditions. This study examines a range of factors – environmental, distance to an edge, substrate specific environment or local‐level environment – to determine which are important in the re‐colonization of bryophyte communities after forest harvesting. As bryophyte communities vary with the particular substrate inhabited, responses were examined across four substrates (rock, exposed roots, ground and CWD). Location: Tasmanian southern forests, Australia. Methods: Bryophyte composition was examined on four substrates (ground, coarse wood debris, exposed roots, rocks) within three ages (~7, ~27 and ~45 years post‐disturbance) of harvested wet eucalypt forest. Re‐colonization success of bryophyte communities was determined by comparing communities in regeneration forest to mature forest communities using axis scores from one‐dimensional constrained ordination. The importance of various environmental conditions for re‐colonization success was then modelled. Finally, path analysis was used to determine whether the impact of distance to a forest edge was meditated through its effects on key environmental variables. Results: Multiple environmental factors impacted re‐colonization of mature bryophyte communities. Local‐level conditions such as microclimate (temperature, humidity and VPD) and LAI were the most important in determining re‐colonization across substrates. Path analysis showed that distance to a forest edge had a significant impact on re‐colonization success, but only a relatively small part of this was mediated through its impact on environmental factors. Conclusions: Bryophyte re‐colonization is driven by a combination of microclimate conditions and factors related to distance from a forest edge (most likely dispersal distance). While some substrate‐specific factors impact bryophyte re‐colonization success, the consistent impact of local environmental factors across substrates suggests that harvesting management strategies that develop more ‘mature’ microclimate conditions and increase proximity to nearby mature forest patches will be beneficial for all bryophytes communities. As bryophyte re‐colonization was correlated with temporally dynamic environmental conditions, we suggest that forest age needs to be considered in future work. [ABSTRACT FROM AUTHOR]

Life-history theory predicts the progressive dwarfing of animal populations that are subjected to chronic mortality stress, but the evolutionary impact of harvesting terrestrial herbivores has seldom been tested. In Australia, marsupials of the genus Macropus (kangaroos and wallabies) are subjected to size-selective commercial harvesting. Mathematical modelling suggests that harvest quotas ( c. 10-20% of population estimates annually) could be driving body-size evolution in these species., We tested this hypothesis for three harvested macropod species with continental-scale distributions. To do so, we measured more than 2000 macropod skulls sourced from wildlife collections spanning the last 130 years. We analysed these data using spatial Bayesian models that controlled for the age and sex of specimens as well as environmental drivers and island effects., We found no evidence for the hypothesized decline in body size for any species; rather, models that fit trend terms supported minor body size increases over time. This apparently counterintuitive result is consistent with reduced mortality due to a depauperate predator guild and increased primary productivity of grassland vegetation following European settlement in Australia., Spatial patterns in macropod body size supported the heat dissipation limit and productivity hypotheses proposed to explain geographic body-size variation (i.e. skull size increased with decreasing summer maximum temperature and increasing rainfall, respectively)., There is no empirical evidence that size-selective harvesting has driven the evolution of smaller body size in Australian macropods. Bayesian models are appropriate for investigating the long-term impact of human harvesting because they can impute missing data, fit nonlinear growth models and account for non-random spatial sampling inherent in wildlife collections. [ABSTRACT FROM AUTHOR]

Lindenmayer et al. proposed that logging makes 'some kinds of forests more prone to increased probability of ignition and increased fire severity.' The proposition was developed most strongly in relation to the wet eucalypt forests of south-eastern Australia. A key argument was that logging in wet forests results in drier forests that tend to be more fire-prone, and this argument has gained prominence both in the literature and in policy debate. We find no support for that argument from considerations of eucalypt stand development, and from reanalysis of the only Australian study cited by Lindenmayer et al. In addition, there is no evidence from recent megafires in Victoria that younger regrowth (<10 years) burnt with greater severity than older forest (>70 years); furthermore, forests in reserves (with no logging) did not burn with less severity than multiple-use forests (with some logging). The flammability of stands of different ages can be explained in terms of stand structure and fuel accumulation, rather than as a dichotomy of regrowth stands being highly flammable but mature and old-growth stands not highly flammable. Lack of management of fire-adapted ecosystems carries long-term social, economic, and environmental consequences. [ABSTRACT FROM AUTHOR]

Berry Sensory Assessment ( BSA) is a technique that can help grapegrowers and winemakers to make decisions about harvest date and allocation of grapes. As a structured technique, BSA has been used by grapegrowers, winemakers and researchers for the last 11 years. The number of studies, however, reporting results of the effect of viticultural practices on berry sensory characteristics and wine quality is limited. The extent to which both Australian and New Zealand winemakers and grapegrowers use BSA and their opinions about the application and their expectations of this technique has not been evaluated. The aims of this review are: first, to review the different BSA techniques employed to date within the wine industry and oenological research, and to consider some practical applications of BSA; and second, to reveal and discuss a survey undertaken by Australian and New Zealand winemakers and grapegrowers about current use of BSA. Knowledge gaps in BSA resultant from the review and the survey are identified. [ABSTRACT FROM AUTHOR]

Spotted gum (Corymbia citriodora subspecies Variegata) has the potential to be the major hardwood species for large-scale plantations in Southeast Queensland, Australia, but production research is limited due to the lack of age of research plots. Optimal spacing is a major subject of concern. Based on time series data from a spotted gum experiment site, growth performance was analyzed for five spacing levels: 11.3 m × 11.3 m (78 stems ha−1), 7.4 m × 7.4 m (182 stems ha−1), 5.4 m × 5.4 m (343 stems ha−1), 3.6 m × 3.6 m (771 stems ha−1), and 2.9 m × 2.9 m (1189 stems ha−1). The major objective was assumed to be to maximize total merchantable log volume. A growth model was produced, and the mean diameter at breast height (DBH) and total merchantable log volume for each spacing level at a range of harvesting ages were estimated. From the analysis, the spacing level of 5.4 m × 5.4 m was found to be optimal for maximizing merchantable log volume to a 10-cm small-end diameter. Further analysis of mean DBH, height, and volume of the largest 200 and 250 trees from this spacing level indicates that merchantable log volume could be maximized by retaining the 250 largest trees ha−1. The total financial revenue from the best spacing level in 25 and 30 yr are predicted to be Australian dollars (A$) 13,637 and A$17,779 ha−1, respectively. If full rotation data could be obtained, more reliable models could be produced, and a more accurate financial estimate could be made. [ABSTRACT FROM PUBLISHER]

Aim To examine the different uses and perceptions of introduced Australian acacias (wattles; Acacia subgenus Phyllodineae) by rural households and communities. Location Eighteen landscape-scale case studies around the world, in Vietnam, India, Réunion, Madagascar, South Africa, Congo, Niger, Ethiopia, Israel, France, Portugal, Brazil, Chile, Dominican Republic and Hawai'i. Methods Qualitative comparison of case studies, based on questionnaire sent to network of acacia researchers. Information based on individual knowledge of local experts, published and unpublished sources. Results We propose a conceptual model to explain current uses and perceptions of introduced acacias. It highlights historically and geographically contingent processes, including economic development, environmental discourses, political context, and local or regional needs. Four main groupings of case studies were united by similar patterns: (1) poor communities benefiting from targeted agroforestry projects; (2) places where residents, generally poor, take advantage of a valuable resource already present in their landscape via plantation and/or invasion; (3) regions of small and mid-scale tree farmers participating in the forestry industry; and (4) a number of high-income communities dealing with the legacies of former or niche use of introduced acacia in a context of increased concern over biodiversity and ecosystem services. Main conclusions Economic conditions play a key role shaping acacia use. Poorer communities rely strongly on acacias (often in, or escaped from, formal plantations) for household needs and, sometimes, for income. Middle-income regions more typically host private farm investments in acacia woodlots for commercialization. Efforts at control of invasive acacias must take care to not adversely impact poor dependent communities. [ABSTRACT FROM AUTHOR]

Introduced species are a major driver of negative ecological change, but some introduced species can potentially offer positive benefits to society. Asian swamp buffalo ( Bubalus bubalis) were introduced to the northern Australian mainland in 1827 and have since become a serious pest. However, buffalo have also supported various profitable industries, including harvesting for hides, meat, and live export. We investigate an indigenous wildlife-based enterprise that harvests wild buffalo from indigenous-held lands in remote northern Australia. We used ecological modelling and social research techniques to quantify the buffalo dynamics and to examine their contributions to sustainable livelihoods in a remote Aboriginal community. Results suggest that the current harvest rate will not drive the species to extinction and it is thus unlikely that the population size of buffalo will be reduced enough to alleviate ecological damage. This enterprise is profitable and provides regular royalty payments to traditional land owners and wage income for employees, along with several additional non-financial capital assets. We demonstrate that the commercial exploitation of introduced species can provide additional or alternative sources of protein and income to promote economic development for indigenous people. This type of enterprise could be expanded to more communities using harvest rates above maximum sustainable yield to provide greater positive social and ecological outcomes for indigenous communities. [ABSTRACT FROM AUTHOR]

Grain yield and grain weight of wheat are often decreased by water-limitation in the north-eastern cropping belt of Australia. Based on knowledge that CIMMYT lines are well-adapted in this region, a recombinant inbred line (RIL) population between two elite CIMMYT bread wheats (Seri M82 and Babax) was evaluated under water-limited environments. Fourteen productivity traits were evaluated in 192 progeny in up to eight trials. For three aggregations of the environments (all, high yield or low yield), multiple quantitative trait loci (QTL) were detected, each explaining <15% of variation. Co-location of multiple trait QTL was greatest on linkage groups 1B-a, 1D-b, 4A-a, 4D-a, 6A-a, 6B-a, 7A-a and an unassigned linkage group. Two putative QTL (LOD > 3) from Seri (6D-b and UA-d) increased grain yield and co-located with a suggestive (2 < LOD < 3) and a putative QTL for increased stem carbohydrate content (WSC), respectively; the latter QTL also co-located with a putative anthesis QTL for earlier flowering. Both QTL were detected only in high yield (>4t ha−1) environments. A third increased grain yield QTL (7A-a) from Babax co-located with QTL for increased grain number. Six putative QTL increased grain weight and co-located with QTL for harvest index, grains per spike and spike number. Three putative QTL for increased grains per spike co-located with strong QTL for earlier flowering, increased grain weight and fewer spikes. A group of progeny that exceeded the mean grain yield and grain weight of commercial checks had an increased frequency of QTL for high WSC, large grain size, increased harvest index and greater height, but fewer stems, when compared to low yielding (20% less), low grain weight progeny. These findings were consistent with agronomic analyses of the germplasm and demonstrate that there should be opportunities to independently manipulate grain number and grain size which is typically difficult due to strong negative correlations. [ABSTRACT FROM AUTHOR]

Evolution was measured over 16 years in a self-regenerating, bulk-hybrid subterranean clover population, consisting of F2 seed from 253 crosses, sown at Nabawa and Mt Barker, short and long growing season sites, respectively, in south-western Australia. Seed bank samples harvested annually were grown in a common garden. Experiment 1 measured flowering time in plants from each year, while Experiment 2 measured 26 variables in the populations 3 and 16 years after sowing, in comparison with the ancestral population. Changes in population means were observed in 20 characters and variability declined in 11 characters at one or both sites, with much of this occurring within the first three years. Natural selection at Nabawa favoured early flowering of long duration, thick peduncles, high harvest index and high hardseededness. At Mt Barker it favoured late flowering of short duration, large leaves and long, thick petioles at flowering, thick stems with long internodes, long, thin peduncles with a high burial angle, large plants at maturity, low hardseededness and high biochanin A and total isoflavone contents. High seed production capacity, with high seed weight and seeds per burr, was important at both sites. The use of bulk-hybrid populations is demonstrated as a low-input means of breeding and selecting well-adapted subterranean clovers. [ABSTRACT FROM AUTHOR]

In subtropical rainforest in eastern Australia, changes in the diversity of trees were compared under natural conditions and eight silvicultural regimes over 35 years. In the treated plots basal area remaining after logging ranged from 12 to 58 m^{2}/ha. In three control plots richness differed little over this period. In the eight treated plots richness per plot generally declined after intervention and then gradually increased to greater than original diversity. After logging there was a reduction in richness per plot and an increase in species richness per stem in all but the lightest selective treatments. The change in species diversity was related to the intensity of the logging, however the time taken for species richness to return to pre-logging levels was similar in all silvicultural treatments and was not effected by the intensity of treatment. These results suggest that light selective logging in these forests mainly affects dominant species. The return to high diversity after only a short time under all silvicultural regimes suggests that sustainability and the manipulation of species composition for desired management outcomes is possible. [ABSTRACT FROM AUTHOR]

1. It has been reported that species from environments where seedlings are prone to drought during establishment tend to have larger seeds. One proposed reason for this is that larger-seeded species might be able to allocate a larger proportion of mass to roots rather than shoots during early growth. 2. Seedlings of 32 species from arid central Australia were grown in coarse sand under standard conditions in a glasshouse. and harvested 10 days after germination. Seedlings from heavier-seeded species did not allocate relatively more resources to roots than lighter-seeded species. Complementary experiments confirmed this result for plants grown on sands loam, in drying as compared to well-watered soil. and under shaded conditions. 3. Seedlings of heavier-seeded species tended to survive longer than seedlings from lighter-seeded species when grown in the absence of any mineral nutrients oilier than those in the seed. 4. Seedlings of heavier-seeded species tended to he able to emerge from greater depths in the soil than lighter-seeded species. 5. Seedlings from heavier-seeded species had a slower relative growth rate than lighter-seeded species during the first 10 days after germination. Nevertheless. among these species, seed size was more important than relative growth rate or germination speed in determining seedling size 10 days after seeds were welled. [ABSTRACT FROM AUTHOR]

Change in the number of red kangaroos (Macropus rufus) in the South Australian pastoral zone is related to rainfall and population size. These relationships are used to assess effects of harvesting red kangaroos by predicting the change in the risk of population decline and explosion under a range of harvesting regimes. The predictions account for the combined influences of rainfall, density dependence and environmental stochasticity. The method illustrates the importance of considering environmental stochasticity when assessing impacts, and how risk assessment may be used to assist wildlife management. Sustainable harvesting rates will be overestimated if environmental stochasticity is ignored. Because of uncertainty about the response of the red kangaroo population to extremes of rainfall, it is difficult to be certain of the effects of harvesting red kangaroos. The relationship between rainfall and population size depends on the scale of observation. The previous yearߣs rainfall is most closely related to changes in population size over the whole pastoral zone. Over smaller areas, summer and autumn is the most critical rainfall period. [ABSTRACT FROM AUTHOR]

Research Highlights: This study evaluated the impacts of biomass recovery on site preparation costs while proposing a mathematical model and framework to catalogue the benefits depending on harvesting system. Background and Objectives: Biomass as a viable product depends on the requisite costs of production compared to the price paid by relative markets. The removal of biomass directly impacts site preparation costs, and the operational and economic ramifications of this should inform the feasibility of biomass harvesting and market viability. The relative incentives for biomass removal depend on the quantity, presentation, and location of the residues and are thus a result of the commercial sawlog harvesting system. This incentive also largely depends on the required work to prepare a site for replanting. Materials and Methods: This study developed a mathematical model to connect the concepts of site preparation, harvesting, and biomass costs and revenues to determine the maximum net revenue. This work also developed a framework for understanding and calculating the key model inputs related to site preparation and the relative economic site preparation incentive for biomass harvesting. The framework was then illustrated by using industry data from plantations in Queensland, Australia. Results and Conclusions: The analysis identified a potential reduction in site preparation costs due to biomass harvesting of USD 75–450 ha−1, with a greater incentive when using cut-to-length harvesting systems compared with whole-tree harvesting due to the greater volume of residues after cut-to-length harvesting. For example, a removal of 20 t ha−1 of recoverable biomass after cut-to-length harvesting may equate to an economic incentive of USD 22 t−1. Depending on the biomass market, this incentive may represent a significant percentage (or even exceed) the biomass market price. The combination of biomass market price plus site preparation economic incentive may make biomass an attractive market opportunity, even in challenging biomarkets. [ABSTRACT FROM AUTHOR]