Northern Regions Of Australia Research Articles

Beeswax rock art from Limmen National Park (Northern Territory), northern Australia: new insights into technique-based patterning and absence in the rock art record

The known geographic distribution of beeswax rock art is largely restricted to the Arnhem Land plateau and Kimberley regions of northern Australia. While considerable research has focussed on the antiquity and meaning of beeswax rock art, much less attention has been directed to the nature and extent of the distribution pattern for this unique motif production technique. In this article, we present details of two beeswax motifs recently discovered in Marra Country at Limmen National Park (southwest Gulf of Carpentaria, Northern Territory). In the first instance, the motifs are explored in the context of their meaning, drawing on ethnography collected in the region over the last 40 years. The motifs are then used as a platform to engage with questions around the low frequency, and in some cases complete absence, of beeswax rock art across other areas of northern Australia. While it is highly unlikely there is one single, homogenous explanation for this in the Gulf country and northeastern Australia, we suggest that exploring the social, cultural and relational understandings of beeswax in these areas offers considerable potential to understand better how people engaged with and inscribed their cultural landscapes.

Snow-Covered Bamboo with Sparrows.

Bamboo is an evergreen perennial plant. Many species are found in diverse climates, ranging from hot tropical regions to cool mountainous regions and highland cloud forests. They are commonly found in the Asia-Pacific region: China, India, Japan, Korea, Southeast Asia, and the northern region of Australia. Bamboo is of notable economic and cultural significance in Asia. Because of its high specific compressive strength, bamboo has often been used as building and furnishing materials. It is also an important food source and versatile raw material for a wide variety of household and arts and craft products. In Chinese culture, bamboo is admired for …

Germination ecology of turnip weed (Rapistrum rugosum (L.) All.) in the northern regions of Australia.

In Australia, turnip weed has been rapidly emerging as one of the major weeds in conservation agricultural systems. Germination and emergence of turnip weed were examined for two populations collected from Gatton and St George regions of Australia; two locations with high and low rainfall, respectively. The seeds of turnip weed germinated at all the tested temperatures, but germination was the lowest at 15/5°C, intermediate at 20/10°C and highest at 25/15°C and 30/20°C. The results indicated a high adaptability of turnip weed to warm environmental conditions, although it is a major problem in the winter season. Germination was higher in dark than light/dark regimes except at 30/20°C. Three was a concomitant reduction in germination as the osmotic potential values decreased from 0 to -1.0 MPa. There was 2 and 4% germination at -0.8 MPa for Gatton and St George populations, respectively, and no germination occurred at an osmotic potential of -1.0 MPa. There was a reduction in germination when the sodium chloride (NaCl) concentration was increased from 0 to 150 mM, and no germination was observed at 200 and 250 mM of NaCl. Turnip weed germinated over a broad range of pH (4 to 10). Seedling emergence was higher at 1 cm depth compared to 0.5 cm or at the soil surface. There was 28 and 33% emergence at the surface for the Gatton and St George populations, respectively, compared to 48 and 56% emergence from 1 cm depth for the Gatton and St George populations, respectively and no emergence was observed from 6 cm depth. The results indicated that tillage leading to shallow burial would promote the emergence of turnip weed; on the contrary, tillage that could bury seeds deep into the soil profile might minimise the emergence. Under ideal conditions and lack of integrated weed management programmes, this weed will emerge, set seeds and enrich the soil seed bank and thereby continue to be a problem in the northern grain region of Australia.

High-resolution mapping of acid sulfate soils in Northern Australia through predictive models

Acid sulfate soils can form when pyrite-rich marshes are drained or tidal influence decreases, naturally or anthropogenically. Often they are vegetated by mangroves, serve as important aquatic bird habitats, and harbor unique microbial biodiversity. They limit coastal development potential. The current best map of Australian acid sulfate soils is based on expert interpretation of soil surveys, most at 1:100,000 scale. In the current study, we attempted the first predictive spatial modeling to map acid sulfate soils and soil sulfur concentration on a 90-m grid. We use 34 national environmental 90-m grids and 614 observations on the presence/absence of acid sulfate soils to train a machine learning algorithm, random forests, to predict the location of acid sulfate soils across three regions of Northern Australia. We use the same environmental data and 1315 measurements of total elemental sulfur at 60–80 cm depth across Australia to train another random forest model to predict the spatial pattern of sulfur concentrations in the three regions. The model for acid sulfate soils is better than that for sulfur but both related maps showed that high sulfur concentrations generally coincide with the predicted presence of acid sulfate soils. This coincidence between the predicted occurrence of acid sulfate soils and sulfur concentrations confirms the modeling approach presented here was reliable and could be applied to map acid sulfate soils at high resolution globally.

Two new species of Pisolithus (Sclerodermataceae) from Australasia, and an assessment of the confused nomenclature of P. tinctorius

Based on morphological data and ITS nrDNA sequence analyses, we formally describe two species from the phylogenetic grouping ‘Martin sp. 10’ as Pisolithus thermaeus sp. nov., endemic to New Zealand, and P. tympanobaculus sp. nov. from Australia. All Pisolithus species in New Zealand are restricted in distribution to geothermally active areas, in ectomycorrhizal association with Kunzea tenuicaulis. In Australia species occur in a broad range of habitats in association with Eucalyptus or Acacia species; and in New Caledonia species form associations with various Myrtaceae or an Acacia species. The distribution ranges of Pisolithus albus, P. marmoratus and P. croceorrhizus are extended to include the Kimberley and Top End regions of northern Australia. We also confirm that neither P. arenarius, nor P. tinctorius sensu stricto, nor P. arhizus are currently known to occur in Australia or New Zealand. The long-used but never formalized combination Pisolithus albus (Cooke & Massee) Priest is validated here and nomenclatural knots relating to three different usages of the name Pisolithus tinctorius are unraveled and suggestions made for their resolution.

Medicinal Plant Images

Figure 1. Scaevola spinescens (commonly known as currant bush, maroon bush and prickly fanflower) is an endemic Australian plant which is distributed in arid areas of the Australian continent, particularly in the western regions. Australian Aborigines used S. spinescens as a medicinal plant to treat a wide variety of conditions.[1, 2] An infusion of the roots was used to treat stomach pain and urinary disorders. A decoction of the stem was used to treat boils, rashes and skin disorders. Fumes from the whole plant were inhaled to treat viral disorders including colds and influenza. A recent study demonstrated the general inhibitory activity of S. spinescens extracts against RNA viruses using an MS2 phage model system, partially verifying the ethnobotanical usages.[2] Earlier studies have also reported the ability of S. spinescens extracts to inhibit more than 25% of human cytomegalovirus (CMV) late antigen production.[3] S. spinescens also had traditional uses in the treatment of various cancers.[4, 5] Whilst the isolated compounds anticancer activity has yet to be confirmed, studies have indicated that S. spinescens taraxerene pentacyclic triterpenoids may be responsible for this anticancer activity.[6] Photograph was taken by Jeannie Crago of Outback Books and is reproduced here with the authors permission. Figure 2. Terminalia ferdinandiana (commonly known as Kakadu plum, gubinge, billy goat plum and salty plum) is an endemic Australian tree which occurs in tropical grassland regions of northern Australia. The fruit has traditional uses for indigenous Australians as food and as a medicinal plant.[1, 7] Recent studies have reported Kakadu plum to be extremely high in antioxidants and to be the richest naturally occurring source of vitamin C.[8, 9] As high antioxidant levels have previously been demonstrated to act as preventative effects against the development of degenerative chronic diseases such as cancer, cardiovascular diseases, neural degeneration, diabeties and obesity, it has been postulated that Kakadu plum fruit may also be an effective preventative against these diseases.[7] Recent studies have shown Kakadu plum fruit extracts to be effective at inhibiting the growth of a panel of microbes.[10] Photograph taken in Brisbane Australia by Dr Ian Cock in 2011.

Germination ecology of Sonchus oleraceus L. in the northern region of Australia

In Australia, Sonchus oleraceus has been emerging as a major weed in conservation agricultural systems. The effect of environmental factors on germination and emergence of S. oleraceus was assessed on populations collected from Gatton (SOG) and St. George (SOS) regions of Australia, which are high and low rainfall regions respectively. Germination of both populations responded similarly to various environmental factors studied. Although S. oleraceus seeds germinated under a broad range of temperatures (15/5, 20/10, 25/15 and 30/20°C day/night), germination was lower at 15/5°C. There was only 47–53% germination under dark conditions compared with 62–87% under alternating light–dark. Germination was only 2 and 3% at –0.8 MPa osmotic potential for SOG and SOS populations respectively, and no germination occurred at –1 MPa. Germination was 6 and 8% at 200 mM NaCl for SOG and SOS populations respectively. Although S. oleraceus seed germination exceeded 80% for pH 6–7, germination was reduced at pH outside this range. Germination was 83 and 87% for SOG and SOS populations respectively at the soil surface; and emergence decreased with increasing depth, with none from seeds buried at 6 cm depth. Wheat residue amount within the range of 0–2000 kg ha–1 did not alter germination; however, germination was significantly reduced when the crop residue amount increased to 4000 kg ha–1 and the lowest germination was at 6000 kg ha–1. The potential to germinate under diverse environmental conditions correlates with the widespread occurrence of this weed in the northern region of Australia. High residue amounts and occasional tillage leading to deep burial of seeds may reduce its emergence and incidence.

An exploratory analysis of the scope for dispersed small-scale irrigation developments to enhance the productivity of northern beef cattle enterprises

The major economic use of the northern Australian rangelands is beef cattle grazing. Beef production enterprises are typically large and employ ‘low-input’ herd and pasture management systems, and the longer-term viability and sustainability of many is uncertain. Productivity gains have been stagnant for most of the past decade, and nutritional constraints are a major source of the poor animal production and financial returns across the sector. There has been a growing interest in the scope for small-scale, dispersed irrigation developments – mosaic irrigation – to provide an augmented supply of higher-quality forages to certain classes of animals in order to alter their reproduction and/or growth potential and to exploit market opportunities. An ex-ante economic review undertaken by the CSIRO of the prospects for mosaic irrigation employed bioeconomic simulation modelling of case studies of irrigation development scenarios conducted at the individual beef enterprise scale in three contrasting regions of northern Australia – the Burdekin (north Queensland), the Barkly Tableland (Northern Territory) and the Kimberley (northern Western Australia). This paper presents a summary of the methods, results and conclusions of the case study modelling. The results present a mixed picture of the economic potential for the various irrigation development options that were canvassed. The level of animal productivity (e.g. average weight of sale animals) increased for all of the irrigation simulation scenarios, but in most instances the projected economic advantage ranged from negative to only moderately positive across the three regional case studies. Where there was an apparently attractive return on the irrigation investment (e.g. a real internal rate of return of >15%), this primarily occurred under the more buoyant market conditions that have prevailed in recent years. The influence of irrigated forage availability on herd structure through management options such as the early weaning of calves appears to be at least as valuable as changes in liveweight gain for particular classes of animals.

Biomass burning emissions in north Australia during the early dry season: an overview of the 2014 SAFIRED campaign

Abstract. The SAFIRED (Savannah Fires in the Early Dry Season) campaign took place from 29 May until 30 June 2014 at the Australian Tropical Atmospheric Research Station (ATARS) in the Northern Territory, Australia. The purpose of this campaign was to investigate emissions from fires in the early dry season in northern Australia. Measurements were made of biomass burning aerosols, volatile organic compounds, polycyclic aromatic carbons, greenhouse gases, radon, speciated atmospheric mercury and trace metals. Aspects of the biomass burning aerosol emissions investigated included; emission factors of various species, physical and chemical aerosol properties, aerosol aging, micronutrient supply to the ocean, nucleation, and aerosol water uptake. Over the course of the month-long campaign, biomass burning signals were prevalent and emissions from several large single burning events were observed at ATARS.Biomass burning emissions dominated the gas and aerosol concentrations in this region. Dry season fires are extremely frequent and widespread across the northern region of Australia, which suggests that the measured aerosol and gaseous emissions at ATARS are likely representative of signals across the entire region of north Australia. Air mass forward trajectories show that these biomass burning emissions are carried north-west over the Timor Sea and could influence the atmosphere over Indonesia and the tropical atmosphere over the Indian Ocean. Here we present characteristics of the biomass burning observed at the sampling site and provide an overview of the more specific outcomes of the SAFIRED campaign.

Human resource management policy choices, management practices and health workforce sustainability: remote Australian perspectives

The challenges for health professionals working in remote regions are diverse, particularly where voluntary turnover is high. This study examined the influence of management practices on workforce sustainability in remote regions of northern Australia using human resource management (HRM) policy choices. In this study, 24 semi‐structured interviews withHRmanagers, health professionals and health managers revealed that the impact ofHRMpolicy choices on remote workforce sustainability is significantly influenced by management practices. The emergent themes depict work environments where ineffective management practices for recruitment, remuneration, resourcing and relationships have profound consequences. Despite these contextual challenges, examples emerged where effective management practices created stability and improved retention. Hence, the findings suggest that sustainable remote health workforces are achievable where localised management practices improve equity, where employee–manager relationships are fostered, and where there is equitable access to resources and professional development.

Host Specificity of Endophytic Mycobiota of Wild Nicotiana Plants from Arid Regions of Northern Australia.

In arid regions of northern Australia, plants survive under water deficit, high temperatures, intense solar radiation and nutrient-impoverished soils. They employ various morpho-physiological and biochemical adaptations including interaction with microbial symbionts. We evaluated identity, host and tissue association with geographical distribution of fungal endophytes isolated from above- and below-ground tissues of plants of three indigenous Australian Nicotiana species. Isolation frequency and α-diversity were significantly higher for root endophyte assemblages than those of stem and leaf tissues. We recorded no differences in endophyte species richness or diversity as a function of sampling location, but did detect differences among different host genotypes and plant tissues. There was a significant pattern of community similarity associated with host genotypes but no consistent pattern of fungal community structuring associated with sampling location and tissue type, regardless of the community similarity measurements used.

Biological control of Ziziphus mauritiana (Rhamnaceae): feasibility, prospective agents and research gaps

AbstractThe tropical fruit tree, Ziziphus mauritiana (Rhamnaceae), a native of the Indian subcontinent, is a pasture and environmental weed in northern Australia and Fiji. In their native range, Ziziphus spp., including commercially cultivated Z. mauritiana and Z. jujuba, are subjected to a wide range of pests and diseases. The feasibility of classical biological control of this weed has not been explored to date. Effective biological control could reduce plant vigour and seed output, thereby limiting the spread of Z. mauritiana in Australia. Two Ziziphus species are native to Australia, hence, any prospective biological control agent should be specific to Z. mauritiana. Opportunistic field surveys and literature searches identified 133 species of phytophagous insects, 9 species of phytophagous mites and 12 plant pathogens on Ziziphus spp. Host records suggest the following are possibly specific to Z. mauritiana and hence are prospective biological control agents in Australia: the seed‐feeding weevil Aubeus himalayanus; the leaf‐feeding gracillariid moth Phyllonorycter iochrysis; the leaf‐mining chrysomelid beetle Platypria erinaceus; the leaf‐folding crambid moth Synclera univocalis; the leaf‐galling midge Phyllodiplosis jujubae; and the gall‐mites Aceria cernuus and Larvacarus transitans. Host range of the rust Phakopsora zizyphi‐vulgaris includes many Ziziphus species, including the native Z. oenoplia and hence would not be a suitable biological control agent in Australia. The powdery mildew Pseudoidium ziziphi, with a host range restricted to Ziziphus species, has not been reported on Z. oenoplia. All available information on the pests and diseases of Z. mauritiana are from cultivated varieties. Hence, future surveys should focus on wild Z. mauritiana in the Indian subcontinent in areas that are climatically similar to the regions of northern Australia, where it is currently most abundant.

Diversity and biogeography of a species-rich ant fauna of the Australian seasonal tropics.

Although ants are an ecologically dominant and extensively studied faunal group throughout the tropics, there is a poor understanding of tropical ant diversity and distribution at large spatial scales. Here we use a collection developed from 3 decades of ant surveys to present the first analysis of ant diversity and biogeography of a large tropical region. Our objective was to document the species richness, composition, and biogeographic distributions of the ant fauna of the 400000 km2 "Top End" of Australia's Northern Territory. The known Top End ant fauna comprises 901 native species from 59 genera. The richest genera are Pheidole (90 species), Melophorus (83), Monomorium (83), Camponotus (71), Meranoplus (63), Polyrhachis (57), Rhytidoponera (50), Tetramorium (43), Cerapachys (32), and Iridomyrmex (31). The fauna is the center of diverse radiations within species-groups of genera such as Meranoplus, Rhytidoponera, and Leptogenys. It also includes IndoMalayan species that have likely bypassed the normal dispersal route into Australia through Cape York Peninsula in North Queensland. Faunistic similarity with other regions of far northern Australia is associated more with rainfall than with geographic proximity. Most (60%) of Top End ant species have not been recorded elsewhere, and, despite uncertainties relating to species delimitation and sampling intensity, this appears to be a credible estimate of the level of endemism. Such exceptionally high endemism can be attributed to the Top End's geographic isolation from other regions of northern Australia with comparably high rainfall.

The Paradise Problem: Painted Experience

This research focuses on a sample group of painters who have worked in the North Queensland wet tropics where they have explored tropical imagery within western traditions. Despite some acknowledgement of the Pacific by Smith (1960) and some engagement by established southern artists in fleeting visits to the North; there has been little research into contributions of the contemporary painters working within the wet tropical regions of northern Australia. This research challenges some of the late 19th century and early 20th century filters established by the painters Gauguin, Matisse and Henri Rousseau in finding a tropical paradise, through the presentation of data collected from the selection of artists working in the tropics, teasing out the contradictions within the work of mainstream art historians.

The impacts of a toxic invasive prey species (the cane toad, Rhinella marina) on a vulnerable predator (the lace monitor, Varanus varius)

The magnitude of impact of an invasive species on native taxa, and the time course of recovery, depend on the native’s ability to adjust to the invader. Here, we examine the impact of a toxic invasive prey species (cane toad Rhinella marina) on a vulnerable top-predator (lace monitor Varanus varius) in southern Australia. Lace monitor populations crash as soon as toads invade, as occurs in related species in tropical Australia. The toad’s impact falls primarily on larger lizards, such that mean body sizes decline precipitously after toad arrival. Feeding trials with free-ranging lizards clarified the reasons for that size-biased vulnerability. Large lizards attacked novel prey more rapidly than did smaller conspecifics, especially in toad-naive populations. Small lizards were more cautious in investigating novel prey (more tongue flicks and bites prior to ingestion) and swallowed the item more slowly. These traits may allow smaller lizards to detect and avoid toad toxins. Seventy percent of monitors from toad-naive populations readily consumed dead cane toads (with parotoid glands removed) and 85 % consumed frogs. In contrast, no conspecifics from toad-exposed populations consumed toads whereas 40 % ate frogs. Following a single meal of toxic toad (typically eliciting illness), all monitors refused toads but 40 % continued to eat frogs. Lace monitors thus can rapidly learn taste aversion to cane toads. This behavioral plasticity enables survival of smaller lizards (that approach and process prey more cautiously than their larger relatives), and may explain this species’ recovery in long-term toad-colonized regions of northern Australia.

Mitochondrial Genome Sequence of the Scabies Mite Provides Insight into the Genetic Diversity of Individual Scabies Infections.

The scabies mite, Sarcoptes scabiei, is an obligate parasite of the skin that infects humans and other animal species, causing scabies, a contagious disease characterized by extreme itching. Scabies infections are a major health problem, particularly in remote Indigenous communities in Australia, where co-infection of epidermal scabies lesions by Group A Streptococci or Staphylococcus aureus is thought to be responsible for the high rate of rheumatic heart disease and chronic kidney disease. We collected and separately sequenced mite DNA from several pools of thousands of whole mites from a porcine model of scabies (S. scabiei var. suis) and two human patients (S. scabiei var. hominis) living in different regions of northern Australia. Our sequencing samples the mite and its metagenome, including the mite gut flora and the wound micro-environment. Here, we describe the mitochondrial genome of the scabies mite. We developed a new de novo assembly pipeline based on a bait-and-reassemble strategy, which produced a 14 kilobase mitochondrial genome sequence assembly. We also annotated 35 genes and have compared these to other Acari mites. We identified single nucleotide polymorphisms (SNPs) and used these to infer the presence of six haplogroups in our samples, Remarkably, these fall into two closely-related clades with one clade including both human and pig varieties. This supports earlier findings that only limited genetic differences may separate some human and animal varieties, and raises the possibility of cross-host infections. Finally, we used these mitochondrial haplotypes to show that the genetic diversity of individual infections is typically small with 1–3 distinct haplotypes per infestation.

Patterns, Pleasure, and the Age of Digital Reproduction

Over the past decade a range of printed textiles designed by Indigenous artisans in remote regions of Northern Australia have gained national prominence; winning awards and achieving commercial success due to their mesmerizing affect. These patterns share a beauty with celebrated textile patterns from the past, such as Mamluk carpets. In this paper, literature regarding aesthetics, perception and brain activity is reviewed to identify the characteristics of patterns that create pleasure by stimulating positive nerve centres in the brain. This knowledge may assist designers who aim to create patterns of lasting value and high esteem in an age of digital design interface and digital reproduction.

Interdecadal variation of Australian summer monsoon during late 1990s

In this study, the variations of Australian summer monsoons (AUSMs) over the last 30 years (1983–2012) were examined. The analysis period for a total of 30 years was divided into 15 years for 1983–1997 (8397) and 15 years for 1998–2012 (9812) to analyse interdecadal variations of AUSMs. The AUSM index (AUSMI) generally showed negative values in the 8397 period while showing positive values in the 9812 period, indicating that clear interdecadal variations exist in the AUSMI over the last 30 years. Recently, AUSMs have been trending towards being reinforced. The precipitable water averaged in the area for defining the AUSMI has also shown a tendency to increase, until recently, along with the characteristics of interdecadal variations. To examine the cause of the recent reinforcement of AUSMs, differences in 850 hPa stream flows between the average of the 9812 period and the average of the 8397 period were analysed. Anomalous cyclones were located in the west of Australia and the South China Sea, and anomalous anticyclones existed in the central and eastern Pacific in both hemispheres. Because of these patterns of anomalous pressure systems, anomalous equatorial easterlies (anomalous trade winds) were reinforced. The 200 hPa stream flows showed patterns opposite to those of the pressure systems shown by 850 hPa stream flows. Because of these patterns of anomalous pressure systems, anomalous equatorial westerlies were reinforced. These results mean that the Walker circulations – in which air currents ascend in the northern region of Australia and the Maritime Continent and descend in the equatorial central Pacific – were reinforced further in the 9812 period. These changes may be related to the interdecadal changes in the Pacific Ocean, including the Pacific Decadal Oscillation and El Nino-Southern Oscillation.

An examination of supportive management practices promoting health workforce stability in remote northern Australia.

The aim of this study is to examine management practices that support the wellbeing of health professionals working in remote regions, which may improve workforce retention. An online questionnaire was distributed to health professionals working in remote regions of the Kimberley and North Queensland. A response rate of 20% was achieved. The findings suggest that, for health professionals working in remote regions of northern Australia, accessing adequate support is one of the most challenging aspects of working in remote regions. Hence, in remote regions where turnover is high, retention of competent health professionals may benefit from management practices that provide improved personal and professional support. Health professionals working in remote Australia face unique pressures due to their geographical and professional isolation. Therefore, providing support improves their professional competence and personal wellbeing, and promotes workforce stability, which benefits the remote community through better access to health services.

Temperature influences the level of glyphosate resistance in barnyardgrass (Echinochloa colona).

Echinochloa colona is an important summer-growing weed species in cropping regions of northern Australia that has evolved resistance to glyphosate owing to intensive use of this herbicide in summer fallow. Pot trials conducted at 20 and 30 °C on six E. colona populations showed a significant increase in the level of glyphosate resistance in resistant populations at 30 °C compared with 20 °C. However, there was no influence of growth temperature on glyphosate susceptibility of the sensitive population. Sequencing of the target-site gene (EPSPS) of the six populations identified a mutation at position 106 leading to a change from proline to serine in the most resistant population A533.1 only. EPSPS gene amplification was not detected in any of the resistant populations examined. Examining (14) C-glyphosate uptake on two resistant and one susceptible population showed a twofold increase at 20 °C; however, few differences in glyphosate translocation occurred from the treated leaf to other plant parts between populations or temperatures. There is reduced efficacy of glyphosate at high temperatures on resistant E. colona populations, making these populations harder to control in summer.