Continental Australia Research Articles

Insights into the structure of the Australian Crust, results from ANSIR?s Seismic Reflection Profiling Program

ANSIR, the National Facility for Earth Sounding, has been responsible for the acquisition of 30 regional deep seismic reflection surveys across many different Australian geological regions and structural environments. The seismic data has provided exciting new images of the Australian Crust at depth. Each survey has produced the unexpected and has usually dispelled some `sacred-cow' in geological understanding of the depth-dimension of that region. ANSIR's deep seismic reflection equipment provides both high quality whole-of-crust images of the Australia continent as well as detailed district and mine scale seismic images. These seismic surveys are providing a clear picture of the architecture of a region and providing information to develop tectonic models a region. In particular, the seismic data is successfully imaging the major basement geological units and structures and therefore providing the necessarydepth constraints to construct 3D geological models ofa region. The seismic data is suggesting possible mineral systems that have operated and allowing explorers to assess the potential of an area for mineral deposits.

The potential impact of climate change on Australia's soil organic carbon resources.

BackgroundSoil organic carbon (SOC) represents a significant pool of carbon within the biosphere. Climatic shifts in temperature and precipitation have a major influence on the decomposition and amount of SOC stored within an ecosystem and that released into the atmosphere. We have linked net primary production (NPP) algorithms, which include the impact of enhanced atmospheric CO2 on plant growth, to the SOCRATES terrestrial carbon model to estimate changes in SOC for the Australia continent between the years 1990 and 2100 in response to climate changes generated by the CSIRO Mark 2 Global Circulation Model (GCM).ResultsWe estimate organic carbon storage in the topsoil (0–10 cm) of the Australian continent in 1990 to be 8.1 Gt. This equates to 19 and 34 Gt in the top 30 and 100 cm of soil, respectively. By the year 2100, under a low emissions scenario, topsoil organic carbon stores of the continent will have increased by 0.6% (49 Mt C). Under a high emissions scenario, the Australian continent becomes a source of CO2 with a net reduction of 6.4% (518 Mt) in topsoil carbon, when compared to no climate change. This is partially offset by the predicted increase in NPP of 20.3%ConclusionClimate change impacts must be studied holistically, requiring integration of climate, plant, ecosystem and soil sciences. The SOCRATES terrestrial carbon cycling model provides realistic estimates of changes in SOC storage in response to climate change over the next century, and confirms the need for greater consideration of soils in assessing the full impact of climate change and the development of quantifiable mitigation strategies.

Ebinania australiae, a new species of fathead sculpin from southern Australia (Scorpaeniformes: Psychrolutidae)

A sixth species of Ebinania is described from nine specimens collected at depths of 982- 1170 off southern Australia. Eight of the specimens were from the vicinity of Tasmania and the nearby mainland, and the ninth is from near Perth, Western Australia. The new species differs from its congeners in having cirri on the head, well-developed orbital rims, cranial arch 3 twisted upwards, prevomerine teeth in a continuous band, a single terminal chin pore, obsolete lateral line pores, and an overall pale colour. This is the third species of psychrolutid known from off continental Australia. Variation in important characters used in diagnosis of species of Ebinania is reported and problems of the characters in diagnosing these species are discussed. A key to species of Ebinania is provided.

Recovery of Alpine Herbfield on a Closed Walking Track in the Kosciuszko Alpine Zone, Australia

Human use of arctic and alpine environments can result in damage to the natural vegetation and soils. Restoration of the damage can have limited success due to the severity of the environment, which restricts plant germination and growth and increases the potential for soil erosion. In this study, we evaluated the success of restoration of a closed track in the alpine area around continental Australia’s highest mountain, Mount Kosciuszko. Vegetation and soils along a 4 km walking track (that was closed and rehabilitated more than 15 yr ago) were compared with the adjacent undisturbed vegetation and soils. There was limited success in restoration with clear differences in soil nutrients, extent of vegetation cover, plant species composition, and height of vegetation between the track and adjacent natural vegetation sampled using 1 m2 quadrats. The study highlights the need for limiting disturbance in such environments, and for ongoing rehabilitation in areas that have been disturbed. It also indicates that when non-native species are used in rehabilitation, they may not necessarily be succeeded by natives, particularly if soil conditions do not return to a state similar to undisturbed areas.

Cenozoic climatic change and the development of the arid vegetation in Australia

Australia has not always been arid, and the central desert was once well watered. This paper traces the changes in climate and vegetation, leading to the present aridity. At the beginning of the Cenozoic, continental Australia had a warm and humid climate, and the vegetation was mainly meso–micro-thermal (warm to cool temperate) rainforest. Central Australia experienced seasonal rainfall and there may have been limited aridity in the northwest. By the mid–late Eocene, rainforest in central Australia was restricted to the well-watered valley bottoms, with sclerophyll vegetation on the slopes and ridges. In the latest Eocene–earliest Oligocene, there was an abrupt cooling of ocean waters and the diversity of megathermal angiosperms decreased. The early–mid-Miocene was warm–humid and there was a considerable diversity of forest types. Woodlands and Casuarinaceae forests became more common. Central Australia was seasonal, with a very warm season of high evaporation. In Western Australia, regular flows in the palaeodrainage systems had stopped by the mid-Miocene and this marked the first major step towards aridity. The late Miocene was cool and dry, with a major reduction of rainforests and an increase of Eucalyptus/casuarinaceous sclerophyll forests in inland southeastern Australia. Regular burning became a feature of the eucalypt forests. Rainforest persisted, however, along the east coast and highlands of Australia. Central Australia became more arid with dry woodland and chenopod shrublands. Rainforests continued to decrease during the Pliocene and grasslands developed in central northern Australia. By the early Pleistocene, the modern climatic regime had been established, but precipitation was higher than today. Cycles of open, shrubland/grasslands/herbfields and wooded vegetation accompanied the arid glacial and humid interglacial cycles (respectively). About 0.5 Ma, there was a change to a drier climate, but it was still wetter than today. The last glacial period was particularly harsh, and the present interglacial period is drier than the previous interglacial. Aridity has thus increased in a number of steps, following the first major step towards aridity in the early Miocene. Distinctive elements of the vegetation can be traced back to times when the arid zone was humid and supported rainforest. The elements, which have remained in arid regions, are the few that could tolerate or adapt to the drier climates. The taxa, which could not cope with these changing conditions, were eliminated from the arid regions.

Successive foraminiferal faunas and inferred palaeoenvironments associated with the postglacial (Holocene) marine transgression, Gulf St Vincent, South Australia

Gulf St Vincent is one of a pair of elongate, triangular, shallow water embayments into the southern coast of continental Australia. From the southern floor of this embayment, within a shallow basin-like depression where present-day water depth is about 40 m, vibracore SV23 recovered c. 4 m of late Quaternary sediments. The uppermost 1.5 m of this core comprises postglacial (Holocene) marine deposits; six radiocarbon ages for the interval 64-130 cm downcore are all around 10 000 cal. yr BP, while two for 18-24 cm are several thousand years younger. Radiocarbon analysis of an oyster shell at 154 cm yielded a minimum age of c. 37 000 cal. yr BP. Well-preserved benthic foraminifera are abundant in all the recovered sediments. The early phase of Holocene marine sedimentation in Gulf St Vincent was marked by the development of a marginal marine, perhaps lacustrine to estuarine environment, as signified by the presence of oogonia, gypsum crystals and the foraminifera Miliolinella labiosa and Elphidium cf. articulatum. Development of seagrass meadows followed; these were inhabited by Nubecularia lucifuga and Discorbis dimidiatus. As the marine transgression proceeded, the environment remained somewhat restricted, as indicated by Ammonia beccarii, but numbers of this species declined giving way to Massilina milletti as conditions began to resemble those of the modern Gulf St Vincent. Culmination of the transgression provided the conditions necessary for the dominance of Ammobaculites reophaciformis and Flintina triquetra. A. reophaciformis and F triquetra therefore record the final episode of the transgression and transition to the modern, deeper water environment. At several lower horizons they also occur as conspicuous spikes, equivalent to their modern abundance. These spikes, which coincide with equivalent decreased numbers of A. beccarii, are interpreted to represent downward bioturbation of the overlying deeper water sediment.

Geographical and seasonal characteristics of the relationship between lightning ground flash density and rainfall within the continent of Australia

Ground-based observations of annual rainfall and lightning incidence collected over periods ranging from 9 to 22 years at 23 stations around the continent of Australia were used to compute values of ‘rain yield’, defined as the mass of rain produced per lightning ground flash (units: kg fl − 1) over a given area of ground. The rain yield was found to vary considerably with geographical location, season and climatic conditions. Of the 23 stations, 5 were mid-continental and these showed a mean rain yield of 2.64 × 10 8 kg fl − 1 in contrast to the coastal and near-coastal stations that showed a corresponding mean value of 9.91 × 10 8 kg fl − 1. The difference was statistically significant at the confidence level of 95%. When the stations were classified according to seasonal climate zones, the winter and winter-dominant rainfall stations showed a rain yield of 1.28 × 10 9 kg fl − 1 while the summer and summer-dominant rainfall stations showed a significantly lower value of 5.44 × 10 8 kg fl − 1. Again the difference was statistically significant at the 95% confidence level. Every one of the 23 stations showed mean winter rain yields that were significantly higher than the summer values. These differences are attributed to surface heating which controls such parameters as cloud base height and convective available potential energy in the atmosphere. In terms of the behaviour of the rain yield with geographical, seasonal and climatic conditions, the Australian observations are in good agreement with studies in other parts of the world.

A history of mass spectrometry in Australia

An interest in mass spectrometry in Australia can be traced back to the 1920s with an early correspondence with Francis Aston who first visited these shores a decade earlier. The region has a rich tradition in both the development of the field and its application, from early measurements of ionization and appearance potentials by Jim Morrison at the Council for Scientific and Industrial Research (CSIR) around 1950 to the design and construction of instrumentation including the first use of a triple quadrupole mass spectrometer for tandem mass spectrometry, the first suite of programs to simulate ion optics (SIMION), the development of early TOF/TOF instruments and orthogonal acceleration and the local design and construction of several generations of a sensitive high-resolution ion microprobe (SHRIMP) instrument. Mass spectrometry has been exploited in the study and characterization of the constituents of this nation's unique flora and fauna from Australian apples, honey, tea plant and eucalyptus oil, snake, spider, fish and frog venoms, coal, oil, sediments and shale, environmental studies of groundwater to geochronological dating of limestone and granite, other terrestrial and meteoritic rocks and coral from the Great Barrier Reef. Peter Jeffery's establishment of geochronological dating techniques in Western Australia in the early 1950s led to the establishment of geochronology research both at the Australian National University and at what is now the Curtin Institute of Technology in the 1960s. This article traces the history of mass spectrometry in its many guises and applications in the island continent of Australia. An article such as this can never be complete. It instead focuses on contributions of scientists who played a major role in the early establishment of mass spectrometry in Australia. In general, those who are presently active in the field, and whose histories are incomplete, have been mentioned at best only briefly despite their important contributions to the field.

Vegetation associated with different walking track types in the Kosciuszko alpine area, Australia

Tourism infrastructure such as walking tracks can have negative effects on vegetation including in mountain regions. In the alpine area around continental Australia's highest mountain, Mt Kosciuszko (2228 m), there is a range of walking tracks (paved, gravel and raised steel mesh surfaces) in addition to an extensive network of informal/non-hardened tracks. Vegetation characteristics were compared between track types on/under tracks, on the track verge, and in the adjacent native vegetation. For a raised steel mesh walkway there was no difference in vegetation under the walkway, on the verge, and 3 m away. In contrast, for a non-hardened track there was 35% bare ground on the track surface but no other detectable impacts. Gravel and paved tracks had distinct verges largely comprising bare ground and exotic species. For non-hardened tracks there was an estimated 270 m 2 of disturbance per km of track. For wide gravel tracks the combined area of bare ground, exotic plants and gravel was estimated as 4290 m 2 per km, while for narrow gravel tracks it was estimated as 2940 m 2 per km. For paved tracks there was around 2680 m 2 per km of damage. In contrast, there was no detectable effect of raised steel mesh walkway on vegetation highlighting some of the benefits of this surface over other track types.

Fire‐induced albedo change and its radiative forcing at the surface in northern Australia

This paper investigates the impact of fire on surface albedo and the associated radiative forcing over 56% of continental Australia encompassing the fire‐prone northern tropical savanna. Fire‐affected areas and albedos are derived for the 2003 fire season using daily Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance data. Near‐infrared and total shortwave albedos are observed to generally decrease after fire occurrence. Regionally, the total shortwave albedo drops by an average of 0.024, with increasing reductions as the dry season progresses and larger reductions in grasslands than woody savannas. These fire‐induced albedo changes exert a positive forcing at the surface that increases from March to November. A mean “instantaneous” shortwave surface radiative forcing of 0.52 Wm−2 is estimated for the study region.

Phylogeography of sexualHeteronotia binoei(Gekkonidae) in the Australian arid zone: climatic cycling and repetitive hybridization

The biota of much of continental Australia have evolved within the context of gradual aridification of the region over several million years, and more recently of climatic cycling between relatively dry and humid conditions. We performed a phylogeographical study of three sexual chromosome races of the Heteronotia binoei complex of geckos found throughout the Australian arid zone. Two of these three races were involved in two separate hybridization events leading to parthenogenetic lineages (also H. binoei), and the third is widespread and broadly sympatric with the parthenogens. Based on our analyses, the three sexual races diversified approximately 6 million years ago in eastern Australia, during a period of aridification, then each moved west through northern, southern, and central dispersal corridors to occupy their current ranges. In each case, the timing of major phylogeographical inferences corresponds to inferred palaeoclimatic changes in continental Australia. This scenario provides a simple explanation for diversification, secondary contact, and hybridization between the races. However, data presented elsewhere indicate that formation of the parthenogens was considerably more recent than the westward expansion of the hybridizing races, and that multiple hybridization events were geographically and temporally distinct. We suggest that cyclical climate changes may have led to regional range changes that facilitated hybridization between the races, which are not currently known to be in sympatry.

The relationship between lightning activity and surface wet bulb temperature and its variation with latitude in Australia

Convective Available Potential Energy (CAPE) is the driving force for thunderstorm development. CAPE is closely controlled by wet bulb temperature. The lightning activity measured by a network of ten lightning flash counters widely distributed across continental Australia was studied as a function of wet bulb temperature. At each of the stations, the monthly total of lightning ground flashes, N, increased sharply with the increase of the monthly mean daily maximum wet bulb temperature, Tw, max. The dependence was strongest in the tropics and became less pronounced at temperate latitudes. In Darwin (latitude 12° S), the lightning ground flash activity increased by over three orders of magnitude over a 7 °C range of Tw, max. The corresponding increases for Coffs Harbour (latitude 30° S) and for Melbourne (latitude 38° S) were about one and a half orders of magnitude and about half an order of magnitude, respectively, each over a 10 °C range of Tw, max. Power law approximations were derived for each of the ten stations and showed that the logarithm of N was directly proportional to the power, P, of Tw, max. The value of P showed a sharp exponential decrease with increasing latitude away from the equator.

An assessment of old and new DNA sequence evidence for the paraphyly of Banksia with respect to Dryandra (Proteaceae)

Banksia (80 spp.; Proteaceae) has undergone extensive speciation and adaptive radiation on the island continent of Australia. Its members range from prostrate shrubs in the dry, infertile sandplains to 25 m tall trees in the loams of river margins, and they display striking variation in their fire survival strategies and floral and foliar morphologies. We examine the weight of both previously published (most trnL intron, trnL/F spacer, and rpl16 intron data) and new (matK, atpB, and waxy data, as well as most ITS data) DNA sequence evidence for the paraphyly of Banksia with respect to a monophyletic Dryandra (93 spp.). The nuclear waxy gene appears to be at two loci in the Proteaceae, and sequences presumably from the same locus resolve Banksia as paraphyletic with respect to Dryandra. The waxy and combined chloroplast DNA (cpDNA) data reject the monophyly of Banksia at a threshold of P = 0.05 using the winning sites and Kishino–Hasegawa tests. We consider this result and the repeated placement of Dryandra in the same clade (/Cryptostomata) of Banksia with each separate analysis of the DNA datasets (cpDNA, ITS, and waxy), to be strong molecular support for the paraphyly of Banksia with respect to Dryandra. The morphological synapomorphy of beaked follicles for /Cryptostomata (including Dryandra) reinforces this conclusion. We argue that realignment of taxa to produce one or more monophyletic genera is best attained by moving the taxa of Dryandra to Banksia. This would produce an easily recognised genus Banksia with four morphological synapomorphies. It would also probably confer some of the research attention garnered by the adaptive radiation of Banksia to the under-studied taxa of Dryandra, for Dryandra makes the radiation of Banksia even more remarkable.

The Flying Doctor Service of Australia Founded by John Flynn

The story of the Royal Flying Doctor Service of Australia is forever linked to its founder, the Reverend John Flynn. This effort combines medicine, aviation, and radio to bring care to the people who live, work, and travel in remote areas of Australia. Established in 1928 and developed on a national basis in the 1930s, the service soon provided not only emergency medical aid to the people of the inland of Australia but also comprehensive health care and community services. In 1957, Australia issued a stamp (Scott No. 305) in honor of the Royal Flying Doctor Service of Australia. The issuance of this stamp offers an opportunity to honor its founder, the Reverend John Flynn. John Flynn was born on November 25, 1880, in Moliagul in central Victoria, Australia. His father was a schoolteacher, and John was the youngest of 3 children; his mother had died in childbirth when John was only 3 years old. For several years, John lived with relatives before the family was reunited at Snake Gully (near Ballarat in south central Victoria, about 70 miles northwest of Melbourne). The family later moved to a suburb of Melbourne, where John’s father began an unsuccessful business venture. In 1898, John graduated from secondary school and began teaching. In 1903, when he was residing in Victoria, he decided to become a minister of the Presbyterian Church. In 1907, he began a 4-year course in divinity training at Melbourne University; he graduated in 1910 and was ordained in January 1911. While preparing for the ministry, Flynn became interested in working in “the outback” (the wild central and northern inland of Australia). In February 1911, he began his work in the outback when he arrived at Beltana in South Australia, about 300 miles north of Adelaide, where medical care was unavailable to the inland residents and travelers. Flynn reported to his church about the conditions in the outback and was appointed head of a new organization, the Australian Inland Mission (AIM). During the next few years, the organization founded several nursing homes and recruited ministers to travel to vast outback parishes by camel or on horseback, visiting communities and households and tending to the people of the inland. Flynn helped establish bush hospitals and hostels in remote outback regions. In 1903, the first powered air flights had taken place, and by 1918, the airplane was beginning to prove itself as a reliable means of transportation. Flynn saw the potential in the use of the airplane. By 1928, AIM had sufficient funds to establish the Flying Doctor Service, and on May 15, 1928, the Aerial Medical Service was established at Cloncurry in northwestern Queensland. After many years of dreaming, hard work, and planning, the Flying Doctor Service became a reality. The first official flight occurred on May 17, 1928, from Cloncurry to Julia Creek, a distance of about 80 miles. The first flying doctor was Sydney surgeon Kenyon St. Vincent Welch. The trial year (1928) began without a radio network. The Flying Doctor Service relied on telephone links between towns and settlements and on people physically traveling long distances for help. What was needed was a portable, cheap, and reliable 2-way radio with a range of 300 miles. This became a reality in 1929 when the Cloncurry Base radio station became operative. By 1932, AIM had a network of 10 small hospitals. During this early period, Dr Alan Vickers, a flying doctor, lobbied for a network of flying doctor bases spread across the entire continent of Australia. In 1934, the Presbyterian Church transferred the work to the Australian Aerial Medical Service, which during the next few years established services across Australia with operational bases at Wyndham (northwestern Western Australia), Kalgoorlie (southern Western Australia), Broken Hill (western New South Wales), Alice Springs (south central Northern Territory), and Meekatharra (Western Australia), along with bases in Charters Towers (eastern Queensland) and Charleville (southern Queensland). In 1942, the service was renamed the “Flying Doctor Service,” and in 1955, the Queen of England granted the use of the Royal prefix. On May 5, 1951, at the age of 70 years, John Flynn died in Sydney, New South Wales, and was buried near Alice Springs in the Northern Territory, the center of the vast area in which he had worked.

Fracture systems in granite pavements of the eastern Pilbara Craton, Western Australia: Indicators of neotectonic activity?

Continental Australia is characterised by high levels of seismic activity in comparison with intracratonic areas worldwide. However, the link between earthquake events and earthquake-related geomorphology in Australia remains poorly understood for all except the largest events, because landscape impact unambiguously attributable to seismic activity is difficult to recognise. In this context, we describe several unusual fracture systems of possible tectonic origin that transect granite pavements in the Archaean eastern Pilbara Craton of Western Australia. Occurring at four localities (Gallery Hill, North Shaw, Mulgandinnah Hill and Muccan) separated by up to 150 km, the fracture systems typically range up to 100 m in length and 20 m in width, locally offset pavement surfaces by up to 15 cm vertically, and expose uniformly fresh-looking rock. At one locality (Muccan), the fractures cross-cut two out of three generations of aboriginal petroglyphs etched into the pavement surface, which suggests that fracture formation occurred both recently and rapidly. All four localities are characterised by extensional structures (tension fractures and dilated joints) striking 020–040°, and three preserve compressional structures (steeply dipping reverse faults at Gallery Hill and North Shaw; A-tent crestal fractures at Mulgandinnah Hill) trending 100–135°. The strongly correlated alignments of the fracture systems militate against a purely weathering-controlled origin, and the observed pattern is compatible with fracture formation in a single East Pilbara-wide stress field, dominated by pure shear and characterised by northeast-southwest- to north-northeast-south-southwest-directed horizontal compression. This orientation is consistent with that derived by spatial averaging of existing stress orientation data from northwest Australia. These preliminary results have exciting implications for the inexpensive field-based determination of regional stress orientation, and for the use of granitic landforms in probabilistic seismic hazard assessment and the identification of earthquake-prone areas.

Black breasts, white milk? Ways of constructing breastfeeding and race in Australia

This article forms part of a larger project I have been writing, and that is to read breastfeeding as a cultural practice, rather than as something natural, innate, or even gendered. As a cultural practice, breastfeeding underwent major changes during the twentieth century, and its frequent presence in contemporary media debates can be read as marking a critical cultural moment in the contestation and renegotiation of social values. In this article I foreground race as another cultural construct which is infused with the negotiation of meanings around breastfeeding and its practice in contemporary Australia. While Patricia Hill Collins argues that feminist theorising about motherhood has often ignored the impact of race and class, which merit special consideration, this project can be fraught for a white academic who either analyses (and thus continues the privileging of) whiteness, or else critiques (and thus perpetuates the otherness of) blackness. I have chosen to take up Jane Haggis and Susanne Schech’s challenge, however, to risk being ‘“bad” feminists whose global manners are always revealed for contestation’. In this article, I recognise the problems with using the term race, which has been used historically to cluster together a disparate range of people under the illusion that they share biological traits which affect their physical and cultural attributes. Race is now understood to be neither biological nor genetic but a social construction, an imaginary concept which is often mobilised as an index of power to bolster white superiority. While the concept of race is metaphorical rather than actual, the history of racism has meant that Indigenous populations have undergone massive deprivation and discrimination. As a white Australian, my knowledge of Indigenous maternal practices can only ever be partial, and in this research I have drawn solely on textual sources which themselves are limited. These sources, however, form the cultural material which represents breastfeeding through particular narratives, and this is what I want to draw attention to in order to trouble some of the dominant discourses around race, Western medicine and breastfeeding practice. I also acknowledge the disparate histories, practices and people that constitute Aboriginals and Torres Strait Islanders over the continent of Australia. The representations I mobilise are in many ways arbitrary, but function strategically to upset prevailing hierarchies of meaning. As a result, they operate as maverick narratives, or coyote discourses as Haraway calls for, in order to shift our vision (or maybe that should be dingo discourses). The article, then, performs a strategic movement of placing representations of Indigenous breastfeeding practices at its centre, inverting the usual direction of knowledge, bodies, maternity, and meanings of breast-feeding which characterise the dominant discourses used by public health and medical professionals. Firstly, however, I briefly trace some of the connections between maternity and nationhood since 1901 as both a colonial and a modernist project.

The role of wild birds in the transmission of avian influenza for Australia: an ecological perspective

Waterbirds, particularly Anatidae, are natural reservoirs for low-pathogenic avian influenza and have been implicated as the primary source of infection in outbreaks of highly pathogenic avian influenza. An understanding of the movements of birds and the ecology of avian influenza viruses within the wild bird population is essential in assessing the risks to human health and production industries. Marked differences in the movements of Australian birds from those of the Northern Hemisphere emphasises the danger of generalising trends of disease prevalence to Australian conditions. Populations of Anatidae in Australia are not migratory, as they are in the Northern Hemisphere, but rather display typical nomadic traits, sometimes moving large distances across continental Australia in response to flooding or drought. There is little known regular interchange of anatids between Australia and Asia. In contrast, species such as shorebirds and some seabirds are annual migrants to Australia along recognised flyways from breeding grounds in the Northern Hemisphere. Movement into Australia by these species mainly occurs into the north-west and along the east coast over the Pacific Ocean. These species primarily arrive during the Australian spring and form large aggregations along the coastline and on inland wetlands. Other Australian migratory species (passerines, bee-eaters, dollar-birds, cuckoos, doves) regularly move to and from Asia through the Torres Strait Islands. The disease status of these birds is unknown. The movements of some species, particularly anatids and ardeids, which have ranges including Australia and regions where the virus is known to occur, have been poorly studied and there is potential for introduction of avian influenza subtypes via this route. Avian influenza viruses are highly unpredictable and can undergo reassortment to more pathogenic forms. There is insufficient knowledge of the epidemiology and transmission of these viruses in Australia and broad-scale surveillance of wild birds is logistically difficult. Long-term studies of anatids that co-habit with Charadriiformes are recommended. This would provide an indication of the spatial and temporal patterns of subtypes entering Australia and improve our understanding of the ecology of endemic viruses. Until such time as these data become available, Australia's preparedness for avian influenza must focus on biosecurity at the wild bird-poultry interface.

Legacy of the ‘Fatal Shore’

Why does the theme of ‘confinement’ link historic-period heritage places across the continent of Australia? This article explores incarceration as not only a dominant theme in heritage-listed and archaeological sites from post-contact Australia, but also as a central underlying element in both Anglo-Australians’ sense of ambiguous difference from their European origins, and indigenous Australians’ painful experiences of engagement with the state. It considers the shared experiences of ‘confinement’ through a wide variety of registered convict, post-convict and indigenous heritage places in order to question how and why this theme has come to hold such a special resonance for different communities within modern Australia. Expanding upon Bruce Trigger’s classic definitions of ‘alternative archaeologies’, the authors suggest this resonance has resulted in the emergence of a post-colonial form of heritage practice within this settler nation.

Molecular systematics of the Acmena alliance (Myrtaceae): phylogenetic analyses and evolutionary implications with reference to Australian taxa

The existence within Australia of several Acmena alliance taxa with morphological features inconsistent with current generic boundaries has meant that phylogenetic assessment of relationships has proved difficult. Sequences of nrDNA from the ITS and ETS regions were obtained for 66 Australian taxa, including representatives from both subfamilies and five genera. The ingroup taxa included 54 Australian endemics and 13 species with distributions that also range outside continental Australia. Parsimony analysis and Bayesian inference of posterior possibilities from the combined molecular datasets do not correlate with the species associations implied by the current taxonomic circumscription of genera: Acmena, Acmenosperma, Anetholea, Syzygium and Waterhousea. The molecular phylogeny recognises five supported lineages within the Acmena alliance, and several novel species associations. The recognition of five species groups indicates a need for a reappraisal of all currently recognised morphological groups within the alliance.

Constrained grid matching of large magnetic databases – the magnetic anomaly grid of Queensland

Unconstrained merging of continental-scale airborne magnetic data into composite grids, which faithfully retain all wavelengths of crustal origin, has traditionally not been an easy task. Geoscience Australia has recently developed a new merging method that aids the solution of this problem, and the software is now commercially available. The method minimises all the differences of the grid boundary overlaps in one process, as an inverse problem. Although this works very successfully, particularly with modern data, edge grids are still difficult to deal with. A much better result can be obtained if the merge is constrained by independent accurate data. Such data are available for continental Australia as a result of the Australia-wide Array of Geomagnetic Stations (AWAGS) experiment in 1990. Concurrent with the AWAGS array two aeromagnetic loops were flown around Australia over several weeks, one well inland, and one closer to the coast. Data acquired along these loops have been diurnally corrected using the array magnetic data, and are now a valuable reference dataset for constrained merging of large areas of magnetic grid data. An example of the value of such constraint is demonstrated for the new magnetic anomaly grid of Queensland. Constrained matching of the data grids reduces magnetic levels in the Cape York Peninsula region by approximately 100 nT. This removes what appears to be an anomalously high area for the region in pseudocolour images of the composite grid.