"December 2006". / Thesis (PhD) -- Macquarie University, Division of Environmental and Life Sciences, Department of Human Geography, 2007. / Bibliography: p. 284-307. / Introduction -- Case-study area profile and methodology -- A walkabout race?: contemporary Aboriginal mobilities in Yamatji country -- State service provision and Aboriginal mobilities -- Security and belonging: re-conceptualising Aboriginal mobilities -- Security and belonging and the mainstream economy -- The ties that bind: negotiating security and belonging through family -- Conclusion. / This dissertation explores contemporary Aboriginal spatial practices in Yamatji country, Western Australia, within the context of rural service provision by the State government. The central themes with which it engages are a) historical and contemporary conceptualisations of Aboriginal spatialities; b) the lived experiences of Aboriginal mobilities in the region; and c) the dialectical, and often contentious, relationship between Aboriginal spatial practices and public health, housing, and education services. Drawing primarily on a range of field interviews, the thesis opens up a discursive space for examining the cultural content and hidden assumptions in constructions of 'appropriate' models of spatial mobility. In taking a policy-oriented focus, it argues that the appropriate provision of basic government services requires a shift away from overly simplistic assumptions and discourses of Aboriginal mobility. Until the often subtle practices of rendering particular Aboriginal mobilities as irrational, deviant, and/or mysterious are challenged and replaced, deep-colonising practices in rural and remote Australia will persist. --The thesis reconceptualises contemporary Aboriginal spatial practices in Yamatji country based upon an examination of dynamics and circumstances that undergird Aboriginal mobilities in the region. With this empirical focus, it argues that Aboriginal spatial practices are fashioned by the processes of procuring, cultivating and contesting a sense of security and belonging. Case study material presented suggests that two primary considerations inform these processes. A post-settlement history of contested alienation from family and country (both sources from which belonging and security were traditionally derived), and a changing engagement with mainstream social and economic institutions, have produced a context in which security and belonging are iteratively derived from a number of sources. Contemporary Aboriginal spatial practices therefore take a complex variety of forms. The thesis concludes that adopting the framework of security and belonging for interpreting contemporary Aboriginal mobilities provides a starting point for engaging more effectively and intentionally with dynamic Aboriginal spatial practices in service delivery policy and practice. / Mode of access: World Wide Web. / x, 320 p. ill., maps

[Truncated abstract. Please see the pdf format for the complete text. Also, formulae and special characters can only be approximated here. Please see the pdf version for an accurate reproduction.] This thesis examines the water use, ecophysiology and hydraulic architecture of Eucalyptus marginata (jarrah) growing on bauxite mine rehabilitation sites in the jarrah forest of south-western Australia. The principal objective was to characterise the key environment and plant-based influences on tree water use, and to better understand the dynamics of water use over a range of spatial and temporal scales in this drought-prone ecosystem. A novel sap flow measurement system (based on the use of the heat pulse method) was developed so that a large number of trees could be monitored concurrently in the field. A validation experiment using potted jarrah saplings showed that rates of sap flow (transpiration) obtained using this system agreed with those obtained gravimetrically. Notably, diurnal patterns of transpiration were measured accurately and with precision using the newly developed heat ratio method. Field studies showed that water stress and water use by jarrah saplings on rehabilitation sites were strongly seasonal: being greatest in summer when it was warm and dry, and least in winter when it was cool and wet. At different times, water use was influenced by soil water availability, vapour pressure deficit (VPD) and plant hydraulic conductance. In some areas, there was evidence of a rapid decline in transpiration in response to dry soil conditions. At the end of summer, most saplings on rehabilitation sites were not water stressed, whereas water status in the forest was poor for small saplings but improved with increasing size. It has been recognised that mature jarrah trees avoid drought by having deep root systems, however, it appears that saplings on rehabilitation sites may have not yet developed functional deep roots, and as such, they may be heavily reliant on moisture stored in surface soil horizons. Simple predictive models of tree water use revealed that stand water use was 74 % of annual rainfall at a high density (leaf area index, LAI = 3.1), high rainfall (1200 mm yr-1) site, and 12 % of rainfall at a low density (LAI = 0.4), low rainfall (600 mm yr-1) site, and that water use increased with stand growth. A controlled field experiment confirmed that: (1) sapling transpiration was restricted as root-zone water availability declined, irrespective of VPD; (2) transpiration was correlated with VPD when water was abundant; and (3) transpiration was limited by soil-to-leaf hydraulic conductance when water was abundant and VPD was high (> 2 kPa). Specifically, transpiration was regulated by stomatal conductance. Large stomatal apertures could sustain high transpiration rates, but stomata were sensitive to hydraulic perturbations caused by soil water deficits and/or high evaporative demand. No other physiological mechanisms conferred immediate resistance to drought. Empirical observations were agreeably linked with a current theory suggesting that stomata regulate transpiration and plant water potential in order to prevent hydraulic dysfunction following a reduction in soil-to-leaf hydraulic conductance. Moreover, it was clear that plant hydraulic capacity determined the pattern and extent of stomatal regulation. Differences in hydraulic capacity across a gradient in water availability were a reflection of differences in root-to-leaf hydraulic conductance, and were possibly related to differences in xylem structure. Saplings on rehabilitation sites had greater hydraulic conductance (by 50 %) and greater leaf-specific rates of transpiration at the high rainfall site (1.5 kg m-2 day1) than at the low rainfall site (0.8 kg m-2 day1) under near optimal conditions. Also, rehabilitation-grown saplings had significantly greater leaf area, leaf area to sapwood area ratios and hydraulic conductance (by 30-50 %) compared to forest-grown saplings, a strong indication that soils in rehabilitation sites contained more water than soils in the forest. Results suggested that: (1) the hydraulic structure and function of saplings growing under the same climatic conditions was determined by soil water availability; (2) drought reduced stomatal conductance and transpiration by reducing whole-tree hydraulic conductance; and (3) saplings growing on open rehabilitation sites utilised more abundant water, light and nutrients than saplings growing in the forest understorey. These findings support a paradigm that trees evolve hydraulic equipment and physiological characteristics suited to the most efficient use of water from a particular spatial and temporal niche in the soil environment.

[Truncated abstract] The expansion of human populations in coastal land margins has resulted in major modifcations to estuarine ecosystems. The use of numerical models as predictive tools for assessing remediation strategies is increasing. However, parameterisation of physical processes, developed mainly through field investigations, is necessary for these models to be reliable and effective management tools. The physical processes in micro–tidal diurnal tidal systems are relatively unknown and the current study examines field measurements obtained from the upper Swan River estuary (Western Australia), a diurnal, partially mixed system during the summer when the freshwater discharge is negligible. The aims of the study were to characterise, temporally and spatially, the dominant physical processes and associated sediment resuspension. Variability at three dominant time-scales were examined: 1) sub–tidal oscillations (∼5 to 10 days) resulting from local and remote forcing; 2) tidal (∼ 24 hours) due to astronomical forcing; and 3) intra-tidal (∼2 to 3 hours) resulting from the interaction between tidal constituents. Circulation in estuaries is widely accepted in the literature to be dominated, in varying proportions, by tidal range, freshwater discharge and gravitational circulation. In the upper Swan River estuary sub–tidal oscillations were responsible for the largest upstream displacement of the salt wedge in the absence of freshwater discharge. Moreover, these sub–tidal fluctuations in water level modified the ‘classic’ estuarine circulation. The dynamics of diurnal tides are largely controlled by the tropic month, which oscillates at a slightly different period to the lunar month, resulting in the spring–neap tidal cycle to be sometimes different from syzygy. The phase lag between the diurnal (O1 + K1) and semi-diurnal (M2 + S2) constituents, at the seasonal time scale cause the maximum tidal range to be near the solstice. Over a 24–hour tidal cycle this phase lag is manifested as an intra–tidal oscillation that occurs on the flood tide. Turbidity events that last ∼1 to 2 hours occur during the intra–tidal oscillation, but are not related to maximum shear stress predicted from the mean flow characteristics. The increases in turbidity during the intra–tidal oscillation is, however, correlated with the near–bed Reynolds fluxes. During the intra–tidal oscillation advection opposes the estuarine circulation in the near–bed region, promoting vertical shear that results in destratifcation of the water column. The turbulent mixing generated at the interface and in the near–bed region coincide with resuspension events. Similar turbidity data have often been disregarded and documented as being ‘spikes’ based on the premise that the mean flow was below a critical level to resuspend sediment. Resuspension events were not simply related to mean processes and may be controlled by turbulent instabilities generated when tidal currents reverse during an intra-tidal oscillation

[Truncated abstract] Kelp beds of South-Western Australia have high alpha (within habitat) diversity, through high species turnover at small spatial scales. The E. radiata canopy has a strong negative influence on the diversity of the understorey through intense interspecific competition for light. Literature suggests that when the competitively dominant species such as E. radiata are physically removed, diversity will increase, as less competitive species become more abundant. Apart from disturbance, evidence suggests that reef topography at the 1-10 m vertical scale also has an influence on the structure of the kelp beds, particularly in reference to relative abundance of canopy algae and species richness of the assemblage. In this thesis, I explore the role of algal assemblage recovery from physical disturbance to maintain high diversity. I also investigate the influence of reef structure (in terms of topography at the 1-10 m vertical scale) on assemblage recovery. This thesis provides a valuable functional explanation for the high diversity observed in South-Western algal assemblages. In addition, it explores the influence of reef topography which has received little attention to date . . . Overall, this thesis argues that the high alpha diversity in algal assemblages of South-Western Australia is due to local scale processes including disturbance and assemblage recovery which generate diversity by the creation of species rich gap states and by phase-shifts during the recovery process, creating a mosaic of different patch types. Assemblage recovery is composed of several processes, including survival of juvenile kelp sporophytes and canopy shading, added to macroalgal diversity through spatial and temporal variation in their outcomes. Reef topography contributed to algal diversity by influencing the processes associated with assemblage recovery through alteration of key physical variables including light levels and water motion.

[Truncated abstract] The prinicipal aim of this thesis was to explore the relationship between 3rd generation cephalosporin antibiotics and hospital-acquired Clostridium difficile-associated diarrhoea (CDAD). This antibiotic class has been implicated in the aetiology of CDAD; therefore restriction of these antibiotics via antibiotic policies represents a potential strategy for prevention and control of CDAD. Successful control of CDAD in hospitals translates to improved quality of care for patients, and a reduction of pressure on hospital resources. Therefore, the objectives of this study were to determine whether 3rd generation cephalosporins were related to CDAD, to evaluate the effect of changes to antibiotic policy on the incidence of CDAD, and to determine the impact of CDAD on patient length of stay and hospital costs. The study was conducted in Sir Charles Gairdner Hospital (SCGH), a public teaching hospital located in Perth, the capital city of the state of Western Australia. Evidence for an association between 3rd generation cephalosporins and CDAD was obtained from studies of ecologic- and individual-level data. A time series analysis of the relationship between monthly consumption of 3rd generation cephalosporins and the incidence of CDAD in SCGH was undertaken covering the period 1994 to 2000. The results demonstrated a positive relationship between the use of 3rd generation cephalosporins and CDAD. A matched case-control study that involved 193 adult inpatients diagnosed with CDAD and 386 adult inpatients without CDAD, selected from the period 1996 to 2000, was conducted. Information was collected on exposure to 3rd generation cephalosporin antibiotics during hospitalisation, as well as exposure to other antibiotics and medications, procedures, and comorbidities. Results from conditional logistic regression analyses found CDAD cases were six times more likely to be exposed to 3rd generation cephalosporins during their admission, prior to the onset of diarrhoea, than controls (adjusted odds ratio [OR] = 6.17, 95% confidence interval [CI] = 1.56-24.37). Approximately one third of CDAD in the study population could be attributed to 3rd generation cephalosporins. CDAD cases were also four times more likely to have been exposed to either amoxicillin-clavulanate or ticarcillin-clavulanate (adjusted OR=4.23, 95% CI=1.81-9.93). In October 1998, an antibiotic policy was introduced at SCGH that restricted the use of ceftriaxone, the 3rd generation cephalosporin most commonly used by the hospital. During 1999 and 2000, the incidence of CDAD halved as ceftriaxone consumption fell in response to this policy. The effect of this policy was demonstrated in the time series model; during the post-policy period the relationship between ceftriaxone and CDAD that was evident prior to the policy was cancelled out. From the individual-level data, obtained from the case-control study, a reduction in the prevalence of exposure to 3rd generation cephalosporins from 11% to 1% accounted for a 30% reduction in the incidence of CDAD. Data from the case-control study was also used to analyse the independent contribution of CDAD to length of stay and admission costs using multiple linear regression

[Truncated abstract. Formulae and special characters can only be approximated here. Please see the pdf version of this abstract for an accurate representation.] The 3.24 Ga Panorama VMS District, located in the Pilbara Craton of Western Australia, is exposed as a cross-section through subvolcanic granite intrusions and a coeval submarine volcanic sequence that hosts Zn-Cu mineralization. The near-complete exposure across the district, the very low metamorphic grade, and the remarkable preservation of primary igneous and volcanic textures provides an unparalleled opportunity to examine the P-T-X-source evolution of a VMS ore-forming system and to assess the role of the subvolcanic intrusions as heat sources and/or metal contributors to the overlying VMS hydrothermal system. Detailed mapping of the Panorama VMS District has revealed seven major vein types related to the VMS hydrothermal system or to the subvolcanic intrusions. (1) Quartz-chalcopyrite veins, hosted in granophyric granite immediately beneath the granite-volcanic contact, formed prior to main stage VMS hydrothermal convection, and were precipitated from mixed H2OCO 2-NaCl-KCl fluids with variable salinities (2.5 to 8.5 wt% NaCl equiv). (2) Quartz-sericite veins, ubiquitous across the top 50m of the volcanic sequence, were formed from an Archean seawater with a salinity of 9.7 to 11.2 wt% NaCl equiv at temperatures of 90° to 135°C. These veins formed synchronous with the regional feldspar-sericite-quartz-ankerite alteration during seawater recharge into the main stage VMS hydrothermal convection cells. (3) Quartz-pyrite veins hosted in granophyric granite, and (4) quartz-carbonate-pyrite veins hosted in andesitebasalt, also formed from relatively unevolved Archean seawater (5.5 to 10.1 wt% NaCl equiv; 150° to 225°C), but during the collapse of the VMS hydrothermal system when cool, unmodified seawater invaded the top of the subvolcanic intrusions. (5) Quartz-topaz-muscovite greisen, (6) quartz-chlorite-chalcopyrite vein greisen, and (7) hydrothermal Cu-Zn-Sn veins are hosted in the subvolcanic intrusions. Primary H2O-NaCl-CaCl2 fluid inclusions in the vein greisens were complex high temperature hypersaline inclusions (up to 590°C and up to 56 wt% NaCl equiv). The H2O-CO2-NaCl fluid inclusions in the Cu-Zn-Sn veins have variable salinities, ranging from 4.9 to 14.1 wt% NaCl equiv, and homogenization temperatures ranging from 160° to 325°C. The hydrothermal quartz veins and magmatic metasomatic phases in the subvolcanic intrusions were formed from a magmatic-hydrothermal fluid that had evolved through wallrock reactions, cooling, and finally mixing with seawater-derived VMS hydrothermal fluids.

[Truncated abstract] Ross River virus (RRV) causes the most common arboviral disease in Australia, with approximately 5000 new cases reported each year, making this virus a major public health concern. The aim of this thesis was to link results from virological, pathogenesis and epidemiological studies to further define RRV disease in the south-west (SW) of Western Australia (WA), a region of endemic and epizootic RRV activity. A crosssectional seroprevalence study was used to show that 7.8 percent of SW communities were seropositive to RRV, comparable to other regions of Australia with similar temperate climates to the SW . . . RRV-specific IgM antibodies were found to persist for at least two years following RRV infection. A murine model was used to conclusively show differences in pathogenesis between RRV genotypes, the SW and northern-eastern (NE) genotypes, which are known to circulate throughout Australia. The SW genotype, unique to the SW of WA induced only poor neutralising antibody production and nonneutralising antibodies after the acute phase of infection. In comparison, the NE genotype which currently predominates in mosquito populations in the SW of WA, induced the most efficient neutralising antibody response and consequently produced the mildest disease in the mouse. These data in the mouse suggest that the infecting genotype will mostly likely influence disease outcome in humans and could at least partially explain why more severe and persistent disease has been reported from the SW of WA. Collectively, results from this thesis provide an important benchmark against which future investigations into BFV and RRV diseases can be measured.

[Truncated abstract] The dibbler, Parantechinus apicalis, is an endangered marsupial that exists on Boullanger, Whitlock and Escape islands off Jurien Bay in Western Australia. The introduced house mouse, Mus domesticus, exists on Boullanger and Whitlock islands, and the King’s skink, Egernia kingii, inhabits Boullanger and Escape islands. The grey-bellied dunnart, Sminthopsis griseoventer, exists on Boullanger Island. Over the last 150 years, the wedge-tailed shearwater, Puffinus pacificus, has colonised the islands to varying degrees. The interaction between dibblers and other island species is not clear. The purpose of this study was to determine the main factors regulating the dynamics of mammals, and in particular dibblers, on the Jurien islands. This was achieved by examining the effect of seabirds, the competitive interactions between species living on the islands, and seasonal changes in the environment. Animals were trapped for a period of 30 months, and their population structure, body condition, longevity, habitat preferences, diet and ecophysiology were examined. The results presented support the theory that by increasing soil nutrient concentrations, burrowing seabirds increase the primary productivity of islands, which has flow on effects to other trophic levels. Densities of seabirds and soil nutrient concentrations were highest on Whitlock Island, intermediate on Escape Island, and lowest on Boullanger Island . . .Thirty-five percent of dibblers on Escape Island were missing their tail or a limb, probably as a result of aggression from King’s skinks. Competition from high numbers of house mice on Boullanger Island, and from high numbers of King’s skinks on Escape Island, may increase the occurrence of male die-off on these islands. The better body condition and greater longevity of dibblers on Whitlock Island, despite high numbers of house mice, suggests that abundant resources are available to sustain both species. This study demonstrates that high densities of seabirds positively affect the population dynamics of mammals on the Jurien islands. Burrowing seabirds appear to influence the dynamics of dibblers more so than competition from house mice or King’s skinks. The findings from this study will assist the Dibbler Recovery Team with future management decisions regarding the viability of dibblers on the Jurien islands, and with decisions regarding the necessity to control house mouse numbers in the presence of native species.

Puccinellia (puccinellia ciliata) and tall wheatgrass (Thinopyrum ponticum) often show ecological zonation in saline landscapes, with puccinellia occurring in less elevated more saline/waterlogged locations, and tall wheatgrass occurring in more elevated less saline/waterlogged locations. The aims of this study were to: (a) characterize the observed ecological zonation at a field site, (b) quantify the effects of variables likely to explain growth differences of the two plants in glasshouse experiments, and (c) identify and compare anatomical and physiological mechanisms that explain these zonation patterns. At an experiment in the field near Kojonup (0522824E, 6244579N), puccinellia was found to colonise the lower more severely salinised and waterlogged zones of the landscape, with tall wheatgrass occupying the higher less affected zones. These differences in zonation were clearly associated with variance in soil salinity and water-table depth. Glasshouse experiments in soil revealed that low pH values, low calcium concentrations and variation in salinity alone did not explain the ecological zonation observed in the field. However, there was a substantial difference in the responses of the two plant species to waterlogging in combination with salinity. Puccinellia grew better under saline waterlogged conditions than tall wheatgrass, which was associated with better regulation of Na+ and K+ under saline/waterlogged conditions than in tall wheatgrass. Under non-saline conditions, waterlogging (hypoxia) decreased shoot weights in puccinellia by 15% and in tall wheatgrass by 20%. Similar growth results were obtained in nutrient solution culture, where waterlogging was simulated by lowering the oxygen in solutions through bubbling with N2 gas. Under saline hypoxic conditions, puccinellia, compared to tall wheatgrass, showed increased growth and maintenance of selectivity of K+ over Na+ across adventitious roots. Solution experiments revealed adaptive traits responsible for conveying better growth and ion maintenance present in puccinellia, but not tall wheatgrass, such as inducement of a barrier to radial oxygen loss in the basal regions of adventitious roots (not previously reported in the literature for puccinellia), formation of root aerenchyma and packing of cortical cells and suberin deposition in hypodermal and endodermal root cell layers. These results should assist in targeting pasture species, and predicting their growth response, in saline and waterlogged landscapes. Further work on examining the genetic material of puccinellia is warranted in order to identify genes that could be transferred into crop plants to convey salt and waterlogging tolerance.

[Truncated abstract] A number of controlled and natural seismic sources are utilised to model the Pwave velocity structure of the southwest of the Yilgarn Craton, Western Australia. The Yilgarn Craton is one of the largest pieces of Archaean crust in the world and is known for its gold and nickel deposits in the east and intraplate seismicity in the west. The aim of the project is to link 2D and 3D models of variations in seismic velocity with the local seismicity and geology. A new set of seismic refraction data, acquired in 25 overlapping deployments between 2002 and 2005, has been processed, picked and analysed using forward modelling. The data comprise two perpendicular traverses of three-component recordings of various delay-fired blasts from local commercial quarries. The data were processed using a variety of techniques. Tests were carried out on a number of data enhancement and picking procedures in order to determine the best method for enhancement of delay-fired data. A new method for automatic phase recognition is presented, where the maximum of the derivative of the rectilinearity of a trace is taken as the first break. Complete shot gathers with first break picks for each seismic source are compiled from the overlapping deployments. ... The starting 3D model was based on the models produced by 2D forward modelling. 14 iterations were carried out and the best-fit 3D model was achieved at the 10th iteration. It is 35% better then the current model used to locate earthquakes in this region. The resultant velocity block model was used to iii construct a density block model. A relative gravity map of the southwest of Yilgarn Craton was made. The results of 2D forward modelling, 3D tomography and forward gravity modelling have been compared and it was found that the HVZ is present in all models. Such a zone has been previously seen on a single seismic refraction profile, but it is the first time, this zone has been mapped in 3D. The gravity high produced by the zone coincides with the gravity high observed in reality. There is strong evidence that suggests that the HVZ forms part of the Archaean terrane boundary within the Yilgarn Craton. The distribution of the local seismicity was then discussed in the framework of the new 3D velocity model. A hypothesis, that the primary control on the seismicity in the study area is rotation of the major horizontal stress orientation, is presented. It is also argued that the secondary control on seismicity in the SWSZ is accommodation of movements along major faults.