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1
Brown, Sarah. "Imagining 'environment' in Australian suburbia : an environmental history of the suburban landscapes of Canberra and Perth, 1946-1996." University of Western Australia. School of Humanities, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0094.
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Australia is a suburban nation. Today, with increasing concern regarding the sustainability of cities, an appreciation of the complexities of Australian suburbia is critical to the debate about urban futures. As a built environment and a cultural phenomenon, the Australian suburbs have inspired considerable scholarly literature. Yet to date, such scholarly work has largely overlooked the changing environmental values and visions of those shaping and residing within suburban landscapes, and the practices through which such values and visions are materialised in the processes of suburban development. Focusing on the post-war suburban landscapes of Canberra and Perth, this thesis centralises the environmental, political and economic forces that have shaped human action to construct suburban spaces, paying particular attention to the extent to which individual understandings and visions of 'environment' have determined the shape and nature of suburban development. Specifically, it examines how those operating within Australias suburbs, including planners, developers, builders, landscape designers and residents have imagined the 'environment', and how such imaginaries have shifted in response to varying spatial, temporal and ideological contexts. Tracing the shifting nature of environmental concern throughout the mid-to-late twentieth century, it argues that despite the somewhat unsustainable nature of Australia's suburban landscapes, the planning and development of such landscapes has long been influenced by and has responded to differing understandings of 'environment', which themselves are the product of changing social, political and economic concerns. In doing so, this thesis challenges a number of perceptions concerning Australian suburbs, environmental awareness and sustainability. In particular, it contests the assumption that environmental concern for Australia's suburban development emerged with the urban consolidation debates of the 1980s and 1990s, and analyses a range of environmental sensibilities not often acknowledged in current histories of Australian environmentalism. By examining, for example, how the deterministic and economic concerns of differing planning bodies, along with the aesthetic and ecological concerns of various planners, are intertwined with the housing and domestic lifestyle preferences of suburban homeowners, this history brings to the fore the often conflicting environmental ideas and practices that arise in the course of suburban development, and provides a more nuanced history of the diversity of environmental sensibilities. In sum, this thesis enhances our understandings of the changing nature of environmental concern and illuminates the complex, still largely misunderstood, environmental ideas and practices that arise in the processes of suburban development.
2
Marshall, Anne. "Ngaparti-ngaparti ecologies of performance in Central Australia : comparative studies in the ecologies of Aboriginal-Australian and European-Australian performances with specific focus on the relationship of context, place, physical environment, and personal experience. /." View thesis, 2001. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20040804.155726/index.html.
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3
Burkett, Danny, and danny burkett@deakin edu au. "Nutrient contribution to hyper-eutrophic wetlands in Perth, Western Australia." Deakin University. School of Life and Environmental Sciences, 2005. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20071115.082506.
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This thesis investigates nutrient contribution to six hyper-eutrophic lakes located within close proximity of each other on the Swan Coastal Plain and 20 kilometres south of the Perth Central Business District, Western Australia. The lakes are located within a mixed land use setting and are under the management of a number of state and local government departments and organisations. These are a number of other lakes on the Swan Coastal Plain for which the majority are less than 3 metres in depth and considered as an expression of the groundwater as their base is below the regional groundwater table throughout most of the year. The limited amount of water quality data available for these six lakes and the surface water and groundwater flowing into them has restricted a thorough understanding of the processes influencing the water quality of the lakes. Various private and public companies and organisations have undertaken studies on some of the individual wetlands and there is a wide difference in scientific opinion as to the major source of the nutrients to those wetlands. These previous studies failed to consider regional surface water and groundwater effects on the nutrient fluxes and they predominantly only investigated single wetland systems. This study attempts for the first time to investigate the regional contribution of nutrients to this system of wetlands existing on the Swan Coastal plain. As such, it also includes new research on the nutrient contribution to some of the remaining wetlands. The research findings indicate that the lake sediments represent a considerable store of nutrients (nitrogen and phosphorus). These sediments in turn control the nutrient status of the lake's water column. Surface water is found to contribute on an event-basis load of nutrients to the lakes whilst the groundwater surprisingly appears to contribute a comparatively low input of nutrients but governs the water depth. Analysis of the regional groundwater shows efficient denitrifying abilities as a result of denitrifying bacteria and the transport is localised. Management recommendations for the remediation of the social and environmental value of the lakes include treatment of the lakes sediments via chemical bonding or atmospheric oxidation; utilising the regional groundwaters denitrifying abilities to treat the surface water via infiltration basins; and investigating the merits of managed or artificial aquifer recharge (MAR).
4
Finnegan, Anthony Maurice. "Teamwork in Australian middle management : a study to investigate attitude of team members, team member effectiveness perception and team environment /." View thesis, 2002. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20031223.095006/index.html.
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Thesis (Ph.D.) -- University of Western Sydney, 2002."Thesis submitted ... in fulfilment of the requirement for the degree of Doctor of Philosophy in the College of Law and Business, University of Western Sydney, NSW, Australia" Bibliography : leaves 186-196.
5
McComas, Magers Robyn. "Interactions in the space of one tree /." View thesis View thesis, 2002. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030331.152733/index.html.
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Borger, Catherine. "The biology and ecology of Salsola australis R.Br. (Chenopodiaceae) in southwest Australian cropping systems." University of Western Australia. School of Plant Biology, 2007. http://theses.library.uwa.edu.au/adt-WU2008.0062.
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Salsola australis is an introduced weed of crop and pasture systems in the Western Australian broad acre cropping and pasture region (wheat-belt). This thesis investigated the classification, biology and ecology of the genus Salsola in southwest Australia, as well as modelling the effectiveness of possible weed control practices. Prior to this research, S. tragus was the only recognised species of the Salsola genus within Australia. However, genetic analysis revealed that four genetically distinct putative taxa of the genus Salsola were found in southwest Australia, none of which were S. tragus. The taxa that is the most prevalent agricultural weed was classified as S. australis, but the other three putative taxa could not be matched to recognised species. All four taxa were diploid (2n = 18), as opposed to tetraploid (2n = 36) S. tragus. Within the agricultural system of southwest Australia, S. australis plants established throughout the year, although the majority of seed production occurred in late summer and autumn. Total seed production (138-7734 seeds per plant) and seed viability (7.6-62.8%) of S. australis were lower than that reported for other agricultural weed species of the Salsola genus. Seed dispersal occurred when the senesced plants broke free of their root system to become mobile. Wind driven plants travelled and shed seed over distances of 1.6 to 1247.2 m. Movement of approximately half the plants was restricted to less than 100 m by entanglement with other S. australis plants within the stand. Some seed was retained on the senesced plants, but the germinability of this seed fell to less than 2% in the two month period following plant senescence (i.e. a decline of 79%). Once seed shed into the soil seed bank, anywhere from 32.3 to 80.7% of the viable seeds germinated in the year following seed production, with the rest remaining dormant or degrading. A model of the life cycle of S. australis based on the population ecology data indicated that the dormant seed bank had very little effect on annual seedling recruitment, but seed dispersal from neighbouring populations had a large impact on population growth rate. Therefore, the most successful weed control measures were those that restricted seed dispersal from neighbouring populations, or those that were applied to all populations in the region rather than to a single population. Weed control techniques applied to a single population, without reducing seed dispersal, could not reduce population size.
7
Wood, Lisa Jane. "Social capital, neighbourhood environments and health : development of measurement tools and exploration of links through qualitative and quantitative research." University of Western Australia. School of Population Health, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0111.
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[Truncated abstract] BACKGROUND This thesis explored the relationship between social capital, sense of community and mental health and wellbeing; and factors that may influence these within the environments in which people live. Area variations in health are well documented and are mirrored in emerging evidence of geographic and neighbourhood variations in social capital. Little is known, however, about the specific facets of the impact of local physical environment on social capital; or about the mechanisms by which these are linked with each other, and with health determinants and outcomes. Despite the recent proliferation of social capital literature and growing research interest within the public health realm, its relationship to mental health and protective factors for mental health have also been relatively unexplored. AIMS The overall aim of this thesis was to explore the potential associations between social capital, health and mental health, and neighbourhood environments. In particular, the thesis considered whether the physical attributes and street network design of neighbourhoods are associated with social capital or particular dimensions of the social capital construct. It also examined the relationship between social capital and demographic and residency factors and pet ownership ... CONCLUSION The combined use of qualitative and quantitative research is a distinguishing feature of this study, and the triangulation of these data has a unique contribution to make to the social capital literature. Studies concerned with the measurement of social capital to date have tended to focus on dimensions pertaining to people’s involvement, perceptions and relationship with others and their community. While these constructs provide insight into what comprises social capital, it is clear that each is in turn influenced by a range of other factors. Elucidating what fosters trust and neighbourly interactions in one community and not in another, and by what mechanisms, is one of many research questions unanswered in the published literature to date. The consideration of measures of social capital that relate to the physical environment is therefore of relevance to the growing research and public policy interest in identifying what might build or restore social capital in communities.
8
Beesley, Leah. "Environmental stability : its role in structuring fish communities and life history strategies in the Fortescue River, Western Australia /." Connect to this title, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0129.
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Baudains, Catherine Mary. "Environmental education in the workplace : inducing voluntary transport behaviour change to decrease single occupant vehicle trips by commuters into the Perth CBD." Access via Murdoch University Digital Theses Project, 2003. http://wwwlib.murdoch.edu.au/adt/browser/view/adt-MU20040310.121357.
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Whitehead, Ayesha L. "The effects of isolation and environmental heterogeneity on intraspecific variation in Calamoecia clitellata, a salt lake-inhabiting copepod." University of Western Australia. School of Animal Biology, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0092.
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[Truncated abstract] This study focussed on how isolation and environmental heterogeneity in salt lakes has influenced intraspecific variation in the calanoid copepod Calamoecia clitellata. Calamoecia clitellata relies on passive vectors for dispersal, and this, coupled with the insular nature of salt lakes, may promote genetic divergence at a molecular level. When contrasting environments are involved, genetic divergence may also occur at the life history level, possibly due to local adaptation. I examined the distribution of genetic variation among 14 populations in Western Australia using molecular genetic markers, and examined variation in life history traits among contrasting environments. To ascertain how isolation had influenced molecular genetic variation, I determined population genetic structure and used a phylogeographic approach to infer the impact of historical events. Environmentally induced variation was also evident in the field, with a switch from subitaneous egg production to resting egg production coinciding with changing environmental conditions. It is proposed that plasticity in life history traits has evolved in response to temporal environmental heterogeneity … It can be concluded that isolation in salt lakes in Western Australia has influenced molecular and phenotypic variation in C. clitellata in contrasting ways. At the molecular level, contemporary and historical isolation have promoted genetic divergence of populations, yet when coupled with environmental heterogeneity, marked phenotype plasticity has arisen. This study raises questions as to whether phenotype plasticity is a widespread phenomena in zooplankton found in temporary saline waters and an adaptive strategy to tolerate marked temporal environmental heterogeneity
11
Georgi, Hans-Teja. "Lithofacies and depositional environments of the upper Goldwyer Formation, central Canning Basin, Western Australia /." Title page, contents and abstract only, 1986. http://web4.library.adelaide.edu.au/theses/09SB/09sbg352.pdf.
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Hardiputra, Bingah Astuti. "Properties of rehabilitated coalmine soils at Collie." University of Western Australia. Soil Science and Plant Nutrition Discipline Group, 2004. http://theses.library.uwa.edu.au/adt-WU2005.0041.
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[Truncated abstract] Many soil properties are involved in supporting the growth of plants and in limiting soil degradation. The present study was carried out to provide a basis for minimising environmental impact by providing a firm understanding of the soil properties that affect plant growth for soils developed from mining waste from the Wesfarmers Premier coalmine at Collie. The purpose of this study was to provide an understanding of the soil materials and to identify the potential interactions between soil properties and plants for soils developed on coalmine materials at the Premier mine, Collie. This research was to identify the nature of the manmade soils so as to determine if soil forming processes are active, to determine soil acidity including pH buffering capacity and the lime requirement of soils, to measure water retention characteristics and soil available water for plant growth, to relate soil properties to possible effects on plant growth, and to identify management strategies to improve soil conditions and overcome plant growth constraints. Seventy-seven manmade horizons from pits in 18 constructed soils, ranging from 9 to 21-years old, were analyzed throughout this study. These samples are classified based on soil depth, layer (topsoil and subsoil), and age of soil since rehabilitation. The methods for doing most of the analyses follow the Australian Soil and Land Survey handbook by Rayment and Higginson (1992). The results are presented quantitatively and soil properties are compared to provide information on pedogenic processes, the extent of soil development, the ability of the soils to resist degradation and to provide an indication of soil parent materials
13
Graham, Tennille. "Economics of protecting road infrastructure from dryland salinity in Western Australia." University of Western Australia. School of Agricultural and Resource Economics, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0207.
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[Truncated abstract] The salinisation of agricultural land, urban infrastructure and natural habitat is a serious and increasing problem in southern Australia. Government funding has been allocated to the problem to attempt to reduce substantial costs associated with degradation of agricultural and non-agricultural assets. Nevertheless, Government funding has been small relative to the size of the problem and therefore expenditure needs to be carefully targeted to interventions that will achieve the greatest net benefits. For intervention to be justified, the level of salinity resulting from private landholder decisions must exceed the level that is optimal from the point of view of society as a whole, and the costs of government intervention must be less than the benefits gained by society. This study aims to identify situations when government intervention is justified to manage dryland salinity that threatens to affect road infrastructure (a public asset). A key gap in the environmental economics literature is research that considers dryland salinity as a pollution that has off-site impacts on public assets. This research developed two hydrological/economic models to achieve this objective. The first was a simple economic model representing external costs from dryland salinity. This model was used to identify those variables that have the biggest impact on the net-benefits possible from government intervention. The second model was a combined hydro/economic model that represents the external costs from dryland salinity on road infrastructure. The hydrological component of the model applied the method of metamodelling to simplify a complex, simulation model to equations that could be easily included in the economic model. The key variables that have the biggest impact on net-benefits of dryland salinity mitigation were the value of the off-site asset and the time lag before the onset of dryland salinity in the absence of intervention. ... In the case study of dryland salinity management in the Date Creek subcatchment of Western Australia, the economics of vegetation-based and engineering strategies were investigated for road infrastructure. In general, the engineering strategies were more economically beneficial than vegetation-based strategies. In the case-study catchment, the cost of dryland salinity affecting roads was low relative to the cost to agricultural land. Nevertheless, some additional change in land management to reduce impacts on roads (beyond the changes justified by agricultural land alone) was found to be optimal in some cases. Reinforcing the results from the simple model, a key factor influencing the economics of dryland salinity management was the urgency of the problem. If costs from dryland salinity were not expected to occur until 30 years or more, the optimal response in the short-term was to do nothing. Overall, the study highlights the need for governments to undertake comprehensive and case-specific analysis before committing resources to the management of dryland salinity affecting roads. There were many scenarios in the modelling analysis where the benefits of interventions would not be sufficient to justify action.
14
Poulter, Rachel. "Investigating the role of soil constraints on the water balance of some annual and perennial systems in a Mediterranean environment." University of Western Australia. Faculty of Agriculture, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0018.
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This thesis compares the in situ water balance of common annual production systems (wheat, lupin, subclover and serradella) with a grazed perennial system (lucerne) at a site in the Avon Catchment, Western Australia. Using a physically-based water balance approach the value of a plant based solution in redressing the hydrological imbalance that has become a feature of much of the dryland agricultural region of Western Australia is investigated. The effectiveness of lucerne in providing greater available storage for buffering large rainfall events, as compared to the annual systems, is illustrated. Continued transpiration following out-of-season rainfall events maintains a larger available storage capacity. In contrast, the annual systems that are fallow over summer only withdrew a small fraction of water by soil evaporation between rainfall events. Under annual systems, the profile moisture store was sequentially increased to the extent that additional increments of rainfall could potentially contribute to deep drainage. A particular focus of this study has been to investigate the presence of soil constraints to root growth, and to assess how these constraints affect the water balance. A site survey indicated the soil penetration resistance was sufficient to impose a physical constraint to root growth. Published literature on the site shows soil acidity is also at a level imposing chemical constraints to root growth. A root growth model “Rootmodel”, for predicting root growth with and without soil constraints is examined in detail as a method for providing root growth parameters for inclusion into the numerical water balance model, SWIM based on Richard’s equation. Functions developed from “Rootmodel” adequately describe the effect of profile limitations to root growth, such as soil strength, moisture availability and temperature. Recommendations are made for inclusion of a growth suppressing function in “rootmodel” based on the chemical limitation of low pH. The effects of soil acidity on the root growth of several species is investigated experimentally and the resultant root data provided a reference point by which the simplified prediction of root growth built into SWIM could be adjusted using a linear reduction function. A similar linear reduction function is also employed to impose a physical constraint in the form of high penetration resistance.
15
au, Pendoley@newton dialix com, and Kellie Lee Pendoley. "Sea Turtles and the Environmental Management of Industrial Activities in North West Western Australia." Murdoch University, 2005. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20060612.120104.
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The nesting demographics of sea turtles using beaches within the Barrow, Lowendal,
Montebello (B-L-M) island complex on the North West Shelf of Western Australia were
examined in the context of their spatial and temporal distribution and potential for
exposure to industrially based artificial light sources. The distribution of overnight turtle
tracks throughout the island complex confirmed high density nesting of Chelonia mydas
(green turtles) on deep, sandy and high energy beaches and Natator depressus
(flatback turtles) on deep, sandy and low energy beaches, while Eretmochelys
imbricata (hawksbill turtle) tracks were most visible on shallow, sandy beaches
adjacent to near shore coral reef habitat. The three species exhibited a summer
nesting peak. Hawksbill turtles commenced nesting in September and continued
through to January, green turtles commenced in November and decreased in March.
Flatback turtles displayed the most constrained nesting season reported to date in
Australia with 86% of the animals visits recorded in December and January only.
Nesting population sizes estimated for the three species suggest that on a national
scale the B-L-M complex is a moderately large green turtle and a large flatback rookery
site. The hawksbill rookery is large on an international scale. While none of the green
turtle nesting beaches fell within a 1.5 km radius of industrially based artificial light
sources an estimated 42% of nesting flatback turtles and 12% of nesting hawksbill
turtles were potentially exposed to these light sources.
Testing of green turtle and hawksbill hatchling response to different wavelengths of
light indicate that hatchlings from the B-L-M region respond to low wavelength much
like hatchlings tested in North America (Witherington 1992a). Flatback hatchlings
displayed a similar preference for low wavelength light however their responses to
discrete light wavelengths between 400 nm and 700 nm suggest that this species may
not discriminate well between wavelengths that lie between 450 nm and 550 nm. This
response may be related to the rapid attenuation of visible light that occurs in the turbid
near shore habitats favoured by this species.
Field based arena studies carried out to investigate hatchling behaviour on nesting
beaches with light types commonly used in industrial settings found green turtle and
flatback hatchlings are significantly attracted to these lights compared to controls.
Lights that emit strongly in the low wavelength range (i.e. metal halide and fluorescent)
caused hatchling misorientation at lower intensities than the test light that emitted
relatively poorly in this range (high pressure sodium vapour). Hawksbill hatchlings
tested in situ under the influence of actual oil and gas onshore and offshore facility
based lighting were disrupted from the most direct line to the ocean by these light
emissions. Emergence fan mapping methods that measure hatchling orientation on
nesting beaches were refined and are proposed as an alternative monitoring tool for
use on beaches that are logistically difficult to access for large scale experimental
orientation studies. The hatchling behaviour was clearly complicated by beach
topography and moon phase.
Satellite tracking of post nesting female green and hawksbill turtles from North West
Shelf rookeries has identified the Western Australian location of migratory corridors and
foraging grounds for these species while Scott Reef turtles migrate from their south
Timor Sea rookery to Northern Territory waters. Green turtle nesting on Barrow Island
and Sandy Island (Scott Reef) forage at feeding grounds 200 1000 km from their
nesting beaches. Hawksbill turtles nesting at Varanus Island and Rosemary Islands
forage at locations 50 450 km from their nesting beaches. While all of the nesting
beaches within the B-L-M island complex are protected under the Barrow-Montebello
Marine Conservation Reserves, the only foraging ground similarly protected is the
Northern Territory foraging ground used by Scott Reef green turtles. None of the
foraging grounds used by North West Shelf green or hawksbill turtles is currently
protected by conservation reserves.
16
Joyce, Sarah Julia. "Demographic, clinical and environmental risk factors for prelabour rupture of membranes in Western Australia." University of Western Australia. School of Population Health, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0126.
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[Truncated abstract] This thesis explores the risk factors and perinatal outcomes associated with prelabour rupture of membranes, with a particular focus on the environmental context. Prelabour rupture of membranes is defined as the rupture of fetal membranes before the onset of labour. It is a relatively common obstetric endpoint, occurring in approximately 8-10% of pregnant women at term (PROM) and in up to 40% of all preterm deliveries (pPROM). Despite the high prevalence of the condition, the biological mechanisms and risk factors, and in particular the role of environmental predictors, behind the development of PROM and pPROM remain largely unclear. A record-based prevalence design was used to analyse a population of 16,229 nulliparous, Caucasian women residing in Perth, Western Australia who gave birth to a single newborn during 2002-2004. Maternal age, socioeconomic status and threatened preterm labour during pregnancy were identified as risk factors for prelabour rupture of membranes. Term PROM was significantly associated with fetal distress (OR 1.19; 95%CI 1.00-1.43) and post-partum haemorrhage (OR 1.99; 95%CI 1.60-2.48). A number of perinatal complications were observed to be associated with the presentation of preterm PROM, including prolapsed cord (OR 13.95; 95%CI 4.57-42.61), ante-partum haemorrhage (OR 3.29; 95%CI 2.20-4.91), post-partum haemorrhage (OR 2.12; 95%CI 1.54-2.91), low birth weight (OR 17.79; 95%CI 13.87-22.82), very low birth weight (OR 20.01; 95%CI 14.12-28.35) and stillbirth (OR 5.42; 95%CI 2.87-10.21). However, the outcomes were similar between pPROM patients and other preterm deliveries, indicating that the complications arose due to the timing of the delivery. In contrast though, the risk factors between the two outcomes varied which may suggest that a different aetiological pathway exists between preterm PROM and other preterm deliveries. The frequency of complications decreased with increasing gestational age at delivery until the pregnancy reached full-term, whereupon an increase in gestational age at delivery resulted in an increased risk of fetal distress and post-partum haemorrhage. This finding is novel and may have important implications for the management of prelabour rupture of membranes, specifically with regard to the relative risks and benefits of expectant management (that is, the patient is admitted to an obstetric facility or hospital and closely monitored) versus planned delivery. ... This study represents the first attempt to investigate the potential associations between environmental risk factors and prelabour rupture of membranes. The results of the thesis provide a substantial contribution to our knowledge on prelabour rupture of membranes, including findings of direct relevance to clinical practice as well as a potentially contributing environmental exposure pathway. These original findings suggest a possible preventative approach to reducing the occurrence and associated morbidity of prelabour rupture of membranes may be feasible, and should be pursued if future research confirms the preliminary findings of this thesis.
17
Pendoley, Kellie Lee. "Sea turtles and the environmental management of industrial activities in North West Western Australia." Pendoley, Kellie Lee (2005) Sea turtles and the environmental management of industrial activities in North West Western Australia. PhD thesis, Murdoch University, 2005. http://researchrepository.murdoch.edu.au/254/.
Full textAbstract:
The nesting demographics of sea turtles using beaches within the Barrow, Lowendal, Montebello (B-L-M) island complex on the North West Shelf of Western Australia were examined in the context of their spatial and temporal distribution and potential for exposure to industrially based artificial light sources. The distribution of overnight turtle tracks throughout the island complex confirmed high density nesting of Chelonia mydas (green turtles) on deep, sandy and high energy beaches and Natator depressus (flatback turtles) on deep, sandy and low energy beaches, while Eretmochelys imbricata (hawksbill turtle) tracks were most visible on shallow, sandy beaches adjacent to near shore coral reef habitat. The three species exhibited a summer nesting peak. Hawksbill turtles commenced nesting in September and continued through to January, green turtles commenced in November and decreased in March. Flatback turtles displayed the most constrained nesting season reported to date in Australia with 86% of the animals visits recorded in December and January only. Nesting population sizes estimated for the three species suggest that on a national scale the B-L-M complex is a moderately large green turtle and a large flatback rookery site. The hawksbill rookery is large on an international scale. While none of the green turtle nesting beaches fell within a 1.5 km radius of industrially based artificial light sources an estimated 42% of nesting flatback turtles and 12% of nesting hawksbill turtles were potentially exposed to these light sources.
Testing of green turtle and hawksbill hatchling response to different wavelengths of light indicate that hatchlings from the B-L-M region respond to low wavelength much like hatchlings tested in North America (Witherington 1992a). Flatback hatchlings displayed a similar preference for low wavelength light however their responses to discrete light wavelengths between 400 nm and 700 nm suggest that this species may not discriminate well between wavelengths that lie between 450 nm and 550 nm. This response may be related to the rapid attenuation of visible light that occurs in the turbid near shore habitats favoured by this species.
Field based arena studies carried out to investigate hatchling behaviour on nesting beaches with light types commonly used in industrial settings found green turtle and flatback hatchlings are significantly attracted to these lights compared to controls. Lights that emit strongly in the low wavelength range (i.e. metal halide and fluorescent) caused hatchling misorientation at lower intensities than the test light that emitted relatively poorly in this range (high pressure sodium vapour). Hawksbill hatchlings tested in situ under the influence of actual oil and gas onshore and offshore facility based lighting were disrupted from the most direct line to the ocean by these light emissions. Emergence fan mapping methods that measure hatchling orientation on nesting beaches were refined and are proposed as an alternative monitoring tool for use on beaches that are logistically difficult to access for large scale experimental orientation studies. The hatchling behaviour was clearly complicated by beach topography and moon phase.
Satellite tracking of post nesting female green and hawksbill turtles from North West Shelf rookeries has identified the Western Australian location of migratory corridors and foraging grounds for these species while Scott Reef turtles migrate from their south Timor Sea rookery to Northern Territory waters. Green turtle nesting on Barrow Island and Sandy Island (Scott Reef) forage at feeding grounds 200 - 1000 km from their nesting beaches. Hawksbill turtles nesting at Varanus Island and Rosemary Islands forage at locations 50 - 450 km from their nesting beaches. While all of the nesting beaches within the B-L-M island complex are protected under the Barrow-Montebello Marine Conservation Reserves, the only foraging ground similarly protected is the Northern Territory foraging ground used by Scott Reef green turtles. None of the foraging grounds used by North West Shelf green or hawksbill turtles is currently protected by conservation reserves.
18
Davis, Jane. "Longing or belonging? : responses to a 'new' land in southern Western Australia 1829-1907." University of Western Australia. History Discipline Group, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0137.
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While it is now well established that many Europeans were delighted with the landscapes they encountered in colonial Australia, the pioneer narrative that portrays colonists as threatened and alienated by a harsh environment and constantly engaged in battles with the land is still powerful in both scholarly and popular writing. This thesis challenges this dominant narrative and demonstrates that in a remarkably short period of time some colonists developed strong connections with, and even affection for, their 'new' place in Western Australia. Using archival materials for twenty-one colonists who settled in five regions across southern Western Australia from the 1830s to the early 1900s, here this complex process of belonging is unravelled and several key questions are posed: what lenses did the colonists utilise to view the land? How did they use and manage the land? How were issues of class, domesticity and gender roles negotiated in their 'new' environment? What connections did they make with the land? And ultimately, to what extent did they feel a sense of belonging in the Colony? I argue that although utilitarian approaches to the land are evident, this was not the only way colonists viewed the land; for example, they often used the picturesque to express delight and charm. Gender roles and ideas of class were modified as men, as well as women, worked in the home and planted flower gardens, and both men and women carried out tasks that in their households in England and Ireland, would have been done by servants. Thus, the demarcation of activities that were traditionally for men, women and servants became less distinct and amplified their connection to place. Boundaries between the colonists' domestic space and the wider environments also became more permeable as women ventured beyond their houses and gardens to explore and journey through the landscapes. The selected colonists had romantic ideas of nature and wilderness, that in the British middle and upper-middle class were associated with being removed from the land, but in colonial Western Australia many of them were intimately engaged with it. Through their interactions with the land and connections they made with their social networks, most of these colonists developed an attachment for their 'new' place and called it home; they belonged there.
19
Nicholson, Lindsay P. "Educational productivity of an open learning environment within the vocational education and training sector in Western Australia." Curtin University of Technology, Faculty of Education, 1997. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=11060.
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Rapid reform in the vocational education and training sector within Australia has driven the need for a more flexible approach to the delivery of education and training. One facet of such flexibility is Open Learning. Currently there is little research on Open Learning within the training sector on which planning decisions can be based.A model of educational productivity (Walberg,1981) has been proposed in the research literature to investigate relationships between key factors such a student antecedents, learning environments and learning outcomes. The Walberg model has been employed in this current study to explore how these factors may be studied in an Open Learning environment and a more Traditional Learning environment within the vocational education and training sector. The research design is a comparative description, utilising techniques from both quantitative and qualitative paradigms.A major aspect of this current study has been to investigate the constructs proposed by Walberg's Productivity Model and source appropriate instruments to measure these constructs. Where the appropriate instruments were not available, a process of instrument development and validation was conducted.The research has identified Walberg's model as being a valid frame of reference within the Vocational Education and Training sector. As expected, significant differences between the Open Learning environment and the Traditional Learning environment were apparent for the measures of Classroom Environment. Of interest, however, was that the productivity factor of Quantity, for students studying in both learning environments, was shown to have a negative relationship with achievement. While small differences were apparent for other factors, generally, the relationship between productivity factors and educational achievement was seen to be similar for both the Open Learning and the ++Traditional Learning environments.The findings of the study should be of significance to a range of people involved in the Open Learning environment, including decision makers in the areas of educational policy, curriculum design and implementation, administration and teaching.
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Lalor, Briony Maree. "An assessment of the recovery of the microbial community in jarrah forest soils after bauxite mining and prescription burning." University of Western Australia. School of Earth and Geographical Sciences, 2009. http://theses.library.uwa.edu.au/adt-WU2010.0037.
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[Truncated abstract] Recovery of soil nutrients, microbial populations and carbon (C) and nitrogen (N) cycling processes are critical to the success of rehabilitation following major ecosystem disturbance. Bauxite mining represents a major ecosystem disturbance to the jarrah (Eucalyptus marginata) forest in the south-west of Western Australia. Mining has created a mosaic of mined areas in various stages of succession surrounded by non-mined forest areas. Initial site preparations within rehabilitation areas such as contour ripping alter soil structure (creation of mound and furrows) and over time also influence the distribution of vegetation and litter. Current performance criteria developed by industry, government and other stakeholders have determined that before post-bauxite mined areas of jarrah forest can be integrated back into normal forest management practises they should be functional and demonstrate resilience to normal forest disturbances such as fire. Furthermore, resilience should be of a manner comparable to non-mined analogue forest sites. Currently little is known of the resilience of microbial communities and C and N cycling in rehabilitation sites to normal forest disturbances such as prescription burning. As such, before rehabilitated jarrah forests can be successfully integrated into broad scale forest management regimes, a more thorough knowledge of the potential impacts of burning practises on the soil microbial community and C and N cycling processes in these systems is required. ... While there are similar rates of C and N cycling the underlying microbial community structure was distinctly different; implying a high degree of functional redundancy with respect to C and N cycling. Differences in the C and N cycling and structure of the microbial communities were likely to be due to differences in soil environmental conditions (i.e. soil alkalinity/acidity, soil moisture) and C substrate availability which influence the physiological status of the microbial community and in turn are related to successional age of the forests. Results also suggest that the measurement of CLPP can be a useful approach for assessment of changes in the functional ability of microbial communities. However, the interpretation of how well these rehabilitation forests have recovered heterotrophic abilities was greatly affected by the methodological approach used (e.g. MicroRespTM or Degens and Harris, 1997). Importantly, results from Chapter 4 and 5 suggested that the effects of a moderate prescription fire on C and N processes, CLPP and microbial community structure of 18 year old rehabilitation forests are likely to be short-lived (< 2 years). Furthermore, the effects of the moderate spring prescription fire were not large enough to decouple C and N cycling processes over the short-term (< 1 years) which suggests that by 18 years of age rehabilitation forests demonstrate comparable functional resilience to a moderate prescription burn.
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Duxbury, M. L. "Implementing a relational worldview : Watershed Torbay, Western Australia - connecting community and place /." Access via Murdoch University Digital Theses Project, 2007. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20080617.132132.
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Siddique, Sharif Rayhan. "Development of policies to ameliorate the environmental impact of cars in Perth City, using the results of a stated preference survey and air pollution modelling." University of Western Australia. Faculty of Business, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0165.
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[Truncated abstract] Air pollution is increasingly perceived to be a serious intangible threat to humanity, with air quality continuing to deteriorate in most urban areas. The main sources of inner city pollution are motor vehicles, which generate emissions from the tail pipe as well as by evaporation. These contain toxic gaseous components which have adverse health effects. The major components are carbon monoxide (CO), nitrogen dioxide (NO2), nitric oxide (NO), sulphur dioxide (SO2), particulates (PM10), and volatile organic compounds (VOC). CO and oxides of nitrogen (NOx) are major emissions from cars. This study focuses on pollutant concentration in Perth city and has sought to develop measures to improve air quality. To estimate concentrations, the study develops air pollution models for CO and NOx; on the basis of the model estimates, effective policy is devised to improve the air quality by managing travel to the city. Two peaks, due to traffic, are observed in hourly CO and NOx concentrations. Unlike traffic, however, the morning peak does not reach the level of the afternoon peak. The reasons for this divergence are assessed and quantified. Separate causal models of hourly concentrations of CO and NOx explain their fluctuations accurately. They take account of the complex effects of the urban street canyon and winds in the city. The angle of incidence of the wind has significant impact on pollution level; a wind flow from the south-west increases pollution and wind from the north-east decreases it. The models have been shown to be equivalent to engineering and scientific models in estimating emission rate in the context of street canyons. However the study models are much more precise in the Perth context. ... The models are used to calculate the marginal effects for all attributes and elasticity for fuel price. In almost all attributes the non-work group is more responsive than the work group. Finally, the SP model results are integrated into an econometric model for the purpose of prediction. The travel behaviour prediction is used to estimate the policy impact on air quality. The benefit from the air quality improvement is reported in terms of life saved. The estimated relationships between probability of death and air pollution determines the number of lives that could be saved under various policy scenarios. A ratio of benefits to the financial and perceived sacrifices by drivers is calculated to compare the effectiveness of the suggested policies. A car size charge policy was found to be the most cost effective measure to ameliorate the environmental impact of cars in Perth, with a morning peak entry time charge being almost as cost effective. The study demonstrates the need for appropriate modelling of air pollution and travel behaviour. It brings together analytical methods at three levels of causality, vehicle to air pollution, charge to travel response, and air pollution to health.
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Collins, Margaret Thora. "Factors affecting the recovery of orchids in a post-mining landscape." University of Western Australia. School of Earth and Geographical Sciences, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0022.
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[Truncated abstract] Currently, Alcoa World Alumina Australia (Alcoa) mines and undertakes procedures to rehabilitate approximately 550 ha of jarrah forest each year at two open-cut bauxite mines in South-West Western Australia. Alcoa aims to establish a self-sustaining jarrah forest ecosystem that maintains the functions of the landscape prior to mining, including biodiversity, on areas that have been mined for bauxite. Indigenous terrestrial orchids form a significant proportion of the indigenous geophytic plant species that either fail to colonise rehabilitated areas or do so very slowly. Terrestrial orchids are considered to be particularly sensitive to competition from weeds and disturbance, which combined with the obligate nature of the orchid-mycorrhizal fungus association suggests that orchids would colonise rehabilitation areas only when both microhabitat sites and soil microflora have established. Occurrence of certain orchids may therefore be expected to be useful as indicators of ecosystem health, the success of vegetation establishment and the recovery of edaphic conditions suitable for orchid mycorrhizal fungi. Vegetation surveys were undertaken to compare orchid species richness and population size of a chrono-sequence of rehabilitation areas with adjacent unmined forest. ... Orchid taxa present in each vegetation assemblage were generally not exclusive to these assemblages, with the following broad exclusions: D. bracteata was found only in species assemblages associated with rehabilitation areas; and Eriochilus sp. and T. crinita were found only in species assemblages associated with unmined forest. No single orchid species appears to be an indicator of ecosystem recovery. However, the presence of populations of C. flava, P. sp. crinkled leaf (G.J.Keighery 13426) or P. recurva in combination with the absence of the disturbance opportunist orchid taxa D. bracteata and M. media appears to be a measure of the maturity of the rehabilitation vegetation. Orchid species richness and clonal orchid population size were correlated with changes in vegetation structure, but apart from the absence of orchids in 1 year old rehabilitation areas, these orchid population characteristics did not show any direct relationship with rehabilitation age or vegetation maturity. Only two orchid taxa appeared to have potential as indicators of vegetation characteristics: T. crinita as an indicator of undisturbed jarrah forest; and D. bracteata as an indicator of disturbed ecosystems. The results of this study suggest that most jarrah forest orchid taxa will readily colonise the post bauxite mining landscape, but that the unassisted colonisation by recalcitrant orchid taxa may be a prolonged process. It is recommended that field-based transplantation and/or seeding trials be undertaken with these recalcitrant taxa to determine if these procedures will enhance recruitment. The results of this work have applications not only in the management of post-mining landscapes but also in vegetation monitoring and conservation work in Western Australia and elsewhere.
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Speldewinde, Peter Christiaan. "Ecosystem health : the relationship between dryland salinity and human health." University of Western Australia. School of Population Health, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0127.
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Australia is experiencing widespread ecosystem degradation, including dryland salinity, erosion and vegetation loss. Approximately 1 million hectares (5.5%) of the south-west agricultural zone of Western Australia is affected by dryland salinity and is predicted to rise to 5.4 million hectares by 2050. Such degradation is associated with many environmental outcomes that may impact on human health, including a decrease in primary productivity, an increase in the number of invasive species, a decrease in the number of large trees, overall decrease in biodiversity, and an increase in dust production. The resulting degradation affects not only farm production but also farm values. This study examines the effects of such severe and widespread environmental degradation on the physical and mental health of residents. Western Australia has an extensive medical record database which links individual health records for all hospital admissions, cancer cases, births and deaths. For the 15 diseases examined in this project, the study area of the south west of Western Australia (excluding the capital city of Perth) contained 1,570,985 morbidity records and 27,627 mortality records for the 15 diseases examined in a population of approximately 460,000. Environmental data were obtained from the Western Australian Department of Agriculture?s soil and landscape mapping database. A spatial Bayesian framework was used to examine associations between these disease and environmental variables. The Bayesian model detected the confounding variables of socio-economic status and proportion of the population identified as Aboriginal or Torres Strait Islander. With the inclusion of these confounders in the model, associations were found between environmental degradation (including dryland salinity) and several diseases with known environmentally-mediated triggers, including asthma, ischaemic heart disease, suicide and depression. However, once records of individuals who had been diagnosed with coexistent depression were removed from the analysis, the effect of dryland salinity was no longer statistically detectable for asthma, ischaemic heart disease or suicide, although the effects of socio-economic status and size of the Aboriginal population remained. The spatial component of this study showed an association between land degradation and human health. These results indicated that such processes are driving the degree of psychological ill-health in these populations, although it remains uncertain whether this 4 is secondary to overall coexisting rural poverty or some other environmental mechanism. To further investigate this complex issue an instrument designed to measure mental health problems in rural communities was developed. Components of the survey included possible triggers for mental health, including environmental factors. The interview was administered in a pilot study through a telephone survey of a small number of farmers in South-Western Australia. Using logistic regression a significant association between the mental health of male farmers and dryland salinity was detected. However, the sample size of the survey was too small to detect any statistically significant associations between dryland salinity and the mental health of women. The results of this study indicate that dryland salinity, as with other examples of ecosystem degradation, is associated with an increased burden of human disease.
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Williams, Mia Gabrielle. "Impact of environmental conditions on the infection behaviour of Western Australian strains of Plasmopara viticola, causal agent of downy mildew in grapevines." University of Western Australia. Soil Science and Plant Nutrition Discipline Group, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0035.
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Downy mildew, caused by the biotrophic Oomycete Plasmopara viticola, is one of the most important diseases of grapevines world wide. It is particularly destructive in temperate viticultural regions that experience warm wet conditions during the vegetative growth of the vine (Wong et al., 2001). The disease is not normally a problem in mediterranean climates where the growing season tends to be hot and dry (Mullins et al., 1992; Sivasithamparam, 1993). Grape downy mildew is however a major disease in Australian viticulture (McLean et al., 1984; Magarey et al., 1991). Grape downy mildew was first reported in Europe in 1878 (Viennot-Bourgin, 1981). In Australia, it was recorded for the first time in 1917 at Rutherglen in Victoria (Vic) (de Castella, 1917). The first recorded outbreak of the disease in Western Australia (WA) occurred in 1997 in a small planting of vines in the far north of the state. In the subsequent year, it was detected in widespread commercial viticulture in the Swan Valley production area, near Perth (McKirdy et al., 1999). The pathogen has since been found in all grape growing regions of WA. Since its introduction into European vineyards in the 1880?s, P. viticola has become one of the world?s most investigated grapevine pathogens. Many aspects its basic biology however remain unknown (Wong et al., 2001). Due to the recent detection of P. viticola in WA, little is known of the nature of strains of the pathogen in the state and their response to local environmental conditions. Much of the research concerning the influence of environmental factors on the development of P. viticola has been conducted in Europe e.g. parts of France and Germany. Due to significant differences in climatic conditions and a shorter selection time on the pathogen in WA, much of the information described in European studies may not be directly applicable to the grape downy mildew disease situation in WA. The focus of this thesis was to examine epidemiological aspects of P. viticola in the mediterranean climate of WA. The environmental conditions that could favour the development of epidemics by strains of the pathogen that have been detected in the state were determined. The existence of P. viticola ecotypes and genetic variation among strains from WA and the Eastern states of Australia was also investigated.
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Bancroft, Wesley J. "Environmental response to burrowing seabird colonies : a study in ecosystem engineering." University of Western Australia. School of Animal Biology, 2004. http://theses.library.uwa.edu.au/adt-WU2005.0064.
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[Truncated abstract] Ecosystem engineers are organisms that physically modify habitat in a manner that modulate resource flows and species within ecosystems. Ecosystem engineering is distinct from classical interactions (competition, predation, parasitism and mutualism) in that it does not involve direct trophic exchange between organisms. The term ‘ecosystem engineer’ is a recently adopted one, and we are just beginning to investigate the occurrence and impact of engineers in ecosystems. My thesis explores the ecosystem engineering actions of Wedge-tailed Shearwaters, Puffinus pacificus, in a Mediterranean island, heathland ecosystem. I have approached this by (1) describing and quantifying the physical impact of these engineers, and (2) describing and quantifying the effects that these actions have on three major ecosystem components: the soil, the vascular plants, and the vertebrate fauna. Wedge-tailed Shearwaters are procellariid seabirds that excavate nesting burrows on offshore islands. The birds are colonial nesters, and on Rottnest Island, 17 km off the mainland coast of south-western Western Australia, their colonies have expanded considerably in recent decades. The expansion fits the trend observed in other tropicalorigin seabirds that breed in south-western Australia. In the last ten years, two new colonies have appeared (in a total of six) and the number of burrows on the island has almost doubled, to 11 745 ± 1320SE. In the same period the area occupied by the birds has increased by almost half ...
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Learnihan, Vincent B. "The physical environment as an influence of walking in the neighbourhood : objective measurement and validation." University of Western Australia. School of Population Health, 2007. http://theses.library.uwa.edu.au/adt-WU2008.0033.
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Over the last decade, there has been rapid growth in research into the influence of the physical environment on physical activity. Previously, individual and social factors dominated research into the influences of physical activity. This new area of study has been built on the understanding that the physical environment may create an opportunity or a barrier to engagement in physical activity behaviours (Sallis & Owen, 1997). This research develops objectively measured features of the physical environment in order to investigate relationships with walking behaviour. Public health research of this nature is still at a preliminary stage, although research expertise outside of public health including transportation, urban planning and geographic information science has much to contribute to this emerging field. This study investigated walking in the neighbourhood in a sample of adults residing in Perth, Western Australia. Objective measurement of the physical environment using Geographic Information Systems (GIS) was conducted including measurement of street connectivity, residential density, land use mix and retail floor area ratio at three different geographic scales (suburb, census collection district, 15 minute walk from a survey participants home). These measures were then combined into an index known as a walkability index and validated against survey participant reported data on walking within the neighbourhood using binary logistic regression. Among other findings, the evidence presented shows that depending on which geographic scale the physical environment is measured at and what type of walking in the neighbourhood is reported, the strength of relationship varies between an objectively measured walkability index and walking behaviour in the neighbourhood. These findings highlight the need to differentiate between walking for transport and walking for recreation, health and exercise when investigating the relationship between physical activity and the environment. These findings also show the importance of geographic scale of measurement in the relationship between physical activity and the physical environment, and the need for current high quality geographic data in this type of research.
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Wood, Dorothy. "The influence of environmental social controls on the capital investment decision-making of the firm : Australian evidence /." View thesis, 2002. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030801.131105/index.html.
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Waddington, Kris Ian. "Diet and trophic role of western rock lobsters (Panulirus cygnus George) in temperate Western Australian deep-coastal ecosystems (35-60m)." University of Western Australia. School of Plant Biology, 2008. http://theses.library.uwa.edu.au/adt-WU2009.0035.
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[Truncated abstract] Removal of consumers through fishing has been shown to influence ecosystem structure and function by changing the biomass and composition of organisms occupying lower trophic levels. The western rock lobster (Panurilus cygnus), an abundant consumer along the temperate west coast of Australia, forms the basis of Australia's largest single species fishery, with catches frequently exceeding 11000 tonnes annually. Despite their high abundance and commercial importance, the diet and trophic role of adult lobster populations in deep-coastal-ecosystems (35-60 m) remains unknown. An understanding of the diet and trophic role of lobsters in these ecosystems is a key component of the assessment of ecosystem effects of the western rock lobster fishery. This study uses gut content and stable isotope analyses to determine the diet and trophic role of lobsters in deep-coastal ecosystems. Dietary analysis indicated adult lobsters in deep-coastal ecosystems were primarily carnivorous with diet reflecting food available on the benthos. Gut content analyses indicate crabs (62 %) and amphipods/isopods (~10 %) are the most important lobster dietary sources. Stable isotope analysis indicates natural diet of lobsters in deep coastal ecosystems is dominated by amphipods/isopods (contributing up to ~50 %) and crabs (to ~75 %), with bivalves/gastropods, red algae and sponges of lesser importance (<10 % of diet each). Diet of lobsters in deep-coastal ecosystems differed from that reported for lobsters inhabiting shallow water ecosystems in this region, reflecting differences in food availability and food choice between these ecosystems. Bait from the fishery was also determined (by stable isotope analyses) to be a significant dietary component of lobsters in deep-coastal ecosystems, contributing between 10 and 80 % of lobster food requirements at some study locations. '...' Given observed effects of organic matter addition in trawl fisheries, and also associated with aquaculture, bait addition is likely to have implications for processes occurring within deep-coastal ecosystems in this region, particularly given its oligotrophic status, most likely by increasing the food available to scavenging species. Removal of lobsters from deep-coastal ecosystems may affect the composition and abundance of lobster prey communities through a reduction in predation pressure. Such effects have been demonstrated for other spiny lobster species. These effects are typically most observable amongst common prey taxa which in other studies have been commonly herbivores. In deep-coastal ecosystems, crabs and amphipods/isopods are the most common prey taxa and most likely to be effected. The ecosystem-impacts of top-down control of non-herbivorous prey species is unknown and constrains the inferences possible from this study. However, the establishment of 'no-take' areas in deep-coastal ecosystems would allow the ecosystem effects of lobster removal to be further assessed in these deep-coastal ecosystems. While data from the current study did not allow the ecosystem effects of lobster removal to be properly assessed, this study provided information regarding the ecology of western rock lobsters in previously unstudied ecosystems.
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Quinn, Matthew J. "Glaucony as an environmental indicator, with examples from the Cretaceous of the Northern Carnarvon Basin, Western Australia /." Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09S.B/09s.bq72.pdf.
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Thesis (B. Sc.(Hons.))--University of Adelaide, National Centre for Petroleum Geology and Geophysics, 1998?Eleven enclosures in six pockets inserted through text. Includes bibliographical references (leaves 52-54).
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Hoyle, Frances Carmen. "The effect of soluble organic carbon substrates, and environmental modulators on soil microbial function and diversity." University of Western Australia. School of Earth and Geographical Sciences, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0050.
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[Truncated abstract] The principal aim of this thesis was to examine the response of the microbial community to the addition of small amounts (<50 μg C g-1 soil) of organic C substrates (‘trigger molecules’) to soil. This addition is comparative to indigenous soluble C concentrations for a range of soil types in Western Australia (typically measured between 20 and 55 μg C g-1 soil). Previously it has been reported that the application of trigger molecules to European soils has caused more CO2-C to be evolved (up to six fold) than was applied . . . Findings from this study indicated that there was an additional CO2 release (i.e. greater than the C added) on application of organic C substrates to some soil treatments. However, findings from this study indicate that the response of the microbial community to small additions of soluble C substrate is not consistent for all soil types and may vary due to greater availability of C, and supports the premise that microbial responses vary in a yet to be predicted manner between soil type and ecosystems. Differences in microbial response to the addition of soluble organic C are likely attributable to differences in soil attributes and environmental factors influencing both the diversity of microbes present and the frequency of food events. Theoretically, trigger molecules could also provide a possible control mechanism for microorganisms in arable farming systems. These mechanisms include stimulating either targeted pathogenic microorganisms that starve after depletion of a suitable substrate; or stimulating beneficial microorganisms to manipulate nutrient cycling, by targeting specific functional groups and altering mineralisation and immobilisation turnover rates.
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Gherardi, Mark James. "Availability and management of manganese and water in bauxite residue revegetation." University of Western Australia. Soil Science and Plant Nutrition Discipline Group, 2004. http://theses.library.uwa.edu.au/adt-WU2005.0038.
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[Truncated abstract] Industrial processing to refine alumina from bauxite ore produces millions of tonnes of refining residue each year in Australia. Revegetation of bauxite residue sand (BRS) is problematic for a number of reasons. Harsh chemical conditions caused by residual NaOH from ore digestion mean plants must overcome extremely high pH (initially >12), saline and sodic conditions. At such high pH, manganese (Mn) is rapidly oxidised from Mn2+ to Mn4+. Plants can take up only Mn2+. Thus, Mn deficiency is common in plants used for direct BRS revegetation, and broadcast Mn fertilisers have low residual value. Added to this, physical conditions of low water-holding capacity and a highly compactable structure make BRS unfavourable for productive plant growth without constant and large inputs of water as well as Mn. However, environmental regulations stipulate that the residue disposal area at Pinjarra, Western Australia, be revegetated to conform with surrounding land uses. The major land use of the area is pasture for grazing stock. Hence, pasture revegetation with minimum requirement for fertiliser and water application is desirable. This thesis investigates a number of avenues with potential for maintaining a productive pasture system on BRS whilst reducing the current level of Mn fertiliser and irrigation input. Emphasis was placed on elucidation of chemical and physical factors affecting Mn availability to plants in BRS
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Szota, Christopher. "Root morphology, photosynthesis, water relations and development of jarrah (Eucalyptus marginata) in response to soil constraints at restores bauxite mines in south-western Australia." University of Western Australia. School of Plant Biology, 2009. http://theses.library.uwa.edu.au/adt-WU2010.0058.
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Bauxite mining is a major activity in the jarrah (Eucalyptus marginata Donn ex Sm.) forest of south-western Australia. After mining, poor tree growth can occur in some areas. This thesis aimed to determine whether soil constraints, including reduced depth and compaction, were responsible for poor tree growth at low-quality restored bauxite mines. In particular, this study determined the response of jarrah root morphology, leaf-scale physiology and growth/development to soil constraints at two contrasting (low-quality and high-quality) restored bauxite-mine sites. Jarrah root excavations at a low-quality restored site revealed that deep-ripping equipment failed to penetrate the cemented lateritic subsoil, causing coarse roots to be restricted to the top 0.5 m of the soil profile, resulting in fewer and smaller jarrah trees. An adjacent area within the same mine pit (high-quality site) had a kaolinitic clay subsoil, which coarse roots were able to penetrate to the average ripping depth of 1.5 m. Impenetrable subsoil prevented development of taproots at the low-quality site, with trees instead producing multiple lateral and sinker roots. Trees in riplines, made by deep-ripping, at the high-quality site accessed the subsoil via a major taproot, while those on crests developed large lateral and sinker roots. Bauxite mining is a major activity in the jarrah (Eucalyptus marginata Donn ex Sm.) forest of south-western Australia. After mining, poor tree growth can occur in some areas. This thesis aimed to determine whether soil constraints, including reduced depth and compaction, were responsible for poor tree growth at low-quality restored bauxite mines. In particular, this study determined the response of jarrah root morphology, leaf-scale physiology and growth/development to soil constraints at two contrasting (low-quality and high-quality) restored bauxite-mine sites. Jarrah root excavations at a low-quality restored site revealed that deep-ripping equipment failed to penetrate the cemented lateritic subsoil, causing coarse roots to be restricted to the top 0.5 m of the soil profile, resulting in fewer and smaller jarrah trees. An adjacent area within the same mine pit (high-quality site) had a kaolinitic clay subsoil, which coarse roots were able to penetrate to the average ripping depth of 1.5 m. Impenetrable subsoil prevented development of taproots at the low-quality site, with trees instead producing multiple lateral and sinker roots. Trees in riplines, made by deep-ripping, at the high-quality site accessed the subsoil via a major taproot, while those on crests developed large lateral and sinker roots.
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Smith, Brett. "The late quaternary history of Southern hemisphere mediterranean climate regions in the Western Cape, South Africa, and Southwestern Australia." Doctoral thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/12162.
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Includes abstract.Includes bibliographical references (leaves 215-241).
The study is focused on four study sites, two in the Western Cape, namely the Bruno section and Lake Michelle and two in southwestern Australia, namely Wambellup Swamp and Devil's Pool. These sites were chosen as they are well situated to investigate the complex interaction between Late Quaternary climate change, the influence of fluctuating sea levels and the impact of human interaction with the environments in question and provide a regional picture of these interactions.
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Fowle, Kenneth. "The use of computer graphics and visualisation (from reconstruction to training) for the resource sector of Western Australia." Thesis, University of Nottingham, 2003. http://eprints.nottingham.ac.uk/10044/.
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The minerals and energy sector can rightly be classified as comprising an extremely hazardous working environment in which numerous situations exist for accidents and incidents involving personnel and equipment to occur. Accidents are often explained by what are referred to as 'human factor'. The often used explanation, 'technical-failure', gives the impression that technology lives a life of its own without human intervention. However, technical failure often occurs because of human errors in construction, installation, maintenance or operation. It is the person who triggers the risks who is made morally (and sometime legally) responsible. When an operator makes a mistake (an active error) he or she is personally blamed. When a designer or constructor makes a mistake, or when cheap or inferior equipment is bought, or when maintenance is faulty, the responsibility is depersonalised and it becomes a 'technology' fault (Sunderstrom-Frisk, 1998). This research examines ways of using expert information using computer graphics and visualisation to produce visual applications that demonstrate and explain, but also have the added ability to teach the user or viewer, with the intent to assess their competency. Today's technology provides educators, students, professional bodies and the general public access to large amounts of information in a visual form. We repackage technical literature and data as movies and videos for audiences to view, instead of reading the information. Understanding may be achieved rapidly instead of taking days, weeks or months. From a visual presentation the viewers absorb information, which is easy to retain. The reconstructions discussed in this research concern the minerals and energy sector of Western Australia. They not only show what went wrong but can also be customised to demonstrate how to prevent an accident/incident. The benefits of this to industry is primarily: the ability to reuse the reconstruction instead of closing down a production line that cost the company and industry many thousands of dollars, and no lives are exposed to hazardous environments while examining the reconstruction for investigation or training purposes.
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O'Brien, R. Christopher. "Forensic animal necrophagy in the South-West of Western Australia : species, feeding patterns and taphonomic effects." University of Western Australia. School of Anatomy and Human Biology, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0195.
Full textAbstract:
[Truncated abstract] One of the standard ways of assessing time since death is from the stages of decomposition of the body. It is well known that the rate of decomposition is affected by environmental factors such as temperature and humidity. Another factor that can affect decompositional rates is the presence of breaches in the protective barrier of the skin, whether arising from antemortem injury or postmortem damage, including that occurring from animal necrophagy. Scavengers have the potential to affect decomposition by breaching the skin allowing access to associated insect material, feeding on the maggot masses, or by consumption of the carcass itself. Each locality will have its own set of features determining the rate of decomposition of the body, and variation may occur within localities based on the seasons. Such variation implies the need for local calibration of time since death against degree of decomposition and to establish the magnitude of interseasonal variation. When the localities are outdoors, the influence of potential scavengers, and the factors affecting their activity need also to be taken into account. This study investigates the interaction of environmental factors and animal scavenging on the rate of decomposition of pig (Sus scrofa) carcasses at four south-west Western Australia sites; Jandakot, Shenton Park, Perup Forest, and Watheroo National Park. Jandakot and Shenton Park are both close to the Perth metropolitan area and the western coast while Perup Forest is southern and inland and Watheroo is northern and inland. ... The most common insectivore feeding in relation to the carcasses was the Willie Wagtail (Rhipidura leucophrys) which was associated with the carcasses in all seasons and all locations except for Perup Forest. The breeding cycle appeared to have a marked influence on the intensity of scavenging by several species. The effect of season on decompositional rates was greatly reduced in carcasses that were exposed to scavenging. It took no additional time for carcasses to achieve skeletonization in winter than in the other seasons in the presence of scavenging. Scavenging had no significant impact on the rate of breakdown of carcasses in summer, when decompositional rates were greatest and scavenging at a minimum. v In Western Australia, it is not uncommon for bodies to remain undiscovered in bush environments for lengthy periods of time due to the low human population density. This study shows conclusively that it is not sufficient simply to consider the accumulated degree day (ADD) when estimating time since death by the degree of decomposition of the body. Attention must also be given to local wildlife assemblages and variations in their activities with the seasons. The implications of this research are in the determination of time of death. If the effects of scavengers accelerate decomposition this must be taken into account when any calculation since time of death is determined. The marked variations between sites in the rates of decomposition of carcasses exposed to natural animal scavenging in this study highlights the need for local calibration of time since death to decompositional stages for all locales. The techniques devised in this study are straight forward and easily conducted yet are informative and essential in determining time since death for bodies which have been exposed to animal scavenging.
37
Kendall, Garth Edward. "Children in families in communities : a modified conceptual framework and an analytic strategy for identifying patterns of factors associated with developmental health outcomes in childhood." University of Western Australia. School of Paediatrics and Child Health, 2003. http://theses.library.uwa.edu.au/adt-WU2004.0006.
Full textAbstract:
Mental health reflects an array of causal influences that span biological, psychological, and social circumstances, with resultant underlying causal pathways to poor mental health outcomes in childhood that are complex. Key features of this complexity are reciprocal interactions between person and environment that take place over time. The core of this thesis seeks to attend to the complexity of development to move the field of developmental health forward toward greater explanation, and more successful prediction and prevention. The focal point of the thesis is the psychosocial determinants of childhood mental health, the resource domain of the developing child, and the interplay between characteristics of the individual child, the family, and the community. The eventual goal is to better understand why and how socioeconomic circumstances impact on developmental health. One component of this thesis focuses on the expansion of extant developmental theory. The other component focuses on the development of an analytic strategy that more appropriately reflects the intricacies of this theoretical expansion. In the process, data are analysed, principally as a heuristic strategy, to illustrate the analytical approach needed to support the theoretical framework. The specification of a bioecological conceptual framework suitable to guide research and policy in developmental health is the first principal objective of the thesis. A critical examination of the resource framework proposed by Brooks-Gunn, Brown, Duncan, and Anderson Moore (1995) reveals it to be centred on family and community resources, but otherwise silent with respect to the physical and psychological resources of the child. The quintessential point of this thesis is that theory in developmental health must be able to account for the contribution individuals make to their own development. A modified resource framework is proposed that acknowledges financial, physical, human, and social capital, within the domains of the individual child, the family, and the community. The second principal objective of the thesis, the development of analytical methods that focus on the individual child and the complexity of data generated by this theoretical approach, is then introduced. Theory and method are thus integrated when comprehensive measures of characteristics in multiple domains across developmental periods are modeled using longitudinal data from the Western Australian Pregnancy Cohort (Raine) Study (Newnham, Evans, Michael, Stanley, & Landau, 1993). The mothers of 2,860 children were enrolled at 18 weeks in pregnancy and the children have been followed at birth, one, two, three, five, and eight years of age. Eighty-nine per cent (2,537 /2,860) of families were available for follow-up at eight and 74 per cent (2,126/2,860) of families responded. Extensive demographic, psychological, and developmental data were available for the children and their families and a limited amount of data were available for the communities in which they reside. A measure of mental health morbidity, the Child Behaviour Checklist (Achenbach, 1991), was available for the children at two, five, and eight years of age. In the first instance, dichotomous summary variables are derived for the demographic, psychological, and developmental variables of interest. Variables are then selected for inclusion in one of several explanatory models. To create a mathematical representation of resource characteristics, the information for each child is concatenated as a series of binary strings. Frequency tabulation is then used to aggregate the data and odds ratios are calculated to determine the degree of risk associated with each string of code, or pattern of factors relative to a nominated mental health outcome. The results provided a scaffold from which this theoretical and analytical approach is compared and contrasted with the reviewed literature. Two principal themes of investigation are pursued. The first theme to be examined is the interplay between characteristics of the child, family, and community and the contribution children make to their own development. The specific approach models the interaction between selected characteristics of the child, family and community in each of four developmentally significant time periods. The theoretical position adopted in the present study suggests that the effect of any personal or contextual factor on later development, if a relationship does truly exist, is most likely to be differential. That is, it is a combination of influences that determines developmental outcomes for children, not any single factor acting independently. The modelling process demonstrates that, for the children involved, personal and contextual factors impact mental health differentially depending on various other individual, family and/or community characteristics. The modelling process identifies patterns of factors that impact relatively small, but significant, numbers of children because the models focus on the effect for individual children rather than the effect for the group. For example, one model suggests that the effect of intra-uterine growth restriction for the group as a whole may be minimal, but the impact for some children could be critical depending on the combination of family and community influences, such as the mothers level of education, the family’s experience of significant life stress, and residence in a relatively disadvantaged community. The second theme to be examined is the possibility that the accumulation of resource deficits or risk characteristics, over time, amplifies the likelihood of mental health problems in childhood. The approach models selected characteristics of the child in each of the four periods of development collectively, and it also models selected characteristics spanning each of the four time periods discretely. The results suggest that latency, pathway, and recency effects may operate simultaneously, and that timing and accumulated burden may both be important determinants of risk. For example, with regard to children whose family experienced life stress, these three effects operated in a systematic way to increase the degree of risk of a mental health problem. In summary, the aggregation of data at the individual level is a productive approach in seeking to explain population level social phenomena. While seemingly paradoxical, the identification of the joint, interactive effects between individual, family, and community characteristics, better allows for the quantification of family and community characteristics operating through multiple causal pathways.
38
Price, Gary Norman. "Assessing the growth performance of European olive (Olea europea L.) on Mount Weld pastoral station." Curtin University of Technology, Department of Environmental Biology, 2006. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=17424.
Full textAbstract:
This thesis describes the growth of European olive (Olea europaea L.) at three different trial sites located near Laverton, in the north-eastern Goldfields region of Western Australia. The local region comprises part ofthe rangelands area of Australia and has a semi-arid climate. The initial reason for planting olives was indirectly related to the rapid decrease in the local population and the economic downturn that resulted within that community during the late 1990's. This prompted an investigation into other possibilities for economic diversity for remote communities such as Laverton, which are located in the rangelands area of Australia. In Australia, much of the southern and eastern areas of the country have similar climate to traditional olive growing areas in Europe. [n the rangelands however, the environment is different to most other areas in the world where olive trees are grown and there is a notable absence of a commercial olive industry. Whilst locally, individual trees were also observed to be growing well and fruiting abundantly, it is not known whether it is possible to grow olive trees successfully on a commercial scale. Two preliminary trials were established in an ad-hoc manner, to examine whether olive trees could be grown successfully in the rangelands environment. Eighty-eight trees of 5 different cultivars were planted on a shallow, clay soil profile at the first trial site. Ninety-eight trees of 11 different cultivar were planted on a deep sand soil profile at the second site. Higher mortality rate occurred at the first site, with most tree deaths being recorded in the first two years. Peak growth of branch tips occurred during the spring-summer seasons at both sites. Differences in trial design and timing of planting prevented statistical comparison of growth performance between sites however.A third olive trial, consisting of 3 olive groves was established according to randomised design. In the north and middle groves, 54 trees of 3 different cultivar were planted on a deep alluvial soil profile. In the south grove, 53 trees of 3 different cultivar were planted on a shallow clay soil profile. High mortality rates were recorded at all 3 groves during the first year, as a result of high salinity levels in irrigation water during the establishment period. Overall, most tree mortality was recorded at the south grove. Significantly higher growth performance occurred within the deeper alluvial soil profile at the north and middle groves, compared to the shallow clay soil profile in the south grove. Negligible olive fruit production occurred at the first site. At the second site, small quantities of olive fruit were produced during some seasons only. No olive fruit production occurred at any grove at the randomized site. Successful fruit formation appears directly related to tree health, as a function of water supply. Ripening of olive fruit occurred earlier than at other more temperate olive growing areas of Australia. Similar major and trace element deficiencies occurred at all sites, interpreted to be a function of universal alkaline ground-water conditions.
This study failed to confirm conclusively, whether European olive could be grown successfully in the semi-arid climate, typical of much of the rangelands area of Australia. As a result of the study however, successful growth in this environment is confirmed to be highly dependent on three factors. Firstly, availability of reliable irrigation waters of sufficient quality. Secondly, choice of suitable soil types. Thirdly, selection of suitable cultivars. Quality of olive oil produced from fruit appears to be influenced by local climatic factors The study also highlighted the issues of land tenure, current management attitudes and level of support within the local community as having a direct and significant impact on the trial.
39
Prow, Natalie A. "Epidemiology of Ross River virus in the south-west of Western Australia and an assessment of genotype involvement in Ross River virus pathogenesis." University of Western Australia. Microbiology and Immunology Discipline Group, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0132.
Full textAbstract:
[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.
40
Wu, Jiale. "Environmental factors affecting the survival and growth of western king prawn, Penaeus latisulcatus, under aquaculture conditions in Spencer Gulf, South Australia." Title page, table of contents and summary only, 1990. http://web4.library.adelaide.edu.au/theses/09ENV/09envw959.pdf.
Full text
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Prananto, Agnes Kristina. "The use of remotely sensed data to analyse spatial and temporal trends in vegetation patchiness within rehabilitated bauxite mines in the Darling Range, W.A." University of Western Australia. School of Earth and Geographical Sciences, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0012.
Full textAbstract:
[Truncated abstract] The assessment of rehabilitation success is time consuming and costly for bauxite miners because large areas of land (~550 ha per year) are involved. In some cases, rehabilitation results in patches of bare or sparsely vegetated soil. This study uses remote sensing imagery to evaluate the growth of vegetation in rehabilitated bauxite mines in the Darling Range, W.A. This work has five aims, which are to (1) compare vegetation biomass within rehabilitated areas and nearby native forest; (2) analyse temporal changes in vegetation growth within the selected rehabilitated areas, in particular rehabilitated areas with patches of bare soil; (3) compare vegetation growth pre- and post- mining; (4) identify the best type of remotely sensed data for this particular study area, and (5) develop an index, which can classify the degree of vegetation patchiness within rehabilitated mine sites. This information will enable rehabilitation workers to identify patches in rehabilitated areas that may require further remediation. The study used RADARSAT, nine years of Normalised Difference Vegetation Index (NDVI) maps (extracted from LANDSAT TM multivariate imagery and Quickbird imagery) and aerial photographs to evaluate forty-seven ~1 ha study sites. Image and map analyses were conducted mainly using ESRI’s software ArcGIS 8.3 and ER Mapper 6.4. Ground truthing was carried out to confirm and recognise the causes of bare patches within the rehabilitated mine sites ... The results indicate that differences in rehabilitation management do not affect this index but the extent of bare patches does. Due to the sensitivity of radar imagery to surface roughness, rehabilitated areas cannot be distinguished from the native forest using radar images. A building (crusher) appears to be the same as mature vegetation. Knowledge of the features in an area is therefore crucial when utilising RADARSAT. The beam elevation angle and profile of the RADARSAT image used, made superimposition of radar and optical imageries impossible. Speckle noise in RADARSAT images made it impossible to detect relatively small bare patches. In addition, the many cloud free days in Western Australia make optical imaging possible so that the ability of radar imagery to penetrate cloud is redundant for this type of study.
42
au, rhoddell@central murdoch edu, and Richard James Hoddell. "A mtDNA study of aspects of the recent evolutionary history and phylogeographic structure of selected teleosts in coastal environments of south-western Australia." Murdoch University, 2003. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20070831.162328.
Full textAbstract:
At present, there is a general lack of information regarding the spatial genetic
architecture and genetic diversity of estuarine and coastal freshwater fish in
Australia or about the interacting intrinsic, extrinsic and historical influences
responsible for sculpting these patterns. This thesis represented the first
investigation of the phylogeographic structure and recent evolutionary histories
of teleost fishes from the coastal and estuarine environments of south-western
Australia, using the resolution afforded by mtDNA sequence data. Available
evidence indicated that, to different degrees, these species have limited
potential for dispersal amongst local assemblages from different water bodies.
As this theoretically reduces the confounding effects of recent gene flow on
extant genetic structure, these fishes were well suited to studying the
influences of historical factors. Historical influences were expected to be
particularly profound, given that these coastal environments underwent
massive modifications during Late Quaternary eustatic fluctuations.
The thesis consists of four major components, which explored different
aspects of interspecific and intraspecific phylogeny and p hylogeograp hy of
three teleost species, based on mtDNA control region and cytochrome b
fragments. First, the relationship between the endemic, 'strictly estuarine'
Leptatherina wallacei (Atherinidae) and the more widespread, 'estuarine &
marine' 6. presbyteroides was examined, with a view to establishing whether
6. wallacei represents a monophyletic or polyphyletic lineage and whether this
species was derived recently (i.e. in Holocene estuaries). Second, the
phylogeographic structure and genetic diversity of L. wallacei were investigated and compared with data from L. presbyteroides, with a view to
using this information to interpret the recent evolutionary histories of each
congener. Third, the divergence between assemblages of L. wallacei
inhabiting two isolated coastal lakes was used to estimate a maximal
substitution rate for the control region, which was then used to infer general
time frames for the divergence between the two Leptatherina species and
between the major phylogeographic partitions within each species. Fourth,
investigations were initiated into phylogeographic patterns and levels of
genetic diversity within and among assemblages of Pseudogobius olorum
(Gobiidae) from several coastal lakes and an estuary.
Phylogenetic analyses indicated that the two Leptatherina species were
characterised by exclusive and reciprocally-monophyletic lineages of
haplotypes from both mtDNA regions, supporting the monophyletic origins of
L. wallacei. Both 6. wallacei and 6. presbyteroides exhibited high levels of
genetic diversity and extensive overall subdivision (e.g. Qsr = 0.691 & 0.644
respectively for control region data). There was a profound phylogeographic
break in both species between all conspecific assemblages from the lower
west coast (LWC phylogroup) and all those from the south coast (SC
phylogroup), which suggested the influences of shared extrinsic and/or
historical factors. There was limited genetic structuring within the two major
phylogroups of either Leptatherina species, apparently reflecting recent
connectivity amongst local assemblages, with subsequent fragmentation and
insufficient time for lineage sorting. However, two major phylogeographic
breaks distinguished monophyletic control region phylogroups of L. wallacei from the isolated coastal Lake Clifton and Lake Walyungup, consistent with
their independent evolution following lacustrine entrapment during the
Holocene.
The divergence between these two isolated lacustrine assemblages of
Leptatherina wallaceiformed the basis for an estimate of the maximal
substitution rate of the control region. While these data were unable to
provide a precise estimate of the actual rate of molecular evolution, all the
evidence suggested that it was proceeding very rapidly. The maximal rate
estimate of 172.3% lineage-' MY-' was among the fastest ever reported.
Based on this rate, the two Leptatherina species diverged at least 1 SKya, thus
rejecting a Holocene origin for L. wallacei. The divergence between the LWC
and SC phylogroups of L. wallacei has been ongoing for at least GKya, while
the equivalent divergence in L. presbyteroides has been ongoing for at least
11 Kya. As the time frames of these divergences were consistent with periods
of massive environmental modifications associated with the end-Pleistocene
fall in sea level and the HMT, it was likely that these factors have played
important roles in sculpting the species' divergence and intra-specific genetic
structure. Although useful in temporally scaling genetic divergences within
and between the two Leptatherina species, wider application of this rate
estimate to questions regarding other taxa was limited. For example, evident
rate heterogeneity between the genera precluded its use with even the
relatively closely-related atherinid Atherinosoma elongafa.
Phylogeographic analyses identified high levels of genetic diversity and
extensive genetic subdivision (e.g. st = 0.652 for control region) amongst an
estuarine and several lacustrine assemblages of Pseudogobius olorum,
although phylogeographic structure was shallower than in either Leptatherina
species. There was increased divergence between three assemblages from
the lower west coast and two from the south coast, consistent with the
profound break evident in the Leptatherina. One lacustrine assemblage
appeared to represent a distinct lineage and a preliminary maximal rate
estimate (~61.4% lineage-1 MY-1) was calculated based on the minimum
divergence of this assemblage from its nearest conspecifics. Although slower
than the rate calculated for L. wallacei, this was still high for teleost fishes.
Overall, this study indicated that historical environmental factors, especially
those related to Quaternary eustatic changes, have played important roles in
sculpting the phylogeography and evolution of three teleost species from
south-western Australia. Moreover, as these species have differential
dependencies on estuarine environments (is. 'strictly estuarine' vs 'estuarine
& marine') and represented two different taxonomic groups (i.e. Atherinoidei &
Gobioidei), historical environmental factors may have exerted similar
influences on other coastal species in the region.
43
Hoddell, Richard James. "A mtDNA study of aspects of the recent evolutionary history and phylogeographic structure of selected teleosts in coastal environments of south-western Australia." Hoddell, Richard James (2003) A mtDNA study of aspects of the recent evolutionary history and phylogeographic structure of selected teleosts in coastal environments of south-western Australia. PhD thesis, Murdoch University, 2003. http://researchrepository.murdoch.edu.au/99/.
Full textAbstract:
At present, there is a general lack of information regarding the spatial genetic architecture and genetic diversity of estuarine and coastal freshwater fish in Australia or about the interacting intrinsic, extrinsic and historical influences responsible for sculpting these patterns. This thesis represented the first investigation of the phylogeographic structure and recent evolutionary histories of teleost fishes from the coastal and estuarine environments of south-western Australia, using the resolution afforded by mtDNA sequence data. Available evidence indicated that, to different degrees, these species have limited potential for dispersal amongst local assemblages from different water bodies. As this theoretically reduces the confounding effects of recent gene flow on extant genetic structure, these fishes were well suited to studying the influences of historical factors. Historical influences were expected to be particularly profound, given that these coastal environments underwent massive modifications during Late Quaternary eustatic fluctuations.
The thesis consists of four major components, which explored different aspects of interspecific and intraspecific phylogeny and p hylogeograp hy of three teleost species, based on mtDNA control region and cytochrome b fragments. First, the relationship between the endemic, 'strictly estuarine' Leptatherina wallacei (Atherinidae) and the more widespread, 'estuarine and marine' 6. presbyteroides was examined, with a view to establishing whether 6. wallacei represents a monophyletic or polyphyletic lineage and whether this species was derived recently (i.e. in Holocene estuaries). Second, the phylogeographic structure and genetic diversity of L. wallacei were investigated and compared with data from L. presbyteroides, with a view to using this information to interpret the recent evolutionary histories of each congener. Third, the divergence between assemblages of L. wallacei inhabiting two isolated coastal lakes was used to estimate a maximal substitution rate for the control region, which was then used to infer general time frames for the divergence between the two Leptatherina species and between the major phylogeographic partitions within each species. Fourth, investigations were initiated into phylogeographic patterns and levels of genetic diversity within and among assemblages of Pseudogobius olorum (Gobiidae) from several coastal lakes and an estuary.
Phylogenetic analyses indicated that the two Leptatherina species were characterised by exclusive and reciprocally-monophyletic lineages of aplotypes from both mtDNA regions, supporting the monophyletic origins of L. wallacei. Both 6. wallacei and 6. presbyteroides exhibited high levels of genetic diversity and extensive overall subdivision (e.g. Qsr = 0.691 and 0.644 respectively for control region data). There was a profound phylogeographic break in both species between all conspecific assemblages from the lower west coast (LWC phylogroup) and all those from the south coast (SC phylogroup), which suggested the influences of shared extrinsic and/or historical factors. There was limited genetic structuring within the two major phylogroups of either Leptatherina species, apparently reflecting recent connectivity amongst local assemblages, with subsequent fragmentation and insufficient time for lineage sorting. However, two major phylogeographic breaks distinguished monophyletic control region phylogroups of L. wallacei from the isolated coastal Lake Clifton and Lake Walyungup, consistent with their independent evolution following lacustrine entrapment during the Holocene.
The divergence between these two isolated lacustrine assemblages of Leptatherina wallaceiformed the basis for an estimate of the maximal substitution rate of the control region. While these data were unable to provide a precise estimate of the actual rate of molecular evolution, all the evidence suggested that it was proceeding very rapidly. The maximal rate estimate of 172.3% lineage-' MY-' was among the fastest ever reported. Based on this rate, the two Leptatherina species diverged at least 1 SKya, thus rejecting a Holocene origin for L. wallacei. The divergence between the LWC and SC phylogroups of L. wallacei has been ongoing for at least GKya, while the equivalent divergence in L. presbyteroides has been ongoing for at least 11 Kya. As the time frames of these divergences were consistent with periods of massive environmental modifications associated with the end-Pleistocene fall in sea level and the HMT, it was likely that these factors have played important roles in sculpting the species' divergence and intra-specific genetic structure. Although useful in temporally scaling genetic divergences within and between the two Leptatherina species, wider application of this rate estimate to questions regarding other taxa was limited. For example, evident rate heterogeneity between the genera precluded its use with even the relatively closely-related atherinid Atherinosoma elongafa.
Phylogeographic analyses identified high levels of genetic diversity and extensive genetic subdivision (e.g. st = 0.652 for control region) amongst an estuarine and several lacustrine assemblages of Pseudogobius olorum, although phylogeographic structure was shallower than in either Leptatherina species. There was increased divergence between three assemblages from the lower west coast and two from the south coast, consistent with the profound break evident in the Leptatherina. One lacustrine assemblage appeared to represent a distinct lineage and a preliminary maximal rate estimate (~61.4% lineage-1 MY-1) was calculated based on the minimum divergence of this assemblage from its nearest conspecifics. Although slower than the rate calculated for L. wallacei, this was still high for teleost fishes.
Overall, this study indicated that historical environmental factors, especially those related to Quaternary eustatic changes, have played important roles in sculpting the phylogeography and evolution of three teleost species from south-western Australia. Moreover, as these species have differential dependencies on estuarine environments (is. 'strictly estuarine' vs 'estuarine and marine') and represented two different taxonomic groups (i.e. Atherinoidei and Gobioidei), historical environmental factors may have exerted similar influences on other coastal species in the region.
44
Grigg, Alasdair M. "An ecophysiological approach to determine problems associated with mine-site rehabilitation : a case study in the Great Sandy Desert, north-western Australia." University of Western Australia. School of Plant Biology, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0118.
Full textAbstract:
[Truncated abstract] Establishment of vegetation and ecosystem functioning is central to the mitigation of environmental impacts associated with mining operations. This study investigated the ecophysiological functioning of mature plants in natural vegetation and applied this knowledge to diagnose problems affecting plant health and causes of poor plant cover at a mine-rehabilitation site. Ecophysiological parameters, including plant water relations and mineral nutrition, were studied in conjunction with soil physical, hydraulic and chemical properties. The natural ecosystem at the study location in the Great Sandy Desert is characterised by sand dunes and interdunes with distinct plant communities on each. One of the most notable features of the vegetation is the presence of large Corymbia chippendalei trees high on the dunes and relatively small scattered shrubs in the interdunes. Triodia grasses (spinifex), dominate the vegetation in both habitats but different species occur in each; T. schinzii is restricted entirely to the dunes, and T. basedowii occurs only in the interdunes. It was hypothesised that the deep sandy dunes afford greater water availability but lower nutrient supply to plants in this habitat compared with those occurring in the lower landscape position of the interdunes. Water-relations parameters (leaf water potentials, stomatal conductance, d13C) revealed that dune plants, particularly woody species, displayed higher water status and water use than closely related and often congeneric plants in the interdunes. Nutrient concentrations in soils were significantly higher in the interdunes, but concentrations in foliage were similar for related species between habitats. It is concluded that the dunes provide a greater store of accessible water than the soil profile in the interdunes. ... Following an experimental wetting pulse equivalent to a summer cyclone event, A. ancistrocarpa plants displayed significant increases in stomatal conductance, leaf water potential and sap velocity in lateral roots within three days of irrigation at the natural site and two days at the rehabilitation site. Secondary sinker roots originating from distal sections of lateral roots were evidently supplying water to maintain hydraulic function in laterals, thus enabling a fast pulse response. This was accentuated at the rehabilitation site where roots were confined closer to the surface. These results indicate that plants at the rehabilitation site are more dependent on small pulses of water and have less access to deep reserves than plants at the natural site. It is concluded that high runoff losses and insufficient soil depth are major factors contributing to plant water stress, and combined with the direct impacts of erosion, are largely responsible for plant death and ultimately poor plant cover. These issues can be alleviated if cover soil depth is increased to more than 0.5 m and slope angles are reduced to <12o. This study demonstrates the value of an ecophysiological approach for diagnosing problems affecting plant establishment at mine-rehabilitation sites. Furthermore, it has provided recommendations that will improve the rehabilitation strategy and lead to the development of a well vegetated, resilient ecosystem on a stable and non-polluting land form.
45
Ayeni, Olutoyosi Olaide. "An investigation into the effect of metals on chlorophyll content and photosynthesis activity of the wetland plant phragmites australis in the lower Diep River, Milnerton, Cape Town." Thesis, Cape Peninsula University of Technology, 2011. http://hdl.handle.net/20.500.11838/2016.
Full textAbstract:
Thesis (MTech (Environmental Management)))--Cape Peninsula University of Technology, 2011.A study involving a wetland plant, common reed (Phragmites australis L.) was carried out along the bank of the lower Diep River and the adjacent soil samples from four different sites (Milnerton Lagoon, Lower Estuary, Milnerton Bowling Club and Woodbridge Island), Cape Town, South Africa. The aim was to determine the extent of metal contamination and its impact on physiological indices. Results showed that among the metals evaluated, AI and Fe were consistently higher in all the soil samples (from both river bank and the adjacent soil) followed by Zn, Mn, Pb, Cu, Cd, Co, Cr and Ni. The concentrations of AI in the river banks ranged between 1214.1 - 3176 mg.kg-1 compared with the adjacent soils, where AI concentration ranged from 434.8 - 2445.4 mg.kq". The Fe concentrations from the river bank values ranged from 1136.4 - 4897.2 mg.kg-1 compared with Fe concentrations of the adjacent soil samples which ranged from 402.2 - 2459.8 mg.kg-1 . Generally, Zn ranged from 2.4 - 211.5 mq.kq"; Mn: 5.5 - 48.05 mg.kq': Pb: 0.97 - 71.7 mg.kq"; Cu: 0.3 - 45.9 mg.kq'; Cd: 0.0 - 9.3 mg.kq": Co: 0.2 - 2.7 mg.kq': Cr: 0.3 - 2.1 mg.kg-1 ; and Ni: 0.02 - 2.6 mg.kg-1. Overall, Ni had the lovest concentrations in the ecosystem. Results also showed that the abundance of metals from plant samples were in the order of AI > Pb > Cd > Co > Ni > Cr; and for micronutrients, Fe > Mn > Zn > Cu both in the shoots and roots sampled from all the sites investigated. The values of chlorophylls a, b and total chlorophyll as well as photosynthesis were significantly higher in the P. australis plant samples and from the adjacent soil compared with those from the river bank. These results suggest that contamination of soils and wetland ecosystem by metals over and above plant requirements may affect the chlorophyll and photosynthesis rate of the plant thereby undermining the physiological functioning of plants growing along river systems.
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Bleby, Timothy Michael. "Water use, ecophysiology and hydraulic architecture of Eucalyptus marginata (jarrah) growing on mine rehabilitation sites in the jarrah forest of south-western Australia." University of Western Australia. School of Plant Biology, 2003. http://theses.library.uwa.edu.au/adt-WU2004.0004.
Full textAbstract:
[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.
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Paul, Suzanna. "Comparative assessment of the effectiveness of online vs paper based post graduate courses in occupational and environmental safety and health at Edith Cowan University, Perth, Western Australia." Connect to thesis, 2006. http://portal.ecu.edu.au/adt-public/adt-ECU2007.0030.html.
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Biddulph, Thomas Benjamin. "Mechanisms of dormancy, preharvest sprouting tolerance and how they are influenced by the environment during grain filling and maturation in wheat (Triticum aestivum L.)." University of Western Australia. School of Plant Biology, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0168.
Full textAbstract:
[Truncated abstract] Wheat is the main crop in Australia and there are stringent quality requirements. Preharvest sprouting induced by rainfall between maturity and harvest lowers grain quality from premium to feed grades and reduces yield. Wheat production has expanded into the southern Western Australian region where preharvest sprouting occurs in ~1 in 4 seasons and development of more preharvest sprouting tolerant genotypes is required. The main mechanism for improving preharvest sprouting tolerance is grain dormancy. There is genetic variation for dormancy based in the embryo and seed coat but dormancy is complex and is influenced by environmental conditions during grain filling and maturation. Screening and selecting for preharvest sprouting tolerance is problematic and the level of tolerance needed for regions which differ in the level of dormancy they impose, requires clarification. The research presented here aims to answer the underlying question for breeders of how much dormancy is required for preharvest sprouting tolerance in contrasting target environments of the central and coastal wheat belt regions of Western Australia. In the central and coastal wheat belt regions, field trials with modified environments were used to determine the environmental influence on dormancy. Water supply (without directly wetting the grain) and air temperature were modified during grain development in a range of genotypes with different mechanisms of dormancy to determine the influence of environment on dormancy. ... Genotypes with embryo dormancy were consistently the most preharvest sprouting tolerant, even though this dormancy was influenced by the environmental conditions in the different seasons. Pyramiding the embryo component with the specific seed coat component and/or awnless head trait removed some of the environmental variation in preharvest sprouting tolerance, but this was generally considered excessive to the environmental requirements. The methods developed here, of field imposed stresses may provide a valuable tool to further understand the influence of environment on the regulation of dormancy, as different phenotypes can be made with the same genotype. Moisture stress, sudden changes in water supply or high temperatures during the late dough stages influenced dormancy phenotype and should be considered and avoided if possible when selecting locations and running trials for screening for genetic differences in preharvest sprouting tolerance. In the Western Australian context, the embryo component of dormancy appeared to be sufficient and should be adopted as the most important trait for breeding for preharvest sprouting tolerance.
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Mamouni, Limnios Elena Alexandra. "Incorporating complex systems dynamics in sustainability assessment frameworks : enhanced prediction and management of socio-ecological systems performance." University of Western Australia. Faculty of Business, 2008. http://theses.library.uwa.edu.au/adt-WU2009.0012.
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[Truncated abstract] The application of reductionism, breaking down problems to simpler components that can be solved and then aggregating the results, is one of the bases of classical science. However, living organisms, ecosystems, social and economic structures are complex systems, characterised by non-linear interactions between their elements and exhibit emergent properties that are not directly traceable to their components. Sustainability assessment frameworks oversimplify system interactions, achieving limited predictive capacity and causing managerial behavior that may reduce system's ability to adapt to external disturbance. Intrigued by the importance of complexity, we explore the central theme of how complex thinking can influence the understanding and progress towards sustainability. The purpose is to conceptualize the relationship of key terms (such as sustainability, functionality and resilience), and consecutively develop new or adjust existing sustainability frameworks to take into account complex systems interactions. We aim at developing theory and frameworks that can be used to raise awareness of the pitfalls of the growth paradigm and direct towards modest positions when managing complex systems. We seek to define the structural elements that influence system adaptive capacity, allowing identification of early signs of system rigidity or vulnerability and the development of knowledge and techniques that can improve our predictive and managerial ability. The focus has been on a variety of system scales and dynamics. At the collective community level, a number of stakeholder engagement practices and frameworks are currently available. However, there is limited awareness of the complexity challenges among stakeholders, who are commonly directed to a triple bottom line analysis aiming at maximizing a combination of outputs. An attempt is conducted to measure the functionality of the processes underlying a standing stock, in contrast to sustainability measures that only assess the variations of the standing stock itself. We develop the Index of Sustainable Functionality (ISF), a framework for the assessment of complex systems interactions within a large-scale geographic domain and apply it to the State of Western Australia. '...' Finally, we focus on smaller systems scales and develop a methodology for the calculation of Product Ecological Footprint (PEF) including elements from the accounting method of activity based costing. We calculate PEF for three apple production systems and identify significant differences from first stage calculations within the same industry. Cross-industry application will provide a practical way to link individuals' consumption with their ecological impact, reduce misperceptions of products' ecological impacts and develop a market-driven approach to internalizing environmental externalities. At the firm level PEF can be compared with investment costs, resulting in the opportunity to optimize both functions of financial cost and ecological impact in decision making. We have developed methods for incorporating complexity in sustainability assessment frameworks. Further work is required in testing and validating these methodologies at multiple system scales and conditions. Integrating such tools in decision making mechanisms will enhance long-term management of socioecological systems performance.
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Peterson, Kylie, and n/a. "Environmental impacts on spawning and survival of fish larvae and juveniles in an upland river system of the Murray-Darling Basin." University of Canberra. Resource, Environmental & Heritage Sciences, 2003. http://erl.canberra.edu.au./public/adt-AUC20060713.121419.
Full textAbstract:
Six rivers within the upper Mumbidgee catchment were sampled for larval and juvenile
fish. The rivers represented both regulated and unregulated flow regimes and varied widely in
size. There was wide variation in the larval fish communities supported by each river, both in
terms of the species diversity and total abundance of fish sampled. The highly regulated reach
of the Mumbidgee River sampled during this study had the highest numbers of native
species and native individuals of any river sampled.
In the two rivers selected for further study, the Murmmbidgee and Goodradigbee, there was a
high level of inter-annual consistency in the species composition within the reaches sampled,
despite considerable change in the temperature and flow regimes of both rivers. This indicates
that at least some spawning of those species sampled may occur each year, regardless of
environmental conditions. Estimates of the relative abundance of each species sampled
changed markedly between years, and it is argued, on the basis of growth information
contained in the otoliths, that differential survival of larvae and juveniles was largely
responsible for this shift in relative abundance.
Otolith microstructure provided information on the date of spawning and early growth patterns
of all species sampled in the upper Mumumbidgee catchment. In addition to determining the
age and thus 'birth-date' of an individual, the effect of a particular event or series of events has
on growth, and subsequent survival, is permanently recorded in the otolith microstructure.
This enables accurate back-calculation and correlation to management actions or natural
events. No other research tool has this ability to retrospectively assess, on a daily basis, the
impacts of management actions on condition and subsequent survival of fish larvae.
Species sampled could be separated into three groups based on spawning requirements; those
linked with flow, those linked with temperature and generalist species that appear to have river
independent cues, such as photoperiod or moon phase.
Patterns in growth rate during the early life history stages enabled quantification of the
consequences of variation in environmental conditions on the survival and recruitment of
various species. Growth was not always highly correlated with water temperature, in fact, for
mountain galaxias, high temperatures appear to negatively affect larval condition and
subsequent survival. Conversely, carp exhibited a strategy more consistent with common
perceptions, with growth and survival increasing with increasing temperature.
The study uncovered spawning and growth patterns that were unexpected. Age analysis of
western carp gudgeon demonstrated that they had undertaken a mid-winter spawning, when
the water temperature in the main channel was far lower than that at which spawning was
previously recorded for this species. Redfin perch from the unregulated Goodradigbee River
exhibited growth rates exceeding the published upper limits for this and other closely related
species. This growth could not be correlated with either temperature or flow, indicating that
there are additional factors that dominate growth rates of redfin perch in the Goodradigbee
River.
The proportion and abundance of native species alone is not necessarily indicative of a
'healthy' or pristine system; some native species may be positively affected by river
regulation, at least as juveniles. Comparison of the current larval fish community with likely
pre-European fish communities does provide an indication of change to the system. The
results of this study suggest that larval fish growth rates can be strongly influenced by
environmental conditions, thus providing a powerful tool for monitoring future change and the
factors which cause it.
This study has demonstrated the value of larval and juvenile fish age and growth information,
derived from otolith microstructure techniques, for many aspects of river management.
Current river management priorities for which these techniques provide unique information
include the determination of environmental flow regimes and the control of undesirable exotic
species such as carp.