Дисертації з теми "River (S. Aust.) Environmental aspects"

Thesis (Ph.D.) -- University of Western Sydney, 2004.
"A thesis submitted for the degree of Doctor of Philosophy of the University of Western Sydney, Sydney, January 2004." Includes bibliography : leaves 359 - 369.

Bibliography :leaves 158-171. A monitoring program, funded by the South Australian government (through the former MFP Development Corporation), was established to monitor the quality and quantity of storm water entering and leaving the wetland. This study formed part of the funded program. Simple regression models were developed; and will assist in the monitoring of performance of the wetland to alleviate the pollutant load into the Barker Inlet.

This thesis examines the destruction of the Torrens River as a natural river ecology and its recreation as an artificial one. The fragile watercourse was transformed in the nineteenth century into an artificial lake on a European scale. The author presents the reasons behind the changes which took place, covering both physical changes and society’s altering conceptions of the river. The period of study ranges from the Kaurna people’s life, which adapted around the river they called Karrawirraparri, to the damming of the river in 1881.
Thesis (M.A.) -- University of Adelaide, School of History and Politics, 2005

Hydraulic conditions (velocity, depth, turbulence) strongly influence the distribution and abundance of organisms in rivers. A diverse hydraulic environment should foster biodiversity, because organisms have different hydraulic preferences. In fact, the relationship between spatial hydraulic diversity and biodiversity is largely presumed, and not well-supported by empirical studies, but it underpins efforts in river restoration and conservation. This is particularly so at the reach scale, indicating a stream- or river-section with large-scale homogeneous geomorphic and hydrological conditions and smaller-scale habitat patches, as perceived by organisms in the community under study. This thesis considers the factors that create spatial hydraulic diversity, and the ways that fish respond. It presents a method to characterise hydraulic diversity, and uses this to describe temporal and spatial changes between reaches. It also demonstrates the use of hydraulic modelling for comparing reaches. Finally, it assesses the Acoustic Doppler Current Profiler (ADCP) as a method to describe hydraulic conditions in a large, open river channel. Swimming ability tests were applied to three small freshwater fish, the pelagic Australian smelt (Retropinna semoni) and common galaxias (Galaxias maculatus ) and the demersal flathead gudgeon (Philypnodon grandiceps). The latter species was the weaker swimmer, but the tests indicated that behaviour also should be considered. A laboratory experiment was designed to investigate how two species with contrasting ecological habits (common galaxias, flathead gudgeon) behave in a diverse hydraulic environment. Habitat choices and activity were monitored in a constructed sinuous channel at three discharges over a 3-hour period. The galaxias favoured the pelagic habitat, and spent 20-60% of the time cruising, whereas the flathead gudgeon preferred the demersal habitat and spent <6% of the time cruising. The flathead gudgeons could access their preferred habitat at all discharges, but the common galaxias were limited by their swimming ability at the highest discharge. Several methods to characterise reaches were compared for eight 3-D model reaches representing the effects of channel form, wood and aquatic plants. The variogram (a measure of the variance between samples as a function of distance) emerged as a superior method because it indicates hydraulic diversity, incorporates the spatial arrangement of hydraulic patches, and facilitates comparisons between reaches. The ADCP proved a quick, reliable means to measure depth and 3-D velocity in rivers. It was effective only in depths >1.5 m, but modified instrumentation may overcome this limitation. Six reaches, including weir-pool and free-flowing sections, were compared at two discharges in the River Murray, Australia. Variograms derived from the ADCP data clearly demonstrated spatial differences between the sections, but temporal differences were less well-defined, suggesting that reaches may retain characteristic hydraulic patterns despite changes in discharge. Opportunities for further research include: the issue of optimal levels of hydraulic diversity for fish and other biota; use of variograms as a tool for field studies of aquatic biota; and measuring reach-scale hydraulic diversity and biodiversity before and after reach manipulation (e.g. the placement of wood), to elucidate the effects of changes in spatial hydraulic diversity on reach biodiversity.
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Thesis (Ph.D.) - University of Adelaide, School of Earth and Environmental Sciences, 2008

Hydraulic conditions (velocity, depth, turbulence) strongly influence the distribution and abundance of organisms in rivers. A diverse hydraulic environment should foster biodiversity, because organisms have different hydraulic preferences. In fact, the relationship between spatial hydraulic diversity and biodiversity is largely presumed, and not well-supported by empirical studies, but it underpins efforts in river restoration and conservation. This is particularly so at the reach scale, indicating a stream- or river-section with large-scale homogeneous geomorphic and hydrological conditions and smaller-scale habitat patches, as perceived by organisms in the community under study. This thesis considers the factors that create spatial hydraulic diversity, and the ways that fish respond. It presents a method to characterise hydraulic diversity, and uses this to describe temporal and spatial changes between reaches. It also demonstrates the use of hydraulic modelling for comparing reaches. Finally, it assesses the Acoustic Doppler Current Profiler (ADCP) as a method to describe hydraulic conditions in a large, open river channel. Swimming ability tests were applied to three small freshwater fish, the pelagic Australian smelt (Retropinna semoni) and common galaxias (Galaxias maculatus ) and the demersal flathead gudgeon (Philypnodon grandiceps). The latter species was the weaker swimmer, but the tests indicated that behaviour also should be considered. A laboratory experiment was designed to investigate how two species with contrasting ecological habits (common galaxias, flathead gudgeon) behave in a diverse hydraulic environment. Habitat choices and activity were monitored in a constructed sinuous channel at three discharges over a 3-hour period. The galaxias favoured the pelagic habitat, and spent 20-60% of the time cruising, whereas the flathead gudgeon preferred the demersal habitat and spent <6% of the time cruising. The flathead gudgeons could access their preferred habitat at all discharges, but the common galaxias were limited by their swimming ability at the highest discharge. Several methods to characterise reaches were compared for eight 3-D model reaches representing the effects of channel form, wood and aquatic plants. The variogram (a measure of the variance between samples as a function of distance) emerged as a superior method because it indicates hydraulic diversity, incorporates the spatial arrangement of hydraulic patches, and facilitates comparisons between reaches. The ADCP proved a quick, reliable means to measure depth and 3-D velocity in rivers. It was effective only in depths >1.5 m, but modified instrumentation may overcome this limitation. Six reaches, including weir-pool and free-flowing sections, were compared at two discharges in the River Murray, Australia. Variograms derived from the ADCP data clearly demonstrated spatial differences between the sections, but temporal differences were less well-defined, suggesting that reaches may retain characteristic hydraulic patterns despite changes in discharge. Opportunities for further research include: the issue of optimal levels of hydraulic diversity for fish and other biota; use of variograms as a tool for field studies of aquatic biota; and measuring reach-scale hydraulic diversity and biodiversity before and after reach manipulation (e.g. the placement of wood), to elucidate the effects of changes in spatial hydraulic diversity on reach biodiversity.
Thesis (Ph.D.) - University of Adelaide, School of Earth and Environmental Sciences, 2008

Most of the lower River Murray and its floodplain wetlands are impacted upon by degradation caused by river regulation. Increasingly the restoration of these ecosystems and the river water quality has become a high priority for federal and state governments and associated departments and agencies. Public concern is adding to the pressures on these departments and agencies to restore these ecosystems and to sustainably maintain the river water quality. The long term monitoring of floodplain wetlands has been limited, compounding the difficulties faced by managers and decision makers on assessing the potential outcome of restoration options. The role of this project in the broad scheme of restoration/rehabilitation is to contribute to the construction of a model capable of increasing managers and decision makers understanding, and build consensus of potential outcomes of management option. This model was to use available data. The developed model, based on WETMOD developed by Cetin (2001), simulates wetland internal nutrient processes, phytoplankton, zooplankton and macrophyte biomass as well as the interaction (nutrient and phytoplankton exchange) between wetlands and the river. The model further simulates the potential impact management options have on the wetlands, and their nutrient retention capacity, and therefore their impact on the river nutrient load. Due to the limitation of data, wetlands were considered in categories for which data was available. Of these two had sufficient data to develop, calibrate and validate the model. Management scenarios for these two wetlands were developed. These scenarios included, the impact of returning a degraded wetland in a turbid state to a rehabilitated clear state, and the impact the removal of nutrient from irrigation drainage inflows has on wetland nutrient retention, and consequent input to the river. Scenarios of the cumulative impact of the management of multiple wetlands were developed based on using these two wetlands, for which adequate data was available, as “exemplar” wetlands, i.e. data from these wetlands were substituted for other similar wetlands (those identified as belonging to the same category). The model scenarios of these multiple wetlands provide some insight into the potential response management may have on individual wetlands, the cumulative impact on river nutrient load and how wetland morphology may relate to management considerations. The model is restricted by data availability and consequently the outputs. Further, some limitations identified during the development of the model need to be addressed before it can be applied for management purposes. However, the model and methods provide a guide by which monitoring efforts can assist in developing future modelling assessments and gain a greater insight not only at the monitoring site but also on a landscape scale.
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Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2008

This thesis examined the impact of anthropogenic alterations in four riverine catchments of the Eastern Mt. Lofty Ranges, South Australia, to identify if creek restoration via environmental flows is a viable management option and if so, to determine; 1) Whether an aquatic/riparian viable seed bank was present and if so what was its composition 2) The ecological condition of selected riverine reaches. This in combination with the seed bank study would identify those creeks that would most benefit from the imposition of environmental flows 3) The response of key species to the water regimes likely to result from the imposition of environmental flows 4) The influence of nutrient enrichment under a fluctuating water level and to use this information to formulate best practice policy for environmental flows 5) Whether aquatic plants promoted by environmental flows were a significant fraction of the diet for higher trophic levels represented by Trichopterans and Amphipods. The seed banks were of comparable density (ranging from 4,000 to 110,000 seeds m-2) and species richness (ranging from 13 to 20 aquatic / riparian species) to the seed banks of other Australian rivers and wetlands, but this varied significantly among riverine sections and across catchments. Out of a total of 81 species recorded, 51 were classified as terrestrial (63% of all species recorded). What is of greater concern was the number of exotic (both aquatic and terrestrial) species recorded: 43% of the species recorded in the Angas, 47% of the species in the Finniss, 39% of the species in Tookayerta creek and 43% of the species recorded in Currency creek were exotic, which are significantly higher in comparison to other Australian studies. There were 24 to 28 aquatic/riparian species recorded in the extant vegetation of each catchment that were not recorded in their seed banks. Likewise, a number of species (3 to 7) were recorded in each catchments seed bank that were not recorded in the extant vegetation of those catchments. A species of particular interest is Crassula sieberana, which is on the State endangered plant species list. Indices for assessing the ecological condition, health or integrity of a river or riparian habitat were employed to investigate the relationship between the river/riparian habitat and the land and water management practices associated with those habitats. Of the four catchments surveyed, each catchment identified a unique set of site parameters (subindex indicators) that were strongly correlated with its ecological condition. Indicator species analyses revealed pasture grasses to be a significant indicator of reaches in very poor condition (p = 0.0010) along the Finniss and Baumea juncea of those reaches in good condition (p = 0.0230). Along the Angas, Cotula coronopifolia was an indicator of those reaches in average condition (p = 0.0240) and along Currency creek, Cladium procerum was an indicator of those reaches in good condition (p = 0.0190). However, when all 115 surveyed reaches were analysed together, those reaches of average to excellent ecological condition were all strongly correlated (R2 = 0.50) with the subindex indicators: bank stability, % riparian cover, grazing, fenced, aquatic wood, and width of the riparian vegetation. This would indicate that these subindex indicators are the main site parameters determining the ecological condition of a riverine reach and hence its restoration potential. Those catchments or sub-catchments containing a high proportion of reaches classified to be in poor to very poor condition had significantly reduced seed banks. The influence of water level fluctuations (±15 cm, ±30 cm and ±45 cm) on the growth of four species of emergent macrophytes (Cyperus vaginatus, Phragmites australis, Typha domingensis and Triglochin procerum) were species dependent. These species naturally inhabits different zones across the elevation gradient. C. vaginatus, which has a high elevation preference, was strongly inhibited by increasing water depth and fluctuations in water levels. In contrast, species with an intermediate elevation preference, such as Phragmites australis and Typha domingensis, were more tolerant to both depth and water level fluctuations. However, the biomass and relative growth rate (RGR) of T. domingensis and P. australis were depressed when grown under the combination of deep elevation and a highly fluctuating water level (±45 cm). Between the static and ±45 cm amplitude treatments, growth of T. domingensis was inhibited by 52%. The growth of P. australis appeared to be enhanced by fluctuating water levels and only showed a severe drop-off in growth in the deep elevation, ±45 cm amplitude treatment. In C. vaginatus the RGR was dependent of the average emergent surface area (and the implied rate of carbon acquisition)(p<0.0001; r2=0.7196; F=87.276; n=36; RGR (mg g-1 day-1) = -5.096 + 4.313 × ln (Average emergent surface area (cm2)), but this was not the case in P. australis and T. domingensis (p>0.05) even when the photosynthetic canopy was partially inundated by rising water levels. Yet these two species demonstrated different growth rates when grown under different water regime amplitudes and at different elevations. Growth of T. procerum did not respond to either amplitude or elevation, but its RGR remained negative. This suggests that another factor(s) was limiting the growth of P. australis, T. domingensis and possibly T. procerum, a factor that varies with water level. Cyperus gymnocaulos had significantly increased plant performance (p <.0001) with increased nutrient loading rates but this effect was significantly reduced under a fluctuating water regime (p =0.0007). Remarkably, under a fluctuating regime, P. australis had a significant reduction in performance with increased nutrient loading rates (p =0.0013), whereas T. domingensis performance was significantly limited (p =0.034) even with increased nutrient loading rates. T. procerum too had increased plant performance with increased nutrient loading rates but this effect was reduced under a fluctuating regime. The morphological response by T. procerum demonstrates that it is mainly limited by the nutrient loading rates and not the water regime. However, it was significantly limited/reduced by its increased turnover rates caused by a stochastic fluctuating water regime. Illustrating that in fact the effects of nutrient enrichment on T. procerum were independent of water regime but bearing in mind that water regime is the primary factor determining the productivity of this species. For those species with higher elevation preferences, e.g. C. gymnocaulos, or low elevation preference, e.g. T. procerum, the effects of nutrient loading are independent of water regime, whereas those species with an intermediate elevation preference, e.g. P. australis and T. domingensis the effects of nutrient loading are largely dependent on the water regime. Amphipoda and Trichoptera selectively fed on succulent semi-emergent macrophytes across sites of average to excellent ecological condition (31-64% to 65-97% of diet), depending on availability. These semi-emergent macrophytes contained the lowest C:N ratio (≈10:1), closest to that of their consumers (≈5:1) and therefore the highest nutritional content. In degraded riverine reaches, there were limited food resources available, hence course particulate organic matter (CPOM) formed the main dietary components of Amphipoda (20-53% of diet) even though it had the highest C:N ratio (≈40:1). At site VP. 1, filamentous algae was the main dietary component of Trichoptera (48-64% of diet) due to its availability and its low C:N ratio (≈14:1) in comparison to the other primary sources available. The imbalanced consumer-resource nutrient ratios in these degraded riverine reaches are likely to impose constraints on the growth and reproduction of their aquatic shredder communities with probable knock-on effects at higher trophic levels. The installation of environmental flows to restore and promote aquatic/riparian plant communities, which in turn would benefit higher trophic organisms, is a viable and realistic management option along selected reaches. Those selected reaches contain a significant aquatic/riparian seed bank and with sufficient physical habitat remaining to promote their germination and establishment. However, the imposition of environmental flows as a control measure to prevent the colonisation and dominance of particular species (T. domingensis and P. australis) was deemed to be redundant as a management technique given the limited water resources available.
Thesis (Ph.D.) -- School of Earth and Environmental Sciences, 2007

This thesis examined the impact of anthropogenic alterations in four riverine catchments of the Eastern Mt. Lofty Ranges, South Australia, to identify if creek restoration via environmental flows is a viable management option and if so, to determine; 1) Whether an aquatic/riparian viable seed bank was present and if so what was its composition 2) The ecological condition of selected riverine reaches. This in combination with the seed bank study would identify those creeks that would most benefit from the imposition of environmental flows 3) The response of key species to the water regimes likely to result from the imposition of environmental flows 4) The influence of nutrient enrichment under a fluctuating water level and to use this information to formulate best practice policy for environmental flows 5) Whether aquatic plants promoted by environmental flows were a significant fraction of the diet for higher trophic levels represented by Trichopterans and Amphipods. The seed banks were of comparable density (ranging from 4,000 to 110,000 seeds m-2) and species richness (ranging from 13 to 20 aquatic / riparian species) to the seed banks of other Australian rivers and wetlands, but this varied significantly among riverine sections and across catchments. Out of a total of 81 species recorded, 51 were classified as terrestrial (63% of all species recorded). What is of greater concern was the number of exotic (both aquatic and terrestrial) species recorded: 43% of the species recorded in the Angas, 47% of the species in the Finniss, 39% of the species in Tookayerta creek and 43% of the species recorded in Currency creek were exotic, which are significantly higher in comparison to other Australian studies. There were 24 to 28 aquatic/riparian species recorded in the extant vegetation of each catchment that were not recorded in their seed banks. Likewise, a number of species (3 to 7) were recorded in each catchments seed bank that were not recorded in the extant vegetation of those catchments. A species of particular interest is Crassula sieberana, which is on the State endangered plant species list. Indices for assessing the ecological condition, health or integrity of a river or riparian habitat were employed to investigate the relationship between the river/riparian habitat and the land and water management practices associated with those habitats. Of the four catchments surveyed, each catchment identified a unique set of site parameters (subindex indicators) that were strongly correlated with its ecological condition. Indicator species analyses revealed pasture grasses to be a significant indicator of reaches in very poor condition (p = 0.0010) along the Finniss and Baumea juncea of those reaches in good condition (p = 0.0230). Along the Angas, Cotula coronopifolia was an indicator of those reaches in average condition (p = 0.0240) and along Currency creek, Cladium procerum was an indicator of those reaches in good condition (p = 0.0190). However, when all 115 surveyed reaches were analysed together, those reaches of average to excellent ecological condition were all strongly correlated (R2 = 0.50) with the subindex indicators: bank stability, % riparian cover, grazing, fenced, aquatic wood, and width of the riparian vegetation. This would indicate that these subindex indicators are the main site parameters determining the ecological condition of a riverine reach and hence its restoration potential. Those catchments or sub-catchments containing a high proportion of reaches classified to be in poor to very poor condition had significantly reduced seed banks. The influence of water level fluctuations (±15 cm, ±30 cm and ±45 cm) on the growth of four species of emergent macrophytes (Cyperus vaginatus, Phragmites australis, Typha domingensis and Triglochin procerum) were species dependent. These species naturally inhabits different zones across the elevation gradient. C. vaginatus, which has a high elevation preference, was strongly inhibited by increasing water depth and fluctuations in water levels. In contrast, species with an intermediate elevation preference, such as Phragmites australis and Typha domingensis, were more tolerant to both depth and water level fluctuations. However, the biomass and relative growth rate (RGR) of T. domingensis and P. australis were depressed when grown under the combination of deep elevation and a highly fluctuating water level (±45 cm). Between the static and ±45 cm amplitude treatments, growth of T. domingensis was inhibited by 52%. The growth of P. australis appeared to be enhanced by fluctuating water levels and only showed a severe drop-off in growth in the deep elevation, ±45 cm amplitude treatment. In C. vaginatus the RGR was dependent of the average emergent surface area (and the implied rate of carbon acquisition)(p<0.0001; r2=0.7196; F=87.276; n=36; RGR (mg g-1 day-1) = -5.096 + 4.313 × ln (Average emergent surface area (cm2)), but this was not the case in P. australis and T. domingensis (p>0.05) even when the photosynthetic canopy was partially inundated by rising water levels. Yet these two species demonstrated different growth rates when grown under different water regime amplitudes and at different elevations. Growth of T. procerum did not respond to either amplitude or elevation, but its RGR remained negative. This suggests that another factor(s) was limiting the growth of P. australis, T. domingensis and possibly T. procerum, a factor that varies with water level. Cyperus gymnocaulos had significantly increased plant performance (p <.0001) with increased nutrient loading rates but this effect was significantly reduced under a fluctuating water regime (p =0.0007). Remarkably, under a fluctuating regime, P. australis had a significant reduction in performance with increased nutrient loading rates (p =0.0013), whereas T. domingensis performance was significantly limited (p =0.034) even with increased nutrient loading rates. T. procerum too had increased plant performance with increased nutrient loading rates but this effect was reduced under a fluctuating regime. The morphological response by T. procerum demonstrates that it is mainly limited by the nutrient loading rates and not the water regime. However, it was significantly limited/reduced by its increased turnover rates caused by a stochastic fluctuating water regime. Illustrating that in fact the effects of nutrient enrichment on T. procerum were independent of water regime but bearing in mind that water regime is the primary factor determining the productivity of this species. For those species with higher elevation preferences, e.g. C. gymnocaulos, or low elevation preference, e.g. T. procerum, the effects of nutrient loading are independent of water regime, whereas those species with an intermediate elevation preference, e.g. P. australis and T. domingensis the effects of nutrient loading are largely dependent on the water regime. Amphipoda and Trichoptera selectively fed on succulent semi-emergent macrophytes across sites of average to excellent ecological condition (31-64% to 65-97% of diet), depending on availability. These semi-emergent macrophytes contained the lowest C:N ratio (≈10:1), closest to that of their consumers (≈5:1) and therefore the highest nutritional content. In degraded riverine reaches, there were limited food resources available, hence course particulate organic matter (CPOM) formed the main dietary components of Amphipoda (20-53% of diet) even though it had the highest C:N ratio (≈40:1). At site VP. 1, filamentous algae was the main dietary component of Trichoptera (48-64% of diet) due to its availability and its low C:N ratio (≈14:1) in comparison to the other primary sources available. The imbalanced consumer-resource nutrient ratios in these degraded riverine reaches are likely to impose constraints on the growth and reproduction of their aquatic shredder communities with probable knock-on effects at higher trophic levels. The installation of environmental flows to restore and promote aquatic/riparian plant communities, which in turn would benefit higher trophic organisms, is a viable and realistic management option along selected reaches. Those selected reaches contain a significant aquatic/riparian seed bank and with sufficient physical habitat remaining to promote their germination and establishment. However, the imposition of environmental flows as a control measure to prevent the colonisation and dominance of particular species (T. domingensis and P. australis) was deemed to be redundant as a management technique given the limited water resources available.
Thesis (Ph.D.) -- School of Earth and Environmental Sciences, 2007

The decline of floodplain vegetation along the Lower River Murray, South Australia, has evoked recommendations for ‘environmental flows’ to restore and maintain the health of the ecosystem. To assist managers to maximize benefits from environmental flows, this thesis considers the significance of water for germination and recruitment in key floodplain plant species. Three dominant species are considered, including two trees, river red gum (Eucalyptus camaldulensis) and black box (E. largiflorens), and an understorey shrub, tangled lignum (Muehlenbeckia florulenta). The soil seed bank was dominated by terrestrial annual native plants. Among 1400 seedlings, a single river red gum was found, and no black box or lignum, suggesting that these species do not contribute to the persistent soil seed bank and rely instead on aerial seed banks (serotiny). Sampling of the soil seed bank was continued to determine when seed fall might coincide with appropriate soil moisture conditions. Responses of the soil seed bank to varied water regimes were compared to determine requirements for seedling survival. The results indicated that species richness, rapidity of response and survival time were all promoted by sustained soil moisture. Stands of eucalypts in various states of health (from very stressed to very healthy) were monitored to identify seasonal patterns in bud crops, flowering, fresh leaves and volumes of seed released from the aerial seed bank. Distinct seasonal phenological patterns were apparent, and suggested alternating flowering among individual trees (biennial for red gum, bi-annual for black box), producing an annual peak in summer. Peak seed rain occurred in summer (December–March) in healthy trees for both red gum and black box, with light seed rain continuing throughout the year. Seed fall from stressed trees was much reduced. Stressed trees responded after a second watering event, with much more varied and extended annual seed fall patterns. Lignum showed a spring peak in flowering and seed production. There was a prolific response of flowering and seeding to rainfall, but few seedlings survived. Vigorous vegetative growth occurred in existing plants in response to rainfall and watering but no new cloned plants were found during the study. An investigation of chromosomes as a potential tool to appraise the balance between sexual and asexual reproduction in lignum proved inconclusive, although a previous report of octoploidy in lignum was confirmed. Seeds from all three species and lignum cuttings were tested for their responses to varied watering regimes, based on combinations of simulated rain and flood conditions. The optimal soil moisture for continued growth and survival in all seeds and cuttings was 10 25%, with moisture values <10% causing wilting and death. The results also suggested that red gum and black box seeds which germinate in water under flooded conditions need to be stranded onto moist soil at the water’s edge within 10 days, for the seedling to continue to grow. It was also concluded that germination on rain-moistened soil is a key supplementary mechanism for recruitment, particularly between irregular flood events. For greatest benefit, the timing of environmental flows should complement any seasonal rainfall and irregular flooding that may occur. Extension of suitable soil moisture conditions (10-25%) for as long as possible after >5 mm rainfall, or after over-bank flows, would increase chances for survival of seedlings. December is the most likely month for maximal benefit from watering in the Lower Murray Valley, for germination and recruitment, based on regional rainfall and flooding patterns.
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Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2008

This thesis examines the archaeological record on the West Coast of the Eyre Peninsula in South Australia with a view to identifying the pattern of behaviour associated with sites present on this coast. The sites are notable in that they are extensive and feature high proportions of stone artefacts but contain little or no shell material. This thesis seeks to explain the virtual absence of shells by considering a number of environmental, behavioural, demographic and cultural issues. Is the archaeological record a product of post-depositional disturbance or resource availability, or did other environmental influences such as a shortage of water restrict adaptive behaviour so as to exclude or minimize interaction with the sea. Alternatively, is the subsistance strategy indicated by the archaeological record a result of other cultural influences. Ethnohistorical evidence is examined to investigate the subsistence patterns which operated on this coastline. Linguistic, technological and social factors which may have influenced the economic choices made by these coastal people are considered and compared with the archaeological record. The thesis then examines the interpretation of the West Coast evidence in the context of other coastal studies both in Australia and overseas to contribute to the current debate regarding the role of the sea in the evolution of hunter-gatherer subsistence economies.

Some of Australia’s most pressing conservation problems are found in the arid and semi-arid rangelands where the traditional major land-use is extensive pastoralism. Yet with the emergence of a change in resource values, the rangelands of Australia have started to move away from a strict production land-use towards a multifunctional land-use where pastoralism, tourism and the environment have an influence on one another. With the present mixture of consumption and protection values in the rangelands, ecotourism represents a model for achieving a symbiotic relationship between tourism activity and conservation in a pastoral setting. This study develops a theoretical framework for understanding the relationships between ecotourism, pastoralism and ecological recovery efforts in the Flinders Ranges through employing mixed qualitative and quantitative research techniques to examine the perceptions and practices of tourism operators, local landholders and visitors to the study site. The study finds that while pastoralism and its level of success often remain variable, the strength and stability of tourism is increasing. Because economics is a central component of the concept of sustainability, and because we must manage the environment while accommodating tourists, ecotourism is one way to help reach rangeland sustainability goals, provided that there are adequate levels of agreement amongst the local community and other land users. The results indicate that the vast majority of stakeholders are currently in a state of co-existence with each other rather than one of conflict, suggesting ecotourism has the potential to assist ecological recovery. However, many landholders are constrained in their ability to integrate ecotourism operations and conservation due to economic difficulties and market barriers. There are also conflicting results among visitors who claim to be interested in ecotourism but do not necessarily act accordingly, highlighting the need for a greater focus on environmental education. Ecotourism should be incorporated into a regional sustainability plan where the public are able to assist decision makers through collaborative planning. The thesis concludes that when well-managed, ecotourism can be a business supporting conservation in the Flinders Ranges. It contributes to knowledge of the role that ecotourism can play in encouraging ecological recovery in the rangelands and explores the complex interrelationships involved through consultation with the primary stakeholders of landholders, tourism operators and visitors.
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Thesis (Ph.D.) - University of Adelaide, School of Social Sciences, 2008

Environmental stress resulting from factors such as over grazing can have far-reaching effects on an ecosystem. This thesis aimed to increase the understanding of the wider biodiversity impact of stress and disturbance in semi-arid systems. The response of the arthropod community, and in particular the ant community, to changes in vegetation associated with over grazing, including the loss of perennial shrubs, was examined in the Flinders Ranges region of South Australia.
Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2006

Bibliography: leaves 378-402.
xviii, 402 leaves : ill. (chiefly col.), maps (chiefly col.) ; 30 cm.
Explores the status and nature of interpretation within the Australian whale watching industry, on both a national scale and as it is practiced at three diverse case study sites along the southern coast, and develops strategies which may enable this form of tourism to reach it's highest educative potential
Thesis (Ph.D.)--University of Adelaide, Dept. of Geographical and Environmental Studies, 2000

The primary contributions of this thesis are the economic studies of proposed water use reductions and climate change, and the development of an integrated hydro-economic model for the Murray-Darling Basin, Australia. This water model not only simulates the land and water use in the Basin, but also optimises these uses for certain targets such as environmental flows. More importantly, this model can be applied to evaluate policy options for the Basin, such as water buybacks, and provide estimates of the possible impacts of climate change. The thesis consists of three main essays focusing on issues in water modelling and management in the Basin. The first essay describes the development of a water model. This model is applied to estimate the impacts of water use reductions in the second essay; and climate change in the third essay. Other issues related to the Basin's water management, such as a review of existing water modelling, the background of the Basin, water trading, possible policy implementations and future research are also discussed. The first essay (Chapter 4) describes the construction of the Integrated Irrigated Water Model (IIA WM) including the structure of llA WM and the data sources. Using the latest hydrological data and revised catchment boundaries, llA WM can simulate and optimise land and water use in the Basin. To address the criticism that existing models have failed to consider water trading barriers, the physical constraints on water trading have been incorporated in llA WM. The model can also evaluate various water policies and estimate the impacts of physical condition changes. The second essay (Chapter 5) evaluates the impacts of proposed water use reductions by the Australian government. To balance the use of water between irrigated industries and environmental purposes, the Australian government draft plan released October 2010 proposed to reduce the volume of used water in the Basin from 3,000 to 4,000 GL/year. Simulations from IIA WM indicate that the impacts from proposed water use reductions will be modest, although there may be substantial impacts in particular locations. The third essay (Chapter 6) investigates the impacts of climate change in the Basin. A full range of climate change scenarios from modest to severe have been applied using IIA WM. This thesis finds that with water trading, profit reductions are substantially smaller than the water use reductions.

Provides insight into the pollutant removal ability of a primary pond in the Barker Inlet Wetland System, one of the largest constructed wetlands in the world. Results show that storm size influences pollutant removal, however significant removal was acheived across a wide range of flow conditions.
Thesis (M.Eng.Sc.) -- University of Adelaide, Dept. of Civil and Environmental Engineering, 2000?

Includes bibliographical references (leaves 136-154) Aims to determine the effects of an outfall discharging secondarily treated wastewater effluent on benthic communities at Christies Beach with the specific objectives of: characterising the physical, biological and chemical environment of Gulf St Vincent and the study area region; ascertaining the extent to which effluent outfall has affected the macrobenthic infaunal community structure; characterising the structure of macrobenthic infaunal communities in the near shore water of the Adelaide metropolitan coast; and, determining the functional response through measurements of sediment community respiration to these changes.