Dissertations / Theses on the topic 'Australian flora'

Malaria is a mosquito-borne disease caused by the parasitic protozoan Plasmodium that is responsible for approximately half a million deaths every year. The vast majority of these deaths are caused by P. falciparum in Sub-Saharan Africa (SSA). Although most cases of P. falciparum malaria can currently be treated effectively using artemisinin-based combination therapies (ACTs), resistance to ACTs is beginning to emerge in South-East Asia. This resistance is likely to proliferate and spread into SSA, after which a public health catastrophe is likely to follow. There is currently no drug poised to replace ACTs as the front-line treatment for malaria and there is a need for the discovery of new drugs. Historically, natural products from plants have been our best source of anti-malarial drugs: the alkaloid quinine (from the bark of the Cinchona tree) and the sesquiterpene lactone artemisinin (from the leaves of Artemisia annua) have formed the backbone of anti-malarial chemotherapeutics for centuries. The primary goal of this thesis was to respond to the need for new anti-plasmodial compounds. This was achieved by collecting and screening a library of Australian Rutaceae species against P. falciparum, selecting species that showed high bioactivity and performing large-scale natural product purification. Isolated natural products were screened against chloroquine-resistant and sensitive P. falciparum and human embryonic kidney (HEK-293) cells to evaluate bioactivity and parasite selectivity. This forms the majority of the thesis (Chapters 2-6). Chapter 2 reports the initial collection, screening and fingerprinting of a library of 30 Australian Rutaceae species. Chemical fingerprinting using LC-MS was used to identify species that were most likely to contain new natural products. From these results, four species were selected for investigation: Clausena brevistyla (Chapter 2) Flindersia pimenteliana (Chapters 3-4), Acronychia pubescens (Chapter 5) and Pitaviaster haplophyllus (Chapter 6). This chapter also reports the isolation of two known pyranocoumarins from C. brevistyla. One of the pyranocoumarins showed potent and selective activity against P. falciparum, with IC50 values between 466 – 822 nM. Chapter 3 reports the chemical investigation of F. pimenteliana leaf material. From this plant, a new class of ascorbic-acid adduct indole alkaloids, pimentelamines A-C, were isolated along with one new indole alkaloid, 2-isoprenyl-N,N-dimethyltryptamine. Five known compounds were also isolated. Although the new natural products did not show strong bioactivity, three of the isolated bis-indole alkaloids, borreverine, 4-methylborreverine and dimethylisoborreverine, showed potent activity with IC50 values between 190 – 670 nM against P. falciparum Chapter 4 reports the isolation of three new isoborreverine-type alkaloids, 10,10’- dimethoxydimethylisoborreverine, 10-methoxydimethylisoborreverine and 10’- methoxydimethylisoborreverine from the bark of F. pimenteliana. Two known borreverinetype alkaloids were also isolated. The moderate anti-plasmodial activity of these alkaloids is reported, with IC50 values ranging from 959 – 2407 ng/mL. Further insights into structureactivity relationships of borreverine-type alkaloids are also discussed. Chapter 5 reports the chemical investigation of the roots of A. pubescens, from which a highly unusual oxidized furo[2,3-c]xanthene, acrotrione, was isolated along with two known acetophenones. Acrotrione is the first natural product of its class to be isolated. Moderate anti-plasmodial activity for the natural products is reported, with IC50 values ranging from 1.7 to 4.7 µM. Chapter 6 reports the isolation of one new quinoline alkaloid, leptanoine D, from P. haplophyllus. Nine known alkaloids were also isolated. The chemotaxonomic relationships between the monotypic Pitaviaster genus and the related Australian genera Euodia, Melicope and Acronychia are discussed. The secondary goal of this thesis was to investigate the factors that influence diversity of natural products in Australian plants. In recent years, natural product-driven drug discovery has seen a decrease in popularity in the pharmaceutical industry, part of which has been caused by the repeated isolation of known natural products. In response to this, there is a requirement for the development of new ideas that expedite the discovery of new natural products. Some recent publications have noted that natural product diversity is positively correlated with diversity of plant-herbivore communities. This may suggest that plants in regions of high biotic stress (i.e. rainforests) should be the focal point of terrestrial plant natural product drug discovery. We aimed to validate this hypothesis by using the Australian Rutaceae genus Flindersia as a case study. Contrary to expectations, our results showed that Flindersia species growing in arid regions of central Australia produced a significantly higher number of structurally unique alkaloids than rainforest species. These unexpected results highlight the potential of the Australian arid zone as a source of new natural products.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
Full Text

Climate changes have been impacting ecosystems worldwide. Southwest Western Australia (SWA) is experiencing increased drought with climate change, causing great concerns for the continuing persistence of its extraordinary plant diversity. The potential of SWA plants to adapt to increased drought through rapid evolution was investigated. Results indicate that the SWA flora has tolerated recent climate changes, with potential for tolerance of further changes; however altered fire regimes may be detrimental to further adaptation and survival.

The Southwest corner of Western Australia has a distinctive culture of flora. In particular, the region is an internationally lauded destination for wildflower tourism. Aesthetic values inform the Southwest’s contemporary culture of flora and its products: photographs of flowers, botanical illustrations, taxonomic schemata and visually based landscape writings. In dynamic combination with sight, however, multi-sensoriality enhances cultures of flora through sensation. Hence, this thesis argues that it is vital to consider how bodily experiences deepen the appreciation of floristic appearances. Through readings of cultural, literary and historical sources, I propose floraesthesis as an embodied aesthetics of plants. The ancient concept of aesthesis, the root of the modern term aesthetics, comprises sensations—induced by the many senses—as gestures of curiosity. Whereas floraesthesis theorises corporeal appreciation, a visual aesthetic tends to distance plants from human appreciators. The latter may posit plants hierarchically as objects of visual art or constructs of quantitative science. This project puts into practice a critical humanities-based model that I call cultural botany. Following a progression of readings from colonial to contemporary times, I trace a continuum from floral aesthetics to floraesthesis through the cultural botany context. Using an integrative Thoreauvian-Heideggerean theoretical framework, I describe floral aesthetics as constituted by culture and language. As Thoreau and Heidegger suggest, embodied appreciation is predicated on language. I then theorise floraesthesis through readings of written and spoken materials: historic and contemporary literatures; colonialera botanical documents; transcriptions of ethnographic interviews; and my poetic enquiries as interludes throughout the text. A qualitative methodology, which I term botanic field aesthetics, comprises poetic practice, ethnographic interviewing and field walking set within an extensive historical context and organised around three places: Lesueur National Park, Fitzgerald River National Park and Anstey-Keane Damplands.

The study has attempted to characterise the physicochemical limnology and distribution of algal flora of two salt lake systems in Western Australia, one from the coastal Esperance region and the other from the inland Kambalda region. Climatic conditions, water regimes and physicochemistry were found to differ markedly between the two lake systems and a total of 171 algal taxa, representing five divisions, were recorded. Of these, 82 were members of Bacillariophyta, 48 of Cyanophyta, 33 of Chlorophyta, two of Euglenophyta and six of Dinophyta. The physical limnology of salt lakes in the Esperance region was seasonally variable, defined by climatic conditions. As such, the lakes investigated in the region exhibited a stable cycle of filling during winter and spring, and drying out in summer. Four of the lakes in the region could be classified as near-permanent, and one as seasonal on the basis of predictability and duration of filling. Seasonal fluctuations in water depth resulted in fluctuations in salinity levels. Salinity levels ranged from subsaline to hypersaline, and all the lakes in the region were alkaline. In addition, the lakes were well mixed in terms of oxygen and temperature, and were impacted by eutrophication from their catchments. They were either mesotrophic or eutrophic with respect to both nitrogen and phosphorus. In geological terms, lakes in the Esperance region were separated only recently from the ocean, and two lakes retain a connection with marine waters, one through a creek during years of high rainfall and one through hydrological interactions with groundwater of marine origin. In general, the algal communities of lakes in the Esperance region were similar to those of other Australian coastal salt lakes.Diatoms and cyanobacteria were dominant in all lakes except the most eutrophic, Lake Warden, in which benthic green algae were most abundant. All algal species recorded were known for their wide geographic distribution and their distribution in Australian coastal waters. Characteristically coastal diatom species included Achnanthes brevipes, Achnanthes coarctata, Achnanthes lanceolata var. dubia, Achnanthidium cruciculum, Campylodiscus clypeus, Cyclotella atomus, Cyclotella meneghiniana, Cyclotella striata, Mastogloia elliptica, Mastoglia pumila, Nitzschia punctata and Thalassiosira weissflogii. The inland salt lakes of the Kambalda region form part of an extensive palaeodrainage system, and were much less predictable in terms water regime than lakes in Esperance. Water depth was determined by seasonal variability in rainfall and evaporation, and by summer cyclonic rainfall events that were unreliable from year to year. In addition, rainfall varied spatially within the region. As such, most lakes were classified as intermittent. Two lakes in the region were not classified on the basis of water regime as they were too highly impacted by mining activities including water diversion and impoundment, water extraction and discharge of groundwater. Salinity varied in accordance with drying and filling cycles in the lakes except the most hypersaline as the volume of water received during rainfall events was insufficient to dilute the extensive surface salt crusts they each supported when dry. Salinities recorded in the region ranged from subsaline to hypersaline, and ionic compositions exhibited the same spectrum as seawater.Calcium levels were significantly higher than in lakes from the Esperance region due to weathering of calcium rich sediments, and pH ranged from weakly acidic in the most hypersaline lakes to alkaline in the least saline lakes. All were well mixed in terms of oxygen and temperature. Kambalda salt lakes support distinctive algal communities dominated by diatoms and cyanobacteria that are adapted to intermittent water regimes, extended periods of desiccation and variable salinity. Not surprisingly then, none of the algal taxa recorded from the region were regionally restricted, all noted previously in the literature to have wide geographic distributions, and to be tolerant of a range of physicochemical conditions. Canonical correspondence analysis showed that, of the physicochemical parameters that were investigated in this study, both salinity and pH interacted in determining algal community structure. Both of these attributes were correlated with water depth, which varied according to climatic conditions in a seasonal drying and filling cycle. The general relationship between species richness and pH and salinity, and species diversity and pH and salinity was simple and linear; with increasing pH and salinity, species diversity and species richness decreased. What was less simple, and non-linear, was the nature of the relationship between species richness and diversity and salinity within more narrowly defined ranges of salinity. As salinity increased from <1ppt to 30ppt there was a dramatic reduction in species richness and diversity, then, as salinity increased from 30ppt to 100ppt the rate of decrease slowed. Between 100ppt and 250ppt there was almost no relationship between salinity and species richness and species diversity, but after 250ppt both species diversity and species richness declined markedly.

This thesis examines the impact of recreational activities, specifically camping and trampling, on alpine and subalpine vegetation communities in Kosciuszko National Park, Australia. A survey approach was first used to determine visitor use levels and types of recreation activities within the main alpine area. An experimental methodology was then used to quantify the relationship between use and damage from camping and trampling to vegetation and soils. Specific questions addressed were: (1) what are the visitor numbers, demographics, activities and patterns of visitation to the Kosciuszko alpine area and have they changed since previous estimates?; (2) what is the relationship between levels of use and damage for camping in undisturbed alpine and subalpine vegetation communities and does this vary between tent and activity areas?; (3) (a) what is the relationship between levels of use and damage for trampling in the undisturbed alpine and subalpine vegetation communities when trampled once and (b) are thresholds and/or the relationship altered when trampling is repeated in the following year?; (4) what is the relationship between use and damage from trampling to plant communities following a large-scale disturbance (bushfire) and do natural processes during the following year of recovery eclipse any recreation impacts?; and (5) what recommendations can be made to minimise impacts of trampling and camping in high altitude sites in the Australian Alps? Research assessing the impact of recreation on the environment is important for conservation of protected areas. Recreation can affect a range of environmental components including vegetation and soils. These impacts can be measured using a range of parameters including vegetation cover, composition and height and soil compaction. When assessing the impact of recreation on vegetation and soils, four factors need to be considered: (1) amount of use; (2) type of use and behaviour; (3) timing of use; and (4) environmental characteristics. In this thesis it is proposed that low levels of recreation use may not cause significant damage to vegetation until a primary threshold point is reached where increasing use results in rapidly increasing amounts of damage. A second threshold may then be found above which increasing use does not result in significantly more damage. Type and intensity of impacts can vary among different activities so the effects of camping and trampling (which are popular activities in the area) were both examined at varying intensities of use. As vegetation types may also vary in their response, the impact of activities on different communities were compared. Finally, the effect of trampling after large scale fires was examined. Kosciuszko National Park is a unique mountain area that has been used for a variety of activities since European settlement. Tourism is now one of the largest land uses of the Park with indications of continued growth from the mid 1950's through until the early 1990's. As the area has high conservation values, minimising the amount of disturbance to the environment caused by tourists is important for the long term management of the Park. Based on an extensive analysis of visitor survey data collected prior to the thesis in the 1999/2000 non-winter period, it was possible to characterise recreational use of the largest alpine area in Australia. Like many protected areas around the world, recreational use in Kosciuszko National Park is increasing during the non-winter period. During this survey, 102 000 visitors were estimated as entering the Kosciuszko alpine area with approximately 47 000 visitors undertaking activities of a half a day or more. This is a 10% increase since the previous estimate from the 1990/91 non-winter period. A variety of activities are undertaken within the area including sightseeing, day walking, mountain biking and camping. For camping, most trips were undertaken by small groups for short periods. Therefore the impacts to vegetation from one and three nights camping by groups of four people were assessed using an experimental approach. Camping for both one and three nights affected vegetation height, but to different extents. After three nights camping, there was a decrease in vegetation height in the tent and activity areas while after one night camping, a decrease in vegetation height only occurred in the tent area. Camping for three nights caused a short term increase in dead material, however six weeks after camping there was no difference in the cover of dead material among the control, tent or activities areas indicating that the effect was short lived. One night camping did not result in any significant increase in dead material. Bushwalking is one of the most popular activities to be undertaken in the Australian Alps including the Kosciuszko alpine area. Many visitors undertaking walks during this time depart hardened tracks in order to reach destinations such as mountain peaks and glacial lakes. An obvious impact of this trampling is the creation of pads and trails as the vegetation cover is replaced by bare soil that then becomes compacted and/or erodes. The thresholds before signs of disturbance occur as a result of trampling vary among vegetation communities and among parameters measured. Generally, primary thresholds were exceeded after moderate use with damage still evident one year later. Reduced vegetation height occurred at lower levels of use, but recovered quickly. Vegetation cover showed limited recovery once damaged. This was particularly apparent for bog communities, which also had very low resistance to damage. Repeat trampling in the following year compounded the damage and lowered the primary thresholds. Impacts and thresholds from trampling in subalpine areas within weeks of the landscape level bushfires in 2003 differed from those in the undisturbed community. Where areas had been burnt, low levels of trampling caused exposure and loss of underlying bare soils with secondary thresholds reached at low to moderate use. These thresholds occurred for both extensively burnt and partially burnt areas. The damage caused by trampling however, was rapidly eclipsed by natural processes with no significant effects after one year. When examining the impacts of trampling in extensively burnt subalpine grasslands one year after the bushfires the thresholds for cover were again lower than undisturbed conditions even though there was substantial vegetation recovery from the fires. Low to moderate use was required to exceed the primary threshold for vegetation cover with a secondary threshold achieved after moderate use. Twelve months of recovery had however, allowed soils to become more cohesive with moderate to high trampling use now required to cause significant losses of soil. This research has shown that the identification of two thresholds of disturbance will be beneficial for management decision making. A primary threshold will define the upper limit of use for dispersed recreational use while a secondary threshold will define when concentrated use should occur. This information is valuable, as while the resistance of the vegetation communities examined in this research was moderate in some communities, resilience was always low. As such, recovery from disturbance will be slow and damage should therefore be minimised as much as possible.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environmental and Applied Science
Full Text

The study has attempted to characterise the physicochemical limnology and distribution of algal flora of two salt lake systems in Western Australia, one from the coastal Esperance region and the other from the inland Kambalda region. Climatic conditions, water regimes and physicochemistry were found to differ markedly between the two lake systems and a total of 171 algal taxa, representing five divisions, were recorded. Of these, 82 were members of Bacillariophyta, 48 of Cyanophyta, 33 of Chlorophyta, two of Euglenophyta and six of Dinophyta. The physical limnology of salt lakes in the Esperance region was seasonally variable, defined by climatic conditions. As such, the lakes investigated in the region exhibited a stable cycle of filling during winter and spring, and drying out in summer. Four of the lakes in the region could be classified as near-permanent, and one as seasonal on the basis of predictability and duration of filling. Seasonal fluctuations in water depth resulted in fluctuations in salinity levels. Salinity levels ranged from subsaline to hypersaline, and all the lakes in the region were alkaline. In addition, the lakes were well mixed in terms of oxygen and temperature, and were impacted by eutrophication from their catchments. They were either mesotrophic or eutrophic with respect to both nitrogen and phosphorus. In geological terms, lakes in the Esperance region were separated only recently from the ocean, and two lakes retain a connection with marine waters, one through a creek during years of high rainfall and one through hydrological interactions with groundwater of marine origin. In general, the algal communities of lakes in the Esperance region were similar to those of other Australian coastal salt lakes.
Diatoms and cyanobacteria were dominant in all lakes except the most eutrophic, Lake Warden, in which benthic green algae were most abundant. All algal species recorded were known for their wide geographic distribution and their distribution in Australian coastal waters. Characteristically coastal diatom species included Achnanthes brevipes, Achnanthes coarctata, Achnanthes lanceolata var. dubia, Achnanthidium cruciculum, Campylodiscus clypeus, Cyclotella atomus, Cyclotella meneghiniana, Cyclotella striata, Mastogloia elliptica, Mastoglia pumila, Nitzschia punctata and Thalassiosira weissflogii. The inland salt lakes of the Kambalda region form part of an extensive palaeodrainage system, and were much less predictable in terms water regime than lakes in Esperance. Water depth was determined by seasonal variability in rainfall and evaporation, and by summer cyclonic rainfall events that were unreliable from year to year. In addition, rainfall varied spatially within the region. As such, most lakes were classified as intermittent. Two lakes in the region were not classified on the basis of water regime as they were too highly impacted by mining activities including water diversion and impoundment, water extraction and discharge of groundwater. Salinity varied in accordance with drying and filling cycles in the lakes except the most hypersaline as the volume of water received during rainfall events was insufficient to dilute the extensive surface salt crusts they each supported when dry. Salinities recorded in the region ranged from subsaline to hypersaline, and ionic compositions exhibited the same spectrum as seawater.
Calcium levels were significantly higher than in lakes from the Esperance region due to weathering of calcium rich sediments, and pH ranged from weakly acidic in the most hypersaline lakes to alkaline in the least saline lakes. All were well mixed in terms of oxygen and temperature. Kambalda salt lakes support distinctive algal communities dominated by diatoms and cyanobacteria that are adapted to intermittent water regimes, extended periods of desiccation and variable salinity. Not surprisingly then, none of the algal taxa recorded from the region were regionally restricted, all noted previously in the literature to have wide geographic distributions, and to be tolerant of a range of physicochemical conditions. Canonical correspondence analysis showed that, of the physicochemical parameters that were investigated in this study, both salinity and pH interacted in determining algal community structure. Both of these attributes were correlated with water depth, which varied according to climatic conditions in a seasonal drying and filling cycle. The general relationship between species richness and pH and salinity, and species diversity and pH and salinity was simple and linear; with increasing pH and salinity, species diversity and species richness decreased. What was less simple, and non-linear, was the nature of the relationship between species richness and diversity and salinity within more narrowly defined ranges of salinity. As salinity increased from <1ppt to 30ppt there was a dramatic reduction in species richness and diversity, then, as salinity increased from 30ppt to 100ppt the rate of decrease slowed. Between 100ppt and 250ppt there was almost no relationship between salinity and species richness and species diversity, but after 250ppt both species diversity and species richness declined markedly.

Early nineteenth-century Eurocentric perceptions of natural history led to the flora and fauna of Australia being thought of as deficient and inferior compared with those of other lands. By the 1820s, Australia had become known as ???the land of contrarieties???. This, and Eurocentric attitudes to nature in general, influenced the expectations and perceptions of immigrants throughout the century. Yet at the same time there was developing an aesthetic appreciation of the natural history of Australia. This thesis examines the tension between these two perceptions in the popular natural history writing of the nineteenth century, mainly through the writing of five authors ??? George Bennett (1804-1893), Louisa Anne Meredith (1812-1895), Samuel Hannaford (1937-1874), Horace Wheelwright (1815-1865) and Donald Macdonald (1859?-1932). George Bennett was a scientist, who saw Australian plants and animals more as scientific specimens than objects of beauty. Louisa Meredith perceived them in the familiar language of English romantic poetry. Samuel Hannaford used another language, that of popular British natural history writers of the mid-nineteenth century. To Horace Wheelwright, Australian animals were equally valuable to the sportsman???s gun as to the naturalist???s pen. Donald Macdonald was the only one of these major writers to have been born in Australia. Although proud of his British heritage, he rejoiced in the beauty of his native land. His writing demonstrates his joy, and his novel attitude to Australian natural history continued and developed in the present century.

This thesis is a comparative study of the life history strategies, and in particular seed germination requirements, in Australian species of the halophyte plant genus Frankenia L. (Frankeniaceae). Frankenia is a cosmopolitan genus that occurs in Mediterranean, semi-arid, and arid regions on distinctive soil types – commonly on saline, sodic or gypseous soils – in habitats such as coastal cliffs, and on the margins of salt lakes, salt-pans and saltmarshes (Summerhayes 1930; Barnsley 1982). The plants are small shrubs or cushion-bushes with pink, white or pale purple flowers, and salt-encrusted recurved leaves. This project investigates germination requirements for Frankenia in relation to seed age, light requirements, temperature preferences, salinity tolerance, and soil characteristics. It also explores two divergent reproductive strategies – notably seed packaging strategies – in relation to environmental variables. Within the 46 currently recognized endemic Australia species, some species have a few ovules per flower and produce only a few larger seeds per fruit, while other species have many ovules per flower and produce many small seeds per fruit. Large-seededness is thought to increase the probability of successful seedling establishment in drought and salt-stressed environments. As both larger- and smaller-seeded species of Frankenia co-occur in close geographical proximity, hypotheses regarding the advantages of large-seededness in stress environments can be tested. By restricting the analysis of seed mass variation to similar habitats and within a single plant genus, it is possible to test ecological correlates that would otherwise be masked by the strong effects of habitat differences and phylogenetic constraints. Overall, larger-seeded Frankenia species were demonstrated to be advantageous for rapid germination after transitory water availability, and for providing resources to seedlings if resources became limiting before their successful establishment. Smaller-seeded species delayed germination until both soil-water availability and cooler temperatures persisted over a longer time period, improving chances of successful establishment for the more slowly growing seedlings that are more reliant on their surroundings for resources. This study produces information on the seed and seedling biology of many Australian species of Frankenia including several that are of conservation significance, e.g. F. crispa with its isolated populations, and the rare and endangered F. plicata. This information is important for the development of conservation management plans for these and other arid zone, halophyte species. In addition, the results of this study are of practical significance in determining the suitability of Frankenia for inclusion in salinity remediation and mine-site rehabilitation projects, and for promoting Frankenia as a drought and salt tolerant garden plant.

Borya mirabilis is one of the world's most critically endangered plants. The research in this thesis has illuminated key aspects of: its reproductive biology; interspecies and intraspecies molecular relationships, mycorrhizal status, tissue culture potential and disease threats. Each of these aspects has fundamental management implications for the active management of B. mirabilis. Floral observations of B. mirabilis and related species affirmed the uniqueness of the Boryaceae amongst the Asparagales. B. mirabilis had an unusually high number of floral abnormalities compared with other species of Borya observed. B. mirabilis is fly-pollinated. Pollen of Borya species showed little difference in the characteristics of mature pollen between species, with viable pollen being prolate and unicolpate with a single colpa-style aperture and a unique patterning of the pila. The structural immaturity of B. mirabilis pollen correlated with evidence from pollen growth experiments, where B. mirabilis pollen had extremely low germination rates, with those grains that did germinate being slow to do so and with slow-growing pollen tubes compared to those of fertile Borya species. Examination of the ovules of B. mirabilis showed that morphologically they were viable compared to viable Borya species. The field population of B. mirabilis was crossed, with one seed produced (the first recorded seed for th is species). Cross-pollination using the pollen of the closely related B. constricta and B. sphaerocephala with B. mirabilis ovules proved unsuccessful. Examination of the chromosome number of B. mirabilis showed that it had approximately 66 chromosomes and is probably hexaploid, relative to the diploid number of 26 in B. constricta. This may explain its low fertility. Interspecies and intraspecies relationships of the Boryaceae and Borya mirabilis were investigated using sequences of chloroplast and nuclear DNA. The closest similarities to B. mirabilis were B. constricta and B. sphaerocephala. B. mirabilis may have emerged from alloploidy of these species in the past. Because of the consistent similarities of B. mirabilis and B. constricta chloroplast sequences, it is proposed that both shared a common ancestor with a chromosome number of 2n=22. A malfunction n meiosis may have resulted in ovules with 2n=44. The high similarity of the nuclear ribosomal ITS region DNA suggests that the nuclear DNA was derived from B. sphaerocephela. B. mirabilis may be an allopolyploid, from fertilisation of a diploid ovule of B. constricta with haploid pollen of B. sphaerocephala, resulting in a reproductively isolated polyploidy of low fertility. The wild population of B. mirabilis was determined to have a small amount of genetic variation. The genetic variation in the field population w as not fully reflected in the ex-situ population. An effective means of micro-propagation of B. nitida for use in B. mirabilis has been established, providing an effective means of mass production of the species. The research has determined: a suitable explant (shoot tips) for regeneration; an effective means of reducing contamination in tissue culture (PPM); what medium is required to micro-propagate the species (LMHM); an appropriate gelling agent (Phytagel); and a practical method for inducing roots on the shoots grown in tissue culture. B. mirabilis has been established as mycorrhizal. The predominant mycorrhizal association is a nodular arbuscular mycorrhiza, present in the form of coils in root nodules over wetter months and as spores in these nodules over dryer months. A significant increase in the health of the ex-situ population of B. mirabilis was recorded after addition of soil containing fine roots of the wild population. Of the plants associated with the wild population, Callitris rhomboidea had the most morphologically similar vesicular arbuscular mycorrhizal relationship. But molecular identification was not achieved due to recalcitrance of DNA in PCR attempts. Potential translocation sites for some of the ex-situ population of B. mirabilis were examined for Phytophthora infestation. Reid's Lookout and Mackey's Peak were infected with P. cinnamomi. Vegetation at Mackey's Peak displayed characteristic infection symptoms, resulted in isolates of P. cinnamomi from baiting and would directly receive runoff from both the walking track and the existing infested B .mirabilis site. At the Reid's Lookout site, both walking track and proposed translocation site were infested with P. cinnamomi, yet did not display the associated symptoms in the vegetation. The Pine Plantation translocation site was uninfected at the level of sampling undertaken. Its vegetation did not display any characteristic infection symptoms and was not isolated when soil samples were baited. It was therefore chosen for translocation and so far the plants are healthy and actively growing. This research has provided critical knowledge to aid the recovery team in its current and future endeavours to manage this species and bring it back from the brink of extinction.

　　　The Annonaceae is a large, early-divergent family of angiosperms. Although the majority is pollinated by small beetles, there is a great diversity of floral morphologies. Evolutionary shifts of pollination mechanisms have occasionally been reported in disparate lineages including shifts to pollination by large beetles, flies, thrips, bees and cockroaches. It was previously hypothesized that floral morphological changes in different lineages are adaptive and correspond to evolutionary shifts of pollination mechanisms. This hypothesis is tested here by comparing selected species that have substantial morphological differences with their close relatives. 　Comprehensive studies of the floral biology of four Annonaceae species, Dasymaschalon trichophorum, Desmos chinensis, Pseuduvaria mulgraveana and Uvaria cordata, are presented. All are beetle-pollinated. Dasymaschalon trichophorum, D. chinensis and U. cordata were inferred to be self-compatible based on inter-simple sequence repeat marker data as there was evidence of significant gene flow and a low level of genetic differentiation between populations. This was corroborated for D. chinensis and U. cordata by experimental controlled pollination tests for geitonogamy, in which both were shown to set fruit. 　　　Similar floral phenological and pollination ecological results were obtained for D. chinensis and D. trichophorum despite significant differences in floral architecture, as the former has six petals (typical of most other Annonaceae species), whilst the latter only has three. The results suggested that the substantial change in floral morphology in these two closely-related genera is probably non-adaptive as there is no change in pollination system. It is hypothesised that the morphological change is likely due to the disruption of homeotic gene expression during floral organ development. 　　　Studies of floral phenology and pollination ecology of Uvaria cordata revealed that it has a 3-day flowering rhythm and is pollinated by small beetles. The pollination ecology is unexpectedly similar to other species with typical beetle-pollination syndromes, although it lacks a pollination chamber and has pale-colored petals. It is suggested that species that lack a pollination chamber are more likely to be pollinated by guilds other than beetles or thrips as a floral chamber increases pollinator specificity. Several morphological and phenological characters are also presumably correlated with the evolution of generalist pollination to increase the pollination efficiency and assure fruit production, including torus shape, petal orientation, stigma shape, petal color, carpel and/or ovule number and the overlap of pistillate and staminate phases. 　　　Pseuduvaria is unusual in the Annonaceae as the majority of species possess unisexual flowers. Most species were previously interpreted as having staminate and structurally pistillate flowers, with infertile staminodes in the latter. The ‘pistillate’ flowers of P. mulgraveana are shown to produce viable pollen, however, contradicting this hypothesis. It is therefore recommended that floral unisexuality in the genus be reassessed by testing more species from different clades. Different strategies to promote xenogamy in the Annonaceae are reviewed, including protogyny, herkogamy, intra- and inter-individual phenological synchrony and dioecy. Three different mechanisms were recognized to achieve dioecy, including incomplete pollen development in hermaphroditic flowers, delayed anther dehiscence in hermaphroditic flowers and loss of androecium or gynoecium (with Pseuduvaria used as a paradigm).
published_or_final_version
Biological Sciences
Doctoral
Doctor of Philosophy

The issue of sustainability has greatest significance in the midst of unilateral bio-socioeconomic degradation resulting from intense and increasing societal pressures placed on the unified global ecology. In such an environment, sustainable development seeks to manage natural resources within a free market economy, aiming to meet the needs of today's population, and to protect and enhance current resource quality and abundance. In this light, techniques of integrated sustainable primary production and wastewater management are the subject matters of this applied research. There are many researchable issues which could be addressed within the subject matter. The first focus in the research scope was driven by the most severe sustainability issue facing Central Queensland (Australia) in 2000: the depletion and degradation of freshwater supplies. Central Queensland (CQ) is an arid sub-tropical region that has suffered from a marked reduction in rainfall and increase in temperature over the last 100 years, {Miles, 2004 #172}, and by the year 2000, conditions had been exacerbated by eight years of severe drought and warmer than average temperatures and resulted in widespread animal and crop failures due to freshwater shortages. Such a problem required a multi-faceted ecological, social, and economic approach. Hence, research centred on investigating the science of integrating regional water-related industries and agribusiness, and biodiverse ecosystems to achieve water and wastewater reuse applications, and associated eco-socioeconomic benefits. Specifically, this research investigates the integration of (a) electrical power station wastewater (b) barramundi culture, (c) red claw culture, (d) constructed wetlands (for water quality management and habitat creation), and (e) hydroponic flower culture. This research produced outcomes of integrated water and wastewater reuse and recycling, marketable agriproducts production (fish, crayfish, and flowers), water and wastewater reuse and conservation, wetland primary production, carbon dioxide sequestration, aquatic pollution control, and biodiversity creation and support. Successful design and management, experimental trialing and evaluation of system components and subjects, and the development of a knowledge base including static and dynamic system models, represent advances in respective research areas, and underpin the emerging discipline of integrated systems approaches to eco-socioeconomic development. Additionally, several gaps in the current body of knowledge regarding integrated systems were filled, and interactive management tools were developed. Apart from this study, the integration of technologies (as described above) has not, to this author's knowledge, been accomplished.

Doctor of Philosophy (PhD)
A renewed focus on generalised pollinator systems has inspired a conceptual framework which highlights that spatial and temporal interactions among plants and their assemblage of pollinators can vary across the individual, population, regional and species levels. Pollination is clearly a dynamic interaction, varying in the number and interdependence of participants and the strength of the outcome of the interaction. Therefore, the role of variation in pollination is fundamental for understanding ecological dynamics of plant populations and is a major factor in the evolution and maintenance of generalised and specialised pollination systems. My study centred on these basic concepts by addressing the following questions: (1) How variable are pollinators in a generalised pollination system? To what degree do insect visitation rates and assemblage composition vary spatially among populations and temporally among flowering seasons? (2) How does variation in pollinators affect plant reproductive success? I chose to do this using a model system, Trachymene incisa subsp. incisa (Apiaceae), which is a widespread Australian herbaceous species with simple white flowers grouped into umbels that attract a high diversity of insect visitors. The Apiaceae are considered to be highly generalist in terms of pollination, due to their simple and uniform floral display and easily accessible floral rewards. Three populations of T. incisa located between 70 km and 210 km apart were studied over 2-3 years. The few studies investigating spatial and temporal variation simultaneously over geographic and yearly/seasonal scales indicate that there is a trend for more spatial than temporal variation in pollinators of generalist-pollinated plants. My study showed both spatial and temporal variation in assemblage composition among all populations and variation in insect visitation rates, in the form of a significant population by year interaction. However, removing ants from the analyses to restrict the assemblage to flying insects and the most likely pollinators, resulted in a significant difference in overall visitation rate between years but no difference in assemblage composition between the Myall Lakes and Tomago populations. These results indicate more temporal than spatial variation in the flying insect visitor assemblage of T. incisa. Foraging behaviour provides another source of variation in plant-pollinator interactions. Trachymene incisa exhibits umbels that function as either male or female at any one time and offer different floral rewards in each phase. For successful pollination, pollinators must visit both male and female umbels during a foraging trip. Insects showed both preferences and non-preferences for umbel phases in natural patches where the gender ratio was male biased. In contrast, insects showed no bias in visitation during a foraging trip or in time spent foraging on male and female umbels in experimental arrays where the gender ratio was equal. Pollinator assemblages consisting of a mixture of different pollinator types coupled with temporal variation in the assemblages of populations among years maintains generalisation at the population/local level. In addition, spatial variation in assemblages among populations maintains generalisation at the species level. Fire alters pollination in T. incisa by shifting the flowering season and reducing the abundance of flying insects. Therefore, fire plays an important role in maintaining spatial and temporal variation in this fire-prone system. Although insect pollinators are important in determining the mating opportunities of 90% of flowering plant species worldwide, few studies have looked at the effects of variation in pollinator assemblages on plant reproductive success and mating. In T. incisa, high insect visitation rates do not guarantee high plant reproductive success, indicating that the quality of visit is more important than the rate of visitation. This is shown by comparing the Agnes Banks and Myall Lakes populations in 2003: Agnes Banks received the highest visitation rate from an assemblage dominated by ants but produced the lowest reproductive output, and Myall Lakes received the lowest visitation rate by an assemblage dominated by a native bee and produced the highest seedling emergence. Interestingly, populations with different assemblage composition can produce similar percentage seed set per umbel. However, similar percentage seed set did not result in similar percentage seedling emergence. Differences among years in reproductive output (total seed production) were due to differences in umbel production (reproductive effort) and proportion of umbels with seeds, and not seed set per umbel. Trachymene incisa is self-compatible and suffers weak to intermediate levels of inbreeding depression through early stages of the life cycle when seeds are self-pollinated and biparentally inbred. Floral phenology, in the form of synchronous protandry, plays an important role in avoiding self-pollination within umbels and reducing the chance of geitonogamous pollination between umbels on the same plant. Although pollinators can increase the rate of inbreeding in T. incisa by foraging on both male and female phase umbels on the same plant or closely related plants, most consecutive insect movements were between plants not located adjacent to each other. This indicates that inbreeding is mostly avoided and that T. incisa is a predominantly outcrossing species, although further genetic analyses are required to confirm this hypothesis. A new conceptual understanding has emerged from the key empirical results in the study of this model generalised pollination system. The large differences among populations and between years indicate that populations are not equally serviced by pollinators and are not equally generalist. Insect visitation rates varied significantly throughout the day, highlighting that sampling of pollinators at one time will result in an inaccurate estimate and usually underestimate the degree of generalisation. The visitor assemblage is not equivalent to the pollinator assemblage, although non-pollinating floral visitors are likely to influence the overall effectiveness of the pollinator assemblage. Given the high degree of variation in both the number of pollinator species and number of pollinator types, I have constructed a model which includes the degree of ecological and functional specialisation of a plant species on pollinators and the variation encountered across different levels of plant organisation. This model describes the ecological or current state of plant species and their pollinators, as well as presenting the patterns of generalisation across a range of populations, which is critical for understanding the evolution and maintenance of the system. In-depth examination of pollination systems is required in order to understand the range of strategies utilised by plants and their pollinators, and I advocate a complete floral visitor assemblage approach to future studies in pollination ecology. In particular, future studies should focus on the role of introduced pollinators in altering generalised plant-pollinator systems and the contribution of non-pollinating floral visitors to pollinator assemblage effectiveness. Comparative studies involving plants with highly conserved floral displays, such as those in the genus Trachymene and in the Apiaceae, will be useful for investigating the dynamics of generalised pollination systems across a range of widespread and restricted species.

The Australian temperate flora mostly comprises sclerophyllous elements that are a dominant and characteristic feature of the southern half of the Australian continent. Despite being a characteristic component of the Australian biota, the diversification dynamics and evolutionary history of this flora remains poorly understood. In particular, studies on evolutionary drivers that gave rise to the plant species disparity observed between the southwest Australian global biodiversity hotspot region (SWA) and southeastern temperate Australia (SEA) are lacking. In this thesis, I address this gap in knowledge through assessments of (1) differences in diversification dynamics between the two Australian temperate floras at different spatial and temporal scales, (2) biogeographic patterns of different groups found in the two regions, and (3) potential evolutionary drivers that might have given rise to these patterns. I utilise a molecular phylogenetic approach and test for region-specific diversification dynamics as well as more detailed investigations on selected case study groups. In Chapter 1, a broad-scale genus-level meta-analysis across 21 plant families is used to assess differences in diversification dynamics between the two regions under several diversification models. I demonstrated that a major extinction pulse event at the Eocene–Oligocene boundary (c. 34 Ma) negatively affected the diversification of major plant groups in SEA, but not in SWA, and this in part, explains current disparities in species richness between the two regions. In Section 2, Chapters 3–5, I assess biogeographic patterns and evolutionary histories of three case study groups of Australian temperate flora: Calytrix (Myrtaceae), Pomaderris (Rhamnaceae), and Adenanthos (Proteaceae). Results indicate all of these plant groups previously had a more widespread distribution, and retreated to the mesic periphery of the continent as Australia progressively cooled in the Oligocene and became increasingly arid from the Miocene onwards. I uncovered significant incongruences between nuclear and chloroplast topologies of Adenanthos, complicating biogeographic inferences for this genus, but revealed a potential link between the radiation of Adenanthos with multiple introgression events during its early evolutionary history in SWA. The lineage-specific evolutionary responses of these case study groups indicate the need for a broader meta-analysis of multiple groups in order to better understand the evolutionary history of the wider regional flora. In Chapter 6 I collate dated phylogenies of 22 Australian temperate plant groups and use these to assess for radiation shifts, evidence of density-dependent slowdowns indicative of niche-space filling, and differences in diversification rates between SWA and SEA. In addition, I compare average region-wide diversification rates of each of the two regions with other global centres of biodiversity. These comparisons indicate that the diversification dynamics of the Australian flora are fundamentally different to most other biodiversity hotspots and species-rich biomes and that SWA that has no comparable global analogue. My thesis highlights the antiquity of the Australian temperate flora, its gradual accumulation of lineages, lack of recent radiation shifts, the persistence of ancient lineages, and low diversification rates. The lack of extreme large-scale environmental pulse events and tectonic activity across the subdued Australian landscape may explain these patterns. I conclude that evolutionary drivers for the Australian temperate flora may be fundamentally different to those seen in other biodiverse regions of the world.
Thesis (Ph.D.) -- University of Adelaide, School of Biological Sciences, 2021

Chenopod taxa are globally prominent in deserts and on coastlines which suggests an evolutionary link, known as a littoral connection, and that remains unexplained. Australia is a global centre of chenopod diversity, where serial invasions of eleven immigrant clades over the last 16 million years, produced ca. 300 species within the continent. Six of these clades adaptively radiated in the Late Miocene-Pliocene within the continental interior. Assuming a littoral connection as a working premise, Australian landscape history can inform the course of chenopod evolution. Almost all species are endemic and each clade must exhibit the three elements of the connection. Coasts and deserts share related taxa, marshy, sandy or saline habitats and adaptive traits for habitat occupation. Phytogeographic analysis defines three groups of Australian chenopods. A Subcontinental Arid-Mediterranean Group has 97% of all species with Centres of Diversity in the west (Yilgarn) and east (Eyre-Murray). Sharing 129 species, the centres are strongly linked through the Great Victoria Desert, suggesting a common migration route. The chenopod poor Northern Tropical and Eastern Highlands groups suggest the barriers to range expansions. Diversification largely occurred inland, with 246 species being remote from coastlines. Only the Scleroblitum Clade lacks coastal taxa, but it has an estuarine ancestor. Under the habitat element of a littoral connection, migration landscapes should be marshy, sandy or saline. Chenopod taxa mainly inhabit Riverine Desert (141 species) and Desert Lake (113 species) within continental drainage systems. Most coastal species are of diverse coastal habitats, with a capacity for inland range expansion through marshy ecosystems. Riverine Desert developed as chenopod clades arrived, connecting coastlines to both Centres of Diversity. Youth and discontinuity of Desert Lake precludes initial continental migration but promoted Pleistocene speciation. Sand Desert has relatively few species; a Pleistocene age postdates inland range expansion and its formation contributed to species population disjunction in rich clades. Molecular phylogeny of Australian Atriplex Clade 1 reveals west to east migrations in two lineages after immigrant landfall on the west coast. One lineage migrated through inland Australia, initially diversifying in Stony Desert. The other lineage is limited to the southern coast and Western Australian catchments. Poor phylogenetic resolution in Atriplex Clade 2 precluded further interpretation, but initial diversification post-dates that of Atriplex Clade 1. Coastal species possibly have basal phylogenetic positions in both clades. These findings suggest evolutionary stages of Australian chenopods involve: coastal landfall, initial inland migration through declining palaeodrainage systems and diversification in drying landscapes, along two possible biogeographic patterns. Either an initial, widespread inland migration fragmented into the Yilgarn and Eyre-Murray Centres, or separate, incipient Centres subsequently enlarged and exchanged species. Species extinction may be associated with dune field formation and loss of ancestral coastal taxa. Riverine Desert provided the species pool for significant speciation in Desert Lake and Stony Desert land types. Each immigrant clade observes the taxon, habitat and trait elements of a littoral connection, which remains the most likely evolutionary scenario for these iconic Australian arid taxa.
Thesis (Ph.D.) -- University of Adelaide, School of Biological Sciences, 2020

Elizabeth Joyce investigated the Sunda-Sahul Floristic Exchange using floristic, phylogeographic and phylogenomic approaches. She compiled the first preliminary regional plant checklist, found the SSFE had a substantial impact on floristic composition, identified two exchange tracks from Southeast Asia into Australia, and found that in Anacardiaceae (Sapindales) extinction affected SSFE dynamics.

Includes bibliographies.
4 v. :
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Thesis (Ph.D.)--University of Adelaide, Depts. of Geology & Geophysics and Botany, 1997?

This practice-led research investigates ways in which representations of Australian flora on ceramic vessels can communicate ideas about current environmental culture. The project developed from a curiosity about whether changing attitudes to Australia's environment, from colonisation to the present time of unprecedented species decline, might be found reflected on historical and contemporary ceramic objects. Botanical exploration and the scientific study of Australia's vast flora have produced a rich resource of natural history documentation. The aim was to establish a framework specific to the project that utilises these resources and current theoretical and practical approaches to understanding flora and the environment in both the sciences and humanities. Through this interdisciplinary enquiry, visual arts and botanical research methodologies intersected in the studio informing material, technical and conceptual developments. This exploration takes the form of an installation of wheel thrown vessels with carved and inlaid surface imagery of Australian flora, where, through form, imagery, material and placement, a metaphorical space is made in which to reflect on current environmental culture.

The research detailed in this dissertation focuses on plant and faunal remains preserved in the accumulating sediments at aestivation sites of the Bogong Moth (Agrotis infusa), in the crevices of granite tors in the northern Australian Alps. Analyses have confirmed the preservation of a diverse range of fossil material, including bird feathers, hairs of small marsupials occupying the rock crevice niche, fossil pollen and spores derived from the summit vegetation, and charcoal from fires in the immediate vicinity of the aestivation sites. The fieldwork focused on the sampling of deposits at various aestivation sites representative of different biogeographical areas to ascertain the sedimentary characteristics of each region. Three aestivation study areas were located and sampled for the study, the Brindabella Ranges, the Bogong Peaks and the Tinderry Range in NSW. The Tinderry Range sites represent the most easterly geographical region, while the Bogong Peaks site and Brindabella Ranges sites represent, respectively, the western and central aestivation site regions of the northern Australian Alps area. Since preservation of organic material typically occurs in a stable low oxygen environment, investigation into the depositional environment is an important aspect of the study to taphonomically contextualise the environmental proxies. The palynological preparation of material from the three regions revealed abundant pollen derived from local vegetation. A rich assemblage of mammal hair was found in the Bogong Peaks and Mt Gingera sediments. This record provides a unique faunal proxy of sub-alpine ecosystems. Levels of charcoal in the sediments reflect past fire frequency, and are presented in both micro- and macro-charcoal graphs. Aestivation site deposits are a unique terrestrial archive recording ecological change in the montane and sub-alpine environments for over 1000 years. Despite some chronometric difficulties, they provide an excellent record of the effects of local disturbance, such as fires, on the biome and provide insights into the impact of European settlement, on both vegetation structure and faunal biodiversity. The study provides evidence of massive cultural, ecological and climatic upheaval at sub-alpine elevations in the northern Australian Alps from the late Holocene up to the present, and illustrates the great value that aestivation sites hold as terrestrial archives, signalling a need for further utilisation and investigation in light of rapid human induced climate change.

"This study was undertaken to increase knowledge of estuarine processes in tropical, macrotidal coasts. It was also done to understand the implications for managing 'sea-change' development in a little known area of the Australian-Pacific zone. The study area is the Capricorn Coast: a newly expanding site that interfaces with the Great Barrier Reef lagoon and lies adjacent to the Fitzroy: the largest Australian river flowing into the Pacific" -- Abstract.

Snow is an important factor in the lives of flora and fauna in those regions where it occurs. Despite this, there is a relative lack of information about the ecological role of snow. In addition, on a global scale the majority of the research on snow ecology has been based in the boreal regions of North America and Eurasia. Insights from these areas may not extrapolate well to Australia. The distribution and physical characteristics of snow are highly variable both temporally and spatially. Its occurrence is affected by a range of factors acting at multiple scales. Working in snow covered areas, however, presents considerable practical problems, particularly for researchers attempting to sample organisms in the subnivean space between the base of the snowpack and the ground surface. As a result, most research has focused on small-scale projects because of logistical and animal-welfare issues. A technique was developed for this study for sampling small mammals beneath the snow using hairtubes fitted with bait and a removable adhesive surface that could be inserted into the subnivean space through a vertical PVC pipe. The technique provided a 39% detection rate with only 0.2% of tubes visited but not collecting hair samples. Using. this technique, it was possible to expand systematic sampling of small mammals in the subnivean space to larger scales at which snow cover can vary spatially and temporally particularly at the landscape scale. The main part of this research was conducted over two winters (2002-2003) at sites established in a series of valleys close to the Summit Road in Kosciuszko National Park, south-eastern Australia. Selection of sites was based on factors considered important in influencing the distribution of snow in the landscape and representative of the key vegetation types occurring in the subalpine zone. The resulting design consisted of 72 sites stratified by elevation (1501-1600 m, 1601-1700 m, 1701-1800 m), aspect (accumulating, ablating) and vegetation type (woodland, wet heath, dry heath, grassland) with each combination replicated three times. Each site consisted of three hairtube plots approximately 10 metres apart, at which small mammals were sampled. In addition, a range of biotic and abiotic factors including snow cover characteristics were measured throughout the winter at these same sites. In January 2003, a major bushfire burned 70% of the subalpine area of Kosciuszko National Park and damaged 83% of the sites established in 2002. As a result sampling during winter 2003 was limited to high elevation sites, along with a fifth habitat type (boulderfields). The snow cover that occurs in the main alpine and subalpine region of the· Snowy Mountains is primarily maritime in areas where there is sufficient accumulation, and ephemeral at lower elevations and ort higher ablating aspects. Maritime snow is generally deep (> lOOcm), with a density >0.30gcm-3, as a result of destructive metamorphism throughout the winter. The formation of depth hoar, which is considered to be important in acilitating the development of the subnivean space, does not occur under these conditions. Ephemeral snow is characterised by warm shallow snow that often melts before new snow is deposited. When snow was present, detections of dusky antechinus, Antechinus swainsonii and the bush rat, Rattus fuscipes were negatively correlated with snow depth and duration, and positively correlated with the complexity of structures and microtopography. At high elevations, detections were largely confined to boulderfields, and at mid- and low elevations, small mammals were detected primarily in habitats where the subnivean space was most extensive. Antechinus swainsonii and R. fuscipes responded differently to snow cover with the latter seeming better able to overwinter where snow cover was shallow and patchy. In contrast, A. swainsonii occurrence was correlated with the size of the subnivean space. The development of the subnivean space in the Snowy Mountains is dependent on the presence of structures such as shrubs, boulders and microtopographic features that are capable of supporting a snow layer above ground level. The temperature in the subnivean space was virtually constant beneath the snowpack, ranging between 0 and + 1 °C. When snow was patchy or absent, temperatures at ground level were highly variable with a minimum as low s -13°C and maximum as high as +47.5°C. Antechinus swainsonii and R. fuscipes were detected more regularly at sites that were thermally variable. At sites with deep and persistent snow cover (maritime snow), subnivean temperatures were stable, but small mammals were detected at low frequencies. At high elevations, boulderfields were favoured by small mammals during the nival period but were no different thermally from other habitats. The limitations imposed by snow cover on small mammals were further verified by a radio tracking study conducted during 2003 at Perisher Creek. That study investigated the home range size and activity patterns of R. fuscipes and A. swainsonii in relation to snow cover. Once continuous snow cover became established, the home range of both species contracted dramatically and there was an increase in home range overlap. Neither species showed any change in diurnal activity patterns. Rattus fascipes showed signs of social interaction during both seasons in contrast to A. swainsonii, which appeared to remain solitary. In winter, R. fuscipes nested communally at a single location, while during autumn the species appeared to use a number of nest sites. There was no significant change in daily activity patterns between autumn and winter in either species. R. fuscipes remained primarily nocturnal during both pre-nival and nival periods while A. swainsonii continued to be active throughout the diel cycle, although there was a slight shift in its peak activity time. Human activities can, have significant effects on the subnivean space and its residents. The physical characteristics of a range of modified snow types were investigated in the vicinity of several ski resorts in Kosciuszko National Park. Human activities associated with snow-based recreation, such as the creation of ski pistes, surface ski lifts and over-snow routes, involve compression of the snowpack and resulted in small or absent subnivean spaces and high snow cover densities compared to unmodified snow cover. To test the effects of the loss of the subnivean space on small mammals, the snowpack was experimentally compressed in high quality subnivean habitats. Detections of R. fascipes and A. swainsonii declined by 75-80%. Burnt sites from the 2002 study were used in 2003 to investigate the effect of removing vegetation on the subnivean space, to simulate the loss of structure associated with ski slope preparation. There was a significant reduction (p<0.0001) in the size of the subnivean space compared to unburnt sites regardless of habitat type. The key conclusions of the work reported in this thesis are listed below: • Snow conditions in the Australian Alps are markedly different from those of higher northern latitudes and altitudes. As a result, conclusions about snow/fauna interactions based on research in regions with particular snow cover types need to be carefully considered before attempting to extrapolate generalisations to other parts of the world. • The subnivean space can be formed either by passive or active processes. The former occurs when there are sufficient competent structures to permit the support of the snow pack above the ground surface, while the latter refers to the ability of small mammals to actively tunnel through relatively low density snow (depth hoar) and thus create their own subnivean space. In Australia the passive process dominates. • The widely held assumption that small mammals are dependent on the thermally stable conditions in the subnivean space was not confirmed. Rattus fascipes and A. swainsonii survive in the Australian Alps because they are able to exploit thermally variable environments. • Management of human activities in nival areas should focus on avoiding disturbance in areas where a subnivean space forms, particularly in high quality winter habitats such as boulderfields. • Global warming resulting from climate change is likely to provide conditions in the Australian Alps that favour an expansion of the distribution and population of R. fuscipes and A. swainsonii, but nival endemics such as Burramys parvus and possibly Mastacomys fuscus may be at a disadvantage. • The extent of alpine and subalpine environments in Australia will decrease in future, imposing greater pressure on a shrinking resource and raising the possibility of conflict between user groups and conservation imperatives.

Assemblages of algae are altered by both bottom - up ( e.g. nutrient availability ) and top - down ( e.g. herbivory ) processes. As a result of the increasing human population in coastal areas, massive changes are forecast to benthic habitats in response to increasing coastal nutrient concentrations and a reduction in consumers. To identify the scales over which nutrients may have an effect, abundance of turf - forming algae growing as epiphytes on kelp ( Ecklonia radiata ) were related to water nutrient concentration across temperate Australia. In general, the percentage cover of epiphytes was greatest at sites with the greatest nutrient concentrations. By experimentally elevating mean nitrate concentration from the low 0.064 ± 0.01 µmol L [superscript - 1 ] to 0.121 ± 0.04 µmol L [superscript - 1 ], which was still only ~ 5 % of that measured on a more eutrophic coast, I was able to increase the percentage cover of epiphytes to match those seen on nutrient rich coasts, despite not matching the nutrient concentrations on those coasts. Hence, it appears that the effects of elevated nutrients will be disproportionately large on relatively oligotrophic coasts. Nutrient concentrations were also experimentally elevated to test whether the presence of an algal canopy or molluscan grazers were able to counter the effects of nutrient enrichment on algal assemblages. The loss of canopy - forming algae is likely to be a key precursor to nutrient driven changes of benthic habitats, because nutrients had no direct effect on algal assemblages in the presence of canopy - forming algae. In the absence of canopy - forming algae, space was quickly monopolised by turf - forming algae, but in the presence of elevated nutrients grazers were able to reduce the monopoly of turf - forming algae in favour of foliose algae. This switch in relative abundance of habitat may reflect greater consumption of nutrient rich turf - forming algae by grazers, possibly creating more space for other algae to colonise. Importantly, greater consumption of turf - forming algae in the presence of elevated nutrients may act as a mechanism to absorb the disproportionate effect of nutrients on oligotrophic coasts. In southern Australia, canopy - forming algae have a negative impact on the abundance of turf - forming algae. To assess the mechanisms by which an algal canopy may suppress turf - forming algae, abrasion by the canopy and water flow were experimentally reduced. Abrasion by the canopy reduced the percentage cover and biomass of turf - forming algae. In contrast to predictions, biomass and percentage cover of turf - forming algae were also reduced when water flow was reduced. Light intensity was substantially reduced when there was less water flow ( because of reduced movement in algal canopy ). However, the reduction in available light ( shading ) did not account for all of the observed reduction in biomass and percentage cover of turf - forming algae, suggesting that other factors are modified by water flow and may contribute to the loss of turf - forming algae. Habitat loss and fragmentation are well known to affect the diversity and abundance of fauna in habitat patches. I used experimental habitats to assess how fragmentation of turf habitats affects the diversity and abundance of two taxa of macroinvertebrates with different dispersal abilities. I established that increased isolation of habitats reduced the species richness and abundance of invertebrates with slow rates of dispersal, while the species richness and abundance of invertebrates with fast rates of dispersal were greatest in habitats that were far apart. In summary, this thesis provides an insight into some of the impacts associated with human populations in coastal areas, namely increased nutrient inputs, loss of grazers ( e.g. harvesting ), and loss of canopy algae and fragmentation of habitats. I show that increased nutrient concentrations in coastal waters can alter the relative abundance of algal species, and that some effects of elevated nutrients can be absorbed by the presence of grazers. I also show that elevated nutrients have no effect on algal assemblage in the presence of canopy - forming algae, and that canopies can suppress the colonisation of turf - forming algae. Finally, I show that the fragmentation of turf habitats affects taxa of invertebrates with different dispersal abilities in different ways. Whilst the contemporary ecology of much of the temperate Australian subtidal coast is considered to be relatively unaffected by human activity, this thesis shows that changes to top - down and bottom - up processes could have large consequences for habitats and their inhabitants.
Thesis (Ph.D.)--School of Earth and Environmental Sciences, 2005.

Assemblages of algae are altered by both bottom - up ( e.g. nutrient availability ) and top - down ( e.g. herbivory ) processes. As a result of the increasing human population in coastal areas, massive changes are forecast to benthic habitats in response to increasing coastal nutrient concentrations and a reduction in consumers. To identify the scales over which nutrients may have an effect, abundance of turf - forming algae growing as epiphytes on kelp ( Ecklonia radiata ) were related to water nutrient concentration across temperate Australia. In general, the percentage cover of epiphytes was greatest at sites with the greatest nutrient concentrations. By experimentally elevating mean nitrate concentration from the low 0.064 ± 0.01 µmol L [superscript - 1 ] to 0.121 ± 0.04 µmol L [superscript - 1 ], which was still only ~ 5 % of that measured on a more eutrophic coast, I was able to increase the percentage cover of epiphytes to match those seen on nutrient rich coasts, despite not matching the nutrient concentrations on those coasts. Hence, it appears that the effects of elevated nutrients will be disproportionately large on relatively oligotrophic coasts. Nutrient concentrations were also experimentally elevated to test whether the presence of an algal canopy or molluscan grazers were able to counter the effects of nutrient enrichment on algal assemblages. The loss of canopy - forming algae is likely to be a key precursor to nutrient driven changes of benthic habitats, because nutrients had no direct effect on algal assemblages in the presence of canopy - forming algae. In the absence of canopy - forming algae, space was quickly monopolised by turf - forming algae, but in the presence of elevated nutrients grazers were able to reduce the monopoly of turf - forming algae in favour of foliose algae. This switch in relative abundance of habitat may reflect greater consumption of nutrient rich turf - forming algae by grazers, possibly creating more space for other algae to colonise. Importantly, greater consumption of turf - forming algae in the presence of elevated nutrients may act as a mechanism to absorb the disproportionate effect of nutrients on oligotrophic coasts. In southern Australia, canopy - forming algae have a negative impact on the abundance of turf - forming algae. To assess the mechanisms by which an algal canopy may suppress turf - forming algae, abrasion by the canopy and water flow were experimentally reduced. Abrasion by the canopy reduced the percentage cover and biomass of turf - forming algae. In contrast to predictions, biomass and percentage cover of turf - forming algae were also reduced when water flow was reduced. Light intensity was substantially reduced when there was less water flow ( because of reduced movement in algal canopy ). However, the reduction in available light ( shading ) did not account for all of the observed reduction in biomass and percentage cover of turf - forming algae, suggesting that other factors are modified by water flow and may contribute to the loss of turf - forming algae. Habitat loss and fragmentation are well known to affect the diversity and abundance of fauna in habitat patches. I used experimental habitats to assess how fragmentation of turf habitats affects the diversity and abundance of two taxa of macroinvertebrates with different dispersal abilities. I established that increased isolation of habitats reduced the species richness and abundance of invertebrates with slow rates of dispersal, while the species richness and abundance of invertebrates with fast rates of dispersal were greatest in habitats that were far apart. In summary, this thesis provides an insight into some of the impacts associated with human populations in coastal areas, namely increased nutrient inputs, loss of grazers ( e.g. harvesting ), and loss of canopy algae and fragmentation of habitats. I show that increased nutrient concentrations in coastal waters can alter the relative abundance of algal species, and that some effects of elevated nutrients can be absorbed by the presence of grazers. I also show that elevated nutrients have no effect on algal assemblage in the presence of canopy - forming algae, and that canopies can suppress the colonisation of turf - forming algae. Finally, I show that the fragmentation of turf habitats affects taxa of invertebrates with different dispersal abilities in different ways. Whilst the contemporary ecology of much of the temperate Australian subtidal coast is considered to be relatively unaffected by human activity, this thesis shows that changes to top - down and bottom - up processes could have large consequences for habitats and their inhabitants.
Thesis (Ph.D.)--School of Earth and Environmental Sciences, 2005.

Offprints of the author's articles inserted
Bibliography: v. 2, leaves 106-111
2 v. : ill. (some col.) ; 30 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Thesis (Ph.D.)--University of Adelaide, Dept. of Agronomy, 1986

There are few other structures in nature from which evolution has generated such wide diversity as the flower or inflorescence, and this diversity is commonly attributed to the influence of their animal visitors. By outsourcing their mate choice to pollinators, plants have left themselves - and especially their flowers - subject to the selective forces imposed by the behaviour, cognition and perception of the pollinators that serve them. The orchids provide some of the most remarkable and extreme examples of adaptations to specific animal pollinators. Perhaps one of the most peculiar of these strategies is sexual deception, whereby male insects are lured to the flower by mimicry of the female sex pheromone. This seemingly unlikely strategy has evolved multiple times independently on different continents in different parts of the orchid phylogeny which raises the question of what adaptive advantages might underlie such a strategy. This multidisciplinary thesis studies gene flow and pollinator behaviour in two sympatric sexually deceptive orchids in the genus Chiloglottis. The two species attract their specific wasp pollinators through emission of distinct species - specific semiochemicals. Since floral volatiles play a pre-eminent role in pollinator attraction, Chiloglottis provides an excellent case study for examining the interaction between floral volatile chemistry, pollinator behaviour and the evolutionary dynamics of populations. The thesis begins with a review of floral volatiles and their role in pollinator attraction and plant speciation. The literature is used to develop a research framework of six testable hypotheses under which we might productively explore the influence of floral volatiles on plant evolution. These hypotheses are then explored in the study system over the following chapters. A study of pollinator specificity, neutral genetic differentiation and floral chemistry demonstrates that the chemical mimicry crucial to sexual deception is responsible for reproductive isolation and potentially even speciation. Mating system and paternity analysis provide the first genetic evidence for multiple paternity in orchid broods. Extensive outcrossing is found to predominate and paternity assignment shows evidence for long distance pollen flow supporting the hypothesis that sexual deception promotes outcrossing and so minimizes the potentially deleterious effects of selfing. Lastly, an innovative new method is developed for tracking wasps in the field. Application of this technique to a population of orchid-pollinating wasps reveals detailed information about their movement and mating behaviour. The findings support the conclusion that sexual deception is a superb adaptive solution to the problem flowers face of simultaneously attracting pollinators and persuading them to leave quickly.

Research techniques of integrated sustainable primary production and wastewater management.. "The issue of sustainability has greatest significance in the midst of unilateral bio-socioeconomic degradation resulting from intense and increasing societal pressures placed on the unified global ecology. In such an environment, sustainable development seeks to manage natural resources within a free market economy, aiming to meet the needs of today's population, and to protect and enhance current resource quality and abundance. In this light, techniques of integrated sustainable primary production and wastewater management are the subject matters of this Applied research There are many researchable issues which could be addressed within the subject matter. The first focus in the research scope was driven by the most severe sustainability issue facing Central Queensland (Australia) in 2000: the depletion and degradation of freshwater supplies. Central Queensland (CQ) is an arid sub-tropical region that has suffered from a marked reduction in rainfall and increase in temperature over the last 100 years, (Miles, 2004), and by the year 2000, conditions had been exacerbated by eight years of severe drought and warmer than average temperatures and resulted in widespread animal and crop failures due to freshwater shortages. Such a problem required a multi-faceted ecological, social, and economic approach. Hence, research centred on investigating the science of integrating regional water-related industries and agribusiness, and biodiverse ecosystems to achieve water and wastewater reuse applications, and associated eco-socioeconomic benefits. Specifically, this research investigates the integration of (a) electrical power station wastewater (b) barramundi culture, (c) red claw culture, (d) constructed wetlands (for water quality management and habitat creation), and (e) hydroponic flower culture. This research produced outcomes of integrated water and wastewater reuse and recycling, marketable agriproducts production (fish, crayfish, and flowers), water and wastewater reuse and conservation, wetland primary production, carbon dioxide sequestration, aquatic pollution control, and biodiversity creation and support. Successful design and management, experimental trialing and evaluation of system components and subjects, and the development of a knowledge base including static and dynamic system models, represent advances in respective research areas, and underpin the emerging discipline of integrated systems approaches to eco-socioeconomic development. Additionally, several gaps in the current body of knowledge regarding integrated systems were filled, and interactive management tools were developed. Apart from this study, the integration of technologies (as described above) has not, to this author's knowledge, been accomplished. -- abstract

Secondary dryland salinity in Australia has been a major environmental concern for a number of decades, yet aspects remain controversial. These include the processes which induce salinised soils, the environmental impacts of salinity, and the way in which it is mapped and managed. Dryland salinity has been almost universally attributed to rising saline groundwater caused by excess water accumulation in the landscape following European settlement and tree clearing. However, there is a body of evidence that instead suggests increased soil salinisation in SE Australia is attributable to localized surface water problems associated with soil and vegetation degradation. The ‘Rising Groundwater Model’ has been widely accepted as the paradigm for understanding, mapping and monitoring dryland salinity. However, little quantitative research has been undertaken to understand the mechanisms and processes that cause secondary dryland salinity in the uplands of south eastern Australia. Further, there is little research that demonstrates adverse impacts of secondary salinity on terrestrial endemic biota even though it is listed as a threatening process to biodiversity. This research tested the applicability of an alternative ‘Surface Water Model’ to explain outbreaks of salinity or soil surface degradation in this region. This research investigated the effects of the joint phenomenon of soil and vegetation degradation and elevated salinity levels on soil biotic and abiotic parameters. Field research was conducted at ten box/gum grassy woodland sites in the agricultural zone of the Southern Tablelands of NSW. A holistic suite of metrics, including soil physical, chemical, hydrological and biological attributes, were assessed in the field and laboratory; geophysical surveys (EM31/EM38) and various fauna and flora surveys were performed. Results indicated that degraded soil surfaces were generally small in area and localized. These surfaces had highly variable soil EC levels (often very low), and were associated with in situ synergistic factors related to in situ soil and vegetation degradation. Some surfaces had accumulated NaCl, but many also had other, both toxic and low cation and anion levels particularly reduced levels of Ca, Fe, N, SOM and SOC. Extreme pH levels and other soil physical, chemical and biological impacts were also common. It is concluded that elevated soil salinity levels are a symptom of soil and vegetation degradation, not the cause. It was found that the predominant water movement in these landscapes occurred as overland runoff and surficial lateral interflow above the clay-dominant B horizon. There was no biological, pedological, geophysical or hydrological evidence of groundwater being a major factor for elevated soil surface salinity levels. Evidence suggests that these degraded ecosystems are relatively stable but urgently require nutrient/SOM input. Many endemic fauna and flora species flourish at highly degraded and salinised sites; tolerating elevated and fluctuating salinity levels, at all life cycle stages, which may effectively increase the gamma biodiversity in these grassy woodlands. No evidence was found to suggest that biodiversity is suffering from rising saline groundwater or elevated soil salinity levels per se, or that elevated salinity levels favour exotic species. It is therefore problematical to directly link soil salinity per se with ecological stress, as many other synergistic factors are involved and are more significant for degraded soils. Management decisions based on reducing the soil surface evaporation potential on site is the most coherent approach. Management activities should focus on stock grazing exclusion, soil amelioration and revegetation activities using endemic species, rather than focusing on excess deep landscape water management with hybrids and exotic plants. The present use of AEM for mapping dryland salinity in upland environments is therefore questionable.