Dissertations / Theses on the topic 'Biodiversity conservation – Australia – Sydney'

A consistent and integrated approach to nature conservation across the landscape and regardless of tenure is widely recognised as essential in ensuring the effective conservation of biodiversity. 'Multi-tenure reserve networks', which incorporate public and private lands managed for conservation, are considered a means of achieving landscape scale conservation. Biosphere Reserves (BR) and Conservation Management Networks (CMN) are characteristic models in Australia. This thesis aims to evaluate the role of such networks in protecting biodiversity, specifically by: (1) analysing the spatial configuration (size, shape, connectivity) of networks and their individual components; (2) evaluating the contribution of networks (in real terms and in reporting procedures) to biodiversity conservation objectives; (3) analysing the influence of the attitudes and perceptions of land managers on the functionality of networks; and (4) evaluating the influence of coordinating bodies on network functionality. In order to account for deficiencies in existing classifications of conservation lands, a new classification system was developed for this thesis - the Conservation Lands Classification. This classification incorporates conservation mechanisms on public and private lands and forms the basis for comparing network components in three Australian case studies - the Bookmark BR located in the Murray Mallee of South Australia, the Gippsland Plains CMN on the eastern Gippsland Plains of Victoria and the Grassy Box Woodlands CMN across the inland slopes of New South Wales. The spatial configuration of individual components within networks was measured using spatial analysis techniques within a geographic information system (GIS). GIS was also used to measure the contribution that networks made to a comprehensive, adequate and representative reserve system through the ecosystems they protected. The attitudes and perceptions of landowners and managers within the networks were obtained using questionnaires. Questionnaires were also sent to network coordinators. Statistical and descriptive analysis was conducted on the results. The sizes of individual components varied markedly between the three networks, however within each network public reserves were on average larger than private conservation lands. Although levels of physical connectivity varied between networks, Bookmark BR and Gippsland Plains CMN showed greater similarity to each other than to the Grassy Box Woodlands CMN. The findings raise important questions about the real and perceived differences in the BR and CMN models. All networks, and particularly those components outside the public protected area estate, contributed to enhancing the protection of ecosystems unrepresented or under-represented in the reserve system, although the extent of this contribution varied between networks. Trade-offs between reserve design efficiency and a contribution to a comprehensive, adequate and representative reserve system were evident between networks. Bookmark BR was characterised by high connectivity, strong reserve design integrity but a lower contribution to protecting under-reserved ecosystems, whereas the opposite was evident in the Grassy Box Woodlands CMN. Over 88% of managers considered their involvement in multi-tenure reserve networks to be a positive or very positive experience. A lack of resources and time for management were considered major limitations of these networks. The majority (80%) of private land managers within networks were willing to be included in a national reserve system of conservation lands. This has important implications for the Australian National Reserve System, which currently incorporates mostly public land. The changing nature of the network coordination arrangements suggests an organic fluid evolution of network structures is likely, contrasting with the desire for legalistic and administrative rigidity promoted by government agencies. The thesis concludes that all the networks studied contribute in varying degrees to biodiversity conservation. The key factors influencing the current and potential contribution that such networks make are: (1) the aims, directions and restrictions set by or imposed upon the coordinating body; and (2) the biophysical nature of the surrounding bioregion and resultant historical land use and tenure pattern. Although the successful operation of such 'multi-tenure' networks ultimately relies on the willing participation of private landholders, ongoing institutional support is likely to be required for maintaining networks in the longer term. Considering networks are increasingly formed outside of the influence of government institutions, this presents a significant challenge for effective coordinated conservation.

[Truncated abstract] Selection of priority areas for Marine Park conservation is often compromised by the lack of comprehensive biodiversity data and the resources and expertise necessary to gain this information directly by sampling. One cost effective alternative is the use of species groups or indicator species as surrogates for total biodiversity. However use of these surrogates requires an ecological understanding of how they reflect biodiversity gradients. A framework for unravelling these relationships has been suggested that involves relating species biodiversity to different and competing ecological models using appropriate statistical analysis. I use this framework to explore coral species biodiversity over a range of environmental gradients encompassing the North West Shelf of Australia and the Great Barrier Reef in North East Australia. ... I assessed physiological responses of corals to physical factors to corroborate crossshelf patterns in species biodiversity. Finally, I investigated to what extent coral cooccurrence based species groups (or guilds) can be used as surrogates for total coral biodiversity. The major findings of this thesis were: i) coral biodiversity along cross-shelf environments was highly correlated to specific gradients of abiotic reef conditions; ii) larval modelling indicates the potential for significant connectivity across continentalshelf environments such that differences in species distribution are not simply as a result of self seeding. iii) similar correlative patterns were demonstrated for coral species that occur along comparable abiotic gradients in reef areas of both Eastern and Western Australia, suggesting a causal relationship between the physical environment and coral biodiversity; iv) coral physiological parameters measured using lipid fractions independently corroborated the hypothesis that there is a biological basis for observed coral distributions; v) reef coral communities are not highly structured across abiotic physical gradients and biodiversity across the shelf increases as conditions become suitable for a wider range of species; vi) total coral biodiversity can be estimated very accurately (within r2 values ranging from 0.75 to 0.90) using a small number (15-30) of optimally chosen indictor species using the randomForest statistical method. These results suggest coral biodiversity over cross-shelf environments conforms most closely to the

The purpose of the present study is to examine the genetic and morphological variation found in narrow-range endemic terrestrial invertebrate species at different geographic scales, and the ramifications of this for their systematics, management and conservation. The listed endangered land snail Meridolum corneovirens and several related forms are restricted to the Sydney region, and were used to address the above issues. Morphological, anatomical, allozyme and DNA data were obtained for a total of 77 populations from across the known range of Meridolum. A particular emphasis was placed on the forms found across the Sydney region. The analysis of the different datasets, both individually and in combination indicate at least 35 taxa mostly parapatric and seven genera were represented. This includes several previously unrecognised taxa. The analysis supports the conclusion that Meridolum corneovirens belongs to a new genus. This includes several species found from eastern Sydney south along the coast to Nowra. A total of six new species and five new genera are described. The conservation and management of narrow-range endemics such as Meridolum corneovirens provide a number of challenges to conservation managers. The alternative of listing a gene pool rather than listing species separately is proposed and explore
Doctor of Philosophy (PhD)

This thesis considers ways to improve biodiversity conservation at the bioregional level in Australia through the use of geospatial science technologies and biological modelling techniques. Following a review of approaches to biodiversity conservation at the bioregional level, including the roles and potential of geospatial science technologies in this regard, I consider biodiversity modelling using a case study of the Burt Plain bioregion in central Australia that focuses on selected taxa, ecosystems and landscapes. The Burt Plain bioregion was chosen since it is one of 19 bioregions nationally that has been given a 'very high' priority status for biological survey, assessment and potential reservation of land for conservation purposes. The specific research objectives for the Burt Plain bioregion study were to: · describe the species composition, distribution and nature of the dominant vegetation communities within the bioregion; · characterise environmental niche of communities with respect to selected environmental and management variables - latitude, longitude, climate, land systems and land units, geology, hydrography, topography, and tenure; · analyse how well or otherwise taxa have been sampled (during previous ground surveys) with respect to geographical and environmental variables; Biodiversity conservation at the bioregional level · develop and compare quantitative habitat models of the potential distribution of selected species based on presence-only distributional data; and · examine the significance of radiometric data as a potential correlate and predictor of the distribution of those selected species. National conservation initiatives such as the bioregional approach and international initiatives such as the biosphere reserves program to support the planning and management of biodiversity conservation are discussed in chapter two. The scientific and related processes underpinning the development of bioregions and strategies across the Australian states and territories are then considered. An important finding arising from this review is the need to improve biological information, especially through systematic surveys and on-going monitoring of ecosystems and populations of species, at the bioregional level to inform land use allocation and management. This finding is consistent with one of the general aims of the thesis to improve the spatial modelling techniques available for bioregional assessment and biodiversity conservation. In chapter three I review the role and limitations of geospatial technologies currently employed for biodiversity conservation management. Current developments and applications of GIS and remote sensing to wildlife research, conservation gap analysis and conservation reserve design are considered. Geographic information systems (GIS) are now routinely used by ecologists to Biodiversity conservation at the bioregional level analyse spatial data. Although various forms of GIS have been available for 15 to 25 years, the biological applications of GIS have figured most prominently in the ecological literature only in the past 15 years. The use of computer-generated models to simulate environmental events can provide a greater understanding of ecosystems, and offers improved predictive powers to conservation and land managers. The decision support offered by computer-based modelling techniques appears likely to underpin conservation and management decisions much more into the future providing that adequate biological and other datasets are available for this purpose. Dominant vegetation communities and various environmental gradients were analysed to characterise environmental niches at the bioregional scale for the Burt Plain bioregion (Chapter 4) and more locally at the catchment scale for the Upper Todd River Catchment (Chapter 5). In Chapters four and five I describe in detail the land tenure and use, land systems, climate soil, geology, topography, hydrology, vegetation and biodiversity of the Burt Plain bioregion and Upper Todd River Catchment. The bioregion contains some ephemeral watercourses, which are generally in fair to good condition, but are afforded little protection from a range of threatening processes, including grazing and trampling by feral animals and livestock and weed infestation. The major river systems occurring in the bioregion include parts of the Plenty, Hanson, Sandover and Lander Rivers. In the Upper Todd River Catchment the major watercourses Biodiversity conservation at the bioregional level are the Todd River and Station Creek, which exit the area via two narrow gaps in the low rocky hills on the southern boundary of the bioregion. The dominant geology can be summarised as plains and low rocky ranges of Pre-Cambrian granites on red earths. The bioregion has approximately 200 - 250 mm of summer rainfall, with rainfall occurring on 20 - 30 days per year. There is a high variability and range of temperatures, with an annual mean temperature of approximately 22-23°C. In Chapter six I consider a range of species found within the Burt Plain bioregion using existing survey data and techniques that enables the prediction of the spatial distribution of taxa. Using GLM and GAM models, Black-footed Rock- Wallaby (Petrogale lateralis), Spinifex Hopping Mouse (Notomys alexis) and Spencers Frog (Limnodynastes spenceri) were chosen for a more in-depth analysis. Environmental variables correlated with the presence of each species are then described and prediction maps showing the probability or likelihood of the presence of the species within the bioregion developed. In Chapter seven I examine the utility of radiometric data for wildlife habitat modelling. Statistical relationships are tested between the concentrations of the elements uranium, thorium and potassium and terrain characteristics such as position in the landscape, slope and aspect as well as other climatic variables. Radiometric data were found to be useful for developing statistical predictive Biodiversity conservation at the bioregional level models of six species: Red Kangaroo (Macropus rufus), Desert Dunnart (Sminthopsis youngsoni), Rabbit (Orcytolagus cuniculus), Brown Honeyeater (Lichmera indistincta), Little Spotted Snake (Suda punctata) and Southern Boobook (Ninox novaeseelandiae). I suggest that the utility of radiometric data for wildlife habitat modelling would appear significant and should be explored further using alternative quantitative modelling techniques and presence/ absence records for target faunal species. Predictions of species distributions may be useful for prioritising land acquisitions for reservation as well as in the future design of biological surveys. The thesis concludes with a synthesis of the major research findings, discussion of the limitations of the datasets available for the study, perspectives on management issues in the Burt Plain bioregion, and possible future research directions. It is important that purposefully-designed biological survey research be undertaken across the bioregions of the arid zone of Australia to enhance basic understanding of biodiversity patterns and their relationships to environmental heterogeneity and site-landscape level processes. Geospatial modelling techniques can assist such biodiversity survey and evaluation and make their conduct more cost-efficient and the inferences drawn from subsequent data analyses more powerful. This knowledge is required to contribute to the emergent concepts and theory of ecosystem dynamics and associated biodiversity patterns in arid Australia and, most significantly, to enhance the conservation and management of the unique biological complement and systems found in this region.

This thesis explores the nexus between landscape design processes and the conservation of wildlife diversity. Extinction of earth’s unique and diverse animal species is progressing at unprecedented rates, due to humanity’s profound alteration of the natural landscape. Scientific literature increasingly points towards opportunities in the urban and landscape design fields to this issue. Unfortunately, the science and needs of wildlife are rarely integrated in rigorous ways in the planning and design of human landscapes. This gap in professional practice protocols and regulatory frameworks in much of the western world is explored and raises questions about how design can successfully protect, restore, and even re-create viable habitat and linkages for wildlife that is integrated with human landscape. Australia has modeled new integrated wildlife-centric design approaches and projects there demonstrate accumulated expertise in the specific area of wildlife habitat design. Through a case study of Australia’s Alice Springs Desert Park, I argue that balancing human and wildlife needs at every step of the design and building process is necessary for successful wildlife habitat design. This integrated approach does not view wildlife and humans as independent, but rather as two interdependent habitat participants that must coexist to ensure the future of both.

Fragmentation of natural vegetation is currently one of the largest threats to biodiversity. Within the southwest Australia global biodiversity hotspot, the Swan Coastal Plain was historically cleared for agriculture and forestry and is now experiencing extensive land clearing for urbanisation. The wavy-leaved smokebush Conospermum undulatum is a rare species endemic to the Swan Coastal Plain, and its future persistence is threatened by urban expansion. Throughout this research, I investigated the pollination ecology of this species and found a specific association between C. undulatum and native bees for pollination. I also demonstrated that C. undulatum has evolved pollen with resistance to the usually negative effect of ant secretions on pollen grains, with ants providing effective pollination services to this threatened species. Native pollinators were drastically reduced in small populations, and urbanisation limited the movement of pollen across built-up areas surrounding remnant bushland. This lack of both pollinators and inter-population pollen flow is severely limiting the production of healthy seeds in smaller populations. I then performed molecular investigations combined with an ecological characterisation of the recently fragmented distribution range of C. undulatum to quantify the genetic structure and levels of genetic diversity across the entire distribution of the species. Despite the current intense fragmentation, I found levels of genetic diversity similar across populations and a weak spatial genetic structure. Since habitat fragmentation is recent and many adult plants are likely to be several decades old, they mainly reflect pre-fragmentation conditions. Therefore, the detailed characterization of fragmentation over time has shown how the low levels of genetic fixation can be attributed to pervasive gene flow through the pre-fragmented landscape, which mostly influenced the current adult cohort. Early signals of the negative effects of habitat fragmentation were found during my study of contemporary gene flow through the paternity assignment of seedlings sampled at the end of the 2017 flowering season. Although gametes of C. undulatum could flow unimpeded through large expanses of unfragmented bushland, inter-population pollen flow was non-existent between fragments surrounded by built-up areas. This study supports the need for an understanding of contemporary mating patterns to detect early signals of gene flow failure in fragmented remnants. Lastly, I found evidence for hybridisation occurring at the edge of the distribution of C. undulatum between this rare and threatened plant and two other related species. This adds to the threats posed by habitat fragmentation to the conservation of C. undulatum. My research highlighted the importance of native pollinators for plants that coevolved with them and adds to the limited research on the effect of habitat fragmentation on native plants that rely exclusively on native insects for pollination. Such pollinators appeared unable to maintain an adequate inter- population pollen flow in heavily fragmented landscapes. Therefore, the often negative effects of habitat fragmentation can be exacerbated in small and isolated populations of plants that rely on species-specific pollinators for sexual reproduction. Outcomes of my research will inform recovery plans to enhance the future persistence of C. undulatum over the long term.

Stock routes have been a feature of the Australian landscape since the mid-1800s. Originally established to provide corridors of forage and shelter for livestock droved 'on the hoof', the vegetation within them remained standing while vast tracts in the surrounding landscape were cleared to make way for agriculture. However, livestock are now more commonly transported in trucks, so managing authorities no longer receive adequate income from droving permits to offset costs. At the commencement of this PhD it was being suggested that some stock routes would be lost to freehold tenure, in spite of the fact that many scientists believed them to be of great value for conservation. This project was structured into three distinct sections, aimed at providing evidence for the values of stock routes, and advice on how to best manage and plan for them into the future. The first section took the form of a literature review and spatial analysis, where I demonstrated that stock routes plays a considerable role in biodiversity conservation, recreation, tourism, preserving Indigenous cultural heritage, and as a stock refuge. I also found that they occupy fertile, low-lying areas of the landscape, and contain associated vegetation communities which have been preferentially cleared for agriculture and are under-represented in protected areas. In the second empirical section of the project I conducted surveys of three taxonomic groups which provide ecosystem services: woodland birds, wild bees, and insectivorous microbats. Data were collected from 32 stock routes which varied in width and vegetation condition, and in the fields adjacent to these stock routes. Statistical modelling was then used to quantify the response of each group to local and landscape variables characterising the survey sites. Although specific responses were different for each taxonomic group, there were some consistencies in my findings. Scattered trees in fields had a positive effect on all taxa, and the value of both native pastures and formal conservation areas close to the stock routes was also a recurring pattern. In the final section of my thesis I concentrated on the debate surrounding connectivity; whether it should be included as a goal in conservation planning, and whether this will result in trade-offs with habitat area and quality, or economic costs. It would seem logical to plan for connectivity if some stock routes are to be sold whilst others are retained for conservation purposes. Using them as a case study, I ran a Marxan minimum-set analysis which demonstrated that only certain connectivity approaches had effects on the costs and siting of reserves in conservation planning, and these effects were substantial only when conservation targets were set high. At the time of writing, the future of the stock route network remains as uncertain as it was in 2009. However, through this work I have been able to provide a much more solid foundation for potential conservation decisions than was previously available. I have also demonstrated that the stock route network is an indispensible environmental heritage asset, which should be retained and managed for conservation in perpetuity.-- provided by Candidate.

The freshwater fish fauna of southern Australia is characterised by low species richness and high endemism in groups displaying southern temperate, temperate-subtropical or temperate-tropical distributions. Comparatively few studies in Australia have incorporated modern molecular techniques to delineate species boundaries and define within-species conservation units. This is problematic because freshwater fishes are likely to show high levels of cryptic speciation and marked spatial sub-structure, and is information which is needed to conserve biological diversity and maintain the integrity of ecological communities and processes. The current study uses a ‘combined evidence’ approach, led principally by a set of nuclear genetic markers (allozymes), to assess species boundaries, spatial sub-structure and conservation units in obligate freshwater fishes from southern Australia. A literature review (Chapter 2) concerns the nature and effects of fragmentation in freshwater environments. It considers the implications for freshwater fishes and the types of extrinsic and intrinsic characteristics, both natural and human accelerated, that might drive population fragmentation and divergence. This theoretical framework is then applied to a suite of six largely co-occurring species groups with contrasting biological characteristics, and derive hypotheses about expected levels of genetic divergence across and within different drainages. Major findings Species of Retropinna (Chapter 3) are widespread and generally regarded as ‘common’ and mobile. Allozyme analyses revealed species-level and population-level sub-divisions, including five distinct species with contiguous ranges and no evidence of genetic exchange. Three occur along the eastern seaboard (including three instances of sympatry), another in coastal and inland southeastern Australia and Tasmania, and a fifth in the Lake Eyre Basin. There is no indication of a simple ‘tasmanica’ versus ‘semoni’ dichotomy, but instead a complex pattern involving discrete clusters for the Upper Murray plus Darling rivers, Lower Murray, Glenelg River and Tasmanian regions. These findings have implications for biodiversity, conservation and ecology. This chapter has been published in modified form (Marine and Freshwater Research 58, 327- 341). Nannoperca obscura (Chapter 4) is a small demersal fish with specialised habitat requirements. It is under threat of extinction, particularly in the western section of its range. Combined nuclear and matrilineal genetic data identified congruent within-species sub-structure, divided by patternsof distribution and biogeography. Four monophyletic mtDNA lineages, each distinct at multiple nuclear loci, indicate four Evolutionarily Significant Units (ESUs), namely (1) Lake Alexandrina in the Murray-Darling Basin (MDB), (2) Glenelg River, Millicent Coast River Basin and the outlying Mt Emu Creek, (3) Merri River and associated coastal streams, and (4) the eastern range section. Additional genetic and ecological data support multiple Management Units (MUs) within ESUs for individual or groups of river basins separated by marine barriers. Nannoperca australis (Chapter 5) has a similar character to its aforementioned congener, except that it occurs across a much wider area. Although generally common, particular populations are threatened, especially in the MDB. Allozyme analyses of 57 populations confirm the presence of two divergent species, with an eastern species containing two ESUs: (1) Gippsland and Flinders Island, and (2) Ansons River in northeastern Tasmania. The western species shows sub-structure across its range, including a separation of MDB and coastal populations as two heterogenous ESUs. The Lower Murray region (Mount Lofty Range streams and the Lower Lakes) harbours a remarkable level of between- and within-population diversity, underscoring its importance for conserving evolutionary potential. Mogurnda adspersa (Chapter 6) has been presumed extinct in South Australia since the early 1970s and has also been assumed lost from the southern MDB. This chapter reports on the rediscovery of M. adspersa from a wetland near the terminus of the Lower Murray, some 2500 river kilometres from the nearest known population. The nature and basic ecology of this population is documented, but the combined effects of drought and water abstraction recently have led to the probable extirpation of the wild population. A combined allozyme and mtDNA dataset confirmed the ‘nativeness’ of the population as a distinct sub-population (and MU), with a moderate level of allele heterogeneity. This information provides a platform for captive breeding as a conservation measure. The endemic genus Philypnodon (Chapter 7) contains two nominal species: P. grandiceps and the long recognised but only recently described P. macrostomus. The former is considered widespread and common (near ubiquitous), whereas the latter is more patchily distributed. Some tolerance to marine conditions is indicated, suggesting that there may be less sub-structure, but allozyme analyses of 269 individuals indicate the presence of multiple, species-level taxa within both described species. This obscures interpretations of existing ecological data. Although the presence of genetically-similar populations within and across some drainage divides indicates higher levels of gene flow, the pattern is complex and suggests historic genetic exchange between some but not other geographically-adjacent taxa. The freshwater blackfish genus Gadopsis (Chapter 8) has been a problem group for taxonomists, and it is unclear where the group is placed phylogenetically and how many species occur. Northern and southern forms on respective sides of the Great Dividing Range have been proposed, but with limited supporting evidence. Its dispersal ability (hence predicted genetic structure) is obscured by opposing life-history traits, including large body size (i.e. good swimming ability) versus habitat specialisation, demersal larvae and restricted home ranges. This chapter provides a genetic overview incorporating 61 locations across the range, and demonstrates unequivocally the presence of distinct northern and southern species of G. ‘marmoratus’. Moreover, distinct genetic discontinuities involving geographically abutting lineages indicate the likely presence of multiple ESUs within each species. A comparison of the allozyme data with previous mtDNA studies also identified two ESUs within G. bispinosus. Overall, considerable complexity is demonstrated signalling the need for a review of how the southern Australian fish fauna should be viewed, studied and protected. The genetic data also provide insight into the interplay of intrinsic biological characters (e.g. dispersal ability, population ecology) with historic and contemporary extrinsic environmental factors (e.g. fragmentation, biogeographic processes). Comparisons between and within traditionally-defined species are problematic, however, owing to multiple species-level splits and other genetic divisions that may have matching biological counterparts. Together with other reports in the literature, the findings presented herein have significant conservation implications, particularly given the rapid pace of human-mediated change in some regions that house high species and genetic diversity and unique evolutionary components, notably southeastern Queensland (especially the Mary River) and the lower River Murray in South Australia. Other regions displaying high genetic substructure or divergent populations include the Clarence River and Lachlan River in New South Wales; Gippsland, Goulburn River, Glenelg River and Mt Emu Creek in Victoria, and the Macquarie River and Ansons River in Tasmania.
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Thesis (Ph.D.) - University of Adelaide, School of Earth and Environmental Sciences, 2008

The Precautionary Principle (or 'the Principle') has been controversial and subject to debate over terminology, definition, and means of implementation and, even when articulated in legislation, it is frequently not used in the discretionary decision-making process. This thesis proposes that the Principle has a role to play in the conservation of threatened species and ecological communities in Australia. In Australia, the protection of threatened species and ecological communities has not been immune from the general reluctance to embrace the Precautionary Principle, although it is an area that lends itself to its use. The potential for serious or irreversible harm is high if incorrect decisions are made about the characterisation or status of species or ecological communities, or processes that may impact on them. Often the available scientific evidence is uncertain, inadequate, or inexact. The decisions are made against a background of potential conflict as there can be numerous stakeholders affected by the outcomes. The decisions are further complicated by being science-based, and the nexus between science and policy is confusing. Under the current national 'listing' system there is no effective provision made for species or communities where there is genuine concern that they are threatened, but the science is uncertain. Uncertainty will generally defeat a listing nomination: there is no ante-room for nominations of concern, no place for species or ecological communities to be watched over pending clarification of the uncertainty. This thesis examines the Australian approach to the Precautionary Principle. The key elements of the Principle and triggers for the application of the Principle are identified, and key issues in relation to the role of science, the choice of science, and 'scientific uncertainty' are clarified. The thesis concludes that the Principle should be a significant tool in the environmental decision-making framework. The thesis then examines the application of precaution in the listing of species, ecological communities, and key threatening processes under the Environment Protection and Biodiversity Conservation Act 1999 (Cth). Precaution is available to both the key decision-makers, the Minister and the Threatened Species Scientific Committee, under the legislation but both have failed to apply the Principle in listing. The thesis draws upon the approaches of the International Union for Conservation of Nature , the Endangered Species Act of 1973 in the United States of America and domestic examples to inform the discussion, and concludes that, under appropriate circumstances, the Precautionary Principle could play a key role in the listing of species, ecological communities and key threatening processes. It is asserted that a lack of will rather than 'way' hinders its appropriate use. A checklist and guidelines are proposed for the application of the Principle and, in the absence of legislative reform, the thesis highlights the potential of the existing legislation for a balanced precautionary approach to listing. The door to the anteroom would thus be opened.

This research aims to develop the present knowledge of arid zone rehabilitation by scientifically testing topsoiling and seeding treatments on the Eyre Peninsula, South Australia, in a way that enables the widest application and comparison to other mining leases throughout the arid lands.

The aim of this research is to assess various options for the management of topsoil stockpiles on disturbed lands and to evaluate the viability and germinability over time of the seedbanks in these stockpiles for use in rehabilitation. To predict their success, experimental trials were designed and conducted.

Research Doctorate - Doctor of Philosophy (PhD)
The Earth is experiencing a period of mass extinction due to human development and expansion (Wake & Vredenburg 2008). It has been estimated that 866 animal, plant, fungi and protist species have become extinct in recent history, and 25,821 species were declared either Critically Endangered, Endangered or Vulnerable in 2017 (IUCN 2017). Causal agents of population declines and biodiversity loss include climate change, land clearing, habitat modification and the introduction of exotic competitor or predator species (Vitousek et al. 1997) and disease (Skerratt et al. 2007) which affect species from global to local scales. The magnitude of species loss and threat of further extinctions has caused worldwide attention, instigating efforts to identify and conserve species at risk (Redford & Richter 1999). Species management programs typically aim to identify causal agents of decline, assess species requirements for survival and reproduction and understand population proce sses so that informed decisions can be made to reverse population declines. An important step in this process is gaining an understanding of the factors which affect species distribution (Guisan et al. 2013; Noss et al. 1997). Conservation programs often aim to understand an animal’s distribution by identifying what constitutes habitat. Factors commonly examined include abiotic and biotic attributes of the landscape including available shelter and food, as well as an animal’s interaction with heterospecifics (Campomizzi et al. 2008). In the instance that these factors or interactions correlate with species presence or abundance either positively or negatively, it is assumed that these factors are actively selected for or avoided (Batt 1992). However, additional behavioural factors can affect distribution, such as attraction to (Ahlering et al. 2010) or avoidance of conspecifics (same species) (Keren-Rotem et al. 2006; Stamps 1983), causing strong aggregations or segregation of animal distribution over a landscape, respectively. Despite the influence of these factors on distribution, conspecific attraction and avoidance are not commonly considered by conservation programs when attempting to understand, predict and alter species distributions (Campomizzi et al. 2008). As animals experiencing conspecific attraction or avoidance may deviate from the correlation model assumed by habitat selection, research programs aimed at assisting endangered species cannot afford to ignore conspecific interactions (Manly et al. 2009). A last resort for conservation initiatives is breeding animals in captivity, creating or restoring habitat and translocating animals back into populations that are experiencing population decline or have become locally extinct. Current research in conservation biology has focused on identifying and assessing animal behaviour which can limit the success of conservation initiatives such as; multi-spatial-level habitat selection (McGarigal et al. 2016), conspecific attraction (Campomizzi et al. 2008) and mate selection within captive breeding (Chargé et al. 2014a; Chargé et al. 2014b). As these factors influence species distribution and survival, they therefore affect the success of habitat construction programmes and the persistence of naturally occurring or translocated populations. Amphibians are a globally threatened taxon with 33 extinct species and 2,100 species declared either critically endangered, endangered or vulnerable (IUCN 2017). Factors causing amphibian decline include the human facilitated spread of chytrid fungus (Batrachochytrium dendrobatidis) (Skerratt et al. 2007), global climate change, introduced species as well as habitat loss and modification (Brown et al. 2012; Stuart et al. 2004). Considerable research has been undertaken on causal agents of decline, along with understanding population processes and habitat requirements that affect the persistence of populations (Wake & Vredenburg 2008). Despite the fact that many amphibian species show signs of conspecific attraction and/or avoidance, the influence of conspecific interactions on spatial distribution and subsequent declines of amphibians is under-investigated. This current research project explores the potential for particular behaviours which may influence species distribution and the success of habitat creation and translocation programmes for the green and golden bell frog (Litoria aurea). For the first research paper, I assessed conspecific call attraction in L. aurea. Over a landscape, animal distributions can be skewed as a result of conspecific attraction and aggregation. This can hinder habitat restoration and creation programmes as species may fail to colonise available habitat, despite its suitability. It has been noted from past research that L. aurea uses particular habitat and has distributional traits which suggest the presence of conspecific attraction, and using speakers playing calls can successfully attracted L. aurea at short distances, forming new aggregations (James et al. 2015: Attachment 1). In the first research chapter, I aimed to use speaker systems playing calls to manipulate the landscape distribution of L. aurea. I placed a stand with a speaker playing call broadcast in a treatment waterbody (T), a stand with no calls broadcasted as a manipulative control (MC) and no stand or speakers as a control (C). This design was replicated in five areas on Kooragang Island, Australia, and waterbodies were surveyed to measure changes in abundance and calling over two and a half breeding seasons. We found that speaker introduction did not increase abundance or calling at T relative to MC and C. We did, however, find that the length of time males called was longer at T, compared to MC and C. As the length of calling time may be extended using conspecific call broadcast , provision of conspecific stimulation at translocation sites may improve breeding activity and retention of the population post-release by reducing dispersal. For the second research chapter, I assessed habitat selection of L. aurea. The site selection of breeding individuals is a crucial component of a species habitat selection and can help to direct conservation programmes. However, very little is known about the microhabitat selection of calling male L. aurea. This study aimed to distinguish if male aggregations are associated with specific habitat features within a waterbody and describe their use of available habitat structures. Within waterbodies we compared calling locations relative to non-calling locations for water variables (temperature, salinity, dissolved oxygen), microclimate (temperature, humidity, average and maximum wind speed) and habitat (percentage coverage of water, ground, emergent vegetation and floating vegetation). Overall, males were associated with lower salinity and higher dissolved oxygen, higher percentage coverage of emergent vegetation and bare ground, and low percentage coverage of open water. Males were most commonly found in the water floating between or beside emergent vegetation or perched on emergent vegetation above water level. This suggests that males may select habitat to protect themselves from predators, or for breeding; providing appropriate vegetation, dissolved oxygen and salinity for embryo and tadpole development. This provides supportive information for previous studies on habitat selection, indicating what habitat is preferred by breeding males to improve monitoring, habitat creation and rehabilitation. For the third research chapter, I assess a habitat construction programme. Habitat creation programmes are often used to compensate for the loss of habitat for endangered species, with varying results. I describe an early stage wetland construction programme implemented for L. aurea on Ash Island, NSW Australia. Seven ephemeral (flooding) and two permanent waterbodies were constructed near an existing population. The wetland was designed to increase landscape aquatic habitat, based on adaptive management learnings from past research. In this study, I assess the initial use of this habitat by L. aurea, and initial findings on the design suitability. Surveys in constructed wetlands and in the broader Kooragang area showed that L. aurea rapidly colonised and called at constructed ephemeral wetlands but not permanent wetlands. The chorus size in constructed wetlands was large in comparison to other populations in coastal NSW, and a range of other frog species also bred onsite. Female L. aurea used a nearby remnant wetland (adjacent to the constructed wetlands), and used different habitat to males. Similar habitat use variation between sexes was reflected in the broader population. Most male and female L. aurea captured on Ash Island were under 12 months of age, and body condition in the constructed wetlands was higher than in the broader population. Waterbody design successfully protected waterbodies from overland flooding, and ephemeral waterbodies dried, which suggests the drying regime may protect the constructed habitat long-term from infestation of predatory fish. Elevated salinity from ground water in permanent waterbodies (intended to ameliorate chytrid disease in the landscape) was higher than anticipated and requires further monitoring. It is hoped that this programme may help guide other conservation projects creating habitat for amphibians under threat. For the fourth research paper, I assess sexual selection in L. aurea. As a conservation strategy for L. aurea, captive breeding programmes supplement at-risk populations and translocate individuals to their former ranges. However, breeding programmes are undertaken with very little information on sexual selection and its exclusion can reduce the fitness of released animals. The aim of the fourth study was to assess whether forms of sexual selection occur for L. aurea to inform captive breeding programmes. In the wild I studied mate selection. Firstly, we aimed to assess if the size and body condition of amplexing individuals (grasping to breed), differed from other individuals in the population as an indication of female sexual selection or male-male competition. Secondly, we investigated if male and female amplexing pairs were size correlated as an indicator of size assortative mating, and thirdly we made observations on behavioural interactions in the breeding waterbody to complement the analysis. In Whangarei, New Zealand, we captured L. aurea over 4 survey nights, undertaking capture-mark-recapture and measuring morphometrics of snout vent length (SVL), right tibia length (RTL) and weight, calculated body condition. We compared the SVL, RTL and weight of breeding individuals to non-breeding individuals and found that amplexing males were larger with better body condition, however, female size did not differ. Male-female pairs were not size assortative and aggressive interactions were recorded between males. Larger male size may be an indicator of either female selectivity or larger-male mating advantage through aggressive interactions. As removal of sexual selection in captive breeding programmes can reduce fitness and place conservation initiatives at risk, I recommend incorporating sexual selection by placing multiple males of varying sizes in breeding tanks with females to facilitate female selectivity or larger-male mating advantage. Based on the results of the current studies, I have identified possible constraints on the use of conspecific attraction for this species, and also recognised its potential use in translocations programmes to improve project outcomes. As a result of microhabitat assessment, habitat creation and management programmes can use specific parameters to design, maintain and monitor habitat for calling males. Assessment of a habitat construction project designed from previous research recommendations shows initial project success and provides information to refine future habitat construction programmes. Finally, assessment of sexual selection in L. aurea provides vital information to conservation programmes breeding animals for translocation to work toward improving the fitness of released individuals. Overall, the current study provides key aspects of L. aurea’s biology and ecology that have not been clearly addressed in the literature and aims to improve conservation efforts. In light of recent extinctions and increasing pressures on wildlife, continued research on key threatening processes and behavioural ecology is crucial to help guide conservation.

After European settlement, Australian rangelands especially in South Australia underwent significant changes because of the main land use of pastoralism. Many studies have revealed that the plant communities are negatively effected by herbivory mainly by sheep. The main aim of this study is to separate the different effects of sheep, rabbits and kangaroos. This was examined by survey supported by experimental and modelling research. A 32,000 km² area previously surveyed by Tiver and Andrew (1997) in eastern South Australia was re-surveyed to monitor populations of perennial plant species at sites of various intensity of grazing by sheep, rabbits and kangaroos (goats populations are low in the study area), the most important vertebrate herbivores. Plant population data were collected in both sheep paddocks and historically ungrazed by sheep (road reserves) by using the Random Walk method and analyzed using Generalized Linear Modelling (GLM) to separate the effects of sheep and rabbits on plant regeneration and their regeneration in response to grazing. These data were also compared to similar data collected by Tiver and Andrew in 1992 (1997) to ascertain if the reduction in rabbit numbers through introduction of RCV had allowed increased regeneration. Regeneration of many species inside paddocks were negatively affected and species in roadside reserves neither did not significantly increase from 1992 to 2004. However, some species showed increase of populations in spite of sheep grazing, with some species being less susceptible than others. This research also indicates kangaroo grazing impact on some plant species. Reduction in rabbit numbers following the 1995 release of calicivirus has not been effective in restoring regeneration. Another experiment was conducted at Middleback Field Station near Whyalla to identify herbivore grazing pressure on the arid zone plant species Acacia aneura using unfenced, sheep fenced and rabbit fenced grazing exclosures. This experiment was set up with seedlings in exclosures, ten replicates of each treatment, at plots four different distances from the watering point to identify the survivorship of seedlings. Data were collected by recording canopy volumes of seedling over an 18 month period and analyzed by Residual Maximal Likelihood (REML). Seedlings both near and far from the watering point were severely effected by large herbivores, either sheep, kangaroos or both, and in a separate experiment kangaroo grazing effects on the seedling were also identified. Seedlings browsed by the rabbits were recovered better than the seedlings grazed by the large herbivores. Decreasing kangaroo activities has been noticed when the rabbit movements increased. Computer modelling was conducted to predict the future plant population structure over 500 years using a matrix population model developed by Tiver et al. (2006) and using data collected in the survey as a starting point. Extinction probabilities of populations of Acacia aneura near watering points, far from watering points and under pulse grazing scenarios were compared. Sheep grazing was found to cause eventual extinction of populations in all parts of sheep paddocks. Together, the results indicate that sheep are the major herbivore suppressing regeneration of perennial plant species. Kangaroo and rabbits have an identifiable but lesser effect. The results have implications for conservation and pastoral management. To achieve ecological sustainability of arid lands a land-use system including a network of reserves ungrazed by sheep and with control of both rabbit and kangaroo numbers will be required.

Landscape modification is a major global threat to terrestrial biodiversity. Managing human-modified landscapes in ecologically sustainable ways is crucial to avoid and mitigate biodiversity loss. However, practitioners (e.g. policymakers and developers) still urgently require research to inform targeted habitat protection policies, on-the-ground land management practices, and biodiversity offset strategies. My research focused on identifying ways to strategically maintain and perpetuate habitat structures for wildlife in modified landscapes. I had three objectives: (1) measure and compare the current and future availability of habitat structures; (2) quantify the biodiversity value of scattered trees; and (3) test the effectiveness of artificial nest boxes as a biodiversity offset tool. First, I conducted vegetation surveys at 300 plots in three dominant landscape contexts (reserves, pasture, urban greenspace). I found that in urban greenspace, the availability of multiple habitat structures (e.g. trees, logs, shrubs) depended upon by biota were significantly reduced compared with reserves, but comparable with agricultural land. Using a simulation model for tree populations, I also found that hollow-bearing trees were predicted to decline by an average of 87% in urban greenspace over the next 300 years under existing tree management policies. I identified that only a combination of tree management approaches can arrest this decline. Second, I completed wildlife surveys at 72 individual trees of three sizes (small, medium, large) located in four landscape contexts (reserves, pasture, urban parklands, urban built-up areas). I recorded high invertebrate, bat and bird abundance and richness at scattered trees, representing a diversity of functional guilds. Furthermore, the biodiversity value of scattered trees in modified landscapes, including even small trees, was comparable or greater than that of trees located in reserves. I also found that several smaller trees could provide habitat compensation equivalent to that of a single large tree for some bird species and in certain landscape contexts (reserves and urban built-up areas). However, this was not a suitable offset strategy for a quarter of bird species and in other landscape contexts (pasture and urban parklands). Finally, I conducted an experiment using 144 nest boxes with different entrance sizes (20, 35, 55, 75, 95 and 115 mm), secured to trees of three sizes (small, medium, large) located in four landscape contexts (reserves, pasture, urban parklands, urban built-up areas). I found that adding nest boxes to large trees resulted in an increase in tree visitation by hollow-nesting birds. However, the same response was not observed at small, medium or control trees. Nest boxes were also only occupied by common native and exotic species and are thus unlikely to be effective at ameliorating the residual impacts of hollow-bearing tree removal, especially for threatened taxa. Based on my collective findings, I recommend: (1) adopting spatial zoning tactics that aim to resolve human-habitat conflicts and retain multiple habitat structures; (2) prioritising the conservation of scattered trees over the long-term by balancing both re-vegetation and mature tree preservation strategies; and (3) exercising caution in the wide-scale application of nest box offsets. These recommendations could assist practitioners in establishing more biodiversity-sensitive modified landscapes.