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The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models.

The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models.

The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models.

The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models.

The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models.

The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models.

The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models.

The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models.

The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models.

Bengal tigers (Panthera tigris tigris) serve a pivotal role as an apex predator in forest ecosystems. To increase our knowledge on factors impacting the viability and health of this endangered species, we studied the gut microbiota in 32 individual Bengal tigers from three geographically separated areas (Chitwan National Park (CNP), Bardia National Park (BNP) and Suklaphanta Wildlife Reserve (SWR)) in Nepal, using noninvasive genetic sampling methods. Gut microbiota influence the immune system, impact various physiological functions, and modulates metabolic reactions, that ultimately impact the host health, behavior and development. Across the tiger populations in Nepal, we found significant differences in the composition of microbial communities based on their geographic locations. Specifically, we detected significant differences between CNP and the other two protected areas (CNP vs BNP: pseudo t = 1.944, P = 0.006; CNP vs SWR: pseudo t = 1.9942, P = 0.0071), but no differences between BNP and SWR. This mirrors what has been found for tiger gene flow in the same populations, suggesting gut microbiota composition and host gene flow may be linked. Furthermore, predictive metagenome functional content analysis (PICRUSt) revealed a higher functional enrichment and diversity for significant gut microbiota in the Chitwan tiger population and the lowest enrichment and diversity in Suklaphanta. The CNP tiger population contained higher proportions of microbiota that are associated with predicted functions relevant for metabolism of amino acid, lipid, xenobiotics biodegradation, terpenoides and polyketides than the SWR population. We conclude the tiger population structure, gut microbiota profile and associated functional metabolic categories are correlated, with geographically most separated CNP and SWR tiger population having the most distinct and different host genotype and microbiota profiles. Our work dramatically expands the understanding of tiger microbiota in wild

Bengal tigers (Panthera tigris tigris) serve a pivotal role as an apex predator in forest ecosystems. To increase our knowledge on factors impacting the viability and health of this endangered species, we studied the gut microbiota in 32 individual Bengal tigers from three geographically separated areas (Chitwan National Park (CNP), Bardia National Park (BNP) and Suklaphanta Wildlife Reserve (SWR)) in Nepal, using noninvasive genetic sampling methods. Gut microbiota influence the immune system, impact various physiological functions, and modulates metabolic reactions, that ultimately impact the host health, behavior and development. Across the tiger populations in Nepal, we found significant differences in the composition of microbial communities based on their geographic locations. Specifically, we detected significant differences between CNP and the other two protected areas (CNP vs BNP: pseudo t = 1.944, P = 0.006; CNP vs SWR: pseudo t = 1.9942, P = 0.0071), but no differences between BNP and SWR. This mirrors what has been found for tiger gene flow in the same populations, suggesting gut microbiota composition and host gene flow may be linked. Furthermore, predictive metagenome functional content analysis (PICRUSt) revealed a higher functional enrichment and diversity for significant gut microbiota in the Chitwan tiger population and the lowest enrichment and diversity in Suklaphanta. The CNP tiger population contained higher proportions of microbiota that are associated with predicted functions relevant for metabolism of amino acid, lipid, xenobiotics biodegradation, terpenoides and polyketides than the SWR population. We conclude the tiger population structure, gut microbiota profile and associated functional metabolic categories are correlated, with geographically most separated CNP and SWR tiger population having the most distinct and different host genotype and microbiota profiles. Our work dramatically expands the understanding of tiger microbiota in wild

With fewer than 200 tigers (Panthera tigris tigris) left in Nepal, that are generally confined to five protected areas across the Terai Arc Landscape, genetic studies are needed to provide crucial information on diversity and connectivity for devising an effective country-wide tiger conservation strategy. As part of the Nepal Tiger Genome Project, we studied landscape change, genetic variation, population structure, and gene flow of tigers across the Terai Arc Landscape by conducting Nepal's first comprehensive and systematic scat-based, non-invasive genetic survey. Of the 770 scat samples collected opportunistically from five protected areas and six presumed corridors, 412 were tiger (57%). Out of ten microsatellite loci, we retain eight markers that were used in identifying 78 individual tigers. We used this data set to examine population structure, genetic variation, contemporary gene flow, and potential population bottlenecks of tigers in Nepal. We detected three genetic clusters consistent with three demographic sub-populations and found moderate levels of genetic variation (H-e = 0.61, A(R) = 3.51) and genetic differentiation (F-ST = 0.14) across the landscape. We detected 3-7 migrants, confirming the potential for dispersal-mediated gene flow across the landscape. We found evidence of a bottleneck signature likely caused by large-scale land-use change documented in the last two centuries in the Terai forest. Securing tiger habitat including functional forest corridors is essential to enhance gene flow across the landscape and ensure long-term tiger survival. This requires cooperation among multiple stakeholders and careful conservation planning to prevent detrimental effects of anthropogenic activities on tigers.

With fewer than 200 tigers (Panthera tigris tigris) left in Nepal, that are generally confined to five protected areas across the Terai Arc Landscape, genetic studies are needed to provide crucial information on diversity and connectivity for devising an effective country-wide tiger conservation strategy. As part of the Nepal Tiger Genome Project, we studied landscape change, genetic variation, population structure, and gene flow of tigers across the Terai Arc Landscape by conducting Nepal's first comprehensive and systematic scat-based, non-invasive genetic survey. Of the 770 scat samples collected opportunistically from five protected areas and six presumed corridors, 412 were tiger (57%). Out of ten microsatellite loci, we retain eight markers that were used in identifying 78 individual tigers. We used this data set to examine population structure, genetic variation, contemporary gene flow, and potential population bottlenecks of tigers in Nepal. We detected three genetic clusters consistent with three demographic sub-populations and found moderate levels of genetic variation (H-e = 0.61, A(R) = 3.51) and genetic differentiation (F-ST = 0.14) across the landscape. We detected 3-7 migrants, confirming the potential for dispersal-mediated gene flow across the landscape. We found evidence of a bottleneck signature likely caused by large-scale land-use change documented in the last two centuries in the Terai forest. Securing tiger habitat including functional forest corridors is essential to enhance gene flow across the landscape and ensure long-term tiger survival. This requires cooperation among multiple stakeholders and careful conservation planning to prevent detrimental effects of anthropogenic activities on tigers.

Tiger (Panthera tigris) populations are in danger across their entire range due to habitat loss, poaching and the demand for tiger parts. The Bengal tiger (Panthera tigris tigris) is an endangered apex predator with a population size estimated to be less than 200 in Nepal. In spite of strict wildlife protection laws, illegal trade of tiger parts is increasing; and Nepal has become one of the major sources and transit routes for poached wildlife parts. Identification of wildlife parts is often challenging for law enforcement officials due to inadequate training and lack of available tools. Here, we describe a molecular forensic approach to gain insight into illegally trafficked tiger parts seized across Nepal. We created Nepal’s first comprehensive reference genetic database of wild tigers through the Nepal Tiger Genome Project (2011–2013). This database has nuclear DNA microsatellite genotype and sex profiles, including geo-spatial information, of over 60% (n = 120) of the wild tigers of Nepal. We analyzed 15 putative cases of confiscated poached tiger parts and all were confirmed to be of tiger. Ten samples were identified as male and five were female. We determined probable geo-source location for 9 of the 14 samples with 6–8 nuclear DNA microsatellite loci using inferences from four different statistical assignment methods. Six samples were assigned to Bardia National Park and one of these was an exact match to a female tiger previously profiled in our fecal DNA reference database. Two tiger samples were assigned to Shuklaphanta Wildlife Reserve and one to Chitwan National Park. We are unable to definitively assign five tiger samples which could be offspring dispersers or might have come from tiger population outside of Nepal. Our study revealed that the western region, particularly Bardia National Park, is a poaching hotspot for illegal tiger trade in Nepal. We present feasibility of using molecular forensic based evidence to incriminate criminals in a court of

Many animals use sounds produced by conspecifics for mate identification. Female insects and anuran amphibians, for instance, use acoustic cues to localize, orient toward and approach conspecific males prior to mating. Here we present a novel technique that utilizes multiple, distributed sound-indication devices and a miniature LED backpack to visualize and record the nocturnal phonotactic approach of females of the Australian orange-eyed tree frog (Litoria chloris) both in a laboratory arena and in the animal’s natural habitat. Continuous high-definition digital recording of the LED coordinates provides automatic tracking of the female’s position, and the illumination patterns of the sound-indication devices allow us to discriminate multiple sound sources including loudspeakers broadcasting calls as well as calls emitted by individual male frogs. This innovative methodology is widely applicable for the study of phonotaxis and spatial structures of acoustically communicating nocturnal animals.

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), Griffith School of Environment, Science, Environment, Engineering and Technology, Bengal tiger (Panthera tigris) is an endangered species found in the lowland areas of Nepal. Much needs to be understood about this species, including its population size, genetic health, habitat and overall ecosystem dynamics. Although there have been efforts to estimate tiger population numbers using camera trapping methods, the information obtained through such efforts has been limited and there is a need to find a better method and technology to understand wild tigers in Nepal. Use of genetic sampling holds significant promise in execution of landscape-level management plans as it may allow managers to measure genetic health and even gene flow with greater certainty. Habitat connectivity and the degree of movement from one habitat patch to another can be inferred through understanding of species behavior, but genetic data can give us landscape level information by directly identifying patterns of distinctiveness, endemism and the degree to which gene flow exists between subpopulations. Non-invasive genetic studies on populations, such as those that use scat samples, have increased in recent years, and have been used to estimate population size of many elusive and endangered species. I have used this technique to understand tiger and its habitat. In my study I have uncovered prevalent sympatric biodiversity in the tiger habitat which aids in understanding the species conservation from an ecological perspective. Out of total collected scat samples (n=420), only 56% (n=237) were of tiger. The remaining non-tiger samples (n=183) included non-focal carnivores; leopard (Panthera pardus, n=83), leopard cat (Prionailurus bengalensis, n=10), jungle cat (Felis chaus, n=2), fishing cat (Prionailurus viverrinus, n=2) and fox (Vulpes spp., n=10). The spatial distribution of three small felids: leopard cat, jungle cat and fishing cat in sub-tropical deciduous forest of Terai has provided insights on sympatric occurrences of small cats with each other and with two other large

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), Griffith School of Environment, Science, Environment, Engineering and Technology, Many animals possess the remarkable ability to change their skin colour. Colour change can have several potential functions, including communication, thermoregulation and camouflage. However, while the physiological mechanisms and functional significance of colour change in other vertebrates have been well studied, the role of colour change in amphibians is still relatively unknown and a disconnection between morphology, physiology and function exists in the literature (review presented in chapter 2). In this thesis, I investigate these multidisciplinary components to understand the processes and functions of colour change in stony creek frogs (Litoria wilcoxii), which are known to turn bright yellow during the breeding season. By (1 – Chapter 3) examining the distribution and structure of dermal pigment cells, (2– Chapter 4) determining hormonal triggers of rapid colour change, (3– Chapter 5) investigating seasonal colour, hormone and disease relationships and (4– Chapter 6) determining the evolutionary functions of colour change, I provide a comprehensive explanation of this phenomenon in L. wilcoxii.

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), Griffith School of Environment, Science, Environment, Engineering and Technology, Evidence clearly shows that climate change has affected ecosystems and individual species, challenging species survival and increasing extinction rates. Assessing species vulnerability to climate change is a key topic in ecology and conservation biology. Uncertainty remains as to which species will be most vulnerable and to what extent. An integrative framework has been developed to guide research towards evaluating species vulnerability. This approach proposes that a species’ vulnerability to climate change is dependent upon the synergistic combination of intrinsic (sensitivity) and extrinsic (exposure) factors. Following this framework, I examined how (i) sensitivity to environmental change (i.e. changes in calling phenology, thermal tolerances, and disease susceptibility) and (ii) exposure to environmental change (i.e. detectability, occupancy and species distribution, and thermal environment and microhabitat buffering) influenced the vulnerability of Philoria loveridgei, a direct-developing anuran, in subtropical rainforests of mid-eastern Australia. This allowed me to evaluate the vulnerability of this species to climate change. Sensitivity results indicated that calling phenology and breeding phenology of P. loveridgei were influenced primarily by the spring and early summer rainfall events associated with the start of the calling season. I hypothesise that these rainfall events increase soil moisture, and hence increase P. loveridgei nest moisture and subsequently forming a suitable environment for egg and larval survival. These early summer rainfall events would therefore cue the onset of the calling, associated with breeding. A diurnal calling pattern was identified for P. loveridgei, with a higher calling frequency during the early morning hours.

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), Griffith School of Environment, Science, Environment, Engineering and Technology, Human activity is altering the global environment at an unprecedented rate. The exploitation of natural resources is adding considerable pressure to already vulnerable ecosystems and declining biodiversity. Ecological restoration has the potential to be a significant part of the solution to this problem by recovering degraded land, connecting and expanding natural areas, re-establishing habitat, and restoring ecosystem services. This has led to the practice being incorporated into natural resource management strategies globally. Much of the on-ground implementation of ecological restoration, however, falls into the hands of local governments as they are generally responsible for town planning and land management. Ensuring that local governments have the ability to deliver sustainable outcomes with restoration is a critical step in returning functionality and resilience to the landscape.

The co-authors of this paper hereby state their intention to work together to launch the Genomic Observatories Network (GOs Network) for which this document will serve as its Founding Charter. We define a Genomic Observatory as an ecosystem and/or site subject to long-term scientific research, including (but not limited to) the sustained study of genomic biodiversity from single-celled microbes to multicellular organisms.An international group of 64 scientists first published the call for a global network of Genomic Observatories in January 2012. The vision for such a network was expanded in a subsequent paper and developed over a series of meetings in Bremen (Germany), Shenzhen (China), Moorea (French Polynesia), Oxford (UK), Pacific Grove (California, USA), Washington (DC, USA), and London (UK). While this community-building process continues, here we express our mutual intent to establish the GOs Network formally, and to describe our shared vision for its future. The views expressed here are ours alone as individual scientists, and do not necessarily represent those of the institutions with which we are affiliated.

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), Griffith School of Environment, Science, Environment, Engineering and Technology, Habitat fragmentation due to rapid urbanisation is occurring globally and results in small and often isolated patches of remnant bushland. These small, forest remnants contribute to the conservation of biodiversity within urban areas, as they can, and often do, contain suitable habitat structures. Habitat structures such as hollow-bearing trees are recognised as important features of forests globally. Therefore, the abundance of hollow-bearing trees within a landscape may be a controlling factor for many biota where no other habitat resources provide a feasible substitute. Therein, this thesis investigates five aspects in relation to the ecology of hollow-bearing trees as a habitat resource within a rapidly urbanising landscape. In the first instance a review of the literature was undertaken. This presents a summary of the importance of hollow-bearing trees globally, and identifies threats associated with their conservation. Focus is centred on the importance of this habitat resource within the Australian context, concluding with a description of the study area and thesis aims. A hierarchical analysis of the current legislation that exists within Australia to protect hollowbearing trees was then undertaken. The evaluation revealed, that despite Federal and State legislation acknowledging the importance of hollow-bearing trees to biodiversity, there are insufficient mechanisms in place at all levels of government to halt the decline of hollowbearing trees across various landscapes.

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), Griffith School of Environment, Science, Environment, Engineering and Technology, Atmospheric temperatures are increasing and precipitation ranges are generally believed to become more variable and more extreme, with a general reduction in rainfall expected across South-eastern Australia. Additionally, increases in evapotranspiration are expected, resulting in an expected prevailing net loss in the terrestrial water balance. Changes in climate are bringing increasing uncertainty to ecological systems, where the predicted changes to climate are likely to have impacts on amphibians due to the close ecological associations of amphibians to temperature and environmental water balances. Amphibians largely have a dependency upon free-standing water to enable recruitment, which for many species is dependent upon the occurrence of seasonally ephemeral, low predator ponds. While climate change is recognised to affect species along gradients, many gradients occur at smaller spatial scales than that of latitudinal and altitudinal gradients.

The co-authors of this paper hereby state their intention to work together to launch the Genomic Observatories Network (GOs Network) for which this document will serve as its Founding Charter. We define a Genomic Observatory as an ecosystem and/or site subject to long-term scientific research, including (but not limited to) the sustained study of genomic biodiversity from single-celled microbes to multicellular organisms.An international group of 64 scientists first published the call for a global network of Genomic Observatories in January 2012. The vision for such a network was expanded in a subsequent paper and developed over a series of meetings in Bremen (Germany), Shenzhen (China), Moorea (French Polynesia), Oxford (UK), Pacific Grove (California, USA), Washington (DC, USA), and London (UK). While this community-building process continues, here we express our mutual intent to establish the GOs Network formally, and to describe our shared vision for its future. The views expressed here are ours alone as individual scientists, and do not necessarily represent those of the institutions with which we are affiliated.

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), Griffith School of Environment, Science, Environment, Engineering and Technology, Many species are threatened by rapidly changing climate and amphibians may be particularly vulnerable. As ectotherms, all aspects of amphibian physiology and life history are directly or indirectly influenced by temperature and moisture. For amphibian conservation, a clear priority is to investigate impacts of climate change on key environmental parameters within breeding habitats, as well as the ecology of threatened species. This information is vital for assessing species vulnerability to climate change and informing conservation efforts. Wallum frogs are species that are restricted to naturally acidic, oligotrophic coastal wetlands of eastern Australia. There is a paucity of ecological data on wallum frogs and their breeding habitats however climate change predictions suggest they are likely to be exposed to changes in the timing and intensity of precipitation, and increases in temperature. Consequently, the aim of this study was to enhance our understanding of the bioclimatic conditions of threatened wallum frogs at a landscape scale. This information was then used to assess climate change vulnerability for these wallum associated frog species, particularly the threatened wallum sedge frog (Litoria olongburensis). This study determined environmental factors influencing reproductive behaviours of L. olongburensis, namely calling phenology and breeding effort. Also, the impacts of fire on wallum frog ecology and morphology were assessed, as their habitat is exposed to regular and intense fires, which are predicted to increase in frequency and/or severity in the future.

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), Griffith School of Environment, Science, Environment, Engineering and Technology, The incursion of the globally notorious pest, red imported fire ant Solenopsis invicta (Buren) (Hymenoptera: Formicidae: Myrmicinae) in Brisbane, Australia necessitated the prompt design and implementation of an integrated pest eradication solution. The solution included the broad-scale application of the insect growth regulators Methoprene and Pyriproxyfen. Known for high efficacy and low toxicity to selected non-target taxa in the laboratory, these chemicals have received scant attention to identify real non-target species impacts in the field. It was the purpose of this study to provide a real-time assessment of the impacts of Methoprene on the soil ecosystem, examining both its chemical and biological composition. This was achieved by constructing a Before-After, Control-Impact (BACI) experiment, where Methoprene was applied to ‘treated’ (i.e. impact) sites following Fire Ant Control Centre (FACC) protocols. A series of soil samples were collected over repeated Methoprene applications, and analysed to determine mite diversity, community structure and chemical composition of the soil. A comparison of these characteristics at ‘control’ and ‘treated’ sites over repeated Methoprene applications enabled the assessment of the non-target impacts of Methoprene on soil mites and soil function.

Full Text, Thesis (Masters), Master of Philosophy (MPhil), Griffith School of Environment, Science, Environment, Engineering and Technology, The emergence of the global amphibian crisis has seen the extinction of 122 species worldwide, with 18.8% of Australia’s 213 amphibian species being threatened. Despite these declines, little is known about the biology and ecology of certain Australian threatened species. Hence, successful conservation and management of threatened amphibian species cannot be fully realised. Several environmental variables may influence amphibian adult or tadpole assemblages. These variables include, but are not limited to, water chemistry factors (i.e. pH, salinity, turbidity), predation, competition, hydroperiod and water flow. These variables will influence individual species differently, with each species displaying differences in tolerance to these specific variables. The coastal wallum vegetation along the eastern coast of Australia is the primary habitat for four specialist frog species (Litoria olongburensis, Litoria freycineti, Litoria cooloolensis and Crinia tinnula) that are listed as Vulnerable under the IUCN Red List. All species are referred to as ‘acid’ frogs due to their association with low pH waters. ‘Acid’ frog populations within protected areas are believed to be stable. However, populations of ‘acid’ frogs occurring outside of protected areas are at risk from ongoing habitat loss and fragmentation. It is therefore vital that conservation managers know which environmental factors influence ‘acid’ frogs to ensure these environmental variables remain constant and populations remain stable. Furthermore, it is imperative to determine if these environmental variables are the same within anthropogenic waterbodies and if ‘acid’ frogs utilise anthropogenic waterbodies. This knowledge would assist in the future prioritisation of waterbodies for conservation. However, the factors influencing ‘acid’ frog species tadpole and adult relative abundance and occupancy within protected and non-protected wallum heathland waterbodies have not been reported.

We identify the 10 major terrestrial and marine ecosystems in Australia most vulnerable to tipping points, in which modest environmental changes can cause disproportionately large changes in ecosystem properties. To accomplish this we independently surveyed the coauthors of this paper to produce a list of candidate ecosystems, and then refined this list during a 2-day workshop. The list includes (1) elevationally restricted mountain ecosystems, (2) tropical savannas, (3) coastal floodplains and wetlands, (4) coral reefs, (5) drier rainforests, (6) wetlands and floodplains in the Murray-Darling Basin, (7) the Mediterranean ecosystems of southwestern Australia, (8) offshore islands, (9) temperate eucalypt forests, and (10) salt marshes and mangroves. Some of these ecosystems are vulnerable to widespread phase-changes that could fundamentally alter ecosystem properties such as habitat structure, species composition, fire regimes, or carbon storage. Others appear susceptible to major changes across only part of their geographic range, whereas yet others are susceptible to a large-scale decline of key biotic components, such as small mammals or stream-dwelling amphibians. For each ecosystem we consider the intrinsic features and external drivers that render it susceptible to tipping points, and identify subtypes of the ecosystem that we deem to be especially vulnerable.

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), Griffith School of Environment, Science, Environment, Engineering and Technology, This study investigated two protocols for use with taxonomic research and provides a significant step toward a comprehensive taxonomic revision of two Australo-Pacific snake genera: taipans (Elapidae: Oxyuranus) and brown snakes (Elapidae: Pseudonaja). These snakes are of interest to many people for reasons such as the proximity of their distribution to major urban centres, the potential lethality associated with their venom, and the morphological variation found in most sub-taxa. Distributed throughout Australia and parts of Indonesia and Papua New Guinea, taipans and brown snakes are noted both for their morphological variability and sub-taxa similarity. These two reasons are partially why, since the first species of brown snake was erected in 1854, 48 different (sub)species of Oxyuranus and Pseudonaja have been described as valid taxa. A third reason may be methodological: the use of inappropriate sampling techniques and laboratory methods. The present study tested and validated a novel systematic sampling methodology for taxonomic and systematic research, investigated the appropriateness for the inclusion of archival DNA in molecular research, and conducted phylogenetic and morphologic analyses of past and present data collected from these taxa. A review of the taxonomic history of these snakes (presented in Chapter 1) shows that the evolutionary relationships of Oxyuranus and Pseudonaja sub-taxa have long been uncertain. Previous taxonomic and systematic inquiries have been descriptive in nature, inconsistent characters have been selected for analysis, specimen selection has been opportunistic, and molecular studies have been reliant on fresh tissue for genetic analyses. These issues may be, in part, why there is still taxonomic uncertainty regarding the number of valid taxa associated with these snakes. This study attempted to uncover the evolutionary relationships of these snakes using novel and improved techniques. These techniques were first tested for thei

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy by Publication (PhD), Griffith School of Environment, Science, Environment, Engineering and Technology, My studies undertaken over the past 30 years have identified the existence of an exceptionally rich and highly diverse scincid lizard fauna in New Caledonia, one typified by regional and localised endemism at a level not indicated by earlier studies. The patterns of broad and finer-scale endemism revealed in the phylogenetic studies indicate a complex evolutionary history for the scincid lizard fauna, one which reflects the historical complexity of the island’s environment, and provides a window into the likely processes that shaped the present day biota. Further, it places the evolution of the New Caledonian lizard fauna in a broader regional context, identifying it as intimately linked with the endemic New Zealand skink fauna, and challenging current conventional theories of a recent post emersion Oligocene origin for the New Caledonia biota.

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), Griffith School of Environment, Faculty of Science, Environment, Engineering and Technology, Pollution of waterways with anthropogenic organic chemicals can pose a risk to the environment and human health. Monitoring the concentrations of such chemicals is indispensable in the assessment of potential risks and in the evaluation of sources and fates, which is crucial to risk management. Monitoring of anthropogenic organic pollutants remains a challenge to regulators. For example, environmentally relevant concentrations of many nonpolar organic anthropogenic chemicals are often in the lower nanogram range. Hence, a substantial concentration of the analytes of interest is required in order to detect these at ultratrace concentrations. Sampling, transport and extraction of large volumes of water pose substantial challenges and are very expensive. Furthermore, snap shot samples may be not representative and can miss point in time or sporadic events. High volume active sampling systems on the other hand can require a great amount of maintenance and are limited by financial as well as logistic issues, such as access to energy to power the system. Passive sampling however, has the potential to exceed active and grab sampling methods, as the sampling devices can be deployed over extended periods of time, they do not require maintenance or electricity and they are relatively cheap. In this study, silicon rubber (SR) was evaluated as a tool for the monitoring of anthropogenic organic chemicals in water. SR passive samplers were calibrated for a broad range of chemicals (i.e. organic pesticides and PAHs), ranging in log from 2.61–6.90. Samplers were calibrated in different environmental flow scenarios, confirming that flow is an important factor in affecting the exchange kinetics of chemicals. The results demonstrated that water side resistance is the rate limiting resistance for the uptake of chemicals into SR passive samplers under most ambient conditions. In addition to the sampling rate––where possible––silicon rubber to water partition coefficients were determined

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), School of Environmental and Applied Sciences, Science, Environment, Engineering and Technology, Rapid amphibian population declines and extinctions have occurred worldwide in recent decades, often in protected areas where no obvious human disturbance can be identified. Chytridiomycocis is an emerging infectious disease caused by Batrachochutrium dendrobatidis, a chytrid fungus that parasitizes the keratinized epidermis of post-metamorphic amphibians and the mouthparts of tadploes. Batrachochutrium dendrobatidis has been detected in over 200 amphibian species from five continents, and has been diagnosed in dead and dying frogs concurrent with population declines, extirpations and extinctions. Chytriiomycocis is thus considered a primary explanation for the global loss of amphibian biodiversity in recent decades.

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), Centre for Innovative Conservation Strategies, Information is required on the ecological value of all urban land types in order to provide an ecological basis for urban zoning decisions, to predict development impacts and to identify much needed opportunities for off-reserve conservation. One land type (the suburban golf course) has experienced a dramatic global proliferation in recent decades, as courses are increasingly constructed as part of new housing developments and resorts. Golf courses account for a growing proportion of the urban land area in Australia and will have an increasingly significant impact on urban biodiversity. The nature of their influence is however contentious. While many suggest golf courses have a negative impact on biodiversity, others believe they can provide refugial habitat for native wildlife. This potential refuge value has been nurtured by the golf industry as a way to improve its environmental reputation. However while the industry has initiated programs to enhance the quality of habitats on golf courses, it is uncertain whether such small-scale conservation efforts can have more than a cosmetic effect. The ubiquity of suburban golf courses makes their possible ecological contribution more significant and thus worthy of investigation. This study assessed the conservation status of suburban golf courses in south-east Queensland Australia between 2001-2004, by comparing assemblages of birds, reptiles, mammals and amphibians on 20 representative golf courses with those in 10 nearby eucalypt remnants and with bird assemblages in 10 suburban areas. The ecological characteristics of wildlife utilising golf courses were compared with those shared by animals common to residential areas and to native eucalypt forest. Local changes in bird diversity were assessed following the clearance of small vegetation remnants on a suburban golf course. Finally, the ecological value gained by increasing the size and complexity of native habitats on golf courses was assessed, by investigating the ext

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), School of Environmental and Applied Science, Global climates are changing rapidly and biological responses are becoming increasingly apparent. Some models indicate that climate warming impacts will largely consist of latitudinal and altitudinal shifts in potential species' distributions while others suggest that the complete disappearance of critical climate types and dependent species are possible. While early investigations have focused on high latitudes where warming has been most pronounced, there is an increasing recognition of the need to understand impacts in biodiverse tropical regions that support many spatially and climatically restricted species. The vertebrate fauna of the Wet Tropics biogeographic region of north-eastern Australia provides a unique opportunity to address this deficiency. First, endemic species are typically associated with cool, wet and relatively aseasonal upland environments; characteristics considered to have predisposed the fauna to being particularly vulnerable to future global climate change. Second, recent projections of species responses to future climate scenarios suggest strong systematic change in the extent and location of species' distributions with even small amounts of warming. Altitude is effectively a surrogate for turnover in temperature in the region and impacts of increasing temperature are expected to be most noticeable along this gradient. Focusing on two ecologically disparate taxa (ie. rainforest birds and microhylid frogs) empirical abundance patterns across altitudinal gradients and predicted altitudinal range shifts are used to: (1) predict changes in total population size; (2) estimate change in total population size relative to distribution area; and (3) quantify the sensitivity and bias of widely used measures for assessing contemporary range shifts along altitudinal gradients. According to the most conservative model scenario, 41 of 55 (74 %) rainforest birds and 6 of 6 (100%) microhylid frogs examined are predicted to become threatened as a result o

Constructed ponds are an important consideration in the conservation of wetland biota in agricultural landscapes. Twenty-two natural ponds and 22 adjacent constructed ponds (farm dams) were surveyed on the Southern Tablelands of New South Wales to compare patterns of use by frogs and develop frog conservation recommendations. Farm dams supported similar numbers of frog species to natural ponds, although differences in frog assemblage were observed between the pond types. Limnodynastes tasmaniensis and Uperolia laevigata were significantly more likely to occur at farm dams while L. peronii was more likely to occur at natural ponds. Results suggest waterbodies with high levels of emergent vegetation cover that lack fish are likely to support a high number of frog species, regardless of origin (i.e. natural or constructed). However, it is important for landholders to conserve natural waterbodies as these environments appear likely to support frog species that do not use farm dams.

Full Text, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), Division of Australian Environmental Studies, Science, Environment, Engineering and Technology, A variety of aquatic habitats with different levels of potential predators are available to larval amphibians in Central Amazon rainforest. The anuran community at Reserva Florestal Adolfo Ducke, 25 km east of Manaus, Amazonas, Brasil, was studied to determine which species have eggs and/or larvae in water and how those larvae are distributed in time and space. The temporal and spatial distribution of potential predators as well as abiotic characteristics of these waterbodies were determined simultaneously to test for correlations with the distribution of tadpoles. The distribution of tadpoles was strongly related to fish predation pressure. Several tadpole species were found only in waterbodies with high fish abundance and thus have the ability to survive with fish. Most of these tadpoles were found to be unpalatable in controlled experiments. Unpalatability is the major adaptation allowing the coexistence of tadpoles and fish and is thus a major factor affecting tadpole community composition in this system. Controlled experiments showed that fish do not eat anuran eggs while the tadpoles of Leptodacrylus knudseni and Osteocephalus taurinus ate all types of eggs offered. The percentage of anurans with aquatic oviposition was positively related to fish abundance and negatively related to the occurrence of species of tadpole that ate eggs in experiments. These findings suggest that the present patterns of anuran distribution represent an evolutionary response to predation on the eggs and larvae. Contrary to the models of Heyer et al. (1975) and Wilbur (1984), desiccation and predation-pressure were not the major factors affecting species richness within waterbodies of the RFAD rainforest. In support of the model of Heyer et al. (1975), anuran species richness was correlated with the size of the waterbody. This could be because the size of the waterbody is related to increased complexity and availability of microhabitats. The range of volumes of waterbodies was also f

A variety of aquatic habitats with different levels of potential predators are available to larval amphibians in Central Amazon rainforest. The anuran community at Reserva Florestal Adolfo Ducke, 25 km east of Manaus, Amazonas, Brasil, was studied to determine which species have eggs and/or larvae in water and how those larvae are distributed in time and space. The temporal and spatial distribution of potential predators as well as abiotic characteristics of these waterbodies were determined simultaneously to test for correlations with the distribution of tadpoles. The distribution of tadpoles was strongly related to fish predation pressure. Several tadpole species were found only in waterbodies with high fish abundance and thus have the ability to survive with fish. Most of these tadpoles were found to be unpalatable in controlled experiments. Unpalatability is the major adaptation allowing the coexistence of tadpoles and fish and is thus a major factor affecting tadpole community composition in this system. Controlled experiments showed that fish do not eat anuran eggs while the tadpoles of Leptodacrylus knudseni and Osteocephalus taurinus ate all types of eggs offered. The percentage of anurans with aquatic oviposition was positively related to fish abundance and negatively related to the occurrence of species of tadpole that ate eggs in experiments. These findings suggest that the present patterns of anuran distribution represent an evolutionary response to predation on the eggs and larvae. Contrary to the models of Heyer et al. (1975) and Wilbur (1984), desiccation and predation-pressure were not the major factors affecting species richness within waterbodies of the RFAD rainforest. In support of the model of Heyer et al. (1975), anuran species richness was correlated with the size of the waterbody. This could be because the size of the waterbody is related to increased complexity and availability of microhabitats. The range of volumes of waterbodies was also f, Thesis (PhD Doctorate), Doctor of Philosophy (PhD), Division of Australian Environmental Studies, Science, Environment, Engineering and Technology, Full Text