Bio-optical model of Antarctic sea-ice algae photosynthesis. Antarctica contains no permanent human population; however the impact of climate change is being observed. Sea-ice is slowly becoming less thick and covering smaller areas of the Southern Ocean. Algae grow on the underside of this sea-ice which feed krill, which in turn support most of the Antarctic food web. Understanding how changes in sea-ice and snow thickness will change the productivity of Antarctica will have significant implica ....Bio-optical model of Antarctic sea-ice algae photosynthesis. Antarctica contains no permanent human population; however the impact of climate change is being observed. Sea-ice is slowly becoming less thick and covering smaller areas of the Southern Ocean. Algae grow on the underside of this sea-ice which feed krill, which in turn support most of the Antarctic food web. Understanding how changes in sea-ice and snow thickness will change the productivity of Antarctica will have significant implications to our management of this wilderness. Knowledge of how sea-ice algae responds to changes in light can be incorporated in climate change models.Read moreRead less
Unsaturation of vapour pressure inside leaves: fundamental, but unknown. This project aims to determine when and to what extent the air inside leaves becomes unsaturated with water vapour. All current interpretation and modelling of leaf gas exchange assumes saturation under all circumstances. Compelling evidence has been obtained that suggests this is not true under moderate air vapour pressure deficits. A novel technique will be employed to assess the water vapour concentration of the air insi ....Unsaturation of vapour pressure inside leaves: fundamental, but unknown. This project aims to determine when and to what extent the air inside leaves becomes unsaturated with water vapour. All current interpretation and modelling of leaf gas exchange assumes saturation under all circumstances. Compelling evidence has been obtained that suggests this is not true under moderate air vapour pressure deficits. A novel technique will be employed to assess the water vapour concentration of the air inside leaves based on stable isotope analysis of carbon dioxide and water vapour exchanged between leaves and air. The project is expected to provide fundamental knowledge about how stomata regulate photosynthesis and water use, with significant implications for modelling vegetation function and for improving the performance of crop plants.Read moreRead less
Climate change and ocean acidification: will southern ocean coccolithophorids be winners or losers? Implications for the global carbon pump. This proposal brings skills on morphotaxonomy, microalgal culturing, physiology and biogeochemistry into the flurry of international activity focusing on consequences of ocean acidification. Increasing atmospheric carbon dioxide (CO2) is predicted to reduce calcification in the phytoplankton Emiliania huxleyi, notably in the Southern Ocean. In contrast, hi ....Climate change and ocean acidification: will southern ocean coccolithophorids be winners or losers? Implications for the global carbon pump. This proposal brings skills on morphotaxonomy, microalgal culturing, physiology and biogeochemistry into the flurry of international activity focusing on consequences of ocean acidification. Increasing atmospheric carbon dioxide (CO2) is predicted to reduce calcification in the phytoplankton Emiliania huxleyi, notably in the Southern Ocean. In contrast, higher CO2 may stimulate photosynthesis and enhanced stratification may also select for E. huxleyi. These changes will affect foodwebs and the ability of the ocean to absorb CO2. Predicting the future success of this key organism is vital to understand the consequences of global change in Australian and Southern Ocean waters and to set targets for carbon emissions.Read moreRead less
Nitrogen characteristics of plant communities along the North Australian Tropical Transect (NATT). It has become evident that biosphere processes need to be addressed at a global scale to understand global changes. Continental transects analyse ecosystem processes in a global context. The North Australian Tropical Transect (Darwin to Tennant Creek) represents 25% of Australia's vegetation. Biogeological research is underway on NATT ecosystems. Nitrogen availability strongly affects ecosystem pro ....Nitrogen characteristics of plant communities along the North Australian Tropical Transect (NATT). It has become evident that biosphere processes need to be addressed at a global scale to understand global changes. Continental transects analyse ecosystem processes in a global context. The North Australian Tropical Transect (Darwin to Tennant Creek) represents 25% of Australia's vegetation. Biogeological research is underway on NATT ecosystems. Nitrogen availability strongly affects ecosystem productivity, and is of major interest as nitrogen pollution threatens the biosphere. In Australia, nitrogen levels are generally low, but overall knowledge is limited. An integrated ecophysiological approach will relate soil and plant nitrogen characteristics, and provide an analysis of nitrogen relations along NATT. Results will be linked to existing NATT and international transect research.Read moreRead less
Why our biota is unique: ecophysiological response, adaptive radiation and changing environments in Cainozoic Australia. We seek to resolve Cainozoic diversification and extinction patterns leading to the modern Australian biota. We propose a broad-scale, multi-disciplinary approach involving systematic palaeontology, palaeobiology, biostratigraphy, molecular and morphological systematics and physiology of modern organisms. For the first time, we will synthesise data on past climatic and environ ....Why our biota is unique: ecophysiological response, adaptive radiation and changing environments in Cainozoic Australia. We seek to resolve Cainozoic diversification and extinction patterns leading to the modern Australian biota. We propose a broad-scale, multi-disciplinary approach involving systematic palaeontology, palaeobiology, biostratigraphy, molecular and morphological systematics and physiology of modern organisms. For the first time, we will synthesise data on past climatic and environmental influences on the evolution of Australian plants, animals and community structure through time. This will provide a solid historical basis to develop management strategies for the Australian biota under different, future, climatic scenarios, and will also provide a biostratigraphic framework essential for high-resolution mineral and hydrocarbon exploration.Read moreRead less
High temperature limits of leaf function. In arid and semi-arid central Australia, Acacia spp. dominate the over-storey, but this shifts to Eucalyptus and Corymbia spp. in more mesic coastal regions. Areas of central Australia are extremely hot, dry and sunny, and it is this combination of stresses that likely excludes Eucalyptus spp. from many landforms. There has been little research on high temperature tolerance of Acacia and Eucalyptus, despite the putative importance of this stress, in co ....High temperature limits of leaf function. In arid and semi-arid central Australia, Acacia spp. dominate the over-storey, but this shifts to Eucalyptus and Corymbia spp. in more mesic coastal regions. Areas of central Australia are extremely hot, dry and sunny, and it is this combination of stresses that likely excludes Eucalyptus spp. from many landforms. There has been little research on high temperature tolerance of Acacia and Eucalyptus, despite the putative importance of this stress, in combination with other stresses, in limiting species? distributions. Our program of collaborative research will examine the tolerance of Acacia and Eucalyptus to a combination of high temperatures, drought and high light.Read moreRead less
Predictive ichthyotoxicity, diagnostics and risk assessment of harmful algal blooms impacting on the Tasmanian salmonid aquaculture industry. We aim to define through a combination of laboratory culture exposure and live cage bioassay experiments the minimum cell concentrations of harmful microalgae (Karenia, Heterosigma, Noctiluca, Chaetoceros) that can cause salmonid mortalities or are a factor in compromising fish health or reducing fish farm productivity. The diagnostic pathology and fish be ....Predictive ichthyotoxicity, diagnostics and risk assessment of harmful algal blooms impacting on the Tasmanian salmonid aquaculture industry. We aim to define through a combination of laboratory culture exposure and live cage bioassay experiments the minimum cell concentrations of harmful microalgae (Karenia, Heterosigma, Noctiluca, Chaetoceros) that can cause salmonid mortalities or are a factor in compromising fish health or reducing fish farm productivity. The diagnostic pathology and fish behaviour caused by different harmful algal taxa will be carefully documented to assist fish health inspectors in the routine diagnosis of algal toxicosis ot compromised fish health. Ultimately, this information will be integrated into a risk assessment strategy for the Tasmanian salmonid industry to manage fish stocks during times of harmful algal bloom events.Read moreRead less
Synergistic interactions between reactive oxygen species, free fatty acids and neurotoxins as the fish-killing mechanism of Australian gymnodinioid dinoflagellates. Provide the scientific basis for sound management and mitigation strategies to prevent algal bloom impacts on aquaculture, fisheries and the environment.
Top-down rehydration: role of multiple water sources in mangrove function. This project aims to combine cutting-edge analytical and imaging techniques to assess contributions of atmospheric water sources to shoot-water balances, identify leaf traits associated with top-down rehydration, and determine the relative importance of different sources of water used by mangroves in maintenance of photosynthetic carbon assimilation along natural gradients in salinity and aridity. The capacity of shoots ....Top-down rehydration: role of multiple water sources in mangrove function. This project aims to combine cutting-edge analytical and imaging techniques to assess contributions of atmospheric water sources to shoot-water balances, identify leaf traits associated with top-down rehydration, and determine the relative importance of different sources of water used by mangroves in maintenance of photosynthetic carbon assimilation along natural gradients in salinity and aridity. The capacity of shoots to absorb atmospheric water could profoundly affect the diversity, survival and productivity of mangroves where high soil salinity limits water uptake by roots, particularly during hot, dry conditions.Read moreRead less
Role of top-down-rehydration in drought tolerance of mangroves. This project aims to understand the role of absorption and storage of atmospheric water (vapour, mist, rain, dew) by shoots in survival of mangroves where high soil salinity limits root water uptake, particularly during hot, dry conditions. This research will advance understanding of drought and salinity tolerance. The project outcomes will include identification of environmental conditions that limit drought survival and functional ....Role of top-down-rehydration in drought tolerance of mangroves. This project aims to understand the role of absorption and storage of atmospheric water (vapour, mist, rain, dew) by shoots in survival of mangroves where high soil salinity limits root water uptake, particularly during hot, dry conditions. This research will advance understanding of drought and salinity tolerance. The project outcomes will include identification of environmental conditions that limit drought survival and functional plant traits that enhance drought survival. These outcomes are fundamental to interpreting mechanisms underlying mangrove dieback under drought and will benefit the development of process-based models for better prediction of mangrove responses to climate change.Read moreRead less