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
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
Water-use efficiency of Australian tropical trees: mechanistic analysis at multiple scales. The proposed research will provide valuable information about the physiological functioning of trees in northern Australia. Experiments will elucidate mechanisms that can result in variation in water-use efficiency among different tree species. Such a mechanistic understanding will have multiple benefits: (1) results will be able to be incorporated into process-based models of carbon and water cycling ....Water-use efficiency of Australian tropical trees: mechanistic analysis at multiple scales. The proposed research will provide valuable information about the physiological functioning of trees in northern Australia. Experiments will elucidate mechanisms that can result in variation in water-use efficiency among different tree species. Such a mechanistic understanding will have multiple benefits: (1) results will be able to be incorporated into process-based models of carbon and water cycling in the north-Australian landscape; (2) they will provide valuable information for land managers interested in optimizing both plant biomass production and water resource management; and (3) they will provide a critical test of proxy methods for identifying high water-use efficiency in taxonomically diverse tree species.Read moreRead less
Leaf respiration under drought: a global perspective. Predicting future net carbon exchange is necessary for better management of vegetation resources by Australia. Incorporating the responses of plant respiration to drought and temperature is crucial for predicting future rates of net carbon exchange. Using laboratory and field studies, this research will develop an understanding of how water availability and temperature impact on plant respiration of a broad range of economically important and ....Leaf respiration under drought: a global perspective. Predicting future net carbon exchange is necessary for better management of vegetation resources by Australia. Incorporating the responses of plant respiration to drought and temperature is crucial for predicting future rates of net carbon exchange. Using laboratory and field studies, this research will develop an understanding of how water availability and temperature impact on plant respiration of a broad range of economically important and ecologically relevant plant species. Equations will be formulated that will improve how modellers calculate drought-dependent variations in plant respiration (and thus plant productivity), thereby improving predictions for a future, warmer world.Read moreRead less
Out of the darkness: predicting rates of respiration of illuminated leaves along nutrient gradients. Our research will greatly assist in predictions of future net carbon exchange necessary if Australia is to better manage its vegetation resources. Crucial to predicting future rates of net carbon exchange is an understanding of how climate and nutrients impact on leaf respiration. Our research will develop an understanding of how light, temperature and phosphorus (the most widespread, limiting nu ....Out of the darkness: predicting rates of respiration of illuminated leaves along nutrient gradients. Our research will greatly assist in predictions of future net carbon exchange necessary if Australia is to better manage its vegetation resources. Crucial to predicting future rates of net carbon exchange is an understanding of how climate and nutrients impact on leaf respiration. Our research will develop an understanding of how light, temperature and phosphorus (the most widespread, limiting nutrient in Australia) impact on leaf respiration of a broad range of contrasting plants representative of several diverse Australian ecosystems. We will develop equations that will allow modellers to better predict climate/nutrient dependent variations in leaf respiration (and thus rates of plant productivity), both now and in the future.Read moreRead less
Climate dependence of plant respiration in a warmer, drier world. This research will greatly assist in predictions of future net carbon exchange that are necessary if Australia is to better manage its vegetation resources. Crucial to predicting future rates of net carbon exchange is an understanding of how drought and long-term changes in temperature impact on plant respiration. Using laboratory and field studies, this research will develop an understanding of how water availability and temperat ....Climate dependence of plant respiration in a warmer, drier world. This research will greatly assist in predictions of future net carbon exchange that are necessary if Australia is to better manage its vegetation resources. Crucial to predicting future rates of net carbon exchange is an understanding of how drought and long-term changes in temperature impact on plant respiration. Using laboratory and field studies, this research will develop an understanding of how water availability and temperature impact on plant respiration of a broad range of economically important and ecologically relevant plant species. Equations will be formulated that allow modellers to better predict drought-dependent variations in plant respiration (and thus plant productivity), both now and in a future, warmer world.Read moreRead less
Global change in the sub-antarctic - Temperature response of vascular plant species from Macquarie and Heard Islands. The aim is to understand how subantarctic and alpine plant species that have evolved, respectively, in equable and highly variable temperature regimes will respond to increase in temperature resulting from global warming and climate change. The proposed project will identify species that are likely to benefit from, or are vulnerable to, rising temperatures. Processes underlying a ....Global change in the sub-antarctic - Temperature response of vascular plant species from Macquarie and Heard Islands. The aim is to understand how subantarctic and alpine plant species that have evolved, respectively, in equable and highly variable temperature regimes will respond to increase in temperature resulting from global warming and climate change. The proposed project will identify species that are likely to benefit from, or are vulnerable to, rising temperatures. Processes underlying adaptation and acclimation of plant growth to increasing temperature will also be identified. These results will be significant for conservation of biodiversity and management of Australia's unique subantarctic and alpine flora.Read moreRead less
Tolerance of temperature extremes under drought: linking physiological processes with morphological constraints on leaf function. Freezing temperatures affect over 70% of Australia. Each year frosts cause substantial damage to agriculture and forestry. We will examine how decrease in hydraulic conduit diameter increases freeze tolerance in native woody species and quantify impacts of this tolerance on productivity of leaves. The results have application in managing temperate woody vegetation un ....Tolerance of temperature extremes under drought: linking physiological processes with morphological constraints on leaf function. Freezing temperatures affect over 70% of Australia. Each year frosts cause substantial damage to agriculture and forestry. We will examine how decrease in hydraulic conduit diameter increases freeze tolerance in native woody species and quantify impacts of this tolerance on productivity of leaves. The results have application in managing temperate woody vegetation under current and future climate scenarios. By improving understanding of the behaviour of water in leaves during freezing, we will contribute to improved models of physical stresses and strains in biological tissues during freezing, which find application in cryo-storage of biological materials important in agriculture, medicine, and conservation.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