What limits CO2 diffusion inside leaves? Dissecting the diffusion path with Arabidopsis mutants. Human induced increase in atmospheric carbon dioxide is now generally accepted as contributing to global warming. Forecasting our future impact relies on models of terrestrial photosynthesis which use a signature in the atmosphere created by plants when they discriminate against the heavy stable isotope of carbon during photosynthesis. Discrimination between isotopes is affected by carbon dioxide dif ....What limits CO2 diffusion inside leaves? Dissecting the diffusion path with Arabidopsis mutants. Human induced increase in atmospheric carbon dioxide is now generally accepted as contributing to global warming. Forecasting our future impact relies on models of terrestrial photosynthesis which use a signature in the atmosphere created by plants when they discriminate against the heavy stable isotope of carbon during photosynthesis. Discrimination between isotopes is affected by carbon dioxide diffusion within leaves and key steps in this process will be identified through the use of Arabidopsis mutants. Better representation of this process in models will improve estimates of terrestrial photosynthesis and climate change forecastsRead 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
Oxygen isotope discrimination during C4 photosynthesis. Plants with the C4 photosynthetic pathway, like sugarcane and pasture grasses, are vital to Australian agriculture and natural ecosystems. This project will use novel laser spectroscopy to measure oxygen isotope discrimination during photosynthesis and quantify the influence of C4 plants on isotopic signatures of atmospheric CO2.
Oxygen-18 in water, carbon dioxide, and organic matter: a tool for linking plant biological processes, hydrology and climate change. The globe is warming but pan evaporation is decreasing, because the world is dimming. We do not understand why. Stable, naturally occurring oxygen isotopes in plants (for example, tree rings) and in the carbon dioxide of the atmosphere vary and record climatic changes and physiological responses. Bringing these disparate areas of research together will help us to i ....Oxygen-18 in water, carbon dioxide, and organic matter: a tool for linking plant biological processes, hydrology and climate change. The globe is warming but pan evaporation is decreasing, because the world is dimming. We do not understand why. Stable, naturally occurring oxygen isotopes in plants (for example, tree rings) and in the carbon dioxide of the atmosphere vary and record climatic changes and physiological responses. Bringing these disparate areas of research together will help us to interpret the changes and responses. Such information is needed for planning future water requirements in Australia (agriculture, natural ecosystems, dams) and around the world. The isotopic composition of tree rings and of the atmospheric carbon dioxide is affected by that in water of leaves, and the processes linking them will be studied in detail. Read moreRead less
Testing climatic, physiological and hydrological assumptions underpinning water yield from montane forests. Water collected in dams and reservoirs remains the mainstay water resource for Australian cities, towns and industry. Overwhelmingly, that water is collected from forested catchments where the water balance of forest stands is dominated by the amount of water used by trees. Characterising tree water use, its response to changing climatic and nocturnal conditions, and other aspects of sta ....Testing climatic, physiological and hydrological assumptions underpinning water yield from montane forests. Water collected in dams and reservoirs remains the mainstay water resource for Australian cities, towns and industry. Overwhelmingly, that water is collected from forested catchments where the water balance of forest stands is dominated by the amount of water used by trees. Characterising tree water use, its response to changing climatic and nocturnal conditions, and other aspects of stand hydrology, are crucial to our ability to predict and model future water yields. Working in the Cotter catchment near Canberra and the upper Kiewa catchment in north-east Victoria, we aim to help the agencies responsible for water and catchment management to improve the security of their forecasts of water yield and their on-ground management. Read moreRead less
Avoiding coral bleaching: investigation into the repair of damaged photosynthetic machinery in symbiotic algae (symbiodinium) within corals. Photosynthesis in symbiotic algae within corals is essential for a healthy alga-coral symbiotic relationship. This project will provide new insights into how symbiotic algae maintain higher photosynthetic performance in corals through elucidating the mechanism associated with the repair of photodamaged photosynthetic machinery.
Disentangling climate and evolutionary controls over the temperature dependence of leaf respiration. The project will use field and laboratory studies to establish if there are systematic differences in the temperature responses of leaf respiration in plants adapted to hot and cold environments. The results will enable climate modellers to better predict impacts of climate change on carbon exchange between vegetation and the atmosphere.
Using Arabidopsis mutants to discover the role of guard cell chloroplasts in the stomatal response to light. This project will use novel molecular approaches to study how guard cells on the surface of leaves regulate plant water loss and CO2 uptake. This will provide new molecular tools for improving plant water use in agricultural species and aid process based modelling of CO2 and water exchange needed for predicting climate change.
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