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
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.
A step change in modeling leaf respiration-photosynthesis relationships . This project aims to use innovative, high-throughput technologies to develop a novel framework that links daytime photosynthesis and starch/amino acid mobilisation to variations in night-time leaf respiration. Variations in leaf respiration can have large impacts on ecosystem functioning and the Earth’s climate. Although advances have been made in respiration modelling, current models are unable to predict dynamic, day-to- ....A step change in modeling leaf respiration-photosynthesis relationships . This project aims to use innovative, high-throughput technologies to develop a novel framework that links daytime photosynthesis and starch/amino acid mobilisation to variations in night-time leaf respiration. Variations in leaf respiration can have large impacts on ecosystem functioning and the Earth’s climate. Although advances have been made in respiration modelling, current models are unable to predict dynamic, day-to-day variations in respiratory rates. Expected outcomes include equations that predict daily variations in night-time leaf respiration for environments across Australia and overseas. Benefits to planners include the ability to more accurately model vegetation-atmosphere carbon exchange and future changes in climate. Read moreRead less
The causes and effects of mortality in tropical Australian trees. Drought can cause the widespread death of tropical trees resulting in large emissions of carbon dioxide to the atmosphere, but predictions of tree death during drought remain rudimentary. This project will combine new data and modelling on how Australian tropical trees respond to drought to improve estimates of tree mortality risk and its impacts.
Incorporating new knowledge of phytoplankton diversity and nutrient utilisation into an ocean-climate model to improve forecasts of ocean function. Phytoplankton drives ocean biogeochemical cycles and regulate Earth’s climate yet are poorly represented in ocean-climate models. This project will use advanced cell sorting and analysis techniques and innovative selection experiments to gain a deeper understanding of phytoplankton diversity and nutrient utilisation under projected climate change. Th ....Incorporating new knowledge of phytoplankton diversity and nutrient utilisation into an ocean-climate model to improve forecasts of ocean function. Phytoplankton drives ocean biogeochemical cycles and regulate Earth’s climate yet are poorly represented in ocean-climate models. This project will use advanced cell sorting and analysis techniques and innovative selection experiments to gain a deeper understanding of phytoplankton diversity and nutrient utilisation under projected climate change. This new knowledge will be used to improve the biological structure of an existing coupled ocean-climate model and reduce key uncertainties in forecasts of ocean function. This research will provide managers and industry with more accurate insight into the effects of ongoing climate change on the delivery of ecosystem services in eastern Australian waters.Read moreRead less
What determines plant sensitivity to heat?: Individual to lifetime impacts. Temperature is a major determinant of the distribution of species and yet the capacity to predict the thermal sensitivity of plants is extremely limited. How vulnerability varies as a plant grows from seed to adult and produces more seed is a key question. Whether chronic warming exacerbates or ameliorates effects of extreme events, e.g. triggering the plant to enlist defensive strategies, is also an open question. This ....What determines plant sensitivity to heat?: Individual to lifetime impacts. Temperature is a major determinant of the distribution of species and yet the capacity to predict the thermal sensitivity of plants is extremely limited. How vulnerability varies as a plant grows from seed to adult and produces more seed is a key question. Whether chronic warming exacerbates or ameliorates effects of extreme events, e.g. triggering the plant to enlist defensive strategies, is also an open question. This project will advance fundamental understanding of how thermal tolerance varies across species and over the plant life cycle and how it scales demographically to lifetime vulnerability. The work will yield a significant advance in our capacity to predict impacts of extreme heat events on plant performance and distribution.
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