Understanding leaf water isotope composition. This project aims to quantify variation in leaf water isotopes and develop mechanistic models for paleoclimatologists and plant scientists to constrain global carbon cycles. Leaf water stable isotopes influence the isotope compositions of atmospheric oxygen, carbon dioxide and water vapour, and impart an evaporative signal on the isotope composition of plant organic material. These isotope signals have been used to constrain global carbon and water c ....Understanding leaf water isotope composition. This project aims to quantify variation in leaf water isotopes and develop mechanistic models for paleoclimatologists and plant scientists to constrain global carbon cycles. Leaf water stable isotopes influence the isotope compositions of atmospheric oxygen, carbon dioxide and water vapour, and impart an evaporative signal on the isotope composition of plant organic material. These isotope signals have been used to constrain global carbon and water cycles and reconstruct past climates. This project aims to quantify variation in leaf water isotopes and develop mechanistic models for use by paleoclimatologists, plant scientists and to constrain global carbon cycles and develop accurate models of leaf water isotopes to reduce uncertainty in climate 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
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.
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.
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.
Understanding the mechanisms of thermal acclimation in the symbiotic algae (Symbiodinium) within cnidarian corals. Global warming is a major threat to coral reefs, contributing to devastating coral bleaching. This project will provide new insight into how coral reefs can respond to rising global temperature through clarifying the thermal acclimation mechanisms in corals using molecular techniques.
Linkage Infrastructure, Equipment And Facilities - Grant ID: LE140100189
Funder
Australian Research Council
Funding Amount
$191,095.00
Summary
A shared mass spectrometer with compound-specific capabilities to support innovative research in biology, the environment and geology. A shared mass spectrometer with compound-specific capabilities to support innovative research in biology, the environment and geology: Stable isotope studies have huge and increasing relevance to environmental studies, many of which form the backbone of understanding Australia's terrestrial and marine systems. Compound-specific isotope analysis yields much more i ....A shared mass spectrometer with compound-specific capabilities to support innovative research in biology, the environment and geology. A shared mass spectrometer with compound-specific capabilities to support innovative research in biology, the environment and geology: Stable isotope studies have huge and increasing relevance to environmental studies, many of which form the backbone of understanding Australia's terrestrial and marine systems. Compound-specific isotope analysis yields much more information than is available through bulk methods. The problem has been that the separations were labour-intensive and employed complex wet chemistry. New methods reduce the work-load enough to make compound-specific studies possible. In the case of carbon isotopes, new liquid chromatographic technology removes the need for derivatisations which dilute the natural signal and can render it unusable.Read moreRead less
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