Linking Stress Tolerance to Molecular Evolution of Grass Stomata. Salinity and drought are two detrimental environmental stresses, affecting agricultural productivity and ecosystem health in Australia and around the world. This project will focus on the evolutionary, physiological and molecular aspects of stomatal regulation between wheat, barley and their wild relatives for salinity and drought tolerance. This project will advance the scientific knowledge in the evolution of stomatal regulation ....Linking Stress Tolerance to Molecular Evolution of Grass Stomata. Salinity and drought are two detrimental environmental stresses, affecting agricultural productivity and ecosystem health in Australia and around the world. This project will focus on the evolutionary, physiological and molecular aspects of stomatal regulation between wheat, barley and their wild relatives for salinity and drought tolerance. This project will advance the scientific knowledge in the evolution of stomatal regulation in two staple crops wheat and barley. The project will also assist plant breeders with increasing crop salinity and drought tolerance for global food security.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
Ecology, Physiology and Phylogeography: an integrated approach to the study of the invasive marine green macroalga Caulerpa taxifolia in Australia. The green marine macroalga Caulerpa taxifolia is one of the world's worst invasive species. In Australia 'exotic strains' of this alga are a listed pest species. Invasions in NSW and SA have caused environmental harm and managing them has cost $10 million since 2000. We propose to integrate ecology, physiology and genetic analyses to provide data to ....Ecology, Physiology and Phylogeography: an integrated approach to the study of the invasive marine green macroalga Caulerpa taxifolia in Australia. The green marine macroalga Caulerpa taxifolia is one of the world's worst invasive species. In Australia 'exotic strains' of this alga are a listed pest species. Invasions in NSW and SA have caused environmental harm and managing them has cost $10 million since 2000. We propose to integrate ecology, physiology and genetic analyses to provide data to better respond to this pest, potentially savings millions of dollars per year. We will produce the first empirical evidence of the effects of climate change and ocean acidification on this marine pest, in the context of increasing coastal human populations.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
Tree-mediated methane fluxes: A new frontier in the global carbon cycle. Methane is an extremely potent greenhouse gas. Recent evidence suggests that tree-mediated fluxes may be a significant, but overlooked source of methane to the atmosphere. This project aims to quantify the magnitude and drivers of tree-mediated methane fluxes from Australia’s dominant forest types. Innovatively, we will be using a novel combination of empirical field based measurements, gas tracer experiments, microbial ana ....Tree-mediated methane fluxes: A new frontier in the global carbon cycle. Methane is an extremely potent greenhouse gas. Recent evidence suggests that tree-mediated fluxes may be a significant, but overlooked source of methane to the atmosphere. This project aims to quantify the magnitude and drivers of tree-mediated methane fluxes from Australia’s dominant forest types. Innovatively, we will be using a novel combination of empirical field based measurements, gas tracer experiments, microbial analysis and modelling methods. Expected outcomes are a mechanistic understanding of tree-mediated methane fluxes, helping to constrain regional, national and global methane budgets. The results of this study will help inform publicly funded greenhouse gas abatement strategies, ensuring a maximal return on investment.Read moreRead less
Will stomatal responses to humidity and carbon dioxide constrain tropical forest productivity as atmospheric carbon dioxide rises? This project will investigate two physiological processes that will partly determine growth responses of tropical forest trees to rising atmospheric carbon dioxide. The project will produce equations summarising physiological responses that can be incorporated into process-based models of tropical forest productivity.
Reading the isotopic archive: carbon and oxygen stable isotope ratios as recorders of plant physiological processes. This project will investigate how plant physiological processes are reflected in stable isotope ratios of carbon and oxygen in plant tissues. Results will contribute towards a mechanistic understanding of the processes that cause isotopic modifications, thereby enabling an improved interpretation of naturally occurring stable isotope signals.
Comparative eco-physiology of two contrasting arid-zone woodlands in Central Australia: hydrological niche separation and ecosystem resilience. This proposal addresses two fundamental questions: how do co-occurring species co-exist and why do Australian ecosystems have larger ecosystem water-use-efficiencies than those in the USA? This proposal will: determine the resilience of two contrasting arid-zone woodlands; compare variation in hydraulic-related plant traits across co-existing species; an ....Comparative eco-physiology of two contrasting arid-zone woodlands in Central Australia: hydrological niche separation and ecosystem resilience. This proposal addresses two fundamental questions: how do co-occurring species co-exist and why do Australian ecosystems have larger ecosystem water-use-efficiencies than those in the USA? This proposal will: determine the resilience of two contrasting arid-zone woodlands; compare variation in hydraulic-related plant traits across co-existing species; and, determine the relative contribution of changes in assimilation and stomatal conductance to variation (across species and time) in water-use-efficiency. Outcomes of this work include a mechanistic understanding of the behaviour of water-limited woodlands in current and future climates. This is significant because such biomes are globally important and are home to two billion people. Read moreRead less
Impacts of groundwater extraction on ecophysiology of Australian trees. The aim of this project is to determine the response of trees to the extraction of shallow groundwater. Groundwater-dependent ecosystems rely on a supply of groundwater to maintain ecosystem health, structure and function, and excessive depletion of groundwater resources has a negative impact on these ecosystems. The project intends to combine a field-scale experimental depletion of groundwater resources simultaneously with ....Impacts of groundwater extraction on ecophysiology of Australian trees. The aim of this project is to determine the response of trees to the extraction of shallow groundwater. Groundwater-dependent ecosystems rely on a supply of groundwater to maintain ecosystem health, structure and function, and excessive depletion of groundwater resources has a negative impact on these ecosystems. The project intends to combine a field-scale experimental depletion of groundwater resources simultaneously with alterations in rainfall input and measurements of tree responses. The results of the project are intended to inform industry regulators and the water supply industry on how to improve management of both groundwater and vegetation resources.Read moreRead less
Is the extreme phosphate sensitivity found among Australian plants a consequence of their adaptation to a severely phosphate-limited environment? The phosphorus (P)-impoverished soils of south-western Australia have allowed the evolution of many plants that are amazingly efficient at retrieving P from dying tissues. This project will contribute to the understanding of the mechanism determining P efficiency and will contribute significantly to the development of crops that are less reliant on non ....Is the extreme phosphate sensitivity found among Australian plants a consequence of their adaptation to a severely phosphate-limited environment? The phosphorus (P)-impoverished soils of south-western Australia have allowed the evolution of many plants that are amazingly efficient at retrieving P from dying tissues. This project will contribute to the understanding of the mechanism determining P efficiency and will contribute significantly to the development of crops that are less reliant on non-renewable P fertilisers.Read moreRead less