Top-down rehydration: role of multiple water sources in mangrove function. This project aims to combine cutting-edge analytical and imaging techniques to assess contributions of atmospheric water sources to shoot-water balances, identify leaf traits associated with top-down rehydration, and determine the relative importance of different sources of water used by mangroves in maintenance of photosynthetic carbon assimilation along natural gradients in salinity and aridity. The capacity of shoots ....Top-down rehydration: role of multiple water sources in mangrove function. This project aims to combine cutting-edge analytical and imaging techniques to assess contributions of atmospheric water sources to shoot-water balances, identify leaf traits associated with top-down rehydration, and determine the relative importance of different sources of water used by mangroves in maintenance of photosynthetic carbon assimilation along natural gradients in salinity and aridity. The capacity of shoots to absorb atmospheric water could profoundly affect the diversity, survival and productivity of mangroves where high soil salinity limits water uptake by roots, particularly during hot, dry conditions.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
Interactive effects of salinity and nutrients: linking physiological processes with patterns in mangrove forest productivity. The proposed research will provide insight into physiological mechanisms that underpin mangrove productivity along salinity and aridity gradients, and determine how these factors affect plant responses to nutrient enrichment. Plant traits that increase salt and drought tolerance will be identified, thereby assisting development of plant varieties suited to Australian cond ....Interactive effects of salinity and nutrients: linking physiological processes with patterns in mangrove forest productivity. The proposed research will provide insight into physiological mechanisms that underpin mangrove productivity along salinity and aridity gradients, and determine how these factors affect plant responses to nutrient enrichment. Plant traits that increase salt and drought tolerance will be identified, thereby assisting development of plant varieties suited to Australian conditions. The results will also contribute to development of process-based models to better manage mangrove resources with climate change and increasing nutrient influx from urban or agricultural activities. Such models are essential for managing mangrove productivity for sustainable fisheries, and protecting the ecological well being of the coastal zone.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.
Salinity tolerance along an aridity gradient: linking physiological processes with morphological constraints on leaf function in mangroves. The proposed research will provide insight into the physiological and morphological features that control the productivity of mangrove forests across broad gradients in salinity and aridity. Central to this is this identification of plant traits that increase salt and drought tolerance, which will assist in the development of plant varieties suited to Austra ....Salinity tolerance along an aridity gradient: linking physiological processes with morphological constraints on leaf function in mangroves. The proposed research will provide insight into the physiological and morphological features that control the productivity of mangrove forests across broad gradients in salinity and aridity. Central to this is this identification of plant traits that increase salt and drought tolerance, which will assist in the development of plant varieties suited to Australian conditions. The results will also contribute to development of process-based models to better predict the response of mangrove vegetation to changing climate. A deep understanding of the processes that influence the growth and survival of mangroves is of fundamental importance to sustainable fisheries and protection of wildlife reliant on coastal ecosystems. Read moreRead less
Photosynthetic traits as “key performance indicators” of coral health. The objective of this project is to advance knowledge on the healthy functioning of the coral–algal symbiosis, which defines the response of coral reef ecosystems to worldwide environmental change. Current approaches to address this problem have linked coral health to algal symbiont diversity but have been unable to resolve the fundamental symbiont functional traits that govern this link – the “key performance indicators (KPI ....Photosynthetic traits as “key performance indicators” of coral health. The objective of this project is to advance knowledge on the healthy functioning of the coral–algal symbiosis, which defines the response of coral reef ecosystems to worldwide environmental change. Current approaches to address this problem have linked coral health to algal symbiont diversity but have been unable to resolve the fundamental symbiont functional traits that govern this link – the “key performance indicators (KPIs)”. This project plans to couple advanced physiological and functional genomics techniques to transform our understanding of how algal symbiont metabolic KPIs regulate coral growth and stress susceptibility. This may provide new diagnostic capability for the assessment of coral health and may enable us to improve coral reef ecosystem management.Read moreRead less
Australia's Distinctive Succulent Flora. The project plans to investigate why Australia, the driest vegetated continent, has no landscape dominated by large succulents but nevertheless supports a distinctive, diverse and widespread succulent flora. Focusing on terrestrial succulents and epiphytic orchids, the project plans to explore the evolution, assembly and biodiversity of Australia’s succulent flora, evaluating the roles of genetic composition, photosynthetic physiology, aridity, fire, soil ....Australia's Distinctive Succulent Flora. The project plans to investigate why Australia, the driest vegetated continent, has no landscape dominated by large succulents but nevertheless supports a distinctive, diverse and widespread succulent flora. Focusing on terrestrial succulents and epiphytic orchids, the project plans to explore the evolution, assembly and biodiversity of Australia’s succulent flora, evaluating the roles of genetic composition, photosynthetic physiology, aridity, fire, soil nutrients and salinity in its historical expansion, and assessing the resilience of the assemblages to changing climate. Of particular interest will be how the most water-use efficient type of photosynthesis, crassulacean acid metabolism, is expressed across the succulent landscape.Read moreRead less
On the physiology of plant transpiration. This project aims to better understand plant transpiration. It is significant from both a basic and a practical perspective. It intends to solve a conundrum of the biophysics of the evaporative sites within leaves. That is, in dry air, the relative humidity of intercellular air spaces suggests much lower liquid water potentials than those typically measured. At a practical level, the failure to sustain transpiration in dry conditions leads to desiccation ....On the physiology of plant transpiration. This project aims to better understand plant transpiration. It is significant from both a basic and a practical perspective. It intends to solve a conundrum of the biophysics of the evaporative sites within leaves. That is, in dry air, the relative humidity of intercellular air spaces suggests much lower liquid water potentials than those typically measured. At a practical level, the failure to sustain transpiration in dry conditions leads to desiccation and tissue death, and plants differ in this vulnerability. The aim is to apply a novel nanoparticle technique to measure the water potential distribution within the leaf, identify hydraulic resilience attributes, and develop a modern theory of optimal transpiration under varying conditions.Read moreRead less
Cereal blueprints for a water-limited world. This project aims to demonstrate that key developmental genes in cereals can be manipulated to design plant architecture for specific resource-limited environments. Producing more food with less water is one of the greatest challenges facing humanity today. This project expects to increase understanding of how shoot and root systems can be uncoupled to enhance crop adaptation in water-limited environments using an accelerated genome editing approach. ....Cereal blueprints for a water-limited world. This project aims to demonstrate that key developmental genes in cereals can be manipulated to design plant architecture for specific resource-limited environments. Producing more food with less water is one of the greatest challenges facing humanity today. This project expects to increase understanding of how shoot and root systems can be uncoupled to enhance crop adaptation in water-limited environments using an accelerated genome editing approach. An expected outcome of the project is enhanced drought adaptation for cereals in a dry world. This should provide significant benefits to farmers and consumers in Australia and worldwide.Read moreRead less
Hydraulic control on water use, growth and survival in tropical rainforest. This project aims to measure drought-related limits to water transport in the woody xylem tissue of trees in Australian tropical rainforests, to understand how this influences tree water use, photosynthesis, health and mortality risk. Tropical rainforests are sensitive to climate variability, especially drought, but this sensitivity is poorly understood, despite large effects regionally and globally. This project will co ....Hydraulic control on water use, growth and survival in tropical rainforest. This project aims to measure drought-related limits to water transport in the woody xylem tissue of trees in Australian tropical rainforests, to understand how this influences tree water use, photosynthesis, health and mortality risk. Tropical rainforests are sensitive to climate variability, especially drought, but this sensitivity is poorly understood, despite large effects regionally and globally. This project will compare forests that contrast strongly in seasonal drought stress, and use the information to develop a model designed for species-diverse forest, with subsequent potential global application. The understanding gained will enable widely applicable advances designed to feed through rapidly to regional- and global-scale models that inform land use, economic and social policy-making.Read moreRead less