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
Temperature sensitivity of soil respiration and its components. This project aims to demonstrate how temperate evergreen forests could buffer against climate change. Soil respiration returns around half the carbon taken up by forests to the atmosphere. This project will characterise and quantify how microbes and roots in soils depend on temperature and substrate supply, and so predict how rising temperatures and drought will affect forests as natural carbon sequestration sinks. This project will ....Temperature sensitivity of soil respiration and its components. This project aims to demonstrate how temperate evergreen forests could buffer against climate change. Soil respiration returns around half the carbon taken up by forests to the atmosphere. This project will characterise and quantify how microbes and roots in soils depend on temperature and substrate supply, and so predict how rising temperatures and drought will affect forests as natural carbon sequestration sinks. This project will resolve the roles of environmental drivers of soil respiration across forests; integrate mechanistic understanding of differing plant and microbial responses to temperature within a common modelling framework; and evaluate the implications of this knowledge in predictions of climatic impacts on terrestrial carbon cycling.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.
To grow or to store: Do plants hedge their bets? This project aims to resolve a long-standing question about the function of perennial plants: how much of the carbon taken up by photosynthesis is used immediately for growth, and how much is kept in reserve as insurance against future stress? This question is important to our understanding of how plants respond to stresses such as severe drought, and yet lack of data and theoretical modelling currently hampers our ability to answer it. By applyin ....To grow or to store: Do plants hedge their bets? This project aims to resolve a long-standing question about the function of perennial plants: how much of the carbon taken up by photosynthesis is used immediately for growth, and how much is kept in reserve as insurance against future stress? This question is important to our understanding of how plants respond to stresses such as severe drought, and yet lack of data and theoretical modelling currently hampers our ability to answer it. By applying novel data analysis and modelling tools to recent experimental results, the project plans to test hypotheses for how plants allocate carbon between growth and storage in response to stress. Insights from the project may underpin better management of Australia’s vulnerable ecosystems.Read moreRead less
Optimisation of catchment management: stable isotope studies of water storage and yield. Focusing on the Cotter catchment, this project will establish how the water content of soils and tree stems regulates the amount of water used by trees in sub-catchments, and thus how much reaches streams and dams. Small areas supply most of the water yield and this project will help identify where managers should focus efforts to increase yield.
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
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
Forecasting live fuel moisture content, the on/off switch for forest fire. Dry forest fuels are a precursor of large bushfires. This research aims to develop, for the first time, a model to reliably forecast the moisture content of live fuels (e.g. the foliage and fine branches of shrubs and trees). This will be achieved by combining (i) satellite-derived estimates of live fuel moisture content, (ii) forecasts of soil moisture, and (iii) plant physiological responses to soil dryness. Forecasts o ....Forecasting live fuel moisture content, the on/off switch for forest fire. Dry forest fuels are a precursor of large bushfires. This research aims to develop, for the first time, a model to reliably forecast the moisture content of live fuels (e.g. the foliage and fine branches of shrubs and trees). This will be achieved by combining (i) satellite-derived estimates of live fuel moisture content, (ii) forecasts of soil moisture, and (iii) plant physiological responses to soil dryness. Forecasts of live fuel moisture content will deliver an early warning system of the risk of bushfires. These forecasts will also facilitate improved planning of prescribed burns: if fuels are too dry there is a risk of burns escaping, conversely, if fuels are too wet there is a risk that burns will fail to meet objectives.Read moreRead less