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
The role of mycorrhizal fungi in the nutrition of temperate terrestrial orchids. This project addresses the role of external mycelial systems in the carbon and mineral nutrition of temperate terrestrial orchids. The project will determine the processes of nutrient transfer in the protocorm and adult phases of development across a range of terrestrial temperate orchids to inform conservation and restoration efforts.
Managing ecosystem change requires the integration of above and belowground hydrological processes at relevant scales. Unprecedented levels of keystone Banksia species mortality and an increased number of species with reduced capacity to provide vital ecosystem services is leading to ecosystem change and reduced resilience of Western Australian woodlands. In water sensitive ecosystems, failure to capture and integrate above- (tree function and ecology) and below-ground (soil hydrology and physic ....Managing ecosystem change requires the integration of above and belowground hydrological processes at relevant scales. Unprecedented levels of keystone Banksia species mortality and an increased number of species with reduced capacity to provide vital ecosystem services is leading to ecosystem change and reduced resilience of Western Australian woodlands. In water sensitive ecosystems, failure to capture and integrate above- (tree function and ecology) and below-ground (soil hydrology and physics) processes at various scales (individual to landscape) has seen global tree decline remain unresolved. Using this approach, the project aims to identify processes leading to, and identify areas at high risk of, significant ecosystem change. Outcomes are expected to include the establishment a benchmark approach in understanding global ecosystem change to inform land management in a changing climate.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
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
Turning water into carbon: a synthesis of plant water-use efficiency from leaf to globe. The efficiency with which plants use water to gain carbon is a fundamental aspect of plant growth that has been frequently measured but is poorly understood. Using our new theory to draw together major datasets, the project will make a dramatic advance in our ability to understand and predict this key aspect of ecosystem function.
The failure-threshold of leaves in drought. This project aims to reveal how specific water-stress thresholds damage the leaves of Australian crop and forest species during drought. Water stress affects agricultural productivity and plant survival in drought-prone regions such as Australia. Using optical and X-ray techniques, this project seeks to visualise and quantify the dynamic processes of damage and repair in leaves under stress. Anticipated outputs include a practical basis to predict drou ....The failure-threshold of leaves in drought. This project aims to reveal how specific water-stress thresholds damage the leaves of Australian crop and forest species during drought. Water stress affects agricultural productivity and plant survival in drought-prone regions such as Australia. Using optical and X-ray techniques, this project seeks to visualise and quantify the dynamic processes of damage and repair in leaves under stress. Anticipated outputs include a practical basis to predict drought-induced canopy death; identification of threats to ecologically sensitive plants; and selection and screening tools to improve the drought resilience of agriculturally important crop species.Read moreRead less
Feast or famine: how Australian plants stay productive under low phosphorus. Phosphorus (P) is in low supply in soils around the nation, and limits plant production in the Australian landscape, as well as for many tropical forests worldwide. How scarce P restricts photosynthetic capacity has remained elusive. We will determine how Australian plants achieve high phosphorus-use efficiency despite low P concentrations in leaves and soils. We will synthesise knowledge of how plants maintain producti ....Feast or famine: how Australian plants stay productive under low phosphorus. Phosphorus (P) is in low supply in soils around the nation, and limits plant production in the Australian landscape, as well as for many tropical forests worldwide. How scarce P restricts photosynthetic capacity has remained elusive. We will determine how Australian plants achieve high phosphorus-use efficiency despite low P concentrations in leaves and soils. We will synthesise knowledge of how plants maintain productivity with low P availability, and inform global models how to represent P biogeochemistry and photosynthesis to improve C-cycle estimates. The understanding of plant photosynthetic and P-saving mechanisms that emerge should provide benefits through improved ecological models and enhanced management of primary production.Read moreRead less
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
Do hotter and drier regions harbour adaptive variation for climate change? This project aims to improve our understanding of the capacity of trees to respond to climate change. This is essential for the maintenance of biodiversity, forest health and productivity. In south-west Australia, climate variation has increased the frequency and intensity of droughts, which has resulted in tree death and negatively affected essential ecosystem services. Adaptive land management is urgently needed to miti ....Do hotter and drier regions harbour adaptive variation for climate change? This project aims to improve our understanding of the capacity of trees to respond to climate change. This is essential for the maintenance of biodiversity, forest health and productivity. In south-west Australia, climate variation has increased the frequency and intensity of droughts, which has resulted in tree death and negatively affected essential ecosystem services. Adaptive land management is urgently needed to mitigate the risk of large-scale drought mortality in a rapidly changing climate. This project seeks to deliver a scientific basis for the adoption of assisted gene migration in south-west forests, through a detailed understanding of genetic adaptation and physiological tolerance, to improve drought-resilience under future hotter and drier climates.Read moreRead less