Range dynamics and demographics of spatially structured populations under global change. Why are particular species present in some locations, but not others? This is a simple, fundamental ecological question, yet surprisingly, our answers on this point remain far from complete. Using an integrated, systems-based approach, we will determine the interplay between: (i) birth, death and movement rates, (ii) species interactions, and (iii) the constraints of the physical environment (temperature, ra ....Range dynamics and demographics of spatially structured populations under global change. Why are particular species present in some locations, but not others? This is a simple, fundamental ecological question, yet surprisingly, our answers on this point remain far from complete. Using an integrated, systems-based approach, we will determine the interplay between: (i) birth, death and movement rates, (ii) species interactions, and (iii) the constraints of the physical environment (temperature, rainfall, soil type), which determine the limits of species' ranges. Our models will provide Australian conservation managers with a novel, validated toolbox to explore the trade-offs, and synergies, inherent in trying to adapt to climate change and other stressors on biodiversity.Read moreRead less
Leaf respiration under drought: a global perspective. Predicting future net carbon exchange is necessary for better management of vegetation resources by Australia. Incorporating the responses of plant respiration to drought and temperature is crucial for predicting future rates of net carbon exchange. Using laboratory and field studies, this research will develop an understanding of how water availability and temperature impact on plant respiration of a broad range of economically important and ....Leaf respiration under drought: a global perspective. Predicting future net carbon exchange is necessary for better management of vegetation resources by Australia. Incorporating the responses of plant respiration to drought and temperature is crucial for predicting future rates of net carbon exchange. Using laboratory and field studies, this research will develop an understanding of how water availability and temperature impact on plant respiration of a broad range of economically important and ecologically relevant plant species. Equations will be formulated that will improve how modellers calculate drought-dependent variations in plant respiration (and thus plant productivity), thereby improving predictions for a future, warmer world.Read moreRead less
Out of the darkness: predicting rates of respiration of illuminated leaves along nutrient gradients. Our research will greatly assist in predictions of future net carbon exchange necessary if Australia is to better manage its vegetation resources. Crucial to predicting future rates of net carbon exchange is an understanding of how climate and nutrients impact on leaf respiration. Our research will develop an understanding of how light, temperature and phosphorus (the most widespread, limiting nu ....Out of the darkness: predicting rates of respiration of illuminated leaves along nutrient gradients. Our research will greatly assist in predictions of future net carbon exchange necessary if Australia is to better manage its vegetation resources. Crucial to predicting future rates of net carbon exchange is an understanding of how climate and nutrients impact on leaf respiration. Our research will develop an understanding of how light, temperature and phosphorus (the most widespread, limiting nutrient in Australia) impact on leaf respiration of a broad range of contrasting plants representative of several diverse Australian ecosystems. We will develop equations that will allow modellers to better predict climate/nutrient dependent variations in leaf respiration (and thus rates of plant productivity), both now and in the future.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
Phyloinformatics and biodiversity: developing bioinformatic tools for understanding the dynamics of extinction and invasion within species assemblages. DNA sequence data provides an exciting new way to study biodiversity, because the genome of each organism records its evolutionary history. By analysing DNA sequences co-existing species, we can reconstruct the ecological and evolutionary history of a biological community. This allows us to track biodiversity changes over time, and examine how th ....Phyloinformatics and biodiversity: developing bioinformatic tools for understanding the dynamics of extinction and invasion within species assemblages. DNA sequence data provides an exciting new way to study biodiversity, because the genome of each organism records its evolutionary history. By analysing DNA sequences co-existing species, we can reconstruct the ecological and evolutionary history of a biological community. This allows us to track biodiversity changes over time, and examine how the state of a species assemblage determines which species are lost through extinction or gained through the invasion of exotic species. Understanding the factors that govern changes in biodiversity over time is essential for planning for future conservation in the face of a rapidly changing environment. Read moreRead less
Re-evaluating the role of tannins in Australian forest ecosystems. As atmospheric CO2 concentrations rise, eucalypts will respond by decreasing the amount of protein in the leaves and increasing the concentrations of toxins called tannins. Together this will have the effect of making the leaves harder for herbivores to eat and slower to break down on the forest floor. We have developed a new way of measuring these effects and will use it to show which eucalypt communities climate change will mo ....Re-evaluating the role of tannins in Australian forest ecosystems. As atmospheric CO2 concentrations rise, eucalypts will respond by decreasing the amount of protein in the leaves and increasing the concentrations of toxins called tannins. Together this will have the effect of making the leaves harder for herbivores to eat and slower to break down on the forest floor. We have developed a new way of measuring these effects and will use it to show which eucalypt communities climate change will most affect and so which forests will become less able to support fauna. Apart from contributing to the better management of Australian forests, this project also enhances the National Carbon Accounting System by measuring how tannins influence litter decomposition and explaining the link with leaf chemistry.Read moreRead less
Oxygen-18 in water, carbon dioxide, and organic matter: a tool for linking plant biological processes, hydrology and climate change. The globe is warming but pan evaporation is decreasing, because the world is dimming. We do not understand why. Stable, naturally occurring oxygen isotopes in plants (for example, tree rings) and in the carbon dioxide of the atmosphere vary and record climatic changes and physiological responses. Bringing these disparate areas of research together will help us to i ....Oxygen-18 in water, carbon dioxide, and organic matter: a tool for linking plant biological processes, hydrology and climate change. The globe is warming but pan evaporation is decreasing, because the world is dimming. We do not understand why. Stable, naturally occurring oxygen isotopes in plants (for example, tree rings) and in the carbon dioxide of the atmosphere vary and record climatic changes and physiological responses. Bringing these disparate areas of research together will help us to interpret the changes and responses. Such information is needed for planning future water requirements in Australia (agriculture, natural ecosystems, dams) and around the world. The isotopic composition of tree rings and of the atmospheric carbon dioxide is affected by that in water of leaves, and the processes linking them will be studied in detail. Read moreRead less
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.
SEA LEVELS, SEA SURFACE TEMPERATURES AND EL NINO VARIABILITY DURING WARM INTERGLACIATIONS. Sea levels, sea surface temperatures and the variability of El Niño will be determined for previous warm interglacial periods using well dated, stratigraphically controlled fossil corals preserved in uplifted reefs. Relationships between past changes in sea level and warmer ocean temperatures will provide insights into the response of sea level to global warming. Knowledge of the frequency and amplitude o ....SEA LEVELS, SEA SURFACE TEMPERATURES AND EL NINO VARIABILITY DURING WARM INTERGLACIATIONS. Sea levels, sea surface temperatures and the variability of El Niño will be determined for previous warm interglacial periods using well dated, stratigraphically controlled fossil corals preserved in uplifted reefs. Relationships between past changes in sea level and warmer ocean temperatures will provide insights into the response of sea level to global warming. Knowledge of the frequency and amplitude of El Nino events that occurred during previous interglacial warm periods will provide a better understanding of processes controlling extreme events in the climate system.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