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.
Linking phytoplankton to fisheries using zooplankton size spectra. This project aims to develop innovative numerical methods to understand the dynamics, carbon export, and trophic structure of zooplankton. The trophic links between phytoplankton, zooplankton and fisheries are unknown. The size- frequency distribution of zooplankton (size spectrum) is an innovative method for estimating their growth, predation and production as food for fish. Analysis of a global synthesis of zooplankton size dis ....Linking phytoplankton to fisheries using zooplankton size spectra. This project aims to develop innovative numerical methods to understand the dynamics, carbon export, and trophic structure of zooplankton. The trophic links between phytoplankton, zooplankton and fisheries are unknown. The size- frequency distribution of zooplankton (size spectrum) is an innovative method for estimating their growth, predation and production as food for fish. Analysis of a global synthesis of zooplankton size distributions from tropical to polar environments are expected to reveal these vital rates of pelagic ecosystems. The zooplankton rates will reveal, for the first time, the link between phytoplankton and fisheries, and will significantly improve ecosystem models and global assessments of environmental change.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
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
Does climatic thermal variability matter? This project aims to research how annual and daily variability in temperature effects the distribution of species, their tolerance to temperature, their dispersal ability and genetic structuring. Expected outcomes include more accurate assessment of the ecological risk of climate change, which is expected to result in altered average temperatures and temperature variability. Such assessments will result in better management of species and ecosystems faci ....Does climatic thermal variability matter? This project aims to research how annual and daily variability in temperature effects the distribution of species, their tolerance to temperature, their dispersal ability and genetic structuring. Expected outcomes include more accurate assessment of the ecological risk of climate change, which is expected to result in altered average temperatures and temperature variability. Such assessments will result in better management of species and ecosystems facing threats from climate change.Read moreRead less
Tipping points and early warning signals in complex ecosystems. This project aims to create a theory of early warning that uses spatial data available on system state, connectivity and environmental stress, and to create tools to infer the risk of ecosystem collapse. Many ecosystems have irreversible tipping points. Since their locations are often unknown, metrics may provide an early warning of collapse but are difficult to apply because they need long time series which are usually lacking. Thi ....Tipping points and early warning signals in complex ecosystems. This project aims to create a theory of early warning that uses spatial data available on system state, connectivity and environmental stress, and to create tools to infer the risk of ecosystem collapse. Many ecosystems have irreversible tipping points. Since their locations are often unknown, metrics may provide an early warning of collapse but are difficult to apply because they need long time series which are usually lacking. This project will use the Great Barrier Reef as a testbed because it has both long time series (standard approach) and rich spatial data (new approach), and exhibits early warning signs. We will use these tools to gauge whether symptoms on the Great Barrier Reef predict local collapse and to develop intervention plans.Read moreRead less
The mighty ape’s last stand. This project aims to study the fate of primates in southern Asia, where evidence for megafaunal extinction is rare. Why Gigantopithecus blacki, the largest ever primate, disappeared is unknown, while humans in the region survived. This project will model dating techniques across sites to identify a precise extinction window and compare behaviour and past environmental conditions to determine why the ape failed and man persevered. Outcomes will generate a new understa ....The mighty ape’s last stand. This project aims to study the fate of primates in southern Asia, where evidence for megafaunal extinction is rare. Why Gigantopithecus blacki, the largest ever primate, disappeared is unknown, while humans in the region survived. This project will model dating techniques across sites to identify a precise extinction window and compare behaviour and past environmental conditions to determine why the ape failed and man persevered. Outcomes will generate a new understanding of past environmental change as a driver of megafaunal extinction in comparison with human adaption and survival.Read moreRead less
GBR as a significant source of climatically relevant aerosol particles. Every cloud drop is formed from a microscopic aerosol particle, known as a cloud condensation nuclei (CCN). In unpolluted environments the CCN particles originate from biogenic sources. Determining the magnitude and driving factors of biogenic aerosol production in different ecosystems is crucial to the development and improvement of climate models. This project aims to determine the mechanisms of new particle production fro ....GBR as a significant source of climatically relevant aerosol particles. Every cloud drop is formed from a microscopic aerosol particle, known as a cloud condensation nuclei (CCN). In unpolluted environments the CCN particles originate from biogenic sources. Determining the magnitude and driving factors of biogenic aerosol production in different ecosystems is crucial to the development and improvement of climate models. This project aims to determine the mechanisms of new particle production from one of the biggest ecosystems in Australia, the Great Barrier Reef. It is expected that the project will establish whether marine aerosol along the Queensland coast is coral-derived and show that this aerosol can affect the CCN concentration and therefore cloud formation and the hydrological cycle.Read moreRead less
Resilience of eucalypts to future droughts. This project aims to examine how resilient Eucalyptus species are to future droughts by combining data synthesis, manipulative experiments and modelling. Climate change is expected to increase the frequency, magnitude and duration of future droughts, with major environmental and socio-economic consequences for Australia. Current predictive capacity is extremely limited: experiments are limited in scale and cannot capture important global change interac ....Resilience of eucalypts to future droughts. This project aims to examine how resilient Eucalyptus species are to future droughts by combining data synthesis, manipulative experiments and modelling. Climate change is expected to increase the frequency, magnitude and duration of future droughts, with major environmental and socio-economic consequences for Australia. Current predictive capacity is extremely limited: experiments are limited in scale and cannot capture important global change interactions, whilst models do not represent the functional characteristics and adaptions of eucalypts. This project will develop a strong evidence- and process-based understanding to quantify the functional behaviour of drought-adapted Eucalyptus species and leverage this insight to make future model projections.Read moreRead less
How does your garden grow? Scaling functional traits to whole-plant growth. Understanding how the traits of leaves and stems influence plant growth is important because plant growth drives emergent ecosystem properties such as rates of water use and carbon and nitrogen cycling. The project will build a new understanding of trait-growth relationships, focusing on species from four Australian forest types.