Water-use efficiency of Australian tropical trees: mechanistic analysis at multiple scales. The proposed research will provide valuable information about the physiological functioning of trees in northern Australia. Experiments will elucidate mechanisms that can result in variation in water-use efficiency among different tree species. Such a mechanistic understanding will have multiple benefits: (1) results will be able to be incorporated into process-based models of carbon and water cycling ....Water-use efficiency of Australian tropical trees: mechanistic analysis at multiple scales. The proposed research will provide valuable information about the physiological functioning of trees in northern Australia. Experiments will elucidate mechanisms that can result in variation in water-use efficiency among different tree species. Such a mechanistic understanding will have multiple benefits: (1) results will be able to be incorporated into process-based models of carbon and water cycling in the north-Australian landscape; (2) they will provide valuable information for land managers interested in optimizing both plant biomass production and water resource management; and (3) they will provide a critical test of proxy methods for identifying high water-use efficiency in taxonomically diverse tree species.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
High temperature limits of leaf function. In arid and semi-arid central Australia, Acacia spp. dominate the over-storey, but this shifts to Eucalyptus and Corymbia spp. in more mesic coastal regions. Areas of central Australia are extremely hot, dry and sunny, and it is this combination of stresses that likely excludes Eucalyptus spp. from many landforms. There has been little research on high temperature tolerance of Acacia and Eucalyptus, despite the putative importance of this stress, in co ....High temperature limits of leaf function. In arid and semi-arid central Australia, Acacia spp. dominate the over-storey, but this shifts to Eucalyptus and Corymbia spp. in more mesic coastal regions. Areas of central Australia are extremely hot, dry and sunny, and it is this combination of stresses that likely excludes Eucalyptus spp. from many landforms. There has been little research on high temperature tolerance of Acacia and Eucalyptus, despite the putative importance of this stress, in combination with other stresses, in limiting species? distributions. Our program of collaborative research will examine the tolerance of Acacia and Eucalyptus to a combination of high temperatures, drought and high light.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
Assessing the impact of a native parasitic plant, Cassytha pubescens, on the weeds gorse (Ulex europaeus) and English broom (Cytisus scoparius). Each year invasive plants cost Australia billions of dollars through costs associated with their control and through lost agricultural production and degradation of native ecosystems. Two particularly damaging plants are gorse and broom. The problems gorse causes are so serious that it has been recognized as a Weed of National Significance (Federal Depa ....Assessing the impact of a native parasitic plant, Cassytha pubescens, on the weeds gorse (Ulex europaeus) and English broom (Cytisus scoparius). Each year invasive plants cost Australia billions of dollars through costs associated with their control and through lost agricultural production and degradation of native ecosystems. Two particularly damaging plants are gorse and broom. The problems gorse causes are so serious that it has been recognized as a Weed of National Significance (Federal Department of Environment and Heritage). Biological control efforts have seldom use native agents, and even less often, parasitic plants. This project will help to develop strategies for the control of two noxious species using a native parsitic plant.Read moreRead less
Predictive ichthyotoxicity, diagnostics and risk assessment of harmful algal blooms impacting on the Tasmanian salmonid aquaculture industry. We aim to define through a combination of laboratory culture exposure and live cage bioassay experiments the minimum cell concentrations of harmful microalgae (Karenia, Heterosigma, Noctiluca, Chaetoceros) that can cause salmonid mortalities or are a factor in compromising fish health or reducing fish farm productivity. The diagnostic pathology and fish be ....Predictive ichthyotoxicity, diagnostics and risk assessment of harmful algal blooms impacting on the Tasmanian salmonid aquaculture industry. We aim to define through a combination of laboratory culture exposure and live cage bioassay experiments the minimum cell concentrations of harmful microalgae (Karenia, Heterosigma, Noctiluca, Chaetoceros) that can cause salmonid mortalities or are a factor in compromising fish health or reducing fish farm productivity. The diagnostic pathology and fish behaviour caused by different harmful algal taxa will be carefully documented to assist fish health inspectors in the routine diagnosis of algal toxicosis ot compromised fish health. Ultimately, this information will be integrated into a risk assessment strategy for the Tasmanian salmonid industry to manage fish stocks during times of harmful algal bloom events.Read moreRead less
Wandoo crown decline - an ecophysiological diagnosis. Eucalyptus wandoo forests and woodlands once covered a large area in SW Western Australia. Remnants of these ecosystems are now threatened by the Wandoo Crown Decline syndrome. We hypothesise that the progressive dieback of branches is due to drought stress, causing irreversible damage to water supply and/or predisposing trees to fungal disease. The project aims at identifying the physiological mechanism of Wandoo Crown Decline. This knowledg ....Wandoo crown decline - an ecophysiological diagnosis. Eucalyptus wandoo forests and woodlands once covered a large area in SW Western Australia. Remnants of these ecosystems are now threatened by the Wandoo Crown Decline syndrome. We hypothesise that the progressive dieback of branches is due to drought stress, causing irreversible damage to water supply and/or predisposing trees to fungal disease. The project aims at identifying the physiological mechanism of Wandoo Crown Decline. This knowledge is imperative for the assessment of risks for wandoo populations and for the formulation of management options.Read moreRead less
The genus Banksia: can ecophysiological traits associated with nutrient acquisition explain species distribution and rarity? We aim to investigate if an important aspect of a specialised mechanism of nutrient acquisition by different species of the genus Banksia (Proteaceae) accounts for their distribution and rarity. This aspect is the pattern of exudates that are produced by their 'proteoid' roots. Different species of the Proteaceae produce different exudates and it is envisaged that variatio ....The genus Banksia: can ecophysiological traits associated with nutrient acquisition explain species distribution and rarity? We aim to investigate if an important aspect of a specialised mechanism of nutrient acquisition by different species of the genus Banksia (Proteaceae) accounts for their distribution and rarity. This aspect is the pattern of exudates that are produced by their 'proteoid' roots. Different species of the Proteaceae produce different exudates and it is envisaged that variation in pattern reflects their capacity to grow on certain soil types. Our studies will provide key information on processes that determine species distribution, with consequences for defining better management regimes for rare and endangered species.Read moreRead less
When corals bleach, what is the weakest photosynthetic link? Despite dire warning of the imminent impact (< 50 y) of climate change of coral reefs, we still do not understand the fundamental processes of coral bleaching. This project will enhance future management of Australia's extensive coral reef ecosystems by providing details on critical gaps in our knowledge. This will feed directly into several layers of management agencies for policy development and risk assessment. Managing our reefs in ....When corals bleach, what is the weakest photosynthetic link? Despite dire warning of the imminent impact (< 50 y) of climate change of coral reefs, we still do not understand the fundamental processes of coral bleaching. This project will enhance future management of Australia's extensive coral reef ecosystems by providing details on critical gaps in our knowledge. This will feed directly into several layers of management agencies for policy development and risk assessment. Managing our reefs in an ecologically sustainable manner is vital to the future economic, social and cultural prosperity of Australia. The economic importance of healthy and biodiverse coral reefs is pivotal to both the tourism and fisheries-based economies of Queensland ($2.4 b/y). Read moreRead less
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