Ecophysiological limitations that affect water and carbon balance within large tree canopies: a comparative investigation. Supply of water to forest canopies is a major control of hydrological, atmospheric and biotic processes that impinge on groundwater stability, catchment yield, the fate of pollutants and plant productivity. Fundamental aspects of water transport and distribution within plant tissues remain obscured by conflicting experimental data and conflicting theoretical models that des ....Ecophysiological limitations that affect water and carbon balance within large tree canopies: a comparative investigation. Supply of water to forest canopies is a major control of hydrological, atmospheric and biotic processes that impinge on groundwater stability, catchment yield, the fate of pollutants and plant productivity. Fundamental aspects of water transport and distribution within plant tissues remain obscured by conflicting experimental data and conflicting theoretical models that describe physiological functioning.
Potential hydraulic constraints to the exchange of water and carbon between leaf and atmosphere require investigation before accurate models and informed decisions can be made with respect to the role of forests in biosphere-atmosphere processes. I will use large trees to investigate physiological and morphological determinants of hydraulic function and consider relationships between tree size, water requirements and water supply.
This project will foster comparative analyses of hydraulic functioning in large angiosperm and conifer species to elucidate universal principles that relate form to function and explain relationships between trees and their environment.
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Tree water use and amelioration of dryland salinity. Dryland salinity is a huge problem for large areas of Australia. One proposal for ameliorating dryland salinity is to plant trees in upslope sites in the landscape. Such planted forests reduce movement of water through the landscape, thereby reducing mobilisation and discharge of stored salts downslope onto agricultural and sensitive riparian areas. This project will investigate tree water use in a native forest, compare it with a planted fo ....Tree water use and amelioration of dryland salinity. Dryland salinity is a huge problem for large areas of Australia. One proposal for ameliorating dryland salinity is to plant trees in upslope sites in the landscape. Such planted forests reduce movement of water through the landscape, thereby reducing mobilisation and discharge of stored salts downslope onto agricultural and sensitive riparian areas. This project will investigate tree water use in a native forest, compare it with a planted forest in the same location and investigate fundamental relationships among climate, tree size, canopy area and water use. The outcome of this project is a deep mechanistic understanding of the efficacy of trees for salinity abatement.Read moreRead less
Understanding plant uptake of organic and inorganic nitrogen for optimal fertiliser application in forestry. Nitrogen (N) in soils occurs in both organic and inorganic forms. Plants can take up inorganic N - nitrate and ammonium - but, on average, these account for only 5% of the soluble N in soils. Recent evidence suggests that plants may be able to tap into some of the 95% of N that occurs in organic forms. We will investigate the importance of organic N uptake for two plantation Eucalyptus sp ....Understanding plant uptake of organic and inorganic nitrogen for optimal fertiliser application in forestry. Nitrogen (N) in soils occurs in both organic and inorganic forms. Plants can take up inorganic N - nitrate and ammonium - but, on average, these account for only 5% of the soluble N in soils. Recent evidence suggests that plants may be able to tap into some of the 95% of N that occurs in organic forms. We will investigate the importance of organic N uptake for two plantation Eucalyptus species by tracing the uptake of different N forms by bacteria, fungi and eucalypts. This information will redefine what is meant by 'available N' and will guide the development of a new test for soil N status.Read moreRead less
Economics of carbon, nitrogen and water use in Acacia and Eucalyptus. Australia's flora is dominated by plants with sclerophyllous foliage, that is hard leaves that are tolerant of nutrient and/or water stress. Either nutrient and/or water stress are suggested as driving the evolution of sclerophylly and distribution of extant species. Mechanisms of tolerance to drought and nutrient stress differ, and these differences are reflected in patterns of nitrogen and carbon allocation and economics o ....Economics of carbon, nitrogen and water use in Acacia and Eucalyptus. Australia's flora is dominated by plants with sclerophyllous foliage, that is hard leaves that are tolerant of nutrient and/or water stress. Either nutrient and/or water stress are suggested as driving the evolution of sclerophylly and distribution of extant species. Mechanisms of tolerance to drought and nutrient stress differ, and these differences are reflected in patterns of nitrogen and carbon allocation and economics of nitrogen and water use in photosynthesis. The present study will use these differences in economics to distinguish between water- and nutrient-driven adaptations in a range of Acacia and Eucalyptus species from mesic to arid environments.Read moreRead less
Organisation and function of embedded oil glands in eucalypts. Some eucalypt leaves contain large quantities of essential oils, which have been extracted for commercial purposes for many years. Advancement of this industry, however, requires basic research directed at enhancing both the yield of oil and the range of valuable constituents. This project will make use of a new protocol for isolating and purifying the foliar oil-producing glands to identify a new suite of oil gland constituents and ....Organisation and function of embedded oil glands in eucalypts. Some eucalypt leaves contain large quantities of essential oils, which have been extracted for commercial purposes for many years. Advancement of this industry, however, requires basic research directed at enhancing both the yield of oil and the range of valuable constituents. This project will make use of a new protocol for isolating and purifying the foliar oil-producing glands to identify a new suite of oil gland constituents and to understand the way in which they are made and deployed in the gland. The research will also contribute to our general understanding of oil gland structure and function.Read moreRead less
Genetic architecture of species divergence and hybridisation in eucalypts. Eucalypts are an icon of Australia and are of great economic and ecological significance to the nation. They are the most widely planted hardwood trees in the world, but Australia is the centre of origin of most species and the custodian of this important native bioresource. Understanding the evolutionary processes that shape diversity in this internationally significant genus is important for its long-term management a ....Genetic architecture of species divergence and hybridisation in eucalypts. Eucalypts are an icon of Australia and are of great economic and ecological significance to the nation. They are the most widely planted hardwood trees in the world, but Australia is the centre of origin of most species and the custodian of this important native bioresource. Understanding the evolutionary processes that shape diversity in this internationally significant genus is important for its long-term management and conservation. This project links to large international initiatives currently underway for high-density mapping and sequencing of the eucalypt genome, to enhance the flow of information gained back to Australia for scientific, economic and environmental benefit.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
Assessing the risk of genetic pollution from Eucalyptus globulus and Corymbia plantations. We will provide the biological information necessary to assess the risk of genetic pollution of native eucalypt forest from plantations of Eucalyptus globulus and Corymbia torelliana. Key biological factors that can act as barriers to hybridisation including flowering time, pollen and seed dispersal distances, crossability, hybrid fitness and the potential for backcrossing will be identified and used to de ....Assessing the risk of genetic pollution from Eucalyptus globulus and Corymbia plantations. We will provide the biological information necessary to assess the risk of genetic pollution of native eucalypt forest from plantations of Eucalyptus globulus and Corymbia torelliana. Key biological factors that can act as barriers to hybridisation including flowering time, pollen and seed dispersal distances, crossability, hybrid fitness and the potential for backcrossing will be identified and used to develop strategies to reduce the risk of genetic pollution. The molecular differentiation between populations of the E. globulus complex, including plantations, will be studied to provide a genetic framework for the management of the genepool of this most important hardwood plantation species.Read moreRead less
Genetic impacts on eucalypt forest biodiversity. Australia is the centre of origin for most of the world's eucalypt genetic resources. This project will provide the research required to develop management strategies to reduce the risk of genetic pollution of this important genetic resource from the expanding eucalypt plantings in Australia. It will provide leading-edge science to better assess the risk and impact of genetic pollution not only on the native eucalypt gene pools per se but also on ....Genetic impacts on eucalypt forest biodiversity. Australia is the centre of origin for most of the world's eucalypt genetic resources. This project will provide the research required to develop management strategies to reduce the risk of genetic pollution of this important genetic resource from the expanding eucalypt plantings in Australia. It will provide leading-edge science to better assess the risk and impact of genetic pollution not only on the native eucalypt gene pools per se but also on the structure and biodiversity of the fungi, insect and vertebrate communities that are dependent on the eucalyptsRead moreRead less
Genetic legacy of climate change in Australian temperate forests. This work will make a significant contribution to the understanding of the Quaternary history of the forests of south-eastern Australia. Finding the location of glacial refugia is crucial to the development of long-term conservation strategies, as they are areas of high genetic and species diversity. Understanding the evolutionary processes that affect genetic diversity and gene flow of these keystone species (Nothofagus cunningha ....Genetic legacy of climate change in Australian temperate forests. This work will make a significant contribution to the understanding of the Quaternary history of the forests of south-eastern Australia. Finding the location of glacial refugia is crucial to the development of long-term conservation strategies, as they are areas of high genetic and species diversity. Understanding the evolutionary processes that affect genetic diversity and gene flow of these keystone species (Nothofagus cunninghamii, N. moorei, Acacia melanoxylon, Eucalyptus viminalis) will help their long-term management.Read moreRead less