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
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
Measuring tree water use and calculating stand water use. The national benefit of this project is significant. Woodlands and forests transpire vast amounts of water into the atmosphere and this water is thus lost to human consumptive use. Given large variation in rainfall between years and between seasons, it is vital that water and catchment resource managers are able to estimate how much water is lost through trees. This allows estimation of the amount of water available for irrigation, drinki ....Measuring tree water use and calculating stand water use. The national benefit of this project is significant. Woodlands and forests transpire vast amounts of water into the atmosphere and this water is thus lost to human consumptive use. Given large variation in rainfall between years and between seasons, it is vital that water and catchment resource managers are able to estimate how much water is lost through trees. This allows estimation of the amount of water available for irrigation, drinking, other industrial uses or maintaining ecosystem health. This project will be the first to generate a mechanistic understanding thereby allowing estimates of water use across a range of woody ecosystems in Australia.Read moreRead less
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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Eucalypt growth in past and future environments - a novel approach to understanding the impacts of atmospheric CO2 and climate. The impact of climate change and rising atmospheric CO2 on Australia's plantation and native forests is a major concern for government and land managers. These forests are important for environmental, aesthetic, and economic purposes, including carbon sequestration and trading. Forests use large amounts of water, reducing stream flow and water supplies for rural and u ....Eucalypt growth in past and future environments - a novel approach to understanding the impacts of atmospheric CO2 and climate. The impact of climate change and rising atmospheric CO2 on Australia's plantation and native forests is a major concern for government and land managers. These forests are important for environmental, aesthetic, and economic purposes, including carbon sequestration and trading. Forests use large amounts of water, reducing stream flow and water supplies for rural and urban communities. Knowledge generated from the proposed project will provide insight into mechanisms driving productivity and water use of forests in current and future environments. The knowledge will be used by land managers and government to develop strategies to cope with future impacts of climate change.Read moreRead less
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
Spatially integrated estimates of landscape water fluxes at several contrasting sites. Woodlands transpire large amounts (> 80 % of rainfall) of water into the atmosphere and this water is lost from the catchment. Australia experiences large annual and seasonal variations in rainfall. Water and catchment managers need to estimate how much water is transpired, especially as climate and land-use practices change, as this determines how much water is available for drinking, use in mining, forestr ....Spatially integrated estimates of landscape water fluxes at several contrasting sites. Woodlands transpire large amounts (> 80 % of rainfall) of water into the atmosphere and this water is lost from the catchment. Australia experiences large annual and seasonal variations in rainfall. Water and catchment managers need to estimate how much water is transpired, especially as climate and land-use practices change, as this determines how much water is available for drinking, use in mining, forestry, irrigation, and for ecosystem health purposes. This project is the first to combine the use of scintillometry to compare spatially averaged rates of water use with development of a model to predict landscape water use. By using 4 contrasting ecosystems we shall provide a deep understanding of the controls of vegetation water use.Read moreRead less
Balancing Water Quality and Ecosystem Health with Water Yield -- Ecosystem Response to Thinning in Wungong Catchment. Reduced rainfall in past decades and future climate uncertainty have added a sense of urgency in Australia to search for new water resources to sustain a growing economy and population. A forest thinning trial is planned in the Wungong Catchment, Western Australia, to substantially increase water yield. Thinning is attractive as a low-cost option, and is potentially suitable for ....Balancing Water Quality and Ecosystem Health with Water Yield -- Ecosystem Response to Thinning in Wungong Catchment. Reduced rainfall in past decades and future climate uncertainty have added a sense of urgency in Australia to search for new water resources to sustain a growing economy and population. A forest thinning trial is planned in the Wungong Catchment, Western Australia, to substantially increase water yield. Thinning is attractive as a low-cost option, and is potentially suitable for other catchments. However the potential environmental and ecological impacts, which are major community concerns, must be investigated. This project will assess the levels of impact, associated ecosystem responses and the capacity of catchment ecosystems to sustain such management intervention.Read moreRead less