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
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
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
Mechanisms linking site water status and net primary productivity. Australia is the driest of all inhabited continents and also has the lowest primary productivity. This project will determine the mechanisms linking these observations. Through development of a detailed mechanistic understanding of how site water balance determines site productivity and application of this understanding in a state-of-the-art model, we shall improve forest and water resource management and our understanding of the ....Mechanisms linking site water status and net primary productivity. Australia is the driest of all inhabited continents and also has the lowest primary productivity. This project will determine the mechanisms linking these observations. Through development of a detailed mechanistic understanding of how site water balance determines site productivity and application of this understanding in a state-of-the-art model, we shall improve forest and water resource management and our understanding of the unique ecology of Australia.Read moreRead less
Testing climatic, physiological and hydrological assumptions underpinning water yield from montane forests. Water collected in dams and reservoirs remains the mainstay water resource for Australian cities, towns and industry. Overwhelmingly, that water is collected from forested catchments where the water balance of forest stands is dominated by the amount of water used by trees. Characterising tree water use, its response to changing climatic and nocturnal conditions, and other aspects of sta ....Testing climatic, physiological and hydrological assumptions underpinning water yield from montane forests. Water collected in dams and reservoirs remains the mainstay water resource for Australian cities, towns and industry. Overwhelmingly, that water is collected from forested catchments where the water balance of forest stands is dominated by the amount of water used by trees. Characterising tree water use, its response to changing climatic and nocturnal conditions, and other aspects of stand hydrology, are crucial to our ability to predict and model future water yields. Working in the Cotter catchment near Canberra and the upper Kiewa catchment in north-east Victoria, we aim to help the agencies responsible for water and catchment management to improve the security of their forecasts of water yield and their on-ground management. Read moreRead less
Why does phosphite protect some plants against Phytophthora but not others? Plant diseases caused by Phytophthora pose a major threat to Australia's biodiversity, horticulture and agriculture. The systemic chemical potassium phosphite is a key component of management strategies, but its effectiveness varies on different plant species. We will use molecular and biochemical techniques to understand why some plant species are protected against Phytophthora dieback by phosphite while others are not. ....Why does phosphite protect some plants against Phytophthora but not others? Plant diseases caused by Phytophthora pose a major threat to Australia's biodiversity, horticulture and agriculture. The systemic chemical potassium phosphite is a key component of management strategies, but its effectiveness varies on different plant species. We will use molecular and biochemical techniques to understand why some plant species are protected against Phytophthora dieback by phosphite while others are not. This will improve the options for managing bushland affected by dieback and will also expand our knowledge of plant disease resistance.Read moreRead less