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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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
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
Life history responses to habitat heterogeneity and implications for conservation. This exciting new research project will provide a novel understanding of how animals respond and adapt to environmental variation. This will fill a critical gap between ecological theory and real-world populations and initiate a major shift in how we view the relationship between environments and the species that inhabit them. Natural resource use practices like forestry are rarely considered compatible with biodi ....Life history responses to habitat heterogeneity and implications for conservation. This exciting new research project will provide a novel understanding of how animals respond and adapt to environmental variation. This will fill a critical gap between ecological theory and real-world populations and initiate a major shift in how we view the relationship between environments and the species that inhabit them. Natural resource use practices like forestry are rarely considered compatible with biodiversity conservation. This research will provide on-the-ground management recommendations to integrate such land uses with conservation, thereby providing both economic and conservation benefits to the Australian community.Read moreRead less
How does warming prevent soil nitrogen availability from declining in response to elevated CO2? The sustainable use of the terrestrial environment depends upon maintaining ecosystem productivity which in turn depends upon nutrient availability within the soil. Increasing levels of CO2 in the atmosphere are known to decrease nutrient availability while warming prevents this from happening. The aims of this project are to determine how warming is able to prevent elevated CO2 concentrations from re ....How does warming prevent soil nitrogen availability from declining in response to elevated CO2? The sustainable use of the terrestrial environment depends upon maintaining ecosystem productivity which in turn depends upon nutrient availability within the soil. Increasing levels of CO2 in the atmosphere are known to decrease nutrient availability while warming prevents this from happening. The aims of this project are to determine how warming is able to prevent elevated CO2 concentrations from reducing soil N availability and hence productivity in a native grassland ecosystems. This is important, as it will allow likely problems caused by global climate change to be predicted by increasing the understanding of the underlying mechanisms as well as improving the management of grasslands in an environmentally sustainable way. Read moreRead less
Nutrition in the Gouldian finch - developing an optimal 'life-history diet'. Native Australian birds such as the budgerigar, cockatiel, cockatoo, zebra finch and Gouldian finch dominate the pet trade with tens of millions kept across the world. Currently these birds are fed inadequate diets based on a few generic seeds (of European origin). Our study will investigate the nutritional needs of the Gouldian finch and the nutritional content of native Australian seeds, ultimately designing an optima ....Nutrition in the Gouldian finch - developing an optimal 'life-history diet'. Native Australian birds such as the budgerigar, cockatiel, cockatoo, zebra finch and Gouldian finch dominate the pet trade with tens of millions kept across the world. Currently these birds are fed inadequate diets based on a few generic seeds (of European origin). Our study will investigate the nutritional needs of the Gouldian finch and the nutritional content of native Australian seeds, ultimately designing an optimal diet that will dramatically improve the health of these captive birds. We will develop a new product based on Australian plants, which are adapted to growing in even in the poorest soils and climates in Australia and which will form the basis of a new commercial crop for domestic and international markets. Read moreRead less