Grazing-fire interactions and vegetation dynamics. Grazing and fire are the two major cost-effective tools that can be used to manipulate the vegetation of reserves and rangelands. This project will result in information and models that will enable a more effective use of grazing than at present in natural vegetation management for both nature conservation and production. An understanding of the ways in which vertebrate grazing animals influence the incidence and intensity of fire is also highly ....Grazing-fire interactions and vegetation dynamics. Grazing and fire are the two major cost-effective tools that can be used to manipulate the vegetation of reserves and rangelands. This project will result in information and models that will enable a more effective use of grazing than at present in natural vegetation management for both nature conservation and production. An understanding of the ways in which vertebrate grazing animals influence the incidence and intensity of fire is also highly important in planning to prevent the occasional vegetation fire that causes substantial losses of life, property and conservation values, especially in the context of predicted climatic change.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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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
Will trees get enough nitrogen to sustain productivity in elevated CO2? The project proposes to explore how tissue nitrogen declines in future elevated carbon dioxide (eCO2) by studying the availability of soil nitrogen to plants and use of nitrogen by Eucalyptus woodland trees. Plant canopy nitrogen concentrations decline in nearly every large-scale eCO2 study done on native soils. The project plans to explore how changes in ecosystem nitrogen balance occur, by investigating if leaf nitrogen de ....Will trees get enough nitrogen to sustain productivity in elevated CO2? The project proposes to explore how tissue nitrogen declines in future elevated carbon dioxide (eCO2) by studying the availability of soil nitrogen to plants and use of nitrogen by Eucalyptus woodland trees. Plant canopy nitrogen concentrations decline in nearly every large-scale eCO2 study done on native soils. The project plans to explore how changes in ecosystem nitrogen balance occur, by investigating if leaf nitrogen declines under eCO2 due to the balance of plant activity versus changes in soil nitrogen availability. The outcomes are central to knowing the extent to which extra nitrogen ‘feeds’ the eCO2 fertilisation response and sustains long-term increases in productivity. Expected outcomes may support the development of management options to sustain future forest productivity.Read moreRead less
Temperature sensitivity of soil respiration and its components. This project aims to demonstrate how temperate evergreen forests could buffer against climate change. Soil respiration returns around half the carbon taken up by forests to the atmosphere. This project will characterise and quantify how microbes and roots in soils depend on temperature and substrate supply, and so predict how rising temperatures and drought will affect forests as natural carbon sequestration sinks. This project will ....Temperature sensitivity of soil respiration and its components. This project aims to demonstrate how temperate evergreen forests could buffer against climate change. Soil respiration returns around half the carbon taken up by forests to the atmosphere. This project will characterise and quantify how microbes and roots in soils depend on temperature and substrate supply, and so predict how rising temperatures and drought will affect forests as natural carbon sequestration sinks. This project will resolve the roles of environmental drivers of soil respiration across forests; integrate mechanistic understanding of differing plant and microbial responses to temperature within a common modelling framework; and evaluate the implications of this knowledge in predictions of climatic impacts on terrestrial carbon cycling.Read moreRead less
Woodland response to elevated CO2 in free air carbon dioxide enrichment: does phosphorus limit the sink for Carbon? This project will determine if growth of Australian woodland trees is limited by phosphorus, and if that limitation means the woodland carbon sink is constrained from responding to rising atmospheric CO2. Assessing the CO2 sink capacity of native eucalypt woodland is central to meeting Australia's domestic and international carbon accounting commitments.
Applying macroecology to assist in the management of Kakadu National Park. The ecological integrity of Kakadu National Park is threatened by fires, weeds, and feral animals. To help tackle these problems, we will develop a cost-effective, culturally appropriate, park-wide monitoring system based on changes in the boundaries of closed forests, woodland and grassland. We will gauge the effect of broad-scale land management interventions, and predict the consequences of future change. The findings ....Applying macroecology to assist in the management of Kakadu National Park. The ecological integrity of Kakadu National Park is threatened by fires, weeds, and feral animals. To help tackle these problems, we will develop a cost-effective, culturally appropriate, park-wide monitoring system based on changes in the boundaries of closed forests, woodland and grassland. We will gauge the effect of broad-scale land management interventions, and predict the consequences of future change. The findings of this study will be transferable to other landscape settings in Australia and overseas. It will contribute to debates about the ecological consequences of current land management practices and how these compare with past Aboriginal land management.Read moreRead less
Landscape-scale monitoring and adaptive management of woodland birds in the Mt Lofty Ranges. Despite the fundamental role of scientific monitoring in nature conservation, its research importance and potential is widely neglected. There is an urgent need to improve quantitative rigour, particularly to ensure adequate statistical power is achieved when monitoring at a landscape scale. We will apply new analytical tools to the problem of devising a powerful and flexible monitoring regime for a high ....Landscape-scale monitoring and adaptive management of woodland birds in the Mt Lofty Ranges. Despite the fundamental role of scientific monitoring in nature conservation, its research importance and potential is widely neglected. There is an urgent need to improve quantitative rigour, particularly to ensure adequate statistical power is achieved when monitoring at a landscape scale. We will apply new analytical tools to the problem of devising a powerful and flexible monitoring regime for a highly threatened woodland bird community in South Australia. Monitoring will be embedded within a decision-making framework with explicit links to local management agencies. Results will be broadly applicable across agricultural areas of Australia, where bird assemblages are in general decline.Read moreRead less
Sustainable Farms: Tree Regeneration and the Future of Farmland Biodiversity. While many government and community initiatives aim to enhance the sustainability of Australian farming systems, none specifically target the important regional-scale threatening process of tree recruitment failure. Unless this problem is addressed urgently, many farming landscapes may be virtually treeless in the future, with severe negative ramifications for both biodiversity and agricultural productivity. 'Sustainab ....Sustainable Farms: Tree Regeneration and the Future of Farmland Biodiversity. While many government and community initiatives aim to enhance the sustainability of Australian farming systems, none specifically target the important regional-scale threatening process of tree recruitment failure. Unless this problem is addressed urgently, many farming landscapes may be virtually treeless in the future, with severe negative ramifications for both biodiversity and agricultural productivity. 'Sustainable Farms' will have major national and community benefits because it will: (1) identify more sustainable farming practices that are conducive to successful tree recruitment in the future, and (2) raise awareness about a much neglected threat to the sustainability of Australian farming landscapes.Read moreRead less
Resilience of eucalypts to future droughts. This project aims to examine how resilient Eucalyptus species are to future droughts by combining data synthesis, manipulative experiments and modelling. Climate change is expected to increase the frequency, magnitude and duration of future droughts, with major environmental and socio-economic consequences for Australia. Current predictive capacity is extremely limited: experiments are limited in scale and cannot capture important global change interac ....Resilience of eucalypts to future droughts. This project aims to examine how resilient Eucalyptus species are to future droughts by combining data synthesis, manipulative experiments and modelling. Climate change is expected to increase the frequency, magnitude and duration of future droughts, with major environmental and socio-economic consequences for Australia. Current predictive capacity is extremely limited: experiments are limited in scale and cannot capture important global change interactions, whilst models do not represent the functional characteristics and adaptions of eucalypts. This project will develop a strong evidence- and process-based understanding to quantify the functional behaviour of drought-adapted Eucalyptus species and leverage this insight to make future model projections.Read moreRead less