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
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
Landscape-scale population dynamics of open forests in the Australian monsoon tropics. Over the last century there has been a trend of increasing tree cover in many landscapes. Yet the causes of this globally important ecological phenomenon are poorly understood, but may include the effects of climate, fire, grazing and CO2. We will determine how an area of forest has changed over 50 years in Kakadu National Park, linking forest demography with remote sensing techniques, re-measurement and analy ....Landscape-scale population dynamics of open forests in the Australian monsoon tropics. Over the last century there has been a trend of increasing tree cover in many landscapes. Yet the causes of this globally important ecological phenomenon are poorly understood, but may include the effects of climate, fire, grazing and CO2. We will determine how an area of forest has changed over 50 years in Kakadu National Park, linking forest demography with remote sensing techniques, re-measurement and analysis of long-term tree demography datasets, and simulation models of tree population dynamics on a landscape scale. This will provide a scientific framework to develop sustainable land management and the conservation of Australia's forest biodiversity.Read moreRead less
Methane uptake of forest soils. This project will provide a detailed understanding of capacity of soils in Australia to sequester the greenhouse gas methane. It will identify the main factors and processes controlling methane uptake in soils and improve predictive models will allow us to predict methane uptake in the future.
Predicting and improving the productivity of plants in future climates. Earth's atmospheric carbon dioxide (CO2) sustains all terrestrial vegetation, yet the effects of increasing concentrations of this gas on plant productivity are difficult to predict. The project aims to undertake experiments on the leaf-level processes that underpin plant productivity in multiple global vegetation systems. This could enable the development of a new theoretical approach to predicting plant productivity in cha ....Predicting and improving the productivity of plants in future climates. Earth's atmospheric carbon dioxide (CO2) sustains all terrestrial vegetation, yet the effects of increasing concentrations of this gas on plant productivity are difficult to predict. The project aims to undertake experiments on the leaf-level processes that underpin plant productivity in multiple global vegetation systems. This could enable the development of a new theoretical approach to predicting plant productivity in changed environmental circumstances at all scales. The results of this project could provide new tools for understanding the vulnerabilities and sensitivities of natural and managed landscapes under environmental pressures associated with increasing CO2.Read moreRead less