Reserving nitrogen in soils through microbial nitrate reduction to ammonium. This project aims to identify those microbes able to transform nitrate to ammonium and thus increase soil nitrogen conservation. More than 50 per cent of the nitrogen in fertilisers applied to soils is lost into the environment, which is both a financial loss to farmers and a main anthropogenic source of nitrogen pollution. Some microbes can transform nitrate into ammonium through dissimilatory reduction (DNRA) and thus ....Reserving nitrogen in soils through microbial nitrate reduction to ammonium. This project aims to identify those microbes able to transform nitrate to ammonium and thus increase soil nitrogen conservation. More than 50 per cent of the nitrogen in fertilisers applied to soils is lost into the environment, which is both a financial loss to farmers and a main anthropogenic source of nitrogen pollution. Some microbes can transform nitrate into ammonium through dissimilatory reduction (DNRA) and thus increase soil nitrogen retention. However, the DNRA process and the responsible microbial groups remain largely unknown. This project plans to use isotope tracing and biomolecular approaches to identify those DNRA microbial groups and elucidate the DNRA reaction process. The findings may support the use of DNRA to improve soil nitrogen.Read moreRead less
A general soil spatial scaling theory. Soil diversity is crucial for maintenance of sustainable ecosystems. Soil varies on a continuum from microbial habitats to fields, regions, continents and the globe. This project will take a unifying approach to derive a general spatial scaling theory that will allow us to estimate the likely behaviour of soil properties at all scales. Understanding the scaling behaviour of soil means one can be certain about describing the changes in relationships between ....A general soil spatial scaling theory. Soil diversity is crucial for maintenance of sustainable ecosystems. Soil varies on a continuum from microbial habitats to fields, regions, continents and the globe. This project will take a unifying approach to derive a general spatial scaling theory that will allow us to estimate the likely behaviour of soil properties at all scales. Understanding the scaling behaviour of soil means one can be certain about describing the changes in relationships between soil properties and processes. It will enhance the ability to monitor soil property changes through time, essential for gauging effects of climate change and achieving food security. Read moreRead less
Global space-time soil carbon assessment. Soil carbon is a key component of functional ecosystems and is crucial for food, water and energy security, and for climate change mitigation. The project will contribute to global understanding of soil carbon and its management for sustainable wellbeing.
Up in smoke and out to sea? Carbon, water and land use change in savanna. This project aims to improve our understanding of carbon cycling in natural and transformed savannas. It seeks to resolve a large discrepancy in savanna carbon sink size as measured by flux towers compared to long-term direct measures of carbon stock change. This would improve our fundamental understanding of carbon balances (gains/losses) and residence times in these dynamic ecosystems. The long-term impacts of these land ....Up in smoke and out to sea? Carbon, water and land use change in savanna. This project aims to improve our understanding of carbon cycling in natural and transformed savannas. It seeks to resolve a large discrepancy in savanna carbon sink size as measured by flux towers compared to long-term direct measures of carbon stock change. This would improve our fundamental understanding of carbon balances (gains/losses) and residence times in these dynamic ecosystems. The long-term impacts of these land use changes on carbon storage are poorly understood, therefore this new knowledge is vital in determining the viability of 'carbon farming' in these landscapes. More accurate information would guide improved land management given the intensification of land use, weed invasion and fire regime change in northern Australia.Read moreRead less
The mechanics of healing and self-healing in clayey soils. This project aims to develop an experimentally-validated theory of healing and self-healing in clay and determine clay-polymer mixtures that heal cracks and fissures in clay. Healing of fissures will improve strength and reduce hydraulic conductivity, which will reduce risks associated with construction on fissured clay and make clay barrier systems in dehydrating environments more reliable. The project’s observations of crack healing ar ....The mechanics of healing and self-healing in clayey soils. This project aims to develop an experimentally-validated theory of healing and self-healing in clay and determine clay-polymer mixtures that heal cracks and fissures in clay. Healing of fissures will improve strength and reduce hydraulic conductivity, which will reduce risks associated with construction on fissured clay and make clay barrier systems in dehydrating environments more reliable. The project’s observations of crack healing are expected to advance understanding of this phenomenon of soil mechanics and of geotechnical applications where cracking can occur, such as in foundation design, waste containment, slope stability and embankment dams.Read moreRead less
Switching partners: a driving force for tree productivity in a changing environment? Eucalypts take part in a mutually beneficial association with diverse communities of mycorrhizal fungi to satisfy nutrient demands. The fungi that eucalypts interact with change as they grow but the reasons for this shift are not known. To improve forestry management strategies, the project will determine why and how this shift occurs.
An experimentally-validated thermo-hydro-mechanical theory for waste containment lining systems. Geosynthetic clay liners are engineering systems that are widely used around the world to protect groundwater from municipal, industrial and mining contaminants. The project will conduct cutting-edge experimental, theoretical and computational research leading to a major improvement in their short-term and long-term performances.
Getting to the root of the matter: predicting plant benefits from arbuscular mycorrhizal symbioses. Massive efforts are underway to select beneficial root traits that enhance resource acquisition and productivity. These efforts are usually conducted while excluding mutually beneficial mycorrhizal partnerships, which include two-thirds of higher plants. These efforts are likely to lead to artifactual outcomes unless the modifying effects of these partnerships are considered. While mycorrhization ....Getting to the root of the matter: predicting plant benefits from arbuscular mycorrhizal symbioses. Massive efforts are underway to select beneficial root traits that enhance resource acquisition and productivity. These efforts are usually conducted while excluding mutually beneficial mycorrhizal partnerships, which include two-thirds of higher plants. These efforts are likely to lead to artifactual outcomes unless the modifying effects of these partnerships are considered. While mycorrhization can substantially enhance plant vigour, results are often difficult to replicate due to widespread 'context-dependence'. This research will identify plant and fungal traits that predict how mycorrhizal plants benefit under a variety of contexts, which will improve varietal selection and productivity gains in marginal environments.Read moreRead less
Carbon conundrum: Functional characterisation of organic matter-clay mineral interactions in relation to carbon sequestration. Carbon sequestration in soil has been recognised as one of the possible measures through which greenhouse gas emissions can be mitigated. The major processes involved in carbon sequestration in soil include chemical immobilisation of carbon with soil particles and physical protection in the pores of soil microaggregates. These two processes are mediated through the funct ....Carbon conundrum: Functional characterisation of organic matter-clay mineral interactions in relation to carbon sequestration. Carbon sequestration in soil has been recognised as one of the possible measures through which greenhouse gas emissions can be mitigated. The major processes involved in carbon sequestration in soil include chemical immobilisation of carbon with soil particles and physical protection in the pores of soil microaggregates. These two processes are mediated through the functional relationships of soil organic matter and clay mineral interactions in soils. This project investigates nanoscale organomineral association underlying microaggregate formation and stability, as well as the distribution and microbial decomposition of carbon within microaggregates using a suite of advanced spectroscopic, molecular and isotopic techniques.Read moreRead less
Do microbial and plant diversity interact to regulate multifunctionality? This project aims to quantify the relative contribution of plant and microbial communities and their interactions on the rate, stability and resilience of ecosystem functions. Plant and soil microbial communities contribute to the functioning of terrestrial ecosystems, driving key processes such as carbon and nutrient cycling. This project will adapt established theories which indicate that greater plant diversity improves ....Do microbial and plant diversity interact to regulate multifunctionality? This project aims to quantify the relative contribution of plant and microbial communities and their interactions on the rate, stability and resilience of ecosystem functions. Plant and soil microbial communities contribute to the functioning of terrestrial ecosystems, driving key processes such as carbon and nutrient cycling. This project will adapt established theories which indicate that greater plant diversity improves ecosystem functions, stability and recovery. The expected outcome is a unifying framework for determining variation in functions across different ecosystem types and environmental disturbance such as rapid climate change.The insight gained into vulnerable ecosystems will help stakeholders (government, conservation, land management) to prioritise the focus on conservation and reduce risks to ecosystem services.Read moreRead less