Turning water into carbon: a synthesis of plant water-use efficiency from leaf to globe. The efficiency with which plants use water to gain carbon is a fundamental aspect of plant growth that has been frequently measured but is poorly understood. Using our new theory to draw together major datasets, the project will make a dramatic advance in our ability to understand and predict this key aspect of ecosystem function.
Enhancing nutrient retention in soils through management of microbial biomass. Soil microbial-processes are generally studied in relation to mineralisation of nutrients but rarely for their potential to retain nutrients and reduce nutrient leaching. We hypothesise that management of microbial immobilisation will enhance nutrient retention in nutrient enriched soils during seasonal rains. This hypothesis will be tested under strongly seasonal environments of southwest Australia where nutrient lea ....Enhancing nutrient retention in soils through management of microbial biomass. Soil microbial-processes are generally studied in relation to mineralisation of nutrients but rarely for their potential to retain nutrients and reduce nutrient leaching. We hypothesise that management of microbial immobilisation will enhance nutrient retention in nutrient enriched soils during seasonal rains. This hypothesis will be tested under strongly seasonal environments of southwest Australia where nutrient leaching from soils degrades quality of surface and groundwater. We will first investigate pathways and conditions leading to microbial immobilisation. We will then explore the regulation of substrate and nutrient conditions to promote such retention, and subsequently develop management interventions based on microbially-mediated nutrient retention.Read moreRead less
Toxic cyanobacterial blooms in a carbon dioxide (CO2)-rich world: assessing the impacts of global climate change. Cyanobacterial blooms in Australia cost the country over $150 million every year because of their impacts on water quality and animal and human health. The frequency, distribution and intensity of these blooms are all expected to increase worldwide as global climate change impacts increase over the next century. This project will provide much needed information of the severity of imp ....Toxic cyanobacterial blooms in a carbon dioxide (CO2)-rich world: assessing the impacts of global climate change. Cyanobacterial blooms in Australia cost the country over $150 million every year because of their impacts on water quality and animal and human health. The frequency, distribution and intensity of these blooms are all expected to increase worldwide as global climate change impacts increase over the next century. This project will provide much needed information of the severity of impacts on cyanobacteria commonly causing blooms in Australian aquatic ecosystems. This information will be important to authorities responsible for managing our precious water resources.Read moreRead less
Resource patchiness, dispersal and species co-occurrence: an experimental and levels-of-evidence approach in some lowland streams. Millions of dollars are being spent on rehabilitating river ecosystems that have often been highly simplified by human activities. It is important that such rehabilitation be well-grounded in sound ecological knowledge. We will test how the availability of essential resources of food and living space affect the identity and density of species present. We expect to p ....Resource patchiness, dispersal and species co-occurrence: an experimental and levels-of-evidence approach in some lowland streams. Millions of dollars are being spent on rehabilitating river ecosystems that have often been highly simplified by human activities. It is important that such rehabilitation be well-grounded in sound ecological knowledge. We will test how the availability of essential resources of food and living space affect the identity and density of species present. We expect to provide practical advice allowing managers to enhance biodiversity in streams surrounded by, and serving, agricultural areas. Likewise, we will be able to advise on the consequences of excessive water extraction on the likely success of such rehabilitation in rivers with highly variable flows.Read moreRead less
Reconstructing the historical frequency and intensity of Australian droughts: A multi-species dendrochronological approach. Drought directly and indirectly impacts every Australian. Severe droughts devastate rural communities, lead to increased water restrictions and bushfire activity, slows the national economy and threatens diverse ecosystems. Our research will improve understanding of where, when, and how intensely droughts have occurred across eastern Australia in the past. The results will ....Reconstructing the historical frequency and intensity of Australian droughts: A multi-species dendrochronological approach. Drought directly and indirectly impacts every Australian. Severe droughts devastate rural communities, lead to increased water restrictions and bushfire activity, slows the national economy and threatens diverse ecosystems. Our research will improve understanding of where, when, and how intensely droughts have occurred across eastern Australia in the past. The results will provide unique insights into the processes that generate Australian droughts and how future droughts might be anticipated. The results will provide farmers, hydrologists, and policy-makers with better data on long-term variability in water supplies to improve local, regional, and national water planning initiatives and infrastructure development.Read moreRead less
Testing the Flood Pulse Concept for rivers with variable flow regimes. For floodplain rivers the major unifying conceptual model linking hydrology, biogeochemistry and ecology is the Flood Pulse Concept (FPC). The model is based on rivers that have a seasonally predictable and long duration inundation of floodplain habitats. Recent reviews of the FPC indicate that the model needs to be broadened to describe the function of rivers with more variable flow regimes. This project will test some of th ....Testing the Flood Pulse Concept for rivers with variable flow regimes. For floodplain rivers the major unifying conceptual model linking hydrology, biogeochemistry and ecology is the Flood Pulse Concept (FPC). The model is based on rivers that have a seasonally predictable and long duration inundation of floodplain habitats. Recent reviews of the FPC indicate that the model needs to be broadened to describe the function of rivers with more variable flow regimes. This project will test some of the predictions of the FPC for variable dryland rivers by investigating how food webs in the channels of a floodplain reach respond to flows of different magnitude, seasonal timing and duration.Read moreRead less
Diadromous stream fishes: a model system for investigating sources of variation in recruitment. Our aim is to examine the relationship between adult abundance and recruitment in local populations of a diadromous stream fish to identify the source(s) of variation in recruitment. We will accomplish this by measuring larval production and recruitment among streams that vary in adult abundance, strength of settlement cues, and potential for larval dispersal. We will also use environmental markers of ....Diadromous stream fishes: a model system for investigating sources of variation in recruitment. Our aim is to examine the relationship between adult abundance and recruitment in local populations of a diadromous stream fish to identify the source(s) of variation in recruitment. We will accomplish this by measuring larval production and recruitment among streams that vary in adult abundance, strength of settlement cues, and potential for larval dispersal. We will also use environmental markers of larval origin to quantify the degree of self-recruitment and dispersal within/among populations. The results will broaden our understanding of the influence of local (production, habitat) versus regional (dispersal) processes to local population dynamics, information needed for effective stream management.Read moreRead less
Open or closed? Dispersal and recruitment in populations of aquatic invertebrates with spatially distributed resources. The general aim of this research is to examine the contribution of fertilised eggs and recently hatched juveniles to the local population dynamics of some stream invertebrates. It seems likely that these stages act as population 'bottlenecks' , and our research will quantify the relations between these two stages and between neonates and mature larvae. Our research will also ....Open or closed? Dispersal and recruitment in populations of aquatic invertebrates with spatially distributed resources. The general aim of this research is to examine the contribution of fertilised eggs and recently hatched juveniles to the local population dynamics of some stream invertebrates. It seems likely that these stages act as population 'bottlenecks' , and our research will quantify the relations between these two stages and between neonates and mature larvae. Our research will also indicate whether these populations are likely to be closed (i.e., groups of individuals are relatively isolated) along channels or not. We believe our results will show much stream research focuses on the wrong life-stages; practices of river management may need re-assessment.Read moreRead less
To grow or to store: Do plants hedge their bets? This project aims to resolve a long-standing question about the function of perennial plants: how much of the carbon taken up by photosynthesis is used immediately for growth, and how much is kept in reserve as insurance against future stress? This question is important to our understanding of how plants respond to stresses such as severe drought, and yet lack of data and theoretical modelling currently hampers our ability to answer it. By applyin ....To grow or to store: Do plants hedge their bets? This project aims to resolve a long-standing question about the function of perennial plants: how much of the carbon taken up by photosynthesis is used immediately for growth, and how much is kept in reserve as insurance against future stress? This question is important to our understanding of how plants respond to stresses such as severe drought, and yet lack of data and theoretical modelling currently hampers our ability to answer it. By applying novel data analysis and modelling tools to recent experimental results, the project plans to test hypotheses for how plants allocate carbon between growth and storage in response to stress. Insights from the project may underpin better management of Australia’s vulnerable ecosystems.Read moreRead less
A novel approach to tracking estuarine food chains: combined use of fatty acid and stable isotope biomarkers. Fatty acid biomarkers provide promising novel tracers for studying estuarine food chains. Stable isotopes, commonly employed in food chain studies, lack specificity to allow easy determination of feeding relationships. Different primary producers are characterised by unique fatty acid sequences. This study will thoroughly evaluate the applicability of fatty acid biomarkers in tracking ....A novel approach to tracking estuarine food chains: combined use of fatty acid and stable isotope biomarkers. Fatty acid biomarkers provide promising novel tracers for studying estuarine food chains. Stable isotopes, commonly employed in food chain studies, lack specificity to allow easy determination of feeding relationships. Different primary producers are characterised by unique fatty acid sequences. This study will thoroughly evaluate the applicability of fatty acid biomarkers in tracking both natural and human-impacted estuarine food chains. By developing a new approach of combining the advantages of fatty acid bioamrkers and stable isotopes in studying estuarine trophodynamics, this study will provide essential information for the management of estuarine biotic resources.Read moreRead less