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
Plant species economics and strategy-dimensions of plant ecology. Ecological strategies of plant species are differentiated mainly along economic dimensions. Four key dimensions are the leaf lifespan - leaf mass per area tradeoff, the seed mass - seed output tradeoff, the leaf size - twig size spectrum, and canopy height at maturity. Each dimension reflects a spectrum of allocation patterns. Costs, benefits, tradeoffs and correlations underpinning these strategy-dimensions will be investigated w ....Plant species economics and strategy-dimensions of plant ecology. Ecological strategies of plant species are differentiated mainly along economic dimensions. Four key dimensions are the leaf lifespan - leaf mass per area tradeoff, the seed mass - seed output tradeoff, the leaf size - twig size spectrum, and canopy height at maturity. Each dimension reflects a spectrum of allocation patterns. Costs, benefits, tradeoffs and correlations underpinning these strategy-dimensions will be investigated within Australia, and in collaboration with partner investigators overseas.Read moreRead less
Plant ecological strategies across species and an evolutionary-ecology vegetation model. This proposal is aimed at fundamental science about plant traits and water use and flammability. These vegetation processes underpin management of bushfires, water, salinity and carbon storage, which are national priorities for An Environmentally Sustainable Australia. The proposal pursues cost-benefit understanding of stem-leaf relations and of flammability, and aims also to develop an evolutionary-ecology ....Plant ecological strategies across species and an evolutionary-ecology vegetation model. This proposal is aimed at fundamental science about plant traits and water use and flammability. These vegetation processes underpin management of bushfires, water, salinity and carbon storage, which are national priorities for An Environmentally Sustainable Australia. The proposal pursues cost-benefit understanding of stem-leaf relations and of flammability, and aims also to develop an evolutionary-ecology vegetation model (EEVM). An EEVM will encapsulate the next generation of fundamental ecological science, with direct application for global change scenarios and for ecosystem management. This proposal forms a network among outstanding laboratories internationally for the purpose, and gives Australia a lead role.Read moreRead less
Patterns of connectivity and hot-spots of recruitment: a basis for prioritising high value coastal rivers. Provision of water for agricultural, industrial and residential use is becoming increasingly difficult in Australia. By determining the need for important migratory fish species to have access to marine conditions, this project aims to assist managers to identify river systems where changing flow patterns will be particularly detrimental. The project will provide information about the ne ....Patterns of connectivity and hot-spots of recruitment: a basis for prioritising high value coastal rivers. Provision of water for agricultural, industrial and residential use is becoming increasingly difficult in Australia. By determining the need for important migratory fish species to have access to marine conditions, this project aims to assist managers to identify river systems where changing flow patterns will be particularly detrimental. The project will provide information about the need for artificial opening of estuary mouths, fish ladders and other practical means to ensure the continued survival of these species. Read moreRead less
How are weeds adapting to life in Australia? Quantifying the rate and direction of evolution in introduced species. Introduced plants are a major problem throughout Australia. Introduced species are listed as one of the most severe threats to biodiversity in Australia, and managing them costs Australia around $4 billion per annum. The information we gather in this project will tell us what sort of changes introduced plants undergo when they arrive in Australia; how quickly plants can adapt to a ....How are weeds adapting to life in Australia? Quantifying the rate and direction of evolution in introduced species. Introduced plants are a major problem throughout Australia. Introduced species are listed as one of the most severe threats to biodiversity in Australia, and managing them costs Australia around $4 billion per annum. The information we gather in this project will tell us what sort of changes introduced plants undergo when they arrive in Australia; how quickly plants can adapt to a new environment, and what sort of species are best able to adapt to new conditions. We will also ask whether introduced species are still adapting to Australian conditions. If so, then we might expect even more naturalised species to become problem weeds in the future. This sort of knowledge is fundamental to our ability to develop appropriate control programs.Read moreRead less
Costs and individual variation in immune function: studies on a long-lived predator in tropical Australia. Enzyme-linked Immunosorbent Assay (ELISA) will be employed to quantify costs and individual variation in antibody response to a non-pathogenic antigen in water pythons (Liasis fuscus). Immune responsiveness is strongly correlated with disease and parasite resistance and has been documented to depend on environmental and genetic factors. All immunized snakes will be known-aged animals (rang ....Costs and individual variation in immune function: studies on a long-lived predator in tropical Australia. Enzyme-linked Immunosorbent Assay (ELISA) will be employed to quantify costs and individual variation in antibody response to a non-pathogenic antigen in water pythons (Liasis fuscus). Immune responsiveness is strongly correlated with disease and parasite resistance and has been documented to depend on environmental and genetic factors. All immunized snakes will be known-aged animals (ranging from 6 months to >20 years), of different nutritional status, known blood and gastro-intestinal parasite load and documented immuno-genetic profiles. This multidisciplinary approach will bring together population ecology, molecular genetics and immunology to elucidate links between these traits and ultimately how they affect python fitness.Read moreRead less
Conservation biology of the largest Australian freshwater tortoise, the broad-shelled tortoise, Chelodina expansa - rare and endangered or cryptic and secure? The Murray is a highly managed river, with flows controlled by catchments and diversions. The combined impacts of water resource development, habitat modification and introduced species are astonishingly diverse, and include extinctions of some fish and invertebrates and depression of populations of many other species. Australia's largest ....Conservation biology of the largest Australian freshwater tortoise, the broad-shelled tortoise, Chelodina expansa - rare and endangered or cryptic and secure? The Murray is a highly managed river, with flows controlled by catchments and diversions. The combined impacts of water resource development, habitat modification and introduced species are astonishingly diverse, and include extinctions of some fish and invertebrates and depression of populations of many other species. Australia's largest chelid turtle, the broad-shelled turtle, is a high-level consumer thought to be particularly sensitive to these changes. We will use an innovative combination of non-destructive technologies to investigate the conservation biology of this species in the Lower Murray, where it is regarded as rare and where its biology is virtually unknown to inform conservation management and restoration initiativesRead 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
Genetic variation without sex: frequency-dependent selection and the maintenance of variation in asexual organisms. The proposed research will gain insight into one of the most fundamental yet puzzling questions in evolutionary biology and determine the generality of frequency-dependent selection as a mechanism for maintaining variation in asexual organisms. The results will have broad appeal, both internationally and nationally, and will also provide insight into why most species reproduce sexu ....Genetic variation without sex: frequency-dependent selection and the maintenance of variation in asexual organisms. The proposed research will gain insight into one of the most fundamental yet puzzling questions in evolutionary biology and determine the generality of frequency-dependent selection as a mechanism for maintaining variation in asexual organisms. The results will have broad appeal, both internationally and nationally, and will also provide insight into why most species reproduce sexually. The results will also help in the development of two asexual species as environmental indicators by linking clones with specific environmental changes. These indicator clones could then be adopted by natural resource managers to monitor environmental pollution and contamination.Read moreRead less