Sex and the generation gap: seasonal changes in sex allocation. Answering the question 'When is it better to produce more sons than daughters?' has shed important insights into fundamental questions in biology and led to theory that can be applied to problems in agriculture, fisheries and conservation. The project will extend the current theory to increase its applicability, and test it using an introduced pest fish.
New approaches to measuring the composition and nutrient status of single phytoplankton cells. Phytoplankton support 90% of aquatic food webs, and are responsible for nearly half of global primary productivity. Conversely, blooms of some phytoplankton, often associated with excess nutrients, can cause major environmental problems, including fish kills and risks to human health. However, current methods for determining the nutrient status of phytoplankton are time consuming and ignore the complex ....New approaches to measuring the composition and nutrient status of single phytoplankton cells. Phytoplankton support 90% of aquatic food webs, and are responsible for nearly half of global primary productivity. Conversely, blooms of some phytoplankton, often associated with excess nutrients, can cause major environmental problems, including fish kills and risks to human health. However, current methods for determining the nutrient status of phytoplankton are time consuming and ignore the complexity of responses of different species in mixed populations. This project will develop new, rapid, ways of examining the nutrient condition of individual algal cells, which will be of considerable use to the water industry as well as to our understanding of aquatic ecology.Read moreRead less
Dispersal and species coexistence across patchy landscapes. Millions of dollars are spent rehabilitating degraded river ecosystems in the absence of knowing whether and how species will be able to disperse to and re-populate repaired sections. This research will provide definitive information allowing restoration efforts to be targeted properly in streams surrounded by, and serving, agricultural areas.
Species coexistence in the real world. This project aims to discover how similar species co-exist without weaker competitors going extinct. Hypotheses offer explanations for stable coexistence in the presence of competition, but logistic barriers mean field tests are almost completely lacking. Recent research on competition and dispersal presents an opportunity to deliver tests using riverine species, leading to experiments at landscape scales. The research will quantify the role of environmenta ....Species coexistence in the real world. This project aims to discover how similar species co-exist without weaker competitors going extinct. Hypotheses offer explanations for stable coexistence in the presence of competition, but logistic barriers mean field tests are almost completely lacking. Recent research on competition and dispersal presents an opportunity to deliver tests using riverine species, leading to experiments at landscape scales. The research will quantify the role of environmental variability and dispersal in permitting stable coexistence of species, thus filling a major knowledge gap. The project expects to provide fresh avenues for research into the causes of species losses – particularly for the 70 per cent that are invertebrates.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
Dispersal and recruitment of species across landscapes: a new synthesis. This project aims to ask: does failure to disperse successfully across landscapes limit the abundances and diversity of species in habitat patches? This is a central question in ecology. The project expects to generate new knowledge about the links between dispersal success and population numbers by using recent advances in river ecology that have overcome logistical barriers to hypothesis tests. Expected outcomes include n ....Dispersal and recruitment of species across landscapes: a new synthesis. This project aims to ask: does failure to disperse successfully across landscapes limit the abundances and diversity of species in habitat patches? This is a central question in ecology. The project expects to generate new knowledge about the links between dispersal success and population numbers by using recent advances in river ecology that have overcome logistical barriers to hypothesis tests. Expected outcomes include new insights into why dispersal failures occur and how they are associated with low population numbers. Benefits should include improved advice to conservation managers about extinction risks, and unique, tangible outcomes for fundamental ecological research in Australia that will spring from international collaboration.Read moreRead less
Explaining species diversity in a fractal world. This project aims to improve our understanding of landscape-scale patterns of species diversity, particularly invertebrates. A central question in ecology asks how habitat patchiness interacts with dispersal abilities to determine species diversity. Field tests of hypotheses are lacking due to logistic difficulties in quantifying habitat patchiness and dispersal over landscape scales. A new model proposes that fractals (a clever way of measuring e ....Explaining species diversity in a fractal world. This project aims to improve our understanding of landscape-scale patterns of species diversity, particularly invertebrates. A central question in ecology asks how habitat patchiness interacts with dispersal abilities to determine species diversity. Field tests of hypotheses are lacking due to logistic difficulties in quantifying habitat patchiness and dispersal over landscape scales. A new model proposes that fractals (a clever way of measuring environmental complexity) can capture both habitat patchiness and species' responses. Advances in river ecology have solved the logistic problems and will allow tests to compare the three main hypotheses about species diversity. The project aims to improve information about which tools will provide the best guidance, benefitting the discipline of ecology and conservation managers.Read moreRead less
Native fish stocking of rivers: discriminating between hatchery-reared and wild fish. Stocking of fish is widely used in attempts to restore native fish populations. Little is known of the fate of stocked fish or the effects of stocking on resident populations. We will develop and evaluate protocols for chemical marking of otoliths of hatchery-reared fish so that their source can be determined. Experimental stocking of hatchery-reared fish will be undertaken and population structure and sourc ....Native fish stocking of rivers: discriminating between hatchery-reared and wild fish. Stocking of fish is widely used in attempts to restore native fish populations. Little is known of the fate of stocked fish or the effects of stocking on resident populations. We will develop and evaluate protocols for chemical marking of otoliths of hatchery-reared fish so that their source can be determined. Experimental stocking of hatchery-reared fish will be undertaken and population structure and source of stocked versus wild fish determined in stocked and unstocked rivers. Natural chemical signatures will also help determine important recruitment areas. The outcomes will allow fisheries managers to make informed decisions regarding stocking strategies.Read moreRead less
The evolution of egg retention and sex allocation: a phylogenetic contrasts study using facultatively ovoviviparous thrips. Australian idolothripine thrips provide an unparalleled opportunity for investigating the evolution of reproduction. They constitute the only group to contain many species in which the females choose among live birth, egg laying or both. They also choose the sex of each offspring. We will use phylogenetics and experimentation to understand the evolutionary pressures that le ....The evolution of egg retention and sex allocation: a phylogenetic contrasts study using facultatively ovoviviparous thrips. Australian idolothripine thrips provide an unparalleled opportunity for investigating the evolution of reproduction. They constitute the only group to contain many species in which the females choose among live birth, egg laying or both. They also choose the sex of each offspring. We will use phylogenetics and experimentation to understand the evolutionary pressures that led to and maintain live birth and the allocation of sex. This will produce new insights into fundamental questions about the evolution of animal reproduction. Our collaborative approach will make Australian thrips and research an international cornerstone in the biology of reproductive evolution.Read moreRead less
Spatial scale of influence of riparian and catchment land use on stream ecosystem health. Human activities at the landscape scale comprise one of the greatest threats to the ecological integrity of river ecosystems. Government and community groups across Australia are making significant efforts in riparian protection and rehabilitation in an attempt to improve the health of degraded waterways but are hampered in their goal to maximise the environmental gains for every dollar or unit effort inve ....Spatial scale of influence of riparian and catchment land use on stream ecosystem health. Human activities at the landscape scale comprise one of the greatest threats to the ecological integrity of river ecosystems. Government and community groups across Australia are making significant efforts in riparian protection and rehabilitation in an attempt to improve the health of degraded waterways but are hampered in their goal to maximise the environmental gains for every dollar or unit effort invested. The proposed research on understanding the spatial scale of influence of land use and the aggregative effects on stream ecosystems will provide a robust framework to assess various options and optimise benefits from management actions. Read moreRead less