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
Transformations of catchment nutrients in southeast Queensland. Human activity in catchments throughout southeast Queensland has increased nutrient loads in receiving waters. However, until recently there has been a lack of accurate quantification of these loads, and little understanding of their role in stimulating algal blooms. This proposal will examine the links between catchment nutrient inputs to waterways, their transformations and effects on stimulating algal growth in freshwater systems ....Transformations of catchment nutrients in southeast Queensland. Human activity in catchments throughout southeast Queensland has increased nutrient loads in receiving waters. However, until recently there has been a lack of accurate quantification of these loads, and little understanding of their role in stimulating algal blooms. This proposal will examine the links between catchment nutrient inputs to waterways, their transformations and effects on stimulating algal growth in freshwater systems. The outcomes from this research will be information on how catchment nutrients are affecting water quality, thus providing a vehicle for targeting management strategies designed to reduce nutrient loads.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
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
How arid zone wetlands persist: linking ecological dynamics with hydrological regimes . This project will investigate how aquatic food webs assemble and persist in mound springs, relict streams and river pools in the Australian arid zone. Knowing how aquatic systems respond to wet and dry phases is the first step towards ‘climate proofing ’ these systems against future extreme events.