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
Transformation of vegetation by big herbivores, from the Pleistocene to now. The project aims to provide a coherent understanding of the effects of extinct and extant large herbivores on ecosystems over space and time. The structure and distribution of vegetation types is determined not only by climate and soils, but also by the impacts of herbivores and fire as consumers of plant biomass. Recent research has shown how fire shapes the large-scale distribution of vegetation types, but we do not h ....Transformation of vegetation by big herbivores, from the Pleistocene to now. The project aims to provide a coherent understanding of the effects of extinct and extant large herbivores on ecosystems over space and time. The structure and distribution of vegetation types is determined not only by climate and soils, but also by the impacts of herbivores and fire as consumers of plant biomass. Recent research has shown how fire shapes the large-scale distribution of vegetation types, but we do not have an equivalent understanding of the effects of large ground-dwelling herbivores. The project plans to test the effects of such animals on vegetation structure in the Pleistocene, when mega-herbivores were common, and today, and thus to compare the impacts of fire and herbivores on the distribution of vegetation types.Read moreRead less
The importance of edge effects in determining the value of seagrass landscapes as fish nurseries. Seagrasses are a conspicuous element of Australian marine environments, and are crucial in the conservation and maintenance of biodiversity. Degradation of seagrass ecosystems from climatic extremes, increased sediment and nutrients in the water, and other pollutants results in loss and fragmentation of meadows. These changes to seagrass are linked with increased coastal erosion, severe loss of bio ....The importance of edge effects in determining the value of seagrass landscapes as fish nurseries. Seagrasses are a conspicuous element of Australian marine environments, and are crucial in the conservation and maintenance of biodiversity. Degradation of seagrass ecosystems from climatic extremes, increased sediment and nutrients in the water, and other pollutants results in loss and fragmentation of meadows. These changes to seagrass are linked with increased coastal erosion, severe loss of biodiversity, and collapse of fisheries. Increased understanding of how biological processes such as predation and food availability influence animal associations with seagrasses, and how these effects change with landscape structure, will have important applications in the sustainable management of Australia's threatened coastal habitats.Read moreRead less
Leaf economics, and the acquisition and use of water and nitrogen for photosynthesis. Successful and sustainable management of both natural and human-modified ecosystems flows from advances in our understanding of the fundamentals of plant ecology. Improved understanding of acquisition and use of water and nutrients by plants should lead not only to better management in the present day, but better-founded management decisions under possible future scenarios such as global warming, higher atmosph ....Leaf economics, and the acquisition and use of water and nitrogen for photosynthesis. Successful and sustainable management of both natural and human-modified ecosystems flows from advances in our understanding of the fundamentals of plant ecology. Improved understanding of acquisition and use of water and nutrients by plants should lead not only to better management in the present day, but better-founded management decisions under possible future scenarios such as global warming, higher atmospheric CO2 concentrations or altered rainfall regimes. High-impact publications resulting from this project will sustain Australian leadership in environmental plant biology.Read moreRead less
How has bushfire activity varied around the Southern Hemisphere over the last 10,000 years? We will determine the relative contribution of climate and human ignitions in driving bushfire activity around the Southern Hemisphere over the last 10,000 years. Such knowledge is crucial for ecologically sustainable fire management, resolving debates about past Aboriginal environmental impacts and understanding the risk posed by climate change.
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.
Ecological dynamics of parasite infections in reptiles. Australian ecosystems are threatened by new epidemics of diseases and parasites, some local, others from overseas. Examples include the facial tumours of Tasmanian devils and the fungus that threatens many native frog species. To manage these epidemics effectively, we must understand how they spread through animal populations. With better knowledge of how diseases of wildlife spread, we can develop more effective control of those diseases t ....Ecological dynamics of parasite infections in reptiles. Australian ecosystems are threatened by new epidemics of diseases and parasites, some local, others from overseas. Examples include the facial tumours of Tasmanian devils and the fungus that threatens many native frog species. To manage these epidemics effectively, we must understand how they spread through animal populations. With better knowledge of how diseases of wildlife spread, we can develop more effective control of those diseases thereby protecting wildlife species, animal populations and, ultimately, Australian ecology. This project will help to protect our fauna from invasive diseases and contribute to sustaining the biodiversity of the country. Read moreRead less
Vocal mimicry in songbirds. Many of the world’s largest clade of birds - the songbirds - incorporate vocal mimicry in their songs, but while scientific interest in vocal mimicry dates from Aristotle, limited progress has been made. With our unique research program we aim to provide an empirically based, theoretically informed understanding of avian vocal mimicry. In an important advance, we will examine both sexes to test long-held male-centric assumptions about evolutionary origins and maintena ....Vocal mimicry in songbirds. Many of the world’s largest clade of birds - the songbirds - incorporate vocal mimicry in their songs, but while scientific interest in vocal mimicry dates from Aristotle, limited progress has been made. With our unique research program we aim to provide an empirically based, theoretically informed understanding of avian vocal mimicry. In an important advance, we will examine both sexes to test long-held male-centric assumptions about evolutionary origins and maintenance of this trait. Crucially, we focus on lineages found only in Australia and PNG, where songbirds originated, to develop a robust scientific understanding of vocal mimicry across the entire songbird clade, and so provide an important new perspective on why and how song began.Read moreRead less
Facultative sex-determination in a montane lizard. Why is the sex of some reptiles determined by their genetic constitution (sometimes involving heteromorphic sex chromosomes) whereas in other species the animal's sex is determined by the environment (especially, incubation temperature)? Multiple phylogenetic transitions between genetic sex determination (GSD) and environmental sex determination (ESD) suggest that these alternative modes of sex determination possess adaptive significance. Howe ....Facultative sex-determination in a montane lizard. Why is the sex of some reptiles determined by their genetic constitution (sometimes involving heteromorphic sex chromosomes) whereas in other species the animal's sex is determined by the environment (especially, incubation temperature)? Multiple phylogenetic transitions between genetic sex determination (GSD) and environmental sex determination (ESD) suggest that these alternative modes of sex determination possess adaptive significance. However, the selective forces favouring one versus the other remain obscure, despite sustained research in this field by many workers. The recent discovery of BOTH sex-determining systems simultaneously within a single population of alpine lizards provides a unique opportunity to test among competing hypotheses for the evolution of sex-determining systems. I propose an integrated study, in both the field and the laboratory, to clarify the mechanisms and the selective forces involved in the evolution of sex-determination.Read moreRead less
Evolutionary ecology of snakes and lizards. Although reptiles provide excellent "model systems" with which to examine evolutionary and ecological processes, most research in this field has been dominated by studies on other kinds of organisms. I propose a broad-ranging series of studies that will use a diverse array of lizard and snake species to erect and test novel hypotheses on the evolution of phenomena such as mating systems, sexual dimorphism, foraging biology, and reproductive investment ....Evolutionary ecology of snakes and lizards. Although reptiles provide excellent "model systems" with which to examine evolutionary and ecological processes, most research in this field has been dominated by studies on other kinds of organisms. I propose a broad-ranging series of studies that will use a diverse array of lizard and snake species to erect and test novel hypotheses on the evolution of phenomena such as mating systems, sexual dimorphism, foraging biology, and reproductive investment. My experimental studies will clarify the evolutionary role of phenotypic plasticity (that is, direct environmental effects) as well as genetic factors.Read moreRead less