Resource Management and Geography - Research Publications
Now showing items 1-12 of 173
Ecological functions of zoosporic hyperparasites.
(Frontiers Media SA, 2014)
Zoosporic parasites have received increased attention during the last years, but it is still largely unnoted that these parasites can themselves be infected by hyperparasites. Some members of the Chytridiomycota, Blastocladiomycota, Cryptomycota, Hyphochytriomycota, Labyrinthulomycota, Oomycota, and Phytomyxea are hyperparasites of zoosporic hosts. Because of sometimes complex tripartite interactions between hyperparasite, their parasite-host, and the primary host, hyperparasites can be difficult to detect and monitor. Some of these hyperparasites use similar mechanisms as their parasite-hosts to find and infect their target and to access food resources. The life cycle of zoosporic hyperparasites is usually shorter than the life cycle of their hosts, so hyperparasites may accelerate the turnaround times of nutrients within the ecosystem. Hyperparasites may increase the complexity of food webs and play significant roles in regulating population sizes and population dynamics of their hosts. We suggest that hyperparasites lengthen food chains but can also play a role in conducting or suppressing diseases of animals, plants, or algae. Hyperparasites can significantly impact ecosystems in various ways, therefore it is important to increase our understanding about these cryptic and diverse organisms.
Hope, despair and transformation: Climate change and the promotion of mental health and wellbeing.
(Springer Science and Business Media LLC, 2008-09-17)
BACKGROUND: This article aims to provide an introduction to emerging evidence and debate about the relationship between climate change and mental health. DISCUSSION AND CONCLUSION: The authors argue that:i) the direct impacts of climate change such as extreme weather events will have significant mental health implications;ii) climate change is already impacting on the social, economic and environmental determinants of mental health with the most severe consequences being felt by disadvantaged communities and populations; iii) understanding the full extent of the long term social and environmental challenges posed by climate change has the potential to create emotional distress and anxiety; and iv) understanding the psycho-social implications of climate change is also an important starting point for informed action to prevent dangerous climate change at individual, community and societal levels.
The Overlooked Biodiversity of Flower-Visiting Invertebrates
(PUBLIC LIBRARY SCIENCE, 2012-09-19)
Estimates suggest that perhaps 40% of all invertebrate species are found in tropical rainforest canopies. Extrapolations of total diversity and food web analyses have been based almost exclusively on species inhabiting the foliage, under the assumption that foliage samples are representative of the entire canopy. We examined the validity of this assumption by comparing the density of invertebrates and the species richness of beetles across three canopy microhabitats (mature leaves, new leaves and flowers) on a one hectare plot in an Australian tropical rainforest. Specifically, we tested two hypotheses: 1) canopy invertebrate density and species richness are directly proportional to the amount of resource available; and 2) canopy microhabitats represent discrete resources that are utilised by their own specialised invertebrate communities. We show that flowers in the canopy support invertebrate densities that are ten to ten thousand times greater than on the nearby foliage when expressed on a per-unit resource biomass basis. Furthermore, species-level analyses of the beetle fauna revealed that flowers support a unique and remarkably rich fauna compared to foliage, with very little species overlap between microhabitats. We reject the hypothesis that the insect fauna on mature foliage is representative of the greater canopy community even though mature foliage comprises a very large proportion of canopy plant biomass. Although the significance of the evolutionary relationship between flowers and insects is well known with respect to plant reproduction, less is known about the importance of flowers as resources for tropical insects. Consequently, we suggest that this constitutes a more important piece of the 'diversity jigsaw puzzle' than has been previously recognised and could alter our understanding of the evolution of plant-herbivore interactions and food web dynamics, and provide a better foundation for accurately estimating global species richness.
Governing for a Healthy Population: Towards an Understanding of How Decision-Making Will Determine Our Global Health in a Changing Climate
Enhancing the adaptive capacity of individuals, communities, institutions and nations is pivotal to protecting and improving human health and well-being in the face of systemic social inequity plus dangerous climate change. However, research on the determinants of adaptive capacity in relation to health, particularly concerning the role of governance, is in its infancy. This paper highlights the intersections between global health, climate change and governance. It presents an overview of these key concerns, their relation to each other, and the potential that a greater understanding of governance may present opportunities to strengthen policy and action responses to the health effects of climate change. Important parallels between addressing health inequities and sustainable development practices in the face of global environmental change are also highlighted. We propose that governance can be investigated through two key lenses within the earth system governance theoretical framework; agency and architecture. These two governance concepts can be evaluated using methods of social network research and policy analysis using case studies and is the subject of further research.
A new cost-effective method to mitigate ammonia loss from intensive cattle feedlots: application of lignite
(NATURE PUBLISHING GROUP, 2015-11-20)
In open beef feedlot systems, more than 50% of dietary nitrogen (N) is lost as ammonia (NH3). Here we report an effective and economically-viable method to mitigate NH3 emissions by the application of lignite. We constructed two cattle pens (20 × 20 m) to determine the effectiveness of lignite in reducing NH3 emissions. Twenty-four steers were fed identical commercial rations in each pen. The treatment pen surface was dressed with 4.5 kg m(-2) lignite dry mass while no lignite was applied in the control pen. We measured volatilised NH3 concentrations using Ecotech EC9842 NH3 analysers in conjunction with a mass balance method to calculate NH3 fluxes. Application of lignite decreased NH3 loss from the pen by approximately 66%. The cumulative NH3 losses were 6.26 and 2.13 kg N head(-1) in the control and lignite treatment, respectively. In addition to the environmental benefits of reduced NH3 losses, the value of retained N nutrient in the lignite treated manure is more than $37 AUD head(-1) yr(-1), based on the current fertiliser cost and estimated cost of lignite application. We show that lignite application is a cost-effective method to reduce NH3 loss from cattle feedlots.
"Cryptic" diagenesis and its implications for speleothem geochronologies
Speleothems are usually considered as one of the most amenable palaeoclimate archives for U-series dating. A number of studies in recent years, however, report cases of diagenetic alteration which compromises the use of U-series systematics in speleothems, resulting in inaccurate U-Th ages. Here we present the results of a high-resolution U-Th dating study of a stalagmite (CC26) from Corchia Cave in Italy where we document a number of departures from an otherwise well-defined age-depth model, and explore potential causes for these outliers. Unlike examples illustrated in previous studies, CC26 contains no visible evidence of neomorphism, and appears, at least superficially, ideally suited to dating. Good reproducibility obtained between multi-aliquot U-Th analyses removes any possibility of analytical issues contributing to these outliers. Furthermore, replicate analyses of samples from the same stratigraphic layer yielded ages in stratigraphic sequence, implying very localized open-system behavior. Uranium loss is suggested as a causative mechanism on account of the fact that all the outliers are older than their assumed true age. A limited number of micro-voids were observed under micro-CT analyses, and it is proposed that these were pathways for U loss. Uranium-loss modelling allows us to constrain the possible timing of diagenetic alteration and indicates that the precursor for the outlier with the largest age discrepancy (309%) must have been aragonite. This study indicates that visibly unaltered speleothems may still contain small domains that have experienced post-depositional alteration. Such “cryptic” diagenesis, as recorded in this stalagmite, has implications for the constancy of accuracy of the U-series dating technique, and suggests a need for careful examination of speleothems prior to dating, particularly in low-resolution U-Th studies.
Socially just publishing: Implications for geographers and their journals
(Geographical Society of Finland, 2017-12-15)
There have been a range of protests against the high journal subscription costs, and author processing charges (APCs) levied for publishing in the more prestigious and commercially run journals that are favoured by geographers. But open protests across the sector like the ‘Academic Spring’ of 2012, and challenges to commercial copyright agreements, have been fragmented and less than successful. I renew the argument for ‘socially just’ publishing in geography. For geographers this is not limited to choosing alternative publication venues. It also involves a considerable effort by senior faculty members that are assessing hiring and promotion cases, to read and assess scholarship independently of its place of publication, and to reward the efforts of colleagues that offer their work as a public good. Criteria other than the citation index and prestige of a journal need to be foregrounded. Geographers can also be publishers, and I offer my experience editing the free online Journal of Political Ecology.
Australia: reclaiming the public university?
(Social Epistemology Review and Reply Collective, 2017)
In a provocative article published in 'Minerva' in 2015, Halffman and Radder discuss the Kafkaesque worlds that academics in the Netherlands now find themselves in, as an underfunded university sector predates upon itself and its workforce (2015, p. 165-166). Their Academic Manifesto observes that Dutch tertiary institutions have become obsessively focused on ‘accountability’ and pursue neoliberal-style imperatives [forced upon them] of ‘efficiency and excellence’. They paint a portrait of academics under siege, untrusted, and constantly micro-managed. The pursuit of so-called efficiency has involved accountability systems that are themselves wasteful, driving seemingly endless institutional restructuring. Moreover, institutions have become obsessed with star-performers in research, driven by competitive targets that undergird global rankings. Metrics – publication outputs, journal quality, citations, impact and grant revenue – produce a culture of competition and sometimes, mercenary behaviours, on the part of academics and managers. While there may be beacons of light, they are heavily shielded in the article, which makes for depressing reading. Their provocation prompts two questions, to which we will try to respond through our own experiences and review of Australia's adoption of,and resistance to, higher education reform: 1.How does Australia compare? 2.What can Australian universities and their staff do?