Water and Natural Resources

Urrbrae, Australia

Water and Natural Resources

Urrbrae, Australia
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Wood C.,Water and Natural Resources | Cook P.G.,Flinders University | Harrington G.A.,Innovative Solutions | Knapton A.,CloudGMS Pty Ltd.SA
Water Resources Research | Year: 2017

Carbon-14 (14C) has been widely used to estimate groundwater recharge rates in arid regions, and is increasingly being used as a tool to assist numerical model calibration. However, lack of knowledge on 14C inputs to groundwater potentially limits its reliability for constraining spatial variability in recharge. In this study, we use direct measurements of 14C in the unsaturated zone to develop a 14C input map for a regional scale unconfined aquifer in the Ti Tree Basin in central Australia. The map is used as a boundary condition for a 3-D groundwater flow and solute transport model for the basin. The model is calibrated to both groundwater 14C activity and groundwater level, and calibration is achieved by varying recharge rates in 18 hydrogeological zones. We test the sensitivity of the calibration to both the 14C boundary condition, and the number or recharge zones used. The calibrated recharge rates help resolve the conceptual model for the basin, and demonstrate that spatially distributed discharge (through evapotranspiration) is an important part of the water balance. This approach demonstrates the importance of boundary conditions for 14C transport modeling (14C input activity), for improving estimates of spatial variability in recharge and discharge. © 2016. American Geophysical Union. All Rights Reserved.

Weisbecker V.,University of Queensland | Blomberg S.,University of Queensland | Goldizen A.W.,University of Queensland | Brown M.,Water and Natural Resources | Fisher D.,University of Queensland
Brain, Behavior and Evolution | Year: 2015

Evolutionary increases in mammalian brain size relative to body size are energetically costly but are also thought to confer selective advantages by permitting the evolution of cognitively complex behaviors. However, many suggested associations between brain size and specific behaviors-particularly related to social complexity-are possibly confounded by the reproductive diversity of placental mammals, whose brain size evolution is the most frequently studied. Based on a phylogenetic generalized least squares analysis of a data set on the reproductively homogenous clade of marsupials, we provide the first quantitative comparison of two hypotheses based on energetic constraints (maternal investment and seasonality) with two hypotheses that posit behavioral selection on relative brain size (social complexity and environmental interactions). We show that the two behavioral hypotheses have far less support than the constraint hypotheses. The only unambiguous associates of brain size are the constraint variables of litter size and seasonality. We also found no association between brain size and specific behavioral complexity categories within kangaroos, dasyurids, and possums. The largest-brained marsupials after phylogenetic correction are from low-seasonality New Guinea, supporting the notion that low seasonality represents greater nutrition safety for brain maintenance. Alternatively, low seasonality might improve the maternal support of offspring brain growth. The lack of behavioral brain size associates, found here and elsewhere, supports the general 'cognitive buffer hypothesis' as the best explanatory framework of mammalian brain size evolution. However, it is possible that brain size alone simply does not provide sufficient resolution on the question of how brain morphology and cognitive capacities coevolve. © 2015 S. Karger AG, Basel.

Disturbances in ecological systems can cause new resources to become available and can free the resources held by strongly competitive species. In intertidal boulder fields, waveaction causes disturbance by overturning boulders and freeing space for re-colonisation. In this study, mensurative experiments showed that boulder disturbance may also cause new biogenic-habitat resources to become available, if pre-disturbance boulders originally had tubeworm encrustations on their undersides. On the high-shore of a South Australian rocky coast, a small proportion of boulders had extensive encrustations of serpulid and spirorbid worm-tubes on their uppersides, and were likely to have recently been overturned, as spirorbid tubeworms are almost always only underneath boulders while living. Ulva macroalgae was absent from all boulders, except those with worm-tubes, where up to 61% Ulva cover was observed. Many boulders with tubes did not, however, have much algae, and this was likely caused by grazing. While limpets were seldom observed attached to tube encrustations, snails such as Nerita atramentosa and Bembicium nanum were equally abundant on and off tubes. N. atramentosa was likely the main grazer, as its densities were negatively correlated with Ulva cover. The mechanism causing association of Ulva and worm-tubes is unknown, but may be related to retention of moisture or algal spores within the complex topography of the tubes. Alternatively, some tubes may still have been living and providing nutrients for Ulva from excretory products. This study takes the first step towards understanding a very distinct habitat requirement which allows an important alga to persist in the hostile environment of the rocky-intertidal high shore. © 2017 Kiran Liversage. 2017 Gattringer et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

News Article | January 7, 2016
Site: phys.org

Published in the journal PLOS ONE, the University of Adelaide research, in partnership with the Department of Environment, Water and Natural Resources (DEWNR) and the Terrestrial Ecosystem Research Network, highlights six biodiversity hotspots. They are western Kangaroo Island, southern Mount Lofty Ranges, Anangu Pitjantjatjara Yankunytjatjara lands, southern Flinders Ranges, southern Eyre Peninsula and the Lower South East. The researchers used detailed biological data collected over time, including from the State's Biological Survey and the State Herbarium, and a suite of sophisticated metrics to identify biodiverse regions and the potential threats to their conservation. "We also looked at the extent to which the vegetation of each site was likely to change under future climates," says lead author Dr Greg Guerin. "We concluded that all of the state's ecosystems are expected to be impacted but the southern Flinders Ranges location is expected to be the most sensitive of these regions to climate change. "All of the 'hotspots', however, are subject to serious conservation issues, such as habitat fragmentation, weed invasion and altered fire regimes." The study found that the southern Mount Lofty Ranges region contained a high proportion of unique species and had high overall diversity but it has been subjected to the highest levels of disturbance since European settlement. The western side of Kangaroo Island has perhaps the most significant plant biodiversity in South Australia, but was rated as less vulnerable due to higher reservation levels and lower incidences of weed species. DEWNR's principal Ecologist Dr Dan Rogers says "This study has contributed to our understanding of South Australia's native biodiversity, particularly in relation to the relative impacts of climate change" "By improving our understanding of potential ecosystem change under future climates, we are able to better inform the management of native biodiversity that reflects these climate-induced changes." Co-author Professor Andrew Lowe, Chair of Plant Conservation Biology at the University of Adelaide, says: "Importantly, this study measures biodiversity at ecosystem rather than individual species level, and it uses numerical methods which can now be repeated and updated to meet future conservation management requirements. "Now we have a tool in place that can contribute to how we assess South Australia's biodiversity." Explore further: Major changes needed to protect Australia's species and ecosystems More information: Greg R. Guerin et al. Identifying Centres of Plant Biodiversity in South Australia, PLOS ONE (2016). DOI: 10.1371/journal.pone.0144779

News Article | December 14, 2016
Site: www.eurekalert.org

The BioScience Talks podcast features discussions of topical issues related to the biological sciences. The science of human microbiomes is advancing at an incredible pace. With each passing day, more is known about the vast suite of microorganisms that inhabit human bodies--and about the important role that they play in maintaining our health. In this episode of BioScience Talks, we look at the human microbiome from an environmentalist's perspective. What are the health benefits of microbiota from environmental sources? What are the threats of altered microbiota? How should we manage the landscapes that play host to this crucial microbial diversity? To help answer these questions, we spoke with Craig Liddicoat of the University of Adelaide and the South Australian government's Department of Environment, Water and Natural Resources. Liddicoat and his colleagues recently published an article in BioScience that shines a light on the myriad benefits of preserving environmental microbiomes and proposes a unifying conceptual framework for the multidisciplinary approach needed to tackle this emerging research area. To hear the whole discussion, visit this link for this latest episode of the Bioscience Talks podcast.

Hollow B.,University of South Australia | Roetman P.E.J.,University of South Australia | Walter M.,Water and Natural Resources | Daniels C.B.,University of South Australia
Environmental Science and Policy | Year: 2015

Citizen science involves the engagement of non-scientists in scientific research. Citizen science projects have been reported to be useful in policy development but there is little detail of how projects have contributed. The citizen science project, the Great Koala Count (GKC) collected ecological data about koalas and social data that have been used in the initial stages of the development of a South Australian Government koala management and conservation policy. After the GKC, we conducted an online survey of people who participated in the project and a control group. The survey focussed on opinions towards possible management options for koalas in South Australia. GKC participants were also asked about project-related changes in knowledge and opinions. We received 970 valid surveys and found some differences in opinions between GKC participants and the control group. Therefore, the GKC did not provide a representative sample of the entire South Australian population. However, we contend that the data from the citizen scientists are still valuable for policy development as it has been provided by people who are highly engaged in the topic (koala management in this case). It can be difficult to engage the public in the policy development process, and the citizen science project enabled the collection of a wide range of opinions, helping to discover and define relevant issues. Additionally, many people learnt about koalas and koala-related management issues, and some changed their opinions regarding koala management, also useful outcomes from the project in the policy development context. Our findings suggest that citizen science is useful for policy makers because projects provide the opportunity for dialogue with the people most interested in the topic of the project. © 2014 Elsevier Ltd.

Lamontagne S.,CSIRO | Taylor A.R.,CSIRO | Herpich D.,Water and Natural Resources | Hancock G.J.,CSIRO
Journal of Environmental Radioactivity | Year: 2015

The Tertiary Limestone Aquifer (TLA) is one of the major regional hydrogeological systems of southern Australia. Submarine groundwater discharge (SGD) of freshwater from the TLA occurs through spring creeks, beach springs and diffusively through beach sands, but the magnitude of the total flux is not known. Here, a range of potential environmental tracers (including temperature, salinity, 222Rn, 223Ra, 224Ra, 226Ra, 228Ra, and 4He) were measured in potential sources of SGD and in seawater along a 45km transect off the coastline to evaluate SGD from the TLA. Whilst most tracers had a distinct signature in the sources of water to the coastline, salinity and the radium quartet had the most distinct SGD signal in seawater. A one-dimensional advection-dispersion model was used to estimate the terrestrial freshwater component of SGD (Qfw) using salinity and the recirculated seawater component (Qrsw) using radium activity in seawater. Qfw was estimated at 1.2-4.6m3s-1, similar in magnitude to previously measured spring creek discharge (~3m3s-1) for the area. This suggests that other terrestrial groundwater discharge processes (beach springs and diffuse discharge through beach sands) were no more than 50% of spring creek discharge. The largest component of total SGD was Qrsw, estimated at 500-1000m3s-1 and possibly greater. The potential for wave, storm, or buoyancy-driven porewater displacement from the seafloor could explain the large recirculation flux for this section of the Southern Ocean Continental Shelf. © 2014.

Jellinek S.,Water and Natural Resources
Ecological Management and Restoration | Year: 2016

Restoring native habitats in heavily cleared and fragmented areas such as agricultural landscapes is important to maintain and increase remaining native floral and faunal communities. Identifying priority vegetation types for restoration - as well as the parcels of land where this restoration could take place at a landscape scale - may assist in strategically protecting these biodiversity assets. To prioritise the restoration of terrestrial habitats around an ecologically and culturally significant Ramsar-listed wetland in South Australia, we used the spatial prioritisation tool Marxan. Originally designed for prioritising the protection of reserve areas, Marxan can also be used to identify parcels of land for restoration purposes. We tested how Marxan prioritised the restoration of four distinct vegetation types around the Coorong and Lower Lakes region of South Australia using the inverse of habitat remnancy as a cost and soil type and distance to ecologically significant bird species as a conservation feature. By prioritising restoration activities around certain landscape features, such as remnant areas, our results indicate that we would be able to strategically restore parcels of native habitat that would maximise biodiversity outcomes. This study highlights the need for robust input data, such as priority vegetation types and bird species associated with these habitats, to ensure informative modelling outputs. It also suggests that other measures, such as the cost of different land types, should be included in future restoration planning. Finally, we illustrate how prioritisation tools such as Marxan can be used by natural resource managers to restore areas within fragmented agricultural landscapes. © 2016 Ecological Society of Australia.

Mosley L.M.,Khan Research Laboratories | Zammit B.,Khan Research Laboratories | Jolley A.M.,Water and Natural Resources | Barnett L.,Water and Natural Resources
Journal of Hydrology | Year: 2014

Droughts are predicted to increase in many river systems due to increased demand on water resources and climate variability. A severe drought in the Murray-Darling Basin of Australia from 2007 to 2009 resulted in unprecedented declines in water levels in the Lower Lakes (Ramsar-listed ecosystem of international importance) at the end of the river system. The receding water exposed large areas (>200km2) of sediments on the lake margins. The pyrite (FeS2) in these sediments oxidised and generated high concentrations of acidity. Upon rewetting of the exposed sediments, by rainfall or lake refill, surface water acidification (pH 2-3) occurred in several locations (total area of 21.7km2). High concentrations of dissolved metals (Al, As, Co, Cr, Cu, Fe, Mn, Ni, Zn), which greatly exceeded aquatic ecosystem protection guidelines, were mobilised in the acidic conditions. In many areas neutralisation of the surface water acidity occurred naturally during lake refill, but aerial limestone dosing was required in two areas to assist in restoring alkalinity. However acidity persists in the submerged lake sediment and groundwater several years after surface water neutralisation. The surface water acidification proved costly to manage and improved water management in the Murray-Darling Basin is required to prevent similar events occurring in the future. © 2014 Elsevier B.V.

Liversage K.,Water and Natural Resources
Transactions of the Royal Society of South Australia | Year: 2016

Marine-springs containing relic intertidal species can be used to observe how assemblages usually found only on open coasts are structured when free from disturbances associated with water movement. This study tested if two previously described patterns from disturbance-prone boulder habitats occurred within a South Australian marine-spring. I aimed to determine how species are associated with the interface between boulders and the surface of the bottom sediment, a habitat feature suggested to be important for some key benthic invertebrates. Testing species associations to this feature is normally difficult because boulders and sediment are regularly disturbed, but on stable marine-spring boulders, finescale associations of species with this interface could be measured. Also investigated was a previously described negative correlation of peracaridan (Crustacea) densities with boulder size. This could possibly occur due to variability in disturbance related to bouldersize/ stability, in which case the correlation would not be expected in this sheltered lake. Seven rocky-benthic marine species were found. The boulder-sediment interface could be easily located on overturned boulders. An anemone (Isanemonia australis) was highly abundant within 5 mm of this interface, providing evidence of this habitat feature's importance. As found previously, correlations were significant between boulder size and densities of peracaridans (in this case, the isopod Zuzara venosa). This correlation, which has been described widely for similar species, has previously been attributed to disturbance. This study found it occurring in extremely sheltered environments, however, so disturbance is unlikely to be involved. Additional larger-scale comparisons could provide further information about the effects of sheltered/ exposed conditions on these taxa. © 2016 Royal Society of South Australia.

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