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Harris J.H.,Harris Research | Harris J.H.,Center for Ecosystem Science | Kingsford R.T.,Center for Ecosystem Science | Peirson W.,University of New South Wales | And 2 more authors.
Marine and Freshwater Research | Year: 2017

Declining fish communities characterise global freshwater environments, including those in Australia. Lost river connectivity through water resource development is a key cause of decline, disrupting fish migrations and threatening species productivity, viability and fisheries. Millions of dams, weirs and lesser barriers arising from water resources projects, road and rail transport and hydro-electricity schemes obstruct fish passage in rivers worldwide. Fishways are in place at few sites in Australia and globally relative to the numbers of barriers, and few mitigate the effects of barriers adequately. Most constrain the passage of fish communities and few have performed effectively when assessed against appropriate biological standards. Herein we focus on Australian experience within the global context of obstructed fish migrations, declining fish biodiversity and inadequate fishway performance. We review the migratory characteristics of Australian freshwater fish, identify the effects of different in-stream barriers and other habitat changes on the four classes of migratory behaviour and note how Australia's highly variable hydrology presents particular challenges in mitigating fish passage barriers. Mitigation options include: basin-scale approaches; improved management of barriers, environmental flows and water quality; barrier removal; and development of improved fishway designs. Mitigation of fish-passage problems can aid in adapting to climate change effects, reversing fisheries declines and rehabilitating fish communities. © CSIRO 2017.


But, how are populations of the planet's most valued wildlife fairing in the 21st centry? How well are societies protecting the species they have chosen to embody their ideals and represent their national identity? In a new study, scientists from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science assessed the extinction risk and conservation status of all the world's national animal symbols. The 189 animal symbols assessed ranged from the lion and bald eagle to the turtle dove and common loon. The analysis by UM researchers Neil Hammerschlag and Austin Gallagher found that an alarming 35 percent of the world's national animal symbols are threatened with extinction and 45 percent are experiencing population declines. They determined that the primary threats facing national animal symbols are killing for food, human-wildlife conflict, and habitat loss. The researchers were surprised to find that only 16 percent of all symbols were receiving any sort of national protection within the country in which they are considered symoblic. The also found that populations of national animal symbols represented by North America and Australia-Oceania were faring better than those found within the African continent, which hosted the highest proportion of threatned animal symbols by geographic region. "If current population trends persist, over 50 percent of national animal symbols may face future extinction," said the study's lead author Hammerschlag, a research assistant professor at UM's Rosenstiel School and Abess Center for Ecosystem Science & Policy. "This clearly shows the opportunity for individual countries to protect their own national symbols." The researchers analyzed data from the IUCN Red List to assess the threat and conservation status of national animal symbols, representing 127 countries, including some countries who share national symbols. The Africa lion, for example, is the national animal symbols of Morocco, Togo, Gambia, and Sierra Leone, although the lion already went extinct wthin the borders of these countires. Some countries, including the U.S. have taken specific conservation actions that have allowed populations of the once-threatened national symbol, the bald eagle, to recover and now thrive, demonstrating that these animals can be conserved with appropriate conservation action. "Given the potential significance of animal symbols to national and personal identity, it may be relatively easy to garner public support and protection for these animals such that they may continue to function as not only a national symbol, but also a flagship species indirectly supporting the conservation of other species and their habitats," said study co-author Gallagher, an adjunct assistant professor at UM Rosenstiel School and director of the non-profit Beneath the Waves Inc. "The results of the study pose a sobering question, if a country isn't able to conserve or protect its own national symbol, what hope do any other species in that country have?" said Gallagher. "Local conservation initiatives may benefit from generating increased awareness of threats facing national animal symbols." The researchers note that it may be relatively easy within a country to garner support for national animal symbols as flagship species if citizens become aware of the risks they face. "The fact that countries have been able to bring their national animal symbols back from near-extinction through strong conservation efforts is an important lesson and excellent sign of hope for all nations," said Hammerschlag. Explore further: Michelangelo's Medici Chapel may contain hidden symbols of female anatomy More information: Neil Hammerschlag et al, Extinction Risk and Conservation of the Earth's National Animal Symbols, BioScience (2017). DOI: 10.1093/biosci/bix054


News Article | May 25, 2017
Site: www.sciencedaily.com

The snowy-feathered head and distinctive brown body of the bald eagle is a proud national symbol of the United States, adorning the country's currency and passports. The lion, known as "King of the Beasts," represents national strength and identity in several African countries. But, how are populations of the planet's most valued wildlife faring in the 21st century? How well are societies protecting the species they have chosen to embody their ideals and represent their national identity? In a new study, scientists from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science assessed the extinction risk and conservation status of all the world's national animal symbols. The 189 animal symbols assessed ranged from the lion and bald eagle to the turtle dove and common loon. The analysis by UM researchers Neil Hammerschlag and Austin Gallagher found that an alarming 35 percent of the world's national animal symbols are threatened with extinction and 45 percent are experiencing population declines. They determined that the primary threats facing national animal symbols are killing for food, human-wildlife conflict, and habitat loss. The researchers were surprised to find that only 16 percent of all symbols were receiving any sort of national protection within the country in which they are considered symbolic. The also found that populations of national animal symbols represented by North America and Australia-Oceania were faring better than those found within the African continent, which hosted the highest proportion of threatened animal symbols by geographic region. "If current population trends persist, over 50 percent of national animal symbols may face future extinction," said the study's lead author Hammerschlag, a research assistant professor at UM's Rosenstiel School and Abess Center for Ecosystem Science & Policy. "This clearly shows the opportunity for individual countries to protect their own national symbols." The researchers analyzed data from the IUCN Red List to assess the threat and conservation status of national animal symbols, representing 127 countries, including some countries who share national symbols. The Africa lion, for example, is the national animal symbols of Morocco, Togo, Gambia, and Sierra Leone, although the lion already went extinct within the borders of these countries. Some countries, including the U.S. have taken specific conservation actions that have allowed populations of the once-threatened national symbol, the bald eagle, to recover and now thrive, demonstrating that these animals can be conserved with appropriate conservation action. "Given the potential significance of animal symbols to national and personal identity, it may be relatively easy to garner public support and protection for these animals such that they may continue to function as not only a national symbol, but also a flagship species indirectly supporting the conservation of other species and their habitats," said study co-author Gallagher, an adjunct assistant professor at UM Rosenstiel School and director of the non-profit Beneath the Waves Inc. "The results of the study pose a sobering question, if a country isn't able to conserve or protect its own national symbol, what hope do any other species in that country have?" said Gallagher. "Local conservation initiatives may benefit from generating increased awareness of threats facing national animal symbols." The researchers note that it may be relatively easy within a country to garner support for national animal symbols as flagship species if citizens become aware of the risks they face. "The fact that countries have been able to bring their national animal symbols back from near-extinction through strong conservation efforts is an important lesson and excellent sign of hope for all nations," said Hammerschlag.


Letten A.D.,Center for Ecosystem Science | Keith D.A.,Center for Ecosystem Science | Keith D.A.,Australian National University | Tozer M.G.,NSW Office of Environment and Heritage
Proceedings of the Royal Society B: Biological Sciences | Year: 2014

Succession has been a focal point of ecological research for over a century, but thus far has been poorly explored through the lens of modern phylogenetic and trait-based approaches to community assembly. The vast majority of studies conducted to date have comprised static analyses where communities are observed at a single snapshot in time. Long-term datasets present a vantage point to compare established and emerging theoretical predictions on the phylogenetic and functional trajectoryof communities through succession. We investigated within, and between, community measures of phylogenetic and functional diversity in a fire-prone heathland along a 21 year time series. Contrary to widely held expectations that increased competition through succession should inhibit the coexistence of species with high niche overlap, plots became more phylogenetically and functionally clustered with time since fire. There were significant directional shifts in individual traits through time indicating deterministic successional processes associated with changing abiotic and/or biotic conditions. However, relative to the observed temporal rate of taxonomic turnover, both phylogenetic and functional turnover were comparatively low, suggesting a degree of functional redundancy among close relatives. These results contribute to an emerging body of evidence indicating that limits to the similarity of coexisting species are rarely observed at fine spatial scales. © 2014 The Author(s) Published by the Royal Society. All rights reserved.


Letten A.D.,Center for Ecosystem Science | Keith D.A.,Center for Ecosystem Science | Keith D.A.,Australian National University | Tozer M.G.,NSW Office of Environment and Heritage | Hui F.K.C.,University of New South Wales
Journal of Ecology | Year: 2015

Theory suggests spatial heterogeneity can facilitate species co-occurrence at fine scales, but environmental data are rarely collected at sufficiently high resolution to test this empirically. Whilst there is emerging evidence that subtle variation in soil hydrology represents a fundamental fine-scale niche axis within plant communities, this is largely derived from studies of soil hydrology in isolation from other environmental factors. We assessed the comparative importance of fine-scale hydrological niche differentiation for species co-occurrence using a high-resolution study of soil hydrology and other edaphic variables, coupled with a long-term (24 years) data set of herbaceous plant plots in a heathland community in south-east Australia. For the analysis, we employed novel latent variable models (LVMs), which offer an explicit, model-based approach to partitioning out the different drivers of species co-occurrence patterns. Whilst the regression component of an LVM models the species-specific environmental responses, the latent variable component can be used to identify residual patterns of co-occurrence, which may be attributable to unmeasured factors and/or biotic interactions. Relative to a host of plant resources, non-resource factors and 'unmeasured' latent variables, soil hydrology emerged as the best predictor of negative co-occurrences within the community, with the dominant species exhibiting strongly differentiated responses across a comparatively narrow moisture gradient. Nevertheless, strong species-specific responses to environmental variability only emerged at scales greater than those at which plants may be expected to compete for resources, throwing doubt on the direct role of spatial heterogeneity as a mechanism for local-scale coexistence. Synthesis. This study confirms the vital role of hydrological niches for the maintenance of within-community plant diversity, but also highlights the need for more rigorous analysis of scale dependencies to better understand the underlying coexistence mechanisms at play. In addition, it illustrates the inferential gains made possible with model-based approaches to the analysis of species co-occurrence. R code illustrating model fitting and inference is provided as a supplement. © 2015 British Ecological Society.


Letten A.D.,Center for Ecosystem Science | Keith D.A.,University of New South Wales | Tozer M.G.,NSW Office of Environment and Heritage
Proceedings. Biological sciences / The Royal Society | Year: 2014

Succession has been a focal point of ecological research for over a century, but thus far has been poorly explored through the lens of modern phylogenetic and trait-based approaches to community assembly. The vast majority of studies conducted to date have comprised static analyses where communities are observed at a single snapshot in time. Long-term datasets present a vantage point to compare established and emerging theoretical predictions on the phylogenetic and functional trajectory of communities through succession. We investigated within, and between, community measures of phylogenetic and functional diversity in a fire-prone heathland along a 21 year time series. Contrary to widely held expectations that increased competition through succession should inhibit the coexistence of species with high niche overlap, plots became more phylogenetically and functionally clustered with time since fire. There were significant directional shifts in individual traits through time indicating deterministic successional processes associated with changing abiotic and/or biotic conditions. However, relative to the observed temporal rate of taxonomic turnover, both phylogenetic and functional turnover were comparatively low, suggesting a degree of functional redundancy among close relatives. These results contribute to an emerging body of evidence indicating that limits to the similarity of coexisting species are rarely observed at fine spatial scales. © 2014 The Author(s) Published by the Royal Society. All rights reserved.


Maleknia S.D.,Civil and Environmental Engineering | Maleknia S.D.,Center for Ecosystem Science | Downard K.M.,University of New South Wales
Natural Products Journal | Year: 2016

Background: A resurgent interest in the use of natural product based inhibitors against the influenza virus has resulted from the widespread resistance to current antiviral therapeutics among circulating strains. Natural products derived from food sources in particular, offer the benefit of a safer pharmacological profile and may offer broader health benefits. Objective: To identify new anthocyanins from black elderberry (Sambucus nigra) that will inhibit the function of influenza neuraminidase while avoiding complications associated with mutations in the active site of strains resistant to current inhibitors. Method: The mild solvent extraction process minimizes the exposure of the anthocyanins to non-acidic pH solutions, high temperature and pressure, and ambient light, in order to prevent their chemical transformation or degradation. Total anthocyanin yields are equivalent or better to those reported based on the recovery of cyanidin-3-O-glucoside. The characterization of additional anthocyanin components has been achieved by liquid chromatography coupled to electrospray ionization mass spectrometry (LC-ESI-MS) in conjunction with tandem mass spectrometry (MS/MS). Results: The results demonstrate an improved mild recovery method that has enabled the isolation and detection of previously unidentified minor anthocyanin components in elderberry of inhibitory potential against the influenza virus including prenylated cyanidin-3-O-sambubioside, prenylated and other derivatives of cyanidin-3-acetylrutinoside, and a type A proanthocyanin dimer of cyanidin-3-O-sambubioside. Conclusion: The improved recovery of anthocyanins from elderberries, under mild extraction conditions in a manner that preserves their structural integrity, and which yields a wider variety of previously unidentified compounds, should aid in their use and development in the treatment of influenza infections. © 2016 Bentham Science Publishers.


Catelotti K.,Center for Ecosystem Science | Kingsford R.T.,Center for Ecosystem Science | Bino G.,Center for Ecosystem Science | Bacon P.,Woodlots and Wetlands Pty Ltd.
Biological Conservation | Year: 2015

Increasing water abstraction is severely degrading the world's wetlands, which is frequently reflected in the condition of flood dependent organisms. Understanding minimum requirements under which thresholds are crossed from desired to undesired states can improve managing for resilience and avoid catastrophic ecological consequences. The Macquarie Marshes, a Ramsar-listed wetland in eastern Australia is located in a catchment with a long history of water resource development. It is also a catchment in which there has been a strong focus on wetland recovery using environmental flows. We investigated changes in the condition of 212 river red gum trees (Eucalyptus camaldulensis), a long-lived flood dependent species, at 17 sites, over 18. years (1993-2011). Four variables were measured for each tree: crown density, crown size, dead branches and epicormic growth. More than half (56.13%, 119) of the healthy trees first measured in 1993, showed no signs of life by 2011. Using historic inundation mapping, we identified that condition declined with reduced flooding. The probability of inundation in the previous five years had the strongest explanatory power, with strong increasing threshold responses of persistence and recovery associated with probabilities of flooding exceeding 5. years in the previous 10. years. We extended our modelling to the river red gum forests of the Macquarie Marshes floodplain, showing that 37% of the area had a predicted survival probability lower than P= 0.6 while similar probabilities were present in only 12% of the area within the Macquarie Marshes Nature Reserve. The condition of river red gum forests, using the relationships identified, provide a useful measure of ecosystem health, particularly if extended to understanding of reproduction, germination and recruitment in relation to different scenarios for environmental flows. Embedding such a monitoring strategy in an adaptive management framework provides considerable promise for ongoing learning and improvement of management, not just for river red gums but also other indicators. There is a possibility that the current poor ecological condition of the Macquarie Marshes can be redressed with increased environmental flows restoring some of the river red gum forests that are a key characteristic of the wetland. © 2015 Elsevier Ltd.


Letten A.D.,Center for Ecosystem Science | Cornwell W.K.,Evolution and Ecology Research Center
Methods in Ecology and Evolution | Year: 2015

An increasingly popular practice in community ecology is to use the evolutionary distance among interacting species as a proxy for their overall functional similarity. At the core of this approach is the implicit, yet poorly recognized, assumption that trait dissimilarity increases linearly with divergence time, that is all evolutionary time is considered equal. However, given a classic Brownian model of trait evolution, we show that the expected functional displacement of any two taxa is more appropriately represented as a linear function of time's square root. In light of this mismatch between theory and methodology, we argue that current methods at the interface of ecology and evolutionary biology often greatly overweight deep time relative to recent time. An easy solution to this weighting problem is a square root transformation of the phylogenetic distance matrix. Using simulated models of trait evolution and community assembly, we show that this transformation yields considerably higher statistical power, with improvements in 92% of trials. This methodological update is likely to improve our understanding of the connection between evolutionary relatedness and contemporary ecological processes. © 2014 British Ecological Society.


News Article | March 9, 2016
Site: phys.org

Researchers led by Bruce Hungate, director of the Center for Ecosystem Science and Society, used the stable hydrogen isotope signature in body tissue of invasive Japanese beetles to model the source of origin and time since arrival of beetles trapped at Portland International Airport over the past decade. The results, published in PLOS ONE, can help answer the question of whether a beetle detected in new territory is new or part of an established population in the area. New arrivals point to more control at the source; localized beetles point to more control at the destination. "Knowing the timing of arrival of these invasive organisms can be really helpful in managing them, and the stable isotope gives us a very useful chemical clock," Hungate said. "It's a powerful addition to the tools we have to understand where these organisms are from and the dynamics of their movements." Japanese beetles wreak havoc by feeding on over 300 plants, contributing to the billions of dollars per year in economic costs caused by invasive species. Japanese beetles are well established in the eastern United States. Control efforts at airports on both coasts aim to keep the beetles from spreading westward, with only partial success. The study used isotopes as a sleuthing tool. One of the heavier isotopes of hydrogen, deuterium, is rare but stable, meaning it does not decay. The amount of this isotope—its signature—in local water sources varies from place to place, and has been found to match the signature in tissues of plants and animals consuming the local water. Researchers found a close relationship between the stable hydrogen isotope signature in beetle tissue and local water from 71 sites around the country. Combined with the signatures of water at known sources of Japanese beetles in the East, these results provide a sort of "geographic fingerprint" to determine where the beetle is from. To model time since arrival, researchers transplanted Eastern beetles to a Western environment and measured the signature change over time. Changes began after two weeks and the signature took about five weeks to equilibrate to the new environment. This offered a new clue: beetles trapped at points of entry to an area, like airports, are likely to be new arrivals if their signature is distinctly different from the signature in local water. The transplant experiment also explored whether the signature from the hard, chitin-rich tissue of the beetle's wing covers changed more slowly than the signature in soft tissue, potentially preserving clues about the beetle's origin longer. They found that signatures did shift more slowly in hard tissue, adding it as another potential tool. The resulting model pointed to the southeastern United States as the origin of beetles trapped at the Portland International Airport. And beetles trapped after 2011 appeared to have been more recent arrivals than beetles trapped in earlier years, suggesting that efforts to prevent beetles from establishing viable populations at the Portland International Airport seemed to be working. Explore further: Bark beetle management and ecology in southern pine forests

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