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Your search keyword '"Johnston, Emma L."' showing total 574 results
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574 results on '"Johnston, Emma L."'

8. A global horizon scan of issues impacting marine and coastal biodiversity conservation

Author

Herbert-Read, James E., Thornton, Ann, Amon, Diva J., Birchenough, Silvana N. R., Côté, Isabelle M., Dias, Maria P., Godley, Brendan J., Keith, Sally A., McKinley, Emma, Peck, Lloyd S., Calado, Ricardo, Defeo, Omar, Degraer, Steven, Johnston, Emma L., Kaartokallio, Hermanni, Macreadie, Peter I., Metaxas, Anna, Muthumbi, Agnes W. N., Obura, David O., Paterson, David M., Piola, Alberto R., Richardson, Anthony J., Schloss, Irene R., Snelgrove, Paul V. R., Stewart, Bryce D., Thompson, Paul M., Watson, Gordon J., Worthington, Thomas A., Yasuhara, Moriaki, and Sutherland, William J.

Published
2022
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12. Variation in Successional Dynamics Shape Biodiversity Patterns over a Tropical-Temperate Latitudinal Gradient.

Author

Bracewell, Sally A., Johnston, Emma L., and Clark, Graeme F.

Subjects
*COMMUNITY development, *ECOLOGICAL succession, *SPECIES diversity, *STOCHASTIC processes, *BIOGEOGRAPHY
Abstract

Successional dynamics can vary because of a range of ecological and environmental factors, but our understanding of biogeographic variation in succession, and the processes contributing to community development across ecosystems, is limited. The pattern and rate of recruitment of dispersive propagules likely differs over large spatial scales and can be an important predictor of successional trajectory. Over a 20° tropical-temperate latitudinal gradient, we measured sessile invertebrates over 12 months of community development and successive 3-month recruitment windows to understand succession and how it is influenced by recruitment. Succession and recruitment patterns varied over latitude. In the tropics, fast temporal turnover, fluctuating abundances, and lack of successional progression suggest that the contribution of stochastic processes was high. As latitude increased, successional progression became more apparent, characterized by increasing species richness and community cover and a shift to more competitive taxa over time. At temperate locations, species identities were similar between older communities and recruiting assemblages; however, community composition became more variable across space over time. Such divergence suggests an important role of early colonizers and species interactions on community structure. These findings demonstrate differences in the processes contributing to community development and biodiversity patterns over latitude. Understanding such biogeographic variation in community dynamics and identifying the prevalence of different processes can provide insights into how communities assemble and persist in response to environmental variability. [ABSTRACT FROM AUTHOR]

Published
2024
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13. A topic model analysis of students' gendered expectations using surveyed critiques of lecturers.

Author

Kim, Fiona, Johnston, Emma L., and Yanan Fan

Subjects
STUDENT evaluation of teachers, LEARNING Management System, SEX discrimination, IMPLICIT bias, INFERENTIAL statistics
Abstract

Student evaluations of teaching (SET) have been examined over the years to better understand the student experience, with an increasing portion of literature exploring the presence of implicit bias in SET surveys against minority gender and ethnic lecturers. This study explores free-text comments made by students from a large public university in Australia over the period 2010-2016, using a semi-supervised statistical approach. Data were collected via surveys administered online at the end of each course to every student officially enrolled in that course via the learning management system, and completion of the surveys was voluntary. We build a probabilistic topic model which incorporates student and lecturer characteristics into the topic formation process. We make statistical inference on the effects of gender and cultural or language backgrounds based on the topic and word prevalence probabilities. The results showed clear separation of topics discussed betweenmale and female lecturers. From a gendered perspective, our topic analyses have found that students are significantly more likely to critique female lecturers to improve on structural aspects of the course, as well as aspects of time management and control of the lecturing environment. In comparison, male lecturers were significantlymore likely to be critiqued on specific aspects related to lecture delivery. Lecturers from non-English speaking backgrounds were more likely to be both critiqued and praised for the clarity of their delivery. [ABSTRACT FROM AUTHOR]

Published
2024
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23. Invasion Expansion: Time since introduction best predicts global ranges of marine invaders.

Author

Byers, James E, Smith, Rachel S, Pringle, James M, Clark, Graeme F, Gribben, Paul E, Hewitt, Chad L, Inglis, Graeme J, Johnston, Emma L, Ruiz, Gregory M, Stachowicz, John J, and Bishop, Melanie J

Subjects
Animals, Invertebrates, Marine Biology, Environment, Ecosystem, Time Factors, Ships, Databases, Factual, United States, Australia, New Zealand, Introduced Species, Aquatic Organisms, Databases, Factual
Abstract

Strategies for managing biological invasions are often based on the premise that characteristics of invading species and the invaded environment are key predictors of the invader's distribution. Yet, for either biological traits or environmental characteristics to explain distribution, adequate time must have elapsed for species to spread to all potential habitats. We compiled and analyzed a database of natural history and ecological traits of 138 coastal marine invertebrate species, the environmental conditions at sites to which they have been introduced, and their date of first introduction. We found that time since introduction explained the largest fraction (20%) of the variability in non-native range size, while traits of the species and environmental variables had significant, but minimal, influence on non-native range size. The positive relationship between time since introduction and range size indicates that non-native marine invertebrate species are not at equilibrium and are still spreading, posing a major challenge for management of coastal ecosystems.

Published
2015

35. An expert-driven framework for applying eDNA tools to improve biosecurity in the Antarctic

Author

Universidad de Alicante. Departamento de Ciencias del Mar y Biología Aplicada, Clarke, Laurence J., Shaw, Justine D., Suter, Leonie, Atalah, Javier, Bergstrom, Dana M., Biersma, Elisabeth Machteld, Convey, Peter, Greve, Michelle, Holland, Oakes, Houghton, Melissa J., Hughes, Kevin A., Johnston, Emma L., King, Catherine K., McCarthy, Arlie H., McGaughran, Angela, Pertierra, Luis R., Robinson, Sharon A., Sherman, Craig D.H., Stark, Jonathan S., Stevens, Mark I., Strugnell, Jan M., von Ammon, Ulla, Wilson, Nerida G., Zaiko, Anastasija, MacDonald, Anna J., Universidad de Alicante. Departamento de Ciencias del Mar y Biología Aplicada, Clarke, Laurence J., Shaw, Justine D., Suter, Leonie, Atalah, Javier, Bergstrom, Dana M., Biersma, Elisabeth Machteld, Convey, Peter, Greve, Michelle, Holland, Oakes, Houghton, Melissa J., Hughes, Kevin A., Johnston, Emma L., King, Catherine K., McCarthy, Arlie H., McGaughran, Angela, Pertierra, Luis R., Robinson, Sharon A., Sherman, Craig D.H., Stark, Jonathan S., Stevens, Mark I., Strugnell, Jan M., von Ammon, Ulla, Wilson, Nerida G., Zaiko, Anastasija, and MacDonald, Anna J.

Abstract

Signatories to the Antarctic Treaty System’s Environmental Protocol are committed to preventing incursions of non-native species into Antarctica, but systematic surveillance is rare. Environmental DNA (eDNA) methods provide new opportunities for enhancing detection of non-native species and biosecurity monitoring. To be effective for Antarctic biosecurity, eDNA tests must have appropriate sensitivity and specificity to distinguish non-native from native Antarctic species, and be fit-for-purpose. This requires knowledge of the priority risk species or taxonomic groups for which eDNA surveillance will be informative, validated eDNA assays for those species or groups, and reference DNA sequences for both target non-native and related native Antarctic species. Here, we used an expert elicitation process and decision-by-consensus approach to identify and assess priority biosecurity risks for the Australian Antarctic Program (AAP) in East Antarctica, including identifying high priority non-native species and their potential transport pathways. We determined that the priority targets for biosecurity monitoring were not individual species, but rather broader taxonomic groups such as mussels (Mytilus species), tunicates (Ascidiacea), springtails (Collembola), and grasses (Poaceae). These groups each include multiple species with high risks of introduction to and/or establishment in Antarctica. The most appropriate eDNA methods for the AAP must be capable of detecting a range of species within these high-risk groups (e.g., eDNA metabarcoding). We conclude that the most beneficial Antarctic eDNA biosecurity applications include surveillance of marine species in nearshore environments, terrestrial invertebrates, and biofouling species on vessels visiting Antarctica. An urgent need exists to identify suitable genetic markers for detecting priority species groups, establish baseline terrestrial and marine biodiversity for Antarctic stations, and develop eDNA sampling methods for

Published
2023

36. An expert-driven framework for applying eDNA tools to improve biosecurity in the Antarctic

Author

Clarke, Laurence J, Shaw, Justine D, Suter, Leonie, Atalah, Javier, Bergstrom, Dana M, Biersma, Elisabeth, Convey, Peter, Greve, Michelle, Holland, Oakes, Houghton, Melissa J, Hughes, Kevin A, Johnston, Emma L, King, Catherine K, McCarthy, Arlie H, McGaughran, Angela, Pertierra, Luis R, Robinson, Sharon A, Sherman, Craig D. H, Stark, Jonathan S, Stevens, Mark I, Strugnell, Jan M, von Ammon, Ulla, Wilson, Nerida G, Zaiko, Anastasija, MacDonald, Anna J, Clarke, Laurence J, Shaw, Justine D, Suter, Leonie, Atalah, Javier, Bergstrom, Dana M, Biersma, Elisabeth, Convey, Peter, Greve, Michelle, Holland, Oakes, Houghton, Melissa J, Hughes, Kevin A, Johnston, Emma L, King, Catherine K, McCarthy, Arlie H, McGaughran, Angela, Pertierra, Luis R, Robinson, Sharon A, Sherman, Craig D. H, Stark, Jonathan S, Stevens, Mark I, Strugnell, Jan M, von Ammon, Ulla, Wilson, Nerida G, Zaiko, Anastasija, and MacDonald, Anna J

Abstract

Signatories to the Antarctic Treaty System’s Environmental Protocol are committed to preventing incursions of non-native species into Antarctica, but systematic surveillance is rare. Environmental DNA (eDNA) methods provide new opportunities for enhancing detection of non-native species and biosecurity monitoring. To be effective for Antarctic biosecurity, eDNA tests must have appropriate sensitivity and specificity to distinguish non-native from native Antarctic species, and be fit-for-purpose. This requires knowledge of the priority risk species or taxonomic groups for which eDNA surveillance will be informative, validated eDNA assays for those species or groups, and reference DNA sequences for both target non-native and related native Antarctic species. Here, we used an expert elicitation process and decision-by-consensus approach to identify and assess priority biosecurity risks for the Australian Antarctic Program (AAP) in East Antarctica, including identifying high priority non-native species and their potential transport pathways. We determined that the priority targets for biosecurity monitoring were not individual species, but rather broader taxonomic groups such as mussels (Mytilus species), tunicates (Ascidiacea), springtails (Collembola), and grasses (Poaceae). These groups each include multiple species with high risks of introduction to and/or establishment in Antarctica. The most appropriate eDNA methods for the AAP must be capable of detecting a range of species within these high-risk groups (e.g., eDNA metabarcoding). We conclude that the most beneficial Antarctic eDNA biosecurity applications include surveillance of marine species in nearshore environments, terrestrial invertebrates, and biofouling species on vessels visiting Antarctica. An urgent need exists to identify suitable genetic markers for detecting priority species groups, establish baseline terrestrial and marine biodiversity for Antarctic stations, and develop eDNA sampling methods for

Published
2023

37. An expert-driven framework for applying eDNA tools to improve biosecurity in the Antarctic

Author

Clarke, Laurence J., Shaw, Justine D., Suter, Leonie, Atalah, Javier, Bergstrom, Dana M., Biersma, Elisabeth, Convey, Peter, Greve, Michelle, Holland, Oakes, Houghton, Melissa J., Hughes, Kevin A., Johnston, Emma L., King, Catherine K., McCarthy, Arlie H., McGaughran, Angela, Pertierra, Luis R., Robinson, Sharon A., Sherman, Craig D. H., Stark, Jonathan S., Stevens, Mark I., Strugnell, Jan M., Ammon, Ulla von, Wilson, Nerida G., Zaiko, Anastasija, MacDonald, Anna J., Clarke, Laurence J., Shaw, Justine D., Suter, Leonie, Atalah, Javier, Bergstrom, Dana M., Biersma, Elisabeth, Convey, Peter, Greve, Michelle, Holland, Oakes, Houghton, Melissa J., Hughes, Kevin A., Johnston, Emma L., King, Catherine K., McCarthy, Arlie H., McGaughran, Angela, Pertierra, Luis R., Robinson, Sharon A., Sherman, Craig D. H., Stark, Jonathan S., Stevens, Mark I., Strugnell, Jan M., Ammon, Ulla von, Wilson, Nerida G., Zaiko, Anastasija, and MacDonald, Anna J.

Abstract

Signatories to the Antarctic Treaty System’s Environmental Protocol are committed to preventing incursions of non-native species into Antarctica, but systematic surveillance is rare. Environmental DNA (eDNA) methods provide new opportunities for enhancing detection of non-native species and biosecurity monitoring. To be effective for Antarctic biosecurity, eDNA tests must have appropriate sensitivity and specificity to distinguish non-native from native Antarctic species, and be fit-for-purpose. This requires knowledge of the priority risk species or taxonomic groups for which eDNA surveillance will be informative, validated eDNA assays for those species or groups, and reference DNA sequences for both target non-native and related native Antarctic species. Here, we used an expert elicitation process and decision-by-consensus approach to identify and assess priority biosecurity risks for the Australian Antarctic Program (AAP) in East Antarctica, including identifying high priority non-native species and their potential transport pathways. We determined that the priority targets for biosecurity monitoring were not individual species, but rather broader taxonomic groups such as mussels (Mytilus species), tunicates (Ascidiacea), springtails (Collembola), and grasses (Poaceae). These groups each include multiple species with high risks of introduction to and/or establishment in Antarctica. The most appropriate eDNA methods for the AAP must be capable of detecting a range of species within these high-risk groups (e.g., eDNA metabarcoding). We conclude that the most beneficial Antarctic eDNA biosecurity applications include surveillance of marine species in nearshore environments, terrestrial invertebrates, and biofouling species on vessels visiting Antarctica. An urgent need exists to identify suitable genetic markers for detecting priority species groups, establish baseline terrestrial and marine biodiversity for Antarctic stations, and develop eDNA sampling methods f

Published
2023

43. The authors' reply

Author

Dafforn, Katherine A, Glasby, Tim M, Airoldi, Laura, Rivero, Natalie K, Pinto, Mariana Mayer, and Johnston, Emma L

Published
2015

47. The Role of Propagule Pressure in Invasion Success

Author

Johnston, Emma L., Piola, Richard F., Clark, Graeme F., Caldwell, M. M., editor, Heldmaier, G., editor, Jackson, R. B., editor, Lange, O. L., editor, Mooney, H. A., editor, Schulze, E. -D., editor, Sommer, U., editor, Rilov, Gil, editor, and Crooks, Jeffrey A., editor

Published
2009
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