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Nunez‐Mir GC, Walter JA, Grayson KL, Johnson DM. Assessing drivers of localized invasive spread to inform large-scale management of a highly damaging insect pest. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2022; 32:e2538. [PMID: 35044021 PMCID: PMC9286796 DOI: 10.1002/eap.2538] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 08/17/2021] [Accepted: 09/15/2021] [Indexed: 05/19/2023]
Abstract
Studies of biological invasions at the macroscale or across multiple scales can provide important insights for management, particularly when localized information about invasion dynamics or environmental contexts is unavailable. In this study, we performed a macroscale analysis of the roles of invasion drivers on the local scale dynamics of a high-profile pest, Lymantria dispar dispar L., with the purpose of improving the prioritization of vulnerable areas for treatment. Specifically, we assessed the relative effects of various anthropogenic and environmental variables on the establishment rate of 8010 quadrats at a localized scale (5 × 5 km) across the entire L. dispar transition zone (the area encompassing the leading population edge, currently from Minnesota to North Carolina). We calculated the number of years from first detection of L. dispar in a quadrat to the year when probability of establishment of L. dispar was greater than 99% (i.e., waiting time to establishment after first detection). To assess the effects of environmental and anthropogenic variables on each quadrat's waiting time to establishment, we performed linear mixed-effects regression models for the full transition zone and three subregions within the zone. Seasonal temperatures were found to be the primary drivers of local establishment rates. Winter temperatures had the strongest effects, especially in the northern parts of the transition zone. Furthermore, the effects of some factors on waiting times to establishment varied across subregions. Our findings contribute to identifying especially vulnerable areas to further L. dispar spread and informing region-specific criteria by invasion managers for the prioritization of areas for treatment.
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Affiliation(s)
- Gabriela C. Nunez‐Mir
- Department of BiologyVirginia Commonwealth UniversityRichmondVirginiaUSA
- Department of Biological SciencesUniversity of Illinois at ChicagoChicagoIllinoisUSA
| | - Jonathan A. Walter
- Department of Environmental SciencesUniversity of VirginiaCharlottesvilleVirginiaUSA
| | | | - Derek M. Johnson
- Department of BiologyVirginia Commonwealth UniversityRichmondVirginiaUSA
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2
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Fukuda Y, Moritz C, Jang N, Webb G, Campbell H, Christian K, Lindner G, Banks S. Environmental resistance and habitat quality influence dispersal of the saltwater crocodile. Mol Ecol 2021; 31:1076-1092. [PMID: 34865283 PMCID: PMC9299799 DOI: 10.1111/mec.16310] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 11/15/2021] [Accepted: 11/22/2021] [Indexed: 11/29/2022]
Abstract
Landscape genetics commonly focuses on the effects of environmental resistance on animal dispersal patterns, but there is an emerging focus on testing environmental effects on emigration and settlement choices. In this study, we used landscape genetics approaches to quantify dispersal patterns in the world's largest crocodilian, the saltwater crocodile (Crocodylus porosus), and demonstrated environmental influences on three processes that comprise dispersal: emigration, movement and settlement. We found that both environmental resistance and properties of the source and destination catchments (proportion of breeding habitat) were important factors influencing observed dispersal events. Our habitat quality variables related to hypotheses about resource competition and represented the ratio of breeding habitat (which limits carrying capacity), suggesting that competition for habitat influences emigration and settlement choices, together with the strong effect of environmental resistance to movement (where high-quality habitat was associated with greatest environmental permeability). Approximately 42% of crocodiles were migrants from populations other than their sampling locations and some outstandingly productive populations had a much higher proportion of emigration rather than immigration. The distance most commonly travelled between source and destination was 150-200 km although a few travelled much longer distances, up to 600-700 km. Given the extensive dispersal range, individual catchments or hydrographic regions that combine two or three adjacent catchments are an appropriate scale for population management.
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Affiliation(s)
- Yusuke Fukuda
- Research School of Biology and Center for Biodiversity Analysis, The Australian National University, Canberra, ACT, Australia.,Department of Environment, Parks and Water Security, Northern Territory Government, Darwin, Northern Territory, Australia
| | - Craig Moritz
- Research School of Biology and Center for Biodiversity Analysis, The Australian National University, Canberra, ACT, Australia
| | - Namchul Jang
- Namchul Photography, Palmerston, Northern Territory, Australia
| | - Grahame Webb
- Wildlife Management International Pty Ltd, Darwin, Northern Territory, Australia
| | - Hamish Campbell
- Research Institute for the Environment and Livelihoods, College of Engineering, IT and the Environment, Charles Darwin University, Darwin, Northern Territory, Australia
| | - Keith Christian
- Research Institute for the Environment and Livelihoods, College of Engineering, IT and the Environment, Charles Darwin University, Darwin, Northern Territory, Australia
| | - Garry Lindner
- Parks Australia, Australian Government, Jabiru, Northern Territory, Australia
| | - Sam Banks
- Research Institute for the Environment and Livelihoods, College of Engineering, IT and the Environment, Charles Darwin University, Darwin, Northern Territory, Australia
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3
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Panetta FD, Grigg A. A weed risk analytical screen to assist in the prioritisation of an invasive flora for containment. NEOBIOTA 2021. [DOI: 10.3897/neobiota.66.67769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Prioritising weeds for control and deciding upon the type of control and its associated investment are fundamental to weed management planning. Risk analysis is central to this process, combining the activities of risk assessment, risk management and risk communication. Risk assessment methodology has a rich history, but management feasibility has typically been a secondary matter, dealt with separately or not at all. Determinants of management feasibility for weeds include the stage of invasion, weed biology, means of control and cost of weed control. Here, we describe a simple weed risk analytical screen that combines risk assessment with species traits that influence management feasibility. We consider stage of invasion, species biological/dispersal characteristics and plant community invasibility in a preliminary analysis of the risk posed by the non-native plant species on Christmas Island in the Indian Ocean. For each of 31 high-risk species considered to be ineradicable under existing funding constraints, we analyse the risk posed to two major plant communities: evergreen closed-canopy rainforest and semi-deciduous scrub forest. Weed risk ratings are combined with ratings for species-intrinsic feasibility of containment (based on a measure that combines time to reproduction with potential for long distance dispersal) to create preliminary rankings for containment specific to each community. These rankings will provide a key input for a more thorough analysis of containment feasibility – one that considers spatial distributions/landscape features, management aspects and the social environment. We propose a general non-symmetric relationship between weed risk and management feasibility, considering risk to be the dominant component of risk analysis. Therefore, in this analysis species are ranked according to their intrinsic containment feasibility within similar levels of risk to produce an initial prioritisation list for containment. Shade-tolerant weeds are of particular concern for the closed-canopy evergreen rainforest on Christmas Island, but a greater diversity of weeds is likely to invade the semi-deciduous scrub forest because of higher light availability. Nevertheless, future invasion of both communities will likely be conditioned by disturbance, both natural and anthropogenic. The plant communities of Christmas Island have undergone significant fragmentation because of clearing for phosphate mining and other purposes. With a substantial number of invasive plant species firmly established and having the potential to spread further, minimising future anthropogenic disturbance is paramount to reducing community invasibility and therefore conserving the island’s unique biodiversity.
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Dai G, Wang S, Geng Y, Dawazhaxi, Ou X, Zhang Z. Potential risks of
Tithonia diversifolia
in Yunnan Province under climate change. Ecol Res 2020. [DOI: 10.1111/1440-1703.12182] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Guanghui Dai
- School of Ecology and Environmental Sciences and Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments Yunnan University Kunming Yunnan China
| | - Shuai Wang
- School of Ecology and Environmental Sciences and Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments Yunnan University Kunming Yunnan China
| | - Yupeng Geng
- School of Ecology and Environmental Sciences and Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments Yunnan University Kunming Yunnan China
| | - Dawazhaxi
- School of Ecology and Environmental Sciences and Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments Yunnan University Kunming Yunnan China
| | - Xiaokun Ou
- School of Ecology and Environmental Sciences and Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments Yunnan University Kunming Yunnan China
| | - Zhiming Zhang
- School of Ecology and Environmental Sciences and Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments Yunnan University Kunming Yunnan China
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Keller JA, Johnson AE, Uyi O, Wurzbacher S, Long D, Hoover K. Dispersal of Lycorma delicatula (Hemiptera: Fulgoridae) Nymphs Through Contiguous, Deciduous Forest. ENVIRONMENTAL ENTOMOLOGY 2020; 49:1012-1018. [PMID: 32814958 DOI: 10.1093/ee/nvaa089] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Indexed: 06/11/2023]
Abstract
Spotted lanternfly (Lycorma delicatula) is a recently introduced pest in the United States, where it threatens the wine, timber, and ornamentals industries. Knowledge of the dispersal ability of L. delicatula is key to developing effective management strategies for this invasive pest. We conducted a mark, release, re-sight study, marking nymphs with fluorescent powders and observing dispersal distances from a central release point at three time points over 7 d following release. To examine how dispersal patterns changed over the course of nymphal development, we repeated this process for each of L. delicatula's four instars. All releases were conducted in contiguous, deciduous forest, which is a widespread habitat type within L. delicatula's invaded range and a habitat where this pest may have negative ecological and economic impacts. We found that nymphs displayed clear directionality in their movement following release, apparently preferring to move uphill on the modest 6° grade at our release site. Most nymphs remained near the release location, while some moved tens of meters. The maximum displacement we observed was 65 m from the release point, 10 d after release. Nymphs were re-sighted singly and in small groups on a variety of trees, shrubs, and understory vegetation. All four instars had similar dispersal distances over time, though third instar nymphs moved farthest on average, with estimated median displacement of 16.9 m 7 d after release. Further studies are needed to provide additional information on what factors influence spotted lanternfly dispersal.
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Affiliation(s)
- Joseph A Keller
- Department of Entomology, Penn State University, University Park, PA
| | - Anne E Johnson
- Department of Entomology, Penn State University, University Park, PA
| | - Osariyekemwen Uyi
- Department of Entomology, Penn State University, University Park, PA
| | - Sarah Wurzbacher
- Penn State Extension, Penn State University, University Park, PA
| | - David Long
- Department of Entomology, Penn State University, University Park, PA
| | - Kelli Hoover
- Department of Entomology, Penn State University, University Park, PA
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Froese JG, Pearse AR, Hamilton G. Rapid spatial risk modelling for management of early weed invasions: Balancing ecological complexity and operational needs. Methods Ecol Evol 2019. [DOI: 10.1111/2041-210x.13284] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jens G. Froese
- School of Earth, Environmental and Biological Sciences Queensland University of Technology (QUT) Brisbane Qld Australia
| | - Alan R. Pearse
- School of Earth, Environmental and Biological Sciences Queensland University of Technology (QUT) Brisbane Qld Australia
- Australian Research Council Centre of Excellence for Mathematical and Statistical Frontiers Queensland University of Technology (QUT) Brisbane Qld Australia
| | - Grant Hamilton
- School of Earth, Environmental and Biological Sciences Queensland University of Technology (QUT) Brisbane Qld Australia
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7
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Pratchett MS, Cowan ZL, Nadler LE, Caballes CF, Hoey AS, Messmer V, Fletcher CS, Westcott DA, Ling SD. Body size and substrate type modulate movement by the western Pacific crown-of-thorns starfish, Acanthaster solaris. PLoS One 2017; 12:e0180805. [PMID: 28877193 PMCID: PMC5587101 DOI: 10.1371/journal.pone.0180805] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 06/21/2017] [Indexed: 11/25/2022] Open
Abstract
The movement capacity of the crown-of-thorns starfishes (Acanthaster spp.) is a primary determinant of both their distribution and impact on coral assemblages. We quantified individual movement rates for the Pacific crown-of-thorns starfish (Acanthaster solaris) ranging in size from 75–480 mm total diameter, across three different substrates (sand, flat consolidated pavement, and coral rubble) on the northern Great Barrier Reef. The mean (±SE) rate of movement for smaller (<150 mm total diameter) A. solaris was 23.99 ± 1.02 cm/ min and 33.41 ± 1.49 cm/ min for individuals >350 mm total diameter. Mean (±SE) rates of movement varied with substrate type, being much higher on sand (36.53 ± 1.31 cm/ min) compared to consolidated pavement (28.04 ± 1.15 cm/ min) and slowest across coral rubble (17.25 ± 0.63 cm/ min). If average rates of movement measured here can be sustained, in combination with strong directionality, displacement distances of adult A. solaris could range from 250–520 m/ day, depending on the prevailing substrate. Sustained movement of A. solaris is, however, likely to be highly constrained by habitat heterogeneity, energetic constraints, resource availability, and diurnal patterns of activity, thereby limiting their capacity to move between reefs or habitats.
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Affiliation(s)
- Morgan S. Pratchett
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia
- * E-mail:
| | - Zara-Louise Cowan
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia
| | - Lauren E. Nadler
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, United States of America
| | - Ciemon F. Caballes
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia
| | - Andrew S. Hoey
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia
| | - Vanessa Messmer
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia
| | | | | | - Scott D. Ling
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
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8
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Spatial mismatch analysis among hotspots of alien plant species, road and railway networks in Germany and Austria. PLoS One 2017; 12:e0183691. [PMID: 28829818 PMCID: PMC5567654 DOI: 10.1371/journal.pone.0183691] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 08/09/2017] [Indexed: 11/29/2022] Open
Abstract
Road and railway networks are pervasive elements of all environments, which have expanded intensively over the last century in all European countries. These transportation infrastructures have major impacts on the surrounding landscape, representing a threat to biodiversity. Roadsides and railways may function as corridors for dispersal of alien species in fragmented landscapes. However, only few studies have explored the spread of invasive species in relationship to transport network at large spatial scales. We performed a spatial mismatch analysis, based on a spatially explicit correlation test, to investigate whether alien plant species hotspots in Germany and Austria correspond to areas of high density of roads and railways. We tested this independently of the effects of dominant environments in each spatial unit, in order to focus just on the correlation between occurrence of alien species and density of linear transportation infrastructures. We found a significant spatial association between alien plant species hotspots distribution and roads and railways density in both countries. As expected, anthropogenic landscapes, such as urban areas, harbored more alien plant species, followed by water bodies. However, our findings suggested that the distribution of neobiota is strongest correlated to road/railways density than to land use composition. This study provides new evidence, from a transnational scale, that alien plants can use roadsides and rail networks as colonization corridors. Furthermore, our approach contributes to the understanding on alien plant species distribution at large spatial scale by the combination with spatial modeling procedures.
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9
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Santos MJ, Khanna S, Hestir EL, Greenberg JA, Ustin SL. Measuring landscape-scale spread and persistence of an invaded submerged plant community from airborne remote sensing. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 26:1733-1744. [PMID: 27755689 DOI: 10.1890/15-0615] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 10/28/2015] [Accepted: 01/11/2016] [Indexed: 06/06/2023]
Abstract
Processes of spread and patterns of persistence of invasive species affect species and communities in the new environment. Predicting future rates of spread is of great interest for timely management decisions, but this depends on models that rely on understanding the processes of invasion and historic observations of spread and persistence. Unfortunately, the rates of spread and patterns of persistence are difficult to model or directly observe, especially when multiple rates of spread and diverse persistence patterns may be co-occurring over the geographic distribution of the invaded ecosystem. Remote sensing systematically acquires data over large areas at fine spatial and spectral resolutions over multiple time periods that can be used to quantify spread processes and persistence patterns. We used airborne imaging spectroscopy data acquired once a year for 5 years from 2004 to 2008 to map an invaded submerged aquatic vegetation (SAV) community across 2220 km2 of waterways in the Sacramento-San Joaquin River Delta, California, USA, and measured its spread rate and its persistence. Submerged aquatic vegetation covered 13-23 km2 of the waterways (6-11%) every year. Yearly new growth accounted for 40-60% of the SAV area, ~50% of which survived to following year. Spread rates were overall negative and persistence decreased with time. From this dataset, we were able to identify both radial and saltatorial spread of the invaded SAV in the entire extent of the Delta over time. With both decreasing spread rate and persistence, it is possible that over time the invasion of this SAV community could decrease its ecological impact. A landscape-scale approach allows measurements of all invasion fronts and the spatial anisotropies associated with spread processes and persistence patterns, without spatial interpolation, at locations both proximate and distant to the focus of invasion at multiple points in time.
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Affiliation(s)
- Maria J Santos
- Center for Spatial Technologies and Remote Sensing (CSTARS), Department of Land, Air and Water Resources, University of California, One Shields Avenue, Davis, California, 95616, USA.
- Department of Innovation, Environmental and Energy Sciences, Utrecht University, Heidelberglaan 2, P.O. Box 80115, 3508 TC Utrecht, The Netherlands.
| | - Shruti Khanna
- Center for Spatial Technologies and Remote Sensing (CSTARS), Department of Land, Air and Water Resources, University of California, One Shields Avenue, Davis, California, 95616, USA
| | - Erin L Hestir
- Center for Spatial Technologies and Remote Sensing (CSTARS), Department of Land, Air and Water Resources, University of California, One Shields Avenue, Davis, California, 95616, USA
- Department of Marine, Earth and Atmospheric Science, North Carolina State University, Raleigh, North Carolina, 27695, USA
| | - Jonathan A Greenberg
- Center for Spatial Technologies and Remote Sensing (CSTARS), Department of Land, Air and Water Resources, University of California, One Shields Avenue, Davis, California, 95616, USA
- Department of Geography, University of Illinois, Urbana-Champaign, Illinois, 61801, USA
| | - Susan L Ustin
- Center for Spatial Technologies and Remote Sensing (CSTARS), Department of Land, Air and Water Resources, University of California, One Shields Avenue, Davis, California, 95616, USA
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10
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Ramaswami G, Kaushik M, Prasad S, Sukumar R, Westcott D. Dispersal by generalist frugivores affects management of an invasive plant. Biotropica 2016. [DOI: 10.1111/btp.12343] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Geetha Ramaswami
- Nature Conservation Foundation; 3076/5, IV Cross, Gokulam Park Mysore 570002 Karnataka India
| | - Monica Kaushik
- Wildlife Institute of India; Chandrabani Dehradun 248001 Uttarakhand India
| | - Soumya Prasad
- Jawaharlal Nehru University; New Mehrauli Road New Delhi 110067 India
| | - Raman Sukumar
- Centre for Ecological Sciences; Indian Institute of Science; Bangalore 560012 Karnataka India
| | - David Westcott
- CSIRO Land and Water; PO Box 780 Atherton Qld 4883 Australia
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11
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McCormick MK, Brooks HEA, Whigham DF. Microsatellite analysis to estimate realized dispersal distance in Phragmites
australis. Biol Invasions 2016. [DOI: 10.1007/s10530-016-1126-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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12
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Muthukrishnan R, West NM, Davis AS, Jordan NR, Forester JD. Evaluating the role of landscape in the spread of invasive species: The case of the biomass crop Miscanthus×giganteus. Ecol Modell 2015. [DOI: 10.1016/j.ecolmodel.2015.08.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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13
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Pittman SE, Muthukrishnan R, West NM, Davis AS, Jordan NR, Forester JD. Mitigating the potential for invasive spread of the exotic biofuel crop, Miscanthus × giganteus. Biol Invasions 2015. [DOI: 10.1007/s10530-015-0950-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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14
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Beeton NJ, McMahon CR, Williamson GJ, Potts J, Bloomer J, Bester MN, Forbes LK, Johnson CN. Using the Spatial Population Abundance Dynamics Engine for conservation management. Methods Ecol Evol 2015. [DOI: 10.1111/2041-210x.12434] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Nicholas J. Beeton
- School of Biological Sciences University of Tasmania Hobart TAS 7001 Australia
| | - Clive R. McMahon
- Sydney Institute of Marine Science 19 Chowder Bay Road Mosman NSW 2088 Australia
- Institute of Marine and Antarctic Studies University of Tasmania Hobart TAS 7001 Australia
| | - Grant J. Williamson
- School of Biological Sciences University of Tasmania Hobart TAS 7001 Australia
| | - Joanne Potts
- The Analytical Edge Pty Ltd. PO Box 47 Blackmans Bay TAS 7052 Australia
| | - Jonathan Bloomer
- Department of Nature Management Centurion Academy Charles de Gaulle Street Centurion 0048 South Africa
| | - Marthán N. Bester
- Department of Zoology and Entomology Mammal Research Institute University of Pretoria Hatfield 0028 South Africa
| | - Larry K. Forbes
- School of Mathematics and Physics University of Tasmania Hobart TAS 7001 Australia
| | - Chris N. Johnson
- School of Biological Sciences University of Tasmania Hobart TAS 7001 Australia
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15
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Fletcher CS, Westcott DA, Murphy HT, Grice AC, Clarkson JR. Managing breaches of containment and eradication of invasive plant populations. J Appl Ecol 2014; 52:59-68. [PMID: 25678718 PMCID: PMC4312900 DOI: 10.1111/1365-2664.12361] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 09/26/2014] [Indexed: 11/29/2022]
Abstract
Containment can be a viable strategy for managing invasive plants, but it is not always cheaper than eradication. In many cases, converting a failed eradication programme to a containment programme is not economically justified. Despite this, many contemporary invasive plant management strategies invoke containment as a fallback for failed eradication, often without detailing how containment would be implemented.We demonstrate a generalized analysis of the costs of eradication and containment, applicable to any plant invasion for which infestation size, dispersal distance, seed bank lifetime and the economic discount rate are specified. We estimate the costs of adapting eradication and containment in response to six types of breach and calculate under what conditions containment may provide a valid fallback to a breached eradication programme.We provide simple, general formulae and plots that can be applied to any invasion and show that containment will be cheaper than eradication only when the size of the occupied zone exceeds a multiple of the dispersal distance determined by seed bank longevity and the discount rate. Containment becomes proportionally cheaper than eradication for invaders with smaller dispersal distances, longer lived seed banks, or for larger discount rates.Both containment and eradication programmes are at risk of breach. Containment is less exposed to risk from reproduction in the 'occupied zone' and three types of breach that lead to a larger 'occupied zone', but more exposed to one type of breach that leads to a larger 'buffer zone'.For a well-specified eradication programme, only the three types of breach leading to reproduction in or just outside the buffer zone can justify falling back to containment, and only if the expected costs of eradication and containment were comparable before the breach.Synthesis and applications. Weed management plans must apply a consistent definition of containment and provide sufficient implementation detail to assess its feasibility. If the infestation extent, dispersal capacity, seed bank longevity and economic discount rate are specified, the general results presented here can be used to assess whether containment can outperform eradication, and under what conditions it would provide a valid fallback to a breached eradication programme.
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Affiliation(s)
- Cameron S Fletcher
- CSIRO Land & Water Flagship, CSIRO Atherton PO Box 780, Atherton, Qld, 4883, Australia
| | - David A Westcott
- CSIRO Land & Water Flagship, CSIRO Atherton PO Box 780, Atherton, Qld, 4883, Australia
| | - Helen T Murphy
- CSIRO Land & Water Flagship, CSIRO Atherton PO Box 780, Atherton, Qld, 4883, Australia
| | - Anthony C Grice
- CSIRO Land & Water Flagship, Australian Tropical Sciences and Innovation Precinct Private Mail Bag PO, Aitkenvale, Qld, 4814, Australia
| | - John R Clarkson
- Department of National Parks, Recreation, Sport and Racing, Queensland Parks and Wildlife Service PO Box 156, Mareeba, Qld, 4880, Australia
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16
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Parry H, Sadler R, Kriticos D. Practical guidelines for modelling post-entry spread in invasion ecology. NEOBIOTA 2013. [DOI: 10.3897/neobiota.18.4305] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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