Optimization and validation of a cost‐effective protocol for biosurveillance of invasive alien species

The threat of invasive alien plant species is progressively becoming a serious global concern. Alien plant invasions adversely affect both ecological services and socio-economic systems. Hence, accurate detection and mapping of invasive alien species is valuable in mitigating adverse ecological and socio-economic effects. Recent advances in active and passive remote sensing technology have created new and cost-effective opportunities for the application of remote sensing to invasive species mapping. In this study, new generation Sentinel-2 (S2) optical imagery was compared to S2 derived Vegetation Indices (VIs) and S2 VIs fused with Sentinel-1 (S1) Synthetic Aperture Radar (SAR) imagery for detecting and mapping the American Bramble (Rubuscuneifolius). Fusion of S2 VIs and S1SAR imagery was conducted at pixel level and multi-class Support Vector Machine (SVM) image classification was used to determine the dominant land use land cover classes. Results indicated that S2 derived VIs were the most accurate (80%) in detecting and mapping Bramble, while fused S2 VIs and S1SAR were the least accurate (54%). Findings from this study suggest that the application of S2 VIs is more suitable for Bramble detection and mapping than the fused S2 VIs and S1SAR. The superior performance of S2 VIs highlights the value of the new generation S2 VIs for invasive alien species detection and mapping. Furthermore, this study recommends the use of freely available new generation satellite imagery for cost effective and timeous mapping of Bramble from surrounding native vegetation and other land use land cover types.

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Reducing uncertainty in impact assessments for alien species

10.1101/2020.05.05.077958 ◽

2020 ◽

Author(s):

David A. Clarke ◽

David J. Palmer ◽

Chris McGrannachan ◽

Treena I. Burgess ◽

Steven L. Chown ◽

...

Keyword(s):

Impact Assessment ◽

Alien Species ◽

Life Histories ◽

Invasive Alien Species ◽

A Priori ◽

Cost Effective ◽

Assessment Tools ◽

Assessment Process ◽

Insect Species ◽

The Impact

AbstractImpact assessment is a widely used and cost-effective tool for prioritising invasive alien species. With the number of alien and invasive alien species expected to increase, reliance on impact assessment tools for the identification of species that pose the greatest threats will continue to grow. Given the importance of such assessments for management and resource allocation, it is critical to understand the uncertainty involved and what effect this may have on the outcome. Using an uncertainty typology and insects as a model taxon, we identified and classified the sources and types of uncertainty when performing impact assessments on alien species. We assessed 100 alien insect species across two rounds of assessments with each species independently assessed by two assessors. Agreement between assessors was relatively low for all three EICAT components (mechanism, severity, confidence) after the first round. For the second round, we revised guidelines and gave assessors access to each other’s assessments which improved agreement by between 20-30%. Of the 12 potential reasons for assessment discrepancies identified a priori, 11 occurred. The most frequent sources (and types) of uncertainty (i.e. differences between assessment outcomes for the same species) were: incomplete information searches (systematic error), unclear mechanism and/or extent of impact (subjective judgment due to a lack of knowledge), and limitations of the assessment framework (context dependence). In response to these findings, we identify actions to reduce uncertainty in the impact assessment process, particularly for assessing speciose taxa with diverse life histories such as Insecta. Evidence of environmental impact was available for most insect species, and (of the non-random original subset of species assessed) 14 or 29% of those with evidence were identified as high impact species (with either ‘Major’ or ‘Massive’ impact). Although uncertainty in risk assessment, including impact assessments, can never be eliminated, identifying and communicating its source and variety is a first step toward its reduction and a more reliable assessment outcome, regardless of the taxa being assessed.

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Suggestions for the Improvement of the Invasive Alien Species Management in Korea - A Comparative Analysis of the Legal Framework for Invasive Alien Species between Japan and Korea

Journal of Environmental Policy and Administration ◽

10.15301/jepa.2013.06.21.2.35 ◽

2013 ◽

Cited By ~ 5

Author(s):

Saeromi Mun

Keyword(s):

Comparative Analysis ◽

Alien Species ◽

Invasive Alien Species ◽

Legal Framework ◽

Species Management

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Achieving Aichi biodiversity targets: Prevention, control, or eradication of invasive alien species that threaten biodiversity, agricultural production, and human well-being

10.1603/ice.2016.93650 ◽

2016 ◽

Author(s):

Junko Shimura

Keyword(s):

Alien Species ◽

Agricultural Production ◽

Invasive Alien Species ◽

Well Being ◽

Aichi Biodiversity Targets

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Invasive alien species in China: the current situation, problems and possible solutions

Advances in Earth and Environmental Sciences ◽

10.2495/icesep131351 ◽

2013 ◽

Author(s):

Congcong Xu

Keyword(s):

Alien Species ◽

Invasive Alien Species ◽

Current Situation

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Introduction and Spread of the Invasive Alien Species Ageratina altissima in a Disturbed Forest Ecosystem

Sustainability ◽

10.3390/su13116152 ◽

2021 ◽

Vol 13 (11) ◽

pp. 6152

Author(s):

Eunyoung Kim ◽

Jaeyong Choi ◽

Wonkyong Song

Keyword(s):

Land Use ◽

South Korea ◽

Alien Species ◽

Invasive Alien Species ◽

Management Policy ◽

Economic Damage ◽

Forest Edges ◽

Forest Interior ◽

Lower Elevation ◽

Canopy Area

Invasive alien species (IAS) not only displace nearby indigenous plants and lead to habitat simplification but also cause severe economic damage by invading arable lands. IAS invasion processes involve external forces such as species characteristics, IAS assemblage traits, environmental conditions, and inter-species interactions. In this study, we analyzed the invasion processes associated with the introduction and spread of Ageratina altissima, a representative invasive plant species in South Korea. We investigated 197 vegetation quadrats (2 × 20 m) in regions bordering 47 forests in southern Seoul and Gyeonggi-do, South Korea. A total of 23 environmental variables were considered, which encompassed vegetation, topography, land use, and landscape ecology indices. The model was divided into an edge and an interior model and analyzed using logistic regression and a decision tree (DT) model. The occurrence of Ageratina altissima was confirmed in 61 sites out of a total of 197. According to our analysis, Ageratina altissima easily invaded forest edges with low density. The likelihood of its occurrence increased with lower elevation and gentler slope. In contrast, the spread of Ageratina altissima in the forest interior, especially based on seed spread and permeability, was favored by a lower elevation and gentler slopes. The analysis of Ageratina altissima settlement processes in forest edges coupled with the DT model demonstrated that land characteristics, such as the proximity to urbanized areas and the number of shrub and tree species, play a pivotal role in IAS settlement. In the forest interior, Ageratina altissima did not occur in 68 of the 71 sites where the soil drainage was under 2.5%, and it was confirmed that the tree canopy area had a significant impact on forest spread. Based on these results, it can be assumed that Ageratina altissima has spread in South Korean forests in much the same way as other naturalized species. Therefore, vegetation management strategies for naturalized species should be developed in parallel with land use management policy in regions surrounding forest edges to successfully manage and control Ageratina altissima invasion.

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