TEASIng apart alien species risk assessments: a framework for best practices

Area of Science:

• Ecology
• Conservation Biology
• Environmental Management

Background:

• Alien species pose variable risks, necessitating effective risk assessment (RA) for management prioritization.
• Existing RA approaches for alien species are diverse, highlighting the need for synthesis and best practice identification.
• Limited resources demand efficient methods to forecast ecological impacts of non-native organisms.

Purpose of the Study:

• To synthesize and evaluate quantitative and scoring risk assessment methods for alien species.
• To develop a comprehensive framework (TEASI: Transport, Establishment, Abundance, Spread, Impact) for evaluating alien species risks.
• To provide guidance for improving the accessibility and applicability of alien species RA in policy.

Main Methods:

• Conducted a systematic review integrating over 300 publications on quantitative and scoring alien species RAs.
• Developed and applied a rigorous quantitative RA framework (TEASI) to map existing studies.
• Compared the coverage of risk components and policy application of quantitative versus scoring approaches.

Main Results:

• Quantitative RAs often focus on single risk components (e.g., Establishment), are underutilized in policy, and require greater accessibility.
• Scoring approaches cover more risk components and are widely used in policy, but heavily rely on expert opinion.
• The proposed TEASI framework can be informative even without complete parameterization, identifying areas for RA improvement.

Conclusions:

• A unified framework for alien species risk assessment is needed to enhance policy relevance and management effectiveness.
• Improving the integration of data, generalization across taxa/regions, and accessibility of quantitative methods are key.
• The developed framework offers guidance for refining current alien species risk assessment practices.