Non-native species have multiple abundance-impact curves

Area of Science:

• Ecology
• Invasive Species Biology
• Conservation Science

Background:

• Abundance-impact curves are crucial tools for assessing and managing non-native species.
• These curves can exhibit diverse shapes (linear, threshold, sigmoid), influencing scientific interpretation and management strategies.
• Traditionally, abundance-impact curves were often considered a fixed characteristic of a species.

Purpose of the Study:

• To challenge the notion of a single, species-specific abundance-impact curve.
• To propose that abundance-impact curves are jointly determined by the invasive species and the host ecosystem.
• To highlight the implications of this species-ecosystem interaction for ecological understanding and management.

Main Methods:

• Utilized modeling approaches to investigate the impacts of the invasive mussel *Dreissena*.
• Analyzed how ecosystem characteristics influence the shape and nature of abundance-impact curves.
• Critically evaluated the use of horizontal (space-for-time) designs in abundance-impact curve studies.

Main Results:

• Demonstrated that a single species, *Dreissena*, can exhibit multiple, distinct abundance-impact curves.
• Showed that ecosystem properties significantly shape these curves, making them non-interchangeable.
• Identified potential misleading outcomes from abundance-impact studies relying solely on horizontal designs.

Conclusions:

• The abundance-impact curve is a dynamic property arising from the interplay between an invasive species and its invaded ecosystem.
• Accurate specification of abundance-impact curves requires considering both species and ecosystem factors.
• Shifting focus to species-ecosystem interactions can enhance understanding of non-native species impacts and reduce management uncertainty.