Biological invasions are a population-level rather than a species-level phenomenon

Area of Science:

• Ecology
• Invasion Biology
• Conservation Science

Background:

• Biological invasions represent a significant global threat to ecosystem persistence, functioning, and services.
• Invasion science has largely focused on species-level approaches, often overlooking population-level processes like natural selection and local adaptation.

Purpose of the Study:

• To analyze non-native species dynamics at the population level using European freshwater macroinvertebrate data.
• To investigate variability in spreading speed, abundance trends, and impact assessments among different populations.

Main Methods:

• Utilized a database of European freshwater macroinvertebrate time series data.
• Analyzed population-level dynamics, including spreading speed and abundance trends.
• Compared species-level risk screenings with actual population-level data.

Main Results:

• Demonstrated substantial variability in spreading speed and abundance trends within and between macroinvertebrate species across biogeographic regions.
• Found marked differences in invasiveness and ecological impact at the population level.
• Identified discrepancies between species-level risk assessments and real-world population-level data.

Conclusions:

• Species-level assessments present challenges in accurately predicting population-level effects.
• Urges a shift towards population-focused invasive species management frameworks that consider environmental context.
• Advocates for adaptive, region-specific, and population-focused approaches to improve risk assessments and conservation strategies.