Non-native ants are breaking down biogeographic boundaries and homogenizing community assemblages

Area of Science:

• Ecology
• Biogeography
• Conservation Biology

Background:

• Geographic distance traditionally defines distinct species assemblages and biogeographic realms.
• Human-mediated dispersal of species poses a significant threat to established biogeographic patterns.
• The extent to which human activities alter these patterns remains largely unknown.

Purpose of the Study:

• To investigate the impact of human-mediated dispersal on global biogeographic patterns.
• To determine if non-native species alter existing biogeographic boundaries.
• To assess the prevalence of biotic homogenization across all ant biodiversity.

Main Methods:

• Analysis of distribution data for 309 non-native ant species.
• Examination of changes in ant assemblage similarity across different regions.
• Comparison of current biodiversity patterns with historical biogeographic realms.

Main Results:

• Historical biogeographic patterns have shifted towards a tropical versus non-tropical regionalization.
• Changes in non-native ant distributions fundamentally alter biogeographic boundaries for all ant species (13,774 species).
• 52% of ant assemblages show increased similarity, indicating widespread biotic homogenization, most pronounced on islands and in the tropics.

Conclusions:

• Anthropogenic impacts on biodiversity are overriding long-term evolutionary biogeographic patterns.
• Biotic homogenization driven by human activities disproportionately affects vulnerable ecosystems like islands and tropics.
• Urgent conservation strategies are needed to mitigate the pervasive effects of human-mediated species dispersal.