WHAT THE EVIDENCE SAYS
A global preprint meta-analysis of 495 reference–impact contrasts found higher beta diversity in impacted assemblages overall, indicating differentiation rather than universal homogenization across taxonomic and functional facets. Yet presence–absence and quantitative data pointed in opposite directions, and removing the heavily represented fish and invertebrate studies reversed the pooled response toward homogenization.
WHY IT MATTERS / OUR READ
The popular shorthand that human disturbance makes ecological communities everywhere more alike is too simple. The inferred direction depends on what organisms are represented, whether abundance matters, and how reference and impacted sites are arranged.
CAVEATS / UNCERTAINTY
This is a version-1 preprint and has not been peer reviewed. The pooled result is highly context-dependent, study designs and taxa are unevenly represented, and the authors explicitly show that reasonable analytical subsets can reverse the headline direction.
SOURCE
EcoEvoRxiv
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