Dictionary

mesocosm en · NOUN

Pronunciation

• (US) audio

Etymology

Etymology tree Proto-Indo-European *me Proto-Indo-European *dʰeh₁-? Proto-Indo-European *-dʰe Proto-Indo-European *médʰi Proto-Indo-European *-os Proto-Indo-European *médʰyos Proto-Hellenic *métsos Ancient Greek μέσος (mésos)der. English meso- English -cosm English mesocosm From meso- + -cosm.

Meanings

1. Any system larger than a microcosm but smaller than a macrocosm, especially when used as an outdoor experimental system that examines the natural environment under controlled conditions.
   • My lab studies the connections between population, community and ecosystem ecology in aquatic environments. We are particularly interested in the flow of energy between trophic levels, the impact of consumers on their resources, and the control of species diversity. We use broad geographic comparisons, mesocosm experiments and theory to address these questions. My students have worked in communities of freshwater plankton, marine fishes and intertidal algae and invertebrates. 2026 January 30 (last accessed), Jonathan Shurin, UC San Diego School of Biological Sciences, archived from the original on 30 Jan 2026:
   • Researchers from the University of Queensland were building an elaborate Plexiglas mesocosm that was going to allow them to manipulate CO₂ levels on a patch of reef, even as it allowed the various creatures that depend on the reef to swim in and out. 2014, Elizabeth Kolbert, chapter 7, in The Sixth Extinction: An Unnatural History, Henry Holt and Company:

Forms