Community-level responses to warming are conserved across diverse biological groupings and taxonomic resolutions. Community-level responses to warming are conserved across diverse biological groupings and taxonomic resolutions

Temperature variability is a major driver of ecological pattern and recent changes in average and extreme temperatures have had significant impacts on populations, communities and ecosystems. In the marine realm, very few experiments have manipulated temperature in situ, and current understanding of temperature effects on community dynamics is limited. Here, we developed new technology to facilitate precise temperature control to examine simultaneous warming effects on communities of bacteria, microbial eukaryotes (protists) and metazoans. Despite highly contrasting phylogenies, size spectra and diversity levels, the 3 community types responded similarly to seawater warming treatments of +3 and +5°C, highlighting the critical and overarching importance of temperature in structuring marine communities. Temperature effects were detectable at coarse taxonomic resolutions and many taxa responded positively to warming, leading to increased abundances at the community-level. Novel field-based experimental approaches are needed to improve mechanistic understanding of how ocean warming will alter the structure and functioning of diverse marine communities.