Résumé
Global environmental change drives diversity loss and shifts in community
structure. A key challenge is to better understand the impacts on
ecosystem function and to connect species and trait diversity of
assemblages with the possible consequences for ecosystem function. Here we
quantify shifts in species composition and trait diversity associated with
ocean acidification (OA) by using field measurements at marine CO2 vent
systems spanning four reef habitats across different depths in a temperate
coastal ecosystem. We find that both species and trait diversity decreased
and that ecosystem properties (understood as the interplay between
species, traits, and ecosystem function) shifted with acidification.
Furthermore, shifts in trait categories such as autotrophs, filter
feeders, herbivores, and habitat-forming species were habitat-specific,
indicating that OA may produce divergent responses across habitats and
depths. Combined, these findings reveal the importance of connecting
species and trait diversity of marine benthic habitats with key ecosystem
properties to anticipate the impacts of global environmental change. Our
results also generate new insights into the predicted general and
habitat-specific ecological consequences of OA.