Habitat‐Forming Species: Buffers or Amplifiers for Mutualistic Organisms in Response to Climate Change?

ABSTRACT Aim Habitat‐forming species play a critical role in coral reef ecosystems by creating complex physical structures for marine species. Driven by climate change, these habitat‐forming species are undergoing considerable shifts in their geographical distribution, which might trigger cascading effects via protection mutualisms, leading to alterations in the relationships between species. We examined the role of habitat‐forming species in regulating spatial distributions of their mutualistic protectors' influence. Location Global coastal ocean. Methods We used species distribution models to examine how suitable habitats for organisms that form mutualistic relationships with habitat‐forming species respond to climate change, focusing on two representative macrosymbiotic relationships in coral reefs: Coral–coral crab and sea anemone–clownfish. Results The results revealed that corals are more sensitive to climate change than sea anemones, experiencing greater range contractions under projected future conditions. Consequently, the distribution ranges of both coral‐mutualistic crabs and sea anemone‐mutualistic clownfishes are expected to reduce even further when protection mutualisms are considered. Coral crabs are projected to undergo a more rapid range size loss than clownfishes. Main Conclusion These findings highlight the importance of incorporating interspecific interactions among habitat‐forming species into predictions of potential shifts in the biogeographic distributions of mutualistic protectors under climate change.