An understanding of ecological and evolutionary responses to climate change is critical to developing scientifically-based ecosystem management in a changing climatic future. For example, given climate change, thermal stress-related mass coral bleaching events present one of the greatest anthropogenic threats to coral reefs. While corals and their symbiotic algae may respond to future increases in temperature extremes through genetic adaptation and shifts in community compositions, the climate may change too rapidly for coral response. To test this potential for response, here we develop a model of coral and symbiont ecological dynamics and symbiont evolutionary dynamics.

Results/Conclusions

Model results without variation in symbiont thermal tolerance predict coral reef collapse within decades under multiple future climate scenarios, consistent with previous threshold-based predictions. However, model results with genetic or community-level variation in symbiont thermal tolerance can predict coral reef persistence into the next century, provided low enough emissions of the greenhouse gas that drive climate change occur. Therefore, the level of greenhouse gas emissions may have a significant effect on the future persistence of coral reefs, and accounting for biodiversity and biological dynamics is vital to estimating the size of this effect as well as understanding how to conserve coral reefs' capacity to respond to climate change.