Climate-mediated threats to ocean forests: Disentangling the impacts of heat and herbivory in Australia's Great Southern Reef

This thesis disentangled two of the most pervasive and arguably greatest threats to kelp forests in Australia: the impacts of heatwaves and fish herbivory. We show that ecological processes like fish herbivory are shaped by extremes in environmental conditions where this process drives and maintains highly reorganised temperate reefs. At the northernmost limit of the Great Southern Reef we find evidence of hysteresis and an alternate canopy-free stable state. These findings demonstrate the fragility of temperate reefs in the long term, as changing fish communities and the associated herbivory pressure affect kelp forest recovery and resilience.