Variables driving the parent and two first nodes (split points) in the regression trees summed overall response variables.

Figures in the supporting information shows the complete tree for each variable. Turf, HC and Abiotic stands for means percentage cover of turf algae, hard coral, and not live substrate respectively. Average SST (sea surface temperature) and PAR (photosynthetic active radiation) are satellite-derived variables calculated over a period of 5 years.