Fig. 1

Variable responses of species from different orders of CCA to global change stressors from previous literature (a,b) and the current experiment (c,d). a Phylogenetic tree, adapted from V Peña, C Vieira, J Carlos Braga, J Aguirre, A Rösler, G Baele, O De Clerck and L Le Gall [17], showing different species across orders of CCA and their estimated divergence time (x axis). Species names are colour coded to show direction of response to elevated temperature + reduced pH; red – significant negative response; green – significant positive response; blue – no significant effect. Data was obtained from 9 studies (Additional file 1, Table S1). b Graphical representation of response data of species (Additional file 1, Table S1) from phylogenetic tree (a). Response is displayed as mean percent difference of photosynthetic rate or capacity per species. Points are colour coded to show direction of response to elevated temperature + reduced pH; red: significant negative response; green: significant positive response; blue: no significant effect. Asterisks signify results from studies using Pulse-Amplitude-Modulation fluorometry to indicate photosynthesis, whereas all other studies directly measured dissolved O₂ in seawater. c Table of differentially expressed genes detected in pairwise comparisons across four treatments, control (27.2 ºC and 8.0 pH), T (29.5 ºC and 8.0 pH), pH (27.2 ºC and 7.7 pH), and T + pH (29.5 ºC and 7.7 pH), for Sporolithon durum and d Porolithon onkodes