Figure 3.

Change in δ¹³C ratios between day 1 (start of the experiment) and day 7 (end of the experiment) of a species with carbon‐concentrating mechanism (Lomentaria australis; CCM species) and a species without (Craspedocarpus ramentaceus; non‐CCM species), in current (8.0) and future (7.7) CO₂ treatment. Data are displayed as mean ± standard error, n = 5–6 (with n = 5 for the ambient CCM treatment, and n = 6 for all other treatments). * denotes significantly different treatments (Tukey's honestly significant difference tests, α = 0.05)