Supplementary material from "Cool-edge populations of the kelp Ecklonia radiata under global ocean change scenarios: strong sensitivity to ocean warming but little effect of ocean acidification" ...

• Main Authors: Britton, Damon, Layton, Cayne, Mundy, Craig N., Brewer, Elizabeth A., Gaitán-Espitia, Juan Diego, Beardall, John, Raven, John A., Hurd, Catriona L.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: The Royal Society 2023
• Subjects: Ecology not elsewhere classified; Plant biology not elsewhere classified; Animal physiology - biophysics; Animal physiology - cell; Animal physiology - systems; Ocean acidification
• Online Access: https://dx.doi.org/10.6084/m9.figshare.c.6991797.v1; https://rs.figshare.com/collections/Supplementary_material_from_Cool-edge_populations_of_the_kelp_i_Ecklonia_radiata_i_under_global_ocean_change_scenarios_strong_sensitivity_to_ocean_warming_but_little_effect_of_ocean_acidification_/6991797/1

Kelp forests are threatened by ocean warming, yet effects of co-occurring drivers such as CO 2 are rarely considered when predicting their performance in the future. In Australia, the kelp Ecklonia radiata forms extensive forests across seawater temperatures of approximately 7–26°C. Cool-edge populations are typically considered more thermally tolerant than their warm-edge counterparts but this ignores the possibility of local adaptation. Moreover, it is unknown whether elevated CO 2 can mitigate negative effects of warming. To identify whether elevated CO 2 could improve thermal performance of a cool-edge population of E. radiata , we constructed thermal performance curves for growth and photosynthesis, under both current and elevated CO 2 (approx. 400 and 1000 µatm). We then modelled annual performance under warming scenarios to highlight thermal susceptibility. Elevated CO 2 had minimal effect on growth but increased photosynthesis around the thermal optimum. Thermal optima were approximately 16°C for ...