Given the ecological and biogeochemical importance of rhodolith beds, it is necessary to investigate how future environmental conditions will affect these organisms. We investigated the impacts of increased nutrient concentrations, acidification, and marine heatwaves on the performance of the rhodolith-forming species Lithothamnion crispatum in a short-term experiment, including the recovery of individuals after stressor removal. Furthermore, we developed an ecological niche model to establish which environmental conditions determine its current distribution along the Brazilian coast and to project responses to future climate scenarios. Although L. crispatum suffered a reduction in photosynthetic performance when exposed to stressors, they returned to pre-experiment values following the return of individuals to control conditions. The model showed that the most important variables in explaining the current distribution of L. crispatum on the Brazilian coast were maximum nitrate and temperature. In future ocean conditions, the model predicted a range expansion of habitat suitability for this species of approximately 58.5% under RCP 8.5. Physiological responses to experimental future environmental conditions corroborated model predictions of the expansion of this species’ habitat suitability in the future. This study, therefore, demonstrates the benefits of applying combined approaches to examine potential species responses to climate-change drivers from multiple angles.

鉴于红石床的生态和生物地球化学重要性，有必要调查未来的环境条件将如何影响这些生物。我们在一项短期实验中研究了营养浓度增加、酸化和海洋热浪对形成红花石的物种Lithothamnioncrispatum性能的影响，包括去除压力源后个体的恢复。此外，我们开发了一个生态位模型，以确定哪些环境条件决定了它在巴西海岸的当前分布，并预测对未来气候情景的响应。虽然L.crispatatum当暴露于压力源时，光合性能会下降，但在个体恢复控制条件后，它们恢复到实验前的值。该模型表明，解释L.crispatum的当前分布的最重要变量在巴西海岸最高硝酸盐和温度。在未来的海洋条件下，该模型预测在 RCP 8.5 下，该物种的栖息地适宜性范围将扩大约 58.5%。对未来实验环境条件的生理反应证实了该物种未来栖息地适宜性扩大的模型预测。因此，这项研究证明了应用组合方法从多个角度检查潜在物种对气候变化驱动因素的反应的好处。