Shifts in species distributions are among the observed consequences of climate change, forcing species to follow suitable environmental conditions. Using species distribution models (SDMs), we aimed at predicting trends in habitat shifts of two seaweed species of commercial interest in the Subantarctic Patagonian region in response to ongoing environmental changes across temperate South America and worldwide. We gathered occurrence data from direct, on-site visual, and taxonomic identification (2009–2018) from global databases of species occurrence and from the scientific literature. We built the SDMs selecting putative predictors of biological relevance to Lessonia flavicans and Gigartina skottsbergii. We calibrated the SDMs using MaxEnt and GLMs for model evaluation, splitting our occurrence datasets into two parts: for model training and for model testing. The models were projected to future climate change scenarios (Representative Concentration Pathway: RCP 2.6 and RCP 8.5) to examine trends in shifting habitat suitability for each species. Maximum sea surface temperature was the main predictor variable, followed by minimum nitrate concentration, explaining both species’ distributional shift across Subantarctic shorelines by the year 2050. Projection of the SDM for each species under altered environmental conditions to 30–40 years into the future resulted in a south poleward shift with a reduction in habitat range for both species. Such responses would threaten their persistence, local marine species richness, biodiversity, ecological function, and thereby, the commercial and ecosystem services provided by L. flavicans and G. skottsbergii in Subantarctic South America.

物种分布的变化属于观测到的气候变化后果，迫使物种遵循适当的环境条件。我们使用物种分布模型（SDM），旨在预测南极巴塔哥尼亚地区两个商业上感兴趣的海藻物种的栖息地迁移趋势，以响应南美温带地区和全球范围内持续的环境变化。我们从全球物种发生数据库和科学文献中直接，现场目测和分类识别（2009-2018）收集了发生数据。我们建立了SDM，以选择与Lessonia flavicans和Gigartina skottsbergii具有生物学相关性的推定预测因子。我们使用MaxEnt和GLM校准了SDM，以进行模型评估，将事件数据集分为两部分：用于模型训练和用于模型测试。这些模型被预测用于未来的气候变化场景（代表性浓度途径：RCP 2.6和RCP 8.5），以检验每种物种的栖息地适应性变化的趋势。最大的海表温度是主要的预测变量，其次是最低的硝酸盐浓度，这解释了到2050年这两种物种在亚南极海岸线上的分布变化。对每种物种的SDM预测，其环境条件将在未来30至40年内变化在南极移动中，这两个物种的栖息地范围都减小了。这种反应将威胁其持久性，当地海洋物种的丰富性，生物多样性，亚南极南美地区的L. flavicans和G. skottsbergii。