As climate change intensifies, what will happen to kelp forest biodiversity? This research forecasts global changes in species richness and community composition of 105 kelp forest species under contrasting Shared Socioeconomic Pathway (SSP) scenarios of climate change (decade 2090–2100): one aligned with the Paris Agreement and another of substantially higher emissions. Machine-learning models are used to predict changes across the globe. A poleward and depth shift in species distributions is forecasted, resulting in ~15% less area in the extent of the global biome, coupled with marked regional biodiversity changes. Community composition changes are mostly projected in the Arctic, the Northern Pacific and Atlantic, and Australasia, due to poleward range expansions and low latitude losses. By surpassing the Paris Agreement expectations, species reshuffling may simplify and impair ecosystem services in numerous temperate regions of Australasia, Southern Africa, Southern America and the Northern Atlantic, and in the tropical Pacific, where complete species losses were projected without replacement. These estimates can inform conservation, management, and restoration practices considering future climate change.
This research on kelp forest diversity aligns with Diversity and Distributions' focus on spatial ecology and biogeography. By forecasting the impact of climate change on kelp forest species richness and community composition, the paper contributes to the journal's coverage of species distributions and environmental change, offering important insights for conservation and management strategies.