Identifying climate refugia through analysis of functional diversity

Abstract Understanding how climate change will influence ecosystems is essential for effective climate adaptation and mitigation. Current approaches in ocean management aim to protect climate refugia, defined as areas where species will persistent over time, or areas where climatic conditions are projected to be more stable. However, these approaches overlook complex shifts in functional diversity of community assemblages resulting from climate-induced species turnover. Here, we approach climate refugia for marine megafauna in the Northeast Pacific ocean from the lens of functional diversity in comparison with species diversity. We find that species turnover explains species and functional diversity change by the year 2100 in the extreme climatic scenario better than in the moderate and intermediate scenarios. Functional diversity is more stable at temperate and tropical latitudes than at poleward latitudes. Our results show that fewer, less abundant species influence functional diversity change across ecoregions. These results highlight opportunities to target conservation on certain species in areas where they support functional diversity. Our approach can assist managers to identify and protect areas that might lose species but not functional diversity. This will help maintaining ecosystem resilience, their capacity to buffer multiple disturbances and to provide benefits to humans across future climate change scenarios.