Rate of Temperature Increase and Genetic Diversity Drives Marine Metapopulation Persistence under Climate Change

AbstractMetapopulations span environmental gradients and experience variable rates of environmental change, with populations differing in their tolerance and evolutionary capacity. Our study aimed to quantify the extent to which interactions between population-specific traits and spatial environmental heterogeneity affect metapopulation persistence under climate change. Using an eco-evolutionary model, we simulated 25 population types with varying thermal tolerance breadths and genetic variance, impacting the strength of selection and rate of evolutionary response, respectively. We applied this framework to marine ecosystems, which face significant threats from climate change, with many habitat-forming organisms such as coral, oysters, and kelp existing as metapopulations connected through propagule dispersal via ocean currents. We tracked the response of different populations under sea surface temperature spatial ranges and projected warming rates to 2100 that are specific to 49 large marine ecosystems. We found that the rate of warming was the strongest predictor of the number of persistent metapopulations, where faster warming reduced the population types that a region could support. We also found that cooler subpopulations outperformed warmer ones, likely due to immigration from warmer sites, suggesting that cooler sites may act as climate refugia.