Forecasting range shifts of a cold-adapted species under climate change: are genomic and ecological diversity within species crucial for future resilience?

Abstract

Cold-adapted taxa are experiencing severe range shifts due to climate change and are expected to suffer a significant reduction of their climatically suitable habitats in the next few decades. However, it has been proposed that taxa with sufficient standing genetic and ecologic diversity will better withstand climate change. These taxa are typically more broadly distributed in geographic and ecological niche space, therefore they are likely to endure higher levels of populations loss than more restricted, less diverse taxa before the effects of those losses impact their overall diversity and resilience. Here, we explore the potential relationship between intraspecific genetic and ecological diversity and future resilience, using the cold-adapted plant Primula farinosa. We employ high-throughput sequencing to assess the genomic diversity of phylogeographic lineages in P. farinosa. Additionally, we use current climatic variables to define niche breadth and niche differentiation across lineages. Finally, we calibrate species distribution models (SDMs) and project the climatic preferences of each lineage on future climate to predict lineage-specific shifts in climatically suitable habitats. Our study predicts relative persistence of future suitable habitats for the most genetically and ecologically diverse lineages of the cold-adapted P. farinosa, but significant reduction of them for two out of its four lineages. While we do not provide specific experiments aimed at identifying the causal links between genetic diversity and resilience to climate change, our results indicate that greater genetic diversity and wider ecological breadth may buffer species responses to rapid climatic changes. This study further highlights the importance of integrating knowledge of intraspecific diversity for predicting species fate in response to climate change.