Landscape genomics of Eriophorum vaginatum

We address a topic of broad interest for evolution and ecology by examining population level and landscape genomics of a foundation species along an Arctic latitudinal gradient. Using genome-wide SNP data, population structure and environmentally-associated genomic variation were found for populations of Eriophorum vaginatum across a region of the Alaskan Arctic that was part of the Beringian refugium during the Last Glacial Maximum. Our study is notable in that we found evidence of isolation to Beringian subrefugia and treeline functioning as a gene flow barrier, both not previously found for Arctic plants. Dense forest cover was also identified as a major obstacle for gene flow using environmental niche modeling. In addition, forty-five candidate SNPs were found with genotype-environment association analyses and many were associated with genes related to abiotic stress. Our results support ecotypic adaptation across an Arctic latitudinal cline that has been proposed through long-term reciprocal transplant studies of plants in the same region. The consequence of genetic structure and adaptive variations were considered in the context of population connectivity and landscape resistance.