In this pilot project, we will use areas with geothermal soil heating on Iceland as a natural experiment to investigate genetic responses and adaptation to warmer temperatures in plants. This setup has the benefit of having fewer confounding factors than studies conducted across latitude or altitude gradients, and also enables the study of longer-term, evolutionary responses. We will do this by investigating genetic responses of the perennial outcrossing crucifer plant Arabidopsis lyrata subsp. petraea to geothermal soil heating. We have chosen to study this species, because it grows in a wide range of geothermally heated and non-heated areas on Iceland and because it is genetically accessible due to its sequenced ~207 Mb genome and close relationship to the model plant A. thaliana. In the project we will generate and analyze whole-genome resequencing data from natural populations on Iceland to study genetic responses to soil heating.