Here, we present supporting information for the study titled "Acclimation of subarctic vegetation to warming and increased cloudiness". This study by Ndah et al. investigates increased temperature and cloudiness effects on vegetation composition and distribution, and leaf anatomical and biochemical traits of four dominant vascular plant species (Empetrum hermaphroditum, Vaccinium myrtillus, Vaccinium vitis-idaea, and Rubus chamaemorus) in mesocosms collected from tundra and palsa mire ecosystems. The result provide new evidence of subarctic vegetation responses to future conditions of climate warming and increased cloud cover.