Fig. 1From: Natural variation in tolerance to sub-zero temperatures among populations of Arabidopsis lyrata ssp. petraeaa: The number of days where the minimum temperature dropped below zero degrees Celsius for each site. b: The number of days with snow cover defined as the number of days with a variation in daily (24 h) temperature of less than 2 degrees Celsius and with temperatures constantly below 1 degree Celsius. Temperature recordings were taken every 120 min over a period of two years (August 2005 – August 2007)Back to article page