Freezing vulnerability

Predicted vulnerability to freezing at -15oC are given as a percentage between 0 and 100 for individuals of each of seven Virentes species based on Bioclim 6 data (mean minimum temperature of the coldest month) for each geographic location. The equation for predicting vulnerability to freezing (FV) was based on empirical relationships from Koehler, Center and Cavender Bares 2012 using the electrolyte leakage method of freezing injury to stems at -15oC: FV =100-[81.202 - 1.4075*X], where X is the mean minimum temperature in the coldest month. Any negative values were assumed to indicate zero vulnerability to freezing at -15oC.