A touch of frost? Cold hardiness of plants in the southern hemisphere

Abstract This review contrasts the frost resistance of plants from the Southern Hemisphere with that of the Northern Hemisphere and is principally concerned with plants from New Zealand, Australia, and South America. It gives a brief overview of methods for determining frost resistance in the field and in controlled environments with intact or excised plant parts. It considers various methods of determining frost resistance and the expression of critical temperatures causing damage, and discusses the problems of using excised plant parts and freezing of tissues. This review, however, is not principally concerned with physiological aspects of frost resistance, but more with biogeographic aspects of the environment and quantification of the relationships between frost resistance and temperature related factors such as altitude and latitude. It gives examples of differences in frost resistance between the two hemispheres and attributes these to the contrast between the climates of largely continental land masses in the Northern Hemisphere and the oceanic environment of the Southern Hemisphere. Furthermore, it also shows similarities between the frost resistance of plants from the Southern Hemisphere during the growing season and the maximum frost resistance of tropical alpine species and further similarities between species on oceanic islands in both hemispheres. Comprehensive lists of species’ frost resistance are included in tables and appendices.