Freezing Resistance of Alpine Plants

During the growing season alpine plants on Mt. Kurodake (1,984 m) in the Taisetsu mountain range in Hokkaido, Japan, survived freezing to only —5° to —7°C. Even after exposure to 0° and —3°C for 2 weeks, the resistance to freezing of these plants increased only slightly. During the winter, however, most alpine plants studied survived freezing at temperatures below —30°. Salix pauciflora, Diapensia lapponica, mosses, an lichens resisted freezing down to —70°C. They also retained viability after immersion in liquid nitrogen following prefreezing at —30°C. Furthermore, there did not appear to be an essential difference in the hardening effect between willows growing in high mountains and in low altitudes in Hookaido. Alpine plants may be characterized by their dwarf form, short growth period, and high freezing resistance of subterranean stems, crowns, and roots.