XVI International Botanical Congess

The alpine phytogeography of Mt. Halla, Cheju Island, Korea has discussed. The presences of large numbers of the arctic-alpine flora on Mt. Halla, Cheju Island, at the mid of the Korea Strait between the Korean Peninsula and Japanese Islands, especially as the southernmost distributional limits of the earth for certain species may primarily be attributed to palaeo-environmental factors, since it can not be wholly explained by reference to present environmental conditions. The arctic-alpine flora on the peak of Mt. Halla, mainly above 1,500m a.s.l. are evidently descended from immigrants from NE Asia via the Korean Peninsula during the epoches of the Ice Age. These plants, which are very intolerant of competition, have been able to persist in alpine belts thanks to their harsh climatic conditions, sterile soil, rugged topography and cryoturbation. The distributional limits of the some species seem to coincide with the maximum summer isotherms.