The Ogasawara Islands are oceanic islands located 1000 km south of Tokyo. Approximately 70% of tree species in the islands are endemic. The soil is thin and of volcanic origin. The precipitation is relatively low, especially in summer, and the islands have exhibited a trend towards increased dryness over the past 100 years. As a result, extremely unique forests called “dry dwarf forests” have developed. I have examined the drought tolerance mechanisms of woody plants in such forests. The most droughttolerant woody plants grow in the island’s extremely thin soils. Ironically, such plants have the highest risk of death because of extreme soil dryness due to prolonged drought. With the predicted future shift in global precipitation patterns, the unique forests of the Ogasawara Islands could suffer irreversible damage. I hope to conserve this rare ecosystem for our next generation.