Forest dynamics in Hawaii.

The land surfaces of the Hawaiian islands represent an age sequence from very recent on the island of Hawaii to over 5 million years old on the island of Kauai. Development of indigenous forest on the new basaltic lava flows of Hawaii begins with Metrosideros polymorpha forming mono-dominant canopy stands within 400 years in lowland rain forest environments. In seasonal environments, M. polymorpha is displaced during succession by species such as Acacia koa and Sophora chrysophylla. In the montane rain forest, M. polymorpha has persisted as the dominant canopy species over millions of years. The mechanism of longterm persistence in the latter biome is explained as resulting from two processes: periodic canopy breakdown or stand-level dieback and the appearance or evolution of successional varieties in M. polymorpha.