Replacement of Metrosideros polymorpha, `Ohi`a, in Hawaiian Dry Forest Succession

Metrosideros polymorpha Gaud. (MYRTACEAE), 'ohi'a, dominates pioneer dry forest communities in Hawai'i, while other tree taxa dominate later seral stages. Tree density is greater in the later seral communities, and the dominant species there exhibit significantly lower mid-day plant water potentials than Metrosideros from nearby pioneer communities. This pattern suggests that the greater water stress experienced by the later seral trees may be due to competition for limited water, and this may restrict Metrosideros from these sites. The replacement of Metrosideros in later seral stages of Hawaiian dry forests contrasts with its maintenance as the dominant canopy component in both early and late seral rain forest communities.