Ohia trees are dying rapidly, Why?

[jackson]

While I don't like quoting Wikipedia, this may be of interest. The Ohia tree we know is unique to Hawaii. It has adapted from it's cousins to life here.
As far as the die off, I have spoken with many experts and there is no one consensus on why. Likely a number of factors.

There are about 50 species in the genus Metrosideros in Southeast Asia and the Pacific, including four other, much more localized species in Hawai#699;i - M. macropus (lehua mamo), M. rugosa (lehua papa), M. tremuloides (lehua #699;#257;hihi), and M. waialealae (Wagner et al. 1999). They are easily confused with M. polymorpha, and are best distinguished by their leaves.
Metrosideros kermadecensis, from the Kermadec Islands north of New Zealand, has recently become naturalized on Maui and may become a pest species. Several cultivars of M. excelsa, the P#333;hutukawa tree of New Zealand, have been sometimes planted as ornamentals in Hawai#699;i but are not reported to have naturalized. Metrosideros polymorpha was originally classified as a variety of M. collina, native to Rarotonga, Tahiti, and other islands of Polynesia, but now is generally accepted as a distinct Hawaiian endemic species.