'Ohi'a forests suffer a dramatic phenomenon called "dieback", where most of the older trees across large areas die over a short period of time. This can lead to surreal "dead" forests dominated by twisted tree skeletons, like an evil forest out of a fantasy novel. 'Ohi'a trees tend to grow thin and twisty, with dark unhealthy-looking leaves, and the mists and darkness of the windward saddle increase the ominous atmosphere of the scenery. Dieback areas are conspicious on the eastern saddle, where vast tracts of ohia forest mysteriously died during the 1950's-1970's. The pictured forest suffered a dieback episode while the older trees were still relatively small - I'll get a photo of one of the more dramatic forests eventually. Changes in drainage, nutrient deficiencies, toxin buildup, pests, diseases, and combinations of these have been proposed as causes of dieback.