Ohia trees are dying rapidly, Why?

[Obie]

Don't need a picture to show why there are no Ohia trees at the PGV site.
Try this historic record:

Olaa Sugar Company was located on the Island of Hawaii just nine miles from Hilo on the road to Volcano and the National Park. The plantation fields extended for ten miles along both sides of this highway as well as in the Pahoa and Kapoho areas of the Puna District.

The task of setting up the plantation was enormous. Before 1900, coffee was the chief agricultural crop in the area. Over 6,000 acres of coffee trees were owned by approximately 200 independent coffee planters and 6 incorporated companies. The coffee trees were uprooted to make way for cane. Ohia forests had to be cleared, field rock piled, land plowed by mules of dug up by hand with a pick, quarters for laborers and staff had to be built, the mill constructed, and the first cane planted.

More

http://www2.hawaii.edu/~speccoll/p_puna.html

The trees were long gone when PGV showed up.