As many of us prepare to attend, participate in and enjoy the annual Merrie Monarch Festival, I am reminded of the beauty of the ʻōhiʻa forest and the misty Kanilehua rain which settles atop the lehua blossoms. “Hoʻonuʻa Hilo i ka lehua” (ʻŌlelo Noʻeau – #1105).
ʻŌhiʻa trees, one of the most ecologically important and culturally significant trees in our moʻolelo and the most abundant native tree in our forests, are dying from fungal disease.
Over a million ʻōhiʻa have already died because of two species of the fungus Ceratocystis, also known as Rapid ʻŌhiʻa Death (ROD). The more virulent pathogen is named Ceratocystis lukuohia (lukuʻōhiʻa – destroyer of ʻōhiʻa) and has been found on Hawaiʻi Island and Kauaʻi. The slower-growing pathogen is named Ceratocystis huliohia (huliʻōhiʻa – disruptor of ʻōhiʻa) and has been found on Hawaiʻi Island, Maui, Oʻahu and Kauaʻi. Healthy trees appear to die within a few days to a few weeks and there is no effective treatment to cure trees that exhibit symptoms; therefore, it is critically important that we all practice preventative measures to stop the spread so that future generations can enjoy the ʻōhiʻa forests.
Even in the worst ROD-affected areas of native ʻōhiʻa forests, some ʻōhiʻa trees seem to be resistant to this disease and survive. These trees are being researched as they may one day be the basis for developing disease-resistant ʻōhiʻa trees in the future. Someday, resistant ʻōhiʻa trees may be planted in seed control areas to restore ʻōhiʻa forests that have been blighted by ROD.
In the words of a mele composed by King David Kalākaua for his beloved Queen Kapiʻolani, he writes, “E nihi ka hele” – tread lightly. As we return to travel within and around our island home, we need to be mindful about how we prepare and behave when spending time in our native forests, to tread lightly and do no harm.
- Prior to visiting any of the islands, wash all your gear and clothing in hot soapy water.
- Protect ʻōhiʻa trees from injury. Wounds serve as entry points for the fungus and increase the odds that the tree will become infected.
- Don’t use heavy machinery near ʻōhiʻa which could injure the bark or roots. There is good evidence to support fencing the land and removing invasive animals (such as pigs, sheep, and cattle) as these actions can help to protect ʻōhiʻa trees and native forests.
- Don’t move ʻōhiʻa wood or anything made from ʻōhiʻa unless it is treated.
- Don’t transport ʻōhiʻa interisland.
- Clean gear and tools, including shoes and clothes, before and after entering forests.
- Prepare by bringing and spraying your shoes with 70% rubbing alcohol or a freshly mixed 10% bleach solution.
- Wash your vehicle with a high-pressure hose or washer if you’ve picked up mud from driving.
Mahalo nui to JB Friday, Ph.D., of the University of Hawaiʻi’s College of Tropical Agriculture and Human Resources for his valuable insight on preventing the spread. To learn more visit www.NaHHA.com/olelo-hawaii and download the Maʻemaʻe Toolkit.