In an effort to recognize the significance and precariousness of the state’s most abundant native tree, Gov. David Ige has proclaimed today Ohia Lehua Day in Hawaii.
A tree-planting ceremony of an ohia lehua with yellow blossoms is scheduled for this morning at the Queen Emma Summer Palace with the Lyons Estate and Daughters of Hawaii to honor the proclamation.
The ohia lehua, or Metrosideros polymorpha, plays a vital role in Hawaii’s ecosystem by providing shelter and food for native birds and insects while helping to replenish island aquifers, according to the governor’s proclamation,
“The ohia lehua tree has played a critical role in our quality of life in Hawaii,” said Ige in a statement. “It is not only a cultural icon — the tree anchors our watershed and is the foundation of Hawaii’s fine water system — perhaps the best in the world. Since rapid ohia death poses a serious threat to our water system, nearly $2 million in state funding has been dedicated to the effort to contain the spread of the disease. The state must work together with our federal and private partners to eliminate rapid ohia death once and for all.”
Approximately 135,000 acres of forest on Hawaii island are affected by rapid ohia death, according to J.B. Friday, a forester at the University of Hawaii at Manoa.
The fungal disease, which afflicted trees in Puna as early as 2010, can be found in every district of Hawaii island, with confirmed cases from Kalapana to Hilo, Volcano, Naalehu, Kona and as far north as Kohala.
It is most severe in a tract of about 1,000 acres, according to Friday, with the hardest-hit areas in lower Puna and above the Kona coffee belt. Within days to weeks of being infected, crowns of trees turn yellow and then brown, resulting in death.
So far, the disease is only on Hawaii island and has not been detected on any other isles.
Both large- and small-scale efforts to save the ohia lehua continue statewide.
The Seed Conservation Laboratory at UH Manoa’s Lyon Arboretum continued collecting and banking ohia seeds following an “ohia love” campaign it launched in 2016. The seeds are now being collected from all the isles, and the arboretum is offering free workshops.
At the Lyons Estate in Mountain View on the Big Island, Lacy Matsumoto and her family are banking seeds from about 200,000 ohia lehua trees on 20 acres. It has become a new, personal mission for Matsumoto, who is raising funds through a crowdfunding campaign.
“It means a lot culturally but also scientifically,” said Matsumoto. “Not only do its roots break up and create a fertile soil for other plants; the lehua, the flower with all the bristles, catches the mist. … The slow drip over time adds to our water sources.”
The governor’s proclamation comes on the heels of newly published research by a team of scientists announcing the discovery of two new species of the pathogenic fungi known to cause rapid ohia death. The species were for the first time given Hawaiian names: Ceratocystis huliohia and Ceratocystis lukuohia.
Lisa Keith, a federal Agricultural Research Service scientist in Hilo, was surprised at the discovery of two unrelated species.
“It’s not every day that a new fungal species is discovered, so to find two at the same time, attacking the same plant, is quite remarkable,” she said in a news release.
Based on genetic results, one of the species had DNA most similar to Ceratocystis in Asia, while the other had roots in Latin America. Ceratocystis huliohia causes a canker disease beneath the bark and spreads slowly throughout the tree, killing off water-conducting tissues. Ceratocystis lukuohia, the more aggressive of the two, causes a systemic wilt.
Both are believed to be recent introductions to Hawaii, brought here in their current form or likely to have evolved after interactions with introduced Ceratocystis strains carried in on propagated plant material.
To help prevent the spread of rapid ohia death, park users are encouraged to stay on established trails and to clean their shoes and gear before and after entering forests. Humans and beetles are believed to be vectors for the disease, which enters trees through a wound that can be caused by cutting, pruning or wild goats.
Current state law prohibits the transport of ohia products or plant parts, including flowers, leaves and stems, from Hawaii island without a permit.
The ohia lehua is present on all the main Hawaiian Islands, with buds that range from crimson red to brilliant yellow. It can grow from sea level to altitudes of 8,000 feet or higher and is usually the first plant to grow back after a new lava eruption.
There is still hope,
according to Friday.
Some forest environments are less conducive to the spread of the disease, he said — for instance, the dryer forests in Ocean View and the cooler climate of Volcano. Also, recent research has found individual ohia lehua trees that show some resistance to the disease.
“I would say that the majority of the forest is manageable,” he said. “Most of the forest is still healthy, and we’re trying to manage the trees.”
