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2019 Rapid ‘Ōhi‘a Death Park Update

ROD Infected Tree
ROD Infected Tree

NPS Photo

First identified in 2014, Rapid ʻŌhiʻa Death (ROD) is a fast-spreading fungal disease that kills ʻōhiʻa trees by blocking water movement. ʻŌhiʻa are the backbone of Hawaiian forests and hold considerable cultural significance through their associated symbolism and history within Hawaiian culture. With its devastating impact to ʻōhiʻa, ROD jeopardizes much more than just a single tree.

The National Park Service recognizes the threat ROD poses to Hawaii Island's native ecosystems and surrounding communities. Through a variety of efforts, biologists at Hawaiʻi Volcanoes National Park (HVNP) are working diligently to prevent ROD from spreading. HVNP is part of an interagency work group that shares information and maps occurrences of ROD in the park and on adjacent lands. Sampling is conducted continually throughout the park to improve understanding of the spread of ROD. To date, nearly 900 trees have been sampled and tested park-wide. Approximately 10 percent of these trees test positive for ROD. Most of these detections occur in the lower elevations of Kahuku, but ROD has also been observed in the native forests in ʻŌlaʻa, Thurston, and Kīpukapuaulu. Efforts to slow the spread of ROD in these areas and surrounding communities are aggressive and ongoing.

ROD is new to science and no cure has been identified yet for infected trees. Scientists have made some strides in understanding the spread of the disease and devising ways to stop it. Although there is no certain cure, a range of treatments may be applied to contain or slow ROD's spread. Once infected trees are identified, HVNP and its partners apply the best available treatment option for the specific tree and environmental conditions. These treatments include monitoring the tree for insect activity that could spread infected sawdust into surrounding areas, possibly felling the infected tree, or cutting the tree into small sections, then covering with a tarp in situ. These techniques help limit the spread of the fungal spores that might infect other trees.

To help prevent people from spreading ROD, informative sanitation stations at trailheads in the park have been designed and deployed. More stations will continue to be deployed in the future. HVNP and its partners are also installing new fencing and carefully monitoring existing fencing to effectively exclude pigs, cattle, and other ungulates that could injure ʻōhiʻa and expose the trees to ROD. We also continue to share information with the public about ROD to increase awareness and educate both visitors and residents how to limit ROD's spread. The National Park Service is doing everything possible to prevent the spread of ROD and continues to pursue the best methods to manage this disease plaguing Hawaii's beloved ʻōhiʻa trees.

HVNP and its partners ask that the public continue to educate themselves on preventative practices, and adopt recommended practices to slow ROD's spread. We also ask that the public practice good sanitation before entering and while inside the park. These practices include not transporting infected wood; avoiding injury to ‘ōhi‘a; sanitizing equipment and vehicles used off-road; and thoroughly cleaning shoes, tools, and clothing used in infected forests. For more information please visit www.nps.gov/havo/learn/nature/rapid-ohia-death.htm and www.rapidohiadeath.org

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Authors: David Benitez and Leila Morrison

Last updated: December 30, 2022