Hawaii is home to a number of unique plants and animals that you can find nowhere else in the world. One of these special plants, is the Ohia Lehua tree and it is a pioneer plant. As a pioneer plant, the Ohia Lehua takes is able to take root in freshly cooled lava fields and shed their leaves throughout the year, which helps create top soil for more native plants to take root. The rest of the forest is provided with nutrient rich soil, and, as plants thrive, so to does our endemic wildlife, which all help make Hawaii such a beautiful and unique place. Not only are they a critical part of the native Hawaiian watershed, but they hold deep significance in native Hawaiian culture. Ohia trees make up almost 80% of our Hawaiian forests and, in recent years, these beloved trees, are facing a crisis.
Discovery and Impact
First discovered on the Big Island of Hawaii in 2014, a fungal pathogen, Ceratocystis (Rapid Ohia Death), is capable of killing Ohia trees that have been growing for hundreds of years, in a matter of weeks, and even as little as a few days. Indicators of Rapid Ohia Death include limbs or entire crowns of trees turning yellow or brown within days or weeks and dark staining of the outer ring of the trunk. The latter, is not visible unless you cut the tree in an infected area. Ongoing research indicates that about 135,000 acres of Ohia forest, on Hawaii island, display symptoms of the disease. In 2018, Rapid Ohia Death disease was discovered on the island of Kauai. Rapid Ohia Death has the potential to affect Ohia forests across the state of Hawaii, as well as much of the watersheds vital to the Hawaiian landscape.
Research shows humans are one of the ways that the disease spreads from tree to tree. This happens by transporting infected wood, contaminated, gear, tools and vehicles. Wild ungulates and beetles are also thought to be responsible for spreading Rapid Ohia Death. The main way that a tree is infected, is through any sort of wound, big or small. This can result from breakage, cutting, high winds, weed whacking, and root trampling, to name a few. Although this may sound bleak there is some good news. There are a few ways that residents and visitors alike, can do their part in helping contain the disease.
What we can do
Five simple things you can do to help diminish the spread of ROD are:
1) Avoid injuring Ohia Lehua
2) Do not transport Ohia inter-island
3) Do not move Ohia wood, especially in areas known to contain ROD
4) Clean your gear/tools- brush off all soil and spray with 70% rubbing alcohol to decontaminate
5) Wash your vehicle including tires and undercarriage especially after off-roading and traveling in areas with ROD
Now you know a little bit more about what’s going on in the Hawaiian ecosystem and together, we can all help reduce the affect of Rapid Ohia Death and ensure the continuity of our Hawaiian rain forests. For more information on ROD check out these websites: