Summary
Welcome to the Invasive Informant, sponsored by Kaua’i Invasive Species Committee. KISC works across Kaua’i to prevent, control, or eliminate the most threatening invasive plant and animal species in order to preserve Kauaʻi’s native biodiversity and minimize adverse ecological, agricultural, economical, and cultural impacts. This month, we celebrate ʻŌhiʻa Lehua Day.
This month, on April 20th at the National Tropical Botanical Gardenʻs south shore visitor center and Limahuli Garden, weʻll be celebrating ʻŌhiʻa Lehua Day—and giving away ʻōhiʻa for you to grow in your yard. More information can be found here.
ʻŌhiʻa can grow a hundred feet tall and live hundreds of years.
ʻŌhiʻa provide a home and nourishment to thousands of different plants and animals, including our endangered nā manu nahele, forest birds. ʻŌhiʻa help capture moisture from the air to refill underground aquifers, providing water for us to drink. And ʻōhiʻa forests keep ocean reefs healthy.
Unfortunately, a fungal disease known as “Rapid ʻŌhiʻa Death” is killing Hawaiiʻs most abundant native tree in the forest. ʻŌhi‘a are infected through open wounds, possibly due to peeling bark, torn roots, or broken branches.
Microscopic fungal pathogens enter the wound and the fungus grows inside the tree, preventing the flow of water. The first external symptom is the sudden browning of the leaf canopy. There is no known cure, and after a few months, the tree dies.
Since the first detection of Rapid ʻŌhiʻa Death in May 2018, approximately 400 trees have tested positive for this fungal disease. While the initial detections were numerous, the recent rate has, thankfully, slowed on Kaua’i.
There are two key ways to continue protecting our native ʻōhiʻa forests:
One is to prevent wounding created by non-native wild animals in the forest by reducing their numbers.
Two, because the fungus moves around the island in mud, we can help stop the spread by brushing mud off footwear and gear before and after entering the forest. Then, spray with isopropyl rubbing alcohol.
But we can also spray down vehicles to remove mud and leave ʻōhiʻa wood, parts, and soil in place.
As well, report any ʻōhiʻa whose leaf canopies have suddenly turned brown to saveohia@hawaii.edu.
