Saving Hawaii's Endangered Trees

are home to around 1,380 native plant species, 90% of which are endemic, meaning they only grow in Hawaii. Many of these plants grow as large shrubs and trees and many are endangered.

Trees are also threatened by diseases like ROD, a fungal pathogen that targets ohia Metrosideros polymorpha, one of Hawaii’s most ecologically and culturally important trees. Since it was first detected on Hawaii Island in 2013, ROD has kill over one million trees and spread to Maui, Oahu, and Kauai.

Hawaii’s trees have allies. Scientists, horticulturists, and conservation practitioners at organizations like the National Tropical Botanical Garden (NTBG) are working with their partners in the Hawaii Plant Conservation Network to protect threatened and endangered species. Under the Hawaii Strategy for Plant Conservation, trees are being saved from extinction.

Many of Hawaii’s endangered trees grow only in remote and difficult to reach areas. NTBG is now mapping the location of these rare trees using drones, GIS, and other new technology. Rare plant populations, previously unknown, are being discovered and rediscovered in places that were once impossible to  reach. 

Conducting plant surveys for the International Union for Conservation of Nature (IUCN)’s Red List of Threatened Species provides valuable information for scientists, educators, and policy makers.

In 2020, NTBG completed conservation assessments of Kauai’s 256 single-island endemic plants. Other projects such as E Mau Ana Ka Ohia (Perpetuating Ohia) and Securing the Survival of the Endangered Endemic Trees of Kauai, Hawaii help save Hawaii’s native trees and plants.

Using exclosure fencing protects sensitive native habitat, safeguarding endangered trees and other vulnerable plants by keeping out destructive animals and allowing scientists to monitor and restore species which might otherwise go extinct.

Scientists in Hawaii are racing to save endangered trees even as they discover undescribed species and rare plants once thought to have gone extinct. In recent years, NTBG botanists and collaborators have collected and named at least 34 plant species endemic to Hawaii. They have also rediscovered endangered species including Hibiscadelphus woodii, Cyanea kuhihewa, and Lysimachia venosa, all endemic to Kauai.

for food, timber, medicine and more. As the “lungs of our planet,” the world’s nearly 60,000 tree species provide clean air, absorb moisture, anchor soil, and help cool the planet. Animals, insects, and other plants also rely on trees for habitat, nutrients, and protection.

Hawaii is home to some of the world’s most unique trees and biodiverse forests on earth. If we want to preserve these species for future generations, each of us has the opportunity and responsibility to protect these endangered trees, to enrich our world today and tomorrow.