Predicting the Effects of Climate Change on the Spread of Fire-Promoting Plants in Hawai‘i: Assessing Emerging Threats to Rare Native Plants and Ecosystems

A patch of fire amidst dry grasses
Climate conditions are shifting to those that promote more frequent wildfires, so it is important to understand how invasive vegetation ties into that fire promotion. (Photo: Hawaiʻi DLNR)

2018 was a record-breaking year for wildfires in Hawai‘i with over 30,000 acres burned statewide, including the habitat of the Oʻahu chewstick, a critically endangered flowering plant with less than 50 individuals remaining. The frequency and severity of wildfire in Hawai‘i has been increasing, and this trend is predicted to worsen with climate change. Wildfires are promoted by highly flammable invasive plants, which can spread across the landscape, providing a widespread fuel source to feed large fires that are hard to control. However, different plant species vary in their flammability, so wildfire risk depends not only on climate, but also on which plants are present. A major concern is that new non-native plants are entering Hawai‘i every year, some of which will spread to become invasive. Some of these recently invading plants have fire-promoting traits, making their spread a serious fire hazard.

This project will assemble information on the distribution and fire-promoting traits of non-native plants in Hawai‘i in order to generate a list of upcoming fire-promoting invaders that can be targeted for eradication and management now, before they spread widely in Hawai‘i . The researchers will also use modeling to predict how climate change will affect these fire-promoting invasive plants and fire distributions, specifically in relation to locations of rare and endangered native plant populations as well as cultural resources in Hawai‘i. The main objective is to identify sites or rare native plant species in need of special fire mitigation or management attention.

The results of this project will help reduce harm caused by wildfires in Hawai‘i by identifying fire-promoting invaders that can be eradicated before they spread widely, and by identifying rare native plants that are at high risk of burning in the future due to climate change and may need special conservation attention. In particular, this project will provide information needed by the National Park Service in developing their Fire Management Plan for the new Hono’uli’uli National Monument on O‘ahu, and will inform Hawai‘i’s Island Invasive Species Committees (ISCs) in developing protocols to prioritize new species for island-wide eradication.

Federal project page

Weed Fire Risk Assessment for Hawaiʻi (factsheet and database) (tool)





Curt Daehler
Professor of Botany, UH Mānoa


Lucas Fortini
Research Ecologist, USGS Pacific Islands Ecosystem Research Center
Clay Trauernicht
Associate Fire Specialist, Department of Natural Resources and Environmental Management, UH Mānoa