UH Hilo to Study Impacts of Rapid ‘Ōhi‘a Death on Animals

The University of Hawaiʻi at Hilo was recently awarded a grant of $197,056 by the National Science Foundation Grants for Rapid Response Research (RAPID) to study the effect of Rapid ‘Ōhi‘a Death (ROD) on animal communities in Hawaiʻi.

Dr. Kristina Paxton. Courtesy photo.

The project, entitled “RAPID: Cascading effects of rapid and widespread mortality of a foundation tree species on animal communities in Hawai‘i,” is under the direction of Drs. Kristina Paxton, adjunct assistant professor of Tropical Conservation Biology and Environmental Science, and Patrick Hart, professor of biology, both members of the Listening Observatory for Hawaiian Ecosystems (LOHE) Bioacoustics Lab.

“This project will use advances in recording technology to continuously record over an extended period of time the entire sound-producing animal community within ‘Ōhi‘a forests across Hawaiʻi Island,” Paxton said. “By using soundscape analysis tools developed within the growing field of soundscape ecology, we will be able to rapidly assess changes in the biodiversity of audible birds, insects, and amphibian species associated with the mortality of ‘Ōhi‘a across the landscape.”

The research will also evaluate whether the diversity and composition of understory plant species moderates how reliant animal communities respond to the loss of a dominant forest tree species.

“The use of soundscape indices to model biodiversity following the loss of a foundation species represents a novel and relatively rapid method for assessing ecological change, and would be applicable in a range of ecosystems outside of Hawaiʻi,” Paxton noted.

ROD is a fungal pathogen causing rapid and widespread mortality of ‘Ōhi‘a (Metrosideros polymorpha), a foundation tree species in Hawaiian forests. ROD poses a serious threat to Hawaiʻi’s remaining native forests and the plants and animals that depend on ‘Ōhi‘a. ROD research has been concentrated on understanding the pathology of the disease, how ROD is spread, and the impacts of ROD on ‘Ōhi‘a trees.

“Despite these studies, however, there has not been an examination of how ROD is affecting animal communities reliant on ‘Ōhi‘a forests, which is an important nesting substrate and food resource for both insectivorous and nectarivorous Hawaiian forest birds, 57% of which are threatened or endangered,” Paxton explained. “Given the foundational role of ‘Ōhi‘a in Hawaiian forests as the dominant tree in the canopy, widespread or total loss of `Ōhi`a would likely be catastrophic for endemic Hawaiian forest birds.”

The grant award ends June 30, 2019.