SANTA RITA, Guam — The University of Guam Center for Island Sustainability and Sea Grant, alongside the Guam Preservation Trust and the U.S. Fish and Wildlife Service, hosted an outplanting event at the Atantåno Heritage Preserve in Santa Rita, returning seedlings of the critically endangered Serianthes nelsonii — known locally as håyun lågu on Guam and tronkon guåfi on Rota — to their natural habitat.
The tree is endemic to Guam and Rota and once grew throughout southern Guam, but is now critically rare due in part to heavy damage from insect pests that attack the trees at vulnerable stages of growth.
Associate Director for UOG CIS and Sea Grant’s Natural Resources division, Else Demeulenaere, Ph.D., said her team in the Island Conservation Lab worked with Rota Forestry to acquire seeds from Rota and grow them into seedlings for the planting. “Our program manager Vince Fabian and I acquired tronkon guåfi seeds from the island of Rota with the help of Rota Forestry, who were instrumental in our team being able to bring these seedlings to Atantåno,” Demeulenaere said.
She noted that while the Serianthes nelsonii found on Guam and Rota are similar, they carry unique genotypes that distinguish the populations on each island.
To give the newly planted trees a better chance of survival, the team placed pest cages around each one. Program manager Vince Fabian said interns play a key role in monitoring the trees regularly and contributing to the species’ long-term recovery.
Demeulenaere said partnerships with organizations like Rota Forestry, the Guam Preservation Trust and the broader community are essential to the project’s success. “Public access and regular hikes at Atantåno help connect people with the island’s natural resources and strengthen stewardship,” she said.
Guam Senator Sabina Perez joined the planting, saying the occasion carried personal significance. Her mother grew up in the Tarague area and often spoke of the tree, and planting one herself reconnected her to that history. “This is really our plantcestor,” Perez said. “When we talk about håyun lågu, håyun means wood and lagu means north, but it can also carry the meaning of something that comes from afar. When we think about it in this way, it becomes a symbol of our origins.”
The outplanting follows earlier introductions of Cycas micronesica, or fadang, at Atantåno, and the UOG CIS and Sea Grant Natural Resources division said it will continue adding endemic plant species to the preserve throughout the year. More information is available at uog.edu/seagrant or on Instagram at @uogcis and @uogcis.islandconservationlab.
