Invasive plants in the understory of Hawai‘i’s forests jeopardize native biodiversity and limit the abundance of culturally significant native plants. Cynthia Nazario-Leary, a doctoral candidate studying with agroforestry professor Travis Idol, is investigating how forest restoration efforts can support Native Hawaiian cultural practices by providing new sources of native plants that can be harvested on a sustainable basis.
At UH Manoa’s Lyon Arboretum in 2005 and 2006, Nazario-Leary planted research plots with three native species chosen for their ecological functions and traditional uses. Mamaki (Pipturus albidus), a small tree or shrub whose leaves are used to make tea, may eventually attain a height comparable to the invasive shrub that currently dominates the site, shoebutton ardesia (Ardesia elliptica). Palapalai (Microlepia strigosa), a fern used in lei, provides ground cover that can shade out ardesia seedlings. Maile (Alyxia oliviformis), a slowgrowing vine or shrub from which fragrant lei are made, is an economically valuable and limited resource.
Nazario-Leary compared native plants grown in plots from which the ardesia had been cleared with native plants transplanted into intact, non-native forest. The native plants grew best at the cleared sites, where they effectively suppressed reinvasion by ardesia. Both the palapalai and the maile have established well. The mamaki proved susceptible to mite damage and drought during establishment, but the surviving plants have flowered and fruited. Arboretum staff are now outplanting palapalai widely to restore other areas and suppress invasive understory species.
The project’s first native plant harvest was held on July 17, 2008 in collaboration with the Na Pua No‘eau Summer Institute program, through which Native Hawaiian high-school students explore the natural and environmental sciences within a framework of Hawaiian values, culture, and language. Students gathered palapalai fronds, collected data to assess frond traits and characterize sustainable yields, and made lei for hula. Nazario-Leary’s research illustrates how cultural practitioners and land managers can create educational opportunities while increasing the availability of culturally important native plant resources.
