Haleakala staff working to conserve rare plant

Outplanting, invasive species control part of efforts to bring back native mint species

National Park staff prepare rare mint species (Phyllostegia haliakalae) saplings for outplanting in Kipahulu. These plants are endemic to Maui Nui, but today is only found in the Valley Isle. NATIONAL PARK SERVICE PHOTO

Fighting to protect Maui Nui’s biodiversity and promote resiliency, Haleakala National Park staff have been conducting outplanting trips of a rare and endangered plant in the mint family on the lower shelf of the Kipahulu Valley Biological Preserve.

“Rare plants such as Phyllostegia haliakalae are part of a complex system that we genuinely don’t know everything about,” said Woody Mallinson, natural resource program manager at Haleakala National Park. “The biodiversity of Kipahulu Valley is truly special and is something we are charged with protecting. One goal here is to retain these areas as diverse and ecologically intact as possible to provide for better resiliency in a changing climate.”

With the help of some interns, National Park Service staff in March outplanted 183 Phyllostegia haliakalae, also known as “mintless mint” that is currently a Plant Extinction Prevention Program species; it is so rare that there are fewer than 50 individuals left in the wild, said Haleakala National Park spokeswoman Jin Prugsawan Harlow.

After the 183 plants were grown at the Haleakala National Park Summit Nursery, they were mixed in with over 200 others planted over the past two years by park staff. The next outplanting — which involves taking a plant from a nursery, greenhouse or other location to an outside area — is scheduled for the end of May.

To ensure that these plants survive and flourish, they need to grow in numbers.

A Phyllostegia haliakalae flowers in the Haleakala National Park Summit Nursery, a protected garden where the rare and endangered plant grows before getting outplanted in Kipahulu Valley Biological Preserve. NATIONAL PARK SERVICE PHOTO

“Even with the continued effort from the park and park partner conservation organizations, many rare plants have a difficult time regenerating in the wild, due to invasive species pressure, loss of native plant pollinators and continued climate change, among other things,” Mallinson said. “Rare plant populations need to be increased and expanded across their ecological range to increase capacity to respond to habitat shifts/reductions and increased stochastic events, like fire or floods, predicted by current climate change scenarios.”

The plant is endemic to Maui Nui, but today is only found in the Valley Isle. Fortunately, these efforts to revive native species seem to be paying off as conservation and restoration work is being carried out.

Over the years, staff have been pairing the outplantings with weeklong work trips in the thick wilderness to control and manage threats, including feral pigs and invasive plant species, such as Himalayan ginger, strawberry guava and the perennial shrub (Clidemia hirta).

Fences have been some of the best lines of defense against keeping out feral ungulates. The Vegetation Management team also outplants between 1,000 to 2,000 threatened and endangered species a year.

“It’s tough but rewarding work,” Mallinson said.

One of the ways that success is measured and generally accomplished is when the plants are flowering and fruiting naturally in the wild, he added.

“The success rate of this plant is dependent on many factors, and protecting the area from invasive species, plant and animal, is foundational,” he said.

Still, the team continues to control invasive species in the area to create better conditions for the mint plants and other native species to survive and thrive.

“The plants are in a protected area in Kipahulu Valley where they will be monitored next year for survival, vigor, phenology and other factors,” he noted. “Right now, it is too soon to check on their success as they need a couple of years before we know they are successful.”

* Dakota Grossman can be reached at dgrossman@mauinews.com.


Today's breaking news and more in your inbox

I'm interested in (please check all that apply)
Are you a paying subscriber to the newspaper?


Starting at $4.62/week.

Subscribe Today