15-year effort brings native plants back to Auwahi forest
Native shrub cover increased from 3 percent to 82 percent over a 15-year period at the Auwahi dryland forest on the leeward flanks of Haleakala, thanks to the efforts of the largely volunteer-based restoration operation named for the forest.
“It’s actually starting to live and breathe now and function as a forest,” said Auwahi Forest Restoration Project founder Art Medeiros last month.
As the native plants returned in the period from 1997 to 2012, non-native grass species, such as kikuyu, decreased from about 75 percent to about 3 percent coverage in the restoration area.
Seven rare dryland forest tree species “have established seedlings and/or saplings within the restoration site, especially notable in that natural reproduction is largely lacking elsewhere,” according to an article published in Pacific Science, a quarterly journal devoted to the biological and physical sciences of the Pacific region,
This means that these plants are reproducing naturally despite difficulty in other areas.
“As a biologist, when all you see is dead and dying trees, it’s really exciting for me,” Medeiros said. “They’re making babies when people thought they would never have babies again.”
The seven species include two types of sandalwood – iliahi and iliahialoe.
Medeiros co-wrote the article, titled “Dry forest restoration and unassisted native tree seedling recruitment at Auwahi, Maui,” with fellow biologists Erica von Allmen and Charles Chimera. It discusses the biological changes in a 10-acre restoration area on Ulupalakua Ranch in the 15-year period, comparing those changes to the lack of dryland forest development in areas of the forest surrounding the restoration site.
“Auwahi is one of the richest forests in terms of tree diversity. It creates many types of hard durable woods that were iron for Hawaiians – kauila, hao,” Medeiros said.
Hao, a type of woody plant, also is the word for iron in the Hawaiian language.
At the onset of the project, Medeiros developed restoration methods based on three factors that have reduced dryland forests to critically endangered levels: the impact of domestic cattle and feral or hoofed mammals; invasive kikuyu grass, which is listed as a noxious weed with prohibited transport by the U.S. Department of Agriculture; and the lack of seedling recruitment and development.
The exclusion of hoofed mammals alone proved to be insufficient for restoration in the 1960s. A fence erected to exclude cattle allowed the kikuyu grass to thrive and out-compete native plants.
Medeiros’ response was to create a multicomponent restoration strategy, involving cattle and feral animal exclusion, weed control and planting of native species.
Restoration was initiated in 1997 with the construction of a 4-foot high fence surrounding the 10-acre area “excluding domestic cattle and feral ungulates,” using U.S. Fish and Wildlife funds, according to the article.
The project used a herbicide to treat kikuyu grass mats, which were not removed but left to decay.
Dodonaea viscosa shrubs then were planted in open areas formerly occupied by kikuyu grass mats. Other nursery plants helped facilitate the growth and development of other plant species.
Medeiros used volunteers to restore the Auwahi forest, located at the 3,800- to 4,100-foot elevation. What began as a way to work within a tight budget evolved into a project that not only helps a Maui forest but helps Maui people.
“After a while it was realizing: who are we restoring? Not just the forest; we were restoring the human community,” Medeiros said.
The Auwahi project makes monthly trips to the restoration site with 20 to 30 volunteers in tow, according to Medeiros. While there, volunteers plant, gather seeds and pull weeds.
“We usually try to have people plant because there’s something rewarding about planting something that will probably outlive you,” Medeiros said.
His biggest worries about the survival of the forest are invasive weeds and fires.
Medeiros did not expect his project to be so successful, but he now feels that it will serve as a model of hope for other restoration groups.
“Sometimes, it was like a patient coming back to life,” he said. “My hope is that it would create a series of similar projects across the Hawaiian archipelago.”
For now, plans are to have the project continue to operate as it has.
“When I started the project, I was pretty much the only person who knew about the area biologically, and since I started the project hundreds, maybe thousands have seen it (the forest), and it’s created aloha for the area, he said. “And when you have aloha, protection for the things you love is very natural. It doesn’t have to be told or forced.”
For more information on the Auwahi Forest Restoration Project or to learn how to volunteer, visit www.auwahi.org.