Kia‘i Moku: Used in reforestation, albizia now poses threat


Near Kualapuu, Molokai, there are Makahiki and hula grounds. Last year, 850 fast-growing invasive trees covered the platforms, where ancient Hawaiians played games as part of the Makahiki festival, the annual celebration marked by several months of peace, thanksgiving and feasting.

These trees originated from the jungles of the Molucca Islands, 5,000 miles away in Indonesia. The islands are part of the Wallaceae “hot spot,” an area of Indonesia with some of the world’s highest levels of biodiversity, including more than 10,000 plant species and 650 different bird species.

Albizia, or Falcataria moluccana, has at least one trait that gives it an advantage over Hawaii’s native plants. Albizia is a nitrogen-fixing tree; bacteria in albizia roots convert nitrogen from the atmosphere into a form available for the tree. These fertilizer factories built into the roots give albizia an extra boost; albizia can reach 30 feet tall in just two years.

Lethal limbs | Hawaii Tribune-Herald

Maui Tree Services

Fast-growing, fragile trees are looming threat

By Colin M. Stewart
Tribune-Herald Staff Writer

It’s only a matter of time, says a group of Hawaiian Beaches residents, before someone is seriously injured, or worse.

"People are going to die soon," agreed University of Hawaii at Hilo associate professor of biology Becky Ostertag.

What has the Puna residents and experts so concerned is the albizia tree.

A relative newcomer to Hawaii, albizia were introduced here in 1917 by botanist Joseph Rock as an ornamental tree and for reforestation purposes.

With its tall white trunk and wide-spreading, umbrella-like canopy capable of shading up to a half acre, the albizia tree makes for a pleasing contrast to the black outcroppings of lava rock and scrubby underbrush so prevalent in the Puna area.

It is one of the fastest growing trees in the world, according to albizia expert Flint Hughes of the U.S. Forest Service.

The tree can grow to 20 feet tall in its first year, 45 feet in its third, and 60 feet by the end of its 10th year.

It is albizia’s ability to grow so quickly, however, that makes it a threat to those under its expansive network of branches, said Hughes.