Kohala moss makes news

By ERIN MILLER

Stephens Media

Roughly 50,000 years ago, a single moss spore found its way to the Kohala Mountains.

That spore, from Sphagnum palustre, cloned itself, spreading across the region, but never leaving Kohala, plant ecologist Eric Karlin said, until people began transporting it to other parts of the Big Island in the 1900s, and later to Oahu.

Karlin, a professor at Ramapo College in New Jersey, co-wrote a new study on the moss, which he has been studying since the 1990s. That study was published in a recent issue of the journal “New Phytologist.” The latest work took on Karlin’s hypothesis that the plant was the descendent of just one founder.

The confirmation came as a surprise, he said. Another discovery during the genetic analysis was also unexpected.

“It had a high genetic diversity,” Karlin said. “Most island populations are known for having low diversity of genes.”

That was a clue that the moss had been in Hawaii for a very long time. Genetic diversity is usually a sign of a population reproducing sexually — for moss, that’s via the production of spores, which can travel from one plant to another via wind, for example, then germinate the plant on which the spores land. Sphagnum palustre’s genetic diversity came from genetic mutations over the course of thousands of years, Karlin said.

“Mutations happen whether you have sex or not,” he added.

Fossils of the moss, found in peat moss, have been dated to show the moss was present on the Big Island 23,900 years ago, he said. Using mutation and growth rates, scientists then reached the estimate that the moss first arrived 50,000 years ago. That would make it one of the oldest multicellular organisms growing on Earth, Karlin said.

The moss is still being studied, he added. Now scientists are trying to determine from where the original spore came. Karlin said it’s likely its origin was somewhere in southern Asia.

Also of interest, he said, is how hardy the plant has proven to be. Kohala has undergone significant environmental changes — including a glacial period — in the last 50,000 years, and the moss survived them all, he said.

“It’s a testimony to how (strong) the plant is,” Karlin said. “It can really hold on.”

While he and other scientists are studying the moss, conservationists on Oahu are trying to eradicate it from the Mount Kaala Natural Area Reserve, where it was introduced several decades ago and is now growing out of control, Karlin said.

People moved the moss around on the Big Island in the last century, but its growth hasn’t rocketed out of control here to the extent it has on Oahu, he said.

“The plant is native, yet when it’s moved around, it acts as invasive,” he said. “That’s the way it is.”

Oahu’s only high-elevation bog is perched atop the Waianae Mountains, featuring a habitat that is home to many rare and endangered species, all of which are only found in Hawaii and some only in the bogs. At 4,025 feet, the bog is located on the island’s highest peak — Mount Kaala.

The Army and the state Department of Land and Natural Resources, or DLNR, share ownership of this bog. DLNR and the Oahu Army Natural Resource Program, or OANRP, Environmental Division take care of the area.

Mount Kaala is a DLNR Natural Area Reserve, set aside to preserve and protect examples of native Hawaiian ecosystems. OANRP actively manages its half of the bog, controlling threats to the native ecosystem, such as invasive plant and animal species.

Bog environments are special because their acidic soils cause the plants that inhabit them to be stunted in their growth form. These environments are very fragile, and scientists have estimated that it takes hundreds of years for the bog to recover from a single footprint.

With this in mind, DLNR crews and volunteers installed a boardwalk over the fragile habitat 20 years ago, allowing people to enjoy the beauty of the place without harming it.

Email Erin Miller at emiller@westhawaiitoday.com.