AMAMI, Kagoshima Prefecture--This southern Japan city is torn between its responsibility to protect a UNESCO World Natural Heritage site and residents’ desire to keep non-native trees.

After listening to various opinions, the municipality on Amami-Oshima island will consider chopping down the old, invasive trees or preserving them.

SYMBOL OF THE CITY

Amami’s dilemma concerns aged trees known as bishopwood, or “akagi,” on school grounds or along a city-managed road.

The trees at the schools have long been cherished as symbolic, while bishopwood trees on a municipal street are believed to have been planted about 130 years ago to strengthen shore protection during river-improvement work, according to local government accounts.

The city designated four bishopwood trees at three elementary and junior high schools for preservation in 1978, a status given to trees beloved among residents.

The 31 bishopwood trees along the municipality’s road were collectively recognized as trees needing special conservation in 1979.

The branches and roots of such trees cannot be cut without permission from the city's mayor.

INVASIVE SPECIES

A problem is that the tree variant, which can be broadly found in Southeast Asia and elsewhere, quickly grows and proliferates.

The species is included in the Ecological Society of Japan’s 2002 list of the 100 worst invasive alien variants in Japan, given the possibility of bishopwood trees negatively impacting indigenous plant vegetation.

Amami-Oshima was named a World Natural Heritage site in 2021 for its unique, diverse ecosystem. The inscription has led to growing concerns about the impact of bishopwood trees and other non-endemic species on the highly esteemed ecosystem.

Mamoru Tsuneda, 69, a nature photographer in Amami who also serves as a guide, said he believes bishopwood trees should be felled as soon as possible, though he acknowledged that discussions needed to be held with locals on the matter.

Tsuneda based his argument on the fact that bishopwood trees are increasingly being spotted on nearby mountains.

“Wild birds widely distribute their seeds, and young trees are being discovered along streets or in well-lit areas in mountains,” he said. “Countermeasures must be taken before it’s too late.”

WITNESSES TO HISTORY

Locals and school staff members have mixed feelings over the issue, since they have spent many years enjoying the bishopwood trees.

Two 10-meter-tall bishopwood trees stand in the yard and by the front gate of Ashikebu Elementary and Junior High School. A signboard installed by students’ guardians tells about the trees’ “hopes of continuing to live for a long time to watch over good children from here on out.”

“Children run around the trees during our school’s athletic meets,” said Shiro Kojima, the school’s principal. “Graduates and residents love the trees, too, making them a symbol of not only the school, but the local community.”

Some citizens have objected in the same vein, saying they feel it is reckless to cut down the trees simply because they are an alien species.

Masaaki Iwata, 68, a resident of Amami who is an expert on the municipality’s history, insists bishopwood trees can play an important part for people to determine how the current townscape has been formed there.

“They constitute the traces of river-improvement work, providing an opportunity to contemplate the town’s history,” said Iwata.

On Jan. 31, the municipality’s committee on environmental preservation recommended to Amami Mayor Sohei Yasuda that the designated bishopwood trees and woods be excluded from the conservation list as they are a non-native species.

However, the panel, chaired by Satoshi Suyama, a geography professor at Komazawa University in Tokyo, also argued the city should pay careful attention to various views of citizens and continue debate to determine whether to eliminate them.

Amami solicited comments from the public through Feb. 21.

“I see an increasingly critical eye is directed at alien species, but caring for trees citizens love represents another significant value,” said the mayor. “We will be offering thorough explanations over what action, if any, to take from now.”

Amami will decide how to deal with the trees after taking into account the findings of the public comments collection drive.

DISASTROUS ELSEWHERE

Included on the World Natural Heritage list in 2011, the Ogasawara island chain south of Tokyo saw bishopwood trees that had been introduced for use as firewood and charcoal invade wider areas of their forests.

The Forestry Agency started work in fiscal 2008 to remove them.

Bishopwood trees have spread on the Hahajima islet of the island chain, according to the agency’s Ogasawara forest ecosystem preservation center.

As indigenous land snails and other creatures live beneath the bishopwood trees, cutting them down all at once may threaten the life of native variants, however.

For that reason, bishopwood trees are reportedly being destroyed solely in less-affected zones. A chemical agent is injected into their trunks in areas requiring special care so the trees will gradually wither.

“Once they spread out in forests, it is difficult to control them,” said Shinichi Oyama, the center’s head. “Countermeasures should be put in place as quickly as we can.”

(This article was written by Kazuaki Kanda, a stringer for The Asahi Shimbun based in Amami-Oshima island, and Staff Writer Kenta Nozaki.)