Photo/Illutration“Juhyo” ice monsters are seen in the Zao mountain range in Yamagata Prefecture in January. (Asahi Shimbun file photo)

  • Photo/Illustraion
  • Photo/Illustraion

SENDAI--Forestry experts are coming to the rescue of “juhyo” ice monsters on the Zao mountain range where blight has affected conifer trees that create a magnificent winter landscape when covered with frost.

The trees, known as maries fir, inhabit a 2,000-hectare area on the Miyagi Prefecture side of the mountains, but many have become blighted in parts of the 500-hectare area south of the top of Mount Kattadake.

Blight damage has also spread on the Yamagata Prefecture side.

The Forestry Agency will begin a forest revival project as early as autumn in which wild seedlings will be collected and transplanted to nearby areas on a trial basis. Maries fir seeds will also be sampled.

Frost-covered natural maries fir forests, known as “ice monsters” and measuring 7 to 8 meters tall, have proven to be a popular tourist spot in the Zao ski resort among visitors from outside Japan.

According to the agency’s Tohoku Regional Forest Office, experts started visually checking trees in the Zao mountains in 2017 and discovered that trees are suffering from blight around the ridge connecting Mount Kattadake and Mount Byobudake.

Many small holes apparently made by wood borers were found on the damaged trees, indicating the plants highly likely wilted because their inside structure was destroyed by the bugs.

“Behind the problem could be factors such as global warming hampering the growth of trees and boosting the activity of bugs,” said an official of the regional office.

Under the revival program, bamboo leaves covering young trees will be removed so that experts can examine whether the leaves affect trees’ growth by comparing bamboo-covered ones with leaf-free trees.

The agency also intends to conduct further research to determine the extent of the damage. As part of such efforts, a drone survey of the Zao mountains will continue this fiscal year.

Although the regional office once considered cutting down trees or spraying a pesticide to kill wood borers, the plan has been dropped because the area is designated by the government as a special natural preservation zone, and such measures could negatively affect living creatures in alpine belts.