Pine Blight Leaves Mt. Geumsam Barren, Threatens Baekdu Range

When Dong-A Ilbo visited Geumsam-ri in Gangneung yesterday with forestry researcher Kim Jong-won (58) and Jang Seok-jun (33), who is in charge of forests management at the Gangwon Provincial Forestry Research Institute, two hectares of forests in the region had been devastated. Pine trees in this region were confirmed to be infested with tree-killing nematodes on October 19.

Devastated Forests-

Because a total of 1,386 pines that are 70 to 80 years old have been cut down to prevent the spread of the blight, the mountain, which rises 100 meters above sea level, has become almost bald. Its hills are covered with lumber cut into one-meter pieces and infected pine branches.

Looking at the piles of blighted trees, Kim Jong-won said, “Considering that these trees are completely withered, it appears that pinewood nematodes blocked the passage of water in the trees.”

He theorizes that the pine blight is attributable to artificial factors because Japanese pine sawyers (a type of insect) that carry the nematodes can move only two to three kilometers a year under their own power, and 35km at the most when they are moved by the wind.

The nematode-infested area is only 10km away from thick pine forests in Daegwanryeong and only 15km away from the center of the Baekdu Range.

Kim is worried that all the pines in Gangwon Province may die if the nematodes spread to other regions as a result of lax pest control.

“We have a glimmer of hope because no pine disease vector has been found 800 meters above sea level, and pine sawyers are known to be inactive in regions with low temperatures,” said Jang. “It turned out that the southern part of Japan suffered greater damage from nematode infestation than the northern part.”

He added, “Studies on Mesosa myops and Monochamus subfasciatus are urgent because Gangwon Province is a likely home to these insects, though this is yet to be confirmed.”

Branches from infested trees are broken into pieces so that the pinewood nematodes cannot live on them. All of the twigs are burned and the roots are fumigated at high temperatures, covered with vinyl, and buried in the ground.

A total of 1.371 million hectares or 81 percent of the entire area of Gangwon Province is forested, including 255,000 hectares of pinewoods. But pines in tens of thousands hectares were destroyed by pine needle gall midge that infested Seo-myeon, Chuncheon in 1968 and a series of wildfires since 2000.

“It is regrettable that we detected the infestation only after we found withered trees,” said Kim. “Forestry workers are actively monitoring regions that are at a high risk of infestation, but they failed to cover the entire region because these are vast forests.”

Baekdu Range on alert after new infestation reports-

Samhwa-dong, Donghae has reported a new case of infestation. Thirty percent of the area’s natural forests are pines that are 80 to 300 years old. These pines may not provide high quality wood, but they create a magnificent landscape.

This area is about 50 kilometers away from Mt. Geumsan in Seongsan-myeon, and is only one and two kilometers apart from Gojeokdae in the Baekdu Range and the summit of Mt. Duta, respectively. So Baekdu Range itself is at risk of infestation.

The Forest Service has cut down and burned all the pines in 0.2 hectare of land around the affected area and has banned the transport of pines from 9,033 hectares of land around Samhwa-dong.

The Forest Service is tracing the distribution route of wood in the belief that the infestation outbreak was caused by Japanese pine sawyers that were on pines used for the construction of a temple in the area late last year.

Pinewood nematodes were first found in Mt. Geumjeong, Busan in 1988 and spread to Andong, North Gyeongsang Province. It has spread to 5,111 hectares of woods in 51 areas nationwide up until now.

Gangwon Province announced that it conducted tests on samples from 282 areas, and that 109 regions among them were found to be parasite-free.

Chang-Soon Choi cschoi@donga.com