Unusual temperatures killing pine trees

By Yun Suh-young

Dozens of pine trees were found to be slowly dying with dried up leaves and reddening tree trunks in a park in Daejeon, Thursday.

Pine trees found on college grounds within the city were also withering in a similar way.

It was because of pine pitch canker, a disease caused by the fungus “fusarium circinatum” which occurs on a species of pine trees called “pinus rigida.”

The fungus infects the branches down to the trunks and the pine trees turn red as they dry up. “The disease first appeared in 1996 in Incheon. In 2001, the disease was reported for the second time and 1,853 hectares were affected out of a total 6.37 million hectares of forest nationwide. The number, however, increased to 11,000 hectares in 2006. The sick trees were detected in North Jeolla and South Chungcheong Provinces,” said Kim Seong-man, an official from the Korea Forest Service.

“The disease is not that common. But I think it returned with the recent continuation of unusual weather. Because of global warming, the temperatures have been unusually warm this spring. Diseases and pests are more common when the weather is warm.”

The pine pitch canker is not the only kind of disease killing pine trees across the nation. Others include pine scale bug disease, pine wilt disease, and pine midge disease caused by pests blocking the pine trees from absorbing nourishments and moisture.

Pine scale bug disease occurs in the southern coastal regions of the peninsula and affects the pine trees slowly— killing them if the pests continue to infect the trees for three to four years. The pine wilt disease also spreads widely in the southern regions such as South Gyeongsang and South Jeolla Provinces. Pine midge disease is most common in Gangwon Province.

“The outbreak of disease and pests in pine trees came faster this year due to the higher temperatures. The unusually warm weather has allowed for disease and pests to be more prevalent. The diseases tend to weaken when the temperatures or the humidity isnright for the pests. But the pests are increasing and we expect more diseases will occur in the future because of global warming,” said Kim.

At the moment, pine wilt disease is the most deathly. If pine trees acquire the disease, they are 100 percent guaranteed to die which is why prevention is important.

“There is a limit to how much humans can prevent. Pest control can damage other parts of the ecosystem. It’s best for the trees if birds eat the pests or the disease naturally dies due to the weather. But if there are too many pests and the weather is continually warm, this is not possible,” said Kim.