Preserving trees isn’t always the answer to climate change, a local environmental group said Monday.

South Korea needs to cut down old trees and plant new ones to help maintain local forests’ carbon-absorbing capacity, the Seoul-based Climate Change Center said. It cited a report written by the Gyeonggi Research Institute that said old forests can’t properly absorb carbon.

“South Korea successfully turned barren mountains into forests by planting trees after the Korean War. As the trees were planted between the 1970s and the 1980s, most of them are now 31 to 50 years old. Unless we make forests young again, their function as carbon sinks will be diminished significantly,” an official with the group said.

According to the National Institute of Forest Science, trees can absorb carbon best when they are 20 to 30 years old. As of 2018, forests between 31 to 50 years old accounted for 65 percent of all forests in Korea, according to the Korea Forest Service.

At this pace, forests’ capacity to absorb carbon, which stood at 45.6 million metric tons as of 2018, will plunge to 15.6 million tons in 2050.

To tackle the aging forests, the forest service said last month that it would plant 3 billion trees by 2050 to address 34 million tons of carbon. Also, the agency will “sort out” coniferous trees and broad-leaved trees once they reach 20 years and 30 years of age, respectively.

By Kim Byung-wook (kbw@heraldcorp.com)