In 2014, the now grown-up Wang Liuyang left his job in nearby Jilin province and returned to his hometown to become a watchtower ranger about 30 kilometers from where his parents worked.

"I was born and grew up in the forest. I am really familiar with it," he said.

"After I took up the position, I understood the responsibility on my shoulders, just like my parents had in the past. I also hope I can do as well as they have."

Every time Wang came home from the tower, he asked his parents how he could learn about the forest's geography and calculate distance.

In the spring of 2015, he spotted smoke from a lightning strike just in time and was able to accurately determine the coordinates and type of forest on the map. The fire was quickly extinguished, preventing it from becoming a mountain fire.

After she married Wang Liuyang in 2016, Xu gave up preparing for the civil service examination and chose to work beside him instead.

"At first, living in such an isolated area was a little unbearable," she said. "As time went by, I spent a lot of time on my work and gradually understood the contribution my mother-in-law had made."

When Zhu retired in 2018, Wang Xuetang continued his wife's work. In spring this year, his son and daughter-in-law were assigned to work with him.

Over the past 35 years, the two generations have reported fire risks and have taken part in 100 firefighting missions. "My daughter was born in 2018, and I sometimes bring her to the forest," Xu said. "I hope she will experience a different kind of childhood."