Liu Jinguo worked as a fire-spotter on the Lesser Khingan Mountains for 12 years before a bear attack ended that part of his working life.

Every day, he had to walk at least 90 minutes up steep, rugged terrain to reach his lookout post, a 30-meter-high tower in Yichun, Heilongjiang province.

"In winter, my pants would get soaking wet in the 1-meter-deep snow on my way up the mountain. I had to carry dry cotton pants with me to replace the wet ones when I arrived," said Liu, 58.

His job was to keep watching for fires and potential hazards. Most days, he would scan the horizon with his binoculars every half an hour. In spring and fall, when the risk of fire was high, he checked every 10 minutes.

So far, only one fire has been spotted in the area Liu used to observe, in April 2010. Liu was first to report it.

Life was lonely in the tower, he said.

"If I read a book, I could get distracted or sleepy, but I needed to concentrate and be alert all the time. The only way for me to relieve the loneliness was to shout loudly at the mountain."

Before Liu took the job in 2004, none of his predecessors had managed to stay for more than a year. Liu said he feels he was able to stick with it so long because he was born into a forest family. It was like home, he said.

"My family has a greenhouse for growing black fungus and earned much more than my salary as a fire lookout, which was about 200 yuan ($30) a month," he said. "I chose to work as a lookout because if the forest burned, how would we be able to plant fungus?"

Now, the ecological situation is much better. The tree coverage has increased and the forest is home to a variety of animals, such as wild pigs, roe deer and black bears.

Around 9 am one day in October 2016, Liu encountered a black bear while chopping snow-covered branches with a machete to clear a path. He did not hear the bear behind him because the snow and leaves muffled its footsteps.

When he sensed the animal, he turned to find the bear standing. It was more than 2 meters tall. Liu was bitten on his hands and head before he was able to swing his machete, which scared the bear away. He called his colleague and was saved.

After the incident, Liu switched to reforestation work, which includes checking new trees.

"I've never left the forest all my life," he said. "Even when I get old and infirm, I'll still be concerned about everything in the forest and will devote myself to protecting it."