The Ailao Mountains in Yunnan is home to the country's best preserved moist broadleaf forests.

The forests, often distributed 1,800 meters above sea level, are much higher than human settlements in the area, Yang says. On the lower slopes, the residents have enough collective forests for firewood and construction-material wood. People of the Dai ethnic group living in the area have no deep-rooted tradition of hunting.

"We don't have too much pressure from hunting and logging," Yang says. "Since a massive mudslide killed more than 40 people in 2002, our (county) government has paid special attention to environmental protection."

In the past decade, more than 40 villages near the reserve were relocated to lower areas. Besides 14,000 hectares of the forests within the jurisdiction of the national reserve, the local government allocated an area of 10,000 hectares as county-level nature reserve and a 4,000-hectare State-owned forest to the reserve's management.

"That means 28,000 hectares of intact forests without any village," Yang says. "It has truly simplified our management work."

Now, Yang is most concerned about forest fires and a shortage of manpower.

"The dry season between November and May is the busiest season," he says. "The mountains are so vast and precipitous that if there is fire, it will be disastrous for the forest and gibbons."

Only 14 formal employees and 50 temporary patrolmen are managing the reserve, Yang says, doing everything from fireproofing to animal monitoring.

"For our 500 gibbons, we have only five patrolmen exclusively responsible to monitor them in the forests," he says.

"It's far from sufficient. But we have the confidence that these forest spirits will be able to swing freely through our forest canopies."

Li Yingqing contributed to the story.