To improve the fragile ecology in the ancient town, 65 farmers were asked to plant trees under the guidance of the local government over a four-month span starting in October 2017.

"The tasks were never easy," said Lin, adding that his group had to plant trees on loose, rocky cliffs with gradients of 80 degrees.

The group, mostly male farmers, was divided into smaller groups — three to four people each. The youngest worker was lowered by rope by his teammates, who had secured relatively flat and stable footing above. After the planting tools were dropped down, the worker below dug a pit — 1.3 meters across and about 1 meter deep. Then an equivalent amount of earth and sand were lowered to line the hole. Once a sapling was planted, the worker was hoisted up.

Lin said rockfall caused many small injuries, but no one hesitated to do the job.

In more than three months, some 10,000 saplings — including liana, red maple, yellow locust and triangle plum — were planted on 71 hectares of steep, rocky faces.