Nanshan park in Lhasa, Tibet autonomous region, June 19, 2018. [Photo/ youth.cn by Liu Liying]

Planting trees on mountains in Tibet is hard because of its dry climate, poor soil, strong winds and big temperature difference between day and night.

However, the local people succeeded to plant trees on Nanshan mountain and Beishan mountain with an average elevation of between 3,650 meters and 4,050 meters, and the average gradient on 60 degrees.

The program of tree planting on mountains around Lhasa started in 2012, and the city has greened its Nanshan mountain and Beishan mountain totaling 4,573 mu now.