Wu Qingxian checks the condition of a tree in the forest of Liping County, southwest China's Guizhou Province, on March 11, 2019. Wu Qingxian, a 75-year-old villager of Dong ethnic group at Sizhai Village in Shuangjiang Township, has been planting trees voluntarily in the mountains around the village since before 1984. Over the decades, the once barren mountains have turned to dense forests. Under his guidance, people of nearby villages have planted over 50,000 mu (about 3333.3 hectares) of trees. (Xinhua/Yang Wenbin)