Inner Mongolian resident Li Zhenhai and his wife Jiang Kaizhi spent 37 years in the mountains.
They forested 133 hectares of land, planting almost 40+ trees per day, creating about $47.2 million in eco-benefits.
Aged 78, Li said this year's goal is 6.67 more hectares of trees.
Photo by Jiang Xiwu; video by Zhang Jing