Photo taken on May 12, 2015 shows villager Huang Shenghong walking past seedlings he planted years ago in Mao'er Village, Huangzhong County, northwest China's Qinghai Province. Friday marks China's National Tree Planting Day. With the efforts of volunteers across the country, green lands has covered more areas of China and the eco-friendly development concept is seeded in people's heart. (Xinhua/Wu Gang)