Aerial photo taken on June 21, 2019 shows the Baijitan national desert park inside the Baijitan national nature reserve in Lingwu, northwest China's Ningxia Hui Autonomous Region. 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/Feng Kaihua)
