Xu Zhigang, 68, clears dead leaves on mountain in Zhangchuan Village of Tongwei County, northwest China's Gansu Province, Aug. 23, 2016. Xu Zhigang and his twin brother Xu Zhiqiang have spent 48 years voluntarily planting trees on barren hills on the Loess Plateau. More than 350 mu (23 hectares) of barren land have turned green with their plantation of over 80,000 trees and flowers. The brothers' efforts not only help create natural beauty but also improve local ecological environment. (Xinhua/Guo Gang)