An aerial view of the Helan Mountain area in the Ningxia Hui autonomous region shows the result of three years' ecological development. [Photo by Su Yong and Li Jing/for chinadaily.com.cn]

An aerial view of the Helan Mountain area in the Ningxia Hui autonomous region shows the result of three years' ecological development. [Photo by Su Yong and Li Jing/for chinadaily.com.cn]

An aerial view of the Helan Mountain area in the Ningxia Hui autonomous region shows the result of three years' ecological development. [Photo by Su Yong and Li Jing/for chinadaily.com.cn]

An aerial view of the Helan Mountain area in the Ningxia Hui autonomous region shows the result of three years' ecological development. [Photo by Su Yong and Li Jing/for chinadaily.com.cn]

An aerial view of the Helan Mountain area in the Ningxia Hui autonomous region shows the result of three years' ecological development. [Photo by Su Yong and Li Jing/for chinadaily.com.cn]

An aerial view of the Helan Mountain area in the Ningxia Hui autonomous region shows the result of three years' ecological development. [Photo by Su Yong and Li Jing/for chinadaily.com.cn]

An aerial view of the Helan Mountain area in the Ningxia Hui autonomous region shows the result of three years' ecological development. [Photo by Su Yong and Li Jing/for chinadaily.com.cn]

An aerial view of the Helan Mountain area in the Ningxia Hui autonomous region shows the result of three years' ecological development. [Photo by Su Yong and Li Jing/for chinadaily.com.cn]

An aerial view of the Helan Mountain area in the Ningxia Hui autonomous region shows the result of three years' ecological development. [Photo by Su Yong and Li Jing/for chinadaily.com.cn]