The ecological environment has steadily improved during the past two decades, evidenced by growing vegetation coverage, clearer water and the increase of wild animals.

"In the Hengquan Reservoir area, birds like egrets and storks can be spotted all year round," said Liu Quanwang, a local farmer.

In Huozhou city in the southwest of Shanxi, officials and residents are hoping the plant wenguanguo, or shiny-leaf yellow-horn, will improve ecology and increase income.

Huozhou used to be one of the top coal-producing regions in Shanxi. During the province's shift from a coal-reliant to a diversified economy, the city is using wenguanguo to repair the ecology at its mining sites.

Due to its ability to resist coldness, drought and alkaline, wenguanguo has been used in many regions in China to prevent desertification.

Medicines and teas made from wenguanguo are good for reducing blood pressure, blood fat and blood sugar.

Zhang Hua, a local businessman in Huozhou, was the first person in the country to found a company engaged in the planting of wenguanguo to make herbal tea.

His company, Wenguanguo Technology, includes a wenguanguo farm of 40 hectares and a factory with an annual capacity of 10 metric tons of herbal tea.

The company currently employs dozens of people from local households.

"We are planning to enlarge the scale of the company with hopes of greening more barren hills and helping more farmers get rich,"Zhang said.

Guo Yanjie contributed to this story.