When Yi Jiefang's son was killed in a car accident, she thought her grief would overwhelm her. But the Shanghai native has found comfort in fulfilling her son's wish to help in the reforestation efforts in China's barren wastelands, finding herself becoming an unlikely environmental crusader. Wu Ni reports in Shanghai.

Yi Jiefang's world collapsed when her only son, Yang Ruizhe, 22, died in a road accident in Japan in 2000.

To work through her grief, the devastated mother decided to devote her life to fulfilling her son's last wish - planting trees in the desert.

Yi established the not-for-profit organization Greenlife in 2003, which has planted more than 1.1 million trees in deserts in northern China.

Earlier this year, at the age of 65, Yi started a new project - to plant 667 hectares of pine forest in Duolun county in the Inner Mongolia autonomous region. The county, with 1,400 square km of desertification, is where many of the sandstorms that affect Beijing start, as it is only about 400 km from the capital.

"To make the desert green was my son's dream. To fulfill his dream is the meaning of my life," she says.

Yi's early life was a long way from the desert. A Shanghai native, she had a stable job and a happy family. But the enterprising woman with big career ambitions moved to Japan by herself at age 38 to study.

Her husband and son joined her in the following years. The couple started a private Chinese medical clinic and the son, a diligent and excellent student, was admitted to the Chuo University in Tokyo.

Life was perfect, until the sudden death of her son. In the depths of her despair, Yi recalled that two weeks before his death, her son said he wanted to return to China to plant trees after graduating from university.

"Ruizhe was concerned about the environment. He often rode his motorbike to the mountain and described to me what beautiful sceneries he had seen," she recalls, tears welling up her eyes.

"His last words are deeply engraved in my mind. I sometimes even felt it might be God's will that I should go back to my country to plant trees," she says.

Her son's wish gave Yi the strength to rebuild her life. After living in Japan for 18 years, Yi sold the clinic and returned to Shanghai with her husband. They devoted all their savings, Ruizhe's life insurance payout and donations from friends, to the Greenlife project.

After her first field trip to the deserts of northern China, Yi chose the Tamin Chagan desert, nicknamed "the sea of death" in Hure Banner at Tongliao city in Inner Mongolia.