For Wang Youde, head of the Baijitan Conservation Area in north-west China's Ningxia Hui Autonomous Region, protecting the environment is more than a vocation; it's personal. When he was a boy, the expanding desert invaded his township and gradually forced all ten thousand inhabitants to abandon their homes. Wang's family gave up the struggle and quit the town when he was just ten years old. The experience had a deep impression on young Wang and made him, as he put it, "determined to make a difference". He turned his personal beef into a lifelong struggle and has been working on desert reclamation projects for the past 23 years.

Under Mr Wang's leadership, the Baijitan conservation project, 50 kilometers north of Ningxia's provincial capital Yinchuan, has constructed a green shield more than 40 kilometers long and 10 kilometers wide to halt and roll back the expansion of the desert. The methods are simple, low-tech but ingenious; workers make "grass squares" by plaiting straw, lay them as webbing on the sand, then plant shrubs in each square. Practically all the work is done by hand. The squares and the roots of the plants fix the sand in place and prevent erosion. Water pumped from the Yellow river or drawn from deep wells is used to irrigate the planted area. Ningxia Hui Autonomous Region, China's smallest province, like neighboring Inner Mongolia and Gansu province, has a long-standing problem of desertification, to a large extent caused by overgrazing of goats reared to provide wool for the hugely profitable cashmere industry. More than 57 percent of Ningxia's land is desert and, according to Mr Wang, 65 percent of the desert areas have yet to be brought under control, and are still expanding.