-PHOTO TAKEN 22JUN06- A tourist walks across Shapotou park in Tengeri Desert on the outskirts in Zhongwei, China's Ningxia Hui Autonomous Region, June 22, 2006. China, which is plagued by sandstorms every spring, has embarked on a campaign to plant billions of trees and says it is slowing the rate of desertification, but leading environmentalists said problem was far from under control.