A worker walks near a forest that shields the city of Karamay from the Gebi Desert in northwest China's Xinjiang Uygur autonomous region, July 29, 2009. Planting and forestation work began in 2002 in the region and a wall of trees covering 148,000 mu of land (about 100 square kilometers) has been grown around Karamay, a city home to about 350,000 people. [Xinhua]