Years of efforts to improve the ecological environment, such as tree planting and irrigation, have helped suppress the desertification at the source of China's sandstorms, said local forestry authority.

Since 2006, forests in Alxa League, in the western most part of north China's Inner Mongolia Autonomous Region, have increased by 270,000 hectares, outpacing the expansion of deserts, said an official with the league's forestry bureau.

Statistics from the bureau show that the annual days with sandstorms have dropped sharply from 10 to 20 days at the end of the 1990s to the current three to nine days.

Climate change, overgrazing and irrational human activities over the years deteriorated the natural environment in the region, renowned for its livestock farming. As desertification increased, the League gradually became one of the main sources of sandstorms affecting north China.

Since 2000, the Chinese government has initiated four of the country's six major forestry projects in the region, including returning cultivated land to forests and pastures to grasslands.

Three deserts spread across two-third of the Alxa League, which is 270,000 square km in size.