Efforts to curb one of the greatest threats to north China's environment will continue over the next five years.

Desertification, which feeds seasonal sandstorms, has long been a focus of national concern.

Plans to create a "Green Great Wall" of forests across north, northwest and northeast China are to be further promoted during the 2006-10 period.

The scheme is believed to be the world's largest ecological project, officials for the State Forestry Administration (SFA) said at a press conference in Beijing over the weekend.

According to Liang Baojun, an official in charge of the massive shelterbelt, more than 7.7 million hectares of trees will be planted along the "Green Great Wall" during the country's 11th Five-Year Plan period.

First started in 1978, the forests are designed to stave off erosion threatening 4 million square kilometers of land across 551 counties of 13 northern provinces 42 percent of China's total territory .

"To date, the barrier forests built over the past two decades have protected over 70 percent of cultivated land across the three northern areas with 167 million rural residents benefiting," said Liang.

"In the years ahead, one of the most important things for us to do is to further consolidate the shelterbelt in the 2006-10 period," Liang said.

The three northern areas account for over 98 percent of China's land affected by desertification and 96 percent of the country's sandy land including the Gobi desert.

Sandstorms and encroaching sand dunes have buried farmland, pastures, towns and villages and threatened railways, highways and irrigation facilities.

China has made significant progress in curbing sandstorms with the help of the shelterbelt. The storms have occurred less frequently over the last two years.

Last year, only three springtime sandstorms hit Beijing, proof of the effectiveness of the Beijing-rim Sandstorm Prevention project, said Liu Tuo, an official with the SFA.

However, he made it clear that sandstorms will not vanish in China and increasing green coverage is the only resort.

"As a natural phenomenon, sandstorms are decided by the climate and the earth's surface," said Liu who is in charge of desertification control.

Sandstorms can be triggered by strong winds blowing across large barren areas which provide abundant sand, he explained.

Situated in the Central Asia sandstorm region, one of the world's four largest sandstorm regions, China now has more than 1.74 million square kilometers of land affected by desertification, only 530,000 square kilometers of which can be curbed, experts say.

The remaining 1.2 million square kilometers are permanent deserts.

In China, areas frequently affected by sandstorms include the Xinjiang Uygur, Ningxia Hui and Inner Mongolia autonomous regions and Shaanxi Province, said Liu.

(China Daily October 12, 2005)