The project along what is known as the roof of the world is expected to cost 1.2 billion yuan (US$145 million), said Lu Chunfang, an official in charge of the construction.

Explaining the advantages of the scheme, Mou Ruifang, an associate professor of the Southwest China Communications University, said the roots of the grass will help stabilize the soil while the grass itself will protect both the roadbed and the slopes from heavy rain.

Though the railway is not as long as the Great Wall, which stretches for more than 6,000 kilometers along the ridges of two mountain ranges and runs through at least seven Chinese provinces and autonomous regions, it will be a great eco-wall maintaining the ecologi-cal balance of the Qinghai-Tibet Plateau, Mou added.

Grass cover in a 10-meter by 100-meter experimental area beside the railway has survived the frigid winter. Early next spring workers will begin extensive grass-planting on gradient slopes which range from three to 10 meters in height.

The planting of grass alongside the railway line will be a challenging task as more than 960 kilometers, or four-fifths of the railway, will be at an altitude of more than 4,000 meters with 547 kilometers, or half its total length, being laid on long-frozen earth.

"We will take effective measures to preserve the moisture, temperature and soil nutrients," said Bao Liming, a senior engineer of the No. 1 Railway Survey and Design Academy.

Tests have proved that planting in this way raises the grass survival rate to 70 percent, doubling the natural growth rate, he added.

The gigantic afforestation scheme also includes conservation of the bush areas the railway cuts through, and the building of 30 animal tunnels to ensure antelope and other species can pass over the railway safely after the line opens to traffic.

The railway extends from Xining, capital of northwestern Qinghai Province, to Lhasa, capital of the Tibet Autono-mous Region in the southwest. It will be the first railway to link Tibet with the rest of China.

The section between Xining and Golmud City was com-pleted in 1984. Work on the line connecting Golmud with Lhasa started in June 2001 and is expected to be ready by 2007.

(eastday.com November 26, 2002)