The trees -- Euphrates Poplar -- formed a "green corridor" in the Xinjiang Uygur Autonomous Region, halting the spread of sand further to the east.

The trees mostly grow in the lower reaches of the Tarim River and serve as sandbreaks in the Bayingolin Mongolian Autonomous Prefecture in the southeast of Xinjiang, a neighbor to the Taklimakan Desert, the country's largest desert.

Statistics reveal this area makes up 30 per cent of the total desertified area of Xinjiang.

Local forestry officials said the trees were dying because of falling water levels in the Tarim River, the largest water body in Xinjiang, which nourishes the trees downstream.

Land reclamation upstream of the Tarim River since the 1950s has resulted in an acute rise in water consumption, reducing the volume of water downstream.

Statistics show the region had a total of 520,000 hectares of Euphrates Poplar forests in 1958 but this had slumped to 280,000 by 1979.

Chen Xinyou, vice-chairperson of the prefecture, said sand dunes were spreading at a speed of 5 to 10 meters per year along the 2,000-kilometre-long sandstorm belt between the Taklimakan Desert and Kum Tagh Desert, threatening nearby farmers' livelihoods.

The deterioration of the environment in Xinjiang has drawn close attention from the central government as well as the local government.

It has injected 10.7 billion yuan (US$1.3 billion) into ecological protection in the area in a bid to prevent the two deserts in Xinjiang from merging completely, said Chen.

(China Daily July 2, 2002)