The Green Wall of China

With the Beijing Olympics just a year away, and desert dunes now only 150 miles away from the city, officials have been dreaming big when it comes to battling legendary Chinese sandstorms in the capital and across the country?s arid north. In 2001, the government approved a new phase of an $8 billion antidesertification campaign, stretching from the capital to Inner Mongolia. The 4,500 kilometer shelterbelt ? with 25 million hectares of trees planted and 10 million more hectares planned by 2050 ? has been the world?s largest reforestation campaign.

Mega antidesertification campaigns have worked in the past. The Dust Bowl of the American west in the 1930s prompted the creation of a 100 mile-wide shelterbelt that stretched from Canada to Texas. ?It was very successful and did a lot for controlling erosion, providing wildlife habitat, and protecting farmsteads,? says James Brandle, a professor at the University of Nebraska, Lincoln.

According to a spokesperson for China?s State Forestry Administration, the project is on the right track: Between 1999 and 2004 (the last year data was available), 8,000 square kilometers of desert were rolled back, and 300 million tons of sand were prevented from flowing into the Yellow River. Around 2,500 square kilometers of land is lost each year to the expanding Gobi Desert. He also says by 2010, 40% of land currently affected by desertification will be brought under control, although he didn?t say whether that land would be arable.

Still, Eugene Takle, an agricultural meteorologist at Iowa State University, says the Great Plains of the 1930s and the arid northeast of China in the new millennium are not parallels. ?The 1930s were just an extreme period that hasn?t been revisited,? he says. ?However, in China you?re trying to put trees in a place that?s always been the desert, so you?re going uphill against nature in that one.?

Others are also skeptical. Among a list of failings, a recent United Nations report criticized the ?poor planting techniques and lack of maintenance? and ?poor matching of species and clones to site conditions.? For example, 1,200 kilometers of the Green Wall withered and died in Gansu Province when the high-tech dune-fixing trees inadvertently sucked up too much water, says Yuanchun Shi, soil conservationist and former president of China Agricultural University. ?Stressing the role of trees over grass and thickets was an arrogant and ill-thought out plan that contradicted scientific and economic rules,? he adds. Countless trees were recently planted in the capital, but moths appeared out of nowhere to strip their foliage along with the hopes for a green Olympics.

And despite the trees, Beijing will continue to suffer from sandstorms, says Shi, because airborne particles blow above the tree line. Nontheless, Shi is quick to shrug off talk about Beijing?s plights, saying a disproportionate amount of funds have gone to the capital while neglecting the rest of the region ? 4 million square kilometers (40% of the country?s landmass) that the Green Wall protects. Shi says simpler measures would cost less money but be equally effective at stopping desertification, such as controlling sheep-grazing patterns.

Xinhua Zhou, a shelterbelt ecologist at University of Nebraska, Lincoln, says more hard science needs to be done. ?We really need to analyze the historical data on sandstorms, examine the structure of turbulence flow, and see what vegetation can minimize these sandstorms.?

Bruce Wight, an agroforester at the US Department of Agriculture, says shelterbelts are normally used to stop the encroachment of the desert. He wonders about the 8,000 square kilometers of land reclaimed from desertification: ?I?d be skeptical how feasible that is.?