Few environmental campaigns in China have been so enthusiastically pursued or so controversial as its Great Green Wall. Every spring, government officials, teachers, students, and company employees go on group tree-planting trips. State media single out forest workers for praise. Film stars line up to be “tree-planting ambassadors.” It’s a campaign in the vein of the old Communist propaganda drives—the workers uniting to dominate the forces of nature. March 12 is National Tree-Planting Day.
Launched in 1978 to protect the north, northwest, and northeast, three regions affected by sandstorms sweeping out of the Gobi Desert, the so-called Three-North Shelter Forest Program aimed to grow 35 million hectares (87 million acres) of new trees—a forest the size of Germany—across the country’s north by 2050. In the ensuing four decades, planting trees became one of both the private and public sectors’ favorite climate change solutions. That makes the fate of China’s sprawling man-made forests a key early indicator for how these other projects may fare.
The program was beset by problems from the start because of poor planning, the unrealistic demands of local party cadres, and a poor understanding of how and where forest can successfully grow. “We were told of the importance of planting trees at a very young age,” says Sun Jing, director of the Alashan Foundation, a Chinese charity that combats desertification. “The idea that more trees equal good is never challenged.”
While the mission was designed to take 72 years, local officials wanted results quickly, so the vast majority of the trees planted were fast-growing poplars that could withstand the region’s cold, dry winters. By the 1990s huge numbers of them started dying, victims of the Asian longhorn beetle, which loves softwoods, including poplars. The more China planted, the more longhorn numbers exploded.
One of those who witnessed the disaster was Zhang Jianlong, a native of the north who holds a degree from Inner Mongolia Forestry College. “We didn’t expect so many trees to die,” Zhang said in an interview with Hong Kong Phoenix TV in 2016, when he headed the Chinese Forestry Bureau. “Having only a single species attracts pests and diseases.”
Officials cut down millions of infected trees, some of which ended up being turned into packing crates for China’s burgeoning international trade. (This allowed the beetle larvae to hitch rides to Europe and North America, where governments are now spending a fortune trying to control infestations.) Meanwhile, planting went on—sometimes using varied species, but often not, if that was easier. Sometimes twice as many trees were planted as the land could sustain, based on the understanding that 50% might die.
Forest coverage has officially increased since 1978, from 12% to almost 22%. NASA satellite images confirm that China is a world leader for afforestation. “Planting monocultures on a degraded area may be better than doing nothing, but it would certainly be much better to plant a mixture,” says Bernhard Schmid, professor of environmental sciences at the University of Zurich and Peking University. “The more species there are, the more it increases ecosystem functions.”