A desert doesn't sound like the most promising¹ place to plant a tree. Yet, since 1978, China has planted at least 66 billion of them across its arid² northern territories, hoping to transform its sandy steppes and yellow dunes³ into a Great Green Wall.

沙漠听上去不像是最理想的种树之地。但是自1978年以来，中国已在干旱的北方地区栽种了至少660亿棵树，希望能将沙质草原和黄色沙丘改造成绿色长城。

Ian Teh documented this epic⁴ undertaking⁵ while traveling through northern China last year. His expansive photographs show workers tending saplings, filling irrigation tanks, and blasting young trees with water. “Planting trees sounds great on paper, but you can feel skeptical⁶,” Teh says. “But in person, it was impressive.”

郑永仁去年穿越中国北方，记录下了这一惊人的壮举。他拍摄了大量的工人管理树苗、给灌溉水车注水和给小树浇水的照片。他说：“从理论上说，种树是好事，但是你可能产生怀疑。不过亲眼目睹后令人难忘。”

The tree-planting strategy is a massive attempt to help fight desertification. Roughly a million square miles of China—a quarter of the country—is covered in sand. Drought, deforestation, overgrazing and other problems threaten an additional 115,000 square miles, fueling brutal⁷ sandstorms that regularly blast cities like Beijing and Dunhuang. Many scientists are skeptical planting trees will make a difference in the long run. But China’s State Forestry⁸ Administration claims the measure has reduced sandstorms by 20 percent and desertification by nearly 5,000 miles in recent years.

这个植树造林的战略是帮助战胜荒漠化的宏大尝试。中国大约有100万平方英里（约合260万平方千米）的土地为黄沙覆盖，占国土面积的四分之一。干旱、森林采伐、过度放牧等等问题威胁着另外11.5万平方英里的土地，引发的严重沙尘暴经常肆虐北京和敦煌等城市。很多科学家怀疑种树从长远来看是否能有很大作用。不过中国国家林业局表示，这一举措近年来使沙尘暴减少了20%，荒漠化土地减少了近5000平方英里。

Teh lives in Malaysia but works throughout Asia, documenting humans’ impact on the landscape. Over six days in May 2016, he photographed tree-planting schemes in the Gobi Desert in northern China. They seemed successful in places like Duolun County, some 220 miles north of Beijing, where the government has planted 2.6 million trees over the past 17 years. The place felt pastoral, almost lush. Teh had to stop his car on the side of the highway and hike several minutes over dunes just to see where the wind-blown grass ended and the sand began. “To be honest, it was hard to imagine it was ever a desert at all,” he says.

郑永仁住在马来西亚，但是工作在亚洲各地奔波，记录人类对地表的影响。在2016年5月份的6天中，他拍摄了中国北部戈壁沙漠的植树造林计划。在北京以北约220英里处的多伦县等地，植树造林计划似乎取得了成功，过去17年政府在那里植树260万棵。那个地方一派乡野风光，草木茂盛，他不得不在公路边上停下车，徒步走几分钟，翻过沙丘，看看在风中摇曳的草的尽头和沙漠开始的地方。他说：“老实讲，难以想象这里在过去是沙漠。”

For contrast, he also flew some 800 miles southwest to the Tengger Desert, one of the places in China most affected⁹ by desertification. Outside the city of Wuwei, farmers struggled to work the dry soil. "It’s incredible to see them tilling land and everything around is dusty," he says.

为了对比，他还乘飞机向西南方向飞行约800英里到腾格里沙漠，那是中国荒漠化最严重的地区之一。在武威市郊区，农民在干旱的土地上艰难地耕作。他说：“看到他们在那里种田，而周围却是黄沙漫漫，令人难以置信。”