Wang Jinlong (left), a postgraduate student from Peking University's school of pharmaceutical sciences, with goods he bought in Beijing through Alipay on March 17, which means his Ant Forest will increase its amount of energy the next day. Nie Yusheng (right), a herdsman, gets ready for planting saxaul trees on sandy grazing land near his home in Alxa League on March 19. [Photo/Xinhua] 

Over a million saxaul trees (haloxylon ammodendron) have been planted to limit sand erosion in deserts in Alxa League, thanks to Ant Forest, an online platform where Alipay users can cultivate a virtual tree via online payment. Once the virtual trees have grown online, real ones will be transported to the desert by low-carbon means.

In August 2016, Ant Finance, an affiliate of Alipay, cooperated with the Alxa SEE (Society of Entrepreneurs and Ecology) Foundation to introduce the Ant Forest platform. It aims to not only encourage citizens to choose "a low-carbon way" for buying, transporting and living, but also to control desertification in the Inner Mongolia autonomous region's Alxa League.

Virtual trees in Ant Forest need to absorb so-called "energy" or "water" exchanged through "green behaviors", including face-to-face QR scans, online payment of water and electricity fees, taking public transport, making doctor's appointments online, purchasing train tickets online and using walking tracks.

The green behaviors usually take 24 hours to transform into watering users' trees. Once a user's Ant Forest page occurs the "green energy ball" with specific grams on it appears the next day. A user's Alipay friends can "steal" the energy if the user doesn't "absorb" it fairly quickly.

During the process, users can not only be easily gratified by seeing their trees grow step by step through green behaviors, but also they can enjoy the fun of stealing energy from their Alipay friends. That's part of the reason why Ant Forest has become popular among Chinese people.

Through the involvement of more online users, Ant Finance and Alxa SEE Fund have been providing subsidies for local herdsmen and farmers in Alxa, while also offering technological support, to plant saxaul trees in the desert.

Known as a desert guardian, a fully grown saxual tree can hold together a 10-square-meter patch of sandy land, according to the local environmental preservation department.

Nie Yusheng, a 52-year-old herdsman in Alxa desert, is one of the local beneficiaries receiving subsidies for planting saxaul trees. The condition of local grazing land has undergone many improvements since this sand-control project began. The project has also provided dozens of jobs for local herdsmen, Nie said.

A photo taken on March 20 shows a bird's-eye view of planting holes for saxaul trees. [Photo/Xinhua]

Workers plant saxaul trees on sandy land in Alxa League. [Photo/Xinhua]

Nie plants a saxaul tree. [Photo/Xinhua]

Pang Zongping (right), director of the desertification control center of Alxa SEE Foundation, and his colleague Yang Jun (left) check the spacing of two planting holes. [Photo/Xinhua]

Local workers plant saxaul trees at dawn on March 20. [Photo/Xinhua]    

A worker hired by Nie Yusheng waters saxaul trees. [Photo/Xinhua]    

Wang presents his prompt message on his Ant Forest page for successfully cultivating a virtual tree that will become a registered saxaul tree in the desert. [Photo/Xinhua]

A water wagon provides irrigation for land in Alxa League. [Photo/Xinhua]    

Wang and his college classmates show their Ant Forest pages on March 17 in Beijing. [Photo/Xinhua]

A cashier scans the Alipay QR code off Wang's smart phone in Beijing on March 17. [Photo/Xinhua]