In Ejina in the west of Inner Mongolia lives a Populus euphratica, or desert poplar tree, that stands as the oldest tree in the forest and has been guarding the place for more than 800 years. The locals call it the "sacred tree".
To the south of the desert poplar forest in Ejina lies Badain Jaran, the third-largest desert in China. Without a 260-square-kilometer desert poplar forest, the Badain Jaran Desert, already 49,200 square kilometers in size, would spread northward, squeezing the living space of humans.
