In June, the People's Fine Arts Publishing House released China's Contemporary Artists Album: Ji Youquan (Zhongguo Dangdai Mingjia Huaji: Ji Youquan) as part of a series on those who have contributed much to Chinese art.

"This tree is a symbol of our nation's spirit. It encourages us to be determined when facing obstacles. As a soldier, as well as an artist, I should tell people what the tree is like and pass down the spirit to the younger generations," Ji says.

"About 90 percent of the desert poplars in the world are found in northwestern China."

Painting desert poplars for 20 years has not been easy. Ji has had to overcome many difficulties.

For example, he has had to go deep into desert poplar forests, where he was bitten by mosquitoes, to observe and sketch the trees.

"There were times when I was too exhausted to stand up due to bad body aches after painting. But the interesting thing was that, as long as I went back to the forest and looked at the old trees, I felt good and could pick up my pen to draw the pictures again," Ji says.

He has walked along the Tarim River in Xinjiang several times.

Ji says desert poplars have supported him spiritually. Whenever he thought of their ability to bear hardships over centuries, he felt encouraged to overcome difficulties himself.