Trees are something of a rarity in the Tibet Autonomous Region. Conditions on the high-altitude plateau of the Nagqu Grassland - 4,500 meters above sea level - are not conducive to their growth, except for a few places in eastern Nagqu Prefecture.
Many of the nomads who inhabit the area had seldom seen a tree in their life until recently, when the remote places of the region were linked by roads and modern communications.
Tsering Chukyi, a nomadic woman from Amdo county in northern Tibet, did not see a tree until 1998 at the age of 10.
"I had never seen what a tree looked like until my parents took me to Lhasa, where I saw trees for the first time in my life," said the 27-year-old.
"I was very excited and pleased to see trees, and I thought a place with trees is a very beautiful place."
President Xi Jinping made reference to encouraging tree planting in Tibet in a recent Central Party School seminar. Xi told of one of his experiences when he was Party chief of Fujian Province and made a survey trip to Tibet's Nagqu Prefecture with several Tibetan officials.
Xi said the local government had increased the award for planting a tree that survived in Tibet from several thousand yuan to more than 100,000 ($16,350) but no one ever received the award. Eventually, people gave up on planting trees.
Despite the failures, Zhao Zexiao has continued since the 1990s to explore ways of making it possible for planted trees to survive at such a high altitude.
Zhao, an agriculture technician in the Nagqu Division of the People's Liberation Army, has a PhD in microbiology from the Third Military Medical University.
His hard work has paid off. Since 2012, he has planted more than 5,300 trees; 200 of those have survived for three years and 280 others for two years. He is pretty confident of his trees surviving longer and growing stronger.
Zhao's success is due to the types of trees he is planting - Tibetan junipers, Qinghai spruce, and Tibetan poplars, which have a better chance of surviving the harsh conditions.
"By planting trees in high altitude places of Tibet, I want to make a small contribution to the fragile environment and fighting desertification," said Zhao.
The 42-year-old said he wants to make Tibet a better place with more azure sky, cleaner water, fresher air and more verdant hills.
Zhao's name and his spirit of perseverance have spread across the grassland and Tibet.
Nagqu Middle School plans to invite him to supervise its tree planting project this month.
"I feel lucky to have met Mr Zhao," said Losang, the school's headmaster. "He has volunteered to help us to plant trees at our school."
Tashi Tsering, 51, a professor of environmental studies at the College of Science at Tibet University, said Zhao "is very persistent with his career, and we believe his success can have great academic value in the areas of city greening and fighting against desertification".
Zhao has already set up a new experimental station in Quxu county in Lhasa to tackle tree planting along the Lhasa River and areas of desertification in Tibet. He plans to conduct further experiments and studies.
Tashi Tsering said, "This new experimental station will have potential value for city greening, and we plan to work together with Zhao."